Application of Antistatic Agent in Polyethylene Packaging Materials

Demand for plastics in the Chinese packaging industry is growing at an average annual growth rate of 10%. A wide variety of plastic packaging materials, polyolefin because of its low price, excellent performance, easy processing, which accounted for a considerable proportion. Plastic packaging products not only have to fulfill the function of containing items, but also meet the requirements of color printing, compounding, and automated packaging in the manufacturing process. The above-mentioned steps all require the plastic packaging material to have antistatic function. Processing Suitability of Antistatic Masterbatches The addition of antistatic agents is generally added in the form of masterbatches. The properties of the antistatic masterbatch are particularly important for the performance of the antistatic agent, and the melt index is one of the important items. When selecting the carrier resin for the masterbatch, in order to ensure the uniform dispersion of the antistatic agent, a higher melt index number is usually selected.
Antistatic agents are mostly surfactants that can act as a lubricant in the resin system to further increase the melt index of the antistatic masterbatch. However, the composition of the antistatic agent system is different, and the increase in the melt index is also different. Application in PP The ASA, ASH and ASP antistatic agents developed by Beijing Research Institute of Chemical Industry are compounded by various nonionic surfactants. ASB series antistatic agents consist of an organoboron surfactant and other nonionic surfactants. After selecting two antistatic agents AB-33 and ASA-51 as masterbatches, they were blended with the base resin to make standard injections (tablets) and CPP films, and their antistatic properties were measured. The results are as follows:
In the CPP film products, the antistatic effects of ASA-51 and AB-33 are basically the same; in the injection products, the initial effect of AB-33 is not obvious. After a period of time (two weeks later), the antistatic effect gradually developed. come out. This is related to the structural composition of ASA-51 and AB-33. ASA-51 has a relatively high proportion of components that migrate faster and has an initial antistatic effect. The main components of AB-33 are boron-containing compounds with special structures. The migration speed of each component is slow. This effect, in the film products, due to the short migration distance of the auxiliary agent, the performance of the antistatic effect is not obvious in the delay, while the phenomenon of the initial antistatic effect is not prominent in the thick product.
However, this property can also be used in certain special occasions, such as the requirement that the functional additives in the film have less precipitation at the initial stage, and the effect on the initial strength of the glue is small, or the electrostatic effect of the product is required to have a relatively long-lasting effect. . The surface resistance data of the PE blown film used in the PE shows that the antistatic effects of several antistatic agents are significant under certain ambient temperature and humidity conditions, among which the effects of ASA-51, ASH-1, and ASP-2 are significant. Obviously, the initial antistatic effect of AB-33 was relatively poor, which is consistent with the application in PP.
The ASA-40 antistatic agent has superior initial antistatic effects compared to the above products. With less dosage, the performance can be balanced in a very short time, showing a good antistatic effect and having a good compatibility with the resin.
In addition, in the cast polyethylene film (CPE) products and foamed PE pearl cotton products, the use of the above-mentioned several antistatic agents, antistatic effect is remarkable, the surface properties of the products (CPE film) and processing performance (PE pearl cotton Medium) No adverse effects, to meet the requirements of manufacturers of such products. Application in the production of BOPP film This method used antistatic masterbatch P5115, using domestic AS-X antistatic masterbatch as a control, produced BOPP film on the three-layer co-extrusion production line of Guangzhou Petrochemical Tianyi Film Factory. Qilu Petrochemical's T36F homopolymer PP resin was used as the base material, and the amount of antistatic masterbatch was 3.3%. According to the normal production process conditions (extrusion system 235 °C -250 °C, longitudinal stretching 160 °C -185 °C) test 19μm film, the test process production process is stable, the film is normal, indicating that the antistatic agent BOPP processing process is not bad influences.
The test done by the manufacturer on the film also shows that the initial antistatic performance of the P5115 masterbatch is basically the same as that of the production material. The experimental masterbatch has little effect on corona treatment (surface wetting tension) and film strength. It is also equivalent to the production material in antistatic durability. Experiments show that the film obtained with P5115 masterbatch has low haze and high surface quality.
The antistatic effect has a certain sensitivity to the environmental humidity, and the effects of applying antistatic agents in different seasons are quite different. However, the test data shows that although the antistatic agent is affected by the dry environment, several new antistatic agents are used by wet workers. The effect of antistatic agents on the surface quality of products Packaging materials Antistatic agents and masterbatches The requirements are higher, especially for thin film materials, and their effect on the surface quality of the products must be examined. The production practice of polypropylene cast film and BOPP film has shown that the addition of antistatic masterbatch P5115, PB3315, PH115 and PB215 has little effect on the transparency and haze of the film, and can meet the requirements of the anti-static masterbatch for film products. The surface quality data of the polypropylene cast film with these antistatic masterbatches added is as shown in the above table.
The safety of antistatic agents Because packaging materials often come into contact with foods, cosmetics and pharmaceuticals, the hygienic safety of the auxiliaries used in packaging materials greatly influences their application. Most newly developed antistatic agents do not contain toxic substances and can meet the safety requirements of packaging materials. The results of the laboratory of the Institute of Occupational Health and Occupational Diseases of the Chinese Preventive Medicine College indicate that ASA-51, AB-31, ASH-1, and ASP-2 are actually non-toxic materials that can be used in food packaging materials. ASA-40 is a low-toxic product, but it has no pungent odor in production and use and can be used in non-food packaging.