High-temperature-resistant high-strength film and preparation method thereof

Abstract

The invention discloses a high-temperature-resistant high-strength thin film which comprises a thin film main body, and the thin film main body is formed by compounding a plurality of layers of structures, namely a reinforcing layer, a middle layer and an inner layer from outside to inside in sequence; the preparation method of the high-temperature-resistant and high-strength thin film is applied to the high-temperature-resistant and high-strength thin film and comprises the following steps: S100, pretreatment; s200, mixed paving is carried out; s300, spinning is carried out; s400, dipping; and S500, micro hot pressing. According to the high-temperature-resistant and high-strength thin film and the preparation method thereof, the reinforced layer is formed by combining the latticed reinforced layer and the high-pressure spraying resin in the production process, and then the reinforced layer, the middle layer and the inner layer are combined together by adopting an electrostatic spinning technology and a micro hot pressing technology to form the thin film; the overall high temperature resistance and the structural strength performance of the produced film are guaranteed, meanwhile, the film is kept in a thin space, and the use requirements of the technical fields of aerospace, electronic equipment, energy and the like are met.

Description

Technical Field

[0001] The invention belongs to the technical field of film preparation, and in particular relates to a high-temperature resistant and high-strength film and a preparation method thereof. Background Art

[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, traditional materials often cannot meet work requirements.

[0003] Especially in application scenarios such as aerospace, electronic equipment, and energy that have extremely stringent requirements on high temperature, high strength, and thickness, how to develop thin film materials with excellent high temperature resistance and high strength properties has become an important issue that needs to be urgently addressed in the field of materials science and engineering technology. Summary of the invention

[0004] The present invention aims at solving the problems in the prior art and proposes the following technical solutions:

[0005] The high-temperature resistant and high-strength film comprises a film body, wherein the film body is composited by a multi-layer structure, which comprises a strengthening layer, a middle layer and an inner layer from the outside to the inside;

[0006] The strengthening layer includes a reinforcing layer and a resin, wherein the reinforcing layer is designed in a grid shape, and the resin is infiltrated 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 white carbon black and 1-3 parts of plasticizer;

[0008] The material components of the inner layer include: 30-60 parts of polyethylene terephthalate, 50-80 parts of polylactic acid, 1-2 parts of white carbon black, 1-2 parts of mildewproofing agent and 1-3 parts of plasticizer.

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

[0010] As a preferred embodiment of the above technical solution, the strengthening layer is compounded 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 mildew inhibitor 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 and trioctyl phosphate.

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

[0014] A method for preparing a high-temperature resistant and high-strength film, the method for preparing a high-temperature resistant and high-strength film is applied to the above-mentioned high-temperature resistant and high-strength film, the method for preparing the high-temperature resistant and high-strength film comprises the following steps:

[0015] S100, pretreatment: soaking the polyethylene terephthalate and polylactic acid in the middle layer and the inner layer in 2-3 wt% ammonia water for 8-12 minutes respectively, then filtering, washing and drying to obtain pretreated polylactic acid and polyethylene terephthalate;

[0016] S200, mixing and spreading: adding the raw materials of the middle layer and the inner layer into two independent mixing kettles according to their respective proportions, stirring and mixing them evenly, and then adding them into two barrels for melting and kneading, and finally spreading them onto the base film under heat and pressure through a double-layer herringbone co-extrusion die;

[0017] S300, spinning: adding the reinforcing material solution into a syringe, spinning by an electrostatic spinning machine to prepare a grid-like reinforcing layer and attaching it to a hot-pressed upper base film;

[0018] S400, impregnation: spray the resin onto the surface of the reinforcement layer using a spray gun, and use air pressure to fully penetrate the resin into the grid gaps of the reinforcement layer, thereby forming a reinforcement layer;

[0019] S500, micro hot pressing: connect the hot pressing upper base film and the hot pressing lower base film, adjust the temperature and load so that the temperature is higher than the glass transition temperature of the polymer and lower than the viscosity transition temperature, press and heat-set to form the main body of the film, and finally perform mold separation, winding and slitting.

[0020] As a preferred embodiment of the above technical solution, the melting and banburying 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 9-11Kv, needle inner diameter 0.8-1mm, receiving distance 19-21cm.

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

[0023] The beneficial effects of the present invention are:

[0024] The high temperature resistant and high strength film and preparation method thereof of the present invention adopts a grid-shaped reinforcement layer and a high-pressure spray resin to form a reinforcement layer in the production process, and then adopts electrostatic spinning technology and micro-hot pressing technology to combine the reinforcement layer with the middle layer and the inner layer to form a film, thereby ensuring the overall high temperature resistance and structural strength performance of the produced film, while maintaining the film in a relatively thin thickness space, which meets the use requirements in technical fields such as aerospace, electronic equipment, and energy. BRIEF DESCRIPTION OF THE DRAWINGS

[0025] Figure 1 Shown is a schematic diagram of the layers of the high temperature resistant and high strength films in Examples 1 and 2;

[0026] Figure 2 Shown is a schematic diagram of the layers of the high temperature resistant and high strength film in Comparative Example 2.

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

[0028] In order to make the purpose, technical solution and advantages of the embodiments of the present invention more clear, the technical solution of the present invention will be clearly and completely described below in conjunction with the embodiments.

[0029] The high-temperature resistant and high-strength film comprises a film body 100, which is composed of a multi-layer structure, including a strengthening layer 10, a middle layer 20 and an inner layer 30 from the outside to the inside;

[0030] The strengthening layer 10 includes a reinforcing layer 11 and a resin 12. The reinforcing layer 11 is designed in a grid shape, and the resin 12 is infiltrated and filled into the grid gaps of the reinforcing layer 11 by a spray impregnation process.

[0031] The material components of the middle layer 20 include: 30-60 parts of polyethylene terephthalate, 50-80 parts of polylactic acid, 1-2 parts of white carbon black and 1-3 parts of plasticizer;

[0032] The material components of the inner layer 30 include: 30-60 parts of polyethylene terephthalate, 50-80 parts of polylactic acid, 1-2 parts of white carbon black, 1-2 parts of mildewproofing agent and 1-3 parts of plasticizer.

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

[0034] As a preferred embodiment of the above technical solution, the reinforcing layer 10 is compounded with the middle layer 20 and the inner layer 30 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.

[0035] The mildew inhibitor is one of citric acid and trimethoxysilane quaternary ammonium salt.

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

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

[0038] A method for preparing a high-temperature resistant and high-strength film, which is applied to the above-mentioned high-temperature resistant and high-strength film, comprises the following steps:

[0039] S100, pretreatment: soaking the polyethylene terephthalate and polylactic acid in the middle layer 20 and the inner layer 30 in 2-3 wt% ammonia water for 8-12 minutes respectively, then filtering, washing and drying to obtain pretreated polylactic acid and polyethylene terephthalate;

[0040] S200, mixing and spreading: adding the raw materials of the middle layer 20 and the inner layer 30 into two independent mixing kettles according to their respective proportions, stirring and mixing them evenly, and then adding them into two barrels for melting and banburying at a melting and banburying temperature of 220-260° C., and finally spreading them onto the base film 300 under heat and pressure through a double-layer herringbone co-extrusion die;

[0041] S300, spinning: adding the reinforcing material solution into a syringe, using an electrostatic spinning machine to spin to prepare a grid-like reinforcing layer 11 and attaching it to the hot-pressed upper base film 200; the spinning process parameters are: positive voltage 9-11Kv, needle inner diameter 0.8-1mm, receiving distance 19-21cm;

[0042] S400, impregnation: spraying the resin 12 onto the surface of the reinforcing layer 11 with a spray gun, and using air pressure to fully penetrate the resin 12 into the grid gaps of the reinforcing layer 11, thereby forming the strengthening layer 10;

[0043] S500, micro hot pressing: connect the hot pressing upper base film 200 and the hot pressing lower base film 300, set the hot pressing temperature to 60-70°C, the pressure head loading speed to 0.008-0.012 mm / s, the holding pressure to 70-90 N, and the holding time to 280-320 s; press and heat-set to form the film body 100, and finally perform mold separation, winding, and slitting.

[0044] Example 1

[0045] The high-temperature resistant and high-strength film comprises a film body 100, which is composed of a multi-layer structure, including a strengthening layer 10, a middle layer 20 and an inner layer 30 from the outside to the inside;

[0046] The strengthening layer 10 includes a reinforcing layer 11 and a resin 12. The reinforcing layer 11 is made of aramid fiber, and the resin 12 is made of thermosetting resin. The reinforcing layer 11 is designed in a grid shape, and the resin 12 is infiltrated and filled into the grid gaps of the reinforcing layer 11 by a spray impregnation process.

[0047] The material components of the middle layer 20 include: 40 parts of polyethylene terephthalate, 60 parts of polylactic acid, 2 parts of white carbon black and 2 parts of trioctyl phosphate;

[0048] The material components of the inner layer 30 include: 45 parts of polyethylene terephthalate, 65 parts of polylactic acid, 2 parts of white carbon black, 2 parts of citric acid and 3 parts of trioctyl phosphate.

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

[0050] The method for preparing a high-temperature resistant and high-strength film comprises the following steps:

[0051] S100, pretreatment: soaking the polyethylene terephthalate and polylactic acid in the middle layer 20 and the inner layer 30 in 2.5wt% ammonia water for 10 minutes respectively, then filtering, washing and drying to obtain pretreated polylactic acid and polyethylene terephthalate;

[0052] S200, mixing and spreading: adding the raw materials of the middle layer 20 and the inner layer 30 into two independent mixing kettles according to their respective proportions, stirring and mixing them evenly, and then adding them into two barrels for melting and banburying at a melting and banburying temperature of 240° C., and finally spreading them onto the base film 300 under hot pressing through a double-layer herringbone co-extrusion die;

[0053] S300, spinning: adding the reinforcing material solution into a syringe, using an electrospinning machine to spin to prepare a grid-like reinforcing layer 11 and attaching it to the hot-pressed upper base film 200; the spinning process parameters are: positive voltage 10Kv, needle inner diameter 0.9mm, receiving distance 20cm;

[0054] S400, impregnation: spraying the resin 12 onto the surface of the reinforcing layer 11 with a spray gun, and using air pressure to fully penetrate the resin 12 into the grid gaps of the reinforcing layer 11, thereby forming the strengthening layer 10;

[0055] S500, micro hot pressing: connect the hot pressing upper base film 200 and the hot pressing lower base film 300, set the hot pressing temperature to 60-70°C, the pressure head loading speed to 0.01mm / s, the holding pressure to 80N, and the holding time to 300s; press and heat-set to form the film body 100, and finally perform mold separation, winding, and slitting.

[0056] Example 2

[0057] The high-temperature resistant and high-strength film comprises a film body 100, which is composed of a multi-layer structure, including a strengthening layer 10, a middle layer 20 and an inner layer 30 from the outside to the inside;

[0058] The strengthening layer 10 includes a reinforcing layer 11 and a resin 12. The reinforcing layer 11 is made of aramid fiber, and the resin 12 is made of thermosetting resin. The reinforcing layer 11 is designed in a grid shape, and the resin 12 is infiltrated and filled into the grid gaps of the reinforcing layer 11 by a spray impregnation process.

[0059] The material components of the middle layer 20 include: 40 parts of polyethylene terephthalate, 60 parts of polylactic acid, 2 parts of white carbon black and 2 parts of phthalate;

[0060] The material components of the inner layer 30 include: 45 parts of polyethylene terephthalate, 65 parts of polylactic acid, 2 parts of white carbon black, 1.5 parts of trimethoxysilane quaternary ammonium salt and 3 parts of phthalate.

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

[0062] The method for preparing a high-temperature resistant and high-strength film comprises the following steps:

[0063] S100, pretreatment: soaking the polyethylene terephthalate and polylactic acid in the middle layer 20 and the inner layer 30 in 2.5wt% ammonia water for 10 minutes respectively, then filtering, washing and drying to obtain pretreated polylactic acid and polyethylene terephthalate;

[0064] S200, mixing and spreading: adding the raw materials of the middle layer 20 and the inner layer 30 into two independent mixing kettles according to their respective proportions, stirring and mixing them evenly, and then adding them into two barrels for melting and banburying at a melting and banburying temperature of 240° C., and finally spreading them onto the base film 300 under hot pressing through a double-layer herringbone co-extrusion die;

[0065] S300, spinning: adding the reinforcing material solution into a syringe, using an electrospinning machine to spin to prepare a grid-like reinforcing layer 11 and attaching it to the hot-pressed upper base film 200; the spinning process parameters are: positive voltage 10Kv, needle inner diameter 0.9mm, receiving distance 20cm;

[0066] S400, impregnation: spraying the resin 12 onto the surface of the reinforcing layer 11 with a spray gun, and using air pressure to fully penetrate the resin 12 into the grid gaps of the reinforcing layer 11, thereby forming the strengthening layer 10;

[0067] S500, micro hot pressing: connect the hot pressing upper base film 200 and the hot pressing lower base film 300, set the hot pressing temperature to 60-70°C, the pressure head loading speed to 0.01mm / s, the holding pressure to 80N, and the holding time to 300s; press and heat-set to form the film body 100, and finally perform mold separation, winding, and slitting.

[0068] Comparative Example 1

[0069] The film is composed of a multi-layer structure, which includes an outer layer, a middle layer and an inner layer from the outside to the inside;

[0070] The material components of the outer layer include: 45 parts of polyethylene terephthalate, 65 parts of polylactic acid, 2 parts of white carbon black, 2 parts of citric acid and 3 parts of trioctyl phosphate;

[0071] The material components of the middle layer include: 40 parts of polyethylene terephthalate, 60 parts of polylactic acid, 2 parts of white carbon black and 2 parts of trioctyl phosphate;

[0072] The material components of the inner layer include: 45 parts of polyethylene terephthalate, 65 parts of polylactic acid, 2 parts of white carbon black, 2 parts of citric acid and 3 parts of trioctyl phosphate.

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

[0074] The method for preparing a high-temperature resistant and high-strength film comprises the following steps:

[0075] S100, pretreatment: soaking the polyethylene terephthalate and polylactic acid in the outer layer, the middle layer and the inner layer in 2.5wt% ammonia water for 10 minutes respectively, and then filtering, washing and drying to obtain pretreated polylactic acid and polyethylene terephthalate;

[0076] S200, mixing and spreading: add the raw materials of the outer layer, middle layer and inner layer into three independent mixing kettles according to their respective proportions, stir and mix evenly, and then add them into three barrels respectively for melting and mixing at a melting and mixing temperature of 240°C. Finally, pass through a three-layer co-extrusion die to form a film through cast film, cooling, stretching, heat setting, winding, and slitting.

[0077] Comparative Example 2

[0078] The high-temperature resistant and high-strength film comprises a film body 100, which is composed of a multi-layer structure, including a strengthening layer 10, a middle layer 20 and an inner layer 30 from the outside to the inside;

[0079] The strengthening layer 10 includes a reinforcing layer 11 and a resin 12. The reinforcing layer 11 is made of aramid fiber, and the resin 12 is made of thermosetting resin. The reinforcing layer 11 is designed in layers, and the resin 12 is infiltrated and filled into the grid gaps of the reinforcing layer 11 by a spray impregnation process.

[0080] The material components of the middle layer 20 include: 40 parts of polyethylene terephthalate, 60 parts of polylactic acid, 2 parts of white carbon black and 2 parts of phthalate;

[0081] The material components of the inner layer 30 include: 45 parts of polyethylene terephthalate, 65 parts of polylactic acid, 2 parts of white carbon black, 1.5 parts of trimethoxysilane quaternary ammonium salt and 3 parts of phthalate.

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

[0083] The method for preparing a high-temperature resistant and high-strength film comprises the following steps:

[0084] S100, pretreatment: soaking the polyethylene terephthalate and polylactic acid in the middle layer 20 and the inner layer 30 in 2.5wt% ammonia water for 10 minutes respectively, then filtering, washing and drying to obtain pretreated polylactic acid and polyethylene terephthalate;

[0085] S200, mixing and spreading: adding the raw materials of the middle layer 20 and the inner layer 30 into two independent mixing kettles according to their respective proportions, stirring and mixing them evenly, and then adding them into two barrels for melting and banburying at a melting and banburying temperature of 240° C., and finally spreading them onto the base film 300 under hot pressing through a double-layer herringbone co-extrusion die;

[0086] S300, spinning: adding the reinforcing material solution into a syringe, using an electrostatic spinning machine to spin to prepare a layered reinforcing layer 11 and attaching it to the hot-pressed upper base film 200; the spinning process parameters are: positive voltage 10Kv, needle inner diameter 0.9mm, receiving distance 20cm;

[0087] S400, impregnation: spraying the resin 12 onto the surface of the reinforcing layer 11 by using a spray gun, and using air pressure to fully penetrate the resin 12 into the reinforcing layer 11, thereby forming the reinforcing layer 10;

[0088] S500, micro hot pressing: connect the hot pressing upper base film 200 and the hot pressing lower base film 300, set the hot pressing temperature to 60-70°C, the pressure head loading speed to 0.01mm / s, the holding pressure to 80N, and the holding time to 300s; press and heat-set to form the film body 100, and finally perform mold separation, winding, and slitting.

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

[0090] Table 1

[0091]

[0092] It can be seen from the data in the above table that the test data of Examples 1 to 2 are all good, with heat deformation temperature ≥181°C, tensile strength ≥53MPa, puncture resistance ≥170N, and thickness ≤3.8mm. The data of Comparative Example 1 show that if the strengthening layer 10 is removed, the prepared film has a significant decrease in heat deformation temperature, tensile strength, and puncture resistance, and the overall high temperature resistance and strength performance are poor; the data of Comparative Example 2 show that if the grid design of the strengthening layer 11 is changed to a flat layered design, the overall thickness of the prepared film is thicker and it is difficult to meet the film thickness requirements.

[0093] The above embodiments are only used to illustrate the technical solutions of the present invention, rather than to limit them.

Claims

1. High temperature resistant and high strength film, characterized in that: The film body (100) comprises a composite of multiple layers, which are, from the outside to the inside, a strengthening layer (10), a middle layer (20) and an inner layer (30); The strengthening layer (10) comprises a reinforcing layer (11) and a resin (12); the reinforcing layer (11) is designed in a grid shape, and the resin (12) is infiltrated and filled into the grid gaps of the reinforcing layer (11) by a spray impregnation process; The material components of the middle layer (20) include: 30-60 parts of polyethylene terephthalate, 50-80 parts of polylactic acid, 1-2 parts of white carbon black and 1-3 parts of plasticizer; The material components of the inner layer (30) include: 30-60 parts of polyethylene terephthalate, 50-80 parts of polylactic acid, 1-2 parts of white carbon black, 1-2 parts of mildewproofing agent and 1-3 parts of plasticizer.

2. The high temperature resistant and high strength film according to claim 1, characterized in that: The material of the reinforcement layer (11) is aramid fiber, and the material of the resin (12) is thermosetting resin.

3. The high temperature resistant and high strength film according to claim 2, characterized in that: The reinforcing layer (10) is compounded with the middle layer (20) and the inner layer (30) by 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.

4. The high temperature resistant and high strength film according to claim 1, characterized in that: The mildew inhibitor is one of citric acid and trimethoxysilane quaternary ammonium salt.

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

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

7. A method for preparing a high-temperature resistant and high-strength film, characterized in that: The method for preparing a high-temperature resistant and high-strength film is applied to the high-temperature resistant and high-strength film according to any one of claims 1 to 5, and the method for preparing the film comprises the following steps: S100, pretreatment: soaking the polyethylene terephthalate and polylactic acid in the middle layer (20) and the inner layer (30) in 2-3 wt% ammonia water for 8-12 minutes respectively, then filtering, washing and drying to obtain pretreated polylactic acid and polyethylene terephthalate; S200, mixing and spreading: adding the raw materials of the middle layer (20) and the inner layer (30) into two independent mixing kettles according to their respective proportions, stirring and mixing them evenly, and then adding them into two barrels for melting and kneading, and finally spreading them onto the hot-pressed base film (300) through a double-layer herringbone co-extrusion die; S300, spinning: adding the reinforcing material into a syringe, spinning using an electrostatic spinning machine to prepare a grid-layered reinforcing layer (11) and attaching it to the hot-pressed upper base film (200); S400, impregnation: spraying the resin (12) onto the surface of the reinforcing layer (11) using a spray gun, and using air pressure to fully penetrate the resin (12) into the grid gaps of the reinforcing layer (11), thereby forming a strengthening layer (10); S500, micro hot pressing: docking the hot pressing upper base film (200) and the hot pressing lower base film (300), adjusting the temperature and load so that the temperature is higher than the glass transition temperature of the polymer and lower than the viscosity transition temperature, pressing and heat-setting to form a film body (100), and finally performing mold separation, winding, and slitting.

8. The method for preparing a high temperature resistant and high strength film according to claim 7, characterized in that: The melting and banburying temperature in S200 is 220-260°C.

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

10. The method for preparing a high temperature resistant and high strength film according to claim 7, characterized in that: The S500 micro hot pressing process parameters are: hot pressing temperature 65° C., pressure head loading speed 0.01 mm / s, holding pressure 80 N, and holding time 300 s.

Images