in the usual manner, and mixed with 65 parts of turpentine, or 250
parts of ketone and 250 parts of ether; 500 parts or 750 parts of
methyl alcohol is added, and a colorant, such as desired. Instead of
turpentine, rosins derived from it may be employed. If the employment
of camphor is desired to a certain extent, it may be added to the
mixture. The whole is shaken and left at rest for about 12 hours. It is
then passed between hot rollers, and finally pressed, cut, and dried,
like ordinary celluloid. {156}
The product thus obtained is without odor, when camphor is not
employed; and in appearance and properties it cannot be distinguished
from ordinary celluloid, while the expense of production is
considerably reduced.
«Formol Albumen for Preparation of Celluloid.»—Formol has the property
of forming combinations with most albuminoid substances. These are
not identical with reference to plasticity, and the use which may be
derived from them for the manufacture of plastic substances. This
difference explains why albumen should not be confounded with gelatin
or casein. With this in view, the Société Anonyme l’Oyonnaxienne has
originated the following processes:
I.—The albumen may be that of the egg or that of the blood, which are
readily found in trade. The formolizing may be effected in the moist
state or in the dry state. The dry or moist albumen is brought into
contact with the solution of commercial formol diluted to 5 or 10 per
cent for an hour. Care must be taken to pulverize the albumen, if it
is dry. The formol penetrates rapidly into the albuminoid matter, and
is filtered or decanted and washed with water until all the formol
in excess has completely disappeared; this it is easy to ascertain by
means of aniline water, which produces a turbid white as long as a
trace of formic aldehyde remains.
The formol albumen is afterwards dried at low temperature by submitting
it to the action of a current of dry air at a temperature not
exceeding 107° F. Thus obtained, the product appears as a transparent
corneous substance. On pulverizing, it becomes opaque and loses its
transparency. It is completely insoluble in water, but swells in this
liquid.
II.—The formol albumen is reduced to a perfectly homogeneous powder,
and mixed intimately with the plastic matter before rolling. This
cannot be considered an adequate means for effecting the mixture. It
is necessary to introduce the formol albumen, in the course of the
moistening, either by making an emulsion with camphor alcohol, or by
mixing it thoroughly with nitro-cellulose, or by making simultaneously
a thorough mixture of the three substances. When the mixture is
accomplished, the paste is rolled according to the usual operation.
The quantity of formol albumen to add is variable, being diminished
according to the quantity of camphor.
Instead of adding the desiccated formol albumen, it may previously be
swollen in water in order to render it more malleable.
Instead of simple water, alkalinized or acidified water may be taken
for this purpose, or even alcoholized water. The albumen, then, should
be pressed between paper or cloth, in order to remove the excess of
moisture.
«Plastic Substances of Nitro-Cellulose Base.»—To manufacture plastic
substances the Compagnie Française du Celluloid commences by submitting
casein to a special operation. It is soaked with a solution of acetate
of urea in alcohol; for 100 parts of casein 5 parts of acetate of
urea and 50 parts of alcohol are employed. The mass swells, and in
48 hours the casein is thoroughly penetrated. It is then ready to be
incorporated with the camphored nitro-cellulose. The nitro-cellulose,
having received the addition of camphor, is soaked in the alcohol, and
the mass is well mixed. The casein prepared as described is introduced
into the mass. The whole is mixed and left at rest for 2 days.
The plastic pulp thus obtained is rolled, cut, and dried like ordinary
cellulose, and by the same processes and apparatus. The pulp may also
be converted into tubes and other forms, like ordinary celluloid.
It is advisable to subject the improved plastic pulp to a treatment
with formaldehyde for the purpose of rendering insoluble the casein
incorporated in the celluloid. The plastic product of nitro-cellulose
base, thus obtained, presents in employment the same general properties
as ordinary celluloid. It may be applied to the various manufacturing
processes in use for the preparation of articles of all kinds, and
its cost price diminishes more or less according to the proportion of
casein associated with the ordinary celluloid. In this plastic product
various colorants may be incorporated, and the appearance of shell,
pearl, wood, marble, or ivory may also be imparted.
«Improved Celluloid.»—This product is obtained by mingling with
celluloid, under suitable conditions, gelatin or strong glue of gelatin
base. It is clear that the replacement of part of the celluloid by the
gelatin, of which the cost is much less, lowers materially the cost
of the final product. The result is obtained without detriment to the
qualities of the objects. These are said to be of superior properties,
having more firmness than those of celluloid. And the new material
{157} is worked more readily than the celluloid employed alone.
The new product may be prepared in open air or in a closed vessel under
pressure. When operated in the air, the gelatin is first immersed cold
(in any form, and in a state more or less pure) in alcohol marking
about 140° F., with the addition of a certain quantity (for example,
5 to 10 per cent) of crystallizable acetic acid. In a few hours the
material has swollen considerably, and it is then introduced in alcohol
of about 90 per cent, and at the same time the celluloid pulp (camphor
and gun cotton), taking care to add a little acetone. The proportion of
celluloid in the mixture may be 50 to 75 per cent of the weight of the
gelatin, more or less, according to the result desired. After heating
the mixture slightly, it is worked, cold, by the rollers ordinarily
employed for celluloid and other similar pastes, or by any other
suitable methods.
The preparation in a closed vessel does not differ from that which
has been described, except for the introduction of the mixture of
gelatin, celluloid, alcohol, and acetone, at the moment when the
heating is to be accomplished in an autoclave heated with steam,
capable of supporting a pressure of 2 to 5 pounds, and furnished with
a mechanical agitator. This method of proceeding abridges the operation
considerably; the paste comes from the autoclave well mingled, and is
then submitted to the action of rollers. There is but little work in
distilling the alcohol and acetic acid in the autoclave. These may be
recovered, and on account of their evaporation the mass presents the
desired consistency when it reaches the rollers. Whichever of the two
methods of preparation may be employed, the substance may be rolled as
in the ordinary process, if a boiler with agitator is made use of; the
mass may be produced in any form.
«Preparation of Uninflammable Celluloid.»—The operation of this process
by Woodward is the following: In a receiver of glass or porcelain,
liquefied fish glue and gum arabic are introduced and allowed to swell
for 24 hours in a very dry position, allowing the air to circulate
freely. The receiver is not covered. Afterwards it is heated on a water
bath, and the contents stirred (for example, by means of a porcelain
spatula) until the gum is completely liquefied. The heating of the mass
should not exceed 77° F. Then the gelatin is added in such a way that
there are no solid pieces. The receiver is removed from the water bath
and colza oil added, while agitating anew. When the mixture is complete
it is left to repose for 24 hours.
Before cooling, the mixture is passed through a sieve in order to
retain the pieces which may not have been dissolved. After swelling,
and the dissolution and purification by means of the sieve, it is
allowed to rest still in the same position, with access of air. The
films formed while cooling may be removed. The treatment of celluloid
necessitates employing a solution completely colorless and clear. The
celluloid to be treated while it is still in the pasty state should be
in a receiver of glass, porcelain, or similar material.
The mass containing the fish glue is poured in, drop by drop, while
stirring carefully, taking care to pour it in the middle of the
celluloid and to increase the surface of contact.
When the mixture is complete, the celluloid is ready to be employed and
does not produce flame when exposed.
The solution of fish glue may be prepared by allowing 200 parts of it
to swell for 48 hours in 1,000 parts of cold distilled water. It is
then passed through the sieve, and the pieces which may remain are
broken up, in order to mingle them thoroughly with the water. Ten parts
of kitchen salt are then added, and the whole mass passed through the
sieve.
This product may be utilized for the preparation of photographic films
or for those used for cinematographs, or for replacing hard caoutchouc
for the insulation of electric conductors, and for the preparation of
plastic objects.
«Substitute for Camphor in the Preparation of Celluloid and Applicable
to Other Purposes.»—In this process commercial oil of turpentine, after
being rectified by distillation over caustic soda, is subjected to
the action of gaseous chlorhydric acid, in order to produce the solid
monochlorhydrate of turpentine. After having, by means of the press,
extracted the liquid monochlorhydrate, and after several washings with
cold water, the solid matter is desiccated and introduced into an
autoclave apparatus capable of resisting a pressure of 6 atmospheres.
Fifty per cent of caustic soda, calculated on the weight of the
monochlorhydrate, and mingled with an equal quantity of alcohol, is
added in the form of a thick solution. The apparatus is closed and
heated for several hours at the {158} temperature of 284° to 302° F.
The material is washed several times for freeing it from the mingled
sodium chloride and sodium hydrate, and the camphor resulting from this
operation is treated in the following manner:
In an autoclave constructed for the purpose, camphene and water
strongly mixed with sulphuric acid are introduced and heated so as
to attain 9 pounds of pressure. Then an electric current is applied,
capable of producing the decomposition of water. The mass is constantly
stirred, either mechanically or more simply by allowing a little of the
steam to escape by a tap. In an hour, at least, the material is drawn
from the apparatus, washed and dried, sublimed according to need, and
is then suitable for replacing camphor in its industrial employments,
for the camphene is converted entirely or in greater part into camphor,
either right-hand camphor, or a product optically inactive, according
to the origin of the oil of turpentine made use of.
In the electrolytic oxidation of the camphene, instead of using
acidulated water, whatever is capable of furnishing, under the
influence of the electric current, the oxygen necessary for the
reaction, such as oxygenized water, barium bioxide, and the
permanganates, may be employed.
«Plastic and Elastic Composition.»—Formaldehyde has the property, as
known, of removing from gelatin its solubility and its fusibility, but
it has also another property, prejudicial in certain applications, of
rendering the composition hard and friable. In order to remedy this
prejudicial action M. Deborda adds to the gelatin treated by means of
formaldehyde, oil of turpentine, or a mixture of oil of turpentine and
German turpentine or Venice turpentine. The addition removes from the
composition its friability and hardness, imparting to it great softness
and elasticity. The effect is accomplished by a slight proportion, 5 to
10 per cent.
«Production of Substances Resembling Celluloid.»—Most of the
substitutes for camphor in the preparation of celluloid are attended
with inconveniences limiting their employment and sometimes causing
their rejection. Thus, in one case the celluloid does not allow of the
preparation of transparent bodies; in another it occasions too much
softness in the products manufactured; and in still another it does not
allow of pressing, folding, or other operations, because the mass is
too brittle; in still others combinations are produced which in time
are affected unfavorably by the coloring substances employed.
Callenberg has found that the halogenous derivatives of etherized oils,
principally oil of turpentine, and especially the solid chloride of
turpentine, which is of a snowy and brilliant white, and of agreeable
odor, are suitable for yielding, either alone or mixed with camphor or
one of its substitutes, and combined by ordinary means with nitrated
cellulose, or other ethers of cellulose, treated with acetic ether, a
celluloidic product, which, it is said, is not inferior to ordinary
celluloid and has the advantage of reduced cost.
«Elastic Substitute for Celluloid.»—Acetic cellulose, like
nitro-cellulose, can be converted into an elastic corneous compound.
The substances particularly suitable for the operation are organic
substances containing one or more hydroxy, aldehydic, amide, or
ketonic groups, as well as the acid amides. Probably a bond is formed
when these combinations act on the acetate of cellulose, but the bond
cannot well be defined, considering the complex nature of the molecule
of cellulose. According to the mode of preparation, the substances
obtained form a hard mass, more or less flexible. In the soft state,
copies of engraved designs can be reproduced in their finest details.
When hardened, they can be cut and polished. In certain respects
they resemble celluloid, without its inflammability, and they can be
employed in the same manner. They can be produced by the following
methods—the Lederer process:
I.—Melt together 1 part of acetate of cellulose and 1 1/2 parts
of phenol at about the temperature of 104° to 122° F. When a clear
solution is obtained place the mass of reaction on plates of glass or
metal slightly heated and allow it to cool gradually. After a rest of
several days the mass, which at the outset is similar to caoutchouc, is
hard and forms flexible plates, which can be worked like celluloid.
II.—Compress an intimate mixture of equal parts of acetic cellulose and
hydrate of chloride or of aniline, at a temperature of 122° to 140° F.,
and proceed as in the previous case.
In the same way a ketone may be employed, as acetophenone, or an acid
amide, as acetamide.
III.—A transparent, celluloid-like substance which is useful for the
{159} production of plates, tubes, and other articles, but especially
as an underlay for sensitive films in photography, is produced by
dissolving 1.8 parts, by weight, of nitro-cellulose in 16 parts of
glacial acetic acid, with heating and stirring and addition of 5 parts
of gelatin. After this has swelled up, add 7.5 parts, by weight, of
alcohol (96 per cent), stirring constantly. The syrupy product may be
pressed into molds or poured, after further dilution with the said
solvents in the stated proportion, upon glass plates to form thin
layers. The dried articles are well washed with water, which may
contain a trace of soda lye, and dried again. Photographic foundations
produced in this manner do not change, nor attack the layers sensitive
to light, nor do they become electric, and in developing they remain
flat.
IV.—Viscose is the name of a new product of the class of substances
like celluloid, pegamoid, etc., substances having most varied and
valuable applications. It is obtained directly from cellulose by
mascerating this substance in a 1 per cent dilution of hydrochloric
acid. The maceration is allowed to continue for several hours, and at
its close the liquid is decanted and the residue is pressed off and
washed thoroughly. The mass (of which we will suppose there is 100
grams) is then treated with a 20 per cent aqueous solution of sodium
hydrate, which dissolves it. The solution is allowed to stand for 3
days in a tightly closed vessel; 100 grams carbon disulphide are then
added, the vessel closed and allowed to stand for 12 hours longer, when
it is ready for purification. Viscose thus formed is soluble in water,
cold or tepid, and yields a solution of a pale brownish color, from
which it is precipitated by alcohol and sodium chloride, which purifies
it, but at the expense of much of its solubility. A solution of the
precipitated article is colorless, or of a slightly pale yellow. Under
the action of heat, long continued, viscose is decomposed, yielding
cellulose, caustic soda, and carbon disulphide.
See also Casein for Celluloid Substitutes.
«Celluloid of Reduced Inflammability.»—I.—A practicable method consists
in incorporating silica, which does not harm the essential properties
of the celluloid. The material is divided by the usual methods, and
dissolved by means of the usual solvents, to which silica has been
added, either in the state of amylic, ethylic, or methylic silicate,
or in the state of any ether derivative of silicic acid. The suitable
proportions vary according to the degree of inflammability desired, and
according to the proportion of silica in the ether derivative employed;
but sufficient freedom from inflammability for practical purposes is
attained by the following proportions: Fifty-five to 65 parts in volume
of the solvent of the celluloid, and 35 to 45 parts of the derivative
of silicic acid.
When the ether derivative is in the solid form, such, for instance,
as ethyl disilicate, it is brought to the liquid state by means of
any of the solvents. The union of the solvent and of the derivative
is accomplished by mixing the two liquids and shaking out the air as
much as possible. The incorporation of this mixture with the celluloid,
previously divided or reduced to the state of chips, is effected by
pouring the mixture on the chips, or inversely, shaking or stirring
as free from the air as possible. The usual methods are employed for
the desiccation of the mass. A good result is obtained by drying very
slowly, preferably at a temperature not above 10° C. (50° F.). The
resulting residue is a new product scarcely distinguished from ordinary
celluloid, except that the inherent inflammability is considerably
reduced. It is not important to employ any individual silicate or
derivative. A mixture of the silicates or derivatives mentioned will
accomplish the same results.
II.—Any ignited body is extinguished in a gaseous medium which is
unsuitable for combustion; the attempt has therefore been made to find
products capable of producing an uninflammable gas; and products have
been selected that yield chlorine, and others producing bromine; it
is also necessary that these bodies should be soluble in a solvent of
celluloid; therefore, among chlorated products, ferric chloride has
been taken; this is soluble in the ether-alcohol mixture.
This is the process: An ether-alcohol solution of celluloid is
made; then an ether-alcohol solution of ferric perchloride. The two
solutions are mingled, and a clear, syrupy liquid of yellow color,
yielding no precipitate, is obtained. The liquid is poured into a
cup or any suitable vessel; it is left for spontaneous evaporation,
and a substance of shell-color is produced, which, after washing and
drying, effects the desired result. The celluloid thus treated loses
none of its properties in pliability and transparency, and is not only
uninflammable, but also incombustible. {160}
Of bromated compounds, calcium bromide has been selected, which
produces nearly the same result; the product obtained fuses in the
flame; outside, it is extinguished, without the power of ignition.
It may be objected that ferric perchloride and calcium bromide, being
soluble in water, may present to the celluloid a surface capable of
being affected by moist air; but the mass of celluloid, not being
liable to penetration by water, fixes the chlorinated or brominated
product. Still, as the celluloid undergoes a slight decomposition,
on exposure to the light, allowing small quantities of camphor to
evaporate, the surface of the perchlorinated celluloid may be fixed by
immersion in albuminous water, after previous treatment with a solution
of oxalic acid, if a light yellow product is desired.
For preventing the calcium bromide from eventually oozing on the
surface of the celluloid, by reason of its deliquescence, it may be
fixed by immersing the celluloid in water acidulated with sulphuric
acid. For industrial products, such as toilet articles, celluloid with
ferric perchloride may be employed.
Another method of preparing an uninflammable celluloid, based on the
principle above mentioned, consists in mixing bromide of camphor with
cotton powder, adding castor oil to soften the product, in order that
it may be less brittle. The latter product is not incombustible, but
it is uninflammable, and its facility of preparation reduces at least
one-half the apparatus ordinarily made use of in the manufacture of
celluloid. The manufacture of this product is not at all dangerous,
for the camphor bromide is strictly uninflammable, and may be melted
without any danger of dissolving the gun cotton.
III.—Dissolve 25 parts of ordinary celluloidin in 250 parts of acetone
and add a solution of 50 parts of magnesium chloride in 150 parts of
alcohol, until a paste results, which occurs with a proportion of about
100 parts of the former solution to 20 parts of the latter solution.
This paste is carefully mixed and worked through, then dried, and gives
an absolutely incombustible material.
IV.—Glass-like plates which are impervious to acids, salts, and
alkalies, flexible, odorless, and infrangible, and still possess a
transparency similar to ordinary glass, are said to be obtained by
dissolving 4 to 8 per cent of collodion wool (soluble pyroxylin) in
1 per cent of ether or alcohol and mixing the solution with 2 to 4
per cent of castor oil, or a similar non-resinifying oil, and with 4
to 6 per cent of Canada balsam. The inflammability of these plates
is claimed to be much less than with others of collodion, and may
be almost entirely obviated by admixture of magnesium chloride. An
addition of zinc white produces the appearance of ivory.
«Solvents for Celluloid.»—Celluloid dissolves in acetone, sulphuric
ether, alcohol, oil of turpentine, benzine, amyl acetate, etc., alone,
or in various combinations of these agents. The following are some
proportions for solutions of celluloid:
I.—Celluloid 5 parts
Amyl acetate 10 parts
Acetone 16 parts
Sulphuric ether 16 parts
II.—Celluloid 10 parts
Sulphuric ether 30 parts
Acetone 30 parts
Amyl acetate 30 parts
Camphor 3 parts
III.—Celluloid 5 parts
Alcohol 50 parts
Camphor 5 parts
IV.—Celluloid 5 parts
Amyl acetate 50 parts
V.—Celluloid 5 parts
Amyl acetate 25 parts
Acetone 25 parts