Coloured luminescent pigment, method for the production thereof and uses of same

Abstract

Disclosed is a colored luminescent composite pigment including an association of at least one luminescent pigment having an average particle size of between 50 and 2000 μm and at least one coloring agent. Also disclosed are compositions and materials including the pigment, to the method for the production thereof and to the use of same for coloring materials, particularly of a hydraulic binder composition.

Claims

1. A colored luminescent composite pigment consisting of particles of one or more luminescent pigment and particles of one or more dye that is different than said one or more luminescent pigment, said colored luminescent composite pigment having an average particle size of between about 50 and about 2000 μm, wherein the color of the luminescent pigment and the dye are different, and wherein the particles of one or more luminescent pigment and the particles of one or more dye are in intimate association such that washing of the colored luminescent composite pigment with water does not cause leaching of the one or more dye.

2. Pigment according to claim 1, wherein the average size of the luminescent pigment particles is between about 50 and about 2000 μm.

3. Pigment according to claim 1, wherein the dye has a particle size of 0.1 to 10 μm.

4. Method for preparing a colored luminescent composite pigment comprising the steps of: a) providing a composition of one or more dyes as defined in claim 1 in a fluid; b) mixing with the composition of step a) at least one luminescent pigment as defined in claim 1; and c) drying the mixture obtained in step b) to obtain a colored luminescent composite pigment according to claim 1.

5. Method according to claim 4 comprising a step b″), before or after step c), of depositing a coating on the mixture obtained in step c).

6. Colored luminescent composite pigment produced by the method according to claim 4.

7. Colored luminescent composition comprising a transparent matrix and at least one colored luminescent composite pigment according to claim 1.

8. Aggregate comprising a transparent matrix and at least one colored luminescent composite pigment according to claim 1.

9. Composition or aggregate according to claim 7, wherein the transparent matrix is chosen from polymethyl methacrylate (PMMA), polycarbonate (PC), polyvinyl chloride (PVC), polyurethane (PU), copolymers styrene acrylonitrile (SAN) and their derivatives and glass.

10. Aggregate according to claim 9 for which the transparent matrix is PMMA.

11. Method for preparing a composition according to claim 7, comprising the steps of: 1) providing a colored luminescent composite pigment; 2) dispersion of the composite pigment in a liquid capable of forming the transparent matrix; 3) optionally shaping the dispersion obtained in step 2), in a mold; 4) optionally solidifying the mixture obtained in step 2) or 3); 5) optionally comminuting the composition obtained in step 4) to obtain aggregates.

12. Preparation method according to claim 11, comprising the step 3) of shaping the dispersion obtained in step 2), in a mold.

13. Method according to claim 11 for preparing a granulate, wherein the transparent matrix is PMMA, comprising the steps of: 1) providing a colored luminescent composite pigment according to claim 1; 2) dispersion of the composite pigment in a solution of melted PMMA; 3) shaping the dispersion obtained in step 2) in a mold, using an injection molding machine or by rotational molding; 4) solidification of the mixture obtained in step 3); 5) comminuting the composition obtained in step 4).

14. A hydraulic binder composition comprising the colored luminescent composite pigment according to claim 1.

15. Material comprising a colored luminescent composite pigment according to claim 1, wherein the material is a hydraulic binder composition, a plastic, a varnish, a paint, a plaster, a coating, an ink, paper, cardboard, a cosmetic composition, a glass, a ceramic, an enamel, a textiles, tile adhesives, or tile joints.

16. Coating comprising a colored luminescent composite pigment according to claim 1.

17. Composition of hydraulic binder comprising a colored luminescent composite pigment according to claim 1.

18. Method for preparing an aggregate according to claim 8, comprising the steps of: 1) providing the colored luminescent composite pigment; 2) dispersion of the composite pigment in a liquid capable of forming the transparent matrix; 3) optionally shaping the dispersion obtained in step 2), in a mold; 4) optionally solidifying the mixture obtained in step 2) or 3); 5) optionally comminuting the composition obtained in step 4) to obtain aggregates.

19. A hydraulic binder composition comprising the colored luminescent composition according to claim 7.

20. A hydraulic binder composition comprising the aggregate according to claim 8.

Description

(1) The present invention will now be described with the aid of figures and non-limiting examples.

(2) FIG. 1 shows the particle volume in vol. % versus particle size in μm and provides the particle size distribution measured by laser granulometry (Mastersizer 2000) (example 7).

(3) FIG. 2 shows the granulometric curve of the aggregates according to the standards NF EN 933-1 and NF EN 933-2 (example 8).

EXAMPLE 1

(4) 3 g of yellow ocher dye (of the brand Universal Dye) are dispersed at 20° C. with stirring in 2 liters of softened water.

(5) The 2 liters of dye suspension are then placed in a kneader.

(6) 1 kg of Realglow PYG 6LLL luminescent pigment emitting in yellow/green (SrAl.sub.2O.sub.4 doped Eu and Dy, particle size 400 μm) is poured in and kneaded for 3 minutes.

(7) After stopping the stirring, the mixture decants rapidly and the decantate is spread on racks to a thickness of 2 to 3 cm. The rack is then placed for 4 hours in a chamber to be heated at 50° C. under a stream of hot air. The pigment is then in the form of a fluid powder that is not necessary to comminute. In daylight, the pigment has the beige color of the dye. In the dark, it emits a yellow/green light identical to that of the luminescent pigment.

(8) The colored pigment is available to be incorporated in materials such as for example cementitious materials (mortar, concrete, screed, . . . ) or plastic materials (PMMA, . . . ), which after comminuting to the desired size, may be used as aggregates in concrete.

EXAMPLES 2 AND 3: THE IMPORTANCE OF HAVING AN UNTREATED LUMINESCENT PIGMENT

(9) Two luminescent pigments A and B composed of strontium aluminate (yellow color in daylight, emitting in the blue in the dark, 350 μm particle size) are used. They differ only in the fact that A is untreated whereas B has been treated with polyethylene wax to give it better resistance to water and moisture. The colored pigments 2 and 3 are prepared according to the procedure of Example 1 from the compositions described in the table below:

(10) TABLE-US-00001 Example 2 Example 3 Luminescent pigment A 250 g Luminescent pigment B 250 g Softened water 500 g 500 g Blue pigment paste  1 g  1 g

(11) The pigment content of the paste is 60% by weight.

(12) After drying according to the same procedure as in Example 1, the colored pigment of Example 2 is in the form of a homogeneous powder of blue color in daylight and emitting blue in the night. On the other hand, the colored pigment of Example 3 is not homogeneous, of generally less intense color, with the presence of dark blue agglomerates. This inhomogeneity is also sensitive when we look at the light emitted in the dark by the sample 3.

(13) In addition, 5 g of each of these two pigments are placed while stirring in 1 liter of tap water. After about 5 minutes, the stirring is stopped. The pigment 2 decants leaving the water transparent. The pigment of Example 3 decants and leaves the water colored blue, indicating that the colored luminescent pigment of Example 3 would be very sensitive to leaching problems, which is detrimental in terms of durability. The comparison of these Example 2 samples shows the importance of having an untreated luminescent pigment in order to achieve an effective coloration.

EXAMPLE 4: IMPORTANCE OF GRANULOMETRY

(14) Untreated luminescent pigments of the same chemical composition as that of Example 2 and variable particle sizes are used. They are mixed with the same blue pigment paste and according to the same procedure as in Example 2.

(15) The brightness remanence is measured according to DIN 67510-1: 2009. The intensities at 10 and 60 min, as well as the extinction times (when the intensity falls below 0.3 mcd/m.sup.2). These data were measured for luminescent pigments before staining and estimated for the colored luminescent pigment. The unit cd is the candela which is the unit of measure of the luminous intensity.

(16) TABLE-US-00002 Colored Luminescent pigment luminescent pigment Intensity Intensity Intensity Intensity after after Extinction after after Diameter 60 min 10 min in min at 60 min 10 min (μm) (mcd/m.sup.2) (mcd/m.sup.2) 0.3 mcd/m.sup.2 (mcd/m.sup.2) (mcd/m.sup.2) 0.5 0.9 0 1 0.9 0 1 3 0 4 2.9 0 3 8 2 10 7.6 1.9 30 100 10 90 95 10 100 250 28 340 238 27 350 430 69 890 409 66 1000 590 89 1100 561 85

(17) It emerges from these measurements that we have an interest in using pigments of large diameters, typically at least 30 μm. In fact, for finer pigments, the remanence lasts less than one hour, which is very short, especially for the applications covered by the present invention.

EXAMPLE 5: PHOTOLUMINESCENCE MEASUREMENT

(18) This measurement is carried out according to the standards NF X 08-050-1 and DIN 67510-1.

(19) The object is to measure the luminance (mcd/m.sub.2) restituted by a composition (C) according to the invention after exposure under illumination produced by a Xenon arc.

(20) The sample is a material consisting of 30 parts of composite luminescent pigment according to the invention and 100 parts of PMMA.

(21) The luminous luminances restituted after 10, 60, 90, 480 and 900 mn after the source has been stopped are given in the following table:

(22) TABLE-US-00003 Restitution Restitution Restitution Restitution Restitution at 10 min at 60 min at 90 min at 480 min at 900 min (mcd/m.sup.2) (mcd/m.sup.2) (mcd/m.sup.2) (mcd/m.sup.2) (mcd/m.sup.2) 103.7 ± 0.1 20.2 ± 0.1 13.2 ± 0.1 1.7 ± 0.1 0.6 ± 0.1

(23) The maximum luminance re-emitted by the sample after 5 minutes of illumination under 1000 lux is about 868 mcd/m.sup.2. In view of the restitution at 60 min, this places the material in Class A of NF X 08-050-1.

(24) The results therefore show a significant remanence of the composite pigments of the invention.

EXAMPLE 6: CHARACTERIZATION OF PERFORMANCE ON MORTAR

(25) The flexural and compressive strengths according to NF EN 196-1 and the setting time (TP) according to NF EN 480-2 of a mortar composition in which 30% of the AFNOR sand was substituted by a luminescent granulate of size 0/2 (average diameter between 0 and 2 mm) according to the invention. The AFNOR sand is a standardized sand with a grain size between 0 and 2 mm (determined by sieving and complies with the requirements of EN 196-1 (2006) and ISO 679 (2009).

(26) Mortar composition (with AFNOR sand substituted by 30% by weight with a 0/2 luminescent material)

(27) TABLE-US-00004 CEM I 52.5N Saint Pierre La Cour 450 g AFNOR sand 945 g Luminescent material 0/2 405 g Water 225 g

(28) The start time (DP), end of setting (FP) and total setting time (TP) are grouped in the table below:

(29) TABLE-US-00005 Time (mn) DP 195 FP 380 TP 185

(30) These results show that the replacement of a portion of the typical aggregates with aggregates according to the invention does not delay the setting of the hydraulic composition.

(31) The results of the compressive and flexural strengths are shown in the tables below:

(32) TABLE-US-00006 Period Resistance to compression (Mpa) 24 h 17 7 days 37 28 days 48

(33) TABLE-US-00007 Period Resistance to flexion (Mpa) 24 h 4 7 days 6 28 days 7

(34) These results show that the replacement of a portion of the typical aggregates with aggregates according to the invention has no detrimental influence on the strengths of the mortar compositions obtained.

EXAMPLE 7: CHARACTERIZATION OF LUMINESCENT PIGMENT SIZE

(35) The particle size of a luminescent pigment obtained according to Example 1 was determined by laser granulometry (Mastersizer 2000).

(36) FIG. 1 shows the particle size distribution in volume.

(37) Ordinate: Volume (%)

(38) Abscissa: Size (μm)

(39) The luminescent powder has the following profile provided in FIG. 1 according to a volume distribution:

(40) D10: 14.6 μm

(41) D50: 50.5 μm

(42) D90: 105.6 μm

EXAMPLE 8: CHARACTERIZATION OF THE GRANULOMETRY OF LUMINESCENT AGGREGATES

(43) The granulometry of the aggregates of size 6/10 comprising 20 parts of luminescent pigment and 100 parts of PMMA was determined according to the standards NF EN 933-1 and NF EN 933-2 and is provided in FIG. 2.

(44) FIG. 2 shows a grain size curve representing the cumulative percentage by weight of sieve (mm).