Electronic devices, such as computers, laptops, tablets, and, smartphones have a touch-surface component, for example a touch pad and a touch screen. The touch-surface component of an electronic device functions as an input device through which a user can perform a variety of input operations on the electronic device. Input operation may be performed on the touch-surface component, for example, using a stylus pen or fingers.
The following detailed description references the drawings, wherein:
Touch-surface components, such as touch pads and touch screens, are commonly present on laptops, tablets, smartphones, and the like, through which users can operate such devices. Regular and rough usage of touch-surface components may lead to scratches on the surface of the touch-surface components. Significant or deep scratches may adversely affect the appearance, functionality and, hence, the user experience of the touch-surface components. The touch-surface components cannot afford to have scratches that affect their functionality.
The touch-surface components are generally retro-coated with a protection layer on top to protect the touch-surface components from scratches. Scratches, however, appearing on the protection layer may lead to frequent replacement of the protection layer. This may impose additional burden and cost on the users.
The present subject matter describes self-healing touch-surface components that can heal or repair scratches on their surface on their own. The present subject matter also describes methods of fabricating self-healing touch-surface components, such as self-healing touch pads. The present subject matter further describes self-healing films which when pasted on touch-surface components make the touch-surface component self-healable.
In accordance with the present subject matter, scratches on the touch-surface components can heal on their own substantially quickly, for example within 3 seconds, and over a wide temperature range starting from 5° C. The self-healing property of the touch-surface components makes them robust, and avoids use and replacement of retro-coatings with a protective layer on top, which provides a better user experience of the touch-surface components.
In an example implementation of the present subject matter, a self-healing touch-surface component includes a self-healing layer disposed over a touch-surface component. The self healing layer includes polyurethane, polyester, epoxy, polyurethane microcapsules filled with di-n-butyltin dilaurate, and a polysiloxane mixture. The polysiloxane mixture may be encapsulated or phase-separated and include poly-dimethylsiloxane, hexamethyldisiloxane, decamethylcyclopentasiloxane, hexamethylcyclotrisiloxane, poly-diethoxysiloxane, and a combination thereof. The chemical composition and concentrations of constituents in the self-healing layer enables self-healing of the self-healing touch-surface component within 3 seconds from the time of scratch and even at a low temperature of 5° C.
In an example implementation, the self-healing touch-surface component includes an anti-smudging layer coated on the self-healing layer. The anti-smudging layer includes at least one of polyurethane and acrylate resin in combination with metal fluorides. The anti-smudging layer on the self-healing touch-surface component helps in increasing the hardness of the self-healing layer and maintaining the cosmetic appearance of the self-healing touch-surface component.
The following detailed description refers to the accompanying drawings. Wherever possible, the same reference numbers are used in the drawings and the following description to refer to the same or similar parts. While several examples are described in the description, modifications, adaptations, and other implementations are possible. Accordingly, the following detailed description does not limit the disclosed examples. Instead, the proper scope of the disclosed examples may be defined by the appended claims.
The self-healing touch-surface component 100 has a self-healing layer 104 on the touch-surface component 102. The self-healing layer 104 includes polyurethane, polyester and epoxy 106 in the form of a base matrix. The base matrix is embedded with a polysiloxane mixture 108 and polyurethane microcapsules filled with di-n-butyltin dilaurate 110. The polysiloxane mixture 108 may include poly-dimethylsiloxane, hexamethyldisiloxane, decamethylcyclopentasiloxane, hexamethylcyclotrisiloxane, poly-diethoxysiloxane, and a combination thereof. The polysiloxane mixture 108 may be encapsulated or phase-separated. The polysiloxane mixture may be encapsulated using a urea-formaldehyde encapsulation procedure. The polyurethane microcapsules may be polyurethane shells filled with di-n-butyltin dilaurate. The di-n-butyltin dilaurate may be mixed with chlorobenzene before encapsulating in the polyurethane microcapsules. The polyurethane microcapsules may be formed through an interfacial polymerization procedure.
In an example implementation, polyurethane in the self-healing layer 104 has a concentration in a range of 60% to 75%, polyester in the self-healing layer 104 has a concentration in a range of 10% to 15%, and epoxy in the self-healing layer 104 has a concentration in a range of 10% to 15%. Further, the polyurethane microcapsules in the self-healing layer 104 has a concentration in a range of 0.1% to 2%, and the polysiloxane mixture in the self-healing layer 104 has a concentration in a range of 2% to 3%.
In an example implementation, the self-healing layer 104 may have a thickness in a range of 10 μm to 30 μm. The self-healing layer 104 may be spray coated on the touch-surface component 102. In an example implementation, the surface of the touch-surface component 102 may be cleaned before coating the self-healing layer 104. Further, after coating the self-healing layer 104, the touch-surface component 102 may be heated at a temperature in a range of 70° C. to 80° C. for a time duration in a range of 20 minutes to 40 minutes for curing the self-healing layer 104.
The base matrix of polyurethane, polyester, and epoxy forms an interpenetrating macromolecular network that provides high impact strength, high toughness, and high wear resistance to the self-healing layer 104 and thus to the self-healing touch-surface component 100. The polysiloxane mixture 108 in the self-healing layer 104 functions as a healing agent, and di-n-butyltin dilaurate, filled in polyurethane microcapsules 110, functions as a catalyst for polymerization within the self-healing layer 104.
A scratch on the self-healing touch-surface component 100 damages the self-healing layer 104. The damage to the self-healing layer 104 ruptures the polyurethane microcapsules 110, which causes di-n-butyltin dilaurate to mix with the polysiloxane mixture 108, polyurethane, polyester, and epoxy within the self-healing layer 104. Mixing of di-n-butyltin dilaurate initiates polymerization within the self-healing layer 104 which heals the scratch within 3 seconds from the time of scratch and even, at a low temperature of 5° C.
The colored base layer 202 includes acrylate, polyurethane, acrylate polyurethane, polycarbonate and cyclic olefin copolymer in combination with one of color dyes and color pigments. The colored base layer 202 provides color to the touch-surface component 102, for example, in the case of a touch pad of a laptop. The colored base layer 202 may be coated on the touch-surface component 102 through spray coating. After coating the colored base layer 202, the touch-surface component 102 may be heated at a temperature in a range of 80° C. to 150° C. for a time duration in a range of 20 minutes to 40 minutes for curing the colored base layer 202. In an example, implementation, the colored base layer 202 may have a thickness in a range of 5 μm to 15 μm.
The anti-smudging layer 302 includes at least one of polyurethane and acrylate resin in combination with metal fluorides. The anti-smudging layer 302 may be coated on the touch-surface component 102 through spray coating or by dipping in a metal fluoride composition. In an example implementation, the anti-smudging layer 302 may have a thickness in a range of 1 μm to 3 μm.
The self-healing film 500 includes an adhesive layer 502. The adhesive layer 502 may be coated on a substrate (not shown) through spray coating. The adhesive layer may have a thickness in a range of 1 μm to 10 μm, and includes acrylics, ethylene-vinyl acetate copolymers, polyamides, polyolefins, styrene copolymers, polyester, polyurethane, rubber-based adhesives, isocyanate based polymers, epoxy, and a combination thereof. The isocyanate based polymers may include polymeric methylene-4,4′-diphenyl diisocyanate (pMDI), urethanes, urea, and such.
The self-healing film 500 also includes a self-healing layer 504 on the adhesive layer 502. The chemical composition and the thickness of the self-healing layer 504 of the self-healing film 500 are the same as those for the self-healing layer 104 described earlier. In an example implementation, after coating the self-healing layer 504, the self-healing film 500 may be heated at a temperature in a range of 70° C. to 80° C for a time duration in a range of 20 minutes to 40 minutes for curing the self-healing layer 504.
In an example implementation, the self-healing film (not shown) may include a colored base layer between the adhesive layer and the self-healing layer, and include an anti-smudging layer on the self-healing layer. The self-healing layer, the colored base layer, and the anti-smudging layer are as described earlier with reference to
In an example implementation, the surface of the touch pad may be cleaned before coating the colored base layer. In an example implementation, after coating the colored base layer, the touch pad may be heated at a temperature in a range of 80° C. to 150° C. for a time duration in a range of 20 minutes to 40 minutes for curing the colored base layer.
At block 804, a self-healing layer is coated on the colored based layer, where the self-healing layer includes polyurethane in a range of 60% to 75%, polyester in a range of 10% to 15%, epoxy in a range of 10% to 15%, polyurethane microcapsules filled with di-n-butyltin dilaurate and in a range of 0.1% to 2%, and a polysiloxane mixture in a range of 2% to 3% and comprising poly-dimethylsiloxane, hexamethyldisiloxane, decamethylcyclopentasiloxane, hexamethylcyclotrisiloxane, and poly-diethoxysiloxane. The polysiloxane mixture may be encapsulated or phase-separated. The self-healing layer may have a thickness in a range of 10 μm to 30 μm.
In an example implementation, the self-healing layer may be deposited on the colored base layer through spray coating. Further, after coating the self-healing layer, the touch pad may be heated at a temperature in a range of 70° C. to 80° C. for a time duration in a range of 20 minutes to 40 minutes for curing the self-healing layer.
Further, in an example implementation, an anti-smudging layer may be coated on the self-healing layer of the touch pad. The anti-smudging layer may be through one of spray coating and dipping in a metal fluoride composition. The anti-smudging layer may have a thickness in a range of 1 μm to 3 μm and include at least one of polyurethane and acrylate resin in combination with metal fluorides.
Although implementations for self-healing touch-surface components, self-healing films, and methods of fabrication of self-healing touch pads have been described in language specific to methods and/or structural features, it is to be understood that the present subject matter is not limited to the specific methods or features described. Rather, the methods and specific features are disclosed and explained as example implementations for self-healing touch-surface components, self-healing films, and methods of fabrication of self-healing touch pads.
Filing Document | Filing Date | Country | Kind |
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PCT/US2016/025838 | 4/4/2016 | WO | 00 |