US1423753A - Method of producing active methylene bodies - Google Patents

Description

came-1n B. CARTER am) ALBERT n coxn, or PITTSBURGH, PENNSYLVANIA, assrenons, BY MESNE ASSIGNMENTS, To s. KARPEN & imos; a conroiaa- TKON OF WEST VIRGINIA.

METHOD OF ERODU'CING ACTIVE METHYLENE BODIES.

ace-ass;

It? Drawing.

' ment in Methods of Producing Active Methylene Bodies, of whichthe following 1 is a specification.

This invention relates particularly to a process of producing active methylene bodies, that is, active bodies containing the methylene radical (CH particularly formaldehyde (CH O) and hexamethylenete- 'tramine (CH N A known method of producing hexamethylenetetramine is to, pass ammonia through formaldehyde. The usual method of producing formaldehyde is to pass wood alcohol over a catalyst. This method is becoming inadequate and expensive, owing to the increasing difliculty of obtaining wood alcohol in suflicient quantity.

According to the present process ozone (U or an ozonized agent, such as ozonized air or ozonized oxygen, is combined with ethylene gas (0 11,) under conditions favoring the immediate or continuous conversion of the ethylene ozonide ((3 11 0 which these bodies combine to form, into constitucuts, of which the main or predominating one is formaldehyde. Thus, the formation of any considerable amount of ethylene ozonide, which is of an explosive nature, is obviated, and a large yield of formaldehyde is obtained. The formaldehyde may be recovered as such, or it may be combined with ammonia to form hexamethylenetetramine and this body may be separated from the other substances formed;

Ethylene'will combine readily-with ozone to form ethylene ozonide, and this tends to split up into formic acid (CHOOH) and formaldehyde, the formic acid largely preene dominating, howevenl The primary object of the present process is to control the reactions in such manner as to produce a large yield of. the active methylbody and reduce the yield of formic acid to a minimum. This, as indicated, is accomplishedwithout the formation of any considerable quantity of ethylene ozonide, or, rather, the ethylene ozonide, if it forms in the process, is continuously converted, as

.ing point of water.

Specification of Letters Patent.

Patented auiyes, i922.

Application filed August 27, 1920. Serial Ho. 406,435.

which can be recovered as an active methylene body.

The agent or medium which it is preferred to employ to prevent the formation formed, into constituents, the main one of of a preponderant proportion of formic acid is water, and this is preferably employed in the form of steam.-

- The preferred method of procedure is as follows:

Introduce ethylene, steam and an ozonized agent, such as ozonized air, into a drum, where an intimate and free commingling of these substances may take place. The introduction may be accomplished, for example,

by passing ethylene gas and steam through pipes which communicate with a third pi e through which the ozonized air passes to tile drum. The junction of the ethylene pipe and steam pipe with the ozonized air-pipe may be near the point where the latter communicates with the drum.

If desired, however, each of the three pipes may lead directly to the drum. The purpose is to have the ozonized air combine with the ethylene in the presence of so water, as water acts as an agent favoring the production of an increased yield of the active methylene body and a diminished yield of formic acid. Apparently, reactions occur in accordance with the following formulae:

As stated, it is preferred to have the water present in the form of-steam or water-vapor, which favors the free commingling of the substances entering into the reaction; and the reaction is favored by an elevated temperature, that is, a temperature above ordinary room temperatures. For example, if steam, ethylene and ozonized air be passed into a drum or large vessel, the steam being at or near the boilin point of water, the re sult will be to maintain the temperature where the gases and water-vapor or steam commingle at a tem erature near the boilnder such conditions, one may obtain a yield of 70 per cent or more of formaldehyde and 15 per cent or less of formic acid. The fine subdivision of the water at the. elevated temperature seems i so - may'falsobe practiced. For example, one

to favor a' larger yield of formaldehyde. The yield will vary according to conditions. If desired, the steam may be superheated which favors a larger yield of formaldehyde. The proportions in which the sub stances may be commingled issufliciently indicated by the formulae. It may be added, however, "that a large excess of steam seems no internal obstructions, such as bafiie-plates. To effect the separation of the substances yielded by the reactions, one may proceed as follows:

Pass the gases from the drum into a scrubber containing water, and thus cause the gases to be -absorbed by the water; then run the saturated water into a tank and neutralize with an alkali, such as potassium hydrate, sodium h drate, ammonium hydrate, or calcium by rate. After neutralization, which fixes the formic acid as a formate, the methylene body may be recovered as hexamethylenetetramine by the following steps:

Introduce into the neutralized solution a solution of ammonium hydrate, and thus change the formaldehyde into hexamethylenetetramine; evaporate the slightly ammoniacal solution to a thick syrup, or dryness, preferably under a vacuum. Then boil the residue in carbontetrachloride ((301,) or other solvent for hexamethyle'netetramine, which is not a solvent for the formates; withdraw the solution while hot, allow to cool and the hexamethylenetetramine will crystallize out; then dry the hexamethylene tetramine, if desired. v,

The formic acid remains fixed in the first residue. The hydrogen peroxide (H 0,) apparently largely disappears or wholly disap ears in theprocess.

f it be desired to recover the formaldehyde as such, the saturated solution from the scrubber. may be neutralized with a nonvolatile alkali, such as lime or caustic soda; the solution 'may then be evaporated to dryness, a percentage of the formaldehyde passing over and being collected. The heating may belcontinued at atem erature above 100 C. to]eva'p orate any p0 ymerized formaldehyde-{and thismay be collected. The

formate remains as a residue. The distillate is a dilute solution of formaldehyde. This may be concentrated by known methods, if desired; I

Various-modifications of the process for efiecting the unionof ethylene and ozone in the presence .of water or water-vapor, so that water may also enter into the reaction,

may pass ethylene and ozone into a scrubbing machine cont'ainln'g water, preferably heated .to nearthe boiling temperature. Again,one

may pass ethylene and ozone into a tower 1 ,aasn'aa filled with broken glass or porcelain, over which hot water trickles. Still, another modification is to mix ethylene and ozone in and steam.

As indicated above, the employment of a large hydrolyzing "essel', or drum, without internal obstructions therein, seems to favor a larger yield of formaldehyde; also the superheating of the steam aflords an increased yield of formaldehyde.

The foregoing detailed descr1ption' has been given for clearness of understanding only, and no unnecessary limitations should be understood therefrom, but the appended claims should be construed as broadly as permissible, in view of the prior art.

What we regardas new, and desire to secure by Letters Patent, is-- l. The method of producing "an active methylene body which comprises reacting upon ethylene with an ozonized agent in the presence of an aqueous medium adapted to favor the formation of a preponderant proportion of the active methylene body.

2. The method of producing an active methylene body which comprises reacting upon ethylene with an ozonized agent in the presence of H 0.

3. The method of producing an active methylene .body which comprises reacting upon ethylene with an ozonized agent in the presence of an aqueous medium adapted to favor the fproduction of a preponderant proportion of ormaldehyde, then absorbing in water the gases produced, and then separating the methylene body from the other constituents.

4:. The method of producing an active methylene body which comprises reacting upon ethylene with an ozonized agent in'the .methylene body which comprises reacting upon ethylene with an ozonized agent in the presence of H 0, then absorbing in water the gases produced, neutralizing the solution, and then efi'ecting the separation of the methlene substance from the formates.

7. The method of producing an active methylene body which comprises reacting upon ethylene with an ozonized agent in the presence of steam.

8. The method of producing an active methylene body which comprises commingling ethylene and an ozonized agent with water-vapor at elevated temperature.

9. The method of producing an active methylene body which comprises commingling ethylene, superheated. steam and an ozonized agent.

10. The method of producing an active