FR2863707A1 - Measuring procedure for resistance to transfer by cosmetic product uses support to apply product to sheet of paper with pressure and relative movement - Google Patents

Abstract

The procedure consists of applying a predetermined quantity of the cosmetic product to one surface of a support, especially of a foam material, and then applying the support's surface to a sheet, especially of paper at a predetermined pressure and a set duration. While maintaining the pressure a relative movement is created between the sheet and support parallel to the surface of the sheet and at a constant speed, and a transfer index for the product is determined from the quantity of the product remaining on the support and the length of the trace on the sheet.

Description

The present invention relates to the in vitro evaluation of resistance to

  transfer of a cosmetic product, in particular but not exclusively from a foundation.

  To test the transfer or the holding of a foundation, it is usually carried out in vivo evaluations.

  These in vivo tests are binding to implement. In addition, a toxicological visa must be obtained before applying any new composition, which further complicates the implementation of the test.

  There is a need to benefit from an in vitro test for evaluating the transfer resistance of a cosmetic product, and capable of replacing the aforementioned in vivo tests.

  US Pat. No. 6,340,466 discloses a test for evaluating in vitro the non-transfer properties of a cosmetic product. This test uses in particular a support constituted by a food envelope to be rehydrated in a predetermined manner and on which a film of the product is applied. After transfer by rotation and pressure of the film on a support, the reflectance of the transferred film is measured on the latter support. This test, relatively complicated to implement, is not entirely satisfactory.

  Also, is it an object of the invention to provide a method for performing an in vitro evaluation of the transfer resistance of a cosmetic product, especially a foundation, and which solves in whole or in part the problems evoked with reference to known methods.

  Still other objects will appear in the following detailed description.

  According to the invention, these objects are achieved by carrying out a method for measuring the transfer resistance of a cosmetic product, in particular a foundation, consisting of: i) on a first face of a support, in particular foam, deposit a determined amount of said product; ii) applying the first face of said support to a sheet, in particular paper, under specified pressure and time conditions; iii) while maintaining a pressure, cause a relative movement of translation between the sheet and the support, substantially in the plane of the sheet and at a substantially constant speed; and iv) determining a transfer index of said cosmetic product: a. depending on the amount of residual product on said first face and; b. in the event of a residual quantity not zero and less than said determined quantity of product, as a function of the length of the drag formed by the product transferred onto the sheet.

  Advantageously, the sheet is moved relative to the support, the latter being fixed.

  The amount of residual product on the support can be assessed visually. Alternatively, it can be weighed before and after the displacement.

  By "residual non-zero amount" is meant an amount greater than 10% of the amount determined, and preferably greater than 5%, and more preferably greater than 0%.

  In the case where the amount of residual product on the support is substantially zero, the product transfer can be qualified as "total".

  Conversely, in the case where the quantity of product transferred to the sheet is substantially zero, that is to say in the case where the amount of residual product on the support is substantially equal to the quantity of product determined, the transfer can be called "null".

  Between these two extreme cases, the level of transfer of the product is partial. The value of the transfer index is then directly related to the length of the product drag on the sheet.

  Thus, the transfer index is in a range framed by a first extreme value assigned when the amount of residual product on the support is substantially zero and by a second extreme value assigned when the amount of residual product on the support is substantially equal. to said determined quantity of product.

  Similarly, and according to a particular embodiment, the product transfer index is equal to the first extreme value when the quantity of residual product is non-zero and substantially less than said determined product quantity and the product drag is extends over a length greater than a maximum length.

  As an indication, the "note" or "transfer index" can be on a scale ranging from 0 to 5.

  According to a first embodiment, the first face of the support is applied to said sheet when the latter is dry.

  Alternatively, the first face of the support is applied to said sheet after having applied to the latter a specific amount of a liquid, including sebum, sweat or water. The nature of the liquid is chosen according to the normal conditions of use of the product and corresponds to one or more liquids with which the cosmetic product is likely to be brought into contact during its use.

  It is understood that the products, depending on their nature, may be required to be tested either dry, or in the presence of a single liquid, or successively in the presence of a plurality of liquids.

  A second face of the support, opposite to the first, may be covered with an adhesive surface. This adhesive surface allows the fixing of the support to the tool for applying the determined pressure.

  The determined pressure can be applied by means of a dynamometer.

  The pressure determined can be between 100 g / cm 2 and 2 kg / cm 2, and preferably between 200 g / cm 2 and 2 kg / cm 2.

  The determined duration can be between 1 s and 20 s, and preferably between 2 s and 10 s.

  Preferably, the sheet is a photo quality paper sheet. The support may be of foam, in particular of neoprene.

  Advantageously, the sheet is moved at a speed of between 1 cm / s and 15 cm / s, and preferably between 2 cm / s and 10 cmis.

  The cosmetic product can be deposited on the first face in the following manner: i) a crown of a predetermined thickness is glued to the first face; ii) the product is deposited inside the crown; iii) the deposition of product thus produced is leveled so that its thickness is substantially identical to that of the crown; iv) the cosmetic product is allowed to dry; and v) the crown is removed.

  Advantageously, the ring is made of a sheet material with a thickness of between 50 μm and 400 μm, and preferably between 150 μm and 300 μm.

  When the cosmetic product is colored, the length of the drag is visually determined preferably. Alternatively, the measurement can be automated by means of a colorimetric measurement, in particular by means of a camera.

  When the cosmetic product is not colored, the method may further comprise a step of revealing so as to make it visible on the sheet. Such an uncolored product may for example be a skin care product or a product for protection against the harmful effects of the sun.

  The revelation step may consist in incorporating into the product a compound able to re-emit in the visible all or part of a radiation to which it is exposed, in particular UV radiation. For example, the radiation emitted by a Wood lamp is used.

  Advantageously, the sheet is subdivided into a plurality of zones, moving successively under the support during the displacement in translation of the sheet, the number of zones on all or part of which extends the product drag being representative of the behavior of the product cosmetic. As an indication, the number of zones can be between 2 and 10, and preferably between 4 and 7.

  Advantageously, the cosmetic product is a foundation, a blush, an eye shadow or a blush.

  The invention consists, apart from the arrangements described above, in a certain number of other arrangements which will be explained below, with reference to a nonlimiting exemplary embodiment, described in detail in the following part. .

  A carrier (square 40 mm X 40 mm) consisting of a layer of adhesive neoprene foam on one of its faces (sold under the name RE70X40 212B from the company JOINT TECHNIQUE LYONNAIS IND) is prepared.

  On the non-adhesive side of the support is fixed an adhesive crown having an internal diameter of 24 mm and whose thickness is about 250 pm. The composition is applied to the interior of the crown, which is scoured with a glass slide to obtain a deposit of the composition of about 250 am thickness, then the crown is removed and allowed to dry for 20 hours at room temperature. oven at 37 degrees C.

  The support is then adhered by its adhesive face to a tip of a diameter of 27 mm fixed on a press (MANUAL STATIF SV-1 from IMADA Co LTD) equipped with a dynamometer (DPS-5R from IMADA Co LTD).

  On a photo-quality coated paper (reference EPSON SO41061 of 102g / m2), a strip 4 cm wide and 21 cm long is drawn and in this strip 5 boxes are drawn each having a length of 4.2 cm according to the longitudinal axis of the band. The paper is placed on the base of the press.

  In the center of the first cell is deposited a drop of 10 μl of artificial sebum having the following composition: - triolein 29% - oleic acid 28.5% - oleyl oleate 18.5% - squalene 14% - cholesterol 7% palmitate Then the support (containing the composition sample) is pressed onto the first box of the paper web at a force of about 4 kg exerted for 5 seconds. Then the paper is moved rectilinearly and evenly along the entire length of the strip so that the support is in contact with the entire length of the strip. The speed of movement of the strip is of the order of 10 cms.

  The product drag deposited on the paper web is then visually observed. A score of 0 to 5 is given in increments of 0.5 depending on the number of boxes, from the first to the fifth, traversed in whole or in part by the possible trail of product.

  Note 5 is attributed to the observation, after having made the relative displacement between the paper and the support, there remains on the support substantially no product. In the latter case, the transfer can be qualified as total.

  Note 5 is also assigned when the drag of product extends beyond the fifth box, regardless of the amount of product remaining on the support.

  The score 0 is assigned in the case where no product on the carrier is transferred to the paper web. No visible trace can be observed on the sheet. The transfer can be qualified as null.

  By convention, the line between box n and box n + 1 is part of box n.

  The table below illustrates how the other notes are assigned based on the location on boxes 1-5 where product drag stops. For these notes, there remains a greater or lesser amount of product on the support. The transfer is partial. Note

  N of the box where product drag stops More than half of the box At most half of the box In the foregoing detailed description, reference has been made to preferred embodiments of the invention. invention. It is obvious that variations can be made without departing from the spirit of the invention as claimed hereinafter. p% f

Claims (19)

  1. A method for measuring the transfer resistance of a cosmetic product, in particular a foundation consisting of: i) on a first face of a support, in particular of foam, depositing a determined quantity of said cosmetic product; ii) applying the first face of said support to a sheet, in particular paper, under specified pressure and time conditions; iii) while maintaining a pressure, cause a relative translation movement between the sheet and the support, parallel to the plane of the sheet and at a substantially constant speed; and iv) determining a transfer index of said cosmetic product: a. depending on the amount of residual product on said first face and; b. in the event of a non-zero residual quantity and less than said determined quantity, as a function of the length of the drag formed by the product transferred onto the sheet.   2. Method according to claim 1 characterized in that the first face of the support is applied to said sheet when the latter is dry.   3. A method according to claim 1 characterized in that the first face of the support is applied to said sheet after applying on the latter a specific amount of a liquid, including sebum, sweat or water.   4. - Process according to any one of claims 1 to 3, characterized in that a second face of the support, opposite to the first, is covered with an adhesive surface.   5. Method according to any one of the preceding claims characterized in that the determined pressure is applied by means of a dynamometer.   6. Method according to any one of claims 1 to 5 characterized in that said determined pressure is between 100 g / cm2 and 2 kglcm2, and preferably between 200 g / cm2 and 2 kg / cm2.   7. Method according to any one of the preceding claims, characterized in that said determined duration is between 1s and 20s, and preferably between 2s and 10s.   8. A method according to any one of the preceding claims characterized in that said sheet is a photo quality paper sheet.   9. Process according to any one of the preceding claims, characterized in that the support is made of foam, in particular neoprene.   10. Method according to any one of claims 1 to 9 characterized in that the sheet is moved at a speed between 1 cm / s and 15 cm / s, and preferably between 2 cm / s and 10 cm / s .   11. Process according to any one of the preceding claims, characterized in that the cosmetic product is deposited on the first face in the following manner: i) a crown of a determined thickness is adhered to the first face; ii) the product is deposited inside the crown; iii) the deposition of product thus produced is leveled so that its thickness is substantially identical to that of the crown; iv) the cosmetic product is allowed to dry; and v) the crown is removed.   12. The method of claim 11 characterized in that the ring is made of a sheet material with a thickness between 50 pm and 400 pm, and preferably between 150 pm and 300 pm.   13. Method according to any one of the preceding claims characterized in that the cosmetic product is colored, the length of the drag being determined visually.   14. Method according to any one of claims 1 to 12 characterized in that the cosmetic product is not colored, the method further comprising a revelation step so as to make it visible on the sheet.   15. Method according to the preceding claim characterized in that the step of developing comprises incorporating into the product a compound capable of reemitting in the visible all or part of a radiation to which it is exposed, in particular UV radiation.   16. Method according to any one of the preceding claims, characterized in that the sheet is subdivided into a plurality of zones, moving successively under the support during the displacement in translation of the sheet, the number of zones on all or part of which extends the product drag being representative of the transfer resistance of the cosmetic product.   17. Method according to any one of the preceding claims, characterized in that the transfer index is in a range framed by a first extreme value assigned when the amount of residual product on the support is substantially zero and by a second extreme value. allocated when the amount of residual product on the support is substantially equal to said determined quantity of product.   18. The method of claim 17 characterized in that the transfer index is equal to the first extreme value when the amount of residual product is non-zero and less than said determined product quantity and the product drag extends over a length greater than a maximum length.   19. Method according to any one of the preceding claims, characterized in that the cosmetic product is a foundation, a blush or eyeshadow, or a blush.