A New or Improved Product Derived from Casein or other Albu- minous Substances, and Processes for Producing the same
Year: 1897

page_text: Date of Application, 26th Oct., 1897-Accepted, 11th Dec., 1897
COMPLETE SPECIFICATION.
"A New or Improved Product Derived from Casein or other Albu-
minous Substances, and Processes for Producing the same."
We, WILHELM KRISCHE of 22 Langelaube Hannover in the Empire of Germany,
Manufacturer, and ADOLF SPITTELER of Wolfratshausen near Munich, Germany
aforesaid, Chemist, 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:-
This invention concerns a certain new and useful product named "Lactoform"
and also the method or process of producing the same.
The invention relates to a new product or article of manufacture obtained from
Casein and similar albuminous substances, and the process of producing the same,
and it has for its object the production of an article of manufacture which is very
hard and tough, and which does not swell or materially soften when immersed in
water.
As is well known, Casein and similar albuminous substances may be rendered
insoluble by the action of salts and acids, and also by other agents having a
specific effect on albuminous substances such as Formaldehyd.
The compounds thus obtained are however not adapted for extensive use in the
arts and manufactures, as they are either too brittle. or lacking in hardness, and
almost all of them have the very serious drawback that they largely increase in
volume and become quite soft and without strength, when exposed to the action of
water for any length of time.
By their improved process, the inventors obtain a new and superior substance.
The new product, which the inventors have named Lactoform, possesses great
hardness combined with elasticity and toughness, and it may be kept immersed
in water for days, without increasing in volume or becoming materially softened.
It is so little acted upon by water and chemicals, that surfaces or paintings pro-
tected by a coating of Lactoform may be washed and even brushed down with soa
and water without detriment. Lactoform closely resembles horn in character, and
it can be manufactured either by itself or in combination with a large variety of
other substances, and may be made of any colour and either opaque or transparent
at the will of the operator.
Lactoform can be employed in the place of horn, ivory, ebony, amber and for
very many other purposes.
Owing to its great hardness and brilliancy when polished it may even be
manufactured as a substitute of jet and coloured stones."
The process by which the new product Lactoform is obtained is as follows:
To a solution containing Casein or other albuminous substances of a similar
nature, such of the salts or acids are added, which have the property of coagulating
them, as may.be appropriate to the special purpose for which the Lactoform is
being manufactured. Thus, merely to give a few instances by way of explanation:
by the addition of a solution of acetate of lead to a solution of Casein a coagulum
or Casein-compound is produced from which Lactoform closely resembling horn
may ultimately be obtained, while to manufacture Lactoform as a substitute for
ivory it would merely be necessary to cause the formation of white lead in the
same coagulum by adding soluble carbonates such as soda to the Casein solution

page_text: before the latter is decomposed by the addition of sugar of lead. If a zinc compound
be employed in place of the lead, the white colour obtained will, as is well known,
be of a more durable character; or the coagulum may be coloured white by
mixing it intimately with sulphate of baryta; or exide of barium may be added
to the Casein solution and the whole precipitated by means of alum, in which case
the coagulum will likewise contain blanc fixe.
By the use of Chromides, blueish-green, also yellow and orange Lactoform is
obtainable, by the action of iron salts rust coloured, and in combination with
tannic acid slate and black coloured Lactoform may ultimately be produced, and
so on.
"If vinegar be chosen as the means of producing the coagulum, or some glycerine
be incorporated with the latter, a comparatively high degree of transparency may
be obtained in the resulting Lactoform. The inventors may, however, state it as
their experience, that Lactoform of greater hardness is obtainable from the
coagula or Casein compounds produced by the metallic salts than from any other
coagula.
The coagula or Casein compounds thus obtained, which are already_generally
known and not claimed as a new invention, are in the manufacture of Lactoform
merely intermediate products. They are converted into Lactoform by exposure to
the vapours, or by immersion in a solution of Formaldehyd, the inventors having
made the discovery that the action of Formaldehyd on these Casein-compounds is
practically very different to what it is on the original Casein. For while the
insoluble product obtained by treating, Casein solutions with Formaldehyd has
after drying the property when immersed in water, of absorbing large quantities
of moisture and greatly increasing in volume, becoming quite soft and unable to
resist mechanical influences, the intermediate products or Casein-compounds on
the contrary entirely lose by the treatment with Formaldehyd the property of
swelling and of materially softening in water; they also increase considerably in
hardness and toughness by being subjected to the action of Formaldehyd.
The length of time during which the intermediate products or Casein-compounds
must be exposed to the action of Formaldehyd to entirely convert them into
Lactoform, naturally depends on their thickness and on the strength of the
Formladehyd or solution employed, but the re-action may be considered completed
as soon as the whole mass is impregnated with Formaldehyd fumes. Thus in the
case of a Casein-compound formed into a plate of inch in thickness and treated
with a solution containing 20 per cent of Formaldehyd, an immersion during one
hour will generally suffice, while thin films will be transformed into Lactoform
almost immediately, especially when they are brought in contact with
Formaldehyd in a moist state. Ample time may however safely be allowed for
the action of the Formaldehyd, the inventors having obtained very good Lactoform
in cases where they experimentally immersed Casein-compounds for 48 hours in a
concentrated solution of Formaldehyd.
As regards the question whether it is preferable to treat the intermediate
products or Casein-compounds in the wet or in the dry state with Formaldehyd,
the inventors have observed that Casein-compounds treated in the wet state usually
give Lactoform which is of lighter colour, but more opaque and brittle than when
they were nearly dry at the time. Ordinarily it will be found most convenient to
subject the intermediate products to the action of Formaldehyd when they have
been allowed to dry until they contain about 30 per cent of moisture, as in this
state they are already firm enough to be safely handled, yet still soft enough to
be readily penetrated by the Formaldehyd.
When the Lactoform is withdrawn from the Formaldehyd it should be dried,
preferably at a higher temperature towards the end, until the penetrating odour
of the Formaldehyd is no longer perceptible, when it is ready for use.
As Casein combines very readily either mechanically or chemically with a large
number of other substances of the most varied nature, and as Casein-solutions can
be prepared, as is well known, in various manners and may be made to show

page_text: either alkaline acid or neutral reaction, it is obvious that either by suitable.
additions to the Casein-solutions, or by incorporating other substances with the
intermediate products or Casein-compounds, the character of the resulting
Lactoform may be varied almost at will; also that it is as easy to produce
Lactoform as au impregnation of, or as a coating on fibres, fabrics, paper, wood,
stones and the like, as it is to produce it as a substance by itself.
It may also be pointed out that thin layers of Casein need not be specially
dissolved to allow of their being transformed into Lactoform as they will take up
sufficient moisture during the process for the reactions to take place.
Lactoform may likewise be produced as will readily be understood, in an
apparently simpler manner than here before described either by the addition of a
sufficient quantity of Formaldehyd to the acid, or salt solution chosen for obtaining
the coagulum, or even by adding the Formaldehyd already to the Casein-solution
in a careful manner, so as not to cause coagulation before the salt or acid is added;
but the results thus obtained are less certain, and the inventors do not recommend
these latter processes for general use.
In order still more explicitly to show the nature of our invention and to
illustrate the manner in which it is carried out, so that any one acquainted with
similar arts and manufactures may be able to practice the same, we now give
three working prescriptions, but by way of examples only and in no way
restricting ourselves to these particular processes or to the particular kinds of
Lactoform produced thereby. The first example is intended to illustrate how
Lactoform is produced as a substance by itself, the second as an instance of Lacto-
form manufactured in combination with other substances, and the third to
show in which manner other substances may be provided with a coating of
Lactoform.
FIRST EXAMPLE. TO PRODUCE LACTOFORM AS A SUBSTITUTE FOR HORN.
Dissolve Casein in water containing 5 percent of soda carbonate and gradually
add, stirring all the time, to the solution thus obtained a weak solution of acetate
of lead until all the Casein is coagulated, which may be recognised by the fluid
surrounding the coagulum becoming clear and colourless.
After removing, the fluid the wet coagulated mass is ground, adding as much
water as may be necessary, in any convenient manner until all the particles are
evenly sub-divided.
Then pour the mass into a form, consisting of an open frame resting on a fine
sieve placed perfectly level. When the water has drained off and the deposit, now
in the shape of a plate of even thickness, has become of sufficient consistency
remove the frame and place the wet Casein-compound on a layer of cotton cloth
or other absorbent surface, and allow it to dry somewhat, turning it over
occasionally and replacing the wet absorbent layer by a dry one whenever
required.
As soon as the plate, which by this time will have contracted considerably, has
become slightly, but uniformly transparent, place it overnight into a solution
containing about 20 per cent of Formaldehyd. The Casein-compound, now
transformed into Lactoform, is removed next morning to the drying room.
good way to prevent warping is to dry the Lactoform plate between folds of cotton
cloth under slight pressure.
A
The Lactoform plate thus obtained can with great ease be cut into a comb of
excellent quality, closely resembling in appearance and properties a comb made of
real horu
SECOND EXAMPLE. TO PRODUCE LACTOFORM OF LIGHT SPECIFIC WEIGHT, AND OF
BLACK COLOUR SHOWING LIGHTER COLOURED SPOTS, AND CAPABLE OF RESISTING
ROUGH USAGE.
Dye the Casein solution to be worked up by means of a paste obtained by
intimately grinding lampblack with a small portion of the solution, calculating

page_text: 3 parts of lampblack to every 100 parts of Casein dissolved. Then add to the
Casein solution 12 per cent of very fine cork dust, likewise calculated on the dry
Casein, mix thoroughly and coagulate by means of acetate of lead, and generally
proceed as in the first example.
:
The cork particles will show in the polished Lactoform plate like the pores in a
the wood, giving it a peculiar and handsome appearance.
The plate thus produced may be forcibly thrown to the ground without
breaking.
THIRD EXAMPLE. TO RENDER A WALL WATERPROOF BY MEANS OF LACTOFORM.
Give the wall a coating of a 15 per cent solution of Casein by means of a brush,
and when nearly dry, follow with a 10 percent solution of zinc chloride. Allow
to dry and repeat both applications. Then finish by washing down the surface
thus prepared with a strong solution of Formaldehyd, when a coating of Lactoform
will result, which will effectually protect the wall against moisture and allow it
to be washed with soap and water when required.
Having now particularly described and ascertained the nature of our said inven-
tion, and in what manner the same is to be performed, we declare that what we
claim is:-
First: A new article of manufacture "Lactoform," partaking of the nature of
horn and not increasing in volume when immersed in water, produced by the
action on Casein, and on other similar albuminous substances, of salts and acids
simply or jointly, and of Formaldehyd, substantially as described.
Secondly:-A new article of manufacture "Lactoform," produced in
combination with any other substances, substantially as described.
"
Thirdly: A new article of manufacture Lactoform," produced as an
impregnation of, and as a coating on, any other substances, substantially as
described.
Dated this 25th day of October 1897
WILHELM KRISCHE.
ADOLF SPITTELER.