KR20120135467A

KR20120135467A - Fingerprint-resistant glass substrates

Info

Publication number: KR20120135467A
Application number: KR1020117029119A
Authority: KR
Inventors: 애드라 에스 베이카; 칼 더블유 코치 3세; 셰리 이 코발; 프랜틱 마줌더; 마크 에이 쿠에사다; 웨기샤 세네렛네; 토드 피 세인트 클레어
Original assignee: 코닝 인코포레이티드
Priority date: 2010-05-05
Filing date: 2010-05-05
Publication date: 2012-12-14

Abstract

The present invention provides a glass substrate having at least one surface having engineering properties including hydrophobicity, oil firing, anti-sticking or adhesion of particulate or liquid, resistance to fingerprints, durability and transparency (i.e. haze <10%). to provide. At least one set of topological features having concave geometries that prevent pinning of the droplets and reduction of contact angles, including at least one of water and lipoenetic oil.

Description

Fingerprint-resistant glass substrate {FINGERPRINT-RESISTANT GLASS SUBSTRATES}

Related application cross-reference

This application is directed to US patent application Ser. No. 12 / 625,020, filed Nov. 24, 2009, filed on May 6, 2009, and claims 12 / 625,020, filed on April 20, 2010. It lasts / 763,649.

The present invention provides a glass substrate having at least one surface having engineering properties including hydrophobicity, oil firing, anti-sticking or adhesion of particulate or liquid, resistance to fingerprints, durability and transparency (i.e. haze <10%). to provide. At least one set of topological features having concave geometries that prevent pinning of the droplets and reduction of contact angles, including at least one of water and lipotropic oil.

Increasingly, surfaces for touch screen applications are required. From an aesthetic and technical point of view, there is a need for a touch screen surface that is resistant to fingerprint movement or smearing. For applications with portable electronic devices, the general needs of user-friendly surfaces include high transmittance, low haze, resistance to fingerprint transfer, robustness to repeated use and nontoxicity. Fingerprint resistant surfaces require resistance to the movement of water and oil when the user's fingers are in contact. Wetting characteristics of these surfaces allow the surfaces to have hydrophobicity and oil plasticity.

The present invention provides for hydrophobicity (i.e. contact angle of water> 90 °), oil firing (i.e. contact angle of oil> 90 °), anti-sticking or adhesion of particulate or liquid particles found in fingerprints, durability and transparency (i.e. haze < Glass substrates having at least one surface having engineering properties, including but not limited to 10%). The glass substrates have at least one set of topological features that provide hydrophobicity and oil firing.

Accordingly, one aspect of the present disclosure is to provide a glass substrate that is light transparent and has at least one side of fingerprint resistance. Glass substrates are resistant to mechanical and chemical abrasion.

A second aspect of the present disclosure is to provide a glass substrate having at least one side of hydrophobicity and oil firing. At least one surface comprises at least one set of topological features of average dimension, wherein the topological features have a concave geometry that prevents a drop in contact angle of the droplets including at least one of water and fatty secreting oil.

A third aspect of the present disclosure is to provide a method of manufacturing a glass substrate having at least one side of hydrophobicity and oil firing. The method includes providing a glass substrate and forming at least one set of topological features on at least one side of the glass substrate. At least one set of topological features has a topological feature of average dimension and the topological features have a concave geometry that prevents a drop in contact angle of the droplets including at least one of water and lipotropic oil.

These and other forms, advantages, and features will become apparent from the following detailed description, the accompanying drawings, and the appended claims.

1A is a schematic representation of the Wenzel model of the wetting behavior of fluidic droplets on rough solid surfaces;
1B is a schematic of the Cassie-Baxter model of wetting behavior of fluidic droplets on rough solid surfaces;
2 is a schematic of a glass substrate having a composite level of topography.
3 is an atomic force microscopy image of a surface topographic feature having dimensions greater than 1 μm.
4A is a cross-sectional view of the column structure of a SnO ₂ film sputtered before etching.
4B is a top view of the column structure of the SnO ₂ film sputtered before etching.
4C is a top view of the column structure of a sputtered SnO ₂ film after etching for 5 minutes with concentrated hydrochloric acid.
5A is a top view of the column structure of a ZnO film sputtered before etching.
5B is a top view of the column structure of a sputtered ZnO film after etching for 15 seconds with 0.1 M HCl.
5C is a top view of the columnar structure of a sputtered ZnO film after etching for 45 seconds with 0.1 HCl.
6A is a schematic representation of a second topography space that serves as the pinning site of the fingerprint.
FIG. 6B is a schematic diagram of a Teflon cusp formed to minimize pinning of the fingerprint in the second topography space shown in FIG. 6A; And
7 is a plot of the projected solid-liquid region fraction as a function of roughness.

In the following description, the same reference numbers refer to similar or corresponding parts throughout the several views shown in the drawings. Unless stated otherwise, "upper", "lower", "outer", "inner" and the like are words for convenience and do not imply a limitation of the terms. Further, whenever a group is described as including at least one of a group of elements and combinations thereof, the group includes, consists essentially of, or consists of any number of elements recited individually or in combination with each other. It is understood that. Likewise, it is understood that any time a group is described as consisting of at least one of a group of elements or combinations thereof, the group may consist of any number of elements recited individually or in combination with each other. As stated otherwise, the range of recited values includes the upper and lower limits of the range.

In general, with respect to the drawings, the description is for the particular embodiments described and is not intended to limit the disclosure or the accompanying claims. The drawings are not necessarily to scale, and specific features and perspectives of the drawings may be scaled up or schematically to scale in terms of clarity and brevity.

A major feature of a product that resists or repels a fingerprint can be that the surface of the product is non-wetting (ie, the contact angle (CA) between the droplet and the surface is greater than 90 °) with respect to the liquid containing such fingerprint. As used herein, "anti-fingerprint", "anti-fingerprint" and "fingerprint resistance" may include resistance of the surface to the movement of fluids and other substances found in human fingerprints; Non-wetting of surfaces for such fluids and materials; Minimize, seal, conceal, and combinations of human fingerprints on the surface. Fingerprints include fatty secretion oils (eg, secreted skin oils, fats and waxes), debris of dead fat-producing cells and aqueous components. Combinations and / or mixtures of these materials are referred to as "fingerprint materials". Anti-fingerprint surfaces require resistance to water and oil movement when the user's fingers are in contact. In one embodiment, the amount of transfer of fingerprint material from the human fingerprint to the fingerprint resistant surface of the glass substrate described herein is less than 0.02 mg per contact of the human finger. In another embodiment, less than 0.01 mg per contact of such material is shifted. In yet another embodiment, less than 0.005 mg is moved per contact of this material. The area of the fingerprint resistant surface covered by the droplets moved per contact is less than 20% of the total area of the glass substrate surface to which the human finger is contacted, and in one embodiment 10% of the area of the glass substrate surface to which the human finger is contacted. Is less than. Wetting of these surfaces ensures that the surfaces are hydrophobic (ie, contact angle (CA) between water and glass substrate is greater than 90 °) and oil firing (ie, contact angle (CA) between oil and glass substrate is greater than 90 °). .

The presence of surface roughness (eg, protrusions, recesses, grooves, pores, pits, spaces, etc.) can modify the contact angle between a given fluid and a flat substrate, and is primarily a “lotus leaf” or “lotus flower”. (lotus) "action. As described in Quere (Ann. Rev. Mater. Res. 2008, vol. 38, pp. 71-99), the wetting behavior of liquids on rough solid surfaces is characterized by Wenzel (low contact angle) model or Cassie-Baxter (high contact angle). May be described as a model. In the Wenzel model shown schematically in FIG. 1A, the fluid droplet 120 penetrates into the free space 114 into the rough solid surface 110, and the pits, holes, grooves, pores, spaces, etc., penetrate the rough solid surface 110. Including but not limited to, in some embodiments is “pinned” to the rough surface 112. The Wenzel model considers the increase in the interface area of the rough solid surface 110 relative to the smooth surface (not shown) and expects to increase their hydrophobicity by the rough surface when the smooth surface is hydrophilic. In contrast, when the smooth surfaces are hydrophilic, the Wenzel model expects these rough surfaces to improve their hydrophilic behavior. In contrast to the Wenzel model, the Cassie-Baxter model (shown schematically in FIG. 1B) expects surface roughening to increase the contact angle θ _Y of the fluidic droplet 120, regardless of whether the smooth solid surface is hydrophilic or hydrophobic. The Cassie-Baxter model has a gas pocket 130 formed in the free space 114 of the rough solid surface 110 and trapped beneath the fluid droplet 120 at the rough solid surface 130 at the rough solid surface 110. The pinning of the fluid droplet 120 and the reduction of the contact angle θ _Y are prevented. In addition to preventing pinning of the fluidic droplet 120, the presence of the gas pocket 130 increases the contact angle θ _Y of the fluidic droplet 120. Pressure, for example the pressure exerted by a human finger applied to the fluidic droplet 120, penetrates the fluidic droplet 120 into the free space 114 and can be pinned to a rough solid surface, ie the Cassie-Baxter state (FIG. Fluid droplet 120 from 1b) to the Wenzel state (FIG. 1A) may be moved. The anti-fingerprint surface provides lotus leaf action when in contact with a given fluid and retains the droplets in the Cassie-Baxter state, where gas pockets are trapped under the fluid droplets on the rough solid surface and pinning of the fluid droplets is avoided. And prevents or prevents to some extent the decrease in contact angle θ _Y and movement to the Wenzel state when pressure is applied to the fluid droplets.

Surface hydrophobicity and oil firing relate to the surface energy γ _SV of the solid substrate. The contact angle θ _Y of the surface with fluid droplets is defined by the following formula.

θ _Y is the contact angle of the flat surface (known as zero contact angle), γ _SV is the surface energy of the solid, γ _SL is the interfacial energy between the liquid and the solid, and γ _LV is the liquid surface tension. At θ _Y > 90 °, cosθ _Y is negative, thus making the surface energy γ _SV be less than γ _SL . The interfacial energy between liquid and solid γ _SL is generally unknown and the contact angle θ _Y is generally 90 ° (ie cosθ _Y <) to minimize the surface energy γ _SV of the solid and to achieve hydrophobicity and / or oil plasticity. 0) Increase to an excess value. For example, typical unwetting unroughened or smooth surfaces, including fluorinated materials such as Teflon ™ (polytetrafluoroethane), have surface energy as low as 18 dynes / cm. The Teflon surface is not oily because the constant studied oil (γ _LV dyne / cm) such as oleic acid exhibits a contact angle for Teflon of about 80 °.

Anti-fingerprint surfaces that are hydrophobic and oily can be achieved by forming rough surfaces with low surface energy. Thus, light transmissive glass articles or substrates (unless otherwise stated, "glass articles" and "glass substrates" are the same term and used herein) provide that they have a fingerprint resistant surface and are resistant to mechanical and chemical friction do. In various embodiments the glass substrate has at least one side having engineering properties including but not limited to hydrophobicity and oil hydrophobicity. Other properties, including anti-fingerprint, anti-sticking or anti-adhesiveness of particulate matter, mechanical and chemical durability, transparency (eg, haze <10%), and the like, are provided in other embodiments. These properties are achieved by providing at least one side of the substrate having at least one set of topological features with a concave geometry that prevents contact angles of the droplets including at least one of water, lipotropic oil and fingerprint material. In some embodiments, at least one set of topology features has an average dimension in the range of about 50 nm to about 1 μm. In some embodiments, the above described characteristics are achieved by providing a surface of a glass substrate having many different sets or levels of topological features, including but not limited to bumps, protrusions, recesses, pits, spaces, and the like. A topology feature in one set or level of topology features has an average dimension that is different from the average dimension of the topology feature in another set or level. A concave geometry is formed together that prevents the pinning of the droplets, including at least one of the water and the lipoenetic oil, and the reduction of the contact angle θ _Y.

A cross-sectional view of one example of a glass substrate surface having a composite set of topography is shown schematically in FIG. 2. The surface structure shown in FIG. 2 provides hydrophobicity, oil plasticity, anti-adhesiveness and anti-fingerprint properties by reducing the contact angle θ _Y and driving the material to penetrate or “pin” droplets in the surface space. In addition, the surface structure shown in FIG. 2 serves as a non-limiting example of surface morphology that may provide some measurement of lotus leaf action. Hydrophobic / oil fired surface 200 includes first topography 210, second topography 220, and third topography 230.

The first topography 210 includes many protrusions 212 and recesses 214. The first topography 210 has the largest length of the topography shown in FIG. 2, and the topography properties (protrusions 212 and concave 214) have a first average dimension, which in some embodiments is 2 탆 or less. In one embodiment, the average dimension of the topological features 210 of the first topography is in the range of about 50 nm to about 300 nm. In other embodiments, the average dimension of the topological features of the first topography 210 ranges from about 1 μm to about 50 μm. In other embodiments, the average dimension of the topological features of the first topography 210 ranges from about 1 μm to about 10 μm. In one embodiment the first topography 210 may comprise any etchable inorganic oxide, including but not limited to SnO ₂ , ZnO, ceria, alumina, zirconia, for example.

The topography 220 of the second or intermediate length scale overlaps the first topography 210. The second topography 220 provides a concave geometry that prevents or delays the movement of the fluid droplet 120 on the rough surface from the Cassie-Baxter (FIG. 1B) to the Wenzel state (FIG. 1A). In the Cassie-Baxter state the fluid droplet 120 stops on top of the protrusion 212 including the first topography 210. The feature of the second topography 220 protrudes from the first topography 210 at an angle a from the face of the glass substrate 200 (referred to as “reentrant angle”), and of the fluid droplet 120. The entry into the free space is at least partially blocked, and the free space is formed in the concave portion 214 between the protrusions 212 and prevents or delays the movement from the surface of the glass substrate to the Wenzel state (FIG. 1A).

As shown in FIG. 2, the second topography 220 may include a protrusion at the surface of the large protrusion of the first topography 210. The average dimension of the topological features in the second topography 220 is less than the average dimension of the first topography 210, and in some embodiments ranges from about 1 nm to 1 μm. In other embodiments, the average dimension of the second topography 220 is in the range of about 1 nm to about 50 nm. In one embodiment, the second topography 220 may include, but is not limited to, metals and any etchable inorganic oxides such as SnO ₂ , ZnO, ceria, alumina, zirconia.

Third or smallest length scale topography 230 has a topological feature at a scale of chemical bonding (in the range of about 0.7 kPa to about 3 kPa (70-300 pm)). Third topography 230 is waxy and has low surface energy derivatization. In some embodiments, third topography 230 is a coating that covers at least a portion of the surfaces of first and second topography 210, 220 and is a low surface energy polymer or oligomer such as Teflon ™ or other Commercially available fluoropolymers or fluorosilanes such as, but not limited to, Dow Corning 2604, 2624, 2634, DK Optool DSX, Shintesu OPTRON, Heptadecafluorosilane (Gelest), FluoroSyl (Cytonix), and the like. It includes. In order to prevent pinning of the droplets 120 in the space within the second topography 210 upon application of pressure (eg pressure applied with a finger), the third topography 230 is cut out and recessed in space or trench. Cuffs 230 are formed in the wells to minimize pinning, thus providing additional effective reentry impeding geometry.

The topographic features of the first and second length scales can be arranged, disordered, self-affine or fractal, or any combination. Regardless of the actual topology and / or microstructure state of the topology texture, certain average geometric states require that the product surface have fingerprint resistance, oil firing and / or super oil plasticity.

For oil firing, it is necessary to meet the following requirements between the surface roughness fraction r _f and the solid-liquid partition region f of the substrate:

For super-oil firing (contact ≧ 150 °), it is necessary to meet the following requirements between the surface roughness fraction r _f of the substrate and the solid-liquid partitioning region f:

For medium levels of oil firing, for example, for contact angles greater than 125 °, the following requirement between the surface roughness fraction r _f and the solid-liquid partition region f of the substrate needs to be met:

The relationship between the solid-liquid region fraction f and the roughness element r _f required to achieve the fingerprint resistant surface is plotted in FIG. 7. For products with minimal fingerprint resistance, the texture should ensure that the coordinates (f, r _f ) are within the CA = 90 ° curve in FIG. 7. For surfaces that exhibit super-oil plastic behavior and / or very high fingerprint resistance, the texture of the substrate surface needs to have the f vs r _f coordinates in the region below the CA = 150 ° curve shown in FIG. The fingerprint resistant surface of the glass substrate described herein has a texture defined by the relationship shown in equation (1). In another embodiment, the texture is defined by the relationship shown in equation (2), and in the third embodiment, the texture is defined by the relationship shown in equation (3).

For light transmission, the length-scale of the texture is within the selected range. Length scale constraints arise due to the fact that the fingerprint droplet has a finite size distribution with an average diameter of 2-5 μm. In the anti-fingerprint surfaces and substrates described herein, the texture has a root mean square (RMS) amplitude between 1 nm and 2 μm. In one embodiment, the RMS amplitude of the texture is between 1 nm and 500 nm, and in yet another embodiment, between 1 nm and 300 nm. The texture has an auto-correlation length scale between 1 nm and 10 nm. In some embodiments, the autocorrelation is between 1 nm and 1 μm, and in still other embodiments 1 nm and 500 nm.

The texture of at least 10% of the second topography to produce a negative Laplace pressure that prevents penetration of the liquid meniscus, in particular the oil meniscus, into the spaces between adjacent irregularities, results in an orientation angle of less than 90 ° (in FIG. 2). Angle) and in one embodiment less than 75 °.

In some embodiments, the glass substrate is a planar or three dimensional sheet having two major surfaces. At least one major surface of the glass substrate has many different sets or levels of topology features described herein. In some embodiments, the major surface of the substrate has many levels of topographic features. In another embodiment, one major surface of the glass substrate has such a feature.

A method for producing a glass substrate having a hydrophobic and oily surface is provided. The method includes providing a glass substrate having one surface; And forming at least one set of topological features having topological features of average dimension on at least one surface of the glass substrate. The topology feature has a concave geometry that prevents a drop in the contact angle of the droplets, including at least one of water and lipotropic oil. In one embodiment, the plurality of sets of topology features are formed on the surface of the substrate. Each set has a topological feature of average dimension different from the average dimension of the topological features in the other set. The set of topological features has a concave geometry that prevents pinning of the droplets and reduction of the contact angle θ _Y including at least one of water and lipotropic oil.

In various embodiments, the plurality of sets of topology features include at least one of the first topography 210, the second topography 220, and the third topography 230 described above.

In one embodiment, the first topography 210 may be formed by sandblasting the surface of the glass substrate 200. In one non-limiting example, the surface of the glass substrate 200 is sandblasted with 50 μm alumina grit for another time to achieve the desired roughness parameter. The sandblast surface is coated with an inorganic oxide through the deposition method described herein to achieve the first topography 210.

In another embodiment, the first topographic graph 210 is formed by depositing a thin oxide film through a shadow mask on the surface of the glass substrate 200 using conventionally known physical or chemical vapor deposition methods. In one embodiment, the shadow mask is disposed on the surface of the glass substrate. ZnO is sputtered through the mask onto the glass substrate to produce a first topography 210 that reproduces the mask feature. 3 is an atomic force microscope (AFM) image of the sputtered ZnO surface and shows the features of the first topography 210. This feature includes a 25 μm-diameter bump 212 having a height a of approximately 50 nm and a pitch or space b of about 55 μm.

Second topography 220 may be formed using conventionally known physical (eg, sputtering, evaporation, laser ablation, etc.) or chemical vapor deposition methods (eg, CVD, plasma enhanced chemical vapor deposition, etc.). Can be. In one embodiment, the second topography 220 is accomplished by etching the sputtered metal oxide thin film or anodizing the evaporated metal film. Sputtered variables (eg, sputtering pressure and substrate temperature) are correlated with etch behavior to produce the desired topography. A modified Thornton model ("Modified Thornton Model for Magnetron Sputtered Zinc Oxide: Film Structure and Etching Behavior," Thin Solid Films, 2003, vol. 442, pp. 80-85) by O. Kluth et al. Is incorporated herein by reference. And the correlation between the sputtering parameters (sputtering pressure and glass substrate temperature), the structural film properties and the etching behavior of the RF sputtered film on the glass substrate. By appropriate adjustment of the sputtering conditions, the next etched sputtering column or particulate morphology is selected and formed.

4A-C and 5A-C are scanning electron microscope (SEM) images showing two examples of how the 10-100 nm surface features of the second topography 220 are formed by etching. The individual surface features shown in FIGS. 4 and 5 have dimensions between about 10 and 500 nm. 4A-4C show the effect of strong etching using concentrated hydrochloric acid for 5 minutes on a sputtered SnO ₂ film having a columnar structure. 4 includes SEM images of side or cross section (FIG. 4A) and top view (FIG. 4B) of column structure 410 of SnO ₂ film prior to etching. 4C shows a microscopic image of a top view of the SnO ₂ film after etching to achieve a desired level of roughness and produce a second topography 420.

5A-C show the action of mild etching on a sputtered ZnO film having a columnar structure similar to that shown for SnO ₂ in FIG. 4A. 5A is a top view of the column structure 510 of a ZnO film before etching and FIGS. 5B and 5C are sputtered ZnO after etching for 15 seconds and 45 seconds with 0.1 M HCl, respectively, to produce a second topography 520. It is a top view of the columnar structure of a film. The roughness of the ZnO film increased with increasing etching time.

The third topography includes low surface energy polymers or oligomers including but not limited to the fluoropolymers or fluorosilanes described herein. The third topography is formed after the formation of the first and second topography layers. The oligomer or polymer including the third topography is deposited on the surface of the glass substrate 200 by sputtering, spray coating, spin coating, dip coating, or the like.

Teflon is easily adhered to and sputtered on the alkali aluminosilicate glass surface depending on the ion exchange of these surfaces. Teflon deposition rate is as fast as about 7 nm / min during argon sputtering (50W, 1-5 millitorr conditions). Sputtered Teflon shows little change in hydrophobicity when treated with O ₂ plasma (5-15 minutes, 200 W); The contact angle of water does not exceed about 100 ° contact angle. However, O ₂ plasma-treatment of sputtered Teflon triples hydrophobicity between 20 ° and 60 °.

Non-limiting examples of third topography including the low surface energy plane of sputtered Teflon are shown schematically in FIGS. 6A and 6B. 6A and 6B schematically illustrate how the pinning and reentry prevention geometry of the fingerprint component is alleviated. In order to prevent the absorbed component of the fingerprint from being dispersed and pinned in the space 610 in the second topography (FIG. 6A) upon application of fingerprint pressure, the deposition conditions for sputtering Teflon are adjusted to concave space (trench). The cusp 620 is formed in the wall 710 to minimize pinning in the space or trench walls, thus providing an inexpensive effective re-entry geometry. This is accomplished by using known sputtering conditions where the average free path is small during deposition. In addition, the surface of the glass substrate is cooled to reduce surface movement.

In one embodiment, the glass substrates described herein have a transmittance of greater than 70% transmittance through the substrate and the anti-fingerprint surface. In some embodiments, the transmission through the glass substrate and anti-glare surface is greater than 80% and in some embodiments greater than 90%.

As used herein, "haze" and "transparent haze" refer to the percentage of transmitted light scattered outside the angular cone ± 4.0 according to ASTM procedure D1003, the contents of which are incorporated herein by reference. For an optically smooth surface, the transmittance haze generally approaches zero. The anti-fingerprint surface of the glass substrate has a haze of less than about 80%. In the second embodiment, the antiglare surface has less than 50% haze, and in the third embodiment, the transmittance haze of the anti-fingerprint surface is less than 10%.

As used herein, “gloss” means the measurement of specular reflectance calibrated to a standard (eg, a certified black glass standard) in accordance with ASTM procedure D523, the content of which is incorporated by reference. The anti-fingerprint surface of the glass substrates described herein has a gloss (i.e., the amount of light reflected frontally from the sample at 60 at over 60%).

In one form, the combination of other surface topography described herein is intended to provide a durable surface of the glass substrate when exposed to chemical friction, such as rubbing with fibers or other means, such as a human finger, or attack by acids or bases. to provide. Coating durability (called Crock Resistance) refers to the ability of a coated glass sample to withstand repeated friction with a cloth. The crock resistance test is similar to physical contact with a garment or cloth with a touch screen device and means determining the durability of the coating after such treatment.

Crockmeters are the standard means used to determine the clock resistance of these frictionally subjected surfaces. The crometer directly contacts the friction tip or finger mounted at the end of the weighted arm to the glass slide. The standard finger supplied to the crometer is a solid acrylic acid rod 15 mm in diameter. A piece of clean standard crock cloth is attached to these acrylic fingers. The finger is stopped on a sample with a pressure of 900 g and the arm is repeatedly moved back and forth throughout the sample in an attempt to observe a change in durability / clock resistance. The crometer used in the tests described herein is an automated model that provides a uniform stroke rate of 60 revolutions per minute. Crommeter tests are described in ASTM Test Procedure F1319-94, entitled “Standard Test Method for Determination of Abrasion and Smudge Resistance of Images Produced from Business Copy Products”.

The crock resistance or durability of the coatings and surfaces described herein is determined by optical (eg haze or transmittance) or chemical (eg water and / or) after a certain number of wipings as defined by ASTM test procedure F1319-94. Oil contact angle). Wiping is defined as two strokes or one cycle of a friction tip or finger. In one embodiment, the contact angle of the oil on the fingerprint-resistant surface described herein of the substrate is within 20% of the initial value after 50 wipes. In some embodiments, the contact angle of oil on the fingerprint resistant surface is within 20% of the initial value after 1000 wipes, and in some embodiments, the contact angle of oil on the fingerprint resistant surface is within 20% of the initial value after 5000 cleanings. . Likewise, the contact angle of water from the surface of the substrate to the fingerprint resistant surface remains within 20% of its initial value after 50 wipes. In another embodiment, the contact angle of water at the surface of the substrate is maintained within 20% of the initial value after 1000 wipes, and in another embodiment within 20% of the initial value after 5000 wipes. The anti-fingerprint surfaces described herein maintain a low level of haze after such repeated wiping. In one embodiment, the glass substrate has less than 10% haze after at least 100 wipes, as defined by ASTM test procedure F1319-94.

The contact angle θ _Y described herein is often used as an advantage for evaluating anti-fingerprint oil firing and hydrophobic properties. As described herein, the contact angle measures the degree of wetting between the hydrophilic and / or lipophilic fingerprint component and the engineered surface of the glass substrate. The smaller the wetting (ie, the greater the contact angle), the lower the adhesion to the surface. For anti-fingerprint and anti-adhesiveness, in one embodiment the contact angle exceeds 90 ° C. for lipophilic and hydrophilic materials.

In one non-limiting example, the water (hydrophilic) and oleic acid (lipophilic) contact angles were measured on alkali aluminosilicate glass samples having the surface of the topography described herein. Each glass surface was prepared for ZnO sputtering by first performing a plasma treatment with O ₂ plasma at 200 W for 5 minutes. ZnO was deposited on the glass surface by sputtering the ZnO target for 60 minutes using 50W RF power in a 1 millitorr argon chamber. Samples were etched in 0.05 M HCl for 15, 30, 45 or 90 seconds and the contact angles of water and oleic acid were measured. Samples were dip coated in a fluorosilane solution containing EZ-Clean ™ (Dow Corning DC2604) and then measured for another contact angle. Water and oleic acid contact angles are listed in Table 1 for each sample. As can be seen from Table 1, the hydrophilic contact angle measured before coating the textured sample with EZ-Clean ("without EZ-clean" in Table 1) is small, from about 15 ° (Sample D) to slightly less than 30 °. It is a small (sample 1) range. After dipcoating in EZ clean ("With EZ-Clena" in Table 1), the hydrophilic contact angle for each sample increased substantially to greater than 90 ° threshold for hydrophobicity, from 131 ° to 139 ° Range. Likewise, the contact angle of oleic acid measured for each sample exceeds the threshold for oil firing behavior and ranges from about 93 ° to 96 °. The glass surface is provided on the surface with the composite topography described herein (including the third topograph provided by EZ-clean), which exhibits hydrophobic and oil plastic behavior as indicated by the results of the contact angle measurements shown in Table 1.

In one embodiment, the glass article comprises, consists essentially of, or consists of soda lime glass. In yet another embodiment, the glass article includes, consists essentially of, or consists of any glass that can be downed, such as, but not limited to, alkali aluminosilicate glass. In one embodiment, the alkali aluminosilicate glass comprises, consists essentially of, or consists of: 60-72 mol% SiO ₂ ; 9-16 mol% Al ₂ O ₃ ; 5-12 mol% B ₂ O ₃ ; 8-16 mol% Na ₂ O; And 0-4 mol% K ₂ O, where

Where the alkali metal modifier is an alkali metal oxide. In yet another embodiment, the alkali aluminosilicate glass comprises, consists essentially of, or consists of: 61-75 mol% SiO ₂ ; 7-15 mol% Al ₂ O ₃ ; 0-12 mol% B ₂ O ₃ ; 9-21 mol% Na ₂ O; 0-4 mol% K ₂ O; 0-7 mol% MgO; And 0-3 mol% CaO. In yet another embodiment, the alkali aluminosilicate glass comprises, consists essentially of, or consists of: 60-70 mol% SiO ₂ ; 6-14 mol% Al ₂ O ₃ ; 0-15 mol% B ₂ O ₃ ; 0-15 mol% Li ₂ O; 0-20 mol% Na ₂ O; 0-10 mol% K ₂ O; 0-8 mol% MgO; 0-10 mol% CaO; 0-5 mol% ZrO ₂ ; 0-1 mol% SnO ₂ ; 0-1 mol% CeO ₂ ; Less than 50 ppm As ₂ O ₃ ; And less than 50 ppm Sb ₂ O ₃ ego; Wherein 12 mol% ≦ Li ₂ O + Na ₂ O + K ₂ O ≦ 20 mol% and 0 mol% ≦ MgO + CaO ≦ 10 mol%. In another embodiment, the alkali alumina silicate glass comprises, consists essentially of, or consists of: 64-68 mol% SiO ₂ ; 12-16 mol% Na ₂ O; 8-12 mol% Al ₂ O ₃ ; 0-3 mol% B ₂ O ₃ ; 2-5 mol% K ₂ O; 4-6 mol% MgO; And 0-5 mol% CaO, wherein 66 mol% ≦ SiO ₂ + B ₂ O ₃ + CaO ≦ 69 mol%; Na ₂ O + K ₂ O + B ₂ O ₃ + MgO + CaO + SrO> 10 mol%; 5 mol% ≦ MgO + CaO + SrO ≦ 8 mol%; (Na ₂ 0 + B ₂ 0 ₃ )-Al ₂ 0 _{3 <} 2 mol%; 2 mol% ≦ Na ₂ O—Al ₂ O ₃ ≦ 6 mol%; And 4 mol% ≦ (Na ₂ O + K ₂ O) −Al ₂ O ₃ ≦ 10 mol%. In a third embodiment, the alkali aluminosilicate glass comprises, consists essentially of or consists of: 50-80 wt% SiO ₂ ; 2-20 wt% Al ₂ O ₃ ; 0-15 wt% B ₂ O ₃ ; 1-20 wt% Na ₂ O; 0-10 wt% Li ₂ O; 0-10 wt% K ₂ O; And 0-5 wt% (MgO + CaO + SrO + BaO); 0-3 wt% (SrO + BaO); And 0-5 wt% (ZrO ₂ + TiO ₂ ), where 0 ≦ (Li ₂ O + K ₂ O) / Na ₂ O ≦ 0.5.

In one specific embodiment, the alkali aluminosilicate glass has the following composition: 66.7 mol% SiO ₂ ; 10.5 mol% Al ₂ O ₃ ; 0.64 mol% B ₂ O ₃ ; 13.8 mol% Na ₂ O; 2.06 mol% K ₂ O; 5.50 mol% MgO; 0.46 mol% CaO; 0.01 mol% ZrO ₂ ; 0.34 mol% As ₂ O ₃ ; And 0.007 mol% Fe ₂ O ₃ . In another specific embodiment, the alkali aluminosilicate glass has the following composition: 66.4 mol% SiO ₂ ; 10.3 mol% Al ₂ O ₃ ; 0.60 mol% B ₂ O ₃ ; 4.0 mol% Na ₂ O; 2.10 mol% K ₂ O; 5.76 mol% MgO; 0.58 mol% CaO; 0.01 mol% ZrO ₂ ; 0.21 mol% SnO ₂ ; And 0.007 mol% Fe ₂ O ₃ .

In some embodiments the alkali aluminosilicate glass is substantially free of lithium, while in other embodiments the alkali aluminosilicate glass is substantially free of at least one of arsenic, antimony and barium. In some embodiments, the glass article is down drawn using known methods such as, but not limited to, fusion-drawing, slot-drawing, leading drawing, and the like.

A non-limiting example of such alkali aluminosilicate glass is described in US Patent Application 11/11 by Adam J. Ellison et al., Entitled “Down-Drawable, Chemically Strengthened Glass for Cover Plate,” filed July 31, 2007. United States of the same name, filed on May 22, 2007, filed on 888,213, claims priority from patent application 60 / 930,808; US patent application 12 / 277,573 by Matthew J. Dejneka et al., Entitled "Glasses Having Improved Toughness and Scratch Resistance," filed November 25, 2008, of the same name filed on November 29, 2007. United States claims priority from patent application 61 / 004,677; US patent application 12 / 392,577 filed on Feb. 25, 2009 by Matthew J. Dejneka et al., Entitled “Fining Agent for silicate Glasses”, filed on Feb. 26, 2008, US Provisional Patent Application 61 / Claim priority from 067,130; US patent application 12 / 393,241 filed on Feb. 26, 2009 by Matthew J. Dejneka et al., Entitled "Ion-Exchanged, Fast Cooled Glasses", filed Feb. 29, 2008 Claim priority of application 61 / 067,732; US patent application 12 / 537,393 filed by Kristen L. Barefoot et al. Entitled “Strengthened Glass Articles and Methods of Making” filed on Aug. 7, 2009, which filed “Chemically Tempered Cover,” filed Aug. 8, 2008. United States, entitled "Glass", claims priority over patent application 61 / 087,324; United States Provisional Patent Application 61 / 235,767 to Kristen L. Barefoot et al., Entitled "Crack and Scratch Resistant Glass and Enclosures Made Therefrom," filed August 21, 2009; And US Provisional Patent Application 61 / 235,762 to Matthew J. Dejneka et al., Entitled “Zircon Compatible Glasses for Down Draw”, filed Aug. 21, 2009; The contents of which are incorporated herein by reference.

The glass article or substrate is chemically or thermally strengthened prior to forming the rough glass substrate surface described herein. In one embodiment, the glass article is reinforced before or after being cut or separated from the "mother sheet" of the glass. The strengthened glass article has a strengthened surface layer that extends from the first and second surfaces to the depth of the layer below each surface. The reinforced surface layer is under compressive stress, while the central region of the glass article is under tension or tensile stress and balances the forces in the glass. In thermal strengthening (also referred to as "thermal tempering"), the glass article is heated to a temperature above the strain point of the glass but below the softening point of the glass and rapidly cooled to a temperature below the strain point to form a strengthened layer on the surface of the glass. do. In yet another embodiment, the glass article may be chemically strengthened by a method known as ion exchange. In this method, ions in the surface layer of glass are exchanged or replaced with larger ions having the same valence or oxidation state. In some embodiments the glass article comprises, consists essentially of, or consists of alkali aluminosilicate glass, the ions and larger ions in the surface layer of the glass are alkali metal cations such as Li ⁺ (present in the glass), Na ⁺ , K ⁺ , Rb ⁺ and Cs ⁺ . In addition, monovalent cations in the surface layer may be replaced by monovalent cations other than alkali metal cations, for example Ag ⁺ .

Ion exchange methods generally include immersing a glass article in a molten salt bath containing larger ions to exchange them for smaller ions in the glass. Variables by ion exchange methods include, but are not limited to, additional steps such as bath composition and temperature, immersion time, number of immersions of glass in salt baths (or baths), use of complex salt baths, annealing, cleaning, etc. What is not generally determined by the compressive stress of the glass achieved by the strengthening operation and the desired depth of the layer and the composition of the glass. As an example, ion exchange of alkali metal containing glass can be accomplished by immersion in at least one molten salt bath containing, but not limited to, salts such as nitrates, sulfates and hydrochlorides of larger alkali metal ions. The temperature of the molten salt bath is generally in the range of 380 ° C to 450 ° C and the immersion time in the range of 15 minutes to 16 hours. However, other temperatures and immersion times than those described above may be used. This ion exchange treatment generally strengthens alkali aluminosilicate glass having a layer depth of about 10 μm to at least 50 μm with a compressive stress in the range of 200 MPa to 800 Mpa and a central tension of less than about 100 MPa.

Non-limiting examples of ion exchange methods are provided in the above-described U.S. Patent Application and U.S. Patent Application. In addition, a non-limiting example of an ion exchange method in which glass is immersed in a complex ion exchange bath by rinsing and / or annealing steps between immersions is described in Douglas C. Allan et al. US Patent Application No. 12 / 500,650 entitled "Compressive Surface for Consumer Applications," which claims priority from US Patent Application No. 61 / 079,995, filed Jul. 11, 2008, wherein the glass is combined, continuous in salt baths of different concentrations. Enhanced by immersion in ion exchange treatment; US patent application 12 / 510,599 by Christopher M. Lee et al. Entitled “Dual Stage Ion Exchange for Chemical Strengthening of Glass” filed on July 28, 2009, which filed on July 29, 2008. Of the United States claim priority from patent application 61 / 084,398, wherein the glass is strengthened by ion exchange in a first bath diluted with release ions and then immersed in a second bath with a lower emission ion concentration than the first bath. Let's do it. The contents of US provisional patent applications Nos 12 / 500,650 and 12 / 510,599 are incorporated herein by reference.

The glass substrates described herein include protective covers, including but not limited to display and touch applications, such as portable communication and entertainment devices such as telephones, music players, video players, and the like; And a display screen of an information related terminal (IT) (eg, portable or laptop computer) device; It can also be used in other applications.

General embodiments have been described for the purpose of illustration and the description is not intended to limit the disclosure or the accompanying claims. Accordingly, various modifications, adjustments, and alternatives may occur to those skilled in the art without departing from the scope and spirit of the disclosure or the accompanying claims of the invention.

Claims

A glass substrate having at least one side that is fingerprint resistant and resistant to light transmission and to mechanical and chemical friction.

The glass substrate of claim 1, wherein less than 2 mg of the natural material of the human finger has moved to the surface per finger contact.

The glass substrate of claim 1, wherein the area coverage by droplets moved to the surface per finger contact is less than 20% of the total area of the glass substrate surface that the finger is in contact with.

The glass substrate of claim 1, wherein the substrate has a transmittance of greater than 70%.

The glass substrate of claim 1, wherein the substrate has a haze of less than 80%.

The glass substrate of claim 1, wherein the surface has a gloss greater than 60% measured at an angle of 60 °.

The glass substrate of claim 1, wherein the contact angle of the oil at the surface of the substrate after 50 wipings is within 20% of an initial value of the contact angle of the oil.

The glass substrate of claim 1, wherein the surface has a contact angle of water within 20% of an initial value of the contact angle of water at the surface after 50 wipes.

The method of claim 1, wherein the at least one face comprises at least one set of topological features having topological features of average dimension, the topological features being concave to prevent a reduction in contact angle of the droplets including at least one of water and fatty secreting oil. It has a geometry, The glass substrate characterized by the above-mentioned.

The method of claim 9, wherein the surface has a solid-liquid interface fraction f and the topological feature has a roughness factor r _f , and It is a glass substrate characterized by the above-mentioned.

The method of claim 10, wherein the glass substrate

It is a glass substrate characterized by the above-mentioned.

The method of claim 10, wherein the glass substrate

It is a glass substrate characterized by the above-mentioned.

10. The glass substrate of claim 9, wherein at least some of the topological features are arranged at an angle of less than 80 degrees with respect to the surface formed by the surface.

The glass substrate of claim 9, wherein the root mean square amplitude of the topological features is between 1 nm and 2 μm.

10. The glass substrate of claim 9, wherein the topology feature is oriented.

The glass substrate of claim 9, wherein the topological features comprise a plurality of sets of topological features, each set having a topological feature of an average dimension that is different from the average dimension of the topological features in another set.

The glass substrate according to claim 9, wherein the average dimension is in a range of 50 nm to 2 μm.

The glass substrate of claim 1, wherein the surface further comprises at least one of a fluoropolymer and a fluorosilane coating.

Having at least one face that is hydrophobic and oily, wherein the at least one face comprises at least one set of topologies having topological features of average dimension, the topological features being capable of reducing the contact angle of the droplets including at least one of water and fatty secreting oil. A glass substrate having a concave geometry prevented.

The glass substrate of claim 19, wherein the average dimension is in the range of 50 nm to 2 μm.

20. The glass substrate of claim 19, wherein the glass substrate comprises a plurality of sets of topological features, each set having a topological feature of an average dimension that is different from the average dimension of the topological features in another set.

The glass substrate of claim 16, wherein the plurality of sets of topological features include at least one of the following:
a. A first level of topology features, wherein the topology features have an average dimension of 2 μm or less;
b. A second level of topology features, wherein at the second level, the topology features are less than the average dimension of the first set of topology features and have an average dimension in the range of about 1 nm to about 1 μm; And
c. Third level of topology feature, wherein at the third level the topology feature has an average dimension in the range of about 70 pm to about 300 pm.

23. The glass substrate of claim 22, wherein the top level topological features comprise sandblasted portions of the surface.

23. The glass substrate of claim 22, wherein the top level topological feature comprises a patterning film deposited on the surface and the patterning film comprises an inorganic oxide.

The glass substrate of claim 24, wherein the inorganic oxide comprises at least one of tin oxide, zinc oxide, ceria, alumina, zirconia, and combinations thereof.

The glass substrate of claim 22, wherein the average dimension of the topological features of the first level ranges from about 1 μm to about 50 μm.

The glass substrate of claim 22, wherein the second level topological feature comprises an etched film, the etched film comprising an inorganic oxide.

The glass substrate of claim 27, wherein the inorganic oxide comprises at least one of tin oxide, zinc oxide, ceria, alumina, zirconia, and combinations thereof.

The glass substrate of claim 19, wherein the third level of topological features comprise at least one of a fluoropolymer and a fluorosilane.

20. The glass substrate of claim 1 or 19, wherein the glass substrate comprises one of alkali aluminosilicate and soda lime glass.

31. The glass substrate of claim 30, wherein the alkali aluminosilicate glass is strengthened by ion exchange.

The glass substrate of claim 30, wherein the alkali aluminosilicate glass comprises one of the following:
a. 60-72 mol% SiO ₂ ; 9-16 mol% Al ₂ O ₃ ; 5-12 mol% B ₂ O ₃ ; 8-16 mol% Na ₂ O; And 0-4 mol% K ₂ O, where

Wherein the alkali metal modifier is an alkali metal oxide;
b. 61-75 mol% SiO ₂ ; 7-15 mol% Al ₂ O ₃ ; 0-12 mol% B ₂ O ₃ ; 9-21 mol% Na ₂ O; 0-4 mol% K ₂ O; 0-7 mol% MgO; And 0-3 mol% CaO; And
c. 60-70 mol% SiO ₂ ; 6-14 mol% Al ₂ O ₃ ; 0-15 mol% B ₂ O ₃ ; 0-15 mol% Li ₂ O; 0-20 mol% Na ₂ O; 0-10 mol% K ₂ O; 0-8 mol% MgO; 0-10 mol% CaO; 0-5 mol% ZrO ₂ ; 0-1 mol% SnO ₂ ; 0-1 mol% CeO ₂ ; Less than 50 ppm As ₂ O ₃ ; And less than 50 ppm Sb ₂ O ₃ ego; Wherein 12 mol% ≦ Li ₂ O + Na ₂ O + K ₂ O ≦ 20 mol% and 0 mol% ≦ MgO + CaO ≦ 10 mol%.

The glass substrate of claim 19, wherein after 100 wipes, the surface of the glass substrate has at least one of a contact angle of water and an oleic acid contact angle greater than 90 °.

The glass substrate of claim 19, wherein the glass substrate has a haze of less than 10% after 100 wipes.

The glass substrate of claim 19, wherein the glass substrate has anti-fingerprint properties.

20. The glass substrate of claim 19, wherein the glass substrate is one of a protective cover glass and a touch screen for at least one of a portable electronic device, an information-related terminal, and a touch sensor device.

A method of making a glass substrate that is fingerprint resistant and has a surface of hydrophobicity and oil firing, comprising the following steps:
a. Providing a transparent glass substrate; And
b. Form at least one set of topological features on at least one side of the glass substrate, the at least one set having topological features of average dimension, wherein the topological features reduce contact angle reduction of droplets including at least one of water and fatty secreting oil Preventing concave geometry.

38. The method of claim 37, wherein at least one set of topology features on at least one side of the glass substrate comprises forming a plurality of sets of topology features on the at least one side, each set having an average dimension of another set of topology features. And having topological features of different average dimensions.

The method of claim 38, wherein forming a plurality of sets of topology features on the surface comprises forming a first surface topology on the surface, the first surface topology having a first average dimension of at least about 2 μm. And a topology feature having the same.

40. The method of claim 39, wherein forming a first surface topology on the surface comprises depositing a metal oxide on the surface by one of physical vapor deposition and chemical vapor deposition.

40. The method of claim 39, wherein forming a first topology on the surface of the glass substrate comprises sandblasting the surface of the glass substrate.

40. The method of claim 39, wherein forming a plurality of sets of topology features on the surface further comprises forming a second surface topology on the surface, wherein the second surface topology is a second smaller than the first average dimension. And a topological feature having an average dimension and in the range of about 1 nm to about 1 μm.

43. The method of claim 42, wherein forming the second surface topology comprises depositing at least one of the metal oxides on the surface by one of physical vapor deposition and chemical vapor deposition.

38. The method of claim 37, wherein forming at least one set of topology features on at least one surface of the glass substrate further comprises forming a third surface topology on the surface, wherein the three surface topology is between about 70 pm and 300. and a topology feature having a third average dimension in the range of pm.

The method of claim 44, wherein at least one of the fluoropolymer and the fluorosilane is deposited on the surface by one of sputtering, spray coating, spin coating and dip coating.