Multi-layer coating for a vehicle interior trim part and associated part and associated manufacturing methods

Abstract

Multi-layer coating for a vehicle interior trim part and associated part and associated manufacturing methods The invention relates to a multi-layer coating (14) for a vehicle interior trim part (10) comprising a sheet (15) comprising at least: - an inner layer (16), and - a covering skin (18) applied to a first side (160) of the inner layer (16), the covering skin (18) being selected from a polyvinyl chloride skin and a thermoplastic polyolefin skin. The multi-layer coating (14) further comprises an outer finishing layer (30) comprising an active agent, the active agent being selected from quaternary ammonium salts and mixtures thereof. Figure for abstract: Figure 1

Description

Title of the invention: Multi-layer coating for a vehicle interior trim part and associated part and associated manufacturing methods

[0001] The present invention relates to a multi-layer coating for an interior vehicle trim part, more particularly in the automotive field.

[0002] The invention also relates to a method of manufacturing such a coating, as well as a vehicle interior part comprising such a coating and a method of manufacturing the same.

[0003] In order to prevent the spread of disease in a pandemic context such as that of the Sars-CoV-2 virus associated with the Covid-19 disease, or to combat episodes of influenza, gastroenteritis, bacterial proliferation, etc., and more generally to improve hygiene inside a vehicle, it may be necessary to regularly disinfect the interior elements of the vehicle, in particular the external surfaces of seats, door panels and / or dashboards with which passengers of the vehicle frequently come into contact.

[0004] This is particularly necessary in the case of shared vehicles, such as rental vehicles, chauffeur-driven vehicles or taxis. A large number of different passengers are likely to use such vehicles.

[0005] Sanitizing or disinfecting surfaces in a vehicle interior has traditionally been performed manually, by applying an external disinfectant, such as spraying a disinfectant aerosol onto or wiping surfaces with a disinfectant-saturated disposable cloth. Such techniques, however, are expensive, time-consuming, prone to human error, and often not environmentally friendly.

[0006] Another option is to apply UV-C light to the surfaces to inactivate the virus. UV-C lamps are then installed temporarily or permanently in the vehicle. Although this option is effective, it has several disadvantages. Multiple applications may be required, during which no one may be inside the vehicle. In addition, the lamps do not deliver a uniform dose of UV-C energy to all surfaces to be disinfected and some hidden areas are not disinfected. In addition, high radiation doses for surfaces close to the lamps can lead to accelerated degradation (i.e., aging) of said surfaces.

[0007] One of the aims of the invention is to overcome the aforementioned drawbacks by proposing a solution for the disinfection of a vehicle interior part that is effective in treating surfaces, autonomous and safe, and easy to integrate.

[0008] For this purpose, the invention relates to a multi-layer coating for a vehicle interior trim part comprising a sheet comprising at least:

[0009] - an inner layer, and

[0010] - a covering skin applied to a first side of the inner layer, the covering skin being chosen between a polyvinyl chloride skin and a thermoplastic polyolefin skin,

[0011] the multi-layer coating further comprising an outer topcoat comprising an active agent, the active agent being selected from quaternary ammonium salts and mixtures thereof.

[0012] The inventors found that the active agent acts as a trap for bacteria and viruses and prevents them from attaching to a living cell.

[0013] The coating according to the invention may comprise one or more of the following characteristics, taken alone or in any technically feasible combination:

[0014] - the active agent is chosen between dimethyl chloride- octadecyl[3-(trimethoxysilyl)-propyl] ammonium and 3-(trimethoxysilyl)-propyldimethylocadecyl ammonium chloride and mixtures thereof;

[0015] - the sheet further comprises a lacquer applied to the covering skin, the active agent being included in said lacquer;

[0016] - the sheet further comprises an adhesive layer applied to a second side of the inner layer, opposite the first side of the inner layer.

[0017] The invention also relates to a method for manufacturing a multi-layer coating of the aforementioned type, comprising the following steps:

[0018] - preparation of a sheet comprising at least the inner layer and the skin of re covering; and

[0019] - applying to the sheet a coating composition comprising the agent active to obtain the external finishing layer.

[0020] The method according to the invention may comprise one or more of the following characteristics, taken alone or in any technically feasible combination:

[0021] - the coating composition is sprayed directly onto the skin of the re covering or on a lacquer deposited on the covering skin;

[0022] - the coating composition comprises, by weight, from 50 to 86% of a coating agent binding agent, the binding agent comprising a matrix polymer selected from polyols and a mixture thereof; from 10 to 30% of the active agent; and from 4 to 10% of a curing agent;

[0023] - the method comprises a step of depositing a lacquer on the covering skin, the lacquer comprising the active agent.

[0024] The invention also relates to a vehicle interior trim part comprising:

[0025] - a substrate made of a polymer material, preferably polypropylene;

[0026] - a multi-layer coating of the aforementioned type, the covering skin being applied to a surface of the substrate.

[0027] The invention also relates to a method of manufacturing a vehicle interior part of the aforementioned type, comprising the following steps:

[0028] - the provision of the substrate; and

[0029] - applying the multi-layer coating of the aforementioned type to a surface of the substrate, the multi-layer coating preferably being applied to the substrate by heat coating, more preferably by vacuum heat coating.

[0030] The invention will be better understood from the following description, given solely by way of example and made with reference to the appended drawing in which:

[0031] [Fig-1] [Fig.l] is a schematic sectional view of an interior part of vehicle according to the invention, the part comprising a multi-layer coating.

[0032] An interior trim part 10 of a vehicle according to the invention is shown in [Fig.l].

[0033] The vehicle interior trim part 10 is intended to be arranged inside a vehicle, in particular inside a motor vehicle.

[0034] The vehicle interior trim part 10 is for example an interior trim part, such as a dashboard, a dashboard insert, a center console or a door panel.

[0035] The vehicle interior trim part 10 comprises a substrate 12 made of a polymer material, preferably a thermoplastic material, and a multilayer coating 14 disposed on an external surface 120 of the substrate 12.

[0036] The substrate 12 gives the interior trim part 10 its shape and also provides some of its mechanical properties, in particular its rigidity. For example, the rigid substrate 12 has a three-dimensional shape.

[0037] The substrate 12 is made of a substantially rigid material, such as a plastic or composite material. As a result, the rigid substrate 12 has a stable shape with substantially stable dimensions under normal conditions of use, i.e. when normal stresses during use of the vehicle are applied to the substrate.

[0038] The substrate 12 is preferably made of a polyolefin material, more preferably polypropylene.

[0039] For example, the substrate 12 is an injected thermoplastic substrate, more preferably an injected polypropylene substrate.

[0040] The multilayer coating 14 covers at least a portion of the substrate 12, advantageously the entire substrate 12. Preferably, the coating 14 covers the surfaces of the substrate 12 that are accessible and that a passenger can touch once the interior part 10 is in place. installed in the vehicle.

[0041] Preferably, the coating 14 has a thickness eM of between 0.3 mm and 2 mm.

[0042] The multi-layer coating 14 contains an active agent having antiviral and antibacterial properties.

[0043] In the context of the invention, the term "active agent" refers to compounds having antiviral and / or antibacterial activity.

[0044] According to the invention, the active agent is a cationic antiviral agent.

[0045] More particularly, the active agent is chosen from quaternary ammonium salts and their mixture.

[0046] The quaternary ammonium salts have the general formula RiR2R3R4N+X, with X representing a halogen atom, such as F, Cl, Br, or I and Ri, R2, R3 and R4, which may be the same or different, independently represent a saturated or unsaturated, linear or branched or cyclic hydrocarbon chain, optionally substituted by one or more functional groups, and optionally comprising one or more heteroatoms.

[0047] For example, Rb R2, R3 and R4 can be selected from CH3, CH3(CH2)X with x ranging from 1 to 25, and (CH2)3Si(OCH3)3.

[0048] Preferably, Ri corresponds to CH3, R2 corresponds to CH3(CH2)i7, R3 corresponds to CH3, R4 corresponds to (CH2)3Si(OCH3)3.

[0049] Preferably, RB R2, R3 and R4 independently represent an aromatic or aliphatic hydrocarbon chain.

[0050] Preferably, said hydrocarbon chain is a C1 to C100 hydrocarbon chain, more preferably a C1 to C25 hydrocarbon chain.

[0051] Specific examples of quaternary ammonium salts that are suitable for use in the present invention include, without limitation, tetraalkylammonium salts, trialkylammonium salts, dialkyldiarylammonium salts, alkyltriarylammonium salts, tetraarylammonium salts, cyclic ammonium salts, and dicyclic ammonium salts.

[0052] Preferably, the active agent is selected from dimethyl-octadecyl[3-(trimethoxysilyl)-propyl] ammonium chloride and 3-(trimethoxysilyl)-propyldimethylocadecyl ammonium chloride and mixtures thereof.

[0053] Without wishing to be bound by any particular theory, the inventors assume that the quaternary ammonium salts attract viruses, which have a negative charge, and hold them on the coating 14, thus inactivating them. The viruses can no longer attach to a living cell and finally die.

[0054] [Fig.l] illustrates a schematic view of a multi-layer coating according to a first embodiment.

[0055] The multi-layer coating 14 comprises a sheet 15 comprising at least one inner layer 16 and a covering skin 18 applied to a first side 160 of the inner layer 16.

[0056] Preferably, as illustrated in [Fig.l], the sheet 15 further comprises an adhesive layer 22 applied to a second side 162 of the inner layer 16, opposite the first side 160 of the inner layer 16.

[0057] Preferably, as illustrated in [Fig.l], the sheet 15 may also comprise a lacquer 24 applied to the covering skin 18 and / or a primer (not shown) sandwiched between the inner layer 16 and the adhesive layer 22.

[0058] Preferably, the active agent is included in said lacquer 24.

[0059] The inner layer 16 has a thickness ei6 of between 0.5 mm and 6 mm, measured between its first side 160 and its second side 162.

[0060] The inner layer 16 is for example made of a compressible foam material to provide a cushioned feel to the multi-layer covering 14 and the interior trim piece 10. Examples of foam materials for the inner layer 16 include a polyolefin-based foam, a polyurethane foam, an acrylic-based foam, or a polyester foam. Other non-foam materials such as felt or textile fibers may also be used.

[0061] Advantageously, the internal layer 16 is a polypropylene-based foam.

[0062] The covering skin 18 covers the first side 160 of the internal layer 16.

[0063] The covering skin 18 covers at least a portion of the first side of the inner layer 16, advantageously the entire first side 160 of the inner layer 16.

[0064] The covering skin 18 has a thickness ei8 which can be between 0.01 mm and 1 mm.

[0065] The cover skin 18 is generally decorative and may be constructed from a pliable material such as those typically used in vehicle interiors, including thermoplastic polyolefins (TPO), thermoplastic elastomers (TPE), polyvinyl chloride (PVC), polyurethane (PUR or PU), leather, leatherette, or other types.

[0066] Advantageously, the skin 18 is chosen between a polyvinyl chloride (PVC) skin and a thermoplastic polyolefin (TPO) skin.

[0067] The adhesive layer 22 is suitable for fixing the multi-layer coating 14 to the substrate 12.

[0068] Advantageously, the adhesive layer 22 is made of a hot-melt adhesive. Hot-melt adhesives are based on thermoplastic polymers. In their application, they must be heated to a temperature in the range of about 50°C above the softening temperature of the thermoplastic-based polymer. As a result of the heating, the viscosity of the thermoplastic-based polymer moplastic is reduced in such a way that it wets the joining surfaces to be bonded and eventually penetrates into pores and depressions in the joining surfaces.

[0069] For example, the hot melt adhesive is isocyanate-terminated prepolymers consisting of highly crystalline and / or amorphous polyester polyols and pure methylene diphenyl diisocyanate (MDI).

[0070] According to a particular embodiment, the multilayer coating 14 comprises a primer (not shown) on which the adhesive layer 22 is applied.

[0071] Alternatively, when the multi-layer coating 14 does not include a primer, the adhesive layer 22 is directly applied to the second side 162 of the inner layer 16.

[0072] The primer facilitates the application of the adhesive layer 22 to the surface of the inner layer 16. The primer is, for example, a polyolefin.

[0073] Advantageously, as visible in [Fig.l], a lacquer 24 is arranged on an external surface 180 of the covering skin 18. This lacquer 24 makes it possible to protect the covering skin 18.

[0074] The lacquer 24 is for example based on a translucent thermosetting material such as a polyurethane.

[0075] According to a first embodiment, the multilayer coating 14 further comprises an external finishing layer 30 comprising the active agent. Said external finishing layer is either formed on the external surface of the covering skin 18 or on the external surface of the lacquer 24 when it is present.

[0076] The external finishing layer 30 is obtained by applying a coating composition to the sheet 15, more particularly to the covering skin 18 or the lacquer 24.

[0077] Said coating composition is water-based and comprises, by weight:

[0078] (a) from 50 to 86% of a binding agent;

[0079] (b) from 10 to 30% of the active agent; and

[0080] (c) from 4 to 10% of a curing agent.

[0081] Preferably, the coating composition comprises from 60 to 85%, more preferably from 65 to 80%, even more preferably from 74 to 78% by weight of the bonding agent.

[0082] By "binding agent" is meant in the context of the invention compounds capable of crosslinking the active ingredient with the substrate and / or of holding all the materials together by means of chemical reactions, to form a cohesive coating.

[0083] The binding agent is a polymer matrix solution comprising at least one polyol.

[0084] For example, the bonding agent is chosen from polyurethanes and polysiloxanes, preferably between polyoxyethylene alkyl ether and polysiloxane fluoropolymer and mixtures thereof.

[0085] Preferably, the coating composition comprises from 10 to 30%, more preferably from 14 to 20%, even more preferably from 15 to 19% by weight of the active agent.

[0086] Preferably, the coating composition comprises from 4 to 10%, more preferably from 5 to 9% and even more preferably an amount equal to 7% by weight of the curing agent.

[0087] By "curing agent" is meant in the context of the invention compounds capable of increasing the viscosity of a liquid without substantially changing their other properties or compounds capable of producing the curing of the coating due to the catalysis of the composition.

[0088] The curing agent is for example chosen from the group of aliphatic isocyanates.

[0089] For example, the curing agent is selected from hydrophilic aliphatic polyisocyanate and hexamethylene diisocyanate and mixtures thereof.

[0090] Optionally, the coating composition also comprises pigments and / or additives. Pigments may be used to color the topcoat to a desired color and enhance its appearance. Additives may increase resistance to UV, chemicals, abrasion, and / or moisture.

[0091] Preferably, the external finishing layer 30 has a thickness of between 5 μm and 30 μm.

[0092] Preferably, the external finishing layer 30 has a surface mass of between 2 g / m2 and 8 g / m2.

[0093] A method for preparing a coating composition as defined above will now be described. Said method comprises mixing the components of the coating composition.

[0094] A first solution comprising the binding agent is first prepared and stirred at room temperature.

[0095] The active agent and the curing agent are then added to the first solution, preferably by stirring the solution.

[0096] In a preferred embodiment, the active agent is first introduced into the first solution in the form of a solution comprising the active agent and a first curing agent. A second curing agent, the same as or different from the first curing agent, is then introduced.

[0097] For example, the first curing agent is selected from (3-chloropropyl)trimethoxysilane and 3-(trimethoxysilyl)-propylamine and the second curing agent is selected from hydrophilic aliphatic polyisocyanate and dii- hexamethylene isocyanate.

[0098] The composition is then stirred for 2 to 10 minutes, preferably for 5 minutes.

[0099] The coating composition obtained preferably has a density of between 0.75 g / cm3 and 1.25 g / cm3, preferably between 0.90 g / cm3 and 1.10 g / cm3.

[0100] The coating composition preferably has a solid volume value of between 10% and 30%, preferably between 20% and 25%.

[0101] These parameters allow easier deposition of the coating deposit on the surface to be coated.

[0102] The coating composition obtained can be maintained at least for 6 hours at 20°C and at least for 4 h at 27°C.

[0103] A method of manufacturing an interior trim part 10 of a vehicle according to the first embodiment as defined above will now be described.

[0104] First, the substrate 12 is provided. For example, the substrate 12 is obtained by melting pellets of polymeric material, preferably polypropylene, and molding the molten material in a molding apparatus to obtain a substrate having the desired shape.

[0105] Then, the sheet 15 is provided and the coating composition is then deposited on the surface of the sheet 15, more particularly on the surface of the covering skin 18 or the lacquer 24 when it is present.

[0106] The coating composition may be applied by spraying, vapor deposition, roller application such as roller coating.

[0107] Advantageously, the coating composition is sprayed onto the surface of the covering skin 18 or the lacquer 24 when it is present.

[0108] Next, the multilayer coating 14 is applied to the outer surface 120 of the substrate 12.

[0109] Preferably, the substrate 12 is heat-coated. That is, the coating 14 is heat-formed onto the substrate 12. Heat-coating includes the combined use of heat and mechanical force to apply the coating 14 to the substrate 12.

[0110] The coating 14 is heated to a particular temperature to activate the adhesive layer 22 and forced against the surface of the substrate 12 to be coated in a thermoforming tool.

[0111] Advantageously, the heat coating process is a vacuum heat coating process in which reduced pressure is provided to one and / or the other of the tool surfaces. This type of process can help provide sharper or more defined features in the outer surface of the coating 14.

[0112] During heat coating, the substrate 12 and the coating 14 are preferably heated to a heating temperature ranging from 160°C to 240°C, more preferably preferably about 200°C. The heating time is preferably between 20 seconds and 120 seconds, more preferably about 60 seconds.

[0113] Optionally, the manufacturing process may further comprise additional steps such as edge folding, cutting and / or the step of manually raising the edges.

[0114] The vehicle interior trim part 10 is thus obtained comprising the substrate 12 and the multilayer coating 14 according to the invention.

[0115] Advantageously, the manufacturing process is devoid of any hardening step after the heat-coating step.

[0116] Alternatively, according to a second embodiment (not shown), the active agent is not included in a coating composition which is deposited on the sheet 15 but is directly included in the lacquer 24 during the production of sheets.

[0117] The lacquer 24 thus comprises the active agent and forms the external finishing layer within the meaning of the invention.

[0118] Preferably, the lacquer 24 comprises polyurethane.

[0119] According to this embodiment, the method of manufacturing the sheet 15 comprises a step of providing a lacquer composition comprising the active agent and depositing the lacquer 24 on the covering skin 18.

[0120] No other coating composition is thus deposited, for example by spraying, on the covering skin 18 or the lacquer 24. Example

[0121] Antibacterial and antiviral properties of the coating 14 according to the invention were then tested.

[0122] A CC coating composition was prepared by mixing the following components:

[0123] [TABLE 1]: Composition of the coating composition Component Proportion (% by weight) A Polyoxyethylene alkyl ether + Fluoropolymer (bonding agent) 76 B Dimethyloctadecyl (3-(trimethoxysilyl)propyl)ammonium chloride (active agent) + 3-chloropropyl Itrimethoxy silane and 3 (Trimethoxysilyl)propylamine (curing agent 1) 17 C Hydrophilic aliphatic polyisocyanate + hexamethylene dii-isocyanate (curing agent 7 2)

[0124] Component A was first placed in a container and stirred by a magnetic stirrer to create a vortex on the surface. Then, components B and C were added and the mixture was allowed to stir at 500 rpm for 5 minutes.

[0125] The resulting CC coating composition had a density of 1.01 g / cm3 and a solid volume value of 22.4% by volume.

[0126] The density of the composition was measured by pycnometer.

[0127] The solid volume value of the composition was measured with a test tube graduated by water displacement.

[0128] The antiviral properties of the part were then measured according to ISO 21702:2019 (Measurement of antiviral activity on plastics and other non-porous surfaces).

[0129] [TABLE 2]: Antiviral properties Virus Strain Material Contact Time Temperature Relative Humidity % Reduction HCoV-229E TPO Sheet 8 hours 55°C 95% 92.06% HCoV-229E PVC Sheet 8 hours 55°C 95% 98.42%

[0130] As seen in Table 2, the virus reduction is excellent.

[0131] The coating composition according to the invention has shown long-lasting antiviral properties.

Claims

Claims

1. A multi-layer coating (14) for a vehicle interior trim part (10) comprising a sheet (15) comprising at least: - an inner layer (16), and - a covering skin (18) applied to a first side (160) of the inner layer (16), the covering skin (18) being selected from a polyvinyl chloride skin and a thermoplastic polyolefin skin, the multi-layer coating (14) further comprising an outer finishing layer (30) comprising an active agent, the active agent being selected from quaternary ammonium salts and mixtures thereof.

2. The multilayer coating (14) of claim 1, wherein the active agent is selected from dimethyloctadecyl[3-(trimethoxysilyl)-propyl] ammonium chloride and 3-(trimethoxysilyl)-propyldimethyloctadecyl ammonium chloride and mixtures thereof.

3. A multi-layer coating (14) according to claim 1 or 2, the sheet (15) further comprising a lacquer (24) applied to the covering skin (18), the active agent being included in said lacquer (24).

4. A multi-layer coating (14) according to any preceding claim, the sheet (15) further comprising an adhesive layer (22) applied to a second side (162) of the inner layer (16), opposite the first side (160) of the inner layer (16).

5. A method of manufacturing a multi-layer coating (14) according to any one of the preceding claims, comprising the following steps: - preparing a sheet (15) comprising at least the inner layer (16) and the covering skin (18); and - applying to the sheet (15) a coating composition comprising the active agent to obtain the outer finishing layer (30).

6. A method according to claim 5, wherein the coating composition is sprayed directly onto the covering skin (18) or onto a lacquer (24) deposited on the covering skin (18).

7. A method according to claim 5 or 6, wherein the coating composition comprises by weight: - from 50 to 86% of a binding agent, the binding agent comprising a matrix polymer selected from polyols and a mixture thereof; - 10 to 30% of the active agent; and - 4 to 10% of a hardening agent.

8. A method according to claim 5, comprising a step of depositing a lacquer (24) on the covering skin (18), the lacquer (24) comprising the active agent.

9. Vehicle interior trim part (10), comprising: - a substrate (12) made of a polymer material, preferably polypropylene; - a multilayer coating (14) according to any one of claims 1 to 4, the covering skin (18) being applied to a surface (120) of the substrate (12).

10. A method of manufacturing a vehicle interior part (10) according to claim 9, comprising the steps of: - providing the substrate (12); and - applying the multi-layer coating (14) according to any one of claims 1 to 4 to a surface (120) of the substrate (12), the multi-layer coating (14) preferably being applied to the substrate (12) by heat coating, more preferably by vacuum heat coating.

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