US2078726A - Soap and the preparation of an oil for use therein - Google Patents

Description

Patented A r, 27, 1937 PATENT OFFICE SOAP AND THE PREPARATION OF AN OIL FOR USE THEREIN Carl B. Haurand, North Plainfleld, N. 1., assignor to The Best Foods, Inc., New York, N. Y., a corporation of Delaware No Drawing. Application October 21, 1933, Serial No. 694,615

13 Claim.

This invention relates to the production of soaps and to the preparation of an oil especially adapted for use in the production of cold process soaps.

In the production of cold process soaps, oils of high saponiflcation number, (for example, above 230) and containing high percentages of low molecular weight fatty acid glycerides, such as laurin and myristin, for example, cocoanut oil or palm kernel oil, are mixed with a relatively concentrated sodium hydroxide solution with no or only slight heating. The soaps produced in this manner are white at first but upon standing develop a yellow surface coating which is objectionable from a sales standpoint. This yellowing is accelerated by subjecting the soap to heat and light and is inhibited to some extent by excluding the air.

It is an object of this invention to provide a method by which this yellowing effect in the finished soap is retarded and to provide an improved cold process soap or semi-boiled soap which does not have this objectionable characteristic. It is also an object to provide an oil particularly adapted for the production of cold process or semi-boiled soaps as well as a method for producing such an oil. Other objects will become apparent.

It has now been found that by subjecting a high saponification number and low iodine number vegetable oil to a slight degree of hydrogenation before saponification, the yellowing effect referred to above is substantially inhibited. The degree of hydrogenation need not be sufficient to materially alter the physical characteristics of the oil and should not be carried to such an extent as to give the product an objectionable hardness or brittleness or to materially reduce its ability to form a lather. It is not intended however, to restrict the degree of hydrogenation to that given in the following example, since this may be varied where the invention is to be utilized under different conditions and where different characteristics are desired.

As an example of the use of the invention, an oil of low iodine number, such as cocoanut oil, having an iodine number of about 9, is heated to about 200 to 400 F., preferably 280 F., in the presence of a reduced nickel catalyst or some other catalyst suitable for use in hydrogenating oils. The oil with the catalyst suspended therein is agitated with hydrogen gas under pressure of about -70 pounds per square inch, until the iodine number has reduced by about 5 to 20% and preferably by about 10%. If desired, for particular types of soap, the oil may also be deodorized by well known processes. In starting with a cocoanut oil having an iodine number of 9, the desired results may be obtained by hydrogenating sufficiently to decrease the iodine numberto about 8. During this operation the melting point and setting point of the oils are varied only slightly. For example, the melting point may be altered from an initial of about '15 to 76 F. to a final melting point of about '77 to 78 F., the setting point increasing from an initial setting point of about 22.5 C. to a final settingpoint of about 23.1 C.

If palm kernel oil is used the initial iodine number will be about 17 and it is preferred to continue the hydrogenation until the iodine numher is reduced to about 15.

To produce a cold process soap from theoil treated as above described, about parts of the slightly hydrogenated cocoanut oil or palm kernel oil is mixed with about 50 parts of about 39 B. caustic soda solution. It is preferred to heat the oil and the caustic soda solutions separately to about -130 F., after which the caustic soda solution is added to the oil while the latter is being thoroughly agitated. The agitation is continued until the mass becomes quite viscous and will just pour. It is then poured into frames, preferably of wood, where it is kept for one to two days, during which time the soapbecomes hard and the saponification is substantially completed. The soap is then taken out of the frame and sliced into bars.

The objectionable surface yellowing upon storage also appears in so-called semi-boiled soaps which are prepared similarly to cold process soaps except that heat is added to the partially saponifled mixture of oil and caustic so that the final temperature may approach the boiling point. The oil treated as above described, when used in semi-boiled soaps. is effective in preventing such discoloration.

The conditions described above may be varied, for example, other oils of higher iodine number, such as cotton seed oil, or mixtures of these with lower iodine number oils, may be used but where such oils are used alone the hydrogenation should be stopped before any substantial change in the physical characteristics of the oil takes place.

Also, the invention may be utilized without hydrogenating sufilcie'ntly to decrease the iodine number to the extent described, the important point being to hydrogenate sufliciently to give the desired resistance to yellowingin the finished ill soap. In some cases, the hydrogenation may be carried somewhat further than indicated above, although if this is done, care should be taken to avoid carrying it-to such an extent that the final soap becomes too hard or brittle. The temperatures, pressure, and other conditions of hydrogenation may be also changed, for example, a lower temperature may be used than is customary in the hydrogenation of vegetable oils. Also the catalyst used may be varied and, since only a relatively slight degree of hydrogenation is required to give the desired results, a partially spent catalyst from other hydrogenation operations may often be used. Other pressures may also be used, from atmospheric or even lower pressures to pressures of 100 or 200 pounds per square inch. Other conditions of saponiflcation, for example, different temperatures or different concentrations or solutions of saponifying agents may be used to meet particular conditions. While caustic soda of about 39 B. is conveniently used for saponification of cold process soaps, other strengths of lye within the range of 32 B. to 42 B. may be used. In some instances it may be desirable to use solutions of potassium hydroxide or solutions of mixed alkali hydroxides.

The terms used in describing the invention have been used in their descriptive sense and not as terms of limitation, and it is intended that all equivalents of the terms used be included within the scope of the appended claims. It is intended that semi-boiled soaps, as distinguished from common boiled soaps, are to be considered the equivalent of cold process soaps for purposes of this invention.

What I claim is:

l. A method for preparing a cold process soap comprising hydrogenating an oil of the group consisting of non-drying and semi-drying glyceridic oils having a saponification number above about 230 to decrease its iodine number by about 5 to 20% and mixing the partially hydrogenated oil with a sufficient quantity of a suitable caustic alkali solution to insure substantially complete saponification of the oil.

2. A method for preparing a non-yellowing cold process soap comprising hydrogenating an oil of the group consisting of non-drying and semidrying gylceridic oils having a saponiflcation number above about 230 and a low iodine number to decrease its iodine number by about 5 to 20% and mixing the partially hydrogenated oil with a sufficient quantity of a suitable caustic alkali solution to insure substantially complete saponification of the oil.

3. A method for preparing cold process soaps comprising hydrogenating cocoanut oil to reduce its iodine number from about 9 to 7 and mixing about 100 parts of the partially hydrogenated oil with 50 parts of about 39 B. caustic soda solution. a

4. A method of producing soap comprising hydrogenating a low iodine number vegetable oil having a saponification number above about 230 sufficiently to retard color change in the finished soap but insufficiently to substantially change the physical properties of the oil, and saponifying the partially hydrogenated oil at a temperature below the boiling point of the mixture.

5. A method of producing a cold process soap comprising hydrogenating a low iodine number vegetable oil having a saponiflcation number above about 230 sufficiently to retard color change in the finished soap but insufficiently to substantially change the physical characteristics of the oil, and saponifying the partially hydrogenated oil at a temperature of not over about 150 F.

6. A cold process soap comprising a saponified slightly hydrogenated vegetable oil having a saponification number above about 230 of low iodine number, the hydrogenation of the oil being insuflicient to substantially change the physical properties of the oil.

'7. A non-yellowing cold process soap comprising a saponifled slightly hydrogenated cocoanut oil the hydrogenation of the oil being insufficient to substantially change the physical properties of the oil.

8. A cold process soap comprising a vegetable oil, having a saponification number of above about 230 which is hydrogenated to decrease its iodine number by not over about 2 and saponified.

9. A cold process soap comprising a vegetable oil having a saponification number above about 230 which is hydrogenated to decrease its iodine number by about 5 to 20% and saponified with caustic alkali.

10. A cold process soap comprising a vegetable oil having a saponiflcation number above about 230 which is hydrogenated only sufficiently to decrease its iodine number by about 10% and saponifled with caustic soda.

11. A method for producing a cold process soap comprising mixing with sufficient caustic solution to substantially completely saponiiy the same, a vegetable oil of the class consisting of non-drying and semi-drying oils having a saponification number above about 230 hydrogenated sufficiently to retard color change in the finished soap but insuificiently to cause substantial hardening of the oil, the hydrogenation serving to decrease the iodine number by about 5-20%.

12. A method of producing a cold process soap comprising hydrogenating a low iodin number vegetable oil of the class consisting of non-drying and semi-drying oils having a saponification number above about 230 to decrease its iodine number by about 5 to said hydrogenation being sufiicient to retard color change in the finished soap but insufficient to increase the melting point of the oil by over about 2 F. and its setting point by over about 1 F., and mixing the partially hydrogenated oil with a sufficient quantity of a suitable caustic alkali solution to insure substantially complete saponification of the oil.

13. A cold process soap comprising a mixture of vegetable oils having a saponification number of above about 230 which is hydrogenated to decrease its iodine number by not more than about 2 and saponifled.

' CARL H. HAURAND.