US 1637475 A
Description (OCR text may contain errors)
Patented Aug. 2, 1927.
E STAT LEWISIDAVIS, OF WORCESTER, AND ELMER W. BENNETT, OE WESTBORO, MASSACHU- SETTS, "ASSIGNORS TO DAVIS & BENNETT, INC., OF WORCESTER, MASSACHUSETTS,
A CORPORATION OF MASSACHUSETTS.
ing the thread, where such discoloration is undesirable. The emulsion for this purpose should be of such consistency and vlscosity that in drawing the thread therethrough, 1t
will be supplied with only the necessary amountof the lubricant, without the formation of an excess at the apertures in the leather or other material through which the thread is passed.
Any suitable wax or waxlike body may be emulsified for this purpose such as japan, spermacetti, shellac or ceresin waxes or beeswax, but preferably we use carnauba wax, which to hasten the process, is mechanically comminuted before subjecting it to the emulsifying or dispersing process. I
We employ, as the stabilizing, emulsifying, or dispersing agent, a colloidal material which is a mixture of hard and soft soaps, preferably stearates. We have found that results are secured by this agent' which are superior to those resulting from the use of either a hard soap or a soft soap. Preferably, as stated, this soap consists of a mixture of sodium stearate and potassiumstearate, and it is produced by the reaction of stearic acid with sodium. and potassium 'alkalis. For example, about 18.75 parts (by weight) of potassium carbonate (K CO 2H O) and about 6.75 parts of sodium carbonate (Na CO J-I O) is dissolved in about 1000 parts of water. To this solution we add about parts by weightof stearic acid (preferably triple pressed) in relatively small pieces. The mass is heated slowly with constant agitation until the solution is effected, precautions being observed to prevent too violent reaction between the carbonates and the acid. The heating is continued until the solution begins to boil. We now add to the boiling solution the wax which is to be dispersed or emulsified. If
the product is to be employed as a lubricant for thread, we preferably usecarnauba wax,
in which case it is usually ground or comminuted'to about 20 mesh size, and about 11.25 parts are added to the solution, while Application filed December 2, 1924. Serial 'No. 753,430.
at the same time the heating and strong agitation of the mass are continued unt l the wax has been dispersed. The vessel in which the dispersion is effected, is preferably jacketed for the circulation of the steam, and when the dispersion has been effected, a cooling or refrigerating 'medium is circulated through the jacket for the purpose of rapidly chilling the mass, while at the same time the agitation is continued. When the mass has reached a temperature of about 659' C. it is now strained through cheese cloth to remove any large particles, and then allowed to cool slowly to room temperature. On standing for about 20 hours, the product is a white milky liquid of colloidal consistency'of about the viscosity of cylinder oil so called. When-produced in accordance with the foregoing example, the product, at F. has a viscosity of 1.34 (Engler) and at 212 F. of 1.09. It is slightly alkaline, having a reaction of PH around 10.
It is miscible with and maybe diluted with water to any reasonableoor required extent. When heated above 65 (1., the liquid becomes nearly transparent, of much thinner consistency and turns from white to strawyellow but on being cooled returns to its original condition. When subjected to a temperature below -4 0., it begins to precipitate as a result of freezing.
1n the operation hereinbefore described, the wax which softens and melts at the temperature of the soap solution into which it is intgoduced, is already in relatively small particles, but with the-strong agitation it is finally dispersed in particles of substantially colloidal size, and on being rapidly chilled while the agitation is continued, the resultant product after reachin a temperatureof about 65 C. is remarkab y stable. It is of such consistency that when a thread is drawn therethrough,1t picks up just suflicient lu bricant to permit the manipulation of the thread in' t e sewing operation, to the best advantage. 1
After prolonged experimentation with the use of soaps, in producing dispersions, we discovered that by using a blend of hard and soft soaps, a final product could be obtained having the proper fluidity or consistency, and having such a slight total alkalinity as would not affect the thread. While we do not desire to be understood as limitother 'thermop ing ourselves to the use of a specific fatty acid, or to exact proportions of the blended soa s, or to the exact ratio of soap to wax an water, et we regard the proportions herein state to be the best for our specific purpose. An amount of wax in excess of that stated, does not produce a stable unchanging dispersion, while a' smaller amount does not give the best lubricating value to the product.
For other slpe'cific uses, we may employ astic waxes or gums or bodies normally immiscible with water which may be initially softened by or dissolved in suit-' able solvents if desired before their being added to the water Edfitaining the blendedsoap colloid. Where discoloration of the thread to be lubricated by the dispersion is undesirable,
LEWIS DAVIS. ELMER W. BENNETT.
one should employ a light'colored wax, rather than a material such as m potassium stearates serving as 25 and having a vis-