A preparation method of a TPU composite film

Abstract

The present invention discloses a preparation method of a TPU composite film, including Step 1: preparation of a modified material, Step 2: preparation of a mixed solution, Step 3: preparation of a first mixture, Step 4: preparation of a second mixture, Step 5: preparation of an upper film body, Step 6: preparation of a lower film body stock solution, and Step 7: film body composite treatment; the TPU composite film prepared by the present invention through preparing multi-layer TPU film materials and performing two casting treatments has a more firm multi-layer composite. At the same time, due to the preparation method of the present application and the addition of the nano-metal powder mixture, the composite TPU film has a heat insulation effect, effectively improving the applicability of the TPU composite film. The addition of nano-scale modified glass fiber powder makes the TPU composite film have better toughness, and the modified glass fiber is better fused with the inside of the TPU film, providing a new direction for the performance and preparation method of the TPU composite film.

Description

Technical Field

[0001] The present invention relates to the technical field of TPU composite films, and particularly to a preparation method of a TPU composite film. Background Art

[0002] Thermoplastic TPU elastomer is made by extrusion and kneading of MDI containing NCO functional groups, POLYOL containing OH functional groups, and 1.4BG. Due to its good elasticity, excellent physical properties, and good mechanical strengths, it is widely used in processing methods such as injection molding, extrusion, calendering, and dissolution into solution-type resins. It is a plastic material often used by plastic processors, and its products cover the scope of industrial applications and civilian necessities. Due to the increasing use range, some fillers are added during the production of TPU films to change their properties to form TPU composite films;

[0003] Currently, most TPU composite films are prepared by mixing with some functional materials, and multi-layer different-function composites cannot be achieved. Currently, multi-layer multi-functional composite TPU films are all adhered by gluing. The glue adhesion is not firm, and wrinkles will appear during adhesion, resulting in certain defects in the composite film. At the same time, the existing TPU composite films have poor heat insulation effect, and their applicability is greatly reduced. Therefore, the present invention proposes a preparation method of a TPU composite film to solve the problems existing in the prior art. Summary of the Invention

[0004] In view of the above problems, the purpose of the present invention is to propose a preparation method of a TPU composite film. The TPU composite film prepared by this preparation method is more firmly multi-layer composite by preparing multi-layer TPU film materials and performing two casting treatments. At the same time, through the preparation method of the present application and the addition of a nano-metal powder mixture, the composite TPU film has a heat insulation effect, effectively improving the applicability of the TPU composite film. The addition of nano-scale modified glass fiber powder makes the TPU composite film have better toughness, and the modified glass fiber is better integrated into the TPU film, providing a new direction for the performance and preparation method of the TPU composite film.

[0005] To achieve the purpose of the present invention, the present invention is realized through the following technical solutions: A preparation method of a TPU composite film includes the following steps:

[0006] Step 1: Preparation of modified materials. Take glass fiber and perform nano-modification treatment using a nano-grinder to prepare modified glass fiber powder, and then take TPU raw materials and modify them with a photochromic material to obtain modified TPU;

[0007] Step 2: Preparation of a mixed solution. Add nano-asbestos powder, polyethylene wax, and water into a mixing device, mix and stir, and then perform dispersion treatment using an ultrasonic dispersion device to obtain a mixed solution;

[0008] Step 3: Preparation of the first mixture. Add the modified TPU into a mixing kettle, then add the modified glass fiber, the antibacterial agent and the mixed solution, and heat and mix them to obtain the first mixture.

[0009] Step 4: Preparation of the second mixture. Add the modified TPU into a mixing kettle, then add the modified glass fiber, the isocyanate and the mixed solution, and heat and mix them to obtain the second mixture.

[0010] Step 5: Preparation of the upper film body. Add the first mixture and the second mixture into the mixing kettle together, add the silane coupling agent, and heat and mix and stir them. Then use a casting machine to prepare the upper film body.

[0011] Step 6: Preparation of the lower film body stock solution. Place the aluminum powder and the copper powder in a nano high-speed grinding and homogenizing machine for nano-level mixing and grinding treatment to obtain a nano metal powder mixture. Add the TPU raw material into the mixing kettle and mix the nano metal powder mixture according to the methods in Step 3 and Step 4. After preparing two groups of mixtures, mix the two groups of mixtures and add the silane coupling agent and stir to obtain the lower film body stock solution.

[0012] Step 7: Film body composite treatment. Uniformly spray a layer of hot-melt poly-4-methyl-1-pentene on the lower surface of the upper film body, and then use a casting machine to cast and coat the lower film body stock solution onto the lower surface of the upper film body to form a composite film.

[0013] Further improvement lies in that: the specific preparation method of the modified glass fiber powder in Step 1 is to add the glass fiber into a pulverizer for fine pulverization treatment, then use a 300-mesh sieve for screening, then wash the screened glass fiber powder with clear water and dry it in an environment of 70-80 °C, and pour the dried glass fiber powder into a nano grinder to prepare nano glass fiber powder. Finally, soak the nano glass fiber powder in the titanate coupling agent for 1-2 h, take it out and air-dry it to obtain the modified glass fiber powder.

[0014] Further improvement lies in that: the specific preparation method of the modified TPU in Step 1 is to add the TPU raw material into a mixing kettle, then add the photochromic material, the silane coupling agent and the dispersant, heat to 70-90 °C and mix and stir at a speed of 120 r / min, and the stirring duration is 15-20 min.

[0015] Further improvement lies in that: when adding the mixed solution prepared in Step 2 in Step 3 and Step 4, the mixed solution needs to be preheated to 70-80 °C in advance and then poured into the mixing kettle for mixing and stirring.

[0016] A further improvement lies in that: in the third, fourth, and fifth steps, the heating and mixing stirring conditions are stirring at a speed of 180 r / min for 30 - 35 min at a temperature of 80 - 95°C. Before adding the modified TPU to the mixing kettle, it is adjusted to 60 - 70°C and preheated for 10 - 15 min. The first mixture and the second mixture prepared in the third and fourth steps need to be placed in a constant temperature water bath at 70 - 80°C for heat preservation and standby.

[0017] A further improvement lies in that: in the first and sixth steps, after preparing the modified TPU and the lower layer film stock solution, they are both sieved through a 500 - mesh sieve and then kept warm for standby.

[0018] A further improvement lies in that: the upper layer film body prepared in the fifth step is composed of modified TPU, modified glass fiber, nano - asbestos powder, polyethylene wax, antibacterial agent, isocyanate, silane coupling agent, and water mixed in a mass ratio of 50 - 60:8 - 12:8 - 10:2 - 4:1 - 2:4 - 6:5 - 8:6 - 8. Among them, in the first mixture in the third step and the second mixture in the fourth step, except for the antibacterial agent and isocyanate, the other components each account for half of the total components.

[0019] A further improvement lies in that: the lower layer film stock solution prepared in the sixth step is composed of TPU raw material, modified glass fiber, nano - asbestos powder, nano - metal powder mixture, polyethylene wax, antibacterial agent, isocyanate, silane coupling agent, and water mixed in a mass ratio of 50 - 60:6 - 8:6 - 8:5 - 8:2 - 4:1 - 2:4 - 6:5 - 8:6 - 8. During the preparation of the two groups of mixtures, except for the antibacterial agent and isocyanate, the other components also each account for half of the total components.

[0020] A further improvement lies in that: when spraying hot - melt poly(4 - methyl - 1 - pentene) on the upper layer film body, it is heated and conveyed at a temperature of 55 - 70°C on a self - heating conveyor belt. Then, immediately after spraying hot - melt poly(4 - methyl - 1 - pentene), the lower layer film stock solution is coated on the lower surface of the upper layer film body by a casting method using a casting machine to form an integral body.

[0021] The beneficial effects of the present invention are as follows: The TPU composite film prepared by the present invention through preparing multi - layer TPU film materials and performing two casting treatments has a more firm multi - layer composite. At the same time, through the preparation method of the present application and the addition of the nano - metal powder mixture, the composite TPU film has a heat - insulation effect, effectively improving the applicability of the TPU composite film. The addition of nano - sized modified glass fiber powder makes the TPU composite film have better toughness, and the modified glass fiber is better integrated with the TPU film, providing a new direction for the performance and preparation method of the TPU composite film. BRIEF DESCRIPTION OF THE DRAWINGS

[0022] Figure 1 It is a flow chart of the preparation method of Embodiment 1 of the present invention.

[0023] Figure 2 This is the flow chart of the preparation method of Embodiment 2 of the present invention.

[0024] Figure 3 This is the flow chart of the preparation method of the modified glass fiber of Embodiment 3 of the present invention. Detailed implementation manners

[0025] To deepen the understanding of the present invention, the present invention will be further described in detail below in conjunction with embodiments. These embodiments are only used to explain the present invention and do not limit the protection scope of the present invention.

[0026] Embodiment 1

[0027] According to Figure 1 as shown, this embodiment provides a preparation method of a TPU composite film, including the following steps:

[0028] Step 1: Preparation of modified materials. Take glass fiber and perform nano-modification treatment using a nano-grinder to prepare modified glass fiber powder. Then take TPU raw material and modify it with a photochromic material to obtain modified TPU;

[0029] The specific preparation method of the modified TPU is to add the TPU raw material into a mixing kettle, then add the photochromic material and add a silane coupling agent and a dispersant, heat to 85 °C and mix and stir at a speed of 120 r / min for 20 min. After preparation, use a 500-mesh sieve for screening, and then keep it warm under the condition of a 60 °C constant temperature water bath for standby.

[0030] Step 2: Preparation of the mixed solution. Add nano-asbestos powder, polyethylene wax and water into a mixing device for mixing and stirring, and after stirring, disperse and process it using an ultrasonic dispersion device to obtain a mixed solution;

[0031] When performing ultrasonic dispersion, the ultrasonic power is 120 W, the ultrasonic frequency is 25 KHz, and the ultrasonic dispersion treatment time is 10 min.

[0032] Step 3: Preparation of the first mixture. Take the modified TPU and add it into a mixing kettle. The mixing kettle is adjusted to 70 °C in advance and preheated for 10 min, then add the modified glass fiber, antibacterial agent and the mixed solution for heating and mixing. The mixed solution needs to be heated to 80 °C in advance and then poured into the mixing kettle for mixing and stirring, and stir at a speed of 180 r / min at 90 °C for 30 min to obtain the first mixture, and place it in a 80 °C constant temperature water bath for standby;

[0033] The first mixture is composed of modified TPU, modified glass fiber, nano-asbestos powder, polyethylene wax, antibacterial agent, silane coupling agent and water in a mass ratio of 28:5:4:1:2:4:4.

[0034] Step 4: Preparation of the second mixture. Take the modified TPU and add it into the mixing kettle. The mixing kettle is pre-adjusted to 70 °C and preheated for 10 - 15 min. Then add the modified glass fiber, isocyanate and the mixed liquid for heating and mixing. The mixed liquid needs to be preheated to 80 °C and then poured into the mixing kettle for mixing and stirring. Stir at a speed of 180 r / min at 90 °C for 30 min to obtain the second mixture, and place it in a constant temperature water bath at 80 °C for heat preservation for standby;

[0035] The second mixture is composed of modified TPU, modified glass fiber, nano-asbestos powder, polyethylene wax, antibacterial agent, isocyanate, silane coupling agent and water, and is mixed in a mass ratio of 28:5:4:1:6:4:4.

[0036] Step 5: Preparation of the upper membrane body. Add the first mixture and the second mixture into the mixing kettle together and add the silane coupling agent for heating, mixing and stirring. The mixing kettle is pre-adjusted to 65 °C and preheated for 15 min. Stir at a speed of 180 r / min at 85 °C for 30 min, and then use a casting machine to prepare the upper membrane body;

[0037] The upper membrane body is composed of modified TPU, modified glass fiber, nano-asbestos powder, polyethylene wax, antibacterial agent, isocyanate, silane coupling agent and water, and is mixed in a mass ratio of 56:10:8:2:2:6:8:8.

[0038] Step 6: Preparation of the lower membrane body stock solution. Take aluminum powder and copper powder and place them in a nano-high-speed grinding and homogenizing machine for nano-level mixing and grinding treatment to obtain a nano-metal powder mixture. Add the TPU raw material into the mixing kettle and mix the nano-metal powder mixture according to the methods of Step 3 and Step 4. After preparing two groups of mixtures, mix the two groups of mixtures and add the silane coupling agent and stir to obtain the lower membrane body stock solution. After preparation, use a 500-mesh sieve for sieving, and then keep it warm for standby in a constant temperature water bath environment at 75 °C;

[0039] The lower membrane body stock solution is composed of TPU raw material, modified glass fiber, nano-asbestos powder, nano-metal powder mixture, polyethylene wax, antibacterial agent, isocyanate, silane coupling agent and water, and is mixed in a mass ratio of 58:7:7:6:2:1:5:6:8. During the preparation of the two groups of mixtures, except for the antibacterial agent and isocyanate, the other components also each account for half of the total components. The antibacterial agent group is mixed in a mass ratio of 29:3.5:3.5:3:1:1:3:4, and the isocyanate group is mixed in a mass ratio of 29:3.5:3.5:3:1:5:3:4.

[0040] Step 7: Membrane body composite treatment. Uniformly spray a layer of hot-melt poly-4-methyl-1-pentene on the lower surface of the upper membrane body, and then use a casting machine to cast and coat the lower membrane body stock solution onto the lower surface of the upper membrane body to form a composite membrane;

[0041] When spraying hot-melt poly(4-methyl-1-pentene), the upper film body is heated and conveyed at a temperature of 65 °C on a self-heating conveyor belt. Then, immediately after spraying hot-melt poly(4-methyl-1-pentene), the lower film body stock solution is coated on the lower surface of the upper film body by a casting method using a casting machine to form an integral structure.

[0042] Example 2

[0043] According to Figure 2 As shown, this example provides a method for preparing a TPU composite film, including the following steps:

[0044] The first step is the preparation of modified materials. Take glass fiber and perform nano-modification treatment using a nano-grinder to prepare modified glass fiber powder. Then, take TPU raw material and modify it with a photochromic material to obtain modified TPU.

[0045] The specific method for preparing modified TPU is to add TPU raw material into a mixing kettle, then add the photochromic material and add a silane coupling agent and a dispersant. Heat to 70 °C and mix and stir at a speed of 120 r / min. The stirring duration is 15 - 20 min. After preparation, sieve it using a 500-mesh sieve, and then keep it warm under the condition of a 55 °C constant temperature water bath for standby.

[0046] The second step is the preparation of the mixed solution. Add nano-asbestos powder, polyethylene wax, and water into a mixing device and mix and stir. After stirring, disperse it using an ultrasonic dispersion device to obtain a mixed solution.

[0047] When performing ultrasonic dispersion, the ultrasonic power is 120 W, the ultrasonic frequency is 25 KHz, and the ultrasonic dispersion treatment time is 10 min.

[0048] The third step is the preparation of the upper film body. Add modified TPU, modified glass fiber, antibacterial agent, isocyanate, and the mixed solution into a mixing kettle and add a silane coupling agent for heating and mixing and stirring. The mixing kettle is adjusted to 70 °C in advance and preheated for 15 min, and stirred at a speed of 180 r / min at a temperature of 80 °C for 35 min. Then, use a casting machine to prepare the upper film body.

[0049] The upper film body is composed of modified TPU, modified glass fiber, nano-asbestos powder, polyethylene wax, antibacterial agent, isocyanate, silane coupling agent, and water mixed in a mass ratio of 58:8:10:2:2:6:8:6.

[0050] Fourth, preparation of the lower film body stock solution. Take aluminum powder and copper powder and place them in a nano high-speed grinding and homogenizing machine for nano-level mixing and grinding treatment to obtain a nano metal powder mixture. Add TPU raw material, modified glass fiber, nano asbestos powder, nano metal powder mixture, polyethylene wax, antibacterial agent, isocyanate, silane coupling agent and water into a mixing kettle for mixing. Then add the silane coupling agent and stir to prepare the lower film body stock solution. After preparation, sieve it through a 500-mesh sieve, and then keep it warm for standby in an 80°C constant temperature water bath environment;

[0051] 50 - 60:6 - 8:6 - 8:5 - 8:2 - 4:1 - 2:4 - 6:5 - 8:6 - 8

[0052] The lower film body stock solution is composed of TPU raw material, modified glass fiber, nano asbestos powder, polyethylene wax, antibacterial agent, isocyanate, silane coupling agent and water in a mass ratio of 58:6:6:7:2:2:6:7:6. During the preparation, for the two groups of mixtures prepared, except for the antibacterial agent and isocyanate, the other components also each account for half of the total components. The antibacterial agent group is mixed in a mass ratio of 29:3:3:3.5:1:1:3.5:4, and the isocyanate group is mixed in a mass ratio of 29:3:3:3.5:1:5:3.5:4.

[0053] Fifth step, film body composite treatment. Uniformly spray a layer of hot-melt poly-4-methyl-1-pentene on the lower surface of the upper film body, and then use a casting machine to cast and coat the lower film body stock solution onto the lower surface of the upper film body to form a composite film;

[0054] When spraying the hot-melt poly-4-methyl-1-pentene on the upper film body, heat and convey it on a self-heating conveyor belt at a temperature of 65°C, and then immediately use a casting machine to coat the lower film body stock solution on the lower surface of the upper film body in a casting method to form an integral shape.

[0055] Example 3

[0056] According to Figure 3 As shown, this example provides a preparation method for modified glass fiber in the preparation method of a TPU composite film, including the following steps:

[0057] S1. First, take glass fiber and add it to a crusher for fine crushing treatment, and then sieve it through a 300-mesh sieve to obtain micron-level glass fiber powder;

[0058] S2. Then, wash the obtained micron-level glass fiber powder with clear water and dry it in an 80°C environment. Crush and disperse the dried glass fiber powder and sieve it through a 300-mesh sieve again until there are no agglomerated powder lumps;

[0059] S3. Then pour the dried glass fiber powder into a nano grinder for processing to obtain nano glass fiber powder;

[0060] S4. Finally, soak the nano glass fiber powder in a titanate coupling agent for 1.5 h, then take it out and let it dry, crush and disperse it, and sieve it with a nano sieve until there are no lumpy powder blocks, thus obtaining the modified glass fiber powder.

[0061] The above shows and describes the basic principles, main features and advantages of the present invention. Those skilled in the art should understand that the present invention is not limited by the above embodiments. What is described in the above embodiments and the specification only illustrates the principles of the present invention. Without departing from the spirit and scope of the present invention, the present invention will have various changes and improvements, and these changes and improvements all fall within the scope of the present invention claimed. The scope of protection claimed by the present invention is defined by the appended claims and their equivalents.

Claims

1. A method for preparing a TPU composite film, characterized in that: The following steps are involved: Step 1: Preparation of modified materials: glass fiber is subjected to nano-modification treatment using a nano-grinder to prepare modified glass fiber powder, and then TPU raw material is modified with a photochromic material to obtain modified TPU; Step 2: preparing a mixed solution, adding nano asbestos powder, polyethylene wax and water into a mixing device, mixing and stirring, and then dispersing the mixture using an ultrasonic dispersing device to obtain a mixed solution; Step 3: preparing a first mixture, adding the modified TPU into a mixing kettle, then adding the modified glass fiber, the antibacterial agent and the mixed solution, heating and mixing, to obtain a first mixture; Step 4: preparing a second mixture, taking the modified TPU and adding it into a mixing kettle, then adding the modified glass fiber, isocyanate and the mixed solution and heating and mixing to obtain a second mixture; Step 5: preparing the upper film body, adding the first mixture and the second mixture into a mixing kettle, adding a silane coupling agent, heating, mixing and stirring, and then using a casting machine to prepare the upper film body; Step 6: Preparation of the lower film stock solution: Aluminum powder and copper powder are placed in a nano-high-speed grinding homogenizer for nano-scale mixing and grinding to obtain a nano-metal powder mixture. The TPU raw material is added to a mixing kettle and the nano-metal powder mixture is mixed according to the method of steps 3 and 4. After preparing two groups of mixtures, the two groups of mixtures are mixed and a silane coupling agent is added and stirred to obtain the lower film stock solution; Step seven, membrane composite treatment, spray a layer of hot-melt poly-4-methyl-1-pentene evenly on the lower surface of the upper membrane, and then use a casting machine to cast the lower membrane stock solution onto the lower surface of the upper membrane to form a composite membrane.

2. The method for preparing a TPU composite film according to claim 1, wherein: The method for preparing the modified glass fiber powder in step 1 is specifically as follows: taking glass fiber and adding it to a grinder for fine grinding, then screening it with a 300-mesh sieve, washing the screened glass fiber powder with clean water and drying it at 70-80°C, and pouring the dried glass fiber powder into a nano grinder to prepare nano glass fiber powder, and finally soaking the nano glass fiber powder in a titanate coupling agent for 1-2 hours, taking it out and drying it to obtain the modified glass fiber powder.

3. The method for preparing a TPU composite film according to claim 1, wherein: The modified TPU preparation method in step 1 is specifically as follows: adding TPU raw materials into a mixing kettle, then adding the photochromic material and the silane coupling agent and the dispersant, heating to 70-90° C. and mixing and stirring at a speed of 120 r / min for 15-20 min.

4. The method for preparing a TPU composite film according to claim 1, wherein: When the mixed solution prepared in step 2 is added in step 3 and step 4, the mixed solution needs to be heated to 70-80° C. in advance and then poured into the mixing kettle for mixing and stirring.

5. The method for preparing a TPU composite film according to claim 1, wherein: The heating, mixing and stirring conditions in step 3, step 4 and step 5 are as follows: stirring at a temperature of 80-95°C and a speed of 180 r / min for 30-35 minutes; the mixing kettle is adjusted to 60-70°C and preheated for 10-15 minutes before adding the modified TPU; the first mixture and the second mixture prepared in step 3 and step 4 need to be placed in a constant temperature water bath of 70-80°C for insulation.

6. The method for preparing a TPU composite film according to claim 1, wherein: In the steps 1 and 6, after preparing the modified TPU and the lower membrane body stock solution, they were both sieved through a 500-mesh sieve and kept warm for later use.

7. The method for preparing a TPU composite film according to claim 1, wherein: The upper film prepared in the step five is formed by mixing modified TPU, modified glass fiber, nano asbestos powder, polyethylene wax, antibacterial agent, isocyanate, silane coupling agent and water in a mass ratio of 50-60:8-12:8-10:2-4:1-2:4-6:5-8:6-8, wherein the first mixture in step three and the second mixture in step four, except for the antibacterial agent and isocyanate, each accounts for half of the total components.

8. The method for preparing a TPU composite film according to claim 1, wherein: The lower membrane stock solution prepared in the step six is mixed with TPU raw material, modified glass fiber, nano asbestos powder, nano metal powder mixture, polyethylene wax, antibacterial agent, isocyanate, silane coupling agent and water in a mass ratio of 50-60:6-8:6-8:5-8:2-4:1-2:4-6:5-8:6-8. The two groups of mixtures prepared during the period, except for the antibacterial agent and isocyanate, the remaining components each account for half of the total components.

9. The method for preparing a TPU composite film according to claim 1, wherein: In the step seven, the upper film body is heated and conveyed at a temperature of 55-70°C on a self-heating conveyor belt when the hot-melt poly-4-methyl-1-pentene is sprayed, and then immediately after the hot-melt poly-4-methyl-1-pentene is sprayed, a casting machine is used to apply the lower film body liquid to the lower surface of the upper film body by a casting method to form an integral body.

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