Patent Number: 059050144
Section: claims

1. A radiation image storage panel having a support, an intermediate layer and a phosphor layer comprising a binder and a stimulable phosphor dispersed therein, said panel being colored with a colorant so that the mean reflectance of said panel in the wavelength region of the stimulating rays for said stimulating phosphor is lower than the mean reflectance of said panel in the wavelength region of the light emitted by said stimulable phosphor upon stimulation thereof, characterized in that said colorant is a triarylmethane dye having at least one aqueous alkaline soluble group and is present in at least one of said support, said phosphor layer or an intermediate layer between said support and said phosphor layer. 2. A radiation image storage panel according to claim 1, wherein the said colorant is a triphenylmethane dye according to the general formula (I), ##STR3## wherein R.sup.1 -R.sup.8 each independently represents hydrogen, alkyl or aryl, provided that at least one of R.sup.1 -R.sup.8 represents an acidic group. 3. A radiation image storage panel according to claim 1, wherein the said colorant has a structure corresponding to formula (II) ##STR4## 4. A radiation image storage panel according to claim 1, wherein the said support has a reflectance percentage of from 45 to 60% in the wavelength range from 350 to 600 nm. 5. A radiation image storage panel according to claim 1, wherein the said intermediate layer has a reflectance percentage of from 85 to 100% in the wavelength range from 350 to 600 nm. 6. A radiation image storage panel according to claim 1, wherein the said support is covered with an aluminum layer which is present between the said support and the said intermediate layer. 7. A radiation image storage panel according to claim 1, wherein the wavelength region of the stimulating rays is between 500 and 700 nm . 8. A radiation image storage panel according to claim 1, wherein the wavelength region of light emitted by said stimulable phosphor upon stimulation thereof is between 350 and 450 nm. 9. A radiation image storage panel according to claim 1, wherein the said binder is a rubbery binder substantially consisting of one or more block copolymers, having a saturated elastomeric midblock and a thermoplastic styrene endblock, as rubbery and/or elastomeric polymers. 10. A radiation image storage panel according to claim 1, wherein said stimulable phosphor has a composition according to the formula EQU Ba.sub.1-x-y-p-3q-z Sr.sub.x M.sub.y.sup.2+ M.sub.2p.sup.1+ M.sub.2q.sup.3+ F.sub.2-a-b Br.sub.a I.sub.b :zEu M.sup.1+ is at least one alkali metal selected from the group consisting of Li, Na, K, Rb and Cs;  M.sup.2+ is at least one divalent metal selected from the group consisting of Ca, Mg and Pb;  M.sup.3+ is at least one trivalent metal selected from the group consisting of Al, Ga, In, Tl, Sb, Bi, Y and a trivalent lanthanide;  0.ltoreq.x.ltoreq.0.30, 0.ltoreq.y.ltoreq.0.10, 10.sup.-6 .ltoreq.z.ltoreq.0.2,  0.ltoreq.p.ltoreq.0.3, 0.ltoreq.q.ltoreq.0.1,  0.05.ltoreq.a.ltoreq.0.76, 0.20.ltoreq.b.ltoreq.0.90 and a+b&lt;1.00.  M.sup.1+ is at least one alkali metal selected from the group consisting of Li, Na, K, Rb and Cs;  M.sup.2+ is at least one divalent metal selected from the group consisting of Ca, Mg and Pb;  M.sup.3+ is at least one trivalent metal selected from the group consisting of Al, Ga, In, Ti, Sb, Bi, Y and a trivalent lanthanide;  0.06.ltoreq.x.ltoreq.0.20, 0.ltoreq.y.ltoreq.0.10, 10.sup.-6 .ltoreq.z.ltoreq.0.2,  .ltoreq. p.ltoreq.0.3, 0.ltoreq.q.ltoreq.0.1,  0.05.ltoreq.a.ltoreq.0.76, 0.20.ltoreq.b.ltoreq.0.90 and 0.85.ltoreq.a+b.ltoreq.0.96.  M.sup.1+ is Rb or Cs;  M.sup.2+ is Pb;  M.sup.3+ is at least one trivalent metal selected from the group consisting of Al, Ga, In, Tl, Sb, Bi, Y and a trivalent lanthanide;  0.06.ltoreq.x.ltoreq.0.20, 10.sup.-4 .ltoreq.y.ltoreq.10.sup.-3,  10.sup.-4 .ltoreq.p.ltoreq.10.sup.-1, q=0, 10.sup.-6 .ltoreq.z.ltoreq.0.2,  0.05.ltoreq.a.ltoreq.0.76, 0.20.ltoreq.b.ltoreq.0.90, and 0.85.ltoreq.a+b.ltoreq.0.96. 11. A radiation image storage panel according to claim 10, wherein said trivalent lanthanide is selected from the group consisting of La, Ce, Pr, Nd, Sm, Gd, Tb, Dy, Ho, Er, Tm, Yb, and Lu. 12. A radiation image storage panel according to claim 1, wherein said stimulable phosphor has a composition according to the formula EQU Ba.sub.1-x-y-p-3q-z Sr.sub.x M.sub.y.sup.2+ M.sub.2p.sup.1+ M.sub.2q.sup.3+ F.sub.2-a-b Br.sub.a I.sub.b :zEu 13. A radiation image storage panel according to claim 1, wherein said stimulable phosphor has a composition according to the formula EQU Ba.sub.1-x-y-p-3q-z Sr.sub.x M.sub.y.sup.2+ M.sub.2p.sup.1+ M.sub.2q.sup.3+ F.sub.2-a-b Br.sub.a I.sub.b :zEu