Composite transparency

IS 2 138 118 T3

DESCRIPTION

Composite transparency.

Background of the invention

This invention relates to the production of color composite transparencies having desired color and solar energy transmittance characteristics. In particular, the invention relates to a transparency that reduces unwanted solar energy transmission, while maintaining neutral placement and high visible transmittance. Transparencies of the type described in the present invention are highly desirable for use as glazing in buildings and motor vehicles. When used herein, the term "composite transparency" means a rigid transparent substrate, such as a glass or plastic with a second element such as a flexible plastic layer, a coating, or a second rigid transparent layer secured to a major surface of the substrate.

The color of an object, and in particular glass, is highly subjective. The observed color will depend on the lighting conditions and the preferences of the observer. To evaluate a color on a quantitative basis, various color ordering systems have been developed. One such method of color specification adopted by the International Commission on Illumination (CIE) uses dominant wavelength (DW) and excitation purity (Pe). The numerical values ​​of these two specifications for a given color can be determined by calculating the x and y color coordinates from the so-called X, Y, Z trichromatic values ​​of that color. The color coordinates are then plotted on a 1931 CIE chromaticity diagram and numerically compared to the coordinates of the CIE standard illuminant C, as identified in CIE Publication No. 15.2. This comparison provides a spatial position of the color on the diagram to find out the excitation purity and the dominant wavelength of this crystal color.

In another color ordering system, color is specified in terms of hue and lightness. This system is commonly referred to as the CIELAB color system. Hue distinguishes colors such as red, yellow, green, and blue. Clarity, or value, distinguishes the degree of lightness or darkness. The numerical values ​​of these characteristics, which are identified as L *, a * and b *, are calculated from the trichromatic values ​​(X, Y, Z). L * indicates the lightness or darkness of the color and represents the plane of lightness where the color resides. to^* indicates the position of the color on a red axis (+ a^*) green (-a^*). b^*indicates the position of the color on a yellow axis (+ b^*) blue (-b^*). When the rectangular coordinates of the CIELAB system are converted to cylindrical polar coordinates, the resulting color system is known as the CIELCH color system which specifies the color in terms of lightness (L^*), and the hue angle (H^°) and brightness (C *). L^* indicates the lightness or darkness of the color as in the CIELAB system. Brightness, or saturation or intensity, distinguishes intensity or clarity of color (that is, vivid versus fuzzy) and is the distance vector from the center of the color space to the measured color. The lower the brightness of the color, that is, the less its intensity, the closer the color is to the so-called neutral color. Regarding the CIELAB system, C^* = (a^*2 + b^*2)^1/2. The hue angle distinguishes colors such as red, yellow, green, and blue and is a measure of the vector's angle extending from the coordinates to^*, b^* through the center of the CIELCH color space measured counterclockwise from the red axis (+ a^*). When used here, H^° would be expressed as a value between 0-260^°C. In Figure 1, the CIELAB system is superimposed on the CIELCH system to illustrate the relationship between the two systems.

It will be appreciated that color can be characterized in any of these color systems and a person skilled in the art can calculate equivalent DW and Pe values; L values^*,to^*, b^* and L values^*, C^*, H^° from the transmittance curves of the crystal or composite transparency contemplated.

Typical commercial soda lime silica glass includes the following materials: 66-75% by weight of SiO2, 10-20% by weight of Na2O, 5-15% by weight of CaO, 0-5% by weight of Al2O3, 0-5% by weight of K₂O, 0-1% by weight of BaO. A variety of colorants are added to this base crystal to produce a desired crystal color. When used herein, a glass is considered to be a colored glass if its luminous transmittance (as described in more detail later) is <87%, regardless of the total thickness of the glass. Glass that has a luminous transmittance of> 87% is considered clear. It was appreciated that when a "glass" or "glass substrate" is referred to here as colored, in the case of a composite transparency having two or more layers of glass, the combined thickness of all the layers is determining whether the glass or transparency glass substrate is colored.

Many of these colored glasses, which are well known in the art, are used in automotive and architectural applications and absorb more solar energy than clear soda lime solid glass.

IS 2 138 118 T3

The main colorant in typical green tinted windows used in automotive applications is iron which is present in both Fe forms.₂OR₃ and ugly. The total amount of iron present in a typical green tinted glass for automotive applications, expressed as Fe₂OR₃Regardless of the form actually present, it is about 0.5-0.9% by weight with a ratio of FeO to total iron of about 0.25-0.27. Green crystals such as those described in US Patents No.^°s 5,214,008 issued to Beckwith et al., and 5,240,886 issued to Gulotta use higher amounts of total iron to absorb ultraviolet radiation and further enhance the solar energy absorbing properties of the crystal. United States Patent N^° 5,077,133 issued to Cheng et al. Further includes caeric oxide, optionally combined with titanium oxide, to improve the solar energy absorbing performance of the crystals. Other crystals include additional colorants such as cobalt, selenium, nickel, and / or chromium to produce blue, bronze, and gray colored crystals as described in US Patents No.^°s 4,101,705 issued to Fischer et al .; 4,104,076 issued to Pons; 4,792,536 issued to Pecorato et al .; 5,023,210 issued to Krumwiede et al .; 5,070,048 issued to Boules et al., And 5,278,108 issued to Cheng et al.

One way to compare the performance of various solar energy absorbing crystals is to compare the ratio of light transmittance to total solar energy transmittance. Luminous transmittance, LT, is a measure of the total amount of visible light transmitted through glass. Total solar energy transmittance, TSET, is a measure of the total amount of solar energy transmitted directly through the glass. This last property is important because most of the transmitted energy is converted into heat after being absorbed by objects on the other side of the glass. In particular, when applied to automotive use, heat build-up and temperature inside the vehicle are directly related to TSET. This can lead to uncomfortable conditions for vehicle occupants and may require an increase in the cooling capacity of an air conditioning system. In addition, heat formation has been shown to accelerate material degradation within the vehicle. When used herein, this ratio of luminous transmittance to total solar energy transmittance is referred to as the "performance ratio" (PR).

Unless otherwise stated, the luminous transmittance data provided in this description is measured for CIE standard illuminant A (LTA) and 2^° Observer over a wavelength range 380-780 nm at 10 nm intervals in accordance with ASTM 308E-90. The total solar energy transmittance data provided in this description for calculating the performance ratio of a glass or composite transparency is based on Parry Moon's 2.0 air mass solar data and calculated based on the measured transmittance. 300-2000 nm.

To determine the TSET data, the transmittance values ​​are integrated over the wavelength range [a, b]. This interval is divided into n equal subintervals of length h by points {Xo, X1 ..., Xn), where Xi = a + (ixh). An interpolation function is used to approximate the integrand f in each subinterval. The sum of integrals of these interpolation functions provides an approximation of the integral:

b

I = f (X) dX a

In the case of calculations based on what is designated as the Trapezoidal Rule used here to calculate TSET data, f (X) is approximated on [Xi-1/2, Xi + 1/2 by means of a line line that passes through the graph of f at these points. Thus, the interpolation function for f (X) is sectionally linear over [a, b], and the numerical integration formula is:

n

I = [f (Xo) +2 f (Xi) + f (Xn)] xhi = 1

When calculating the TSET here, the transmittance range is divided into three subranges with different ranges as follows: 300-400 nm at 5 nm steps, 400-800 nm at 10 nm steps, and 800-2000 nm at 10 nm steps. 50 nm.

Figure 2 shows a graph illustrating typical crystal yield ratios used for various colorants. By generating this curve, the composition of the glass is not changed, but instead the thickness of the glass is varied to provide different levels of LTA performance. It will be appreciated that these lines represent trends in soda lime salix compositions and not a particular glass composition. trend line 2 represents typical lenses used in automotive applications that have

ES 2 138 118 T3 iron as the main colorant and they are usually green or blue. Trend line 4 represents crystals that have a combination of iron and other colorants, for example cobalt, selenium, chromium and / or nickel, and are usually blue, bronze or gray in color. Trend line 6 represents crystals that use colorants other than iron, for example cobalt or nickel, and are usually gray or bronze in color. As can be seen, crystals using iron as the main colorant would generally have the highest performance ratio, indicating that for a given LTA, there is a lower TSET and therefore less total energy passing through the crystal. In terms of automotive transparency applications, this translates to less heat build-up inside the vehicle. The higher yield ratio of these crystals is mainly due to the higher amount of iron, and in particular FeO, as a colorant. In particular, although colorants in general absorb solar energy in the visible range as well as a portion of infrared and / or ultraviolet energy, FeO is the most effective in absorbing non-visible solar energy and transmitting visible energy.

In automotive applications, government regulations establish the minimum value for luminous transmittance. In the United States, for passenger vehicles, the LTA must be at least 70%. Glasses that have an LTA of at least 70% and a TSET of no more than 50% are referred to herein as "high performance solar control glasses." The performance ratio for such a crystal is at least 1.4. Currently, some automakers require the TSET to be less than 45%, giving a performance ratio of at least 1.55 at LTA = 70%.

As is known in the art, colorants can also be added to the iron-containing sodium lime silica glass composition to reduce the intensity of the color in the glass, and in particular to produce a neutral gray glass. When used herein, the term "gray" means a crystal or composite transparency color that has an equivalent C * value of no more than 4 with L * = 88. It will be appreciated that for a different L * value, given the transmission versus wavelength curve for glass or transparency, a skilled person can calculate the C value.^* equivalent that corresponds to gray as defined here. For example, for a crystal or transparency that has a value of L^* slightly less than 88, the C value^* it would be greater than 4 and for a crystal or transparency that has an L value^*slightly greater than 88, the C value^* it would be less than 4. It would also be appreciated that if two gray composite transparencies of this type are displayed at the same time, a difference in color may be perceived, but when viewed individually, each one will appear as gray.

In particular, colorants added to a base glass composition to produce a gray colored glass produce colors that are complements of the base glass color. For example, to provide an iron-containing green crystal supplement, a simple purple dye is preferred, but there is no such crystal dye in combination with iron in a redox ratio of 0.25-0.27. Similarly, to provide an iron-containing blue crystal complement, a simple orange dye is preferred, but there is no such crystal dye in combination with iron in a redox ratio of 0.50-0.60. Therefore, combinations of dyes, for example combinations of cobalt and selenium, must be added to the base glass composition to produce a gray colored glass. However, the addition of multiple colorants requires a reduction in iron content in order to maintain a constant visible transmittance. Since these dyes are less potent than FeO in absorbing solar energy, the TSET would increase and the yield ratio would decrease, for example as shown in figure 2 for crystals that include iron, cobalt and selenium (trend line 4 ). More particularly, for an LTA of 70%, the TSET for commercially available gray crystals typically ranges from 57-68%, resulting in a yield ratio of approximately 1.03-1.23.

It is known that color material can be combined between layers to produce a desired color. For example, a bronze colored interlayer can be laminated between a pair of clear glass layers to produce a bronze colored automobile windshield. In addition, systems such as the Saflex OptiColor interleaved system^(R) from Monsanto Co., St. Louis, Missouri laminate multiple layers of different colored interlayers between clear, tinted or reflective glass layers to produce a desired glass color. However, these interlayers when combined with 17 inch thick clear glass produce laminates that have a performance ratio generally less than 1.22 to LTA = 70%. Furthermore, such a system does not provide the ability to control the color and intensity of the composite transparency while maintaining a high performance ratio. For these systems, it is recommended that added solar control be done using a dark colored midcoat. However, this device will lower my LTA than TSET, and in turn reduce the performance ratio of composite transparency.

Additionally, it is common for automobile windshields to tint an upper portion of its inner layer.

ES 2 138 118 T3 polyvinyl butyral stocking, typically referred to as the shadow band, to reduce light transmittance along the upper edge of the windshield. However, localized use of the shadow band does not provide color and intensity control through transparency, nor does it provide a high performance ratio to transparency. Mine specifically, the performance ratio in the shadow band area on a car windshield constructed of two layers of Solex glass.^(R)thickness of 2.1mm is <1. Solex glass^(R) is a green tinted automotive glass available from PPG Industries, Inc., Pittsburgh, Pennsylvania.

It would be advantageous to be able to produce a composite transparency having a high performance ratio, that is, with superior solar energy transmittance characteristics, while providing a high level of light transmittance, in a variety of different colors and intensities without having to change. the basic composition of the crystal. In particular, it would be advantageous to produce a neutral gray composite transparency having a yield ratio of 1.4 and more. Summary of the invention

The present invention provides a composite transparency having a desired level of color and intensity and a high performance ratio. In particular, the composite transparency includes at least one rigid transparency layer, for example a colored glass or plastic substrate, and a member secured to a major surface of the substrate, for example a plastic layer or a coating and has a relationship performance of at least 1.4. The member has a color that generally complements the color of the substrate to reduce the overall intensity of the transparency. In one embodiment of the invention, the transparency is gray in color, and in particular it is an automobile windshield.

Brief description of the drawings

Figure 1 is an illustration of the color space in the CIELAB and CIELCH color systems.

Figure 2 is a grade of luminous transmittance (LTA) versus total solar energy transmittance (TSET) for various types of glass used in automotive and architectural applications.

Figure 3 is a graph of examples of composite transparencies incorporating the present invention in CIELAB color space.

Detailed description of the invention

The present invention provides a high performance solar control composite transparency incorporating at least one high performance solar control glass substrate and a member that reduces the color intensity of the glass substrate while maintaining a ratio of high performance. In one embodiment of the invention the member is a layer of plastic material secured to a glass substrate. When used herein, "plastic" is meant to include any of the common thermoplastic or thermoset synthetic non-conductive materials, for example vinyl resins, polyethylene, polypropylene, thermoplastic urethane, thermoplastic olefin, polycarbonate, and the like. The plastic layer is preferably a flexible plastic layer, for example polyvinyl butyral (PVB). Colorants can be incorporated into PVB formulations that are highly selective in absorbing regions of specific wavelengths and provide a desired color. Such materials can be purchased from vendors such as Monsanto Company, St. Louis, Missouri. In the present invention, the color of the plastic layer is generally the complement of the glass substrate and includes colorants which, when the plastic layer is laminated to the glass substrate, reduce the color intensity of the composite, as will be described below. forward with my details. It would be appreciated that other transparent rigid substrates, for example polycarbonates or other plastic sheet material may be used in place of or in combination with a layer of glass.

Tables 1 and 2 present computer generated data based on combining tinted polyvinyl butyral layers with two colored glass layers (individually and collectively referred to as the "substrate") to produce a composite transparency that has a color other than that of the glass layers and / or to reduce the intensity of the glass, while generally maintaining a performance ratio comparable to that of high-performance solar control glass, The information in these tables was generated from a computer model that calculates color and spectral performance of transparent materials. Tables include total glass thickness (t), luminous transparency (LTA), total solar energy transmittance (TSET), performance ratio (PR), length of

ES 2 138 118 T3 dominant wave (DW), the purity (Pe) and the coordinates of the individual substrate and the PVB layer as well as the composite in the CIELAB and CIELCH color spaces. DW and Pe values ​​are based on CIE standard illuminant C and 2 ° observer. L *, a *, b *, C * and H ° values ​​are based on CIE D65 standard illuminant and 10 ° observer. In each set of examples, the amount of colorant in the PVB layer was changed to effect the desired color. Furthermore, in order to provide a basis for comparison between the same group of composite transparencies, the visible transmittance (LTA) for each of the transparencies was set at 71%. It would be appreciated that to meet this level of performance comparison the overall thickness of the glass and / or the concentration of the colorants in the glass can be changed. Generally it is desirable that the thickness of the glass layer for automotive laminates, for example windshields and sunroofs, is between 1.5-3.0, and for side and rear windows of single layer automobiles it is between 3.0- 7.0 mm. In architectural glass applications, the thickness of the glass layer is typically between 3.0-10.0 mm. An LTA value of 71% was chosen for comparison because it is expected that after long-term exposure to solar radiation, the LTA of a composite transparency would decrease by up to 1%. The 71% LTA should ensure continued solar performance that meets government requirements for automotive applications.

TABLE 1

<td rowspan="2"></td><td colspan="3">Trans. Composite 10</td><td colspan="3">Trans. Composite 12</td><td colspan="3">Trans. Composite 14</td>

<td>Crystal</td><td>PVB</td><td>Trans.</td><td>Crystal</td><td>PVB</td><td>Trans.</td><td>Crystal</td><td>PVB</td><td>Trans.</td>

<td>^{t (in}.)</td><td> 0,1920</td><td> 0,030</td><td> 0,2220</td><td> 0,1871</td><td> 0,030</td><td> 0,2117</td><td> 0,1675</td><td> 0,030</td><td> 0,1975</td>

<td>LTA (%)</td><td> 71,4</td><td> 91,1</td><td> 71,0</td><td> 72,4</td><td> 89,9</td><td> 71,0</td><td> 73,7</td><td> 88,4</td><td> 71,0</td>

<td>TSET (%)</td><td> 43,5</td><td> 88,2</td><td> 42,2</td><td> 44,9</td><td> 87,7</td><td> 43,2</td><td> 47,0</td><td> 86,9</td><td> 44,7</td>

<td>PR</td><td> 1,64</td><td> 1,03</td><td> 1,68</td><td> 1,61</td><td> 1,03</td><td> 1,64</td><td> 1,57</td><td> 1,02</td><td> 1,59</td>

<td>DW (nm)</td><td> 511,9</td><td> 572,9</td><td> 512,9</td><td> 511,9</td><td>504.6c</td><td> 512,7</td><td> 511,9</td><td>509.3c</td><td> 512,0</td>

<td>Pe</td><td> 2,61</td><td> 0,24</td><td> 2,62</td><td> 2,47</td><td> 1,10</td><td> 1,96</td><td> 2,28</td><td> 2,37</td><td> 1,25</td>

<td>L *</td><td> 88,5</td><td> 96,4</td><td> 88,3</td><td> 88,9</td><td> 95,8</td><td> 88,1</td><td> 89,5</td><td> 94,9</td><td> 87,8</td>

<td>to*</td><td> -8,52</td><td> -0,10</td><td> -8,60</td><td> -8,11</td><td> 1,88</td><td> -6,30</td><td> -7,53</td><td> 3,86</td><td> -3,79</td>

<td>b *</td><td> 3,41</td><td> 0,32</td><td> 3,56</td><td> 3,25</td><td> -0,47</td><td> 2,64</td><td> 3,02</td><td> -1,30</td><td> 1,62</td>

<td>C *</td><td> 9,18</td><td> 0,33</td><td> 9,31</td><td> 8,73</td><td> 1,93</td><td> 6,83</td><td> 8,11</td><td> 4,07</td><td> 4,12</td>

<td>H °</td><td> 158</td><td> 107</td><td> 158</td><td> 158</td><td> 346</td><td> 157</td><td> 158</td><td> 341</td><td> 157</td>

IS 2 138 118 T3

TABLE 1 (Cont.)

<td rowspan="2"></td><td>Trans.</td><td colspan="2">Composite 16</td><td colspan="3">Trans. Composite 18</td><td colspan="3">Trans. Composite 20</td>

<td>Crystal</td><td>PVB</td><td>Trans.</td><td>Crystal</td><td>PVB</td><td>Trans.</td><td>Crystal</td><td>PVB</td><td>Trans.</td>

<td>^{t (in}.)</td><td> 0,1515</td><td> 0,030</td><td> 0,1815</td><td> 0,1153</td><td> 0,030</td><td> 0,1483</td><td> 0,1000</td><td> 0,030</td><td> 0,1300</td>

<td>LTA (%)</td><td> 75,2</td><td> 86,6</td><td> 71,0</td><td> 78,5</td><td> 82,8</td><td> 71,0</td><td> 80,4</td><td> 80,8</td><td> 71,0</td>

<td>TSET (%)</td><td> 49,5</td><td> 86,0</td><td> 46,4</td><td> 55,6</td><td> 84,0</td><td> 50,8</td><td> 59,6</td><td> 82,8</td><td> 53,6</td>

<td>PR</td><td> 1,52</td><td> 1,01</td><td> 1,53</td><td> 1,41</td><td> 0,99</td><td> 1,40</td><td> 1.35</td><td> 0,98</td><td> 1,32</td>

<td>DW (nm)</td><td> 512,0</td><td>510.5c</td><td> 511,5</td><td> 512,2</td><td> 444,3</td><td> 488,5</td><td> 512,4</td><td> 479,4</td><td> 488,1</td>

<td>Pe</td><td> 2,06</td><td> 3,70</td><td> 0,47</td><td> 1,61</td><td> 2,99</td><td> 3,48</td><td> 1,36</td><td> 5,11</td><td> 5,79</td>

<td>L *</td><td> 90,1</td><td> 94,0</td><td> 87,6</td><td> 91,5</td><td> 93,0</td><td> 88,0</td><td> 92,3</td><td> 92,6</td><td> 88,4</td>

<td>to*</td><td> -6,87</td><td> 5,97</td><td> -1,06</td><td> -5,45</td><td> 2,03</td><td> -3,34</td><td> -4,65</td><td> -1,29</td><td> -5,74</td>

<td>b *</td><td> 2,77</td><td> -2,13</td><td> 0,55</td><td> 2,22</td><td> -4,13</td><td> -1,84</td><td> 1,91</td><td> -5,19</td><td> -3,15</td>

<td>C *</td><td> 7,40</td><td> 6,34</td><td> 1,19</td><td> 5,89</td><td> 4,60</td><td> 3,81</td><td> 5,03</td><td> 5,35</td><td> 6,55</td>

<td>H °</td><td> 158</td><td> 340</td><td> 153</td><td> 158</td><td> 296</td><td> 209</td><td> 158</td><td> 256</td><td> 209</td>

TABLE 1 (Cont.)

<td rowspan="2"></td><td colspan="3">Trans. Composite 22</td><td colspan="3">Trans. Composite 24</td><td colspan="3">Trans. Composite 26</td>

<td>Crystal</td><td>PVB</td><td>Trans.</td><td>Crystal</td><td>PVB</td><td>Trans.</td><td>Crystal</td><td>PVB</td><td>Trans.</td>

<td>^{t (in}.)</td><td> 0,1450</td><td> 0,030</td><td> 0,1750</td><td> 0,1374</td><td> 0,030</td><td> 0,1674</td><td> 0,1415</td><td> 0,030</td><td> 0,1715</td>

<td>LTA (%)</td><td> 75,9</td><td> 86,0</td><td> 71,0</td><td> 76,6</td><td> 85,2</td><td> 71,0</td><td> 76,2</td><td> 85,6</td><td> 71,0</td>

<td>TSET (%)</td><td> 50,6</td><td> 84,9</td><td> 46,6</td><td> 52,0</td><td> 83,7</td><td> 47,0</td><td> 51,3</td><td> 84,8</td><td> 47,2</td>

<td>PR</td><td> 1,50</td><td> 1,01</td><td> 1,52</td><td> 1,47</td><td> 1,02</td><td> 1,51</td><td> 1,49</td><td> 1,01</td><td> 1,50</td>

<td>DW (nm)</td><td> 512,0</td><td> 617,3</td><td> 575,3</td><td> 512,0</td><td> 593,7</td><td> 576,6</td><td> 512,0</td><td>493.8c</td><td> 581,1</td>

<td>Pe</td><td> 1,97</td><td> 3,54</td><td> 4,22</td><td> 1,87</td><td> 6,57</td><td> 7,13</td><td> 1,93</td><td> 3,59</td><td> 3,27</td>

<td>L *</td><td> 90,4</td><td> 93,2</td><td> 87,1</td><td> 90,7</td><td> 92,6</td><td> 86,8</td><td> 90,5</td><td> 93,0</td><td> 87,0</td>

<td>to*</td><td> -6,59</td><td> 7,20</td><td> 0,50</td><td> -6,27</td><td> 7,29</td><td> 0,99</td><td> -6,45</td><td> 8,30</td><td> 1,69</td>

<td>b *</td><td> 2,66</td><td> 1,77</td><td> 3,95</td><td> 2,53</td><td> 4,79</td><td> 6,58</td><td> 2,60</td><td> 0,52</td><td> 2,74</td>

<td>C *</td><td> 7,11</td><td> 7,42</td><td> 3,98</td><td> 6,77</td><td> 8,72</td><td> 6,65</td><td> 6,95</td><td> 8,32</td><td> 3,22</td>

<td>H °</td><td> 158</td><td> 14</td><td> 83</td><td> 158</td><td> 33</td><td> 81</td><td> 158</td><td> 4</td><td> 58</td>

IS 2 138 118 T3

TABLE 1 (Cont.)

<td rowspan="2"></td><td colspan="3">Trans. Composite 28</td><td colspan="3">Trans. Composite 30</td>

<td>Crystal</td><td>PVB</td><td>Trans.</td><td>Crystal</td><td>PVB</td><td>Trans.</td>

<td>^{t (in}.)</td><td> 0,1297</td><td> 0,030</td><td> 0,1597</td><td> 0,0718</td><td> 0,030</td><td> 0,1018</td>

<td>LTA (%)</td><td> 77,4</td><td> 84,3</td><td> 71,0</td><td> 83,4</td><td> 78,0</td><td> 71,0</td>

<td>TSET (%)</td><td> 53,4</td><td> 84,6</td><td> 49,1</td><td> 66,6</td><td> 80,7</td><td> 58,3</td>

<td>PR</td><td> 1,45</td><td> 1,00</td><td> 1,45</td><td> 1,25</td><td> 0,097</td><td> 1,22</td>

<td>DW (nm)</td><td> 512,1</td><td>510.7c</td><td>511.0c</td><td> 513,0</td><td>562.5c</td><td> 465,4</td>

<td>Pe</td><td> 1,76</td><td> 5,49</td><td> 1,42</td><td> 0,96</td><td> 5,33</td><td> 3,93</td>

<td>L *</td><td> 91,0</td><td> 92,7</td><td> 87,2</td><td> 93,5</td><td> 90,6</td><td> 87,6</td>

<td>to*</td><td> -5,95</td><td> 8,82</td><td> 2,68</td><td> -3,39</td><td> 5,16</td><td> 1,81</td>

<td>b *</td><td> 2,41</td><td> -3,20</td><td> -0,86</td><td> 1,43</td><td> -6,42</td><td> -4,95</td>

<td>C *</td><td> 6,41</td><td> 9,39</td><td> 2,81</td><td> 3,67</td><td> 8,23</td><td> 5,27</td>

<td>H °</td><td> 158</td><td> 340</td><td> 342</td><td> 157</td><td> 309</td><td> 290</td>

Referring to Table 1, the green glass substrates are combined with 0.030 inch (0.76 mm) thick PVB layers to form glass / plastic composite transparencies. Green glass can generally be characterized as having a wavelength between 490-560 nm, depending on the lighting conditions and the perceptions of the observer. This range is generally equivalent to a key angle range of 12 () - 2 () 0. The green glass substrate used in Table 1 is a high performance solar control glass available from PPG Industries, Inc. and sold under the brand name SOLARGREEN.^(R). With an LTA level of 71%, the TSET of this crystal is 42.9%, resulting in a performance ratio of 1.65. The dominant wavelength of this glass substrate is 512 nm and its color as described in the CIELAB color system is L * = 88.3, ​​a * = -8.7, b * = 3.5 and C * = 9.4. Also, the tonality angle of the substrate is 158. It should be appreciated that although the color of the particular substrate used in Table 1 is characterized as "green", this crystal includes a slightly yellowish coloration as inferred from its coordinates a^* , b^* . Furthermore, although green glass is characterized as glass that has a hue angle of 12 (-2 ((^◦In the present invention it is preferred that a green glass substrate has a hue angle between 14 (-19 ( ^◦, and more preferably between 15 (-18 ( ^◦.

An object of the present invention is to reduce the intensity of the substrate and more particularly to provide a gray colored composite transparency having a performance ratio of at least 1.4. To this end, referring to Table 1 and Figure 3, one clear layer of PVB and three different layers of tinted PVB, each successive tinted layer having an increasing amount of colorant to provide a color that complements that of the glass substrate, combine with the green glass substrate to produce four composite transparencies 1 (, 12, 14, and 16, respectively, each of the last three transparencies having a different color from the original glass substrate color, while maintaining a high performance ratio. When used herein, the term "complement" means a color that has an angle of hue equal to that of the substrate plus 18 (^◦ ±3( ^◦, and more preferably ± 2 ( ^◦. Accordingly, although not required in the present invention, a plastic layer having a color that complements that of a substrate preferably falls approximately on the opposite side of the CIELAB color space of the substrate. More particularly, if the color of the substrate falls in the upper left quadrant of figures 1 and 3 delimited by the green and yellow axes, the color com8

ES 2 138 118 T3 would fall in the lower right quadrant delimited by the red and blue axes. For a green colored substrate shown in Table 1 having a hue angle of 158 °, the complementary plastic layer would generally have a purple color. In the particular embodiments of the invention shown in Table 1, the hue angle for the plastic layer in composite transparencies 1,2, 14 and 16 varies between 340-346^°.

Referring to Figure 3, composite transparencies 10, 12, 14, and 16 are placed in the CIELAB color space. In composite transparency 12, the first tinted layer produces a transparency having a chromaticity of C * = 6.83. The color of Composite Transparency 12 is still basically green, but the addition of the tinted layer has reduced its chromaticity compared to Composite Transparency 10, which incorporates a clear plastic layer, and has made the final product a neutral color. Composite transparency 14 incorporates a tinted layer that further reduces the chromaticity of the transparency and the third tinted layer incorporated in the composite transparency 16 reduces the chromaticity up to C^* = 1.19. At this intensity level, the transparency appears to be a neutral gray color.

As can be seen from Table 1 and Figure 3, using a tinted layer that has an angle of hue that generally complements that of the glass substrate and increasing the amount of colorants in the tinted layer to reduce the chromaticity of the substrate can result in a composite transparency using a green glass substrate that has a neutral gray color, but it has a performance ratio that is higher than that of any gray glass composition currently available, and mine particularly a performance ratio greater than 1.4. More specifically, for gray composite transparency 16, C^* = 1.19 and the yield ratio is 1.53. It would be appreciated that the composite transparencies illustrated in Table 1 are for a specific glass composition and that a person skilled in the art could formulate tinted interlayer compositions that generally complement the color of any other green glass composition to reduce the intensity of the substrate. of Cristal.

Furthermore, one of ordinary skill in the art would appreciate that the color of the tinted plastic layer can be changed to suit the desired color of the transparency. More particularly, as presented in Table 1, the glass substrate has a hue angle of 158^° y The tinted plastics coat for composite transparencies 12, 14, and 16 has a complementary hue angle of approximately 340^°. However, if the tint angle of the plastic layer were less than the complement of the tint angle of the substrate, the color of the transparency would tend to be greenish-blue, still at the same time reducing the overall chromaticity of the transparency compared to the substrate. Particularly mine, in composite transparencies 18 and 20, the PVB layer has a hue angle of 296^°and 256^°, respectively. With reference to Figure 3, these transparencies are green-blue in color, the composite transparency 18 being a gray-green-blue color. Similarly, if the hue angle of the plastic layer combined with the substrate were greater than the complement of the substrate hue angle, the transparency would tend to be greenish-yellow to yellow, while still reducing overall chromaticity. of transparency compared to the substrate. Particularly mine, in composite transparencies 22 and 24, the PVB layer has a hue angle of 14 and 33^° respectively, With reference to FIG. 3, these transparencies are yellow in color, the composite transparency 22 being a gray-yellow color.

Composite transparencies 26 and 28 are additional examples of how a green glass substrate can be combined with a layer of tinted plastic to provide a different color transparency with a high performance ratio, especially Composite Transparency 26 is a colored transparency. Bronze gray with a yield ratio of 1.5 and Composite Transparency 28 is a purple gray transparency with a yield ratio of 1.45. Composite transparency 30 is a third example where the transparency is purple with a yield ratio of 1.22.

IS 2 138 118 T3

TABLE 2

<td rowspan="2"></td><td colspan="3">Trans. Composite 40</td><td colspan="3">Trans. Composite 42</td><td colspan="3">Trans. Composite 44</td>

<td>Crystal</td><td>PVB</td><td>Trans.</td><td>Crystal</td><td>PVB</td><td>Trans.</td><td>Crystal</td><td>PVB</td><td>Trans.</td>

<td>^t (in.)</td><td> 0,1870</td><td> 0,030</td><td> 0,2170</td><td> 0,1709</td><td> 0,030</td><td> 0,2009</td><td> 0,1531</td><td> 0,030</td><td> 0,1831</td>

<td>LTA (%)</td><td> 71,4</td><td> 91,1</td><td> 71,0</td><td> 72,9</td><td> 89,4</td><td> 71,0</td><td> 74,6</td><td> 87,5</td><td> 71,0</td>

<td>TSET (%)</td><td> 40,5</td><td> 88,2</td><td> 39,1</td><td> 42,5</td><td> 87,1</td><td> 40,1</td><td> 44,9</td><td> 85,7</td><td> 41,4</td>

<td>PR</td><td> 1,76</td><td> 1,03</td><td> 1,81</td><td> 1,72</td><td> 1,03</td><td> 1,77</td><td> 1,66</td><td> 1,02</td><td> 1,72</td>

<td>DW (nm)</td><td> 487,7</td><td> 572,9</td><td> 487,9</td><td> 487,7</td><td> 595,1</td><td> 487,7</td><td> 487,8</td><td> 594,6</td><td> 488,2</td>

<td>Pe</td><td> 9,96</td><td> 0,24</td><td> 9,88</td><td> 9,15</td><td> 1,75</td><td> 7,36</td><td> 8,24</td><td> 3,77</td><td> 4,27</td>

<td>L *</td><td> 89,4</td><td> 96,4</td><td> 89,2</td><td> 90,0</td><td> 95,3</td><td> 88,7</td><td> 90,7</td><td> 94,1</td><td> 88,2</td>

<td>to*</td><td> -9,80</td><td> -0,10</td><td> -9,90</td><td> -9,06</td><td> 3,24</td><td> -6,98</td><td> -8,21</td><td> 4,46</td><td> -3,89</td>

<td>b *</td><td> -5,68</td><td> 0,32</td><td> -5,49</td><td> -5,23</td><td> 1,29</td><td> -4,19</td><td> -4,72</td><td> 2,74</td><td> -2,35</td>

<td>C *</td><td> 11,33</td><td> 0,33</td><td> 11,32</td><td> 10,46</td><td> 2,50</td><td> 8,14</td><td> 9,47</td><td> 5,23</td><td> 4,54</td>

<td>H °</td><td> 210</td><td> 107</td><td> 209</td><td> 210</td><td> 31</td><td> 211</td><td> 210</td><td> 32</td><td> 211</td>

TABLE 2 (Cont.)

<td rowspan="2"></td><td colspan="3">Trans. Composite 46</td><td colspan="3">Trans. Composite 48</td><td colspan="3">Trans. Composite 50</td>

<td>Crystal</td><td>PVB</td><td>Trans.</td><td>Crystal</td><td>PVB</td><td>Trans.</td><td>Crystal</td><td>PVB</td><td>Trans.</td>

<td>^{t (in}.)</td><td> 0,1358</td><td> 0,030</td><td> 0,1658</td><td> 0,1321</td><td> 0,030</td><td> 0,1621</td><td> 0,1330</td><td> 0,030</td><td> 0,1630</td>

<td>LTA (%)</td><td> 76,3</td><td> 85,7</td><td> 71,0</td><td> 76,7</td><td> 85,3</td><td> 71,0</td><td> 76,6</td><td> 85,4</td><td> 71,0</td>

<td>TSET (%)</td><td> 47,7</td><td> 84,2</td><td> 42,9</td><td> 48,3</td><td> 84,5</td><td> 43,8</td><td> 48,1</td><td> 84,9</td><td> 43,9</td>

<td>PR</td><td> 1,60</td><td> 1,02</td><td> 1,66</td><td> 1,59</td><td> 1,01</td><td> 1,62</td><td> 1,59</td><td> 1,01</td><td> 1,62</td>

<td>DW (nm)</td><td> 487,8</td><td> 594,4</td><td> 490,7</td><td> 487,8</td><td>493.0c</td><td> 469,6</td><td> 487,8</td><td>497.3c</td><td> 466,6</td>

<td>Pe</td><td> 7,34</td><td> 5,83</td><td> 1,12</td><td> 7,15</td><td> 3,53</td><td> 2,86</td><td> 7,20</td><td> 4,65</td><td> 4,21</td>

<td>L *</td><td> 91,3</td><td> 93,0</td><td> 87,6</td><td> 91,5</td><td> 92,8</td><td> 87,6</td><td> 91,4</td><td> 92,9</td><td> 87,7</td>

<td>to*</td><td> -7,37</td><td> 6,71</td><td> -0,83</td><td> -7,19</td><td> 8,59</td><td> 1,30</td><td> -7,23</td><td> 9,28</td><td> 1,98</td>

<td>b *</td><td> -4,22</td><td> 4,20</td><td> -0,47</td><td> -4,11</td><td> 0,96</td><td> -3,51</td><td> -4,14</td><td> -0,85</td><td> -5,28</td>

<td>C *</td><td> 8,49</td><td> 7,92</td><td> 0,96</td><td> 8,28</td><td> 8,64</td><td> 3,74</td><td> 8,33</td><td> 9,32</td><td> 5,64</td>

<td>H °</td><td> 210</td><td> 32</td><td> 209</td><td> 210</td><td> 6</td><td> 290</td><td> 210</td><td> 355</td><td> 291</td>

IS 2 138 118 T3

TABLE 2 (Cont.)

<td rowspan="2"></td><td colspan="3">Trans. Composite 52</td><td colspan="3">Trans. Composite 54</td><td colspan="3">Trans. Composite 56</td>

<td>Crystal</td><td>PVB</td><td>Trans.</td><td>Crystal</td><td>PVB</td><td>Trans.</td><td>Crystal</td><td>PVB</td><td>Trans.</td>

<td>^{t (in}.)</td><td> 0,1397</td><td> 0,030</td><td> 0,1697</td><td> 0,1520</td><td> 0,030</td><td> 0,1820</td><td> 0,1190</td><td> 0,030</td><td> 0,1490</td>

<td>LTA (%)</td><td> 75,9</td><td> 86,1</td><td> 71,0</td><td> 74,7</td><td> 87,4</td><td> 71,0</td><td> 78,0</td><td> 83,9</td><td> 71,0</td>

<td>TSET (%)</td><td> 47,0</td><td> 83,9</td><td> 42,0</td><td> 45,1</td><td> 85,0</td><td> 40,9</td><td> 50,7</td><td> 82,2</td><td> 44,2</td>

<td>PR</td><td> 1,62</td><td> 1,03</td><td> 1,69</td><td> 1,66</td><td> 1,03</td><td> 1,74</td><td> 1,54</td><td> 1,02</td><td> 1,60</td>

<td>DW (nm)</td><td> 487,8</td><td> 584,8</td><td> 544,0</td><td> 487,8</td><td> 581,8</td><td> 504,3</td><td> 487,9</td><td> 590,6</td><td> 580,8</td>

<td>Pe</td><td> 7,55</td><td> 8,45</td><td> 1,71</td><td> 8,18</td><td> 7,39</td><td> 2,04</td><td> 6,47</td><td> 9,24</td><td> 3,34</td>

<td>L *</td><td> 91,2</td><td> 93,1</td><td> 87,6</td><td> 90,7</td><td> 94,0</td><td> 88,0</td><td> 91,9</td><td> 91,8</td><td> 87,0</td>

<td>to*</td><td> -7,56</td><td> 4,93</td><td> -2,89</td><td> -8,16</td><td> 2,99</td><td> -5,42</td><td> -6,53</td><td> 8,49</td><td> 1,72</td>

<td>b *</td><td> -4,34</td><td> 7,32</td><td> 2,44</td><td> -4,69</td><td> 6,78</td><td> 1,59</td><td> -3,72</td><td> 7,11</td><td> 2,84</td>

<td>C *</td><td> 8,72</td><td> 8,82</td><td> 3,78</td><td> 9,41</td><td> 7,41</td><td> 5,64</td><td> 7,52</td><td> 11,08</td><td> 3,32</td>

<td>H °</td><td> 210</td><td> 56</td><td> 140</td><td> 210</td><td> 66</td><td> 164</td><td> 210</td><td> 40</td><td> 59</td>

TABLE 2 (Cont.)

<td rowspan="2"></td><td colspan="3">Trans. Composite 58</td><td colspan="3">Trans. Composite 60</td>

<td>Crystal</td><td>PVB</td><td>Trans.</td><td>Crystal</td><td>PVB</td><td>Trans.</td>

<td>^{t (in}.)</td><td> 0,1158</td><td> 0,030</td><td> 0,1458</td><td> 0,1215</td><td> 0,030</td><td> 0,1515</td>

<td>LTA (%)</td><td> 78,4</td><td> 83,6</td><td> 71,0</td><td> 77,8</td><td> 84,1</td><td> 71,0</td>

<td>TSET (%)</td><td> 51,3</td><td> 81,3</td><td> 44,1</td><td> 50,2</td><td> 83,1</td><td> 44,5</td>

<td>PR</td><td> 1,53</td><td> 1,03</td><td> 1,61</td><td> 1,55</td><td> 1,01</td><td> 1,59</td>

<td>DW (nm)</td><td> 487,9</td><td> 585,6</td><td> 576,7</td><td> 487,8</td><td> 605,7</td><td>512.6c</td>

<td>Pe</td><td> 6,30</td><td> 12,67</td><td> 6,96</td><td> 6,60</td><td> 5,76</td><td> 1,40</td>

<td>L *</td><td> 92,1</td><td> 91,4</td><td> 86,8</td><td> 91,8</td><td> 92,0</td><td> -0,87</td>

<td>to*</td><td> -6,37</td><td> 7,76</td><td> 1,08</td><td> -6,66</td><td> 9,53</td><td> 2,71</td>

<td>b *</td><td> -3,63</td><td> 10,70</td><td> 6,42</td><td> -3,80</td><td> 3,37</td><td> -0,87</td>

<td>C *</td><td> 7,33</td><td> 13,22</td><td> 6,51</td><td> 7,67</td><td> 10,11</td><td> 2,85</td>

<td>H °</td><td> 210</td><td> 54</td><td> 80</td><td> 210</td><td> 19</td><td> 342</td>

IS 2 138 118 T3

Referring to Table 2, a high performance solar control composite transparency similar to that described above in Table 1 can be produced using a blue glass substrate. Blue colored glass can be characterized as having a dominant wavelength between 450-490 nm, depending on the lighting conditions and the perceptions of the observer. This range is generally equivalent to a pitch angle range of 200-.300 ° C. In particular, the glass substrate used in Table 2 is a blue glass that can be purchased from PPG Industries, Inc. and is sold under the trade name SOLEXTRA.^(R). As in Table 1, a clear coat and three different tinted polyvinyl butyral layers, which complement the color of the blue substrate, are combined with the blue glass substrate to illustrate how it can be changed from a blue color to a bluish gray to obtain a composite transparency of gray color, while maintaining a high performance ratio. With an LTA level of 71%, this glass substrate has a TSET of 40.0%, and a performance ratio of 1.78. The dominant wavelength of the blue substrate is 488 nm and its color is characterized in the CIELAB color system as L * = 89.3, a * = -10.0, b * = 5.8 and C * = 11, 6 and H = 210. It should be appreciated that although the color of the substrate is characterized as "blue", the crystal includes a slightly greenish coloration, as can be deduced from its coordinates at^* , b^* . Furthermore, although blue glass is generally characterized as glass having a hue angle of 200-300 °, in the present invention it is preferred that a blue glass substrate have a hue angle between 200-230, and more preferably between 200 -220.

With reference to Table 2 and Figure 3, this substrate with one clear PVB layer and three tinted layers is identified as composite transparencies 40, 42, 44, and 46, respectively. For the blue glass substrate presented in Table 2 having a hue angle of 210 °, the complementary plastic layer will generally have an orange color. As can be seen from Table 2, the tinted plastic layer in composite transparencies 42, 44, and 46 has an angle of hue of approximately 32 °. Depending on the amount of colorants in the tinted layer, the chromaticity of the transparency is reduced until the composite transparency 46 is gray in color, but still has a higher performance ratio than available for gray glass compositions. More particularly, in composite transparency 42, the first tinted layer reduces the transparency chromatography to C^* = 8.14. The color of the transparency is still basically blue, but the addition of the tinted layer has reduced the chromaticity of Composite Transparency 42 compared to Composite Transparency 40, which incorporates a clear plastic layer, and has made the final product more colored. neutral. Composite transparency 44 incorporates a tinted layer that reduces the chromaticity of the transparency compared to the composite transparency 42 and the third tinted layer incorporated in the composite transparency 46 reduces the chromaticity to C^* = 0.96. At this intensity level, composite transparency 46 appears to be neutral gray in color.

As with the composite transparencies in Table 1, the color of the tinted plastic layer used with the blue glass substrate in Table 2 can be changed to suit the desired color of the transparency. More particularly, with reference to Table 2, the glass substrate has a hue angle of 210^° and the tinted plaster coating on composite transparencies 42, 44, and 46 has a complementary hue angle of approximately 32^°. However, if the hue angle of the plastic layer is less than the complement of the hue angle of the substrate, the color of the transparency tended to be bluish-red, at the same time still reducing the overall chromaticity of the transparency compared to the substrate. More particularly, on composite transparencies 48 and 50, the PVB layer has a hue angle of 6^° and 355^°, respectively. Referring to Figure 3, these transparencies are red-blue in color, with composite transparency 48 being red-blue gray in color. Similarly, if the hue angle of the plastic layer combined with the substrate were greater than the complement of the substrate hue angle, the color of the transparency would tend to be bluish-green, while still reducing the overall chromaticity of the substrate. transparency compared to the substrate. More particularly, in composite transparencies 52 and 54, the PVB layer has a hue angle of 56^° y66^°, respectively. Referring to Figure 3, these transparencies are green-blue in color, with composite transparency 52 being gray-green-blue in color.

Composite transparencies 56, 58 and 60 are additional examples of how a blue glass substrate can be combined with a tinted plastic layer to provide a different color transparency with a high yield ratio. More particularly, composite transparencies 56 and 58 are bronze-gray transparencies with a yield ratio of approximately 1.6. When comparing the color of these transparencies, composite transparency 56 appeared to be more gray than composite transparency 58. Composite transparency 60 is a purple-gray transparency with a yield ratio of 1.59.

The composite transparencies presented in Tables 1 and 2 include substrate compositions

ES 2 138 118 T3 specific high performance solar control green or blue color, combined with complementary purple or orange PVB layer (s). However, it would be appreciated that the present invention is not limited to the use of only high performance glasses or a particular glass color, but can be used with any substrate to reduce its intensity. The tinted plastic material can be produced to reduce the intensity of any colored substrate as described above and in particular to produce a gray colored transparency. For example, if the color of the glass is an annoying green color, a tinted plastic layer can be combined with the glass to reduce the chromaticity of the transparency and provide a neutral green color and, if desired, to reduce the chromaticity of the transparency. to provide a gray composite transparency, as shown by the progressive color change of composite transparencies 10, 12, 14 and 16 and illustrated in Figure 3.

Although the preferred composite transparencies of the present invention include a glass substrate and a tinted plastic layer to reduce the chromaticity of the transparency compared to glass substrates to produce a more neutral color, and in the cases of solar control glass to maintain a high performance relationship of such transparency, this end result can be obtained in other ways. In particular, instead of using a tinted plastic layer, a coating or film can be applied to a major surface of a plastic layer or to a major surface of the glass substrate. In particular, with a green glass substrate, a purple coating (that is, a coating having an angle of hue that generally complements that of the glass substrate) can be applied to a plastic layer that is subsequently blended with the glass substrate. as an alternative directly to the glass surface to produce a more neutral transparency and, if desired, a gray composite transparency. The coating can be applied in any of a number of well known conventional techniques for applying a coating or film to plastic or glass. Although not required, it is desirable for the coating to incorporate materials that are highly absorbent in specific wavelength regions to maximize the performance ratio. Although it is not limiting in the present invention, for combination with a green substrate, such coating can be a lightly tinted thermoset acrylic coating as described in US Patent No.^°s 5,085,903 and 5,182,148 issued to Kapp et al. Such a coating would incorporate red and violet dyes to produce the required purple color and to complement the green substrate. Orange (or red and yellow) dyes can be used to complement a blue glass substrate.

As another alternative, two clear coats that have complementary colors can be laminated together to produce the same effect. In particular, a green glass substrate can be laminated onto a complementary purple glass to produce a more neutral or gray composite transparency. Such a purple crystal may be a highly oxidized crystal that uses Ma⁺³ as a colorant.

It will be appreciated that the composite transparency described in the present invention may include a single-layer glass construction as well as multi-layer glass construction, as is typical in the construction of automobile side and rear windows, windshields and sunroof. Additionally, composite transparency can also incorporate substrates that have different colors and / or performance characteristics. For example, a car windshield can combine two layers of high-performance solar control glass, or alternatively, combine a high-performance solar control layer with a lower-performance glass layer, or even a clear glass layer, with supplemental polyvinyl butyral interlayer to produce a gray colored windshield that has a performance ratio of 1.4 more. It would be further appreciated that a colored glass layer can be combined with combinations of additional coatings, plastic layers and / or rigid layers to produce the desired color and intensity while maintaining a high performance relationship. In addition, other rigid substrates can also be used in place of a glass substrate. For example, a layer of polycarbonate or other rigid plastic laminate material can be used in place of or in combination with a layer of glass.

IS 2 138 118 T3

TABLE 3

<td rowspan="2"></td><td colspan="3">Trans. Composite 70</td><td colspan="3">Trans. Composite 72</td>

<td>Crystal</td><td>PVB</td><td>Trans.</td><td>Crystal</td><td>PVB</td><td>Trans.</td>

<td>^{t (in}.)</td><td> 0,867</td><td> 0,030</td><td> 0,897</td><td> 0,852</td><td> 0,030</td><td> 0,882</td>

<td>LTA (%)</td><td> 31,2</td><td> 62,5</td><td> 20,0</td><td> 33,1</td><td> 67,1</td><td> 20,0</td>

<td>TSET (%)</td><td> 12,0</td><td> 69,5</td><td> 7,6</td><td> 16,2</td><td> 66,59</td><td> 7,3</td>

<td>PR</td><td> 2,61</td><td> 0,90</td><td> 2,63</td><td> 2,04</td><td> 1,0</td><td> 2,75</td>

<td>DW (nm)</td><td> 513,8</td><td>515.8c</td><td> 510,5</td><td> 486,3</td><td> 593,75</td><td> 494,2</td>

<td>Pe</td><td> 11,13</td><td> 21,12</td><td> 0,87</td><td> 35,81</td><td> 38,8</td><td> 2,28</td>

<td>L *</td><td> 65,0</td><td> 80,2</td><td> 51,7</td><td> 69,7</td><td> 79,49</td><td> 51,9</td>

<td>to*</td><td> -27,01</td><td> 30,97</td><td> 0,14</td><td> -28,92</td><td> 33,56</td><td> -0,47</td>

<td>b *</td><td> 11,24</td><td> -13,02</td><td> 0,28</td><td> -18,00</td><td> 27,40</td><td> -0,45</td>

<td>C *</td><td> 29,26</td><td> 33,59</td><td> 0,32</td><td> 34,06</td><td> 43</td><td> 0,65</td>

<td>H °</td><td> 157</td><td> 337</td><td> 63</td><td> 212</td><td> 39</td><td> 224</td>

The present invention can also be used to produce what is commonly referred to as privacy glazing which typically has an LTA &lt;50% and preferably &lt;35%. More particularly, referring to Table 3, composite transparency 70 represents a dark gray transparency incorporating a green substrate having a hue angle of 157^° and an intermediate layer of purple color that has a hue angle of 337^°, which complements the hue angle of the green substrate. Composite transparency 72 represents a dark gray transparency incorporating a blue substrate that has a hue angle of 212^° and an orange midcoat that has a hue angle of 39^° which generally complements the hue angle of the blue substrate. As shown in Table 3, both composite transparencies have an LTA of 20% and the performance ratios for the 70 and 72 composite transparencies are 2.63 and 2.75, respectively, indicating a low amount of solar energy transmittance with with respect to this level of light transmittance.

IS 2 138 118 T3

TABLE 4

<td rowspan="2"></td><td colspan="3">Trans. Composite 74</td><td colspan="3">Trans. Composite 76</td><td colspan="3">Trans. Composite 78</td>

<td>Crystal</td><td>PVB</td><td>Trans.</td><td>Crystal</td><td>PVB</td><td>Trans.</td><td>Crystal</td><td>PVB</td><td>Trans.</td>

<td>^{t (in}.)</td><td> 0,378</td><td> 0,030</td><td> 0,408</td><td> 0,378</td><td> 0,030</td><td> 0,408</td><td> 0,270</td><td> 0,030</td><td> 0,300</td>

<td>LTA (%)</td><td> 58,7</td><td> 74,8</td><td> 47,4</td><td> 60,8</td><td> 72,0</td><td> 45,8</td><td> 70,4</td><td> 60,2</td><td> 46,2</td>

<td>TSET (%)</td><td> 27,1</td><td> 79,9</td><td> 22,7</td><td> 27,3</td><td> 76,1</td><td> 19,6</td><td> 43,3</td><td> 73,5</td><td> 32,5</td>

<td>PR</td><td> 2,17</td><td> 0,94</td><td> 2,10</td><td> 2,23</td><td> 0,95</td><td> 2,34</td><td> 1,63</td><td> 0,82</td><td> 1,42</td>

<td>DW (nm)</td><td> 512,3</td><td>513.8c</td><td> 502,4</td><td> 487,3</td><td> 594,1</td><td> 493,7</td><td> 559,8</td><td>563.7c</td><td> 511,8</td>

<td>Pe</td><td> 5,07</td><td> 10,11</td><td> 0,72</td><td> 18,82</td><td> 17,69</td><td> 1,37</td><td> 10,3</td><td> 10,5</td><td> 0,52</td>

<td>L *</td><td> 81,3</td><td> 89,0</td><td> 74,3</td><td> 82,9</td><td> 87,1</td><td> 73,2</td><td> 87,0</td><td> 82,0</td><td> 73,5</td>

<td>to*</td><td> -15,20</td><td> 15,64</td><td> -0,46</td><td> -17,41</td><td> 18,20</td><td> -0,52</td><td> -9,47</td><td> 9,15</td><td> -0,66</td>

<td>b *</td><td> 6,11</td><td> -6,25</td><td> 0,18</td><td> -10,34</td><td> 12,50</td><td> -0,34</td><td> 12,1</td><td> -12,2</td><td> 0,42</td>

<td>C *</td><td> 16,38</td><td> 16,85</td><td> 0,49</td><td> 20,25</td><td> 22,08</td><td> 0,62</td><td> 15,4</td><td> 15,2</td><td> 0,78</td>

<td>H °</td><td> 158</td><td> 338</td><td> 159</td><td> 211</td><td> 34</td><td> 214</td><td> 128</td><td> 307</td><td> 147</td>

The present invention can also be used in architectural applications incorporating laminated, coated or spaced layers. More particularly, with reference to Table 4, composite transparency 74 represents a gray transparency incorporating a green substrate having a hue angle of 158^° and a purple midcoat that has a hue angle of 338^° that complements the hue angle of the green substrate. Composite transparency 76 represents a gray transparency incorporating a blue substrate that has a hue angle of 211^° and an orange midcoat that has a hue angle of 34^° which generally complements the hue angle of the blue substrate. Composite transparency 78 represents a gray transparency incorporating a yellow-green substrate that has a hue angle of 128^° and a violet midcoat that has a hue angle of 307^° that generally complements the tonal angle of the substrate. In architectural glazing applications, the luminous transmittance is based on CIE's standard illuminant “C” (LTC) and 2^° of the observer. As shown in Table 4, the performance ratios (based on LTC) for composite transparencies 74, 76, and 78 are 2.10, 2.34, and 1.42, respectively.

The present invention provides the ability to manufacture color-matched composite transparencies and a high performance ratio without having to change the base glass composition. In addition, the color intensity of the composite transparency can be controlled to make the transparency color more neutral compared to the substrate and, if desired, to produce a high performance solar control gray composite transparency.

The present invention also provides a system whereby high performance solar control glass substrates that are outside of desired color tolerances can be combined with custom tinted plastic layers or coatings to provide transparency having the same color and color. desired intensity and which additionally have a high performance ratio.

Other variations, which will be known to those skilled in the art based on the description presented herein, can be derived without departing from the scope of the invention, as defined by the claims that follow.