The Universal Selection Source: Coatings Ingredients

Selection Guide

Techno Brief: Wax Emulsions for Coatings

This techno brief will tell you how to improve specific surface effects using wax emulsions. It describes the mechanisms by which waxes work in formulation, their applications, and how to formulate with wax emulsions & dispersions. It also describes the risks and benefits of Wax Emulsions depending on your application.

Wax Types and Properties

Wax is a generic term that encompasses materials that have some specific properties such as:

  • Solid at 20°C, varying from soft / plastic to brittle / hard
  • A mp > 40°C without decomposing
  • A relatively low viscosity slightly above the melting point
  • Transparency to opaque, but not glass-like
  • Buffable under slight pressure

This includes:

  • Natural products based on C16 - C 36 Fatty Acids or
  • Some synthetic polymers with Mw from 700 to 10.000

Waxes are often classified according to their origin as illustrated in Table below:

Naturally Occuring Waxes
Synthetic Waxes
Animal Vegetable Mineral
Beeswax Carnauba Montan PP, PE & PTFE
Lanolin Candellila Paraffin Fischer-Tropsch
Lanocerin Jojoba Microcrytalline Fatty Acid Amine
Shellac Ouricourl Intermediate PTFE
Ozokerite     Polyamide
PP = polypropylene
PE = polyethylene
HDPE = High Density Polyethylene
PTFE = Polytetrafluoroethylene
Table 1: Wax Classification

Table 2 summarizes the main wax properties and corresponding effects imparted or improved in paint, coating and ink formulations.

Type
Properties
Main Performances
 Carnauba
  • High melting naturally occuring wax
  • Different grades (T1, T2, T3)
  • Hard & brittles
  • Excellent clarity
  • Generally Recognised As Save

  • Slip & Lubricity
  • Anti-Blocking
  • Mar Resistance

 Paraffin
  • Various grades, hence properties depending on refinement degree
  • Hard to oily feeling
  • Mainly composed of straight alkane chains, hence some parafffin's have good crystalline structure, giving excellent barrier effects against water repellency
  • Very low polarity
  • Anti-Blocking
  • Water Repellency
  • Slip & Lubricity

 PE
  • Obtained by polymerization of Ethylene monomers
  • Various grades, hence properties depending on Mw and polymerisation process
  • Two main families: LDPE and HDPE (Low and High Density PE) whose difference is the extend and type of branching
  • LDPE's display more thoughness, better scuff / mar resistance and are more flexible
  • HDPE's contribute to better slip properties and abrasion resistance
  • Slip
  • Abrasion Resistance
  • Anti-Blocking
 PP
  • Obtained by polymerization of propylene monomers
  • Good film toughness but poor slip & lubricity properties
  • Not really a wax but often classify as such because of impact to surface properties
  • Anti-Slip
  • Anti-Blocking
  • Abrasion Resistance
 PTFE
  • Obtained by polymerization of C2F4 monomers
  • High melting point and outstanding heat resistance properties (up to 600°F)
  • Give the lowest known CoF, hence excellent slip & lubricity, anti-blocking and abrasion resistance
  • Chemically inert
  • Not really a wax but often classify as such because of impact to surface properties
  • Slip & Lubricity
  • Anti-Blocking
  • Abrasion Resistance
Table 2: Wax Properties and Performances

Wax can easily be incorporated into liquid formulations in an emulsion or dispersion form (see Wax Emulsions & Dispersions)

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