FR3045131A1 - LUMINOUS MODULE COMPRISING A THERMALLY CONDUCTIVE MASK - Google Patents

Abstract

The present invention relates to a light module (1, 10) of a motor vehicle comprising at least one light source, a shaping optics (2, 12) and a mask (16) comprising at least one portion (3, 16a) for receiving light rays (4) focused by the shaping optics (2, 12), characterized in that said portion (3, 16a) of the mask comprises at least one thermally conductive polymeric element.

Description

LUMINOUS MODULE COMPRISING A THERMALLY MASK

The invention relates to a light module of a motor vehicle and a light device of a motor vehicle comprising said light module.

A light device of a motor vehicle generally comprises a housing closed by an ice in which is placed a light module. The light module comprises a light source and a shaping optics for forming, focusing and / or guiding light rays from the light source.

Various mechanical and electrical elements are also present in the light module to ensure the mounting and / or the power supply of the light source and the shaping optics. In order to protect and hide these unsightly elements, the light module includes a mask which may be of different shapes and which includes a portion placed under the shaping optics.

Depending on the sun conditions, this portion of the mask located under the shaping optics may be exposed to a risk called "sunburn", that is to say, a risk of deterioration by the sun's rays. Indeed, depending on the position of the vehicle relative to the sun, the sun's rays can be focused by the shaping optics, on the portion of the mask located under the shaping optics creating significant local heating that can cause the deterioration of the mask.

Another phenomenon, equivalent to "sunburn", can also damage the mask. This other phenomenon is known as "lightburn". More particularly, the portion of the mask located under the shaping optics may be exposed to a risk of deterioration due to light rays coming from the light source and focused by the shaping optics.

The phenomena of "sunburn" and "lightburn" can be accentuated if the mask is made of a dark colored material that absorbs heat. Conventionally, the dark-colored mask is made of a metallic material that is not sensitive to local heating due to "sunburn" and / or "lightburn" phenomena.

However, the use of a metallic material for the manufacture of the mask has certain disadvantages. Indeed, masks made of metallic material are relatively heavy and expensive. In addition, they have a limited choice of shapes due to the difficulty of shaping the metal and the aesthetic appearance can not be optimized.

The object of the present invention is to overcome the disadvantages of the prior art by providing a motor vehicle light module comprising a mask at least a portion of which is resistant to local heating due to "sunburn" and / or "lightburn" phenomena. ", Whatever its color. The mask of the invention also has the advantage of being light and easy to shape.

The present invention relates to a motor vehicle light module comprising at least one light source, a shaping optics and a mask comprising at least one portion for receiving light rays focused by the shaping optics, characterized in that said portion of the mask comprises at least one thermally conductive polymeric element. It should be noted that the light rays focused by the shaping optics can come from inside the module, for example from the light source ("lightburn") and / or from the outside of the module, for example the sun's rays ("sunburn"). The optical shaping of the light module of the present invention allows to deflect at least one of the light rays emitted by the light source. In other words, the direction of entry of the light beam into the shaping optics may be different from the output direction of the light beam of the shaping optics. The shaping optics comprise at least one optical element, such as a lens or a reflector. The shaping optics also receives light rays from the outside of the light module, such as the sun's rays. These light rays coming from outside the module can be focused by the shaping optics on a portion of the mask, which creates significant local heating on said mask. Equivalent local heating can be created by focusing, on a portion of the mask, by the shaping optics, a portion of the light rays from the light source. The thermally conductive polymeric element of said portion of the mask according to the invention makes it possible to dissipate the heat generated by the focusing, by the shaping optics, of the light rays coming from outside and / or from inside, and thus to avoid that the portion of the mask receiving these light rays is damaged, even when the portion of the mask comprising the thermally conductive polymer element is dark in color. In addition, the use of the polymeric element of the present invention allows said portion of the mask to be relatively light and easy to implement. It is thus possible to give any type of shape to the mask and its aesthetics can thus be adapted to any form requirement.

Mask and portion of the mask

The mask of a light module of a motor vehicle according to the invention is a piece whose particular function is to conceal and protect various mechanical and electrical elements that are present in the light module. It allows more particularly to ensure the mounting and maintenance of the shaping optics. The mask must therefore adapt, on the one hand to the shape of the assembly comprising the light source and shaping optics, and on the other hand to the position of the mechanical and electrical elements to be concealed. In this context, it is advantageous to use the thermally conductive polymeric element of the invention which can take different forms in operational configuration.

The mask is conventionally a part surrounding the shaping optics and placed between the shaping optics and the outside of the light module. The mask can take any type of shape, for example the shape of a ring, a crown or a rectangular shape. It can also marry the edges and / or contours of the shaping optics. The mask may furthermore not completely surround the shaping optics and form a band in the shape of the shaping optics. Whatever its shape, the mask may advantageously comprise a portion comprising said thermally conductive polymeric element according to the invention, this portion being located in particular at the place where the light rays coming from outside and / or from inside are focused by the shaping optics, and this when the light module is placed in a vehicle. More particularly, the portion may be located in the lower portion of the shaping optics.

According to a first embodiment of the portion of the mask of the invention, the portion of the mask may be the thermally conductive polymeric element. As such, the portion of the mask of the light module is a thermally conductive polymeric element. The mask is thus very different from the metal element according to the prior art. In this first embodiment of the portion of the mask, the portion may have a thickness of at least 1.5 mm, and preferably at least 2.5 mm. Thus, the portion of the mask is effective to dissipate local heating due to the focusing of light rays from outside and / or inside, by the shaping optics. In addition, this thickness allows the mask to withstand the various mechanical stresses to which it is subjected such as vibration in operational configuration or constraints during the introduction of the mask in the light module, for example by clipping.

According to a second embodiment of the portion of the mask of the invention, the portion of the mask may comprise a support covered by said thermally conductive polymeric element.

In this second embodiment of the portion, the thermally conductive polymeric element covering the support may have a thickness of at least 0.8 mm, and preferably at least 1.5 mm, in order to dissipate the heatings effectively. local due to the focusing of light rays from the outside and / or inside, by the shaping optics while having good mechanical strength.

According to this embodiment, the support may comprise any type of material since the support is not exposed directly to light rays coming from outside and / or from inside, and focused by the shaping optics. The support may, for example, be a polymeric or metallic material. Thus, only the portion of the mask comprising the thermally conductive polymeric element of the invention is exposed to light rays coming from outside and / or inside, and focused by the shaping optics and the support can not be damaged by these light rays, regardless of its material and color.

The portion of the mask comprising the thermally conductive polymeric element may be associated with the support by any technique well known to those skilled in the art, for example by gluing, welding, fixing by screws or bi-injection.

According to a first embodiment of the mask, the mask may be said thermally conductive polymeric element.

In this first embodiment of the mask, the mask of the invention may have a thickness of at least 1.5 mm, and preferably at least 2.5 mm. Thus, the mask is effective for dissipating local heating due to the focusing of the light rays coming from outside and / or inside, by the shaping optics. In addition, this thickness allows the mask to withstand the various mechanical stresses to which it is subjected, such as vibration in operational configuration or constraints during the introduction of the mask into the light module by clipping.

According to this first embodiment of the mask, the mask may not comprise any other material than the thermally conductive polymeric element. Thus, the mask is light and easy to shape.

According to a second embodiment of the mask, the mask may comprise a support covered by said conductive polymeric element.

According to this second embodiment of the mask, the mask and the support may comprise any type of material since neither the mask nor the support are exposed directly to light rays coming from outside and / or from inside, and focused by the shaping optics. They can also be of any color. Only one layer of the thermally conductive polymeric element covering the mask is exposed to the light rays focused by the shaping optics.

In this second embodiment of the mask, the thermally conductive polymeric element covering the support may have a thickness of at least 0.8 mm, and preferably at least 1.5 mm in order to effectively dissipate local heating due to focusing the light rays coming from outside and / or inside by the shaping optics, while having good mechanical strength.

In the present invention, the portion of the mask may be a part associated with said mask.

More particularly, the portion of the mask comprising the thermally conductive polymeric element may be associated with the mask by any technique well known to those skilled in the art, for example by gluing, welding, fixing by screws, or bi-injection

Emissivity of the thermally conductive polymeric element

In the present invention, the thermally conductive polymeric element can advantageously make it possible to dissipate the heat due to the focusing of the light rays coming from outside and / or inside, on the portion of the mask comprising this polymeric element and this, whatever the color of the polymeric element and therefore whatever its emissivity. The emissivity of a material is a unitless value from 0 to 1, which characterizes the radiation of this material. A perfect black material has an emissivity of 1, and all other materials have an emissivity from 0 to a value strictly less than 1. The emissivity value of a material can be measured by techniques well known in the art. a person skilled in the art, for example by infrared or laser. It should be noted that the lower the emissivity of a material, the more reflective the material.

In the present invention, the thermally conductive polymeric element has the property of dissipating the heat received by the light rays coming from outside and / or inside, and focused by the shaping optics and this, what whatever its color and therefore whatever its emissivity. Thus, the thermally conductive polymeric element of the invention used to form at least a portion of the mask exposed to light rays from outside and / or inside, and focused by the shaping optics can be advantageously of any color and therefore have an emissivity ranging from 0 to 1. This is advantageous because from an aesthetic point of view, the dark-colored masks are preferred, especially those having an emissivity greater than 0.3, preferably greater than 0.5, and more preferably greater than 0.7.

Conductivity of the thermally conductive polymeric element

In the present invention, the thermal conductivity is a physical quantity characterizing the thermal behavior of a material during a heat transfer by conduction. It represents the energy transferred per unit area and time under a temperature gradient of 1 Kelvin per meter, denoted "W / (m.K)".

The thermal conductivity of the support according to the invention can easily be determined by the so-called "flash laser" method, according to the ASTM E1461 standard (thermal conductivity called "In-Plane" expressed in W / (m.K)).

In the present invention, the term "thermally conductive" or "thermally conductive" means a thermal conductivity which may be at least 1.0 W / (mK), and preferably at least 20 W / (mK). ). Said thermal conductivity may be at most 380 W / (m · K) (= copper conductivity), and preferably at most 100 W / (m · K).

According to one embodiment, the thermal conductivity of the thermally conductive polymeric element may be at least 1.0 W / (m.K). According to this embodiment, the thermally conductive polymeric element is intended to be used in a light device of the type of taillight or front light (projector) of a motor vehicle.

In a particular embodiment of the invention, the electrical conductivity of the thermally conductive polymeric element may be at least 1.108 S / m (Siemens per meter) (25 ° C), and preferably at most 1.103. S / m (25 ° C).

Thermally conductive polymeric element

In the present invention, the thermally conductive polymeric element can be obtained from a polymer composition comprising at least one polymer.

The polymer composition of the invention may comprise one or more polymers, the term "polymer" being understood by any type of polymer well known to those skilled in the art such as homopolymer or copolymer (eg block copolymer, copolymer statistical, terpolymer, etc ...).

The polymer may be of the thermoplastic or elastomer type, and may be crosslinked or not, the crosslinking being carried out by techniques well known to those skilled in the art, such as, for example, heating, peroxide crosslinking, silane crosslinking, ultraviolet crosslinking.

According to a first variant, the thermally conductive polymeric element may be a non-crosslinked material, in particular of the thermoplastic or elastomer type.

According to a second variant, the thermally conductive polymeric element may be a crosslinked material, by techniques well known to those skilled in the art.

The thermal properties (i.e. thermal conductivity) of the thermally conductive polymeric element can be obtained according to different embodiments.

According to a first embodiment of the thermally conductive polymeric element, the thermally conductive polymeric element is obtained from a polymer composition comprising at least one thermally conductive polymer and optionally at least one filler.

More particularly, the thermally conductive polymer is a polymer capable of conducting heat by the intrinsic nature of said polymer.

According to a first variant, the thermally conductive polymers of the invention may be typically composed of macromolecules comprising delocalized π bonds at least in part or all along their macromolecular chains (ie main chains or "backbone chains"). .

Preferably, the delocalized π bonds may be of the π-σ-π type, alternating single and multiple covalent bonds. For example, mention may be made of the conjugated double bond system, for example "-C = C-C = C-".

According to a second variant, the thermal conductivity of the thermally conductive polymers of the invention may result in their macromolecular chains acquiring positive or negative charges through the oxidation or reduction of electron donors or acceptors, which can be for example doping elements.

According to a third variant, the electrical conductivity of the thermally conductive polymers of the invention may result in that the charge mentioned above is transported by dissolving the ions.

According to a fourth variant, the thermally conductive polymers of the invention may be a combination of the first variant and / or the second variant and / or the third variant. By way of example in this first embodiment, the thermally conductive polymer may be chosen from polyanilines, preferably in the form of emeraldine; polythiophenes; polypyrroles; polyacetylenes; and one of their mixtures. As a commercial reference, mention may be made of the Panipol reference from Panipol Ltd, which comprises a polyaniline; the Baytron P reference from Clevios, which comprises a polythiophene and more particularly a poly (3,4-ethylenedioxythiophene) -poly (styrene sulfonate) (PEDOT: PSS); or the Conquest commercial reference of Sigma-Aldrich, which comprises a polypyrrole.

The optional filler can be any type of filler well known to those skilled in the art, of the mineral or organic type.

The optional charge may be thermally conductive or not.

The thermally conductive filler may be chosen in particular from: carbonaceous fillers, such as, for example, carbon black, graphite, graphene, a carbon polymorph (e.g., diamond); metallic fillers, such as aluminum, magnesium, silver, gold, copper, iron, steel, cast iron, tin; composite metals, such as AlSiC (aluminum matrix comprising particles of silicon carbide); metal nitrides or metalloids, such as boron nitride, aluminum nitride; and metal oxides or metalloids, such as, for example, Al 2 O 3, SiO 2, ZnO, TiO 2; - one of their mixtures.

The thermally conductive polymer may be introduced into the polymer composition in an amount sufficient to render the composition thermally conductive.

According to a second embodiment of the thermally conductive polymeric element, the thermally conductive polymeric element can be obtained from a polymer composition comprising at least one polymer and at least one thermally conductive filler.

The polymer of this second embodiment may be a thermally conductive polymer or not.

The polymer may be any type of polymer well known to those skilled in the art, of the organic type and may be chosen from polyolefins, polycarbonates, polyamides, polyesters, and a mixture thereof. The polymer may also be of the inorganic type such as, for example, polyorganosiloxanes.

More particularly, polyolefins (i.e., olefin polymers) include ethylene and / or propylene polymers. An olefin polymer is conventionally a polymer obtained from at least one olefin monomer, and may be for example an ethylene homopolymer or an ethylene copolymer.

Mention may be made, as polyamide, of polycaprolactam (PA6 or nylon 6), or polyhexamethylene adipamide (PA66 or nylon 66). Polyester, polyethylene terephthalate (PET) may be mentioned.

The thermally conductive filler may be any type of filler well known to those skilled in the art, of the mineral or organic type.

The thermally conductive filler may be chosen in particular from: carbonaceous fillers, such as, for example, carbon black, graphite, graphene, a carbon polymorph (e.g., diamond); metallic fillers, such as aluminum, magnesium, silver, gold, copper, iron, steel, cast iron, tin; composite metals, such as AlSiC (aluminum matrix comprising particles of silicon carbide); metal nitrides or metalloids, such as boron nitride, aluminum nitride; metal oxides or metalloids, such as, for example, Al 2 O 3, SiO 2, ZnO, TiO 2; and - one of their mixtures.

The thermally conductive filler may be introduced into the polymer composition in an amount sufficient to make the composition thermally conductive, this amount may in particular vary depending on the type and morphology of the selected thermally conductive filler. By way of example in this second embodiment, mention may be made, as a polymer composition comprising at least one polymer and at least one thermally conductive filler, with the following commercial references: Arnite AV2 370 XL-T-PET-GF35 marketed by the DSM company, based on polyester (PET) and metallic filler (s) as thermally conductive filler, with thermal conductivity (In-Plane) according to ASTM E1461 standard of 1.7 W / (mK) Celanese RS1723, sold by Celanese, based on polyamide (PA6) and metal filler (s) as a thermally conductive filler, with thermal conductivity (In-Plane) according to ASTM standard E1461. 20 W / (mK).

According to a third embodiment, the thermally conductive polymeric element can be obtained from a polymer composition comprising at least one thermally conductive polymer and at least one thermally conductive filler, the thermally conductive polymer and the thermally conductive filler being such that defined in the first and second embodiments.

The thermally conductive polymer and the thermally conductive filler may be introduced into the polymer composition in an amount sufficient to render the composition thermally conductive.

In a particular embodiment, the polymer composition comprises at least 30% by volume of polymer (s) relative to the total volume of the polymer composition and, preferably, at least 50% by volume of polymer (s), relative to to the total volume of the polymer composition.

It may also comprise at most 95% by volume of polymer (s), and preferably at most 80% by volume of polymer (s), relative to the total volume of the polymer composition.

The amount by volume of polymer (s) in the polymer composition represents the total amount of all the polymers constituting the polymer composition, whether these polymers are thermally conductive or not.

Furthermore, the polymer composition of the invention may comprise at least 5% by volume of filler (s), and preferably at least 20% by volume of filler (s), relative to the total volume of the polymer composition.

It may also comprise at most 70% by volume of filler (s), and preferably at most 50% by volume of filler (s), relative to the total volume of the polymer composition.

The quantity by volume of filler (s) in the polymer composition, when the polymer composition comprises at least one filler, represents the total amount of all the constituent fillers of the polymer composition, whether these fillers are thermally conductive or not.

Preferably, the polymer composition of the invention comprises at least 95% by volume of polymer (s), or at least 95% by volume of polymer (s) and filler (s), relative to the total volume of the composition polymer.

The polymer composition of the invention may typically additionally comprise additives in an amount of 0.01 to 10% by volume (inclusive) based on the total volume of the polymeric composition.

The additives are well known to those skilled in the art and may be for example chosen from: protective agents such as antioxidants; processing agents, such as plasticizers, lubricants, oils; crosslinking agents, such as, for example, organic peroxides; and - one of their mixtures.

Luminous module

The light module of the invention is able to emit a light beam, and may be a lighting unit comprising at least one light source. The light source may comprise one or more semiconductor photoemissive elements, for example a light emitting diode and / or a laser diode.

In a particular embodiment, the light module is able to emit a light beam to perform all or part of a lighting function and / or light signaling, for a motor vehicle.

The light module of the invention also comprises a shaping optics for forming, focusing and / or guiding the light rays coming from the light source, such as, for example, an elliptical lens of an Adaptive Driving Beam module ( ADB).

In a particular embodiment, the light device further comprises a heat sink, such as a radiator. The heat sink is adapted to cool said light source in operational configuration.

Typically, the heat sink may be associated with at least one light module. More particularly, the light module can be positioned or mounted on said heat sink.

The light module may further comprise a printed circuit board, in particular of the PCB ("Printed Circuit Board") type, and / or a flexible printed circuit board, in particular of the FPCB ("Flexible Printed Circuit Board") type, and / or a variable geometry interconnection device, in particular of the type "MID" ("Molded In Device"), this type of configuration being well known to those skilled in the art.

The process for manufacturing the thermally conductive polymeric element The thermally conductive polymeric element of the invention being based on a polymer material, any type of process well known to those skilled in the field of formulation and the shaping of the polymers can be used. As an example of a manufacturing process, mention may be made of injection, molding, injection-molding, thermoforming or extrusion. It will be preferred to use for the manufacture of the thermally conductive polymeric element molding, injection-molding or thermoforming, in order to easily achieve the most suitable shapes for positioning the portion of the mask or the mask as such.

When the polymer composition of the invention comprises at least one filler, said filler is preferably incorporated into the polymer in the malleable or molten state in order to obtain a homogeneous final blend between the polymer and the filler.

When the polymer composition comprises a crosslinking agent, such as for example an organic peroxide, in order to obtain a portion of the so-called crosslinked mask, the crosslinking agent is first mixed with the polymer composition at a temperature sufficient to render the malleable or molten polymer but less than the decomposition temperature of said organic peroxide. Then, once the composition is shaped, it can be crosslinked at a temperature sufficient to trigger the decomposition of the peroxide and thus allow the crosslinking of the polymer composition.

The light device of a motor vehicle

The present invention applies preferably to the fields of light devices of a motor vehicle.

More particularly, the light device of a motor vehicle may be a lighting device and / or a light signaling device. For example, the light device may be a front light (projector) or a rear light of a motor vehicle, or an interior lighting device of a motor vehicle. More particularly, the light device may include one or more of the following elements: a high beam, a low beam, a daytime running lamp, a lantern, a brake light, a direction indicator, a fog lamp.

The light device of a motor vehicle may comprise at least one light module as defined above.

The light device according to the invention may further comprise a light device housing, and in particular for a car projector. Said housing can be classically closed by an ice, said at least said light module being placed in said housing. Other features and advantages of the present invention will become apparent in the light of the description of non-limiting examples of light modules according to the invention, with reference to the figures.

FIG. 1 represents a schematic and simplified sectional view of a light module according to the invention.

FIG. 2 represents a simplified schematic perspective view of a light module according to the invention.

For the sake of clarity, only the essential elements for understanding the invention have been shown schematically, and this without respect of the scale.

In order to simplify the presentation, the light module of the invention shown in FIGS. 1 and 2 comprises a single light source for lighting and / or signaling. However, the invention also applies to light modules comprising more than one light source.

FIG. 1 represents a schematic and simplified sectional view of a light module 1 according to the invention. This light module 1 comprises in particular a light source, not shown, and a shaping optics 2 intended to form, focus and / or guide the light rays coming from the light source. The light module 1 also comprises a portion 3 of the mask according to the invention comprising the thermally conductive polymeric element and located under the optics 2 shaping. More particularly, the portion of the mask lies below the horizontal plane delimited by the axis YY 'according to the configuration of the figure. In this figure, it is possible to see light rays 4 coming from the outside (e.g. sun rays) which are focused by the shaping optics 2 in a zone 5 of the portion 3 of the mask. The focusing of the light rays at the zone 5 creates a significant local heating which is dissipated by the thermally conductive polymeric element included in the portion 3 of the mask. As the heat is dissipated, the portion 3 of the mask exposed directly to the light rays 4 coming from the outside and focused is not damaged.

It should be noted that in Figure 1, only the external light rays focused by the shaping optics are shown. However, the mask of the invention can also receive light rays from the light source of the module and focused by the shaping optics.

FIG. 2 represents a simplified schematic perspective view of a light module 10 according to the invention in an operational configuration which comprises a light source, not shown, and an optics 12 for shaping. The light module 10 comprises a mask 16 according to the invention, completely surrounding the optical 12 shaping. In FIG. 2, a portion 16a of the mask is situated in the lower part of the shaping optics 12, said lower part corresponding to the part situated under the horizontal plane delimited by the axis YY 'according to the configuration of the Fig.

According to a not shown embodiment of a light module according to the invention, the whole of the mask 16 may comprise the thermally conductive polymeric element of the invention, and preferably the whole of the mask 16 is the polymeric element. thermally conductive of the invention.

Examples

Table 1 below shows the effects of light rays coming from outside the module and focused by a lens on polymeric elements.

The tests were performed using an elliptical lens of an Adaptive Driving Beam (ADB) module. The different polymeric elements were placed under the lens so as to reproduce the position of the portion of the mask relative to the shaping optics in a light module of the invention. The tests were carried out in an outdoor environment in full sun under a clear sky, with a solar radiation of 1000 W / m2.

The presence or absence of a "sunburn" effect after a given time of exposure to solar radiation through the lens was evaluated visually, and more particularly it was evaluated whether the polymeric element was damaged or not. The set of polymeric elements tested and the results obtained are collated in Table 1 below. The polymeric elements EPI and EP2 correspond to comparative tests, while the elements EP3 and EP4 correspond to thermally conductive polymeric elements according to the invention.

Table 1 The origin of the various polymeric elements collected in Table 1 is as follows: EPI is a polycarbonate polished black polymeric element marketed by the company Bayer under the reference PC Makrolon 2405 or 2407 and having a thermal conductivity of 0. , 2 W / (mK); EP2 is a high temperature polycarbonate polished black polymeric element marketed by Sabic under the reference Resin XHT3141 and having a thermal conductivity of 0.2 W / (m · K); EP3 is a dark gray polymeric element based on PET and metal filler (s) as a thermally conductive filler, sold by the company DSM under the reference Arnite AV2 370 XL-T-PET-GF35 and having a thermal conductivity of 1.7 W / (mK); EP4 is a dark gray polymeric element based on polyamide and metallic filler (s) as a thermally conductive filler, sold by Celanese under the reference Celanese RS1723 and having a thermal conductivity of 12 W / (mK ).

As shown by the results presented in Table 1, the thermally conductive polymeric elements of the invention are not damaged by even long exposure to light rays from outside and focused by shaping optics, in particular of the elliptical lens type of an ADB module.

Claims (14)

Motor vehicle light module (1, 10) comprising at least one light source, a shaping optics (2, 12) and a mask (16) comprising at least one portion (3, 16a) for receiving light rays (4) focused by the optics (2, 12) shaping, characterized in that said portion (3, 16a) of the mask comprises at least one thermally conductive polymeric element. 2. Light module (1, 10) according to claim 1, characterized in that the portion (3, 16a) of the mask is the thermally conductive polymeric element. 3. Light module (1, 10) according to claim 1, characterized in that the portion (3, 16a) of the mask comprises a support covered by said thermally conductive polymer element. 4. Light module (1, 10) according to claim 1, characterized in that the mask (16) is said conductive polymeric element. 5. Light module (1, 10) according to claim 1, characterized in that the mask (16) comprises a support covered by said conductive polymeric element. 6. Light module (1, 10) according to any one of claims 1 to 5, characterized in that the thermal conductivity of the thermally conductive polymer element is at least 1.0 W / (m.K). 7. Light module (1, 10) according to any one of claims 1 to 6, characterized in that the conductivity of the thermally conductive polymeric element is at least 10.0 W / (m.K). 8. Light module (1, 10) according to any one of claims 1 to 7, characterized in that the polymer thermally conductive element is obtained from a polymer composition comprising at least one thermally conductive polymer and optionally at least a charge. 9. Light module (1, 10) according to any one of claims 1 to 7, characterized in that the thermally conductive polymeric element is obtained from a polymer composition comprising at least one polymer and at least one heat load. conductive. 10. Light module (1, 10) according to claim 9, characterized in that the polymer is selected from polyolefins, polycarbonates, polyamides, polyesters, and mixtures thereof. 11. Light module (1, 10) according to any one of claims 8 to 10, characterized in that the polymer composition comprises at least 30% by volume of polymer (s) relative to the total volume of the polymer composition. 12. Light module (1, 10) according to any one of claims 8 to 11, characterized in that the polymer composition comprises at least 5% by volume of filler (s) relative to the total volume of the polymer composition. 13. Light module (1,10) according to any one of claims 1 to 12, characterized in that the portion of the mask is a part associated with said mask. 14. Lighting device of a motor vehicle, characterized in that it comprises at least one light module (1, 10) according to claims 1 to 13.