01.19.23
US Patent No. 11,554,087 B2 (Valerie Jean Bradford, Erte Xi, Mason, Alison Fiona Stephens, Ilaria Ambrogio); The Gillette Company LLC has been awarded a patent for a shaving aid that has a lubricant; and an antioxidant, wherein the antioxidant is represented by a general formula shown below.
High temperatures and/or shear such as that experienced during processing, or storage and use conditions such as high temperatures and/or exposure to water and/or oxygen, can limit the stability (i.e., in-process stability and long-term stability such as on-shelf stability) of the PEO. Further, the availability and/or effectiveness of stabilizing agents may be limited by the processing conditions (i.e. temperature, shear). By way of example, commercially available PEO products may include an antioxidant, such as butylated hydroxytoluene (BHT), to help maintain the stability of the PEO. Unfortunately, BHT and other known antioxidants suffer from one or more critical disadvantages when applied to shaving aids, and particularly to shaving aids that are heated and/or sheared during manufacture.
According to the patent, there is a need for an improved shaving aid that maintains the stability of the lubricant and avoids the known disadvantages of antioxidants.
Patent Background
This patent addresses the lubristrip that provides lubrication during shaving. The lubricant is most commonly composed, at least partly, of polyethylene oxide (PEO), a high molecular weight water soluble polymer. When activated by water during the shave cycle, the PEO deposits onto the skin, adding a layer of lubrication. PEO in water is a viscoelastic fluid, and the rheological properties are directly correlated to the coefficient of friction (CoF) of the fluid. As the molecular weight of the polymer increases, the viscoelastic fluid properties increase as well, which can lead to a lower CoF. Many currently marketed shaving aids use a matrix polymer material of high impact polystyrene (HIPS). The shaving aid is formed by co-extruding the matrix polymer (e.g. HIPS) and the PEO under set conditions. Importantly, the matrix (i.e., the HIPS) must be flowable during extrusion, which requires heating and/or shearing of the HIPS/PEO mixture.High temperatures and/or shear such as that experienced during processing, or storage and use conditions such as high temperatures and/or exposure to water and/or oxygen, can limit the stability (i.e., in-process stability and long-term stability such as on-shelf stability) of the PEO. Further, the availability and/or effectiveness of stabilizing agents may be limited by the processing conditions (i.e. temperature, shear). By way of example, commercially available PEO products may include an antioxidant, such as butylated hydroxytoluene (BHT), to help maintain the stability of the PEO. Unfortunately, BHT and other known antioxidants suffer from one or more critical disadvantages when applied to shaving aids, and particularly to shaving aids that are heated and/or sheared during manufacture.
According to the patent, there is a need for an improved shaving aid that maintains the stability of the lubricant and avoids the known disadvantages of antioxidants.