DE604500C

DE604500C - Carbonless paper and process for its manufacture

Info

Publication number: DE604500C
Application number: DES104862D
Authority: DE
Original assignee: ANCIENS BRAUNST Ets
Current assignee: ANCIENS BRAUNST Ets
Priority date: 1932-05-26
Filing date: 1932-06-03
Publication date: 1934-10-22
Also published as: GB403002A; FR751410A; US2063226A

Description

Die Durchschreibepapiere werden gegenwärtig· in der Weise hergestellt, daß auf das fertige Papier eine Fettstoff enthaltende Kopierfarbe aufgetragen wird. Ä'uqb, ist bereits vorgeschlagen worden, das fertige Papier vor dem Auftrag der Kopierfaybe ein- oder beidseitig mit einem wachs- oder fettartigen Stoff zu. behandeln. ^! ...-■"The carbonless papers are currently produced in such a way that a copying ink containing grease is applied to the finished paper. Ä'uqb, it has already been suggested that the finished paper should be covered with a wax or fat-like substance on one or both sides before the application of the copy ink. treat. ^! ...- ■ "

Einer der wesentlichen Nachteile dieser ίο bekannten Durchschreibepapiere besteht darin, daß sie in Form dünner Blätter die Neigung haben, sich an. ihren Rändern einzurollen, besonders wenn die Luft ihrer Umgebung mehr oder weniger feucht ist.
Dieses Einrollen rührt wahrscheinlich von den.unterschiedlichen hygroskopischen Eigenschaften der einzelnen Schichten des Durchschreibepapiers her, mit anderen Worteil·, . von der verschiedenartigen. Zusammensetzung eines solchen Durchschreibepapiers. In. der Tat lassen sich die Fettstoffe durch die Behandlung des fertigen Papiers nur bis zu einer gewissen Tiefe einführen, da das Pa-. pier ein schlechter Wärmeleiter ist und nur langsam beim Eintauchen in den geschmolzenen Fettstoff erwärmt wird, jedenfalls wesentlich langsamer, als es bei der üblichen Geschwindigkeit der Papierbahn möglich wäre, um in seiner ganzen Diebe die Temperatur des Fettstoffes anzunehmen. Infolgedessen bleibt in den Mittelschichten der Papierbahn noch eine bestimmte Dicke des Papiers von dem Fettstoff frei. Beim Auftragen des Fettstoffes auf die Oberfläche des Papiers wird die. Ungleichmäßigkeit der Tränkung noch -wesentlich verstärkt. Es ist daher ersichtlich, daß. es nicht möglich ist, ein Papier gleichmäßig mit dem Fettstoff zu tränken, -vorausgesetzt, daß man es vor der Tränkung genügend hoch erwärmt, was aber aus praktischen Gründen kaum ausführbar wäre. Durch die bis jetzt bekannte Art der Tränkung des Papiers vor dem Auftragen! der Kopierfarbe ist es daher nicht möglidi, einen Träger zu erzielen, welcher vollkominen gleichmäßig mit dem Fettstoff durchsetzt wäre und daher hygroskopische Eigenschaften besäße, die an jeder Stelle des Papiers ein und dieselben wären.One of the main disadvantages of these ίο known carbonless papers is that they have a tendency to stick in the form of thin sheets. to curl their edges, especially if the air around them is more or less humid.
This curling is probably due to the different hygroscopic properties of the individual layers of the carbonless paper, in other words, ·,. from the diverse. Composition of such a carbonless paper. In. In fact, by treating the finished paper, the fatty substances can only be introduced to a certain depth, since the pa-. pier is a poor conductor of heat and is heated only slowly when immersed in the molten fatty substance, at least much more slowly than it would be possible at the usual speed of the paper web in order to assume the temperature of the fatty substance in all its thieves. As a result, a certain thickness of the paper still remains free of the fatty substance in the middle layers of the paper web. When the fatty substance is applied to the surface of the paper, the. Irregularity of the impregnation still significantly increased. It can therefore be seen that. it is not possible to soak a paper evenly with the fatty substance, provided that it is heated sufficiently high before the soak, but this would hardly be feasible for practical reasons. Due to the previously known type of impregnation of the paper before application! It is therefore not possible for the copier color to obtain a carrier which would be completely uniformly permeated with the fatty substance and which would therefore have hygroscopic properties which would be one and the same at every point on the paper.

Das vorliegende Verfahren ermöglicht dagegen, sämtliche Papierfasern, bevor sie in die Blattform übergeführt werden, mit dem Fettstoff gleichmäßig zu tränken, so daß, ganz unabhängig von der Dicke des Papierblattes, der Fettstoff in allen Schichten desselben gleichmäßig verteilt ist. Wird nun auf ein so gleichmäßig mit dem Fettstoff getränktes Papier in üblicher Weise bei erhöhter Temperatur Kopierfarbe· aufgetragen, so kann die letztere in geschmolzenem Zustände in die ganze Dicke des Papierblattes· eindringen, weil der in dem Papierblatt ent-In contrast, the present process enables all paper fibers to be removed before they are in the leaf shape are transferred to soak evenly with the fatty substance, so that, regardless of the thickness of the sheet of paper, the fatty substance in all layers of it is evenly distributed. Will now be so even with the fatty substance impregnated paper in the usual way at elevated temperature copying ink applied, so the latter can in a molten state in the entire thickness of the sheet of paper penetrate because the

Claims

The retained fatty substance is also more or less liquefied by the melted copy color and combines with the copy color to form a whole. The invention consists in that a paper is used as the support for the dye-donating layer, which paper has been made from greasy milled paper fibers sized in a known manner with stearin in the fabric.
ίο To produce such a paper, the paper fibers are also first milled in a known manner to make them greasy, ie the processing of the paper stock in the Hollander is extended to the extent that it is customary in the production of glassine papers. This enables the fibers to mix intimately with the stearin to a greater extent.

A solution of sodium stearate is then added to the substance while it is still in the Hollander and, after complete mixing, an acid solution, preferably oxalic acid, is added to cause the precipitation of free stearic acid. The addition of sodium stearate is measured in such a way that the finished paper contains 0.2 to 5 o / _o parts by weight of stearin. It is expedient to use so much oxalic acid that the excess chemically reacts with the calcium salts usually contained in water to form insoluble calcium oxalate, which increases the opacity of the paper as well as its strength. If necessary, additional quantities of soluble calcium salts can be added. From this mixture, a paper with a square meter weight of about ι ο to 25g is produced in a known manner. Finally, the paper is provided with the usual layer of copying ink. It is preferred to use copy dyes which dissolve easily in the stearic acid when the color layer is applied.

The copy color therefore permeates the paper completely evenly. The backside, d. H. the side of the paper not provided with copy ink is colored strongly and evenly and there as a result of the use If there are no holes in the paper on the greasy ground material, there can be no stains of color on the back appear. The finished paper does not change after the paint layer has dried and is also insensitive to hygroscopic changes in the atmosphere, i.e. does not show the undesirable property of curling and its attendant inconvenient handling. As a result of the presence of the stearin, the paper also becomes substantially opaque, which is preferred by consumers.

Ρλ τ ι; ν τ λ ν s ι κ Γϊ c hi ::

ι. Carbonless paper, its dye-releasing Layer is supported by a paper containing fatty matter, characterized in that the fatty matter containing carrier of the dye-donating layer consists of a paper, made from greasily ground paper fibers glued to the fabric with stearin.

2. Process for the production of carbonless paper according to claim. 1, in which soluble Stearate is precipitated by means of an acid, characterized by the use of oxalic acid as a precipitating agent.