WO2025232376A1 - Decorative film, housing assembly, and electronic device - Google Patents

Abstract

The present application provides a decorative film, a housing assembly and an electronic device. The decorative film of the present application comprises a substrate layer and a color changing layer. The color changing layer is arranged on one side of the substrate layer. When the temperature of the color changing layer is lower than or equal to a first temperature, the color changing layer is in a first color, when the temperature of the color changing layer is higher than or equal to a second temperature, the color changing layer is in a second color, and when the temperature of the color changing layer is between the first temperature and the second temperature, the color changing layer is in at least one of the first color and the second color, wherein the first temperature is lower than the second temperature. The decorative film of the present application allows users to customize patterns, offering better aesthetic expressiveness.

Description

Decorative films, housing components, and electronic devices Technical Field

This application relates to the field of electronics, specifically to a decorative film, a housing assembly, and an electronic device.

Background Technology

With the development of technology and the improvement of living standards, people have put forward higher requirements for the appearance and visual effects of electronic devices. However, the appearance of existing electronic devices is not good enough and cannot meet the needs of consumers.

Summary of the Invention

The first aspect of this application provides a decorative film, which includes:

Substrate layer; and

A color-changing layer is disposed on one side of the substrate layer. When the temperature of the color-changing layer is less than or equal to a first temperature, the color-changing layer is a first color; when the temperature of the color-changing layer is greater than or equal to a second temperature, the color-changing layer is a second color; when the color-changing layer is located between the first temperature and the second temperature, the color-changing layer is at least one of the first color and the second color; wherein the first temperature is less than the second temperature.

A second aspect of this application provides a housing assembly comprising:

Casing; and

The decorative film described in this application embodiment is disposed on one side of the housing, and the color-changing layer is disposed further away from the housing than the substrate layer.

A third aspect of this application provides an electronic device comprising:

Display screen;

The housing assembly described in this application embodiment is disposed on one side of the display screen; and

A processor, electrically connected to the display screen, is used to control the display screen to perform a display.

Attached Figure Description

To more clearly illustrate the technical solutions of the embodiments of this application, the drawings used in the embodiments will be briefly introduced below. Obviously, the drawings described below are only some embodiments of this application. For those skilled in the art, other drawings can be obtained based on these drawings without creative effort.

Figure 1 is a schematic diagram of the planar structure of a decorative film according to an embodiment of this application.

Figure 2 is a cross-sectional view of the decorative film of the first embodiment of this application along the A-A direction in Figure 1.

Figure 3 is a schematic diagram of the reversible cyclic change of the color-changing layer of the decorative film in a color-developing state and a color-disappearing state according to an embodiment of this application.

Figure 4 is a schematic diagram of the color change switching of the decorative film in Example 1 of this application.

Figure 5 is a schematic diagram of the color and pattern changes of the decorative film in Example 2 of this application.

Figure 6 is a schematic diagram of the color and pattern changes of the decorative film in Example 3 of this application.

Figure 7 is a schematic diagram of the color and pattern changes of the decorative film in Example 4 of this application.

Figure 8 is a schematic diagram of the color and pattern changes of the decorative film in Example 5 of this application.

Figure 9 is a schematic diagram of the structure of a microcapsule in a chromogenic and achromogenic state according to an embodiment of the present application, wherein (a) is the chromogenic state and (b) is the achromogenic state.

Figure 10 is a cross-sectional view of the decorative film of the second embodiment of this application along the A-A direction in Figure 1.

Figure 11 is a cross-sectional view of the decorative film of the third embodiment of this application along the A-A direction in Figure 1.

Figure 12 is a cross-sectional view of the decorative film of the fourth embodiment of this application along the A-A direction in Figure 1.

Figure 13 is a cross-sectional view of the decorative film of the fifth embodiment of this application along the A-A direction in Figure 1.

Figure 14 is a schematic flowchart of a method for preparing a decorative film according to an embodiment of this application.

Figure 15 is a flowchart illustrating a method for preparing a decorative film according to another embodiment of this application.

Figure 16 is a schematic diagram of the structure of a housing assembly according to an embodiment of this application.

Figure 17 is a cross-sectional view of the housing assembly according to an embodiment of the present application along the B-B direction in Figure 16.

Figure 18 is a cross-sectional view of the housing assembly according to another embodiment of this application along the B-B direction in Figure 16.

Figure 19 is a structural schematic diagram of a housing assembly according to another embodiment of this application.

Figure 20 is a schematic diagram of the structure of an electronic device according to an embodiment of this application.

Figure 21 is a partial exploded view of an electronic device according to an embodiment of this application.

Figure 22 is a circuit block diagram of an electronic device according to an embodiment of this application.

Explanation of reference numerals in the attached figures:
100-Decorative film, 10-Substrate layer, 20-Color-changing layer, 21-Microcapsule, 211-Color developer, 212-Color developer, 213-Capsule wall, 30-Barrier layer.
40 - Texture layer, 50 - Coating layer, 60 - Color layer, 70 - Flame retardant layer, 400 - Housing assembly, 410 - Housing, 420 - Adhesive layer, 430 - Temperature pen, 500 - Electronic device, 510 - Display screen, 520 - Mid-frame, 530 - Processor, 550 - Memory, 570 - Camera module, 401 - Light-transmitting part.

Detailed Implementation

In a first aspect, this application provides a decorative film comprising:

Substrate layer; and

A color-changing layer is disposed on one side of the substrate layer. When the temperature of the color-changing layer is less than or equal to a first temperature, the color-changing layer is a first color; when the temperature of the color-changing layer is greater than or equal to a second temperature, the color-changing layer is a second color; when the color-changing layer is located between the first temperature and the second temperature, the color-changing layer is at least one of the first color and the second color; wherein the first temperature is less than the second temperature.

Specifically, when the color-changing layer is heated from a first temperature to a temperature between the first and second temperatures, the color-changing layer retains the first color; when the color-changing layer is cooled from a second temperature to a temperature between the first and second temperatures, the color-changing layer retains the second color.

Wherein, the color-changing layer is between a first temperature and a second temperature and the color-changing layer is a first color. The local temperature of the color-changing layer is controlled to be raised to a temperature greater than or equal to the second temperature so that the local area presents a second color. Then the local area is cooled down to the first temperature to the second temperature so that the local area maintains the second color. When the color-changing layer is between the first temperature and the second temperature, a colored pattern composed of the first color and the second color is presented.

or,

The color-changing layer is located between a first temperature and a second temperature and is in the second color. The local temperature of the color-changing layer is controlled to be lower than or equal to the first temperature so that the local area presents the first color. Then the local area is heated to the first temperature to the second temperature so that the local area maintains the first color. When the color-changing layer is between the first temperature and the second temperature, it presents a colored pattern composed of the first color and the second color.

The difference between the second temperature T2 and the first temperature T1, T2-T1, is in the range of 40℃≤T2-T1≤88℃.

The range of the first temperature T1 is: -18℃≤T1≤10℃.

The range of the second temperature T2 is: 50℃≤T2≤70℃.

The color-changing layer includes microcapsules, each microcapsule containing a color-developing agent, a color-developing agent, and a solvent. When the temperature of the color-changing layer is less than or equal to a first temperature, the color-developing agent combines with the color-developing agent to give the color-changing layer a first color. When the temperature of the color-changing layer is greater than or equal to a second temperature, the color-developing agent separates from the color-developing agent to give the color-changing layer a second color.

The crystallization temperature of the solvent is lower than its melting point.

The crystallization temperature Tc of the solvent is in the range of -18℃≤Tc≤10℃.

The melting point Tm of the solvent is in the range of 50℃≤Tm≤70℃.

The microcapsule further includes a capsule wall, and the color-developing agent, the color-developing agent and the solvent are all located within the capsule wall. The particle size D of the microcapsule is in the range of 1μm≤D≤20μm.

The color-changing ink is formed by curing color-changing ink, and the mass fraction of the microcapsules in the color-changing ink ranges from 5% to 40%.

The thickness of the color-changing layer ranges from 8 μm to 12 μm.

The decorative film further includes a barrier layer, which is disposed on the side of the color-changing layer opposite to the substrate layer, and is used to block water and oxygen.

The decorative film further includes a color-adjusting layer, which is disposed between the color-changing layer and the barrier layer, and is used to adjust the color of the decorative film.

The decorative film further includes a flame-retardant layer, which is disposed on the side of the barrier layer opposite to the substrate layer.

The decorative film further includes a texture layer and a coating layer. The texture layer is disposed between the substrate layer and the color-changing layer, and the coating layer is disposed between the texture layer and the color-changing layer.

Secondly, this application also provides a housing assembly comprising:

Casing; and

The decorative film described in the first aspect of this application is disposed on one side of the housing, and the color-changing layer is disposed further away from the housing than the substrate layer.

The housing assembly further includes:

A temperature-adjustable pen, the temperature of which is adjustable, is used to draw patterns on the decorative film.

Thirdly, this application also provides an electronic device comprising:

Display screen;

The housing assembly described in the second aspect of this application is disposed on one side of the display screen; and

A processor, electrically connected to the display screen, is used to control the display screen to perform a display.

To enable those skilled in the art to better understand the present application, the technical solutions in the embodiments of the present application will be clearly and completely described below with reference to the accompanying drawings. Obviously, the described embodiments are only some embodiments of the present application, and not all embodiments. Based on the embodiments in the present application, all other embodiments obtained by those of ordinary skill in the art without creative effort are within the scope of protection of the present application.

The terms "first," "second," etc., in the specification, claims, and accompanying drawings of this application are used to distinguish different objects, not to describe a specific order. Furthermore, the terms "comprising" and "having," and any variations thereof, are intended to cover non-exclusive inclusion. For example, a process, method, system, product, or apparatus that includes a series of steps or units is not limited to the listed steps or units, but may optionally include steps or units not listed, or may optionally include other steps or units inherent to these processes, methods, products, or apparatuses.

The technical solutions in the embodiments of this application will now be described with reference to the accompanying drawings.

It should be noted that, for ease of explanation, the same reference numerals denote the same components in the embodiments of this application, and for the sake of brevity, detailed descriptions of the same components are omitted in different embodiments.

To prevent visual fatigue for consumers, back covers for portable electronic devices such as mobile phones and tablets have been designed with preset patterns. However, these back covers usually only allow for variations between specific colors or patterns, and do not allow users to edit the patterns themselves, resulting in a poor user experience.

The relevant room-temperature reversible thermochromic materials cannot maintain the edited state for a long time at room temperature: room-temperature reversible thermochromic materials achieve color change using a certain critical temperature, such as 31℃. Above this temperature, the color disappears, and below this temperature, the color appears. Mobile phones can easily reach high temperatures of 40℃ when playing games or charging, and the edited patterns made with room-temperature reversible thermochromic materials will be destroyed by the high temperature. In addition, if the edit is activated by the temperature of a hand, it will quickly return to room temperature after the hand is removed, and the phone will restore the original effect.

Please refer to Figures 1 and 2. This application embodiment provides a decorative film 100, which includes a substrate layer 10 and a color-changing layer 20. The color-changing layer 20 is disposed on one side of the substrate layer 10. When the temperature of the color-changing layer 20 is less than or equal to a first temperature, the color-changing layer 20 is a first color; when the temperature of the color-changing layer 20 is greater than or equal to a second temperature, the color-changing layer 20 is a second color; when the color-changing layer 20 is located between the first temperature and the second temperature, the color-changing layer 20 is at least one of the first color and the second color; wherein, the first temperature is less than the second temperature.

The decorative film 100 of this application embodiment can be applied to the back cover film of portable electronic devices such as mobile phones, tablets, laptops, desktop computers, smart bracelets, smartwatches, e-readers, and game consoles to improve the appearance of electronic devices.

Understandably, the color-changing layer 20 can change color between the first color and the second color.

Understandably, the substrate layer 10 and the color-changing layer 20 are stacked together.

It should be noted that the first color is different from the second color.

It should be noted that the phrase "deposited on one side of a component" in this application can mean that it is disposed on the surface of the component; or it can mean that it is disposed opposite to the component and spaced apart, with other components disposed between it and the component. For example, the color-changing layer 20 is disposed on one side of the substrate layer 10, which can mean that the color-changing layer 20 is disposed on the surface of the substrate layer 10; or it can mean that the color-changing layer 20 is disposed opposite to the substrate layer 10 and spaced apart, with other film layers disposed between the color-changing layer 20 and the substrate layer 10.

Optionally, the first color may be, but is not limited to, at least one of colorless, red, green, blue, orange, yellow, cyan, purple, black, gray, silver, gold, etc.

Optionally, the second color can be, but is not limited to, at least one of colorless, red, green, blue, orange, yellow, cyan, purple, black, gray, silver, gold, etc.

It should be noted that when the color-changing layer 20 is located between the first temperature and the second temperature, the color-changing layer 20 is at least one of the first color and the second color. It can be understood that when the color-changing layer 20 is located between the first temperature and the second temperature, the color-changing layer 20 can present the first color as a whole; or the color-changing layer 20 can present the second color as a whole; or the color-changing layer 20 can present the first color and the second color in parts, with the color-changing layer 20 presenting a pattern composed of the first color or a pattern composed of the second color, so that the color-changing layer 20 presents a colored pattern.

Understandably, when the color-changing layer 20 is located between the first temperature and the second temperature, both the first color and the second color can be stably maintained. Understandably, the color-changing layer 20 is a reversible thermochromic layer 20 that does not change color between the first temperature and the second temperature. Specifically, when the temperature range between the first temperature and the second temperature is at room temperature, the material of the color-changing layer 20 is a reversible thermochromic material that does not change color at room temperature.

It should be noted that when the temperature of the color-changing layer 20 is below the first temperature, the color-changing layer 20 displays the first color. When the temperature of the color-changing layer 20 rises to between the first and second temperatures, the color-changing layer 20 retains the first color. When the temperature of the color-changing layer 20 continues to rise above the second temperature, the color-changing layer 20 changes from the first color to the second color. When the temperature of the color-changing layer 20 drops from the second temperature back to between the first and second temperatures, the color-changing layer 20 retains the second color. In this embodiment, since both the first and second colors can be stably maintained when the color-changing layer 20 is between the first and second temperatures, the temperature can be controlled to rise and then fall, or fall and then rise, in other words, the temperature application point can be controlled within a small area or a local area. This allows the color-changing layer 20 to locally maintain the first color and locally maintain the second color, thus presenting a colored pattern and giving the color-changing layer 20 a better appearance. Furthermore, the area of color change can be edited and controlled by the user, allowing the decorative film 100 to display colored patterns edited by the user, thereby enhancing the interactivity between the decorative film 100 and the user and bringing a more valuable experience to the user.

In a specific example, the color-changing layer 20 is located between a first temperature and a second temperature and is in a first color. A portion of the color-changing layer 20 is heated to a temperature greater than or equal to the second temperature to make that portion exhibit the second color. Then, it is cooled back to the first temperature to the second temperature, maintaining the second color in that portion. Thus, when the color-changing layer 20 is between the first and second temperatures, it partially exhibits the first color and partially exhibits the second color, thereby presenting a colored pattern. For example, the color-changing layer 20 is located between -10°C and 50°C and is red (in a color-developing state). A portion of the color-changing layer 20 is heated to above 60°C to make that portion disappear and exhibit an achromatic state. Then, it is cooled back to -10°C to 50°C, maintaining the achromatic state in that portion. Thus, when the color-changing layer 20 is between -10°C and 50°C, it partially exhibits red and partially exhibits no color, thereby presenting a specific colored pattern.

In the embodiments of this application, when the numerical range a to b is involved, unless otherwise specified, the numerical value can be any value between a and b, including the endpoint value a and the endpoint value b.

In another specific example, the color-changing layer 20 is located between a first temperature and a second temperature and exhibits a second color. A portion of the color-changing layer 20 is cooled to a temperature less than or equal to the first temperature, causing that portion to exhibit the first color. Then, the temperature is raised back to the first temperature and then to the second temperature, maintaining the first color in that portion. Thus, when the color-changing layer 20 is located between the first and second temperatures, it partially exhibits the first color and partially exhibits the second color, thereby presenting a colored pattern. For example, the color-changing layer 20 is located between -10°C and 50°C and is colorless (achromatic state). A portion of the color-changing layer 20 is cooled to below -10°C, causing that portion to exhibit red (color-developing state). Then, the temperature is raised back to -10°C and then to 50°C, maintaining the red color in that portion. Thus, when the color-changing layer 20 is located between -10°C and 50°C, it partially exhibits red and partially exhibits colorless, thereby presenting a specific colored pattern.

Optionally, when the color-changing layer 20 is in the first color, the color-changing layer 20 is in a color-developing state; when the color-changing layer 20 is in the second color, the color-changing layer 20 is in a colorless state (i.e., colorless).

As shown in Figure 3, in another specific example, when the color-changing layer 20 is at a temperature less than or equal to -10℃, the color-changing layer 20 exhibits a colored state (red area in Figure 3). When the temperature of the color-changing layer 20 is controlled to rise from -10℃ to 50℃, the color-changing layer 20 still exhibits a colored state. When the temperature of the color-changing layer 20 is controlled to continue rising above 50℃, the color of the color-changing layer 20 gradually disappears, exhibiting a decolorized state (white area in Figure 3). When the temperature of the color-changing layer 20 is controlled to drop from -10℃ to 50℃, the color-changing layer 20 still exhibits a decolorized state. When the temperature of the color-changing layer 20 is controlled to continue dropping to less than or equal to -10℃, the color-changing layer 20 reverts to a colored state.

The decorative film 100 of this application embodiment includes a substrate layer 10 and a color-changing layer 20 stacked together. When the temperature of the color-changing layer 20 is less than or equal to a first temperature, the color-changing layer 20 displays a first color; when the temperature of the color-changing layer 20 is greater than or equal to a second temperature, the color-changing layer 20 displays a second color; when the color-changing layer 20 is between the first and second temperatures, the color-changing layer 20 displays at least one of the first and second colors. Since both the first and second colors of the color-changing layer 20 can be maintained when it is between the first and second temperatures, patterns can be displayed on the color-changing layer 20 when it is between the first and second temperatures by controlling local heating and reheating, or local cooling and reheating. These patterns can be edited by the user, allowing the color-changing layer 20 to switch between more patterns. Users can draw according to their preferences, improving the user experience.

The following examples further illustrate the application scenarios of the decorative film 100 of this application.

Example 1: As shown in Figure 4, the decorative film 100 can maintain the first color in winter (as shown in Figure 4(a)) and the second color in summer (as shown in Figure 4(b)), for example, maintaining the color-developing state in summer and the colorless state in winter.

Example 2: As shown in Figure 5, the decorative film 100 can be thermally edited to achieve pattern effects, which can be maintained for a long time at room temperature.

Example 3: As shown in Figure 6, the color-changing layer 20 itself is used as a pattern, which can be displayed when needed (as shown in Figure 6(b)) and disappear when not needed (as shown in Figure 6(a)).

Example 4: As shown in Figure 7(a) and Figure 7(b), the color-changing layer 20 itself is used as a pattern, and the pattern can change color according to mood.

Example 5: As shown in Figure 8(a) and Figure 8(b), control the local temperature to draw patterns, and change the shape and position of the patterns according to your mood.

Optionally, the substrate layer 10 may be, but is not limited to, at least one of polymethyl methacrylate, polycarbonate, and polyethylene terephthalate (PET). PET is a highly crystalline polymer with a smooth and glossy surface, excellent light transmittance and mechanical properties. As the substrate of the decorative film 100, it serves to support various functional layers.

Optionally, the range of the first temperature T1 is: -18℃≤T1≤10℃.

Specifically, the first temperature T1 can be, but is not limited to, -18℃, -16℃, -14℃, -12℃, -10℃, -8℃, -6℃, -4℃, -2℃, 0℃, 2℃, 4℃, 6℃, 8℃, 10℃, etc.

In this embodiment, if the first temperature T1 is too low, the user will find it difficult to obtain this temperature (because household refrigerators typically freeze at around -18°C), making it inconvenient for the user to edit the pattern and color of the color-changing layer 20. If the first temperature T1 is too high, when the color-changing layer 20 is at room temperature (i.e., between the first and second temperatures), it will be difficult to stably retain the edited pattern and color of the color-changing layer 20. When the first temperature T1 is within this range, it is easier for the user to obtain this temperature to edit the color and pattern of the color-changing layer 20 of the decorative film 100; and it also allows the edited color and pattern of the color-changing layer 20 to be maintained or preserved for a longer period of time at room temperature.

Furthermore, the range of the first temperature T1 is: -15℃≤T1≤5℃. When the first temperature T1 is within this range, it makes it easier for the user to obtain the temperature to edit the color and pattern of the color-changing layer 20 of the decorative film 100; it also allows the edited color and pattern of the color-changing layer 20 to be maintained or preserved for a longer period of time at room temperature.

Furthermore, the range of the first temperature T1 is: -15℃≤T1≤0℃. When the first temperature T1 is within this range, it makes it easier for the user to obtain the temperature to edit the color and pattern of the color-changing layer 20 of the decorative film 100; it also allows the edited color and pattern of the color-changing layer 20 to be maintained or preserved for a longer period of time at room temperature.

Optionally, the range of the second temperature T2 is: 50℃≤T2≤70℃.

Specifically, the second temperature T2 can be, but is not limited to, 50℃, 52℃, 54℃, 56℃, 58℃, 60℃, 62℃, 64℃, 66℃, 68℃, 70℃, etc.

In this embodiment, if the second temperature T2 is too low, when the decorative film 100 is applied to an electronic device, under normal use, the main heat-generating components of the electronic device may generate heat, causing the local temperature of the electronic device to approach or reach the second temperature. This could cause local discoloration of the color-changing layer 20 of the decorative film 100, or the disappearance or change of local color or pattern, affecting the decorative effect of the decorative film 100 and the user experience. If the second temperature T2 is too high, when the user draws or edits patterns on the decorative film 100, the electronic device using the decorative film 100 needs to be at a high temperature, affecting the safety of the electronic device. When the second temperature T2 is within this range, the heat-generating temperature area of the electronic device can be better avoided, allowing the decorative film 100 to maintain the edited color and pattern well under normal use of the electronic device, while also ensuring high safety for the electronic device during the color and pattern drawing process of the decorative film 100.

Furthermore, the range of the second temperature T2 is: 50℃≤T2≤65℃. When the second temperature T2 is within this range, it can better avoid the temperature range where the electronic device generates heat, allowing the decorative film 100 to better maintain the edited color and pattern under normal use of the electronic device, and also ensuring high safety for the electronic device during the color and pattern drawing process of the decorative film 100.

Furthermore, the range of the second temperature T2 is: 55℃≤T2≤65℃. When the second temperature T2 is within this range, it can better avoid the temperature range where the electronic device generates heat, allowing the decorative film 100 to better maintain the edited color and pattern under normal use of the electronic device, and also ensuring high safety for the electronic device during the color and pattern drawing process of the decorative film 100.

Optionally, the range of the difference T2-T1 between the second temperature T2 and the first temperature T1 is: 40℃ ≤ T2-T1 ≤ 88℃. Specifically, the difference T2-T1 between the second temperature T2 and the first temperature T1 can be, but is not limited to, 40℃, 43℃, 45℃, 48℃, 50℃, 52℃, 54℃, 56℃, 58℃, 60℃, 62℃, 64℃, 66℃, 68℃, 70℃, 73℃, 75℃, 78℃, 80℃, 83℃, 85℃, 88℃, etc. If the difference T2-T1 between the second temperature T2 and the first temperature T1 is too large, the first temperature may be too low, making it difficult for the user to obtain the temperature, thus hindering the user from editing the pattern and color of the color-changing layer 20. Alternatively, the second temperature may be too high, requiring the electronic device using the decorative film 100 to be at a high temperature when the user draws or edits the pattern on the decorative film 100, affecting the safety of the electronic device. If the difference between the second temperature T2 and the first temperature T1, T2-T1, is too small, the first temperature may be too high. In this case, when the color-changing layer 20 is at room temperature (between the first and second temperatures), it will be difficult to retain the edited pattern and color of the color-changing layer 20. Alternatively, if the second temperature is too low, when the decorative film 100 is applied to an electronic device, under normal operating conditions, the main heating element of the electronic device may generate heat, causing the local temperature of the electronic device to approach or reach the second temperature. This could cause local discoloration of the color-changing layer 20 of the decorative film 100, or the disappearance or change of local color or pattern, affecting the decorative effect and user experience of the decorative film 100. When the difference between the second temperature T2 and the first temperature T1, T2-T1, is in the range of 40℃≤T2-T1≤88℃, it is convenient for users to draw or edit patterns on the decorative film 100 according to their preferences, and the pattern can be maintained for a longer period at room temperature.

Furthermore, the difference between the second temperature T2 and the first temperature T1, T2-T1, is in the range of 50℃≤T2-T1≤80℃. This not only makes it more convenient for users to draw or edit patterns on the decorative film 100 according to their own preferences, but also allows the pattern to be maintained for a longer period of time at room temperature.

Please refer to Figure 9. In some embodiments, the color-changing layer 20 includes microcapsules 21, which include a color-developing agent 211, a color-developing agent 212, and a solvent (referred to as the first solvent here to distinguish it from the solvent below). When the temperature of the color-changing layer 20 is less than or equal to a first temperature, the color-developing agent 211 combines with the color-developing agent 212 (as shown in Figure 9(a)) to make the color-changing layer 20 exhibit a first color. When the temperature of the color-changing layer 20 is greater than or equal to a second temperature, the color-developing agent 211 separates from the color-developing agent 212 (as shown in Figure 9(b)) to make the color-changing layer 20 exhibit a second color.

Optionally, the microcapsule 21 contains a complex system of electron-transfer type organic compounds. Optionally, the chromogenic agent 211 can be an electron donor, which determines the color of the color-changing layer 20, the chromogenic agent 212 can be an electron acceptor, which determines the depth of color development, and the first solvent determines the color-changing temperature.

In this embodiment, by providing a color-developing agent 211, a color-developing agent 212, and a first solvent in the microcapsule 21, and by combining the color-developing agent 211 and the color-developing agent 212 to present a first color when the temperature is below a first temperature, and separating the color-developing agent 211 and the color-developing agent 212 to present a second color when the temperature is above a second temperature, the color-changing layer 20 can present at least one of the first and second colors when the temperature is between the first and second temperatures. Thus, by controlling the change in local temperature, the color change in a local area of the color-changing layer 20 can be controlled, allowing for the editing and drawing of colors and patterns on the color-changing layer 20, thereby improving the appearance of the decorative film 100.

Optionally, the color-developing agent 211 includes at least one of leuco dyes such as peptide compounds and fluorane compounds.

Optionally, the colorant 211 can be a lactone ring compound or a lactam ring compound.

Optionally, the fluorane compound may be at least one of 2-phenylamino-3-methyl-6-dibutylaminofluorane (melanin-2) and 6'-(diethylamino)-1',2'-benzofluorane. The peptide compound may be, but is not limited to, 3,3-bis(4-diethylamino-2-ethoxyphenyl)-4-azaphthalide.

Optionally, the color developer 212 includes at least one of phenolic hydroxyl compounds and their metal salts (weakly acidic). Optionally, the color developer 212 may include, but is not limited to, at least one of alkylphenols, gallic esters, etc.

Optionally, the crystallization temperature of the first solvent is lower than its melting point. In this embodiment, by using a first solvent with a crystallization temperature lower than its melting point (i.e., a first solvent exhibiting supercooling), the crystallization and melting temperatures of the first solvent are staggered. When the first solvent crystallizes, the color-developing agent 211 and the color-developing agent 212 can combine to form a conjugated system. The color-developing agent 211 molecules open their rings to display the color, resulting in the color-changing layer 20 exhibiting the first color. When the first solvent melts, the color-developing agent 211 and the color-developing agent 212 separate, losing their conjugated system. The color-developing agent 211 molecules close their rings and lose their color, resulting in a colorless (second color) layer. In this embodiment, by using a first solvent with a crystallization temperature and melting point different from the first solvent, the color-developing agent 211 and the color-developing agent 212 can switch between the first and second colors at two different temperatures. Furthermore, the color-developing agent 211 and the color-developing agent 212 can maintain their original combined or separated state between the crystallization temperature and the melting point of the first solvent, thereby achieving color changes in the color-changing layer 20 and enabling pattern self-editing.

Optionally, the crystallization temperature Tc of the first solvent is in the range of -18℃≤Tc≤10℃.

Specifically, the crystallization temperature Tc of the first solvent can be, but is not limited to, -18℃, -16℃, -14℃, -12℃, -10℃, -8℃, -6℃, -4℃, -2℃, 0℃, 2℃, 4℃, 6℃, 8℃, 10℃, etc.

In this embodiment, if the crystallization temperature Tc of the first solvent is too low, it is difficult for the user to obtain this temperature (because household refrigerators are generally around -18°C), making it inconvenient for the user to edit the pattern and color of the color-changing layer 20. If the crystallization temperature Tc of the first solvent is too high, it is difficult to stably retain the edited pattern and color of the color-changing layer 20 when it is at room temperature (i.e., between the first temperature and the second temperature). When the crystallization temperature Tc of the first solvent is within this range, it is easier for the user to obtain this temperature to edit the color and pattern of the color-changing layer 20 of the decorative film 100, and it also allows the edited color and pattern of the color-changing layer 20 to be maintained or preserved for a longer period of time at room temperature.

Optionally, the melting point Tm of the first solvent is in the range of 50℃≤Tm≤70℃.

Specifically, the melting point Tm of the first solvent can be, but is not limited to, 50°C, 52°C, 54°C, 56°C, 58°C, 60°C, 62°C, 64°C, 66°C, 68°C, 70°C, etc.

In this embodiment, if the melting point Tm of the first solvent is too low, when the decorative film 100 is applied to an electronic device, under normal use, the main heat-generating element of the electronic device may cause the local temperature of the electronic device to approach or reach the second temperature, resulting in local discoloration of the color-changing layer 20 of the decorative film 100, or the disappearance or change of local color or pattern, affecting the decorative effect of the decorative film 100 and the user experience. If the melting point Tm of the first solvent is too high, when the user draws or edits patterns on the decorative film 100, the electronic device using the decorative film 100 needs to be at a high temperature, affecting the safety of the electronic device. When the melting point Tm of the first solvent is within this range, the temperature range where the electronic device heats up can be better avoided, allowing the decorative film 100 to maintain the edited color and pattern well under normal use of the electronic device, and also ensuring high safety of the electronic device during the color and pattern drawing process of the decorative film 100.

Optionally, the first solvent includes solvents such as esters, amides, aldehydes, or ethers.

In some embodiments, the microcapsule 21 further includes a capsule wall 213, the color-developing agent 211, the color-developing agent 212 and the first solvent are all located within the capsule wall 213, and the particle size D of the microcapsule 21 is in the range of 1μm≤D≤20μm.

Specifically, the particle size D of the microcapsule 21 can be, but is not limited to, 1μm, 2μm, 4μm, 6μm, 8μm, 10μm, 12μm, 14μm, 16μm, 18μm, 20μm, etc.

Optionally, D90 ≤ 10 μm. D90 refers to the particle size corresponding to 90% of the cumulative particle size distribution of a sample. Physically, it means that 90% of the particles are smaller (or larger) than D90.

Optionally, the capsule wall 213 may be, but is not limited to, at least one of melamine-formaldehyde resin, epoxy resin, and phenolic resin.

In this embodiment, if the particle size of the microcapsule 21 is too small, it will increase the difficulty and cost of preparing the microcapsule 21; if the particle size of the microcapsule 21 is too large, the microcapsule 21 will not be easily dispersed, which is not conducive to the preparation of the color-changing layer 20.

Optionally, the color-changing layer 20 is formed by curing color-changing ink. The color-changing ink includes microcapsules 21, polyester resin, a second solvent, a curing agent, a defoamer, a leveling agent, etc.

Optionally, the mass fraction of microcapsules 21 in the color-changing ink is 5% to 40%. Specifically, the mass fraction of microcapsules 21 in the color-changing ink can be, but is not limited to, 5%, 10%, 15%, 20%, 25%, 30%, 35%, 40%, etc. If the mass fraction of microcapsules 21 in the color-changing ink is too low, the color or pattern will not be obvious when the formed color-changing layer 20 is used for color changing or pattern drawing, affecting the appearance of the decorative film 100; if the mass fraction of microcapsules 21 in the color-changing ink is too high, the adhesion of the color-changing layer 20 will be reduced, thereby reducing the stability of the decorative film 100.

Optionally, the color-changing ink further includes an adhesion promoter for improving the adhesion of the color-changing layer 20.

In preparation, microcapsules 21 are added to polyester resin, a second solvent, a defoamer, and a leveling agent in a certain proportion and mixed. Then, a curing agent and an adhesion promoter are added and mixed to obtain a color-changing ink. In the color-changing ink, the mass ratio of polyester resin, curing agent, solvent, and adhesion promoter is 100:10:(10 to 15):3. The ink is printed using a 250-350 mesh screen printing plate and baked at 75°C to 85°C (e.g., 75°C, 78°C, 80°C, 83°C, 85°C, etc.) for 20 to 40 minutes (e.g., but not limited to 20 minutes, 25 minutes, 30 minutes, 35 minutes, 40 minutes, etc.) to obtain a color-changing layer 20.

Optionally, the second solvent may include, but is not limited to, at least one of trimethylbenzene, tetramethylbenzene, and isophorone. The second solvent can reduce ink viscosity for easier application, adjust drying speed, aid in the dispersion of microcapsules 21, improve the printability of the color-changing ink, and prevent the ink from drying out.

Optionally, the curing agent may include, but is not limited to, at least one of polyhexamethylene diisocyanate, isononyl isocyanate (IPDI), polymethylene diisocyanate (PMDI), and epoxy isocyanate. Polyhexamethylene diisocyanate can react with the hydroxyl groups in the color-changing ink to generate amino groups, and then the amino groups further react with the isocyanate to generate urea, forming a network cross-linked structure that transforms the color-changing ink from a liquid state to a solid state, thereby achieving the curing effect.

Optionally, the adhesion promoter may include, but is not limited to, at least one of the following: 3-aminopropyltrimethoxysilane, chlorinated polyvinyl chloride (CPVC), chlorinated rubber, polyurethane resin, anhydride resin, silane coupling agent, organosilicon resin, and acid phosphate. Chlorinated polyvinyl chloride (CPVC) is suitable as an adhesion promoter for plastic surfaces such as polyvinyl chloride (PVC). Chlorinated rubber is used to increase the adhesion of ink to rubber surfaces. Polyurethane resin is widely used to improve the adhesion of ink to various material surfaces, such as metals, plastics, ceramics, and glass. Anhydride resin has good adhesion to materials such as metals, ceramics, and certain plastics. Silane coupling agents are suitable for increasing the adhesion of ink to inorganic material surfaces such as glass and ceramics. Organosilicon resin is suitable for improving the adhesion of ink to silicone rubber and silicone products. Acid phosphate can improve the adhesion of ink to metal surfaces and is mainly used in the electronics and automotive industries. Adhesion promoters can improve the adhesion of color-changing inks to different material surfaces, making the printed pattern more durable and wear-resistant.

Optionally, the thickness of the color-changing layer 20 can be from 8 μm to 12 μm. Specifically, the thickness of the color-changing layer 20 can be, but is not limited to, 8 μm, 9 μm, 10 μm, 11 μm, 12 μm, etc. If the thickness of the color-changing layer 20 is too thin, the color effect of the color-changing layer 20 will not be obvious, and the pattern effect will be unclear when drawing and editing patterns, affecting the appearance of the decorative film 100. If the thickness of the color-changing layer 20 is too thick, it increases the cost of the decorative film 100, and increases the color-changing response time when drawing patterns on the color-changing layer 20.

Please refer to Figure 10. In some embodiments, the decorative film 100 further includes a barrier layer 30, which is disposed on the side of the color-changing layer 20 opposite to the substrate layer 10, and is used to block water and oxygen.

Optionally, the barrier layer 30 can be, but is not limited to, a silicon oxide layer or a water-oxygen barrier layer 30 (water-oxygen barrier polyethylene terephthalate, i.e., a PET layer). When the barrier layer 30 is a silicon oxide layer, the barrier layer 30 and the color-changing layer 20 are spaced apart. In other words, other film layers are provided between the barrier layer 30 and the color-changing layer 20. If the barrier layer 30 is directly placed on the color-changing layer 20, it will affect the color effect of the decorative film 100 after color change, reducing the appearance effect of the decorative film 100. When the barrier layer 30 is a water-oxygen barrier layer 30, the water-oxygen barrier layer 30 can be attached to the color-changing layer 20 or spaced apart.

Optionally, the water vapor transmission rate (WVTR) of the barrier layer 30 is less than or equal to ^10⁻³ g/ ^m² /day. This can better block water and oxygen, extending the light resistance time and service life of the color-changing layer 20.

In this embodiment, the color-changing layer 20 is prone to aging and failure due to photo-oxidation under light conditions. A barrier layer 30 is provided on the side of the color-changing layer 20 away from the substrate layer 10. This can prevent water and oxygen from entering the color-changing layer 20, thereby reducing the photo-oxidation reaction of the color-changing layer 20, extending the life of the color-changing layer 20, and making the decorative film 100 more reliable when applied to electronic devices.

Please refer to Figure 11. In some embodiments, the decorative film 100 further includes a texture layer 40 and a coating layer 50. The texture layer 40 is disposed between the substrate layer 10 and the color-changing layer 20, and the coating layer 50 is disposed between the texture layer 40 and the color-changing layer 20.

Optionally, the texture layer 40 has a textured structure, and the texture layer 40 is a photocurable texture layer 40, such as a UV-curable texture layer 40 (UV texture layer 40). Optionally, the texture layer 40 is formed by transferring a photocurable adhesive (e.g., UV adhesive) and then photocuring it, for example, by transferring UV adhesive onto the surface of the housing and then photocuring it to form a photocurable texture layer 40. The texture layer 40 serves to create light and shadow flow variations and acts as a substrate for the coating layer 50.

During preparation, the texture mold is placed on the carrier platform of the transfer machine with the texture facing upwards. A layer of liquid UV adhesive is applied to the texture mold, and the substrate layer 10 is placed on top of the UV adhesive layer. Then, a roller is used to roll the surface of the substrate layer 10 to ensure that the UV adhesive is applied evenly. While rolling, an LED light is moved and followed below the texture mold to irradiate it, so that the UV adhesive is initially cured at a curing energy of 800mJ to 1500mJ. The substrate layer 10 with the texture layer 40 is removed and then cured a second time with a mercury lamp at a curing energy of 800mJ to 1500mJ to ensure that the UV adhesive layer is completely cured and to prevent performance problems.

Optionally, the coating layer 50 can be, but is not limited to, a metal oxide layer. The coating layer has a variety of color effects and is also called an optical film. The coating layer 50 serves to reflect light and provide a metallic luster effect.

Optionally, the coating layer 50 can be an optical coating layer 50, i.e., an optical color film. The thickness of the coating layer 50 can be from 200nm to 400nm, specifically, the thickness of the coating layer 50 can be, but is not limited to, 200nm, 230nm, 250nm, 280nm, 300nm, 330nm, 350nm, 380nm, 400nm, etc. The thicker the coating layer 50, the brighter the metallic luster.

The coating layer 50 can be deposited by electron gun evaporation or magnetron sputtering. Specifically, electron gun evaporation uses Si as the base layer, and alternately deposits Ti ₃ O ₅ layers and SiO ₂ layers as the coating layer 50; or magnetron sputtering also uses Si as the base layer, and alternately deposits Nb ₂ O ₅ layers and SiO ₂ layers as the coating layer 50.

Referring to Figure 12, in some embodiments, the decorative film 100 of this application further includes a color-adjusting layer 60, which is disposed between the color-changing layer 20 and the barrier layer 30, and is used to adjust the color of the decorative film 100. Specifically, by adding the color-adjusting layer 60, different colors can be presented after the color-changing layer 20 and the color-adjusting layer 60 are superimposed, thereby enabling the production of decorative films 100 with different colors or those that can switch between two different colors.

Optionally, the color layer 60 can be prepared by mixing the color ink with a curing agent, diluent and additives in a certain proportion, stirring thoroughly, and then printing with a 250-300 mesh screen printing plate and baking at 75-85°C (e.g. 75°C, 78°C, 80°C, 83°C, 85°C, etc.) for 20-40 minutes (e.g., but not limited to 20 minutes, 25 minutes, 30 minutes, 35 minutes, 40 minutes, etc.) to obtain the color layer 60.

Optionally, the thickness of the color-tone layer 60 is 8 μm to 12 μm. Specifically, the thickness of the color-tone layer 60 can be, but is not limited to, 8 μm, 9 μm, 10 μm, 11 μm, 12 μm, etc. If the thickness of the color-tone layer 60 is too thin, the color concentration of the color-tone layer 60 will be insufficient, and the color-tone effect will be insignificant; if the thickness of the color-tone layer 60 is too thick, it will be difficult to bake dry during preparation, reducing the adhesion of the color-changing layer 60 to the color-changing layer 20.

Please refer to Figure 13. In some embodiments, the decorative film 100 of this application further includes a flame-retardant layer 70 (also known as a fireproof layer), which is disposed on the side of the barrier layer 30 away from the substrate layer 10.

Optionally, the thickness of the flame-retardant layer 70 is 8 μm to 12 μm. Specifically, the thickness of the flame-retardant layer 70 can be, but is not limited to, 8 μm, 9 μm, 10 μm, 11 μm, 12 μm, etc. If the thickness of the flame-retardant layer 70 is too small, the fireproof or flame-retardant effect will be insignificant; if the thickness of the flame-retardant layer 70 is too large, it increases the thickness and cost of the decorative film 100.

During preparation, the flame-retardant ink main agent, curing agent, diluent and additives are first mixed in a certain proportion, and then printed using a 250-300 mesh screen printing plate; it can be screen printed twice, in other words, the flame-retardant layer 70 is two layers. The first layer is baked at 80℃ for 30 minutes, and the second layer is baked at 80℃ for 90 minutes to ensure that the ink of the flame-retardant layer 70 is completely dried.

Optionally, the dyne value of the flame-retardant layer 70 facing away from the barrier layer 30 is greater than or equal to 32. This improves the adhesion between the decorative film and the adhesive backing of electronic devices, ensuring the reliability of the adhesive bonding.

In this embodiment, by providing the flame retardant layer 70, the decorative film 100 can have a better flame retardant or fireproof effect. In addition, the flame retardant layer 70 is also used to block light and protect other film layers inside the flame retardant layer 70.

The decorative film 100 of this application embodiment can be prepared by the methods described in the following embodiments of this application. In addition, it can also be prepared by other methods. The preparation methods of this application embodiment are merely one or more preparation methods of the decorative film 100 of this application and should not be construed as limiting the decorative film 100 provided in the embodiments of this application.

Please refer to Figure 14. This application embodiment also provides a method for preparing the decorative film 100, which includes:

S201, providing a substrate layer 10; and

For a description of other features of the substrate layer 10, please refer to the description of the corresponding part of the above embodiments, which will not be repeated here.

S202, a color-changing layer 20 is formed on one side of the substrate layer 10. When the temperature of the color-changing layer 20 is less than or equal to a first temperature, the color-changing layer 20 is a first color; when the temperature of the color-changing layer 20 is greater than or equal to a second temperature, the color-changing layer 20 is a second color; when the color-changing layer 20 is located between the first temperature and the second temperature, the color-changing layer 20 is at least one of the first color and the second color; wherein, the first temperature is less than the second temperature.

For a description of other features of the color-changing layer 20, please refer to the description of the corresponding part of the above embodiments, which will not be repeated here.

The decorative film 100 prepared by the method of this application embodiment includes a substrate layer 10 and a color-changing layer 20 stacked together. When the temperature of the color-changing layer 20 is less than or equal to a first temperature, the color-changing layer 20 displays a first color; when the temperature of the color-changing layer 20 is greater than or equal to a second temperature, the color-changing layer 20 displays a second color; when the color-changing layer 20 is between the first temperature and the second temperature, the color-changing layer 20 displays at least one of the first color and the second color. Since both the first color and the second color of the color-changing layer 20 can be maintained when the color-changing layer 20 is between the first temperature and the second temperature, patterns can be displayed when the color-changing layer 20 is between the first temperature and the second temperature by controlling the local heating and then heating, or the local cooling and then heating. Furthermore, the patterns can be edited by the user, allowing the color-changing layer 20 to switch between more patterns. Users can draw according to their preferences, improving the user experience.

Please refer to Figure 15. This application embodiment also provides a method for preparing the decorative film 100, which includes:

S301, providing a substrate layer 10;

S302, a textured layer 40 is formed on the surface of the substrate layer 10;

Optionally, the texture mold is placed on the carrier table of the transfer machine with the texture facing upwards. A layer of liquid UV adhesive is applied to the texture mold, and the substrate layer 10 is placed on top of the UV adhesive layer. Then, a roller is used to roll the surface of the substrate layer 10 to ensure that the UV adhesive is applied evenly. While rolling, an LED light is moved and followed below the texture mold to irradiate it, so that the UV adhesive is initially cured at a curing energy of 800mJ to 1500mJ. The substrate layer 10 with the texture layer 40 is removed, and the substrate layer 10 with the texture layer 40 is then cured a second time with a mercury lamp at a curing energy of 800mJ to ensure that the UV adhesive layer is completely cured to prevent performance problems.

S303, a coating layer 50 is formed on the surface of the textured layer 40 that is away from the substrate layer 10;

Optionally, electron gun evaporation deposition uses Si as the base layer, and alternately deposits Ti ₃ O ₅ layers and SiO ₂ layers as the coating layer 50; or, magnetron sputtering deposition also uses Si as the base layer, and alternately deposits Nb ₂ O ₅ layers and SiO ₂ layers as the coating layer 50.

S304, a color-changing layer 20 is formed on the surface of the coating layer 50 away from the substrate layer 10;

Optionally, microcapsules 21 are added to polyester resin, a second solvent, a defoamer, and a leveling agent in a certain proportion and mixed. Then, a curing agent and an adhesion promoter are added and mixed to obtain a color-changing ink. In the color-changing ink, the mass ratio of polyester resin, curing agent, solvent, and adhesion promoter is 100:10:(10 to 15):3. The ink is printed using a 250-350 mesh screen printing plate and baked at 75°C to 85°C (e.g., 75°C, 78°C, 80°C, 83°C, 85°C, etc.) for 20 to 40 minutes (e.g., but not limited to 20 minutes, 25 minutes, 30 minutes, 35 minutes, 40 minutes, etc.) to obtain a color-changing layer 20.

S305, a color-changing layer 60 is formed on the surface of the color-changing layer 20 that is away from the substrate layer 10;

Optionally, the color layer 60 can be prepared by mixing the color ink with a curing agent, diluent and additives in a certain proportion, stirring thoroughly, and then printing with a 250-300 mesh screen printing plate and baking at 75-85°C (e.g. 75°C, 78°C, 80°C, 83°C, 85°C, etc.) for 20-40 minutes (e.g., but not limited to 20 minutes, 25 minutes, 30 minutes, 35 minutes, 40 minutes, etc.) to obtain the color layer 60.

S306, a barrier layer 30 is formed on the surface of the color-tone layer 60 opposite to the substrate layer 10; and

Optionally, a silicon oxide layer is deposited on the surface of the color layer 60 facing away from the substrate layer 10 as a barrier layer 30.

S307, a flame retardant layer 70 is formed on the surface of the barrier layer 30 opposite to the substrate layer 10.

Optionally, the flame-retardant ink main agent, curing agent, diluent and additives are first mixed in a certain proportion, and then printed using a 250-mesh to 300-mesh screen printing plate; Optionally, the flame-retardant layer 70 is two layers, the first layer is baked at 80℃ for 30 minutes, and the second layer is baked at 80℃ for 90 minutes to ensure that the ink of the flame-retardant layer 70 is completely dried.

For further detailed descriptions of the substrate layer 10, texture layer 40, coating layer 50, color-changing layer 20, color-tone layer 60, barrier layer 30, and flame-retardant layer 70, please refer to the descriptions of the corresponding sections of the above embodiments, which will not be repeated here.

Optionally, the decorative film 100 is cut into the size required for bonding to the housing (e.g., glass) using an infrared laser cutting machine. The dimensional accuracy needs to be controlled within ±0.05mm to ensure the precision of the bonding. The decorative film 100 of the preset size is then bonded to the surface of the housing using a vacuum bonding process with optical adhesive. After degassing, the housing with the decorative film 100 is obtained.

Please refer to Figures 16 and 17. This application embodiment also provides a housing assembly 400, which includes a housing 410 and a decorative film 100 as described in this application embodiment. The decorative film 100 is disposed on one side of the housing 410, and the color-changing layer 20 is disposed further away from the housing 410 than the substrate layer 10.

Understandably, the housing 410 and the decorative film 100 are stacked together.

Optionally, the material of the housing 410 can be, but is not limited to, one or more of inorganic glass or resin. Optionally, the resin can be one or more of polymethyl methacrylate, polycarbonate, polyethylene terephthalate, etc. Understandably, when the material of the housing 410 is a resin layer, the housing 410 can be a single resin layer or a composite board. When the housing 410 is made of resin, a hardening layer can be coated on the surface of the resin housing 410 to improve the mechanical strength of the housing 410.

Referring to Figure 18, optionally, the housing assembly 400 further includes an adhesive layer 420 disposed between the housing 410 and the decorative film 100 for bonding the decorative film 100 to the surface of the housing 410.

Optionally, the adhesive layer 420 can be, but is not limited to, an optically clear adhesive (OCA adhesive). OCA adhesive is a special adhesive used to bond transparent optical components. Here, it serves to bond the housing 410 to the substrate layer 10 of the decorative film 100, while also providing UV protection. It generally features colorless transparency, light transmittance of over 95%, good bonding strength, and the ability to cure at room temperature or medium temperature.

For a detailed description of other aspects of the decorative film 100, please refer to the description of the corresponding part of the above embodiments, which will not be repeated here.

The decorative film 100 of this application embodiment includes a substrate layer 10 and a color-changing layer 20 stacked together. When the temperature of the color-changing layer 20 is less than or equal to a first temperature, the color-changing layer 20 displays a first color; when the temperature of the color-changing layer 20 is greater than or equal to a second temperature, the color-changing layer 20 displays a second color; when the color-changing layer 20 is between the first and second temperatures, the color-changing layer 20 displays at least one of the first and second colors. Since both the first and second colors of the color-changing layer 20 can be maintained when it is between the first and second temperatures, patterns can be displayed on the color-changing layer 20 when it is between the first and second temperatures by controlling local heating and reheating, or local cooling and reheating. These patterns can be edited by the user, allowing the color-changing layer 20 to switch between more patterns. Users can draw according to their preferences, improving the user experience.

Referring to Figure 19, in some embodiments, the housing assembly 400 further includes a temperature-adjustable pen 430, which is used to draw patterns on the decorative film 100.

It should be noted that the temperature pen 430 is separately disposed from the housing 410.

Optionally, the temperature-regulating pen 430 can be a metal pen that can be externally heated (e.g., heated by boiling or hot water) or frozen (e.g., frozen in a refrigerator) to regulate its temperature.

Optionally, the temperature-changing pen 430 may also be a temperature-changing pen 430 whose temperature can be changed electronically.

For example, when the color-changing layer 20 is between the first temperature and the second temperature and the color-changing layer 20 is the first color, the temperature-changing pen 430 is heated to a temperature greater than or equal to the second temperature. The temperature-changing pen 430 is used to draw or edit patterns on the decorative film 100 so that the area drawn by the temperature-changing pen 430 on the decorative film 100 presents the second color. After the temperature-changing pen 430 is removed, part of the decorative film 100 presents the first color and part of the second color, thus presenting a colored pattern.

For example, the color-changing layer 20 is located between a first temperature and a second temperature and is in the second color. The temperature-changing pen 430 is cooled to less than or equal to the first temperature. The temperature-changing pen 430 is used to draw or edit patterns on the decorative film 100 so that the area drawn by the temperature-changing pen 430 on the decorative film 100 is in the first color. After the temperature-changing pen 430 is removed, part of the decorative film 100 is in the first color and part is in the second color, thus presenting a colored pattern.

In this embodiment, by setting a temperature-adjustable pen 430, the user can easily edit the color and pattern of the decorative film 100, thus improving the user experience.

Please refer to Figures 20 and 22. This application embodiment also provides an electronic device 500, which includes a display screen 510, a housing assembly 400 as described in this application embodiment, and a processor 530. The housing assembly 400 is disposed on one side of the display screen 510. The processor 530 is electrically connected to the display screen 510 and is used to control the display screen 510 to display.

Understandably, the decorative film 100 is positioned closer to the display screen 510 than the housing 410; that is, the decorative film 100 is positioned between the housing 410 and the display screen 510.

The electronic device 500 in this application embodiment can be, but is not limited to, a mobile phone, tablet computer, laptop computer, desktop computer, smart bracelet, smartwatch, e-reader, game console, or other portable electronic device 500.

For a detailed description of the housing assembly 400, please refer to the description of the corresponding part of the above embodiments, which will not be repeated here.

Optionally, the display screen 510 may be, but is not limited to, one or more of the following: liquid crystal display screen, light-emitting diode display screen (LED display screen), micro light-emitting diode display screen (Micro LED display screen), mini light-emitting diode display screen (Mini LED display screen), organic light-emitting diode display screen (OLED display screen).

Optionally, processor 530 includes one or more general-purpose processors, wherein the general-purpose processor can be any type of device capable of processing electronic instructions, including a central processing unit (CPU), microprocessor, microcontroller, main processor, controller, and ASIC, etc. Processor 530 is used to execute various types of digital storage instructions, such as software or firmware programs stored in memory, which enables the computing device to provide a wide range of services.

Optionally, the electronic device 500 of this application further includes a memory 550. The memory 550 is electrically connected to the processor 530 and is used to store the program code required for the processor 530 to run, the program code required to control the display screen 510, the display content of the display screen 510, etc.

Optionally, memory 550 may include volatile memory, such as random access memory (RAM); memory 550 may also include non-volatile memory (NVM), such as read-only memory (ROM), flash memory (FM), hard disk drive (HDD), or solid-state drive (SSD). Memory 550 may also include combinations of the above types of memory.

In some embodiments, the electronic device 500 of this application further includes a mid-frame 520 and a camera module 570. The mid-frame 520 is disposed between the display screen 510 and the housing assembly 400, and the side of the mid-frame 520 is exposed between the housing assembly 400 and the display screen 510. The mid-frame 520 and the housing assembly 400 enclose an accommodating space (not shown), which is used to accommodate the processor 530, the memory 550, and the camera module 570. The camera module 570 is electrically connected to the processor 530 and is used to take pictures under the control of the processor 530.

Optionally, the housing assembly 400 has a light-transmitting portion 401, through which the camera module 570 can capture images. That is, in this embodiment, the camera module 570 is a rear-facing camera module 570. It is understood that in other embodiments, the light-transmitting portion 401 may be disposed on the display screen 510, i.e., the camera module 570 is a front-facing camera module 570. In the schematic diagram of this embodiment, the light-transmitting portion 401 is shown as an opening. In other embodiments, the light-transmitting portion 401 may not be an opening, but may be made of a light-transmitting material, such as plastic or glass.

It is understood that the electronic device 500 described in this embodiment is merely one form of the electronic device 500 used in the housing assembly 400 and the decorative film 100, and should not be construed as a limitation on the electronic device 500 provided in this application, nor should it be construed as a limitation on the housing assembly 400 and the decorative film 100 provided in various embodiments of this application.

In this application, the terms "embodiment" and "implementation" mean that a specific feature, structure, or characteristic described in connection with an embodiment can be included in at least one embodiment of this application. The appearance of these phrases in various locations throughout the specification does not necessarily refer to the same embodiment, nor are they independent or alternative embodiments mutually exclusive with other embodiments. Those skilled in the art will understand, explicitly and implicitly, that the embodiments described in this application can be combined with other embodiments. Furthermore, it should be understood that the features, structures, or characteristics described in the various embodiments of this application can be arbitrarily combined to form yet another embodiment that does not depart from the spirit and scope of the technical solution of this application, provided there is no contradiction between them.

Finally, it should be noted that the above embodiments are only used to illustrate the technical solutions of this application and are not intended to limit it. Although this application has been described in detail with reference to the above preferred embodiments, those skilled in the art should understand that modifications or equivalent substitutions to the technical solutions of this application should not depart from the spirit and scope of the technical solutions of this application.

Claims (20)

A decorative film, characterized in that it comprises: Substrate layer; and A color-changing layer is disposed on one side of the substrate layer. When the temperature of the color-changing layer is less than or equal to a first temperature, the color-changing layer is a first color; when the temperature of the color-changing layer is greater than or equal to a second temperature, the color-changing layer is a second color; when the color-changing layer is located between the first temperature and the second temperature, the color-changing layer is at least one of the first color and the second color; wherein the first temperature is less than the second temperature. According to claim 1, the decorative film is characterized in that, when the color-changing layer is heated from a first temperature to a temperature between the first temperature and a second temperature, the color-changing layer retains the first color; when the color-changing layer is cooled from a second temperature to a temperature between the first temperature and a second temperature, the color-changing layer retains the second color. According to claim 1, the decorative film is characterized in that the color-changing layer is between a first temperature and a second temperature and the color-changing layer is a first color, the local temperature of the color-changing layer is controlled to be raised to a temperature greater than or equal to the second temperature so that the local area presents a second color, and then the local area is cooled down to the first temperature to the second temperature so that the local area maintains the second color, so that when the color-changing layer is between the first temperature and the second temperature, a colored pattern composed of the first color and the second color is presented. or, The color-changing layer is located between a first temperature and a second temperature and is in the second color. The local temperature of the color-changing layer is controlled to be lower than or equal to the first temperature so that the local area presents the first color. Then the local area is heated to the first temperature to the second temperature so that the local area maintains the first color. When the color-changing layer is between the first temperature and the second temperature, it presents a colored pattern composed of the first color and the second color. According to claim 1, the decorative film is characterized in that the difference between the second temperature T2 and the first temperature T1, T2-T1, is in the range of 40℃≤T2-T1≤88℃. According to claim 1, the decorative film is characterized in that the range of the first temperature T1 is: -18℃≤T1≤10℃. According to claim 1, the decorative film is characterized in that the range of the second temperature T2 is: 50℃≤T2≤70℃. According to claim 1, the decorative film is characterized in that the color-changing layer comprises microcapsules, the microcapsules comprising a color-developing agent, a color-developing agent, and a solvent; when the temperature of the color-changing layer is less than or equal to a first temperature, the color-developing agent combines with the color-developing agent to make the color-changing layer exhibit a first color; when the temperature of the color-changing layer is greater than or equal to a second temperature, the color-developing agent separates from the color-developing agent to make the color-changing layer exhibit a second color. The decorative film according to claim 7 is characterized in that the crystallization temperature of the solvent is lower than the melting point of the solvent. According to claim 7, the decorative film is characterized in that the crystallization temperature Tc of the solvent is in the range of -18℃≤Tc≤10℃. The decorative film according to claim 7 is characterized in that the melting point Tm of the solvent is in the range of 50℃≤Tm≤70℃. According to claim 7, the decorative film is characterized in that the microcapsule further includes a capsule wall, the colorant, the color developer and the solvent are all located within the capsule wall, and the particle size D of the microcapsule is in the range of 1μm≤D≤20μm. According to claim 7, the decorative film is characterized in that the color-changing ink is formed by curing color-changing ink, and the mass fraction of the microcapsules in the color-changing ink ranges from 5% to 40%. The decorative film according to claim 1 is characterized in that the thickness of the color-changing layer ranges from 8 μm to 12 μm. According to claim 1, the decorative film further includes a barrier layer disposed on the side of the color-changing layer opposite to the substrate layer, for blocking water and oxygen. The decorative film according to claim 14 is characterized in that the decorative film further includes a color-adjusting layer, which is disposed between the color-changing layer and the barrier layer for adjusting the color of the decorative film. The decorative film according to claim 14 is characterized in that the decorative film further includes a flame-retardant layer, the flame-retardant layer being disposed on the side of the barrier layer opposite to the substrate layer. According to claim 1, the decorative film further includes a texture layer and a coating layer, wherein the texture layer is disposed between the substrate layer and the color-changing layer, and the coating layer is disposed between the texture layer and the color-changing layer. A housing assembly, characterized in that it comprises: Casing; and The decorative film according to any one of claims 1-17, wherein the decorative film is disposed on one side of the housing, and the color-changing layer is disposed further away from the housing than the substrate layer. The housing assembly according to claim 18, wherein the housing assembly further comprises: A temperature-adjustable pen, the temperature of which is adjustable, is used to draw patterns on the decorative film. An electronic device, characterized in that it comprises: Display screen; The housing assembly of claim 18 or 19, wherein the housing assembly is disposed on one side of the display screen; and A processor, electrically connected to the display screen, is used to control the display screen to perform a display.