High-performance anti-fog film and preparation process thereof

Abstract

The invention relates to a preparation process of a high-performance anti-fog film, which comprises the following steps of: unwinding a raw material TAC (triallyl cyanurate), performing corona treatment, saponifying and pre-stretching treatment, saponifying and deep stretching treatment, washing with water, drying, and finally winding. Wherein the saponification pre-stretching treatment is carried out in a first saponification tank, and the saponification deep-stretching treatment is carried out in a second saponification tank; saponification liquid is filled in the first saponification tank and the second saponification tank; a groove inlet position A of the first saponification groove, a groove outlet position B of the first saponification groove and a groove outlet position C of the second saponification groove are respectively provided with a pair of pressing wheels, one pressing wheel of each pair of pressing wheels is controlled by air pressure of an air cylinder, the other pressing wheel is a driving wheel, and the rotating speed of the driving wheel is controlled by a servo motor; and the traction rates of the servo motors at the positions A, B and C are sequentially increased. The preparation process disclosed by the invention effectively prolongs the antifogging aging of the antifogging film, so that the application range of the antifogging film is expanded.

Description

Technical Field

[0001] The invention relates to the field of optical materials, and in particular to a high-performance anti-fog film and a preparation process thereof. Background Art

[0002] The lens fogs up mainly when the water vapor in the air meets the lens surface with a lower temperature. The water vapor cools down quickly and condenses into tiny water droplets on the lens surface and adheres to the surface. The light passes through the small water droplets and undergoes irregular diffuse reflection, refraction and other optical phenomena, causing blurred vision. The common anti-fog technologies on the market mainly include electric heating anti-fog and coating anti-fog. Electric heating anti-fog has a good anti-fog effect, but its application range is small, and it is costly, energy-intensive and not environmentally friendly. Coating anti-fog has low anti-fog performance and a short anti-fog effect.

[0003] In response to the problems of electric heating anti-fog and coating anti-fog, a new anti-fog film has appeared on the market, which is produced by a saponification process. For example, the Chinese invention patent CN105572772A published on May 11, 2016 discloses an anti-fog polarized lens and a preparation method thereof, and specifically discloses the preparation process of the anti-fog film layer: the diacetate cellulose film is saponified with an alkaline solution, washed three times with water, and dried to obtain the anti-fog film layer. The anti-fog performance of the anti-fog film obtained by the existing saponification preparation process is effectively improved, but its anti-fog time is short, generally less than 120 seconds, and therefore cannot be widely used. Summary of the invention

[0004] In view of the problems existing in the prior art, the object of the present invention is to provide a high-performance anti-fog film and a preparation process thereof, so as to prolong the anti-fog effect of the anti-fog film.

[0005] To achieve the above object, the technical solution adopted by the present invention is: A preparation process of a high-performance anti-fog film, wherein the raw material TAC is unwound and then sequentially subjected to the following steps: corona treatment, saponification pre-stretching treatment, saponification deep-stretching treatment, water washing treatment and drying treatment, and finally rolled up; The saponification pre-stretching treatment is carried out in the first saponification tank, and the saponification deep-stretching treatment is carried out in the second saponification tank; the first saponification tank and the second saponification tank are both filled with saponification liquid, the saponification liquid is NaOH solution, and the NaOH concentration of the first saponification tank is lower than that of the second saponification tank; a pair of pressing wheels are provided at the inlet position A of the first saponification tank, the outlet position B of the first saponification tank and the outlet position C of the second saponification tank, one of the pressing wheels in each pair is controlled by the cylinder air pressure, and the other pressing wheel is a driving wheel, and the speed is controlled by a servo motor; the traction speeds of the servo motors at positions A, B and C increase successively.

[0006] The saponification liquid in the first saponification tank is configured as follows: 30%-50% NaOH, 70%-50% deionized water, and the liquid temperature is 40°C-75°C; the saponification liquid in the second saponification tank is configured as follows: 30%-65% NaOH, 70%-35% deionized water, and the liquid temperature is 50°C-85°C.

[0007] The first saponification tank and the second saponification tank are equipped with an ultrasonic cleaning machine so that the ultrasonic path is directly opposite to the membrane surface; the ultrasonic frequency emitted by the ultrasonic cleaning machine is set to 20KHz-80KHz; during the saponification pre-stretching treatment and the saponification deep-stretching treatment, the TAC film is treated with low-frequency ultrasonic waves.

[0008] The corona treatment process is carried out using a corona treatment machine, and the setting parameters of the corona treatment machine are: treatment width is 0.6m±0.02m, output frequency is 15KHZ-25KHZ, electrode gap is 1㎜-1.5㎜, and corona treatment power is 3KW-4KW.

[0009] The transformation treatment process is replaced by a repair treatment process, which utilizes the temperature control of the repair box to activate the molecules between the TAC film structure; by reducing the traction force of the treated film, the tensile internal stress of the treated TAC mold is slowly recovered and reduced, and the repair reduces the extension in the MD direction; at the same time, a repair curved roller is used to increase the extension of the treated TAC film in the TD direction, so that the material film becomes larger in the TD direction and reduces shrinkage; finally, a steel roller is used to flatten the film surface.

[0010] The repair process is implemented by a repair box, and a pair of pressing wheels are provided at the inlet position D and the outlet position E of the repair box, one pressing wheel of each pair of pressing wheels is controlled by the air pressure of the cylinder, and the other pressing wheel is a driving wheel, and the speed is controlled by a servo motor, and the traction speed of the servo motor at the D position is less than the traction speed of the servo motor at the E position; The parameters of the repair box are as follows: The temperature of the first section of the repair box: 30℃-130℃ dry; The temperature of the second section of the repair box: 30℃-130℃ repair; The third section temperature of the repair box: 30℃-130℃ repair; The temperature of the fourth section of the repair box: 30℃-130℃ repair; The fifth section temperature of the repair box: 30℃-130℃ for final shaping; The sixth section temperature of the repair box: 30℃-130℃ for final shaping; In the first to fourth sections of the repair box, a repair curved roller is used to repair the TAC film during the conveying process. In the fifth and sixth sections of the repair box, a steel roller is used to shape the TAC film during the conveying process.

[0011] The radius of the repairing curved roller is 700 mm-2500 mm.

[0012] During the production process of anti-fog film, the pulling speed of TAC film is: 2.0m / min-3.5m / min.

[0013] The water washing process is as follows: the TAC film after the saponification deep drawing process is sequentially washed three times, neutralized once, and washed three times to complete the water washing process and enter the next process.

[0014] A high-performance anti-fog film is prepared by using the above-mentioned preparation process for the high-performance anti-fog film.

[0015] After adopting the above scheme, the present invention performs pre-stretching and deep stretching during the saponification process, and opens the gaps between the material molecules in the MD direction by stretching, so that the saponification liquid can more easily penetrate the interior of the material, destroying the chemical bonds inside the TAC film material, and forming more hydrophilic groups inside the TAC material, thereby achieving higher anti-fog performance.

[0016] At the same time, the present invention effectively repairs the warping deformation of the TAC film during the saponification process by repairing the TAC film. Specifically, the present invention uses the temperature control of the repair box to activate the molecules between the TAC film structure; by reducing the traction of the treated film, the tensile internal stress of the treated material is slowly recovered and reduced, and the MD direction extension is repaired and reduced; at the same time, the repair curved roller is used to increase the extension of the treated material in the TD direction, so that the material film becomes wider in the TD direction and reduces shrinkage; finally, a steel roller is used to flatten the film surface.

[0017] In addition, the present invention utilizes low-frequency ultrasound to have stronger penetrating power and smaller cavitation noise, etc. The saponified liquid penetrates into the material, destroys the chemical bonds inside the TAC material, forms more hydrophilic groups inside the TAC material, and thus achieves higher anti-fog performance. BRIEF DESCRIPTION OF THE DRAWINGS

[0018] Figure 1 is a flow chart of the preparation process of the present invention; Figure 2 It is a schematic diagram of the corona process of the present invention; Figure 3 This is a schematic diagram of the saponification pre-stretching process of the present invention; Figure 4 This is a schematic diagram of the saponification deep drawing process of the present invention; Figure 5 This is a schematic diagram of the repair process of the present invention; Figure 6 This is a process flow chart of the first section of the repair box of the present invention; Figure 7 This is a repair process flow chart of the second section of the repair box of the present invention; Figure 8 This is a repair process flow chart of the third section of the repair box of the present invention; Fig. 9 This is a repair process flow chart of the fourth section of the repair box of the present invention; Fig.10 This is a repair process flow chart of the fifth section of the repair box of the present invention; Fig.11 This is a repair process flow chart of Section 6 of the repair box of the present invention; Fig.12 A schematic diagram of a repaired curved roller according to the present invention; Fig.13 This is the test curve of the waterproof fog performance of raw materials; Fig.14 The anti-fog performance test curve of the pre-stretched anti-fog film of the present invention is shown; Fig.15 This is a test curve of the anti-fog performance of the anti-fog film before repair of the present invention; Fig.16 This is a test curve of the anti-fog performance of the anti-fog film repaired by the present invention.

[0019] Description of labels: Corona treatment machine 1; first saponification tank 2; second saponification tank 3; ultrasonic vibrator 4; repair box 5; repair curved roller 51; steel rod 52. DETAILED DESCRIPTION

[0020] The preferred embodiments of the present invention will be described in more detail below. Although the preferred embodiments of the present invention are described below, it should be understood that the present invention can be realized in various forms and should not be limited by the embodiments set forth herein. In the examples, those without specifying specific techniques or conditions are carried out according to the techniques or conditions described in the documents in this area or according to the product specification. Those without specifying the manufacturer of reagents used or instruments are conventional products that can be obtained commercially. In the following examples, if not clearly stated, "%" refers to weight percentage.

[0021] like Figure 1 As shown, the present invention discloses a preparation process of a high-performance anti-fog film, which unwinds the raw material TAC and sequentially undergoes the following steps: corona treatment, saponification pre-stretching treatment, saponification deep stretching treatment, water washing treatment and repair treatment, and finally rewinds.

[0022] In this embodiment, during the production process of the anti-fog film, the pulling speed of the TAC film is 2.0 m / min-3.5 m / min.

[0023] like Figure 2As shown, the corona treatment process is carried out using a corona treatment machine 1. When the corona treatment machine 1 applies high-frequency high-voltage electricity to the treatment electrode, the electrode interacts with the gas molecules in the air to generate corona discharge. During the discharge process, the gas molecules in the air are ionized to form ions and electrons, generating low-temperature plasma. The chemical bonds on the surface of the TAC film are broken by the bombardment of the low-temperature plasma, generating free radicals and polar groups, making the TAC film surface rough and enhancing its surface activity. The surface tension of the TAC film surface can reach 25mN / m-30mN / m.

[0024] In this embodiment, the corona treatment machine 1 has the following setting parameters: treatment width is 0.6m±0.02m, output frequency is 15KHZ-25KHZ, electrode gap is 1mm-1.5mm, and corona treatment power is 3KW-4KW.

[0025] like Figure 3 and Figure 4 As shown, the saponification pre-stretching treatment is carried out in the first saponification tank 2, and the saponification deep stretching treatment is carried out in the second saponification tank 3. The first saponification tank 2 and the second saponification tank 3 are both filled with saponification liquid, which is a NaOH solution, and the NaOH concentration of the first saponification tank 2 is lower than the NaOH concentration of the second saponification tank 3. The entry position A of the first saponification tank 2, the exit position B of the first saponification tank 2 (entry position of the second saponification tank 3) and the exit position C of the second saponification tank 3 are each provided with a pair of pressing wheels, one of which is controlled by the cylinder air pressure, and the other is a driving wheel, and the speed is controlled by the servo motor. In this embodiment, the exit position and entry position of the first saponification tank 2 are the same. When the speeds of the servo motors at positions A, B, and C are different, that is, the traction rates of the servo motors at positions A, B, and C increase successively, different tensions are generated between them, thereby stretching the TAC film. The traction range of the servo motor can be set to 1%-100%, and the specific output shall be subject to the production value after experimental testing.

[0026] The corona-treated TAC enters the first saponification tank 2 via the pressing wheel at position A for saponification pre-stretching treatment, then enters the second saponification tank 3 via the pressing wheel at position B for saponification deep stretching treatment, and finally enters the next process via the pressing wheel at position C.

[0027] The saponification liquid in the first saponification tank 2 is configured as follows: 30%-50% NaOH, 70%-50% deionized water, and the liquid temperature is 40°C-75°C. The saponification liquid in the second saponification tank 3 is configured as follows: 30%-65% NaOH, 70%-35% deionized water, and the liquid temperature is 50°C-85°C.

[0028] Stretching during the saponification process can open up the gaps between the material molecules in the MD direction, making it easier for the saponification liquid to penetrate the material, destroying the chemical bonds inside the TAC film material, and forming more hydrophilic groups inside the TAC material, thereby achieving higher anti-fog performance.

[0029] During the saponification pre-stretching treatment and saponification deep-stretching treatment, the TAC film is treated with low-frequency ultrasonic waves. Specifically, ultrasonic vibrators 4 are installed at the front and rear ends of the first saponification tank 2 and the second saponification tank 3, so that the ultrasonic path is directly opposite to the film surface. The ultrasonic frequency emitted by the ultrasonic vibrator 4 is set to 20KHz-80KHz, and a low-frequency ultrasonic wave of 25KHz is further preferred.

[0030] The present invention utilizes the characteristics of low-frequency ultrasound with stronger penetrating power and smaller cavitation noise, etc. The saponified liquid penetrates into the material, destroys the chemical bonds inside the TAC material, forms more hydrophilic groups inside the TAC material, and thus achieves higher anti-fog performance.

[0031] The washing process of this embodiment is as follows: the TAC film after saponification deep drawing is washed three times, neutralized once, and washed three times in sequence to complete the washing process and enter the next process. Washing and neutralization are the same as in the prior art, and will not be described in detail. In this embodiment, pure water filtered by carbon is used for washing, and 0.5% acid is used for neutralization.

[0032] Because the TAC material is subjected to saponification and deep stretching treatment, the molecular structure is destroyed, which further causes a certain degree of change in the length and width of the material. The material is stretched in the unwinding direction and shrinks in the width direction, resulting in a certain degree of curling. Figure 5-Figure 11 As shown, in order to repair the deformation of the material, the present invention performs a repair process: the temperature control of the repair box 5 is used to activate the molecules between the TAC film structure; by reducing the traction force of the treated film, the tensile internal stress of the treated material is slowly recovered and reduced, and the repair reduces the extension in the MD direction (transmission direction); at the same time, a repair curved roller is used to increase the extension in the TD direction of the treated material, so that the material film in the TD direction (the lateral direction perpendicular to the transmission direction) becomes wider and reduces shrinkage; finally, a steel roller is used to flatten the film surface.

[0033] In this embodiment, the repair process includes six repairs, which are specifically implemented through the repair box 5. The entry position D and the exit position E of the repair box 5 are each provided with a pair of pressure wheels. One of the pressure wheels in each pair is controlled by the cylinder air pressure, and the other pressure wheel is the driving wheel, and the speed is controlled by the servo motor. The traction rate of the servo motor at the D position is less than the traction rate of the servo motor at the E position.

[0034] The parameters of repair box 5 are as follows: The first section temperature of the repair box: 30℃-130℃ dry Repair box second section temperature: 30℃-130℃ repair Repair box third section temperature: 30℃-130℃ repair Repair box fourth section temperature: 30℃-130℃ repair Repair box section 5 temperature: 30℃-130℃ for final shaping Repair box section 6 temperature: 30℃-130℃ for final shaping The pull-in rate of the servo motor at the D position is set to 12.5%, and the pull-in rate of the servo motor at the E position is set to 11.2%.

[0035] In the first to fourth sections of the above-mentioned repair box 5, the TAC film is repaired by using a repairing curved roller during the conveying process. Fig.12 As shown, the radius of the repair roller is 700 mm-2500 mm. In order to prevent the film from wrinkling and other quality problems, the repair rollers 51 in the first to fourth sections of the repair box 5 need to be used together with the steel rod.

[0036] In the fifth and sixth sections of the above-mentioned repair box 5, a steel roller (cylindrical) is used to shape the TAC film during its conveyance.

[0037] In order to better illustrate the technical effects achieved by the present invention, a number of embodiments are listed below for illustration.

[0038] After the raw material TAC is unwound, it is sequentially subjected to corona treatment, saponification pre-stretching treatment, saponification deep-stretching treatment, water washing treatment and repair treatment.

[0039] The parameters of the corona treatment are as follows: the output frequency of the corona treatment machine 1 is 20KHZ, the electrode gap is 1mm, and the corona treatment power is 3KW.

[0040] The parameter conditions of saponification pre-stretching treatment and saponification deep-stretching treatment are: The saponification liquid in the first saponification tank 2 is specifically configured as follows: 30% NaOH, 70% deionized water, a liquid temperature of 45°C, and a soaking time of 85″±0.5″; the saponification liquid in the second saponification tank 3 is specifically configured as follows: 45% NaOH, 55% deionized water, a liquid temperature of 65°C, and a soaking time of 210″±0.5″.

[0041] When the traction rate input of the servo motor at position A is 10% and the pressure of the pressing wheel is 0.45MPA, and the traction rate input of the servo motor at position B is 10.5% and the pressure of the pressing wheel is 0.55MPA, after the TAC film is corroded and softened by the saponification liquid in the first saponification tank 2, the material will be stretched due to different output rates, and its stretching ratio is about 100.3%±0.2%. When the traction rate input of the servo motor at position C is 12.5% ​​and the pressure of the pressing wheel is 0.55MPA, after the TAC film is corroded and softened by the saponification liquid in the saponification tank, the material will be stretched due to different output rates, and its stretching ratio is 101.7%±3%.

[0042] The parameter conditions of the repair process are: Parameters of repair box 5: temperature of the first section of the repair box: 75°C; temperature of the second section of the repair box: 85°C; temperature of the third section of the repair box: 85°C; temperature of the fourth section of the repair box: 80°C; temperature of the fifth section of the repair box: 70°C; temperature of the sixth section of the repair box: 65°C.

[0043] The radius of the repaired curved roller is 1775.42 mm, the spacing between the highest points of the arc is 100 mm, and the spacing between the lowest points of the arc is 40 mm.

[0044] The pull-in rate of the servo motor at the D position is set to 12.5%, and the pull-in rate of the servo motor at the E position is set to 11.2%.

[0045]

[0046]

[0047]

[0048]

[0049]

[0050] By comparing the anti-fog data in Table 2-5 and combining Figure 13-16 It can be seen that the anti-fog time of TAC after saponification pre-stretching and saponification deep stretching treatment reaches 600 seconds. Compared with the existing 120 seconds, the anti-fog time of the anti-fog film prepared by the process of the present invention is effectively extended, thereby expanding the application range of the anti-fog film.

[0051] The above description is merely an embodiment of the present invention and does not limit the technical scope of the present invention. Therefore, any minor modifications, equivalent changes and modifications made to the above embodiments based on the technical essence of the present invention are still within the scope of the technical solution of the present invention.

Claims

1. A process for preparing a high-performance anti-fog film, characterized in that: After the raw material TAC is unwound, it undergoes the following steps in sequence: corona treatment, saponification pre-stretching treatment, saponification deep-stretching treatment, water washing treatment and drying treatment, and finally rewinding; The saponification pre-stretching treatment is carried out in the first saponification tank, and the saponification deep-stretching treatment is carried out in the second saponification tank; the first saponification tank and the second saponification tank are both filled with saponification liquid, the saponification liquid is NaOH solution, and the NaOH concentration of the first saponification tank is lower than that of the second saponification tank; a pair of pressing wheels are provided at the inlet position A of the first saponification tank, the outlet position B of the first saponification tank and the outlet position C of the second saponification tank, one of the pressing wheels in each pair is controlled by the cylinder air pressure, and the other pressing wheel is a driving wheel, and the speed is controlled by a servo motor; the traction speeds of the servo motors at positions A, B and C increase successively.

2. The process for preparing a high-performance anti-fog film according to claim 1, characterized in that: The saponification liquid in the first saponification tank is configured as follows: 30%-50% NaOH, 70%-50% deionized water, and the liquid temperature is 40°C-75°C; the saponification liquid in the second saponification tank is configured as follows: 30%-65% NaOH, 70%-35% deionized water, and the liquid temperature is 50°C-85°C.

3. The process for preparing a high-performance anti-fog film according to claim 1, characterized in that: The first saponification tank and the second saponification tank are equipped with an ultrasonic cleaning machine so that the ultrasonic path is directly opposite to the membrane surface; the ultrasonic frequency emitted by the ultrasonic cleaning machine is set to 20KHz-80KHz; during the saponification pre-stretching treatment and the saponification deep-stretching treatment, the TAC film is treated with low-frequency ultrasonic waves.

4. The process for preparing a high-performance anti-fog film according to claim 1, characterized in that: The corona treatment process is carried out using a corona treatment machine, and the setting parameters of the corona treatment machine are: treatment width is 0.6m±0.02m, output frequency is 15KHZ-25KHZ, electrode gap is 1㎜-1.5㎜, and corona treatment power is 3KW-4KW.

5. The process for preparing a high-performance anti-fog film according to claim 1, characterized in that: The transformation process is replaced by a repair process, and the repair process uses the temperature control of the repair box to activate the molecules between the TAC film structures; By reducing the traction force of the treated film, the tensile internal stress of the treated TAC mold is slowly recovered and reduced, and the extension in the MD direction is repaired and reduced; at the same time, the repair curved roller is used to increase the extension of the treated TAC film in the TD direction, so that the material film in the TD direction becomes larger and the shrinkage is reduced; finally, a steel roller is used to flatten the film surface.

6. The process for preparing a high-performance anti-fog film according to claim 5, characterized in that: The repair process is implemented by a repair box, and a pair of pressing wheels are provided at the inlet position D and the outlet position E of the repair box, one pressing wheel of each pair of pressing wheels is controlled by the air pressure of the cylinder, and the other pressing wheel is a driving wheel, and the speed is controlled by a servo motor, and the traction speed of the servo motor at the D position is less than the traction speed of the servo motor at the E position; The parameters of the repair box are as follows: The temperature of the first section of the repair box: 30℃-130℃ dry; The temperature of the second section of the repair box: 30℃-130℃ repair; The third section temperature of the repair box: 30℃-130℃ repair; The temperature of the fourth section of the repair box: 30℃-130℃ repair; The fifth section temperature of the repair box: 30℃-130℃ for final shaping; The sixth section temperature of the repair box: 30℃-130℃ for final shaping; In the first to fourth sections of the repair box, a repair curved roller is used to repair the TAC film during the conveying process. In the fifth and sixth sections of the repair box, a steel roller is used to shape the TAC film during the conveying process.

7. The process for preparing a high-performance anti-fog film according to claim 5, characterized in that: The radius of the repairing curved roller is 700 mm-2500 mm.

8. The process for preparing a high-performance anti-fog film according to claim 1, characterized in that: During the production process of anti-fog film, the pulling speed of TAC film is: 2.0m / min-3.5m / min.

9. The process for preparing a high-performance anti-fog film according to claim 1, characterized in that: The water washing process is as follows: the TAC film after the saponification deep drawing process is sequentially washed three times, neutralized once, and washed three times to complete the water washing process and enter the next process.

10. A high-performance anti-fog film, characterized in that: The anti-fog film is prepared by using a high-performance anti-fog film preparation process as described in any one of claims 1-9.

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