DE310894C

DE310894C -

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Publication number: DE310894C
Application number: DENDAT310894D
Authority: DE

Description

KAISERLICHES 7ί IMPERIAL 7ί

PATENTAMT.PATENT OFFICE.

Es ist bekannt, daß sich reine Phenole (z. B. reine , kristallisierte Karbolsäure) mit Formaldehyd und dessen Polymeren, wie Paraformaldehyd, bei Gegenwart von Kondensationsmitteln zu löslichen Harzen kondensieren lassen. Diese Verfahren haben jedoch den Nachteil, daß die erhaltenen Kondensationsprodukte die verwendeten Kondensationsmittel hartnäckig zurückhalten. Diese Eigenschaft der HarzeIt is known that pure phenols (e.g. pure, crystallized carbolic acid) react with formaldehyde and its polymers, such as paraformaldehyde, condense to soluble resins in the presence of condensing agents. However, these methods have the disadvantage that the condensation products obtained persist in the condensation agents used hold back. This property of the resins

ίο zwingt zu einer Reihe von Wasch-, Schlemm- und Reinigungsverfahren, welche die technische Herstellung bedeutend erschweren.ίο forces a series of washing, feasting and cleaning processes, which make technical production significantly more difficult.

Läßt man an dererseits die übliche 40 prozentige Formaldehydlösung oder Paraformaldehyd ohne Koridensationsmittel auf reine Phenole einwirken, so findet erst nach mehrtägiger Erhitzung eine Reaktion statt und diese bleibt auch nach langem Kochen stets unvollständig, so daß das Harz durch große Mengen unveränderter Ausgangsstoffe verunreinigt ist.If, on the other hand, the usual 40 percent formaldehyde solution or paraformaldehyde is left without Coridants act on pure phenols only after several days of heating a reaction takes place and this always remains incomplete even after long cooking, so that the resin is contaminated by large amounts of unchanged starting materials.

Es wurde nun gefunden, daß man chemisch reines kristallisiertes Phenol ohne Verwendung von Kondensationsmitteln rasch und glatt mit Formaldehyd kondensieren kann, wenn man statt der Formaldehydlösung oder des Paraformaldehyds die wasserfreie, ganz oder teilweise in Natriumsulfitlösung unlösliche Polymerisationsform des Formaldehyds verwendet, die neuerdings unter der auch für den gewohnlichen wasserhaltigen, in Natriumsulfit vollständig'löslichen Paraformaldehyd gebräuchlichen Bezeichnung »Trioxymethylen« in den Handel kommt, und diese in möglichst feinpulveriger Form auf das Phenol einwirken läßt. It has now been found that chemically pure crystallized phenol can be obtained without using it of condensing agents can condense quickly and smoothly with formaldehyde if one instead of the formaldehyde solution or the paraformaldehyde, the anhydrous, wholly or partially Polymerization form of formaldehyde which is insoluble in sodium sulphite solution is used, the more recently also for the usual water-containing ones, in sodium sulphite completely 'soluble paraformaldehyde common name "trioxymethylene" in the Trade comes, and lets act on the phenol in as finely powdered form as possible.

Es findet hierbei schon bei 8o° unter Selbsterhitzung der Masse eine so stürmische Reaktion statt, daß sie im Großen sogar durch Zusatz von Verdünnungsmitteln gemäßigt werden muß. Dieses Verhalten des wasserfreien Trioxymethylens war nicht vorherzusehen. Es war vielmehr wahrscheinlich, daß diese Polymerisationsform des Formaldehyds sich nicht anders verhalten würde als der Paraformaldehyd, und daß sie weniger reaktionsfähig sein würde als Formaldehydlösung, da ja in der Regel monomolekulare Produkte schneller und stärker zu reagieren pflegen als hochmolekulare Körper. Die erwähnte Eigenschaft, mit dem chemisch reinen Phenol exotherm zu reagieren, ist nicht etwa auf die höhere Konzentration der Masse zurückzuführen, da sie sich dann ja auch beim Paraformaldehyd zeigen müßte und da ferner die Reaktion selbst dann noch kräftig und unter Selbsterhitzung verläuft, wenn der Masse so viel Wasser zugesetzt wird, als zur Bildung eines Trioxymethylen-Trihydrats nötig ist.It takes place here already at 80 ° with self-heating the masses had such a stormy reaction that they were on a large scale even by addition of diluents must be moderated. This behavior of the anhydrous trioxymethylene could not have been foreseen. Rather, it was more likely that this form of polymerization of formaldehyde would behave no differently than paraformaldehyde, and that it would be less reactive than formaldehyde solution, since it is usually monomolecular Products tend to react faster and more strongly than high-molecular bodies. The one mentioned It is not possible to react exothermically with the chemically pure phenol can be attributed to the higher concentration of the mass, since they are then also at Paraformaldehyde would have to show and, furthermore, the reaction itself would still be strong and proceeds with self-heating if as much water is added to the mass as to form it of a trioxymethylene trihydrate is necessary.

Das neue Verfahren bietet ferner den Vorteil, daß es eine so genaue Dosierung der eintretenden Form aldehydmenge gestattet, wie sie bei der bisher üblichen Methode nicht möglich war. Verwendet man z.B. wässerige Formaldehydlösung, unter Zusatz eines sauren Kondensationsmittels, so findet die Reaktion stets nur unvollkommen statt, weil das gebildete Harz nicht bis zum Schluß in Lösung verbleibt. Sobald die Konzentration der Formaldehydlösung entsprechend abgenommen hat, fällt das Harz aus und reißt das nochThe new method also has the advantage that there is such a precise dosage of the occurring Form aldehyde allowed, as it was not possible with the usual method. If you use e.g. aqueous Formaldehyde solution, with the addition of an acidic condensing agent, is how the reaction takes place always only imperfectly, because the resin formed is not in solution until the end remains. As soon as the concentration of the formaldehyde solution has decreased accordingly the resin falls out and still cracks

Claims

existing free phenol with. This will. prevents further conversion of the phenol and the "continuation of the heating then only has the result that the formaldehyde solution by. The action of the condensing agent is precipitated as paxa / formaldehyde. The resin `` contains '' both free phenol and free paraformaldehyde in suspension. When draining leaves behind the escaping phenol

ίο tan empyreumatic substances that the resin contaminate and stain. This also makes the melting point of the resin a relative one lower, which is unprecedented for practical use in place of shellac.

iS participates. '

'■' 'The previously made of pure crystallized carbolic acid and formaldehyde solution or paraformaldehyde using acidic condensing agents also possessed resins a tough adhering phenol odor, which is why it has already been proposed for their production to use o-cresol instead of the crystallized carbolic acid. In contrast are those made by the present process from chemically pure, crystallized phenol and anhydrous trioxymethylene obtained resins odorless, provided only those for binding the amount of trioxymethylene required for all phenol is used; because the anhydrous Trioxymethylene binds phenol in a much higher ratio than paraformaldehyde or formaldehyde solution. As a result, by increasing the amount of trioxymethylene accordingly, it is possible to obtain a resin with a higher level Establish softening point than when using formaldehyde solution or Paraformaldehyde can be obtained.

The execution of the procedure is a very simple: finely powdered trioxymethylene dissolves in the warm phenol; as soon as a partial dissolution has taken place, the mass heats up automatically, whereby water arises. This water of reaction can be removed as soon as it is formed by distillation become or remain in the crowd.

The resin formed emits only very small amounts of volatile substances when it is dehydrated. In. dehydrated it is only slightly yellow in color, may soften- « only in boiling water, dissolves without any residue in alcohol, ether, acetone and j caustic soda and can be used in the usual way.

Example.

94 parts of chemically pure crystallized phenol and 25.7 parts of finely powdered anhydrous trioxymethylene are added to 3 parts of water and i with stirring ^back: flußkühler heated to 85 °. The temperature of the mass rises with vigorous boil at about 113 ^0th As soon as the internal heating subsides, the mixture is heated to 100 to 110 ° for a short time and then the mass is drained into the drainage tank. In these it is heated up to 160 to 170 ", whereby it becomes clear with foaming. It is now ready for use.

A stream of an inert gas can also be passed through during the heating process. It is also possible to proceed in such a way that the process is gradually added of trioxymethylene works moderately and without the addition of water., '·, ■■ -. ■■■' ■■■

The resins formed can of course be used before or after their dehydration by adding further amounts of formaldehyde or its polymers to insoluble plastic masses are processed.

Sponsorship τ claim:

Process for the preparation of soluble resinous condensation products from phenols and formaldehyde, consisting in being finely divided exothermic with phenols reacting trioxymethylene without the addition of condensation agents on chemical pure crystallized phenol, expediently in the presence of a diluent, can act.