KR102484827B1 - Insulating glass laminate with a non-uniform coating layer and a plurality of gas molecule sealing cavities - Google Patents

Abstract

This disclosure describes an insulating glass laminate that mitigates or prevents heat loss from a heating cavity. The present disclosure also provides a heating device, such as an oven, that includes its insulating glass laminate as a diffuser to shield a functional element. In some embodiments, the insulating glass laminate includes a non-uniform low-conductivity or non-conductive coating layer that forms a chemical bond with the first substrate, the second substrate, and an inner surface of at least one of the substrates. The coating layer may have a thickness of about 0.010 inches or less and forms a pattern that contacts about 30% or less of at least one inner surface of the substrate. The coating layer also forms a plurality of gas molecule sealing cavities between the substrates. Because of the small amount of gas molecules present in each cavity, convective heat transfer between the substrates is minimized, thereby minimizing heat loss through the laminate to the surrounding environment.

Description

Insulating glass laminate with a non-uniform coating layer and a plurality of gas molecule sealing cavities

This disclosure relates to insulating glass laminates.

Glass laminates are used in high temperature applications as windows or sight glasses to view heated cavities. To minimize heat loss from the cavity, the laminate has a plurality of glass panes with gaps therebetween to prevent direct heat transfer from the cavity to the outer glass panes, but convection through the air in the gaps between the glass panes. Due to the heat transfer, the temperature of the outer glass pane still increases so that the heat escapes to the surrounding environment. Thermally insulating coatings have been used to prevent heat loss, but many coatings are inadequate.

An optical diffuser is an element that transmits visible light but minimizes transmission of medium and long wavelength infrared rays. Most light diffusers are not necessarily suitable for insulating functional elements such as LEDs, cameras, lighting assemblies, wiring, sensors and semiconductor components from the high temperatures in residential and commercial ovens and other heating cavities. This is a particular problem for functional elements such as LEDs that are not designed to withstand high temperatures. One technique to insulate the lighting assembly from the high temperatures in the oven is to provide an air gap that cools the lighting assembly by convection. Another technique is to use a heat sink. Another technique is to shield the lighting assembly with lenses coated with a low-e coating. However, these techniques do not necessarily adequately insulate functional elements from high temperatures.

Publication No. 10-2016-0055183 (2016.05.17.)

This disclosure describes an insulating glass laminate that mitigates or prevents heat loss from a heating cavity. In some embodiments, the insulating glass laminate includes a non-uniform low-conductivity or non-conductive coating layer that forms a chemical bond with at least one surface of the substrates, and the coating layer may have a thickness of about 0.010 inches or less. In some embodiments, the non-uniform low-conductivity or non-conductive coating layer forms a plurality of sealed three-dimensional cavities between the substrates, each having a very small volume with a small amount of gas molecules therein. Because of the small amount of gas molecules present in each cavity, convective heat transfer between the substrates is minimized, thereby minimizing heat loss through the laminate to the surrounding environment.

Some prior literature suggests that insulating glass laminates are optimal insulators when gas cavities have a thickness of about 15 mm, with thinner cavities increasing conduction losses and thicker cavities increasing convective losses. This knowledge suggests that reducing the thickness of the cavity will increase conduction losses, but conduction losses do not increase in the present disclosure.

Insulating glass laminates of the present disclosure are used, in one non-limiting example, in high temperature applications such as windows and sight glasses in residential and commercial ovens, and applications with heating cavities that require low heat loss and low temperature of exit windows. It can be. In some embodiments, high temperature applications are above about 175°C.

In one embodiment, the present disclosure provides an insulating laminate comprising: a first glass substrate having an inner surface; a second glass substrate having an inner surface; and a non-uniform low-conductivity or non-conductive coating layer forming a chemical bond with at least one inner surface. The coating layer has a thickness of about 0.010 inch or less and forms a pattern that contacts no more than about 30% of the at least one inner surface. There are a plurality of gas molecule sealed cavities between the substrates.

The present disclosure also relates to light diffusers that insulate functional elements such as LEDs, cameras, lighting assemblies, wiring, sensors and semiconductor components in or near a heating cavity. In some embodiments, the light diffuser includes an insulating glass laminate as described herein. The light diffuser may include an insulating glass laminate disposed between the oven cavity and the functional element to partially or completely insulate the functional element from temperatures within the oven cavity. In some embodiments, one or more components of the laminate are provided with a heat reflective coating to provide additional thermal insulation.

1 shows a portion of a laminate having a plurality of circular cavities formed using a non-uniform coating layer that contacts no more than about 30% of the inner surface of at least one of the substrates.
2 shows a schematic diagram of a laminate of the present disclosure.
3 shows a schematic diagram of an oven using a laminate of the present disclosure to shield functional elements.

This disclosure describes an insulating glass laminate that mitigates or prevents heat loss from a heating cavity. In some embodiments, an insulating glass laminate includes a first glass substrate having an inner surface; a second glass substrate having an inner surface; and a non-uniform low-conductive or non-conductive coating layer forming a chemical bond with the at least one inner surface, the non-uniform low-conductive or non-conductive coating layer having a thickness of less than about 0.010 inch and covering less than or equal to about 30% of the at least one inner surface. A plurality of gas molecule sealing cavities exist between the substrates, forming a contact pattern.

The plurality of gas molecule confinement cavities may include, but is not limited to, about 5 to about 400, about 100 to about 400, or about 5 to 50 cavities per square centimeter of the coating layer in some embodiments. The width of the coating measured between each cavity can be, but is not limited to, less than about 0.5 mm, about 0.01 mm to about 0.5 mm, or about 0.02 mm to about 0.1 mm. The coating layer should prevent the substrates from contacting. One of the uses of the coating layer is to provide a gap between the substrates, trapping gas molecules within a plurality of sealed cavities between the substrates.

In some embodiments, the conductivity of the coating layer is about 5 W/(m·K) or less, or about 3.5 W/(m·K) or less. In some embodiments, the conductivity of the coating layer is lower than the conductivity of the substrate in contact with the coating composition. For purposes of this disclosure, a “low-conductivity” coating layer has a conductivity of about 5 W/(m·K) or less, and a “non-conductive” coating layer has a conductivity of zero or approximately 0 W/(m·K).

The coating layer creates an insulating layer between the substrates to minimize convective flow and reduce heat transfer between the substrates. In some embodiments, the coating layer each includes, in one non-limiting example, a ceramic compound, a glass compound, or a combination thereof, and optionally other compounds, some of which may evaporate upon curing the coating composition to form the coating layer. It is a low-conductivity or non-conductive coating layer formed of a coating composition such as enamel, frit, or a combination thereof. In certain embodiments, the ceramic or glass compound within the coating layer has similar composition and thermal expansion properties compared to the substrate in contact with the coating layer.

1 and 2 show schematic diagrams of a laminate 10 of the present disclosure. Laminate 10 includes a first glass substrate 20 , a second glass substrate 30 and a coating 40 . The coating 40 has a void 45 forming a cavity between the substrates 20 and 30 in the laminate 10 as described above.

The coating composition may include a frit, which is created by rapidly cooling the molten composite material combination and confining the chemical to be prepared as a non-migrating component of glassy solid flakes or granules. It is a mixture of inorganic chemicals. In one non-limiting example, the frit includes all of the chemicals specified below when intentionally manufactured at the time of the frit's creation. The main components are aluminum, antimony, arsenic, barium, bismuth, boron, cadmium, calcium, cerium, chromium, cobalt, copper, gold, iron, lanthanum, lead, lithium, magnesium, manganese, molybdenum, neodymium, nickel, niobium, phosphorus , potassium, silicon, silver, sodium, strontium, tin, titanium, tungsten, vanadium, zinc, zirconium, and combinations of all or part of the oxides, and may also include fluorides of those elements, but are not limited thereto. It doesn't work. The most common frits are bismuth and zinc based frit. The frits may contain pigments added in small proportions for color.

Non-limiting examples of suitable coating compositions are as follows.

Crystalline Silica: 11-15%

Borate: 19-22%

Zinc Oxide: 25-29%

Titanium Dioxide: 32-36%

Manganese compounds: 0-2%

Iron Oxide: 0-2%

Chromium compound: 0-2%

Cobalt compounds: 0-3%

Alumina: 3-6%

Other non-limiting examples of suitable coating compositions are as follows.

Crystalline Silica: 34-38%

Borate: 8-12%

Zinc Oxide: 16-20%

Titanium Dioxide: 5-9%

Manganese compounds: 0-3%

Iron Oxide: 0-3%

Chromium compounds: 11-15%

Copper compound: 8-12%

The non-uniform coating layer may be applied to the substrate by silk screen or any other suitable technique. As shown in Figure 1, the non-uniform layer has voids and does not contact the entire surface of the substrate. The non-uniform coating layer may form a regular or irregular pattern. For example, in the case of a silk screen, the coating composition is sprayed through the screen to form a pattern. The patterned non-uniform coating composition helps form a plurality of gas molecule sealed cavities between the substrates. The coating layer may be transparent or colored. Intermediate layers, additional substrates and additional coating layers may be present, if desired.

The laminate may be formed by chemically bonding the coating layer to at least one of the substrates in any manner known in the art. In a non-limiting example, the laminate includes applying a coating composition to a first substrate, heating the coating composition to adhere the coating composition to the first substrate, depositing a second substrate onto the heated coating composition, and It may be formed by steps comprising firing a heated coating composition to form a chemical bond between at least one of the substrates and the coating layer. In another embodiment, the laminate comprises applying a coating composition to a first substrate, attaching a second substrate onto the coating composition, and firing the coating composition to form a chemical bond between at least one of the substrates and the coating layer. It is formed by steps including In all embodiments, at least one of the coating layer, the first substrate and the second substrate may form a chemical bond with at least one other of them.

The coating layer of this disclosure, at least the coating layer in contact with the substrate, is a pyrolytic coating because it is chemically coated on the substrate by sharing oxygen atoms to form part of a Si-O-X chain. Pyrolytic coatings are "hard" coatings as opposed to "soft" coatings such as paint that mechanically adhere to the substrate. Compared to adhesive coatings, pyrolytic coatings have superior abrasion resistance, are not easily marred, and do not usually require a protective topcoat. The pyrolytic coatings of the present disclosure may be applied in a manner known to those skilled in the art, such as film deposition using a high temperature plasma process or silk screen.

The term "glass" as used herein includes glass and glass-ceramics including, but not limited to, soda lime, borosilicate, lithium aluminosilicate, and combinations thereof. The term “substrate” refers to a platform to which coatings and other elements described herein are applied. The substrate is not limited in its shape. The substrate may be flat, curved, concave or convex, and may also have rectangular, square or other dimensions. In some embodiments, the substrate includes a glass material and has a thickness of about 1 to about 10 mm, or about 2 to 5 mm.

The coating layer is non-uniform because it does not cover the entire surface area of the substrate. Instead, the non-uniform coating layer is distributed in a pattern that helps form a plurality of gas molecule sealing cavities between the substrates. The pattern may include a number of coating segments connected in a grid fashion to enclose a plurality of cavities. Cavities are essentially voids that gas molecules can occupy without substantial movement. The shape of the cavity is not critical. The cavity can be honeycomb shaped, circular, or any other shape that creates a plurality of gas-filled three-dimensional voids between the two substrates and coating segments between the voids. 1 shows a portion of a laminate having a plurality of circular cavities and a non-uniform patterned coating layer that contacts no more than about 30% of the inner surface of at least one of the substrates.

In some embodiments, the coating layer is less than about 0.010 inches thick, less than about 0.005 inches, or less than about 0.001 inches thick. It is desirable to form a coating layer having such a small thickness and to minimize heat transfer by conduction by using a low-conductivity or non-conductive coating composition. In some embodiments, the non-uniform coating layer is distributed over a majority of the substrate and is in contact with no more than about 30% of the inner surface of at least one of the substrates, in contact with no more than about 20% of the inner surface of at least one of the substrates, or on at least one of the substrates. Form a pattern that contacts no more than about 10% of the inner surface (ie, the cavity/void contacts at least about 70%, about 80%, or about 90% of the inner surface of at least one of the substrates). Such a small thickness non-uniform coating helps to create a plurality of sealed three-dimensional cavities each having a very small volume with a small amount of gas molecules therein. Because of the small amount of gas molecules present in each cavity, convective heat transfer between the substrates is minimized, thereby minimizing heat loss through the laminate to the surrounding environment. The cavity essentially acts as an insulator. The gas may be air or an inert gas. In some embodiments, the cavity is a partial vacuum or full vacuum. In other embodiments, it is not a vacuum.

The present disclosure also relates to light diffusers that insulate functional elements such as LEDs, cameras, lighting assemblies, wiring, sensors and semiconductor components in or near a heating cavity. In some embodiments, the light diffuser includes an insulating glass laminate as described herein. The light diffuser may include an insulating glass laminate disposed between the oven cavity and the functional element to partially or completely insulate the functional element from temperatures within the oven cavity. In some embodiments, one or more components of the laminate are provided with a heat reflective coating to provide additional thermal insulation.

Unlike lenses with or without low-e coatings, the insulative laminates disclosed herein are as visually transparent as a window or sight glass because they do not significantly distort the image of the element behind the laminate. As a result, the laminate could be used, for example, as a light diffuser to insulate functional elements in or near an oven while also providing sufficient transparency for visible light, allowing a camera or functional element to view the contents of a cavity through the laminate. can

The light diffuser and functional elements can be placed anywhere, for example behind, to the side or top of the heating cavity. In some embodiments, the light diffuser is positioned such that the light diffuser is located between the center of the oven cavity and the functional element, such as within the perimeter of one of the six sides of the oven cavity in a manner similar to an oven window in the front door of the oven. parallel to the side

3 shows a schematic view of an oven interior 100 comprising a laminate 10 shielding a functional element 50 . In the illustrated embodiment, the laminate 10 is placed adjacent to and flush with one of the sides of the oven interior 100 and shields the functional element 50 from heat. As discussed above, other locations for laminate 10 and functional element 50 are contemplated by the present disclosure.

Although the present disclosure has been described with reference to one or more specific embodiments, those skilled in the art will appreciate that various changes may be made and equivalents may be substituted for elements without departing from the scope of the present disclosure. In addition, numerous modifications may be made to suit a particular situation or material to the teachings of this disclosure without departing from its scope. Accordingly, the present disclosure is not limited to the particular embodiment described as the best mode to be sought for practicing the present disclosure. Ranges disclosed herein include all subranges therebetween.

Claims (15)

As an insulating laminate:
a first glass substrate having an inner surface;
a second glass substrate having an inner surface; and
A non-uniform coating layer between the first glass substrate and the second glass substrate, having a conductivity of 5 W/(m K) or less, and forming a chemical bond with at least one of the inner surfaces.
including,
The coating layer has a thickness of 0.010 inch or less and includes a plurality of segments connected to each other having a plurality of pores,
wherein the inner surface of the first glass substrate, the inner surface of the second glass substrate, the coating layer and the voids form a plurality of sealed cavities between the first and second glass substrates. According to claim 1,
5 to 400 cavities per square centimeter in the coating layer. According to claim 1,
Wherein the width of the coating layer measured between each of the plurality of sealed cavities is from 0.01 to 0.5 mm. According to claim 1,
The thickness of the coating layer is less than 0.005 inches of the insulating laminate. According to claim 1,
The thickness of the coating layer is 0.001 inch or less of the insulating laminate. A method of forming the laminate of claim 1 comprising:
applying a coating composition for forming the coating layer to the first glass substrate;
heating the coating composition to adhere the coating composition to the first glass substrate;
attaching the second glass substrate on the heated coating composition; and
firing the heated coating composition to form the chemical bond;
How to include. A method of forming the laminate of claim 1 comprising:
applying a coating composition for forming the coating layer to the first glass substrate;
attaching the second glass substrate on the coating composition; and
firing the coating composition to form the chemical bond;
How to include. According to claim 1,
Wherein the coating layer is an enamel or frit comprising a ceramic compound, a glass compound or a combination thereof. According to claim 1,
wherein the coating layer is transparent. According to claim 1,
wherein the coating layer has a conductivity lower than that of the first and second glass substrates. According to claim 1,
and wherein no vacuum exists within the cavity. An oven comprising the laminate of claim 1,
Ovens operating at temperatures above 175°C. According to claim 12,
The oven of claim 1 , wherein a window or sight glass of the oven comprises the laminate. As an oven:
light diffuser; and
Functional elements in or near the oven
wherein the light diffuser insulates the functional element, transmits visible light, and minimizes transmission of medium and long wavelength infrared rays;
wherein the light diffuser comprises the laminate of claim 1 . According to claim 14,
wherein the functional element includes an LED, camera, lighting assembly, wiring, sensor, semiconductor component, or combination thereof.

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