US1848883A

US1848883A - Joseph bennett hill

Info

Publication number: US1848883A
Authority: US
Publication date: 1932-03-08
Anticipated expiration: 1949-03-08

Description

Patented Mar. 8, 1932 UNITED STATES PATENT .orrlcs JOSEPH BENNETT HILL, PHILADELPHIA, PENNSYLVANIA, ASSIGNOB TO IRE BARRETT COMPANY, A CORPORATION OF NEW JERSEY rnocnss or mow-c sunrnomc acme Io Drawing.

M invention relates to the production of t etic tannin materials and more especlally to the pro notion of sulphonic acid de'- rivatives free from free sulphuric acid.

8 The common synthetic tanning materials are made as is well known byvsulphonating aromatic hydrocarbons or their derivatives, such as phenol, naphthalene, anthracene, carbazole, etc., and either using these sulphonic acids so produced without further treatment for tanning purposes or condensing them with formaldehyde, sulphur-monochloride or other condensing agents. In view of the fact that the chemistry of the condensation reactions between the sulphonic acids and agents such as formaldehyde, sulphur monochloride and the like is not fully understood, I intend that the term condensing agent as used throughout the specification 29 and claims shall include those materials which react in the presence of sulphonic acids to effect condensation of either the sulphonic acids themselves or of the sulphonic acids with the agents added to effect the condensation reaction. The sulphonation of the h,

drocarbon as ordinarily effected cannot readily carried to completion on account of the accompanying dilution of the sulphuric acid, and, therefore, gives a sulphonic acid product containing a considerable percent age of free sulphuric acid. The presence of this free sulphuric acid in the finished tannin material is considered harmful to the leat er produced therefrom in that it tends to produce rotting in the leather or ageing.

This effect may be partly eliminated by partially neutralizin the sulphonic acid or its condensation pro uct with soda, whereby the sulphuric acid being a somewhat stronger.

acid than the sulphonic acid,"is more com- Eletely neutralized than the sulphonic acid.

venthis treatment, however, is not wholly satisfactory and it is highly desirable to actually remove or eliminate free sulphuric acid from the tanning material before it is used in the tanning process.

I have found that the well known procedure of efiecting the sulphonation under reduced pressure, so as to vaporize out the water of reaction from the sulphonation mixture and Application fled October 8, 1824. Serial No. 742,400.

While the above procedure is readily applicable to the sulphonation of a large num-. ber of hydrocarbons without causin difliculty, there are cases, particularly w ere a low water insoluble content of the sulphonic acid is desired, to which the above process does not readily lend itself on account of the fact,-for example, that under certain conditions of temperature, concentration, etc., and where the sulphuric acid is exhausted or present in the sulphonation mixture in relatively small amount, side reactions take place giving rise to the formation of insoluble compounds.

' I have found that thedifiiculties ma be overcome by a very simple expedient wit out materially affecting the quality of the product. In the sulphonation of naphthalene, for example, under reduced pressure, the formation of insoluble products does not appear, to begin until the remaining free sul huricacid gets down to the neighborhood of 5% of they sulphonation mix. The sulphonation can, therefore, be carried-this far without endangering the quality of the finished product. I 1

have found that this residual'sulphu'ric acid' j can be readily consumed in sulphonatingjs'ome lower boiling hydrocarbon, such as benzol or one of its 'homologues, which causes the absorption or elimination of'the residual free sulphuric acid due to its interaction with these hydrocarbons to form the corresponding sulphonic acids at a lower temaperature than that necessary when naphth ene alone: is sulphonated. These low boiling hydrocarbons are preferably added in quantity in excess of that required to interact with the residual acid-and this excess may be removedafter the completion of the sulphonation by distillation. The lower temperature used for this second sulphonation relative to that maintained in sulphonating the naphthalene or similar compounds is not conducive to the formation of insoluble compounds, and this sulphonation can, therefore, be carried to completion and any excess of the more read- .ily sulphonatable hydrocarbons distilled off fraction from coal tar naphtha boiling approxima'ting between 150 C. and 200 C. and consisting in large measure of the trimethylbenzenes which, like benzol, a compound hereinbefore referred to, are aromatic compounds,

specifically of the benzene series.

While I do not wish to limit my invention to the sulphonation of naphthalene or to' any exact process for effecting this sulphonation, the following will serve as an example of the manner in which my invention may be carried out.

One hundred and twenty pounds of refined naphthalene may be mixed with 100 pounds of 66 B. sulphuric acid and heated to 160 C. for a period of one hour. The sulphonator is put under a vacuum of about 22 inches of mercury, below atmospheric pressure, and maintained at this pressure at a temperature of 155 C.160 C. for about one hour additional. The vacuum is interrupted, the temperature reduced to 130 C. in any convenient way and 35 pounds of the fraction from coal tar na htha. boiling approximately between 150 and 200 C. are added to the sulphonator and the contents thoroughly agitated. Vacuum is again applied and the excess of hydrocarbons distilled oil". The product may be drawn off and used directly or may be condensed with formaldehyde in the usual mannor to form the synthetic tanning material.

I claim:

1. The process which comprises incompletely utilizing a quantity of sulphuric acid added to an aromatic hydrocarbon for the sulphonation thereof, adding a more readily added to naphthalene for the sulplhonation thereof, adding a more readily sulp onatable compound of the benzene series to the sulphonation mixture; and causing the residual sulphuric acid to be absorbed in the sulphonation of said more readily sulphonatable compound.

3. The process which comprises incompletely utilizing a quantity of sulphuric acid added to an aromatic hydrocarbon for the sulphonation thereof, adding a more readily sulphonatable aromatic compound to the sulphonation mixture in excess of the quantity needed to combine with the residual sulphuric acid, causing the residual sulphuric acid to be absorbed in the sulphonatlon of said more readily sulphonatable compound and distilling off the excess of the more readily sulphonatable compound.

4. The process which comprises incompletely utilizing a quanity of sulphuric acid added to naphthalene for the sulphonation hydrocarbon by causing it to interact with said acid under such conditions as to leave a small quantity of residual acid, then adding a more readily sulphonatable compound of the benzene series in quantity sufiicient to interact with substantially all of said residual acid and causing said compound to be sulphonated by the residual sulphuric acid.

6. The process which comprises mixing with an aromaticv hydrocarbon at least the theoretical quantity of sulphuric acid required for its sulphonation, sulphonating the hydrocarbon under reduced pressure under such conditions as to leave a small quantity of residual sulphuric acid, then adding a more readily sulphonatable aromatic compound in quantity suflicient to interact with substantially all of said residualacid and causing said compound to be sulphonated by the residul sulphuric acid.

7. The process which comprises mixing with an aromatic hydrocarbon at least the theoretical quantity of sulphuric acid required for its sulphonation, sulphonating the hydrocarbon under such conditions as to leave a small quantity of residual sulphuric acid, then adding an excess of a more readily sulphonatable compound of the benzene series,

causing a portion thereof to be sulphonated by the residual sulphuric acid and distilling ofi the excess of the more readily sulphonatable compound.

8. In the sulphonation of an aromatic hy drocarbon the step of eliminating residual sulphuric acid contained in the sulphonation mix which comprises causin it to-react with a more readily sulphonata 1e hydrocarbon added thereto.

9. In the sulphonation of an aromatic hym drocarbon the steps which comprise eliminating residual sulphuric acid contained in the sulphonation mix by causing it to react with a more readily sulphonatable hydrocarbon added in excess thereto and removing the excess of the latter by distillation.

10. In a process of sulphonating naphthalene by. reacting sulphuric acid therewith, the improvements which comprise sulphonating the naphthalene so as to leave at the completion of the sulphonation a quantity of residual acid in the sulphonation mixture equal to about 5% of the content thereof, then adding to said mixture a more readily sulphonatable compound of the benzene series and sulphpinating said compound with the residual 11. The process which comprises mixing with an aromatic hydrocarbon a quantity of sulphuric acid, sulphonating said hydrocarbon until the sulphonation mix contains about 5% free sulphuric acid, then adding an excess of coal tar naphtha boiling between 150 C. and 200 C.

12. The process which comprises mixing approximately lbs. of 66 Baum sulphuric acid with lbs. of refined naphthalene, sulphonating said naphthalene until approximately 5% free sulphuric acid results, then adding an excess of coal tar naph- 40 tha boiling between approximately and 200 C. and causing a portion thereof to be sulphonated by the residual sulphuric acid.

13. A tanning composition comprising a sulphonated aromatic compound in admix- 45 ture with a small -"quantity of a sulphonated derivative of a more readily sulphonatable aromatic compound.

14. A product as in claim 13 combined with formaldehyde. 8

60 15. A tanning composition comprising sulphonated naphthalene in admixture with a small quantity of a sulphonated derivative of a more readily sulphonatable compound of the benzene series.

" 16. A product as in claim 15 combined with formaldehyde.

In testimony whereof I aflix my signature.

JOSEPH BENNETT HILL.