Rosin — Use in soap

R o s i n , U s e in Soap

j. N. BORGLIN, P. R. MOSHER, BARBARA NOBLE, and T. PUNSHON H e r c u l e s E x p e r i m e n t S t a t i o n , W i l m i n g t o n , D e l a w a r e

Rosin--Use in Soap Rosin is the cheapest, high-molecular-weight organic

acid available in dependably large quantities. There are two types of rosin: namely, gum rosin which is procured from the living tree, and wood rosin which is extracted from the dead wood such as stumps and top wood. Both rosins are derived from such pines

COLOR BODIES

OxidlzedResin Acids Pheno l i c Compounds Vlnso l Components

CRUDE WOOD ROSIN

85~ Resin Atlas I0~ Resenss or

Unsaponlflables 5~ E s t e r s

I REFINED WOOD ROSIN

1900~ I~aln Acifis Neutral

Bodies

FIG. 1. C o m p o s i t i o n o f c r u d e w o o d r o s i n .

TABLE 1

Refined Wood Rosin Composition

91% Resin Acids 9% l~eutral Bodies

Abietic Acid ........................... 4 0 % Steam-volatile Material ........ 0 .3% d*Pimaric Acid .................. 10-15% Esters, Hydrocarbons , etc. . , , .8.7% Noncrystal l ine

Isomeric Acids ................ 41-36% •

F i e . 2. T h i s p i c t u r e i l l u s t r a t e s t h e u n i f o r m c l e a n l i n e s s a n d b r i l l i a n c e o f r e f i ned w o o d r o s i n .

as longleaf, loblolly, cuban, slash, etc., which grow in the states of Florida, Georgia, Alabama, Mississippi, Louisiana, and Texas.

Rosin is composed of about 85% resin acids, 10% resenes or unsaponifiable, and 5% esters. The unsaponifiable consists of hydrocarbons and h igh- molecular-weight secondary alcohols of the sterol type. The resin acid portion consists of abietic, /-pimaric, d-pimaric, and other resin acids of uncertain strue-

CH3 COOH

°

H2 C C H2

1 J I H2C. ~C -- .C-H

. .c-c k ~ c / " c"3

~2

Dihydroablet Ic Acid Fro. 3.

CH3 /COOH \ / H2

C C

/ \ i / R2c .?-- cH

.C-C~ H2 H2~~c/H H CH3

H2 T e t r a h y d r o a b i e t i c A c i d

I~IG. 4.

[ 7 7 ]

78 OIL & SOAP, MAY, 1943

A~IETIO ~ D PD(ARXC ACIDS i~DROGF~IATION OF R~SIN ACXDB

% k~IS?IC AOID ~- anal-)

Fleeer ' • Fozsml~

% ,[-P l:ul*lo ~ I d

( l - ~ p i e ~ i e Aola) Fm/ 5

H2 ~ 2 :

tI~IETIC A C I D ~ Ruz, ioF..= ' I F o I I I DibT~L;.oable t le Tott-al~d~o~biello

~OOH AoI~

CH3 d -Pi~uuelo kei~ De~T~Labl ' t l °

FIG. 7. Hydrogenation and Disproportionation of Rosin.

ture and properties. Contrary to general belief, abietie acid represents only a portion of the total resin acids and may be present to the extent of 0% to about 40% depending upon the history of the rosin.

The resin acids present in rosin are unsaturated and contain two double bonds. One of these double bonds is more reactive than the other. This unsaturation causes rosin to absorb oxygen or oxidize. For some purposes, this unsaturation is desirable while for other purposes it is detrimental. For the latter type of uses rosin can be markedly improved by hydrogenation or disproportionation.

, ~ ~ ' ( , .''% ~ . , " .

l-Pimaric Abietie Acid Acid

FiG. 6. Moiecular Models.

TABLE 2 Properties of Staybelitc and N Wood Rosin

Staybelito*

Acid Number. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 162 Melting Point (Drop Method) ................ 167°~. Saponification Number ............................ 167 Unsaponifiable Matter ............................... 8.9% Specific Rotation ..................................... +26 ° Petroleum Ether Insoluble ...................... 0.1% Gasoline Insoluble. .................................. 0.015%

* Hercules grade of hydrogenated rosin.

N Wood Rosin

167 18I°F. 172

6% +12 °

o.1% 0.015%

As can be seen from the following graph, wood rosin is somewhat more resistant to oxidation than is gum rosin. Moreover, hydrogenated rosin (Stay-

,zo

/ / o - - - -

i ~oo

- / - 4°

/o [_ ,

~wou~'osH>/- / / /

/ , / 1

m

p

0 / 0 zo ~ 0 4o so 6 o 7 0 a o q o i c e / / 0 / 2 0 / J o / 4 0 lye /~o / ~ 0 ~

FIO. 8.

belite) is extremely resistant to oxidation. This oxidation resistance of hydrogenated ros in carries through to the various derivatives made therefrom. As will be seen (Figure 9), hydrogenated rosin soap is resistant to oxidation and consequent discoloration.

F• /O

I 7

.£

__ , , i

/

Ay, ~ ,' "T[ j .....

4 2 4 4 8 ?-lAdE-- HOMES

~IG. 9.

OIL & SOA,P MAY, 1943 79

The versatility of rosin causes it to enjoy a large variety of uses. Suffice it here to point out that the major large-volume uses are in soap, paints, varnishes, synthetic resins, paper size, disinfectants, etc.

The use of rosin in soap manufacture began in the middle of the nineteenth century when it was used largely in high-tallow-content soaps. The presence of rosin was said to improve water solubility and sudsing.

In the past it has been the belief of many that rosin was of limited value for use in soap manufacture. Ac- cording to this school of thought rosin serves pri- marily as a filler or extender. The work performed in this present investigation shows conclusively that the use of rosin imparts desirable properties which will be further discussed.

The advantages may be listed as follows: 1. Low price.

2. Dependable a v a i l a b i l i t y in l a rge volume.

3. Quick and l a s t i n g suds.

4. I m p r o v e d solubi l i ty .

5. No skin i r r i t a t ion .

6. I n h i b i t s dus t i ng o£ spray-dr ied soaps.

The heretofore believed disadvantages may be listed as follows :

1. D a r k color of the o r i g i n a l and aged soap.

2, Somewha t h igh unsaponif iabte content as compared to fa ts .

3. Low so lub i l i ty of l ime soaps.

4. Revers ion of the powdered ros in -con ta in ing soaps.

5. No by-produc t glycer in .

6. Odor is d i f fe ren t f rom t h a t of f a t t y acid soaps.

7. Poor d e t e r g e n t act ion.

8. S t ick iness of soaps.

There has been much difference of opinion regarding the use of rosin in soap manufacture. Until re- cently no published data were available upon which a definite and accurate opinion or conclusion could be drawn. Hercules Powder Company therefore under- took an extensive research program to determine the true facts. This program was started several years ago and is still in progress. The results of this work have confirmed some of the opinions previously held but have also definitely made other beliefs no longer tenable.

A portion of the results of this research investigation wilt be briefly described. However, before going into details of this work, we wish to call attention to the work of W. D. Pohle and C. F. Spell of the Naval Stores Research Division, Bureau of Agricultural Chemistry and Engineering (Oil and Soap, July 1940, p. 150; Oil and Soap, December 1941, pages 244 and 247; Soap, February 1942, page 29), (W. D. Pohle and C. F. Speh, Oil and Soap, October 1940, page 214; Oil and Soap, May 1940, page 100). Also the work of L. D. Edwards (Soap, December 1941, page 65) who tested "The Action of Rosin Soaps on the Human Skin," and who stated that " i t seems fair to conclude that rosin soaps and rosin acid soaps under the several conditions as outlined are relatively nonirritant to human skin."

The work of Pohle and Speh dealt largely with gum rosins and rosin acids. Tests were conducted with distilled water. In the work to be described, gum and wood rosins were used in order that the data obtained

should be representative for all commercial rosins now available. Moreover, all of our tests were conducted using water of two different degrees of hardness, therefore more closely approaching the probable conditions under which soaps are actually used.

Rosins and Fats Used The rosins and fats used in this work had the fol-

lowing analytical constants:

TABLE 3

Rosins and Pats Used

Staybelite .................. N Wood Rosin .......... H Gum Rosin ............ N Gum Ros in* ..........

White Ta l low ............ B r o w n Tallow...,, ....... Coconut Oil ...............

Softening Point oC.

Colo Drop Rinl and

I M ~ h o d Bal

85 80 89 82 84 77

?rim~ .... ~row ?rim(

Acid No.

16'/ 171 164

Sapon. No.

174 178 1 6 7

2O0

26O

F r e e AoidRy

3.3 31.0

* Specially refined.

Preparation of Bar Soaps The preparation of experimental soaps at the Her-

cules Experiment Station is by the full-boiled process which is the process used by industry for the bulk of its soap production.

7"M~r Kn~rT/.~ P~JIIT I$

AV~AG~ ¢r .S.'Zf C ~

~O,,¢1,,¢~ ,KETT,, E

/ 7 L/rg~s Vo¢...

,~,480R,~I-fOR ),"" ,5o,,~p

K~7-Tz..,~

/ 8 r a ~

/ N

~'Cu 7uat~ ~oPr. LoN~

I ]OMM. ~ E

/ - /EA r / N ~ ~ , n r H b ' o ~ ~ , ~ o , et,-,~ ~

Fie . 10.

P y , ~ E X

6~ss

~ ~ONST~MCTION A/_I-

~ AROMN~

I


The apparatus used consists of a 17-liter Pyrex ket- tle (enabling full vision of all changes) slung in a wire rope harness, raised and lowered with rope and pulley, to permit easy siphoning off of a spent lye layer after a change. The soap after fitting and settling overnight at 90°C. is removed through the stopcock. The nigre, being considerably more fluid than neat soap, is easily removed in its entirety first if due care is used. This eliminates need of a swing- pipe and pump in the laboratory.

The technique used for soap boiling in our laboratory is essentially the same as that described by Dr. W. C. Preston of Procter and Gamble (entitled "Soap Boiling on a Laboratory Scale" in the J. Chem. Ed., October 1940, pages 476-8), and also described by R. E. Divine of the Soap Laboratory of Hooker Elec- trochemical Company (entitled "Laboratory Boiling of Soap in Glass" in Oil and Soap, 17, 1940, pages 2-4). The change made lies in the use of rosin as a component of the soap.

Titre Value The titre value of a soap stock is often considered

as one of several criterions by which a raw material may be evaluated for use in soap manufacture. Fat ty acids have a definite titre value, but rosin being amorphous has no titre and must necessarily be tested for titre value in conjunction with a fat ty acid and the relative change in titre noted for each rosin. Using a high grade of white tallow fatty acid with gum and wood rosin, the following titre values were ascertained :

T A B L E 4

Ta l low fa t ty ac id soap stock only . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . Ta l low fa t ty ac id soap stock ~- N g u m ros in (50 : 5 0 ) .. . . . . . . . . . . . . . . . Ta l l ow fa t ty ac id soap s tock ~- N wood ros in (50 : 5 0 ) . . . . . . . . . . . . . . .

Titre

4 7 . 8 ° 0 , 38.2 37.8

The titre values of the soap stocks used in the work here reported were as follows:

T A B L E 5

T i t r e V a l u e

W h i t e t a l low fa t ty ac ids a lone . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 44 .5 B r o w n ta l low f a t t y ac ids a lone . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 39.3 Coconut oil f a t ty ac ids . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 22 .3 W h i t e ta l low fa t ty ac ids wi th N wood ros in ( 5 0 : 5 0 ) ................. 37 .8 B r o w n ta l low fa t ty ac ids wi th H g u m ros in ( 5 0 : 5 0 ) . . . . . . . . . . . . . . . . 38 .2

Sudsing Action The apparatus used in the sudsing or foam test was

described in detail with theory of operation in " A n Apparatus for Comparison of Foaming Properties of Soaps and Detergents" by John Ross and Gilbert D. Miles in the May 1941 issue of Oil and Soap, pp. 99-102. The data obtained are illustrated in the following graph. These data show clearly that in moderately soft water (50 p.p.m, or 2.9 grains per gallon) the rosins in white or brown tallow-coconut oil base soap are quite effective in maintaining or improving the sudsing action. Refined wood rosin, however, was generally superior to gum rosin or Staybelite. This was true not only regarding the volume of suds de- veloped but also in the stability of the suds. In moderately hard water (300 p.p.m, or 17.5 grains per gallon) all of the rosins were about equivalent. While

.,~PPAI ~A yU3 ,~'o,~ Po ug/N ~ f O,,q M 7"EJ" 7

i . . . .

_ Eq.-,,_I-_-'f~_ ~.

I I II

L, , . I

RUN OuT T / N 1 A P p , ~ o x , Z 2 8K¢.

F r o . 1 1 .

they did not enhance the suds volume or stability, they also did not detract from this desirable property of soap.

U 20(

Z

bJ

a5c

EFFECT OF ROSIN SOAPS ON SUDSING VALUE OF WHITE TALLOW-COCONUT OIL SOAP SOFT

SUDS I M M E D I A T E L Y

250 ~ .

| J

NATER I S U D S A F T E R 5 M I N U T E S

I

N WOOD ROSIN - - - - H GUM ROSIN . . . . STAYBELITE

I , I i | I i o , i I

HARD WATER >0 250.

t \ \

, s e ; ,b ~o ~'o 4b ' o ,~ ~o 3b 4b °/o ROSIN SOAP

Fro. 12.


250

6 u

20C ILl 3E 3 o

! 5 C

<~ 25C

20(:

EFFECT OF ROSIN SOAPS ON SUDSING VALUE OF BROWN TALLOW-COCOi~UT OIL SOAP

15(

S O F T

, , t ! i

HA R D

WATER SUDS AFTER S M~NUTE$

% ko

N WOOD ROSIN - - - - H G U M ROSIN . . . . S T A Y B E L I T E

, i i

WATER

,j \ \ \

o ,o io 4'0 ' % ROSIN SOAP

Fro. 13.

Detergent Action of Rosin-Containing Soaps In determining detergent efficiency the s tandard

washing test was used and comprised three steps; namely, (1) the soiling of a s tandard cotton cloth, (2) measuring the brightness of the cloth soiled with a vegetable oil, mineral oil and carbon black, and (3) washing the standard soiled cloth in a Launder- Ometer.

When used in conjunction with a white tallow- coconut oil base soap containing no builder, Hercules refined wood rosin, regular gum rosin, and Staybelite were about equivalent. Over the range of rosin concentrations normally used, these rosins not only maintained the high detergent action but actually enhanced this proper ty of the base soap. The specially refined gum rosin was somewhat less effective. This was true when tested in water of moderately low hardness (50 p.p.m, or 2.9 grains per gallon). When harder water (300 p.p.m, or 17.5 grains per gallon) was used, Her- cules refined rosin and regular gum rosin were substantially equivalent and maintained the detergent action of the base soap. Staybelite and specially refined gum rosin were equivalent and somewhat in- fer ior to the previously mentioned rosins.

The use of rosins in brown tallow-coconut oil base soap gave a detergent action quite different f rom that in the white base soap. While all the rosins were somewhat less effective from the detergent viewpoint when used in the brown base soap, Hereule~ refined rosin and Staybelite were quite similar and superior to regular or specially refined gum rosins. This refers to evaluation in a moderately soft water (50 p.p.m, or 2.9 grains per gallon) and also a moderately hard water (300 p.p.m, or 17.5 grains per gallon).

While rosin-containing soaps are not so effective as f a t ty acid soap in hard water, this difference is not too great over the range of rosin concentrations normally used.

The above conclusions are based on the data f rom which the following graphs were plotted. I t will be observed that according to these graphs rosin soaps possess substantially zero detergency when tested per

se. I t must however be kept in mind that a soiled cloth was used which was not easily scoured. More- over, certain commercial l aundry soaps which contained no rosin when tested with this soiled cloth also gave zero detergent action.

z uJ u

u. U. IAJ

l- z id 0 n, ILl I-

o

ROSIN CONTENT vs. DETERGENT EFFICIENCY, 7 5 % BROWN TALLOW-25% COCONUT OIL SOAP BASE 0.30% SOAP IN WATER OF 50PPM. (•AS C A C O 3 ) HARDNESS.

!00

g0

8 0 soaps

70

6O

5O

3C

2C

IC T E M P I~O*F

,b 2b 3b do 6'o ?b 8b 9b PERCENT ROSIN

Fro. 14.

ROSIN CONTENT vs. DETERGENT EFFICIENCY, 7 5 % WHITE TALLOW-25% COCONUT OIL SOAP BASE 0.30% SOAP IN WATER OF . ~ P P M ( A S CACO~)HARDNES5

IIC

9C

8C

60

40

3 0

20

10

SOA P

N WOO0 ROSIN ~ P

REGULAR ANO ' ' ~ SPECIALLY REFINED GUM

ROSIN SOAP GUM ROSIN SOAP

TEMP. I lOeF.

IO 20 30 40 50 60 70 80 90 I00 PERCENT ROSIN

FIG. 15.

White tallow (high-titre) base soaps which contained 15 and 25% of K wood rosin possessed ap- proximately the same detergent value in soft and hard water as did the tallow base soap.


ROSIN CONTENT vs. DETERGENT EFFICIENCY. 7 5 % BROWN TALLOW-25% COCONUT OIL SOAP BASE 0.55%SOAP IN WATER OF 300PPM.CCACOs) H~ ~RDNESS.

I00

90

b so Z bl

u.

l -

bi

I- w Q 3 0

I 0

0 10 2 0 30 4 0 50 bO 70 80 go I00 P E R C E N T ROSIN

F r o . 16.

ROSIN CONTENT vs. DETERGENT EFFICIENCY, 75% WHITE T A L L O W - - 2 5 % COCONUT OIL SOAP BASE 0 .55%SOAP IN WATER OF 300PPM. CASCACO 3)

, ,~t HARDNESS.

>. U Z

U. U. Ill

I - Z Id O n, tU l - Id

Gt/M IllOSIN SOAP

7(

SOAP

WOOD ROSIN ,~OAP

SPECIALLY R E F I N E D ROSIN SOAP

TEMP. I IOeP.

0 i0 20 30 4 0 5 0 6 0 TO P E R C E N T R O S I N

F~(~. 17.

8 0 9 0 I 0 0

TABLE 6

Soap

White tallow (100%) . . . . . . . . . . . . . .

White tallow (85 % ) ................. K wood rosin (15%)... ,~ ..........

White tallow ( 7 5 % ) ................ K wood rosin (25%) ...............

Detergent Efficiency +

0.30% Soap 50 p.p.m. H a r d n e s s 2.94 gra ins per gal.

93

88

92

0 .55% Soap 300 p.p.m. H a r d n e s s 17.5 g ra ins per gal.

93

89

90

The sudsing power of these soaps decreased somewhat with increase in rosin content. This was more evident in the case of hard water than soft water.

T A B L E 7

S u d s i n g V a l u e

Soap

White tallow ( 1 0 0 % ) ...................

Whit~ tallow ( 8 5 % ) ...................... K wood rosin (15%) . . .~ .............. .~

White tallow ( 7 5 % ) ..................... K wood ros in ( 2 5 % ) .....................

0.30% Soap in Soft Wate r

Imme- After 5 diate Minutes

245

240 225

230 215

0 . 5 5 % S o a p in H a r d Wate r

Imme* After 5 diate I Minutes

240 t 220

220 ] 190

200 1 150

Staybelite when used in a white high-titre tallow base soap enhanced the detergent action in soft and also hard water. Regular rosin, on the other hand, had no apparent effect on detergent action. The sudsing action was, however, somewhat reduced. Stay- belite caused a greater reduction than did regular rosin. Less reduction took place in the case of soft water than hard water.

T A B L E 8

De te rgen tEmciency

Percen t Staybelite in 0 .30% Soap in 0 .55% Soap in White Tallow Soap Soft W a t e r H a r d Wate r

0 93 93 10 99 104 20 97 103 30 96 91

T A B L E 9

Suds ing Value

H a r d Wate r Soft W a t e r i Percen t S tayb~i te in • -I- White Tallow Soap Imme- t After 5 {

diate Minutes

o 240 - - - - -

10 235 I 215 20 220 205 I 30 t 220 [ 140 I

Imme- AVer 5 diate Minutes

235 225 225 190 205 180 200 170

ROSIN CONTENT VS DETERGENT EFFICIENCY 100°/o WHITE TALLOW BASE SOAP

O ,3 e/e SOAP IN 5 0 F T WATER - SO PPM HARDNESS

' 0 0 ! F o ~ e - ST2YSEoLIT[

°f 7o

6ol . . . . . . . b. bJ

1-

wZIO0 O

atg0 I.- W " 8 0

70

60

0 -SS e/e S0AP IN HARD WATER ° 3 0 0 PPM HARDN($5

r ~ ' ' ' . . - - - - - - O _ _ . _ _ . - - . O . _ _ ~ WOO0 ROSIN

ib 2b °/o ROSIN

FIG. 18.


E F F E C T OF ROSIN ON S U D S I N G V A L U E OF" 1 0 0 % W H I T E T A L L O W B A S E S O A P

S O F T WATER . ' S U D S I M M I [ I:1 I A l r IE~. y

t O

/

z 2oof

150" . . . . . .

~ U D a A ~ r E R ~ M I N U T E S

HARD W A T E R

150 0 10 20 30 0

° /o ROSIN

Fro. 19.

K W O O D R O S I N STAYBELITE

i0 20 30

Rosin when substituted for par t of the brown beef tallow of moderately high-titre value did not detract from the detergent efficiency of the base soap, when the rosin concentration was within the range of that. normally used in soap manufacture. The detergent efficiency was somewhat better in the hard wa£er than in the soft water.

The sudsing values for these same soaps were un- changed by the presence of the rosin soaps. This was true for the suds volume and also suds stability in both hard and soft water.

EFFECT OF K WOOD ROSIN SOAP (T ITRE VALUE 39) ON THE SUDSING V A L U E OF B R O W N T A L L O W SOAP

I f * ~ l E O i ~ , VALUE VALU~ A~TI~R ,,~ M I N U T E S

SOFT WATER

2 5 0

o

2 0 0

w I$0

250 Z

~ 2 0 0

t,S,O

~ C

HARD WA'TER

ol I

20 O IO 20 o / . ROSIN IN SOAP

Fz~. 20.

THE DETERGENT EFFICIENCY OF A BROWN TALLOW (TITRE 39) BASE SOAP CONTAINING VARIOUS AMOUNTS OF K WOOD ROSIN.

' 1 0 r 0,55~Y ". SOAP IN HARD WATER

r, / x x

/ ~ °0 | o 3o ,. oA, IN

/ IN SOFT *ATER ~ ~

R O S I N I N S O A P

FIG. 21.

I t appears f rom these results that the t i tre value of the tallow used determines to some extent the detergent action of the rosin-containing tallow soaps but has a more pronounced effect on the sudsing value and suds stability. Tallow of moderately high t i tre when used with rosin soaps is apparent ly superior with respect to sudsing properties.

Built Soaps Built soaps were prepared using a brown tallow

(90%)- -g rease (10%) stock as the base. These soaps were prepared so as to contain three different concentrations of rosin soap. To these finished soaps the builders were incorporated by crutching. The detergent efficiency of these built soaps was high as can be seen from the following test results.

T A B L E 10

Soap Composi t ion

K wood ros in soap .... . . . . . . . . . Sodium s i l ica te . . . . . . . . . . . . . . . . . . Sod ium ca rbona t e . . . . . . . . . . . . . . B a s e soap . . . . . . . . . . . . . . . . . . . . . . . . . . .

K wood ros in soap .. . . . . . . . . . . . Sod ium s i l ica te . . . . . . . . . . . . . . . . . . Sod ium c a r b o n a t e .. . . . . . . . . . . . . B a s e soap . . . . . . . . . . . . . . . . . . . . . . . . . . .

K wood ros in soap .. . . . . . . . . . . . Sodium s i l i ca te . . . . . . . . . . . . . . . . . . Sod ium c a r b o n a t e . . . . . . . . . . . . . . B a s e soap . . . . . . . . . . . . . . . . . . . . . . . . . . .

( D r y B a s i s )

12 4

54

2 7 % 6 3.6

63 .4

1 8 %

~.7 72.3

p H of Solu t ion

9.4

9 .95

10

D e t e r g e n t Eff ie iency

0.30% 0.55% Soft H a r d

W a t e r W a t e r

84 73

84 79

103 83

Spray-Dried Soaps Containing Rosia

Spray-dried soaps (white tallow 75%--coconut oil 25% base) which contained various percentages of rosin were prepared and tested.

FIG. 2 2 . E f f e c t o f r o s i n a n d S t a y b e l i t o o n c o l o r o f b a r s o a p s .

I . W h i t e toi let soap, 2. 5 % Staybel i te . 3. 5 % N wood.

The spray-dried soaps were prepared by placing the molten soap in an autoclave at 325°F., which gave a gage pressure of 80 lb. per square inch. The molten soap at this temperature was increased in pressure by means of nitrogen to 250 lb. per square inch and sprayed into a chamber, countereurrent to air at 240°F.

Results showed quite definitely tha t powdered soaps which contained about 15% or less of the various rosins (dry basis) were not only light in color (substantially snow white) but had no apparent tendency to rever t or coalesce when exposed to a temperature


Fro. 23. :Effect of rosin and Staybelite on spray-dried soaps. 1. Regular so~p powder containing no rosin. 2. As 1 containing 15%

of Staybelite. 3. As 1 containing 15% WG wood rosin. 4. As 1 containing 15% 1~ wood rosin. 5. As 1 containing 15% WG gum rosin.

of 80°F. and high humidi ty (saturated air) for over 300 hours. These aged, spray-dr ied soaps showed no apparen t tendency to discolor. Spray-dr ied soaps which contained 15% of Staybeli te were definitely white in color.

Buil t soaps (15% rosin) which contained 12% of sodium silicate (d ry basis) and 4% sodium carbonate were about equivalent in color and resistance to re- version as the unbuil t soaps.

All of the spray-dried, rosin-containing soaps were effective detergents.

R a t e o f S o l u t i o n of R o s i n - C o n t a i n i n g S o a p s

Results indicate that Staybeli te is appreciably mor~ efficient than K wood rosin in increasing the solubility of soaps of certain soap bases.

The method used in testing the ~'solubility of soap is one approaching that of actual use, and uses the type water (not distilled water) one would be using and at a t empera ture normally used. The details of the test are as follows: measure the dissolving rate of the soap in question as 15 lb./rain, of 50 p.p.m, hardness tap w a t e r at 110°F. (the tempera ture u s e d in Launder-Ometer and foam tests) falls ten inches upon a 2 x 2 cm. slab of soap supported on a 16 mesh wire screen. The solution rate is equal to the weight of the soap sample, divided by the time in minutes to dissolve the soap.

Since coconut is no longer available in quanti ty, soaps now made will be composed largely of tallow and whatever other materials may be available. Ba- bassu oil is quite sat isfactory as a replacement material for coconut oil; however, it too is imported and consequently the supply is dependent upon oceanic t ransportat ion. Rosin and Staybelite (hydrogenated rosin), both of which are produced domestically, de- serve serious consideration.

We have prepared and examined white and also brown tallow base soaps which contained vary ing percentages of rosin and also Staybelite. Evaluat ion of these soaps indicates that rosin does not improve the solubility of high-ti tre white tallow base soaps. Stay-

O = al I- D z

< er O

cn

EFFECT OF ROSIN UPON SOAP ,SOLUBILITY 0.70 !

Z ~

0 . ~ / v j FATTY ACID BASE WHITE TALLOW 75% COCONUT o i l Z 5%

0.50

0.30

q 0 WHITE TALLOW 100% m 0.10 K wooo

5 IO 15 2O 25 3O % ROSIN SOAP (.DRY BASIS)

('/.~E.L~":E~,E.T OF .A~E S, "OS,. )

FIG. 24.

belite, however, does ineraase the solubility rate. Both rosin and Staybeli te increase solution rate of mod- era te ly high-ti tre brown tallow or tallow-coconut oil base soaps.

= O.SC < lr o 0.4G b,l ,~ Q3C n,

~ O.IG

_ O.O0 0 0

DISSOLVING RATE OF ROSIN SOAPS WHEN 15LBS./MIN. OF 50PPM. HARDNESS TAP NATER AT tlO°F. FALLS I0 INCHES ON 2X2¢u, SLAB OF SOAP,

WHITE TALLOW BASE

Ib i; a'o '2'5 ~o K WOOD ROSIN ( D R Y BASIS)

Fzo. 25.

4

~J I- <

o _=

g

DISSOLVING RATE OF ROSIN SOAPS WHEN 15LBS. /MIN. OF 50 PpU. HARDNESS TAP WATER AT IIO°F. FALLS 10INCHES ON 2X2CM. SLAB OF SOAP.

1.00 ~ o W , ~ T,L-OW-COCO.u'r 0.8¢ ',As= (7,~:z=)

0.6¢~

0.4( e , , ~ ~ ~ l ' r E TALLOW--COCONUT

0.20 , . . ( , , : , , )

t i o.% s ,; ,'s zo 2; % K WOOD ROSIN (DRY BASIS)

P~Q. 26.

Documents

Rosin — Use in soap