Method for Scouring Wool

Abstract

The present invention provides for a method for scouring wool by contacting the wool with an aqueous composition comprising an alcohol alkoxylate, water, and optional additives such as hydrotropes serving as stabilizer and/or dispersant. The compositions were found to exhibit both high detergency in wool scouring, and high stability when stored at room temperature or a lower temperature, while still remain lanolin recovery rate at a high level.

Claims

1. A method for scouring wool, comprising contacting the wool with an aqueous composition comprising an alcohol alkoxylate with the following general formula (I):
RO(AO).sub.nH (I) wherein R represents linear or branched hydrocarbyl group having 4 to 22 carbon atoms, AO represents an alkyleneoxy unit having 2 to 6 carbon atoms, n is within the range from 1 to 20, and not less than 40 wt % of the alcohol alkoxylates has a distribution of the addition of alcohol alkyleneoxy units ranging from 2-20.

2. A method according to claim 1, wherein not less than 40 wt % of the alcohol alkoxylates has a distribution of the addition of alcohol alkyleneoxy units ranging from 4-9.

3. A method according to claim 1, wherein not less than 40 wt % of the alcohol alkoxylates has a distribution of the addition of alcohol alkyleneoxy units ranging from 4-7.

4. A method according to claim 1, wherein AO is selected from ethylene oxide units, propylene oxide units, or a combination thereof.

5. A method according to claim 3, wherein AO is selected from the combination of ethylene oxide units and propylene oxide units, with the addition of ethylene oxide units being within the range of 2-9, and the addition of propylene oxide units being within the range of 0-5.

6. A method according to claim 1, wherein R represents linear or branched hydrocarbyl group having 4 to 22 carbon atoms.

7. A method according to claim 1, wherein R represents linear or branched hydrocarbyl group having 6 to 13 carbon atoms.

8. A method according to claim 1, wherein R represents linear or branched hydrocarbyl group having 9 to 11 carbon atoms.

9. A method according to claim 1, wherein the composition further comprises a hydrotrope selected from bis(ethoxylated) monoalkyl quaternary ammonium compound having the formula (II), ##STR00002## wherein R is C.sub.6-C.sub.22 hydrocarbyl, preferably C.sub.6-C.sub.22 alkyl or alkenyl, more preferably C.sub.8-C.sub.20 alkyl or alkenyl, and most preferably C.sub.10-C.sub.18 alkyl or alkenyl; R.sup.1 is C.sub.1-C.sub.4 alkyl, preferably methyl or ethyl, and most preferably methyl; x is an number from 1 to 40, y is a number from 1 to 40 with the sum of x+y ranging from 8 to 25; and A.sup. is an anion.

10. A method according to claim 9, wherein the weight ratio between the alcohol alkoxylate of formula (I) and the hydrotrope of formula (II) is from 99:1 to 60:40.

11. A method according to claim 9 wherein the total amount of the alcohol alkoxylate of formula (I) and, if present, the hydrotrope of formula (II) in said composition is from 10 to 1000 ppm.

Description

DESCRIPTION OF DRAWINGS

[0033] The above and other objectives, features and advantages of the present invention will become more apparent to those of ordinary skill in the art by describing in embodiments thereof with reference to the accompanying drawings.

[0034] FIG. 1 provides pictures showing whiteness of the wool after rinsing and drying with different detergent formulations;

[0035] FIG. 2 provides pictures showing the results of lanolin recovery efficiency test on different detergent formulations and at different time points;

[0036] FIG. 3 provides pictures showing the results of separation test on different detergent formulations.

EXPERIMENTAL

[0037] The following examples are offered to illustrate, but not to limit the claimed invention. Unless otherwise specified, all percentages are by weight.

EXAMPLE 1

[0038] Detergent formulations with compositions specified in Table 1 were made. The quanternary ammonium compound was added as a hydrotrope to stabilize the formulation at elevated temperature and to assist cleaning.

[0039] To evaluate the cleaning efficiency of the formulations in Table 1 the following wool scouring test was used. Three 800 gram hot (65-70 C) baths were prepared with only the 2.sup.nd one containing the detergent blend (0.01%) while the rest two having just tap water. The dirty raw wool (20 gram) was subsequently washed (5 minutes in each bath), squeezed dry, and transferred to one bath after another. The process was designed to mimic the simplified wool scouring process with the 1.sup.st bath for suint deposition, the 2.sup.nd one primarily for wool cleaning, and 3.sup.rd one for rinsing.

[0040] The detergent efficiency was evaluated based on the whiteness of the wool after rinsing and drying, and was summarized in FIG. 1.

TABLE-US-00001 TABLE 1 Ingredient #1 #2 #3 #4 #5 C9-11-alcohol + 5.5 EO* 95% 90% 80% 70% (Coco alkyl) amine + 15EO 5% 10% 20% 30% quanternized by CH3Cl Nonyl phenol + 9EO 100% Cleaning efficiency 2** 3 4 5 5 *Narrow range ethoxylate **scale of whiteness: 5 being the most white, 1 being least white. Numbers are assigned by visual judgment.

[0041] Comparing the detergency results with #1, #2, #3, #4, it is evident that the increasing concentration of hydrotrope improves the whiteness of washed wool. When the blend is composed of 30% of hydrotrope, the whiteness of the washed wool is comparable to that of the wool washed by NP-9. As the detergency efficiency of the nonionic surfactant is constrained by its cloud point which is correlated with the concentration of hydrotrope, this set of scouring results demonstrate that hydrotrope concentration is critical to achieve the optimal detergency efficiency.

EXAMPLE 2

[0042] Hydrotrope Test

[0043] In this example formulations were made with a number of hydrotropes specified in Table 2 to compare hydrotrope efficiency. The less amount of hydrotrope needed to add to turn the formulation to clarity at room temperature, the more effective it is as a solubilizing agent. The numbers in the Table 2 are expressed in wt. %, and water is added to balance the total to 100%.

TABLE-US-00002 TABLE 2 Ingredient #1 #2 #3 #4 #5 #6 #7 #8 #9 C9-11-alcohol + 4EO* 9.83 9.75 4.94 4.91 9.75 9.43 9.35 4.81 9.47 wt % wt % wt % wt % wt % wt % wt % wt % wt % (Coco alkyl) amine + 1.67 2.53 1.28 1.86 15EO quanternized by CH.sub.3Cl Octadecanamine + 2.53 15EO quanternized by CH.sub.3Cl C.sub.8 Alkyl glucoside 5.66 6.54 C.sub.6 Alkyl glucoside 3.85 5.30 water Bal.** Bal. Bal. Bal. Bal. Bal. Bal. Bal. Bal. Appearance (RT) s*** c**** s c s s c s c *Narrow range ethoxylate **Bal. = add to balance ***s = separate ****c = clear

EXAMPLE 3

[0044] Lanolin Recovery Efficiency Test

[0045] In order to compare lanolin recovery efficiency, a series of formulations with 1.00 g detergent, 8.00 g H.sub.2O and 0.50 g lanolin were mixed well, and pictures were taken to characterize the demulsifying process at 70 C.

[0046] As shown in FIGS. 2 and 3, arranged from left to right are detergents C9-11-alcohol+4EO (narrow range ethoxylate), C9-11-alcohol+5.5EO (narrow range ethoxylate), C9-11-alcohol+6EO (normal range ethoxylate), C9-11-alcohol+8EO (normal range ethoxylate), and Nonylphenol+9EO.

[0047] Lanolin was enriched in the nonionic surfactant layer which appears as light amber color. The results show that C9-11-alcohol+4EO (narrow range ethoxylate)started demulsifying within 5 minutes, while the rest didn't start demulsifying until half hour. C9-11-alcohol+4EO and C9-11-alcohol+5.5EO (both narrow range ethoxylate show more complete separation than the rest. These results clearly demonstrate that narrow range alcohol ethoxylates with lower numbers of EO addition have advantages over their normal range counterparts in lanolin recovery. Nonylphenol+9EO in comparison shows little if any lanolin enrichment layer but has all the lanolin well soluablized in the aqueous layer instead.

EXAMPLE 4

Low Temperature Stability Test

[0048] As the detergent is usually pumped to the washing bath, it is important to study the stability of the detergent under the cold condition. A series of detergent blends with the compositions listed in Table 3 were mixed, and the phase behavior was observed after the blends were stored overnight at 2 degree C. and 22 degree C.

TABLE-US-00003 TABLE 3 Ingredient #1 #2 #3 #4 #5 C9-11-alcohol + 5.5 EO* 95% 90% 85% 80% 70% (Coco alkyl) amine + 15EO 5% 10% 15% 20% 30% quanternized by CH3Cl *Narrow range ethoxylate

[0049] All five blends appeared clear one phase liquid at room temperature. They turned to hazy translucent liquid under 2 degree C. overnight. No phase separation was observed in any of them. They turned to white solid under 22 degree C. overnight without phase separation. It is worth noting that there was no gelling or precipitation happening for these blends under cold temperature (2 and 22 degree C.), and all samples when taken out of the cold temperature were able to restore to clear one phase liquid without any shaking or mixing when left at room temperature. This study demonstrates that these detergent blends exhibit excellent stability under low temperature. Therefore they are suitable for use during the winter time at those cold areas.