Cleaning compositions for solid surfaces – auxiliary compositions – Cleaning compositions or processes of preparing – For cleaning a specific substrate or removing a specific...
Reexamination Certificate
2000-06-30
2001-10-30
Ogden, Necholus (Department: 1751)
Cleaning compositions for solid surfaces, auxiliary compositions
Cleaning compositions or processes of preparing
For cleaning a specific substrate or removing a specific...
C510S147000, C510S152000, C510S155000
Reexamination Certificate
active
06310015
ABSTRACT:
FIELD OF THE INVENTION
The present invention is directed to transparent/translucent moisturizing/cosmetic/personal cleansing bars (hereinafter “cleansing bars”) having a melting point of at least 55° C. and increased hardness/durability, primarily due to the bars containing polyhydric solvents, in an amount of about 15% to about 65% by weight, preferably about 25% to about 65% by weight, including (A) one or more polyhydric solvents that include at least three hydroxyl groups, in an amount of 5% by weight to about 35% by weight, and (B) one or more polyhydric solvents that include two hydroxyl groups, e.g., diols or glycols, in an amount of about 10% by weight to about 30% by weight. The transparent/translucent cleansing bars contain about 4% to about 13% by weight water, preferably about 4% to about 12% water, most preferably about 7% to about 12% water. The transparent/translucent cleansing bars lose less water with time via atmospheric evaporation and have increased durability and avoid melting and deformation during shipping and handling while maintaining transparency/translucency. The bars are manufactured by forming a molten composition in liquid form, and pouring the molten composition into a mold to harden, upon cooling. The bar can be manufactured without a monohydric alcohol, or may contain a monohydric alcohol in relatively small amounts, e.g., 0.1% to 4%, preferably 0.5% to 2% by weight, for increased clarity. The bars can be manufactured to include relatively high foam, as personal cleansing/moisturizing bars, or may contain low foam surfactants as moisturizing/facial cleansing/cosmetic bars.
BACKGROUND OF THE INVENTION AND PRIOR ART
Transparent personal cleansing bars are well known in the art. They are prepared by dissolving soap in a combination of water soluble solvents (normally urea and/or polyhydric alcohols) with the addition of surfactants to improve the cleansing and lathering characteristics of the product. Water is also part of the composition and is incorporated into the bars by the direct addition of water or added from the surfactants or soap that form part of the cleansing bars.
A common problem with transparent personal cleansing bars is that they have a melting point of about 50° C., which is too close to the temperatures that are reached during shipping or storage of the products. When shipped or stored at temperatures approaching 50° C., the solid personal cleansing bars either melt or become sufficiently soft to deform. Another common problem of the personal cleansing bars is that they lose more weight than regular, opaque cleansing bars due to their relatively higher content of water, and the presence of volatile solvents, such as monohydric alcohols, e.g., ethanol.
U.S. Pat. No. 5,041,234 to Instone, et al. discloses a transparent personal cleansing bar which contains greater than 40 percent by weight of soap (high soap bar). Like other “high soap” transparent bars, the bars disclosed by Instone et al. have good lather, low smear, and good bar hardness. Such high soap level transparent bars, however, are rather harsh to the skin. Another drawback to such bars is that their processing generally require the use of at least about 5% by weight volatile, short chain monohydric alcohols, or require special milling to obtain transparency.
Transparent bars which contain lower levels of soap are also known in the art. “Lower soap” transparent bars contain less than 40 percent by weight of soap. U.S. Pat. No. 5,002,685 to Chambers et al. discloses a transparent bar made with 25% to 34% by weight soap, 5% to 15% by weight monohydric alcohol, 15% to 30% by weight sugar and/or cyclic polyol, and 15% to 30% by weight water. Unfortunately, transparent bars which require the use of at least about 5% by weight monohydric alcohols are prone to excessive weight loss due to the volatile nature of most monohydric alcohols. Such transparent bars are also more expensive to prepare and require special equipment designed to accommodate the explosion hazard associated with most monohydric alcohols.
Zyngier et al. U.S. Pat. No. 5,703,025 discloses a monohydric alcohol-free process for making pour molded transparent and translucent cleansing bars that have good hardness, are mild to the skin, low smearing and good lathering. These bars, however, require at least 14% by weight water, particularly 14% to 32% by weight water, and preferably more than 20% by weight water, so that the bars melt and deform at a relatively low temperature, e.g., about 50° C., and readily lose weight via water evaporation at room temperature and pressure. As stated in the '025 patent, “The water level within the personal cleansing bars prepared by the process of the present invention is critical to obtain a transparent bar having desirable hardness characteristics. When the water is less than about 14 parts by weight of the bar, the bar may not be transparent.”
A transparent/translucent cleansing bar containing 20% by weight water loses about 17% of its original weight when exposed to room temperature for three weeks, whereas a bar containing only 10% by weight water only loses about 7.5% of its original weight under the same, standard temperature (room temperature) and pressure conditions.
SUMMARY OF THE INVENTION
In brief, the present invention is directed to a composition and a method of preparing a transparent/translucent moisturizing/cosmetic/personal cleansing bar containing polyhydric solvents, in an amount of about 15% to about 65% by weight, preferably about 25% to about 65% by weight, including one or more polyhydric solvents that include at least three hydroxyl groups, in an amount of 5% by weight to about 35% by weight, and one or more polyhydric solvents that include two hydroxyl groups, e.g., diols or glycols, in an amount of about 10% by weight to about 30% by weight. The transparent/translucent cleansing bars contain a final water content of about 13% by weight or less, preferably about 4% to about 12%, more preferably about 7% to about 12% water, thereby increasing the melting temperature of the bar to prevent melting and reduce deformation during storage and handling, increasing its hardness and durability, and substantially reducing the tendency of the bar to lose weight over time by evaporation of water by exposure to room temperature.
Accordingly, one aspect of the present invention is to provide a transparent/translucent moisturizing/cosmetic/personal cleansing bar that is more durable, has a relatively high melting point, and a lower water content than prior art personal cleansing bars, while maintaining clarity (transparency).
Another aspect of the present invention is to provide a transparent/translucent moisturizing/cosmetic/personal cleansing bar that is less susceptible to being deformed by heat and/or pressure and includes a combination of polyhydric solvents (1) having three or more hydroxyl groups; and (2) two hydroxyl groups, while providing a bar having a minimum amount of water (4-13% by weight) so that hydrolyzable bar components, such as antibacterial components, e.g., triclocarban (TCC), maintain more of their efficacy, for longer periods of time.
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Diez Ricardo
Garcia Maria Mercedes
Marshall Gerstein & Borun
Ogden Necholus
The Dial Corporation
LandOfFree
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