Definition

1. Noun:
   • An oil that hardens in air due to oxidation and is often used as a paint or varnish base: A drying oil is a type of vegetable oil that, when exposed to air, undergoes a chemical reaction (oxidation) and polymerizes to form a tough, solid film. This property makes it a crucial component in oil-based paints, varnishes, and printing inks.

Usage Examples

• Noun:
  • Linseed oil is a common drying oil used by artists.
  • The durability of the finish depends on the quality of the drying oil in the varnish.
  • Traditional oil paints are made by grinding pigments into a drying oil.

Advanced Usage

• Technical Context: In industrial chemistry, the term "drying oil" specifically refers to oils with a high proportion of polyunsaturated fatty acids (like linolenic acid), which facilitate rapid cross-linking and film formation upon exposure to oxygen.
  • The iodine value is a key indicator used to classify an oil as a drying, semi-drying, or non-drying oil.

Variants and Related Words

• Semi-drying oil (n): An oil that hardens to a lesser extent or more slowly than a true drying oil (e.g., soybean oil).
• Non-drying oil (n): An oil that does not harden upon exposure to air (e.g., olive oil, castor oil).
• Oil paint (n): A type of paint made with pigments suspended in a drying oil.
• Oil varnish (n): A varnish made by dissolving a resin in a drying oil.

Synonyms

• Film-forming oil: A technical synonym emphasizing the oil's ability to create a solid layer.
• Oxidizing oil: A synonym highlighting the chemical process involved.

Related Phrases

• To dry by oxidation: The process by which a drying oil hardens.
  • The paint film dries by oxidation, not simply by evaporation.

Related Idioms

(This term is highly technical and is not commonly used in idiomatic expressions.)

Noun

1. an oil that hardens in air due to oxidation and is often used as a paint or varnish base