I rather think it is a typo for Patentblau ...

1 April 1995 Bovine Offal (Prohibition) (Amendment) Regulations (1995).
Demanded that Patent Blue V be added to stain SBO to prevent its use.
http://www.priondata.org/data/A_UKlaw.html


4. By the addition of, for each 100 kgs. of skimmed milk powder, a minimum of 35 kgs. of undeodorized fish meal and 200 grs. of carbonate of iron or sulphate of iron and

(a) 1.5 kgs. of activated carbon;

(b) or 100 grs. of mixture composed of four fifths of yellow tartrazine (E 102) and one fifth of patent blue V (E 131);

(c) or 20 grs. of cochineal red A (E 124);

(d) or 40 grs. of patent blue V (E 131).

http://www.lawphil.net/international/wto/annex4c.html


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Note added at 37 mins (2005-07-29 18:05:57 GMT)
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Many sites capitalize it, and it is probably a proper name, but Kucera\'s WB der Chemie does not.