Alpha blue coloured pigment is introduced as ‘brilliant blue’ in the industries of dyes and paints. Though in the chemical industry, it is better known for its chemical name – Copper Phthalocyanine.
Copper Phthalocyanine or Phthalocyanine Blue BN has multiple trade names. But this crystalline, bright coloured synthetic blue pigment is a famous dye that belongs to the Phthalocyanine dyes’ group.
Properties of Copper Phthalocyanine:
Alpha blue pigment is hugely appreciated for its greater properties, such as-
- Lightfastness
- Dyeing strength
- Covering powder
- Superior resistance towards acids and alkalis
- Colour is blue
- Not soluble in water and other solvents
Trade names of Copper Phthalocyanine:
Copper Phthalocyanine substance is also popular with several other names except for alpha blue coloured pigment or Phthalocyanine Blue BN, which are monastral blue, helio blue, winsor blue, C.I. Pigment blue, copper tetra-benzoporphyrazine, phthalo blue, thalo blue, Phthalocyanine blue, Copper Phthalocyanine blue, Cu-Phthaloblue, and many more to mention.
‘CuPc’ abbreviation is used for this substance, and later in this article we will use it instead of Copper Phthalocyanine.
History of alpha blue coloured pigment:
CuPc was invented in the year 1927, and it was the outcome of a chemical reaction between o-dibromobenzene and copper cyanide, which was originally made to prepare phthalonitrile.
After a couple of years to that, researchers at Scottish found CuPc along with NiPc and FePc during the reaction between ammonia and phthalic anhydride. When metal detector was used after this reaction, phthalimide made a reaction to the iron traces present in it, and then everybody noticed the trace of a by-product as a blue contaminant.
The researchers and chemists who were present there used this blue sample and resolved in sulphuric acid, which resulted in a workable pigment, which was then sold as ‘Monastral’.
Applications of CuPc:
1. Catalysis
Long-time back, for the purpose of redox reactions, metal phthalocyanines was observed to serve the role of a catalyst. It also reacted in a similar manner during –
- Hydrogen sulfide removal process to sweeten the gas streams
- The reaction of oxygen reduction
2. Colorant
CuPc is highly stable and thus is immensely used in the making of plastics, coatings, and inks. It is an insoluble pigment and does not tend to transfer into the material. In the packaging industry, this standard pigment is largely used to prepare printing ink. In the 1980-90 time period, only Japan has holds its record industrial production of 10000/annum, which was the highest amount produced in the whole world.
CuPc cool blue is biased towards the colour green. It is extremely powerful and thus when gets mixed with other colour pigments, suppress the mix with its blue colour.
Structure/ reactivity:
- Alpha blue pigment includes phthalocyanine conjugate base with a copper complex – Cu2+Pc2-.
- This colour pigment does not get soluble in water but has the solubility in concentrated sulphuric acid.
- Its density is approximately 1.6 gm./cc.
- It crystallizes in many forms, five of them has identified yet.
- It is non-biodegradable
- It has no toxic effects on plants or fish
- It offers no carcinogenic effects
Alpha blue pigment powder manufacturers do a great business with the industries of ink, color pigment, chemical, and packaging.
