In the production process of PVC products, polymers, additives, and processing equipment are the three main material conditions. There are many types and quantities of additives used in thermoplastics, and the demand for other additives in the processing of thermosets is relatively small except for the additives required for curing. The dosage of additives is small, generally a few percent or even a few thousandths of the weight of the polymer. However, the dosage of plasticizers, reinforcing agents, fillers, softeners, flame retardants, etc. is large, up to 10 to dozens of copies. The amount of additives is small but effective, and can even turn some polymers that have almost lost their practical value due to large performance defects or difficult processing into valuable materials. Thanks to the use of additives, many fine chemical products can be applied more efficiently. Therefore, the additives are vividly called "industrial monosodium glutamate". (Crosslinker manufacturers, how to use PVC crosslinkers, PVC adhesion promoters)

1. Select additives according to the purpose

1. Toughening: select elastomers, thermoplastic elastomers and rigid toughening materials;

2. Reinforcement: glass fiber, carbon fiber, whiskers and organic fibers;

3. Flame retardant: bromine (ordinary bromine and environmental protection bromine), phosphorus, nitrogen, nitrogen/phosphorus compound intumescent flame retardant, antimony trioxide, hydrated metal hydroxide;

4. Antistatic: all kinds of antistatic agents;

5. Conductivity: carbon (carbon black, graphite, carbon fiber, carbon nanotube), metal fiber and metal powder, metal oxide;

6. Magnetism: ferrite magnetic powders and rare earth magnetic powders include samarium cobalt (SmCo5 or Sm2Co17), neodymium iron boron (NdFeB), samarium iron nitrogen (SmFeN), and alnicol magnetic powders;

7. Thermal conductivity: metal fibers and metal powders, metal oxides, nitrides and carbides; carbon materials such as carbon black, carbon fiber, graphite and carbon nanotubes; semiconductor materials such as silicon and boron;

8. Heat resistance: glass fiber, inorganic fillers, heat resistant agents such as substituting maleimides and β crystalline nucleating agents;

9. Transparent: nucleating agent, for PP α the crystalline nucleating agent sorbitol series Millad 3988 has the best effect; (Crosslinker manufacturers, how to use PVC crosslinkers, PVC adhesion promoters)

10. Wear resistance: graphite, molybdenum disulfide, copper powder, etc.;

11. Insulation: calcined kaolin, etc.;

12. Barrier: mica, montmorillonite, quartz, etc.

2. Select additives according to the characteristics of the product

(1) The additives that improve stability, i.e., stabilizers, are to prevent or delay the aging and deterioration of polymers during processing, storage and use. Due to the different mechanisms of aging, stabilizing additives are divided into the following four categories:

1. Antioxidants

(1) Free radical inhibitors: main antioxidants, including amines and phenols;

(2) Peroxide decomposers: auxiliary antioxidants, mainly thiodicarboxylates and phosphotes, are usually used in conjunction with main antioxidants.

2. Light stabilizer

Also known as UV light stabilizer.

(1) Light shielding agent: carbon black, zinc oxide and some inorganic pigments;

(2) Ultraviolet light absorbers: salicylates, benzophenones, benzotriazoles, substituted acrylonitriles, triazines, etc.; 　　(3) Quenching agent: mainly organic chelates of nickel. 　　3. Heat stabilizer generally refers to the stabilizer used in polyvinyl chloride and vinyl chloride copolymer. 　　(1) Main stabilizers: basic lead salts, metal soaps and salts, organotin compounds, rare earth environmental protection stabilizers, hydrotalcite stabilizers, etc. 　　(2) Auxiliary stabilizers: epoxy compounds, phosphates, polyols, etc. 　　(3) Composite stabilizer: composed of main stabilizer (mainly metal soaps and salts and organotin compounds), auxiliary stabilizer and other stabilization additives. (Crosslinker manufacturers, how to use PVC crosslinking agents, PVC adhesion promoters) 4. Antifungal agents Most polymers are insensitive to mold, but due to the addition of plasticizers, lubricants, fatty acid soap heat stabilizers and other substances that can breed mold in processing, they are susceptible to mold. There are many chemical types of mold inhibitors, including elemental organic compounds, nitrogenous organic matter, dithiocarbamate, trihalomethyl sulfides, organic halides and phenolic derivatives. 　　(2) Improvement of additives to improve mechanical properties, such as tensile strength, hardness, rigidity, impact strength, thermal deformation, etc. It mainly includes the following three categories: 1. Resin crosslinking agent: divided into radiation crosslinking and chemical crosslinking. Chemical crosslinking uses crosslinking agents, and organic peroxides are commonly used in conjunction with some crosslinking agents and crosslinking promoters to improve the degree and speed of crosslinking. The crosslinking agent of epoxy resin is the curing agent, which is often used with amines and organic anhydrides. Photosensitizers of ultraviolet cross-linking are also cross-linkers. (Crosslinking agent manufacturers, how to use PVC crosslinking agents, PVC adhesion promoters) 2. Reinforcements, fillers and coupling agents Fiber-type fillers with reinforcing effects, such as glass fiber, carbon fiber, metal whiskers, etc.; Fillers mainly include calcium carbonate, terracotta, talc, mica, silicon oxide, calcium sulfate, calcium sulfite, wood powder and fiber, etc.; Coupling agents are the bridge between inorganic reinforcements and fillers and organic polymers, which can significantly improve the mechanical strength of plastics, mainly silanes and titanates containing functional groups. 　　3. Anti-impact agent: used to improve the impact resistance of rigid plastic products. Commonly used are: MBS (methacrylate-butadiene-styrene copolymer), ABS (acrylonitrile-butadiene-styrene copolymer) and CPE (chlorinated polyethylene). 　　(3) Additives to improve processing performance include lubricants, release agents, softeners, etc. Plasticizers also have the effect of improving polymer processing properties. Lubricants can improve the fluidity and release properties of polymers during heat molding, including hydrocarbons, fatty acids and their amides, esters, metal soaps, and other derivatives. The release agent is applied to the surface of the mold to make the molded product easy to release and make its surface smooth, often using silicone oil. (Crosslinker manufacturers, how to use PVC crosslinkers, PVC adhesion promoters) 　　(4) Softening and lightweight additives 1. Plasticizers