KR20210024558A - Continuous method of making glass ribbon and glass article as-drawn therefrom - Google Patents

Abstract

A method for manufacturing a glass ribbon, the method comprising: _{a caster having a width (W cast} ) of about 100 mm to about 5 m and a thickness (t) of about 1 mm to about 500 mm to form a cast glass. flowing into (caster); Cooling the cast glass in the caster to a viscosity of ^{at least 10 8 Poise;} Conveying the cast glass from the caster; Drawing the cast glass from the caster, the drawing comprises heating the cast glass to an average viscosity of less than ^{10 7} Poise and drawing the cast glass into a glass ribbon having a width (W _{ribbon ) less than W cast.} Includes; And thereafter cooling the glass ribbon to ambient temperature. Also, the cast glass is above about 50° C. during the cooling, conveying and drawing steps.

Description

Continuous method of making glass ribbon and glass article as-drawn therefrom

This application claims the benefit of priority to Dutch Patent Application No. 2021322, filed on July 17, 2018, the content of which is dependent on this application and is incorporated herein by reference in its entirety.

The present disclosure relates generally to a method of making a glass ribbon, and more particularly, to a continuous method of making a glass ribbon having high dimensional stability from a glass composition having a relatively low liquidus viscosity.

Conventional methods of making lenses and other optical components from glass compositions with low liquidus viscosity and high refractive index are very expensive due to the low efficiency of use of molten glass resulting from these methods. In general, these methods involve casting the composition into long bars that are much thicker than the final product. In other words, these forming methods produce cast bars that require additional processing to obtain the final product shape and dimensions.

The further processing of these cast bars is often extensive. In particular, the cast bar is then cut into disks. Next, the disc is polished to polish its outer diameter to the outer dimension of the final product lens. The disk is then wire cut to the thickness of the final lens product and then introduced into a significant grinding and polishing step to achieve the required warp and dimensional uniformity of the final product lens. As a result, conventional processes for forming lenses and other optical components from these glass compositions are expensive and the use efficiency of molten glass is low.

According to some aspects of the present disclosure, a method for manufacturing a glass ribbon is provided, the method comprising: a width W _{cast of about 100 mm to about 5 m and a width of about 1 mm to about 5 m to form a cast glass.} Flowing into a caster having a thickness t of 500 mm; Cooling the cast glass in the caster to a viscosity of ^{at least 10 8 Poise;} Conveying the cast glass from the caster; Drawing the cast glass from the caster, the drawing comprises heating the cast glass to an average viscosity of less than ^{10 7} Poise and drawing the cast glass into a glass ribbon having a width (W _{ribbon ) less than W cast.} Includes; And thereafter cooling the glass ribbon to ambient temperature. Also, the cast glass is above about 50° C. during the cooling, conveying and drawing steps.

According to some aspects of the present disclosure, a glass article is provided, the glass article comprising: an unpolished glass ribbon having a thickness of about 1 mm to about 25 mm and a width of 25 mm to about 200 mm. . The glass ribbon is borosilicate glass, aluminoborosilicate glass, aluminosilicate glass, fluorosilicate glass, phosphosilicate glass, fluorophosphate glass, sulfophosphate glass, germanate glass, vanadate glass, phosphate glass and It includes a composition selected from the group consisting of borate glass. In addition, the composition comprises an upper liquidus viscosity of less than ^{5×10 5 Poise.} In addition, the glass ribbon may be cut into a glass wafer having a thickness change of about 0.01 μm to about 50 μm and a warp of about 0.01 μm to about 200 μm.

According to some aspects of the present disclosure, a glass article is provided, the glass article comprising: an unpolished glass wafer having a thickness of about 1 mm to about 25 mm and a width of 100 mm to about 200 mm. The ribbon is a borosilicate glass, aluminoborosilicate glass, aluminosilicate glass, fluorosilicate glass, phosphosilicate glass, fluorophosphate glass, sulfophosphate glass, germanate glass, vanadate glass, phosphate glass and borate. It includes a composition selected from the group consisting of glass. In addition, the composition further comprises an upper liquidus viscosity of less than ^{5×10 5 Poise.} In addition, the glass wafer has a thickness change of about 0.01 μm to about 50 μm and a warp of about 0.01 μm to about 200 μm.

Additional features and advantages will be described in the following detailed description, which is very obvious to those skilled in the art from that description or recognized by practicing the embodiments described herein, including the following detailed description, claims, and accompanying drawings. Will be.

It is to be understood that both the foregoing general description and the following detailed description are intended to describe various embodiments and provide an overview or framework for understanding the nature and nature of the claimed subject matter.

The accompanying drawings are included to provide a further understanding of various embodiments, and are incorporated herein to form a part of the specification. The drawings illustrate various embodiments described herein and together with the description serve to explain the principles and operation of the claimed subject matter.

The following is a description of the drawings in the accompanying drawings. The drawings are not necessarily to scale, and certain features and specific views of the drawings may be scaled or schematically exaggerated for clarity and brevity.
In the drawing:
1 is a schematic diagram of a method of manufacturing a glass ribbon according to an embodiment.
Fig. 2 is a schematic diagram of a device that can be used according to a method of manufacturing a glass ribbon according to an embodiment, in particular a melting device having an orifice, a caster and a heating device.
3A and 3B are schematic diagrams of an overflow forming apparatus having an isopipe for glass flow used in a method of manufacturing a glass ribbon according to an embodiment.
The foregoing summary and the following detailed description of specific inventive techniques will be better understood when read in conjunction with the drawings. The claims are based on the arrangement shown in the drawings and
It should be understood that as a means, not limited. In addition, the appearance shown in the drawings is one of many decorative appearances that can be used to achieve the specified function of the device.

Additional features and advantages will be described in the following detailed description, which will be apparent to those skilled in the art from the above description, or will be recognized by practicing the embodiments as set forth in the following description, claims, and accompanying drawings.

As used herein, the term “and/or” when used in a list of two or more items indicates that any one of the listed items may be used by itself, or any combination of two or more of the listed items may be used. it means. For example, if the composition is described as containing components A, B, and/or C, the composition may contain only A; B only; C only; A combination of A and B; A combination of A and C; A combination of B and C; Or a combination of A, B and C.

In this document, relational terms such as first and second, top and bottom, etc. do not necessarily require or imply an actual relationship or order between the objects or actions, and refer to one object or action as another object or action. It is used only to distinguish it from.

Modifications of the present disclosure will occur to those skilled in the art and to those who make or use the present disclosure. Accordingly, it is understood that the embodiments shown in the drawings and described above are for illustrative purposes only and are not intended to limit the scope of the present disclosure as defined by the following claims, which are interpreted in accordance with the principles of patent law, including the theory of equivalents. .

As used herein, the term “about” means that amounts, sizes, formulations, parameters, and other quantities and properties are not accurate and need not be accurate, but as desired, tolerances, conversion factors, rounding off, measurement errors, etc., and It is meant that it may be approximated and/or greater or less than by reflecting other factors known to those skilled in the art. When the term “about” is used to describe an endpoint of a value or range, it is to be understood that the present disclosure includes the specific value or endpoint referred to. Regardless of whether the end point of a numerical value or range in the specification refers to “about”, the end point of the numerical value or range is modified by two embodiments: “about” and not modified by “about”. It is also intended to include. It will be further understood that the endpoints of each range are important both in relation to the other endpoints and independently of the other endpoints.

The terms “substantially”, “substantially” and variations thereof, as used herein, are intended to indicate that the described feature is the same or nearly identical to the value or description. For example, a “substantially planar” surface refers to a planar or nearly planar surface. Also, "substantially" is intended to indicate that the two values are the same or about the same. In some embodiments, “substantially” can refer to values that are within about 10% of each other, such as within about 5% of each other, or within about 2% of each other.

Directional terms used herein-for example, up, down, right, left, front, back, top, bottom-are made only with reference to the drawings and are not intended to imply an absolute direction.

As used herein, the terms “the” and “a, an” mean “at least one” and should not be limited to “only one” unless explicitly indicated otherwise. Thus, for example, reference to “a component” includes embodiments having two or more such components unless the context clearly dictates otherwise.

As used herein, the terms "upper liquidus viscosity" and "upper liquidus temperature" refer to the respective viscosity and temperature of the glass used in the articles and methods of the present disclosure where the glass forms a crystal-free, uniform melt. do. Also, the terms "upper liquidus viscosity" and "liquidus viscosity" are used interchangeably herein; The terms "upper liquidus temperature" and "liquidus temperature" are also used interchangeably herein.

As also used herein, “lower liquidus viscosity” and “lower liquidus temperature” refer to the viscosity and temperature of each of the glass used in the articles and methods of the present disclosure at which the glass may be sensitive to the growth of one or more crystalline phases. Refers to.

As used herein, the "devitrification zone" of the glass used in the articles and methods of the present disclosure is a temperature range given by the upper liquidus temperature to the lower liquidus temperature, for example, the glass is 0.01 μm. It is the temperature range that experiences crystal growth of more than one crystalline phase per minute.

As used herein, the "average viscosity" of the glass used in the articles and methods of the present disclosure is analyzed over the area of the article during the stated process or method step and as understood by one of ordinary skill in the art of the present disclosure. And the viscosity of the glass, glass ribbon, glass sheet or other article of the present disclosure as measured for a time sufficient to determine the average viscosity value according to the measurement method.

As used herein, the term “continuous” does not require any intermediate and/or post-cooling heat treatment, such as annealing or re-drawing, and is configured to form glass sheets, ribbons, and other articles. ) Refers to the method and process of the present disclosure. In other words, the processes and methods of the present disclosure are arranged to form cut or uncut glass sheets, glass ribbons, and other articles prior to the drawing step.

As used herein, "maximum crystal growth rate" means the maximum growth rate of any crystal phase of the glass used in the articles and methods of the present disclosure within the stated temperature or within the stated temperature range, for example, It is in units of μm/minute. As also used herein, “crystal growth rate” means the rate of growth of any crystalline phase of the glass used in the articles and methods of the present disclosure within the stated temperature or within the stated temperature range, for example, It is in units of μm/minute.

As used herein, a "thickness change" of a glass wafer, glass ribbon, glass sheet, or other article of the present disclosure refers to a mechanical contact caliper or micrometer, or non-contact, to an article having a thickness of at least 1 mm. It is measured by determining the difference between the minimum and maximum thickness of a glass wafer, glass ribbon, glass sheet, or other article by means of a laser gauge.

As used herein, the "warpage" of a glass wafer, glass ribbon, glass sheet, or other article of the present disclosure is measured as the distance between two planes containing the article, minus the average thickness of the article. For glass ribbons, glass sheets, and other glass articles of the present disclosure having a substantially rectangular shape, warpage is measured according to principles understood by one of ordinary skill in the art of the present disclosure. In particular, warpage is evaluated in a circular measurement area with a diameter defined as the outer radius of the wafer minus 5 mm.

As used herein, the “critical cooling rate” of a glass, glass ribbon, glass sheet, or other article of the present disclosure is the melting of multiple samples of the glass, glass sheet, or other article to a glass transition temperature at various, selected cooling rates. It is determined by The sample is then cross-sectioned according to standard cutting and polishing techniques and optical microscopy at 100x to confirm the presence of crystals in the bulk and its free surface (i.e., the top, the exposed surface and the bottom surface with the interface with the crucible, etc.). It is evaluated as. The critical cooling rate corresponds to the sample with the lowest cooling rate in which no crystals appear on the surface and in the bulk.

With reference to the drawings in general, and in particular to FIG. 1, it will be understood that the illustrations are intended to illustrate specific embodiments and are not intended to limit the disclosure to which the claims are appended. The drawings are not necessarily to scale, and specific features and specific views of the drawings may be exaggerated and displayed in scale or schematic form for clarity and conciseness.

Described in the present disclosure is a method of making a glass ribbon, and more specifically, ^{a lens from a glass composition having a relatively low liquidus viscosity (e.g., <5×10 5} Poise) and/or a relatively high refractive index, and It is a continuous method of manufacturing glass ribbons for different optical elements. Glass ribbons produced according to this method have high dimensional stability and low distortion, and are produced with final dimensions similar to the intended final product. Consequently, glass ribbons produced according to the method of the present disclosure require limited post-treatment. As a result, the method of the present disclosure has a significantly lower manufacturing cost compared to conventional glass-forming processes used to manufacture lenses from glass compositions with low liquidus viscosity. In addition, the method of the present disclosure has a significant number of uses of as-melted glass with low waste.

In particular, the method of making the glass ribbon of the present disclosure is continuous in that it does not require any post-production annealing or other post-production heat treatment. The method uses cooling to a temperature above ambient (eg> 50° C.) through the devitrification zone, for example by conveying the cast glass through a caster. After cooling the glass to a temperature above ambient, the method uses an additional drawing step with some re-heating into the devitrification zone. The drawing step produces a glass ribbon with the order of thickness dimensions of the intended one in the final product (eg, a wafer, lens or other optical element having a high index of refraction). In addition, the drawing step is advantageously carried out for a limited period of time at a glass viscosity and temperature that minimizes or eliminates the possibility of devitrification. In addition, the method does not require any post-cooling (i.e. after reaching ambient temperature) heat treatment such as annealing or re-drawing to obtain the final product, e.g., a glass ribbon, wafer, lens or other glass article. It is particularly advantageous in that it does not. Also advantageously, aspects of the method of the present disclosure are glass ribbons, wafers, lenses that do not require any additional mechanical treatment, e.g. polishing, grinding, etc. to meet the level of warpage and/or thickness variation of the optical element. Or other glass articles.

Referring now to FIG. 1, a schematic diagram of a method 100 of manufacturing a glass ribbon 30b is provided. As shown in FIG. 1, the method 100 of making the glass ribbon 30b is to remove the glass 30 from the melting apparatus 10 to form the cast glass 30a from about 200 mm to about 5 m. It is provided to include a step 110 of flowing into a gaster 20 having a width W _cast 22 and a thickness t 24 (see FIG. 2) of at least 1 mm. The method 100 of making the glass ribbon 30b ^{further comprises cooling 120 the cast glass 30a in the caster 20 to a viscosity of at least 10 8} Poise and a temperature of 50° C. or higher. The method 100 of making the glass ribbon 30b also includes a step 130 of conveying the cast glass 30a from the caster 20. In addition, the method 100 for manufacturing the glass ribbon 30b is the ^{cast glass 30a at an average viscosity of less than 10 7} Poise and the width of the cast glass 30a (W _cast ) (22) is less than the width (W _ribbon ). And drawing 140 to a final thickness 24 (t) with a glass ribbon 30b. Further, the drawing step 140 includes heating the cast glass 30a to an average viscosity of less than ^{10 7 Poise.} The method 100 of making the glass ribbon 30b further includes a step 150 of cooling the glass ribbon 30b to ambient temperature.

Regarding the step 110 of flowing the glass shown in FIG. 1, a suitable melting device 10 has a maximum dimension (which is the approximate width of the glass 30 as it leaves the melting device 10 and flows into the caster 20). It is possible to pass the glass 30 through the outlet element 4 with 12). Depending on the viscosity of the glass 30 flowing from the melting apparatus 10, it may have a width that is approximately equal to or less than the maximum dimension 12 of the outlet element 4. According to some embodiments of the method 100 of making the glass ribbon 30b, the maximum dimension 12 of the outlet element 4 is less than or equal to _{the width W cast 22 of the caster 20.} According to some embodiments of the method 100 of making the glass ribbon 30b, the maximum dimension of the outlet element 4 is less than or equal to _{the width W cast 22 of the caster 20.} In another embodiment, the maximum dimension 12 of the outlet element 4 is caster for a composition of glass 30 having a relatively low upper liquidus viscosity (e.g. 5 Poise to 5000 Poise), for example. _{It may be greater} than the width (W cast) of (20) (22). In particular, upon melting these glasses may become'necks' when leaving the outlet element 4 of the melting apparatus 10, which is the maximum dimension 12 of the outlet element 4 of the melting apparatus 10 It allows the flow to a caster 20 with a smaller dimension width 22.

Referring again to the method 100 for manufacturing the glass ribbon 30b shown in FIG. 1, an embodiment of the melting device 10 is an outlet element 4 with an outlet element 4 in the form of an orifice and a glass ( 30) or an overflow forming device serving to dispense the melter. In the latter embodiment, the melting apparatus 10 may comprise a weir that allows the glass 30 to overflow in the form of an isopipe and spread along the outlet element 4 (e.g., FIG. See overflow forming apparatus with isopipes shown in 3a and 3b). In this embodiment, the glass 30 may be spread over one or both of the isopipes. In the former embodiment, the melting device 10 may comprise a melter having an orifice that dispenses the molten glass 30 upon leaving the melting device 10. In addition, those skilled in the art of the present disclosure may configure other melting apparatus 10 suitable for use in the method 100 of making the glass ribbon 30b.

In a specific example of the method 100 for manufacturing the glass ribbon 30b shown in FIG. 1, the glass 30 is a borosilicate glass, aluminoborosilicate glass, aluminosilicate glass, fluorosilicate glass, phosphosilicate. It is derived from glass compositions comprising glass, fluorophosphate glass, sulfophosphate glass, germanate glass, vanadate glass, borate glass, and phosphate glass. According to an embodiment, the glass 30 is derived from any glass composition that exhibits suitable optical properties (eg, transmittance, refractive index, coefficient of thermal expansion, etc.) suitable for lenses and optical components. According to an embodiment, the glass 30 is derived from the following glass composition (referred to herein as “Glass A”): 40.2 mol% SiO ₂ ; 2.4 mol% B ₂ O ₃ ; 11.3 mol% Li ₂ O; 22.9 mol% CaO; 5.4 mol% La ₂ O ₃ ; 3.8 mol% ZrO ₂ ; 4.8 mol% Nb ₂ O ₅ ; And 9.3 mol% TiO ₂ . According to another embodiment, the glass 30 is derived from the following glass composition (referred to herein as “Glass B”): 42.7 mol% SiO ₂ ; 3.9 mol% B ₂ O ₃ ; 4.7 mol% BaO; 26.6 mol% CaO; 4.5 mol% La ₂ O ₃ ; 2.2 mol% ZrO ₂ ; 6.1 mol% Nb ₂ O ₅ ; And 9.3 mol% TiO ₂ .

In some embodiments of the method 100 of making the glass ribbon 30b shown in FIG. 1, the glass 30 has an upper liquidus viscosity of less than ^{5×10 5 Poise.} According to some implementations, the glass 30 is ^{less than 5×10 5} Poise, less than 1×10 ⁵ Poise, less than 5×10 ⁴ Poise, less than 1×10 ⁴ Poise, less than 5×10 ³ Poise, 1×10 ³ Poise. Less than 5×10 ² Poise, less than 100 Poise, less than 50 Poise, less than 40 Poise, less than 30 Poise, less than 20 Poise, less than 10 Poise, and any upper liquidus viscosity between these levels. have. According to some implementations of the method, the upper liquidus viscosity of the glass 30 during step 110 ranges from 5 Poise to about 50000 Poise. Further, in a particular implementation of the method 100, the glass 30 is derived from a glass composition having a refractive index of about 1.5 to about 2.1. In some embodiments, the glass 30 is derived from a glass composition having about 1.6 to about 2.0, about 1.65 to about 1.9, about 1.7 to about 1.85, and all refractive index values between these levels.

Referring back to the flow step 110 of the method 100 for manufacturing the glass ribbon 30b shown in FIG. 1, this step may be performed such that the glass 30 flows at a temperature of 1000° C. or higher. Glass 30 is from about 1000 ℃ to about 1500 ℃, about 1000 ℃ to about 1400 ℃, about 1000 ℃ to about 1300 ℃, about 1000 ℃ to about 1250 ℃, about 1000 ℃ to about 1200 ℃, about 1000 ℃ to about It can flow at temperatures of 1150° C., and all values between these levels. The flow step 110 may be performed such that the glass 30 has a viscosity of less than ^{5×10 4 Poise when flowing from the melting apparatus 10. In some implementations, the glass 30 is less than 5×10 4} Poise, less than 1×10 ⁴ Poise, 5×10 ³ as it leaves the outlet element 4 of the melting device 10 and flows into the caster 20. Less than poise, less than 1×10 ³ poise, less than 5×10 ² poise, less than 100 poise, less than 50 poise, less than 40 poise, less than 30 poise, less than 20 poise, less than 10 poise, and all viscosities between these levels . According to some implementations of the method 100, the glass 30, when leaving the melting apparatus 10, has a viscosity during step 110 ranging from about 10 Poise to about 1000 Poise, or from about 10 Poise to about 50000 Poise. Has.

Referring back to step 110 of the method 100 of manufacturing the glass ribbon 30b shown in FIG. 1, the step is to remove the glass 30 from about 200 mm to about 5 to form the cast glass 30a. _{Flow to a caster 20 having a width W cast} 22 of meters (m) and a thickness t 24 of about 1 mm to about 500 mm (see FIG. 2 ). In some embodiments, the width W _cast 22 of the caster 20 is from about 200 mm to about 5 meters (m), from about 250 mm to about 5 m, from about 300 mm to about 5 m, from about 350 mm to About 5 m, about 400 mm to about 5 m, about 450 mm to about 5 m, about 500 mm to about 5 m, and all width values between these levels. According to some implementations, the width W _cast 22 of the caster 20 is about 200 mm to about 5 m, about 200 mm to about 4 m, about 200 mm to about 3 m, about 200 mm to about 2 m. , About 200 mm to about 1 m, about 200 mm to about 0.9 m, about 200 mm to about 0.8 m, about 200 mm to about 0.7 m, about 200 mm to about 0.6 m, about 200 mm to about 0.5 m, and All width values between these levels. Further, in some embodiments, the thickness (t) 24 (see FIG. 2) of the casters 20 is about 1 mm or more, about 7 mm or more, about 8 mm or more, about 9 mm or more, about 10 mm or more, At least about 15 mm, at least about 20 mm, at least about 25 mm, at least about 30 mm, at least about 35 mm, at least about 40 mm, at least about 45 mm, at least about 50 mm, or up to about 500 mm .

Referring now to step 120 of the method 100 of manufacturing the glass ribbon 30b shown in FIG. 1, this step is to bring the cast glass 30a in the caster 20 to ^{a viscosity of at least 10 8} Poise and 50°C. It is for cooling to the above temperature. As such, the casters 20 may be of various configurations, for example, those with or without additional cooling capabilities, as understood by those of ordinary skill in the present disclosure, which are driven by, for example, the tractor 40. When conveyed in the direction of the arrow indicated in 1, it is possible to cool the glass 30 through its devitrification zone that cools the cast glass 30a to a temperature of 50°C or higher. Step 120 of cooling the cast glass 30a, the maximum growth rate of any crystalline phase is 10 μm from the upper liquidus viscosity of the glass 30a to the lower liquidus viscosity (also referred to herein as the “deficit zone”). It can be done to be less than /min. In some implementations, the step 120 of cooling the cast glass 30a has a maximum growth rate of any crystalline phase of the glass 30 through the devitrification zone is less than 10 μm/min, less than 9 μm/min, 8 μm/min. Less than, less than 7 μm/min, less than 6 μm/min, less than 5 μm/min, less than 4 μm/min, less than 3 μm/min, less than 2 μm/min, less than 1 μm/min, less than 0.5 μm/min, It is carried out to be less than 0.1 μm/min, less than 0.01 μm/min, and all growth rates below and/or between these rates. In particular, the maximum crystal growth rates (V _max ) for the Glass A and Glass B compositions are about 6 to 7 μm/min at 1030° C. and about 2 to 3 μm/min at 1050° C., respectively. Accordingly, an aspect of the method 100 is to perform the cooling step 120 such that the crystal growth rate of the glass 30 when made from a glass A or glass B composition is _{less than these maximum crystal growth rate (V max) values.} Includes.

According to another aspect of the method 100 for manufacturing the glass ribbon 30b shown in FIG. 1, the cooling step 120 includes a predetermined cooling rate above the critical cooling rate for the cast glass 30a. It can be done to cool to a temperature (ie, 50° C. or higher). As used herein, the “critical cooling rate” is determined by melting multiple samples of a given glass composition from various, selected cooling rates to the glass transition temperature. Samples are then sectioned according to standard cutting and polishing techniques and under an optical microscope at 100x to confirm the presence of crystals on the bulk and free surfaces (i.e., top, exposed and bottom surfaces with interfaces with crucibles, etc.). Is evaluated. The critical cooling rate corresponds to the sample with the lowest cooling rate that does not show crystals on its surface and in bulk.

According to an embodiment, the tractor 40 has one or more rollers for controlling the speed of the cast glass 30a when moving through and exiting the caster 20 during each cooling step 120 and the conveying step 130. Includes. Advantageously, the cooling step 120 is carried out in a manner that ensures that the cast glass 30a does not fall below 50° C., so that the method 100 is performed during the subsequent conveying step 130 and the drawing step 140, respectively. It ensures that continuity can be maintained in terms of the additional heating that occurs. In some aspects, the thermal energy remaining in the cast glass 30a after the cooling step 120 is used to re-heat the cast glass 30a from its core toward the surface during the subsequent conveying and drawing steps 130 and 140 respectively Is used.

In some implementations of the method 100 shown in FIG. 1, the temperature during the cooling step 120 is at least 50°C, at least 100°C, at least 150°C, at least 200°C, at least 250°C, at least 300°C, at least 350°C. , 400°C or higher, 450°C or higher, 500°C or higher, and all temperature values between these lower threshold levels. In the implementation of the method 100, the cooling step 120 includes cooling the cast glass 30a in the caster 20 to a temperature of less than 800°C and above 50°C. According to the implementation of the method 100, the flow, cooling, pulling and drawing steps 110 to 140 are such that the cast glass 30a does not reach a temperature of less than 50°C, for example the method 100 ) Is performed in a continuous manner. According to some embodiments of method 100, the step of cooling 120 is that the cast glass 30a in caster 20 is at least 10 ⁸ Poise, at least 5×10 ⁸ Poise, at least 10 ⁹ Poise, at least 5×10 ⁹ Poise, at least 10 ¹⁰ Poise, at least 5×10 ¹⁰ Poise or higher viscosity. In some aspects of the method 100 of making the glass ribbon 30b, the cooling step 120 is performed such that the cast glass 30a is maintained at a temperature of about 650° C. to about 750° C. and a viscosity of ^{at least 10 9 Poise.} .

Referring back to the method 100 of manufacturing the glass ribbon 30b shown in FIG. 1, the method further comprises a conveying step 130 for conveying the cast glass 30a from the caster 20. The transport aspect of step 130 may be influenced in part by the action of tractor 40. In particular, the cast glass 30a may be moved during step 130 or otherwise by the tractor 40 from the end of the caster 20 an optional bank 50 and edge roller 60 of the heater 50. Can be transported towards. If present, heater 50 may include ^{various structures and components for heating cast glass 30a to an average viscosity of less than 10 7} Poise, including heating elements, induction heating elements, infrared heating elements and bones. Including, but not limited to, others understood by one of ordinary skill in the art of the disclosure. In some embodiments, the aspect of heating the cast glass 30a to ^{an average viscosity of less than 10 7} Poise does not impart any additional thermal energy to the cast glass 30a. For example, the drawing step 140 may be performed such that the core of the cast glass 30a heats the surface of the cast glass 30a at least partially to an average viscosity of less than ^{10 7 Poise.}

In addition, the drawing step 140 of drawing the cast glass 30a includes the cast glass 30a with a width 22 (W _cast ) or less _{of the caster 20 with a width 32 (W ribbon} ) and a cast glass 30a. It is performed to draw into a glass ribbon 30b having a final thickness t that is less than or equal to the thickness t of 24 (see Fig. 2). In some aspects, the width 32 (W _ribbon ) of the glass ribbon 30b is about 10 mm to about 5 mm, about 20 mm to about 5 mm, about 30 mm to about 5 mm, about 40 mm to about 5 mm. , About 50 mm to about 5 mm, about 100 mm to about 5 mm, about 200 mm to about 5 mm, about 250 mm to about 5 mm, about 300 mm to about 5 mm, about 350 mm to about 5 mm, about 400 mm to about 5 mm, and all width values between these levels. The perspective of the step 140 of drawing the cast glass 30a into the ribbon 30b can be partially influenced by the action of the edge roller 60 shown in FIG. 1.

In addition, the drawing step 140 of drawing the cast glass 30a includes the cast glass 30a with a width 22 (W _cast ) or less _{of the caster 20 with a width 32 (W ribbon} ) and a cast glass 30a. It is performed to draw into a glass ribbon 30b having a final thickness (t) 34 that is less than or equal to the thickness (t) 24 of. In some aspects, the width 32 (W _ribbon ) of the glass ribbon 30b is about 10 mm to about 5 mm, about 20 mm to about 5 mm, about 30 mm to about 5 mm, about 40 mm to about 5 mm. , About 50 mm to about 5 mm, about 100 mm to about 5 mm, about 200 mm to about 5 mm, about 250 mm to about 5 mm, about 300 mm to about 5 mm, about 350 mm to about 5 mm, about 400 mm to about 5 mm, and all width values between these levels. The perspective of the step 140 of drawing the cast glass 30a into the ribbon 30b may be partially influenced by the action of the edge roller 60 shown in FIG. 1.

According to some implementations of the method 100 of making the glass ribbon 30b, the drawing step 140 may be carried out for 30 minutes or less (i.e., the step 120 for cooling the cast glass 30a and the cast glass 30a). After step 130 for, and before the subsequent step 150 for cooling the glass ribbon 30b to ambient temperature), it is performed on the cast glass 30a. It should be understood that according to method 100, cast glass 30a is at a temperature of about 50° C. or higher during each of steps 110-140. In some implementations, draw step 140 is less than these upper threshold periods while maintaining periods of 30 minutes or less, 25 minutes or less, 20 minutes or less, 15 minutes or less, 10 minutes or less, 5 minutes or less, and at least 30 seconds. It can be done for any period. As mentioned above, the aspect of the method 100 of making the glass ribbon 30b is that the temperature and/or time during the drawing step 140 advantageously causes the cast glass 30a to undergo any or very little crystallization. Without experiencing it, keeping the cast glass 30a at a sufficiently low viscosity to affect the drawing point of this stage-i.e., keeping the cast glass 30a at a width that is less than the width 22 of the cast glass 30a ( 32) is performed to ensure that it is deformed into a glass ribbon 30b.

According to some embodiments of the method 100 of manufacturing the glass ribbon 30b shown in FIG. 1, the conveying step 130 and the drawing step 140 have cast glass 30a ^{less than 10 7} Poise, 5×10 ^{Less than 6} Poise, less than 10 ⁶ Poise, less than 5×10 ⁵ Poise, less than 10 ⁵ Poise, less than 5×10 ⁴ Poise, while maintaining all average viscosities between these levels, exceeding ^{10 4 Poise.} In some implementations of the method 100, the average viscosity of the cast glass 30a is maintained ^{between 10 6} Poise and 10 ⁴ Poise at a temperature of 750° C. to 900° C. during conveying step 130 and drawing step 140.

Referring back to the method 100 of manufacturing the glass ribbon 30b shown in FIG. 1, the final cooling step 150 of the method may include cooling the glass ribbon 30b to ambient temperature. As previously mentioned, an embodiment of the method 100 is performed such that the glass 30 and the cast glass 30a are maintained at a temperature of 50° C. or higher during steps 110 to 140, so that the method 100 is continuous. It is guaranteed that it can be done in a way. According to some embodiments of the method 100, steps 110 to 140 include at least 50°C, at least 75°C, at least 100°C, at least 150°C, at least 200°C, at least 250°C, at least 300°C, and at these temperatures. It is carried out at temperatures of all lower temperature thresholds between the lower limits. Further, the step 150 for cooling the glass ribbon 30b may be performed with or without external cooling, as will be understood by those skilled in the art of the present disclosure. Also, in some aspects of the method 100, the edge roller 60 may include a cooling capability that affects some or all of the cooling in the cooling step 150.

Referring back to the method 100 of manufacturing the glass ribbon 30b shown in FIG. 1, an embodiment of the method 100 is performed such that the glass ribbon 30b has a thickness change of less than 200 μm. According to some embodiments, the glass ribbon 30b is less than 200 μm, less than 150 μm, less than 100 μm, less than 75 μm, less than 50 μm, less than 40 μm, less than 30 μm, less than 20 μm, less than 10 μm, 5 μm It can have less than, less than 4 μm, less than 3 μm, less than 2 μm, less than 1 μm, less than 0.5 μm, and all thickness variation levels between these levels. From a practical point of view, the glass ribbon 30b manufactured according to the method 100 may have a thickness change as low as 0.01 μm. In some implementations of method 100, the glass ribbon 30b made by method 100 has a warp of less than 500 μm. According to some implementations, the glass ribbon 30b produced by the method 100 is less than 500 μm, less than 400 μm, less than 300 μm, less than 200 μm, less than 150 μm, less than 100 μm, less than 50 μm, less than 40 μm. , Less than 30 μm, less than 20 μm, less than 10 μm, less than 5 μm, less than 0.1 μm, greater than 0.05 μm, and all warpage values between these levels. From a practical point of view, the glass ribbon 30b manufactured according to the method 100 may have a warp as low as 0.01 μm. In addition, some embodiments of method 100 are performed such that the glass ribbon 30b has a surface roughness Ra of less than 5 μm (as measured prior to any post-treatment). According to some implementations, the glass ribbon 30b produced by the method 100 is less than 5 μm, less than 4 μm, less than 3 μm, less than 2 μm, less than 1 μm, less than 0.75 μm, less than 0.5 μm, less than 0.25 μm. , Has a surface roughness (Ra) of less than 0.1 μm, less than 50 nm, as low as 10 nm, and all surface roughness values between these levels. According to an embodiment, the glass ribbon 30b produced by the method 100 is less than 1 μm, less than 0.9 μm, less than 0.8 μm, less than 0.7 μm, less than 0.6 μm, less than 0.5 μm, less than 0.4 μm, less than 0.3 μm , Less than 0.2 μm, less than 0.1 μm, less than 90 nm, less than 80 nm, less than 70 nm, less than 60 nm, less than 50 nm, less than 40 nm, less than 30 nm, less than 20 nm, at least 10 nm, and between these levels It has the surface roughness (Ra) of all surface roughness values.

Turning now to FIG. 2, a schematic diagram of an apparatus that may be used in accordance with a method 100 of manufacturing a glass ribbon 30b (see FIG. 1) according to the present disclosure is provided. In particular, FIG. 2 shows a melting apparatus having an orifice 4a, a caster 20 and a heater 50, among other features. In all other respects, the apparatus shown in FIG. 2 is the same or substantially similar to the apparatus shown in FIG. 1 for use with a method 100 of making a glass ribbon 30b (see FIG. 1 and the previous description). . Thus, like-numbered elements in FIG. 2 have the same or substantially similar functions and structures as shown in FIG. 1. Thus, according to an embodiment of the method 100 (see FIG. 1 ), the flow step 110 is a melting apparatus 10a (FIG. 2) having a maximum dimension 12 of less than 5 meters (m) of the glass 30. Reference) can be carried out by flowing from the orifice 4a. The maximum dimension 12 of the orifice 4a may be less than or equal to _{the width W cast of the caster 20.} Further, the width 14 of the orifice 4a is about 1 mm or more, about 2 mm or more, about 3 mm or more, about 4 mm or more, about 5 mm or more, about 7 mm or more, about 8 mm or more, about 9 mm Or more, about 10 mm or more, about 15 mm or more, about 20 mm or more, about 25 mm or more, about 30 mm or more, about 35 mm or more, about 40 mm or more, about 45 mm or more, about 50 mm or more, or about 500 It can be any width up to mm.

Referring back to Fig. 2, depending on the viscosity of the glass 30 flowing from the melting device 10a during the flow step 110 (see Fig. 1), the glass 30 is approximately equal to the maximum dimension of the orifice 4a. Or, it can have a smaller width. As such, the maximum dimension 12 of the orifice 4a may be less than or equal to _{the width (W cast) 22 of the caster 20.} In another embodiment, the maximum dimension 12 of the orifice 4a is, for example, the caster 20 for a composition of glass 30 having a relatively low upper liquidus viscosity (e.g., 5 Poise to 50000 Poise). ) Can be larger than the width (W _{cast ).} In particular, upon melting, these glasses may be'necked' when leaving the orifice 4a of the melting device 10a, which means that they have a width that is less than the maximum dimension 12 of the orifice 4a of the melting device 10a. To flow into the caster 20 with 22.

Also, as shown in Figure 2, the glass ribbon 30b is _{substantially equal to the width 32 (W ribbon} ) of the glass ribbon 30b to about 50% of the width 32 of the glass ribbon 30b. It can be cut into a wafer 36 having an outer diameter of. In an embodiment, the step of cutting the wafer 36 from the glass ribbon 30b may be performed after the cooling step 150 of the method 100 mentioned above and illustrated in FIG. 1. The wafer 36 shown in the exemplary form in FIG. 2 is in the form of a disk. Nevertheless, the wafer 36 may take a variety of shapes including, but not limited to, square, rectangular, circle, ellipse, and other shapes. According to some embodiments, the wafer 36 may have a thickness 34(t) of about 2 mm or less and a maximum dimension (e.g., diameter, width, or other maximum dimension) of about 100 mm to about 500 mm. have. In some aspects, the wafer 36 has a thickness 34(t) of about 1 mm or less and a maximum dimension of 150 mm to about 300 mm. Wafer 36 also has a thickness in the range of about 1 mm to about 50 mm, or about 1 mm to about 25 mm. Wafer 36 may also have a maximum dimension ranging from about 25 mm to about 300 mm, from about 50 mm to about 250 mm, from about 50 mm to about 200 mm, or from about 100 mm to about 200 mm. Advantageously, without any additional surface polishing, the wafer 36 formed according to the method 100 may exhibit the same level of thickness change, surface roughness and/or warpage as previously mentioned with respect to the glass ribbon 30b. . In embodiments, the wafer 36 may be subjected to some limited grinding and polishing of its outer diameter to obtain the final dimensions of the final product, eg, a lens for optical applications.

Referring now to FIGS. 3A and 3B, a schematic diagram of an overflow melting apparatus 10b having an isopipe 8 for flowing the glass 30 used in the method of manufacturing the glass ribbon 30b (see FIG. 1). Is provided according to an embodiment. In particular, the overflow melting apparatus 10b may be used during the flow step 110 of the glass 30. According to an embodiment, the glass 30 may be melted according to the melting point of the method 100 and may flow from the vessel 6 to the isopipe 8. The vessel 6 contains any of a variety of heating elements understood by one of ordinary skill in the art for melting of glass. When the glass 30 overflows from the weir or similar perspective of the isopipe 8, it flows over the isopipe 8 and down into the caster 20 (not shown). As shown in exemplary form in FIGS. 3A and 3B, the overflow melting apparatus 10b may include a weir in the isopipe 8, which allows the glass 30 to cover the outer surface of the isopipe 8. Overflow and let it spread along. In this embodiment, the glass 30 may be spread across one side or both sides of the isopipe 8 in a width 4b. 3A and 3B, the isopipe 8 has one side angled by an angle 9 from the vertical. Typically, the angle 9 is between about 0° and 30°, preferably between 0° and 20°. According to an embodiment of the method 100 of manufacturing the glass ribbon 30b (see FIG. 1 ), the overflow melting device 10b has a width 4b of less than 5 m, which is the width of the caster 20 ( 22)(W _cast ) or less.

While exemplary embodiments and examples have been presented for purposes of illustration, the foregoing description is not intended to limit the scope of the disclosure and appended claims in any way. Accordingly, changes and modifications may be made to the above-described embodiments and embodiments without substantially departing from the spirit and various principles of the present disclosure. All such modifications and changes are intended to be included within the scope of this disclosure and protected by the following claims.

Claims (28)

As a method for manufacturing a glass ribbon, the method comprises:
_{Flowing the glass into a caster having a width (W cast} ) of about 100 mm to about 5 m and a thickness (t) of about 1 mm to about 500 mm to form a cast glass;
Cooling the cast glass in the caster to a viscosity of ^{at least 10 8 Poise;}
Conveying the cast glass from the caster;
Drawing the cast glass from the caster, the drawing comprises heating the cast glass to an average viscosity of less than ^{10 7} Poise and drawing the cast glass into a glass ribbon having a width (W _{ribbon ) less than W cast.} Includes; And after
Cooling the glass ribbon to ambient temperature,
Wherein the cast glass is at least about 50° C. during the cooling, conveying and drawing steps. The method according to claim 1,
Wherein said flowing step comprises flowing the glass at a viscosity of about 50,000 Poise to about 10 Poise. The method according to any one of the preceding claims,
The method for manufacturing a glass ribbon, wherein the cast glass is at least about 200° C. during the cooling, conveying and drawing steps. The method according to any one of the preceding claims,
The method for manufacturing a glass ribbon, characterized in that the step of cooling the cast glass is ^{carried out such that the cast glass in the caster is cooled to a viscosity of at least 10 9 Poise.} The method according to any one of the preceding claims,
The drawing step is performed such that the cast glass is heated to an average viscosity of less than ^{10 6 Poise.} The method according to any one of the preceding claims,
The method for making a glass ribbon, characterized in that the glass comprises an upper liquidus viscosity of less than 5×10 ^{5 Poise.} The method according to any one of the preceding claims,
The glass is borosilicate glass, aluminoborosilicate glass, aluminosilicate glass, fluorosilicate glass, phosphosilicate glass, fluorophosphate glass, sulfophosphate glass, germanate glass, vanadate glass, borate glass, and A method for producing a glass ribbon comprising a composition selected from the group consisting of phosphate glasses. The method according to any one of the preceding claims,
The flowing step includes flowing the glass at a temperature of 1000° C. or higher, and cooling the cast glass comprises cooling the cast glass in the caster to a temperature of less than 800° C. and 50° C. or higher. A method for making a glass ribbon. The method according to any one of the preceding claims,
_Wherein the width (W cast) is from about 400 mm to about 5 m and the thickness (t) is from about 5 mm to about 500 mm. The method according to any one of the preceding claims,
The drawing step is performed on the cast glass for about 30 seconds to about 30 minutes after the step of cooling the cast glass. The method according to any one of the preceding claims,
Wherein the drawing is performed such that the core of the cast glass at least partially heats the surface of the cast glass to an average viscosity of less than ^{10 7 Poise.} The method according to any one of the preceding claims,
The method for manufacturing a glass ribbon, wherein the glass ribbon has a thickness variation of about 0.01 μm to about 50 μm. The method according to any one of the preceding claims,
Wherein the glass ribbon has a warp of about 0.01 μm to about 100 μm. The method according to any one of the preceding claims,
The flow step is performed by flowing the glass from an orifice of a melting apparatus having a width of about 100 mm to about 5 mm, and the width of the orifice is less than or equal to _{the width of the caster (W cast ).} Way. The method of claim 14,
The method for manufacturing a glass ribbon, characterized in that the melting device is an overflow forming device. The method according to any one of the preceding claims,
A method for making a glass ribbon, wherein the maximum crystal growth rate of any crystalline phase of the cast glass is from about 0.01 μm/min to about 10 μm/min during the cooling, conveying and drawing steps of the cast glass. The method according to any one of claims 1 to 15,
A method for manufacturing a glass ribbon, wherein the maximum crystal growth rate of any crystalline phase of the cast glass is from about 0.01 μm/min to about 5 μm/min during the cooling, conveying and drawing steps of the cast glass. The method of claim 7,
The composition of the glass further comprises a crystal growth rate of any crystalline phase of about 0.01 μm/min to less than 1 μm/min, as measured from the upper liquidus temperature to the lower liquidus temperature of the cast glass. A method for manufacturing a ribbon. The method according to any one of claims 16 to 18,
The method for manufacturing a glass ribbon, wherein the glass ribbon has a thickness variation of about 0.01 μm to about 50 μm. The method according to any one of claims 16 to 19,
The method for manufacturing a glass ribbon, wherein the glass ribbon has a warp of about 0.01 μm to about 100 μm. The method according to any one of claims 16 to 20,
The method for manufacturing a glass ribbon, characterized in that the step of cooling the cast glass is performed to cool the cast glass to a temperature above a critical cooling rate for the cast glass. As a glass article, the glass article comprises:
An unpolished glass ribbon having a thickness of about 1 mm to about 25 mm and a width of 25 mm to about 200 mm,
Here, the glass ribbon is borosilicate glass, aluminoborosilicate glass, aluminosilicate glass, fluorosilicate glass, phosphosilicate glass, fluorophosphate glass, sulfophosphate glass, germanate glass, vanadate glass, phosphate glass And a composition selected from the group consisting of borate glass,
Wherein the composition further comprises an upper liquidus viscosity of less than ^{5×10 5 Poise,}
Wherein the glass ribbon can be cut into a glass wafer having a thickness change of about 0.01 μm to about 50 μm and a warp of about 0.01 μm to about 200 μm. The method of claim 22,
Wherein the glass ribbon has an index of refraction of about 1.65 to about 1.90. The method of claim 22 or 23,
Wherein the glass ribbon can be cut into a glass wafer having a thickness change of about 0.01 μm to about 0.5 μm and a warp of about 0.01 μm to about 10 μm. The method according to any one of claims 22 to 24,
The glass article, wherein the glass ribbon has a thickness change of about 0.01 μm to about 50 μm and a warp of about 0.01 μm to about 200 μm. As a glass article, the glass article comprises:
An unpolished glass wafer having a thickness of about 1 mm to about 25 mm and a width of 100 mm to about 200 mm,
Here, the glass wafer is borosilicate glass, aluminoborosilicate glass, aluminosilicate glass, fluorosilicate glass, phosphosilicate glass, fluorophosphate glass, sulfophosphate glass, germanate glass, vanadate glass, phosphate glass And a composition selected from the group consisting of borate glass,
Wherein the composition further comprises an upper liquidus viscosity of less than ^{5×10 5 Poise,}
Wherein the glass wafer has a thickness change of about 0.01 μm to about 50 μm and a warp of about 0.01 μm to about 200 μm. The method of claim 26,
Wherein the glass wafer has a refractive index of about 1.65 to about 1.90. The method of claim 26 or 27,
The glass article, wherein the glass wafer has a thickness change of about 0.01 μm to about 0.5 μm and a warp of about 0.01 μm to about 10 μm.

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