FILTER FOR GLASS CONTAINER

Abstract

A light filtering glass container including a glass container coated with a light filtering coating obtained by curing a polymerizable composition including semi-conductive nanoparticles. The absorbance through a 5-micrometer thick light filtering coating is greater than 0.5 for each light wavelength ranging from 350 nm to λ.sub.cut, λ.sub.cut being in the range from 420 nm to 480 nm, and the difference of lightness between the uncoated glass container and the glass container with the light filtering coating is lower than 5.

Claims

1.-14. (canceled)

15. A light filtering glass container comprising: (i) a glass container having a colour (L*ug, C*ug, h*ug); (ii) a light filtering coating obtained by curing a polymerizable composition comprising semi-conductive nanoparticles, said light filtering coating being on at least a part of the glass container; wherein the absorbance through a 5-micrometer thick light filtering coating is greater than 0.5 for each light wavelength ranging from 350 nm to λ.sub.cut, λ.sub.cut being in the range from 420 nm to 480 nm; and wherein the difference of lightness between the uncoated glass container and the glass container with the light filtering coating is lower than 5.

16. The light filtering glass container according to claim 15, wherein the luminous transmission of the glass container with the light filtering coating is greater than 90% of the luminous transmission of the uncoated glass container.

17. The light filtering glass container according to claim 16, wherein the luminous transmission of the glass container with the light filtering coating is greater than 95% of the luminous transmission of the uncoated glass container.

18. The light filtering glass container according to claim 15, having a chroma C*cg lower than 60.

19. The light filtering glass container according to claim 18, having a chroma C*cg lower than 50.

20. The light filtering glass container according to claim 15, wherein polymerizable composition is a Sol-Gel polymerizable composition.

21. The light filtering glass container according to claim 20, wherein Sol-Gel polymerizable composition comprises monomers or oligomers selected from metal alkoxides, alkoxysilanes, alkylalkoxysilanes, epoxysilanes, epoxyalkoxysilanes, and mixtures thereof.

22. The light filtering glass container according to claim 20, wherein the thickness of light filtering coating is in a range from 1 μm to 15 μm.

23. The light filtering glass container according to claim 20, wherein the thickness of light filtering coating is in a range from 1 μm to 10 μm.

24. The light filtering glass container according to claim 15, wherein polymerizable composition comprises (meth)acrylics monomers or oligomers, epoxy monomers or oligomers, or mixture thereof.

25. The light filtering glass container according to claim 24, wherein the thickness of the light filtering coating is in a range from 2 μm to 100 μm.

26. The light filtering glass container according to claim 24, wherein the thickness of the light filtering coating is in a range from 3 μm to 50 μm.

27. The light filtering glass container according to claim 15, wherein the semi-conductive nanoparticles comprise a material of formula
M.sub.xQ.sub.yE.sub.zA.sub.w(I), wherein: M is selected from the group consisting of Zn, Cd, Hg, Cu, Ag, Au, Ni, Pd, Pt, Co, Fe, Ru, Os, Mn, Tc, Re, Cr, Mo, W, V, Nd, Ta, Ti, Zr, Hf, Be, Mg, Ca, Sr, Ba, Al, Ga, In, Tl, Si, Ge, Sn, Pb, As, Sb, Bi, Sc, Y, La, Ce, Pr, Nd, Sm, Eu, Gd, Tb, Dy, Ho, Er, Tm, Yb, Cs or a mixture thereof; Q is selected from the group consisting of Zn, Cd, Hg, Cu, Ag, Au, Ni, Pd, Pt, Co, Fe, Ru, Os, Mn, Tc, Re, Cr, Mo, W, V, Nd, Ta, Ti, Zr, Hf, Be, Mg, Ca, Sr, Ba, Al, Ga, In, Tl, Si, Ge, Sn, Pb, As, Sb, Bi, Sc, Y, La, Ce, Pr, Nd, Sm, Eu, Gd, Tb, Dy, Ho, Er, Tm, Yb, Cs or a mixture thereof; E is selected from the group consisting of O, S, Se, Te, C, N, P, As, Sb, F, Cl, Br, I, or a mixture thereof; A is selected from the group consisting of O, S, Se, Te, C, N, P, As, Sb, F, Cl, Br, I, or a mixture thereof; and x, y, z and w are independently a decimal number from 0 to 5; x, y, z and w are not simultaneously equal to 0; x and y are not simultaneously equal to 0; z and w may not be simultaneously equal to 0.

28. A light filter for a glass container obtained by curing a polymerizable composition comprising semi-conductive nanoparticles wherein the absorbance through a 5-micrometer thick light filtering coating is higher than 0.5 for each light wavelength ranging from 350 nm to λ.sub.cut, λ.sub.cut being in the range from 420 nm to 480 nm; and wherein the lightness of the light filter is greater than 95.

29. The light filter according to claim 28, having a chroma C* lower than 60.

30. The light filter according to claim 29, having a chroma C* lower than 50.

31. The light filter according to claim 28, wherein polymerizable composition is a Sol-Gel polymerizable composition.

32. The light filter according to claim 28, wherein Sol-Gel polymerizable composition comprises monomers or oligomers selected from metal alkoxides, alkoxysilanes, alkylalkoxysilanes, epoxysilanes, epoxyalkoxysilanes, and mixtures thereof.

33. The light filter according to claim 28, wherein polymerizable composition comprises (meth)acrylics monomers or oligomers, epoxy monomers or oligomers, or mixture thereof.

Description

BRIEF DESCRIPTION OF THE DRAWINGS

[0163] FIG. 1 shows the generic absorbance of a polymerizable composition or material comprising semi conductive nanoparticles (logarithm scale) as a function of wavelength of light from 350 nm to 780 nm (linear scale): A (λ) and the principle of determination of λ.sub.cut.

[0164] FIG. 2 is a schematic representation of various shapes (spheres and plates) and structure (homostructure, core/shell, core/crown, dot in plate) of semi-conductive nanoparticles.

[0165] FIG. 3 shows a glass container with a light filtering coating.

[0166] FIG. 4 shows absorbance curves of nanoparticles NP1, dispersion D1 and coated sheet of glass S1 of example 1.

[0167] FIG. 5 shows transmission curves T of comparative bottles and bottles coated with light filters according to this disclosure, as a function of light wavelength λ.

[0168] FIG. 6 shows Absorbance A of a Riboflavin solution as a function of light wavelength λ. The solution is irradiated with blue light and Absorbance is measured after increasing duration of light exposition (from 0 to 30 hours).

EXAMPLES

[0169] The present invention is further illustrated by the following examples.

[0170] Colorimetry Measurement:

[0171] All colorimetry measurements have been obtained after a measure of transmission followed by computation of colour.

[0172] Transmission was measured with a JASCO UV-VIS770 spectrometer, with Xenon light source, for a range of wavelength from 380 nm to 780 nm.

[0173] Spectrum of Illuminant D.sub.65 is defined in CIE standards.

[0174] Light Filters

[0175] Various coatings have been prepared and applied on glass.

Example 1: Filters

[0176] Dot in plate semi-conductive nanoparticles (hereafter NP1) of formula CdSe.sub.xS.sub.1−X, with x=0.3, comprising a CdSe.sub.0.5S.sub.0.5 dot included in a nanoplate of CdS in which composition varies continuously from core to shell, having a thickness of 1.2 nm (corresponding to 4 monolayers), length of 15 nm and width of 20 nm were prepared in heptane according to procedure disclosed in European Patent EP2633102.

[0177] 0.5 mL of a dispersion comprising NP1 in 10 mM NaHCO.sub.3 solution was mixed with 5 mg of Poly(DHLA-co-PEGMEMA) copolymer of 20 mol % dihydrolipoic acid methacrylate and 80 mol % poly(ethylene glycol) methyl ether methacrylate having Mn of 40 and kept under gentle stirring overnight at 60° C. Then sample was washed with ethanol and nanoparticles capped with polymer in ethanol was obtained. This dispersion D1 has a weight content in nanoparticles of 5%.

[0178] In addition, a Sol-Gel solution SG was also prepared in a separated vial with 100 μL of (3-Glycidyloxypropyl)trimethoxysilane, 65 μL of diethoxydimethylsilane and 35 μL of 0.1 M HCl. Solution SG was stirred for 24 hours at room temperature.

[0179] 50 μL of dispersion D1 was added to 200 μL of solution SG to obtain a polymerizable composition then deposited by spin coating on a glass sheet S0 at 400 rpm during 30 s (dispensing step) then 2000 rpm during 2 min (spreading step). The resulting sample was then heated at 150° C. for 6 h in order to obtain a condensed 5 μm thick Sol-Gel coating having a weight content in CdS nanoplates of 1% after curing. The coated glass sheet is S1.

[0180] The glass sheet before coating has a lightness of 86,3 and a luminous transmittance of 95%.

[0181] After coating, the coated glass sheet has a lightness of 85,73 and a luminous transmittance of 95%. Light filtering coating is highly clear and cosmetic properties of coated bottles are maintained: they appear as bright as uncoated.

[0182] Absorbance curves (A) of nanoparticles NP1 in heptane (semi-dotted line), of dispersion D1 (dotted line) and of the coated glass sheet S1 (solid line) were measured as a function of light wavelength in the UV-visible and are shown on FIG. 4 (logarithmic scale). A wavelength of transition λ.sub.cut of 425 nm is obtained for the coated glass sheet S1.

[0183] Other coatings have been prepared with the same protocol.

[0184] Semi-conductive nanoparticles (hereafter NP2) of formula CdSe.sub.0.75S.sub.0.25 and having a shape of plate with length of 12 nm; width of 20 nm and thickness of 1.2 nm (corresponding to 4 monolayers) were prepared according to procedure disclosed in EP2633102.

[0185] Semi-conductive nanoparticles (hereafter NP3) of formula CdSe and having a shape of plate with length of 10 nm; width of 22 nm and thickness of 1.2 nm (corresponding to 4 monolayers) were prepared according to procedure disclosed in EP2633102.

[0186] Semi-conductive nanoparticles (hereafter NP4) of formula CdSe.sub.0.5S.sub.0.5 and having a shape of plate with length of 10 nm; width of 21 nm and thickness of 1.2 nm (corresponding to 4 monolayers) were prepared according to procedure disclosed in EP2633102.

[0187] Semi-conductive nanoparticles (hereafter NP5) of formula CdS and having a shape of plate with length of 10 nm; width of 20 nm and thickness of 1.5 nm (corresponding to 5 monolayers) were prepared according to procedure disclosed in EP2633102.

[0188] As reported in example 1, the nanoparticles NP2, NP3, NP4 and NP5 were capped with a Poly(DHLA-co-PEGMEMA) copolymer to respectively prepare dispersions D2-D5.

[0189] Table 2 below shows absorbance properties of dispersions D1 and D5:

TABLE-US-00002 TABLE 2 D1 D5 λ.sub.max 422 nm 445 nm λ.sub.0.9 (at 0.9*A.sub.max) 427 nm 450 nm λ.sub.0.5 (0.5*A.sub.max) 434 nm 462 nm λ.sub.0.1 (0.1*A.sub.max) 446 nm 479 nm |λ.sub.0.5 − λ.sub.0.9|  7 nm  12 nm |λ.sub.0.1 − λ.sub.0.9|  19 nm  29 nm

Examples 2: Light Filtering Glass Containers

[0190] A commercial glass bottle B0 was used as glass container. The color of B0 is measured in L*a*b* color system: L*=86,3; a*=−0.16 and b*=0.23.

[0191] The commercial bottle B0 is dip-coated with dispersions D1-D5, then heated at 150° C. for 6 h in order to obtain a condensed 5 μm thick Sol-Gel coating having a weight content in nanoparticles NP1-NP5 of 1% after curing. Coated bottles are B1-B5.

[0192] In addition, a commercial bottle B6 coated with a light filtering film conceived to absorb blue light has been characterized.

[0193] FIG. 3 shows such a light filtering glass container (100), where bottle B0 (110) is totally covered with a light filtering coating (120).

[0194] FIG. 5 shows light transmission through bottles B0 and B6 as a control and B1-B5.

[0195] λ.sub.cut for bottles B1-B5 are respectively 425 nm, 480 nm, 512 nm, 445 nm and 460 nm. The characteristics of bottles B1 and B5 for λ.sub.max, λ.sub.0.9, λ.sub.0.5 and λ.sub.0.1 are the same as the characteristics of dispersion of nanoparticles D1 and D5 listed in table 2: incorporation of nanoparticles in Sol-Gel coating didn't change absorbance features.

[0196] Application to Lightstruck Flavour—Degradation of Riboflavin

[0197] A solution of Riboflavin at concentration of 250 mg. L.sup.−1 is prepared. This solution when measured in a 1 cm path light cuvette presents a maximum of absorbance at 442 nm with absorbance 1.03.

[0198] Bottle B0 was filled with the solution of Riboflavin and exposed to blue LED light exposure for 30 hours (emission spectrum of LED 430-465 nm, irradiance 0.1 W/cm.sup.2). Absorbance curves were recorded at different duration of blue light exposure and are shown on FIG. 6 for 0, 1, 4, 7, 12, 15, 24 and 30 hours (in order defined by the arrow). Absorbance at 442 nm is decreasing from 1.03 to 0.124 demonstrating that 88% Riboflavin has been photodegraded after 30 hours of blue light exposure.

[0199] The same experiment was reproduced using bottles B1 to B6. As a control, the same measurement was done in a bottle B0, without light exposure.

[0200] Table 3 below shows Riboflavine degradation and colorimetric properties of the bottles.

TABLE-US-00003 TABLE 3 Lightness λ.sub.cut % (variation Luminous Bottle (nm) degradation from B0) Chroma transmission B0 NA 88 86.3 0.3 >95% B1 425 73 85.7 (−0.6) 19.5 >95% B2 480 13 84.5 (−1.8) 60 >95% B3 512 8 81.2 (−5.1) 83.5 >95% B4 445 39 85.1 (−1.2) 52.2 >95% B5 460 16 85.5 (−0.8) 56.7 >95% B6 NA 12   70 (−16.3) 72 >95% B0-No NA <2% 86.3 (0)     0.3 NA light

[0201] Table 3 demonstrates that degradation of Riboflavin contained in bottles B1 to B5 has been prevented thanks to light filtering coating.

[0202] Comparative bottle B6 is efficient for Riboflavin protection (12% degradation) but decreases lightness by 16.3: Bottle B6 appears drab, and strongly coloured in orange.

[0203] Besides, bottle B3 has a large effect on brightness (−5.1) and a very strong colour (larger chroma than reference B6, even if lightness is less decreased). Indeed, λcut for B3 is about 512 nm, much larger than 480 nm which has been identified as the upper limit for λ.sub.cut providing a good balance between an efficient light filtering and a high lightness.

[0204] Comparison of bottles B2 and B6 shows that the same protection of Riboflavin is achieved (13% and 12% of degradation), but B2 is brighter: lightness of glass bottle is almost unchanged (from 86.3 to 84.5, to be compared to the lightness of B6:70) and chroma is lower (60 for B2 and 72 for B6).

[0205] Finally, bottles B1, B2, B4 and B5 are good light filtering glass containers, providing protection against development of lightstruck flavour in beverages without degrading brightness of glass containers.