Ultrahigh-water-drop-angle 9H curved-surface protective film capable of being bent and shaped and production process

Abstract

The invention discloses an ultrahigh water drop angle 9H curved surface protective film capable of being bent and shaped and a production process, the structure of the protective film comprises a first substrate layer, a second substrate layer and a UV shaping layer arranged between the first substrate layer and the second substrate layer, and the upper surface of the first substrate layer is sequentially provided with a hardened scratch-resistant layer, a priming coat, a fluorine-containing anti-fingerprint layer and a protective film layer. Through a composite structure of the hardened scratch-resistant layer and the fluorine-containing fingerprint-resistant layer, glass-grade protection can be realized synergistically, 9H ultrahigh hardness is achieved, and a test shows that a water drop angle exceeds 115 degrees. Through the core design of the UV shaping layer, the process of plane cutting and curved surface curing can be achieved, the plane state is kept before a curved surface screen is attached, cutting can be directly conducted through a film attaching robot, and the storage pressure that curved surface protection films need to be pre-stored for different machine types is relieved. Through UV irradiation shaping, the same using hand feeling of a tempered film is achieved, the defects that tempered glass is prone to edge breakage and is not explosion-proof can be overcome, and the method can be synchronously applied to surface protection of a plane touch display module.

Description

Technical Field

[0001] The present invention relates to the technical field of curved surface protective films, and particularly to a curved surface protective film with an ultra-high water droplet angle of 9H that can be bent and shaped. Background Art

[0002] With the rapid iteration of electronic devices such as smart phones towards curved screens, the demand for screen protection has become increasingly prominent. The current mainstream protective film technologies mainly include three categories: Flexible polymer soft films (such as TPU, EPU) can fit curved surfaces, but have defects such as poor tear resistance, easy to leave nail indentations, and easy to deform and turn yellow after long-term use, making it difficult to meet high-end protection requirements; Although the curved tempered glass lamination solution provides high hardness, due to the need to pre-process specific arcs for different models, it leads to a huge inventory pressure in the supply chain, and the inherent brittleness of the glass makes its edges fragile and the whole not drop-resistant, posing a safety hazard; The UV-cured flexible protective film that emerged in recent years can achieve curved surface adaptation through a photocured adhesive layer, but its hardness is only 2H - 5H, the scratch resistance is insufficient, the highest water droplet angle is only 110°, the hydrophobic and anti-fouling performance is limited, and it is easy to warp and deform in high-temperature and high-humidity environments.

[0003] None of the above technologies can break through the multiple performance barriers of curved surface lamination adaptability, ultra-high hardness (≥9H), ultra-high hydrophobicity (water droplet angle > 110°), environmental stability, and explosion protection. In particular, it faces two core contradictions: on the one hand, the inventory and fragility problems of tempered glass restrict the mass production efficiency; on the other hand, it is difficult to match the glass-level feel in terms of the hardness and hydrophobicity of flexible materials. Summary of the Invention

[0004] One of the purposes of the present invention is to provide a curved surface protective film with an ultra-high water droplet angle of 9H that can be bent and shaped, avoiding the bursting risk of glass and providing more reliable full-scenario protection for curved screens.

[0005] To solve the above technical problems, the present invention adopts the following technical solution: A curved surface protective film with an ultra-high water droplet angle of 9H that can be bent and shaped, comprising a first substrate layer, a second substrate layer, and a UV shaping layer disposed therebetween. On the upper surface of the first substrate layer, a hardening and scratch-resistant layer, a primer layer, a fluorine-containing anti-fingerprint layer, and a protective film layer are sequentially arranged; The hardening and scratch-resistant layer is a printable hardening coating, and the fluorine-containing anti-fingerprint layer is an anti-fingerprint liquid medicine containing fluororesin and added with a silicon-based lubricating aid. The hardening and scratch-resistant layer and the fluorine-containing anti-fingerprint layer are compounded through the primer layer to form a synergistic protection structure to improve the hardness and water droplet angle of the protective film; The UV shaping layer is a hydroxyl-modified UV polyurethane multi-functional resin material, which is initially cured between the first substrate layer and the second substrate layer by thermal curing with isocyanate, and is used for secondary UV curing during curved surface lamination to achieve curved surface bending and shaping.

[0006] Preferably, the first substrate layer is selected from one of PET, PC, COP, CPI or a PC+PMMA composite optical film, and has a thickness of 23-188 um.

[0007] More preferably, the thickness of the hard anti-scratch layer is 2-25 um; the primer layer is a silane coupling agent primer layer or a primer layer of a resin mixed with SiO2; the protective film layer includes a UV release adhesive layer and a PET protective film layer; the UV shaping layer is a modified UV polyurethane multi-functional resin material containing hydroxyl groups and added with a photoinitiator, which is used for thermal curing with isocyanate to achieve primary curing on the surface of the second substrate layer.

[0008] More preferably, the second substrate layer includes a PET substrate layer, an adhesive layer and a release film layer arranged in sequence from top to bottom, and the adhesive layer is silica gel or exhaust adhesive.

[0009] Alternatively, the second substrate layer includes a stretch film layer and an adhesive layer arranged in sequence from top to bottom; the stretch film layer is TPU or EPU; the adhesive layer is silica gel or exhaust adhesive.

[0010] Alternatively, the second substrate layer includes a PET substrate layer, a stretch film layer and an adhesive layer arranged in sequence from top to bottom; the stretch film layer is EPU; the adhesive layer is silica gel or exhaust adhesive.

[0011] Alternatively, the second substrate layer includes a PET substrate layer, an OCA adhesive layer, a third substrate layer and an adhesive layer arranged in sequence from top to bottom; the third substrate layer is PET or EPU or a PC film; the adhesive layer is silica gel or exhaust adhesive.

[0012] Alternatively, the second substrate layer includes a PET substrate layer, a UV shaping layer, an adhesive layer and a release film layer arranged in sequence from top to bottom; the adhesive layer is silica gel or acrylic adhesive or PU exhaust adhesive.

[0013] Alternatively, the second substrate layer includes a PET substrate layer, a UV shaping layer, a PET substrate layer, an adhesive layer and a release film layer arranged in sequence from top to bottom; the adhesive layer is silica gel or acrylic adhesive or PU exhaust adhesive.

[0014] In addition, the present invention also provides a production process of the above-mentioned ultra-high water contact angle 9H bendable and shapeable curved surface protective film, which includes the following steps: S1. Coating a hardening coating on the upper surface of the first substrate layer, and forming a hard anti-scratch layer through thermal curing and UV curing; S2. Coating a primer solution on the surface of the hard anti-scratch layer and drying to form a primer layer; S3. Coating a fluorine-containing anti-fingerprint solution on the surface of the primer layer, curing to form a fluorine-containing anti-fingerprint layer, and then laminating a protective film layer; S4. Coat an adhesive layer on the lower surface of the PET substrate layer, and after curing, laminate a release film layer; S5. Coat a UV setting adhesive on the upper surface of the PET substrate layer, form a UV setting layer through thermal curing and laminate it with the lower surface of the first substrate layer, thus obtaining the ultra-high water droplet angle 9H bendable and shapeable curved surface protection film.

[0015] Compared with the prior art, the beneficial effects of the present invention are as follows: Through the composite structure of the hardened scratch-resistant layer and the fluorine-containing fingerprint-proof layer, glass-level protection can be synergistically achieved, reaching an ultra-high hardness of 9H. After testing, the water droplet angle exceeds 115°, significantly exceeding the hydrophobicity of traditional UV films. Moreover, through the core design of the UV setting layer, the processes of flat cutting and curved surface curing can be realized. It remains in a flat state before fitting the curved surface screen and can be directly cut by a film-applying robot, completely solving the inventory pressure of pre-storing curved surface protection films for different models. After being shaped by UV irradiation, curved surface fitting, ultra-high hardness, and ultra-high water droplet angle are achieved, realizing the same feel as that of a tempered film, being able to solve the defects of the tempered glass being prone to chipping and not explosion-proof, and being able to be synchronously applied to the surface protection of flat touch display modules. Description of the Drawings

[0016] Figure 1 It is a schematic diagram of the overall structure in Embodiment 1; Figure 2 It is a schematic diagram of the overall structure in Embodiment 2; Figure 3 It is a schematic diagram of the overall structure in Embodiment 3; Figure 4 It is a schematic diagram of the overall structure in Embodiment 4; Figure 5 It is a schematic diagram of the overall structure in Embodiment 5; Figure 6 It is a schematic diagram of the overall structure in Embodiment 6; Figure 7 It is a schematic diagram of the overall structure in Embodiment 7.

[0017] In the figure: 1. First substrate layer; 2. Hardened scratch-resistant layer; 3. Primer layer; 4. Fluorine-containing fingerprint-proof layer; 5. Protection film layer; 6. UV setting layer; 7. PET substrate layer; 8. Adhesive layer; 9. Release film layer; 10. Stretch film layer; 11. OCA adhesive layer; 12. Third substrate layer. Detailed Embodiments

[0018] For the convenience of understanding by those skilled in the art, the present invention will be further described below in conjunction with the embodiments and the drawings. The content mentioned in the embodiments does not limit the present invention.

[0019] Embodiment 1

[0020] AsFigure 1 As shown in the figure, a curved surface protective film with an ultra-high water droplet angle of 9H and bendable and shape-setting properties includes a first base material layer 1, a second base material layer, and a UV shape-setting layer 6 disposed therebetween. On the upper surface of the first base material layer 1, a hardening and scratch-resistant layer 2, a primer layer 3, a fluorine-containing fingerprint-resistant layer 4, and a protective film layer 5 are sequentially provided. The UV shape-setting layer 6 is used to achieve curved surface bending and curing.

[0021] Specifically, the first base material layer 1 in this embodiment is a PET optical film, which has few crystal points and secondary points and high flatness. Its thickness is 23 - 188 um, the light transmittance is ≥90%, the haze is ≤2%, and the heat-resistant shrinkage performance remains for 30 minutes at 150 °C, with a shrinkage rate of ≤0.2%.

[0022] The second base material layer includes a PET base material layer 7, an adhesive layer 8, and a release film layer 9 sequentially arranged from top to bottom. The thickness of the PET base material layer 7 is 4 - 75 um. The adhesive layer 8 specifically uses silicone or high-viscosity UV acrylic adhesive with good adhesion effect on the AF screen. The AF adhesion force is ≥10 gf (AF water droplet angle is 115°), and the thickness of the adhesive layer is 15 - 40 um. The release film layer 9 is a fluoroplastic film or a PET release film.

[0023] The hardening and scratch-resistant layer 2 is a printable hardening coating with good wear resistance, scratch resistance, and low shrinkage during curing. The thickness of this coating is 2 - 25 um, the wear resistance is ≥3000 times (0000# steel wool, 1 kg), the pencil hardness is 9H (500 g), and the shrinkage rate is ≤0.4%.

[0024] The primer layer 3 is a silane coupling agent or a mixed primer layer of resin and SiO2, which is used to improve the adhesion between the fluorine-containing AF liquid medicine and the high-hardness hardening and scratch-resistant layer and the wiping resistance effect.

[0025] The fluorine-containing fingerprint-resistant layer 4 is a fingerprint-resistant liquid medicine containing fluorine resin and doped with silicon-based lubricating aids, which can achieve a water droplet angle of more than 115°. The dynamic friction coefficient μ≤0.05, and it can meet a water droplet angle of more than 110° after being rubbed with a rubber for more than 3000 times. The thickness of this coating is 15 - 100 nm.

[0026] The protective film layer 5 of this embodiment includes a UV de-bonding adhesive layer and a PET protective film layer, which has a good bonding effect on AF and is not easy to precipitate. The thickness is 30 - 95 um, among which the thickness of the PET protective film layer is 25 - 75 um, and the thickness of the UV de-bonding adhesive layer is 5 - 20 um. A high-viscosity UV de-bonding and low-precipitation acrylic protective film is selected to ensure the water droplet angle and smoothness performance on the surface. The adhesion to the steel plate is more than 1200 gf / in, and the adhesion to the AF surface with a water droplet angle of 115° is 2 - 50 gf. After UV light irradiation of 400 - 800 mj, the adhesion is reduced to ≤20 gf to the steel plate and ≤1 gf to the AF surface, which can achieve automatic springing open of the edge after fitting the curved surface and realize rapid removal of the surface protective film.

[0027] The UV shaping layer 6 is a modified UV polyurethane multi-functional resin material containing hydroxyl groups and added with a photoinitiator (TPO or 184), which is used for thermosetting with isocyanate to achieve primary curing on the surface of the second substrate layer, and achieve UV secondary curing during the process of using and fitting the curved surface, improve the overall hardness and achieve curved surface shaping, so that the product has the same feel as glass, with a thickness of 30 - 200um and a pencil hardness of 9H (500g).

[0028] The total thickness of the curved surface protective film in this embodiment is 0.08 - 0.45mm, the light transmittance ≥ 90%, and the haze ≤ 2%.

[0029] The production process steps of the above-mentioned curved surface protective film are as follows: S1. Coat a hardening coating on the upper surface of the first substrate layer 1 (PET optical film with a thickness of 23um), and form a hard anti-scratch layer 2 through thermosetting and UV curing; S2. Perform plasma treatment on the surface of the hard anti-scratch layer 2, synchronously coat a silane coupling agent primer layer, and dry it at 80 - 130°C to form a primer layer 3 and then wind it up; S3. Coat a fluorine-containing anti-fingerprint liquid on the surface of the primer layer 3, bake and cure it at 80 - 140°C to form a fluorine-containing anti-fingerprint layer 4, and then laminate the protective film layer 5 and wind it up; S4. Coating an organosilicon pressure-sensitive adhesive on the lower surface of the PET substrate layer 7 (also using a PET optical film with a thickness of 23um), baking and curing it at 80 - 150°C and laminating it with a fluoroplastic film and winding it up; or, coating a UV-curable modified exhaust adhesive on the lower surface of the PET substrate layer 7 (also using a PET optical film with a thickness of 23um), and performing UV curing and laminating it with a PET release film and winding it up.

[0030] S5. Coat a UV shaping adhesive on the upper surface of the PET substrate layer 7, form a UV shaping layer 6 through thermosetting and laminate it with the lower surface of the first substrate layer 1 to form a curved surface protective film with an ultra-high water droplet angle of 9H and bendable shaping.

[0031] Finally, the finished product is stored in the dark, cut into mobile phone model films by a film laminating robot and vacuum laminated with the mobile phone for UV re-curing, realizing the same effect as tempered glass, but a 9H curved surface protective film without the risk of being fragile.

[0032] After testing, the final results are as follows:

[0033] Example 2

[0034] As Figure 2 shown, the difference between this embodiment and Example 1 is only in the structure of the second substrate layer. Specifically, the second substrate layer in this embodiment is only a glue layer 8, and the glue layer 8 is silicone or exhaust glue.

[0035] By simplifying the second substrate layer into a single adhesive layer, the overall thickness is significantly reduced, and the flexibility of curved surface bending is improved. The adhesive layer 8 is directly compounded with the UV shaping layer 6, saving the cost of the PET substrate. Meanwhile, an AF adhesion force of ≥10 gf is maintained, which is suitable for flexible screen devices (such as folding mobile phones) sensitive to thickness.

[0036] Example 3

[0037] As Figure 3 shown, the difference between this example and Example 1 lies only in the structure of the second substrate layer. Specifically, the second substrate layer of this example includes a stretching film layer 10 and an adhesive layer 8 arranged in sequence from top to bottom. Among them, the stretching film layer 10 is TPU or EPU; the adhesive layer 8 is silica gel or exhaust adhesive.

[0038] The high ductility of the stretching film (elongation at break > 500%) cooperates with the rigidity of the UV shaping layer 6, enabling dynamic stress dispersion during curved surface bending, solving the micro-crack problem during the lamination of large-curvature screens (such as 88° waterfall screens), and reducing the warpage curvature to ≤0.1 mm under the cyclic test of high-temperature and high-humidity environment.

[0039] Example 4

[0040] As Figure 4 shown, the difference between this example and Example 1 lies only in the structure of the second substrate layer. Specifically, the second substrate layer of this example includes a PET substrate layer 7, a stretching film layer 10, and an adhesive layer 8 arranged in sequence from top to bottom. Among them, the stretching film layer 10 is EPU; the adhesive layer 8 is silica gel or exhaust adhesive.

[0041] The PET substrate layer 7 of this example provides dimensional stability, and the EPU layer absorbs impact energy, further improving the explosion-proof performance, especially suitable for the anti-vibration scenario of in-vehicle curved screens.

[0042] Example 5

[0043] As Figure 5 shown, the difference between this example and Example 1 lies only in the structure of the second substrate layer. Specifically, the second substrate layer of this example includes a PET substrate layer 7, an OCA adhesive layer 11, a third substrate layer 12, and an adhesive layer 8 arranged in sequence from top to bottom. Among them, the third substrate layer 12 is a PET or EPU or PC film; the adhesive layer 8 is silica gel or exhaust adhesive.

[0044] In this example, an OCA optical adhesive layer is introduced between the PET substrate layer 7 and the third substrate layer 12. OCA (refractive index 1.50) matches the optical parameters of the upper and lower layers, which can eliminate the interlayer interference fringes, thereby increasing the light transmittance, reducing the haze, and solving the problem of color rendering deviation of the AMOLED screen.

[0045] Example 6

[0046] As Figure 6 shown, the difference between this embodiment and Embodiment 1 lies only in the structure of the second substrate layer. Specifically, the second substrate layer of this embodiment includes a PET substrate layer 7, a UV shaping layer 6, an adhesive layer 8, and a release film layer 9 arranged in sequence from top to bottom. Among them, the adhesive layer 8 is silicone or acrylic adhesive or PU exhaust adhesive.

[0047] This structure realizes a dual UV curing path: the first curing forms the curved surface radian, and the second curing (when fitting the screen) activates the viscosity of the adhesive layer 8. The process efficiency is improved, and the shaping accuracy standard can also be adapted to special-shaped curved surfaces (such as the camera cutout area).

[0048] Embodiment 7

[0049] As Figure 7 shown, the difference between this embodiment and Embodiment 1 lies only in the structure of the second substrate layer. Specifically, the second substrate layer of this embodiment includes a PET substrate layer 7, a UV shaping layer 6, a PET substrate layer 7, an adhesive layer 8, and a release film layer 9 arranged in sequence from top to bottom; the adhesive layer 8 is silicone or acrylic adhesive or PU exhaust adhesive.

[0050] Through the nested UV shaping layer design (two PET substrates sandwich the UV shaping layer), a rigid-flexible gradient structure is formed. The upper PET provides a 9H surface hardness, and the lower PET buffers the drop impact, enabling a bionic protection mechanism of "rigid outside and flexible inside", while maintaining the characteristic of a thin total thickness.

[0051] In order to make it more convenient for those of ordinary skill in the art to understand the improvements of the present invention over the prior art, some drawings and descriptions of the present invention have been simplified, and the above embodiments are preferred implementation solutions of the present invention. In addition, the present invention can also be implemented in other ways. Any obvious substitution without departing from the concept of the technical solution of the present invention is within the protection scope of the present invention.

Claims

1. A curved surface protective film with an ultra-high water droplet angle of 9H and bendable and shapeable characteristics, characterized in that: It includes a first substrate layer (1), a second substrate layer, and a UV shaping layer (6) disposed therebetween. On the upper surface of the first substrate layer (1), a hardening and scratch-resistant layer (2), a primer layer (3), a fluorine-containing fingerprint-proof layer (4), and a protective film layer (5) are sequentially provided; The hardening and scratch-resistant layer (2) is a printable hardening coating, and the fluorine-containing fingerprint-proof layer (4) is a fingerprint-proof liquid medicine containing fluororesin and added with a silicone-based slip additive. The hardening and scratch-resistant layer (2) and the fluorine-containing fingerprint-proof layer (4) are compounded through the primer layer (3) to form a synergistic protection structure to improve the hardness and water contact angle of the protective film; The UV shaping layer (6) is initially cured between the first substrate layer (1) and the second substrate layer through thermal curing, and is curved and shaped through UV secondary curing during curved surface lamination.

2. The curved surface protection film with a super high water droplet angle of 9H and bendable and shapeable as claimed in claim 1, wherein: The first substrate layer (1) is selected from one of PET, PC, COP, CPI, or a PC+PMMA composite optical film, and has a thickness of 23-188 um.

3. The ultra-high water droplet angle 9H bendable and shape-setting curved surface protective film according to claim 2, wherein: The thickness of the hardening and scratch-resistant layer (2) is 2-25 um; the primer layer (3) is a silane coupling agent primer layer or a primer layer of a resin mixed with SiO2; the protective film layer (5) includes a UV release adhesive layer and a PET protective film layer; the UV shaping layer (6) is a modified UV polyurethane multi-functional resin material containing hydroxyl groups and added with a photoinitiator, which is used for thermal curing with isocyanate to achieve initial curing on the surface of the second substrate layer.

4. The curved surface protection film with an ultra-high water droplet angle of 9H and bendable and shapeable as claimed in claim 3, wherein: The second substrate layer includes a PET substrate layer (7), an adhesive layer (8), and a release film layer (9) sequentially arranged from top to bottom, and the adhesive layer (8) is silicone or exhaust adhesive.

5. The ultra-high water droplet angle 9H bendable and shaped curved surface protective film according to claim 3, characterized in that: The second substrate layer includes a stretch film layer (10) and an adhesive layer (8) sequentially arranged from top to bottom; the stretch film layer (10) is TPU or EPU; the adhesive layer (8) is silicone or exhaust adhesive.

6. The ultra-high water droplet angle 9H bendable and shape-setting curved surface protective film according to claim 3, characterized in that: The second substrate layer includes a PET substrate layer (7), a stretch film layer (10), and an adhesive layer (8) sequentially arranged from top to bottom; the stretch film layer (10) is EPU; the adhesive layer (8) is silicone or exhaust adhesive.

7. The curved surface protection film with an ultra-high water droplet angle of 9H and bendable and shapeable according to claim 3, characterized in that: The second substrate layer includes a PET substrate layer (7), an OCA adhesive layer (11), a third substrate layer (12), and an adhesive layer (8) sequentially arranged from top to bottom; the third substrate layer (12) is PET or EPU or a PC film; the adhesive layer (8) is silicone or exhaust adhesive.

8. The curved surface protective film with an ultra-high water droplet angle of 9H and bendable and shapeable according to claim 3, characterized in that: The second substrate layer includes a PET substrate layer (7), a UV shaping layer (6), an adhesive layer (8), and a release film layer (9) sequentially arranged from top to bottom; the adhesive layer (8) is silicone or acrylic adhesive or PU exhaust adhesive.

9. The ultra-high water droplet angle 9H bendable and shape-setting curved surface protective film according to claim 3, wherein: The second substrate layer includes a PET substrate layer (7), a UV shaping layer (6), a PET substrate layer (7), an adhesive layer (8), and a release film layer (9) sequentially arranged from top to bottom; the adhesive layer (8) is silicone or acrylic adhesive or PU exhaust adhesive.

10. The production process of a curved protective film with an ultra-high water droplet angle of 9H and bendable and shapeable as claimed in claim 4, characterized in that: It includes the following steps: S1. Coat a hardening coating on the upper surface of the first substrate layer (1), and form a hardening and scratch-resistant layer (2) through thermal curing and UV curing; S2. Coat a primer solution on the surface of the hardening and scratch-resistant layer (2), and dry it to form a primer layer (3); S3. Coating a fluorine-containing anti-fingerprint liquid on the surface of the bottom coating layer (3), curing to form a fluorine-containing anti-fingerprint layer (4), and then laminating a protective film layer (5); S4. Coating an adhesive layer (8) on the lower surface of the PET substrate layer (7), and laminating a release film layer (9) after curing; S5. Coating a UV setting adhesive on the upper surface of the PET substrate layer (7), thermally curing to form a UV setting layer (6) and laminating it with the lower surface of the first substrate layer (1), thus obtaining the ultra-high water droplet angle 9H bendable and shapeable curved surface protective film.

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