2 BULLETIN 855, U. S. DEPARTMENT OF AGRICULTURE. 



flask. Further dilution increases the hydrolysis and subsequently 

 brings on additional clouding. 



PROPERTIES OF MIXTURES WITH ROSIN SOAP 



It was found that soaps of some vegetable oils, fatty acids, and 

 fish oil (menhaden) when mixed with rosin soap had the property of 

 retarding the clouding and precipitating of rosin in rosin-so ap-cresol 

 solutions. A number of different soaps were tried as ingredients 

 of 50 per cent saponified cresol solutions. Those tried were rosin 

 soap, soy-bean-oil soap, linseed-oil soap, oleic-acid soap, fish-oil 

 soap, rosin-soy-bean-oil soap, rosin-linseed-oil soap, rosin-oleic-acid 

 soap, and rosin-fish-oil soap. These soaps were used in proportions 

 equivalent to 28 per cent linseed oil in the finished product. 



Saponified cresol solutions were made with rosin soap, the sodium 

 hydroxid varying from enough to saponify the rosin to an excess of 

 20 per cent. On dilution to a 3 per cent solution with distilled water 

 the saponified cresol solution containing no excess alkali dissolved 

 quickly and clouded after about 3 minutes ; beyond 5 per cent excess 

 alkali the solutions dissolved more slowly and clouded after about 3 

 minutes. Increasing the excess of alkali beyond 5 per cent has 

 therefore no beneficial results, and at the same time this excess com- 

 bines with the cresol, lowering the coefficient of the finished product. 

 Saponified cresol solutions were prepared by mixing rosin and 

 soy-bean oil, saponifying the mixture with just enough sodium- 

 hydroxid solution and then adding the cresol. These had the same 

 properties as saponified cresol solutions containing varying propor- 

 tions of rosin soap to soy-bean-oil soap prepared by mixing a saponi- 

 fied cresol solution containing soy-bean-oil soap and one containing 

 rosin soap. 

 Analysis of the soy-bean oil saponified cresol solution : 



Phenols, 53.5 per cent. 



Fatty acids + unsaponifiable matter equivalent to 28 per cent oil. 



Total alkali as sodium hydroxid, 4.0 per cent. 



Water not determined. 

 Analysis of the rosin saponified cresol solution: 



Phenols, 53.5 per cent. 



Rosin acids (equivalent to 33.6 per cent rosin or 28 per cent oil), 30.2 per cent. 



Total alkali as sodium hydroxid, 4.0 per cent. 



Water not determined. 



The table following gives the proportion of soy-bean-oil soap to 

 rosin soap in the total soap present in these saponified cresol solu- 

 tions. Under the heading " Remarks" are recorded the results of 

 adding the saponified cresol solutions to distilled water at 20° C. to 

 form 3 per cent solutions. 



