WO2017155779A1 - Vacuum glazing pillars for insulated glass units and insulated glass units therefrom - Google Patents

Abstract

The present disclosure relates to pillars useful in the fabrication of insulated glass units, particularly, vacuum glazing, insulated glass units. The invention also relates to insulated glass units containing said pillars. The present disclosure provides a pillar for use in a vacuum insulated glass unit wherein the pillar includes a body comprising (i) a hub region and (ii) a plurality of arms radiating from and integral with the hub region, each arm comprising a neck and a lobe, the neck connecting the lobe to the hub region. The body has a thickness, a first contact surface with first surface area, an opposed second contact surface with a second surface area and at least one sidewalk The first contact surface comprises at least one first structure, integral with the first contact surface, the at least one first structure having a first structure base and a first structure face opposite the base, a thickness and a first structure face surface area.

Description

VACUUM GLAZING PILLARS FOR INSULATED GLASS UNITS AND

INSULATED GLASS UNITS THEREFROM

Technical Field

The present disclosure relates to pillars useful in insulated glass units (IGUs), particularly vacuum glazing, insulated glass units and insulated glass units containing the same

Background

Pillars useful for insulated glass units have been described in, for example, U.S. Pat No. 6,479, 112 and U.S. Pat. Publ. No. 2010/0260950.

Summary

Single pane, glass windows are generally poor thermal insulators and their use in buildings results in significant heat loss for the structure and leads to both higher building maintenance costs, due to higher heating/cooling costs, and higher initial fabrication costs, as the heating/cooling equipment specified for the building must be larger to compensate for the energy losses. Double pane windows, which include two glass panes with major surfaces substantially parallel to one another with a "space" or "gap" there between, are an improvement, as they provide a thermally insulating layer of gas, e.g. air, argon or the like, in the space between the window panes. Further improvement in a window's insulating capability can be achieved if the space between a double pane window is free of gas, i.e. the space is sealed and a vacuum is applied, removing the gas between the window panes. Windows of this type are often referred to as vacuum insulated glass units. However, in these window constructions, particularly in larger windows, which may be found in, for example, commercial structures, the pressure difference between the interior of the window and the exterior of the window may cause the glass panes to bow inward. The bow is undesirable, as it adds undesirable stress to what generally are brittle materials, e.g. glass, and, in extreme cases, the window panes may contact one another, thereby reducing the thermal insulating effect of the evacuated gap. To solve this problem, manufactures have placed an array of small structures, often referred to as pillars, between the glass panels of a double pane window, to prevent the panels from bowing when vacuum is applied. Windows with this array of pillars are referred to as vacuum insulated glazing units. Window structures, including vacuum glazing, have reduce the bow of the glass panels, with the addition of an array of pillars that supports the window panes and prevent the glass panels from bowing inward.

Vacuum glazing offers an improvement with respect to thermal insulation and the bowing of the glass panes is inhibited by the addition of an array of pillars. However, the pillars create an additional problem. The pillars have a higher thermal conductivity than the evacuated space between panes and each pillar creates a path of heat transfer between the two window panes that reduces the thermal insulating capability of the window. As such, it is generally desirable to keep the total pillar surface area in contact with the glass panes small, to reduce the heat transfer increase associated with the pillars. Additionally, for aesthetic reasons, the total surface area of the pillar and the individual pillars themselves are minimized, to minimize disruption of light propagation through the window and to minimize disruption of a viewer's view through the window. As the surface area of the total array of pillars is generally small, the compressive stress transferred to the pillars from the glass panes may be high and the pillars may fracture, crack and/or deform under the applied load. Thus, the pillars must have a suitably high compressive strength so as not to fail under the applied load. Conversely, the compressive stress the glass panes experience may be exacerbated at the edge of a pillar, as the edge, particularly a sharp edge, e.g. about a 90 degree angle between the face of the pillar contacting the glass and a corresponding pillar side-wall, may cause a stress concentration in the glass at the edge of the pillar. Many current pillar designs currently employ a sharp pillar edge and may be prone to cause the glass to fracture due to stress concentration generated by the edges of the pillar.

Overall, as one decrease the size of the pillars and/or the total surface area of the pillar array, to reduce heat transfer, the compressive stress on an individual pillar is increased and there is a greater tendency for the pillars to fail under the high loads. Thus, there is a need for pillars with improved heat transfer characteristics, e.g. lower thermal conductivity, that can withstand the compressive loads. The present disclosure provides new pillar designs that can lower thermal conductivity through the pillar, by reducing the contact area of the pillar with respect to the glass surfaces and/or improving the load bearing capabilities of the pillar and/or reducing stress concentration in the glass panes generated at the pillar edge. Additionally, if the pillar design includes an intricate structure, the design allows for fluid communication with the local environment throughout the pillar structure, preventing the trapping of undesirable gas within the pillar itself.

The present disclosure relates to pillars useful in the fabrication of insulated glass units, particularly, vacuum glazing, insulated glass units. The invention also relates to insulated glass units containing said pillars.

In one embodiment, the present disclosure provides a pillar for use in a vacuum insulated glass unit comprising:

a body comprising:

a hub region; and

a plurality of arms radiating from and integral with the hub region, each arm comprising a neck and a lobe, the neck connecting the lobe to the hub region; wherein the body has a thickness, Tb, a first contact surface with first area Abl, an opposed second contact surface with a second surface area, Ab2 and at least one sidewall, wherein the first contact surface comprises at least one first structure integral with the contact surface, the at least one first structure having a first structure base and a first structure face opposite the base, a thickness Tsl and a first structure face surface area, Asl . In some embodiments, the ratio of Tsl/Tb is between about 0.01 and about 0.6, the ratio of Asl/Abl is between about 0.03 and about 0.95 and/or the largest dimension of the body parallel to the first contact surface is between about 10 microns and about 2000 microns. The at least one first structure may be a plurality of first structures. If a plurality of first structures is used, each of the individual first structures of the plurality of first structures has a first structure face opposite its base, each individual first structure face having a surface area asl . The first structure face surface area, Asl, may then be the sum of the first structure face surface area, asl, of each individual first structure of the plurality of first structures. The opposed second contact surface of the body may further comprise at least one second structure having a second structure base and a second structure face opposite the base, a thickness Ts2 and a second structure face surface area, As2. In some embodiments, the ratio of Ts2/Tb is between about 0.01 and 0.6 and/or the ratio of As2/Ab2 is between about 0.03 and about 0.95. The at least one second stmcture may be a plurality of second structures. If a plurality of second structures is used, each of the individual second structures of the plurality of second structures has a second structure face opposite its base, each individual second structure face having a surface area as2. The second structure face surface area, As2, may then be the sum of the second structure face surface area, as2, of each individual second structure of the plurality of second structures.

Brief Description of the Drawings

FIG. 1 A is a schematic top view of an exemplary pillar according to one exemplary embodiment of the present disclosure.

FIG. IB is a schematic front view of the exemplary pillar of FIG. 1 A according to one exemplary embodiment of the present disclosure.

FIG. 2A is a schematic top view of an exemplary pillar according to one exemplary embodiment of the present disclosure.

FIG. 2B is a schematic perspective view of the exemplary pillar of FIG. 2 A according to one exemplary embodiment of the present disclosure.

FIG. 3 A is a schematic top view of an exemplary pillar according to one exemplary embodiment of the present disclosure.

FIG. 3B is a schematic perspective view of the exemplary pillar of FIG. 3 A according to one exemplary embodiment of the present disclosure.

FIG. 4A is a schematic top view of an exemplary pillar according to one exemplary embodiment of the present disclosure.

FIG. 4B is a schematic perspective view of the exemplary pillar of FIG. 4 A according to one exemplary embodiment of the present disclosure.

FIG. 5A is a schematic top view of an exemplary pillar according to one exemplary embodiment of the present disclosure.

FIG. 5B is a schematic perspective view of the exemplary pillar of FIG. 5 A according to one exemplary embodiment of the present disclosure.

FIG. 6A is a schematic top view of an exemplary pillar according to one exemplary embodiment of the present disclosure.

FIG. 6B is a schematic perspective view of the exemplary pillar of FIG. 6 A according to one exemplary embodiment of the present disclosure. FIG. 7 A is a schematic top view of an exemplary pillar according to one exemplary embodiment of the present disclosure.

FIG. 7B is a schematic perspective view of the exemplary pillar of FIG. 7 A according to one exemplary embodiment of the present disclosure.

FIG. 8A is an exploded perspective view of a vacuum insulated glass unit.

FIG. 8B is a side sectional view of a portion of a vacuum insulated glass unit.

FIG. 9A is an SEM image, top view, of an exemplary pillar according to one exemplary embodiment (Example 1) of the present disclosure.

FIG. 9B is an SEM image, perspective view, of the exemplary pillar of FIG. 9A according to one exemplary embodiment (Example 1) of the present disclosure.

Repeated use of reference characters in the specification and drawings is intended to represent the same or analogous features or elements of the disclosure. The drawings may not be drawn to scale. As used herein, the word "between", as applied to numerical ranges, includes the endpoints of the ranges, unless otherwise specified. The recitation of numerical ranges by endpoints includes all numbers within that range (e.g. 1 to 5 includes 1, 1.5, 2, 2.75, 3, 3.80, 4, and 5) and any range within that range. Unless otherwise indicated, all numbers expressing feature sizes, amounts, and physical properties used in the specification and claims are to be understood as being modified in all instances by the term "about." Accordingly, unless indicated to the contrary, the numerical parameters set forth in the foregoing specification and attached claims are approximations that can vary depending upon the desired properties sought to be obtained by those skilled in the art utilizing the teachings disclosed herein.

It should be understood that numerous other modifications and embodiments can be devised by those skilled in the art, which fall within the scope and spirit of the principles of the disclosure. All scientific and technical terms used herein have meanings commonly used in the art unless otherwise specified. The definitions provided herein are to facilitate understanding of certain terms used frequently herein and are not meant to limit the scope of the present disclosure. As used in this specification and the appended claims, the singular forms "a", "an", and "the" encompass embodiments having plural referents, unless the context clearly dictates otherwise. As used in this specification and the appended claims, the term "or" is generally employed in its sense including "and/or" unless the context clearly dictates otherwise. Throughout this disclosure the phrase "contact area" relates to the surface area of a pillar or pillars designed to be in contact with the surface of another substrate, e.g. glass panels of an insulated glass unit (IGU) or vacuum insulated glass unit (VIGU).

Throughout this disclosure the terms, "insulate", "insulating", "insulation", "insulated" and the like, refer to thermally insulating characteristics, unless otherwise noted.

Throughout this disclosure the term, "rounded" means a smooth, continuous curve having a shape that is at least one of a portion of a circle or a portion of an ellipse.

Throughout this disclosure the term "contact surface" of a pillar refers to a surface of a pillar designed to be adjacent a pane of glass in an IGU or VIGU.

Detailed Description

The present disclosure relates to pillars useful in the fabrication of insulated glass units, particularly, vacuum insulated glass units. The pillars of the present disclosure have reduced contact area which may be achieved by including structures within the contact surface of the pillars. This may lead to reduced thermal conductivity through the pillars and better overall insulating characteristics of a VIGU containing the pillars. The pillars of the present disclosure include a body. The body has a thickness, Tb, a first contact surface with first surface area Abl, an opposed second contact surface with second surface area Ab2 and at least one sidewalk The first contact surface comprises at least one first structure, integral with the first contact surface, the at least one first structure having a first structure base and a first structure face opposite the base, a thickness Tsl and a first structure face surface area, Asl . In some embodiments, the ratio of Tsl/Tb is between about 0.01 and about 0.6, the ratio of Asl/Abl is between about 0.03 and about 0.95 and/or the largest dimension of the body parallel to the first contact surface is between about 10 microns and about 2000 microns.

The at least one first structure may be a plurality of first structures. If a plurality of first structures is used, each of the individual first structures of the plurality of first structures has a first structure face opposite its base, each individual first structure face having a surface area asl . The first structure face surface area, Asl, may then be the sum of the first structure face surface area, asl, of each individual first structure of the plurality of first structures. The opposed second contact surface of the body may further comprise at least one second structure having a second structure base and a second structure face opposite the base, a thickness Ts2 and a second structure face surface area, As2. In some embodiments, the ratio of Ts2/Tb is between about 0.01 and 0.6 and/or the ratio of As2/Ab2 is between about 0.03 and about 0.95. The at least one second structure may be a plurality of second structures. If a plurality of second structures is used, each of the individual second structures of the plurality of second structures has a second structure face opposite its base, each individual second structure face having a surface area as2. The second structure face surface area, As2, may then be the sum of the second structure face surface area, as2, of each individual second structure of the plurality of second structures. A first draft angle, related to an included angle between at least one sidewall and the first contact surface of the body, is defined. In some embodiments, the first draft angle may be between about 90 degrees and 135 degrees. In some embodiments, the largest dimension of the body parallel to the first contact surface may be between about 10 microns and about 2000 microns. Several specific, but non-limiting, embodiments are shown in FIGS. 1 A through 7B and FIGS. 9A and 9B.

Referring now to FIG. 1 A, a schematic top view of an exemplary pillar according to one exemplary embodiment of the present disclosure. FIG. 1A shows pillar 100-1 which includes body 101 (a C-shaped body in this exemplary embodiment), having a first contact surface 110a, with surface area Abl, and an opposed second contact surface 110b, with surface area Ab2 (see FIG. IB) and at least one sidewall 120. First contact surface 110a includes at least one first structure 150a integral with first contact surface 110a. At least one first structure 150a has a first structure face 152a. First surface area Abl represents the projection of the shown major surface of the body and would include the surface area (circular area) of the at least one first structure 150a. At least one first structure 150a has a first structure face surface area, Asl . FIG. IB, a schematic front view of the exemplary pillar of FIG. 1A, shows pillar 100-1 including body 101 having sidewalls 120, first contact surface 110a and second contact surface 110b. Body 101 includes at least one first structure 150a having a first structure base 151a (represented by the imaginary dashed line) and a first structure face 152a opposite the base. In this exemplary embodiment, body 101 includes a plurality of first structures 150a, each first structure includes a first structure base, 151a (represented by the imaginary dashed line) and a first structure face, 152a, opposite the base. Each first structure has a first structure face surface area, asl (FIG. 1A). The surface area Asl (the total surface area of the at least one first structure) may then be the sum of the first structure face surface area, asl, of each individual first structure of the plurality of first structures. A first structure face, e.g. 152a, may be referred to as a distal end. The body has a thickness Tb. Tb may be the maximum distance between first contact surface 110a and second contact surface 110b.

The thickness of the at least one first structure is Tsl . The body may optionally include at least one at least one second structure 150b integral with second contact surface, having a second surface area As2. In this exemplary embodiment, body 101 includes a plurality of second structures 150b, each second structure includes a second structure base, 151b (represented by the imaginary dashed line) and a second structure face, 152b, opposite the base. Each second structure has a second structure face surface area, as2 (not shown, but analogous to asl). The surface area As2 (the total surface area of the at least one second structure) may then be the sum of the second structure face surface area, as2, of each individual second structure of the plurality of second structures. A second structure face, e.g. 152b, may be referred to as a distal end. The thickness of the at least one second structure is Ts2. A first draft angle, al, is defined as the angle between first surface 110a, e.g. a line parallel to first structure face 152a, and at least one sidewall 120. A second draft angle, a2, is defined as the angle between second contact surface 110b (as depicted by the horizontal dashed line extended from second contact surface 110b) and at least one sidewall 120. The first draft angle and the second draft angle may be congruent angles. In the embodiment of FIGS. 1 A and IB, draft angles al and a2 are each about 90 degrees. A dimension, Ld, is defined as the largest dimension of the body parallel to the first contact surface. The interior of the body is in fluid communication with the local environment through the opening, N, in the C-shaped body and/or the open region between the at least one first structure 150a. The body may have an exterior perimeter P, of length Lp.

In some embodiments, the C-shaped body is an annular segment shaped body, as shown in FIGS 1 A and IB. For annular segment shaped bodies of the present disclosure, the annular segment shaped body may include a segment angle theta (Θ). In some embodiments theta is between about 130 degrees and about 355 degrees, between about 140 degrees and about 355 degrees, 150 degrees and about 355 degrees, between about 160 degrees and about 355 degrees, between about 170 degrees and about 355 degrees, between about 180 degrees and about 355 degrees, or even between about 190 degrees and about 355 degrees, from about 310 degrees to about 355 degrees. In some embodiments theta is between about 130 degrees and about 358 degrees, between about 140 degrees and about 358 degrees, 150 degrees and about 358 degrees, between about 160 degrees and about 358 degrees, between about 170 degrees and about 358 degrees, between about 180 degrees and about 358 degrees, or even between about 190 degrees and about 358 degrees, from about 310 degrees to about 358 degrees. Segment angle theta may define the size of opening N. A cord drawn between one end of the C-shaped body and the other end, may also define opening N, e.g. a cord drawn between points PI and P2. In FIG. 1 A, point "C" represents the center point of the circular, annular segment shaped body, Ri represents the interior radius and Re represents the exterior radius.

In another embodiment, the present disclosure provides a pillar for use in a vacuum insulated glass unit comprising: a body comprising: (i) a hub region; and (ii) a plurality of arms radiating from and integral with the hub region, each arm comprising a neck and a lobe, the neck connecting the lobe to the hub region. The body has a thickness, Tb, a first contact surface with first area Abl, an opposed second contact surface with a second surface area, Ab2 and at least one sidewalk The first contact surface comprises at least one first structure integral with the contact surface, the at least one first structure having a first structure base and a first structure face opposite the base, a thickness Tsl and a first structure face surface area, Asl . In some embodiments, the ratio of Tsl/Tb is between about 0.01 and about 0.6, the ratio of Asl/Abl is between about 0.03 and about 0.95 and/or the largest dimension of the body parallel to the first contact surface is between about 10 microns and about 2000 microns. The at least one first structure may be a plurality of first structures. If a plurality of first structures is used, each of the individual first structures of the plurality of first structures has a first structure face opposite its base, each individual first structure face having a surface area asl . The first structure face surface area, Asl, may then be the sum of the first structure face surface area, asl, of each individual first structure of the plurality of first structures. The opposed second contact surface of the body may further comprise at least one second structure having a second structure base and a second structure face opposite the base, a thickness Ts2 and a second structure face surface area, As2. In some embodiments, the ratio of Ts2/Tb is between about 0.01 and 0.6 and/or the ratio of As2/Ab2 is between about 0.03 and about 0.95. The at least one second structure may be a plurality of second structures. If a plurality of second structures is used, each of the individual second structures of the plurality of second structures has a second structure face opposite its base, each individual second structure face having a surface area as2. The second structure face surface area, As2, may then be the sum of the second structure face surface area, as2, of each individual second structure of the plurality of second structures.

Referring now to FIGS. 2A and 2B, a schematic top view and perspective view, respectively, of an exemplary pillar according to one exemplary embodiment of the present disclosure, FIGS. 2A and 2B shows pillar 100-9 comprising a body 101 including a hub region 180 and a plurality of arms 190, radiating from and integral with hub region 180 (three arms in this exemplary embodiment), each arm 190 comprising a neck 192 and a lobe 194, the neck connecting the lobe to the hub region. The body has a thickness, Tb, a first contact surface 110a with first area Abl, an opposed second contact surface 110b with a second surface area, Ab2, and at least one sidewall 120. First contact surface 110a comprises at least one first structure 150a integral with the first contact surface, the at least one first structure 150a having a first structure base 151a (not shown, but similarly defined as the body of FIGS 1 A and IB) and a first structure face 152a opposite the base, a thickness Tsl and a first structure face surface area, Asl . In this exemplary embodiment, at least one first structure 150a is a circular, cylindrical shaped structure, having a thickness significantly less than its diameter. In this exemplary embodiment, at least one first structure 150a includes a plurality of first structures, four first structures, and the sum of their individual areas, asl, would be equal to Asl . In some embodiments, the ratio of Tsl/Tb is between about 0.01 and about 0.6, the ratio of Asl/Abl is between about 0.03 and about 0.95 and/or the largest dimension of the body parallel to the first contact surface is between about 10 microns and about 2000 microns. The at least one first structure 150a may be a plurality of first structures. If a plurality of first structures is used, each of the individual first structures 150a of the plurality of first structures has a first structure face 152a opposite its base 151a, each individual first structure face having a surface area asl . The first structure face surface area, Asl, may then be the sum of the first structure face surface area, asl, of each individual first structure of the plurality of first structures. The opposed second contact surface of the body may further comprise at least one second structure (not shown, but similar to that described in FIGS. 1 A and IB) having a second structure base and a second structure face opposite the base, a thickness Ts2 and a second structure face surface area, As2. In some embodiments, the ratio of Ts2/Tb is between about 0.01 and 0.6 and/or the ratio of As2/Ab2 is between about 0.03 and about 0.95. The at least one second structure may be a plurali