LUMINESCENT ADHESIVE DECORATION FOR HOROLOGY COMPONENTS

Abstract

A luminescent adhesive (1) for horology components including: a first layer (10) of an adhesive material; a second layer (11), referred to as the intermediate layer, including a binder loaded with between 10% and 80% by mass of a phosphorescent pigment emitting in the UVA spectrum; and a third layer (12), semi-transparent to UV rays, including a binder loaded with between 10% and 50% by mass of a phosphorescent pigment emitting in the visible spectrum.

Claims

1. A luminescent adhesive (1) for horology components comprising: a first layer (10) of an adhesive material; a second layer (11), referred to as the intermediate layer, comprising a binder loaded with between 10% and 80% by mass of a phosphorescent pigment emitting in the UVA spectrum; and a third layer (12) comprising a binder loaded with between 10% and 50% by mass of a phosphorescent pigment emitting in the visible spectrum.

2. The adhesive (1) according to claim 1, wherein the third layer (12) is semi-transparent to UV rays.

3. The adhesive (1) according to claim 1, wherein the first layer (10) is an epoxy, an acrylic, a polyurethane or a rubber solvent.

4. The adhesive (1) according to claim 1, wherein the phosphorescent pigment emitting in the UVA spectrum exhibits an emission peak at a wavelength comprised between 300 nm and 400 nm.

5. The adhesive (1) according to claim 1, wherein the first layer (10) has a thickness comprised between 20 m and 200 m.

6. The adhesive (1) according to claim 1, wherein the second layer (11) has a thickness comprised between 50 m and 500 m.

7. The adhesive (1) according to claim 1, wherein the third layer (12) has a thickness comprised between 50 m and 500 m.

8. The adhesive (1) according to claim 1, wherein the phosphorescent pigment emitting in the visible spectrum is strontium aluminate (SrAl.sub.2O.sub.4) spiked with europium (Eu.sup.2+) or with dysprosium (Dy.sup.3+).

9. The adhesive (1) according to claim 1, wherein the phosphorescent pigment emitting in the UVA spectrum is a compound such as LiScGeO.sub.4:Bi.sup.3+, LiYGeO.sub.4:Bi.sup.3+, Sr.sub.2MgGe.sub.2O.sub.7Pb.sup.2+, NaLuGeO.sub.4Bi.sup.3+, or CaMgGeO.sub.4:Bi.sup.3+.

10. The adhesive (1) according to claim 1, wherein the second layer (11) has a thickness greater than that of the third layer (12).

11. The adhesive (1) according to claim 1, wherein the binder of the second layer (11) and of the third layer (12) is polyvinyl chloride or polyurethane

Description

BRIEF DESCRIPTION OF THE FIGURES

[0024] Other features and advantages of the invention will become apparent from the following detailed description, given by way of non-limiting example, with reference to the attached drawings in which:

[0025] The FIGURE shows a schematic cross-sectional view of an adhesive according to the invention.

DETAILED DESCRIPTION OF THE INVENTION

[0026] The luminescent adhesive 1 for horology components according to the invention comprises a first layer 10 of an adhesive material, a second layer 11, referred to as the intermediate layer, comprising a binder loaded with between 10% and 80% by mass of a phosphorescent pigment emitting in the UVA spectrum, and a third layer 12 comprising a binder loaded with between 10% and 50% by mass of a phosphorescent pigment emitting in the visible spectrum.

[0027] The adhesive material used for the first layer is an adhesive material that allows the adhesive to be repositioned if necessary. Preferably, the adhesive material of the first layer is chosen among epoxy, acrylic, polyurethane or a rubber solvent.

[0028] The first layer has a thickness comprised between 20 m and 200 m, and preferably between 20 m and 50 m.

[0029] The second layer 11 of the adhesive comprises a phosphorescent pigment emitting in the UVA spectrum; this pigment exhibits an emission peak at a wavelength comprised between 300 nm and 400 nm.

[0030] The second layer has a thickness comprised between 50 m and 500 m, and preferably a thickness comprised between 200 m and 300 m. The second layer must be thick enough to be sufficiently opaque and reflective so as to force the pigments to be emitted towards the third layer.

[0031] Preferably, the phosphorescent pigment emitting in the UVA spectrum used for the second layer is a compound such as LiScGeO.sub.4:Bi.sup.3+, LiYGeO.sub.4:Bi.sup.3+, Sr.sub.2MgGe.sub.2O.sub.7:Pb.sup.2+, NaLuGeO.sub.4:Bi.sup.3+, or CaMgGeO.sub.4:Bi.sup.3+.

[0032] The binder used for the second layer 11 and the third layer 12 is polyvinyl chloride or polyurethane.

[0033] The third layer has a thickness comprised between 50 m and 500 m, and preferably comprised between 150 m and 250 m.

[0034] Advantageously, the third layer has a thickness less than the thickness of the second layer to achieve sufficient transparency for UV rays to pass through to the second layer 11.

[0035] The phosphorescent pigment emitting in the visible spectrum used in the third layer is from the strontium aluminate family (Sr.sub.xAl.sub.yO.sub.z) spiked with europium (Eu2+) or dysprosium (Dy3+).

[0036] These various aspects of the invention provide a luminescent adhesive capable of giving off light for a longer period of time.

[0037] Of course, the present invention is not limited to the illustrated example and is open to various variants and modifications as will be apparent to the person skilled in the art, without departing from the scope of the invention as defined by the claims.