Lac dye is the scarlet colorant present in the live, pre-emergent insects (Laccifer
lacca; syn. Kerria lacca) which advance in a adhering cocoon, accepted as
"sticklac" on the twigs of over 160 host copse in an arc from arctic
India through to Indo-China. The color is acquired by aqueous abstraction of
sticklac; the adhering balance is added candy to "seedlac" and to the
absolutely aesthetic "shellac".
The
water-soluble dyestuff, lac dye is composed of analogues of laccaic acid,
mainly in the anatomy of ammonium salts. These pigments are present at up to
10% in sticklac which has been harvested afore developed insects abandon their
cocoon. Candy seedlac and attack accept a low agreeable of laccaic acids but
absorb a chicken water-insoluble pigment, erythrolaccin.
From
age-old times, lac dye has been active in India as a derma corrective and for
the dyeing of absolute and silk, while China has a attitude of acceptance for
covering dyeing. The colour of the dye can be adapted by the adapted best of
acerbic from violet to red and brown.
Seedlac
and shellac, the above candy articles of sticklac, are active in varnishes,
paints, press inks, sealing wax, micanite compounds, as coatings for biologic
and confectionery products.
没有评论:
发表评论