Composite material and preparation method thereof

Abstract

The invention discloses a composite material and a preparation method thereof, and belongs to the field of organic materials. The composite material comprises a transparent base material layer and a first protective layer stacked on the transparent base material layer. The preparation raw materials of the transparent base material layer comprise a base material, an ultraviolet light absorber and an antioxidant; the preparation raw material of the first protective layer is selected from at least one of polyfunctional group acrylic resin, epoxy modified acrylic resin, polyurethane modified acrylic resin, fluoropolyether modified acrylic resin, polysiloxane resin, epoxy resin and polyurethane resin. The composite material not only has excellent anti-ultraviolet yellowing performance, but also has excellent anti-smudginess yellowing performance.

Description

Technical Field

[0001] The present disclosure relates to the field of organic materials, and in particular to composite materials and preparation methods thereof. Background Art

[0002] The transparent protective case of the mobile phone can not only protect the mobile phone, but also display the material and design of the mobile phone itself. TPU (Thermoplastic Urethane) is usually used to prepare transparent protective cases due to its high transparency and low hardness.

[0003] However, the transparent protective case made of TPU material is prone to irreversible yellowing after a certain period of use, which affects the user experience. It can be seen that it is very necessary to improve the yellowing resistance of the transparent protective case.

[0004] Public Content

[0005] In view of this, the present disclosure provides a composite material and a preparation method thereof, which can solve the technical problem that the transparent protective cover in the related art has poor yellowing resistance.

[0006] Specifically, the following technical solutions are included:

[0007] In one aspect, a composite material is provided, the composite material comprising: a transparent substrate layer and a first protective layer stacked on the transparent substrate layer;

[0008] The raw materials for preparing the transparent substrate layer include a base material, an ultraviolet absorber and an antioxidant;

[0009] The raw material for preparing the first protective layer is selected from at least one of multifunctional acrylic resin, epoxy-modified acrylic resin, polyurethane-modified acrylic resin, fluoropolyether-modified acrylic resin, polysiloxane resin, epoxy resin, and polyurethane resin.

[0010] The composite material provided by the embodiment of the present disclosure includes a transparent substrate layer and a first protective layer. By making the raw materials for preparing the transparent substrate layer include an ultraviolet absorber and an antioxidant, the ultraviolet absorber can absorb ultraviolet rays, reduce the damage caused by UV light irradiation of the transparent substrate layer, improve its weather resistance and aging resistance, thereby delaying its yellowing. The antioxidant and the ultraviolet absorber work synergistically to achieve a good synergistic anti-aging effect, and further improve the UV yellowing resistance of the transparent substrate layer itself. By arranging the first protective layer on the transparent substrate layer, the raw materials for preparing the first protective layer are selected from at least one of multifunctional acrylic resin, epoxy-modified acrylic resin, polyurethane-modified acrylic resin, fluoropolyether-modified acrylic resin, polysiloxane resin, epoxy resin, and polyurethane resin. Such resin layers have good compactness and hardness, which can avoid yellowing caused by the penetration of sweat and dirt such as cosmetics into the transparent substrate layer, and at the same time improve its wear resistance, thereby increasing its yellowing resistance life. It can be seen that the composite material provided by the embodiment of the present disclosure not only has excellent anti-ultraviolet yellowing performance, but also has excellent anti-dirty yellowing performance.

[0011] In some possible implementations, the curing degree of the first protective layer is greater than or equal to 85%, thereby ensuring high density of the first protective layer and effectively preventing dirt such as chemicals and moisture from penetrating into the transparent substrate layer.

[0012] In some possible implementations, the composite material further includes: a second protective layer, and the second protective layer is selected from one of a reflection-enhancing layer and a dirt-resistant layer.

[0013] In some possible implementations, the composite material further includes: a third protective layer, and the third protective layer is selected from the other one of the reflection-enhancing layer and the anti-fouling layer.

[0014] The reflective enhancement layer can further improve the surface hardness of the composite material, and can also reflect UV light, further preventing UV light from entering the transparent substrate layer, and effectively improving the UV yellowing resistance of the composite material.

[0015] The anti-fouling layer can improve the surface hydrophobicity and oleophobicity of the composite material and reduce the residual dirt on its surface. This can effectively prevent dirt such as chemicals and water from invading the transparent substrate layer, and further avoid yellowing of the transparent substrate layer caused by the intrusion of dirt such as chemicals and water.

[0016] In some possible implementations, the raw material for preparing the reflection enhancement layer includes at least one of titanium oxide, zirconium oxide, tin oxide, zinc oxide, silicon oxide, niobium oxide, aluminum oxide, chromium oxide, magnesium oxide, germanium oxide, gallium oxide, antimony oxide, and platinum oxide.

[0017] In some possible implementations, the raw material for preparing the anti-fouling layer is at least one of a fluorine-containing multifunctional acrylic resin, a fluorine-containing epoxy-modified acrylic resin, a fluorine-containing polyurethane-modified acrylic resin, a fluorine-containing fluoropolyether-modified acrylic resin, a fluorine-containing polysiloxane resin, a fluorine-containing epoxy resin, and a fluorine-containing polyurethane resin.

[0018] In some possible implementations, the anti-fouling layer is an anti-fingerprint coating.

[0019] The anti-fingerprint coating has good hydrophobicity and oleophobicity, which can make the composite material have an excellent smooth feel and is not easy to produce fingerprints.

[0020] In some possible implementations, the base material satisfies at least one of the following conditions: light transmittance ≥ 50%, haze ≤ 20%, hardness ≥ Shore hardness 60A, tensile strength ≥ 30 MPa, and elongation at break ≥ 50%.

[0021] By limiting the physical properties of the base material as above, it is ensured that the transparent substrate has good transparency, impact resistance and touch feel, thereby meeting the needs of protective cases for hand-touch devices such as mobile phones.

[0022] In some possible implementations, the base material is selected from at least one of TPU, TPE, TPEE, PC, PMMA, TPO, and transparent nylon.

[0023] In some possible implementations, in the raw materials for preparing the transparent substrate layer, the mass percentage of the base material is 94%-97%, the mass percentage of the ultraviolet absorber is 2%-5%, and the mass percentage of the antioxidant is 0.1%-1.5%.

[0024] In some possible implementations, the composite material is in the form of a plate.

[0025] In some possible implementations, the composite material has a structural form of a shell.

[0026] In some possible implementations, the shell is a protective shell of a handheld device, and the handheld device includes a mobile phone, a tablet computer, a camera, or a remote control, for example, a mobile phone protective shell.

[0027] In another aspect, a method for preparing a composite material is provided, wherein the composite material is as described above;

[0028] The method for preparing the composite material comprises: preparing a transparent substrate layer;

[0029] A first protective layer is prepared on at least one surface of the transparent substrate layer.

[0030] In some possible implementations, the method for preparing the composite material further includes: preparing a second protective layer on a surface of the first protective layer away from the transparent substrate layer.

[0031] In some possible implementations, the method for preparing the composite material further includes: preparing a third protective layer on a surface of the second protective layer away from the first protective layer. BRIEF DESCRIPTION OF THE DRAWINGS

[0032] Figure 1 A schematic diagram of the structure of a first exemplary composite material provided in an embodiment of the present disclosure;

[0033] Figure 2 A schematic diagram of the structure of a second exemplary composite material provided in an embodiment of the present disclosure;

[0034] Figure 3 A schematic diagram of the structure of a third exemplary composite material provided in an embodiment of the present disclosure;

[0035] Figure 4 A schematic structural diagram of a fourth exemplary composite material provided in an embodiment of the present disclosure;

[0036] Figure 5 A schematic diagram of the structure of a fifth exemplary composite material provided in an embodiment of the present disclosure.

[0037] The reference numerals represent:

[0038] 100. A transparent substrate layer;

[0039] 200, first protective layer;

[0040] 300, second protective layer;

[0041] 400, the third protective layer;

[0042] 001, reflective layer;

[0043] 002. Dirt-resistant layer. DETAILED DESCRIPTION

[0044] The following will be combined with the drawings in the embodiments of the present disclosure to clearly and completely describe the technical solutions in the embodiments of the present disclosure. Obviously, the described embodiments are part of the embodiments of the present disclosure, rather than all of the embodiments. Based on the embodiments in the present disclosure, all other embodiments obtained by ordinary technicians in this field without creative work are within the scope of protection of the present disclosure.

[0045] Exemplary embodiments will be described in detail herein, examples of which are shown in the accompanying drawings. When the following description refers to the drawings, the same numbers in different drawings represent the same or similar elements unless otherwise indicated. The embodiments described in the following exemplary embodiments do not represent all embodiments consistent with the present disclosure. Instead, they are merely examples of devices and methods consistent with some aspects of the present disclosure as detailed in the appended claims.

[0046] In the description of the present disclosure, it should be understood that the terms "upper" and "lower" and the like indicate positions or positional relationships based on the positions or positional relationships shown in the drawings, and are only for the convenience of describing the present disclosure and simplifying the description, rather than indicating or implying that the device or element referred to must have a specific position, be constructed and operated in a specific position, and therefore cannot be understood as limiting the present disclosure. For example, these positional nouns are generally used in Figure 1-Figure 5 The relative relationship of the orientation shown in the figure is used as the basis, and these orientation terms are used only to more clearly describe the relationship between structures, not to describe absolute orientation. When the product is placed in different postures, the orientation may change, for example, "up" and "down" may be interchangeable.

[0047] In the related art, after a certain period of use, a transparent protective case made of TPU material is easily affected by ultraviolet (UV) and becomes irreversibly yellowed, thus affecting the user experience. It can be seen that it is very necessary to improve the yellowing resistance of the transparent protective case.

[0048] The present disclosure provides a composite material, which includes: a transparent substrate layer and a first protective layer stacked on the transparent substrate layer. The raw materials for preparing the transparent substrate layer include a base material, an ultraviolet absorber and an antioxidant; the raw materials for preparing the first protective layer are selected from at least one of a multifunctional acrylic resin, an epoxy-modified acrylic resin, a polyurethane-modified acrylic resin, a fluoropolyether-modified acrylic resin, a polysiloxane resin, an epoxy resin, and a polyurethane resin.

[0049] The composite material provided by the embodiment of the present disclosure includes a transparent substrate layer and a first protective layer. By making the raw materials for preparing the transparent substrate layer include an ultraviolet absorber and an antioxidant, the ultraviolet absorber can absorb ultraviolet rays, reduce the damage caused by UV light irradiation of the transparent substrate layer, improve its weather resistance and aging resistance, thereby delaying its yellowing. The antioxidant and the ultraviolet absorber work synergistically to achieve a good synergistic anti-aging effect, and further improve the UV yellowing resistance of the transparent substrate layer itself. By arranging the first protective layer on the transparent substrate layer, the raw materials for preparing the first protective layer are selected from at least one of multifunctional acrylic resin, epoxy-modified acrylic resin, polyurethane-modified acrylic resin, fluoropolyether-modified acrylic resin, polysiloxane resin, epoxy resin, and polyurethane resin. Such resin layers have good compactness and hardness, which can avoid yellowing caused by the penetration of sweat and dirt such as cosmetics into the transparent substrate layer, and at the same time improve its wear resistance, thereby increasing its yellowing resistance life. It can be seen that the composite material provided by the embodiment of the present disclosure not only has excellent anti-ultraviolet yellowing performance, but also has excellent anti-dirty yellowing performance.

[0050] Research has found that cosmetics, hand creams and other chemicals usually remain on the hands of users. When the chemicals remaining on the hands of users penetrate into materials such as TPU together with hand sweat, the chemical compounds contained in the materials, such as tocopherol acetate, are easily hydrolyzed into tocopherol, which is oxidized into tocopherol quinone under the promotion of hand sweat and light. Tocopherol quinone is yellowish brown, which causes yellowing of the material due to the infiltration of dirt. The disclosed embodiment further adds a first protective layer on the transparent substrate layer, and utilizes its good density and hardness characteristics to effectively prevent the intrusion of chemicals and hand sweat into the transparent substrate layer, thereby improving its anti-dirty and yellowing effect.

[0051] For the transparent substrate layer, the base material used therein satisfies at least one of the following conditions: light transmittance ≥ 50%, haze ≤ 20%, hardness ≥ Shore hardness 60A, tensile strength ≥ 30 MPa, and elongation at break ≥ 50%.

[0052] In some examples, the base material can at least meet the requirements of light transmittance ≥ 50% and haze ≤ 20%. On this basis, the base material can meet at least one of the following conditions: hardness ≥ Shore hardness 60A, tensile strength ≥ 30 MPa, and elongation at break ≥ 50%. For example, the base material can meet all of the above conditions at the same time.

[0053] By limiting the physical properties of the base material as above, it is ensured that the transparent substrate has good transparency, impact resistance and touch feel, thereby meeting the needs of protective cases for hand-touch devices such as mobile phones.

[0054] Exemplarily, the matrix material satisfying at least one of the above conditions can be selected from at least one of TPU (Thermoplastic Urethane, thermoplastic polyurethane elastomer), TPE (Thermoplastic Elastomer, thermoplastic elastomer), TPEE (Thermoplastic Polyester Elastomer, thermoplastic polyester elastomer), PC (Polycarbonate, polycarbonate), PMMA (Polymethyl Methacrylate, polymethyl methacrylate), TPO (Thermoplastic polyolefin, thermoplastic polyolefin), and transparent nylon.

[0055] In the embodiments of the present disclosure, ultraviolet absorbers that can be applied to the above-mentioned base material and achieve good ultraviolet absorption effect include but are not limited to: salicylate ultraviolet absorbers, benzophenone ultraviolet absorbers, benzotriazole ultraviolet absorbers, substituted acrylonitrile ultraviolet absorbers, triazine ultraviolet absorbers and hindered amine ultraviolet absorbers.

[0056] For example, the ultraviolet absorbers involved in the embodiments of the present disclosure include but are not limited to the following: ultraviolet absorber UV-0 (2,4-dihydroxybenzophenone), ultraviolet absorber UV-1 (N-(ethoxycarbonylphenyl)-N'-methyl-N'-phenylformamidine), ultraviolet absorber UV-9 (4-methoxy-2-hydroxybenzophenone), ultraviolet absorber UV-234 (2-(2H-benzotriazole-2)-4,6-bis(1-methyl-1-phenylethyl)phenol), ultraviolet absorber UV-326 (2'-(2'-hydroxy-3'-tert-butyl-5'-methylphenyl)-5-chlorobenzotriazole), ultraviolet absorber UV-327 (2-(2'-hydroxy-3',5'-di-tert-butylphenyl)-5-chlorobenzotriazole), ultraviolet absorber UV-328 (2 -(2'-hydroxy-3',5'-di-tert-amylphenyl)benzotriazole), UV-329 (2-(2'-hydroxy-5'-tert-octylphenyl)benzotriazole), UV-360 (2,2'-methylenebis(4-tert-octyl-6-benzotriazolephenol)), UV-531 (2-hydroxy-4-n-octyloxybenzophenone), UV-1164 (2-(4,6-bis(2,4-dimethylphenyl)-1,3,5-triazine-2-yl)-5-octyloxyphenol), UV-1577 (2-(4,6-diphenyl-1,3,5-triazine-2-yl)-5-hexyloxy-phenol), UV-P (2-(2'-hydroxy-5'-methylphenyl)benzotriazole).

[0057] In the embodiments of the present disclosure, the antioxidant that can be applied to the above-mentioned base material and can act synergistically with the ultraviolet absorber can be a hindered phenol antioxidant, a thioester antioxidant, etc. Some exemplary antioxidants include but are not limited to: antioxidant 1010, antioxidant 1076, antioxidant 168, antioxidant 245, antioxidant 1790, antioxidant 330, antioxidant DSTP, antioxidant DSTDP, etc.

[0058] In some examples, based on 100% by mass of the raw materials for preparing the transparent substrate layer, the mass percentage of the base material is 94%-97%, the mass percentage of the ultraviolet absorber is 2%-5%, and the mass percentage of the antioxidant is 0.1%-1.5%.

[0059] Illustratively, the mass percentage of the matrix material includes but is not limited to 94%, 94.5%, 95%, 95.5%, 96%, 96.5%, 97% and the like, the mass percentage of the UV absorber includes but is not limited to 2%, 2.5%, 3%, 3.5%, 4%, 4.5%, 5% and the like, and the mass percentage of the antioxidant includes but is not limited to 0.1%, 0.2%, 0.3%, 0.4%, 0.5%, 0.6%, 0.7%, 0.8%, 0.9%, 1%, 1.1%, 1.2%, 1.3%, 1.4%, 1.5% and the like.

[0060] The base material, ultraviolet absorber and antioxidant work synergistically in the above ratio to ensure that the prepared transparent substrate layer has excellent transparency, mechanical properties and touch, as well as excellent resistance to UV yellowing and dirt yellowing.

[0061] When used, the base material can be in the form of particles. For example, the particle size of the base material particles can be 1 mm-10 mm, which is conducive to storage and melting processing.

[0062] In the disclosed embodiment, the first protective layer is a dense resin layer, and its degree of curing is greater than or equal to 85%. For example, its degree of curing can be further greater than or equal to 90%, and further greater than or equal to 95%. This can ensure that the first protective layer has high density and effectively prevents chemicals, moisture and other dirt from penetrating into the transparent substrate layer.

[0063] The raw material for preparing the first protective layer is selected from at least one of multifunctional acrylic resin, epoxy-modified acrylic resin, polyurethane-modified acrylic resin, fluoropolyether-modified acrylic resin, polysiloxane resin, epoxy resin and polyurethane resin.

[0064] The functionality of the multifunctional acrylic resin may be 2-12, and further 2-6. Some applicable multifunctional acrylic resins include but are not limited to polyurethane acrylates, polyester acrylates, epoxy acrylates, and the like.

[0065] Taking multifunctional polyurethane acrylates as an example, this includes but is not limited to at least one of aromatic polyurethane hexaacrylate resin, aromatic polyurethane triacrylate resin, aromatic polyurethane diacrylate resin, aliphatic polyurethane methyl pentaacrylate resin, aliphatic polyurethane methyl hexaacrylate resin, aliphatic polyurethane methyl tetraacrylate resin, aliphatic polyurethane trimethacrylate resin, aliphatic polyurethane tetramethacrylate resin and aliphatic polyurethane pentamethacrylate resin.

[0066] In some implementations, the composite material provided by the embodiments of the present disclosure further includes: a second protective layer, wherein the second protective layer is selected from one of a reflection enhancement layer and a dirt resistance layer.

[0067] The reflective enhancement layer can further improve the surface hardness of the composite material, and can also reflect UV light, further preventing UV light from entering the transparent substrate layer, and effectively improving the UV yellowing resistance of the composite material.

[0068] The anti-fouling layer can improve the surface hydrophobicity and oleophobicity of the composite material and reduce the residual dirt on its surface. This can effectively prevent dirt such as chemicals and water from invading the transparent substrate layer, and further avoid yellowing of the transparent substrate layer caused by the intrusion of dirt such as chemicals and water.

[0069] In some implementations, the composite material provided by the embodiments of the present disclosure further includes: a third protective layer, the third protective layer is different from the second protective layer, and the third protective layer is selected from another one of a reflection-enhancing layer and a dirt-resistant layer.

[0070] By further arranging the third protective layer, it is further ensured that the transparent substrate layer can not only effectively prevent the yellowing of the transparent substrate layer due to UV light, but also effectively prevent the yellowing of the transparent substrate layer due to the intrusion of dirt such as chemicals and moisture.

[0071] In some examples, such as the attached Figure 1 As shown, the composite material provided by the embodiment of the present disclosure includes: a transparent substrate layer 100 and a first protective layer 200, the first protective layer 200 is stacked and arranged on at least one surface of the transparent substrate layer 100, for example, the first protective layer 200 is stacked and arranged on Figure 1 The upper surface of the transparent substrate layer 100 is shown. Of course, the first protective layer 200 can be further stacked on the lower surface of the transparent substrate layer 100 .

[0072] In some examples, such as the attached Figure 2As shown, the composite material provided by the embodiment of the present disclosure includes: a transparent substrate layer 100, a first protective layer 200 and a second protective layer 300, wherein the first protective layer 200 is stacked and arranged on at least one surface of the transparent substrate layer 100, and the second protective layer 300 is stacked and arranged on a surface of the first protective layer 200 away from the transparent substrate layer 100. The second protective layer 300 is a reflection enhancement layer 001.

[0073] In some examples, such as the attached Figure 3 As shown, the composite material provided by the embodiment of the present disclosure includes: a transparent substrate layer 100, a first protective layer 200 and a second protective layer 300, wherein the first protective layer 200 is stacked and arranged on at least one surface of the transparent substrate layer 100, and the second protective layer 300 is stacked and arranged on a surface of the first protective layer 200 away from the transparent substrate layer 100. Among them, the second protective layer 300 is an anti-fouling layer 002.

[0074] In some examples, such as the attached Figure 4 As shown, the composite material provided by the embodiment of the present disclosure includes: a transparent substrate layer 100, a first protective layer 200, a second protective layer 300 and a third protective layer 400, wherein the first protective layer 200 is stacked and arranged on at least one surface of the transparent substrate layer 100, the second protective layer 300 is stacked and arranged on the surface of the first protective layer 200 away from the transparent substrate layer 100, and the third protective layer 400 is stacked and arranged on the surface of the second protective layer 300 away from the first protective layer 200. Among them, the second protective layer 300 is a reflection enhancement layer 001, and the third protective layer 400 is an anti-fouling layer 002.

[0075] In some examples, such as the attached Figure 5 As shown, the composite material provided by the embodiment of the present disclosure includes: a transparent substrate layer 100, a first protective layer 200, a second protective layer 300 and a third protective layer 400, wherein the first protective layer 200 is stacked and arranged on at least one surface of the transparent substrate layer 100, the second protective layer 300 is stacked and arranged on the surface of the first protective layer 200 away from the transparent substrate layer 100, and the third protective layer 400 is stacked and arranged on the surface of the second protective layer 300 away from the first protective layer 200. Among them, the second protective layer 300 is an anti-fouling layer 002, and the third protective layer 400 is a reflection enhancement layer 001.

[0076] On the basis of ensuring the yellowing resistance of the composite material, the thickness of each layer can be determined according to the actual application scenario of the composite material.

[0077] Taking the composite material used as the shell as an example, the thickness of the transparent substrate layer can be 0.3mm-2mm, the thickness of the first protective layer can be 1μm-30μm, the thickness of the reflection enhancement layer can be 10nm-300nm, and the thickness of the anti-fouling layer can be 1μm-10μm.

[0078] The thickness of the transparent substrate layer includes but is not limited to 0.3 mm, 0.4 mm, 0.5 mm, 0.6 mm, 0.7 mm, 0.8 mm, 0.9 mm, 1 mm, 1.1 mm, 1.2 mm, 1.3 mm, 1.4 mm, 1.5 mm, 1.6 mm, 1.7 mm, 1.8 mm, 1.9 mm, 2 mm, etc.

[0079] The thickness of the first protective layer includes but is not limited to 1μm, 5μm, 6μm, 7μm, 8μm, 9μm, 10μm, 11μm, 12μm, 13μm, 14μm, 15μm, 16μm, 17μm, 18μm, 19μm, 20μm, 21μm, 22μm, 23μm, 24μm, 25μm, 26μm, 27μm, 28μm, 29μm, 30μm, etc.

[0080] The thickness of the reflection-enhancing layer includes but is not limited to 50 nm, 70 nm, 100 nm, 120 nm, 150 nm, 170 nm, 200 nm, 230 nm, 250 nm, 280 nm, 300 nm, etc.

[0081] The thickness of the anti-fouling layer includes but is not limited to 1 μm, 2 μm, 3 μm, 4 μm, 5 μm, 6 μm, 7 μm, 8 μm, 9 μm, 10 μm, etc.

[0082] In the embodiment of the present disclosure, the raw materials for preparing the reflection enhancement layer include at least one of titanium oxide, zirconium oxide, tin oxide, zinc oxide, silicon oxide, niobium oxide, aluminum oxide, chromium oxide, magnesium oxide, germanium oxide, gallium oxide, antimony oxide, and platinum oxide.

[0083] The reflection-enhancing layer may be a single-layer structure, which is prepared by any of the above-mentioned metal oxides. The reflection-enhancing layer may also be a multi-layer structure, wherein the multiple layers are prepared by using different metal oxides respectively.

[0084] The anti-reflection layer prepared by using the metal oxide can achieve a reflectivity of ≥20% for UV light with a wavelength of 280nm-400nm and a reflectivity of ≤5% in the visible light region of 400nm-700nm.

[0085] In the disclosed embodiment, the raw material for preparing the anti-fouling layer is at least one of fluorine-containing multifunctional acrylic resin, fluorine-containing epoxy-modified acrylic resin, fluorine-containing polyurethane-modified acrylic resin, fluorine-containing fluoropolyether-modified acrylic resin, fluorine-containing polysiloxane resin, fluorine-containing epoxy resin, and fluorine-containing polyurethane resin. Fluorine is added to the above resins to improve their hydrophobic and oleophobic properties.

[0086] For example, the anti-fouling layer involved in the embodiment of the present disclosure is an anti-fingerprint coating (AFC), which has good hydrophobicity and oleophobicity, which can make the composite material have an excellent smooth feel and is not easy to produce fingerprints. The anti-fingerprint coating currently disclosed in the art is applicable to the embodiment of the present disclosure.

[0087] In some examples, for the first protective layer, its modulus can be 1 GPa-10 GPa, which includes but is not limited to 1 GPa, 2 GPa, 3 GPa, 4 GPa, 5 GPa, 6 GPa, 7 GPa, 8 GPa, 9 GPa, 10 GPa, etc., so that the first protective layer has a desired hardness.

[0088] In some examples, for the anti-fouling layer, its modulus can be 1 GPa-10 GPa, which includes but is not limited to 1 GPa, 2 GPa, 3 GPa, 4 GPa, 5 GPa, 6 GPa, 7 GPa, 8 GPa, 9 GPa, 10 GPa, etc., so that the anti-fouling layer has a desired hardness.

[0089] For the anti-fouling layer, its water drop angle is ≥90°, and its oil drop angle is ≥50°. For example, the water drop angle of the anti-fouling layer can be greater than or equal to 100°, 110°, 120°, 130°, etc., and the oil drop angle can be greater than or equal to 60°, 70°, 80°, 90°, etc. In this way, the anti-fouling layer has excellent hydrophobic and oleophobic properties to prevent dirt from adhering to its surface.

[0090] The composite material provided by the embodiments of the present disclosure can be designed into various structural forms so that it can be applied in various application scenarios.

[0091] One example is that the composite material has a structural form of a plate, and the composite material in the form of a plate can be cut into a variety of shapes, and can also be formed into a variety of shapes by molds, and is suitable for existing in a flat state. For example, the plate can be used as a surface protection pad, such as for a desktop, etc.

[0092] Another example is that the structure of the composite material is in the form of a shell. For example, the shell can be a protective shell for a handheld device, wherein the handheld device involved includes but is not limited to a mobile phone, a tablet computer, a camera, a remote control, and the like.

[0093] In some embodiments, the embodiments of the present disclosure provide a mobile phone protective case, the material of which is the composite material involved in the embodiments of the present disclosure, so that even if the user's hands are sweaty or there are chemicals such as cosmetics and hand creams on their hands and touch the mobile phone protective case for a long time, the mobile phone protective case will not turn yellow.

[0094] The plate or shell provided in the embodiment of the present disclosure has all the advantages mentioned in the composite material. That is to say, the plate or shell provided in the embodiment of the present disclosure has at least excellent anti-UV yellowing ability, anti-dirty yellowing ability, and impact resistance. Furthermore, the shell also has excellent smoothness and anti-fingerprint performance.

[0095] On the other hand, the present disclosure also provides a method for preparing a composite material, which comprises: preparing a transparent substrate layer; and preparing a first protective layer on at least one surface of the transparent substrate layer. Thus, a composite material including a transparent substrate layer and a first protective layer can be prepared.

[0096] Furthermore, the method for preparing the composite material provided in the embodiment of the present disclosure also includes: preparing a second protective layer on the surface of the first protective layer away from the transparent substrate layer. Thus, a composite material including the transparent substrate layer, the first protective layer and the second protective layer can be prepared.

[0097] Furthermore, the method for preparing the composite material provided in the embodiment of the present disclosure also includes: preparing a third protective layer on the surface of the second protective layer away from the first protective layer. Thus, a composite material including a transparent substrate layer, a first protective layer, a second protective layer and a third protective layer can be prepared.

[0098] For the preparation of the transparent substrate layer, its preparation process can be adaptively designed according to the structural form of the composite material. For example, for a composite material in the form of a plate, the preparation method of the transparent substrate layer includes: using the raw materials for preparing the transparent substrate layer, through a coating process, to prepare the transparent substrate layer on a substrate. Among them, some applicable coating processes include but are not limited to: spraying, dipping, blade coating, roller coating, ultrasonic spraying, slit coating, etc.

[0099] For the composite material in the form of a shell, the preparation method of the transparent substrate layer includes: using the raw material for preparing the transparent substrate layer, through an injection molding process, a hot pressing molding process or an extrusion molding process, to obtain the transparent substrate layer. Wherein, when the transparent substrate layer is formed by injection molding, a mold with a specific structural form is used to obtain the transparent substrate layer with a specific structural form.

[0100] For the preparation of the first protective layer, the first protective layer can be prepared on the transparent substrate layer by using the raw materials for preparing the first protective layer through a coating process. Among them, some applicable coating processes include but are not limited to: spraying, dipping, blade coating, roller coating, ultrasonic spraying, slit coating, etc.

[0101] For the preparation of the second protective layer and the third protective layer, the preparation processes thereof are as follows according to the raw materials for the preparation of the two layers. When one of the second protective layer and the third protective layer is a reflection enhancement layer, the reflection enhancement layer is prepared on the surface of the corresponding layer by using the raw materials for the reflection enhancement layer through a vapor deposition process.

[0102] When one of the second protective layer and the third protective layer is an anti-fouling layer, the anti-fouling layer is prepared on the surface of the corresponding layer by using the raw materials for preparing the anti-fouling layer through a vapor deposition process or a coating process. Some applicable coating processes include but are not limited to: spraying, dipping, scraping, roller coating, ultrasonic spraying, slit coating, etc.

[0103] The preferred embodiments of the present invention will be described in more detail below. Although the preferred embodiments of the present invention are described below, it should be understood that the present invention can be implemented in various forms and should not be limited by the embodiments set forth herein. In the embodiment, if no specific technology or conditions are indicated, the technology or conditions described in the document in this area or the product specification are carried out. If the manufacturer is not indicated for reagents used or instruments, they are all conventional products that can be obtained commercially.

[0104] Example 1

[0105] This embodiment 1 provides a composite material, see Figure 2 The composite material includes a transparent substrate layer 100 with a thickness of 2 mm, a first protective layer 200 with a thickness of 20 μm, and a second protective layer 300 with a thickness of 200 nm. The first protective layer 200 is stacked on the upper surface of the transparent substrate layer 100, and the second protective layer 300 is a reflection enhancement layer 001, which is stacked on the upper surface of the first protective layer 200.

[0106] The raw materials for preparing the transparent substrate layer 100 are as follows: 96% by mass of aliphatic TPU, 3% by mass of ultraviolet absorber 326, and 1% by mass of antioxidant 245. The aliphatic TPU is prepared using hexamethylene diisocyanate (HDI) as a monomer.

[0107] The material of the first protective layer is epoxy-modified acrylic resin, and the second protective layer 300 is an anti-fingerprint coating, which is prepared by Shin-Etsu fluorine antifouling coating.

[0108] The composite material provided in Example 1 was subjected to an anti-UV yellowing test, using a UVA bulb, and was sequentially irradiated with ultraviolet light at 50°C for 4 hours and condensed at 60°C for 4 hours, and the test was continued for 100 hours, and no yellowing of the composite material was detected. The composite material provided in Example 1 was subjected to an anti-dirty yellowing test, and a mixture of cosmetics containing tocopherol acetate and water (the mass ratio of cosmetics to water was 1:1) was coated on the surface of the composite material, and stored in a closed environment. After 100 hours, no yellowing of the composite material was detected.

[0109] It can be seen that the composite material provided in Example 1 uses aliphatic TPU as the matrix material. Since there is no benzene ring in it, UV irradiation will not cause irreversible yellowing due to the formation of quinoneimine. By adding ultraviolet absorber 326 and antioxidant 245 to the transparent substrate layer 100, the two work together to absorb UV light incident on the inside of the transparent substrate, further effectively improving its ability to resist UV yellowing. By providing a first protective layer 200, by utilizing its good density, it is possible to effectively prevent dirt from entering the transparent substrate layer 100, reduce the penetration of dirt into the transparent substrate layer 100, and effectively improve its ability to resist dirt and yellowing. By providing a second protective layer 300, the surface of the composite material is given excellent hydrophobic and oleophobic properties, effectively reducing the residue of dirt on the surface, and further improving the composite material's ability to resist dirt and yellowing.

[0110] Example 2

[0111] This embodiment 2 provides a composite material, see Figure 3 The composite material includes a transparent substrate layer 100 with a thickness of 2 mm, a first protective layer 200 with a thickness of 20 μm, and a second protective layer 300 with a thickness of 6 μm. The first protective layer 200 is stacked on the upper surface of the transparent substrate layer 100, and the second protective layer 300 is an anti-fouling layer 002, which is stacked on the upper surface of the first protective layer 200.

[0112] The raw materials for preparing the transparent substrate layer 100 are the same as those in Example 1, and will not be described again. The material of the first protective layer is polyurethane-modified acrylic resin, and the second protective layer 300 is a reflection enhancement layer 001, and its material is zirconium dioxide.

[0113] The composite material provided in Example 2 was subjected to an anti-UV yellowing test and an anti-dirt yellowing test using the same yellowing test method as in Example 1, and no yellowing phenomenon was detected in the composite material.

[0114] The composite material provided in Example 2 effectively improves its ability to resist UV yellowing by adding an ultraviolet absorber 326 and an antioxidant 245 to the transparent substrate layer 100. By providing the first protective layer 200, by utilizing its good compactness, it can effectively prevent dirt from entering the transparent substrate layer 100, reduce the penetration of dirt into the transparent substrate layer 100, and effectively improve its ability to resist dirt yellowing. By providing the second protective layer 300, while ensuring that the composite material has a high light transmittance, more UV light is reflected, further improving the ability of the composite material to resist UV yellowing.

[0115] Example 3

[0116] This embodiment 3 provides a composite material, see Figure 4 The composite material includes a transparent substrate layer 100 with a thickness of 2 mm, a first protective layer 200 with a thickness of 20 μm, a second protective layer 300 with a thickness of 200 nm, and a third protective layer 400 with a thickness of 5 μm. The first protective layer 200 is stacked on the upper surface of the transparent substrate layer 100, the second protective layer 300 is a reflection-enhancing layer 001, which is stacked on the upper surface of the first protective layer 200, and the third protective layer 400 is an anti-fouling layer 002, which is stacked on the upper surface of the second protective layer 300.

[0117] The raw materials for preparing the transparent substrate layer 100 are the same as those in Example 1, and will not be described again. The material of the first protective layer 200 is aliphatic polyurethane methyl hexaacrylate resin, the material of the second protective layer 300 is zirconium dioxide, and the third protective layer 400 is an anti-fingerprint coating, which is prepared using Shin-Etsu fluorine antifouling coating.

[0118] The composite material provided in Example 3 was subjected to an anti-UV yellowing test and an anti-dirt yellowing test using the same yellowing test method as in Example 1, and no yellowing phenomenon was detected in the composite material.

[0119] The composite material provided in Example 3 effectively improves its resistance to UV yellowing by adding ultraviolet absorber 326 and antioxidant 245 to the transparent substrate layer 100. By providing the first protective layer 200, by utilizing its good compactness, it can effectively prevent dirt from entering the transparent substrate layer 100, reduce the penetration of dirt into the transparent substrate layer 100, and effectively improve its resistance to dirt and yellowing. By providing the second protective layer 300, while ensuring that the composite material has a high light transmittance, more UV light is reflected, further improving the resistance of the composite material to UV yellowing. By providing the third protective layer 400, the surface of the composite material is endowed with excellent hydrophobic and oleophobic properties, effectively reducing the residue of dirt on the surface, and further improving the resistance of the composite material to dirt and yellowing.

[0120] Example 4

[0121] This embodiment 4 provides a composite material, the structure of which is shown in FIG. Figure 4 The composite material described in Example 4 is substantially the same as the composite material described in Example 3, except that the aliphatic TPU in the transparent substrate is replaced with an aromatic TPU, wherein the aromatic TPU is prepared using diphenylmethane diisocyanate (MDI) as a monomer.

[0122] The composite material provided in Example 4 was subjected to an anti-UV yellowing test and an anti-fouling yellowing test using the same yellowing test method as in Example 1, and no yellowing phenomenon was detected in the composite material. It can be seen that the composite material can also achieve excellent anti-UV yellowing and anti-fouling yellowing effects.

[0123] Example 5

[0124] This embodiment 5 provides a composite material, the structure of which is shown in Figure 4 The composite material described in Example 5 is basically the same as the composite material described in Example 3, except that the aliphatic TPU in the transparent substrate is replaced with TPEE.

[0125] The composite material provided in Example 4 was subjected to anti-UV yellowing test and anti-fouling yellowing test by the same yellowing test method as in Example 1, and no yellowing phenomenon was detected in the composite material. It can be seen that the composite material can also achieve excellent anti-UV yellowing and anti-fouling yellowing effects, and in particular, its anti-fouling yellowing effect is even better.

[0126] The above description is only for the purpose of facilitating those skilled in the art to understand the technical solution of the present disclosure and is not intended to limit the present disclosure. Any modification, equivalent replacement, improvement, etc. made within the spirit and principle of the present disclosure shall be included in the protection scope of the present disclosure.

Claims

1. A composite material, characterized in that: The composite material comprises: a transparent substrate layer and a first protective layer stacked on the transparent substrate layer; The raw materials for preparing the transparent substrate layer include a base material, an ultraviolet absorber and an antioxidant; The raw material for preparing the first protective layer is selected from at least one of multifunctional acrylic resin, epoxy-modified acrylic resin, polyurethane-modified acrylic resin, fluoropolyether-modified acrylic resin, polysiloxane resin, epoxy resin, and polyurethane resin.

2. The composite material according to claim 1, characterized in that The curing degree of the first protective layer is greater than or equal to 85%.

3. The composite material according to claim 1, characterized in that The composite material further comprises: a second protective layer, which is selected from a reflection enhancement layer and a dirt resistance layer.

4. The composite material according to claim 3, characterized in that The composite material further includes: a third protective layer, and the third protective layer is selected from the other of the reflection enhancement layer and the dirt resistance layer.

5. The composite material according to claim 3, characterized in that The raw material for preparing the reflection enhancement layer includes at least one of titanium oxide, zirconium oxide, tin oxide, zinc oxide, silicon oxide, niobium oxide, aluminum oxide, chromium oxide, magnesium oxide, germanium oxide, gallium oxide, antimony oxide and platinum oxide.

6. The composite material according to claim 3, characterized in that The raw material for preparing the anti-fouling layer is at least one of fluorine-containing multifunctional acrylic resin, fluorine-containing epoxy-modified acrylic resin, fluorine-containing polyurethane-modified acrylic resin, fluorine-containing fluoropolyether-modified acrylic resin, fluorine-containing polysiloxane resin, fluorine-containing epoxy resin, and fluorine-containing polyurethane resin.

7. The composite material according to claim 3, characterized in that The anti-fouling layer is an anti-fingerprint coating.

8. The composite material according to any one of claims 1 to 7, characterized in that: The base material meets at least one of the following conditions: light transmittance ≥ 50%, haze ≤ 20%, hardness ≥ Shore hardness 60A, tensile strength ≥ 30 MPa, and elongation at break ≥ 50%.

9. The composite material according to any one of claims 1 to 7, characterized in that: The matrix material is selected from at least one of TPU, TPE, TPEE, PC, PMMA, TPO and transparent nylon.

10. The composite material according to any one of claims 1 to 9, characterized in that: In the raw materials for preparing the transparent substrate layer, the mass percentage of the base material is 94%-97%, the mass percentage of the ultraviolet absorber is 2%-5%, and the mass percentage of the antioxidant is 0.1%-1.5%.

11. The composite material according to any one of claims 1 to 10, characterized in that: The composite material is in the form of a plate.

12. The composite material according to any one of claims 1 to 10, characterized in that: The composite material has a structural form of a shell.

13. The composite material according to claim 12, characterized in that The housing is a protective shell of a handheld device, and the handheld device includes a mobile phone, a tablet computer, a camera or a remote controller.

14. A method for preparing a composite material, characterized in that: The composite material is as described in any one of claims 1 to 13; The method for preparing the composite material comprises: preparing a transparent substrate layer; A first protective layer is prepared on at least one surface of the transparent substrate layer.

15. The method for preparing a composite material according to claim 14, characterized in that: The method for preparing the composite material further includes: preparing a second protective layer on a surface of the first protective layer away from the transparent substrate layer.

16. The method for preparing a composite material according to claim 15, characterized in that: The method for preparing the composite material further includes: preparing a third protective layer on a surface of the second protective layer away from the first protective layer.

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