Seatons Natural Oils for use in resins
Vegetable oils are widely used in the production of resins, particularly alkyd resins, where a number of Seatons oils can be used in the production of long, medium and short chain alkyds.
Refined linseed oil
This product is characterised by its high level of unsaturation (iodine value 175-200), low acidity and pale colour. It has a low viscosity and is a popular choice of oil for long and medium chain length alkyds.
Refined soyabean, sunflower and safflower oils
These three products are characterised by pale colours, low odour and low acidity. They have iodine values in the range of 110-150 and, as a result, are slow drying, giving soft films. However, their non-yellowing properties are very good and they find extensive use in alkyd production, particularly in resins for pale coloured paints. They can also be added to drying oil formulations as a means of controlling drying times. Refined safflower and sunflower oils are used in the manufacture of pale coloured oil paints for artists. In this application, the non-yellowing properties are much more important than drying time.
Polymerised linseed oil (linseed stand oil)
This product is pale in colour and has a low acidity. It is manufactured to viscosity specifications ranging from 4 poise to 800 poise @ 25ºC. Lower viscosity grades can replace or partially replace refined linseed oil as a starting material in alkyd resin production, where it will help reduce production times.
Polymerised soyabean oil (soya stand oil)
This polymerised semi-drying oil is available in several viscosity grades, the popular one for alkyd resins being 2 poise @ 25°C. As with polymerised linseed oil, this oil can be used as a starting material to reduce production times, and would be preferable to linseed oil in resins for white or pale coloured products, where non-yellowing properties are paramount.
Castor oil is a non-drying oil with functionality provided by the presence of ricinoleic acid (12-hydroxyoleic acid). It is often the oil of choice for the production of short chain length alkyds, which go on to be used as stoved coatings on vehicles and domestic white goods.