Polaroid for vehicle-mounted HUD (Head Up Display) system and preparation method thereof

Abstract

The invention discloses a polaroid for a vehicle-mounted HUD system and a preparation method of the polaroid, and belongs to the field of polaroids, and the polaroid is characterized by comprising a first protective film layer, a first adhesive, a second protective film layer, a PVA film, a third protective film layer, a second adhesive and a fourth protective film layer, a covering protective film layer for covering the whole body of the first protective film layer, the first adhesive, the second protective film layer, the polyvinyl alcohol film, the third protective film layer, the second adhesive and the fourth protective film layer is arranged outside the combination body of the first protective film layer, the first adhesive, the second protective film layer, the polyvinyl alcohol film, the third protective film layer, the second adhesive and the fourth protective film layer. The overall weather resistance, especially the high temperature and humidity resistance, of the polaroid is effectively improved; and the coating of the barrier layer is realized in a finished product dip-coating manner, so that the effects of completely coating the whole polaroid and effectively improving the production efficiency can be achieved.

Description

Technical Field

[0001] The present application relates to the field of polarizers, and more specifically, to a polarizer for a vehicle-mounted HUD system and a preparation method thereof. Background Art

[0002] HUD (HeadUpDisplay) display technology uses the principle of optical reflection to directly project navigation, traffic information, and other real-time data onto the front windshield within the driver's line of sight, enabling the driver to obtain information without being distracted to view the instrument panel or other devices.

[0003] Currently, for the polarizer used in the HUD dust cover, a surface hardening coating needs to be applied to the outer layer of PC to play a role in preventing scratches. However, due to the penetration of water vapor around the cutting edge, the PVA film of the polarizer is easily affected by moisture and shrinks, resulting in polarization failure and light leakage at the edge of the polarizer, and especially in a harsh environment such as a vehicle-mounted display environment, the service life is short.

[0004] In view of this, the inventor of the present invention has designed a polarizer for a vehicle-mounted HUD system and a preparation method thereof. Summary of the Invention

[0005] Aiming at the deficiencies of the existing technology, the purpose of the present invention is to provide a polarizer for a vehicle-mounted HUD system and a preparation method thereof. The advantage lies in that a coating barrier layer is provided for the whole polarizer, and the barrier layer blocks the penetration of water vapor, effectively improving the overall weather resistance of the polarizer, especially the high temperature and humidity resistance; and the coating of the barrier layer is achieved by the method of dip-coating the finished product, which can completely coat the whole polarizer and effectively improve the production efficiency.

[0006] To achieve the above object, the present invention provides the following technical solution: A polarizer for a vehicle-mounted HUD system, which sequentially includes a first protective film layer, a first adhesive, a second protective film layer, a PVA film, a third protective film layer, a second adhesive, and a fourth protective film layer from top to bottom. An overall coating protective film layer for wrapping the combination of the first protective film layer, the first adhesive, the second protective film layer, the polyvinyl alcohol film, the third protective film layer, the second adhesive, and the fourth protective film layer is provided outside.

[0007] The present invention is further preferably: The material of the coating protective film layer is a cured resin, and the thickness of the coating protective film layer is 3 - 50um.

[0008] The present invention is further preferably: The materials of the first protective film layer and the fourth protective film layer include at least one of PC film, COP film, and PMMA film, and the thickness of the first protective film layer and the fourth protective film layer is 60 - 200um.

[0009] Further preferably, in the present invention, the materials of the second protective film layer and the third protective film layer are TAC films, and the thicknesses of the second protective film layer and the third protective film layer are 20-60 um.

[0010] Further preferably, in the present invention, the thickness of the polyvinyl alcohol film is 7-35 um.

[0011] Further preferably, in the present invention, the first adhesive and the second adhesive include any one of UV glue and PSA glue.

[0012] A preparation method of a polarizer for an in-vehicle HUD system includes the following specific steps:

[0013] S1. After the polyvinyl alcohol film undergoes swelling, dyeing, stretching, and drying processes, a polyvinyl alcohol film with a thickness of 7-35 um is made. Then, the second protective film layer and the third protective film layer are respectively adhered to the polyvinyl alcohol film. Next, the first protective film layer is fixed on the second protective film layer through the first adhesive, and the fourth protective film layer is fixed on the third protective film layer through the second adhesive, obtaining a polarizer with a structure composed of a first protective film layer, a first adhesive, a second protective film layer, a PVA film, a third protective film layer, a second adhesive, and a fourth protective film layer.

[0014] S2. The polarizer composed of a first protective film layer, a first adhesive, a second protective film layer, a PVA film, a third protective film layer, a second adhesive, and a fourth protective film layer is produced and compounded and then cut into required specifications;

[0015] S3. The surface of the cut polarizer is subjected to corona treatment, and the contact angle range after corona treatment is 10°-80°;

[0016] S4. The corona-treated polarizer is subjected to coating treatment, and the cured resin is used to coat the entire outer surface of the corona-treated polarizer;

[0017] S5. The polarizer with the cured resin coated on the entire outer surface is subjected to curing treatment, and a coating protective film layer that wraps the entire polarizer can be formed.

[0018] Further preferably, in the present invention, the coating treatment in step S4 includes any one of spraying, curtain coating, dip coating, roll coating, spin coating, extrusion coating, gravure coating, die coating, rod coating, and applicator coating. Further preferably, the dip coating method includes the following steps:

[0019] S41. The cut polarizer is placed in a dip coating device with specific dimensions, including the following steps:

[0020] S411. The cut polarizer is stretched and flattened in a transparent device;

[0021] S412. Then close the transparent device.

[0022] S42. After the device is closed for molding, inject the curable resin, including the following steps:

[0023] S421. The curable resin is injected into the transparent device through the tension control device, and the air inside the transparent device is discharged through the tension control device.

[0024] S422. After the curable resin fills the inside of the transparent device, perform UV curing; after overall curing, shrink out of the mold, inject resin to fill the gaps generated by shrinkage, and then perform UV curing on the area of the tension control device.

[0025] The dip coating device is a transparent device that can penetrate UV optics with an internal coating release function, and a tension control device for ensuring the flatness during the dip coating of the polarizer is provided inside the dip coating device.

[0026] A further preference of the present invention: The curing treatment in step S5 includes any one of electron beam curing, thermal curing, and UV curing.

[0027] In summary, the present invention has the following advantages:

[0028] The combination formed by the first protective film layer, the first adhesive, the second protective film layer, the PVA film, the third protective film layer, the second adhesive, and the fourth protective film layer is integrally coated on the outer surface by coating the protective film layer to form a coating barrier layer, thereby blocking the penetration of water vapor and effectively improving the overall weather resistance of the polarizer, especially the high temperature and humidity resistance; and through this preparation method, the polarizer can be effectively and completely coated, and the production efficiency can be effectively improved. Description of the Drawings

[0029] Figure 1 is the structural schematic diagram of this embodiment;

[0030] Figure 2 is the edge light leakage diagram of the polarizer in this embodiment;

[0031] Figure 3 is the edge non-light leakage diagram of the polarizer in this embodiment;

[0032] Figure 4 is the structural schematic diagram of the dip coating device in this embodiment;

[0033] Figure 5 is the cross-sectional structural schematic diagram of the dip coating device in this embodiment;

[0034] Figure 6 is the structural schematic diagram of the resin delivery pipe and the gas exhaust pipe in the dip coating device of this embodiment.

[0035] Description of reference numerals: 1. First protective film layer; 2. First adhesive; 3. Second protective film layer; 4. Polyvinyl alcohol film; 5. Third protective film layer; 6. Second adhesive; 7. Fourth protective film layer; 8. Coating protective film layer; 9. Transparent frame; 10. Through hole; 11. Resin delivery pipe; 12. Gas exhaust pipe; 13. Pipe body; 14. Port; 15. Polarizer. Detailed implementation mode

[0036] The present invention will be further described in detail below with reference to the accompanying drawings.

[0037] A polarizer for a vehicle-mounted HUD system, as Figure 1 shown, sequentially includes a first protective film layer 1, a first adhesive 2, a second protective film layer 3, a polyvinyl alcohol film 4, a third protective film layer 5, a second adhesive 6, and a fourth protective film layer 7 from top to bottom. An outer part of the combination of the first protective film layer, the first adhesive 2, the second protective film layer 3, the polyvinyl alcohol film 4, the third protective film layer 5, the second adhesive 6, and the fourth protective film layer 7 is provided with a coating protective film layer 8 that wraps the whole thereof.

[0038] As Figure 4 , 5 , 6 shown, the dip coating device includes a transparent device and a tension control device. The transparent device further includes a transparent frame 9 that is combined up and down to form a closed space and is used for installing the polarizer. Four through holes 10 communicating with the closed space are opened on the panel of the transparent frame 9. The tension control device further includes a resin delivery pipe 11 and a gas exhaust pipe 12 respectively installed on the through holes 10. Both the resin delivery pipe 11 and the gas exhaust pipe 12 penetrate through one end of a pipe body 13, and the other end is sealed. A port 14 communicating with the inside of the pipe body 13 is opened on the side wall of the pipe body 13 close to the sealed end.

[0039] A preparation method of a polarizer for a vehicle-mounted HUD system, Example 1:

[0040] S1. After the polyvinyl alcohol film 4 undergoes swelling, dyeing, stretching, and drying processes, a polyvinyl alcohol film 4 with a thickness of 7 μm is made. Then, the second protective film layer 3 and the third protective film layer 5 are respectively adhered to the polyvinyl alcohol film 4. Both the second protective film layer 3 and the third protective film layer 5 are made of TAC films with a thickness of 20 μm. Then, the first protective film layer 1 is fixed on the second protective film layer 3 through the first adhesive 2, and the fourth protective film layer 7 is fixed on the third protective film layer 5 through the second adhesive 6. The first protective film layer 1 and the second protective film layer 3 are PC films with a thickness of 125 μm, and the first adhesive 2 and the second adhesive 6 are UV adhesives with a thickness of 7 μm, obtaining a polarizer composed of a first protective film layer 1, a first adhesive 2, a second protective film layer 3, a PVA film, a third protective film layer 5, a second adhesive 6, and a fourth protective film layer 7.

[0041] S2. Compose and produce the polarizer consisting of the first protective film layer 1, the first adhesive 2, the second protective film layer 3, the PVA film, the third protective film layer 5, the second adhesive 6, and the fourth protective film layer 7, and then cut it into a size of 140 * 220 mm;

[0042] S3. Perform corona treatment on the surface of the cut polarizer, and the contact angle range after corona treatment is 50°;

[0043] S4. Place the corona-treated polarizer in a transparent dip-coating device for dip-coating treatment, and coat the entire outer surface of the corona-treated polarizer with a cured resin;

[0044] S5. Cure the entire device using UV curing. After the resin is cured, remove the dip-coating device to form a coating protective film layer 8 that entirely covers the polarizer and has a thickness of 20 μm.

[0045] A preparation method of a polarizer for a vehicle-mounted HUD system, Example 2:

[0046] S1. After subjecting the polyvinyl alcohol film 4 to swelling, dyeing, stretching, and drying processes, make a polyvinyl alcohol film 4 with a thickness of 23 μm. Then, bond the second protective film layer 3 and the third protective film layer 5 to the polyvinyl alcohol film 4 respectively. Both the second protective film layer 3 and the third protective film layer 5 are made of TAC films with a thickness of 40 μm. Then, fix the first protective film layer 1 on the second protective film layer 3 through the first adhesive 2, and fix the fourth protective film layer 7 on the third protective film layer 5 through the second adhesive 6. The first protective film layer 1 and the second protective film layer 3 are PC films with a thickness of 125 μm, and the first adhesive 2 and the second adhesive 6 are PSA adhesives with a thickness of 20 μm, obtaining a polarizer structured by the first protective film layer 1, the first adhesive 2, the second protective film layer 3, the PVA film, the third protective film layer 5, the second adhesive 6, and the fourth protective film layer 7.

[0047] S2. Compose and produce the polarizer consisting of the first protective film layer 1, the first adhesive 2, the second protective film layer 3, the PVA film, the third protective film layer 5, the second adhesive 6, and the fourth protective film layer 7, and then cut it into a size of 140 * 220 mm;

[0048] S3. Perform corona treatment on the surface of the cut polarizer, and the contact angle range after corona treatment is 50°;

[0049] S4. Place the corona-treated polarizer in a transparent dip-coating device for dip-coating treatment, and coat the entire outer surface of the corona-treated polarizer with a cured resin;

[0050] S5. Cure the whole device by UV curing. After the resin is cured, remove the dip coating device to form a coating protective film layer 8 that entirely wraps the polarizer and has a thickness of 5 μm.

[0051] Comparative Example 1:

[0052] S1. After subjecting the polyvinyl alcohol film 4 to swelling, dyeing, stretching, and drying processes, a polyvinyl alcohol film 4 with a thickness of 23 μm is made. Then, the second protective film layer 3 and the third protective film layer 5 are respectively adhered to the polyvinyl alcohol film 4. Both the second protective film layer 3 and the third protective film layer 5 are made of TAC films with a thickness of 40 μm. Further, the first protective film layer 1 is fixed on the second protective film layer 3 through the first adhesive 2, and the fourth protective film layer 7 is fixed on the third protective film layer 5 through the second adhesive 6. The first protective film layer 1 and the second protective film layer 3 are PC films with a thickness of 125 μm, and the first adhesive 2 and the second adhesive 6 are PSA adhesives with a thickness of 20 μm, obtaining a polarizer with a structure composed of the first protective film layer 1, the first adhesive 2, the second protective film layer 3, the PVA film, the third protective film layer 5, the second adhesive 6, and the fourth protective film layer 7.

[0053] S2. The polarizer composed of the first protective film layer 1, the first adhesive 2, the second protective film layer 3, the PVA film, the third protective film layer 5, the second adhesive 6, and the fourth protective film layer 7 is produced and compounded and then cut into a size of 140 * 220 mm.

[0054] Comparative Example 2:

[0055] S1. After subjecting the polyvinyl alcohol film 4 to swelling, dyeing, stretching, and drying processes, a polyvinyl alcohol film 4 with a thickness of 23 μm is made. Then, the second protective film layer 3 and the third protective film layer 5 are respectively adhered to the polyvinyl alcohol film 4. Both the second protective film layer 3 and the third protective film layer 5 are made of TAC films with a thickness of 40 μm. Further, the first protective film layer 1 is fixed on the second protective film layer 3 through the first adhesive 2, and the fourth protective film layer 7 is fixed on the third protective film layer 5 through the second adhesive 6. The first protective film layer 1 and the second protective film layer 3 are PC films with a thickness of 125 μm, and the first adhesive 2 and the second adhesive 6 are PSA adhesives with a thickness of 20 μm, obtaining a polarizer with a structure composed of the first protective film layer 1, the first adhesive 2, the second protective film layer 3, the PVA film, the third protective film layer 5, the second adhesive 6, and the fourth protective film layer 7.

[0056] S2. The polarizer composed of the first protective film layer 1, the first adhesive 2, the second protective film layer 3, the PVA film, the third protective film layer 5, the second adhesive 6, and the fourth protective film layer 7 is produced and compounded and then cut into a size of 140 * 220 mm.

[0057] S3. Place the corona-treated polarizer in a transparent dip-coating device for dip-coating treatment, and coat the entire outer surface of the corona-treated polarizer with a curing resin.

[0058] S4. Cure the entire device using UV curing. After the resin cures, remove the dip-coating device to form a coating protective film layer 8 that entirely wraps the polarizer and has a thickness of 5 μm.

[0059] Comparative Example 3:

[0060] S1. After subjecting the polyvinyl alcohol film 4 to swelling, dyeing, stretching, and drying processes, a polyvinyl alcohol film 4 with a thickness of 23 μm is made. Then, the second protective film layer 3 and the third protective film layer 5 are respectively adhered to the polyvinyl alcohol film 4. Both the second protective film layer 3 and the third protective film layer 5 are made of TAC films with a thickness of 40 μm. Then, the first protective film layer 1 is fixed on the second protective film layer 3 through the first adhesive 2, and the fourth protective film layer 7 is fixed on the third protective film layer 5 through the second adhesive 6. The first protective film layer 1 and the second protective film layer 3 are PC films with a thickness of 125 μm, and the first adhesive 2 and the second adhesive 6 are PSA adhesives with a thickness of 20 μm, obtaining a polarizer with a structure composed of the first protective film layer 1, the first adhesive 2, the second protective film layer 3, the PVA film, the third protective film layer 5, the second adhesive 6, and the fourth protective film layer 7.

[0061] S2. After the polarizer composed of the first protective film layer 1, the first adhesive 2, the second protective film layer 3, the PVA film, the third protective film layer 5, the second adhesive 6, and the fourth protective film layer 7 is produced and compounded, it is cut into a size of 140 * 220 mm.

[0062] S3. Place the corona-treated polarizer in a transparent dip-coating device for dip-coating treatment, and coat the entire outer surface of the corona-treated polarizer with a curing resin.

[0063] S4. Cure the entire device using UV curing. After the resin cures, remove the dip-coating device to form a coating protective film layer 8 that entirely wraps the polarizer and has a thickness of 40 μm.

[0064] <Adhesion Performance Test>

[0065] Perform a cross-cut test on the examples and comparative examples according to GB / T 9286 - 1998. Consider the situation where peeling phenomenon can be confirmed inside the polarizing film as "×", and the situation where no peeling phenomenon can be confirmed as "〇".

[0066] <Damp Heat Resistance Test>

[0067] For the polarizers in the examples and comparative examples, they were placed in a thermo-hygrostat chamber at a temperature of 85 °C and a humidity of 85% RH for 500 h. After being taken out, they were placed on a backlight module equipped with a lower polarizer and placed orthogonally to the lower polarizer. The backlight module was lit, and the edge failure state was observed. The situation of edge light leakage failure could be observed (as shown in Appendix Figure 3 ) was judged as "×", and the situation where no failure was observed (as shown in Appendix Figure 2 ) was judged as "○".

[0068] <Bending property test>

[0069] The polarizers obtained in the examples and comparative examples were cut into 25 mm × 200 mm. Using a cylindrical bending resistance tester, the cut film was wound around an axial rod with a diameter of 4 mm (bending radius R = 2 mm) at a temperature of 25 °C and a relative humidity of 55% RH to conduct a bending property test. Using the film after the test, in a darkroom environment, visual confirmation was carried out with transmitted light for illumination, and the generation condition of cracks was observed. The situation where rupture could be observed was judged as "×", and the situation where no rupture was observed was judged as "○".

[0070] The above Examples 1, 2, Comparative Example 1, Comparative Example 2, and Comparative Example 3 obtained the following table through adhesion performance test, damp heat resistance test, and bending property test:

[0071] Item Adhesion performance Damp heat resistance performance Flexibility Example 1 〇 〇 〇 Example 2 〇 〇 〇 Comparative Example 1 Without coating layer × Without coating layer Comparative Example 2 × 〇 × Comparative Example 3 〇 〇 ×

[0072] The working process and beneficial effects of the present invention are as follows:

[0073] The combination formed by the first protective film layer, the first adhesive, the second protective film layer, the PVA film, the third protective film layer, the second adhesive, and the fourth protective film layer is integrally coated on the whole outer surface by coating the protective film layer to form a coating barrier layer, thereby blocking the penetration of water vapor and effectively improving the overall weather resistance of the polarizer, especially the high temperature and humidity resistance; and through this preparation method, the polarizer can be effectively and completely coated, and the production efficiency can be effectively improved.

[0074] The above are only the preferred embodiments of the present invention and are not used to limit the present invention. Any modifications, equivalent replacements, improvements, etc. made within the design concept of the present invention shall be included within the protection scope of the present invention.

Claims

1. A polarizer for a vehicle-mounted HUD system, characterized in that: The invention comprises, from top to bottom, a first protective film layer (1), a first adhesive (2), a second protective film layer (3), a PVA film, a third protective film layer (5), a second adhesive (6), and a fourth protective film layer (7); a protective film layer (8) is disposed on the outside of the assembly of the first protective film layer, the first adhesive (2), the second protective film layer (3), the polyvinyl alcohol film (4), the third protective film layer (5), the second adhesive (6), and the fourth protective film layer (7) to cover the entire assembly.

2. The polarizer for a vehicle-mounted HUD system according to claim 1, characterized in that: The material of the coating protective film layer (8) is a cured resin, and the thickness of the coating protective film layer (8) is 3-50 um.

3. The polarizer for a vehicle-mounted HUD system according to claim 1, characterized in that: The material of the first protective film layer (1) and the fourth protective film layer (7) comprises at least one of a PC film, a COP film and a PMMA film, and the thickness of the first protective film layer (1) and the fourth protective film layer (7) is 60-200 um.

4. The polarizer for a vehicle-mounted HUD system according to claim 1, characterized in that: The material of the second protective film layer (3) and the third protective film layer (5) is TAC film, and the thickness of the second protective film layer (3) and the third protective film layer (5) is 20-60 um.

5. The polarizer for a vehicle-mounted HUD system according to claim 1, characterized in that: The thickness of the polyvinyl alcohol film (4) is 7-35 um.

6. The polarizer for a vehicle-mounted HUD system according to claim 1, characterized in that: The first adhesive (2) and the second adhesive (6) include any one of UV adhesive and PSA adhesive.

7. The method for preparing a polarizer for a vehicle-mounted HUD system according to any one of claims 1 to 6, characterized in that: The specific steps include: S1. The polyvinyl alcohol film (4) is subjected to swelling, dyeing, stretching and drying processes to prepare a polyvinyl alcohol film (4) with a thickness of 7-35 μm. The second protective film layer (3) and the third protective film layer (5) are then laminated to the polyvinyl alcohol film (4) respectively. The first protective film layer (1) is fixed to the second protective film layer (3) by a first adhesive (2), and the fourth protective film layer (7) is fixed to the third protective film layer (5) by a second adhesive (6), thereby obtaining a polarizing film having a structure consisting of the first protective film layer (1), the first adhesive (2), the second protective film layer (3), the PVA film, the third protective film layer (5), the second adhesive (6) and the fourth protective film layer (7). S2, compounding the polarizer composed of the first protective film layer (1), the first adhesive (2), the second protective film layer (3), the PVA film, the third protective film layer (5), the second adhesive (6), and the fourth protective film layer (7), and cutting the composite polarizer into the required specifications; S3, performing corona treatment on the surface of the cut polarizer, and the contact angle after corona treatment is in the range of 10°-80°; S4, coating the polarizer after the corona treatment, coating the entire outer surface of the polarizer after the corona treatment with a curing resin; S5. The polarizer with the curing resin coated on the entire outer surface is cured to form a protective film layer (8) that covers the entire polarizer.

8. The method for preparing a polarizer for a vehicle-mounted HUD system according to claim 7, characterized in that: The coating process in step S4 includes any one of spray coating, flow coating, dip coating, roller coating, spin coating, extrusion, gravure coating, die coating, rod coating, and applicator coating.

9. The method for preparing a polarizer for a vehicle-mounted HUD system according to claim 8, characterized in that: The dip coating method comprises the following steps: S41, placing the cut polarizer in a dipping device of a specific size, comprising the following steps: S411, stretching and flattening the cut polarizer in a transparent device; S412, then close the transparent device. S42, injecting curing resin after the device is molded, including the following steps: S421, the solidified resin is injected into the transparent device through the tension control device, and the air inside the transparent device is discharged through the tension control device; S422, after the transparent device is filled with the resin to be cured, UV curing is performed; After the whole part is cured, it is shrunk out of the mold and resin is injected to fill the gap caused by shrinkage. Finally, UV curing is performed on the tension control device area. The dipping device is a transparent device that is internally coated with a release function and can penetrate UV optics. The dipping device is provided with a tension control device for ensuring the flatness of the polarizer during dipping.

10. The method for preparing a polarizer for a vehicle-mounted HUD system according to claim 7, characterized in that: The curing process in step S5 includes any one of electron beam curing, thermal curing, and UV curing.

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