Chlorinated paraffins are manufactured by the chlorination of n-paraffin or paraffin wax, normally in a batch process. The reaction is exothermic and leads to the generation of the by-product hydrochloric acid. After removing residual traces of acid, a stabilizer is added to produce finished batches.
Chlorinated paraffins, which contain 30-70% chlorine, are largely inert and almost insoluble in water. Paraffins have extremely low vapour pressure. Most commercial chlorinated paraffin products are liquid and range from relatively low to extremely high viscosity. There are also solid types which have longer carbon chain lengths and usually contain 70-72% chlorine.
Increasing the chlorine content results in products with higher viscosity and density. Chlorinated paraffins are capable of mixing with many organic solvents such as aliphatic and aromatic hydrocarbons, chlorinated solvents, ketones and esters.
The range of chlorinated paraffins available are generally grouped into a number of distinct 'families', depending on the chain-length of the feedstock, i.e. :
based on c10-13 paraffin
based on c14-17 paraffin
Based on c18-20 (liquids), c>20 (liquids) and c20 wax grades (average carbon chain length approximately c25)
- Chlorinated paraffin is a plasticizer largely used in PVC. CPW is used as an additive in industrial lubricants like gear oil as a fire retardant chemical additive.
- Chlorinated paraffins are used as plasticizers in paint sealants and adhesives. The main advantage over other alternatives is inertness and it enhances flame retardant properties. Cpw with high chlorine content is used as flame retardants in a wide range of rubbers and polymer systems.
- Chlorinated paraffins are also used in formulation of metal working lubricants as they are one of the most effective extreme pressure additives for lubricants used in a wide range of machining and engineering operations.
|CP grade ||cp 40 ||cp 45 ||cp 50 ||cp 56 ||cp 58 ||cp 65 |
|Chlorine content ||40-42% ||45-46% ||50-52% ||54-56% ||58-60% ||58-60% |
|Appearance ||pale yellow liquid ||pale yellow liquid ||pale yellow liquid ||pale yellow liquid ||pale yellow liquid ||pale yellow liquid |
|Colour in hazen unit ||80 ||80 ||120 ||120 ||200 ||200 |
|Specific gr. At 30 c ||1. 16-1. 18 ||1. 20-1. 22 ||1. 26-1. 28 ||1. 31-1. 33 ||1. 36-1. 38 ||1. 40-1. 42 |
|Viscosity at 25 c in poise ||4-feb ||5-apr ||13-18 ||30-60 ||200-400 ||700 & above |
|Thermal stability at 180 c for 1 hour ||pale yellow to light yellow ||pale yellow to light yellow ||pale yellow to light yellow ||pale yellow to light yellow ||pale yellow to light yellow ||pale yellow to light yellow |