Improvements in the Manufacture of Dry Alizarine Colours.
Year: 1898

page_text: Date of Application, 10th Nov., 1898
Complete Specification Left, 19th July, 1899-Accepted, 19th Aug., 1899
PROVISIONAL SPECIFICATION.
Improvements in the Manufacture of Dry Alizarine Colours.
I, DAVID CARL BENDIX, of The British Alizarine Company Limited, of Silver-
town, Victoria Docks, London, Chemist, Fellow of the Institute of Chemistry of
Great Britain and Ireland, do hereby declare the nature of this invention
to be as follows:--
The alizarine colours such as alizarine, anthrapurpurine, flavopurpurine,
alizarine orange, and the like, are ordinarily introduced into the market in
paste form owing to the fact that when they are dried it is not possible by the
addition of water to again bring them into the fine state of division necessary
for use in dyeing. For the purpose of saving duties, cost of carriage, packages, &c.,
they are sometimes sold in the dry form but then require to be dissolved in alkalis,
and the solution re-precipitated by acids to acquire the condition suitable for dye-
ing. Methods for the production of dry alizarine which on treatment with water
assumes again the paste form have been described in various patent specifications.
Some of these methods such as the addition of glycerine and readily soluble
neutral salts have not been found practicable, inasmuch as their application
was restricted within certain limits as to actual percentage of alizarine in the
dry product. Other methods, such as the use of starch and of certain insoluble
mineral bodies such as silica in the form of tripoli or of kieselguhr, or of silica
compounds such as fullers earth and pipeclay have been described in the
Specification of English Patents No. 5444 of 1894 and No. 21398 of 1897.
I have discovered that dry alizarine of any desired percentage can be pro-
duced with advantage by the use of cellulose in the form of wood fibre, wood
pulp, paper pulp, and the like as an admixture to the alizarine colours.
The dry alizarine produced in this manner has the advantage over all products
hitherto obtained that it can be more easily converted into a paste by means
of water, seeing that a product containing as much as 95 per cent. of actual
alizarine absorbs water very rapidly and can be readily brought into a homo-
geneous paste. Further, it possesses the advantage that it leaves no soluble
foreign matters in the dye bath and does not introduce earthy impurities such
as lime, magnesia, iron &c., which are liable to be contained in kieselguhr,
fullers earth, pipe clay, and the like, which impurities it is well known have
a deteriorating influence on the shade and brilliancy of the dyed material, whilst
their removal can only be effected at considerable cost. On the other hand,
cellulose, for instance in the form of finely ground wood can be obtained at a
very small cost and has not the slightest unfavourable influence on the dyeing
result.
The following example may be given as a type of the method of preparing
dry alizarine containing say 50 per cent. of actual alizarine:-
Twenty parts by weight of dry wood fibre, or an equivalent quantity of
commercial wood fibre containing a certain percentage of moisture, are
thoroughly mixed to a thin paste with water and one hundred parts by weight
of commercial alizarine of 20 per cent. strength are added. The mixture is then

page_text: introduced into a filter press in order to remove therefrom as much water as
possible. The resulting cakes are then dried, preferably at a low temperature,
say from 50 to 60° C. and broken up into lumps or pieces of a convenient size.
Dated this 10th day of November 1898.
ABEL & IMRAY,
Agents for the Applicant.
Improvements in the Manufacture of Dry Alizarine Colours.
I, DAVID CARL BENDIX, of The British Alizarine Company Limited, of Silver-
town, Victoria Docks, London, Chemist, Fellow of the Institute of Chemistry of
Great Britain and Ireland, do hereby declare the nature of this invention
and in what manner the same is to be performed, to be particularly described and
ascertained in and by the following statement: -
The alizarine colours such as alizarine, anthrapurpurine, flavopurpurine,
alizarine orange, and the like, are ordinarily introduced into the market in
paste form owing to the fact that when they are dried it is not possible by the
addition of water to again bring them into the fine state of division necessary
for use in dyeing. For the purpose of saving duties, cost of carriage, packages &c.,
they are sometimes soid in the dry form but then require to be dissolved in alkalis,
and the solution re-precipitated by acids to acquire the condition suitable for dyeing.
Methods for the production of dry alizarine which on treatment with water
assumes again the paste form have been described in various patent specifications.
Some of these methods such as the addition of glycerine and readily soluble
neutral salts have not been found practicable, inasmuch as their application
was restricted within certain limits as to actual percentage of alizarine in the
dry product. Other methods, such as the use of starch and of certain insoluble
mineral bodies such as silica in the form of tripoli or of kieselguhr, or of silica
compounds such as fullers earth and pipeclay have been described in the
Specification of English Patents No. 5444 of 1894 and No. 21398 of 1897.
I have discovered that dry. alizarine of any desired percentage can be pro-
duced with advantage by the use of cellulose in the form of wood fibre, wood
pulp, paper pulp, and the like as an admixture to the alizarine colours.
The dry alizarine produced in this manner has the advantage over all products
hitherto obtained that it can be more easily converted into a paste by means
of water, seeing that a product containing as much as 95 per cent. of actual
alizarine absorbs water very rapidly and can be readily brought into a homo-
geneous paste. Further, it possesses the advantage that it leaves no soluble
foreign matters in the dye bath and does not introduce earthy impurities such
as lime, magnesia, iron &c., which are liable to be contained in kieselguhr,
fullers earth, pipe-clay, and the like, which impurities it is well known have
a deteriorating influence on the shade and brilliancy of the dyed material, whilst
their removal can only be effected at considerable cost. On the other hand
cellulose, for instance in the form of finely ground wood can be obtained at a
very small cost and has not the slightest unfavourable influence on the dyeing
result.
The following example may be given as a type of the method of preparing
dry alizarine containing say 50 per cent. of actual alizarine.
Twenty parts by weight of dry wood fibre or an equivalent quantity of
commercial wood fibre containing a certain per centage of moisture, are
thoroughly mixed to a thin paste with water and one hundred parts by weight

page_text: of commercial alizarine of 20 per cent. strength are added. The mixture is then
introduced into a filter press in order to remove therefrom as much water as
possible. The resulting cakes are then dried preferably at a low temperature
say from 50 to 60° C and broken up into lumps or pieces of a convenient size.
Having now particularly described and ascertained the nature of this
invention and in what manner the same is to be performed, I declare that what
I claim is:
1. The manufacture of dry alizarine colours by combining the alizarine
colour with finely divided cellulose mixed with water and then separating the
water therefrom and evaporating to dryness substantially as described.
2. As a new manufacture consisting of alizarine colour incorporated with finely
divide cellulose substantially as described.