Plastic sol usually refers to a suspension of powdered vinyl chloride polymer or copolymer in a liquid plasticizer. At room temperature, liquid plasticizer has no or only a small dissolving effect on the resin, but becomes a solvent for the resin after heating. When a certain temperature is reached, the resin is completely dissolved in the plasticizer to form a homogeneous plastic body, which becomes a flexible solid when cooled.

Introduction

Plastic sol refers to a paste formed by resin powder with very small particle size (less than 2ж╠m) and plasticizer, which can be used as adhesive and sealant. For example, suspended polyvinyl chloride (also known as polyvinyl chloride paste resin) and plasticizers such as DOP can be made into PVC plastic sol. In the plastic sol, PVC particles cannot dissolve in the plasticizer, but can only swell to a certain extent to form an opaque emulsion. When the plastic sol is heated to a certain temperature (above 140буC for PVC plastic sol), semi-plasticization and full plasticization will occur, that is, the PVC particles will be semi-soluble or even fully dissolved in DOP, and become translucent solid plastic after cooling.

Because PVC plastic sol has poor adhesion. Therefore, some kind of tackifier and other modifiers must be added to the glue to modify it. Commonly used tackifiers include polyamide, polyurethane, internal olefin epoxy ester, etc. Other additives include viscosity regulator, defoamer, antioxidant, thixotropic agent, filler, etc.

Now the largest use of PVC plastic sol adhesive is automobile body sealant and automobile chassis anti-stone impact coating. This glue is a single-component, thixotropic paste that is easy to scrape and not flow. After applying the glue, it can also be dried and cured together with the paint, which is extremely convenient to use.

In addition, PVC paste resin can also be used to make plastic floor leather, injection molded toys, electrical insulation layer, etc.

Additives

Plastic sols are usually added with additives such as fillers, stabilizers and colorants. Plastic sols modified with volatile solvents or diluents that evaporate when heated are called organic sols. Dispersions that produce oily viscosity at room temperature after adding gelling agents or thickeners are called plastic gels. Plastic sols that are rigid when molten and modified with polymerizable monomers or cross-linkable monomers are called hard sols. Plastic sols are used in centrifugal casting, hollow mold molding, dipping, spraying, film casting and coating.

Common formulas

Plastic sols are suspensions of high molecular polymers (resins) in liquid plasticizers. At room temperature, high molecular polymers (resins) are slightly soluble or insoluble in liquid plasticizers. When a certain high temperature is reached, the resin is completely dissolved in the liquid plasticizer to form a homogeneous plastic body, which becomes a flexible solid after cooling. Plastic banyan gum is often used for centrifugal casting, hollow mold molding, impregnation, spraying, film casting, etc.

Formula 1

Polyvinyl chloride resin (Geon 178)

Dioctyl phthalate (DOP)

Calcium bicarbonate (Atomite)

Preparation method: Mix the raw materials in a mixer.

Formula 2

Polyvinyl chloride resin (VC411)

Dioctyl titanate (DOP)

Calcium bicarbonate chloride (tomite)

Preparation method: Mix the raw materials in a mixer.

Plastic Industry Video