US839204A - Process of tanning hides, skins, and the like. - Google Patents

Description

v UNITED STATES PATENT OFFICE.

WILLIAM G. ROACH, OF CINCINNATI, OHIO, AND ALBERT C.ROAGH, OF I-NEWPORT, KENTUCKY, ASSIGNORS, BY MESNE ASSIGNMENTS, TO THE CINCINNATI CHROME LEATHER CORPORATION OF orno.

, Pnocsss OFY TANNING mam. I

To all whom it may-concern:

Be it known thatwe, WILLIAM G. Roaon, resi at Cincinnati, in the county of Hamilton an State of Ohio, and ALBERT C. ROACH,

I ing into the fibers of the 7 be seen that the c omic oxid will also be uni- ,the ordinary two bath residing at Ne ort in the county of Cam bell and Statd iif Kentucky, citizens of tlie United States, have invented certain new and useful Improvements in the-Process of Tanning Hides, Skins, and the Like, of which the following is a-specification.

The object'of our invention is to provide a piocess for the metallic tanning or tawing of 'des which produces a leather having substantially the same capacity for finishing,

'working, or use as bark-tanned leather while retaining the to hness and durablity of the metallictanned eather. It consists, broadly speaking, in introduces in a substantially inactive chemical state substances, containing tanning matter adapted to be released by reactionbetw'een'smd compounds and then establishing a condition under which said reaction will take place. We

prefer; to employ chromic acid as the substance contammgh the tanning matter and introduce it into t e hide in substantially the same form and manner as in the first bath of rocess. After the hide has become thoroughly soaked and impregnated with the chromic acid we introduce a reducing agent, such as glucose, which does not act at onceupon the chromic acid, but is what may be termed chemically inactive for the time being toward said acid. When the hide has become thoroughly soakedand impre ated with the glucose, it will be seen that t e chromic acid and glucose are intimately and uniformly associated together and with the fibers of the hide Thus, in effect, we bring each molecule of the chromic acid into intimate association with its molecule of glucose on the particular fiber upon which their product is to .act before said product is released. Under these circumstances when the: reaction does take place the chromic oxid is deposited directly and immediately upon the hide fibers. 'As the chromic acid and glucose are uniformly distributed thro bout the hide fiber, it wil I Specification of Letters Patent. Application-filed larch 4.1904. Serial No. 196.667.

fibers will COMPANY, OF CINCINNATI, OHIO, A

HIDES. SKINSQAND THE LIKE. Y

Patented n... so, 1900.

formly deposited thereon and the interior receive their dueproportion of the oxid.

In practice for one hundred poundsof hides we employ as the first bath six pounds of bichromate of potash or soda, four pounds of alum, four to six ounds of common salt, twelve ounces of sulfiiric acid, twenty ounces of hydrochloric acid, sixty gallons of water. The hides tobe treated are pre ared in the usual manner for tanning and allowed to soak in this bath until thorou hly im regnated with the chromic acid. glhls wil ordinaril take from twelve to ei hteen hours, depen ing u on the weight an thickness of the hides. he hides are then removed from the bath, sliked, set out, and hung up until about three-fourths of the moisture therein has evaporated. When in this state, the hides are spread out and painted on both sides with a solution of glucose and packed in piles for from three to six hours to allow the glucose to soak in and become uniformly distributed throughout the hide. The glucose solution may contain from fifteen to fifty per cent. of glucose dissolved in water. If applied under ordinary atmos heric temperatures, there will be substantially no immediate reaction between the glucose and chromic acid, they being under the conditions ap lied in an inactive state toward each other. husthe lucose will soak into the hide and thorou hIy and uniforml associate itself with the c omic acid and 'de fibers before any reducing action takes place. By painting the glucose solution onto the hide possible contact between the chromic acid in the hide and the glucose solution from which the painting-supply is taken is prevented.

To prevent the glucose from so in warm weather, we use for, say, three gal one of water, about a half-pound of'quassia chips, and, say, a half an ounce of carbolic acid. The uassia chips are boiled with the water and t e carbolic acidadded, and into this is stirred the glucose to make up the necessary strength of the solution.

' In the chromic-acid bath a small excess of sulfuric and hydrochloric acid tends to has-- ten the reduct1on.- a larger excess of acid be used, the reduction will t e place in a prop y cess of acid is not enough to cause the reducglucose is uniformly distribp ose. the afourth of t 4 think a slower.

condition under whic portionately shorter time. Thus if itis desired to hasten the reduction an excess of acid, referably sulfuric acid, may be embut care should be taken that the ex tion before the uted through the hide or cause the acid to injuriously affect the hide fiber. We prefer to use glucose as the reducing agent.

All organic substances have more or less reducingaction on chromic acid, and we at an organic compound will generally be found preferable to employ as a reducing a ent, since their action is generally However, even an inorgamc reducmg agent may be employed if the proper conditions are 0 tained for preventing immediate reduction. After the hides have been uniformly inpregnated with the chromic acid and glucose a condition is established under which the reaction between said substances takes place to release the chromic oxid or tannin substance.

This condition may be established in a number of wa s; but we prefer to use a bath of hot grease or this After the hides have been treated lucose solution and about one e moisture has evaporated therefrom they are immersed in a bath of hot grease, the proportions of-the in redients of this bath bemg dependent upon t e purposes for which the leather is to be used.

For the production of a suitable soleleather we make up a bath as follows: one hundred pounds stearic acid, twelve and onehalf pounds carnauba-wax, six and onefourth pounds Vaseline, six and one-fourth pounds beeswax. This grease-bath is reduced to a liquid and kept at a temperature between and centigrade, and the hides are suspended in this bath until the grease has thoroughly enetrated the thickest parts of the hide. his will be found to take only a comparativel short time, an hour or more being all t at is necessary. The effect-of the hot ease is to establish a the chromic acid is thoroughly reduced and at the same time the hide is thoroughly filled with grease. For sole-leather the hides are then rolled and finished in the usual way. For harness-leather the proportion of Vaseline in the stufling-bath must be increased to make the leather as soft as wanted-say twenty-five pounds of vaseline instead of six and a uarter pounds, as above stated. To obtaint e best results, the glucose should be kept at about 50 centigrade.

While our process attains its greatest utility in tanning thick or heavy hides, it may also be used to advantage for thin hides and will be found to produce a high grade of uniformly-tanned leather.

We claim as our invention- LgThBSPIOCGSS of tanning hides which coned to be released by reaction between said substances, and then appl lg heat to establish a condition under w 1c will take place, substantially as specified.

3. The process of tanning hides which consaid reaction sists in introducing into the fibers of the hide,

in a substantially inactive chemical state, substances containing tanning matter adapted to be released by'reaction 'between'said substances, and then subjectin the hide to a bath of hot grease to establis a condition under which said reaction will take place, substantially as specified.

4. The process of tanning hides which consists in introducing a reducible metallic substance into the fiber of the hide; then introducing a reducing agent into the hide fiber in a substantially inactive chemical state to ward said metallic substance; and then establishing a condition under which reduction will take place, substantially as specified.

5. The process of tanning hides which consists in introducing a reducible metallic substance into the fiber of the hide; then introducing a reducing agent into the hide fiber in a substantially inactive chemical state to ward said metallic substance; and then applying heat to establish a condition under which reduction will take place, substantiallyas specified.

6. The process of tanning hides which consists in introducing a reducible metallic substance into the fiber of the hide; then introducing a reducing agent into the hide fiber in a substantially inactive chemical state toward said metallic substance; and then subjecting the hides to a bath of hot grease toestablish a condition under which reduction will take place, substantially as specified.

7. The process of tanning hides whichbonsists in subjecting them to a bath of chromic acid; then to that of an organic reducingagent, substantially inactive chemically to ward the chromic acid; and then establishing a condition under which reduction will take place, substantially as specified.

8. The process of tanning hides which consists in subjecting them to a bath of chromic acid; then to that of an organic reducing agent, substantially inactive chemically to ward the chromic acid; and then to a bath of hot grease to cause the reduction, substantially as specified.

9. The process of tanning hides which con- ICC IIO

sists in subjecting them to a bath of chromic acid; then to that of a solution of glucose under conditions in which the chromic acid and glucose are chemically inactive; and then establishing a condition under which the chromic acid is reduced by the glucose, sub} acid, then painting the hides with a reducing agent chemically inactive toward the chromic acid, and then establishing a condition under which reduction will tially as specified.

11. The recess of tanning hides which consists in su jecting them to a bath. of chromic acid, then painting the hides with a solution of ilucose, and then subjecting them to a bat of hot grease, substantiall as specified.

WILLIAM ROACH.

ALBERT O. ROACH.

' Witnesses:

GLENA. PRITOHARD, I O. M. ROGERS.

take place, substan- I