![]() Process for impregnating a plastic part
专利摘要:
The invention relates to a process for the impregnation of a finished piece of plastic material with an additive, comprising the following steps: dissolving the additive in a carrier liquid to form a solution; placing the plastic part at ambient pressure in an enclosure that can be pressurized; close the enclosure hermetically; impregnating the plastic part of the solution with a fluid under supercritical conditions or close to supercritical conditions in the chamber at a pressure of between 3 MPa and 6 MPa, at a temperature between 25 ° C and 65 ° C for a period of between 1 min and 15 min; releasing the pressure in the enclosure so that the carrier liquid diffuses out of the plastic part and trapping the additive inside the plastic part. The invention also relates to a plastic watch or jeweler component obtained by this method. 公开号:CH711883A2 申请号:CH01787/15 申请日:2015-12-08 公开日:2017-06-15 发明作者:François Nicolas 申请人:Swatch Group Res & Dev Ltd; IPC主号:
专利说明:
Description Field of the Invention [0001] The present invention relates to a method for impregnating a plastic part with an additive using a supercritical fluid. More specifically, the invention relates to a method of impregnating timepieces, as well as the parts obtained. BACKGROUND OF THE INVENTION [0002] Supercritical CO 2 has known commercial applications, such as the extensive cleaning of industrial parts or the extraction of caffeine from coffee. Many impregnation processes using a supercritical fluid have been patented and are known for their speed and lower costs. Carbon dioxide is often used for its low cost and very low risks when it is handled. Thus, it is known from EP 0 200 197 to impregnate thermoplastic polymer material parts of an odorant material with a fluid in or near supercritical conditions of temperature and pressure. In this document the impregnation is carried out at a pressure of 17 MPa and at a temperature between 25 ° C and 60 ° C for polymers such as polypropylene, polyethylene, ethylene-vinyl acetate copolymers (EVA) and ethylene acrylate copolymers of ethylene. It is also known from EP 0 683 804 a process for impregnating a polymeric substrate with an additive by means of a supercritical fluid. In this document the impregnation is carried out at a pressure of preferably between 7 MPa and 30 MPa and at a temperature between 30 ° C and 60 ° C for polymers such as polyolefins, polyamides, polyurethanes, silicones, albumin, lactic and glycolic acid polymers, and combinations thereof. [0006] Thus, impregnation processes using supercritical CO 2 have already been described in the prior art. However none of them describes a quick process, easy to implement and usable regardless of the type of polymeric materials to be impregnated. Indeed, the processes described are relatively long, two hours or more, and the pressure used is very high, between 7 MPa and 30 MPa. According to the findings of the inventor these processes in particular do not allow the impregnation of timepieces made from polymeric materials while maintaining a satisfactory quality of these parts for the watch industry ( fine dimensional tolerances, surface quality and color quality), and more specifically for copolymer materials such as methylmethacrylate-acrylonitrile-butadiene-styrene (M-ABS) and thermoplastic polyurethane (TPU) materials. Indeed, after experiments the inventor has found that the pressure and temperature parameters used in the prior art to impregnate certain materials led to many defects in the materials, or significant deformation or foaming of the part, which is particularly troublesome for the manufacture of plastic timepieces for example. SUMMARY OF THE INVENTION [0009] The object of the invention is in particular to overcome the various drawbacks of these known techniques for an application in the watchmaking or jeweler world. More specifically, an object of the invention is to provide a method for quickly impregnating plastic finished parts with an additive which would be too sensitive to temperature or shear to be added during a test. conventional mixing or molding process. Such a method also allows to gain flexibility for production. With such a method can be easily set up by model molding a single reference of white or transparent without additive. This reference is then colored or functionalized (that is, provided with a new property) by the process according to the needs of the market. Another object of the invention is to provide a method for reducing the time and cost of manufacturing plastic watches. These objectives, as well as others which will appear more clearly later, are achieved according to the invention with the aid of an impregnation process in the heart of a finished piece of plastic with at least one additive. According to the invention, the process comprises the following steps: dissolving at least one additive in a carrier liquid to form a solution; placing the plastic part at ambient pressure in a chamber that can be pressurized; - hermetically seal the enclosure; impregnating the plastic part of the solution with a fluid under supercritical conditions or close to supercritical conditions in the chamber at a pressure of between 3 MPa and 6 MPa, at a temperature of between 25 ° C. and 65 ° C. ° C for a period preferably between 1 min and 15 min, and even more preferably between 1 min and 10 min; releasing the pressure in the enclosure so that the carrier liquid diffuses outside the plastic part and traps at least a part of the additive inside the plastic part. In accordance with other advantageous variants of the process according to the invention: the supercritical fluid is carbon dioxide or CO 2; the material is chosen from thermoplastic polyurethanes, polyamides, methyl acrylonitrile butadiene styrene or polymethyl methacrylates; the support liquid is chosen from hexane, isopropanol and d-limonene; the additive is chosen from dyes, anti-odor agents, fragrances, and active cosmetic additives; the plastic is impregnated with a combination of at least two additives; the impregnation is carried out under constant flow; the method comprises a step of washing the plastic part after releasing the pressure in the chamber to eliminate the residues; the washing step is carried out with clear water and with a brush or the like. The invention also relates to all timepieces and jewelry made of copolymer material obtained by the process according to the invention. BRIEF DESCRIPTION OF THE DRAWINGS Other features and advantages of the invention will appear more clearly on reading the following description of a particular embodiment of the invention, given as a simple illustrative and nonlimiting example, and appended figures, among which: FIG. 1 is a photo of plastic timepieces illustrating the results of a first test; fig. 2 is a photo of plastic timepieces illustrating the results of a second test; fig. 3 is a photograph of a section of a timepiece made of plastic illustrating the results of a third test; fig. 4 is a photo of a plastic timepiece illustrating the results of a fourth test; fig. 5 is a photograph of a timepiece of plastic material illustrating the results of a fifth test; fig. 6 is a photo of a plastic timepiece illustrating the results of a sixth test; fig. 7 is a photo of plastic timepieces illustrating the results of a seventh test, FIG. 8 is a photograph of a plastic timepiece illustrating the results of an eighth test; Fig. 9 is a photo of a plastic timepiece illustrating the results of a ninth test. DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS [0016] The invention relates to a process for impregnating a plastic finished piece with at least one additive. According to the invention, the process comprises the following steps: dissolving at least one additive in a carrier liquid to form a solution; placing the plastic part at ambient pressure in a chamber that can be pressurized; - hermetically seal the enclosure; impregnating the plastic part of the solution with a fluid under supercritical conditions or close to supercritical conditions in the chamber at a pressure of between 3 MPa and 6 MPa, at a temperature of between 25 ° C. and 65 ° C. ° C for a period preferably between 1 min and 15 min, and even more preferably between 1 min and 10 min; releasing the pressure in the enclosure so that the carrier liquid diffuses outside the plastic part and trapping the at least one additive inside the plastic part. By fluid under supercritical conditions, or supercritical fluid is meant in the sense of the present invention a fluid used at a temperature and a pressure greater than its critical value so as to place it in its supercritical state and thus disperse it more easily in a material, such as polymers, copolymers or elastomers. By fluid close to supercritical conditions is meant in the sense of the present invention a fluid used at a pressure slightly lower than its critical value so as to obtain a liquid vapor mixture. By impregnation in the heart means penetration of the additive into the thickness of the material so as to have a color resistant to wear of the workpiece. Finished part means any machined part derived for example from an injection operation, extrusion, thermoforming, molding, and ready to be assembled. There are many supercritical fluids to impregnate materials, and preferably use a non-reactive and non-toxic supercritical fluid such as CO 2 on the one hand to avoid altering certain additives and, on the other hand, to treat materials intended to be in contact with the skin and avoid skin reactions. The CO 2 also limits the costs of the impregnation operation by its temperature and its pressure to reach the supercritical state. According to the invention, the pressure is between 3 MPa and 6 MPa, and the temperature is between 25 ° C and 65 ° C. The inventor has found that beyond these parameters many defects were present in the material of the plastic part according to the polymers used, and in particular for the following thermoplastics which are commonly used to make watches in plastic: thermoplastic polyurethanes, polyamides, methyl acrylonitrile butadiene styrene, polymethylmethacrylates. For the purposes of the present invention, the term "additive" means any organic or inorganic additive having a density of less than 3 and a particle size of less than 50 microns, whether soluble or poorly soluble in a liquid medium. This process is therefore not limited to additives soluble in a liquid medium. According to one embodiment of the invention, the additive may be a dye or a pigment (organic or inorganic). By way of example, mention may be made of azo dyes. The additive may also be an active substance of the cosmetic, there may be mentioned by way of example hyaluronic acid or ceramides. The additive may also be an anti-odor agent such as zinc pyrithium or a fragrance such as essential oils for example. According to the invention, the plastic material may be impregnated with a combination of additives. For example, the plastic may be impregnated with a dye and an odor control agent. For the purposes of the present invention, the term "carrier liquid" means a co-solvent such as hexane, isopropanol or d-limonene. According to a preferred embodiment of the invention, the process is carried out under constant flow of supercritical CO 2, that is to say that all the reagents are simultaneously brought into contact and the supercritical CO 2 is injected during a fixed term. For example, in the fourth step of the invention, supercritical CO 2 is injected for a predetermined time into the chamber receiving the mixture obtained in the first step and the plastic part to be impregnated. According to one embodiment of the invention, the material to be impregnated is selected from the family of acrylates or polyurethanes. The first step of the process according to the invention allows for the intimate mixing of the additive and the co-solvent before the diffusion step. Intimate mixing is understood to mean a mixture in which the additive and the co-solvent are found uniformly distributed (either a dispersion or a dissolution) within the mixture obtained. The first step thus allows to optimize the impregnation and to obtain better results. The mixture obtained at the end of the first step is therefore preferably a liquid mixture so as to reduce the impregnation time during the fourth step. The first three steps of the process are carried out at ambient temperature and pressure. The fourth step of the method according to the invention allows to impregnate the material with the additive. In a particular embodiment, the fourth step is performed in a hermetically sealed enclosure. The mixture obtained during the first step is introduced into an enclosure with the plastic part to be impregnated, before closing the enclosure hermetically. During the third and fourth stage of the process, the chamber is closed, pressurized and brought to the desired temperature for the time required for the CO2 then in close-su-percritical form to allow the impregnation of the piece plastic material by the additive to the desired content. The longer the treatment, the more the plastic part will be impregnated with however a saturation phenomenon when the porosities of the plastic part are filled. During the fourth step, the plastic part to be impregnated remains in solid form. In a particular embodiment of the invention, the temperature during the fourth step is between 25 and 65 ° G. Such temperatures make it possible to avoid deterioration of the plastic material during impregnation. In another particular embodiment, the pressure during the fourth step is between 3 MPa and 6 MPa, for example equal to 4 MPa. Such pressures have the advantage of being able to use inexpensive infrastructures compared to the state of the art. In a particular embodiment, the contact time during the fourth step is preferably between one minute and fifteen minutes, and more preferably between one minute and ten minutes, for example equal to five minutes. Such a treatment time makes it possible to rapidly impregnate the plastic parts and thus to process a larger quantity of parts. Depending on the desired coloration, the impregnation time or the pressure can be adjusted to obtain a lighter or darker coloration. The fifth step retrieves and isolate the impregnated plastic part obtained after the fourth step and optionally to separate the additive that has not impregnated the plastic part. For this, the chamber used is depressurized and gradually cooled. It is then maintained at ambient pressure for 2 minutes. According to the invention, the method may comprise a step of washing the plastic part, after releasing the pressure in the chamber, to remove residues remaining on the surface such as excess dye for example. According to a preferred embodiment of the invention, the washing step is preferably carried out with clean water and with a brush or the like. One could also use low pressure water jets or pass the impregnated parts in a bath. The agitation of the bath can also be provided and adapted to the necessary cleaning. The plastic part impregnated with the additive can be used in the manufacture of timepieces or jewelery, and more particularly plastic timepieces or jewelery. In particular, the method can be used in the manufacture of watch cases, bracelets, glasses, crowns, dials, pushers, mirrors, buckles, or any plastic part forming part of a watch or of a jewel. The present invention further relates to a timepiece or jewelery made of plastic, in solid form, and impregnated with an additive by the method according to the present invention as described above. Thus, watch components or plastic jeweler already molded or machined can be impregnated by this process while retaining the initial properties of the component, including dimensions and mechanical characteristics. The following examples are given for information only and not limiting. The coloring and impregnation treatments were carried out on watch cases injected into the indicated materials. [0045] Table 1: Table 2: In these two tables, the same additives were used, namely an azo dye, chromophthal®, and an aromatic hydrocarbon, anthraquinone (oracet®). A single co-solvent is used, hexane, and three plastics have been tested, Acrylonitrile Butadiene Styrene, Polyurethane Thermoplastic (Polyether Base) and Methylmethacrylate Butadiene Styrene. In FIG. 1 corresponding to the tests 1 and 2, one can observe a complete deformation of the part due to a foaming as well as a non-uniform coloring. These same results are observed in FIG. 2 for tests 3 and 4; deformations are visible on the parts. In FIG. 3 corresponding to the test 5, it is observed that the piece is colored only on the surface and on a very shallow depth; the dye has not penetrated deep enough to provide a correct color and perennial over time despite wear. In FIG. 4, corresponding to the test 7, there is a bleaching of the piece after impregnation, which is not acceptable. In FIG. 5 corresponding to the test 8, there is a significant foaming of the piece after impregnation which renders it unusable. FIG. 6 illustrates the result of the test 9, a slight is observed on the surface of the room following the impregnation due to the migration of waxes used in the plastic MABS as an implementing agent, however the coloring is satisfactory. FIG. 7 illustrates colored pieces according to the conditions of the test 10. A homogeneous coloration of good quality is observed without any deformation of the plastic parts. Nevertheless a very slight white veil is visible on the surface, indicating the beginning of migration of certain plastic additives.
权利要求:
Claims (10) [1] FIG. 8 illustrates two butadiene styrene methacrylate parts corresponding to the test 11. A homogeneous coloration is observed without deformation and without bleaching. FIG. 9 illustrates two pieces of thermoplastic polyurethane corresponding to the test 12. A homogeneous coloration is observed without deformation and without bleaching. Of course, the present invention is not limited to the example shown and is susceptible to various variations and modifications that will occur to those skilled in the art. claims 1. A method of impregnating a plastic finished piece with at least one additive, characterized in that it comprises the following steps: dissolving the at least one additive in a liquid carrier to form a solution; placing the plastic part at ambient pressure in a chamber that can be pressurized; - hermetically seal the enclosure; impregnating the plastic part of the solution with a fluid under supercritical conditions or close to supercritical conditions in the enclosure at a pressure of between 3 MPa and 6 MPa, at a temperature between 25 ° C. and 65 ° C. for a duration preferably between 1 min and 15 min, and even more preferably between 1 min and 10 min; releasing the pressure in the enclosure so that the carrier liquid diffuses outside the plastic part and trapping the at least one additive inside the plastic part. [2] The process of claim 1, wherein the supercritical fluid is carbon dioxide. [3] 3. Method according to claims 1 or 2, wherein the material is selected from polyurethane thermoplastics, polyamides, methyl acrylonitrile butadiene styrene, polymethyl methacrylates. [4] 4. Method according to one of claims 1 to 3, wherein the carrier liquid is selected from hexane, isopropanol or d-limonene. [5] 5. Method according to one of claims 1 to 4, wherein the additive is selected from dyestuffs, anti-odor agents, fragrances, cosmetic active additives. [6] 6. The method of claim 5, wherein the plastic is impregnated with a combination of at least two additives. [7] 7. Method according to one of claims 1 to 6, wherein the impregnation is carried out under constant flow. [8] 8. Method according to one of claims 1 to 7, comprising a step of washing the plastic part to remove residues. [9] 9. The method of claim 8, wherein the washing step is performed with clean water and with a brush. [10] Plastic watch or jeweler component obtained by the process according to claims 1 to 9.
类似技术:
公开号 | 公开日 | 专利标题 EP0496687B1|1995-05-31|Composition for manufacturing of a stopper and its manufacturing method CH707581A1|2014-08-15|Timepiece, and method of manufacturing such a part. CH711883A2|2017-06-15|Process for impregnating a plastic part EP3387049B1|2021-08-04|Method for impregnating a plastic part CH715086B1|2021-12-15|Composition of a lubricant for watchmaking, treatment liquid for lubricating a watch, and watch. EP2811938B1|2018-07-25|Metastable polymer compositons for devices for injection of ophthalmic implants EP0919003B1|2002-06-19|Method for incorporating additives into an ophthalmic article by means of a fluid in supercritical state FR3001874A1|2014-08-15|METHOD FOR MANUFACTURING AT LEAST ONE COSMETIC PRODUCT BLOCK, INSTALLATION AND TETINE THEREFOR EP1209004A2|2002-05-29|Ink-following plunger for ballpoint pen and method for making the same CH713671B1|2021-02-15|Lubricated watch component. FR3034779A1|2016-10-14|CLEANING COMPOSITION EP3935200A1|2022-01-12|Austenitic stainless steel powder composition without nickel and part made by sintering by means of said powder FR2907220A1|2008-04-18|PROCESS FOR COLORING CELLS FR3101076A1|2021-03-26|PROCESS FOR TREATMENT OF A GLASS CONTAINING LEAD ALLOWING TO LIMIT MIGRATION IN SOLUTION OF THE LEAD CONTAINED IN THIS GLASS FR2788268A1|2000-07-13|PASTE CERAMIC COMPOSITION FOR SUPPLYING A RAPID PROTOTYPING MACHINE AND MANUFACTURING METHOD EP3741247A1|2020-11-25|Piece of jewellery made from natural elastomer material CH715999A2|2020-09-30|Piece of jewelry in composite elastomer material. CH715061A2|2019-12-13|Timepiece or jewelry or fine gold alloy jewelry. CH713072A2|2018-04-30|Process for epilamizing an element of a timepiece or jewelery. CH714349A2|2019-05-31|Sintering process of austenitic stainless steel FR2792073A1|2000-10-13|PROCESS FOR DETERMINING THE FAULTY COLORFULNESS OF A TRANSPARENT MOLDED ARTICLE OF POLYMER MATERIAL AND ARTICLE OBTAINED CH711884A2|2017-06-15|Comfortable elastomeric material. FR3020814A1|2015-11-13|PROCESS FOR PROCESSING OBJECTS INTO A POLYMERIC COMPOSITION COMPRISING A VINYL CHLORIDE POLYMER CH716213A2|2020-11-30|Piece of jewelry in natural elastomer material. WO2000045198A1|2000-08-03|Method for colouring flexible hydrophilic contact lenses
同族专利:
公开号 | 公开日 CH711883B1|2020-07-15|
引用文献:
公开号 | 申请日 | 公开日 | 申请人 | 专利标题 WO2020016589A1|2018-07-18|2020-01-23|Michael John Flaherty|Polymer composition|
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申请号 | 申请日 | 专利标题 CH01787/15A|CH711883B1|2015-12-08|2015-12-08|Process of impregnating a plastic part.|CH01787/15A| CH711883B1|2015-12-08|2015-12-08|Process of impregnating a plastic part.| 相关专利
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