Metal colourant

As a decorative finish on steel and zinc-base alloys for a variety of domestic and ornamental articles. The finish may be protected by clear lacquers or may be coloured by metal colouring techniques for use on, for example, door handles, luggage trim, etc. 

Non-metal, colour depending from the allotropic form. 

Coatings derived from cholesteric liquid crystalline polymers are used commercially as reflective sheets and polarisers. The liquid crystal is cooled below the vitrification temperature resulting in a solid polymer that is amorphous but contains large regions of frozen liquid crystalline order. Such structures are also found in nature in the iridescent, almost metallic colours of beetles and other insects, which result from helical cholesteric structures in the outer layer of the carapace. 

Contamination None High concentration of metal Colour, requires further step for removal... 

Other potential organic pigments are those that show metallic colours , such as the dithienyl pyrroles above, which form high melting (>300 °C) golden lustrous crystals. ... 

Plastics can have a layer of metallic aluminium deposited on the surface by vacuum. Although aluminium is basically a bright silver, it may be lacquer tinted to give a wide range of metallic colours. Polyester, polystyrene, urea and phenol formaldehyde, and polypropylene are readily metallised. Other plastics need a pretreatment. 

Molten lead passed as drops through a card or colander perforated with numerous holes— 1448 for the smallest shot — and fell into water which usually contained a little sodium sulphide. This coated the shot with a thin layer of sulphide of a lustrous black metallic colour which remained permanent in moist air. The size of the shot depended not only on the diameter of the holes in the colander, but also on the initial temperature and composition of the molten metal. The shot was sorted by sieves and by rolling down an inclined plane, the imperfectly shaped pellets remaining behind. Finally the shot was polished by rolling with plumbago in a barrel or rumble. 

Properties.—In elongated prisms also fibrous, massive and granular. H. = 2-3. G. =4-4-3. Lustre metallic. Colour dark steel-gray Before blowpipe on charcoal gives off sulphurous and antimonial fumes, leaving behind a black magnetic slag. 

Projicrties.—In plumose masses, showing on tho fraeture a c.ry.stal-lino struoturo also gnuiul-ar and compact. H. = 2 r>-3. (1. — r) 7r>-(i-O. Lustre metallic. Colour bluish Icad-gmy. Behaves before tho blowpipe like ziiikenite. 

Properties. — Orthorhombic. H. = 3-4. G. = 4-75-5-0. Lustre metallic. Colour between lead-gray and iron-gray... 

Properties.—Monocliiiic. Habit jn-i.suiatic prismatio pbuies vorti- illy striated. Rather brittle. 11. = 2-2-5. G. = G 2-6-4. Lustre metallic. Colour and sti-eak light stcol-gray. I uses easily before blowpipe. 

Properties.—In groups of slender prismatic crystals also columnar, massive, resembling stibnite. H. = 2-0. G. =4-81. Lustre metallic. Colour bright lead-gray. Streak red. 

A metal coloured two component epoxy paste for metal bonding, also good for GRP or SMC. a. 1.2 e. 50-80/23 i. 60 ... 

Fig. 21.35 The structures (X-ray diffraction) of (a) [Cu2Br5] in the [Me4N] salt [M. Asplund et al. (1985) Acta Chem. Scand., Ser. A, vol. 39, p. 47] and (b) [Cu4Brg] in the ["Pr4N] salt [M. Asplund et al. (1984) Acta Chem. Scand. Ser. A, vol. 38, p. 725]. In both, the Cu(I) centres are in trigonal planar environments and in [Cu4Brg] , the copper atoms are in a tetrahedral arrangement the Cu" Cu distances are longer than in the bulk metal. Colour code Cu, brown Br, pink.

Properties.—Orthorhombic. H. = 3-3 5. G. =5 3-5 35. Lustre metallic. Colour and streak steel-gray. 

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