SYMBOL KNOB FOR A VEHICLE AND MANUFACTURING METHOD OF THE SAME

Abstract

Symbol button for a vehicle, showing: a button body; a button surface section that is positioned on an upper section of the button body; a symbol print section that is positioned on the button surface section; an anti-plating section positioned on a lower section of the button body; and a metal plating layer positioned on the outside of a button, excluding the symbol printing section and the anti-plating section, wherein the symbol printing section contains a polymer composition comprising a polyvinyl chloride resin (PVC resin), a solvent and an antistatic agent, and Based on 100 wt.% of the polymer composition, the solvent content is in the range of 3 to 7 wt.%.

Description

CROSS-REFERENCE TO RELATED REGISTRATION

[0001] This application claims the priority and benefits of the Korean patent application filed on December 29, 2017, with the Korean Intellectual Property Office, published as KR 10 2019 081 858 A, the entire contents of which are incorporated herein by reference. TECHNICAL AREA

[0002] The present disclosure relates to a symbol button for a vehicle and a manufacturing process thereof. BACKGROUND

[0003] A vehicle has various control buttons for operating different vehicle functions. These buttons typically serve a dual purpose: operating or handling vehicle components such as an audio system, air conditioning, and windows, while also providing an aesthetic function by allowing visual inspection and tactile feedback.

[0004] For vehicle switch knobs, metallic aluminium, metallic paint or lacquer, a matte coating, ion plating and an in-mould film or in-mould foil are generally used for decoration.

[0005] Ion plating and metallic paint are used to give the switch knobs a metallic texture, but since there is a difference between feeling them when seeing them with the naked eye and feeling them when touching them, there is a disadvantage in terms of marketability.

[0006] Therefore, a method for plating a metal onto a button surface made of a polymer material was proposed.

[0007] Currently, there are two typical methods for plating the metal.

[0008] One method is a partial plating process using multiple injections or a multiple injection partial plating process. Fig. Figure 1 is a schematic view of the multiple injection partial plating process.

[0009] In this process, different materials are injected into a plating area and a non-plating area for partial plating and bonded together. A polycarbonate material is injected first to form the shape of a desired symbol (character or pattern) for the non-plating area, and an ABS or PC+ABS material, which is metal-platable, is injected onto the surface of the non-plating area.

[0010] In this case, molten ABS or PC+ABS is bonded to a PC material. Then, during wet chrome plating or wet chrome plating (chemical plating + electroplating), a plating layer is formed only on the ABS or PC+ABS surface, and the PC material becomes a non-plating area.

[0011] Since a new mold is required each time the symbol is changed, mold investment increases according to this procedure, and a plating error occurs if an injection failure occurs due to insufficient flowability during injection molding.

[0012] A second method is a method for partial plating using laser cutting. Fig. Figure 2 is a schematic representation of a process for partial plating using laser cutting.

[0013] A plastic plating process involves a sequential process in which conductivity is imparted to a non-conductive injection material by chemical plating and then a metal layer is formed by electroplating, and this applies equally to the plastic plating described above.

[0014] The process of partial plating using laser cutting is a method for forming a symbol, a pattern, etc. on a product surface by partially removing a chemical plating layer using laser cutting after chemical plating and then performing electroplating.

[0015] However, conventional partial plating using laser cutting, which involves a sequential process, has problems such as the formation of a plating layer in the process of removing a product from a plating fixture after chemical plating, laser cutting the product and then remounting it on the plating fixture to perform electroplating on it.

[0016] Consequently, a metal plating process is needed that can more effectively form symbols on plastics.

[0017] The above information disclosed in this background section is intended solely to improve the understanding of the background of the invention and may therefore contain information that does not constitute the prior art which is already known to someone with ordinary technical skills in this country.

[0018] US 2003 / 0034241A1 discloses a method for manufacturing a keycap for a push-button switch, wherein a base layer of an insulating resin that can be plated with metal, an electroless plated layer formed on the surface of the base layer, and, if required, a polymer coating layer are applied to the surface of a keycap body. Alternatively, an electroplated layer formed by electroplating can be applied to the electroless plated layer. This allows a coating layer to be formed directly and easily on the insulating resin, resulting in a keycap for a push-button switch with, among other things, a metallic feel. SUMMARY

[0019] The present disclosure was made in an effort to provide a symbolic vehicle button and a manufacturing process thereof which can provide a metallic, cool tactile feel and improve its marketability by applying a surface treatment in the form of wet chrome plating to buttons which a driver frequently touches with his hand.

[0020] Furthermore, the present disclosure was made in an effort to provide a symbol button for a vehicle and a manufacturing process thereof, which can form a sign / symbol to give daytime visibility to a surface of a switch button and can provide illumination to the sign / symbol for nighttime visibility.

[0021] The present invention provides a symbol button for a vehicle comprising: a button body; a button surface section positioned on an upper section of the button body; a symbol print section positioned on the button surface section; an anti-plating section positioned on a lower section of the button body; and a metal plating layer positioned on the outside of a button, with the exception of the symbol print section and the anti-plating section.

[0022] The symbol print section can be made of a material that allows light to pass through.

[0023] The anti-plating section can be printed with the same material as the symbol printing section.

[0024] An anti-plating film can be applied to the anti-plating section.

[0025] The button body and the button surface section can be made of the same material, formed by a single injection molding process.

[0026] The button body and the button surface section can be made of polymer materials suitable for metal plating.

[0027] The symbol printing section and the anti-plating section can consist of polymer materials onto which no metal is plated.

[0028] The symbol printing section is produced using a polymer composition containing a polyvinyl chloride resin (PVC resin), a solvent and an antistatic agent, and based on 100 wt% of the polymer composition, the solvent content is in the range of 3 to 7 wt%.

[0029] According to a further aspect, the present invention provides a manufacturing method for a symbol button for a vehicle, comprising: manufacturing a button by simple injection molding with a polymer material onto which a metal is plated; printing a symbol onto a surface section of the button with a polymer material onto which no metal is plated; forming an anti-plating section on a lower section of a body section of the button; and forming a metal plating layer outside the button.

[0030] Forming the anti-plating section on the lower part of the button's body section may involve printing a polymer material, which is not plated with metal, onto the lower part of the body section.

[0031] Forming the anti-plating section on the lower part of the body section of the button may include forming a strip to prevent metal plating on the lower part of the body section.

[0032] The polymer material, onto which no metal is plated, is produced according to the invention using a polymer composition containing a PVC resin, a solvent and an antistatic agent, and based on 100 wt.% of the polymer composition, the solvent content is in the range of 3 to 7 wt.%.

[0033] According to the embodiments of the present disclosure, when different characters / symbols are applied at the same position, an additional mold for changing a character / symbol is unnecessary in contrast to conventional partial plating using double injection, and it is possible to simplify a process compared to partial plating using laser cutting after chemical plating. BRIEF DESCRIPTION OF THE DRAWINGS Fig. Figure 1 illustrates a schematic representation of a conventional method for partial plating using multiple injections. Fig. Figure 2 illustrates a schematic representation of a conventional method for partial cladding using laser cutting. The Fig. Figures 3A-3E illustrate a manufacturing process of a button according to an exemplary embodiment of the present disclosure. Fig. Figure 4 illustrates photographs of the respective manufacturing processes of a button according to an exemplary embodiment of the present disclosure. Fig. Section 5 illustrates criteria for identifying a printing error. Fig. Section 6 illustrates criteria for determining chemical resistance. Fig. Figure 7 illustrates photographs of buttons manufactured using a strip to shield them before plating. DETAILED DESCRIPTION OF THE EXECUTION FORMS

[0034] Exemplary embodiments of the present disclosure are described in detail below. However, these exemplary embodiments are provided as examples, and the present disclosure is not limited to them but is defined within the scope of the claims, which will be described below.

[0035] An exemplary embodiment of the present disclosure relates to a process for preventing the formation of a plating layer on a character / symbol section by carrying out a wet chrome plating process after printing a printing ink on which no plating layer is formed onto a product surface for the partial plating of a conventional switch knob.

[0036] In this case, the printing ink on which the plating layer is not formed should have characteristics that allow light to pass through for illumination and that do not erode, wear away, or flake off due to the plating of chemicals during the plating process.

[0037] First, the button is produced using a single-injection process with a polymer material suitable for metal plating. A shielding print layer is then applied to prevent the plating layer from forming on the injected material. When the printed injection-molded part undergoes the wet chrome plating process, a plating layer forms only on the unprinted area of ​​a transparent or semi-transparent injection material; no plating layer forms on the printed area or on the opaque material.

[0038] In this case, a sign / symbol is formed in the printed area where no plating layer is applied, allowing a driver to recognize the sign / symbol with the naked eye. Additionally, the printed area provides illumination at night, ensuring the sign / symbol is visible.

[0039] In the exemplary embodiment of the present disclosure, a plastic injection process, a process for printing a symbol (character / symbol), a process for forming a layer for shielding a bottom surface, and a wet plating process are carried out sequentially. Fig. Figures 3A-3E illustrate a flow chart of a manufacturing process for a button according to an exemplary embodiment of the present disclosure.

[0040] In this case, an injection material is used to clad an end section in the plastic injection molding process. A transparent cladding material can be acrylonitrile butadiene styrene (ABS), polycarbonate (PC) + ABS, PC, etc., which possesses cladding properties and light transmittance.

[0041] Then the printing process is carried out to prevent plating.

[0042] A polyvinyl chloride resin (PVC resin)-based printing ink is used in the printing process to prevent plating, and the printing process to prevent plating can be carried out by pad printing, screen printing, laser printing, and the like.

[0043] The printing ink can contain a PVC resin with a molecular weight of 15,000 to 25,000 Mw. The PVC resin exhibits excellent chemical resistance to sulfuric acid, chromic acid, and hydrochloric acid during the plating process and possesses a characteristic that prevents metal plating.

[0044] After the printing process, the printing ink can be cured by drying at a temperature of 60 to 80°C for 0.5 to 2.0 hours.

[0045] Then a layer is formed to shield against plating on one underside of the button.

[0046] The shielding layer on the underside of the button, applied before plating, prevents the plating layer from forming by blocking the flow of electricity to the back surface of the product. When the button is injection-molded using a plating material and undergoes a plating process, a metal layer forms on the back surface of the material, thus blocking light transmission.

[0047] Consequently, a shielding layer is formed on the lower section of the button to prevent the formation of a plating layer on the back surface of the injected material.

[0048] The shielding layer, applied before plating, prevents electrical conduction between the button and the lighting structure, such as a polychlorinated biphenyl (PCB) button and a light-emitting diode (LED). This prevents product damage and malfunctions when exposed to external electrical influences. Furthermore, it prevents light from escaping from one side of the button when a backlight is applied.

[0049] Fig. 3A illustrates a method for forming a layer to shield prior to plating by immersion in a printing ink printed to a symbol and using pad printing or the like.

[0050] When the printing process is used, the plating process is carried out after a drying process at 80°C for 30 minutes.

[0051] Fig.Figure 3B illustrates a process in which a film that does not react with plating chemicals is applied to a side surface of the product and then a plating process is carried out.

[0052] The film can be a PVC film, a thermoplastic polyurethane film (TPU film), or a polypropylene film (PP film).

[0053] The film must have characteristics in which there is no deformation and elongation and no decrease in adhesion strength under a plating process condition of 80°C or less.

[0054] For example, the film can be made of 3M Scotchcal™ Automotive Grade with high adhesive strength, which is a PVC material.

[0055] Then a wet chrome plating process can be carried out, as in the Fig. 3C-3E shown.

[0056] The wet chrome plating process is primarily divided into etching, chemical plating, and electroplating processes.

[0057] The etching process (pretreatment process) serves to dissolve a butadiene component of the ABS and PC+ABS surfaces using chromic acid / sulfuric acid and to form an anchor hole in them, thereby imparting plating adhesion.

[0058] The chemical plating process is a process for forming a thin, chemical nickel plating layer of, for example, 1 µm, so that a surface of a non-conductive plastic injection material exhibits conductivity.

[0059] The electroplating process is a process for sequentially forming a layer of copper, nickel and chromium by applying electricity to the surface of the product.

[0060] In the case of the pressure layer to prevent plating, the PVC material is not dissolved in the chromic acid / sulfuric acid, consequently no chemical nickel plating layer is formed, so that no plating layer is formed in the electroplating process.

[0061] An exemplary embodiment of the present disclosure and a comparative example are described below. However, the following exemplary embodiments are for illustrative purposes only, and the scope of the disclosure is not limited to them. Exemplary embodiments: Selection of an injection material for plating

[0062] One condition required for a transparent injection material for plating is the ability to exhibit plating adhesion strength and illumination.

[0063] ABS, PC+ABS, and PC materials are available. The thickness of these materials in a single product ranges from 1.0 to 1.5 mm.

[0064] If the material thickness is 1.0 mm or less, its flowability is insufficient, consequently reducing its formability during injection molding. If the material thickness is 2.0 mm or more, the overall light transmittance is 5 or less and the haze (or haze) is 95 or higher, thus reducing light transmittance and making it difficult to apply as an illumination component. Selection of the printing ink resin

[0065] To implement printing to prevent the formation of a plating layer on a character / symbol section, PVC, poly(methyl methacrylate) (PMMA) and polyurethane (PU) resins were evaluated.

[0066] The PMMA or PU resin was dissolved in chemicals such as sulfuric acid, hydrochloric acid, and chromic acid during the plating process, consequently removing the printed layer or forming the plating layer on its surface, even if the printed layer was still present. In the case of PVC resin, due to its high chemical resistance, the printed layer was not removed even after the chrome plating process, and consequently, the plating layer was not formed.

[0067] In the case of the PVC resin, regardless of its molecular weight, no plating layer was formed after wet chrome plating. The molecular weight of the PVC resin can be between 20,000 and 30,000 Mw.

[0068] If the molecular weight of the PVC resin is less than 20,000 Mw, the printability is reduced due to printing spread, and it is difficult to ensure a printed thickness after printing.

[0069] If the molecular weight of the PVC resin exceeds 30,000 Mw, the resin's sliding properties are reduced to such an extent that the ink surface becomes rough after printing, and the image sharpness is diminished due to printing dispersion, making reprinting difficult. Furthermore, the plating uniformity is reduced to such an extent that the character / symbol is inconsistent.

[0070] In printing, it is possible to create characters and symbols using pad printing, screen printing and laser printing processes.

[0071] An organic solvent is used to ensure the printability of the PVC resin. This solvent serves to adjust the viscosity and disperse the resin. In this case, the organic solvent can be acetonitrile, isophorone, or xylene. The concentration of the organic solvent can be approximately 3 to 7% by weight of the resin.

[0072] If the solvent content is less than 3% by weight, the viscosity of the printing ink solution can reach up to 5000 cP, thus reducing its dispersibility. Furthermore, if the viscosity of the printing ink is high, it will not be transferred to an injection product during pad printing but will remain on the pad (silicone rubber), thus reducing its printability.

[0073] If the solvent content is more than 7 wt%, the viscosity of the printing solution is as low as 2000 cP or less, so that the printing scatter becomes severe and it becomes difficult to ensure a coating film thickness after printing and drying.

[0074] A curing agent is used to enhance durability properties, such as chemical resistance, heat resistance, and adhesion strength, by curing with the PVC resin. The curing agent may contain an isocyanate-based curing agent, HDI, MDI, TDI, or IPDI, and may be applied at a concentration of 20 parts by weight.

[0075] If the curing agent content is less than 10 parts by weight, chemical resistance is reduced due to insufficient curing of the coating film. Conversely, if the curing agent content is more than 20 parts by weight, durability is improved, but printability is reduced and the pot life of the printing ink is shortened due to exposure to air. Furthermore, excessive curing with the resin leads to cracking of the coating film after lightfastness evaluation.

[0076] Fig. Figure 4 illustrates photographs of the respective manufacturing processes of a button according to an exemplary embodiment of the present disclosure. [Table 1] #1 #2 #3 #3 #4 #5 Resin type PVC-1 (molecular weight: 10,000) PVC (molecular weight: 20,000) PVC (molecular weight: 30,000) PVC (molecular weight: 40,000) PMMA (molecular weight: 10,000 or less) PU (Acrylurethane) Printability △ ⊚ ⊚ △ ⊚ ⊚ Non-plating performance ⊚ ⊚ ⊚ ⊚ × × Light transmission capacity ⊚ ⊚ ⊚ ⊚ ⊚ ⊚ [Table 2] #6 #7 #8 #9 #10 #11 #12 #13 Resin type PVC (molecular weight: 20,000) PVC (molecular weight: 20,000) PVC (molecular weight: 20,000) PVC (molecular weight: 20,000) PVC (molecular weight: 20,000) PVC (molecular weight: 20,000) PVC (molecular weight: 20,000) PVC (molecular weight: 20,000) resin 30 50 70 90 90 90 90 90 solvent 70 47 30 7 7 7 3 10 Antistatic agent 3 3 3 3 7 In total 100% by weight 100% by weight 100% by weight 100% by weight 100% by weight 100% by weight 100% by weight 100% by weight Curing agent 10 weight parts 20 weight parts 10 weight parts 30 weight parts 20 weight parts 20 weight parts Typographical error ◯(Print) ⊚ ◯(Print) ⊚ ⊚ ◯(not) ⊚(not) ◯(Print) - dispersion) - dispersion) printed 'short usage time' printed 'viscosity increase ) - dispersion) Chemical resistance (ethanol / gasoline) × ◯ × ⊚ ◯ ⊚ ⊚ ⊚

[0077] Fig. Section 5 illustrates criteria for identifying a printing error. Fig.Section 6 illustrates criteria for determining chemical resistance. Selection of the shielding printing ink

[0078] As a performance characteristic required for a shielding strip, no chemical plating layer should be formed in the shielding strip during the plating process, and the shielding strip should exhibit insulating properties during the electroplating process and not react with chemicals during the plating process.

[0079] The PVC strip was Scotchcal™ High Performance Automotive Grade from 3M.

[0080] Fig. Figure 7 illustrates photographs of the buttons, which are illustrated using a strip to shield them before plating. [Table 3] PE film PVC film PET film Shielding performance Dissatisfaction arises when plating chemicals are melted during a plating process. No abnormalities Dissatisfaction: During a plating process, chemicals penetrate between injection products due to a shrinkage event.

[0081] According to the method of the present disclosure, which is a method for replacing the partial plating by means of a double injection applied to conventional buttons by forming characters and symbols on buttons by a method of partial plating without double injection, it is possible to provide the user with a metallic appearance and a cool touch sensation.

[0082] According to the present disclosure, by forming a printing layer capable of preventing plating and light transmission on a surface of a plating material capable of transmitting light, by a pad printing or screen printing process and by carrying out a wet chrome plating process, it is possible to form a metal layer only in the remaining area with the exception of a character / symbol printing layer and to allow light to pass through only in a character / symbol area, thereby providing a character / symbol image during the day and an illuminated image at night.

[0083] According to the embodiment of the present disclosure, compared to conventional double-injection partial plating, it is possible to provide a relatively simple structure, and it is possible to change a character / symbol by changing a print pattern without an additional mold when the character / symbol is changed. Furthermore, to reduce costs, it is possible to switch from double injection to single injection to form a non-plating area.

Claims

[1] Symbol button for a vehicle, showing: a button body; a button surface section that is positioned on an upper section of the button body; a symbol print section that is positioned on the button surface section; an anti-plating section positioned on a lower section of the button body; and a metal plating layer positioned on the outside of a button, excluding the symbol printing section and the anti-plating section, wherein the symbol printing section contains a polymer composition comprising a polyvinyl chloride resin (PVC resin), a solvent and an antistatic agent, and Based on 100 wt.% of the polymer composition, the solvent content is in the range of 3 to 7 wt.%. [2] Symbol button for the vehicle according to claim 1, wherein the symbol print section contains a material through which light is transmitted. [3] Symbol button for the vehicle according to claim 1, wherein the anti-plating section is printed with the same material as the symbol printing section. [4] Symbol button for the vehicle according to claim 1, wherein an anti-plating film is applied to the anti-plating section. [5] Symbol button for the vehicle according to claim 1, wherein the button body and the button surface section are made of the same material. [6] Symbol button for the vehicle according to claim 5, wherein the button body and the button surface section are made of polymer materials. [7] Symbol button for the vehicle according to claim 1, wherein the symbol printing section and the anti-plating section consist of polymer materials onto which no metal is plated. [8] Manufacturing process of a symbol button for a vehicle comprising the following steps: Manufacturing a button by simple injection molding with a polymer material onto which a metal is plated; Printing a symbol onto a surface section of the button using a polymer material that is not plated with metal; Forming an anti-plating section on a lower section of the body of the button; and Forming a metal plating layer outside the button, wherein the polymer material, onto which no metal is plated, a polymer composition containing a PVC resin, a solvent and an antistatic agent, and Based on 100 wt.% of the polymer composition, the solvent content is in the range of 3 to 7 wt.%. [9] Manufacturing method according to claim 8, wherein the step to form the antiplating section includes printing the polymer material, onto which no metal is plated, onto the lower section of the body section. [10] Manufacturing method according to claim 8, wherein the step to form the anti-plating section includes forming a strip to prevent metal plating on the lower section of the body section.

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