EFFECT OF BASE COMPONENTS ON OXIDATION HAIR DYES 42,5 was added, the cap screwed on tightly, and the jar or polyethylene "applicator bottle" then turned end-over-end ten times. Temperature rises were then recorded after 5 minutes, 30 minutes, and longer if the temperature continued to rise. Where extreme temperature rises occur, it is not unusual to find the temperature still climbing after one hour. It is postulated that such temperature rises are due to exothermic reactions wherein amine oxides are formed. It is not understood exactly what role the dye plays in these reactions however, they do not occur in the absence of dye. Viscosity Viscosities were measured on the color base itself, and after admix- ture with an equal amount of 20 vol hydrogen peroxide, in the same jars which were used to measure temperature rise. Viscosities were mea- sured with the Brookfield Synchroelectric Viscometer rotating at 30 rpm, using a •2 or •3 spindle which was allowed to turn ten times before being "stopped" for measurement. Temperature of viscosity readings was approximately 25 øC to start, and climbed considerably in a few cases. Most results reported were in the 23-7 øC range. Viscosity measured in this manner was not related to the "drop-movement" of these hair dye bases. Drop-Movement Cook noted (6) that the lack of movement of a drop of dye solution down a glass plate is an indication that it will not drip from the hair. This approach was modified into a semiquantitative procedure. The drop-movement test consists of measuring the distance which a standard size drop of the dye solution will travel down an inclined glass plate in specific time intervals. Samples were prepared in the same manner as for the tests above. The resulting product was transferred to a beaker and three drops from a standardized eye dropper were then placed on an inclined glass plate set at an angle of 67.5 ø (Fig. 1). After 5 minutes, the amount of travel (measured in inches) of this "Fresh Mixture" (Table II) was recorded, and again after 30 minutes. Thirty minutes after the addition of the peroxide, a second set of three drops was put on the plate ("30 Minute Mixture"), and their movement recorded after 5 and 30 minutes. All results shown are average movements of three drops. In extreme cases, drop-movements for a particular solution varied as much as 50%, but generally the three drops travelling down the plate simultaneously were no more than 10% apart.

426 JOURNAL OF THE SOCIETY OF COSMETIC CHEMISTS ß .: ...•..,J '.• .. ',: ....... • •,,•.•... Figure 1. Drop-movement test apparatus Temperature rise of the dye solutions is not a factor in these meas- urements since only single drops were placed on a 100-sq in. glass plate which was at room temperature. Often the drop did not move at all after the first five minutes. A drop-movement of under 1 in. is con- sidered excellent (presumably relating to very little dripping on the head) up to 3 in. is considered reasonable. The plate did not extend beyond 10 in. therefore results recorded as 10 in. in some cases mean Table II Commercial Hair Dyes (Oxidation Dyes--Black Shade) Max. Viscosity (cps) Drop-Movements b (in.) Temp. After Adding H202 Fresh Mix 30 Min Mix Prod- Final Rise Base uct a pH (øC) Alone 5 Min 30 Min 5 Min 30 Min 5 Min 30 Min A 9.9 5 40 1264 1460 0.3 1.2 1.5 B 10.0 2 25 1000 2052 1.9 2.0 2.8 C 9.9 1 125 2132 2132 0.6 4.5 0.7 D 9.6 5 70 200 144 3.8 4.5 2.8 E 10.1 4 46 836 964 0.5 1.3 0.3 F 10.0 2 40 520 335 1.0 1.5 1.1 G 10.0 9 30 146 155 1.4 1.8 1.7 H 10.1 5 129 756 620 2.0 3.5 1.0 I 10.1 2 33 110 113 3.7 5.5 4.8 J 9.5 4 1528 360 355 2.0 2.2 2.3 K 9.9 4 85 1856 1600 2.1 10.0 2.5 L 9.6 2 140 640 580 5.8 10.0 10.0 59 29 31 34 10 13 35 12 4.9 9.5 10.0 10.0 a Samples A-F are "Creme" Hair Colors Samples G-L are "Shampoo In" Hair Colors. b Two sets of drops are recorded, one from a "Fresh Mixture" (newly mixed dye base plus oxidizer) and one from a "30 Minute Mixture," the same batch 30 minutes after mixing the two components together.