The business, which had total sales of pounds 5.5m last year, strengthens Courtaulds Aerospace, which supplies adhesives and coatings to customers worldwide.
The deal does not involve the purchase of any fixed assets and is less than 1 per cent of ICI's assets.
The purchase strengthens Courtaulds' position in Germany and brings in several new customers from the European defence and aerospace coatings industry.
Courtaulds' worldwide sales in aerospace materials totalled pounds 130m last year. The business has operations is North America, the Far East and Europe.
ICI is selling the business to concentrate on core activities.
Gordon Campbell, Courtaulds Aerospace director, said: 'This move continues our development of a strong international aerospace business. Bringing Courtaulds and ICI's aerospace and defence coatings business together will give us a presence in the EC's three largest aerospace coatings markets and enable us to provide a full service to the aerospace industry in Europe.'
The deal is subject to regulatory approvals.