Study on Production of Low-toxic Adhesive for Plastics by Rectifying PVC Residue

2.2 The choice of initiator

The choice of initiator is the key in the synthesis of multi-component copolymer resins. Water-soluble peroxide initiators (such as ammonium persulfate, potassium persulfate, etc.) cannot be used because they are insoluble in the system; benzoyl peroxide is used in this system. Although it can be dissolved, due to the complex composition of the PVC lye, there are partially reduced substances, and the polyhalogenated olefins are not used to initiate the polymerization reaction and therefore cannot be used.

According to the characteristics of the system, the use of azo compounds as initiators is excellent, and the activation amount is about 4% of the total monomers. It should be particularly noted that azo compounds are poorly stable and must be stored at low temperatures.

2.3 Formulation Selection of Adhesives for Plastics

The multi-component copolymer resin liquid can be used as a plastic adhesive, but after being modified by other materials, its performance in various aspects is even better. The tackifying resin is mainly used to improve the adhesive strength of the adhesive layer, and the modified phenolic resin (2402 phenolic resin) is preferably used here. Plasticizers are mainly used to improve the plasticity of the adhesive layer after drying, which is very important in the bonding of soft plastics (such as films), commonly used plasticizers (such as phthalic acid, dibutyl ester, o-phenylene) For example, dioctyl formate, etc.) can be used, the amount of which can be flexibly controlled according to the scope of use of the product. When the product is used for hard plastic bonding, it can be used with little or no force. When it is used for soft plastic, it must be added. However, when it is excessive, it will affect the bonding strength. The solvent volatilization rate of the solvent-based adhesive product has a great relationship with the storage stability and the drying speed of the product. In this study, the 1,1-dichloroethane solvent mainly exists in the multi-component copolymer resin glue solution, and its boiling point (57.3). °C) is low, especially volatile, so the adhesive product is extremely unstable. It is necessary to add appropriate amount of high-boiling low-toxic organic solvents (such as isoamyl acetate, 200# solvent oil, etc.) to adjust the volatilization rate of the mixed solvent.

2.4 Product Toxicity

With the improvement of people’s environmental awareness and living standards, people’s toxicity requirements for various products (especially chemical products) are more demanding, and non-toxic and low-toxic environmental protection products are generally favored by people. The organic adhesive products on the market, mainly toxic benzene solvents, have caused great harm to society and people.

In this study, a reasonable production process was adopted to convert the more toxic chlorinated olefins in PVC raffinate into macromolecule polymers as the main adhesive material for adhesives, while unreacted low-toxic 1,1-dichloroethane. Alkane becomes its main solvent, and low-toxic volatilization rate regulators are properly added. The product becomes a low-toxic environmental protection product, and the LDS0 values ​​of some common solvents are shown in Table 5.

The larger the LD50 is, the lower the toxicity is. It can be seen that 1,1-dichloroethane is a low toxic solvent and its toxicity is similar to gasoline.

This product is suitable for the bonding of all kinds of hard and soft plastic products, especially applicable to the up and downstairs plastic pipe, decoration (decoration) industry and packaging engineering industry. Its usage is the same as all types of organic adhesives on the market, characterized by low toxicity, quick drying, and strong adhesion.

3 Conclusion

In this study, PVC residue distillates were used to synthesize multi-component copolymer resin gums, and various low-toxicity fine chemical products were developed. This not only rationally utilized resources, but also reduced environmental pollution, greatly improving the comprehensive utilization level of PVC residue. And additional value.

(Wen / Liu Changchun Tian Jingcheng Su Yongxiang Jiaozuo University)

"Packaging Project"