MXPA96004126A

MXPA96004126A - System for afei

Info

Publication number: MXPA96004126A
Application number: MXPA/A/1996/004126A
Authority: MX
Inventors: Yin Yuling; Michael Tseng Mingchih
Original assignee: The Gillette Company
Priority date: 1994-03-17
Filing date: 1996-09-17
Publication date: 1998-10-30

Abstract

The present invention relates to a shaving system of the wet shaving type, characterized in that it comprises a blade or blade element and a structure defining a portion that makes contact with the skin, externally, in proximity with the blade element. , the portion that makes contact with the skin includes an adjuvant shaving compound comprising a matrix of a water-insoluble polymer, a defective amount of a water-soluble polymer, skin lubricant, dispersed in the matrix, and a compatibilizing material which improves the compatibility of the water-soluble polymer with the water-insoluble polymer, to reduce the size of the domain of the water-soluble polymer within the matr

Description

SYSTEM FOR SHAVING FIELD OF THE INVENTION The present invention relates to a shaving system of the wet shaving type, more particularly to a shaving system with an improved shaving aid or adjuvant.

BACKGROUND OF THE INVENTION It is now well known that comfort in shaving can be improved by fixing to a shaving cartridge an auxiliary or shaving aid, also known as a lubricant strip, which continuously releases a shaving aid, typically a lubricant, during the process of shaving. See, for example, U.S. 4,170,821 and GB 2,024,082. The shaving adjuvant compound generally comprises a water-insoluble polymer matrix, typically polystyrene, and a water-soluble shaving aid, typically polyethylene oxide, which is separated by leaching the compound during shaving to improve the comfort of the shaving. shaved The addition of a small amount of a plasticizing agent such as propylene glycol for No. Ref. 23180 to improve the processing of injection molded adjuvants for shaving is described in U.S. Pat. No. 4,778,640. Unfortunately, conventional shaving adjuvant compounds suffer from the disadvantage that they release an insufficient amount of the shaving aid, particularly after the first three or four shaves where the shaving aid release can be lost by dripping in negligible amounts. Accordingly, recent efforts have been made to improve the adjuvants for shaving, to improve and prolong the release of the adjuvant for shaving. Such efforts have led to improved shaving adjuvant compounds which include the following: the incorporation of a low molecular weight release enhancing agent, such as polyethylene glycol, into the matrix, described in U.S. Pat. No. 5,113,585; the use of the ethylene-vinyl acetate copolymer as the matrix material, described in U.S. (U.S. Serial No. 07 / 865,594); and the incorporation of a swellable polymer with water such as Salsorb 84, a crosslinked polyacrylic, described in a U.S. (U.S. Serial No. 08 / 121,153). All of the patents or patent applications mentioned above are incorporated herein by reference.

Figure 1 is a perspective view of a shaving unit according to the invention; Figure 2 is a sectional view taken along line 2-2 of Figure 1; and Figure 3 is a perspective view of another shaving unit according to the invention.

DETAILED DESCRIPTION OF THE INVENTION The present invention is directed to a system for shaving the type of wet shaving, comprising a blade or blade element (one or more) and a structure which supports or holds the blade or blade element and which It has a portion that makes contact with the skin, external, in proximity with the element of the leaf or blade. The system for shaving can be a disposable razor cartridge adapted for coupling and for decoupling a sleeve from the shaving device or it can be a shaving head which is integral with a sleeve of the shaving device. , so that the whole machine or device for shaving is discarded as a unit when the blade or sheets lose the edge. The edge of the blade cooperates with the portion that contacts the skin to define the geometry of the shaving. The portion that makes contact with the skin includes an improved adjuvant shaving compound, which comprises a matrix of a water-insoluble polymer, an effective amount of a water-soluble polymer, skin lubricant, dispersed within the matrix, and a compatibilizing material that improves the compatibility of the water-soluble polymer with the water-insoluble polymer to reduce the size of the domain of the water-soluble polymer within the matrix. The improved shaving adjuvant compound provides a larger and more sustained release of the water soluble polymer during use, while maintaining good structural and mechanical integrity. The shaving unit 10 shown in Figures 1 and 2 includes the base or platform element 12 molded of high impact polystyrene including the integral coupling notch structure 14 for attachment to a shaving machine sleeve and a protective structure 16 defining a surface 18 that makes contact with the skin, front, which extends transversely. On the upper surface of the platform 12 there are placed the steel front blades or blades 20, which have a sharp edge 22, a subsequent steel blade 24 having a sharp edge 26, and an aluminum spacer element 28 which holds the blades or blades 20 and 24 in a spaced relationship. The lid element 30 is molded of high impact polystyrene and has the body portion 32 defining the surface 34 that contacts the skin, which extends transversely between the end walls 36 that project forward and have a front edge 38 which is positioned behind the edge 26 of the sheet. The integral rivet portions 40 extend downwardly from the transversely extending body portion 32 and pass through the holes in the sheets 20 and 24, the spacer 28, and the platform 12 to secure the lid 30, the sheets 20. , 24 and spacer 28 on platform 12. Attached adhesively to skin contacting surface 34, there is adjuvant shaving compound 42. Shaving unit 50 shown in Figure 3 is of the type shown in Jacobson , in the US patent No. 4,586,255, and includes the body 52 with the front portion 54 and the rear portion 56. Elastically secured in the body 52 are the protective element 58, the front sheet unit 60 and the back sheet unit 62. An adjuvant compound for the shaving in the shape of the elongated insert element 64 is frictionally fixed in the opening 66 of the rear portion 56. The adjuvant shaving compound comprises a matrix of a water insoluble polymer, an effective amount of a polymer water-soluble, skin lubricant, dispersed within the matrix a compatibilizing material that improves the compatibility of the water-soluble polymer with the water-insoluble polymer, to reduce the size of the water-soluble polymer domain within the matrix and improving the release of the water soluble polymer during its use. The adjuvant shaving compound may also optionally include water soluble, low molecular weight releasing agents, such as polyethylene glycol, release enhancing agents, which may be swollen with water, such as crosslinked polyacrylates, dyes, antioxidants. , preservatives, microbiocidal agents, beard softeners, astringents, depilators, medicinal agents, conditioning agents, cooling agents, etc. Suitable water-insoluble polymers which can be used for the matrix include polyethylene, polypropylene, polystyrene, butadiene-styrene copolymer (for example intermediate impact polystyrene and high impact polystyrene), polyacetal, acrylonitrile butadiene styrene copolymer, copolymer of ethylene vinyl acetate and mixtures such as a mixture of polypropylene / polystyrene. Preferably, the water-insoluble polymer comprises about 10 to 50, more preferably about 15 to 40%, and even more preferably about 20 to 30% by weight of the adjuvant compound of shaving. The most preferred water-insoluble polymer is polystyrene, preferably a general purpose polystyrene such as Dow STYRON (Dow Chemical Company) or a high impact polystyrene, such as Mobil 4324 (Mobil Corporation). The compound must contain a sufficient amount of the water insoluble polymer to provide adequate mechanical strength, both during its production and during its use. Suitable water-soluble olimers, skin lubricants, include polyethylene oxide, polyvinyl pyrrolidone, polyacrylamide, hydroxypropyl cellulose, polyvinyl imidazoline, and polyhydroxyethyl methacrylate. Preferably, the water soluble polymer comprises about 20 to 90%, more preferably about 40 to 80%, and even more preferably about 60 to 80% by weight of the adjuvant for shaving. The most preferred water-soluble polymers are polyethylene oxides generally known as P0LY0X (available from Union Carbide Corporation) or ALK0X (available from Meisei Chemical Works, Kyoto, Japan). These polyethylene oxides will preferably have molecular weights of from about 100,000 to 6 million, more preferably in the approximate form of 300,000 to 5 million. The most preferred polyethylene oxide comprises a mixture of about 40 to 80% polyethylene oxide having a molecular weight of about 5 million (eg POLYOX COAGULANT) and about 60 to 20% polyethylene oxide having an average molecular weight of approximately 300,000 (for example POLYOX WSR-N-750). The compatibilizer material can be any agent which has an affinity for both the water insoluble polymer and the water soluble polymer such that it improves the dispersibility of one polymer within the other and reduces the size of the soluble polymer domain in water inside the matrix. It also changes the phase behavior and the mechanical properties of the final polymer mixture, making it softer while retaining structural integrity. Without being bound by any theory, it is believed that the compatibilizing material acts on the polymer blends in a manner very similar to that of a surfactant in oil and water systems. In conventional shaving adjunct compounds, which mainly comprise a dispersion of a polyethylene oxide lubricant in a polystyrene matrix, the domain size of the polyethylene oxide phase is typically in the range of about 30-100 l. when a cross section of the compound is observed by SEM. The shaving adjuncting compounds containing a compatibilizing material according to the present invention generally have a water soluble polymer domain size of at least 50%, preferably at least 80%, smaller than that of similar compounds without compatibilizer. Typically, such compounds will have a domain size of the water soluble polymer below 10 [mu] m, preferably approximately 1 [mu] m or less. Since the water-soluble polymer is dispersed more evenly within the matrix due to the smaller domain size, the new shaving adjuvant compounds have completely different (generally softer) mechanical properties compared to conventional compounds and a more facilitated release. of the water-soluble polymer of the matrix during shaving. Indeed, the mechanical properties of the adjuvant compound for shaving can be adjusted by varying the levels of the compatibilizer in such a way that the complete compound (ie, both the matrix and the lubricant) is gradually removed by wear during use, exposing by the user is continually subjected to a fresh composite surface that provides excellent lubrication for numerous shaves. In general, the compatibilizer material will comprise approximately 0.5 to 15%, preferably in the form of about 1 to 10% and more preferably about 2 to 7% by weight of the adjuvant compound for shaving. Suitable compatibilizing materials for use in accordance with the present invention include the following: (a) Polyethylene oxide-polypropylene oxide copolymers, generally those having a molecular weight of from about 1000 to about 20,000, preferably in about 2000 to about about 10,000, and a ratio of ethylene oxide: propylene oxide from about 10:90 to about 80:20, preferably about 10:90 to about 50:50. These include, for example, the Poloxamer 181 (CHEMAL BP-261), Poloxamer 182 (CHEMAL BP-262), Poloxamer 183 (PLURONIC L-63), Poloxamer 184 (PLURONIC L-64), Poloxamer 188 (PLURONIC F-68). ), Poloxamer 212 (PLURONIC L-72), Poloxamer 217 (PLURONIC F-77), Poloxamer 231 (PLURONIC L-81), Poloxamer 282 (PLURONIC L-92), Poloxamer 402 (PLURONIC L-122) and Poloxamer 403 ( PLURONIC P-123). b) Polyethylene oxide-ethylene diamine polypropylene oxide copolymers such as Poloxamine 702 (TETRONIC 702), Poloxamine 901 (TETRONIC 901) and Poloxamine 1101 (TETRONIC 1101). (c) Polystyrene-polyethylene oxide copolymers. (d) Alkyl polyglycol ethers such as Steareth-10 and Laureth-23. (e) Fatty alkanolamides such as Lauramide MEA and Stearamide DEA. (f) Alkyl polyethyleneimines such as lauryl polyethyleneimine. (g) Anionic surfactants such as sodium lauryl sulfate and dodecylbenzenesulfonic acid. (h) Cationic surfactants such as alkyl trimethyl ammonium salts, for example dodecyltrimethylammonium chloride. The adjuvant shaving compound can be formed by extrusion, injection molding or in situ molding on a shaving machine lid. Extrusion is the preferred method and should normally be carried out in a controlled environment to minimize the absorption of moisture during manufacturing. The invention can be further illustrated by the following example in which all parts and percentages are by weight.

EXAMPLE The shaving adjuvant compositions similar to the insert element 64 shown in Figure 3 were manufactured from the mixtures indicated below by extruding the blends through a Haake System 90 extruder with a diameter of 1905 cm (3/4 inch). a barrel pressure of approximately 70.37 kg / cm2-126.67 kg / cm2 (1000-1800 lb / in.2) and a temperature of approximately 180-185 ° C and a die temperature of approximately 190 ° C. The extruded strip of the composite is cooled and cut to the appropriate lengths for fixing or securing in the openings 66 of the shaving units 50. In all of the mixtures listed below, the polystyrene is Dow STYR0N and the polyethylene oxide is a blend of POLYOX COAGULANT at 60% (MW 5 million) and POLYOX WSR-N-750 at 40% (MW 300,000).

Mix A % polystyrene 69% polyethylene oxide 10% polyethylene oxide-polypropylene oxide copolymer (CHEMAL BP-262) 1% white dye Mix B % Polystyrene Mix B (Cont ,,) 64% polyethylene oxide 3% crosslinked polyacrylic hydrogel (SALSORB 88) 5% polyethylene glycol (P.M. 4500) 7% polyethylene oxide copolymer - polypropylene oxide (CHEMAL BP-262) 1% white dye Mix C % polystyrene 63% polyethylene oxide 3% crosslinked polyacrylic hydrogel (SALSORB 88) 3% polyethylene glycol (PM 4500) 5% polyethylene oxide copolymer - polypropylene oxide (CHEMAL BP-262) 1% dye White Mix D % polystyrene 63% polyethylene oxide 3% crosslinked polyacrylic hydrogel (SALSORB 88) 3% polyethylene glycol (P.M. 4500) 5% dodecylbenzenesulfonic acid 1% white dye E mix % polystyrene irene 63% polyethylene oxide 3% crosslinked polyacrylic hydrogel (SALSORB 88) 3% polyethylene glycol (PM 4500) 5% polyethylene oxide-polypropylene oxide copolymer (PLURONIC P-77) 1% white coloring The adjuvant shaving compounds made from the blends identified above provided a larger release of polyethylene oxide over a longer period of time than conventional compounds made without any compatibilizer. When subjected to a leach / wear test with a wool felt which simulates the use, these adjuvant shaving compounds lose substantially more weight than similar strips without compatibilizer, while retaining good structural integrity.

It is noted that in relation to this date, the best method known by the applicant to carry out the aforementioned invention, is the conventional one for the manufacture of the objects to which it relates.

Having described the invention as above, property is claimed as contained in the following

Claims

R E I V I N D I C A C I O N S

1. A shaving system of the wet shaving type, characterized in that it comprises a blade or blade element and a structure defining a portion that makes contact with the skin, external, in proximity with the blade element, the portion that makes contact with the skin includes an adjuvant shaving compound comprising a matrix of a water-insoluble polymer, an effective amount of a water-soluble polymer, skin lubricant, dispersed in the matrix, and a compatibilizing material that improves the compatibility of the water-soluble polymer with the water-insoluble polymer, to reduce the size of the domain of the water-soluble polymer within the matrix.

2. The system for shaving according to claim 1, characterized in that the water soluble polymer comprises about 40% up to about 80% by weight of the adjuvant compound for shaving and is selected from the group consisting of polyethylene oxide, polyvinyl pyrrolidone , polyacrylamide, hydroxypropyl cellulose, polyvinyl imidazoline, and polyhydroxyethylmethacrylate.

3. The system for shaving according to claim 2, characterized in that the water-insoluble polymer comprises about 15% to about 40% by weight of the adjuvant compound for shaving and is selected from the group consisting of polyethylene, polypropylene, polystyrene, polystyrene butadiene copolymer, polyacetal, acrylonitrile butadiene styrene copolymer, and ethylene vinyl acetate copolymer.

4. The system for shaving according to claim 3, characterized in that the water-insoluble polymer comprises polystyrene and the water-soluble polymer comprises polyethylene oxide.

5. The system for shaving according to claim 4, characterized in that the compatibilizer material comprises a copolymer of polyethylene oxide-polypropylene oxide.

6. The system for shaving according to claim 5, characterized in that the copolymer of polyethylene oxide-polypropylene oxide has a molecular weight of about 1000 to about 20,000 and a proportion of ethylene oxide: propylene oxide of about 10: 90 up to about 80:20.

7. The system for shaving according to claim 6, characterized in that the water-soluble polymer comprises a mixture of polyethylene oxide having an average molecular weight of about 5 million and a polyethylene oxide having an average molecular weight of about 300,000.

8. The system for shaving according to claim 7, characterized in that the compatibilizer material comprises about 0.5% to about 15% by weight of the adjuvant compound for shaving.

9. The system for shaving according to claim 3, characterized in that the compatibilizer material comprises about 0.5% to about 15% by weight of the adjuvant compound for shaving and is selected from the group consisting of polyethylene oxide-polypropylene oxide copolymers , polyethylene oxide-polypropylene oxide copolymers of ethylene diamine, polystyrene-polyethylene oxide copolymers, alkyl polyglycol ethers, fatty alkanolamides, alkyl polyethylene imines, anionic surfactants, and cationic surfactants

10. The system for shaving according to claim 9, characterized in that the water-insoluble polymer comprises polystyrene and the water-soluble polymer comprises polyethylene oxide.

11. The system for shaving according to claim 1, characterized in that the adjuvant shaving compound comprises about 20% up to about 30% by weight of polystyrene, about 60% up to about 80% by weight of polyethylene oxide and about 1% up to about 10% by weight of the compatibilizer material.

12. The system for shaving according to claim 11, characterized in that the compatibilizer material is selected from the group consisting of copolymers of polyethylene oxide-polypropylene oxide, copolymers of polyethylene oxide-polypropylene oxide of ethylene diamine, polystyrene copolymers polyethylene, alkyl polyglycol ethers, fatty alkanolamides, alkyl polyethylene imines, anionic surfactants, and cationic surfactants.

13. The system for shaving according to claim 12, characterized in that the size of the domain of the polyethylene oxide within the matrix is less than 10 M.

14. The system for shaving according to claim 11, characterized in that the compatibilizer material comprises a copolymer of polyethylene oxide-polypropylene oxide having a molecular weight of from about 2000 to about 10,000 and a proportion of ethylene oxide: propylene oxide of approximately 10:90 to approximately 50:50.

15. The system for shaving according to claim 11, characterized in that the compatibilizer material is Poloxamer 182.

16. The system for shaving according to claim 11, characterized in that the compatibilizing material is dodecylbenzenesulfonic acid.

17. The system for shaving according to claim 11, characterized in that the compatibilizer material is the Poloxamer 217.