阅读说明：本技术 玻璃制品 (glass product ) 是由 T·D·派克 R·M·布洛吉特 于 2019-05-31 设计创作，主要内容包括：本发明涉及玻璃制品,其包括：第一最外面的窗格玻璃、与所述第一最外面的窗格玻璃相对设置的第二最外面的窗格玻璃和设置在所述第一最外面的窗格玻璃和第二最外面的窗格玻璃之间的透明中间层。所述第一最外面的窗格玻璃具有1.1-4.0mm的厚度,并且具有第一玻璃化转变温度。所述第二最外面的窗格玻璃具有0.3-1.05mm的厚度,并且具有第二玻璃化转变温度。所述第二最外面的窗格玻璃的所述第二玻璃化转变温度比所述第一最外面的窗格玻璃的所述第一玻璃化转变温度高1-40℃。(The present invention relates to a glass article comprising: a first outermost glass pane, a second outermost glass pane disposed opposite the first outermost glass pane, and a transparent interlayer disposed between the first outermost glass pane and the second outermost glass pane. The first outermost pane has a thickness of 1.1-4.0mm and has a first glass transition temperature. The second outermost pane has a thickness of 0.3-1.05mm and has a second glass transition temperature. The second glass transition temperature of the second outermost glass pane is 1-40 ℃ higher than the first glass transition temperature of the first outermost glass pane.)

1. A glass article comprising:

A. A first outermost pane comprising soda lime glass having a thickness of 1.1-4.0mm and a first glass transition temperature;

B. A second outermost glass pane comprising soda lime glass and/or aluminosilicate glass disposed opposite the first outermost glass pane, having a thickness of 0.3-1.05mm and a second glass transition temperature; and

C. A transparent interlayer disposed between the first outermost glass pane and the second outermost glass pane;

Wherein the second glass transition temperature of the second outermost glass pane is 1-40 ℃ higher than the first glass transition temperature of the first outermost glass pane.

2. The glass article of claim 1, wherein the second glass transition temperature of the second outermost glass pane is 5-10 ℃ higher than the first glass transition temperature of the first outermost glass pane.

3. The glass article of claim 1, wherein the first glass transition temperature is 535-554 ℃ and the second glass transition temperature is 550-590 ℃.

4. The glass article of any of claims 1 to 3, wherein the soda lime glass of the first outermost pane and/or the second outermost pane each independently comprises SiO ₂ in an amount of 65-75 wt%, Al ₂ O ₃ in an amount of 0-3 wt%, CaO in an amount of 5-15 wt%, MgO in an amount of 0-10 wt%, Na ₂ O in an amount of 5-15 wt%, and K ₂ O in an amount of 0-5 wt%, wherein the total amount of Na ₂ O and K ₂ O is 10-15 wt%, each based on the total weight of the soda lime glass.

5. A glass article according to any one of claims 1 to 3, wherein the second outermost pane comprises an aluminosilicate glass comprising SiO ₂ in an amount of 60 to 70 wt%, B ₂ O ₃ in an amount of 0 to 5 wt%, Al ₂ O ₃ in an amount of 1 to 15 wt%, P ₂ O ₅ in an amount of 0 to 5 wt%, Li ₂ O in an amount of 0 to 5 wt%, Na ₂ O in an amount of 12 to 18 wt%, K ₂ O in an amount of 0 to 5 wt%, MgO in an amount of 5 to 12 wt%, CaO in an amount of 0 to 10 wt%, SrO in an amount of 0 to 5 wt%, BaO in an amount of 0 to 5 wt%, ZnO in an amount of 0 to 5 wt%, ZrO 4 in an amount of 0 to 5 wt%, TiO ₂ in an amount of 0 to 5 wt%, SnO in an amount of 0 to 24 wt%, based on the total weight of the aluminosilicate glass and SnO, the glass.

6. The glass article of any of claims 1 to 3, having a transverse bend dimension of 0.1-50mm and a radius of curvature of 0-50000mm, as determined by LP-150F-C conductive plastic linear sensor and 5200 spring-loaded probe, respectively.

7. The glass article of any of claims 1 to 3, wherein the first outermost glass pane is soda lime glass.

8. The glass article of any of claims 1 to 3, wherein the first outermost glass pane has a thickness of 1.6-2.4mm, and wherein the second outermost glass pane has a thickness of 0.5-0.75 mm.

9. The glass article of any of claims 1 to 3, wherein the second outermost glass pane is soda lime glass.

10. the glass article of any of claims 1 to 3, wherein the second outermost glass pane is an aluminosilicate glass.

11. A glass article according to any of claims 1 to 3, wherein the second outermost glass pane is a composite of soda lime glass and aluminosilicate glass.

12. A glass article as set forth in any one of claims 1-3 further defined as a windshield.

13. A glass article according to any of claims 1 to 3, wherein each of the first and second outermost glass panes is curved.

14. The glass article of any of claims 1 to 3, wherein the transparent interlayer is in direct contact with the first and second outermost glass panes.

15. A method of forming a glass article, the method comprising the steps of:

A. Forming a first glass pane of soda lime glass by a float process, wherein the first glass pane has a thickness of 1.1-4.0mm and a first glass transition temperature,

B. forming a second glass pane of soda lime glass and/or aluminosilicate glass by float process, wherein the second glass pane has a thickness of 0.3-1.05mm and a second glass transition temperature,

C. Cutting a first blank from the first glass pane and a second blank from the second glass pane, wherein each blank has a length and a first glass transition temperature and a second glass transition temperature, respectively;

D. Forming the first and second blanks into a desired shape;

E. Providing an intermediate layer;

F. combining a first shaped blank, an interlayer, and a second shaped blank to form a glass article comprising: a first outermost glass pane having a thickness of 1.1-4.0mm and the first glass transition temperature; a second outermost glass pane disposed opposite the first outermost glass pane having a thickness of 0.3-1.05mm and the second glass transition temperature; and the interlayer disposed between the first outermost glass pane and a second outermost glass pane, wherein the second glass transition temperature of the second outermost glass pane is 1-40 ℃ higher than the first glass transition temperature of the first outermost glass pane.

16. The method of claim 15, wherein the second glass transition temperature of the second outermost glass pane is 5-10 ℃ higher than the first glass transition temperature of the first outermost glass pane.

17. The method of claim 15 or 16 further comprising the step of simultaneously heating each of the first and second shaped blanks to a preselected temperature.

18. A method as set forth in claim 15 or 16 wherein the step of combining is further defined as laminating such that the intermediate layer is further defined as a transparent intermediate layer.

19. The method of claim 15 or 16, wherein the first outermost glass pane is soda lime glass.

20. The method according to claim 15 or 16, wherein the first outermost glass pane has a thickness of 1.6-2.4mm, and wherein the second outermost glass pane has a thickness of 0.5-0.75 mm.

21. The method of claim 15 or 16, wherein the second outermost pane is a soda lime glass, an aluminosilicate glass, or a composite of soda lime glass and aluminosilicate glass.

22. The method of claim 15 or 16, wherein the intermediate layer is in direct contact with the first and second outermost glass panes.

Technical Field

the present disclosure generally relates to glass articles having a first outermost glass pane and a second outermost glass pane, wherein the second outermost glass pane has a glass transition temperature that is 1-40 ℃ higher than the first glass transition temperature of the first outermost glass pane, which results in the formation of a quality glass article.

Background

It is known to manufacture windshields by laminating a first ply of glass, a plastic interlayer and a second ply of glass. The glass layer used in this process was ground and polished flat glass, which was excellently free from distortion (distortion) before 1960. Recently, float glass having a thickness of 1.1 to 4mm is generally used for the first layer and the second layer. Float glass is produced by a process as described in U.S. Pat. nos. 3,083,551 and 3,700,542. While such float glass may be useful in making excellent windshields, it may deform when heated in a manner that is undesirable for certain applications.

The glass transition temperature of soda lime glass is about 530 to 560 ℃. If the glass is heated above this temperature, the glass may deform and/or shrink, thereby changing dimensions and becoming unusable. This is especially true when a continuous furnace, such as a belt furnace, is used. This type of furnace can lead to temperature differences between the sides of the individual glass panes or between the individual glass panes in the furnace. For example, if two glass panes are to be used for the manufacture of a windscreen, the temperature difference may lead to physical asymmetry when they are placed in an oven for bending. This is particularly evident in panes of glass having different thicknesses or compositions and may result in areas having optical and physical anomalies. In some cases, these anomalies can be severe enough to cause quality control checks of the glass to fail. Thus, there remains an opportunity for improvement.

Disclosure of Invention

The present disclosure provides a glass article comprising: a first outermost glass pane, a second outermost glass pane disposed opposite the first outermost glass pane, and a transparent interlayer disposed between the first and second outermost glass panes. The first outermost pane comprises soda lime glass, has a thickness of 1.1-4.0mm, and has a first glass transition temperature. The second outermost pane comprises soda lime glass and/or aluminosilicate glass, has a thickness of 0.3-1.0mm, and has a second glass transition temperature. The second glass transition temperature of the second outermost glass pane is 1-40 ℃ higher than the first glass transition temperature of the first outermost glass pane.

Drawings

Other advantages of the present disclosure will be readily appreciated as the same becomes better understood by reference to the following detailed description when considered in connection with the accompanying drawings. This patent or application document contains at least one drawing executed in color. Copies of this patent or patent application publication with color drawing(s) will be provided by the office upon request and payment of the necessary fee.

Figure 1 is a process diagram illustrating the movement of glass panes moving through a series of furnaces.

Fig. 2 is a side view of a glass article comprising a first outermost glass pane, a second outermost glass pane, and a transparent interlayer: each being curved and complementary in shape to each other.

Fig. 3 is an exploded view of the glass article of fig. 2, including thicknesses t ₁, t ₂, and t ₃.

figure 4a is a color table listing the results described in the examples.

fig. 4b is a grayscale version of the table of fig. 4 a.

Detailed Description

The present disclosure provides a glass article 10 having a first outermost glass pane 12, a second outermost glass pane 14, and an intermediate layer 16, for example as shown in fig. 2 and 3. The type, configuration, or design of the glass article 10 is not particularly limited, except as described herein. For example, the glass article 10 is typically a windshield, such as for an automobile, truck, train, boat, airplane, and the like. Most typically, the glass article 10 is a front windshield of an automobile.

Alternatively, one or both outermost glass panes 12, 14 may be described as layers or sheets. The term "outermost" describes that the first and second outermost glass panes 12, 14 are disposed on the outside of the article 10 and do not have any other layers on top of themselves. In other words, these outermost glass panes 12, 14 face the environment and are the outermost portions of the article 10. The first and second outermost glass panes 12, 14 may alternatively be described as top and bottom glass panes, outside glass panes, front and back glass panes, or exterior glass panes. Typically, the first outermost pane 12 of the article 10, if an automotive windshield, faces the exterior of the automobile, while the second outermost pane 14 faces the interior of the automobile. Thus, in some embodiments, the first and second outermost glass panes 12, 14 may instead be described as the out-of-plane and in-plane panes of an automotive windshield, respectively.

The first and second outermost glass panes 12, 14 may have any shape and size. Typically, the first and second outermost glass panes 12, 14 are complementary in shape. In one embodiment, the first and second outermost glass panes 12, 14 are each curved. The first and second outermost glass panes 12, 14 may each independently have a transverse bend (cross) of 0.1 to 100mm at the center. Alternatively, the first and second outermost glass panes 12, 14 may each independently have a transverse curvature of 0.1 to 50mm at the center. The first and second outermost glass panes 12, 14 may also each independently have a radius of curvature of 0 to 100000 mm. Alternatively, the first and second outermost glass panes 12, 14 may also each independently have a radius of curvature of 0 to 50000 mm. In other embodiments, all values and value ranges including and between those described above are explicitly contemplated. The lateral curvature and radius of curvature at the center can be determined using a CMM table or any other suitable 3D physical measurement device. For example, a LP-150F-C Conductive Plastic Linear Sensor (Conductive Plastic Linear Sensor) manufactured by Green Pot can be used to determine lateral bending, and a 5200 Spring loaded probe (Spring loaded probes) manufactured by Linear Measurement Instruments (LMI), Corp.

The thickness (t ₁) of the first outermost pane 12 is 1.1-4.0mm, for example as shown in fig. 3. in various embodiments, the thickness (t ₁) is 1.1, 1.15, 1.2, 1.25, 1.3, 1.35, 1.4, 1.45, 1.5, 1.55, 1.6, 1.65, 1.7, 1.75, 1.8, 1.85, 1.9, 1.95, 2.0, 2.05, 2.1, 2.15, 2.2, 2.25, 2.3, 2.35, 2.4, 2.45, 2.5, 2.55, 2.6, 2.65, 2.7, 2.75, 2.8, 2.85, 2.9, 2.95, 3.0, 3.05, 3.1, 3.15, 3.2, 3.25, 3.7, 3.75, 3.8, 2.85, 2.9, 2.95, 3.0, 3.05, 3.1, 3.15, 3.25, 3.5, 3.75, 3.85, 3.5, 3.0, 3.5.

The second outermost glass pane 14 is generally described as an ultra-thin glass (UTG) and has a thickness (t ₂) of 0.3 to 1.5mm, e.g., as shown in fig. 3, in various embodiments the thickness (t ₂) is 0.3, 0.35, 0.4, 0.45, 0.5, 0.55, 0.6, 0.65, 0.7, 0.75, 0.8, 0.85, 0.9, 0.95, 1.0, or 1.05mm in other embodiments all values and value ranges including and between those described above.

The first and second outermost glass panes 12, 14 may have the same or different chemical compositions. For example, as understood in the art, the first and second outermost glass panes 12, 14 can independently be, include, consist essentially of, or consist of soda lime glass. The term "consisting essentially of describes embodiments in which the soda lime glass is free of elements, reactants, compounds, or additives of other types of glass recognized in the art (e.g., aluminosilicate glass). In various embodiments, the article 10 and/or the first and second outermost glass panes 12, 14 as a whole are free of aluminosilicate glass, ground glass, sheet glass, and the like.

In various embodiments, the first and/or second outermost glass panes 12, 14 comprise, are, consist essentially of, or consist of soda lime glass having the following composition:

Compound (I)	Embodiment 1	Embodiment 2
			SiO2	60 to 80% by weight	65 to 75% by weight
Al2O3	0 to 5% by weight	0 to 3% by weight
			CaO	5 to 20% by weight	5 to 15% by weight
MgO	0 to 15% by weight	0 to 10% by weight
			Na2O	5 to 20% by weight	5 to 15% by weight
K2O	0 to 8% by weight	0 to 5% by weight
			Na2O and K2O total	10 to 20% by weight	10 to 15% by weight

In other embodiments, all values and value ranges including and between those described above are explicitly contemplated. For example, all integer values and fractional values to the tenth of a digit (e.g., 0.1, 1.1, etc.) between those described above are expressly contemplated herein in various non-limiting embodiments.

In further embodiments, the first and/or second outermost glass pane 12, 14 comprises, is, consists essentially of, or consists of a soda lime glass having the following elements:

Element(s)	Embodiment 3	Embodiment 4
			Oxygen gas	45 to 55% by weight	48 to 54% by weight
Sodium salt	0 to 7% by weight	0 to 5% by weight
			Magnesium alloy	0 to 7% by weight	0 to 5% by weight
Aluminium	0 to 5% by weight	0 to 3% by weight
			Silicon	20 to 40% by weight	25 to 35% by weight
Potassium salt	0 to 15% by weight	5 to 15% by weight
			Calcium carbonate	3 to 10% by weight	3 to 7% by weight

In other embodiments, all values and value ranges including and between those described above are explicitly contemplated. For example, all integer values and fractional values to the tenth of a digit (e.g., 0.1, 1.1, etc.) between those described above are expressly contemplated herein in various non-limiting embodiments.

in still other embodiments, the second outermost glass pane 14 comprises, is, consists essentially of, or consists of an aluminosilicate glass having a composition of:

In further embodiments, the second outermost glass pane 14 comprises, is, consists essentially of, or consists of an aluminosilicate glass having the following composition:

in other embodiments, all values and value ranges including and between those described above are explicitly contemplated. For example, all integer values and fractional values to the tenth of a digit (e.g., 0.1, 1.1, etc.) between those described above are expressly contemplated herein in various non-limiting embodiments.

In still further embodiments, the second outermost glass pane 14 comprises, is, consists essentially of, or consists of an aluminosilicate glass having the following composition:

Element(s)	Embodiment 15	Embodiment 16
			Oxygen gas	45 to 55% by weight	48 to 54% by weight
Sodium salt	0 to 7% by weight	0 to 5% by weight
			Magnesium alloy	0 to 7% by weight	0 to 5% by weight
Aluminium	1 to 5% by weight	1 to 3% by weight
			Silicon	20 to 40% by weight	25 to 35% by weight
Potassium salt	0 to 15% by weight	5 to 15% by weight
			Calcium carbonate	0 to 5% by weight	0 to 3% by weight

In other embodiments, all values and value ranges including and between those described above are explicitly contemplated. For example, all integer values and fractional values to the tenth of a digit (e.g., 0.1, 1.1, etc.) between those described above are expressly contemplated herein in various non-limiting embodiments.

In a further embodiment, the first outermost glass pane 12 is soda lime glass including Al ₂ O ₃: 0 to 2.0 wt%, and Na ₂ O and K ₂ O combined: 13.0 to 15.5 wt%, while the second outermost glass pane is soda lime glass including Al ₂ O ₃: 0 to 3.5 wt%, and Na ₂ O and K ₂ O combined: 12.0 to 14.5 wt%, in another embodiment, the first outermost glass is soda lime glass including SiO ₂: 68.0 to 75.0 wt%, Al ₂ O ₃: 0 to 2.0 wt%, CaO: 7.0 to 13.0 wt%, MgO: 0 to 7.0 wt%, Na ₂ O: 12.0 to 15.0 wt%, K ₂ O: 0 to 3.0 wt%, and Na 5O and K ₂ O combined: 13.0 to 15.5 wt%, while the second outermost glass pane 12.0 to 15.0 wt%, and all other outermost glass panes include values such as specified in the above ranges of 0.5% to 15.5% Na 7.5O, 9 wt%, 27% to 15.5% and K9 wt%, including those specified in the above ranges of values of Na 630 to 15.5O 27% and K27O, including 0 to 7.0% by wt%, and 10.5% by wt%, including ranges of the stated values for example, 2% and 10.0 to 7.0 to 15.0 to 7.0% of the ranges of the total of the values of the ranges of the values for all of the values of the ranges specified above are included between 0 to 7.0% O3.5O and 3.0 to 7.0 wt%, including 0 wt%, and 7.0 to 7.0 wt%, and 3.0 wt%, including the values of the ranges of the values of the ranges of the values of the ranges.

In still other embodiments, the soda lime glass of the first outermost pane and/or the second outermost pane 12, 14 each independently comprises SiO ₂ in an amount of 65 to 75 wt.%, Al ₂ O ₃ in an amount of 0 to 3 wt.%, CaO in an amount of 5 to 15 wt.%, MgO in an amount of 0 to 10 wt.%, Na ₂ O in an amount of 5 to 15 wt.%, and K ₂ O in an amount of 0 to 5 wt.%, wherein the total amount of Na ₂ O and K ₂ O is 10 to 15 wt.%, each based on the total weight of the soda lime glass.

If the second outermost pane 14 comprises an aluminosilicate glass, and also in a separate embodiment, the aluminosilicate glass may comprise SiO ₂ in an amount of 60-70 wt%, B ₂ O ₃ in an amount of 0-5 wt%, Al ₂ O ₃ in an amount of 1-15 wt%, P ₂ O ₅ in an amount of 0-5 wt%, Li ₂ O in an amount of 0-5 wt%, Na ₂ O in an amount of 12-18 wt%, K ₂ O in an amount of 0-5 wt%, MgO in an amount of 5-12 wt%, CaO in an amount of 0-10 wt%, SrO in an amount of 0-5 wt%, BaO in an amount of 0-5 wt%, ZnO in an amount of 0-5 wt%, ZrO ₂ in an amount of 0-5 wt%, TiO 7 in an amount of 0-5 wt%, 5395 wt%, SnO 62 in an amount of 0-5 wt%, and combinations of the above-specified amounts (all of the above non-mixed glass values considered as being limiting), the above-specified combinations of sodium ₂, SnO 2, and SnO 2 in amounts of the above embodiments (see the ranges of the absolute).

The glass article 10 also includes a transparent interlayer 16 disposed between the first and second outermost glass panes 12, 14. In other words, the transparent interlayer 16 is sandwiched between the first and second outermost glass panes 12, 14. In some embodiments, the transparent interlayer 16 is in direct contact with the first and second outermost glass panes 12, 14 without any intervening layers, such as tie layers, for example as shown in fig. 3. In other embodiments, a portion of the transparent layer 16 is in direct contact with both the first and second outermost panes 12, 14. For example, when the glass article 10 includes black ceramic edges, heating grid lines, or the like, a portion of the transparent layer 16 may be in direct contact with both the first and second outermost glass panes 12, 14. In still further embodiments, the transparent interlayer 16 may be disposed between the first and second outermost glass panes 12, 14, wherein the transparent interlayer 16 is physically isolated from one or both of the first or second outermost glass panes 12, 14, for example, when the glass article 10 comprises a silver layer or other coating. The term "transparent" is as understood in the float and windshield art and generally describes light passing through the interlayer 16. The transparent intermediate layer 16 is not opaque.

The size and shape of the transparent interlayer 16 is also not particularly limited and is most often shaped to complement the shape of the first and second outermost panes of glass 12, 14, for example as shown in fig. 2 and 3. the thickness (t ₃) of the transparent interlayer 16 is typically 0.3-2.28mm, for example as shown in fig. 3. in various embodiments, the thickness (t ₃) is 0.3, 0.35, 0.4, 0.45, 0.5, 0.55, 0.6, 0.65, 0.7, 0.75, 0.76, 0.8, 0.85, 0.9, 0.95, 1.0, 1.05, 1.1, 1.15, 1.2, 1.25, 1.3, 1.35, 1.4, 1.45, 1.5, 1.52, 1.55, 1.6, 1.65, 1.7, 1.75, 1.8, 1.85, 1.2, 2.2, 2.5, 2.55, 1.6, 1.65, 1.7, 2.8, 2.85, 2.2.2, 2, 2.2 mm, 2, 2.15 mm, 2, 2.5, 2.

The composition of the transparent interlayer 16 is not particularly limited, and is typically or includes polyvinyl butyral or ethylene vinyl acetate. The transparent intermediate layer 16 may be utilized in sheet form, in polymer form, or in the form of a separate reactive component that subsequently reacts to form the transparent intermediate layer 16. The transparent intermediate layer 16 may be provided in a cured, partially cured or uncured state. Other non-limiting examples of suitable polymers for the transparent interlayer 16 include plasticized polyvinyl butyral, polyurethane, and the like. The transparent interlayer 16 may be provided in the form of a non-transparent polymer or compound that subsequently becomes transparent upon heating and/or processing.

In one embodiment, the thickness of the first outermost pane 12 (t ₁) is 2.1mm ± 0.05mm in another embodiment, the thickness of the second outermost pane 14 (t ₂) is 0.7mm ± 0.05mm in yet another embodiment, the thickness of the transparent interlayer 16 (t ₃) is 0.76mm ± 0.25 mm.

The first and second outermost panes 12, 14 each have a glass transition temperature T _g1 and T _g2, respectively, more specifically, the first outermost pane 12 has a first glass transition temperature T _g1 and the second outermost pane 14 has a second glass transition temperature T _g2. T _g1 is typically 535-554 ℃. alternatively, T _g1 is 535-550, 535-545, 540-554, 545-554, or 540-550 ℃. T _g2 is typically 550-590 ℃. alternatively, T _g2 is 560-590, 570-590, 550-580, 550-570, or 560-580 ℃.

The second outermost glass pane 14 has a second glass transition temperature T _g2 that is 1-40 ℃ higher than the first glass transition temperature T _g1 of the first outermost glass pane 12 in various embodiments, the second glass transition temperature T _g2 is 1-5, 1-10, 1-15, 1-20, 1-25, 1-30, 1-35, 5-10, 5-15, 10-15 ℃ higher than the first glass transition temperature T _g1 of the first outermost glass pane 12 in various embodiments, the second glass transition temperature T _g2 can be any value or range of values including and between the values recited above.

The difference in glass transition temperatures, T _g1 and T _g2, can generally be tailored based on the composition of the first and second outermost glass panes, 12, 14, respectively in various embodiments, the second glass transition temperature, T _g2, of the second outermost glass pane 14 is tailored such that the second outermost glass pane 14 can bend in the same manner or consistently as the first outermost glass pane 12 in the furnace, despite the difference in thickness and therefore thermal mass, since the second outermost glass pane 14 is thinner than the first outermost glass pane 12, the difference in glass transition temperatures, T _g1 and T _g2 promotes a more predictable and consistent bend between the first and second outermost glass panes 12, 14.

Without being bound by any particular theory, it is believed that the combination of a particular glass pane thickness (i.e., the thickness of the first and second outermost panes of glass 12, 14) and the difference in T _g between the first and second outermost panes of glass 12, 14 cooperate to establish the excellent optical properties of the glass article 10 as evidenced by the ISRA values.

a method of forming a glass article:

The present disclosure also provides a method of forming a glass article 10. The method comprises the step of forming a first glass pane of soda lime glass by a float process, wherein the first glass pane has a thickness of 1.1-4.0 mm. The first glass pane may be any glass pane as described above. The method further comprises the step of forming a second glass pane of soda lime glass and/or aluminosilicate glass by float process, wherein the second glass pane has a thickness of 0.3-1.05 mm. The second glass pane may also be any glass pane as described above. Float processes are known in the art, and the present disclosure may utilize any one or more steps of the float process herein. The blank may have the same thickness as described above.

The method further comprises the steps of cutting the first blank from the first glass pane and cutting the second blank from the second glass pane. The size and shape of the first and second blanks are not limited and can be selected by one skilled in the art.

Generally, there are two different methods for cutting blanks from glass produced by a glass float line. The glass float line produces a continuous "ribbon" of glass that is then cut into blanks using any technique known in the art. For example, blanks for automotive windshields are typically rectangular. The rectangular blanks can be oriented such that the long axis is parallel to the axis of the glass ribbon from the float process, or such that the long axis is perpendicular to the axis of the ribbon. After cutting the blank, it is typically cut using a pattern cutter from a blank block having a suitable contoured shape to produce glass for a particular window of a particular vehicle. Subsequently, edging, chamfering or inspection may be completed.

The method further includes the step of forming the first and second blanks into a desired shape. Again, the desired shape may be any shape selected by one skilled in the art and may be curved, for example for a windshield. Further, the shaping step may be accomplished by any step known in the art. For example, the forming step may be further defined as bending or curving the first and second blanks. To produce a curved blank, the profile of the first and second blanks may be slightly different. The first and second blanks may be mounted on a series of concave elevation bending dies 20 with a suitable separating material such as diatomaceous earth or calcium carbonate between the blanks, as shown for example in fig. 1. The glass-loaded mold 20 can then be conveyed through an elongated channel in which the blank is heated to a bending temperature to cause the blank to sag into the concave convex shape of the mold 20. The bent blanks may then be cooled at a controlled rate until they are sufficiently cool for processing. An alternative technique involves press bending each blank to its desired shape.

the method further comprises the step of providing an intermediate layer. The intermediate layer may be provided in sheet form, in polymer form or in the form of a reactive component which is subsequently reacted to form the transparent intermediate layer. The intermediate layer may be provided in a cured, partially cured or uncured state. For example, the intermediate layer may be opaque or may be non-transparent when provided and may subsequently become transparent upon processing or heating.

The method further includes the step of aligning the first shaped blank, the intermediate layer, and the second shaped blank. The alignment step may be any step known in the art. The first formed blank, the intermediate layer and the second formed blank may be rotated to a desired position.

The method also includes the step of combining the first shaped blank, the intermediate layer, and the second shaped blank to form the glass article. The combining step may include or may be further defined as laminating the first shaped blank, the intermediate layer, and the second shaped blank such that the intermediate layer changes from opaque or non-transparent to transparent. After lamination, the first shaped blank may be described as a first outermost glass pane 12. Similarly, after lamination, the second shaped blank may be described as the second outermost glass pane 14 and the interlayer may be described as the transparent interlayer 16.

In various embodiments, when the first and second shaped blanks are laminated to the middle ply, the middle ply is assembled to form a concave outer surface of the middle ply to face an interior of the vehicle and the other curved blank of the pair forms a convex outer surface of the middle ply to face an exterior of the vehicle.

In other embodiments, the lamination step is performed in two stages. The first stage, e.g. pre-pressing, can be performed using a rubber tube rim channel (i.e. a vacuum ring). The mated curved first and second blank pairs may be assembled with an intermediate layer disposed therebetween to form a sandwich structure. Tubes may then be mounted around the edge perimeter of each sandwich and connected to a vacuum source. The pre-compaction may be performed under vacuum at a set point temperature of about 120 ℃. and 150 ℃ and a target glass temperature of about 95 ℃ for 10-30 minutes. One of ordinary skill in the art will appreciate that alternative methods may also be used for pre-compaction, such as vacuum bag or nip roll (niproller) methods. After pre-pressing, the sandwich may then be autoclaved (autoclave) and allowed to cool to room temperature.