EP1211093A1 - Thermographic recording material with improved image tone - Google Patents
Thermographic recording material with improved image tone Download PDFInfo
- Publication number
- EP1211093A1 EP1211093A1 EP01000630A EP01000630A EP1211093A1 EP 1211093 A1 EP1211093 A1 EP 1211093A1 EP 01000630 A EP01000630 A EP 01000630A EP 01000630 A EP01000630 A EP 01000630A EP 1211093 A1 EP1211093 A1 EP 1211093A1
- Authority
- EP
- European Patent Office
- Prior art keywords
- recording material
- thermographic recording
- substantially light
- insensitive
- image tone
- Prior art date
- Legal status (The legal status is an assumption and is not a legal conclusion. Google has not performed a legal analysis and makes no representation as to the accuracy of the status listed.)
- Withdrawn
Links
- 239000000463 material Substances 0.000 title claims abstract description 103
- 239000003638 chemical reducing agent Substances 0.000 claims abstract description 32
- GGCZERPQGJTIQP-UHFFFAOYSA-N sodium;9,10-dioxoanthracene-2-sulfonic acid Chemical compound [Na+].C1=CC=C2C(=O)C3=CC(S(=O)(=O)O)=CC=C3C(=O)C2=C1 GGCZERPQGJTIQP-UHFFFAOYSA-N 0.000 claims abstract description 23
- 239000003381 stabilizer Substances 0.000 claims abstract description 21
- 239000011230 binding agent Substances 0.000 claims abstract description 20
- -1 4-substituted isoxazole compounds Chemical class 0.000 claims abstract description 18
- 238000000034 method Methods 0.000 claims abstract description 17
- ISWSIDIOOBJBQZ-UHFFFAOYSA-N Phenol Chemical compound OC1=CC=CC=C1 ISWSIDIOOBJBQZ-UHFFFAOYSA-N 0.000 claims abstract description 14
- 125000003118 aryl group Chemical group 0.000 claims abstract description 12
- 230000008569 process Effects 0.000 claims abstract description 10
- 229910052739 hydrogen Inorganic materials 0.000 claims abstract description 8
- 239000001257 hydrogen Substances 0.000 claims abstract description 8
- 150000002894 organic compounds Chemical class 0.000 claims abstract description 7
- IISBACLAFKSPIT-UHFFFAOYSA-N bisphenol A Chemical class C=1C=C(O)C=CC=1C(C)(C)C1=CC=C(O)C=C1 IISBACLAFKSPIT-UHFFFAOYSA-N 0.000 claims abstract description 6
- 125000006575 electron-withdrawing group Chemical group 0.000 claims abstract description 6
- 239000003795 chemical substances by application Substances 0.000 claims description 12
- 150000001875 compounds Chemical class 0.000 claims description 9
- IJAPPYDYQCXOEF-UHFFFAOYSA-N phthalazin-1(2H)-one Chemical group C1=CC=C2C(=O)NN=CC2=C1 IJAPPYDYQCXOEF-UHFFFAOYSA-N 0.000 claims description 5
- 239000010409 thin film Substances 0.000 claims description 3
- YEXOWHQZWLCHHD-UHFFFAOYSA-N 3,5-ditert-butyl-4-hydroxybenzoic acid Chemical compound CC(C)(C)C1=CC(C(O)=O)=CC(C(C)(C)C)=C1O YEXOWHQZWLCHHD-UHFFFAOYSA-N 0.000 claims description 2
- 150000005130 benzoxazines Chemical class 0.000 claims 2
- 239000006185 dispersion Substances 0.000 description 20
- 239000010410 layer Substances 0.000 description 18
- 238000010438 heat treatment Methods 0.000 description 17
- 230000000052 comparative effect Effects 0.000 description 13
- 238000007639 printing Methods 0.000 description 13
- 239000011241 protective layer Substances 0.000 description 13
- AQRYNYUOKMNDDV-UHFFFAOYSA-M silver behenate Chemical compound [Ag+].CCCCCCCCCCCCCCCCCCCCCC([O-])=O AQRYNYUOKMNDDV-UHFFFAOYSA-M 0.000 description 12
- BQCADISMDOOEFD-UHFFFAOYSA-N Silver Chemical compound [Ag] BQCADISMDOOEFD-UHFFFAOYSA-N 0.000 description 11
- 229910052709 silver Inorganic materials 0.000 description 11
- 239000004332 silver Substances 0.000 description 11
- 125000004432 carbon atom Chemical group C* 0.000 description 10
- 239000011248 coating agent Substances 0.000 description 9
- 238000000576 coating method Methods 0.000 description 9
- 239000002253 acid Substances 0.000 description 8
- 239000004094 surface-active agent Substances 0.000 description 8
- 238000003756 stirring Methods 0.000 description 7
- 238000001931 thermography Methods 0.000 description 7
- XLYOFNOQVPJJNP-UHFFFAOYSA-N water Substances O XLYOFNOQVPJJNP-UHFFFAOYSA-N 0.000 description 7
- LFQSCWFLJHTTHZ-UHFFFAOYSA-N Ethanol Chemical compound CCO LFQSCWFLJHTTHZ-UHFFFAOYSA-N 0.000 description 6
- UKMSUNONTOPOIO-UHFFFAOYSA-N docosanoic acid Chemical compound CCCCCCCCCCCCCCCCCCCCCC(O)=O UKMSUNONTOPOIO-UHFFFAOYSA-N 0.000 description 6
- 229920000159 gelatin Polymers 0.000 description 6
- 239000004615 ingredient Substances 0.000 description 6
- 150000003378 silver Chemical class 0.000 description 6
- 239000000344 soap Substances 0.000 description 6
- FOIXSVOLVBLSDH-UHFFFAOYSA-N Silver ion Chemical compound [Ag+] FOIXSVOLVBLSDH-UHFFFAOYSA-N 0.000 description 5
- 235000019322 gelatine Nutrition 0.000 description 5
- 125000002887 hydroxy group Chemical group [H]O* 0.000 description 5
- 239000000243 solution Substances 0.000 description 5
- 125000000217 alkyl group Chemical group 0.000 description 4
- 150000008064 anhydrides Chemical class 0.000 description 4
- 229920002678 cellulose Polymers 0.000 description 4
- 238000006243 chemical reaction Methods 0.000 description 4
- 229920001577 copolymer Polymers 0.000 description 4
- 239000008367 deionised water Substances 0.000 description 4
- 229910021641 deionized water Inorganic materials 0.000 description 4
- KBPUBCVJHFXPOC-UHFFFAOYSA-N ethyl 3,4-dihydroxybenzoate Chemical compound CCOC(=O)C1=CC=C(O)C(O)=C1 KBPUBCVJHFXPOC-UHFFFAOYSA-N 0.000 description 4
- 229940042795 hydrazides for tuberculosis treatment Drugs 0.000 description 4
- 125000004435 hydrogen atom Chemical group [H]* 0.000 description 4
- 239000000203 mixture Substances 0.000 description 4
- 239000002245 particle Substances 0.000 description 4
- 150000003254 radicals Chemical class 0.000 description 4
- 235000021357 Behenic acid Nutrition 0.000 description 3
- 239000004372 Polyvinyl alcohol Substances 0.000 description 3
- HEMHJVSKTPXQMS-UHFFFAOYSA-M Sodium hydroxide Chemical compound [OH-].[Na+] HEMHJVSKTPXQMS-UHFFFAOYSA-M 0.000 description 3
- 239000000654 additive Substances 0.000 description 3
- 125000001931 aliphatic group Chemical group 0.000 description 3
- 239000007864 aqueous solution Substances 0.000 description 3
- 229940116226 behenic acid Drugs 0.000 description 3
- YCIMNLLNPGFGHC-UHFFFAOYSA-N catechol Chemical group OC1=CC=CC=C1O YCIMNLLNPGFGHC-UHFFFAOYSA-N 0.000 description 3
- 239000012141 concentrate Substances 0.000 description 3
- 230000001419 dependent effect Effects 0.000 description 3
- 150000002148 esters Chemical class 0.000 description 3
- 238000011156 evaluation Methods 0.000 description 3
- 239000008273 gelatin Substances 0.000 description 3
- 230000003287 optical effect Effects 0.000 description 3
- 150000002989 phenols Chemical class 0.000 description 3
- 229920000139 polyethylene terephthalate Polymers 0.000 description 3
- 239000005020 polyethylene terephthalate Substances 0.000 description 3
- 229920002451 polyvinyl alcohol Polymers 0.000 description 3
- 239000000376 reactant Substances 0.000 description 3
- 230000009467 reduction Effects 0.000 description 3
- 229920005989 resin Polymers 0.000 description 3
- 239000011347 resin Substances 0.000 description 3
- 230000000087 stabilizing effect Effects 0.000 description 3
- 238000003860 storage Methods 0.000 description 3
- 238000007651 thermal printing Methods 0.000 description 3
- 125000002221 trityl group Chemical group [H]C1=C([H])C([H])=C([H])C([H])=C1C([*])(C1=C(C(=C(C(=C1[H])[H])[H])[H])[H])C1=C([H])C([H])=C([H])C([H])=C1[H] 0.000 description 3
- GGZHVNZHFYCSEV-UHFFFAOYSA-N 1-Phenyl-5-mercaptotetrazole Chemical compound SC1=NN=NN1C1=CC=CC=C1 GGZHVNZHFYCSEV-UHFFFAOYSA-N 0.000 description 2
- NUWHYWYSMAPBHK-UHFFFAOYSA-N 3,4-dihydroxybenzonitrile Chemical compound OC1=CC=C(C#N)C=C1O NUWHYWYSMAPBHK-UHFFFAOYSA-N 0.000 description 2
- DZAUWHJDUNRCTF-UHFFFAOYSA-N 3-(3,4-dihydroxyphenyl)propanoic acid Chemical compound OC(=O)CCC1=CC=C(O)C(O)=C1 DZAUWHJDUNRCTF-UHFFFAOYSA-N 0.000 description 2
- 108010010803 Gelatin Proteins 0.000 description 2
- 239000001828 Gelatine Substances 0.000 description 2
- 229920002845 Poly(methacrylic acid) Chemical class 0.000 description 2
- ZTHYODDOHIVTJV-UHFFFAOYSA-N Propyl gallate Chemical compound CCCOC(=O)C1=CC(O)=C(O)C(O)=C1 ZTHYODDOHIVTJV-UHFFFAOYSA-N 0.000 description 2
- 229920002125 Sokalan® Chemical class 0.000 description 2
- 229920002472 Starch Polymers 0.000 description 2
- PPBRXRYQALVLMV-UHFFFAOYSA-N Styrene Chemical compound C=CC1=CC=CC=C1 PPBRXRYQALVLMV-UHFFFAOYSA-N 0.000 description 2
- BZHJMEDXRYGGRV-UHFFFAOYSA-N Vinyl chloride Chemical compound ClC=C BZHJMEDXRYGGRV-UHFFFAOYSA-N 0.000 description 2
- 150000007513 acids Chemical class 0.000 description 2
- 230000004913 activation Effects 0.000 description 2
- 150000007933 aliphatic carboxylic acids Chemical class 0.000 description 2
- 239000002216 antistatic agent Substances 0.000 description 2
- 125000004104 aryloxy group Chemical group 0.000 description 2
- 230000005540 biological transmission Effects 0.000 description 2
- 229910052799 carbon Inorganic materials 0.000 description 2
- 150000001732 carboxylic acid derivatives Chemical class 0.000 description 2
- 150000001735 carboxylic acids Chemical class 0.000 description 2
- 239000001913 cellulose Substances 0.000 description 2
- 125000000753 cycloalkyl group Chemical group 0.000 description 2
- 235000014113 dietary fatty acids Nutrition 0.000 description 2
- 239000002270 dispersing agent Substances 0.000 description 2
- 238000001035 drying Methods 0.000 description 2
- 230000000694 effects Effects 0.000 description 2
- 239000000839 emulsion Substances 0.000 description 2
- VFPFQHQNJCMNBZ-UHFFFAOYSA-N ethyl gallate Chemical compound CCOC(=O)C1=CC(O)=C(O)C(O)=C1 VFPFQHQNJCMNBZ-UHFFFAOYSA-N 0.000 description 2
- 239000000194 fatty acid Substances 0.000 description 2
- 229930195729 fatty acid Natural products 0.000 description 2
- 150000004665 fatty acids Chemical class 0.000 description 2
- LNTHITQWFMADLM-UHFFFAOYSA-N gallic acid Chemical compound OC(=O)C1=CC(O)=C(O)C(O)=C1 LNTHITQWFMADLM-UHFFFAOYSA-N 0.000 description 2
- 235000011852 gelatine desserts Nutrition 0.000 description 2
- IPCSVZSSVZVIGE-UHFFFAOYSA-N hexadecanoic acid Chemical compound CCCCCCCCCCCCCCCC(O)=O IPCSVZSSVZVIGE-UHFFFAOYSA-N 0.000 description 2
- 125000000959 isobutyl group Chemical group [H]C([H])([H])C([H])(C([H])([H])[H])C([H])([H])* 0.000 description 2
- 125000001449 isopropyl group Chemical group [H]C([H])([H])C([H])(*)C([H])([H])[H] 0.000 description 2
- YDSWCNNOKPMOTP-UHFFFAOYSA-N mellitic acid Chemical compound OC(=O)C1=C(C(O)=O)C(C(O)=O)=C(C(O)=O)C(C(O)=O)=C1C(O)=O YDSWCNNOKPMOTP-UHFFFAOYSA-N 0.000 description 2
- VNWKTOKETHGBQD-UHFFFAOYSA-N methane Chemical compound C VNWKTOKETHGBQD-UHFFFAOYSA-N 0.000 description 2
- FBSFWRHWHYMIOG-UHFFFAOYSA-N methyl 3,4,5-trihydroxybenzoate Chemical compound COC(=O)C1=CC(O)=C(O)C(O)=C1 FBSFWRHWHYMIOG-UHFFFAOYSA-N 0.000 description 2
- 230000007935 neutral effect Effects 0.000 description 2
- 150000007524 organic acids Chemical class 0.000 description 2
- 239000004584 polyacrylic acid Chemical class 0.000 description 2
- 229920000515 polycarbonate Polymers 0.000 description 2
- 239000004417 polycarbonate Substances 0.000 description 2
- 229920002689 polyvinyl acetate Polymers 0.000 description 2
- 239000011118 polyvinyl acetate Substances 0.000 description 2
- 238000002360 preparation method Methods 0.000 description 2
- CYIDZMCFTVVTJO-UHFFFAOYSA-N pyromellitic acid Chemical compound OC(=O)C1=CC(C(O)=O)=C(C(O)=O)C=C1C(O)=O CYIDZMCFTVVTJO-UHFFFAOYSA-N 0.000 description 2
- 125000006413 ring segment Chemical group 0.000 description 2
- 229920006395 saturated elastomer Polymers 0.000 description 2
- SQGYOTSLMSWVJD-UHFFFAOYSA-N silver(1+) nitrate Chemical compound [Ag+].[O-]N(=O)=O SQGYOTSLMSWVJD-UHFFFAOYSA-N 0.000 description 2
- CVYDEWKUJFCYJO-UHFFFAOYSA-M sodium;docosanoate Chemical compound [Na+].CCCCCCCCCCCCCCCCCCCCCC([O-])=O CVYDEWKUJFCYJO-UHFFFAOYSA-M 0.000 description 2
- 239000007787 solid Substances 0.000 description 2
- 238000002798 spectrophotometry method Methods 0.000 description 2
- 239000008107 starch Substances 0.000 description 2
- 235000019698 starch Nutrition 0.000 description 2
- 238000012360 testing method Methods 0.000 description 2
- 238000012546 transfer Methods 0.000 description 2
- ARCGXLSVLAOJQL-UHFFFAOYSA-N trimellitic acid Chemical compound OC(=O)C1=CC=C(C(O)=O)C(C(O)=O)=C1 ARCGXLSVLAOJQL-UHFFFAOYSA-N 0.000 description 2
- OMDQUFIYNPYJFM-XKDAHURESA-N (2r,3r,4s,5r,6s)-2-(hydroxymethyl)-6-[[(2r,3s,4r,5s,6r)-4,5,6-trihydroxy-3-[(2s,3s,4s,5s,6r)-3,4,5-trihydroxy-6-(hydroxymethyl)oxan-2-yl]oxyoxan-2-yl]methoxy]oxane-3,4,5-triol Chemical compound O[C@@H]1[C@@H](O)[C@@H](O)[C@@H](CO)O[C@@H]1OC[C@@H]1[C@@H](O[C@H]2[C@H]([C@@H](O)[C@H](O)[C@@H](CO)O2)O)[C@H](O)[C@H](O)[C@H](O)O1 OMDQUFIYNPYJFM-XKDAHURESA-N 0.000 description 1
- UXTZUUVTGMDXNG-UHFFFAOYSA-N 1,2-benzoxazine-3,4-dione Chemical compound C1=CC=C2C(=O)C(=O)NOC2=C1 UXTZUUVTGMDXNG-UHFFFAOYSA-N 0.000 description 1
- PUCYIVFXTPWJDD-UHFFFAOYSA-N 1,6-dihydroxycyclohexa-2,4-dienecarboxylic acid Chemical compound OC1C=CC=CC1(O)C(O)=O PUCYIVFXTPWJDD-UHFFFAOYSA-N 0.000 description 1
- TUSDEZXZIZRFGC-UHFFFAOYSA-N 1-O-galloyl-3,6-(R)-HHDP-beta-D-glucose Natural products OC1C(O2)COC(=O)C3=CC(O)=C(O)C(O)=C3C3=C(O)C(O)=C(O)C=C3C(=O)OC1C(O)C2OC(=O)C1=CC(O)=C(O)C(O)=C1 TUSDEZXZIZRFGC-UHFFFAOYSA-N 0.000 description 1
- KJUGUADJHNHALS-UHFFFAOYSA-N 1H-tetrazole Substances C=1N=NNN=1 KJUGUADJHNHALS-UHFFFAOYSA-N 0.000 description 1
- JAAIPIWKKXCNOC-UHFFFAOYSA-N 1h-tetrazol-1-ium-5-thiolate Chemical class SC1=NN=NN1 JAAIPIWKKXCNOC-UHFFFAOYSA-N 0.000 description 1
- PAWQVTBBRAZDMG-UHFFFAOYSA-N 2-(3-bromo-2-fluorophenyl)acetic acid Chemical compound OC(=O)CC1=CC=CC(Br)=C1F PAWQVTBBRAZDMG-UHFFFAOYSA-N 0.000 description 1
- OEPOKWHJYJXUGD-UHFFFAOYSA-N 2-(3-phenylmethoxyphenyl)-1,3-thiazole-4-carbaldehyde Chemical compound O=CC1=CSC(C=2C=C(OCC=3C=CC=CC=3)C=CC=2)=N1 OEPOKWHJYJXUGD-UHFFFAOYSA-N 0.000 description 1
- DFZVZKUDBIJAHK-UHFFFAOYSA-N 2-hydroxyoctadecanoic acid silver Chemical compound [Ag].OC(C(=O)O)CCCCCCCCCCCCCCCC DFZVZKUDBIJAHK-UHFFFAOYSA-N 0.000 description 1
- 125000004493 2-methylbut-1-yl group Chemical group CC(C*)CC 0.000 description 1
- WZHHYIOUKQNLQM-UHFFFAOYSA-N 3,4,5,6-tetrachlorophthalic acid Chemical compound OC(=O)C1=C(Cl)C(Cl)=C(Cl)C(Cl)=C1C(O)=O WZHHYIOUKQNLQM-UHFFFAOYSA-N 0.000 description 1
- KFIRODWJCYBBHY-UHFFFAOYSA-N 3-nitrophthalic acid Chemical compound OC(=O)C1=CC=CC([N+]([O-])=O)=C1C(O)=O KFIRODWJCYBBHY-UHFFFAOYSA-N 0.000 description 1
- HQUVXRFXGBZDNB-UHFFFAOYSA-N 7-methyl-1,3-benzoxazine-2,4-dione Chemical compound O1C(=O)NC(=O)C=2C1=CC(C)=CC=2 HQUVXRFXGBZDNB-UHFFFAOYSA-N 0.000 description 1
- HRPVXLWXLXDGHG-UHFFFAOYSA-N Acrylamide Chemical class NC(=O)C=C HRPVXLWXLXDGHG-UHFFFAOYSA-N 0.000 description 1
- NLHHRLWOUZZQLW-UHFFFAOYSA-N Acrylonitrile Chemical class C=CC#N NLHHRLWOUZZQLW-UHFFFAOYSA-N 0.000 description 1
- QGZKDVFQNNGYKY-UHFFFAOYSA-O Ammonium Chemical compound [NH4+] QGZKDVFQNNGYKY-UHFFFAOYSA-O 0.000 description 1
- 229930185605 Bisphenol Natural products 0.000 description 1
- 229920002134 Carboxymethyl cellulose Polymers 0.000 description 1
- 229920002284 Cellulose triacetate Polymers 0.000 description 1
- VEXZGXHMUGYJMC-UHFFFAOYSA-M Chloride anion Chemical compound [Cl-] VEXZGXHMUGYJMC-UHFFFAOYSA-M 0.000 description 1
- 239000004801 Chlorinated PVC Substances 0.000 description 1
- 229920002307 Dextran Polymers 0.000 description 1
- IMROMDMJAWUWLK-UHFFFAOYSA-N Ethenol Chemical group OC=C IMROMDMJAWUWLK-UHFFFAOYSA-N 0.000 description 1
- 239000001856 Ethyl cellulose Substances 0.000 description 1
- ZZSNKZQZMQGXPY-UHFFFAOYSA-N Ethyl cellulose Chemical compound CCOCC1OC(OC)C(OCC)C(OCC)C1OC1C(O)C(O)C(OC)C(CO)O1 ZZSNKZQZMQGXPY-UHFFFAOYSA-N 0.000 description 1
- 239000004262 Ethyl gallate Substances 0.000 description 1
- 239000001263 FEMA 3042 Substances 0.000 description 1
- 229920000926 Galactomannan Polymers 0.000 description 1
- 229920000084 Gum arabic Polymers 0.000 description 1
- DGAQECJNVWCQMB-PUAWFVPOSA-M Ilexoside XXIX Chemical compound C[C@@H]1CC[C@@]2(CC[C@@]3(C(=CC[C@H]4[C@]3(CC[C@@H]5[C@@]4(CC[C@@H](C5(C)C)OS(=O)(=O)[O-])C)C)[C@@H]2[C@]1(C)O)C)C(=O)O[C@H]6[C@@H]([C@H]([C@@H]([C@H](O6)CO)O)O)O.[Na+] DGAQECJNVWCQMB-PUAWFVPOSA-M 0.000 description 1
- WSMYVTOQOOLQHP-UHFFFAOYSA-N Malondialdehyde Chemical class O=CCC=O WSMYVTOQOOLQHP-UHFFFAOYSA-N 0.000 description 1
- 239000000020 Nitrocellulose Substances 0.000 description 1
- 235000021314 Palmitic acid Nutrition 0.000 description 1
- LRBQNJMCXXYXIU-PPKXGCFTSA-N Penta-digallate-beta-D-glucose Natural products OC1=C(O)C(O)=CC(C(=O)OC=2C(=C(O)C=C(C=2)C(=O)OC[C@@H]2[C@H]([C@H](OC(=O)C=3C=C(OC(=O)C=4C=C(O)C(O)=C(O)C=4)C(O)=C(O)C=3)[C@@H](OC(=O)C=3C=C(OC(=O)C=4C=C(O)C(O)=C(O)C=4)C(O)=C(O)C=3)[C@H](OC(=O)C=3C=C(OC(=O)C=4C=C(O)C(O)=C(O)C=4)C(O)=C(O)C=3)O2)OC(=O)C=2C=C(OC(=O)C=3C=C(O)C(O)=C(O)C=3)C(O)=C(O)C=2)O)=C1 LRBQNJMCXXYXIU-PPKXGCFTSA-N 0.000 description 1
- 239000004698 Polyethylene Substances 0.000 description 1
- 239000002202 Polyethylene glycol Substances 0.000 description 1
- 239000004743 Polypropylene Substances 0.000 description 1
- 239000004793 Polystyrene Substances 0.000 description 1
- NPYPAHLBTDXSSS-UHFFFAOYSA-N Potassium ion Chemical compound [K+] NPYPAHLBTDXSSS-UHFFFAOYSA-N 0.000 description 1
- 241000978776 Senegalia senegal Species 0.000 description 1
- FKNQFGJONOIPTF-UHFFFAOYSA-N Sodium cation Chemical compound [Na+] FKNQFGJONOIPTF-UHFFFAOYSA-N 0.000 description 1
- 235000021355 Stearic acid Nutrition 0.000 description 1
- XTXRWKRVRITETP-UHFFFAOYSA-N Vinyl acetate Chemical compound CC(=O)OC=C XTXRWKRVRITETP-UHFFFAOYSA-N 0.000 description 1
- NNLVGZFZQQXQNW-ADJNRHBOSA-N [(2r,3r,4s,5r,6s)-4,5-diacetyloxy-3-[(2s,3r,4s,5r,6r)-3,4,5-triacetyloxy-6-(acetyloxymethyl)oxan-2-yl]oxy-6-[(2r,3r,4s,5r,6s)-4,5,6-triacetyloxy-2-(acetyloxymethyl)oxan-3-yl]oxyoxan-2-yl]methyl acetate Chemical compound O([C@@H]1O[C@@H]([C@H]([C@H](OC(C)=O)[C@H]1OC(C)=O)O[C@H]1[C@@H]([C@@H](OC(C)=O)[C@H](OC(C)=O)[C@@H](COC(C)=O)O1)OC(C)=O)COC(=O)C)[C@@H]1[C@@H](COC(C)=O)O[C@@H](OC(C)=O)[C@H](OC(C)=O)[C@H]1OC(C)=O NNLVGZFZQQXQNW-ADJNRHBOSA-N 0.000 description 1
- FJWGYAHXMCUOOM-QHOUIDNNSA-N [(2s,3r,4s,5r,6r)-2-[(2r,3r,4s,5r,6s)-4,5-dinitrooxy-2-(nitrooxymethyl)-6-[(2r,3r,4s,5r,6s)-4,5,6-trinitrooxy-2-(nitrooxymethyl)oxan-3-yl]oxyoxan-3-yl]oxy-3,5-dinitrooxy-6-(nitrooxymethyl)oxan-4-yl] nitrate Chemical compound O([C@@H]1O[C@@H]([C@H]([C@H](O[N+]([O-])=O)[C@H]1O[N+]([O-])=O)O[C@H]1[C@@H]([C@@H](O[N+]([O-])=O)[C@H](O[N+]([O-])=O)[C@@H](CO[N+]([O-])=O)O1)O[N+]([O-])=O)CO[N+](=O)[O-])[C@@H]1[C@@H](CO[N+]([O-])=O)O[C@@H](O[N+]([O-])=O)[C@H](O[N+]([O-])=O)[C@H]1O[N+]([O-])=O FJWGYAHXMCUOOM-QHOUIDNNSA-N 0.000 description 1
- 238000005299 abrasion Methods 0.000 description 1
- 239000000205 acacia gum Substances 0.000 description 1
- 235000010489 acacia gum Nutrition 0.000 description 1
- 150000001241 acetals Chemical class 0.000 description 1
- 150000008360 acrylonitriles Chemical class 0.000 description 1
- 230000002411 adverse Effects 0.000 description 1
- 150000001299 aldehydes Chemical class 0.000 description 1
- 150000001338 aliphatic hydrocarbons Chemical class 0.000 description 1
- 125000003342 alkenyl group Chemical group 0.000 description 1
- 125000003545 alkoxy group Chemical group 0.000 description 1
- 125000002877 alkyl aryl group Chemical group 0.000 description 1
- 150000003863 ammonium salts Chemical class 0.000 description 1
- 125000002490 anilino group Chemical group [H]N(*)C1=C([H])C([H])=C([H])C([H])=C1[H] 0.000 description 1
- 125000000129 anionic group Chemical group 0.000 description 1
- 239000003945 anionic surfactant Substances 0.000 description 1
- 125000006615 aromatic heterocyclic group Chemical group 0.000 description 1
- 125000003710 aryl alkyl group Chemical group 0.000 description 1
- 239000011324 bead Substances 0.000 description 1
- CCGGDOVGIDSGQN-UHFFFAOYSA-N benzo[f][1,2]benzoxazine-1,2-dione Chemical compound C1=CC=CC2=C(C(C(=O)NO3)=O)C3=CC=C21 CCGGDOVGIDSGQN-UHFFFAOYSA-N 0.000 description 1
- QRUDEWIWKLJBPS-UHFFFAOYSA-N benzotriazole Chemical compound C1=CC=C2N[N][N]C2=C1 QRUDEWIWKLJBPS-UHFFFAOYSA-N 0.000 description 1
- 239000012964 benzotriazole Substances 0.000 description 1
- 125000003354 benzotriazolyl group Chemical class N1N=NC2=C1C=CC=C2* 0.000 description 1
- 230000015572 biosynthetic process Effects 0.000 description 1
- 239000001055 blue pigment Substances 0.000 description 1
- CBDBLXUJRXZQMK-UHFFFAOYSA-N butyl 3,4-dihydroxybenzoate Chemical compound CCCCOC(=O)C1=CC=C(O)C(O)=C1 CBDBLXUJRXZQMK-UHFFFAOYSA-N 0.000 description 1
- CQEYYJKEWSMYFG-UHFFFAOYSA-N butyl acrylate Chemical compound CCCCOC(=O)C=C CQEYYJKEWSMYFG-UHFFFAOYSA-N 0.000 description 1
- 125000000484 butyl group Chemical group [H]C([*])([H])C([H])([H])C([H])([H])C([H])([H])[H] 0.000 description 1
- 125000002837 carbocyclic group Chemical group 0.000 description 1
- 150000001721 carbon Chemical group 0.000 description 1
- 125000003178 carboxy group Chemical group [H]OC(*)=O 0.000 description 1
- 239000001768 carboxy methyl cellulose Substances 0.000 description 1
- 235000010948 carboxy methyl cellulose Nutrition 0.000 description 1
- 125000004181 carboxyalkyl group Chemical group 0.000 description 1
- 239000008112 carboxymethyl-cellulose Substances 0.000 description 1
- OAYRYNVEFFWSHK-UHFFFAOYSA-N carsalam Chemical compound C1=CC=C2OC(=O)NC(=O)C2=C1 OAYRYNVEFFWSHK-UHFFFAOYSA-N 0.000 description 1
- 239000003093 cationic surfactant Substances 0.000 description 1
- 230000008859 change Effects 0.000 description 1
- 229920000457 chlorinated polyvinyl chloride Polymers 0.000 description 1
- 239000003431 cross linking reagent Substances 0.000 description 1
- 239000013078 crystal Substances 0.000 description 1
- 125000000113 cyclohexyl group Chemical group [H]C1([H])C([H])([H])C([H])([H])C([H])(*)C([H])([H])C1([H])[H] 0.000 description 1
- 125000001511 cyclopentyl group Chemical group [H]C1([H])C([H])([H])C([H])([H])C([H])(*)C1([H])[H] 0.000 description 1
- 238000011161 development Methods 0.000 description 1
- 238000003745 diagnosis Methods 0.000 description 1
- 239000002612 dispersion medium Substances 0.000 description 1
- 238000005516 engineering process Methods 0.000 description 1
- 150000002170 ethers Chemical class 0.000 description 1
- 229920001249 ethyl cellulose Polymers 0.000 description 1
- 235000019325 ethyl cellulose Nutrition 0.000 description 1
- 235000019277 ethyl gallate Nutrition 0.000 description 1
- 230000001747 exhibiting effect Effects 0.000 description 1
- 239000010408 film Substances 0.000 description 1
- NBVXSUQYWXRMNV-UHFFFAOYSA-N fluoromethane Chemical group FC NBVXSUQYWXRMNV-UHFFFAOYSA-N 0.000 description 1
- 235000004515 gallic acid Nutrition 0.000 description 1
- 229940074391 gallic acid Drugs 0.000 description 1
- 150000004676 glycans Chemical class 0.000 description 1
- 125000000623 heterocyclic group Chemical group 0.000 description 1
- 150000002431 hydrogen Chemical group 0.000 description 1
- 238000003384 imaging method Methods 0.000 description 1
- 239000012535 impurity Substances 0.000 description 1
- 230000001939 inductive effect Effects 0.000 description 1
- 238000007689 inspection Methods 0.000 description 1
- 230000007774 longterm Effects 0.000 description 1
- 239000000314 lubricant Substances 0.000 description 1
- 239000010687 lubricating oil Substances 0.000 description 1
- 238000004519 manufacturing process Methods 0.000 description 1
- 239000006224 matting agent Substances 0.000 description 1
- 238000005259 measurement Methods 0.000 description 1
- FQPSGWSUVKBHSU-UHFFFAOYSA-N methacrylamide Chemical compound CC(=C)C(N)=O FQPSGWSUVKBHSU-UHFFFAOYSA-N 0.000 description 1
- IBKQQKPQRYUGBJ-UHFFFAOYSA-N methyl gallate Natural products CC(=O)C1=CC(O)=C(O)C(O)=C1 IBKQQKPQRYUGBJ-UHFFFAOYSA-N 0.000 description 1
- 238000002156 mixing Methods 0.000 description 1
- 238000012986 modification Methods 0.000 description 1
- 230000004048 modification Effects 0.000 description 1
- WQEPLUUGTLDZJY-UHFFFAOYSA-N n-Pentadecanoic acid Natural products CCCCCCCCCCCCCCC(O)=O WQEPLUUGTLDZJY-UHFFFAOYSA-N 0.000 description 1
- 125000004108 n-butyl group Chemical group [H]C([H])([H])C([H])([H])C([H])([H])C([H])([H])* 0.000 description 1
- 125000000740 n-pentyl group Chemical group [H]C([H])([H])C([H])([H])C([H])([H])C([H])([H])C([H])([H])* 0.000 description 1
- 125000004123 n-propyl group Chemical group [H]C([H])([H])C([H])([H])C([H])([H])* 0.000 description 1
- 239000000025 natural resin Substances 0.000 description 1
- 125000001971 neopentyl group Chemical group [H]C([*])([H])C(C([H])([H])[H])(C([H])([H])[H])C([H])([H])[H] 0.000 description 1
- 229920001220 nitrocellulos Polymers 0.000 description 1
- 239000002736 nonionic surfactant Substances 0.000 description 1
- QIQXTHQIDYTFRH-UHFFFAOYSA-N octadecanoic acid Chemical compound CCCCCCCCCCCCCCCCCC(O)=O QIQXTHQIDYTFRH-UHFFFAOYSA-N 0.000 description 1
- OQCDKBAXFALNLD-UHFFFAOYSA-N octadecanoic acid Natural products CCCCCCCC(C)CCCCCCCCC(O)=O OQCDKBAXFALNLD-UHFFFAOYSA-N 0.000 description 1
- 125000002347 octyl group Chemical group [H]C([*])([H])C([H])([H])C([H])([H])C([H])([H])C([H])([H])C([H])([H])C([H])([H])C([H])([H])[H] 0.000 description 1
- XNGIFLGASWRNHJ-UHFFFAOYSA-N phthalic acid Chemical compound OC(=O)C1=CC=CC=C1C(O)=O XNGIFLGASWRNHJ-UHFFFAOYSA-N 0.000 description 1
- 125000005543 phthalimide group Chemical class 0.000 description 1
- 125000000612 phthaloyl group Chemical group C(C=1C(C(=O)*)=CC=CC1)(=O)* 0.000 description 1
- 230000000704 physical effect Effects 0.000 description 1
- 229920002492 poly(sulfone) Polymers 0.000 description 1
- 229920002037 poly(vinyl butyral) polymer Polymers 0.000 description 1
- 229920002401 polyacrylamide Polymers 0.000 description 1
- 229920000728 polyester Polymers 0.000 description 1
- 229920000573 polyethylene Polymers 0.000 description 1
- 229920001223 polyethylene glycol Polymers 0.000 description 1
- 229920000642 polymer Polymers 0.000 description 1
- 229920001155 polypropylene Polymers 0.000 description 1
- 229920001282 polysaccharide Polymers 0.000 description 1
- 239000005017 polysaccharide Substances 0.000 description 1
- 229920002223 polystyrene Polymers 0.000 description 1
- 239000004800 polyvinyl chloride Substances 0.000 description 1
- 229920000915 polyvinyl chloride Polymers 0.000 description 1
- 229920000036 polyvinylpyrrolidone Polymers 0.000 description 1
- 239000001267 polyvinylpyrrolidone Substances 0.000 description 1
- 235000013855 polyvinylpyrrolidone Nutrition 0.000 description 1
- XAEFZNCEHLXOMS-UHFFFAOYSA-M potassium benzoate Chemical compound [K+].[O-]C(=O)C1=CC=CC=C1 XAEFZNCEHLXOMS-UHFFFAOYSA-M 0.000 description 1
- 229910001414 potassium ion Inorganic materials 0.000 description 1
- 238000012545 processing Methods 0.000 description 1
- 230000001737 promoting effect Effects 0.000 description 1
- 235000010388 propyl gallate Nutrition 0.000 description 1
- 239000000473 propyl gallate Substances 0.000 description 1
- 229940075579 propyl gallate Drugs 0.000 description 1
- YQUVCSBJEUQKSH-UHFFFAOYSA-N protochatechuic acid Natural products OC(=O)C1=CC=C(O)C(O)=C1 YQUVCSBJEUQKSH-UHFFFAOYSA-N 0.000 description 1
- 230000005855 radiation Effects 0.000 description 1
- 229920002545 silicone oil Polymers 0.000 description 1
- 229910001961 silver nitrate Inorganic materials 0.000 description 1
- YRSQDSCQMOUOKO-KVVVOXFISA-M silver;(z)-octadec-9-enoate Chemical compound [Ag+].CCCCCCCC\C=C/CCCCCCCC([O-])=O YRSQDSCQMOUOKO-KVVVOXFISA-M 0.000 description 1
- CLDWGXZGFUNWKB-UHFFFAOYSA-M silver;benzoate Chemical compound [Ag+].[O-]C(=O)C1=CC=CC=C1 CLDWGXZGFUNWKB-UHFFFAOYSA-M 0.000 description 1
- MNMYRUHURLPFQW-UHFFFAOYSA-M silver;dodecanoate Chemical compound [Ag+].CCCCCCCCCCCC([O-])=O MNMYRUHURLPFQW-UHFFFAOYSA-M 0.000 description 1
- LTYHQUJGIQUHMS-UHFFFAOYSA-M silver;hexadecanoate Chemical compound [Ag+].CCCCCCCCCCCCCCCC([O-])=O LTYHQUJGIQUHMS-UHFFFAOYSA-M 0.000 description 1
- ORYURPRSXLUCSS-UHFFFAOYSA-M silver;octadecanoate Chemical compound [Ag+].CCCCCCCCCCCCCCCCCC([O-])=O ORYURPRSXLUCSS-UHFFFAOYSA-M 0.000 description 1
- 229910052708 sodium Inorganic materials 0.000 description 1
- 239000011734 sodium Substances 0.000 description 1
- 229910001415 sodium ion Inorganic materials 0.000 description 1
- 239000002904 solvent Substances 0.000 description 1
- 239000007858 starting material Substances 0.000 description 1
- 230000003068 static effect Effects 0.000 description 1
- 239000008117 stearic acid Substances 0.000 description 1
- 125000001424 substituent group Chemical group 0.000 description 1
- 125000000547 substituted alkyl group Chemical group 0.000 description 1
- 125000000472 sulfonyl group Chemical group *S(*)(=O)=O 0.000 description 1
- 239000000057 synthetic resin Substances 0.000 description 1
- 229920003002 synthetic resin Polymers 0.000 description 1
- 239000000454 talc Substances 0.000 description 1
- 229910052623 talc Inorganic materials 0.000 description 1
- LRBQNJMCXXYXIU-NRMVVENXSA-N tannic acid Chemical compound OC1=C(O)C(O)=CC(C(=O)OC=2C(=C(O)C=C(C=2)C(=O)OC[C@@H]2[C@H]([C@H](OC(=O)C=3C=C(OC(=O)C=4C=C(O)C(O)=C(O)C=4)C(O)=C(O)C=3)[C@@H](OC(=O)C=3C=C(OC(=O)C=4C=C(O)C(O)=C(O)C=4)C(O)=C(O)C=3)[C@@H](OC(=O)C=3C=C(OC(=O)C=4C=C(O)C(O)=C(O)C=4)C(O)=C(O)C=3)O2)OC(=O)C=2C=C(OC(=O)C=3C=C(O)C(O)=C(O)C=3)C(O)=C(O)C=2)O)=C1 LRBQNJMCXXYXIU-NRMVVENXSA-N 0.000 description 1
- 235000015523 tannic acid Nutrition 0.000 description 1
- 229920002258 tannic acid Polymers 0.000 description 1
- 229940033123 tannic acid Drugs 0.000 description 1
- 125000001973 tert-pentyl group Chemical group [H]C([H])([H])C([H])([H])C(*)(C([H])([H])[H])C([H])([H])[H] 0.000 description 1
- 150000003536 tetrazoles Chemical class 0.000 description 1
- 125000005296 thioaryloxy group Chemical group 0.000 description 1
- 238000000108 ultra-filtration Methods 0.000 description 1
- 238000002604 ultrasonography Methods 0.000 description 1
- 229920002554 vinyl polymer Polymers 0.000 description 1
- 230000016776 visual perception Effects 0.000 description 1
Classifications
-
- B—PERFORMING OPERATIONS; TRANSPORTING
- B41—PRINTING; LINING MACHINES; TYPEWRITERS; STAMPS
- B41M—PRINTING, DUPLICATING, MARKING, OR COPYING PROCESSES; COLOUR PRINTING
- B41M5/00—Duplicating or marking methods; Sheet materials for use therein
- B41M5/26—Thermography ; Marking by high energetic means, e.g. laser otherwise than by burning, and characterised by the material used
- B41M5/30—Thermography ; Marking by high energetic means, e.g. laser otherwise than by burning, and characterised by the material used using chemical colour formers
- B41M5/337—Additives; Binders
- B41M5/3375—Non-macromolecular compounds
-
- G—PHYSICS
- G03—PHOTOGRAPHY; CINEMATOGRAPHY; ANALOGOUS TECHNIQUES USING WAVES OTHER THAN OPTICAL WAVES; ELECTROGRAPHY; HOLOGRAPHY
- G03C—PHOTOSENSITIVE MATERIALS FOR PHOTOGRAPHIC PURPOSES; PHOTOGRAPHIC PROCESSES, e.g. CINE, X-RAY, COLOUR, STEREO-PHOTOGRAPHIC PROCESSES; AUXILIARY PROCESSES IN PHOTOGRAPHY
- G03C1/00—Photosensitive materials
- G03C1/494—Silver salt compositions other than silver halide emulsions; Photothermographic systems ; Thermographic systems using noble metal compounds
- G03C1/498—Photothermographic systems, e.g. dry silver
- G03C1/49836—Additives
- G03C1/49845—Active additives, e.g. toners, stabilisers, sensitisers
-
- G—PHYSICS
- G03—PHOTOGRAPHY; CINEMATOGRAPHY; ANALOGOUS TECHNIQUES USING WAVES OTHER THAN OPTICAL WAVES; ELECTROGRAPHY; HOLOGRAPHY
- G03C—PHOTOSENSITIVE MATERIALS FOR PHOTOGRAPHIC PURPOSES; PHOTOGRAPHIC PROCESSES, e.g. CINE, X-RAY, COLOUR, STEREO-PHOTOGRAPHIC PROCESSES; AUXILIARY PROCESSES IN PHOTOGRAPHY
- G03C1/00—Photosensitive materials
- G03C1/494—Silver salt compositions other than silver halide emulsions; Photothermographic systems ; Thermographic systems using noble metal compounds
- G03C1/498—Photothermographic systems, e.g. dry silver
- G03C1/4989—Photothermographic systems, e.g. dry silver characterised by a thermal imaging step, with or without exposure to light, e.g. with a thermal head, using a laser
-
- B—PERFORMING OPERATIONS; TRANSPORTING
- B41—PRINTING; LINING MACHINES; TYPEWRITERS; STAMPS
- B41M—PRINTING, DUPLICATING, MARKING, OR COPYING PROCESSES; COLOUR PRINTING
- B41M5/00—Duplicating or marking methods; Sheet materials for use therein
- B41M5/26—Thermography ; Marking by high energetic means, e.g. laser otherwise than by burning, and characterised by the material used
- B41M5/30—Thermography ; Marking by high energetic means, e.g. laser otherwise than by burning, and characterised by the material used using chemical colour formers
Definitions
- the present invention relates to thermographic recording materials whose prints have improved shelf-life image tone stability.
- Thermal imaging or thermography is a recording process wherein images are generated by the use of thermal energy.
- direct thermal thermography a visible image pattern is formed by image-wise heating of a recording material.
- US 3,218,166 discloses a heat-sensitive copy sheet product capable of providing high contrast dense black images on a white background when briefly heated at image areas to conversion temperature within the approximate range of 90-150°C, said product containing, uniformly applied over a paperlike carrier and in position for heat-induced inter-reaction, reactants comprising a silver soap of an organic acid, a toner for the silver image, a ditertiaryalkyl substituted phenol first reducing agent for the silver ion in an amount of at least about 0.01 mol per mol of silver soap and insufficient to form with said silver soap a dense image when briefly heated therewith, and a photosensitive different active-hydrogen aromatic organic second reducing agent for said silver ion in an amount no greater than that of said first reducing agent, said first reducing agent being further characterized as forming with an equal weight of silver behenate and one-fifth said weight of phthalazinone a uniformly blended trace deposit requiring at least six seconds preheat at 100°C, before rapidly darkening at
- US 3,547,648 discloses sheet material in copying processes, including a reactant layer comprising a silver soap of an organic acid, a tertiary-alkyl-substituted monophenol, and a tertiaryalkyl-substituted bisphenol, said substituted phenols each being a reducing agent for the silver ion and being characterized as forming with an equal weight of silver behenate and one fifth said weight of phthalazinone a uniformly blended trace deposit requiring at least six seconds preheat at 100°C before rapidly darkening at that temperature.
- thermographic element comprising a support bearing at least one, image-forming, thermographic emulsion layer comprising: (a) a non-photosensitive, reducible silver source; (b) a reducing agent system for silver ion; and (c) a binder; wherein said reducing agent system comprises: (i) at least one hindered phenol; and (ii) at least one co-developer of the formula wherein: R represents an aromatic group or an electron withdrawing group.
- ingredients are required for substantially light-insensitive thermographic recording materials, which provide a balance of image tone stabilizing properties, enabling prints to be obtained with image tone which after pretempering is less dependent upon storage time prior to printing and to archival time after printing, while exhibiting image tone acceptable for radiologists viewing images in transmission on a light box.
- thermographic recording materials with improved image tone stability not only capable of producing prints with image tone which is less dependent upon storage time prior to printing.
- thermographic recording materials comprising a thermosensitive element containing sterically hindered monophenols are capable of providing prints whose image tone is less dependent upon storage time prior to printing than prior art materials substantially light-insensitive thermographic recording materials.
- thermosensitive black and white thermographic recording material comprising a support and a thermosensitive element exclusive of bisphenol compounds, 4-substituted isoxazole compounds of the formula wherein R represents an aromatic group or an electron withdrawing group, organic compounds represented by R 3 -H, the corresponding radical of which, R 3• , has a stability of from 350 to 6000 times that of a primary alkyl radical, and photosensitive active-hydrogen aromatic organic reducing agents, the thermosensitive element containing at least one substantially light-insensitive organic silver salt, an organic reducing agent therefor in thermal working relationship therewith, an image tone stabilizer and a binder, characterized in that the image tone stabilizer is a sterically hindered monophenol.
- thermographic recording material as described above into proximity with a heat source; (ii) applying heat from the heat source imagewise to the thermographic recording material in a substantially water-free condition while maintaining proximity to the heat source to produce an image; and (iii) removing the thermographic recording material from the heat source.
- thermographic recording material Use of a sterically hindered monophenol in a substantially light-insensitive thermographic recording material as an image tone stabilizer is also provided by the present invention.
- the heat source is a thermal head.
- the heat source is a thin film thermal head.
- alkyl means all variants possible for each number of carbon atoms in the alkyl group i.e. for three carbon atoms: n-propyl and isopropyl; for four carbon atoms: n-butyl, isobutyl and tertiary-butyl; for five carbon atoms: n-pentyl, 1,1-dimethylpropyl, 2,2-dimethylpropyl and 2-methyl-butyl etc.
- substantially light-insensitive is meant not intentionally light sensitive.
- ortho to the hydroxy group is meant covalently bonded to the carbon atoms immediately adjacent to the carbon atom to which the hydroxy group is covalently bonded.
- a fatty acid is an organic monobasic acid of general formula C n H 2n + 1 COOH derived from the saturated series of aliphatic hydrocarbons, such as palmitic acid, stearic acid, behenic acid and arichidic acid.
- Heating in a substantially water-free condition means heating at a temperature of 80 to 250°C.
- substantially water-free condition means that the reaction system is approximately in equilibrium with water in the air, and water for inducing or promoting the reaction is not particularly or positively supplied from the exterior to the element. Such a condition is described in T.H. James, "The Theory of the Photographic Process", Fourth Edition, Macmillan 1977, page 374.
- thermographic recording material comprising a support and a thermosensitive element of bisphenol compounds, 4-substituted isoxazole compounds of the formula wherein R represents an aromatic group or an electron withdrawing group, organic compounds represented by R 3 -H, the corresponding radical of which, R 3• , has a stability of from 350 to 6000 times that of a primary alkyl radical, and photosensitive active-hydrogen aromatic organic reducing agents, the thermosensitive element containing at least one substantially light-insensitive organic silver salt, an organic reducing agent therefor in thermal working relationship therewith, an image tone stabilizer and a binder, characterized in that the image tone stabilizer is a sterically hindered monophenol.
- the sterically hindering groups in the sterically hindered monophenol are alkyl and cycloalkyl groups ortho to the hydroxy group.
- the sterically hindering groups in the sterically hindered monophenol ortho to the hydroxy group are selected from the group consisting of optionally substituted isopropyl, tertiary butyl, isobutyl, tertiary octyl, cyclopentyl and cyclohexyl groups.
- the sterically hindered monophenol has substituents other than the sterically hindering groups ortho to the hydroxy group selected from the group consisting of optionally substituted alkyl, cycloalkyl, alkoxy, aryloxy, carboxy and carboxyalkyl groups.
- Suitable image tone stabilizing compounds according to the present invention are:
- the image tone stabilizer is 3,5-di-tert-butyl-4-hydroxybenzoic acid (ITS-1).
- thermosensitive element as used herein is that element which contains all the ingredients which contribute to image formation.
- the thermosensitive element is exclusive of bisphenol compounds, 4-substituted isoxazole compounds of the formula wherein R represents an aromatic group or an electron withdrawing group, organic compounds represented by R 3 -H, the corresponding radical of which, R 3• , has a stability of from 350 to 6000 times that of a primary alkyl radical, and photosensitive active-hydrogen aromatic organic reducing agents.
- the thermosensitive contains a substantially light-insensitive organic silver salt, an organic reducing agent therefor in thermal working relationship therewith, a sterically hindered phenol image tone stabilizer and a binder.
- thermosensitive element is exclusive of 4-substituted isoxazole compounds.
- thermosensitive element is exclusive of hydrogen atom donor compounds.
- thermosensitive element is exclusive of hydrazide compounds.
- the thermosensitive element comprises a layer system in which the above-mentioned ingredients may be dispersed in different layers, with the proviso that the substantially light-insensitive organic silver salt is in reactive association with the reducing agent i.e. during the thermal development process the reducing agent must be present in such a way that it is able to diffuse to the particles of substantially light-insensitive organic silver salt so that reduction to silver can occur.
- the substantially light-insensitive organic silver salt is a substantially light-insensitive silver salt of an organic carboxylic acid.
- the substantially light-insensitive silver salt is a silver salt of an aliphatic carboxylic acid.
- the substantially light-insensitive silver salt is a silver salt of a fatty acid.
- the substantially light-insensitive silver salt is a silver salt of an aliphatic carboxylic acid, wherein the aliphatic carbon chain has between 12 and 30 C-atoms, e.g. silver laurate, silver palmitate, silver stearate, silver hydroxystearate, silver oleate and silver behenate, which silver salts are also called "silver soaps".
- the substantially light-insensitive silver salt is an organic carboxylic acid as described in GB-P 1,439,478, e.g. silver benzoate.
- Combinations of different silver salts of an organic carboxylic acids may also be used in the present invention, as disclosed in EP-A 964 300, hereby incorporated by reference.
- Organic silver salts may be dispersed by standard dispersion techniques e.g. using ball mills, bead mills, microfluidizers, ultrasonic apparatuses, rotor stator mixers etc. have been found to be useful in this regard. Mixtures of organic silver salt dispersions produced by different techniques may also be used to obtain the desired thermographic properties e.g. of coarser and a more finely ground dispersions of organic silver salts.
- the organic reducing agent for the reduction of the substantially light-insensitive organic silver salt is an organic compound containing at least one active hydrogen atom linked to O, N or C, such as is the case with, aromatic di- and tri-hydroxy compounds.
- the organic reducing agent is a 1,2-dihydroxybenzene derivative, such as catechol, 3-(3,4-dihydroxyphenyl) propionic acid, 1,2-dihydroxybenzoic acid, gallic acid and esters e.g. methyl gallate, ethyl gallate, propyl gallate, tannic acid, and 3,4-dihydroxy-benzoic acid ester.
- 1,2-dihydroxybenzene derivative such as catechol, 3-(3,4-dihydroxyphenyl) propionic acid, 1,2-dihydroxybenzoic acid, gallic acid and esters e.g. methyl gallate, ethyl gallate, propyl gallate, tannic acid, and 3,4-dihydroxy-benzoic acid ester.
- the organic reducing agent is an organic reducing agent disclosed in EP-B 692 733, herein incorporated by reference, e.g. ethyl 3,4-dihydroxybenzoate and n-butyl 3,4-dihydroxybenzoate,
- thermographic recording material is an organic reducing agent disclosed in EP-A 903 625, herein incorporated by reference, e.g. 3,4-dihydroxybenzonitrile.
- Combinations of reducing agents may also be used that on heating become reactive partners in the reduction of the substantially light-insensitive organic silver salt containing mixed crystals of two or more organic silver salts.
- combinations of sterically hindered phenols with sulfonyl hydrazide reducing agents such as disclosed in US-P 5,464,738; trityl hydrazides and formyl-phenyl-hydrazides such as disclosed in US-P 5,496,695; trityl hydrazides and formyl-phenyl-hydrazides with diverse auxiliary reducing agents such as disclosed in US-P 5,545,505, US-P 5.545.507 and US-P 5,558,983; acrylonitrile compounds as disclosed in US-P 5,545,515 and US-P 5,635,339; and 2-substituted malonodialdehyde compounds as disclosed in US-P 5,654,130.
- thermosensitive element Binder of the thermosensitive element
- the binder is a natural, modified natural or synthetic resins or mixtures of such resins, in which the substantially light-insensitive organic silver salt can be homogeneously dispersed either in aqueous or solvent media: e.g. cellulose derivatives such as ethylcellulose, cellulose esters, e.g.
- cellulose nitrate carboxymethylcellulose, starch ethers, galactomannan
- polymers derived from ⁇ , ⁇ -ethylenically unsaturated compounds such as polyvinyl chloride, after-chlorinated polyvinyl chloride, copolymers of vinyl chloride and vinylidene chloride, copolymers of vinyl chloride and vinyl acetate, polyvinyl acetate and partially hydrolyzed polyvinyl acetate, polyvinyl alcohol, polyvinyl acetals that are made from polyvinyl alcohol as starting material in which only a part of the repeating vinyl alcohol units may have reacted with an aldehyde, preferably polyvinyl butyral, copolymers of acrylonitrile and acrylamide, polyacrylic acid esters, polymethacrylic acid esters, polystyrene and polyethylene or mixtures thereof.
- the binder is a water-soluble film-forming binder, for example: polyvinyl alcohol, polyacrylamide, polymethacrylamide, polyacrylic acid, polymethacrylic acid, polyvinylpyrrolidone, polyethyleneglycol, proteinaceous binders such as gelatine, modified gelatines such as phthaloyl gelatine, polysaccharides, such as starch, gum arabic and dextran and water-soluble cellulose derivatives.
- a water-soluble film-forming binder for example: polyvinyl alcohol, polyacrylamide, polymethacrylamide, polyacrylic acid, polymethacrylic acid, polyvinylpyrrolidone, polyethyleneglycol, proteinaceous binders such as gelatine, modified gelatines such as phthaloyl gelatine, polysaccharides, such as starch, gum arabic and dextran and water-soluble cellulose derivatives.
- the binder is gelatin.
- the weight ratio of binder to substantially light-insensitive organic silver salt is in the range of 0.2 to 7.
- the thickness of the thermosensitive element is in the range of 5 to 50 ⁇ m.
- the binder does not contain additives or impurities which adversely affect the thermographic properties of the substantially thermographic recording material.
- thermosensitive element further contains a toning agent in order to obtain a neutral black image tone in the higher densities and neutral grey in the lower densities.
- the thermosensitive element further contains at least one toning agent selected from the group consisting of phthalimides and phthalazinones.
- Suitable toning agents are those within the scope of the general formulae described in US 4,082,901. Further reference is made to the toning agents described in US 3,074,809, 3,446,648 and 3,844,797.
- the thermosensitive element contains at least one heterocyclic toning compounds of the benzoxazine dione or naphthoxazine dione type as disclosed in GB 1,439,478, US 3,951,660, e.g. benzo[e][1,3]oxazine-2,4-dione and 7-methyl-benzo[e][1,3]oxazine-2,4-dione, and US 5,599,647, e.g. 7-(ethylcarbonato)-benzo[e][1,3]oxazine-2,4-dione, herein incorporated by reference.
- the substantially light-insensitive thermographic recording material further contains an antifoggant to obtain improved shelf-life and reduced fogging.
- the substantially light-insensitive thermographic recording material further contains at least one antifoggant selected from the group consisting of benzotriazole, substituted benzotriazoles, tetrazoles, mercaptotetrazoles such as 1-phenyl-5-mercapto-tetrazole, and aromatic polycarboxylic acids such as ortho-phthalic acid, 3-nitro-phthalic acid, tetrachlorophthalic acid, mellitic acid, pyromellitic acid and trimellitic acid, and anhydrides thereof.
- at least one antifoggant selected from the group consisting of benzotriazole, substituted benzotriazoles, tetrazoles, mercaptotetrazoles such as 1-phenyl-5-mercapto-tetrazole, and aromatic polycarboxylic acids such as ortho-phthalic acid, 3-nitro-phthalic acid, tetrachlorophthalic acid, mellitic acid, pyromellitic acid and trimellitic
- the thermosensitive element further comprises at least one polycarboxylic acid and/or anhydride thereof in a molar percentage of at least 15 with respect to all the organic silver salt(s) present and in thermal working relationship therewith.
- the thermosensitive element further comprises at least one aliphatic (saturated as well as unsaturated aliphatic and also cycloaliphatic) or aromatic polycarboxylic acid, optionally substituted and optionally used in anhydride form or partially esterified form on the condition that at least two free carboxylic acids remain or are available in the heat recording step.
- at least one aliphatic (saturated as well as unsaturated aliphatic and also cycloaliphatic) or aromatic polycarboxylic acid optionally substituted and optionally used in anhydride form or partially esterified form on the condition that at least two free carboxylic acids remain or are available in the heat recording step.
- Surfactants and dispersants aid the dispersion of ingredients or reactants which are insoluble in the particular dispersion medium.
- the substantially light-insensitive thermographic recording material further comprises one or more surfactants, which may be anionic, non-ionic or cationic surfactants, and/or one or more dispersants.
- one or more surfactants which may be anionic, non-ionic or cationic surfactants, and/or one or more dispersants.
- the recording material may contain in addition to the ingredients mentioned above other additives such as antistatic agents, e.g. non-ionic antistatic agents including a fluorocarbon group as e.g. in F 3 C(CF 2 ) 6 CONH(CH 2 CH 2 O)-H, silicone oil, e.g. BAYSILONTM MA (from BAYER AG, GERMANY).
- antistatic agents e.g. non-ionic antistatic agents including a fluorocarbon group as e.g. in F 3 C(CF 2 ) 6 CONH(CH 2 CH 2 O)-H
- silicone oil e.g. BAYSILONTM MA (from BAYER AG, GERMANY).
- the support for the thermosensitive element according to the present invention may be transparent, translucent or opaque and is a thin flexible carrier made of transparent resin film, e.g. made of a cellulose ester, cellulose triacetate, polypropylene, polycarbonate or polyester, e.g. polyethylene terephthalate.
- transparent resin film e.g. made of a cellulose ester, cellulose triacetate, polypropylene, polycarbonate or polyester, e.g. polyethylene terephthalate.
- the support may be in sheet, ribbon or web form and subbed if need be to improve the adherence to the thereon coated thermosensitive element. It may be pigmented with a blue pigment as so-called blue-base.
- One or more backing layers may be provided to control physical properties such as curl and static.
- thermosensitive element is provided with a protective layer to avoid local deformation of the thermosensitive element and to improve resistance against abrasion.
- thermosensitive element is provided with a protective layer comprising a binder, which may be solvent-soluble, solvent-dispersible, water-soluble or water- dispersible.
- a binder which may be solvent-soluble, solvent-dispersible, water-soluble or water- dispersible.
- thermosensitive element is provided with a protective layer comprising a solvent-soluble polycarbonate binder as described in EP-A 614 769, herein incorporated by reference.
- the thermosensitive element is provided with a protective layer comprising a water-soluble or water-dispersible binders, as coating can be performed from an aqueous composition and mixing of the protective layer with the immediate underlayer can be avoided by using a solvent-soluble or solvent-dispersible binder in the immediate underlayer.
- thermosensitive element is provided with a crosslinked protective layer.
- thermosensitive element is provided with a protective layer crosslinked with crosslinking agents such as described in WO 95/12495, herein incorporated by reference.
- thermosensitive element is provided with a protective layer comprising solid or liquid lubricants or combinations thereof for improving the slip characteristics of the substantially light-insensitive thermographic recording material.
- thermosensitive element is provided with a protective layer comprising thermomeltable particles as solid lubricants are thermomeltable particles, such as those described in WO 94/11199, herein incorporated by reference.
- the thermosensitive element is provided with a protective layer comprising a matting agent, such as described in WO 94/11198, herein incorporated by reference, e.g. talc particles, which optionally protrude from the protective layer.
- a matting agent such as described in WO 94/11198, herein incorporated by reference, e.g. talc particles, which optionally protrude from the protective layer.
- any layer of the recording material of the present invention may proceed by any coating technique e.g. such as described in Modern Coating and Drying Technology, edited by Edward D. Cohen and Edgar B. Gutoff, (1992) VCH Publishers Inc. 220 East 23rd Street, Suite 909 New York, NY 10010, U.S.A.
- Thermographic imaging is carried out by the image-wise application of heat either in analogue fashion by direct exposure through an image or by reflection from an image, or in digital fashion pixel by pixel either by using an infra-red heat source, for example with a Nd-YAG laser or other infra-red laser, with a substantially light-insensitive thermographic material preferably containing an infra-red absorbing compound, or by direct thermal imaging with a thermal head.
- Image-wise heating of the recording material can also be carried out using an electrically resistive ribbon incorporated into the material.
- Image- or pattern-wise heating of the recording material may also proceed by means of pixel-wise modulated ultrasound.
- the silver behenate dispersion was produced as follows: 25kg (73.5M) behenic acid was dispersed with stirring at 80°C in 100L of a 10% solution of Surfactant Nr. 1 per g behenic acid made up to 250L with deionized water at a temperature of 80°C; then 36.75L of a 2M aqueous solution of sodium hydroxide was added over a period of 10 to 20 minutes to give a clear solution substantially containing sodium behenate; then 25L of a 2.94M aqueous solution of silver nitrate was added with stirring at a rate of 0.163 moles/moles silver behenate ⁇ min to convert the sodium behenate completely into silver behenate; and finally ultrafiltration was carried out with a 500000 MW polysulfone cartridge filter at room temperature to concentrate the resulting silver behenate dispersion while adding ammonium nitrate to convert Surfactant Nr 1 into its ammonium salt, the final AgBeh-concentration was 20.4% with 0.062g
- thermographic recording materials Preparation of thermographic recording materials
- the coating dispersion for the thermosensitive element was produced by first allowing 3.44g of K17881 to swell in 16.33g of deionized water over a period of 30 minutes. 3.05g of a first aqueous toning agent dispersion containing 18.08% of T01 and 9.95% of K17881 and 0.8g of a second toning agent dispersion containing 20.12% of T02 and 8.88% of R16875 were then added and the resulting dispersion heated with stirring up to 50°C.
- This coating dispersion at a temperature of 36°C was then doctor-blade coated onto the non-backing layer side of a subbed 168 ⁇ m thick blue-pigmented polyethylene terephthalate support with a backing layer (optical density upon measurement with a MACBETHTM TR924 densitometer through visible and blue filters in transmission of subbed support with backing layer was 0.19 and 0.05 respectively) to a wet coating weight of 72 g/m 2 and while undried was overcoated with 11g/m 2 of an aqueous solution with 1.8% by weight of 1,1-bis(vinylsulfono)methane and 0.9091% by weight of Surfactant Nr. 1.
- thermosensitive elements of COMPARATIVE EXAMPLE 1 and INVENTION EXAMPLE 1 were obtained.
- thermographic printing of the substantially light-insensitive thermographic recording materials of COMPARATIVE EXAMPLE 1 and INVENTION EXAMPLE 1 the print head was separated from the imaging layer by a thin intermediate material contacted with a slipping layer of a separable 5 ⁇ m thick polyethylene terephthalate ribbon coated successively with a subbing layer, heat-resistant layer and the slipping layer (anti-friction layer) giving a ribbon with a total thickness of 6 ⁇ m.
- the DRYSTAR® 2000 printer from AGFA-GEVAERT was equipped with a thin film thermal head with a resolution of 300 dpi and was operated with a line time of 11.8ms (the line time being the time needed for printing one line). During this line time the print head received constant power. The printing power was 90mW and the thermal head resistors were time-modulated to produce different image densities.
- the image tone of fresh prints made with the substantially light-insensitive thermographic recording materials of COMPARATIVE EXAMPLE 1 and INVENTION EXAMPLE 1 was assessed on the basis of the L*, a* and b* CIELAB-values.
- the L*, a* and b* CIELAB-values were determined by spectrophotometric measurements according to ASTM Norm E179-90 in a R(45/0) geometry with evaluation according to ASTM Norm E308-90.
- the a* and b* CIELAB-values of fresh prints of the substantially light-insensitive thermographic recording materials of COMPARATIVE EXAMPLE 1 and INVENTION EXAMPLE 1 at optical densities, D, of 1.0 are also given in Table 2.
- a negative CIELAB a*-value indicates a greenish image-tone becoming greener as a* becomes more negative, a positive a*-value indicating a reddish image-tone becoming redder as a* becomes more positive.
- a negative CIELAB b*-value indicates a bluish tone which becomes increasingly bluer as b* becomes more negative and a positive b*-value indicates a yellowish image-tone becoming more yellow as b* becomes more positive.
- the image tone of elements of the image with a density of 1.0 have a stronger effect than the image tone of elements with lower or higher optical density.
- thermographic recording materials of INVENTION EXAMPLE 1 after 3 days at 45°C and 70% relative humidity have a CIELAB b* value which is more blue at a density of 1.0 i.e. b* is negative and closer to the desired level for b* of - 8.8, as can be seen from Table 3 above.
- thermographic recording materials incorporating sterically hindered monophenols as image tone stabilizing compounds exhibit an improved shelf-life image tone stability over substantially light-insensitive thermographic recording materials without sterically hindered monophenols.
Landscapes
- Physics & Mathematics (AREA)
- Chemical & Material Sciences (AREA)
- Engineering & Computer Science (AREA)
- Materials Engineering (AREA)
- General Physics & Mathematics (AREA)
- Optics & Photonics (AREA)
- Chemical Kinetics & Catalysis (AREA)
- General Chemical & Material Sciences (AREA)
- Heat Sensitive Colour Forming Recording (AREA)
Abstract
Description
- The present invention relates to thermographic recording materials whose prints have improved shelf-life image tone stability.
- Thermal imaging or thermography is a recording process wherein images are generated by the use of thermal energy. In direct thermal thermography a visible image pattern is formed by image-wise heating of a recording material.
- US 3,218,166 discloses a heat-sensitive copy sheet product capable of providing high contrast dense black images on a white background when briefly heated at image areas to conversion temperature within the approximate range of 90-150°C, said product containing, uniformly applied over a paperlike carrier and in position for heat-induced inter-reaction, reactants comprising a silver soap of an organic acid, a toner for the silver image, a ditertiaryalkyl substituted phenol first reducing agent for the silver ion in an amount of at least about 0.01 mol per mol of silver soap and insufficient to form with said silver soap a dense image when briefly heated therewith, and a photosensitive different active-hydrogen aromatic organic second reducing agent for said silver ion in an amount no greater than that of said first reducing agent, said first reducing agent being further characterized as forming with an equal weight of silver behenate and one-fifth said weight of phthalazinone a uniformly blended trace deposit requiring at least six seconds preheat at 100°C, before rapidly darkening at that temperature, and said second reducing agent on exposure to actinic radiation being rendered incapable of reducing silver ion on briefly heating with silver soap at 150°C.
- US 3,547,648 discloses sheet material in copying processes, including a reactant layer comprising a silver soap of an organic acid, a tertiary-alkyl-substituted monophenol, and a tertiaryalkyl-substituted bisphenol, said substituted phenols each being a reducing agent for the silver ion and being characterized as forming with an equal weight of silver behenate and one fifth said weight of phthalazinone a uniformly blended trace deposit requiring at least six seconds preheat at 100°C before rapidly darkening at that temperature.
- WO 97/34196 discloses a black and white thermographic element comprising a support bearing at least one, image-forming, thermographic emulsion layer comprising: (a) a non-photosensitive, reducible silver source; (b) a reducing agent system for silver ion; and (c) a binder; wherein said reducing agent system comprises: (i) at least one hindered phenol; and (ii) at least one co-developer of the formula wherein: R represents an aromatic group or an electron withdrawing group.
- A thermographic element comprising a support bearing a support bearing at least one image-forming, thermographic emulsion layer comprising: (a) a non-photosensitive, reducible silver source; (b) a reducing agent system for said non-photosensitive, reducible silver source; and (c) a binder; wherein said reducing agent system comprises: (i) at least one hindered phenol; (ii) at least one co-developer of the formula R1-(C=O)-NHNH-R2 wherein R1 represents hydrogen and R2 represents an aryl group; or, R1 represents hydrogen, alkyl or alkenyl of 1 to 20 carbon atoms; aryl, alkaryl, or aralkyl groups of up to 20 carbon atoms; aryloxy, thioaryloxy, or anilino groups of up to 20 carbon atoms; aliphatic or aromatic heterocyclic ring groups containing up to 6 ring atoms; carbocyclic ring groups comprising up to 6 ring carbon atoms; or fused ring or bridging groups comprising up to 14 ring atoms; and R2 represents a trityl group; and (iii) at least one hydrogen atom donor compound of the formula: R3-H wherein R3-H represents an organic compound, the corresponding radical of which, R3•, has a stability of from 350 to 6000 times that of a primary alkyl radical.
- In printing with thermographic materials for medical applications for viewing with a light box, optimum diagnosis requires a blue-black image tone so that the higher ability of the human eye to distinguish detail with such image tone can be exploited, thereby improving the diagnostic value of such prints. Such image tone should be independent of the shelf-life of the thermographic recording material prior to printing and also of archival time after printing. Image tone can be assessed on the basis of the L*, a* and b* CIELAB-values as determined by spectrophotometric measurements according to ASTM Norm E179-90 in a R(45/0) geometry with evaluation according to ASTM Norm E308-90. Ingredients are required for substantially light-insensitive thermographic recording materials, which provide a balance of image tone stabilizing properties, enabling prints to be obtained with image tone which after pretempering is less dependent upon storage time prior to printing and to archival time after printing, while exhibiting image tone acceptable for radiologists viewing images in transmission on a light box.
- It is therefore an aspect of the present invention to provide substantially light-insensitive black and white thermographic recording materials with improved image tone stability not only capable of producing prints with image tone which is less dependent upon storage time prior to printing.
- Further objects and advantages of the invention will become apparent from the description hereinafter.
- It has been surprisingly found that substantially light-insensitive thermographic recording materials comprising a thermosensitive element containing sterically hindered monophenols are capable of providing prints whose image tone is less dependent upon storage time prior to printing than prior art materials substantially light-insensitive thermographic recording materials.
- Aspects of the present invention are provided by a substantially light-insensitive black and white thermographic recording material comprising a support and a thermosensitive element exclusive of bisphenol compounds, 4-substituted isoxazole compounds of the formula wherein R represents an aromatic group or an electron withdrawing group, organic compounds represented by R3-H, the corresponding radical of which, R3•, has a stability of from 350 to 6000 times that of a primary alkyl radical, and photosensitive active-hydrogen aromatic organic reducing agents, the thermosensitive element containing at least one substantially light-insensitive organic silver salt, an organic reducing agent therefor in thermal working relationship therewith, an image tone stabilizer and a binder, characterized in that the image tone stabilizer is a sterically hindered monophenol.
- Aspects of the present invention are also provided by a recording process comprising the steps of: (i) bringing an outermost layer of a thermographic recording material as described above into proximity with a heat source; (ii) applying heat from the heat source imagewise to the thermographic recording material in a substantially water-free condition while maintaining proximity to the heat source to produce an image; and (iii) removing the thermographic recording material from the heat source.
- Use of a sterically hindered monophenol in a substantially light-insensitive thermographic recording material as an image tone stabilizer is also provided by the present invention.
- Further advantages and embodiments of the present invention will become apparent from the following description.
- According to a first aspect of the thermographic recording process, according to the present invention, the heat source is a thermal head.
- According to a second aspect of the thermographic recording process, according to the present invention, the heat source is a thin film thermal head.
- The term alkyl means all variants possible for each number of carbon atoms in the alkyl group i.e. for three carbon atoms: n-propyl and isopropyl; for four carbon atoms: n-butyl, isobutyl and tertiary-butyl; for five carbon atoms: n-pentyl, 1,1-dimethylpropyl, 2,2-dimethylpropyl and 2-methyl-butyl etc.
- By substantially light-insensitive is meant not intentionally light sensitive.
- By the expression "ortho to the hydroxy group" is meant covalently bonded to the carbon atoms immediately adjacent to the carbon atom to which the hydroxy group is covalently bonded.
- A fatty acid is an organic monobasic acid of general formula CnH2n + 1COOH derived from the saturated series of aliphatic hydrocarbons, such as palmitic acid, stearic acid, behenic acid and arichidic acid.
- Heating in a substantially water-free condition as used herein, means heating at a temperature of 80 to 250°C. The term "substantially water-free condition" means that the reaction system is approximately in equilibrium with water in the air, and water for inducing or promoting the reaction is not particularly or positively supplied from the exterior to the element. Such a condition is described in T.H. James, "The Theory of the Photographic Process", Fourth Edition, Macmillan 1977, page 374.
- According to the present invention a substantially light-insensitive black and white thermographic recording material is provided comprising a support and a thermosensitive element of bisphenol compounds, 4-substituted isoxazole compounds of the formula wherein R represents an aromatic group or an electron withdrawing group, organic compounds represented by R3-H, the corresponding radical of which, R3•, has a stability of from 350 to 6000 times that of a primary alkyl radical, and photosensitive active-hydrogen aromatic organic reducing agents, the thermosensitive element containing at least one substantially light-insensitive organic silver salt, an organic reducing agent therefor in thermal working relationship therewith, an image tone stabilizer and a binder, characterized in that the image tone stabilizer is a sterically hindered monophenol.
- According to a first aspect of the substantially light-insensitive thermographic recording material, according to the present invention, the sterically hindering groups in the sterically hindered monophenol are alkyl and cycloalkyl groups ortho to the hydroxy group.
- According to a second aspect of the substantially light-insensitive thermographic recording material, according to the present invention, the sterically hindering groups in the sterically hindered monophenol ortho to the hydroxy group are selected from the group consisting of optionally substituted isopropyl, tertiary butyl, isobutyl, tertiary octyl, cyclopentyl and cyclohexyl groups.
- According to a third aspect of the substantially light-insensitive thermographic recording material, according to the present invention, the sterically hindered monophenol has substituents other than the sterically hindering groups ortho to the hydroxy group selected from the group consisting of optionally substituted alkyl, cycloalkyl, alkoxy, aryloxy, carboxy and carboxyalkyl groups.
-
- According to a fourth aspect of the substantially light-insensitive thermographic recording material, according to the present invention, the image tone stabilizer is 3,5-di-tert-butyl-4-hydroxybenzoic acid (ITS-1).
- The thermosensitive element as used herein is that element which contains all the ingredients which contribute to image formation. According to the substantially light-insensitive thermographic recording material of the present invention the thermosensitive element is exclusive of bisphenol compounds, 4-substituted isoxazole compounds of the formula wherein R represents an aromatic group or an electron withdrawing group, organic compounds represented by R3-H, the corresponding radical of which, R3•, has a stability of from 350 to 6000 times that of a primary alkyl radical, and photosensitive active-hydrogen aromatic organic reducing agents. The thermosensitive contains a substantially light-insensitive organic silver salt, an organic reducing agent therefor in thermal working relationship therewith, a sterically hindered phenol image tone stabilizer and a binder.
- According to a fifth aspect of the substantially light-insensitive thermographic recording material, according to the present invention, the thermosensitive element is exclusive of 4-substituted isoxazole compounds.
- According to a sixth aspect of the substantially light-insensitive thermographic recording material, according to the present invention, the thermosensitive element is exclusive of hydrogen atom donor compounds.
- According to a seventh aspect of the substantially light-insensitive thermographic recording material, according to the present invention, the thermosensitive element is exclusive of hydrazide compounds.
- According to a eighth aspect of the substantially light-insensitive thermographic recording material, according to the present invention, the thermosensitive element comprises a layer system in which the above-mentioned ingredients may be dispersed in different layers, with the proviso that the substantially light-insensitive organic silver salt is in reactive association with the reducing agent i.e. during the thermal development process the reducing agent must be present in such a way that it is able to diffuse to the particles of substantially light-insensitive organic silver salt so that reduction to silver can occur.
- According to a ninth aspect of the substantially light-insensitive thermographic recording material, according to the present invention, the substantially light-insensitive organic silver salt is a substantially light-insensitive silver salt of an organic carboxylic acid.
- According to a tenth aspect of the substantially light-insensitive thermographic recording material, according to the present invention, the substantially light-insensitive silver salt is a silver salt of an aliphatic carboxylic acid.
- According to an eleventh aspect of the substantially light-insensitive thermographic recording material, according to the present invention, the substantially light-insensitive silver salt is a silver salt of a fatty acid.
- According to a twelfth aspect of the substantially light-insensitive thermographic recording material, according to the present invention, the substantially light-insensitive silver salt is a silver salt of an aliphatic carboxylic acid, wherein the aliphatic carbon chain has between 12 and 30 C-atoms, e.g. silver laurate, silver palmitate, silver stearate, silver hydroxystearate, silver oleate and silver behenate, which silver salts are also called "silver soaps".
- According to an thirteenth aspect of the substantially light-insensitive thermographic recording material, according to the present invention, the substantially light-insensitive silver salt is an organic carboxylic acid as described in GB-P 1,439,478, e.g. silver benzoate.
- Combinations of different silver salts of an organic carboxylic acids may also be used in the present invention, as disclosed in EP-A 964 300, hereby incorporated by reference.
- Organic silver salts may be dispersed by standard dispersion techniques e.g. using ball mills, bead mills, microfluidizers, ultrasonic apparatuses, rotor stator mixers etc. have been found to be useful in this regard. Mixtures of organic silver salt dispersions produced by different techniques may also be used to obtain the desired thermographic properties e.g. of coarser and a more finely ground dispersions of organic silver salts.
- According to a fourteenth aspect of the substantially light-insensitive thermographic recording material, according to the present invention, the organic reducing agent for the reduction of the substantially light-insensitive organic silver salt is an organic compound containing at least one active hydrogen atom linked to O, N or C, such as is the case with, aromatic di- and tri-hydroxy compounds.
- According to a fifteenth aspect of the substantially light-insensitive thermographic recording material, according to the present invention, the organic reducing agent is a 1,2-dihydroxybenzene derivative, such as catechol, 3-(3,4-dihydroxyphenyl) propionic acid, 1,2-dihydroxybenzoic acid, gallic acid and esters e.g. methyl gallate, ethyl gallate, propyl gallate, tannic acid, and 3,4-dihydroxy-benzoic acid ester.
- According to an sixteenth aspect of the substantially light-insensitive thermographic recording material, according to the present invention, the organic reducing agent is an organic reducing agent disclosed in EP-B 692 733, herein incorporated by reference, e.g. ethyl 3,4-dihydroxybenzoate and n-butyl 3,4-dihydroxybenzoate,
- According to a seventeenth aspect of the substantially light-insensitive thermographic recording material, according to the present invention, is an organic reducing agent disclosed in EP-A 903 625, herein incorporated by reference, e.g. 3,4-dihydroxybenzonitrile.
- Combinations of reducing agents may also be used that on heating become reactive partners in the reduction of the substantially light-insensitive organic silver salt containing mixed crystals of two or more organic silver salts. For example, combinations of sterically hindered phenols with sulfonyl hydrazide reducing agents such as disclosed in US-P 5,464,738; trityl hydrazides and formyl-phenyl-hydrazides such as disclosed in US-P 5,496,695; trityl hydrazides and formyl-phenyl-hydrazides with diverse auxiliary reducing agents such as disclosed in US-P 5,545,505, US-P 5.545.507 and US-P 5,558,983; acrylonitrile compounds as disclosed in US-P 5,545,515 and US-P 5,635,339; and 2-substituted malonodialdehyde compounds as disclosed in US-P 5,654,130.
- According to an eighteenth aspect of the substantially light-insensitive thermographic recording material, according to the present invention, the binder is a natural, modified natural or synthetic resins or mixtures of such resins, in which the substantially light-insensitive organic silver salt can be homogeneously dispersed either in aqueous or solvent media: e.g. cellulose derivatives such as ethylcellulose, cellulose esters, e.g. cellulose nitrate, carboxymethylcellulose, starch ethers, galactomannan, polymers derived from α,β-ethylenically unsaturated compounds such as polyvinyl chloride, after-chlorinated polyvinyl chloride, copolymers of vinyl chloride and vinylidene chloride, copolymers of vinyl chloride and vinyl acetate, polyvinyl acetate and partially hydrolyzed polyvinyl acetate, polyvinyl alcohol, polyvinyl acetals that are made from polyvinyl alcohol as starting material in which only a part of the repeating vinyl alcohol units may have reacted with an aldehyde, preferably polyvinyl butyral, copolymers of acrylonitrile and acrylamide, polyacrylic acid esters, polymethacrylic acid esters, polystyrene and polyethylene or mixtures thereof.
- According to a nineteenth aspect of the substantially light-insensitive thermographic recording material, according to the present invention, the binder is a water-soluble film-forming binder, for example: polyvinyl alcohol, polyacrylamide, polymethacrylamide, polyacrylic acid, polymethacrylic acid, polyvinylpyrrolidone, polyethyleneglycol, proteinaceous binders such as gelatine, modified gelatines such as phthaloyl gelatine, polysaccharides, such as starch, gum arabic and dextran and water-soluble cellulose derivatives.
- According to a twentieth aspect of the substantially light-insensitive thermographic recording material, according to the present invention, the binder is gelatin.
- According to a twenty-first aspect of the substantially light-insensitive thermographic recording material, according to the present invention, the weight ratio of binder to substantially light-insensitive organic silver salt is in the range of 0.2 to 7.
- According to a twenty-second aspect of the substantially light-insensitive thermographic recording material, according to the present invention, the thickness of the thermosensitive element is in the range of 5 to 50 µm.
- According to an twenty-third aspect of the substantially light-insensitive thermographic recording material, according to the present invention, the binder does not contain additives or impurities which adversely affect the thermographic properties of the substantially thermographic recording material.
- According to a twenty-fourth aspect of the substantially light-insensitive thermographic recording material, according to the present invention, the thermosensitive element further contains a toning agent in order to obtain a neutral black image tone in the higher densities and neutral grey in the lower densities.
- According to a twenty-fifth aspect of the substantially light-insensitive thermographic recording material, according to the present invention, the thermosensitive element further contains at least one toning agent selected from the group consisting of phthalimides and phthalazinones. Suitable toning agents are those within the scope of the general formulae described in US 4,082,901. Further reference is made to the toning agents described in US 3,074,809, 3,446,648 and 3,844,797.
- According to a twenty-sixth aspect of the substantially light-insensitive thermographic recording material, according to the present invention, the thermosensitive element contains at least one heterocyclic toning compounds of the benzoxazine dione or naphthoxazine dione type as disclosed in GB 1,439,478, US 3,951,660, e.g. benzo[e][1,3]oxazine-2,4-dione and 7-methyl-benzo[e][1,3]oxazine-2,4-dione, and US 5,599,647, e.g. 7-(ethylcarbonato)-benzo[e][1,3]oxazine-2,4-dione, herein incorporated by reference.
- According to a twenty-seventh aspect of the substantially light-insensitive thermographic recording material, according to the present invention, the substantially light-insensitive thermographic recording material further contains an antifoggant to obtain improved shelf-life and reduced fogging.
- According to a twenty-eighth aspect of the substantially light-insensitive thermographic recording material, according to the present invention, the substantially light-insensitive thermographic recording material further contains at least one antifoggant selected from the group consisting of benzotriazole, substituted benzotriazoles, tetrazoles, mercaptotetrazoles such as 1-phenyl-5-mercapto-tetrazole, and aromatic polycarboxylic acids such as ortho-phthalic acid, 3-nitro-phthalic acid, tetrachlorophthalic acid, mellitic acid, pyromellitic acid and trimellitic acid, and anhydrides thereof.
- According to a twenty-ninth aspect of the substantially light-insensitive thermographic recording material, according to the present invention, the thermosensitive element further comprises at least one polycarboxylic acid and/or anhydride thereof in a molar percentage of at least 15 with respect to all the organic silver salt(s) present and in thermal working relationship therewith.
- According to a thirtieth aspect of the substantially light-insensitive thermographic recording material, according to the present invention, the thermosensitive element further comprises at least one aliphatic (saturated as well as unsaturated aliphatic and also cycloaliphatic) or aromatic polycarboxylic acid, optionally substituted and optionally used in anhydride form or partially esterified form on the condition that at least two free carboxylic acids remain or are available in the heat recording step.
- Surfactants and dispersants aid the dispersion of ingredients or reactants which are insoluble in the particular dispersion medium.
- According to a thirty-first aspect of the substantially light-insensitive thermographic recording material, according to the present invention, the substantially light-insensitive thermographic recording material further comprises one or more surfactants, which may be anionic, non-ionic or cationic surfactants, and/or one or more dispersants.
- The recording material may contain in addition to the ingredients mentioned above other additives such as antistatic agents, e.g. non-ionic antistatic agents including a fluorocarbon group as e.g. in F3C(CF2)6CONH(CH2CH2O)-H, silicone oil, e.g. BAYSILON™ MA (from BAYER AG, GERMANY).
- The support for the thermosensitive element according to the present invention may be transparent, translucent or opaque and is a thin flexible carrier made of transparent resin film, e.g. made of a cellulose ester, cellulose triacetate, polypropylene, polycarbonate or polyester, e.g. polyethylene terephthalate.
- The support may be in sheet, ribbon or web form and subbed if need be to improve the adherence to the thereon coated thermosensitive element. It may be pigmented with a blue pigment as so-called blue-base. One or more backing layers may be provided to control physical properties such as curl and static.
- According to a thirty-second aspect of the substantially light-insensitive thermographic recording material, according to the present invention, the thermosensitive element is provided with a protective layer to avoid local deformation of the thermosensitive element and to improve resistance against abrasion.
- According to a thirty-third aspect of the substantially light-insensitive thermographic recording material, according to the present invention, the thermosensitive element is provided with a protective layer comprising a binder, which may be solvent-soluble, solvent-dispersible, water-soluble or water- dispersible.
- According to a thirty-fourth aspect of the substantially light-insensitive thermographic recording material, according to the present invention, the thermosensitive element is provided with a protective layer comprising a solvent-soluble polycarbonate binder as described in EP-A 614 769, herein incorporated by reference.
- According to a thirty-fifth aspect of the substantially light-insensitive thermographic recording material, according to the present invention, the thermosensitive element is provided with a protective layer comprising a water-soluble or water-dispersible binders, as coating can be performed from an aqueous composition and mixing of the protective layer with the immediate underlayer can be avoided by using a solvent-soluble or solvent-dispersible binder in the immediate underlayer.
- According to a thirty-sixth aspect of the substantially light-insensitive thermographic recording material, according to the present invention, the thermosensitive element is provided with a crosslinked protective layer.
- According to a thirty-seventh aspect of the substantially light-insensitive thermographic recording material, according to the present invention, the thermosensitive element is provided with a protective layer crosslinked with crosslinking agents such as described in WO 95/12495, herein incorporated by reference.
- According to a thirty-eighth aspect of the substantially light-insensitive thermographic recording material, according to the present invention, the thermosensitive element is provided with a protective layer comprising solid or liquid lubricants or combinations thereof for improving the slip characteristics of the substantially light-insensitive thermographic recording material.
- According to a thirty-ninth aspect of the substantially light-insensitive thermographic recording material, according to the present invention, the thermosensitive element is provided with a protective layer comprising thermomeltable particles as solid lubricants are thermomeltable particles, such as those described in WO 94/11199, herein incorporated by reference.
- According to a fortieth aspect of the substantially light-insensitive thermographic recording material, according to the present invention, the thermosensitive element is provided with a protective layer comprising a matting agent, such as described in WO 94/11198, herein incorporated by reference, e.g. talc particles, which optionally protrude from the protective layer.
- The coating of any layer of the recording material of the present invention may proceed by any coating technique e.g. such as described in Modern Coating and Drying Technology, edited by Edward D. Cohen and Edgar B. Gutoff, (1992) VCH Publishers Inc. 220 East 23rd Street, Suite 909 New York, NY 10010, U.S.A.
- Thermographic imaging is carried out by the image-wise application of heat either in analogue fashion by direct exposure through an image or by reflection from an image, or in digital fashion pixel by pixel either by using an infra-red heat source, for example with a Nd-YAG laser or other infra-red laser, with a substantially light-insensitive thermographic material preferably containing an infra-red absorbing compound, or by direct thermal imaging with a thermal head.
- In thermal printing image signals are converted into electric pulses and then through a driver circuit selectively transferred to a thermal printhead. The thermal printhead consists of microscopic heat resistor elements, which convert the electrical energy into heat via Joule effect. The operating temperature of common thermal printheads is in the range of 300 to 400°C and the heating time per picture element (pixel) may be less than 1.0ms, the pressure contact of the thermal printhead with the recording material being e.g. 200-500g/cm2 to ensure a good transfer of heat.
- In order to avoid direct contact of the thermal printing heads with the outermost layer on the same side of the support as the thermosensitive element when this outermost layen is not a protective layer, the image-wise heating of the recording material with the thermal printing heads may proceed through a contacting but removable resin sheet or web wherefrom during the heating no transfer of recording material can take place.
- Activation of the heating elements can be power-modulated or pulse-length modulated at constant power. EP-A 654 355 discloses a method for making an image by image-wise heating by means of a thermal head having energizable heating elements, wherein the activation of the heating elements is executed duty cycled pulsewise. EP-A 622 217 discloses a method for making an image using a direct thermal imaging element producing improvements in continuous tone reproduction.
- Image-wise heating of the recording material can also be carried out using an electrically resistive ribbon incorporated into the material. Image- or pattern-wise heating of the recording material may also proceed by means of pixel-wise modulated ultrasound.
- Thermographic imaging can be used for the production of reflection type prints and transparencies, in particular for use in the medical diagnostic field in which black-imaged transparencies are widely used in inspection techniques operating with a light box.
- The invention is illustrated hereinafter by way of comparative examples and invention examples. The percentages and ratios given in these examples are by weight unless otherwise indicated. The ingredients used in the invention and comparative examples, are:
- organic silver salts:
- AgB =
- silver behenate;
- the reducing agent:
- R01 =
- ethyl 3,4-dihydroxybenzoate;
- R02 =
- 3,4-dihydroxybenzonitrile;
- the binders:
- K17881 =
- type 17881, a gelatin with low potassium ion, sodium ion and chloride-ion concentrations from AGFA-GEVAERT GELATINEFABRIEK vorm. KOEPFF & SÖHNE;
- R16875 =
- type 16875, a phthaloyl-gelatin from Rousselot;
- LATEX01 =
- a copolymer consisting of 54.25 wt.% styrene, 43.25 wt.% butyl acrylate and 2.5 wt.% potassium salt of N-[(4'-sulfobenzamido)-oxo-decyl]methacrylamide;
- S01 = 1-phenyl-5-mercapto-tetrazole;
- the toning agents:
- T01 =
- 7-(ethylcarbonato)-benzo[e][1,3]oxazine-2,4-dione;
- T02 =
- phthalazinone.
- Surfactant Nr. 1 = MARLON™ A-365, supplied as a 65% concentrate of a sodium alkyl-phenylsulfonate by HÜLS;
- Surfactant Nr. 2 = MARLON™ AS3, supplied as a 98% concentrate of an alkylphenylsulfonic acid by HÜLS.
- The silver behenate dispersion was produced as follows: 25kg (73.5M) behenic acid was dispersed with stirring at 80°C in 100L of a 10% solution of Surfactant Nr. 1 per g behenic acid made up to 250L with deionized water at a temperature of 80°C; then 36.75L of a 2M aqueous solution of sodium hydroxide was added over a period of 10 to 20 minutes to give a clear solution substantially containing sodium behenate; then 25L of a 2.94M aqueous solution of silver nitrate was added with stirring at a rate of 0.163 moles/moles silver behenate·min to convert the sodium behenate completely into silver behenate; and finally ultrafiltration was carried out with a 500000 MW polysulfone cartridge filter at room temperature to concentrate the resulting silver behenate dispersion while adding ammonium nitrate to convert Surfactant Nr 1 into its ammonium salt, the final AgBeh-concentration was 20.4% with 0.062g of ammonium alkyl-phenylsulfonate/g AgBeh, the residual conductivity was 1.0mS/cm.
- The coating dispersion for the thermosensitive element was produced by first allowing 3.44g of K17881 to swell in 16.33g of deionized water over a period of 30 minutes. 3.05g of a first aqueous toning agent dispersion containing 18.08% of T01 and 9.95% of K17881 and 0.8g of a second toning agent dispersion containing 20.12% of T02 and 8.88% of R16875 were then added and the resulting dispersion heated with stirring up to 50°C. 2g of the above-mentioned dispersion of silver behenate were then added and after 10 minutes stirring a further 22.2g of the same silver behenate dispersion were added and the resulting dispersion stirred for a further 10 minutes before 3.955g of a 25.28% dispersion of LATEX01 was added. After a further 10 minutes stirring 2.222g of 5.9% polyitaconic acid in water was added and after a further 10 minutes stirring, the resulting dispersion was cooled to 36°C. Finally 18g of deionized water was added in the case of COMPARATIVE EXAMPLE 1 or quantities or solutions or dispersions of the different stabilizers according to US 5,672,560 and the image stabilizing agents according to the present invention to produce a concentration of 10mol% with respect to silver behenate made up to 18g with deionized water were added in the case INVENTION EXAMPLE 1 (see Table 1 for method of addition) and the dispersion stirred for a further 15 minutes. Shortly before coating 6g of an aqueous ethanol solution containing 9.909% of R02 and 4.9% of S01 was added with stirring.
- This coating dispersion at a temperature of 36°C was then doctor-blade coated onto the non-backing layer side of a subbed 168µm thick blue-pigmented polyethylene terephthalate support with a backing layer (optical density upon measurement with a MACBETH™ TR924 densitometer through visible and blue filters in transmission of subbed support with backing layer was 0.19 and 0.05 respectively) to a wet coating weight of 72 g/m2 and while undried was overcoated with 11g/m2 of an aqueous solution with 1.8% by weight of 1,1-bis(vinylsulfono)methane and 0.9091% by weight of Surfactant Nr. 1. Upon drying, the thermosensitive elements of COMPARATIVE EXAMPLE 1 and INVENTION EXAMPLE 1 were obtained.
Comparative example nr AgB g/m2 Image tone stabilizer type mol% vs AgB Added as 1 4.847 - - - Invention example nr 1 5.163 ITS-1 10 2.6% solution in aqueous ethanol (75 vol% ethanol) - During the thermographic printing of the substantially light-insensitive thermographic recording materials of COMPARATIVE EXAMPLE 1 and INVENTION EXAMPLE 1, the print head was separated from the imaging layer by a thin intermediate material contacted with a slipping layer of a separable 5µm thick polyethylene terephthalate ribbon coated successively with a subbing layer, heat-resistant layer and the slipping layer (anti-friction layer) giving a ribbon with a total thickness of 6µm.
- The DRYSTAR® 2000 printer from AGFA-GEVAERT was equipped with a thin film thermal head with a resolution of 300 dpi and was operated with a line time of 11.8ms (the line time being the time needed for printing one line). During this line time the print head received constant power. The printing power was 90mW and the thermal head resistors were time-modulated to produce different image densities.
- The maximum densities of the images (Dmax) measured through a visible filter with a MACBETH™ TR924 densitometer in the grey scale step corresponding to a data level of 64 are given in Table 2.
- The image tone of fresh prints made with the substantially light-insensitive thermographic recording materials of COMPARATIVE EXAMPLE 1 and INVENTION EXAMPLE 1 was assessed on the basis of the L*, a* and b* CIELAB-values. The L*, a* and b* CIELAB-values were determined by spectrophotometric measurements according to ASTM Norm E179-90 in a R(45/0) geometry with evaluation according to ASTM Norm E308-90. The a* and b* CIELAB-values of fresh prints of the substantially light-insensitive thermographic recording materials of COMPARATIVE EXAMPLE 1 and INVENTION EXAMPLE 1 at optical densities, D, of 1.0 are also given in Table 2.
Comparative example number AgB g/m2 Image tone stabilizer Print with fresh material CIELAB-values for print with fresh material Dmax vis Dmin vis for D=1 a* b* 1 4.847 - 3.30 0.21 -3.11 -4.37 Invention example nr 1 5.163 ITS-1 3.33 0.21 -3.45 -4.54 - Simulated long-term shelf-life tests were performed by heating fresh thermographic recording materials of COMPARATIVE EXAMPLE 1 and INVENTION EXAMPLE 1 at 45°C in 70% relative humidity in the dark for 3 and 7 days respectively before printing. Prints with these materials were evaluated as described above for prints of the corresponding fresh thermographic recording materials and the results are given in Table 3 and Table 4 respectively.
Comparative example number Image tone stabilizer Print of material after 3d/45°C/70%RH CIELAB-values of material printed after 3d/45°C/ 70%RH for D=1 ΔCIELAB-values versus printing of fresh material for D=1 Dmaxvis Dmin Vis a* b* Δa* Δb* 1 - 4.04 0.20 -4.81 -0.17 -1.70 +4.20 Invention example nr 1 ITS-1 3.99 0.20 -4.68 -1.25 -1.23 +3.29 - In the CIELAB-system a negative CIELAB a*-value indicates a greenish image-tone becoming greener as a* becomes more negative, a positive a*-value indicating a reddish image-tone becoming redder as a* becomes more positive. A negative CIELAB b*-value indicates a bluish tone which becomes increasingly bluer as b* becomes more negative and a positive b*-value indicates a yellowish image-tone becoming more yellow as b* becomes more positive. In terms of the visual perception of an image as a whole, the image tone of elements of the image with a density of 1.0 have a stronger effect than the image tone of elements with lower or higher optical density.
- Shelf-life performance was evaluated by comparing the change in a* and b* CIELAB values between prints produced with a sheet of the thermographic recording material subjected to heating in the dark for 3 days at 45°C and 70% relative humidity and a sheet which has been subjected to heating in the dark for a further 4 days at 45°C and 70% relative humidity i.e. 7 days in all at 45°C and 70% relative humidity. More acceptable shelf-life behaviour is represented by lower shifts in a* and b* CIELAB values at D = 1.
- Prints produced with the thermographic recording materials of INVENTION EXAMPLE 1 after 3 days at 45°C and 70% relative humidity have a CIELAB b* value which is more blue at a density of 1.0 i.e. b* is negative and closer to the desired level for b* of - 8.8, as can be seen from Table 3 above.
- This difference is more pronounced for prints produced with the thermographic recording materials after a further 4 days at 45°C and 70% relative humidity, making 7 days in all, as can be seen from Table 4 below.
Comparative Example number Image tone stabilizer Print of material after 7d 45°C/70%RH CIELAB-values for print of material after 7d at 45°C/ 70%RH for D=1 ΔCIELAB-values versus material printed after 3d at 45°C/70% RH for D=1 Dmax vis Dminvis a* b* Δa* Δb* 1 - 4.00 0.20 -7.5 +0.75 -2.69 +0.92 Invention example nr 1 ITS-1 4.41 0.22 -6.77 -0.41 -2.09 +0.84 - In conclusion substantially light-insensitive thermographic recording materials incorporating sterically hindered monophenols as image tone stabilizing compounds exhibit an improved shelf-life image tone stability over substantially light-insensitive thermographic recording materials without sterically hindered monophenols.
- Having described in detail preferred embodiments of the current invention, it will now be apparent to those skilled in the art that numerous modifications can be made therein without departing from the scope of the invention as defined in the following claims.
Claims (7)
- A substantially light-insensitive black and white thermographic recording material comprising a support and a thermosensitive element exclusive of bisphenol compounds, 4-substituted isoxazole compounds of the formula wherein R represents an aromatic group or an electron withdrawing group, organic compounds represented by R3-H, the corresponding radical of which, R3•, has a stability of from 350 to 6000 times that of a primary alkyl radical, and photosensitive active-hydrogen aromatic organic reducing agents, said thermosensitive element containing at least one substantially light-insensitive organic silver salt, an organic reducing agent therefor in thermal working relationship therewith, an image tone stabilizer and a binder, characterized in that said image tone stabilizer is a sterically hindered monophenol.
- Thermographic recording material according to claim 1, wherein said thermosensitive element further contains a toning agent.
- Thermographic recording material according to claim 2, wherein said toning agent is phthalazinone, a phthalazinone derivative, pyridazone, a pyridazone derivative, a benzoxazine derivative or a substituted benzoxazine derivative.
- Thermographic recording material according to any of the preceding claims, wherein said stabilizer compound is 3,5-di-tert-butyl-4-hydroxybenzoic acid.
- A recording process comprising the steps of: (i) bringing an outermost layer of a thermographic recording material according to claim 1 into proximity with a heat source; (ii) applying heat from said heat source imagewise to said thermographic recording material in a substantially water-free condition while maintaining proximity to said heat source to produce an image; and (iii) removing said thermographic recording material from said heat source.
- Recording process according to claim 5, wherein said heat source is a thin film thermal head.
- Use of a sterically hindered monophenol in a substantially light-insensitive thermographic recording material as an image tone stabilizer.
Priority Applications (1)
Application Number | Priority Date | Filing Date | Title |
---|---|---|---|
EP01000630A EP1211093A1 (en) | 2000-11-30 | 2001-11-14 | Thermographic recording material with improved image tone |
Applications Claiming Priority (3)
Application Number | Priority Date | Filing Date | Title |
---|---|---|---|
EP00204255 | 2000-11-30 | ||
EP00204255 | 2000-11-30 | ||
EP01000630A EP1211093A1 (en) | 2000-11-30 | 2001-11-14 | Thermographic recording material with improved image tone |
Publications (1)
Publication Number | Publication Date |
---|---|
EP1211093A1 true EP1211093A1 (en) | 2002-06-05 |
Family
ID=26072877
Family Applications (1)
Application Number | Title | Priority Date | Filing Date |
---|---|---|---|
EP01000630A Withdrawn EP1211093A1 (en) | 2000-11-30 | 2001-11-14 | Thermographic recording material with improved image tone |
Country Status (1)
Country | Link |
---|---|
EP (1) | EP1211093A1 (en) |
Cited By (4)
Publication number | Priority date | Publication date | Assignee | Title |
---|---|---|---|---|
EP1388753A1 (en) * | 2002-08-09 | 2004-02-11 | Eastman Kodak Company | Thermally developable emulsions and imaging material containing binder mixture |
WO2007010777A1 (en) | 2005-07-20 | 2007-01-25 | Konica Minolta Medical & Graphic, Inc. | Method for image formation |
EP1953592A1 (en) | 2007-02-02 | 2008-08-06 | Konica Minolta Medical & Graphic, Inc. | Photothermographic material |
EP1557669B1 (en) * | 2004-01-14 | 2014-09-24 | FUJIFILM Corporation | Use of a gas sensing material and gas inspecting method |
Citations (6)
Publication number | Priority date | Publication date | Assignee | Title |
---|---|---|---|---|
US3218166A (en) * | 1962-11-23 | 1965-11-16 | Minnesota Mining & Mfg | Heat sensitive copy sheet |
US3547648A (en) * | 1968-01-26 | 1970-12-15 | Minnesota Mining & Mfg | Copy-sheet |
GB1410991A (en) * | 1972-06-13 | 1975-10-22 | Agfa Gevaert | Method and materials for thermographic recording |
US4013473A (en) * | 1974-08-24 | 1977-03-22 | Agfa-Gevaert N.V. | Recording materials and image receiving materials for producing copies in a dry way |
WO1997011407A1 (en) * | 1995-09-19 | 1997-03-27 | Imation Corp. | Black-and-white photothermographic and thermographic elements comprising hydrogen atom donor compounds as contrast enhancers |
WO1997034196A1 (en) * | 1996-03-14 | 1997-09-18 | Imation Corp. | Black-and-white photothermographic and thermographic elements comprising 4-substituted isoxazole compounds as co-developers |
-
2001
- 2001-11-14 EP EP01000630A patent/EP1211093A1/en not_active Withdrawn
Patent Citations (6)
Publication number | Priority date | Publication date | Assignee | Title |
---|---|---|---|---|
US3218166A (en) * | 1962-11-23 | 1965-11-16 | Minnesota Mining & Mfg | Heat sensitive copy sheet |
US3547648A (en) * | 1968-01-26 | 1970-12-15 | Minnesota Mining & Mfg | Copy-sheet |
GB1410991A (en) * | 1972-06-13 | 1975-10-22 | Agfa Gevaert | Method and materials for thermographic recording |
US4013473A (en) * | 1974-08-24 | 1977-03-22 | Agfa-Gevaert N.V. | Recording materials and image receiving materials for producing copies in a dry way |
WO1997011407A1 (en) * | 1995-09-19 | 1997-03-27 | Imation Corp. | Black-and-white photothermographic and thermographic elements comprising hydrogen atom donor compounds as contrast enhancers |
WO1997034196A1 (en) * | 1996-03-14 | 1997-09-18 | Imation Corp. | Black-and-white photothermographic and thermographic elements comprising 4-substituted isoxazole compounds as co-developers |
Cited By (4)
Publication number | Priority date | Publication date | Assignee | Title |
---|---|---|---|---|
EP1388753A1 (en) * | 2002-08-09 | 2004-02-11 | Eastman Kodak Company | Thermally developable emulsions and imaging material containing binder mixture |
EP1557669B1 (en) * | 2004-01-14 | 2014-09-24 | FUJIFILM Corporation | Use of a gas sensing material and gas inspecting method |
WO2007010777A1 (en) | 2005-07-20 | 2007-01-25 | Konica Minolta Medical & Graphic, Inc. | Method for image formation |
EP1953592A1 (en) | 2007-02-02 | 2008-08-06 | Konica Minolta Medical & Graphic, Inc. | Photothermographic material |
Similar Documents
Publication | Publication Date | Title |
---|---|---|
EP0964300B1 (en) | Black and white thermographic recording material with improved image tone | |
EP0848286B1 (en) | Thermographic recording material with improved image tone and/or stability upon thermal development | |
EP0903625B1 (en) | Thermographic recording materials | |
US6159667A (en) | Thermographic recording material with improved image tone and/or stability upon thermal development | |
EP1211093A1 (en) | Thermographic recording material with improved image tone | |
US6586363B2 (en) | Thermographic recording material with improved image tone | |
US6664211B2 (en) | Thermographic recording material with improved image tone | |
US6037114A (en) | Thermographic recording material with improved image density and/or image gradation upon thermal development | |
US6211116B1 (en) | Substantially light-insensitive black and white thermographic recording material with improved image tone | |
EP1211092B1 (en) | Thermographic recording material with improved image tone | |
US6207614B1 (en) | Substantially light-insensitive black and white monosheet thermographic recording material with improved image tone | |
US6337303B1 (en) | Thermographic recording materials with improved image tone | |
US6284442B1 (en) | Black and white thermographic recording material with improved diagnostic capability | |
US6686313B2 (en) | Thermographic recording material with improved image tone | |
US6093528A (en) | Reducing agents for use in thermographic recording materials | |
EP0903624B1 (en) | Binders for thermographic materials | |
EP0921434B1 (en) | Thermographic recording material with improved image density and/or image gradation upon thermal development | |
EP1004929B1 (en) | Black and white monosheet thermographic recording material with improved diagnostic capability | |
EP1059560A1 (en) | Thermographic recording material with improved image tone | |
US6127102A (en) | Recording material with improved shelf-line producing prints upon thermal development with improved archivability | |
EP1211091A1 (en) | Thermographic recording material with improved image tone | |
US6579671B2 (en) | Recording materials with improved shelf-life, image tone and/or stability upon thermal development | |
US7179768B2 (en) | Toning agents for use in thermographic recording materials | |
US6114100A (en) | Recording material with improved image tone and or stability upon thermal development | |
JP2002234262A (en) | Thermography recording material having improved image tone |
Legal Events
Date | Code | Title | Description |
---|---|---|---|
PUAI | Public reference made under article 153(3) epc to a published international application that has entered the european phase |
Free format text: ORIGINAL CODE: 0009012 |
|
AK | Designated contracting states |
Kind code of ref document: A1 Designated state(s): AT BE CH CY DE DK ES FI FR GB GR IE IT LI LU MC NL PT SE TR |
|
AX | Request for extension of the european patent |
Free format text: AL;LT;LV;MK;RO;SI |
|
17P | Request for examination filed |
Effective date: 20021205 |
|
AKX | Designation fees paid |
Designated state(s): DE FR GB |
|
RAP1 | Party data changed (applicant data changed or rights of an application transferred) |
Owner name: AGFA HEALTHCARE NV |
|
RAP1 | Party data changed (applicant data changed or rights of an application transferred) |
Owner name: AGFA HEALTHCARE NV |
|
STAA | Information on the status of an ep patent application or granted ep patent |
Free format text: STATUS: THE APPLICATION IS DEEMED TO BE WITHDRAWN |
|
18D | Application deemed to be withdrawn |
Effective date: 20090603 |