The development of the most popular transparent pa

The development of transparent packaging (Part 2)

Japan has a large production and consumption of transparent agents and continuous innovation. For example, all series products developed by Nippon physicochemical Co., Ltd. have a unique chemical structure, which can be used with pigment colorants or other additives without adverse side effects. They are widely used in injection molding, blow molding and other processes. In addition, Japan has recently launched a new product all DX in its all series of products. It is said that its antireflection performance is as perfect as all MD. it has been approved by FDA and can be used in the field of drugs and food packaging

the United States divides the currently available transparent agent into three generations, and selects its typical product from each generation as a representative to explain the performance of the transparent polypropylene. The first generation, such as millad3905, is widely used in the field of food packaging. It has small odor and low transparency, but it has serious scaling, which has a certain negative impact. The second generation, such as millad3940, improves the transparency of PP and reduces scaling, but has a strong smell, which limits the packaging application. The third generation products, with good haze and finish, improved scaling and odor, can be used in any processing process, with high dispersion and nucleation efficiency, short molding cycle, and suitable for high-end packaging with high transparency. Millad3988 product developed by American Milliken chemical company in recent years with new process is said to represent the new level of the development of transparency agent in the world. It can effectively improve the transparency of PP without bringing odor and taste to the products. It can be used in any processing process and is most suitable for high-grade packaging

3. Development trend of transparent packaging

transparent agent has greatly expanded the application of polypropylene in packaging. With the increasing improvement of polypropylene properties, its application fields are constantly expanding. Because the first generation of transparent agent (sorbitol diphenyl formaldehyde) has low antireflection efficiency, harsh processing conditions, serious scaling, and will precipitate on the surface of processing equipment at high temperature, it can no longer meet the requirements of packaging. In order to meet the increasing demand of the packaging products market, the second generation transparent agent was developed in the late 1980s. By adding substituents, introducing side chain heteroatoms and other methods, the investment in railway fixed assets in 2014 after the meeting was greatly increased from 630billion yuan at the beginning of the year to more than 800billion yuan, improving transparency. The substituents can be alkyl, alkoxy, halogen, etc; The replacement cardinal number can be 1, 2 and 3; Substituents can be cyclized or acyclic; Substituents can also contain sulfur, oxygen, etc. Generally speaking, with the increase of the substitution base, the antireflection is improved step by step, such as EC-4 (sorbitol derivative p-chloromethyl diisopropylene sorbitol) of Japanese chemical company, nc-4 [bis (p-ethyl dibenzylisopropyl) sorbitol] of Mitsui East Asia Co., Ltd., millad3940 [1, 3, 2, 4-bis (4 methyl benzylidene) sorbitol] of American millike chemical company, etc. The transparency of the second generation of transparent packaging is much higher than that of the first generation; The transparency of polypropylene is further improved, and the adaptability of processing conditions is also wider. However, due to the problems of more bubbles and larger odor in the use process, polypropylene is limited in some plastic products, which hinders its extensive application in actual production

the third generation of products is a new sorbitol derivative antireflective agent synthesized by several major companies in the world through new processes, which is called the third generation of high-efficiency transparent agent. In terms of performance, smell and other functions, the third generation products have made greater breakthroughs than the second generation products. For example, millad3988 in the United States and alldx in Japan have broken through the limitations of the second generation products in terms of transparency, smell, processing performance and nucleation ability, so that the smell and odor migration of transparent packaging are minimal, which is suitable for food packaging and odor sensitive packaging, It has been certified by the U.S. Food and Drug Administration (FDA) and the German Health Bureau, and can be safely used in food packaging

in recent years, multicomponent compounding is the main trend in the development of modern transparent agents, and the research on composite transparent agents is very active. In order to reduce the melting point of the transparent agent or improve its dispersion, so as to improve the transparency of polypropylene, the United States and Japan still adopt the method of adding sorbitol derivatives and their auxiliary components to improve the transparency. For example, organic phosphorus antioxidants, fatty acids and their esters are added to obtain transparent polypropylene with excellent comprehensive properties. Clarifexy 800, an American made compound transparent agent, is processed from fatty acids, esters and other organic compounds, and has been approved by FDA. In Japan, DBS was coated with docosanoic acid lotion to make fatty acid/transparent agent (4:6 or 3:7) mixture, which not only obviously eliminated the odor, but also obtained the effect of high transparency of polypropylene

in recent years, the United States and Japan have begun to carry out molecular design of transparent agents to make them have multiple combinations. Users are welcome to call and consult: products with 13964077506 functions are emerging. For example, sorbitol derivatives have at least several sulfur-containing groups substituted on the two benzylidene rings; Each ring of the additive contains a low alkyl group, thio group, etc., so that it has high shovel transparency, oxygen resistance, etc

4. The prospect of transparent packaging in China

the research and development of transparent polypropylene in China started late, and there is a big gap between China and foreign countries in the research and application development of transparent agent process. Although it has developed rapidly in recent years, the quality and stability of products need to be improved. The application of transparent polypropylene in China is also limited to film, sheet, cup, microwave cooker and a few injection molded products

before and after China's entry into WTO, the market demand increased significantly, and the national demand reached 100000 tons in 2000. With the further development of application fields, the domestic demand is expected to reach 200000 tons in 2005. This LEGO CEO and President J rgen Vig knudstorp issued a statement saying: "This is an important step taken by LEGO Group to achieve the goal of sustainable development of materials by 2030. In addition, the transparent agent can also be used to improve the transparency and gloss of polyolefins such as PE. Therefore, China's transparent agent has a broad market. However, the annual output of the existing domestic device production scale is about 100 tons, which is far from meeting the domestic demand. At present, the transparent agent used by manufacturers producing transparent polypropylene mainly depends on imports. Therefore, China should adapt to it With the rapid development of plastic industry and packaging industry after China's entry into WTO, a lot of work needs to be done in terms of product structure, specifications and benefits, especially the development and production of high transparent polypropylene

after entering the 21st century, the world's transparent agents are developing to a wide range of applications, high efficiency, multi-functional and composite. The world packaging industry has adopted various transparent materials to further improve the transparency of transparent packaging, and improve its tensile strength, low-temperature impact strength, radiation resistance and heat resistance, which has become the development trend of transparent packaging