Composite tempered film with skin-like soft touch and preparation method thereof

Abstract

The application discloses a tempered film with skin-like soft touch, and belongs to the technical field of electronic device protective film. The tempered film comprises, from top to bottom, a skin-like soft surface layer, a flexible buffer layer, a tempered glass base layer and a bottom adhesive layer. The flexible buffer layer and the soft skin-friendly surface layer are arranged on the upper part of the tempered film, so that the product surface has a soft pressing feeling close to human skin, and the problem of hard texture, hard pressing and poor hand feeling of traditional tempered films is solved. Meanwhile, the tempered glass retains the protection performance of explosion-proof, scratch-proof and wear-resistant, and is sensitive to touch, stable in structure, comfortable to use, and suitable for use in protection of various electronic screens such as mobile phones and tablets.

Description

Technical Field

[0001] This invention belongs to the technical field of screen protection materials for electronic devices, specifically relating to a composite tempered glass film that combines high protective performance with a soft, skin-like feel, and its preparation process. It is suitable for protecting the screens of various electronic devices such as mobile phones, tablets, and smart wearable devices. Background Technology

[0002] With the widespread use of smartphones, tablets, and other electronic devices, screen protectors have become an essential accessory for users. Currently, the mainstream screen protectors on the market can be divided into two main categories: 1. Traditional tempered glass screen protectors: Made primarily of high-alumina-silicon tempered glass, these screen protectors have high hardness (typically up to 9H) and excellent scratch, explosion-proof, and impact-resistant properties, effectively protecting the screen. However, due to the high Young's modulus and hard texture of the glass itself, it feels stiff and inelastic when touched or pressed, which is very different from the feel of human skin. This results in poor comfort during long-term use, and the glass is also brittle and easily breaks at the edges. 2. Flexible films (such as TPU and PET films): They are soft, elastic when pressed, and relatively comfortable to the touch; however, their protective performance is far lower than that of tempered glass films. They are easily scratched and deformed, and cannot effectively resist impacts from hard objects or screen drop damage, thus failing to meet users' core needs for protection. While some existing composite film products attempt to combine the advantages of both technologies, they are mostly simple glass + soft film laminated structures, which have the following core defects: • It lacks softness and cannot achieve a pressing feel close to human skin; it can only slightly alleviate the stiffness. • The interlayer bonding process is simple, but it is prone to problems such as delamination, bubbles, and debonding, resulting in a short service life; • Improper control of the thickness of the soft layer leads to decreased touch sensitivity and reduced light transmittance, affecting the user experience; • Without material selection and structural optimization for a "skin-like feel," the technical contradiction of "the inability to achieve both protection and softness" cannot be fundamentally resolved. Therefore, developing a composite tempered glass film that retains the high protective performance of tempered glass while achieving a skin-like soft pressing feel, sensitive touch, and stable structure is a technical problem that urgently needs to be solved in this field. Summary of the Invention

[0003] Purpose of the invention To address the shortcomings of existing technologies, the present invention aims to provide a composite tempered glass screen protector with a skin-like soft touch and its preparation method. Through multi-layer composite structure design and material optimization, while ensuring the core protective performance of tempered glass screen protectors such as explosion-proof, scratch-proof, and wear-resistant properties, the product surface has a soft, pressable feel close to human skin, while also taking into account high light transmittance and touch sensitivity, thus solving the technical pain points of traditional tempered glass screen protectors, such as a stiff feel and poor protective performance of soft films. (II) Technical Solution To achieve the above objectives, the present invention adopts the following technical solution: A composite tempered glass screen protector with a skin-like soft touch comprises, from top to bottom: a skin-like soft surface layer, a flexible buffer layer, a tempered glass base layer, and a bottom adhesive layer; • The skin-like soft surface layer: located on the top layer of the composite membrane, is made of skin-friendly elastomer material with a Shore hardness of 20-40A (highly matched with the Shore hardness of human skin of 20-35A) and a thickness of 0.03-0.1mm, used to provide a soft, skin-like pressing feel; • The flexible buffer layer: It is set between the skin-like soft surface layer and the tempered glass base layer. It is a highly elastic buffer material with a thickness of 0.05-0.2mm. It is used to bear the surface pressure, provide elastic rebound, further enhance the soft feel, and buffer external impacts. • The tempered glass base layer: is the main support layer of the composite film, using 0.15-0.4mm thick high-alumina-silicon tempered glass with a hardness ≥9H, used to provide core scratch-proof, explosion-proof, and impact-resistant protection performance; • The bottom adhesive layer: Located below the tempered glass base layer, it is an optical grade OCA (optical transparent adhesive) with a thickness of 0.02-0.05mm, used to adhere the composite film to the screen of electronic devices, ensuring high light transmittance and bubble-free bonding. Furthermore, the present invention also provides a method for preparing the composite tempered glass film, comprising the following steps: 1. Composite of surface layer and buffer layer: The skin-like soft surface layer material (modified TPU / liquid silicone) is formed by casting process and then rolled together with the flexible buffer layer (nano silicone / high elastic acrylic) to prepare a soft composite layer; 2. Tempered glass pretreatment: The high-alumina-silicon tempered glass substrate is subjected to double-sided polishing, ultrasonic cleaning, and plasma surface modification to improve surface adhesion and light transmittance; 3. Vacuum hot pressing: Place the soft composite layer and the pre-treated tempered glass base layer into a vacuum hot press and hot press them together for 30-60 seconds at 80-100℃, 0.2-0.4MPa pressure, and a vacuum degree ≥-0.09MPa to ensure that there are no air bubbles between the layers and that the bond is strong. 4. Adhesive layer coating and curing: Apply optical grade OCA adhesive to the bottom of the tempered glass substrate and cure it for 24-48 hours at 25-30℃ and 40-60% humidity to complete the preparation of the composite film; 5. Cutting and Quality Inspection: Cut the screen according to the size of the electronic device screen, and conduct performance tests such as light transmittance, hardness, adhesion, and touch sensitivity. Packaging is carried out after passing the tests. (III) Beneficial Effects Compared with the prior art, the beneficial effects of the present invention are as follows: 1. Ultimate Skin-like Touch: Through the synergistic effect of a skin-like soft surface layer (Shore hardness 20-40A) and a flexible buffer layer, the surface of the composite film has a pressing feel that is highly consistent with human skin, completely solving the problem of traditional tempered glass screen protectors being hard and stiff, and greatly improving the comfort of use; 2. Uncompromised protective performance: Retains the high-alumina-silicon tempered glass base layer with a hardness ≥9H, possessing the same scratch-resistant, explosion-proof, and impact-resistant performance as traditional tempered glass films. At the same time, the flexible buffer layer can further cushion the impact of drops, improving the protective effect. 3. Excellent touch control and light transmittance: The thickness of each layer is precisely controlled, and optical bonding technology is used between the layers. The light transmittance is ≥92%, and the touch sensitivity is consistent with the bare screen. There is no delay or disconnection, and it does not affect the user's operating experience. 4. Stable and durable structure: Through plasma surface modification and vacuum hot pressing bonding process, the interlayer adhesion is strong, with no delamination, no bubbles, no delamination, and it is resistant to bending and aging, with a service life far exceeding that of ordinary composite films. 5. The process is suitable for mass production: the preparation method is simple, adaptable to existing production lines, can be mass-produced, has controllable costs, and is suitable for market promotion. Attached Figure Description Figure 1 This is a cross-sectional view of the layered structure of the composite tempered glass film described in this invention; Among them: 1 is a skin-like soft surface layer, 2 is a flexible buffer layer, 3 is a tempered glass base layer, and 4 is a bottom adhesive layer. Detailed Implementation

[0004] The technical solution of the present invention will be further described in detail below with reference to the accompanying drawings and specific embodiments. Those skilled in the art can realize the present invention without creative effort based on the content of this embodiment. Example like Figure 1 As shown, the composite tempered glass film in this embodiment, from top to bottom, consists of: 1. Skin-like soft surface layer 1: Made of modified TPU material with a Shore hardness of 30A and a thickness of 0.05mm. The surface is treated with a skin-friendly finish and has a coefficient of friction of 0.45, which is close to the coefficient of friction of human skin. 2. Flexible buffer layer 2: Made of nano-silicone material, 0.1mm thick, with a rebound time ≤0.3s, providing elastic cushioning; 3. Tempered glass base layer 3: Made of 0.3mm thick high-alumina-silicon tempered glass, with a hardness of 9H and a light transmittance of 93%; 4. Bottom adhesive layer 4: Made of optical grade OCA adhesive, 0.03mm thick, with 99% light transmittance. Preparation method: 1. Modified TPU particles are melted using a twin-screw extruder and cast into a 0.05mm thick soft surface layer using a casting machine. This soft composite layer is then bonded to a 0.1mm thick nano-silicone buffer layer by roll forming. 2. The 0.3mm high-alumina-silicon tempered glass was polished on both sides, ultrasonically cleaned for 10 minutes, and then subjected to argon plasma surface modification with a processing power of 100W for 30 seconds. 3. Place the flexible composite layer and the tempered glass base layer into a vacuum hot press, set the temperature to 90℃, the pressure to 0.3MPa, and the vacuum degree to -0.095MPa, and hot press for 40 seconds; 4. Apply a 0.03mm thick layer of OCA adhesive to the bottom of the tempered glass and cure it for 36 hours at 25℃ and 50% humidity; 5. Cut to the size of the mobile phone screen, test the light transmittance (92.5%), hardness (9H), and touch sensitivity (100%), and package after passing the test. Example The difference between this embodiment and Embodiment 1 is that: • The skin-like soft surface layer 1 is made of liquid silicone material with a Shore hardness of 25A and a thickness of 0.08mm; • The flexible buffer layer 2 is made of high-elasticity acrylic material with a thickness of 0.15mm; • The tempered glass base layer 3 is made of 0.2mm thick high-alumina-silicon tempered glass; • The hot-pressing temperature in the preparation process is 85℃, the pressure is 0.35MPa, and the hot-pressing time is 50s.

Claims

1. A composite tempered glass film with a skin-like soft touch, characterized in that, From top to bottom, it includes: a skin-like soft surface layer, a flexible buffer layer, a tempered glass base layer, and a bottom adhesive layer; The skin-like soft surface layer is made of a skin-friendly elastomer material with a Shore hardness of 20-40A and a thickness of 0.03-0.1mm; The flexible buffer layer is a highly elastic buffer material with a thickness of 0.05-0.2mm, and is disposed between the skin-like soft surface layer and the tempered glass base layer; The tempered glass base layer is high-alumina-silicon tempered glass with a thickness of 0.15-0.4mm and a hardness ≥9H; The bottom adhesive layer is optical grade OCA adhesive with a thickness of 0.02-0.05mm, and is located below the tempered glass substrate.

2. A method for preparing a composite tempered glass film with a skin-like soft touch as described in claim 1, characterized in that, Includes the following steps: S1: The skin-like soft surface material is formed by casting process and rolled and bonded with a flexible buffer layer to prepare a soft composite layer; S2: Double-sided polishing, ultrasonic cleaning, and plasma surface modification treatment are performed on the high-alumina-silicon tempered glass substrate. S3: Place the soft composite layer and the pretreated tempered glass base layer into a vacuum hot press and hot press them together for 30-60 seconds under the conditions of 80-100℃, 0.2-0.4MPa pressure, and vacuum degree ≥-0.09MPa. S4: Apply optical-grade OCA adhesive to the bottom of the tempered glass substrate and cure it for 24-48 hours at 25-30℃ and 40-60% humidity. S5: Cut to the target screen size to complete the preparation of the composite tempered glass film.

3. The composite tempered glass film according to claim 1, characterized in that, The material of the skin-like soft surface layer is one of modified TPU, liquid silicone or soft polyurethane, with a surface friction coefficient of 0.4-0.

6.

4. The composite tempered glass film according to claim 1, characterized in that, The flexible buffer layer is made of nano-silicone or high-elasticity acrylic, with a rebound time of ≤0.3s.

5. The composite tempered glass film according to claim 1, characterized in that, The light transmittance of the tempered glass substrate is ≥92%.

6. The preparation method according to claim 2, characterized in that, In step S2, argon plasma is used for plasma surface modification, with a processing power of 80-120W and a processing time of 20-40s.

7. The preparation method according to claim 2, characterized in that, In step S3, the hot-pressing temperature is 90℃, the pressure is 0.3MPa, the vacuum degree is -0.095MPa, and the hot-pressing time is 40s.

8. The preparation method according to claim 2, characterized in that, In step S4, the curing environment temperature is 25℃, the humidity is 50%, and the curing time is 36h.

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