JP5913608B2 - Cover glass for electronic equipment and manufacturing method thereof - Google Patents

Description

  The present invention relates to a cover glass for an electronic device used for protecting a display screen of a portable device such as a mobile phone, a portable game machine, a PDA (Personal Digital Assistant), a digital still camera, a video camera, or a slate PC (Personal Computer). And a manufacturing method thereof.

  Conventionally, in order to protect a display screen of a mobile device such as a mobile phone, an acrylic resin plate having excellent transparency and light weight has been generally used. In recent years, touch-panel portable devices have become the mainstream, and there is a need to improve the strength of the display screen in order to support this touch panel function. Instead of conventional acrylic resin materials, glass materials with high strength even though they are thin Are increasingly being used. Furthermore, compared to conventional acrylic resin materials, glass materials have mechanical strength (scratch resistance, impact resistance), surface smoothness, protective properties (weather resistance, antifouling properties), appearance and luxury, It is advantageous in any respect.

  In touch-panel portable devices, the display screen is operated by directly touching a finger, so that dirt such as fingerprints and sebum tends to adhere to the cover glass that protects the display screen. Therefore, it is desirable to prevent or suppress the dirt such as fingerprints from adhering to the cover glass, or to easily wipe off even if dirt such as fingerprints adheres. Therefore, an antifouling coating layer is usually formed on the surface of the cover glass.

  Patent Document 1 describes that a fluorine-based surface layer is provided on the surface of a cover glass as an antifouling coating layer. As the coating material, alkoxysilyl perfluoropolyether is exemplified. In Patent Document 1, the coating treatment is described as being rinsed with a solvent in order to remove the unbonded coating after being applied by immersion, vapor deposition polymerization, spraying, roller and cured. Patent Document 1 describes that by providing a fluorine-based surface layer, a cover glass having antifouling properties (hydrophobic and oleophobic, collectively referred to as both lyophobic) and damage resistance can be obtained. Has been.

Special table 2011-510904 gazette

  However, since a cover glass for a touch panel type electronic device is rubbed with a finger by a user for operation, the antifouling coating layer is required to be slippery when touched with a finger.

  In addition, mobile devices such as smartphones that have been widely used in recent years have a longer product life (use period) in terms of software than conventional touch panel portable devices such as PDAs, due to software update functions such as OS. Yes. Along with this, portable devices are also required to have improved durability during long-term use in terms of hardware. In particular, since the cover glass for electronic devices is incorporated into electronic devices with the surface exposed, the antifouling coating layer resists the friction of the user's fingers and contacts with various objects, and is antifouling and slippery. Durability is required for long-term performance.

  That is, the antifouling coating layer of the cover glass for electronic devices is required to have both slipperiness and durability.

  Here, although Patent Document 1 discloses the antifouling property and the damage resistance of the antifouling coating layer, the slipping property is not considered, and the structure satisfying both the slipping property and the durability is also included. Not disclosed. Therefore, only the technique disclosed in Patent Document 1 cannot achieve desired characteristics as an antifouling coating layer.

  Then, this invention aims at providing the cover glass for electronic devices which can exhibit the performance of both the slipperiness and durability of an antifouling coating layer, and its manufacturing method.

  The inventors have intensively studied to solve the above problems, and the inside of the antifouling coating layer of the cover glass for electronic devices is attached to the glass surface and affects the durability, and contributes to slipperiness. We focused on the existence of a flowing region. The inventors have conceived that both the slipperiness and the durability are exhibited by appropriately forming these regions, and the present invention has been completed.

  That is, a typical configuration of the cover glass for an electronic device according to the present invention includes a glass substrate and an antifouling coating layer formed on the surface of the glass substrate, and the antifouling coating layer adheres to the surface of the glass substrate. It has an adhesion area and a flow area arranged on the surface of the adhesion area.

  According to the above configuration, both slipperiness and durability can be exhibited. The adhesion region is a region that remains when immersed in a solvent (for example, immersed in HFE for 1 minute), and the flow region is a region that dissolves when immersed in a solvent.

  The ratio of the thickness of the adhesion region to the thickness of the antifouling coating layer is preferably 20% to 80%, more preferably 40% to 70%. This is because if the thickness ratio of the adhesion region is less than 20%, the durability cannot be exhibited. Further, if the ratio of the thickness of the adhesion region is more than 80%, the slipping property cannot be exhibited.

  It is preferable that the antifouling coating layer has a thickness of 3 nm to 30 nm. This is because when the thickness of the antifouling coating layer is less than 3 nm, durability cannot be exhibited. Further, when the thickness of the antifouling coating layer is more than 30 nm, the uniformity of the film thickness cannot be maintained, or the transparency is lowered, so that it does not comply with the request of the portable device.

  It is preferable that the static friction coefficient of the surface of the flow region is 0.2 to 0.4, the dynamic friction coefficient is 0.1 to 0.3, and the contact angle of water is 100 degrees to 120 degrees. If it is the said range, comfortable slipperiness and antifouling property can be acquired.

  The antifouling coating layer preferably contains a perfluoropolyether compound having a hydroxyl group at the terminal group. Thereby, it can bond | bond firmly with functional groups, such as a hydroxyl group and a carboxyl group, on the surface of a glass substrate, and can exhibit high durability.

  Moreover, the typical structure of the manufacturing method of the cover glass for electronic devices concerning this invention is a manufacturing method of the cover glass for electronic devices, Comprising: Coating which has antifouling property with respect to a glass substrate creation process and a glass substrate An antifouling coat layer forming step, wherein the antifouling coat layer forming step forms an adhesion region that adheres to the surface of the glass substrate and a flow region that is disposed on the surface of the adhesion region. To do.

  It is preferable to further include a region thickness adjusting step of adjusting the ratio of the thickness of the adhesion region to the thickness of the antifouling coating layer by adjusting the thickness of the flow region after the antifouling coating layer forming step. Thereby, the thickness of the adhesion region can be set to a desired ratio. In the region thickness adjusting step, the ratio of the thickness of the adhered region to the thickness of the antifouling coating layer is preferably 20% to 80%, and more preferably 40% to 70%.

  In the region thickness adjustment step, it is preferable to adjust the thickness of the flow region by baking, ultraviolet irradiation, or vacuum degree adjustment by decompression.

  In the antifouling coat layer forming step, the thickness of the antifouling coat layer is preferably 3 nm to 30 nm.

  Another representative configuration of the cover glass for an electronic device according to the present invention is that the surface of the glass substrate is coated with a coating material containing a perfluoropolyether compound having a hydroxyl group as a terminal group on the surface of the glass substrate. An antifouling coating layer having an adhesion area that adheres to the surface and a flow area that is disposed on the surface of the adhesion area is formed.

  The electronic device cover glass is an external electronic device cover glass that is detachable so as to cover a part of the exterior of the electronic device, the first main surface being a back surface with respect to the first main surface. A second main surface to be arranged toward the exterior of the electronic device, and an end surface connecting the first main surface and the second main surface, and at least one of outer peripheries of the second main surface The part may be provided with a recessed part that is recessed from the end face toward the inside in the surface direction of the second main surface.

  According to the said structure, when the cover glass for electronic devices is affixed on an electronic device, a clearance gap will arise by a hollow part between the cover glass for electronic devices and an electronic device. Since the user can detach the cover glass for electronic devices by hooking a nail or the like in this gap, it is possible to exhibit slipperiness and durability and realize a glass cover glass for electronic devices with good releasability. can do.

  A glass substrate having the first main surface, the second main surface, and the end surface, and the second main surface, and at least a part of the outer peripheral end of the second main surface is more than the end surface. It is good to provide the sticking part for making a hollow part arrange | positioned in the surface direction inside at intervals, and making a glass substrate detachable to the exterior of an electronic device. According to the above configuration, at least a part of the outer peripheral end of the sticking portion is arranged at an interval on the inner side in the plane direction of the second main surface with respect to the end surface to form the recess. Therefore, a hollow part can be formed easily.

  The depth from the end surface of the recess is preferably in the range of 0.1 mm to 0.3 mm. According to the said structure, coexistence of peelability and aesthetics can be aimed at. That is, when the depth from the end face is 0.1 mm or more, the peelability can be further exhibited. When the depth from the end surface exceeds 0.3 mm, dust or the like accumulates in the recessed portion with the passage of time, which may impair the beauty.

  When the glass substrate having the first main surface, the second main surface, and the end surface is provided, and an interposed surface forming at least a part of the recess is formed between the end surface and the second main surface. Good. According to the said structure, a part of hollow part can be formed with the structure of a glass substrate. This configuration also makes it easier for the user to hook a nail or the like into this gap, so that the peelability of the electronic device cover glass can be improved.

  The end face may be an inclined face that is inclined so as to taper from the second main surface side toward the first main surface side and forms a straight line or a curve in a sectional view. According to the said structure, a user's finger | toe etc. can be prevented from being caught in the edge of a glass substrate. Therefore, it is particularly effective in the case of a smartphone having a touch panel display.

  The cover glass for electronic devices may be detachable so as to cover the main surface of the cover glass for exterior that forms part of the exterior of the electronic device. According to the said structure, it can prevent that a damage | wound and dirt are attached to the cover glass of an electronic device.

  Before the antifouling coating layer forming step, it is preferable to perform glass surface modification treatment comprising both planar plasma processing and downstream plasma processing. Thereby, the adhesion stability of the antifouling coating material to the glass substrate can be improved, and the durability of the antifouling coating surface can be remarkably improved.

  According to the cover glass for an electronic device and the method for producing the same according to the present invention, both the slipperiness and durability of the antifouling coating layer can be exhibited.

It is a schematic sectional drawing which shows one Embodiment of the cover glass for electronic devices which concerns on this invention. It is a flowchart of the manufacturing method of the cover glass for electronic devices which concerns on this invention. It is a top view which shows an example of the shape of the glass substrate for cover glasses. It is a schematic sectional drawing which shows the manufacturing method of the cover glass for electronic devices which concerns on this invention in process order. It is a figure which shows the state which affixed the cover glass for electronic devices concerning 2nd Embodiment on the electronic device. It is a typical cross-sectional view after affixing the cover glass for electronic devices of FIG. 5 to an electronic device. It is an enlarged view of the range X of FIG. It is a figure which shows the layer structure of the cover glass for electronic devices of FIG. It is a figure shown about the procedure which forms the cover glass for electronic devices of FIG. It is explanatory drawing about the range which forms the hollow part of FIG. It is a figure which shows the outer peripheral part of the cover glass for electronic devices concerning 3rd Embodiment. It is a figure which shows the other example of the cover glass for electronic devices concerning 3rd Embodiment. It is a figure which illustrates the processing method of the outer peripheral part of the glass substrate of FIG. 11, FIG.

  Hereinafter, preferred embodiments of the present invention will be described in detail with reference to the accompanying drawings. The dimensions, materials, and other specific numerical values shown in the embodiments are merely examples for facilitating understanding of the invention, and do not limit the present invention unless otherwise specified. In the present specification and drawings, elements having substantially the same function and configuration are denoted by the same reference numerals, and redundant description is omitted, and elements not directly related to the present invention are not illustrated. To do.

[First Embodiment]
In the first embodiment, a cover glass incorporated in a housing so as to form a part of the exterior of an electronic device will be described as an example of the cover glass for an electronic device.

  FIG. 1 is a schematic cross-sectional view showing an embodiment of a cover glass for an electronic device according to the present invention, and shows only a part near the surface in an enlarged manner. The electronic device cover glass 1 according to the present embodiment includes a flat glass substrate 10. An antifouling coating layer 20 is formed on the main surface 12 of the glass substrate 10. As will be described later, the antifouling coating layer 20 has an adhesion region 22 that adheres to the surface of the glass substrate 10 and a flow region 24 that is disposed on the surface of the adhesion region 22.

  The adhesion region 22 is a region where molecules of the coating material are firmly bonded to a functional group such as a hydroxyl group or a carboxyl group on the surface of the glass substrate. The flow region 24 is a region where the molecular chains of the coating materials are intertwined to maintain the state. The adhesion region 22 and the flow region 24 have the same composition, and there is no difference in appearance by a micrograph or the like. However, the flow region 24 is easily dissolved in the solvent, and the adhesion region 22 is not easily dissolved in the solvent. Therefore, the adhesion region 22 is a region that remains when immersed in a solvent (for example, immersed in HFE for 1 minute), and the flow region 24 can be identified as a region that dissolves when immersed in a solvent.

  The material of the antifouling coating layer 20 will be described. When a user uses a touch panel operation type portable device, the display screen is directly touched with a finger to operate, and thus a fingerprint or the like is likely to adhere to the display screen. Therefore, it is desirable to prevent or suppress the fingerprints and the like from adhering to the display screen, or to easily wipe off even if the fingerprints and the like are attached. For that purpose, as a material of the antifouling coating layer 20, even if it is directly touched (pressed) with a finger, it prevents or suppresses fingerprints and the like from being attached or makes it easy to wipe off even if fingerprints and other items are attached. It is preferable to select a material having antifouling properties. It is also important to have excellent transparency. In the present invention, as a material having a good antifouling property and excellent in transparency, a material that lowers the surface energy such as a fluorine resin material (for example, a perfluoropolyether compound) is preferably cited. It is done.

  The contact angle of water on the surface of the antifouling coating layer 20 (the surface opposite to the glass substrate 10) is 100 to 120 degrees, and the contact angle of oil such as hexadecane is preferably 60 to 70 degrees. . The contact angle is a value measured in an atmosphere of 22 ± 2 ° C.

  When the contact angle with water or oil is within the above range, even if it is directly touched (pressed) with a finger, it prevents or suppresses fingerprints and other dirt from being deposited, or fingerprints and other dirt are adhered. Demonstrates good antifouling property that facilitates wiping. The above contact angle is an initial contact angle after the antifouling coating layer is formed, but even if a durability test by sliding steel wool described in the examples below is performed, the decrease in the contact angle is small. Good antifouling property can be maintained.

  Moreover, in the cover glass 1 for electronic devices in this invention, the static friction coefficient in the surface of the antifouling coating layer 20 formed in the main surface 12 of a glass substrate is 0.2-0.4, and a dynamic friction coefficient is 0. It is preferable that it is 0.1-0.3. Since the static friction coefficient or the dynamic friction coefficient of the surface of the antifouling coating layer 20 is within the above range, the antifouling coating surface is slippery and has a good feeling when touched with a finger. In the portable device provided with the cover glass, the operability of the touch panel, for example, by the user is good.

  The glass constituting the glass substrate 10 is preferably amorphous aluminosilicate glass. A glass substrate made of such an aluminosilicate glass has high strength after chemical strengthening and is suitable for a cover glass for electronic devices. As such an aluminosilicate glass, for example, aluminosilicate containing SiO2 as a main component contains 58 to 75 wt%, Al2O3 as 4 to 20 wt%, Li2O as 0 to 10 wt%, and Na2O as 4 to 20 wt%. Glass can be used.

  The thickness of the glass substrate 10 is preferably in the range of, for example, about 0.3 mm to 1.5 mm, more preferably 0.5 mm to 0 mm, from the viewpoint of meeting the recent market needs for thinner and lighter portable devices. The range is about 7 mm.

  Next, the manufacturing method of the cover glass for electronic devices which concerns on this invention which was demonstrated above is demonstrated. FIG. 2 is a flowchart of a method for manufacturing a cover glass for electronic equipment according to the present invention, FIG. 3 is a plan view showing an example of the shape of a glass substrate, and FIG. 4 shows the method for manufacturing a cover glass for electronic equipment according to the present invention in order of steps. It is a schematic sectional drawing shown.

[Creation of glass substrate (step S100)]
First, a large-sized plate glass is cut into a predetermined size by machining or the like to produce a glass substrate 10 for cover glass.

  For example, a large number (for example, about several tens) of sheet glass having a thickness of, for example, about 0.5 mm manufactured by the downdraw method or the float method is laminated (laminated), and a predetermined size is obtained using a glass cutter. Cut into small pieces. As described above, if the laminated state is cut at a time, the laminated pieces can be shaped at the same time in the next shape processing step, which is advantageous in production. The size of the small piece is determined in consideration of the size of the cover glass of the product plus the margin necessary for the outer shape processing.

  Here, regarding the outer shape processing, instead of the cutting processing in the laminated state, the sheet-like glass material may be processed one by one. In addition, an etching method may be applied to the outer shape processing as a means other than machining.

  Next, necessary drilling processing, outer peripheral shape processing, and the like are performed on the glass substrate 10 processed into small pieces of a predetermined size by machining or etching. In the example shown in FIG. 3, the glass substrate 10 has an outer peripheral end face 10a, a notch 10b, an ear hole 10c, and a key operation hole 10d. Such drilling and outer peripheral shape processing may be machined by sandblasting or the like, or these drilling processing and outer peripheral shape processing may be collectively performed by etching. In particular, etching is advantageous for complex shape processing. Moreover, you may use together machining and an etching process according to a process shape. Furthermore, the sheet-like glass material may be made into small pieces by appropriately setting the dissolution pattern at the time of etching, and the pieces may be made into the shape of the glass substrate 10 shown in FIG. .

  Next, a chemical strengthening process is performed on the glass substrate 10 that has undergone the shape processing. As a method of chemical strengthening treatment, for example, a low-temperature ion exchange method in which ion exchange is performed in a temperature range that does not exceed the temperature of the glass transition point, for example, a temperature of 300 to 500 degrees Celsius is preferable. The chemical strengthening treatment is a process in which a molten chemical strengthening salt is brought into contact with a glass substrate, whereby an alkali metal element having a relatively large atomic radius in the chemical strengthening salt and a relatively small atomic radius in the glass substrate. This is a treatment in which an alkali metal element is ion-exchanged, an alkali metal element having a large ion radius is permeated into the surface layer of the glass substrate, and compressive stress is generated on the surface of the glass substrate. As the chemical strengthening salt, alkali metal nitric acid such as potassium nitrate or sodium nitrate can be preferably used. A chemically strengthened glass substrate is improved in strength and excellent in impact resistance, and thus is suitable for a cover glass used for a portable device that requires impact and pressure and requires high strength.

[Glass substrate modification process (step S102)]
Next, a glass surface modification treatment is performed on the glass substrate 10 produced as described above. Usually, since the printing surface side formed on the surface of the glass substrate 10 is mounted toward the inside of the portable device, the main surface 12 exposed to the opposite side of the printing surface, that is, the outside of the portable device. Glass surface modification treatment.

  The planar plasma processing is a mode in which two discharge electrodes are provided at a certain interval, a substrate to be processed is mounted within the interval, and plasma is generated to perform the processing. In this case, for example, He, Ar, N2 or the like is used as a gas used for plasma generation. A voltage necessary for plasma generation is applied between the two electrodes, and ions ionized in the plasma space are accelerated in this space and collide with the surface of the substrate to be processed. Thereby, the glass substrate surface is modified so that the skewness (Rsk: skewness) of the contour curve on the glass substrate surface approaches 0, and the unevenness of the uneven shape on the glass substrate surface is reduced. Here, Rsk is preferably in the range of 0 ± 0.3, more preferably in the range of 0 ± 0.15.

  In addition, the downstream type plasma processing means that a voltage required for plasma generation is applied between two electrodes arranged opposite to each other so as to sandwich a gas supply path to a substrate to be processed, and the plasmaized gas is processed. In this mode, the substrate is irradiated and supplied for processing. By irradiating the surface of the substrate to be processed with an excitation gas, a functional group such as a hydroxyl group or a carboxyl group is formed on the substrate surface, and the substrate surface is modified. It can also be used to remove organic contaminants on the substrate surface. As a gas used in this case, for example, a mixed gas of N 2 and O 2 or air is used.

  In the present embodiment, it is important to perform both the above-described planar plasma processing and downstream plasma processing as the glass surface modification processing. By performing such a glass surface modification treatment, for example, the adhesion stability of the antifouling coating material to the glass substrate is higher than that of a conventional antifouling coating layer formed by the dip method without particularly performing a surface treatment or the like on the glass substrate. The durability of the antifouling coating surface can be remarkably improved. As the antifouling coating material applied to the glass surface, a fluorine resin material is preferably used. However, when this fluororesin material is applied to a glass substrate by a dip method, the adhesion stability to the glass substrate is particularly bad. For this reason, even when such a fluororesin material is used as an antifouling coating material and applied to a glass substrate by the dip method, the adhesion stability to the glass substrate is improved and the durability of the antifouling coating surface is remarkably improved. Can be made.

  In the case of the planar plasma treatment, the reaction gas used is preferably He, Ar, or N2, and more preferably He. Moreover, although it changes somewhat according to the kind of reaction gas to be used, the electric power used has the preferable range of 200-500W, and 300-400W is more preferable. The treatment time is preferably 10 to 250 seconds, more preferably 30 to 90 seconds. On the other hand, in the case of the downstream type plasma treatment, the reaction gas to be used is preferably a mixed gas of an inert gas and air or O2, and more preferably a mixed gas of N2 and air. Moreover, although it changes somewhat depending on the kind of reaction gas to be used, the power used is preferably in the range of 400 to 1200 W, and more preferably in the range of 600 to 1000 W. Moreover, as processing time, it is suitable to process in the range of 5 to 60 seconds, and it is more suitable to process in the range of 10 to 15 seconds.

  As the order of the planar plasma processing and the downstream plasma processing, the planar plasma processing is first performed, and then the downstream plasma processing is performed. This is preferable because the glass surface shape is changed and a functional group is generated on the glass surface.

[Anti-fouling coating layer formation (step S104)]
Next, the antifouling coating layer 20 is formed on the main surface 12. As a result, the antifouling coating layer 20 is formed as shown in FIG. 4B from the state of only the glass substrate 10 as shown in FIG. The coating material is preferably a perfluoropolyether compound (fluorine resin) having a hydroxyl group at the terminal group. Thereby, it can bond | bond firmly with functional groups, such as a hydroxyl group and a carboxyl group, on the surface of a glass substrate, and can exhibit high durability.

  The antifouling coating layer 20 can be applied and formed by, for example, a dip method. The dipping method is performed by immersing the entire glass substrate 10 in a coating solution containing a coating material in an appropriate solvent, and taking out and drying the glass substrate 10. According to this dip method, the antifouling coating layer 20 having a uniform film thickness can be formed on the entire surface of the glass substrate 10 without using a vacuum film forming apparatus. Note that the film formation method is not limited to the dip method, and there are a spin coating method in which a film is formed using centrifugal force, a spray method in which a target substance is sprayed using a spray gun, and a vapor deposition method. However, the lubricating layer 128 may be formed by these methods.

  The coating thickness of the antifouling coating layer 20 is not particularly limited, but is preferably in the range of 3 nm to 30 nm, for example. When the film thickness is less than 3 nm, the durability is insufficient, and the antifouling function may not be sufficiently exhibited during long-term use. On the other hand, if the film thickness exceeds 30 nm, the uniformity of the thickness of the antifouling coating layer 20 cannot be maintained, or the transparency is lowered, so that it does not comply with the demand for portable devices.

  By providing an antifouling coating layer, when an external force is applied to the cover glass, the impact on the glass substrate surface is mitigated by the antifouling coating layer, and cracks that cause a reduction in the strength of the glass, which is a brittle material, occur. Since it becomes difficult to produce in a glass substrate, the mechanical strength of a cover glass can be improved. That is, the mechanical strength as the cover glass can be further improved by forming the antifouling coating layer on the chemically strengthened glass substrate.

[Region Thickness Adjustment Step (Step S106)]
As the antifouling coating layer 20 formed as described above is cured (the solvent evaporates), an adhesion region 22 and a flow region 24 are formed therein. The adhesion region 22 is a region that is adhered to the main surface 12 and affects durability. The flow region 24 is a region that contributes to slipperiness. Therefore, in the present invention, the region thickness adjustment step is performed next to adjust the ratio of the thickness of the adhesion region 22 to the thickness of the antifouling coating layer 20.

  In the region thickness adjustment step, the thickness of the flow region 24 is decreased and adjusted as shown in FIG. 4C by adjusting the evaporation rate of the solvent and volatilizing the molecules having a small molecular weight. That is, the region thickness adjustment step is a step of indirectly adjusting the ratio of the thickness of the adhesion region 22 to the antifouling coating layer 20. In the region thickness adjustment step, no significant decrease in thickness is observed in the adhesion region 22 as compared with the flow region 24. This is presumably because the molecules of the coating material constituting the adhesion region 22 are firmly bonded to functional groups such as hydroxyl groups and carboxyl groups on the surface of the glass substrate.

  The ratio of the thickness of the adhesion region to the thickness of the antifouling coating layer is preferably 20% to 80%, more preferably 40% to 70%. This is because if the thickness ratio of the adhesion region is less than 20%, the durability cannot be exhibited. Further, if the ratio of the thickness of the adhesion region is more than 80%, the slipping property cannot be exhibited. Furthermore, if it is 40%-70%, durability and slipperiness can be exhibited better.

  Specifically, as the region thickness adjusting step, a baking process, an ultraviolet irradiation process, and a vacuum degree adjusting process using reduced pressure can be performed.

  In the baking process, the antifouling coating layer 20 can be dried by heating at a temperature equal to or higher than the evaporation temperature of the solvent in a constant temperature furnace. The heating temperature is preferably 120 ° C to 180 ° C. The heating time is preferably 30 minutes to 1 hour. Here, as the heating temperature is increased and the heating time is increased, the thickness of the flow region 24 can be reduced. At the same time, the bonding between the molecules of the coating material constituting the adhesion region 22 and the surface of the glass substrate is promoted by heat, and the adhesion region 22 can be enlarged.

  In the ultraviolet irradiation treatment, the ultraviolet rays having a wavelength of 150 to 400 nanometers are preferable. Further, as the ultraviolet light source, for example, a low-pressure mercury lamp, a high-pressure mercury lamp, or an ultrahigh-pressure mercury lamp can be used. The illuminance of the ultraviolet light source can be about 300 [cmW / cm 2]. The thickness of the flow region 24 can be reduced as the illuminance of the ultraviolet light is increased and the irradiation time is lengthened. Further, in the ultraviolet irradiation treatment, the atmospheric temperature may be adjusted and the heat treatment may be performed simultaneously. Thereby, the adhesion area | region 22 can be expanded.

  In the vacuum degree adjustment process, the solvent can be evaporated by adjusting the degree of vacuum so that the pressure is lower than the vapor pressure of the solvent. The higher the degree of vacuum (lowering the atmospheric pressure) and the longer the processing time, the more the thickness of the flow region 24 can be reduced. Further, in the vacuum degree adjustment process, the atmospheric temperature may be adjusted and the heat treatment may be performed simultaneously. Thereby, the adhesion area | region 22 can be expanded.

  In addition, after performing printing as necessary or forming a transparent electrode for a touch panel, the cover glass is incorporated into the portable device.

[Example]
Hereinafter, examples will be given to more specifically explain the cover glass for an electronic device and the method for producing the same according to the present invention. In addition, this invention is not limited to a following example.

(1) Glass substrate production process First, a glass substrate for a cover glass was produced by cutting out a predetermined size from a 0.5 mm thick plate glass made of an aluminosilicate glass produced by a downdraw method or a float method. As this aluminosilicate glass, the glass for chemical strengthening containing SiO2: 58-75 weight%, Al2O3: 4-20 weight%, Li2O: 3-10 weight%, Na2O: 4-13 weight% was used.

  Next, a hole was made in the glass substrate using a grindstone (for processing a small opening diameter) or the like, and shape processing of the outer peripheral end face as shown in FIG. 3, for example, was performed. The glass substrate that had undergone the shape processing was chemically strengthened, and immersed in each of washing tanks of sulfuric acid, neutral detergent, pure water, pure water, IPA, and IPA (steam drying) in order, ultrasonically cleaned, and dried. Thus, a glass substrate was prepared.

(2) Antifouling coating layer forming step Glass is formed by a dipping method using a coating solution (liquid temperature 25 ° C.) in which a fluororesin (manufactured by Shin-Etsu Chemical Co., Ltd. (trade name) KY100 series) is adjusted to an appropriate concentration with a solvent An antifouling coating layer made of a fluororesin was applied to the entire surface of the substrate. The coating thickness of the antifouling coating layer was 10 nm.

(3) Region thickness adjusting step Next, as a region thickness adjusting step, hot air drying was performed for 30 minutes. Here, a plurality of samples were manufactured at different drying temperatures as shown in Table 1. And after measuring the thickness of the antifouling coating layer 20 after drying, it was immersed in HFE as a solvent for 1 minute to remove the flow region 24, and the thickness of the adhesion region 22 was measured. Table 1 shows the ratio of the thickness of the adhesion region 22 to the antifouling coating layer 20 thus obtained. The film thickness is a value measured with an ellipsometer MARY-102 manufactured by FiveLab.

  Steel wool (# 0000) was slid against the surface of the antifouling coat layer of each sample at a load of 1 kg, and the static friction coefficient, the dynamic friction coefficient, and the variation of the contact angle with water on the antifouling coat layer surface were examined. The measurement results are shown in Tables 2 to 4. The initial values of the static friction coefficient and the dynamic friction coefficient were 0.35 for the static friction coefficient and 0.21 for the dynamic friction coefficient. The friction coefficient was measured using a slider having a load of 50 gf, a sliding speed of 50 mm / second, a sliding distance of 50 mm, a tip surface material of polyethylene, and a tip having a curved shape. The initial value of the water contact angle was 115 degrees. The contact angle of water was measured according to JIS R3257 using a contact angle meter DM-501 manufactured by Kyowa Interface Science.

In Table 2, the evaluation was made based on whether or not the static friction coefficient on the surface of the flow region was 0.2 to 0.4. In Table 3, the evaluation was made based on whether or not the dynamic friction coefficient was 0.1 to 0.3. In Table 4, the evaluation was made based on whether or not the contact angle of water was 100 degrees to 120 degrees.

  Referring to Samples 1 and 2 in Tables 2 and 3, it can be seen that the coefficient of friction increases significantly as the steel wool is slid 1000 times and 2000 times. In Table 4, when Samples 1 and 2 are referred to, the contact angle of water is greatly reduced. This is thought to be a result of the glass substrate being exposed because the flow region 24 was easily removed by sliding of the steel wool, and the adhesion region 22 was thin, and this was also removed. From this, it can be seen that when the thickness ratio of the adhesion region is less than 20%, the durability cannot be exhibited.

  Also, referring to Sample 9 in Tables 2 and 3, it can be seen that although not as much as Samples 1 and 2, the coefficient of friction has increased. This is presumably because the molecular chain of the coating material is fragmented by baking at 200 ° C., the fluidity of the molecules in the fluidized bed is further increased, and the durability of the fluidized bed itself is significantly reduced. From this, it is understood that when the ratio of the thickness of the adhesion region is more than 80%, the slipperiness cannot be exhibited after the durability test.

  From these things, it is preferable that the ratio of the thickness of the adhesion region is 20% to 80%. Furthermore, in Tables 2 and 3, in samples 4 to 7, the coefficient of friction hardly changed even after sliding 2000 times. From this, it can be seen that the ratio of the thickness of the adhesion region is more preferably 40% to 70%.

  In addition, when the sample 9 is referred in Table 4, the contact angle of water has hardly decreased. This is considered to be because the contact angle of water was maintained because the adhesion region 22 remained even after 2000 times of sliding. To summarize the above results, if only the adhesion region 22 is formed as a coating layer, the antifouling property (which can be evaluated by a contact angle) has durability, but the slipperiness (which can be evaluated by a friction coefficient) It turns out that it has no durability. And by making the ratio of the thickness of the adhesion area | region with respect to the thickness of an antifouling coating layer into 20%-80% like this invention, the performance of both the slipperiness and durability of an antifouling coating layer is exhibited. You can see that

[Second Embodiment]
2nd Embodiment of the cover glass for electronic devices concerning this invention is described. In the present embodiment, an external protective cover glass that is detachably attached so as to cover a part of the exterior of the electronic device will be described as an example of the electronic device cover glass.

  FIG. 5 is a diagram illustrating a state in which an electronic device cover glass (hereinafter referred to as a protective cover glass 100) according to the second embodiment is attached to an electronic device. As shown in FIG. 5, the protective cover glass 100 is an external protective cover glass that is detachably attached so as to cover a part of the exterior of the electronic device. In the second embodiment, the smartphone 300 is exemplified as the electronic device. However, the electronic device is not limited to this, and other mobile phones, portable game machines, PDAs (Personal Digital Assistants), digital still cameras, video cameras, Alternatively, a slate PC (Personal Computer) or the like may be used.

  The smartphone 300 includes a touch panel display 302 and an exterior cover glass (electronic device cover glass) 304 that covers the surface of the touch panel display 302. The exterior cover glass 304 is attached to the inside of the bezel of the housing 306 so as to form a part of the exterior of the smartphone 300.

  The protective cover glass 100 includes a glass substrate 102. The protective cover glass 100 is attached by the user of the smartphone 300 so as to cover the outer main surface of the exterior cover glass 304 in order to protect the exterior cover glass 304.

  FIG. 6 is a schematic cross-sectional view after the protective cover glass 100 of FIG. 5 is attached to an electronic device (smartphone 300). In FIG. 6, the exterior cover glass 304 is illustrated for the smartphone 300, and components other than the exterior cover glass 304 are schematically illustrated as the smartphone body 300 </ b> A.

  As shown in FIG. 6, the protective cover glass 100 is provided on the back side of the glass substrate 102 for protecting the electronic device (for example, the smart phone 300) and the glass substrate 102. The glass substrate 102 is used as the electronic device (the smart phone 300). An attaching portion (attachment layer) 104 for attaching in a detachable manner is included. The glass substrate 102 includes a front surface 102B (first main surface), a back surface 102C (second main surface) for placement toward the exterior of the electronic device, and an end surface 102A that connects the front surface 102B and the back surface 102C. Have. Moreover, the thickness of the glass substrate 102 is 0.2-0.5 mm. Further, as shown in FIG. 5, an opening is formed in the glass substrate 102 so as to correspond to a position of a microphone, a speaker, a button, or the like of the electronic device. The affixing portion 104 is formed over the entire surface other than the opening portion and the outer peripheral portion of the back surface 102C of the glass substrate 102 in plan view.

  FIG. 7 is an enlarged view of a range X in FIG. As shown in FIG. 7, the protective cover glass 100 has, as an overall structure, a recess 106 that is recessed toward the inside in the surface direction on the back surface side of the outer peripheral portion thereof. In the second embodiment, the recess 106 is arranged such that the outer peripheral edge 104A of the sticking part 104 is arranged on the inner side in the plane direction (left and right direction in FIG. 7) with respect to the back surface 102C from the end surface 102A of the glass substrate 102. Are formed as a space surrounded by the outer peripheral portion 104A, the outer peripheral end 104A of the sticking portion, and the cover glass 304 for exterior.

  By forming the recess 106 as described above, when the protective cover glass 100 is attached to the smartphone 300, a gap is generated between the protective cover glass 100 and the smartphone 300 by the recess 106. Therefore, the user can detach the protective cover glass 100 by hooking a nail or the like into the gap. Therefore, the protective cover glass 100 made of glass with good peelability can be realized.

  In particular, by forming the recess 106 by arranging the outer peripheral edge 104A of the affixing portion 104 at a distance from the end face 102A, the recess 106 can be easily formed without processing the glass with high hardness. Can do.

  FIG. 8 is a diagram showing a layer structure of the protective cover glass 100 of FIG. 5, and FIG. 9 is a diagram showing a procedure for forming the protective cover glass 100 of FIG. As shown in FIG. 9, the protective cover glass 100 includes (1) glass substrate forming step S400, (2) chemical strengthening step S402, (4) glass surface modification treatment S404, and (4) antifouling coat layer forming step S406. (5) Manufactured through the pasting part forming step S410.

  In the glass substrate forming step S400, the glass substrate 102 having a desired shape is formed by machining or etching. For the glass substrate 102, it is preferable to use an alumina silicate glass containing SiO2: 58 to 75 wt%, Al2O3: 4 to 20 wt%, Li2O: 3 to 10 wt%, Na2O: 4 to 13 wt%, Not only this but soda lime glass etc. may be used.

  In the chemical strengthening step S402, the glass substrate 102 obtained in step S400 is chemically strengthened. In the chemical strengthening treatment, a glass substrate 102 is brought into contact with a molten chemical strengthened salt, whereby alkali metal ions having a relatively large atomic radius in the chemically strengthened salt and relatively small atomic radii in the glass substrate 102 are used. This is a process of exchanging the alkali metal ions with the alkali metal ions to infiltrate the surface layer of the glass substrate 102 with alkali metal ions having a large ion radius, thereby generating a compressive stress.

  As the chemically strengthened salt, it is preferable to use an alkali metal nitrate such as potassium nitrate or sodium nitrate. Further, as a method of chemical strengthening treatment, a low temperature type ion exchange method in which ion exchange is performed in a temperature range not exceeding the temperature of the glass transition point, for example, a temperature of 300 to 500 degrees Celsius is preferable. Since the chemically strengthened glass substrate 102 is improved in strength and excellent in impact resistance, the glass substrate 102 for the cover glass 100 exhibits a sufficient effect as a cover glass even with a thickness of about 0.3 mm, for example. it can.

  In the glass surface modification process S404, a glass surface modification process including both a planar plasma process and a downstream plasma process is performed on the surface of the glass substrate 102. Thereby, the adhesion stability of the antifouling coating layer to the glass substrate can be sufficiently increased, and the durability of the antifouling coating surface can be improved. The details of the glass surface modification treatment S404 are the same as step S102 shown in the first embodiment.

  In the antifouling coating layer forming step S406, the antifouling coating layer 110 is formed on the glass substrate 102 chemically strengthened in step S402. The antifouling coating layer 110 is applied and formed on the surface of the glass substrate 102 by, for example, a spray method, a dip method, a vapor deposition method, or a brush coating method. The coating material is preferably a perfluoropolyether compound (fluorine resin) having a hydroxyl group at the terminal group. Thereby, it can couple | bond firmly with functional groups, such as a hydroxyl group and a carboxyl group in the surface of the glass substrate 102, and can exhibit high slipperiness and durability. In addition, by forming the antifouling coating layer 110, it is possible to suppress the adhesion of dirt such as fingerprints, and to easily wipe off even if dirt such as fingerprints adheres.

  As the antifouling coating layer 110 is cured (the solvent evaporates), an adhesion region 110a and a flow region 110b are formed therein. In the region thickness adjustment step S408, the thickness of the flow region 110b is decreased and adjusted by adjusting the evaporation rate of the solvent and volatilizing the molecules having a small molecular weight. The ratio of the thickness of the adhesion region 110a to the thickness of the antifouling coating layer 110 is 20% to 80%, and further 40% to 70%. Specifically, as the region thickness adjusting step, a baking process, an ultraviolet irradiation process, and a vacuum degree adjusting process using reduced pressure are performed.

  In the pasting part forming step S <b> 410, the pasting part 104 is formed on the glass substrate 102. The affixing part 104 is formed of a silicon adhesive. Here, the affixing part 104 affixes the reinforcing film for reinforcing the glass substrate 102, the first adhesive layer for adhering the back surface 102C and the reinforcing film, and the reinforcing film to the cover glass 304 for exterior use. The structure which has the 2nd contact bonding layer which consists of this silicon type adhesive agent (all are not shown in figure) may be sufficient. By providing such a reinforcing film, the glass substrate 102 can be reinforced from the back side. Moreover, it is preferable that the thickness of the sticking part 104 exists in the range of 0.02-0.2 mm from a viewpoint which makes compatible the exhibit of peelability and thickness reduction of the protective cover glass 100, More preferably, it is 0.00. It is in the range of 05-0.1 mm.

  Refer to FIG. 7 again. As shown in FIG. 7, the length L1 (the depth dimension from the end surface 102A of the recess 106) L1 that is recessed toward the inside of the recess 106 is 0.1 mm to 0.3 mm than the end surface 102A of the glass substrate 102. It is good to be in the range. Thereby, coexistence of peelability and aesthetics can be aimed at. That is, when length L1 is 0.1 mm or more, peelability can be exhibited more. When the length L1 exceeds 0.3 mm, dust, sebum, etc. accumulate in the hollow part 106 with the passage of time, and there is a possibility that the aesthetic appearance of the smartphone 300 may be impaired. In particular, portable electronic devices such as a mobile phone including the smartphone 300 are often placed in a pocket of a user's clothes, and therefore, clothes fibers and the like tend to collect in the recess 106 as dust.

  FIG. 10 is an explanatory diagram of a range in which the recess 106 in FIG. 7 is formed. FIG. 10A is a diagram showing a first example, and FIG. 10B is a diagram showing a second example. 10A and 10B, the range of the depression 106 is indicated by a dotted line.

  As shown in FIG. 10A, a recess 106 may be provided on the entire circumference on the back surface side of the outer peripheral portion of the protective cover glass 100. Moreover, as shown in FIG.10 (b), you may provide the hollow part 106 only in the one part edge | side of the back surface side of the outer peripheral part of the protective cover glass 100. FIG. In FIG. 10B, the depression 106 is provided on one side of the pair of short sides of the smartphone 300 (the upper side of FIG. 10B). The depression 106 may be provided in at least a part of the outer peripheral portion of the protective cover glass 100, such as providing a depression in the shape of a circular arc in plan view, or in a corner portion of the protective cover glass 100 in plan view. .

[Third embodiment]
In the said 2nd Embodiment, although demonstrated so that the hollow part 106 might be formed by the position of 104 A of outer peripheral ends of the sticking part 104, as for the protective cover glass 200 concerning 3rd Embodiment, the back surface side of the outer peripheral part of the glass substrate 202 is inside. It is different from the protective cover glass 100 according to the second embodiment in that it is recessed toward the surface and forms a part of the recessed portion 106.

  FIG. 11 is a view showing an outer peripheral portion of the protective cover glass 200 according to the third embodiment, and FIG. 12 is a view showing another example of the third embodiment. 11 and 12 are views corresponding to FIG. 7 of the second embodiment.

  In the protective cover glass 200 shown in FIG. 11, between the end surface 202A and the back surface 202C of the glass substrate 202, an interposition surface 202D that is inclined toward the inner side (the inner side in the surface direction of the back surface 202C) than the end surface 202A is formed. Yes. The interposition surface 202 </ b> D may be formed on the entire outer periphery of the glass substrate 202, or may be formed only on a part of the outer periphery, a part of the outer periphery, or only a corner portion in plan view of the glass substrate 202. May be. The interposed surface 202D constitutes a part of the contour of the recess 106.

  With such a configuration, a gap generated between the protective cover glass 200 and the smartphone 300 can be made larger than the thickness of the pasting portion 104. This makes it easier for the user to hook a nail or the like into the gap of the recess 106. Therefore, the peelability of the protective cover glass 200 can be enhanced as compared with the second embodiment.

  In the protective cover glass 210 shown in FIG. 12, the glass substrate 212 includes a front surface (first main surface) 212B, a back surface (second main surface) 212C, an end surface 212E that is an inclined surface that forms a curve in a cross-sectional view, and a back surface. An interposition surface 212D is provided between 212C and the end surface 212E. The end surface 212E is inclined so as to taper from the back surface 212C side to the front surface 212B side. Further, a boundary portion 212F between the surface 212B and the end surface 212E of the glass substrate 212 has a rounded shape. Further, the boundary portion 212A between the end surface 212E and the interposition surface 212D (the outermost peripheral portion of the end surface 212E) is also rounded.

  In addition, in the height of the thickness direction of the glass substrate 212, it is preferable that the height of the end surface 212E is higher than the height of the interposition surface 212D. This is because the smoothness when touched is more important than the ease of hooking during normal use (after completion of the pasting operation).

  As described above, since the end surface 212E is inclined so as to taper from the back surface 212C side to the front surface 212B side, it is possible to prevent the user's finger or the like from being caught when operating the user's electronic device. . Further, by rounding the boundary portion 212A between the surface 212B and the end surface 212E of the glass substrate 212, the tactile sensation when the user touches the boundary portion with a finger can be made smoother. Therefore, it is particularly effective in the case of the smartphone 300 having the touch panel display 302.

  FIG. 13 is a diagram illustrating a method for processing the outer peripheral portion of the glass substrates 202 and 212 of FIGS. 11 and 12.

  FIG. 13A is a diagram for processing the glass substrate 202 by machining. When forming the interposition surface 202D having a straight cross-sectional shape like the glass substrate 202 of FIG. 11, the machining (for example, processing using the rotating grindstone 308) illustrated in FIG. 13A is effective. .

  FIG. 13B is a diagram for processing the glass substrate 212 by etching. When the intervening surface 212D having a curved cross-sectional shape is formed like the glass substrate 212 of FIG. 12, processing by etching illustrated in FIG. 13B is effective. Further, in the case where the end surface 212E is formed in addition to the intervening surface 212D and the boundary portion 212F is rounded, it is advantageous because it can be formed at a time by etching. Specifically, by masking the region other than the etched region of the glass substrate 212 with the resist material 310 and etching the front surface side more than the back surface side, the intervening surface 212D, the end surface 212E, FIG. In addition, the shapes of the boundary portions 212A and 212F can be suitably formed.

  In addition, in each said embodiment, the structure which affixes the protective cover glass 100,200,210 on the cover glass 304 for exterior | packing of the smart phone 300 was demonstrated. However, the present invention is not limited to this, and for example, a configuration in which the smartphone 300 is attached to the back side of the housing 306 may be used.

[Example]
As an example, as shown in FIG. 7 of the second embodiment, only the outer peripheral end 104A of the sticking part 104 is arranged at a distance from the end face 102A to form the recessed part 106, and the length L1 of the recessed part 106 is changed. Then, testing and evaluation were performed. The thickness of the glass substrate 102 was 0.3 mm, and the height of the recess 106 was 0.1 mm.

Each of the protective cover glasses 100 having the length L1 of the hollow portion 106 of the samples 101 to 110 shown in Table 5 was prepared, and the following test was performed. That is, each protective cover glass of samples 101 to 110 was actually attached to the smartphone 300, and it was tested how many times the test subject could peel off the protective cover glass with a finger. The criteria for evaluation are as follows.
◎… Success in one time, ○… Success in two to three times, △… Success in four to five times, ×… Success in six times

Furthermore, in order to investigate the product quality of each protective cover glass of Samples 101 to 110, after each protective cover glass was attached to the smartphone 300, the state after 30 days of use was examined. In the present embodiment, as the smartphone 300, a smartphone whose outer periphery is covered with black paint is used.

[result]
From Table 5 above, it was found that the length L1 (depth dimension from the end surface 102A of the recess 106) L1 should be in the range of 0.1 mm to 0.3 mm.

  Although the preferred embodiments of the present invention have been described above with reference to the accompanying drawings, it goes without saying that the present invention is not limited to such examples. It will be apparent to those skilled in the art that various changes and modifications can be made within the scope of the claims, and these are naturally within the technical scope of the present invention. Understood.

  In particular, in the second and third embodiments described above, the description has been made centering on the configuration in which the outer peripheral end of the pasting portion is arranged at an interval on the inner side in the surface direction of the back surface of the glass substrate rather than the end surface of the glass substrate. However, a notch structure may be provided between the second main surface and the end surface of the glass substrate, and only this notch structure may be used as the depression. For example, in this case, in the cross-sectional view, the position of the outer peripheral edge of the sticking part and the position of the end face of the glass substrate may be matched, and the outer peripheral part of the sticking part may be configured to follow the inner surface of the notch structure of the glass substrate. Good. Thereby, a clearance gap is formed between the outer peripheral part of a sticking part and the exterior of an electronic device, and this clearance gap can be made into a hollow. In such a configuration, a process of reducing the adhesiveness of the outer peripheral portion of the pasting portion may be performed in advance.

  The present invention relates to a cover glass for an electronic device used for protecting a display screen of a portable device such as a mobile phone, a portable game machine, a PDA (Personal Digital Assistant), a digital still camera, a video camera, or a slate PC (Personal Computer). And can be used as a manufacturing method thereof.

DESCRIPTION OF SYMBOLS 1 ... Cover glass for electronic devices, 10 ... Glass substrate, 10a ... Outer peripheral surface, 10b ... Notch, 10c ... Ear hole, 10d ... Key operation hole, 12 ... Main surface, 20 ... Antifouling coating layer, 22 ... Adhesion area, 24 ... Flow region, 100, 200, 210 ... Protective cover glass, 102, 202, 212 ... Glass substrate, 102A, 202A ... End face, 102B, 202B, 212B ... Surface (first main surface), 102C, 202C, 212C ... back surface (second main surface), 202D, 212D ... intervening surface, 212E ... end face, 212A, 212F ... boundary portion, 104 ... sticking portion, 104A ... outer peripheral end, 106 ... recessed portion, 110 ... antifouling coating layer, DESCRIPTION OF SYMBOLS 300 ... Smartphone, 300A ... Smartphone main-body part, 302 ... Touch panel display, 304 ... Cover glass for exterior | packing, 306 ... Housing | casing 308 ... rotary grindstone, 310 ... resist material

Claims (11)

A glass substrate;
An antifouling coating layer formed on the surface of the glass substrate,
The antifouling coating layer contains a perfluoropolyether compound having a hydroxyl group as a terminal group, adheres to the surface of the glass substrate, and adheres to an area that remains when immersed in a solvent made of HFE for 1 minute ; possess a flow region disposed on the surface of the said adhesion region is a region which dissolves when immersed for one minute in the solvent, the thickness of the antifouling coat layer in 3nm or more 30nm or less, and the antifouling coat layer A cover glass for electronic equipment, wherein the ratio of the thickness of the adhesion region to the thickness of the glass is in the range of 20% to 80% .   2. The cover glass for an electronic device according to claim 1, wherein a ratio of the thickness of the adhesion region to the thickness of the antifouling coating layer is 40% to 70%. The cover glass for electronic devices according to claim 1 or 2, wherein a static friction coefficient of a surface of the flow region is 0.2 to 0.4 . Electronics cover glass according to any one of claims 1 to 3, characterized in that the dynamic friction coefficient of the surface of the flow area is from 0.1 to 0.3. Electronics cover glass according to claim 1, any one of 4, wherein the contact angle of water on the surface of the flow area is 100 to 120 degrees. A cover glass for an external electronic device that is detachable so as to cover a part of the exterior of the electronic device,
A first main surface, a second main surface that is a back surface with respect to the first main surface and is arranged toward the exterior of the electronic device, and the first main surface and the second main surface. And connecting end faces,
Wherein at least a part is of the outer periphery of the second main surface, from claim 1, wherein a recess portion which is recessed toward the face inward of said from said end surface and the second major surface is provided The cover glass for electronic devices according to any one of 5 . A method of manufacturing a cover glass for electronic equipment,
A glass substrate making process;
Including an antifouling coat layer forming step of applying a coating having antifouling property to a glass substrate,
In the antifouling coat layer forming step,
Using a coating material containing a perfluoropolyether compound having a hydroxyl group as a terminal group, an adhesion region that adheres to the surface of the glass substrate and remains when immersed in a solvent made of HFE for 1 minute, and the adhesion Forming a fluidized region that is disposed on the surface of the region and dissolves when immersed in the solvent for 1 minute;
After the antifouling coat layer forming step, by adjusting the thickness of the flow region by any one of baking treatment, ultraviolet irradiation treatment, and vacuum degree adjustment processing by reduced pressure, The manufacturing method of the cover glass for electronic devices characterized by further including the area | region thickness adjustment process which adjusts the ratio of thickness . The ratio of the thickness of the adhesion area | region with respect to the thickness of the said antifouling coating layer shall be 20%-80% by the said area | region thickness adjustment process, The manufacture of the cover glass for electronic devices of Claim 7 characterized by the above-mentioned. Method. The ratio of the thickness of the adhesion area | region with respect to the thickness of the said antifouling coating layer shall be 40%-70% by the said area | region thickness adjustment process, The manufacture of the cover glass for electronic devices of Claim 7 characterized by the above-mentioned. Method. 10. The method for manufacturing a cover glass for an electronic device according to claim 7 , wherein in the antifouling coat layer forming step, the antifouling coat layer has a thickness of 3 nm to 30 nm. Before the antifouling coat layer forming step, planar type plasma treatment and wherein the down-stream method according to claim 7, wherein applying the glass surface modification treatment consisting of both treatments of plasma treatment in any one of the 10 Of manufacturing cover glass for electronic equipment.

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