Laser protective plate and its preparation method

Abstract

This application discloses a laser protective plate and its preparation method. The provided laser protective plate includes a substrate layer and a reflective layer disposed on at least one side of the substrate layer; wherein, the substrate layer contains a substrate and a composite absorber and a silane coupling agent modified heat dissipation agent uniformly dispersed in the substrate; the reflective layer contains a distributed Bragg reflective film formed by alternating deposition of high-refractive-index materials and low-refractive-index materials. The provided laser protective plate, through a photothermal low-temperature synergistic design, achieves an OD value greater than or equal to 8 at both 532nm and 1064nm wavelengths on a plastic substrate, with a visible light transmittance ≥50%; the plate shows no perforation under continuous irradiation with a 1kW-level laser for 60 seconds. It can be widely used in industrial, medical, and military fields.

Description

Technical Field

[0001] This application belongs to the field of laser protection technology and relates to a laser protection plate and its preparation method. Background Technology

[0002] Laser protection technology is a core component of optoelectronic safety and is crucial in fields such as industrial processing, medical surgery, and military equipment. With the widespread application of high-power lasers, traditional protective materials cannot simultaneously achieve both laser protection performance and light transmittance. In the preparation of traditional protective materials, increasing the absorber concentration to improve the optical density (OD) value requires increasing the absorber concentration; however, increasing the absorber concentration leads to a sharp drop in light transmittance. Summary of the Invention

[0003] Therefore, it is necessary to provide a laser protection plate that balances laser protection performance and light transmittance, as well as its preparation method.

[0004] In some embodiments, a laser protection plate is provided, including a substrate layer and a reflective layer disposed on at least one side of the substrate layer;

[0005] The substrate layer comprises a substrate and a composite absorbent and a silane coupling agent modified with heat dissipation agent uniformly dispersed in the substrate;

[0006] The reflective layer comprises a distributed Bragg reflective film formed by alternating deposition of high-refractive-index and low-refractive-index materials.

[0007] In some embodiments, the provided laser protective plate has a reflective layer with a thickness of 0.5 μm to 2.5 μm and a substrate layer with a thickness of 500 μm to 9500 μm.

[0008] In some implementations, the provided laser protection plate satisfies one or more of the following conditions:

[0009] (1) The refractive index of the high refractive index material is 1.9~2.5, and the refractive index of the low refractive index material is 1.4~1.8;

[0010] (2) The high refractive index material comprises one or more of TiO2, Ta2O5, Nb2O5 and HfO2; the low refractive index material comprises one or two of Al2O3 and SiO2;

[0011] (3) The material of the reflective layer comprises one or more of the following combinations: a combination of TiO2 and SiO2, a combination of Ta2O5 and SiO2, a combination of Nb2O5 and SiO2, a combination of HfO2 and Al2O3, a combination of TiO2, Al2O3 and SiO2, a combination of Ta2O5, Al2O3 and SiO2, a combination of Nb2O5, Al2O3 and SiO2, and at least one of the combinations of HfO2, Al2O3 and SiO2; and

[0012] (4) The number of distributed Bragg reflective film layers in the reflective layer is greater than or equal to 4. Optionally, the number of distributed Bragg reflective film layers in the reflective layer is 4 to 200.

[0013] In some implementations, the provided laser protection plate satisfies one or more of the following conditions:

[0014] (1) The composite absorbent comprises multi-walled carbon nanotubes@ZnO-CuO, hydrated samarium carbonate oxide (Sm2O(CO3)2·xH2O), samarium-doped yttrium lutetium scandium aluminum garnet (Sm:YLSAG), and cobalt-doped erbium borate (Co). 2+ One or more of the following: ErBO3), calcium-doped bismuth trioxide (Ca-Bi2O3), phthalocyanines, porphyrins, Michler's ketone, liquid dye salt ASDPT, liquid dye salt IR-530, and liquid dye salt IR-1065;

[0015] (2) The composite absorbent has a mass fraction of 3% to 20% in the material of the substrate layer;

[0016] (3) The mass fraction of the silane coupling agent modified heat dissipation agent in the material of the substrate layer is 1%~10%;

[0017] (4) The mass fraction of the substrate in the material of the substrate layer is 70%~96%; and

[0018] (5) The substrate comprises one or more of polycarbonate, polymethyl methacrylate and polyvinyl chloride.

[0019] In some embodiments, the laser protection plate provided, wherein the preparation method of the multi-walled carbon nanotubes@ZnO-CuO includes the following steps:

[0020] Carboxylated carbon nanotubes were prepared by carboxylating multi-walled carbon nanotubes.

[0021] The multi-walled carbon nanotubes (@ZnO-CuO) were prepared by coating ZnO and CuO onto the surface of the carboxylated multi-walled carbon nanotubes using a sol-gel method.

[0022] In some implementations, the provided laser protection plate satisfies one or both of the following conditions:

[0023] (1) In the carboxylation treatment step of multi-walled carbon nanotubes, the multi-walled carbon nanotubes are mixed with acid solution at 70℃~80℃ and subjected to ultrasonic treatment to be cleaned until the pH value is greater than or equal to 6.5. Optionally, the acid solution contains sulfuric acid and nitric acid, and the mass ratio of sulfuric acid to nitric acid is (1~3):1. Optionally, the mass ratio of multi-walled carbon nanotubes to acid solution is (1~3):1.

[0024] (2) In the step of coating ZnO and CuO onto the surface of the carboxylated multi-walled carbon nanotubes by the sol-gel method, zinc salt, copper salt, the carboxylated multi-walled carbon nanotubes and alcohol solvent are mixed and heated under reflux; optionally, the amount of zinc salt and copper salt added is controlled to control the mass ratio of the carboxylated multi-walled carbon nanotubes, ZnO and CuO to be (1~2):1:2; optionally, the zinc salt is zinc acetate and the copper salt is copper chloride; the concentration of the zinc salt is 0.1mol / L~1mol / L and the concentration of the copper salt is 0.01mol / L~1mol / L; optionally, reflux is carried out at 120℃~130℃ for 6h~10h.

[0025] In some embodiments, the laser protective plate provided includes a method for preparing the silane coupling agent modified heat dissipation agent, comprising the following steps: mixing the heat dissipation agent, the silane coupling agent, and an alcohol solvent, ultrasonically dispersing the mixture, and drying it to obtain the silane coupling agent modified heat dissipation agent; optionally, the mass ratio of the heat dissipation agent to the silane coupling agent is (1~5):(2~10).

[0026] Optionally, the heat dissipation agent comprises one or more of graphene, aluminum nitride, carbon nanotubes, diamond, and hexagonal boron nitride; optionally, the silane coupling agent comprises one or more of aminosilane (KH-550), mercaptosilane, epoxysilane (KH-560), and vinylsilane.

[0027] In some embodiments, a method for preparing the laser protective plate is provided, comprising the following steps:

[0028] The substrate, the composite absorbent, and the silane coupling agent modified heat dissipation agent are mixed, melted, and extruded to prepare the substrate layer.

[0029] The high-refractive-index material and the low-refractive-index material are alternately deposited on at least one side of the surface of the substrate layer to form the reflective layer containing the distributed Bragg reflector film; gradient curing is then performed to prepare the laser protection plate.

[0030] In some embodiments, a method for preparing the laser protective plate is provided, satisfying one or more of the following conditions:

[0031] (1) Melting is carried out at 220℃~260℃;

[0032] (2) Before the step of alternately depositing the high-refractive-index material and the low-refractive-index material, the substrate layer is further subjected to plasma pretreatment. Optionally, the working gas for plasma pretreatment is argon and oxygen, and the power of plasma pretreatment is 300W~500W; and

[0033] (3) In the gradient curing step, the temperature is kept at 80℃~90℃ for 5min~20min, at 120℃~130℃ for 10min~30min, and at 150℃~160℃ for 20min~50min.

[0034] In some embodiments, a method for preparing the laser protective plate is provided, which involves alternating deposition of the high-refractive-index material and the low-refractive-index material on at least one side of the surface of the substrate layer using a sol-gel method.

[0035] The aforementioned laser protection plate comprises a substrate layer and a reflective layer. The composite absorber in the substrate layer exhibits high thermal decomposition temperature and stability, and possesses dual-band synergistic absorption characteristics. The silane coupling agent-modified heat dissipation agent constructs a three-dimensional thermally conductive network structure, increasing the heat dissipation area and accelerating heat convection. The distributed Bragg reflector in the reflective layer exhibits high-temperature resistance, with a reflection bandgap precisely matched to the 532nm and 1064nm wavelengths. The gradual refractive index matching between the substrate and reflective layers reduces interface reflection loss and avoids a sudden drop in transmittance. Through a photo-thermal low-temperature synergistic design, an OD value greater than or equal to 8 is achieved at both 532nm and 1064nm wavelengths on the plastic substrate, with a visible light transmittance ≥50%. The plate shows no perforation under continuous irradiation with a 1kW laser for 60 seconds. It can be widely applied in industrial, medical, and military fields. Attached Figure Description

[0036] To more clearly illustrate the technical solutions in the embodiments and examples of this application, and to more completely understand this application and its beneficial effects, the accompanying drawings used in the description of the embodiments or examples will be briefly introduced below. Obviously, the drawings described below are merely some embodiments of this application. Those skilled in the art can obtain other drawings based on these drawings without any creative effort.

[0037] Figure 1 The diagram shows a cross-sectional structure of a laser protective plate in some embodiments, where 1 is a reflective layer, 2 is a substrate layer, 3 is a composite absorber, and 4 is a silane coupling agent modified heat dissipation agent.

[0038] Figure 2 This is a process flow diagram for the fabrication of the laser protective plate in some embodiments. Detailed Implementation

[0039] To facilitate understanding of the present invention, a more complete description will be given below with reference to the accompanying drawings. Preferred embodiments of the invention are shown in the drawings. However, the invention can be implemented in many different forms and is not limited to the embodiments described herein. Rather, these embodiments are provided to provide a thorough and complete understanding of the disclosure of the invention.

[0040] It should be noted that when a component is said to be "fixed to" another component, it can be directly attached to the other component or there may be an intervening component. When a component is said to be "connected to" another component, it can be directly connected to the other component or there may be an intervening component.

[0041] 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 pertains. The terminology used herein in the description of the invention is for the purpose of describing particular embodiments only and is not intended to be limiting of the invention. The term "and / or" as used herein includes any and all combinations of one or more of the associated listed items.

[0042] Unless otherwise stated or in case of contradiction, the terms or phrases used herein shall have the following meanings:

[0043] The terms "and / or," "or / and," and "and / or" as used in this application encompass any one of two or more related listed items, as well as any and all combinations of the related listed items. These arbitrary and all combinations include any two related listed items, any more related listed items, or a combination of all related listed items. It should be noted that when at least three items are connected using at least two conjunctions selected from "and / or," "or / and," and "and / or," it should be understood that in this application, the technical solution undoubtedly includes solutions connected by "logical AND," and also undoubtedly includes solutions connected by "logical OR." For example, "A and / or B" includes three parallel solutions: A, B, and "a combination of A and B."

[0044] In this application, the terms "multiple", "various", "multiple times", "multi-dimensional", etc., unless otherwise specified, refer to a quantity greater than or equal to 2. For example, "one or more" means one or more than or equal to two.

[0045] The terms “combinations thereof,” “any combination thereof,” and “any combination thereof” as used in this application include all suitable combinations of any two or more of the listed items.

[0046] In this application, the term "suitable" as used in "suitable combination", "suitable method", "any suitable method", etc., refers to the ability to implement the technical solution of this application, solve the technical problem of this application, and achieve the expected technical effect of this application.

[0047] In this application, terms such as "preferred," "better," "more suitable," and "ideal" are merely used to describe implementation methods or embodiments that achieve better results, and should be understood not to limit the scope of protection of this application.

[0048] In this application, terms such as "further," "even further," and "particularly" are used to describe purposes and indicate differences in content, but should not be construed as limiting the scope of protection of this application.

[0049] In this application, "optionally," "optionally," and "optional" mean that something is optional, that is, it means that it is selected from either "with" or "without." If there are multiple "optional" entries in a technical solution, unless otherwise specified, and there are no contradictions or mutual constraints, each "optional" entry shall be independent.

[0050] In this invention, the terms "first aspect," "second aspect," "third aspect," and "fourth aspect," etc., are used for descriptive purposes only and should not be construed as indicating or implying relative importance or quantity, nor should they be construed as implicitly indicating the importance or quantity of the indicated technical features. Moreover, "first," "second," "third," and "fourth," etc., serve only as a non-exhaustive enumeration and should be understood not to constitute a closed limitation on quantity.

[0051] In this application, the technical features described in an open-ended manner include both closed technical solutions consisting of the listed features and open technical solutions that include the listed features.

[0052] In this application, numerical intervals (i.e., numerical ranges) are involved. Unless otherwise specified, the selected numerical distributions within the aforementioned numerical intervals are considered continuous and include the two endpoints (i.e., the minimum and maximum values) of the numerical range, as well as every value between these two endpoints. Unless otherwise specified, when a numerical interval refers only to integers within that interval, it includes the two endpoint integers of the numerical range, as well as every integer between the two endpoints. In this document, this is equivalent to directly listing every integer. For example, if t is an integer selected from 1 to 10, it means that t is any integer selected from the group of integers consisting of 1, 2, 3, 4, 5, 6, 7, 8, 9, and 10. Furthermore, when multiple ranges are provided to describe features or characteristics, these ranges can be merged. In other words, unless otherwise specified, the ranges disclosed herein should be understood to include any and all subranges to which they are included.

[0053] Unless otherwise specified, the temperature parameters in this application are permitted to be either constant-temperature treatment or variations within a certain temperature range. It should be understood that the constant-temperature treatment allows temperature fluctuations within the precision range of the instrument control, such as ±5℃, ±4℃, ±3℃, ±2℃, or ±1℃.

[0054] In this application, % (w / w) and wt% both represent weight percentage, % (v / v) refers to volume percentage, and % (w / v) refers to mass-volume percentage.

[0055] In this application, "room temperature" generally refers to 5℃~30℃, and more preferably 25±5℃.

[0056] In this application, "optical density" and "OD" in the context are physical quantities used to measure a material's ability to absorb or block light, and are defined as the commonly used logarithmic value of the ratio of incident light intensity (I0) to transmitted light intensity (I).

[0057] In this application, "MWCNTs" in the context refers to "multi-walled carbon nanotubes".

[0058] In some embodiments, a laser protection plate is provided, including a substrate layer and a reflective layer disposed on at least one side of the substrate layer;

[0059] The substrate layer comprises a substrate and a composite absorbent and a silane coupling agent modified with heat dissipation agent uniformly dispersed in the substrate;

[0060] The reflective layer comprises a distributed Bragg reflective film formed by alternating deposition of high-refractive-index and low-refractive-index materials. Figure 1 The diagram shows a cross-sectional structure of a laser protective plate in some embodiments, where 1 is a reflective layer, 2 is a substrate layer, 3 is a composite absorber, and 4 is a silane coupling agent modified heat dissipation agent.

[0061] The distributed Bragg reflector in the reflective layer is resistant to high temperatures, and its reflective bandgap is precisely matched with the dual wavelengths of 532nm and 1064nm, which can reflect 99% of the laser and significantly reduce the heat load of the absorption layer.

[0062] The composite absorbent is heat-resistant and does not easily decompose at high temperatures, thus improving independent absorption at both wavelengths.

[0063] The silane coupling agent modified heat dissipation agent has high axial thermal conductivity and high thermal diffusivity, which can construct a three-dimensional heat conduction network to achieve rapid heat dissipation and prevent heat accumulation from causing the laser protective plate to perforate under continuous irradiation by a 1kW laser for 60 seconds.

[0064] The substrate has high light transmittance, high heat resistance, and impact resistance. Its light transmittance exceeds 90%, its heat resistance is greater than or equal to 150℃, and its impact resistance is greater than or equal to 60kJ / m². 2 .

[0065] In some embodiments, the provided laser protective plate has a reflective layer with a thickness of 0.5 μm to 2.5 μm and a substrate layer with a thickness of 500 μm to 9500 μm. For example, the thickness of the reflective layer can be 0.5 μm, 1 μm, 1.5 μm, 2 μm, 2.5 μm, etc., or it can be a range consisting of any two of the aforementioned values; the thickness of the substrate layer can be 500 μm, 1000 μm, 1500 μm, 2000 μm, 2500 μm, 3000 μm, 3500 μm, 4000 μm, 4500 μm, 5000 μm, 5500 μm, 6000 μm, 6500 μm, 7000 μm, 7500 μm, 8000 μm, 8500 μm, 9000 μm, 9500 μm, etc., or it can be a range consisting of any two of the aforementioned values.

[0066] In some embodiments, the provided laser protective plate has a high refractive index material with a refractive index of 1.9 to 2.5 and a low refractive index material with a refractive index of 1.4 to 1.8. For example, the refractive index of the high refractive index material can be 1.9, 2, 2.1, 2.2, 2.3, 2.4, 2.5, etc., or any range of two of the aforementioned values; the refractive index of the low refractive index material can be 1.4, 1.5, 1.6, 1.7, 1.8, etc., or any range of two of the aforementioned values.

[0067] In some embodiments, the provided laser protective plate contains a high-refractive-index material comprising one or more of TiO2, Ta2O5, Nb2O5, and HfO2; and a low-refractive-index material comprising one or two of Al2O3 and SiO2.

[0068] In some embodiments, the provided laser protective plate has a reflective layer made of one or more of the following combinations: a combination of TiO2 and SiO2, a combination of Ta2O5 and SiO2, a combination of Nb2O5 and SiO2, a combination of HfO2 and Al2O3, a combination of TiO2, Al2O3 and SiO2, a combination of Ta2O5, Al2O3 and SiO2, a combination of Nb2O5, Al2O3 and SiO2, and at least one of the combinations of HfO2, Al2O3 and SiO2.

[0069] In some embodiments, the laser protective plate has a distributed Bragg reflector layer with a number of layers greater than or equal to 4; in some embodiments, the number of distributed Bragg reflector layers in the reflective layer is 4 to 200, for example, it can be 4, 5, 8, 10, 12, 15, 18, 20, 30, 50, 80, 100, 120, 140, 160, 180, 200, etc., or it can be a range composed of any two of the aforementioned values.

[0070] In some embodiments, the provided laser shielding plate contains a composite absorber comprising multi-walled carbon nanotubes@ZnO-CuO, hydrated samarium carbonate oxide (Sm2O(CO3)2·xH2O), samarium-doped yttrium lutetium scandium aluminum garnet (Sm:YLSAG), and cobalt-doped erbium borate (Co). 2+ One or more of the following: ErBO3), calcium-doped bismuth trioxide (Ca-Bi2O3), phthalocyanines, porphyrins, Michler's ketone, liquid dye salt ASDPT, liquid dye salt IR-530, and liquid dye salt IR-1065.

[0071] The core-shell structured MWCNTs@Cu0-Zn0 nanocomposite absorber exhibits a thermal decomposition temperature >400℃, remains stable at 230℃, and possesses dual-band synergistic absorption characteristics. MWCNTs primarily absorb in the 1064nm band (absorption profile 8.7×10⁻⁶). -17 cm 2 The Cu0-Zn0 heterojunction enhances the absorption at 532nm, increasing the absorption coefficient by 2.3 times.

[0072] In some embodiments, the laser protective plate provided has a composite absorber in the substrate layer material with a mass fraction of 3% to 20%, for example, it can be 3%, 4%, 5%, 6%, 7%, 8%, 9%, 10%, 11%, 12%, 13%, 14%, 15%, 16%, 17%, 18%, 19%, 20%, etc., or it can be a range composed of any two of the aforementioned values.

[0073] In some embodiments, the provided laser protective plate has a silane coupling agent modified heat dissipation agent in a material of 1% to 10% by mass, for example, it can be 1%, 2%, 3%, 4%, 5%, 6%, 7%, 8%, 9%, 10%, etc., or it can be a range of any two of the aforementioned values.

[0074] In some embodiments, the provided laser protective plate has a substrate in which the mass fraction of the material in the substrate layer is 70% to 96%. For example, it can be 70%, 71%, 72%, 73%, 74%, 75%, 76%, 77%, 78%, 79%, 80%, 81%, 82%, 83%, 84%, 85%, 86%, 87%, 88%, 89%, 90%, 91%, 92%, 93%, 94%, 95%, 96%, etc., or it can be a range composed of any two of the aforementioned values.

[0075] In some embodiments, the provided laser protection plate has a substrate comprising one or more of polycarbonate, polymethyl methacrylate, and polyvinyl chloride.

[0076] In some embodiments, the laser protection plate provided, wherein the preparation method of the multi-walled carbon nanotubes@ZnO-CuO includes the following steps:

[0077] Carboxylated carbon nanotubes were prepared by carboxylating multi-walled carbon nanotubes.

[0078] The multi-walled carbon nanotubes (@ZnO-CuO) were prepared by coating ZnO and CuO onto the surface of the carboxylated multi-walled carbon nanotubes using a sol-gel method.

[0079] In some embodiments, in the laser protection plate provided, in the preparation method of the multi-walled carbon nanotubes@ZnO-CuO, in the carboxylation treatment step of the multi-walled carbon nanotubes, the multi-walled carbon nanotubes are mixed with an acid solution at 70℃~80℃, subjected to ultrasonic treatment, and cleaned until the pH value is greater than or equal to 6.5; in some embodiments, the acid solution contains sulfuric acid and nitric acid, and the mass ratio of the sulfuric acid to the nitric acid is (1~3):1; in some embodiments, the mass ratio of the multi-walled carbon nanotubes to the acid solution is (1~3):1.

[0080] In some embodiments, in the laser protective plate provided, in the preparation method of the multi-walled carbon nanotubes @ZnO-CuO, in the step of coating ZnO and CuO on the surface of the carboxylated multi-walled carbon nanotubes by sol-gel method, zinc salt, copper salt, the carboxylated multi-walled carbon nanotubes and alcohol solvent are mixed and heated to reflux; in some embodiments, the amount of zinc salt and copper salt added is controlled to control the mass ratio of the carboxylated multi-walled carbon nanotubes, ZnO and CuO to be (1~2):1:2; in some embodiments, the zinc salt is zinc acetate and the copper salt is copper chloride; the concentration of the zinc salt is 0.1mol / L~1mol / L and the concentration of the copper salt is 0.01mol / L~1mol / L; in some embodiments, reflux is carried out at 120℃~130℃ for 6h~10h.

[0081] In some embodiments, the laser protective plate provided includes a method for preparing the silane coupling agent modified heat dissipation agent, comprising the following steps: mixing the heat dissipation agent, the silane coupling agent, and an alcohol solvent, ultrasonically dispersing the mixture, and drying it to obtain the silane coupling agent modified heat dissipation agent. In some embodiments, the mass ratio of the heat dissipation agent to the silane coupling agent is (1~5):(2~10), for example, 1:2, 1:5, 1:8, 1:10, 2:2, 2:5, 2:8, 2:10, 3:2, 3:5, 3:8, 3:10, 4:2, 4:5, 4:8, 4:10, 5:2, 5:6, 5:8, 5:10, etc., or any range of the aforementioned two ratios. In some embodiments, ultrasonic dispersion is performed under ice-water bath conditions.

[0082] In some embodiments, the heat dissipation agent comprises one or more of graphene, aluminum nitride, carbon nanotubes, diamond, and hexagonal boron nitride; in some embodiments, the silane coupling agent comprises aminosilane, mercaptosilane, epoxysilane (KH-560), vinylsilane, etc. In some embodiments, the aminosilane comprises KH-550, etc.; in some embodiments, the epoxysilane comprises KH-560, etc.

[0083] In some embodiments, a method for preparing the laser protective plate is provided, comprising the following steps:

[0084] The substrate, the composite absorbent, and the silane coupling agent modified heat dissipation agent are mixed, melted, and extruded to prepare the substrate layer.

[0085] The high-refractive-index material and the low-refractive-index material are alternately deposited on at least one side of the surface of the substrate layer to form the reflective layer containing the distributed Bragg reflector film; gradient curing is then performed to prepare the laser protection plate.

[0086] In some embodiments, a method for preparing the laser protective plate is provided, wherein melting is performed at 220°C to 260°C;

[0087] In some embodiments, the method for preparing the laser protective plate further includes plasma pretreatment of the substrate layer before the step of alternately depositing the high refractive index material and the low refractive index material; in some embodiments, the working gas for plasma pretreatment is argon and oxygen, and the power of plasma pretreatment is 300W~500W.

[0088] In some embodiments, a method for preparing the laser protective plate is provided, wherein the gradient curing step includes holding at 80°C to 90°C for 5 min to 20 min, holding at 120°C to 130°C for 10 min to 30 min, and holding at 150°C to 160°C for 20 min to 50 min.

[0089] In some embodiments, a method for preparing the laser protective plate is provided, which involves alternating deposition of the high-refractive-index material and the low-refractive-index material on at least one side of the surface of the substrate layer using a sol-gel method.

[0090] In some implementations, the process flow diagram for manufacturing the laser protective plate is as follows: Figure 2 As shown.

[0091] The reflective layer is prepared by using a sol-gel method, which is less likely to cause substrate warping and deformation, and less likely to cause particle aggregation that would lead to loss of light transmittance and decreased scattering efficiency.

[0092] In some embodiments, a distributed Bragg reflector film reflecting 1064nm laser light is first deposited on the surface of the substrate layer, followed by a distributed Bragg reflector film reflecting 532nm laser light, so that the reflectivity at both 532nm and 1064nm is greater than 99%, and the average reflectivity at 400nm~500nm and 550nm~1000nm is less than 8%, so that the visible light transmittance is greater than or equal to 50%.

[0093] The following are specific embodiments. They are intended to provide a more detailed description of this application to help those skilled in the art and researchers better understand it. The technical conditions described do not constitute any limitation on this application. Any modifications made within the scope of the claims of this application are protected by the claims.

[0094] Unless otherwise stated, all raw materials and reagents used in the following examples are commercially available or can be prepared by known methods. Experimental methods not specifying particular conditions in the examples were performed under conventional conditions, such as those described in literature, books, or methods recommended by the manufacturer.

[0095] Example 1

[0096] This embodiment provides a laser protection plate, the preparation method of which is as follows:

[0097] Step 1, Raw material pretreatment:

[0098] (1) Absorbent modification treatment: H2SO4 and HNO3 were mixed at a mass ratio of 3:1 to obtain acid solution. Multi-walled carbon nanotubes were added at a mass ratio of 2:1 to acid solution. The mixture was ultrasonically treated at 70℃ for 4 hours and centrifuged and washed until the pH was 6.5 to obtain carboxylated MWCNTs.

[0099] ZnO / CuO was coated onto the surface of carboxylated MWCNTs using a sol-gel method: ZnAc2·2H2O and CuCl2·2H2O were dissolved in ethylene glycol, with the concentration of ZnAc2·2H2O being 0.1 M and the concentration of CuCl2·2H2O being 0.05 M. Carboxylated MWCNTs were then added, and the mass ratio of carboxylated MWCNTs to ZnO and CuO was controlled at 1.25:1:2. The mixture was refluxed at 120 °C for 6 h to obtain MWCNTs@ZnO-CuO.

[0100] (2) Heat dissipation agent modification treatment: under ice water bath conditions, boron nitride nanosheets (BNNSs) were ultrasonically dispersed in an ethanol solution containing 2wt% KH-550 aminosilane for 2h, wherein the mass ratio of BNNSs to aminosilane was 3:2. After drying at 80℃, silane coupling agent modified BNNSs were obtained.

[0101] (3) The polycarbonate (PC) particles and silane coupling agent modified BNNSs were vacuum dried at 80°C for 4 hours;

[0102] (4) 89wt% PC, 8wt% composite absorbent MWCNTs@ZnO-CuO and 3wt% silane coupling agent modified BNNSs are premixed to obtain the raw material mixture of the substrate layer, wherein the content of each component is the proportion in the total weight of the raw material mixture of the substrate layer.

[0103] Step 2, Single-layer extrusion molding:

[0104] (5) The raw material mixture of the substrate layer is subjected to high shear dispersion and twin-screw blending in a twin-screw extruder at a screw speed of 120 rpm;

[0105] (6) After the uniformly dispersed mixture is melted and plasticized at 220°C, it is extruded once through a mold, rolled by a three-roll mill, and cooled to form a single-layer laser protective plate containing absorbent and heat dissipation agent. The thickness of the substrate layer is 4500μm.

[0106] Step 3: Sol-gel method for depositing reflective layer:

[0107] (7) Plasma cleaning was performed using a mixture of Ar (argon) and O2 (oxygen) gas at a power of 300W for 60s to treat the surface of the substrate; (8) Using a sol-gel process, 5 pairs of alternating 532nm: TiO2 (58nm) / SiO2 (92nm) and 5 pairs of alternating 1064nm: TiO2 (115nm) / SiO2 (183nm) were coated alternately on the surface of the substrate, for a total of 20 layers, at a spin coating speed of 3000rpm, to obtain a reflective layer with a thickness of 2.24μm. The preparation process is as follows:

[0108] 1. Sol preparation

[0109] 1.1. Preparation of TiO2 sol (high refractive index layer)

[0110] Tetrabutyl titanate (TBOT) was mixed with 60% volume of anhydrous ethanol (EtOH) and magnetically stirred at 300 rpm for 30 min. Acetylacetone (AcAc) was added to inhibit the hydrolysis rate, and stirring was continued for 15 min. The remaining EtOH was mixed with H2O and HNO3 and added dropwise to the above solution at a rate of 2 mL / min. The mixture was reacted in a water bath at 40 °C for 24 h to obtain a pale yellow transparent sol. The sol was filtered through a 0.2 μm PTFE membrane and stored in a sealed container protected from light.

[0111] 1.2. Preparation of SiO2 sol (low refractive index layer)

[0112] Tetraethyl orthosilicate (TEOS) was mixed with EtOH and stirred for 20 min; H2O and ammonia were added, and the mixture was reacted in a water bath at 60 °C for 6 h; after cooling, it was filtered through a 0.2 μm PTFE membrane and stored in a sealed container.

[0113] 2. Spin coating

[0114] 2.1. TiO2 layer coating

[0115] The TiO2 layer was prepared using a spin coater. The coating parameters were set as follows: low speed 800 rpm for 10 s to achieve uniform sol spreading, and high speed 3000 rpm for 30 s to precisely control the film thickness. The coating environment was controlled at a temperature of 25±1℃ and a humidity of <40%RH. The TiO2 film thickness was adjusted to 58±3 nm by calibrating using a speed-viscosity model.

[0116] 2.2. SiO2 layer coating

[0117] The SiO2 layer was coated using a spin coater with the following parameters: low speed 1000 rpm for 10 s and high speed 4000 rpm for 30 s. The film thickness was controlled to be 92 ± 3 nm.

[0118] After alternating between steps 2.1 and 2.2 five times, five pairs of TiO2 (115nm) / SiO2 (183nm) are coated alternately using the above coating parameters. After each coating, preheat at 80°C for 5 minutes to evaporate the solvent; interlayer doping is strictly prohibited to prevent interface mixing. (9) Low-temperature curing steps: Pre-crosslinking is performed at 80°C for 10 minutes, dehydration is performed at 120°C for 20 minutes, and densification is performed at 150°C for 30 minutes to avoid PC thermal deformation and obtain the laser protective plate.

[0119] Example 2

[0120] This embodiment provides a laser protection plate, similar to that of Embodiment 1, except that the absorbent in the substrate layer is an amination-modified Co / ZnO / C powder. The preparation method of the amination-modified Co / ZnO / C powder is as follows:

[0121] 1. Synthesis of ZnCo-ZIF precursor (solvothermal method): Solution preparation: Dissolve 2-methylimidazole (4.10 g, 50 mmol) in 50 mL of methanol and stir until completely dissolved (Solution A). Dissolve zinc nitrate hexahydrate (Zn(NO3)2·6H2O, 1.49 g, 5 mmol) and cobalt nitrate hexahydrate (Co(NO3)2·6H2O, 1.46 g, 5 mmol) together in 50 mL of methanol (Solution B). 2+ With Co 2+ The molar ratio can be adjusted as needed, between 1:1 and 4:1. Mixing and reaction: Under vigorous stirring, solution B is quickly poured into solution A. Stirring continues for 6 hours at room temperature, then allowed to stand for 24 hours. The precipitate is collected by centrifugation, washed three times with methanol, and vacuum dried overnight at 60°C to obtain ZnCo-ZIF powder. 2. High-temperature pyrolysis preparation of Co / ZnO / C: Pyrolysis process: The above ZnCo-ZIF precursor powder is placed in a tube furnace. Under an argon (Ar) atmosphere (flow rate: 50 sccm), it is heated to 700°C at a heating rate of 5°C / min and held for 2 hours. After natural cooling to room temperature, black Co / ZnO / C composite powder is obtained. 3. Surface modification (improving polymer compatibility): Coupling agent treatment: Co / ZnO / C powder (2g) is dispersed in 100mL ethanol and ultrasonically treated for 30 minutes. Add 2 wt% of silane coupling agent KH-550 (aminopropyltriethoxysilane) and reflux at 80 °C for 4 hours. After the reaction is complete, collect the product by centrifugation, wash three times with ethanol, and dry under vacuum at 80 °C to obtain amination-modified Co / ZnO / C powder.

[0122] Example 3

[0123] This embodiment provides a laser protective plate, and the preparation method is similar to that of Example 1. The difference is that the heat dissipation agent modified by silane coupling agent is aluminum nitride modified by aminosilane. The heat dissipation agent modification process in step (2) of step 1 is as follows: 1. Preparation of precursor: All operations must be carried out in an inert atmosphere glove box (such as argon) to strictly isolate water and oxygen; at low temperature (such as liquid ammonia environment at -34°C), aluminum trichloride (AlCl3) reacts with potassium amide (KNH2) to generate aluminum amide-imide intermediate. 2. Microwave-assisted crystallization: The precursor is mixed with a hydrophobic ionic liquid (which also serves as a reaction medium and stabilizer); a microwave reactor is used for rapid heating (e.g., rising to 300°C within 120 seconds and maintaining at this temperature for a period of time) to promote the rapid crystallization and growth of nanocrystals. 3. Purification and post-treatment: After the reaction is completed, the product is washed by alternating centrifugation with solvents such as methanol / acetonitrile to remove byproducts (such as KCl) and excess ionic liquid. 4. Coupling agent hydrolysis and grafting: The selected KH-550 silane coupling agent is hydrolyzed in an ethanol / water solution to generate silanol; AlN nanosheets are dispersed in this solution and stirred at a specific temperature and pH value to allow the silanol to condense with the hydroxyl groups on the AlN surface, thus grafting the coupling agent. 5. Washing and drying: After the reaction is complete, the nanosheets are washed repeatedly by centrifugation with solvent to remove the physically adsorbed coupling agent, and then thoroughly dried to obtain the modified nanosheets.

[0124] Example 4

[0125] This embodiment provides a laser protection plate. The preparation method is similar to that of embodiment 1. The difference is that in step 1 (4), 94wt% PC, 3wt% composite absorber MWCNTs@ZnO-CuO, and 3wt% silane coupling agent modified BNNSs are premixed to obtain the raw material mixture of the substrate layer. The content of each component is the proportion in the total weight of the raw material mixture of the substrate layer.

[0126] Example 5

[0127] This embodiment provides a laser protective plate, similar to that of Embodiment 1, except that the reflective layer consists of three alternating pairs of 532nm TiO2 (58nm) / SiO2 (92nm) films and three alternating pairs of 1064nm TiO2 (115nm) / SiO2 (183nm) films. The preparation method is similar to that in Embodiment 1, except that the total number of layers is 12, and the thickness is approximately 1.344μm.

[0128] Example 6

[0129] This embodiment provides a laser protective plate, similar to that of Embodiment 1, except that the reflective layer consists of a 532nm film layer: alternating pairs of TiO2 (58nm) and SiO2 (92nm); and a 1064nm film layer: alternating pairs of TiO2 (115nm) and SiO2 (183nm). The preparation method is similar to that in Embodiment 1, except that the total number of layers is 4, and the thickness is approximately 0.448μm.

[0130] Comparative Example 1

[0131] This comparative example provides a laser protective plate, similar to Example 1, except that no reflective layer is provided. Steps (7) and (8) in step 3 are omitted compared to the preparation method of Example 1.

[0132] Comparative Example 2

[0133] This comparative example provides a laser protection plate, which is similar to Example 1, except that steps (2) and (3) in step 1 are omitted, and silane coupling agent modified BNNSs is not added in step (4) of step 1. That is, 92wt% PC and 8wt% composite absorber MWCNTs@ZnO-CuO are premixed to obtain the raw material mixture of the substrate layer, wherein the content of each component is the proportion in the total weight of the raw material mixture of the substrate layer.

[0134] The laser protective plates prepared in the above embodiments and comparative examples were subjected to performance tests, and the test methods included:

[0135] (1) Visible light transmittance: Tested according to GB / T 2410 standard;

[0136] (2) OD value: Tested according to EN 207:2020 standard;

[0137] (3) Perforation test: The laser protective plate was irradiated with a 500W 532nm laser for 10s. The test results are shown in Table 1.

[0138] Table 1

[0139]

[0140] As shown in Table 1, the provided laser protective plate exhibits superior laser protection performance and high light transmittance. Comparing Examples 2-3 with Example 1, it can be seen that replacing the composite absorber with amino-modified Co / ZnO / C powder containing C powder affects the light transmittance of the laser protective plate, while changing the heat dissipation agent has a relatively small impact on the OD value and light transmittance of the laser protective plate.

[0141] Compared with Example 4, Example 1 shows that reducing the mass percentage of absorber reduces the absorption of 532nm and 1064nm lasers, thereby reducing the OD value of the laser protection plate.

[0142] Compared with Examples 5-6, Example 1 shows that reducing the thickness of the DBR reflective film layer will reduce the reflection of 532nm and 1064nm lasers, and will also reduce the OD value of the laser protection plate. In addition, if the reflective film layer is too thin, it will cause the surface energy of the laser protection plate to accumulate and cause perforation.

[0143] Compared with Comparative Examples 1-2, Example 1 shows that by setting a reflective layer, not only can the surface energy accumulation of the laser protective plate be reduced, but the OD value can also be increased. By adding a heat dissipation agent, heat accumulation under high-energy laser irradiation can be effectively avoided, which would lead to perforation of the plate.

[0144] The technical features of the above embodiments can be combined in any way. For the sake of brevity, not all possible combinations of the technical features in the above embodiments are described. However, as long as there is no contradiction in the combination of these technical features, they should be considered to be within the scope of this specification.

[0145] The embodiments described above are merely illustrative of several implementations of the present invention, and while the descriptions are relatively specific and detailed, they should not be construed as limiting the scope of the invention. It should be noted that those skilled in the art can make various modifications and improvements without departing from the concept of the present invention, and these all fall within the protection scope of the present invention. Therefore, the protection scope of this invention should be determined by the appended claims, and the specification and drawings can be used to interpret the content of the claims.

Claims

1. A laser protection plate, characterized in that, It includes a substrate layer and a reflective layer disposed on at least one side of the substrate layer; The substrate layer comprises a substrate and a composite absorbent and a silane coupling agent modified with heat dissipation agent uniformly dispersed in the substrate; The reflective layer comprises a distributed Bragg reflective film formed by alternating deposition of high-refractive-index and low-refractive-index materials.

2. The laser protection plate according to claim 1, characterized in that, The thickness of the reflective layer is 0.5μm to 2.5μm, and the thickness of the substrate layer is 500μm to 9500μm.

3. The laser protection plate according to claim 1, characterized in that, One or more of the following conditions must be met: (1) The refractive index of the high refractive index material is 1.9~2.5, and the refractive index of the low refractive index material is 1.4~1.8; (2) The high refractive index material comprises one or more of TiO2, Ta2O5, Nb2O5 and HfO2; the low refractive index material comprises one or two of Al2O3 and SiO2; (3) The material of the reflective layer comprises one or more of the following combinations: a combination of TiO2 and SiO2, a combination of Ta2O5 and SiO2, a combination of Nb2O5 and SiO2, a combination of HfO2 and Al2O3, a combination of TiO2, Al2O3 and SiO2, a combination of Ta2O5, Al2O3 and SiO2, a combination of Nb2O5, Al2O3 and SiO2, and at least one of the combinations of HfO2, Al2O3 and SiO2; and (4) The number of distributed Bragg reflective film layers in the reflective layer is greater than or equal to 4. Optionally, the number of distributed Bragg reflective film layers in the reflective layer is 4 to 200.

4. The laser protective plate according to any one of claims 1 to 3, characterized in that, One or more of the following conditions must be met: (1) The composite absorbent comprises one or more of the following: multi-walled carbon nanotubes@ZnO-CuO, hydrated samarium carbonate, samarium-doped yttrium lutetium scandium aluminum garnet, cobalt-doped erbium borate, calcium-doped bismuth trioxide, phthalocyanine compounds, porphyrin compounds, Mischel ketone, liquid dye salt ASDPT, liquid dye salt IR-530 and liquid dye salt IR-1065; (2) The composite absorbent has a mass fraction of 3% to 20% in the material of the substrate layer; (3) The mass fraction of the silane coupling agent modified heat dissipation agent in the material of the substrate layer is 1%~10%; (4) The mass fraction of the substrate in the material of the substrate layer is 70%~96%; and (5) The substrate comprises one or more of polycarbonate, polymethyl methacrylate and polyvinyl chloride.

5. The laser protection plate according to claim 4, characterized in that, The preparation method of the multi-walled carbon nanotubes@ZnO-CuO includes the following steps: Carboxylated carbon nanotubes were prepared by carboxylating multi-walled carbon nanotubes. The multi-walled carbon nanotubes (@ZnO-CuO) were prepared by coating ZnO and CuO onto the surface of the carboxylated multi-walled carbon nanotubes using a sol-gel method.

6. The laser protection plate according to claim 5, characterized in that, One or both of the following conditions must be met: (1) In the carboxylation treatment step of multi-walled carbon nanotubes, the multi-walled carbon nanotubes are mixed with acid solution at 70℃~80℃ and subjected to ultrasonic treatment to be cleaned until the pH value is greater than or equal to 6.

5. Optionally, the acid solution contains sulfuric acid and nitric acid, and the mass ratio of sulfuric acid to nitric acid is (1~3):

1. Optionally, the mass ratio of multi-walled carbon nanotubes to acid solution is (1~3):

1. (2) In the step of coating ZnO and CuO onto the surface of the carboxylated multi-walled carbon nanotubes by the sol-gel method, zinc salt, copper salt, the carboxylated multi-walled carbon nanotubes and alcohol solvent are mixed and heated under reflux; optionally, the amount of zinc salt and copper salt added is controlled to control the mass ratio of the carboxylated multi-walled carbon nanotubes, ZnO and CuO to be (1~2):1:2; optionally, the zinc salt is zinc acetate and the copper salt is copper chloride; the concentration of the zinc salt is 0.1mol / L~1mol / L and the concentration of the copper salt is 0.01mol / L~1mol / L; optionally, reflux is carried out at 120℃~130℃ for 6h~10h.

7. The laser protective plate according to any one of claims 1 to 3, characterized in that, The preparation method of the silane coupling agent modified heat dissipation agent includes the following steps: mixing the heat dissipation agent, the silane coupling agent and the alcohol solvent, dispersing them ultrasonically, and drying them to prepare the silane coupling agent modified heat dissipation agent; optionally, the mass ratio of the heat dissipation agent to the silane coupling agent is (1~5):(2~10). Optionally, the heat dissipation agent comprises one or more of graphene, aluminum nitride, carbon nanotubes, diamond, and hexagonal boron nitride; optionally, the silane coupling agent comprises one or more of aminosilane, mercaptosilane, epoxysilane, and vinylsilane.

8. The method for preparing the laser protective plate according to any one of claims 1 to 7, characterized in that, Includes the following steps: The substrate, the composite absorbent, and the silane coupling agent modified heat dissipation agent are mixed, melted, and extruded to prepare the substrate layer. The high-refractive-index material and the low-refractive-index material are alternately deposited on at least one side of the surface of the substrate layer to form the reflective layer containing the distributed Bragg reflector film; gradient curing is then performed to prepare the laser protection plate.

9. The method for preparing a laser protective plate according to claim 8, characterized in that, One or more of the following conditions must be met: (1) Melting is carried out at 220℃~260℃; (2) Before the step of alternately depositing the high-refractive-index material and the low-refractive-index material, the substrate layer is further subjected to plasma pretreatment. Optionally, the working gas for plasma pretreatment is argon and oxygen, and the power of plasma pretreatment is 300W~500W; and (3) In the gradient curing step, the temperature is kept at 80℃~90℃ for 5min~20min, at 120℃~130℃ for 10min~30min, and at 150℃~160℃ for 20min~50min.

10. The method for preparing a laser protective plate according to claim 8 or 9, characterized in that, The high-refractive-index material and the low-refractive-index material are alternately deposited on at least one side of the surface of the substrate layer using a sol-gel method.

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