Article for repair of painted surfaces, and method for manufacture of such article

Description

1 / 12 ARTICLE FOR REPAIRING PAINTED SURFACES, AND METHOD FOR MANUFACTURING SUCH AN ARTICLE FIELD OF THE INVENTION

[001] The present invention relates generally to the repair of painted surfaces, in particular surfaces having quality requirements in accordance with technical regulations. STATE OF THE ART

[002] Traditionally, repairing painted surfaces is done by removing a minimum area to be repainted, smoothing it out, and applying one or more coats of liquid paint.

[003] It is understood that these operations are tedious and time-consuming, and expose operators to volatile organic compounds that are hazardous to health. Furthermore, in some areas, such as aircraft maintenance, certain regulations prohibit the simultaneous execution of such operations, which adversely increases maintenance times.

[004] The present invention aims to propose an article that significantly facilitates the repair of areas with damaged paint, taking into account these problems, as well as proposing a specific method for manufacturing such an article. SUMMARY OF THE INVENTION

[005] For this purpose, an article is proposed specifically intended for the repair of painted surfaces, comprising: - a layer of dried paint; - a layer of an activatable adhesive adjacent to the dry paint layer; - a protective layer adhered to the dry paint layer on the opposite side from the adhesive layer; and - a protective film attached to the adhesive layer on the opposite side from the dried paint layer; - in which the adhesive forces between the protective layer and the dry paint layer are controlled and maintained between the adhesive forces between the protective film and the adhesive layer, before its activation, and the adhesive forces between the paint layer and a final substrate, through the adhesive layer, after its activation. Petition 870250093844, dated 10 / 14 / 2025, pp. 77 / 97 2 / 12

[006] Some preferred but not limiting aspects of this article include the following features, considered individually or in any combination, that a specialist in the field considers to be technically compatible with each other: * The protective layer is coated with an adhesive chosen to provide controlled adhesive strength; * The outline of the protective layer differs from the outline of the assembly formed by the paint layer and the activatable adhesive layer, by the presence of at least one tab to be held, projecting externally; * The outline of the protective film projects on all sides in relation to the outline of the assembly formed by the paint layer and the activatable adhesive layer; * the tab(s) to be held are inscribed within the outline of the protective film.

[007] According to a second aspect, a method is proposed for manufacturing an article for repairing painted surfaces, comprising the following steps: - Apply at least one coat of paint material over a temporary molding support; - allow the, or each, layer of paint material to dry; - Apply a protective layer to the intermediate section of the paint layer; - to separate an intermediate item, consisting of the paint layer and the protective layer, from the temporary support; - Apply a layer of an activatable adhesive with a protective film to the exposed face of the paint layer, with the protective film located on the side of the adhesive layer opposite the paint layer; - in which the adhesive forces between the protective layer and the dry paint layer are controlled and maintained between the adhesive forces between the protective film and the adhesive layer, before its activation, and the adhesive forces between the paint layer and a final substrate, through the adhesive layer, after its activation.

[008] According to a third aspect, a method is proposed for the manufacture of an article for repairing painted surfaces, comprising the following steps: Petition 870250093844, dated 10 / 14 / 2025, pp. 78 / 97 3 / 12 - Apply at least one coat of paint material over a temporary molding support; - Allow the, or each, layer of paint to dry; - Apply a layer of an activatable adhesive with a protective film to the exposed face of the paint layer, with the protective film located on the side of the adhesive layer opposite the paint layer; - to separate from the temporary support an intermediate article formed by the paint layer, the adhesive layer and the protective film; and - Apply a protective layer to the intermediate section of the paint layer; - in which the adhesive forces between the protective layer and the dry paint layer are controlled and maintained between the adhesive forces between the protective film and the adhesive layer, before its activation, and the adhesive forces between the paint layer and a final substrate, through the adhesive layer, after its activation.

[009] Some preferential but not limiting aspects of this method include the following characteristics, considered individually or in any combination, that a specialist in the field considers to be technically compatible with each other: * The temporary molding support has aerodynamic performance notches / embosses that are transferred to the paint layer after application; * The protective layer has a marking on its outer surface indicating the orientation of the notches / reliefs; * The first protective layer is coated with an adhesive chosen to provide controlled adhesive strength; * The outline of the first protective layer differs from the outline of the assembly formed by the paint layer and the activatable adhesive layer, by the presence of at least one tab to be held, projecting externally; * The outline of the protective film projects on all sides in relation to the outline of the assembly formed by the paint layer and the activatable adhesive layer; * the tab(s) to be held are inscribed within the outline of the protective film. BRIEF DESCRIPTION OF THE DRAWINGS Petition 870250093844, dated 10 / 14 / 2025, pp. 79 / 97 4 / 12

[010] Other aspects, objectives and advantages of the present invention will become clearer by reading the following detailed description of preferred embodiments, provided by way of non-limiting example and made with reference to the accompanying drawings, in which: - Figures IA to 1E are shown in enlarged cross-section illustrating different stages of manufacturing an article according to a first embodiment of the invention; Figure 2 is a cross-sectional view, enlarged in the thickness direction, of an article according to an embodiment of the invention; Figure 3 is a view of the underside of the item shown in Figure 2; Figure 4 is a cross-sectional view of the article after application; and Figures 5A to 5E are enlarged cross-sectional views illustrating different manufacturing steps of an article according to a second embodiment of the invention. DETAILED DESCRIPTION OF PREFERRED EMBODIMENTS. [Oil] The following article describes an application that allows, in particular, the repair of damage to paint applied to a structure, especially an aircraft, avoiding the need to repeat all the steps required for applying paint in liquid form, thus saving time and easily meeting health, safety and environmental (HSE) regulatory criteria, resulting in a repair with excellent durability.

[012] With reference to the drawings, and firstly to figures IA to 1E, a temporary molding support 10 is initially provided (fig. IA), the condition of which is suitable for determining, by molding effect, the surface condition of a paint layer. In this embodiment, this surface is generally smooth or has a surface condition adapted to the adhesion of an adhesive layer, as will be described below.

[013] This molded support is made, for example, from one of the following materials: polypropylene, polyethylene, polyethylene terephthalate, silicone paper.

[014] In the step shown in fig. 1B, one or more layers of paint 20 are applied to face 11 of the molding support. Petition 870250093844, dated 10 / 14 / 2025, pp. 80 / 97 5 / 12

[015] If necessary, a surface activity modifier of the face 11 of the molding support 10, such as a surfactant, is applied before the application of the paint 20, in order to limit coalescence and enable the obtaining of a film of homogeneous thickness.

[016] The paint can be single-component or two-component, for example, polyurethane, epoxy, acrylic or polyester. Depending on the desired application, one or more layers are applied with the appropriate thickness.

[017] In general, the total thickness of the paint layer(s) 20 is chosen according to the type of paint and the type of application. For an aircraft repair application, the chosen thickness is the thinnest possible, in accordance with any regulatory requirements, for reasons of weight minimization. The thickness may depend on the repair area in question. For other applications, criteria of mechanical impact resistance, erosion, UV barrier, chemical resistance to certain aggressive agents, etc. may be maintained.

[018] 'Paint also means gel coatings and clear varnishes, whereby a layer of varnish is first applied to the temporary substrate 10, so as to become the outer layer, as will be understood below.

[019] In the case of an item qualified as a repair for a specific application, a paint qualified for that application is used, available from various manufacturers. For example, for an aviation application, a paint conforming to the AMS 3095A standard is used, while for marine or industrial applications, a paint certified by ACQPA (Association pour la Certification et la Qualification en Peinture Anticorrosion - Association for Certification and Qualification in Anticorrosion Paint) is advantageously used.

[020] One property that can be important for applications is resistance to aggressive agents, such as Skydrol®.

[021] As mentioned, the thickness of layer 20 depends, in particular, on the type of paint and the application in question. The thickness may result from a compromise between the degree of protection to be provided (e.g., UV barrier) and weight constraints, particularly in aeronautics. Petition 870250093844, dated 10 / 14 / 2025, p. 81 / 97 6 / 12

[022] As a general rule, the total thickness of layer 20 is on the order of 25 to 100 µm, preferably around 40 to 70 µm, for a repair application on non-exposed parts in aviation.

[023] For certain applications, in particular for repairing anti-erosion coatings on certain aircraft parts (wing leading edges, and in particular radomes), the paint layer thickness can reach 600 µm. In industrial or marine applications, intermediate thicknesses can be used.

[024] Referring now to figure 1C, a protective film 40 is applied to the intermediate article, consisting of the intermediate support 10 and the paint layer 20 after it has dried, on the side of the latter, in order to protect the paint layer during application of the article, as will be described below.

[025] This protective film 40 preferably consists of: - in the combination of a transfer film (or application tape), made for example of polypropylene, and an adhesive layer, such as an acrylic adhesive or an elastomer / resin mixture, typically having a total thickness between 25 and 100 µm; or - in a peelable varnish, which is applied, for example, by coating it over the paint layer which, after drying, forms a flexible, unbreakable and cohesive protective film; such varnish may be based on polyvinyl acetate or polyester, for example, and may have a thickness between 100 and 300 µm after drying.

[026] The adhesive properties of the protective film 40 on the paint layer 20 after application are determined in such a way that the adhesive forces between the film 40 and the paint layer 20 are greater than the adhesive forces between the aforementioned paint layer 20 and the temporary support 10. In this way, it becomes possible to separate the assembly formed by the paint layer 20 and the protective film 40 from the temporary support 10 by applying traction to the protective film, as illustrated in figure 1D. Thus, an intermediate article is obtained consisting of the paint layer 20 and the protective film 40.

[027] With reference to fig. IE, the next step consists of applying a layer of adhesive 30 to the face of the paint layer 20 opposite the protective film 40. The adhesive is Petition 870250093844, dated 10 / 14 / 2025, pp. 82 / 97 7 / 12 advantageously selected from a group comprising pressure-sensitive adhesives (PSAs), structural liquid adhesives, in particular of the acrylic, polyurethane, cyanoacrylate, vinyl acetate, epoxy, phenolic, anaerobic (e.g., UV cured), or hot melt type.

[028] The application of the adhesive depends on its nature. In the case of a film adhesive, it is simply laminated with the assembly formed by the protective film of the paint layer 20, on the side of the paint layer. It should be noted that the adhesive layer 30, at this stage, may be attached to a protective film 31 (or liner, in terminology) which is intended to support and / or protect it.

[029] If applicable, the protective film 31 that accompanies the adhesive 30 during its application may be removed and replaced by another protective film 31' having dimensions larger than the final size of the assembly formed by the paint layer 20 and the adhesive layer 30, as will be observed in detail below. The film 31 or 3Γ is advantageously a paper coated with polyethylene, polypropylene or polyester, coated with a silicone-type release agent, having a thickness of the order of 50 to 150 µm.

[030] The adhesive is preferably a pressure-sensitive adhesive (PSA), chosen according to the constraints of the application in question (in particular, resistance to various aggressive phenomena, such as temperature differences, UV radiation, chemical attack by products such as Skydrol® in the aeronautical industry, or other aggressive agents in other industries), and to provide adhesion properties adapted to the application (tensile or shear strength).

[031] The thickness of the adhesive layer is typically between 25 and 250 µm.

[032] A successfully tested product is an acrylic type transfer adhesive tape having a thickness of approximately 50 µm.

[033] The final article is illustrated in figures 2 and 3.

[034] The assembly formed by the layers of paint 20 and adhesive 30 generally has a circular shape here, with a diameter typically between 1 and 100 cm, with the Petition 870250093844, dated 10 / 14 / 2025, pp. 83 / 97 8 / 12 of this set's outline is designated by Cl. Naturally, all other formats can be considered.

[035] The protective film 31' of the adhesive 30 has larger dimensions than those of the assembly 20, 30, so as to have a contour C2, which here has a square shape, extending beyond the contour Cl on all sides, for the purposes explained below, forming a marginal zone 310'.

[036] Finally, the protective film 40 for application has a contour generally identical to contour Cl, with the notable presence of a fixing tab 42 (or two or more tabs) projecting outwards from this contour, for the purposes explained below.

[037] The application of the article will be described below.

[038] First, the protective film 3Γ is placed in any of the regions of its marginal zone 310', to progressively expose the adhesive layer on the side of the final support, consisting of an area to be repaired, previously cleaned and prepared, which in this case is an area to be repaired from an aircraft. The removal of the film 3Γ is carried out gradually as the article is applied against the area to be repaired, avoiding the entrapment of air bubbles. For this purpose, the mechanical properties of the film 31 are chosen so as to allow its bending above 180° with a limited radius of curvature, without inducing a risk of rupture.

[039] This type of procedure is suitable for certain simple PSA or hot-melt PSA type adhesives, allowing significant bending without loss of cohesion. With other types of adhesives, such as a structural adhesive, it may be preferable to first remove all 3Γ protective film and then apply the article to the surface to be repaired, implementing any suitable method for removing bubbles.

[040] The fact that the 3Γ film projects on all sides relative to the Cl contour facilitates its removal, regardless of the orientation of the article at the time of application.

[041] Once the article has been applied and the protective film 31' has been completely removed, a mask-type tool is applied with appropriate pressure to the exposed surface of the protective film 40 to smooth the article and activate the Petition 870250093844, dated 10 / 14 / 2025, pp. 84 / 97 9 / 12 adhesive 30, in order to obtain a final bond between the article and the area to be repaired. It should be noted here that the presence of the thin adhesive layer between the film 40 and the paint layer 20 prevents relative slippage between these two elements during this operation. This risk of slippage or damage to the film 40, or, even more disadvantageously, damage to the paint layer, can be further minimized by the existence of minimal frictional forces between the outer surface of the film 40 and the tool, thanks to the materials chosen for these elements.

[042] After this activation, the adhesive forces between the treated area (or final support) and the article are greater than the adhesive forces between the paint layer 20 and the protective film 40, exerted by the adhesive 41. Thus, by applying gradual traction to the tab 42, the protective film 40 can be removed without the risk of detaching the article from its final support. The resulting assembly is illustrated in Fig. 4, with exaggerated thickness.

[043] In practice, the thicknesses of layers 30 and 20 are such that the transition between the edges of the article and the rest of the substrate S (part of the aircraft) is almost imperceptible, and the physical and chemical resistance of the article is comparable to that of the adjacent parts of the substrate S.

[044] It should be noted that, at an industrial level, it may be advantageous to provide the articles described above in the form of a larger element, in which a plurality of articles are obtained by cutting.

[045] In this case, the manufacturing method described above comprises the production of a set of individual intermediate articles on a strip constituting the molding support 10, and the transfer, by calendering, of the intermediate articles to the protective film 40, which then constitutes, for the handling portion, a common support for the articles.

[046] Another embodiment of a method for manufacturing an article according to the invention will be described below, with reference to figures 5A to 5E.

[047] First, a temporary molding support 10 is provided (fig. 5A), the condition of which molding surface 11 is suitable for determining, by molding effect, the condition of the surface of a paint layer that will be externally exposed after application of the article, as will be understood later. Petition 870250093844, dated 10 / 14 / 2025, pp. 85 / 97 10 / 12

[048] This molding support 10 can be structurally analogous to that of the first form of incorporation. It can be smooth or have any desired pattern with notches or reliefs, such as a material effect with microgrooves or microribs, obtained, for example, by calendering, to form, by molding effect, corresponding notches / reliefs on the exposed face of the paint, as will be understood below.

[049] In the step shown in fig. 5B, one or more layers of paint 20 are applied to face 11 of the molding support.

[050] Again, if necessary, a surface activity modifier of the face 11 of the molding support 10, such as a surfactant, is applied before the application of the paint 20, in order to limit coalescence and enable the obtaining of a film of homogeneous thickness.

[051] The type of paint (or varnish), the number of layers and the thicknesses of the layers may be similar to those described for the first form of embedding, with the adaptations necessary for the type of application. However, it should be noted that the first layer (applied to the substrate 10) will be the layer exposed to the outside, and its characteristics will be adapted, if necessary (whereas, in the first form of embedding, it is the final layer that is exposed externally).

[052] Referring to figure 5C, the next step consists of applying an adhesive layer 30 over the paint layer 20, after drying. The nature of the adhesive and the application method can be of the same type described in the first embodiment of the method.

[053] Here again, the choice of adhesive 30, its thickness, and the conditions of its application to the paint layer 20 are such that the adhesive forces between the adhesive 30 and the paint are greater than the adhesive forces between the paint film 20 and the temporary support 10. In this way, it becomes possible to separate from the temporary support 10 the assembly formed by the paint layer 20 and the adhesive layer 30, possibly provided with its film 31, by exerting traction on the adhesive layer 30, as illustrated in Fig. 5D. Thus, an intermediate article is obtained consisting of Petition 870250093844, dated 10 / 14 / 2025, pp. 86 / 97 11 / 12 layer of paint 20 and by the adhesive layer 30, possibly protected by its film 31.

[054] As described above, if applicable, the protective film 31 that accompanied the adhesive 30 during its application may be removed and replaced by another protective film 31' having dimensions larger than the final size of the assembly formed by the paint layer 20 and the adhesive layer 30, as will be observed in detail below. The film 31 or 31' is advantageously identical or similar to that described above.

[055] With reference now to fig. 5E, a protective film 40 is applied to the intermediate article, on the side of the paint layer 20, in order to protect the paint layer during application of the article, as will be described below.

[056] This protective film 40 is, for example, identical or similar to that described with reference to the first embodiment.

[057] The final article, in its general configuration, is an article as illustrated in figs. 2 and 3. The outlines and dimensions of the different components of the article may also be as described above, and their method of application will also be similar.

[058] As mentioned, the present invention finds numerous applications, particularly in repair and decoration, in the aviation, aerospace, naval / maritime / coastal, land transport, industrial, construction and renewable energy sectors. Decoration, herein, means the application of articles having decorative, marking, and / or identification characteristics, on bare (metallic, synthetic, composite, etc.) or painted surfaces.

[059] A person versed in the art will be able to make numerous variations and modifications using habitual skills.

[060] In particular, in an aviation application, with the implementation of the second form of incorporation, the paint layer can, as mentioned, be provided with notches / reliefs for aerodynamic performance (in particular of the riblets type, longitudinal microgrooves), obtained by molding effect through the appropriate structuring of the molding support 10.

[061] These aerodynamic elements must have a certain orientation in relation to the airflow to which the aircraft is exposed during flight, and in this case a Petition 870250093844, dated 10 / 14 / 2025, pp. 87 / 97 12 / 12 marking can be provided on the visible surface of layer 40 indicating the orientation of these notches / rises, so that, at the time of application, the article is applied with the orientation appropriate to the airflow that will circulate over that area during flight. Petition 870250093844, dated 10 / 14 / 2025, pp. 88 / 97

Claims

1 / 3 Claims 1. ARTICLE, IN PARTICULAR FOR REPAIRING PAINTED SURFACES, comprising: - a layer (20) of dry paint; - a layer (30) of an activatable adhesive adjacent to the dry paint layer; - a protective layer (40) adhered to the dry paint layer on the opposite side to the adhesive layer; and - a protective film (31; 3Γ) fixed to the adhesive layer (30) on the opposite side to the dry paint layer; characterized in that the adhesive forces between the protective layer (40) and the dry paint layer (20) are controlled and maintained between the adhesive forces between the protective film (31; 31') and the adhesive layer, before its activation, and the adhesive forces between the paint layer (20) and a final support, through the adhesive layer (30), after its activation.

2. ARTICLE, according to claim 1, characterized in that the protective layer (40) is coated with an adhesive (41) chosen so as to provide controlled adhesive forces.

3. ARTICLE, according to claims 1 or 2, characterized in that the contour of the protective layer (40) differs from the contour (11) of the assembly formed by the paint layer (20) and the activatable adhesive layer (30) by the presence of at least one tab to be held (42) projecting externally.

4. ARTICLE, according to any one of claims 1 to 3, characterized in that the contour (C2) of the protective film (31; 31') projects on all sides in relation to the contour (Cl) of the assembly formed by the paint layer (20) and the activatable adhesive layer (30).

5. ARTICLE, according to claims 3 or 4 characterized by the, or each, tab to be held (42) being inscribed within the contour (C2) of the protective film (31; 31'). Petition 870250093844, dated 10 / 14 / 2025, pp. 89 / 97 2 / 3 6. METHOD FOR MANUFACTURING AN ARTICLE FOR REPAIRING PAINTED SURFACES, as described in claim 1, comprising the following steps: - applying at least one layer of paint material (20) onto a temporary molding support (10); - allowing the, or each, layer of paint material (20) to dry; - applying a protective layer (40) to the intermediate article for the paint layer (20); - separating from the temporary support (10) an intermediate article formed by the paint layer (20) and the protective layer (40); - applying a layer (30) of an activatable adhesive provided with a protective film (31) against the exposed face of the paint layer (20), with the protective film (31) being located on the side of the adhesive layer (30) opposite the paint layer (20); characterized by the adhesive forces between the protective layer (40) and the dry paint layer (20) being controlled and maintained between the adhesive forces between the protective film (31;31Q and the adhesive layer, before its activation, and the adhesive forces between the paint layer (20) and a final support, through the adhesive layer (30), after its activation.; 7. METHOD FOR MANUFACTURING AN ARTICLE FOR REPAIRING PAINTED SURFACES, as described in claim 1, comprising the following steps: - applying at least one layer of paint material (20) onto a temporary molding support (10); - allowing the, or each, layer of paint material (20) to dry; - applying a layer (30) of an activatable adhesive provided with a protective film (31) against the exposed face of the paint layer (20), with such protective film being located on the side of the adhesive layer (30) opposite the paint layer (20); - separating from the temporary support (10) an intermediate article formed by the paint layer (20), the adhesive layer (30) and the protective film (31); and Petition 870250093844, dated 10 / 14 / 2025, p.90 / 97 3 / 3 - applying a protective layer (40) to the intermediate article for the paint layer (20); characterized in that the adhesive forces between the protective layer (40) and the dry paint layer (20) are controlled and maintained between the adhesive forces between the protective film (31; 3Γ) and the adhesive layer, before activation, and the adhesive forces between the paint layer (20) and a final support, by means of the adhesive layer (30), after its activation.

8. METHOD, according to claim 7, characterized in that the temporary molding support has aerodynamic performance notches / reliefs transferred to the paint layer after application.

9. METHOD, according to claim 8, characterized in that the protective layer (40) has a marking on its outer face indicating the orientation of the notches / reliefs.

10. METHOD, according to any one of claims 7 to 9, characterized in that the first protective layer (40) is coated with an adhesive (41) chosen so as to provide controlled adhesive forces.

11. METHOD, according to any one of claims 7 to 10, characterized in that the contour of the first protective layer (40) differs from the contour (11) of the assembly formed by the paint layer (20) and the activatable adhesive layer (30) by the presence of at least one tab to be held (42) projecting outwards.

12. METHOD, according to any one of claims 7 to 11, characterized in that the contour (C2) of the protective film (31; 31') projects on all sides in relation to the contour (Cl) of the assembly formed by the paint layer (20) and the activatable adhesive layer (30).

13. METHOD, according to claims 11 or 12, characterized in that the, or each, tab to be held (42) is inscribed within the contour (C2) of the protective film (31; 31'). Petition 870250093844, dated 10 / 14 / 2025, pp. 91 / 97

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