A Composition of Matter consisting in Casein-cement.
Year: 1891

page_text: Date of Application, 15th May, 1891-Accepted, 4th July, 1891
COMPLETE SPECIFICATION.
A Composition of Matter consisting in Casein-cement.
I, CARL WITTKOWSKY, of 11, Horn Strasse, Berlin, in the Kingdom of Prussia,
German Empire, Manufacturer, 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:-
Casein has until this day been very little made use of in compounding a cement
for timber or the like, not to speak of industrial undertakings, where wood-cementing
This
is to be applied on a large scale, there it could not be introduced at all.
fine cement was prepared by dissolving casein in burnt or slaked lime, and
answered to its purpose very well, as far as its faculty in holding bodies together
is concerned, but the solution very quickly coagulates and then can no more be
smeared or brought into a glutinous state again, it is in fact hereafter robbed of all
further adhesive qualities, and the time, in which it retains these adhesive qualities,
is by far too short, as to render the application or the preparation of any utility.
This is the reason, why this cement which besides being very cheap, has the
enormous advantage of being insoluble in water, could not find its way into the
trade in general. And above all it could not be made use of at all in that part of
industry where wood has to be cemented by high pressure and by heat; as for
instance, where tlie wood at the same time has to be pressed into moulds. Because
in this branch of fabrication it is a main point, that the cement be perfectly dry
before submitting the articles to pressure and heat. A liquid cement is by the
pressure squeezed out, and the moisture creates steam by the application of heat
and therefore also bubbles. For these same reasons no waterproof cement could be
found at all for the branches of industry mentioned above, since by the heat the
rosin becomes so liquid, that it runs away, and albumen in a dry state does not
coagulate so densely as to be water-proof enough.
After many trials I have succeeded in producing out of casein a perfect water-
proof cement, which may be submitted to pressure and heat and therefore is especially
adapted to unite wood. It is possessed of all the requisite qualites. Firstly it
does not coagulate before times, secondly it may be diluted with water, for the
purpose of easily coating therewith, thirdly it retains its glutinous capacity after
drying on the wood and finally it turns into a perfect firm and waterproof state,
when pressure and heat is applied.
My invention now consists in adding water-glass to a solution of casein and lime,
which confers unto the cement all the qualities here mentioned.
The effect that the water-glass takes upon the solution is a double-one, probably
a retro-active one. Firstly the effect of the lime upon the casein will be annihilated
and hereafter the lime combines with the silicate. It is observed, that firstly in
the stuff a deposit appears, which afterwards slowly vanishes by degrees and a
slimy mass is left, which remains glutinous for days and coated upon wood, will dry
in proper time.
The proportions in which I prefer to compound the cement are: 100 parts of
casein, 20-35 parts of water-glass and 8 parts of lime, this will give a cement,
which by aid of pressure and heat will become perfectly waterproof and will be
qualified to be used in the manufacture of wooden articles on a large scale, since
after being dried, it turns into a viscid glutinous state by applying heat and here-
after soon indurated into an unchangeable hard mass, which no more can be brought
to dissolve.
It is a well-known fact, that water-glass for itself absorbs moisture and therefore
does not seem to be applicable for a waterproof compound, to cement wood, yet
the experiments, I have made, have sufficiently proved, that it is otherwise in

page_text: combination with lime and casein. It may be said, that the tendency of the water-glass
to attract moisture, in this case, before being chemically thoroughly bound to the
lime, is employed to maintain the glutinous liquid state and to prevent the lime to
take effect upon the' casein too soon: Therefore the water-glass not only acts
chemically but also mechanically.
Water-glass has been made use of heretofore, to produce a waterproof cement in
combination with casein, as, for instance in the manufacture of china-ware, whereby
the china-clay itself was combined with the casein to a waterproof cement, which is
similar to that forming the object of my invention. But the until this day unknown
compound of the said three chemicals not only is possessed of the qualifications,
common with the said cement for china-ware, but above all is possessed of the
perfect new and decidedly unexpected faculty to stick and adhere by aid of pressure
and heat, after having previously dried upon the surfaces to be united, and hereafter
indurated, and becomes lastingly insoluble.
It is evident that in the mixture of the three chemicals, casein, lime and water-
glass, the two latter prevent each other to take effect upon the casein, until by the
next following treatment this effecting is brought about.
My present invention therefore not only consists in the combination and application
of the three chemicals casein, lime, and waterglass, but in second line is based upon
the fact, that this cement, after having dried, turns into its final waterproof state by
applying heat, that is to say, upon the application of the said cement under the
influence of heat and pressure after previously having dried.
Having thus described the nature of my invention, I will now proceed to set
forth, in what particular manner I prefer to carry the same into effect :
I take 100 parts of a purified or unpurified albuminous matter preferably casein,
and mix the same with 8 parts of the hydroxide of an earthy metal, preferably
slaked lime for reasons of its energetic qualities and its cheapness.
This mixture
being in a pulpy or pappy state is added unto 20-35 parts of water-glass, care
being taken, that these last ingredients are quickly applied before the mixture of
the two first named chemicals dry or coagulate. Firstly a deposit arises, which
however again disappears, and a slimy smearable mass results.
a
Now the surfaces of the wooden articles to be united are covered with thin
coating of this mass, and allowed to dry. Then the parts are brought together, so
that the coated surfaces touch each other and are submitted for a short time to a
pressure and heat, which effects the adhesion and hereafter induration. This is
done by means of a press heated by gas or steam. The heat may be about 100°
and the application of the same together with the pressure need only take place for
a short time, since very soon after the cement becoines liquid, the final induration
sets in. However before this heat and pressure is applied, the previously dried
coatings on wood may be laid aside for months, without harm.
Good results are also arrived at, by varying the above mentioned proportions, as
long as the three chemicals are mixed up at the same time, and even, when coating
only one side, a good adhesion will take place, but the experiments, I have made,
have proved most successful, when the proportions were taken as heretofore set
forth.
My improved cement, prepared and made use of in the manner described, not
only serves to unite wood lengthways or crossways ad libitum, but also may be
employed in the preparation of compositions to be used in the plastic art by mixing
it up with saw-dust, wood-pulp, cellulose, and the like. The wood pulp or saw-dust
after being added to the cement is also submitted to heat and pressure, whereby all
the small particles are densely brought to unite.
For the sake of definition I mention, that albuminous matters are: casein, fibrine
and albumin proper, which for sake of economy may be employed in unpurified
state, for instance also ox-blood may be taken, which represents a rather concentrated
solution of albumen.
Earthy metals are calcium, barium, strontium, the hydroxide of the first
preferably being made use of.

page_text: Having now particularly described and ascertained the nature of my said inven-
tion, and in what manner the same is to be performed, I declare that what I
claim is :-
1. A cement to unite pieces of wood consisting of an albuminous matter, water-
glass and the hydroxide of an earthy metal, for the purpose as described.
2. A. cement to unite pieces of wood consisting of casein, water-glass and lime,
for the purpose as described.
3. A cement to unite pieces of wood by aid of pressure and heat, consisting of
casein, water-glass and lime, for the purpose as described.
Dated this 15th day of May 1891
CARL
WITTKOWSKY,
By Rayner & Cassell,
Agents for the Applicant.