X-ray intensifying screen

• US 6,162,553 A
• Filed: 11/02/1998
• Issued: 12/19/2000
• Est. Priority Date: 11/05/1997
• Status: Expired due to Fees

• Current Assignee: CareStream Health Incorporated
• Original Assignee: Eastman Kodak Company
• Inventors: della Rocca, Carlo Morozzo, Ercoli, Marcella
• Primary Examiner(s): Krynski, William
• Assistant Examiner(s): Garrett, Dawn L.
• Application Number:
  US09/184,211
• Time in Patent Office: 778 Days
• Field of Search: 428/690, 428/913, 428/522, 428/423.1, 250/483.1
• US Class Current: 428/690
• CPC Class Codes: C09K 11/02 Use of particular materials as binders, particle coatings or suspension media therefor
• CPC Class Codes: C09K 11/7701 Chalogenides
• CPC Class Codes: G21K 2004/08 with a binder in the phosphor layer
• CPC Class Codes: G21K 4/00 Conversion screens for the conversion of the spatial distribution of X-rays or particle radiation into visible images, e.g. fluoroscopic screens photographic processes using X-ray intensifiers G03C5/17; discharge tubes comprising luminescent screens H01J1/62; cathode ray tubes for X-ray conversion with optical output H01J31/50
• CPC Class Codes: Y10T 428/31551 Of polyamidoester [polyurethane, polyisocyanate, polycarbamate, etc.]
• CPC Class Codes: Y10T 428/31935 Ester, halide or nitrile of addition polymer

Abstract

The present invention relates to an X-ray intensifying screen and to the method of manufacturing thereof. The X-ray intensifying screen comprises a support having deposited thereon a phosphorescent layer comprising a phosphor dispersed in a photocurable binder, wherein said binder comprises a photopolymerizable mixture of at least one urethane (meth)acrylate prepolymer, at least one photopolymerizable monomer and/or oligomer, and a photoinitiator, and said phosphorescent layer is cured by radiation after deposition onto said support.

Claims

1. An X-ray intensifying screen comprising a support having deposited thereon a phosphorescent layer comprising a phosphor dispersed in a photocurable binder, wherein said binder comprises a photopolymerizable mixture of at least one urethane (meth)acrylate prepolymer, at least one photopolymerizable monomer and/or oligomer, and a photoinitiator, and said phosphorescent layer is cured by radiation after deposition onto said support, wherein said urethane (meth)acrylate prepolymer has a weight-average molecular weight ranging from 600 to 10,000.

2. The X-ray intensifying screen of claim 1, wherein said urethane (meth)acrylate prepolymer is selected from the group consisting of polyether urethane (meth)acrylates, polyester urethane (meth)acrylates, and polyol urethane (meth)acrylates.

3. The X-ray intensifying screen of claim 1, wherein said urethane (meth)acrylate prepolymer is selected from the group consisting of aliphatic polyether urethane (meth)acrylates and aliphatic polyester urethane (meth)acrylates.

4. The X-ray intensifying screen of claim 1, wherein said photopolymerizable monomer and/or oligomer is selected from the group consisting of (meth)acrylic esters of polyhydroxy alcohol derivatives.

5. The X-ray intensifying screen of claim 1, wherein said photopolymerizable mixture further comprises at least one additional prepolymer.

6. The X-ray intensifying screen of claim 5, wherein said additional prepolymer is selected from the group consisting of epoxy (meth)acrylates and polyester (meth)acrylates.

7. The X-ray intensifying screen of claim 1, wherein said photoinitiator absorbs light having wavelength of from 200 to 500 nm.

8. The X-ray intensifying screen of claim 1, wherein said photoinitiator is selected from the group consisting of benzoin derivatives, acethophenone derivatives, benzylketals, α

-hydroxyalkylphenones, α

-aminoalkylphenones, acylphosphine oxides, acylphosphonates, benzophenone, xanthones, tioxanthones and aromatic 1,2-diketones.

9. The X-ray intensifying screen of claim 1, wherein said urethane (meth)acrylate prepolymer are added in an amount ranging from 20% to 50% by weight of the photocurable resinous binder.

10. The X-ray intensifying screen of claim 5, wherein said additional prepolymer has a weight-average molecular weight ranging from 600 to 10,000.

11. The X-ray intensifying screen of claim 1, wherein said additional prepolymer is added in an amount ranging from 1% to 30% by weight of the photocurable resinous binder.

12. The X-ray intensifying screen of claim 1, wherein said photopolymerizable monomer has a weight-average molecular weight lower than 500.

13. The X-ray intensifying screen of claim 1, wherein said photopolymerizable monomer is added in an amount ranging from 0.01% to 10% by weight of the photocurable resinous binder.

14. The X-ray intensifying screen of claim 1, wherein said photopolymerizable mixture further comprises at least one additional reacting monomer.

15. The X-ray intensifying screen of claim 14, wherein said additional reacting monomer is selected from the group consisting of monofunctional (meth)acrylates and non-acrylate monomers.

16. The X-ray intensifying screen of claim 15, wherein said monofunctional (meth)acrylate monomer is selected from the group consisting of alkyl (meth)acrylates, hydroxyalkyl (meth)acrylates, b-carboxyethyl (meth)acrylate, isobornyl (meth)acrylate, tetrahydrofurfuryl (meth)acrylate, 2-(2-ethoxyethoxy)ethyl (meth)acrylate, and aliphatic urethane (meth)acrylates.

17. The X-ray intensifying screen of claim 15, wherein said non-acrylate monomer is selected from the group consisting of styrene, vinyl acetate, and N-vinyl pyrrolidone.

18. The X-ray intensifying screen of claim 1, wherein said phosphor dispersion has a viscosity value comprised in the range of from 10,000 to 1,000,000 cps at 35°

C.

19. The X-ray intensifying screen of claim 1, wherein said phosphor dispersion has a phosphor to binder weight ratio of from 1:

1 to 20;

1.