This disclosure relates to glass ribbons, and more particularly to methods and systems for continuous processing of glass ribbons.
Flexible glass substrates can be used in a variety of applications including, for example, display devices (e.g., thin, flexible, and/or curved display devices), touch sensors, photovoltaic devices, and optical products. Such substrates can be processed as individual sheets or as a long ribbons that can be wound to form spools of glass. When the substrates are processed as long ribbons, the substrates typically are passed over various rollers or other mechanisms that support and guide the substrates through various processing apparatus. In some processes, coatings can be applied to the surfaces of the glass substrates. However, the adhesion between the coatings and the glass substrates may not be sufficiently strong to remain intact during processing of the glass substrates or handling of the glass substrates following processing. For example, contact between rollers during processing can cause the coatings to separate from the glass substrates.
Disclosed herein are methods for surface treating a flexible glass ribbon with a coupling agent and rolled glass ribbons formed thereby.
Disclosed herein is a method comprising applying a coupling agent solution to a major surface of a continuously moving glass ribbon to form a coupling agent coated region of the glass ribbon. The glass ribbon comprises a flexible glass ribbon having a thickness of at most about 300 μm. The method comprises heating the coupling agent coated region of the glass ribbon to form a coupling agent treated region of the glass ribbon and winding the glass ribbon onto a collection roll.
Disclosed herein is a method comprising passing a glass ribbon continuously through a coating unit to apply a coupling agent solution to a major surface of the glass ribbon and form a coupling agent coated region of the glass ribbon. The glass ribbon comprises a flexible glass ribbon having a thickness of at most about 300 μm. The method comprises passing the glass ribbon through a heating unit to heat the coupling agent coated region and form a coupling agent treated region of the glass ribbon and winding the glass ribbon onto a collection roll.
Disclosed herein is a glass ribbon comprising a thickness of at most about 300 μm and a major surface. At least a portion of the major surface comprises a coupling agent treated region. Upon forming a polymeric layer on the coupling agent treated region at least five months after forming the coupling agent treated region, the polymeric layer comprises a peel force of at least 200 gf/in.
Additional features and advantages will be set forth in the detailed description which follows, and in part will be readily apparent to those skilled in the art from that description or recognized by practicing the embodiments as described herein, including the detailed description which follows, the claims, as well as the appended drawings.
It is to be understood that both the foregoing general description and the following detailed description are merely exemplary, and are intended to provide an overview or framework to understanding the nature and character of the claims. The accompanying drawings are included to provide a further understanding, and are incorporated in and constitute a part of this specification. The drawings illustrate one or more embodiment(s), and together with the description serve to explain principles and operation of the various embodiments.
Reference will now be made in detail to exemplary embodiments which are illustrated in the accompanying drawings. Whenever possible, the same reference numerals will be used throughout the drawings to refer to the same or like parts. The components in the drawings are not necessarily to scale, emphasis instead being placed upon illustrating the principles of the exemplary embodiments.
In some embodiments, glass ribbon 100 is processed in a continuous manner. For example, glass ribbon 100 comprises a continuously moving glass ribbon. A central region of continuously moving glass ribbon 100 moves continuously in a longitudinal direction 112 (e.g., toward roll 110) through one or more processing units. Such continuous movement of the glass ribbon can enable processing of the central region of the glass ribbon (e.g., prior to winding the central region into the roll) by the one or more processing units. Such processing can include, for example, segmenting, grinding, polishing, cleaning, treating (e.g., surface treating), or depositing a coating (e.g., a resin, an ink, an adhesive, a paint, or another suitable organic or inorganic composition) or component (e.g., a transistor, an electroluminescent layer, or another suitable component) on glass ribbon 100. In some embodiments, after processing, the central region of glass ribbon 100 is wound into roll 110. In some embodiments, the glass ribbon is fed from a roll as described herein. Thus, the processing in a continuous manner comprises roll-to-roll processing. In other embodiments, the glass ribbon is fed from a glass forming unit.
In the embodiment shown in
Although
In some embodiments, system 200 comprises a surface treating unit 220 that can be disposed downstream of forming unit 210 to treat a surface of glass ribbon 100. In the embodiment shown in
Drying unit 224 is configured to heat the coupling agent coated region of glass ribbon 100 to form a coupling agent treated region of the glass ribbon. In such embodiments, the method comprises heating the coupling agent coated region of glass ribbon 100 to form a coupling agent treated region of the glass ribbon. For example, glass ribbon 100 is passed continuously through drying unit 224 to heat the coupling agent coated region and form a coupling agent treated region of the glass ribbon. Heating the coupling agent coated region can drive off at least a portion of the coupling agent solution (e.g., by evaporating at least a portion of a solvent component) to form the coupling agent treated region. Additionally, or alternatively, heating the coupling agent coated region can activate the coupling agent solution (e.g., a silane component) to form the coupling agent treated region. Drying unit 224 comprises a furnace, an oven, a lehr, or another suitable heating unit. Additionally, or alternatively, drying unit 224 heats glass ribbon 100 by convection, radiation, conduction, or another suitable heating process.
In some embodiments, system 200 comprises a spacer application unit 230 that can be disposed downstream of forming unit 210 and/or surface treating unit 220 to apply a spacer to glass ribbon 100. In such embodiments, the method comprises applying a spacer to at least one major surface of glass ribbon 100. In some embodiments, the spacer comprises one or more edge tabs 116. Thus, the method comprises applying an edge tab to an edge region of at least one major surface of glass ribbon 100. In other embodiments, the spacer comprises an interleaf material that is applied to a major surface of the glass ribbon. The interleaf material comprises foam, paper, plastic, or another suitable interleaf material. The interleaf material can be adhered to the glass ribbon (e.g., using an adhesive, static pinning, or another suitable adhesion process) or non-adhered to the glass ribbon. The spacer can help to space adjacent windings from one another when the glass ribbon is wound onto the roll as described herein.
In some embodiments, system 200 comprises a winding unit 240 that can be disposed downstream of forming unit 210, surface treating unit 220, and/or spacer application unit 230 to wind glass ribbon 100 into roll 110. In such embodiments, the method comprises winding glass ribbon 100 onto a collection roll. In some embodiments, the winding step is performed subsequent to the heating step. Thus, winding unit 240 is disposed downstream of drying unit 224 In other embodiments, the winding step is performed prior to the heating step. Thus, the winding unit is disposed between the coating unit and the drying unit. In such embodiments, the glass ribbon wound onto the roll can be placed into the drying unit as part of a batch process as opposed to passing the glass ribbon continuously through the drying unit.
The glass ribbon can be stored on the roll for further processing. Thus, the glass ribbon can be formed, surface treated, and then wound onto a spool that can be used as a supply spool in a roll-to-roll process such as a coating, printing, laminating, or other process. The surface treating unit can modify the surface of the glass ribbon for such further processing. For example, the modified surface of the glass ribbon can enable more effective coating of the glass ribbon (e.g., with a polymeric material) compared to an unmodified surface as described herein.
In some embodiments, the glass ribbon can be formed using a suitable glass forming process and wound onto the supply roll. The glass ribbon then can be unwound from the supply roll, fed through the surface treating unit and the processing unit, and rewound onto the collection roll. Thus, the glass forming process and the glass treating/processing can be separated from one another (e.g., to be performed at different times and/or in different locations). The glass ribbon can be treated in-line with, for example, a coating process, a printing process, a laminating process, or another suitable process as part of a continuous, roll-to-roll process.
In various embodiments, the glass forming unit, the glass feeding unit, the surface treating unit, the processing unit, and/or the winding unit can comprise one or more glass handling devices (e.g., rollers, air bearings, or other suitable handling devices). The handling devices can be configured, for example, to guide, support, and/or tension the glass ribbon as it moves continuously through the system.
A thin glass ribbon or web can be processed at high speed using a continuous process as described herein. For example, the thin glass ribbon or web can be processed using roll-to-roll spooling, where the glass is dispensed from one roll, passes through manufacturing process steps, and then is spooled onto a second roll. The processing can include coating a resin, an ink, an adhesive, a paint, or another suitable organic or inorganic component on the glass. Adhesion of such coatings to the glass can be problematic. In particular, such coatings should have a relatively high adhesion to the glass to survive through the coating process and any downstream processes. If the coating does not adhere to the glass with sufficient strength, the glass can break during processing, which can cause downtime in the operation. Additionally, or alternatively, the coating can delaminate during downstream processes and/or during storage.
Silanes, such as organosilanes, can be used as adhesion promoters for glass. In various embodiments, the coupling agent solution comprises a silane component (e.g., an acryloxy silane, a methacryloxy silane, a mercapto silane, a glycidoxy silane, or combinations thereof) and a solvent (e.g., acetone, ethanol, water, or combinations thereof). In some embodiments, the silane component comprises an alkoxysilane. Additionally, or alternatively, the solvent comprises an alcohol. Additionally, or alternatively, the coupling agent solution comprises about 2% silane in an aqueous or organic solvent (e.g., acetone, ethanol, or combinations thereof). In some embodiments, the silane is acidified with a diluted acid (e.g., acetic acid) to activate the silane by hydrolysis.
In some embodiments, applying the coupling agent solution to the major surface of the continuously moving glass ribbon to form the coupling agent coated region of the glass ribbon comprises applying a layer of the coupling agent solution to the major surface of the continuously moving glass ribbon, and a wet thickness of the layer is about 100 μm to about 200 μm.
Heating the coupling agent coated surface can help to remove the solvent component from the coupling agent solution (e.g., by evaporation) and/or activate the silane component of the coupling agent solution to bond to the glass ribbon. In some embodiments, heating the coupling agent coated region of the glass ribbon to form the coupling agent treated region comprises exposing the coupling agent coated region of the glass ribbon to a heating temperature of about 100° C. to about 120° C. for a heating time of about 5 min to about 15 min. In other embodiments, heating the coupling agent coated region of the glass ribbon to form the coupling agent treated region comprises exposing the coupling agent coated region of the glass ribbon to a first heating temperature of about 90° C. to about 110° C. for a first heating time of about 5 s to about 30 s and subsequently exposing the coupling agent coated region of the glass ribbon to a second heating temperature of about 30° C. to about 50° C. for a second heating time of about 45 s to about 90 s.
In some embodiments, the heating is part of a continuous process as described herein. Thus, the heating time can be determined by the size of the drying unit and the speed of the continuously moving glass ribbon. For example, the heating time can be increased by increasing a length of the drying unit and/or by decreasing the speed of the glass ribbon. Alternatively, the heating time can be decreased by decreasing the length of the drying unit and/or by increasing the speed of the glass ribbon. In some embodiments, the drying unit comprises multiple segments that can be maintained at different temperatures. For example, a first segment is maintained at the first heating temperature and a second segment is maintained at the second heating temperature. Passing the glass ribbon continuously through the drying unit (e.g., through the first segment and subsequently through the second segment) can enable exposing the coupling agent coated region to the first heating temperature and subsequently exposing the coupling agent coated region to the second heating temperature.
In some embodiments, each of the applying step, the heating step, and the winding step is part of a continuous process (e.g., as shown in
Various embodiments will be further clarified by the following examples.
A diluted acetic acid was prepared by mixing one part of glacial acetic acid with 9 parts of deionized (DI) water, on a volume basis. An acidified alcohol was prepared by mixing one part of the diluted acetic acid with 50 parts of ethanol, on a volume basis. Coupling agent solutions having various silane concentrations were prepared by mixing 3-acryloxypropyl trimethoxysilane with the acidified alcohol and stirring for 5 min to 10 min.
Various samples were prepared by casting a layer of the coupling agent solution having a thickness of about 13 μm (0.0005 in) wet onto a glass plate having a thickness of about 150 μm. The glass plate with the coupling agent solution was heat treated at 110° C. for 10 min. The glass plate was not cleaned prior to the silane treatment. An ultraviolet (UV) curable coating was cast on the treated glass plate and cured.
A sample was prepared by casting a layer of a coupling agent solution onto a glass plate as described in Example 1. The silane concentration of the coupling agent solution was 0.05%. The glass plate with the coupling agent solution was heat treated at 100° C. for 12 s and then subsequently heat treated at 40° C. for 1 min. A UV curable coating was cast on the treated glass plate and cured.
The peel force of the UV curable coating was 688 g/in. The heat treatment used in Example 2 was relatively low temperature and relatively short compared to the heat treatment used in Example 1 (110° C. for 10 min). Thus, Example 2 demonstrates that a relatively low temperature and relatively short heat treatment is capable of yielding a sufficient peel force (e.g., at least about 200 g/in).
Various samples were prepared by wiping a coupling agent solution onto a glass plate having a thickness of about 150 μm. The coupling agent solution was 1% acrylate silane in 95% ethanol. The glass plate with the coupling agent solution was heat treated at 110° C. for 10 min.
The samples were stored in a dark storage condition. Periodically, a sample was removed from storage and coated with a UV curable coating. The UV curable coating had a wet laydown thickness of 0.254 mm (0.01 in) and was cured at 1 J/cm2. The coated sample was maintained at ambient temperature (about 25° C.) and 50% relative humidity overnight (about 12 h), and then the peel force of the UV curable coating was measured.
Various samples were prepared by casting UV curable coatings on untreated and treated glass plates and curing the coatings.
It will be apparent to those skilled in the art that various modifications and variations can be made without departing from the spirit or scope of the invention. Accordingly, the invention is not to be restricted except in light of the attached claims and their equivalents.
This application claims the benefit of priority to U.S. Application No. 62/132,841, filed on Mar. 13, 2015, the content of which is incorporated herein by reference in its entirety.
Filing Document | Filing Date | Country | Kind |
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PCT/US16/21645 | 3/10/2016 | WO | 00 |
Number | Date | Country | |
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62132841 | Mar 2015 | US |