ZIMMER JOSE (DE)
HOU YUNFEI (CN)
GABEL FALK (DE)
| CN203007139U | 2013-06-19 | |||
| US20120189843A1 | 2012-07-26 | |||
| US20090047506A1 | 2009-02-19 | |||
| CN201857351U | 2011-06-08 |
| What is claimed: 1. A laminated glass for mobile electronic device, comprising at least two layers of glass bonded together and selected from glass ceramics and ordinary glass, wherein the outmost layer is a glass ceramics layer. 2. A laminated glass according to claim 1 , wherein the ordinary glass is chemical toughened, thermal toughened, chemical etched or surface polished, or undergone combined treatment of the above processes. 3. A laminated glass according to claim 1 , comprising at least one layer of ordinary glass and at (east one layer of glass ceramics. 4. A laminated glass according to claim 1, comprising at least two layers of the glass ceramics. 5. A laminated glass according to any of the preceding claims, wherein the glass ceramics is white, black, green, yellow, blue, red, grey, or any desired color obtained based on mixing of three-primary colors. 6. A laminated glass according to any of the preceding claims, wherein the glass ceramics are chemical toughened. 7. A laminated glass according to any of the preceding claims, wherein the layer of ordinary glass or the layer of glass ceramics in the laminated glass has a thickness of 0.05-2mm. 8. A laminated glass according to claim 1 , wherein the laminated glass is a three-layered laminated glass. 9. A laminated glass according to claim 8, wherein the laminated glass has an intermediate layer, which is an optical transparent adhesive, pressure-sensitive adhesive, polyurathane, ethylene-vinyl acetate copolymer, polyvinyl butyral, polyethylene terephthalate, or a composition of the above two or more materials. 10. A laminated glass according to claim 8, wherein the laminated glass has an intermediate layer, which is an optically transparent adhesive tape or a pressure-sensitive adhesive tape. 1 1. A laminated glass according to claim 8, wherein the laminated glass has an intermediate layer having a thickness of 5-300μιη. 12. A laminated glass according to any of preceding claims, wherein the laminated glass has a total thickness of 0.1 -4.0mm. 13. A laminated glass according to any of preceding claims, wherein the laminated glass has an outer surface coated with a functional coating. 14. A laminated glass according to any of preceding claims, wherein the functional coating is an anti-microbial layer, a anti-finger print layer, an antifouling layer, and an ultraviolet- or infrared-absorbing layer. 15. A laminated glass according to any of preceding claims, wherein the laminated glass has an inner surface coated with a conductive layer. 16. A laminated glass according to claim 15, wherein the conductive layer is a tactile sensor. 17. A laminated glass according to any of preceding claims, wherein the laminated glass is provided with a pore or a hole for arranging additional light sensor or electrical sensor. 18. A laminated glass according to any of preceding claims, wherein the laminated glass is smart phones, tablets, notebook, TVs, and back or front cover of household appliances. 19. A laminated glass according to any of preceding claims, wherein the household appliances are refrigerators and cooking devices. 20. A laminated glass according to any of preceding claims, wherein the laminated glass is tough panel. |
Technical Field
The present utility model relates to back or front cover for mobile electronic devices. Specifically, the present utility model relates to laminated glass comprising at least two glass layers prepared by bounding glasses selected from glass ceramics and ordinary glass together.
Background
Mobile devices like mobile phones, tablet PC, notebooks, game consoles, etc as the most dynamic market need more and more diversified designs to develop unique functions, appearance to attract consumers. Glass materials as the functional & structural substrate have been widely used in the touch panels based on capacitive touch technology, and the trend to use glass as decoration material at the back side seems to develop as well.
The mobile products in the market having glass as backside normally use a pes of chemically toughened aluminosilicate glass with white or black color made by screen printing. However, the white or black color of the back cover comes not from the material itself but the coating. Coatings can show discoloration and delamination over time. Design need has been shown at mobile electronic industry to have material with the intrinsic colors (including black and white) which can range from transparent over translucent to opaque whereby avoiding the coating process for applying color to improve efficiency and reduce costs.
Ceramic or glass ceramic is such material that can be produced with different colors. However, ceramic material is normally difficult to be polished, and is not completely porosity, flaw free and production costs are high. The strength of ceramics with the lower thickness e.g. 1.0mm is very much limited by the microstructure of ceramics, which contains grain boundary, defects, pores etc. Especially for thinner thickness, ceramics need a lot of efforts on grinding and polishing to get the desired dimensions, resulting in a high processing cost.
Glass ceramics have the advantage regarding optical appearance, production costs, and also the possibility for chemical strengthening to overcome strength limitations.
In addition, polymers such as polycarbonates show too low scratch and wear resistance comparing to inorganic materials, and therefore, lack competence when used as outer materials of the consumer electronic products.
The glass ceramics is a two-phase mixture of glass and ceramics. Compared to chemically strengthened aluminosilicate glasses, the strength especially the ball drop strength of glass ceramic is relatively low, not fulfilling the requirements for mobile devices owing to the two phase structure. A typical specification for such application is to reach a >500MPa 4-point bending strength, and a >20cm ball drop impact with the 132g steel ball.
In general neither a single layer of glass nor a single layer of glass ceramics can fulfill the high strength requirements e.g. the requirement in drop tests for outer cover of mobile device not only for flat 2D shapes, but especially in case of complex curved 3 D shaped
Normally a laminate can significantly improve the strength of glass, and also has the low risk to injure people after breakage, and therefore is called safety glass. A thin laminate can offer a good combination of reasonable strength, safety, and colors, and match the unique design need for mobile electronic device. The structure of ordinary glass and glass ceramic laminates are used and well known in high end protection applications like aircraft windows, bullet proof windows for vehicles and architecture etc. such as US 6479155 (fire-resistant laminates), US 2009/0100872 (methods of laminating glass ceramics), US 2010/0154622(protection application).
Summary of the utility model The present utility model relates to a laminated glass, comprising at least two layers of glasses selected from ordinary glasses and glass ceramics bounded together, characterized in having the glass ceramic layer as the outmost layer. The laminated glass can be used for back or front cover of mobile electronic devices, and the back or front cover can provide the advantages of colors, strength, anti-scratch resistance, and also safety when broken.
The laminated glass of the present utility model can contain only glass ceramic layers or a composite of ordinary glass and glass ceramics. The ordinary glasses and glass ceramics can be toughened or untoughened depending on strength requirements.
In a special embodiment of the present utility model, layers of polymer can be introduced for applications such as cover sheets of notebooks. In a very special embodiment of the present utility model, only transparent sheets are combined to have a transparent laminated glass.
The thickness of the laminated glass of the present utility model typically is smaller than 4 mm, preferably smaller than 3 mm, particularly preferably smaller than 2mm, especially smaller than 1 mm, and can be smaller than 0.5 mm in a particular embodiment.
The 4 point bending strength of the laminated glass of the present utility model is bigger than 500MPa, preferably bigger than 600MPa, particularly preferably bigger than 700 MPa, and the most preferably bigger than 800MPa.
In a special embodiment of the present utility model, a strengthened ordinary glass is combined with a colored glass ceramic sheet.
Ordinary glass can be for example chemical toughened, thermal toughened, chemical etched or surface polished, or undergone combined treatment of the above processes.
The glass ceramics in the laminated glass of the present utility model is based on the system of e.g. lithium aluminosilicate system (LAS), sodium aluminosilicate, magnesium aluminosilicate, lithium disilcate, preferably based on LAS system.
Glass ceramics in the laminated glass of the present utility model can be produced via sintering methods or via melting and subsequent crystallization.
The glass ceramics in the laminated glass of the present utility model can have color of white, black, green, yellow, blue, red, grey, or other color obtained based on mixing of three-primary colors.
The glass ceramics in the laminated glass of the present utility model has a thickness of 0.05mm-2mm.
In some embodiments of the present utility model, the glass ceramics is not chemical toughened, while in some other embodiments of the present utility model, the glass ceramics is chemical toughened.
The glass ceramics in the laminated glass of the present utility model is chemically toughened in KN0 3 salt, NaN0 3 salt, or a mixed salt of NaN0 3 and KN0 3 .
The ordinary glass of the laminated glass of the present utility model is soda-lime, aluminosilicate, borosilicate, or glass ceramics.
The ordinary glass of the laminated glass of present utility model has a thickness of 0.05-2mm.
The laminated glass of the present utility model has a total thickness of 0.1mm-4.0mm.
The laminated glass of the present utility model has the largest ball drop strength height (132g ball) of 100 cm.
The intermediate layer between the inner side and outer side of the laminated glass of the present utility model is optical adhesive, pressure-sensitive adhesive, polyurathane, ethylene-vinyl acetate copolymer, polyvinyl butyral, polyethylene terephthalate, or a combination of the above two or more.
The intermediate layer of the laminated glass of the present utility model has a thickness of 2-300μηι.
The material of the intermediate layer of the laminated glass of the present utility model can provide very good adhesion for the two layers of glasses, which prevents the glasses from breaking into pieces whereby increasing safety. The Vickers hardness of the surface of the glass ceramics is 680kgf/mm 2 , preferably 700kgf/mm 2 , and the most preferably 750kgf/mm 2 .
The laminated glass of the present utility model is not limited to planer shape, it can also have other shape such as curved surface, cambered surface or non-planer. The laminated glass of the present utility model can also integrate a touch functional layer e.g., by having a touch conductive layer on the inner side.
The laminated glass of the present utility model can be used as back cover or front cover of smart phones, tablets, notebook, TVs, white goods like e.g. refrigerators, cooking devices.
In a particular embodiment of the present utility model, it can be used in combination with touch technologies such as touch plate. It also can be combined with other sensor functions e.g. fingerprint detection.
The order of glass, glass ceramic and polymer layers are variable depending on the application requirements.
In one specific embodiment, the outer surface layer is the glass ceramics and the inner surface layer is the toughened ordinary glass. In this case, the laminated glass has a remarkably increased strength compared with a single sheet of glass ceramics.
The outer surface of the laminated glass of the present utility model can also have a functional coating like an antimicrobial, anti-finger print, anti-contamination, UV or IR absorbing functional layer. The surface of the inner layer can also have conductive coatings to realize electrical functionalities e.g. touch sensors.
In one particular embodiment of the present utility model, the backside of the laminated glass has a touch sensor.
In another particular embodiment of the present utility model, holes and cavities can be introduced in the laminated glass to arrange additional optical or electronic sensors.
Explanation of the figures:
Fig. la is a front view of the back cover of a touch screen mobile phone; Fig. lb is a side view of the back cover of a mobile phone; wherein 101: glass ceramics; 102: optically transparent adhesive; 103: chemically toughened ordinary glass; 104: through hole; 105: a camera; 106: flash.
Fig. 2a is a front view of a mobile phone tough board; Fig 2b is a side view of the touch board of a mobile phone; wherein 201 : glass ceramics; 202: optically transparent adhesive; 203: chemically toughened ordinary glass.
Fig. 3a is a front view of a touch board of a notebook; Fig. 3b is a side view of a touch board of a notebook; wherein 301 : touch board; 302: left key; 303: right key; 304: glass ceramics; 305: adhesive tape; 306: glass ceramics.
Fig. 4a is a front view of a back cover of e-book; Fig. 4b is a side view of a back cover of e-book; wherein 401 : glass ceramics; 402: optical adhesive; 403: chemically toughened ordinary glass.
Fig. 5a is a cover glass of a display of mobile electronic device or instrument used in complicated environment; Fig. 5b is a side view of a cover glass of a display of mobile electronic device or instrument used in complicated environment; wherein 501 : display screen; 502: glass ceramics; 503: optically transparent adhesive; 504: chemically toughened ordinary glass.
Fig. 6a is a front view of a bended back cover of a mobile phone; Fig. 6b is a side view of a bended back cover of a mobile phone; wherein 601 : glass ceramics; 602: adhesive tape; 603: chemically toughened ordinary glass.
Example 1 :
A back cover of the touch screen mobile phone with the structure of a 0.7 mm glass ceramics (white, LAS glass ceramic with a trademark of Nextrema, made by SCHOTT, 724-8) + 10 μηι of transparent optical adhesive (SEKISUI, A-720) + 0.7 mm of aluminosilicate glass (transparent, aluminosilicate with a trademark of Xensation Cover, made by SCHOTT). Pores are provided thereon for placing a camera and flash lamp. The 4-point bending strength reaches 800MPa, and the ball drop height is above 30 cm.
Example 2:
A touch board of a mobile phone; 0.5 mm of chemically toughened sodium calcium glass + 10 μιη of transparent optical adhesive (SEKISUI, A-720) + 0.5 mm of glass ceramics (white, LAS glass ceramics with a trademark of Nextrema, 724-8, made by SCHOTT). Numbers and symbols are provided on the glass ceramics for dialing. The 4-point bending strength reaches 600 MPa, and the ball drop height is above 30 cm.
Example 3: A touch board of a notebook; 0.5 mm of glass ceramics (grey, LAS glass ceramics of Nextrema, 712-8, made by SCHOTT) + 25 μιη of optically transparent OCA adhesive tape (3M™ optical adhesive tape, 8171) + 0.5 mm of glass ceramics (grey, LAS glass ceramics with a trademark of Nextrema, 712-8 made by SCHOTT). The 4-point bending strength reaches 600 MPa, and the ball drop height is above 30 cm.
Example 4: A back cover of e-book; 0.5 mm of glass ceramics (dark brown, LAS glass ceramics with a trademark of Nextrema, 712-3, made by SCHOTT) + 10 μηι of transparent optical adhesive (SEKISUI, A-720) + 0.6 mm of chemically toughened ordinary glass (aluminosilicate glass with a trademark of Xensation Cover, made by SCHOTT). The 4-point bending strength reaches 700 MPa, and the ball drop height is above 35 cm.
Example 5:
A cover glass of a display of mobile electronic device or instrument used in complicated environment; 0.7 mm of glass ceramics (transparent, LAS glass ceramics with a trademark of Nextrema, 724-3, made by SCHOTT) + 15 μπι of transparent optical adhesive (SEKISUI, A-720) + 0.5 mm of chemically toughened ordinary glass (aluminosilicate glass with a trademark of Xensation Cover made by SCHOTT) + 15 μηι transparent optical adhesive (SEKISUI, model A-720) + 0.5 mm of chemically toughened ordinary glass
(aluminosilicate glass with a trademark of Xensation Cover made by SCHOTT). The 4-point bending strength reaches 900 MPa, and the ball drop height is above 50 cm.
Example 6: Curved glass back cover of a mobile electronic device; 0.7 mm of glass ceramics (white, LAS glass ceramics with a trademark of Nextrema, 724-8, made by SCHOTT) + 25 μπι of optically transparent OCA adhesive tape (3M™ optical adhesive tape, 8171) + 0.7 mm of chemically toughened ordinary glass
(aluminosilicate glass with a trademark of Xensation Cover, made by SCHOTT). The 4-point bending strength reaches 800 MPa, and the ball drop height is above 40 cm.