High-temperature resistant and high-strength thin films and their preparation methods

Abstract

This invention discloses a high-temperature resistant and high-strength film, comprising a film body composed of a multi-layered structure, consisting of a reinforcing layer, a middle layer, and an inner layer from the outside to the inside. A method for preparing the high-temperature resistant and high-strength film is applied to the above-mentioned film, comprising the following steps: S100, pretreatment; S200, mixing and spreading; S300, spinning; S400, impregnation; and S500, micro-hot pressing. The high-temperature resistant and high-strength film and its preparation method of this invention utilize a combination of a mesh-like reinforcing layer and high-pressure sprayed resin to form the reinforcing layer. Then, electrospinning and micro-hot pressing techniques are used to combine the reinforcing layer with the middle and inner layers to form the film. This ensures the overall high-temperature resistance and structural strength of the produced film while maintaining a relatively thin thickness, meeting the application requirements of aerospace, electronic equipment, energy, and other technical fields.

Description

Technical Field

[0001] This invention belongs to the field of thin film preparation technology, and particularly relates to high-temperature resistant and high-strength thin films and their preparation methods. Background Technology

[0002] With the advancement of science and technology and the improvement of industrialization, modern society has increasingly higher requirements for material performance, especially in some high-temperature and high-strength environments, where traditional materials often cannot meet the working requirements.

[0003] Especially in applications such as aerospace, electronic equipment, and energy, where high temperature, high strength, and thickness requirements are extremely stringent, how to develop thin film materials with excellent high temperature resistance and high strength has become an important problem that needs to be solved in the fields of materials science and engineering. Summary of the Invention

[0004] To address the problems in the prior art, the present invention proposes the following technical solution:

[0005] A high-temperature resistant and high-strength film, comprising a film body, wherein the film body is composed of a multi-layer structure, consisting of a reinforcing layer, a middle layer and an inner layer from the outside to the inside;

[0006] The reinforcing layer includes a reinforcing layer and a resin. The reinforcing layer is designed in a grid pattern, and the resin is permeated and filled into the grid gaps of the reinforcing layer by a spray impregnation process.

[0007] The material components of the middle layer include: 30-60 parts of polyethylene terephthalate, 50-80 parts of polylactic acid, 1-2 parts of silica, and 1-3 parts of plasticizer;

[0008] The inner layer comprises: 30-60 parts of polyethylene terephthalate, 50-80 parts of polylactic acid, 1-2 parts of silica, 1-2 parts of antifungal agent, and 1-3 parts of plasticizer.

[0009] As a preferred embodiment of the above technical solution, the reinforcing layer is made of aramid fiber, and the resin material is a thermosetting resin.

[0010] As a preferred embodiment of the above technical solution, the reinforcing layer is composited with the middle layer and the inner layer through a micro-hot pressing process, and the micro-hot pressing base mold material is selected from at least one of PE, PMMA, PC, PLLA, PDLA, PVA, PCL, PEG, PEO, PBS or TPU.

[0011] As a preferred embodiment of the above technical solution, the antifungal agent is one of citric acid and trimethoxysilane quaternary ammonium salt.

[0012] As a preferred embodiment of the above technical solution, the plasticizer is one of phthalate ester and trioctyl phosphate.

[0013] As a preferred embodiment of the above technical solution, the thickness ratio of the reinforcing layer, the middle layer, and the inner layer is 5:4:5, and the total thickness is 35-45 micrometers.

[0014] A method for preparing a high-temperature resistant and high-strength thin film, wherein the method is applied to the aforementioned high-temperature resistant and high-strength thin film, and the preparation method includes the following steps:

[0015] S100, Pretreatment: Polyethylene terephthalate and polylactic acid in the middle and inner layers are respectively soaked in 2-3 wt% ammonia water for 8-12 minutes, then filtered, washed with water and dried to obtain pretreated polylactic acid and polyethylene terephthalate.

[0016] S200, Mixing and spreading: The raw materials in the middle layer and inner layer are added to two independent mixing kettles according to their respective proportions, stirred and mixed evenly, and then added to two barrels for melting and internal mixing. Finally, they are cast and spread onto the hot-pressed base film through a double-layer herringbone co-extrusion die.

[0017] S300, spinning: The reinforcing material solution is added to the syringe, and an electrospinning machine is used to spin a mesh-like reinforcing layer and attach it to the hot-pressed base film.

[0018] S400, Impregnation: Resin is sprayed onto the surface of the reinforcing layer using a spray gun, and air pressure is used to fully penetrate and fill the gaps in the grid of the reinforcing layer, thereby forming a reinforced layer;

[0019] S500, Micro Hot Pressing: Hot pressing the upper base film and the lower base film together, adjusting the temperature and load to make the temperature higher than the glass transition temperature of the polymer but lower than the viscosity transition temperature, pressing and heat-setting to form the film body, and finally performing mold separation, winding and slitting.

[0020] As a preferred embodiment of the above technical solution, the melting and mixing temperature in S200 is 220-260°C.

[0021] As a preferred embodiment of the above technical solution, the S300 spinning process parameters are: positive voltage 9-11 kV, needle inner diameter 0.8-1 mm, and receiving distance 19-21 cm.

[0022] As a preferred embodiment of the above technical solution, the S500 micro hot pressing process parameters are: hot pressing temperature 60~70℃, pressure head loading speed 0.008~0.012mm / s, holding pressure 70~90N, and holding time 280~320s.

[0023] The beneficial effects of this invention are as follows:

[0024] The high-temperature resistant and high-strength film of the present invention and its preparation method adopt a combination of a grid-like reinforcing layer and high-pressure sprayed resin to form a reinforcing layer in the production process. Then, electrospinning technology and micro-hot pressing technology are used to combine the reinforcing layer, the middle layer and the inner layer to form a film. This ensures the overall high-temperature resistance and structural strength of the produced film, while maintaining the film at a relatively thin thickness, which meets the application requirements of aerospace, electronic equipment, energy and other technical fields. Attached Figure Description

[0025] Figure 1 The diagram shown is a layered schematic of the high-temperature resistant and high-strength film in Examples 1 and 2;

[0026] Figure 2 The diagram shown is a schematic diagram of the layering of the high-temperature resistant and high-strength film in Comparative Example 2.

[0027] In the figure: 100, film body; 10, reinforcing layer; 11, strengthening layer; 12, resin; 20, middle layer; 30, inner layer; 200, hot-pressed upper base film; 300, hot-pressed lower base film. Detailed Implementation

[0028] To make the objectives, technical solutions, and advantages of the embodiments of the present invention clearer, the technical solutions of the present invention will be clearly and completely described below in conjunction with the embodiments.

[0029] A high-temperature and high-strength film includes a film body 100, which is composed of a multi-layer structure, consisting of a reinforcing layer 10, a middle layer 20, and an inner layer 30 from the outside to the inside.

[0030] The reinforcing layer 10 includes a reinforcing layer 11 and a resin 12. The reinforcing layer 11 has a grid-like design, and the resin 12 is filled into the grid gaps of the reinforcing layer 11 by a spray impregnation process.

[0031] The material composition of the middle layer 20 includes: 30-60 parts of polyethylene terephthalate, 50-80 parts of polylactic acid, 1-2 parts of silica, and 1-3 parts of plasticizer;

[0032] The inner layer 30 consists of the following components: 30-60 parts of polyethylene terephthalate, 50-80 parts of polylactic acid, 1-2 parts of silica, 1-2 parts of antifungal agent, and 1-3 parts of plasticizer.

[0033] As a preferred embodiment of the above technical solution, the reinforcing layer 11 is made of aramid fiber, and the resin 12 is made of thermosetting resin.

[0034] As a preferred embodiment of the above technical solution, the reinforcing layer 10 is composited with the middle layer 20 and the inner layer 30 through a micro-hot pressing process. The micro-hot pressing base material is selected from at least one of PE, PMMA, PC, PLLA, PDLA, PVA, PCL, PEG, PEO, PBS or TPU.

[0035] The antifungal agent is one of citric acid or trimethoxysilane quaternary ammonium salt.

[0036] The plasticizer is one of phthalate or trioctyl phosphate.

[0037] The thickness ratio of the reinforcing layer 10, the middle layer 20, and the inner layer 30 is 5:4:5, and the total thickness is 35-45 micrometers.

[0038] A method for preparing a high-temperature resistant and high-strength thin film, applicable to the aforementioned high-temperature resistant and high-strength thin film, includes the following steps:

[0039] S100, Pretreatment: Polyethylene terephthalate and polylactic acid in the middle layer 20 and inner layer 30 are respectively soaked in 2-3 wt% ammonia water for 8-12 minutes, then filtered, washed with water and dried to obtain pretreated polylactic acid and polyethylene terephthalate.

[0040] S200, Mixing and spreading: Add the raw materials of the middle layer 20 and the inner layer 30 to two independent mixing kettles according to their respective proportions, stir and mix evenly, and then add them to two barrels for melting and intensive mixing. The melting and intensive mixing temperature is 220-260℃. Finally, it is cast and spread onto the hot-pressed base film 300 through a double-layer herringbone co-extrusion die.

[0041] S300, Spinning: The reinforcing material solution is added to the syringe, and a mesh-like reinforcing layer 11 is prepared by electrospinning using an electrospinning machine and attached to the hot-pressed base film 200; the spinning process parameters are: positive voltage 9-11Kv, needle inner diameter 0.8-1mm, and receiving distance 19-21cm.

[0042] S400, Impregnation: Resin 12 is sprayed onto the surface of the reinforcing layer 11 using a spray gun, and air pressure is used to fully penetrate and fill the mesh gaps of the reinforcing layer 11 with resin 12, thereby forming the reinforcing layer 10.

[0043] S500, Micro-hot pressing: The hot pressing upper base film 200 and the hot pressing lower base film 300 are joined together. The hot pressing temperature is set to 60-70℃, the pressure head loading speed is 0.008-0.012mm / s, the holding pressure is 70-90N, and the holding time is 280-320s. The film body 100 is formed by hot pressing and heat setting. Finally, the film is separated, wound up, and cut.

[0044] Example 1

[0045] A high-temperature and high-strength film includes a film body 100, which is composed of a multi-layer structure, consisting of a reinforcing layer 10, a middle layer 20, and an inner layer 30 from the outside to the inside.

[0046] The reinforcing layer 10 includes a reinforcing layer 11 and a resin 12. The material of the reinforcing layer 11 is aramid fiber, and the material of the resin 12 is thermosetting resin. The reinforcing layer 11 has a grid-like design, and the resin 12 is filled into the grid gaps of the reinforcing layer 11 by a spray impregnation process.

[0047] The material composition of the middle layer 20 includes: 40 parts of polyethylene terephthalate, 60 parts of polylactic acid, 2 parts of silica, and 2 parts of trioctyl phosphate;

[0048] The inner layer 30 consists of the following components: 45 parts polyethylene terephthalate, 65 parts polylactic acid, 2 parts silica, 2 parts citric acid, and 3 parts trioctyl phosphate.

[0049] The thickness ratio of the reinforcing layer 11, the middle layer 20, and the inner layer 30 is 4:4:5.

[0050] A method for preparing high-temperature resistant and high-strength thin films includes the following steps:

[0051] S100, Pretreatment: Polyethylene terephthalate and polylactic acid in the middle layer 20 and inner layer 30 are respectively soaked in 2.5wt% ammonia water for 10 minutes, then filtered, washed with water and dried to obtain pretreated polylactic acid and polyethylene terephthalate.

[0052] S200, Mixing and spreading: The raw materials in the middle layer 20 and the inner layer 30 are added to two independent mixing kettles according to their respective proportions, stirred and mixed evenly, and then added to two barrels for melting and intensive mixing. The melting and intensive mixing temperature is 240℃. Finally, the mixture is cast and spread onto the hot-pressed base film 300 through a double-layer herringbone co-extrusion die.

[0053] S300, Spinning: The reinforcing material solution is added to the syringe, and a mesh-like reinforcing layer 11 is prepared by electrospinning using an electrospinning machine and attached to the hot-pressed base film 200; the spinning process parameters are: positive voltage 10Kv, needle inner diameter 0.9mm, receiving distance 20cm;

[0054] S400, Impregnation: Resin 12 is sprayed onto the surface of the reinforcing layer 11 using a spray gun, and air pressure is used to fully penetrate and fill the mesh gaps of the reinforcing layer 11 with resin 12, thereby forming the reinforcing layer 10.

[0055] S500, Micro-hot pressing: The hot pressing upper base film 200 and the hot pressing lower base film 300 are joined together. The hot pressing temperature is set to 60-70℃, the pressure head loading speed is 0.01mm / s, the holding pressure is 80N, and the holding time is 300s. The film body 100 is formed by hot pressing and heat setting. Finally, the film is separated, wound up, and cut.

[0056] Example 2

[0057] A high-temperature and high-strength film includes a film body 100, which is composed of a multi-layer structure, consisting of a reinforcing layer 10, a middle layer 20, and an inner layer 30 from the outside to the inside.

[0058] The reinforcing layer 10 includes a reinforcing layer 11 and a resin 12. The material of the reinforcing layer 11 is aramid fiber, and the material of the resin 12 is thermosetting resin. The reinforcing layer 11 has a grid-like design, and the resin 12 is filled into the grid gaps of the reinforcing layer 11 by a spray impregnation process.

[0059] The material composition of the middle layer 20 includes: 40 parts of polyethylene terephthalate, 60 parts of polylactic acid, 2 parts of silica, and 2 parts of phthalate.

[0060] The inner layer 30 consists of the following components: 45 parts polyethylene terephthalate, 65 parts polylactic acid, 2 parts silica, 1.5 parts trimethoxysilane quaternary ammonium salt, and 3 parts phthalate.

[0061] The thickness ratio of the reinforcing layer 11, the middle layer 20, and the inner layer 30 is 4:4:5.

[0062] A method for preparing high-temperature resistant and high-strength thin films includes the following steps:

[0063] S100, Pretreatment: Polyethylene terephthalate and polylactic acid in the middle layer 20 and inner layer 30 are respectively soaked in 2.5wt% ammonia water for 10 minutes, then filtered, washed with water and dried to obtain pretreated polylactic acid and polyethylene terephthalate.

[0064] S200, Mixing and spreading: The raw materials in the middle layer 20 and the inner layer 30 are added to two independent mixing kettles according to their respective proportions, stirred and mixed evenly, and then added to two barrels for melting and intensive mixing. The melting and intensive mixing temperature is 240℃. Finally, the mixture is cast and spread onto the hot-pressed base film 300 through a double-layer herringbone co-extrusion die.

[0065] S300, Spinning: The reinforcing material solution is added to the syringe, and a mesh-like reinforcing layer 11 is prepared by electrospinning using an electrospinning machine and attached to the hot-pressed base film 200; the spinning process parameters are: positive voltage 10Kv, needle inner diameter 0.9mm, receiving distance 20cm;

[0066] S400, Impregnation: Resin 12 is sprayed onto the surface of the reinforcing layer 11 using a spray gun, and air pressure is used to fully penetrate and fill the mesh gaps of the reinforcing layer 11 with resin 12, thereby forming the reinforcing layer 10.

[0067] S500, Micro-hot pressing: The hot pressing upper base film 200 and the hot pressing lower base film 300 are joined together. The hot pressing temperature is set to 60-70℃, the pressure head loading speed is 0.01mm / s, the holding pressure is 80N, and the holding time is 300s. The film body 100 is formed by hot pressing and heat setting. Finally, the film is separated, wound up, and cut.

[0068] Comparative Example 1

[0069] Thin film is composed of a multilayer structure, consisting of an outer layer, a middle layer, and an inner layer from the outside to the inside.

[0070] The outer layer consists of the following components: 45 parts polyethylene terephthalate, 65 parts polylactic acid, 2 parts silica, 2 parts citric acid, and 3 parts trioctyl phosphate.

[0071] The middle layer consists of: 40 parts polyethylene terephthalate, 60 parts polylactic acid, 2 parts silica, and 2 parts trioctyl phosphate.

[0072] The inner layer consists of the following components: 45 parts polyethylene terephthalate, 65 parts polylactic acid, 2 parts silica, 2 parts citric acid, and 3 parts trioctyl phosphate.

[0073] The thickness ratio of the outer layer, middle layer, and inner layer is 5:4:5.

[0074] A method for preparing high-temperature resistant and high-strength thin films includes the following steps:

[0075] S100, Pretreatment: Polyethylene terephthalate and polylactic acid in the outer layer, middle layer and inner layer are soaked in 2.5wt% ammonia water for 10 minutes, then filtered, washed with water and dried to obtain pretreated polylactic acid and polyethylene terephthalate.

[0076] S200, Mixing and spreading: The raw materials for the outer layer, middle layer and inner layer are added to three independent mixing tanks according to their respective proportions, stirred and mixed evenly, and then added to three barrels for melting and intensive mixing. The melting and intensive mixing temperature is 240℃. Finally, the film is cast into a film through a three-layer co-extrusion die, cooled, stretched, heat-set, wound and cut to form a thin film.

[0077] Comparative Example 2

[0078] A high-temperature and high-strength film includes a film body 100, which is composed of a multi-layer structure, consisting of a reinforcing layer 10, a middle layer 20, and an inner layer 30 from the outside to the inside.

[0079] The reinforcing layer 10 includes a reinforcing layer 11 and a resin 12. The material of the reinforcing layer 11 is aramid fiber, and the material of the resin 12 is thermosetting resin. The reinforcing layer 11 is designed in a layered manner, and the resin 12 is filled into the mesh gaps of the reinforcing layer 11 by a spray impregnation process.

[0080] The material composition of the middle layer 20 includes: 40 parts of polyethylene terephthalate, 60 parts of polylactic acid, 2 parts of silica, and 2 parts of phthalate.

[0081] The inner layer 30 consists of the following components: 45 parts polyethylene terephthalate, 65 parts polylactic acid, 2 parts silica, 1.5 parts trimethoxysilane quaternary ammonium salt, and 3 parts phthalate.

[0082] The thickness ratio of the reinforcing layer 11, the middle layer 20, and the inner layer 30 is 4:4:5.

[0083] A method for preparing high-temperature resistant and high-strength thin films includes the following steps:

[0084] S100, Pretreatment: Polyethylene terephthalate and polylactic acid in the middle layer 20 and inner layer 30 are respectively soaked in 2.5wt% ammonia water for 10 minutes, then filtered, washed with water and dried to obtain pretreated polylactic acid and polyethylene terephthalate.

[0085] S200, Mixing and spreading: The raw materials in the middle layer 20 and the inner layer 30 are added to two independent mixing kettles according to their respective proportions, stirred and mixed evenly, and then added to two barrels for melting and intensive mixing. The melting and intensive mixing temperature is 240℃. Finally, the mixture is cast and spread onto the hot-pressed base film 300 through a double-layer herringbone co-extrusion die.

[0086] S300, Spinning: The reinforcing material solution is added to the syringe, and a layered reinforcing layer 11 is prepared by electrospinning using an electrospinning machine and attached to the hot-pressed base film 200; the spinning process parameters are: positive voltage 10Kv, needle inner diameter 0.9mm, receiving distance 20cm;

[0087] S400, Impregnation: The resin 12 is sprayed onto the surface of the reinforcing layer 11 using a spray gun, and the resin 12 is fully penetrated into the reinforcing layer 11 using air pressure, thereby forming the reinforcing layer 10.

[0088] S500, Micro-hot pressing: The hot pressing upper base film 200 and the hot pressing lower base film 300 are joined together. The hot pressing temperature is set to 60-70℃, the pressure head loading speed is 0.01mm / s, the holding pressure is 80N, and the holding time is 300s. The film body 100 is formed by hot pressing and heat setting. Finally, the film is separated, wound up, and cut.

[0089] The performance of the films prepared in the above embodiments and comparative examples was tested, and the results are shown in Table 1.

[0090] Table 1

[0091]

[0092] As can be seen from the data in the table above, the test data of Examples 1 and 2 are all good, with heat distortion temperature ≥181℃, tensile strength ≥53MPa, puncture strength ≥170N, and thickness ≤3.8mm. The data of Comparative Example 1 shows that if the reinforcing layer 10 is removed, the prepared film shows a significant decrease in heat distortion temperature, tensile strength, and puncture strength, and the overall high-temperature resistance and strength performance are poor. The data of Comparative Example 2 shows that if the grid design of the reinforcing layer 11 is changed to a flat layered design, the overall thickness of the prepared film is too thick, making it difficult to meet the film thickness requirements.

[0093] The above embodiments are only used to illustrate the technical solutions of the present invention, and are not intended to limit it.

Claims

1. A high-temperature resistant and high-strength film, characterized in that, It includes a thin film body (100), which is composed of a multi-layer structure, consisting of a reinforcing layer (10), a middle layer (20), and an inner layer (30) from the outside to the inside. The reinforcing layer (10) includes a reinforcing layer (11) and a resin (12). The reinforcing layer (11) is designed in a grid pattern, and the resin (12) is injected and filled into the grid gaps of the reinforcing layer (11) by a spray impregnation process. The material composition of the middle layer (20) includes: 30-60 parts of polyethylene terephthalate, 50-80 parts of polylactic acid, 1-2 parts of silica and 1-3 parts of plasticizer; The material composition of the inner layer (30) includes: 30-60 parts of polyethylene terephthalate, 50-80 parts of polylactic acid, 1-2 parts of silica, 1-2 parts of antifungal agent and 1-3 parts of plasticizer; The reinforcing layer (11) is made of aramid fiber, and the resin (12) is made of thermosetting resin. The reinforcing layer (10) is composited with the middle layer (20) and the inner layer (30) through a micro-hot pressing process. The micro-hot pressing base material is selected from at least one of PE, PMMA, PC, PLLA, PDLA, PVA, PCL, PEG, PEO, PBS or TPU.

2. The high-temperature resistant and high-strength film according to claim 1, characterized in that, The antifungal agent is one of citric acid and trimethoxysilane quaternary ammonium salt.

3. The high-temperature resistant and high-strength film according to claim 1, characterized in that, The plasticizer is one of phthalate or trioctyl phosphate.

4. The high-temperature resistant and high-strength film according to claim 1, characterized in that, The thickness ratio of the reinforcing layer (10), the middle layer (20), and the inner layer (30) is 5:4:5, and the total thickness is 35~45 micrometers.

5. A method for preparing a high-temperature resistant and high-strength thin film, characterized in that, The method for preparing high-temperature resistant and high-strength thin films is applied to any of the high-temperature resistant and high-strength thin films described in claims 1-4, and the preparation method includes the following steps: S100, Pretreatment: Polyethylene terephthalate and polylactic acid in the middle layer (20) and inner layer (30) are soaked in 2-3 wt% ammonia water for 8-12 minutes, then filtered, washed with water and dried to obtain pretreated polylactic acid and polyethylene terephthalate. S200, Mixing and spreading: The raw materials in the middle layer (20) and inner layer (30) are added to two independent mixing kettles according to their respective proportions, stirred and mixed evenly, and then added to two barrels for melting and intensive mixing. Finally, they are spread onto the hot-pressed base film (300) through a double-layer herringbone co-extrusion die. S300, Spinning: The reinforcing material is added to the syringe, and a mesh-like reinforcing layer (11) is prepared by electrospinning machine and attached to the hot-pressed base film (200); S400, Impregnation: The resin (12) is sprayed onto the surface of the reinforcing layer (11) using a spray gun, and the resin (12) is fully penetrated and filled into the mesh gaps of the reinforcing layer (11) by air pressure, thereby forming a reinforcing layer (10). S500, Micro-hot pressing: Hot pressing upper base film (200) and hot pressing lower base film (300) are joined together, and the temperature and load are adjusted so that the temperature is higher than the glass transition temperature of the polymer and lower than the viscosity transition temperature. The film body (100) is formed by hot pressing and heat setting. Finally, the film is separated, wound up and cut.

6. The method for preparing a high-temperature resistant and high-strength thin film according to claim 5, characterized in that, The melting and mixing temperature in S200 is 220~260℃.

7. The method for preparing a high-temperature resistant and high-strength thin film according to claim 5, characterized in that, The S300 spinning process parameters are: positive voltage 10KV, needle inner diameter 0.9mm, and receiving distance 20cm.

8. The method for preparing a high-temperature resistant and high-strength thin film according to claim 5, characterized in that, The S500 micro hot pressing process parameters are: hot pressing temperature 65°C, pressure head loading speed 0.01mm / s, holding pressure 80N, and holding time 300s.

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