Skin material for vehicle and vehicle decoration comprising skin material

Abstract

The present invention relates to a skin material for a vehicle, said material comprising: a skin layer, which is formed by performing injection molding processing on a material containing a thermoplastic polyester elastomer, and a coating layer, which is located on the surface of the skin layer. In the present invention, through the design of the skin layer and coating layer, the obtained skin material has the advantages of excellent hand feel, scratch resistance, stain resistance, weather resistance, and so on. In addition, the coating layer and the skin layer have strong bonding force and a good bonding effect. The preparation process of the skin material of the present invention is simple and environmentally friendly, and said material has very good market application prospects.

Description

Surface material for vehicle and vehicle trim comprising the surface material

[0001] This patent application claims priority to the Chinese patent application with application number 202311443381.6 filed on November 1, 2023, entitled “A surface material for a vehicle and a vehicle trim comprising the surface material”, the full text of which is hereby expressly incorporated herein by reference. Technical Field

[0002] The present invention relates to the field of surface materials for vehicles, and more particularly to a surface material for a vehicle and a vehicle trim comprising the surface material. Background Art

[0003] As people's living standards improve, car consumers not only have high demands for car drivability and safety, but also have continuously upgraded their requirements for the vehicle's interior environment. As a key component of the vehicle's interior environment, optimizing the performance of the interior is of great significance to improving the user experience.

[0004] Vehicle interiors require a soft, smooth surface to provide a comfortable ride. Currently, these parts are often covered with soft artificial leather or genuine leather to optimize their performance. However, this processing method can involve numerous steps and high costs.

[0005] CN215856916U discloses an artificial leather with a suede-like pattern, which includes a surface layer and a paint layer. By providing a color brightening coating on one side of the suede-like pattern, the surface brightness of the artificial leather is improved, thereby making the appearance of the suede-like pattern better.

[0006] Using soft rubber materials (typically thermoplastic elastomers) as vehicle interior materials can provide users with a pleasant soft touch and increased comfort. However, due to the inherent characteristics of soft rubber's molecular structure, products made from soft rubber materials can have a sticky feel on the surface and lack properties such as scratch and stain resistance, which can, to a certain extent, provide users with a poor riding experience.

[0007] Summary of the Invention

[0008] In order to solve the above-mentioned deficiencies in the prior art, the present invention provides a surface material for a carrier.

[0009] In one aspect, the present invention provides a skin material for a carrier, comprising: a skin layer formed of a material including a thermoplastic polyester elastomer through an injection molding process; and a coating layer on a surface of the skin layer.

[0010] In one embodiment, the skin layer comprises: a soft foam layer, and self-skinning layers located on both sides of the soft foam layer.

[0011] In another aspect, the present invention further provides a vehicle trim comprising the skin material of the present invention.

[0012] In yet another aspect, the present invention provides a vehicle comprising the vehicle trim of the present invention. BRIEF DESCRIPTION OF THE DRAWINGS

[0013] Figure 1: Graph showing the test results of the water drop angle using the sessile drop method for the sample of comparative example 1 of the present application.

[0014] Figure 2: Graph showing the test results of the sessile drop method for the water drop angle of the sample of Example 1 of the present application.

[0015] FIG3 : Taber wear test results of samples of Examples 1-4 of the present application.

[0016] FIG4 is a diagram showing Taber wear test results of the sample of Comparative Example 1 of the present application.

[0017] FIG5 is a diagram showing the humidity cross-cut test results of the sample of Example 1 of the present application.

[0018] Figure 6: Diagram of the stick-slip testing equipment used in this application.

[0019] FIG7 : Stick-slip test results of the sample of Comparative Example 1 of the present application.

[0020] FIG8 : Stick-slip test results of the sample of Example 1 of the present application. DETAILED DESCRIPTION

[0021] General Definitions and Terminology

[0022] Unless otherwise indicated, all publications, patent applications, patents, and other references mentioned herein are incorporated by reference in their entirety.

[0023] Unless otherwise defined, all technical and scientific terms used herein have the same meaning as commonly understood by one of ordinary skill in the art to which this invention belongs. In the event of a conflict, the definitions provided herein will prevail.

[0024] Unless otherwise indicated, all percentages, parts, ratios, etc. are by weight.

[0025] When quantity, concentration or other value or parameter is given as range, preferred range or preferred upper limit and lower limit or specific value, it should be understood that all ranges formed from the paired values ​​of any upper limit range or preferred value and any lower limit range or preferred value are specifically disclosed, regardless of whether the range is disclosed separately. Unless otherwise stated, when numerical range is quoted herein, the range is meant to include its endpoints and integers and fractions within all such ranges. The scope of the present invention is not limited to the specific numerical value quoted when defining the range. For example, "1-8" encompasses 1, 2, 3, 4, 5, 6, 7, 8 and any sub-range consisting of any two values ​​thereof, such as 2-6, 3-5.

[0026] The terms "about" and "approximately" when used in conjunction with a numerical variable generally refer to the value of that variable and all values ​​of that variable are within experimental error (e.g., within a 95% confidence interval for the mean) or within ±10% of the stated value, or wider.

[0027] The terms "comprises," "includes," "has," "contains," or "involves," and other variations thereof herein, are inclusive or open-ended and do not exclude other unrecited elements or method steps. It will be understood by those skilled in the art that the above terms such as "comprising" encompass the meaning of "consisting of." The expression "consisting of" excludes any element, step, or ingredient not specified. The expression "consisting essentially of" means that the scope is limited to the specified elements, steps, or ingredients, plus the optional presence of elements, steps, or ingredients that do not materially affect the basic and novel characteristics of the claimed subject matter. It will be understood that the expression "comprising" encompasses the expressions "consisting essentially of" and "consisting of."

[0028] The term "selected from..." means one or more elements from the group listed thereafter, selected independently, and may include combinations of two or more elements.

[0029] When values ​​or end-points of a range are described herein, it should be understood that the disclosure includes the specific value or end-point recited.

[0030] As used herein, the terms "one or more" or "at least one" refer to one, two, three, four, five, six, seven, eight, nine or more.

[0031] Unless otherwise indicated, the terms "combinations thereof" and "mixtures thereof" refer to multi-component mixtures of the elements described, such as two-, three-, four- and up to the maximum possible multi-component mixtures.

[0032] In addition, if the number of parts or components of the present invention is not indicated before, it means that there is no limit to the number of occurrences (or existence) of the parts or components. Therefore, it should be interpreted as including one or at least one, and the singular form of the parts or components also includes the plural form unless the value obviously represents the singular.

[0033] As used herein, the term "optional" or "optionally" means that the subsequently described event or circumstance may or may not occur, and that the description includes both occurring and not occurring.

[0034] When describing methods, components or steps, letters or numbers are used for identification purposes only and do not limit these methods, components or steps to be performed in the order or sequence indicated. Those skilled in the art can make reasonable adjustments.

[0035] In this article, thermoplastic polyester elastomer (TPEE) refers to a polymer composed of hard segments (typically polyester) and soft segments (typically polyester or polyether). The hard segments in these polymers have a regular structure and can phase separate into crystalline domains, maximizing the intermolecular attraction between the hard segments. These crystalline domains physically crosslink the amorphous elastic segments. These materials maintain their integrity at temperatures close to the melting point of the crystallites, only beginning to flow under the higher temperatures and shear stresses encountered during thermoplastic processing.

[0036] Herein, "room temperature" generally refers to 25°C.

[0037] Unless otherwise specified, the "molecular weight of a polymer" herein refers to the weight average molecular weight of the polymer, which can be measured by conventional methods and instruments in the art.

[0038] Skin materials for vehicles

[0039] The surface material for a vehicle of the present invention comprises: a surface layer, and a coating located on the surface of the surface layer. In the present invention, the surface layer and coating of the surface material are rationally designed from the perspectives of chemical composition and physical structure, so that the surface material has excellent properties such as feel, scratch resistance, stain resistance, and weather resistance. In addition, the coating and the surface layer have strong adhesion and good bonding effect, and the coating is not easy to fall off, which can extend the service life. The preparation process of the surface material of the present invention is simple and environmentally friendly, and it has a wide range of applicable scenarios, so it has very good market application prospects.

[0040] As used herein, the term "vehicle" may also be referred to as "transportation vehicle," which is a general term for machinery or equipment used to transport materials, people, etc., including but not limited to cars, airplanes, ships, bicycles, trams, trains, subways, light rails, etc.

[0041] The surface material of the present invention is generally used in vehicles and can be used to cover vehicle accessories to enhance the usability of the vehicle accessories.

[0042] Epidermis

[0043] The surface layer serves as the base material and the main structure of the surface material. A suitable surface layer can give the product the desired properties, such as appropriate color rendering, good touch, excellent mechanical strength and weather resistance.

[0044] The skin layer of the present invention may be formed of a material including a thermoplastic polyester elastomer through an injection molding process.

[0045] Thermoplastic polyester elastomers possess excellent properties, such as superior mechanical strength, good tear resistance, chemical resistance, easy processing, and good resilience, making them suitable for use as coverings for automotive interior components. Therefore, the surface material of the present invention, when used in vehicle trim, such as covering interior trims, can provide users with a soft touch that is close to or similar to genuine leather, thereby enhancing the user experience.

[0046] To further enhance the soft touch and cushioning properties of the surface material, the surface layer can be foamed to form a sandwich structure with a soft foam layer in the middle and self-skinning layers on both sides. In one embodiment, the surface layer comprises a soft foam layer and self-skinning layers on both sides of the soft foam layer.

[0047] The foaming process may be chemical foaming, for example, by mixing a foaming agent into the raw materials forming the skin layer and foaming in a closed or open mold. The foaming agent may be a foaming agent commonly used in the field of polymer processing.

[0048] Physical foaming can also be used, for example by mixing a supercritical fluid into the raw materials that form the surface layer. This reduces the use of blowing agents, making the process more environmentally friendly. It also avoids the potential for residual chemical solvents in chemical foaming, which can lead to product performance degradation (such as unpleasant odors).

[0049] The present application adopts an injection molding process to prepare the skin layer. Specifically, the material forming the skin layer is added to an injection molding machine, the material is heated, melted and dispersed in the injection molding machine screw, and then injected into the mold cavity at high speed. After filling the mold cavity, it is cooled and formed to obtain a molded product.

[0050] One advantage of the injection molding process is that it can easily achieve specific shapes or textures, which is advantageous for products requiring styling or texturing. For example, by creating a texture on the inner wall of the mold cavity, once the molten material fills the cavity, the surface texture can be replicated on the inner wall, and then replicated on the surface layer, resulting in a textured surface material. For example, by designing the mold cavity shape, a surface material with a corresponding shape can be obtained.

[0051] In automotive applications, the thickness of the surface layer is typically 0.3-2.5mm. A surface layer that is too thin cannot effectively protect interior components, and the material strength may be too low, making it susceptible to damage from external factors (such as friction, weathering, and sunlight), resulting in a loss of functionality and aesthetics. An overly thick surface layer not only increases product costs but may also reduce aesthetics. For example, for interior components with delicate structures, an overly thick surface layer may not provide adequate coverage.

[0052] In order to facilitate the preparation of a desired skin layer (with a desired thickness range and optionally with a texture structure) through an injection molding process, the present application adjusts the composition of the material forming the skin layer to make the material suitable for use.

[0053] In this application, the material forming the skin layer has a suitable range of physical and chemical parameters to ensure the feasibility of preparation during the injection molding process. In addition, it can also improve the performance of the product to meet the performance requirements of the automotive industry (such as strength, wear resistance, etc.).

[0054] In one embodiment, the material forming the skin layer has a melt index of 50-400 g / 10 min, preferably 200-300 g / 10 min, such as 200 g / 10 min, 250 g / 10 min, 300 g / 10 min, etc., measured at 220 ° C and 2.16 kg. The melt index can be measured according to ISO 1133 at 220 ° C and 2.16 kg. If the melt index is too low, the fluidity of the material melt is too poor for the desired thickness of the skin material in this application, and the narrow mold cavity cannot be fully filled. When the skin material has texture or three-dimensional modeling requirements, materials with too low a melt index cannot fill the detailed positions well. The appropriate melt index can meet the requirements for the achievable thickness, texture or three-dimensional modeling of the material, and the minimum achievable radius R of the curved corner of the obtained product is 1 mm, and the limit radius R is 0.5 mm.

[0055] In one embodiment, the density of the material forming the skin layer is 0.95-1.15 g / cm 3 , preferably 1.05-1.15g / cm 3 , for example 0.95 g / cm 3, 1.00g / cm 3 , 1.05g / cm 3 , 1.10g / cm 3 , 1.15g / cm 3 The density of the material can be measured according to ISO 1133. Appropriate material density helps to improve the properties of the skin material, such as making it have appropriate physical characteristics.

[0056] Appropriate parameter characteristics of the material help to obtain a skin material with desired properties, so that the skin material meets the performance requirements of the automotive industry for interior parts.

[0057] In one embodiment, the Shore A hardness of the material forming the skin layer is 60-80, preferably 65-75, for example 60, 65, 70, 75, 80, etc. The Shore A hardness of the material can be measured according to ISO 868 15s.

[0058] In one embodiment, the tensile strength of the material forming the skin layer is 3-10 MPa, preferably 5-8 MPa, such as 3 MPa, 4 MPa, 5 MPa, 6 MPa, 7 MPa, 8 MPa, 9 MPa, 10 MPa, etc. The tensile strength of the material can be measured according to ISO 37 or ISO 527, for example, it can be measured by ISO 527-1.

[0059] In one embodiment, the elongation at break of the material forming the skin layer is 100% to 800%, for example, 100%, 150%, 200%, 250%, 300%, 350%, 400%, 500%, 600%, 700%, 800%, etc. The elongation at break of the material can be measured according to ISO 37 or ISO 527, for example, it can be measured by ISO 527-1.

[0060] In one embodiment, the tear strength of the material forming the skin layer is 20-60 kN / m, preferably 30-50 kN / m, for example 20 kN / m, 30 kN / m, 40 kN / m, 42 kN / m, 45 kN / m, 48 kN / m, 50 kN / m, 55 kN / m, 60 kN / m, etc. The tear strength of the material can be measured according to ISO 34.

[0061] The desired skin layer can be obtained by adjusting the chemical structure of the thermoplastic polyester elastomer so that the material forming the skin layer has the above-mentioned desired properties.

[0062] Suitable soft and hard segments in thermoplastic polyester elastomers help adjust material properties. The hard segment of the thermoplastic polyester elastomer can include: polybutylene terephthalate, polyethylene terephthalate, polypropylene terephthalate, poly(1,4-dimethylene cyclohexane terephthalate), poly(2,6-butylene naphthalate), poly(xylene terephthalate), polyethylene terephthalate / polybutylene terephthalate copolymer, poly(dimethyl terephthalate / isophthalene diol) / 1,4-butanediol copolymer, polyethylene 2,5-furandicarboxylate, poly(propylene 2,5-furandicarboxylate), poly(2,5-furandicarboxylate), poly(2,5-butylene furandicarboxylate), poly(2,5-hexane furandicarboxylate), or a combination thereof. Preferably, the hard segment of the thermoplastic polyester elastomer may include: polybutylene terephthalate, polybutylene 2,5-furandicarboxylate, or a combination thereof. The soft segment of the thermoplastic polyester elastomer may include: polyethylene glycol, polybutylene glycol, polycaprolactone, polymethyl glycol, fatty acid dimer glycol, polytetramethylene ether, ethylene oxide-propylene oxide copolymer bisphenol A ether, polypropylene glycol, polylactide, polyglycolide, or a combination thereof. Preferably, the soft segment of the thermoplastic polyester elastomer may include: polyethylene glycol, polycaprolactone, polytetramethylene ether, or a combination thereof.

[0063] The ratio of the soft segment to the hard segment in the thermoplastic polyester elastomer can be within a suitable range to impart good properties to the formed skin layer. The molar ratio of the hard segment to the total copolyester elastomer in the thermoplastic polyester elastomer is preferably in the range of 25% to 60%, preferably 30% to 40%, and the molar ratio of the soft segment to the total copolyester elastomer is preferably in the range of 40% to 75%, preferably 60% to 70%.

[0064] In the present invention, it is preferred to use a thermoplastic polyester elastomer with a higher molecular weight to form the skin layer, which is conducive to optimizing the properties of the skin layer. The molecular weight of the thermoplastic polyester elastomer can be 20,000-40,000, preferably 30,000-40,000, and more preferably 33,000-38,000.

[0065] Based on the total weight of the material forming the skin layer, the content of the thermoplastic polyester elastomer can be 20-97% by weight, preferably 30-80% by weight, preferably 60-90% by weight, for example, 20% by weight, 30% by weight, 40% by weight, 50% by weight, 60% by weight, 65% by weight, 70% by weight, 75% by weight, 77% by weight, 80% by weight, 84% by weight, 85% by weight, 90% by weight, 95% by weight, 97% by weight, etc.

[0066] The material forming the skin layer may contain other components to adjust the properties. The other components include but are not limited to: compatible resins, lubricants, plasticizers, fillers, antioxidants, colorants, anti-ultraviolet agents, etc.

[0067] Suitable compatible resin can form a good combination effect with the thermoplastic polyester elastomer of the application, helps to promote the fluidity of the material melt, and is also conducive to the optimization of material performance. Compatible resin can be polybutylene terephthalate, polyethylene terephthalate, polyamide, acrylonitrile-butadiene-styrene copolymer, polycarbonate, epoxy resin or its combination, preferably polybutylene terephthalate or polyamide. Based on the gross weight of the material forming the epidermis, the content of compatible resin can be 3-70 weight %, preferably 3-50 weight %, more preferably 3-10 weight %, such as 3 weight %, 4 weight %, 5 weight %, 6 weight %, 7 weight %, 8 weight %, 9 weight %, 10 weight %, 15 weight %, 20 weight %, 40 weight %, 50 weight %, 70 weight % etc.

[0068] The weight average molecular weight of the compatible resin may be from 8,000 to 12,000, preferably from 8,500 to 11,000, preferably from 9,000 to 10,500, and especially 10,000 Daltons.

[0069] The viscosity number of the compatible resin measured according to ISO 307 may be 82±15 ml / g, 90±15 ml / g, 100±15 ml / g, 115±15 ml / g, 118±15 ml / g, 120±15 ml / g, in particular 105±15 ml / g.

[0070] The compatible resin may have a tensile strength measured according to ISO 527-1 of 31 to 46 MPa, preferably 35 to 43 MPa, preferably 38 to 41 MPa, especially 40 MPa.

[0071] The compatible resin may have an elongation at break measured according to ISO 527-1 of 35 to 56%, preferably 45 to 53%, preferably 48 to 51%, in particular >50%.

[0072] The compatible resin may have a Shore D hardness of 50 to 80, preferably 55 to 70, preferably 62 to 68, especially 65, measured according to ISO 868 15s.

[0073] Plasticizers can also be added to the material forming the epidermis to improve the fluidity and softness of the material. Plasticizers can include: phthalate compounds, phthalate compounds, aliphatic dibasic acid compounds, epoxy ester compounds, phosphate compounds or combinations thereof. Examples of phthalate compounds include: dioctyl phthalate (DOP), diester phthalate (DBP), diisobutyl phthalate (DIDP). Examples of phthalate compounds include trioctyl trimellitate. Examples of aliphatic dibasic acid compounds include: dioctyl adipate (DOA), dioctyl azelate (DOZ), dioctyl sebacic acid (DOS), etc. Based on the total weight of the material forming the skin layer, the content of the plasticizer can be 3-15 weight%, preferably 6-12 weight%, for example, 3 weight%, 4 weight%, 5 weight%, 6 weight%, 7 weight%, 8 weight%, 9 weight%, 10 weight%, 11 weight%, 12 weight%, 13 weight%, 14 weight%, 15 weight%, etc.

[0074] The material forming the skin layer may also contain additives commonly used in the art, including but not limited to lubricants, plasticizers, fillers, antioxidants, UV inhibitors, colorants, etc. It should be understood that the addition of additives is used to appropriately adjust the properties of the system, and their dosage should generally not be too high. They can be added in appropriate amounts according to actual needs.

[0075] Suitable lubricants may include silicone, polyethylene wax, calcium stearate, or combinations thereof.

[0076] Suitable fillers are selected from talc, white carbon black, diatomaceous earth, bentonite, calcium carbonate, calcium oxide, magnesium carbonate, barium sulfate, light calcium carbonate, nano zinc oxide, anhydrous calcium sulfate, calcium hydroxide, clay, ceramic microbeads, kaolin, magnesium oxide, magnesium hydroxide, calcium oxide, aluminum oxide, aluminum hydroxide, perlite, wollastonite, hydrotalcite, zinc sulfide and combinations thereof.

[0077] The antioxidant may be selected from hindered phenol antioxidants, hindered amine antioxidants, aromatic secondary amine antioxidants, thioester antioxidants, phosphite antioxidants, phosphite antioxidants, thioether antioxidants, nitrogen oxide resistant antioxidants and combinations thereof.

[0078] The anti-ultraviolet agent may be selected from oxalic acid anilides, benzophenones, benzotriazoles, benzotriazines, salicylates, benzophenones, substituted acrylonitriles and combinations thereof.

[0079] The colorant can be selected from phenylimidazoline, DPP red, quinacridone, phthalocyanine blue, anthraquinone, carbon black, titanium dioxide, iron oxide series color powder, lead chromate series color powder, organic color powder such as phthalocyanine blue powder or ultramarine powder, inorganic color powder such as iron oxide red, iron oxide black or chrome green, composite color powder such as iron oxide orange or sea blue powder and combinations thereof.

[0080] As described above, the skin layer of the present application is formed by an injection molding process of a material containing a thermoplastic polyester elastomer. By adjusting the chemical composition and physical properties of the material forming the skin layer, a skin layer with excellent soft touch, mechanical strength and other properties can be obtained.

[0081] The inventors of the present application have discovered that thermoplastic polyester elastomers, as soft-glue materials, possess the aforementioned advantageous properties (e.g., good mechanical strength, good tear resistance, chemical resistance, easy processing, excellent resilience, and a soft touch) when used as vehicle interior materials. However, due to the inherent characteristics of thermoplastic polyester elastomers, the chemical structure of these materials can result in a sticky feel on the surface and poor scratch and stain resistance. While these issues can be alleviated to some extent through material modifications (e.g., adjusting the chemical structure of the thermoplastic polyester elastomer, adding suitable compatible resins or other additives), they are not satisfactory. To achieve a surface material that retains the advantages of thermoplastic polyester elastomers while also combining a smooth feel with good scratch and stain resistance, the inventors of the present application have surprisingly discovered that this goal can be achieved by applying a special coating to the surface layer.

[0082] The coating of the present application (as described below) can improve the properties of the epidermal material, wherein the adhesion between the coating and the epidermal layer is one of the important factors affecting the service life of the epidermal material. The stronger the adhesion between the coating and the epidermal layer, the less likely the coating will fall off, which is conducive to extending the service life and making the product more environmentally friendly. In order to improve the adhesion performance between the coating and the epidermal layer, the chain segments of the thermoplastic polyester elastomer of the present application contain active functional groups, which can form a strong chemical bond with the components contained in the coating of the present application, thereby increasing the adhesion between the epidermal layer and the coating. In addition, the inventors of the present application also found that the active functional groups in the chain segments of the thermoplastic polyester elastomer can also form a strong chemical bond with the compatible resin, so that the mechanical properties of the obtained epidermal layer (such as tear resistance, tensile strength, etc.) are optimized.

[0083] In this application, active functional groups refer to functional groups that can chemically react with components in the coating. Preferably, these chemical reactions can be completed during conventional preparation processes or conditions for the surface material, preferably using components inherent to the surface layer and coating without the need for the addition of additional components. This has the advantage of achieving good adhesion between the coating and the surface layer during the surface material preparation process without the need for the introduction of additional components or additional processing steps, thereby reducing production costs and improving production efficiency.

[0084] Based on the above considerations, the inventors of this application have creatively discovered that selecting an appropriate crosslinking agent (described below) in the coating material not only improves the properties of the coating itself but also chemically reacts with the active functional groups in the thermoplastic polyester elastomer chain segments to form strong chemical bonds, thereby improving the adhesion between the coating and the surface layer. Preferred active functional groups in the thermoplastic polyester elastomer chain segments include hydroxyl groups, carboxyl groups, amine groups, or combinations thereof.

[0085] The injection-molded skin layer and the coating layer of the present invention can form an excellent bond, forming a two-layer structure. The injection-molded skin layer does not require additional surface polarity treatment or spraying of primer materials, which greatly simplifies the process flow and is more environmentally friendly.

[0086] coating

[0087] The present application applies a suitable coating on the surface of the epidermis layer to give the epidermis material a smooth feel and provide excellent anti-scratch, wear-resistant, light-resistant, and yellowing-resistant properties, thereby extending the service life of the product.

[0088] The coating can be located on one or both sides of the surface layer. For cost considerations, the coating can be provided on only one side of the surface layer. In actual use, the coating is located on the side of the surface layer closest to the user. That is, the user can touch or see the coated surface layer, which can provide a good user experience while protecting against adverse external factors (such as light, weathering, scratches, etc.).

[0089] For environmental and health reasons, it is of great significance to use a water-based coating system to form a coating. In this application, by selecting appropriate coating components, a water-based coating system with good performance is obtained to form the coating of the present invention.

[0090] A suitable film-forming agent in the coating system helps improve the compatibility between the coating and the surface layer, imparting excellent feel and performance to the surface material. Preferred film-forming agents in this application include, but are not limited to, polyacrylates, polyurethanes, or combinations thereof. The film-forming agent content can be 30-45% by weight, based on the total weight of the coating system, for example, approximately 30%, 31.3%, 32%, 34%, 36%, 38%, 38.7%, 40%, 42%, 45%, and the like.

[0091] A suitable crosslinker can not only improve the coating's own properties but also form a good bonding effect with the epidermis of the present application. Suitable reactive groups in the crosslinker can form stable chemical bonds with reactive functional groups on the thermoplastic polyester elastomer molecular segments (as described above). Preferred crosslinkers in the present application include, but are not limited to, aziridine, isocyanate, carbodiimide, or a combination thereof. Unlike conventional methods where crosslinkers are only used to provide a crosslinking effect on the coating itself, the crosslinker of the present application further provides sufficient chemical bonding between the coating and the epidermis. The present application has discovered that this excellent effect can be achieved using an appropriate amount of crosslinker. Based on the total weight of the coating system, the crosslinker content can be 3-15% by weight, for example, about 3%, 4%, 5%, 6%, 8%, 10%, 12%, 14%, 15%, etc. If the crosslinker content is too low, the coating may suffer from insufficient crosslinking, resulting in a decline in its own performance and also impairing the bonding strength between the coating and the epidermis. If the crosslinker content is too high, the crosslinker residue may increase to an undesirable level. Therefore, too high or too low a crosslinking agent content is not conducive to obtaining the desired skin material.

[0092] In one embodiment, in the coating system, the film-forming agent is a polyacrylic resin emulsion, and the cross-linking agent is aziridine. In another embodiment, in the coating system, the film-forming agent is a polyurethane resin emulsion, and the cross-linking agent is isocyanate.

[0093] In coating systems, solvents are used to disperse solid components. Aqueous solvents are preferred in this application to address environmental and health concerns. Preferred solvents include water or alcoholic solvents, such as water, ethanol, and isopropanol. These solvents allow for a good and stable dispersion of the preferred film-forming agents, crosslinking agents, and other components that may be present.

[0094] In order to further improve the feel, weather resistance and other properties of the surface material, appropriate amounts of other additives may be added to the coating, including but not limited to feel agents, leveling agents, anti-fouling agents, etc.

[0095] The feel agent can further optimize the feel of the coating. In one embodiment, the feel agent includes a silane auxiliary agent.

[0096] Leveling agents help the coating form a smooth, even film during drying. They can effectively reduce the surface tension of the coating liquid, improving its leveling and uniformity. Suitable feel agents for this application include polyacrylic acid, carboxymethyl cellulose, or a combination thereof.

[0097] Antifouling agents can improve the antifouling performance of the product. Suitable antifouling agents for the present application include: acrylic fluorine-containing polymers, organosiloxane polymers or combinations thereof.

[0098] The coating system of the present application may further include other additives, such as antioxidants, defoamers, colorants, anti-UV additives, fillers, etc., to improve the coating performance.

[0099] Appropriate coating thickness can improve product performance. Coating thicknesses can range from 5 to 18 μm, such as 5 μm, 6 μm, 8 μm, 10 μm, 12 μm, 14 μm, 16 μm, and 18 μm. A coating that is too thin will compromise the surface protection and performance optimization, while a coating that is too thick may increase the likelihood of coating shedding.

[0100] Appropriate coating density can make the coating provide the desired effect. The density of the coating is 0.7-1.3g / cm 3 , preferably 0.9-1.1g / cm 3 In this article, coating density refers to dry film density, that is, the density of the coating formed after the coating system cures and dries. A coating density that is too low will not significantly improve the smooth feel and weather resistance of the surface layer. A coating density that is too high may increase hardness and reduce the soft touch.

[0101] The coating density can be adjusted by adjusting the appropriate solid content. Solid content is the mass percentage of the remaining portion of the coating after drying under specified conditions. The solid content of the coating system of the present application can be 10-30% by weight.

[0102] In this application, the combination of components and contents in the coating system can obtain a coating that can significantly improve the performance of the epidermis (such as reducing surface viscosity, improving anti-fouling properties, providing a smooth feel, improving weather resistance, etc.), and can also form an excellent bonding effect with the epidermis.

[0103] The thickness of the epidermis and the elongation at break of the coating can satisfy a specific relationship to further optimize product performance. In order to improve the soft touch and appropriately reduce the thickness of the epidermis, the reduction in the thickness of the epidermis may lead to an increase in the stretching borne during actual use. Improving the elongation at break of the coating helps to ensure that the force between the coating and the epidermis changes evenly, but if the elongation at break of the coating is too high, the proportion of soft segment molecules in the corresponding coating material will increase, which is not conducive to maintaining the physical properties of the coating (such as wear resistance, stain resistance, resistance to chemical solvents, etc.). In this application, the elongation at break of the coating matches the thickness of the epidermis. For the applicable epidermis thickness in different applications, a suitable elongation at break of the coating is selected to provide good force uniformity between the coating and the epidermis, and at the same time balance the other physical properties of the coating. The epidermis layer and coating of the present application can satisfy the following relationship: when the thickness of the epidermis layer is 1.5-2.5 mm, the elongation at break of the coating is 100-200%; when the thickness of the epidermis layer is 1.2-1.5 mm, the elongation at break of the coating is 200-300%; when the thickness of the epidermis layer is 0.3-1.2 mm, the elongation at break of the coating is 300-500%.

[0104] The surface material of the present application has good anti-fouling properties. The anti-fouling properties can be evaluated by conventional methods in the field. For example, the water drop angle test using the sessile drop method can be used to judge the anti-fouling properties of the surface by the wetting properties of the surface to water droplets. The larger the water drop angle, the stronger the ability of the surface to resist liquid stains. The water drop angle of the surface material of the present application at room temperature can be above 100°, preferably above 110°, for example, about 100°, 105°, 110°, 111°, 112°, 113°, 115°, 120°, 130°, etc.

[0105] The coating of the present application has good bonding properties with the injection-molded surface layer and can pass the cross-cut test, Taber friction test, alcohol friction resistance test and the like.

[0106] The bond strength between the coating and the skin layer can be assessed using the Taber rub test, based on the change in sample gloss before and after the test. The skin material of this application has a gloss change rate of less than 20%, preferably less than 15%, according to ISO 5470-1-2016. Gloss change rate = (sample gloss before Taber rub test - sample gloss after Taber rub test) / sample gloss before Taber rub test.

[0107] The skin material of the present application has a peeling grade of 1 or 0 according to the cross-cut test of ISO 2409:1992.

[0108] The maximum acceleration of the skin material of the present application measured according to the German automotive industry standard VDA 230-206 Stick-slip test standard is 0.05-1.50; preferably 0.08-1.00, for example, about 0.05, 0.06, 0.07, 0.08, 0.0882, 0.0891, 0.0835, 0.0803, 0.09, 0.1, 0.2, 0.3, 0.4, 0.5, 1.0, 1.5, etc.

[0109] The maximum dynamic friction coefficient of the skin material of the present application measured according to the German automotive industry standard VDA 230-206 Stick-slip test standard is 0.2-1.2, preferably 0.3-1.0, for example, about 0.2, 0.3, 0.3701, 0.3662, 0.3447, 0.4, 0.4231, 0.5, 0.6, 0.7, 0.8, 0.9, 1.0, 1.1, 1.2, etc.

[0110] The maximum static friction coefficient of the skin material of the present application measured according to the German automotive industry standard VDA 230-206 Stick-slip test standard is 0.2-1.50, preferably 0.3-1.2, for example, about 0.2, 0.3, 0.3905, 0.4, 0.4252, 0.4109, 0.4357, 0.5, 0.6, 0.7, 0.8, 0.9, 1.0, 1.1, 1.2, 1.3, 1.4, 1.5, etc.

[0111] The surface material of the present application may have a texture for the purpose of aesthetics, hand feel, etc. The texture of the surface material may be achieved during the process of injection molding the surface layer.

[0112] The coating system of the present application can be formed into a coating by a spraying process. The spraying process is particularly advantageous for surface materials with textures because it can effectively cover the fine structure of the texture. The coating system can be sprayed onto the surface of the surface layer and then cured to obtain a coating. Before spraying, the surface layer can be cleaned to enhance the bonding effect between the coating and the surface layer.

[0113] When the surface layer has texture, the adhesion requirements between the coating and the surface layer are improved. For example, the protruding parts of the texture are more susceptible to wear. Therefore, the excellent adhesion between the coating and the surface layer of the present application can improve the service life and performance of the surface material with texture.

[0114] Including surface materials, vehicle accessories and vehicles

[0115] The surface material of the present invention has a wide range of application scenarios and can be used as a covering material for vehicle accessories. For example, it can be used in the fields of dashboards, door panels, center consoles, armrests, seats, etc.

[0116] The coating of the surface material is located on the side of the surface layer that is closest to the user. That is, the user can touch or see the coated surface layer.

[0117] Herein, vehicles include but are not limited to cars, airplanes, ships, bicycles, trams, trains, subways, and light rails, with cars being preferred.

[0118] In one embodiment, the skin material of the present invention is used as a covering material for vehicle interior parts. Beneficial effects

[0119] In the present invention, a material comprising a thermoplastic polyester elastomer is formed into a skin layer through an injection molding process, which exhibits excellent soft touch and mechanical properties. By applying a suitable coating to the skin layer, the surface feel and weather resistance are further improved. Through rational design of the material and physical properties of the skin layer and coating, the resulting skin material exhibits advantages such as excellent feel, scratch resistance, stain resistance, and weather resistance. Furthermore, the coating and skin layer exhibit strong adhesion, resulting in a good bonding effect. The preparation process of the skin material of the present invention is simple and environmentally friendly, and has excellent market application prospects.

[0120] Example

[0121] The solution of the present invention is further described in detail below with reference to specific embodiments.

[0122] It should be noted that the following embodiments are merely examples for the purpose of clearly illustrating the technical solutions of the present invention and are not intended to limit the present invention. Those skilled in the art will appreciate that other variations or modifications may be made based on the above description. It is not necessary and impossible to enumerate all embodiments here. Obvious variations or modifications derived therefrom remain within the scope of protection of the present invention.

[0123] The samples of the examples and comparative examples of this application were prepared according to the following process:

[0124] Skin layer preparation: The thermoplastic polyester elastomer and compatible resin in the skin layer material are dried, and the remaining additives are added and mixed evenly. The mixture is then homogenized through twin-screw extrusion and granulation, and further baked to obtain the raw material pellets for the skin layer. The raw material pellets for the skin layer are then added to the injection molding machine. The material is heated, melted, and dispersed in the injection molding screw to form a melt. The melt is then injected into the mold cavity at high speed, filling the cavity, and then cooled to form the injection-molded skin layer.

[0125] Coating preparation: After cleaning the surface of the injection-molded skin layer, spray the coating system to form a uniform coating liquid film on the surface of the injection-molded skin layer, and then solidify the coating liquid film to obtain the coating.

[0126] The specific formulas of the samples in the examples are shown in Table 1. Tables 2 and 3 respectively show the specific formulas of the material for forming the skin layer and the specific formulas of the coating system.

[0127] Table 1

[0128] Table 2

[0129] Table 3

[0130] performance

[0131] Stain Resistance Evaluation: The sessile drop method was used to evaluate the stain resistance of the sample using the water drop angle test. The sample was placed flat on a sample table. A water drop was suspended from the tip of a needle. The sample table was raised to contact the sample surface with the suspended drop, and the sample was then removed to complete the droplet transfer. Within (60 ± 10) seconds after the droplet was transferred, the drop angle was measured from the droplet image.

[0132] The surface's stain resistance is determined by its wettability to water droplets. A larger droplet angle indicates a surface's greater resistance to liquid stains. The test results are shown in Table 4 below.

[0133] Table 4

[0134] Figure 1(a) shows that the water drop angle on the surface of the sample from Comparative Example 1 is approximately 89°. Figure 1(b) shows that after the sample from Comparative Example 1 was placed on its side at 90°, the water droplet adhered to the surface. Figure 2(a) shows that the water drop angle on the surface of the sample from Example 2 was approximately 111°. Figure 2(b) shows that after the sample from Example 2 was placed on its side at 90°, the water droplet rolled off without adhering to the surface.

[0135] Abrasion Resistance Evaluation: The abrasion resistance of the surface was evaluated using the Taber abrasion test. Testing was performed according to ISO 5470-1-2016, with a load of 500 g and 500 cycles. The test results are shown in Table 5 below.

[0136] Table 5

[0137] Figures 3(a)-(d) respectively show the surface conditions of the samples of Examples 1-4 after the Taber abrasion test. Figure 4 shows the surface conditions of the sample of Comparative Example 1 after the Taber abrasion test.

[0138] Adhesion testing of coatings and skins

[0139] The sample from Example 1 was subjected to a cross-hatch test under different conditions according to ISO 2409:1992. A series of cuts were made on the coating, taped, and then removed. The cross-hatch pattern was inspected for any coating detachment or delamination. The results are shown in Table 6.

[0140] Cross-cut test result level description: Level 0 - the cut edge is smooth, and no grid has fallen off; Level 1 - a small amount of coating has fallen off at the intersection, and the affected area cannot be significantly larger than 5%; Level 2 - the coating has fallen off at the intersection of the cut or along the cut edge, and the affected area is 5%-15%; Level 3 - the coating has fallen off in a large area along the cut edge partially or completely, and the affected cross-cut area is 15%-35%; Level 4 - the coating has fallen off along the entire edge, and some grids have fallen off partially or completely, and the affected area is 35%-65%; Level 5 - the degree of peeling exceeds Level 4.

[0141] Table 6

[0142] The samples in the examples passed the cross-cut test. Figure 5 shows an image of the sample from Example 1 after the humidity cross-cut test. As can be seen from the image, the cut edges are smooth, with no peeling at all. The coating thickness in Example 4 is 25 μm, which is relatively thick. After ambient storage, the cross-cut test showed significant coating peeling.

[0143] Hand feel test

[0144] Qualitative evaluation:

[0145] The smoothness, softness, warmth and coldness of the touch, and silkiness of the samples were manually rated, and the rating results were averaged. The average value represents the human sensory rating result of the sample. The results are shown in Table 7 below.

[0146] Smoothness test result description: 1 point - rough; 2 points - relatively rough; 3 points - average; 4 points - relatively smooth; 5 points - smooth.

[0147] Softness test result description: 1 point - hard; 2 points - relatively hard; 3 points - average; 4 points - relatively soft; 5 points - soft.

[0148] Description of the tactile warmth and coldness test results: 1 point - cold; 2 points - relatively cold; 3 points - average; 4 points - relatively warm; 5 points - warm.

[0149] Description of silkiness test results: 1 point - dry; 2 points - relatively dry; 3 points - average; 4 points - relatively sticky; 5 points - sticky.

[0150] Table 7

[0151] In the qualitative evaluation of the hand feel test, the sample of Example 1 scored higher on average than the sample of Comparative Example 1 without coating, that is, Example 1 had a better hand feel.

[0152] Quantitative evaluation:

[0153] According to the German automotive industry standard VDA 230-206, stick-slip testing was performed on the samples of the examples and comparative examples using the Zins-Ziegler-Instruments Stick-Slip Test Stand SSP-04. Figure 6 shows the stick-slip testing apparatus, and the test results are shown in Figures 7-8. Specific test results are summarized in Table 8 below.

[0154] Table 8

[0155] Abnormal Noise Level*: A comprehensive evaluation result based on pulse rate, pulse value, maximum acceleration, and other related parameters, determined by the test instrument's software. The lower the level, the better the performance of the measured sample.

[0156] The stick-slip test results above demonstrate that Example 1 achieved a noise level of 1, significantly lower than that of Comparative Example 1. For the test samples, the lower the maximum acceleration of the surface, the lower the dynamic and static friction coefficients, and the smoother the surface feel. The maximum acceleration, maximum dynamic friction coefficient, and maximum static friction coefficient of the sample in Example 1 were all lower than those of Comparative Example 1, indicating a smoother feel.

[0157] It will be apparent to those skilled in the art that many modifications and variations of the present invention may be made without departing from its spirit and scope. The specific embodiments described herein are provided by way of example only and are not intended to be limiting in any way. The true scope and spirit of the present invention are shown by the appended claims, and the description and examples are merely exemplary.

Claims

1. A skin material for a carrier, comprising: A skin layer formed of a material including a thermoplastic polyester elastomer by an injection molding process; and A coating layer is located on the surface of the epidermis layer.

2. The skin material according to claim 1, wherein The epidermis comprises: A soft foam layer, and self-skinning layers located on both sides of the soft foam layer.

3. The surface material according to claim 1 or 2, wherein The thermoplastic polyester elastomer contains active functional groups in its chain segments; Preferably, The active functional groups include: hydroxyl, carboxyl, amine or a combination thereof.

4. The surface material according to claim 1 or 2, wherein The thermoplastic polyester elastomer comprises a hard segment and a soft segment, The hard segment of the thermoplastic polyester elastomer includes: polybutylene terephthalate, polyethylene terephthalate, polypropylene terephthalate, poly-1,4-dimethylene cyclohexane terephthalate, poly-2,6-butylene naphthalate, poly-xylene terephthalate, polyethylene terephthalate / polybutylene terephthalate copolymer, poly-dimethyl terephthalate / isophthalate / 1,4-butanediol copolymer, poly-2,5-furandicarboxylic acid ethylene glycol, poly-2,5-furandicarboxylic acid propylene glycol, poly-2,5-furandicarboxylic acid butylene glycol, poly-2,5-furandicarboxylic acid hexanediol or a combination thereof; preferably includes: polybutylene terephthalate, poly-2,5-furandicarboxylic acid butylene glycol or a combination thereof; The soft segment of the thermoplastic polyester elastomer includes: polyethylene glycol, polybutylene glycol, polycaprolactone, polymethyl glycol, fatty acid dimer glycol, polytetramethylene ether, ethylene oxide-propylene oxide copolymer bisphenol A ether, polypropylene glycol, polylactide, polyglycolide or a combination thereof; preferably includes: polyethylene glycol, polycaprolactone, polytetramethylene ether or a combination thereof.

5. The surface material according to claim 1 or 2, wherein The material forming the skin layer further comprises: a compatible resin, a plasticizer or a combination thereof; Preferably, The compatible resin includes: polybutylene terephthalate, polyethylene terephthalate, polyamide, acrylonitrile-butadiene-styrene copolymer, polycarbonate, epoxy resin or a combination thereof, The plasticizer includes: phthalate compounds, phthalate compounds, aliphatic dibasic acid compounds, epoxy ester compounds, phosphate compounds or a combination thereof.

6. The surface material according to claim 1 or 2, wherein The material forming the skin layer has a melt index of 50-400 g / 10 min, preferably 200-300 g / 10 min, measured at 220° C. and 2.16 kg; and / or The density of the material forming the epidermis is 0.95-1.15 g / cm 3 , preferably 1.05-1.15g / cm 3 .

7. The surface material according to claim 1 or 2, wherein The coating is formed by a coating system, and the coating system comprises: a film former and a cross-linking agent; Preferably, The film-forming agent includes: polyacrylate, polyurethane or a combination thereof; The cross-linking agent includes: aziridine, isocyanate, carbodiimide or a combination thereof.

8. The surface material according to claim 7, wherein The coating system further comprises: a solvent, a feel agent, a leveling agent, an antifouling agent or a combination thereof; Preferably, The solvent includes: water, ethanol, isopropanol or a combination thereof; The hand feeling agent includes: silane additives; The leveling agent includes: polyacrylic acid, carboxymethyl cellulose or a combination thereof; The antifouling agent includes: acrylic fluorine-containing polymer, organic siloxane polymer or a combination thereof.

9. The surface material according to claim 8, wherein The solid content of the coating system is 10-30% by weight.

10. The surface material according to claim 1 or 2, wherein The coating has a thickness of 5-18 μm; and / or The density of the coating is 0.7-1.3 g / cm 3 , preferably 0.9-1.1g / cm 3 .

11. The surface material according to claim 1 or 2, wherein The coating is formed by a spraying process.

12. The surface material according to claim 1 or 2, wherein The skin material has a texture.

13. The surface material according to claim 1 or 2, wherein The epidermis and the coating satisfy the following relationship: When the thickness of the epidermis is 1.5-2.5 mm, the elongation at break of the coating is 100-200%; When the thickness of the epidermis is 1.2-1.5 mm, the elongation at break of the coating is 200-300%; When the thickness of the skin layer is 0.3-1.2 mm, the elongation at break of the coating is 300-500%.

14. The surface material according to claim 1 or 2, wherein The skin material has one or more of the following: The water drop angle of the skin material at room temperature is above 100°, preferably above 110°; The gloss change rate of the skin material according to ISO 5470-1-2016 is less than 20%, preferably less than 15%; The peeling grade of the skin material according to the cross-cut test of ISO 2409:1992 is 1 or 0; The maximum acceleration of the skin material measured according to the German automotive industry standard VDA 230-206 Stick-slip test standard is 0.05-1.50; preferably 0.08-1.00; The maximum dynamic friction coefficient of the skin material measured according to the German automotive industry standard VDA 230-206 Stick-slip test standard is 0.2-1.2, preferably 0.3-1.0; The maximum static friction coefficient of the skin material measured according to the German automotive industry standard VDA 230-206 Stick-slip test standard is 0.2-1.50, preferably 0.3-1.

2.

15. A vehicle trim comprising the skin material according to any one of claims 1 to 14, Preferably, the vehicle trim comprises: Dashboard, door panels, center console, armrests or seats.

16. A vehicle, comprising the vehicle trim according to claim 15, Preferably, the vehicle includes a car, an airplane, a ship, a bicycle, a tram, a train, a subway, or a light rail.

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