EP0767403A2 - Heat-sensitive recording material - Google Patents
Heat-sensitive recording material Download PDFInfo
- Publication number
- EP0767403A2 EP0767403A2 EP96114797A EP96114797A EP0767403A2 EP 0767403 A2 EP0767403 A2 EP 0767403A2 EP 96114797 A EP96114797 A EP 96114797A EP 96114797 A EP96114797 A EP 96114797A EP 0767403 A2 EP0767403 A2 EP 0767403A2
- Authority
- EP
- European Patent Office
- Prior art keywords
- layer
- leuco dye
- heat
- silver salt
- binder
- 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.)
- Granted
Links
- 239000000463 material Substances 0.000 title claims abstract description 43
- 239000011230 binding agent Substances 0.000 claims abstract description 30
- 229920000642 polymer Polymers 0.000 claims abstract description 17
- 239000003638 chemical reducing agent Substances 0.000 claims abstract description 14
- 239000002253 acid Substances 0.000 claims abstract description 8
- 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 description 28
- 238000003384 imaging method Methods 0.000 claims description 10
- 150000001875 compounds Chemical class 0.000 claims description 9
- 239000004372 Polyvinyl alcohol Substances 0.000 claims description 7
- 230000004888 barrier function Effects 0.000 claims description 7
- 229920002451 polyvinyl alcohol Polymers 0.000 claims description 7
- 239000012876 carrier material Substances 0.000 claims description 6
- 238000004519 manufacturing process Methods 0.000 claims description 6
- 239000000020 Nitrocellulose Substances 0.000 claims description 5
- 229920001220 nitrocellulos Polymers 0.000 claims description 5
- 150000007513 acids Chemical class 0.000 claims description 4
- 230000003993 interaction Effects 0.000 claims description 2
- 238000000034 method Methods 0.000 abstract description 10
- 230000002378 acidificating effect Effects 0.000 abstract description 2
- 150000003839 salts Chemical class 0.000 abstract description 2
- 239000000975 dye Substances 0.000 description 36
- -1 bisphenol compound Chemical class 0.000 description 12
- 230000003287 optical effect Effects 0.000 description 12
- 239000000126 substance Substances 0.000 description 12
- ZWEHNKRNPOVVGH-UHFFFAOYSA-N 2-Butanone Chemical compound CCC(C)=O ZWEHNKRNPOVVGH-UHFFFAOYSA-N 0.000 description 9
- 229920002037 poly(vinyl butyral) polymer Polymers 0.000 description 9
- 239000000203 mixture Substances 0.000 description 7
- 239000002904 solvent Substances 0.000 description 7
- 238000001931 thermography Methods 0.000 description 7
- OKKJLVBELUTLKV-UHFFFAOYSA-N Methanol Chemical compound OC OKKJLVBELUTLKV-UHFFFAOYSA-N 0.000 description 6
- 125000003118 aryl group Chemical group 0.000 description 6
- 229920001577 copolymer Polymers 0.000 description 6
- 238000010438 heat treatment Methods 0.000 description 6
- 230000008569 process Effects 0.000 description 6
- LFQSCWFLJHTTHZ-UHFFFAOYSA-N Ethanol Chemical compound CCO LFQSCWFLJHTTHZ-UHFFFAOYSA-N 0.000 description 5
- 229920002678 cellulose Polymers 0.000 description 5
- YCIMNLLNPGFGHC-UHFFFAOYSA-N catechol Chemical class OC1=CC=CC=C1O YCIMNLLNPGFGHC-UHFFFAOYSA-N 0.000 description 4
- 238000006243 chemical reaction Methods 0.000 description 4
- 238000005516 engineering process Methods 0.000 description 4
- 235000019441 ethanol Nutrition 0.000 description 4
- 125000001997 phenyl group Chemical group [H]C1=C([H])C([H])=C(*)C([H])=C1[H] 0.000 description 4
- 229920000139 polyethylene terephthalate Polymers 0.000 description 4
- 239000005020 polyethylene terephthalate Substances 0.000 description 4
- AQRYNYUOKMNDDV-UHFFFAOYSA-M silver behenate Chemical compound [Ag+].CCCCCCCCCCCCCCCCCCCCCC([O-])=O AQRYNYUOKMNDDV-UHFFFAOYSA-M 0.000 description 4
- 239000000243 solution Substances 0.000 description 4
- 229920002554 vinyl polymer Polymers 0.000 description 4
- CSCPPACGZOOCGX-UHFFFAOYSA-N Acetone Chemical compound CC(C)=O CSCPPACGZOOCGX-UHFFFAOYSA-N 0.000 description 3
- YMWUJEATGCHHMB-UHFFFAOYSA-N Dichloromethane Chemical compound ClCCl YMWUJEATGCHHMB-UHFFFAOYSA-N 0.000 description 3
- XEKOWRVHYACXOJ-UHFFFAOYSA-N Ethyl acetate Chemical compound CCOC(C)=O XEKOWRVHYACXOJ-UHFFFAOYSA-N 0.000 description 3
- 239000001856 Ethyl cellulose Substances 0.000 description 3
- 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 3
- KFZMGEQAYNKOFK-UHFFFAOYSA-N Isopropanol Chemical compound CC(C)O KFZMGEQAYNKOFK-UHFFFAOYSA-N 0.000 description 3
- 239000004698 Polyethylene Substances 0.000 description 3
- BQCADISMDOOEFD-UHFFFAOYSA-N Silver Chemical compound [Ag] BQCADISMDOOEFD-UHFFFAOYSA-N 0.000 description 3
- XTXRWKRVRITETP-UHFFFAOYSA-N Vinyl acetate Chemical compound CC(=O)OC=C XTXRWKRVRITETP-UHFFFAOYSA-N 0.000 description 3
- 238000005266 casting Methods 0.000 description 3
- 230000008859 change Effects 0.000 description 3
- 229920001249 ethyl cellulose Polymers 0.000 description 3
- 235000019325 ethyl cellulose Nutrition 0.000 description 3
- 230000007935 neutral effect Effects 0.000 description 3
- 239000004417 polycarbonate Substances 0.000 description 3
- 229920000515 polycarbonate Polymers 0.000 description 3
- 229920000573 polyethylene Polymers 0.000 description 3
- 150000003378 silver Chemical class 0.000 description 3
- 229910052709 silver Inorganic materials 0.000 description 3
- 239000004332 silver Substances 0.000 description 3
- 125000000391 vinyl group Chemical group [H]C([*])=C([H])[H] 0.000 description 3
- XLYOFNOQVPJJNP-UHFFFAOYSA-N water Substances O XLYOFNOQVPJJNP-UHFFFAOYSA-N 0.000 description 3
- 125000004178 (C1-C4) alkyl group Chemical group 0.000 description 2
- 125000006527 (C1-C5) alkyl group Chemical group 0.000 description 2
- CIWBSHSKHKDKBQ-JLAZNSOCSA-N Ascorbic acid Chemical compound OC[C@H](O)[C@H]1OC(=O)C(O)=C1O CIWBSHSKHKDKBQ-JLAZNSOCSA-N 0.000 description 2
- MOZDKDIOPSPTBH-UHFFFAOYSA-N Benzyl parahydroxybenzoate Chemical compound C1=CC(O)=CC=C1C(=O)OCC1=CC=CC=C1 MOZDKDIOPSPTBH-UHFFFAOYSA-N 0.000 description 2
- 229930185605 Bisphenol Natural products 0.000 description 2
- QFOHBWFCKVYLES-UHFFFAOYSA-N Butylparaben Chemical compound CCCCOC(=O)C1=CC=C(O)C=C1 QFOHBWFCKVYLES-UHFFFAOYSA-N 0.000 description 2
- 239000004801 Chlorinated PVC Substances 0.000 description 2
- RTZKZFJDLAIYFH-UHFFFAOYSA-N Diethyl ether Chemical compound CCOCC RTZKZFJDLAIYFH-UHFFFAOYSA-N 0.000 description 2
- IMROMDMJAWUWLK-UHFFFAOYSA-N Ethenol Chemical group OC=C IMROMDMJAWUWLK-UHFFFAOYSA-N 0.000 description 2
- UFHFLCQGNIYNRP-UHFFFAOYSA-N Hydrogen Chemical compound [H][H] UFHFLCQGNIYNRP-UHFFFAOYSA-N 0.000 description 2
- QIGBRXMKCJKVMJ-UHFFFAOYSA-N Hydroquinone Chemical compound OC1=CC=C(O)C=C1 QIGBRXMKCJKVMJ-UHFFFAOYSA-N 0.000 description 2
- 238000005481 NMR spectroscopy Methods 0.000 description 2
- WYURNTSHIVDZCO-UHFFFAOYSA-N Tetrahydrofuran Chemical compound C1CCOC1 WYURNTSHIVDZCO-UHFFFAOYSA-N 0.000 description 2
- BZHJMEDXRYGGRV-UHFFFAOYSA-N Vinyl chloride Chemical compound ClC=C BZHJMEDXRYGGRV-UHFFFAOYSA-N 0.000 description 2
- 125000002877 alkyl aryl group Chemical group 0.000 description 2
- 125000001797 benzyl group Chemical group [H]C1=C([H])C([H])=C(C([H])=C1[H])C([H])([H])* 0.000 description 2
- 239000001913 cellulose Substances 0.000 description 2
- 229920000457 chlorinated polyvinyl chloride Polymers 0.000 description 2
- 125000000753 cycloalkyl group Chemical group 0.000 description 2
- 230000000694 effects Effects 0.000 description 2
- 150000002148 esters Chemical class 0.000 description 2
- LNTHITQWFMADLM-UHFFFAOYSA-N gallic acid Chemical class OC(=O)C1=CC(O)=C(O)C(O)=C1 LNTHITQWFMADLM-UHFFFAOYSA-N 0.000 description 2
- 125000000623 heterocyclic group Chemical group 0.000 description 2
- 150000002431 hydrogen Chemical class 0.000 description 2
- 229910052739 hydrogen Inorganic materials 0.000 description 2
- 239000001257 hydrogen Substances 0.000 description 2
- 229920002689 polyvinyl acetate Polymers 0.000 description 2
- 239000011118 polyvinyl acetate Substances 0.000 description 2
- 229920000036 polyvinylpyrrolidone Polymers 0.000 description 2
- 239000001267 polyvinylpyrrolidone Substances 0.000 description 2
- 235000013855 polyvinylpyrrolidone Nutrition 0.000 description 2
- WQGWDDDVZFFDIG-UHFFFAOYSA-N pyrogallol Chemical class OC1=CC=CC(O)=C1O WQGWDDDVZFFDIG-UHFFFAOYSA-N 0.000 description 2
- 230000009467 reduction Effects 0.000 description 2
- ORYURPRSXLUCSS-UHFFFAOYSA-M silver;octadecanoate Chemical compound [Ag+].CCCCCCCCCCCCCCCCCC([O-])=O ORYURPRSXLUCSS-UHFFFAOYSA-M 0.000 description 2
- 239000000758 substrate Substances 0.000 description 2
- VZGDMQKNWNREIO-UHFFFAOYSA-N tetrachloromethane Chemical compound ClC(Cl)(Cl)Cl VZGDMQKNWNREIO-UHFFFAOYSA-N 0.000 description 2
- 229920001169 thermoplastic Polymers 0.000 description 2
- 239000004416 thermosoftening plastic Substances 0.000 description 2
- 238000010023 transfer printing Methods 0.000 description 2
- 230000007704 transition Effects 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
- LIZLYZVAYZQVPG-UHFFFAOYSA-N (3-bromo-2-fluorophenyl)methanol Chemical compound OCC1=CC=CC(Br)=C1F LIZLYZVAYZQVPG-UHFFFAOYSA-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
- XBYRMPXUBGMOJC-UHFFFAOYSA-N 1,2-dihydropyrazol-3-one Chemical compound OC=1C=CNN=1 XBYRMPXUBGMOJC-UHFFFAOYSA-N 0.000 description 1
- RYHBNJHYFVUHQT-UHFFFAOYSA-N 1,4-Dioxane Chemical compound C1COCCO1 RYHBNJHYFVUHQT-UHFFFAOYSA-N 0.000 description 1
- QMIYKBFAWPSBQJ-UHFFFAOYSA-N 1,4-bis(2-ethylhexoxy)-1,4-dioxobutane-2-sulfonic acid;silver Chemical compound [Ag].CCCCC(CC)COC(=O)CC(S(O)(=O)=O)C(=O)OCC(CC)CCCC QMIYKBFAWPSBQJ-UHFFFAOYSA-N 0.000 description 1
- NLFKAHRURQOOPN-UHFFFAOYSA-N 1,4-bis(2-phenylpropan-2-yl)benzene Chemical compound C=1C=C(C(C)(C)C=2C=CC=CC=2)C=CC=1C(C)(C)C1=CC=CC=C1 NLFKAHRURQOOPN-UHFFFAOYSA-N 0.000 description 1
- 150000005208 1,4-dihydroxybenzenes Chemical class 0.000 description 1
- HIAGSPVAYSSKHL-UHFFFAOYSA-N 1-methyl-9h-carbazole Chemical class N1C2=CC=CC=C2C2=C1C(C)=CC=C2 HIAGSPVAYSSKHL-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
- CDAWCLOXVUBKRW-UHFFFAOYSA-N 2-aminophenol Chemical class NC1=CC=CC=C1O CDAWCLOXVUBKRW-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
- VPWNQTHUCYMVMZ-UHFFFAOYSA-N 4,4'-sulfonyldiphenol Chemical class C1=CC(O)=CC=C1S(=O)(=O)C1=CC=C(O)C=C1 VPWNQTHUCYMVMZ-UHFFFAOYSA-N 0.000 description 1
- BOTGCZBEERTTDQ-UHFFFAOYSA-N 4-Methoxy-1-naphthol Chemical compound C1=CC=C2C(OC)=CC=C(O)C2=C1 BOTGCZBEERTTDQ-UHFFFAOYSA-N 0.000 description 1
- PZSCUHISJBQKSN-UHFFFAOYSA-N 4-methoxy-1,2-dihydronaphthalen-1-ol Chemical compound C1=CC=C2C(OC)=CCC(O)C2=C1 PZSCUHISJBQKSN-UHFFFAOYSA-N 0.000 description 1
- ZVNPWFOVUDMGRP-UHFFFAOYSA-N 4-methylaminophenol sulfate Chemical compound OS(O)(=O)=O.CNC1=CC=C(O)C=C1.CNC1=CC=C(O)C=C1 ZVNPWFOVUDMGRP-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
- 229920002134 Carboxymethyl cellulose Polymers 0.000 description 1
- 229920002284 Cellulose triacetate Polymers 0.000 description 1
- 229920000926 Galactomannan Polymers 0.000 description 1
- OAZWDJGLIYNYMU-UHFFFAOYSA-N Leucocrystal Violet Chemical compound C1=CC(N(C)C)=CC=C1C(C=1C=CC(=CC=1)N(C)C)C1=CC=C(N(C)C)C=C1 OAZWDJGLIYNYMU-UHFFFAOYSA-N 0.000 description 1
- 241001082241 Lythrum hyssopifolia Species 0.000 description 1
- WHNWPMSKXPGLAX-UHFFFAOYSA-N N-Vinyl-2-pyrrolidone Chemical compound C=CN1CCCC1=O WHNWPMSKXPGLAX-UHFFFAOYSA-N 0.000 description 1
- 229920003171 Poly (ethylene oxide) Polymers 0.000 description 1
- 229920002845 Poly(methacrylic acid) Chemical class 0.000 description 1
- 239000002202 Polyethylene glycol Substances 0.000 description 1
- 239000004721 Polyphenylene oxide Substances 0.000 description 1
- 239000004743 Polypropylene Substances 0.000 description 1
- 229920002125 Sokalan® Chemical class 0.000 description 1
- 229920002472 Starch Polymers 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
- ZKURGBYDCVNWKH-UHFFFAOYSA-N [3,7-bis(dimethylamino)phenothiazin-10-yl]-phenylmethanone Chemical compound C12=CC=C(N(C)C)C=C2SC2=CC(N(C)C)=CC=C2N1C(=O)C1=CC=CC=C1 ZKURGBYDCVNWKH-UHFFFAOYSA-N 0.000 description 1
- 238000005299 abrasion Methods 0.000 description 1
- 239000006096 absorbing agent Substances 0.000 description 1
- 238000010521 absorption reaction Methods 0.000 description 1
- 238000004026 adhesive bonding Methods 0.000 description 1
- 150000001299 aldehydes Chemical class 0.000 description 1
- 150000007933 aliphatic carboxylic acids Chemical class 0.000 description 1
- 239000007864 aqueous solution Substances 0.000 description 1
- 239000003125 aqueous solvent Substances 0.000 description 1
- 229960005070 ascorbic acid Drugs 0.000 description 1
- 235000010323 ascorbic acid Nutrition 0.000 description 1
- 239000011668 ascorbic acid Substances 0.000 description 1
- 230000009286 beneficial effect Effects 0.000 description 1
- 230000008901 benefit Effects 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
- 230000005540 biological transmission Effects 0.000 description 1
- IISBACLAFKSPIT-UHFFFAOYSA-N bisphenol A Chemical compound C=1C=C(O)C=CC=1C(C)(C)C1=CC=C(O)C=C1 IISBACLAFKSPIT-UHFFFAOYSA-N 0.000 description 1
- 229920001400 block copolymer Polymers 0.000 description 1
- 229910052799 carbon Inorganic materials 0.000 description 1
- 125000004432 carbon atom Chemical group C* 0.000 description 1
- 239000001768 carboxy methyl cellulose Substances 0.000 description 1
- 235000010948 carboxy methyl cellulose Nutrition 0.000 description 1
- 239000008112 carboxymethyl-cellulose Substances 0.000 description 1
- 229920003086 cellulose ether Polymers 0.000 description 1
- 238000011109 contamination Methods 0.000 description 1
- 125000004663 dialkyl amino group Chemical group 0.000 description 1
- 235000014113 dietary fatty acids Nutrition 0.000 description 1
- 238000009792 diffusion process Methods 0.000 description 1
- ZINJLDJMHCUBIP-UHFFFAOYSA-N ethametsulfuron-methyl Chemical compound CCOC1=NC(NC)=NC(NC(=O)NS(=O)(=O)C=2C(=CC=CC=2)C(=O)OC)=N1 ZINJLDJMHCUBIP-UHFFFAOYSA-N 0.000 description 1
- PROZFBRPPCAADD-UHFFFAOYSA-N ethenyl but-3-enoate Chemical compound C=CCC(=O)OC=C PROZFBRPPCAADD-UHFFFAOYSA-N 0.000 description 1
- 125000001495 ethyl group Chemical group [H]C([H])([H])C([H])([H])* 0.000 description 1
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- 229940074391 gallic acid Drugs 0.000 description 1
- 235000004515 gallic acid Nutrition 0.000 description 1
- 229920001519 homopolymer Polymers 0.000 description 1
- 150000002429 hydrazines Chemical class 0.000 description 1
- 125000004435 hydrogen atom Chemical group [H]* 0.000 description 1
- 150000002443 hydroxylamines Chemical class 0.000 description 1
- 230000002427 irreversible effect Effects 0.000 description 1
- FDZZZRQASAIRJF-UHFFFAOYSA-M malachite green Chemical compound [Cl-].C1=CC(N(C)C)=CC=C1C(C=1C=CC=CC=1)=C1C=CC(=[N+](C)C)C=C1 FDZZZRQASAIRJF-UHFFFAOYSA-M 0.000 description 1
- 229940107698 malachite green Drugs 0.000 description 1
- 229910052751 metal Inorganic materials 0.000 description 1
- 239000002184 metal Substances 0.000 description 1
- 239000003094 microcapsule Substances 0.000 description 1
- 229920005615 natural polymer Polymers 0.000 description 1
- 239000000025 natural resin Substances 0.000 description 1
- 150000002894 organic compounds Chemical class 0.000 description 1
- 239000011368 organic material Substances 0.000 description 1
- 239000003960 organic solvent Substances 0.000 description 1
- 150000004989 p-phenylenediamines Chemical class 0.000 description 1
- CMCWWLVWPDLCRM-UHFFFAOYSA-N phenidone Chemical compound N1C(=O)CCN1C1=CC=CC=C1 CMCWWLVWPDLCRM-UHFFFAOYSA-N 0.000 description 1
- IJAPPYDYQCXOEF-UHFFFAOYSA-N phthalazin-1(2H)-one Chemical compound C1=CC=C2C(=O)NN=CC2=C1 IJAPPYDYQCXOEF-UHFFFAOYSA-N 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
- 239000000049 pigment Substances 0.000 description 1
- 229920003023 plastic Polymers 0.000 description 1
- 239000002985 plastic film Substances 0.000 description 1
- 239000004014 plasticizer Substances 0.000 description 1
- 239000004584 polyacrylic acid Chemical class 0.000 description 1
- 229920000728 polyester Polymers 0.000 description 1
- 229920000570 polyether Polymers 0.000 description 1
- 229920001223 polyethylene glycol Polymers 0.000 description 1
- 229920001155 polypropylene Polymers 0.000 description 1
- 229920001451 polypropylene glycol Polymers 0.000 description 1
- 229920001296 polysiloxane Polymers 0.000 description 1
- 239000004800 polyvinyl chloride Substances 0.000 description 1
- 229920000915 polyvinyl chloride Polymers 0.000 description 1
- NDGRWYRVNANFNB-UHFFFAOYSA-N pyrazolidin-3-one Chemical compound O=C1CCNN1 NDGRWYRVNANFNB-UHFFFAOYSA-N 0.000 description 1
- 229940079877 pyrogallol Drugs 0.000 description 1
- 239000000376 reactant Substances 0.000 description 1
- 238000006479 redox reaction Methods 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
- ILTLXKRUPFUFIP-UHFFFAOYSA-M silver;dodecane-1-sulfonate Chemical compound [Ag+].CCCCCCCCCCCCS([O-])(=O)=O ILTLXKRUPFUFIP-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
- 239000000344 soap Substances 0.000 description 1
- 239000007787 solid Substances 0.000 description 1
- 239000008107 starch Substances 0.000 description 1
- 235000019698 starch Nutrition 0.000 description 1
- 229920001059 synthetic polymer Polymers 0.000 description 1
- 229920003002 synthetic resin Polymers 0.000 description 1
- 239000000057 synthetic resin Substances 0.000 description 1
- 238000010345 tape casting Methods 0.000 description 1
- YLQBMQCUIZJEEH-UHFFFAOYSA-N tetrahydrofuran Natural products C=1C=COC=1 YLQBMQCUIZJEEH-UHFFFAOYSA-N 0.000 description 1
- 125000003718 tetrahydrofuranyl group Chemical group 0.000 description 1
- 238000002604 ultrasonography Methods 0.000 description 1
- QYSXJUFSXHHAJI-YRZJJWOYSA-N vitamin D3 Chemical compound C1(/[C@@H]2CC[C@@H]([C@]2(CCC1)C)[C@H](C)CCCC(C)C)=C\C=C1\C[C@@H](O)CCC1=C QYSXJUFSXHHAJI-YRZJJWOYSA-N 0.000 description 1
- 239000003232 water-soluble binding agent Substances 0.000 description 1
- 239000001993 wax Substances 0.000 description 1
Classifications
-
- 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
Definitions
- the invention relates to a heat-sensitive recording material based on a combination of a heat-sensitive silver salt and an acid-sensitive leuco dye.
- Thermography uses materials that are essentially not sensitive to light or photos, but are sensitive to heat or thermosensitive. The heat applied in the image areas is sufficient to cause a visible change in a heat-sensitive recording material.
- thermographic recording materials are chemical. When heated to a certain transition temperature, an irreversible chemical reaction takes place, which creates a colored image.
- thermosensitive copy paper in the thermosensitive layer comprised a thermoplastic binder, e.g. Ethyl cellulose, a water-insoluble silver salt, e.g. Silver stearate and a suitable organic reducing agent, for which 4-methoxy-1-hydroxy-dihydronaphthalene is a representative example.
- a thermoplastic binder e.g. Ethyl cellulose
- a water-insoluble silver salt e.g. Silver stearate
- suitable organic reducing agent for which 4-methoxy-1-hydroxy-dihydronaphthalene is a representative example.
- the localized heating of the recording material in the thermographic reproduction process to a suitable transition temperature in the range from 90 ° C. to 150 ° C. causes a visible change in the heat-sensitive layer.
- the initially white or slightly colored layer becomes darker and acquires a brownish appearance when heated.
- the heat sensitive layer is treated with a heterocyclic organic toner substance, e.g. Phthalazinone added.
- Heat-sensitive copier papers comprising a recording layer with a substantially light-insensitive organic silver salt and a hydroxylamine-like reducing agent in a thermoplastic binder such as e.g. Having ethyl cellulose and post-chlorinated polyvinyl chloride are described in U.S. Patent 4,082,901.
- a thermoplastic binder such as e.g. Having ethyl cellulose and post-chlorinated polyvinyl chloride
- a specific leuco dye system works on a transparent film support encapsulated leuco dyes in a recording layer which contains a so-called "developer” (for example an acid-reacting bisphenol compound which is dissolved in an organic solvent and dispersed in a water-soluble binder). From the curve of the optical density as a function of temperature ( Figure 11 on page 236) it can be seen that the optical density at temperatures of around 130 ° C is not higher than 1.5 and does not increase further.
- developer for example an acid-reacting bisphenol compound which is dissolved in an organic solvent and dispersed in a water-soluble binder
- a heat-sensitive recording material on the same side of a carrier material has one or more binder layers on which an essentially light-insensitive metal salt in combination with at least one organic reducing agent and an acid-sensitive leuco dye in combination with an acidic compound that serves as a dye developer.
- the materials according to EP application 94 201 207 result in images with high optical density and good grayscale reproduction.
- thermo effect relationship is the possibility to understand that the relevant image density-increasing reactive substances can come into reactive contact with each other when exposed to heat, for. B. by thermally induced diffusion or in that separating elements such as barrier layers or the walls of a reaction component enveloping microcapsules become permeable when exposed to heat.
- the carrier material for the heat-sensitive recording material according to the invention is preferably a thin flexible carrier e.g. made of paper, polyethylene-coated paper or transparent plastic film, e.g. from a cellulose ester, e.g. Cellulose triacetate, polypropylene, polycarbonate or polyester, e.g. Polyethylene terephthalate.
- the layer support can have an arch, tape or web shape and, if necessary, be provided with a base in order to improve the adhesion of the heat-sensitive recording layer applied thereon.
- the layer thickness of the support can be, for example, between 10 and 2000 ⁇ m, preferably between 50 and 500 ⁇ m.
- the recording material according to the invention can be used for the production of transparency and supervisory images.
- the substrate can be transparent or opaque, in the latter case the substrate has a white, light-reflecting surface.
- a paper carrier is used which can contain white, light-reflecting pigments, optionally also in an intermediate layer between a receiving layer and said carrier.
- the said support can be colorless or colored, e.g. tinted blue.
- recording materials on a white, opaque support are used, while in the field of medical diagnostics, black-screen slides are often used for viewing with a light box.
- Organic silver salts suitable according to the invention are essentially insensitive to light.
- Silver salts of aliphatic carboxylic acids, the so-called fatty acids, in which the aliphatic carbon chain preferably has at least 12 carbon atoms, for example silver laurate, silver palmitate, silver stearate, silver hydroxystearate, silver oleate and silver behenate, and the like, are particularly suitable Silver dodecyl sulfonate according to US patent 4,504,575 and silver di (2-ethylhexyl) sulfosuccinate according to European patent application 227 141.
- Suitable organic reducing agents for the reduction of the silver salt are organic compounds with at least one active hydrogen atom on O, N or C, such as with aromatic di- and trihydroxy compounds, e.g. Hydroquinone and substituted hydroquinones, catechol, pyrogallol, gallic acid and gallates, aminophenols, METOL (trade name), p-phenylenediamines, alkoxynaphthols, e.g. 4-methoxy-1-naphthol according to U.S. Patent 3,094,417, pyrazolidin-3-one type reducing agents, e.g.
- aromatic di- and trihydroxy compounds e.g. Hydroquinone and substituted hydroquinones, catechol, pyrogallol, gallic acid and gallates, aminophenols, METOL (trade name), p-phenylenediamines, alkoxynaphthols, e.g. 4-methoxy-1-naphthol according to U.S.
- PHENIDONE (trade name), pyrazolin-5-one, indanedione-1,3-derivatives, hydroxytetronic acids, hydroxytetronimides, hydroxylamine derivatives (see e.g. U.S. Patent 4,082,901), hydrazine derivatives, reductones and ascorbic acid; see also U.S. Patents 3,074,809, 3,080,254, 3,094,417 and 3,887,378. Catechol and polyhydroxy spiro-bis-indan compounds are preferred.
- the reducing agent is preferably incorporated into the heat-sensitive image layer, but it can be wholly or partially embedded in an adjacent layer, from where it can diffuse into the layer with the organic silver salt.
- Natural, modified natural or synthetic resins are primarily suitable as binders.
- binders e.g. Cellulose derivatives such as ethyl cellulose, cellulose esters, carboxymethyl cellulose, starch ether, galactomannan, polymers of a, b-ethylenically unsaturated compounds such as polyvinyl chloride, post-chlorinated polyvinyl chloride, copolymers of vinyl acetate and vinylidene chloride, copolymers of vinyl chloride and vinyl acetate, polyvinyl acetate and partially hydrolyzed polyvinyl vinyl vinyl acetate from polyvinyl alcohol, in which only a part of the repeating vinyl alcohol units is reacted with an aldehyde, preferably polyvinyl butyral, copolymers of acrylonitrile and acrylamide, polyacrylic acid esters, polymethacrylic acid esters and polyethylene or mixtures thereof.
- a particularly suitable binder is polyvinyl butyral with
- the reducible silver salts and the reducing agents can advantageously be used in conjunction with a so-called toner substance known from thermography or photo-thermography be used.
- Suitable toner substances are the phthalimides and phthalazinones according to the general formulas described in US Pat. No. 4,082,901. Reference is also made to the toner substances described in US Patents 3,074,809, 3,446,648 and 3,844,797.
- Particularly suitable toner substances are also the heterocyclic toner compounds of the benzoxazinedione or naphthoxazinedione type.
- the weight ratio of binder to organic silver salt is preferably between 0.2 and 6.
- This layer preferably has a thickness between 8 ⁇ m and 32 ⁇ m.
- the layer with the water- or alcohol-soluble polymer has the function of a barrier layer.
- Suitable polymers are e.g. Polyvinyl alcohol, partially saponified polyvinyl acetate, polyvinyl pyrrolidone, polyethylene oxide, polyethylene oxide-polypropylene oxide copolymers, cellulose esters and cellulose ethers. Polyvinyl alcohol is particularly suitable.
- the thickness of the barrier layer is 0.1 to 10 ⁇ m, preferably 0.2 to 5 ⁇ m.
- leuco dye layer Particularly suitable for the leuco dye layer are leuco dyes belonging to the class of the fluoranes, such as those e.g. in EP-A-0 155796, in DE-A-35 34 594 and DE-A-43 29 133 as well as in US Patents 3,957,288, 4,011,352 and 5,206,118.
- leuco dyes that form a colored compound upon reaction with an acid are leuco crystal violet, leuko malachite green, crystal violet lactone, benzoyl leuko methylene blue, and the acid sensitive leuco dye compounds in the bisindophthalide and carbazolylmethane class described in U.S. Patent 5,206,118 are described.
- binders as for the silver salt layer are suitable as binders for the leuco dye layer.
- Vinyl chloride and vinylidene chloride copolymers such as e.g. Poly (vinyl chloride-co-vinyl acetate).
- binders mentioned can be used in conjunction with waxes or "heat solvents” , also referred to as “thermal solvents”, which improve the reaction rate of the dye formation reaction and the image-silver-producing redox reaction at elevated temperatures.
- heat solvent in the sense of the present invention denotes a non-hydrolyzable organic material which has a solid form at temperatures below 50 ° C, but from around 60 ° C serves as a plasticizer for the binder with which it is in the heated area connects and / or then acts as a solvent for at least one of the color-forming reactants.
- Suitable for this purpose is e.g. a polyethylene glycol having an average molecular weight between 1,500 and 20,000 as described in U.S. Patent 3,347,675.
- the thickness of the leuco dye layer is 2 to 25 ⁇ m, preferably 4 to 15 ⁇ m.
- Suitable developers for the leuco dye are electron-accepting or acid-reacting compounds. Examples include: 1,3-bis-p-hydroxycumylbenzene or 1,4-bis-cumylbenzene, p-hydroxybenzoic acid butyl ester (PHBB) and bisphenols such as 4,4'-isopropylidenediphenol (bisphenol A) and analogues Compounds described in the Journal of Imaging Technology, vol. 16, No. 6, December 1990, p. 235, as well as in DE-A-35 34 594 and DE-A-43 29 133.
- Other suitable acid-reacting compounds which serve as developers for leuco dyes are monoesters of aromatic ortho-carboxylic acids, which are described, for example, in US Pat. No. 4,011,352, in particular the ethyl half-ester of ortho-phthalic acid.
- the developer layer is expediently produced using solvents which have no solvent effect for the binder of the leuco dye layer.
- the binders used in the developer layer are water or alcohol soluble. These can be modified natural or synthetic polymers. Cellulose derivatives, polyvinylpyrrolidone and copolymers of vinylpyrrolidone and vinyl acetate may be mentioned as examples.
- a preferred binder is nitrocellulose.
- the layer thickness of the developer layer is 1 to 15 ⁇ m, preferably 3 ⁇ m to 10 ⁇ m.
- the recording material according to the invention can contain further layers known for this purpose. It can be beneficial to apply a top coat as the top layer.
- a common thickness of this cover layer is 0.05 to 2.5 ⁇ m.
- the cover layer can have non-stick properties, e.g. can be achieved by using polysiloxanes, polysiloxane-polyether block copolymers or fluoropolymers.
- Polyvinyl alcohol is also suitable as a cover layer.
- thermostable cover layer For writing the image material with a thermal head, it has proven to be advantageous to attach a thermostable cover layer.
- Polymers suitable for this have a softening point above 100 ° C., preferably above 130 ° C.
- Polycarbonate is particularly suitable, in particular homopolymers and copolymers of trimethylcyclohexylbisphenol polycarbonate. The latter polymers result in image materials with a particularly high gloss and good image sharpness. There is no contamination of the thermal head by the image material due to gluing or abrasion.
- An additional advantage of these polymers is their ease of processing, for example by casting from an organic solution.
- the recording materials according to the invention can be produced using known technologies. Production by casting or knife coating is cheap.
- the layer with the water or alcohol soluble polymer and the developer layer can easily be made from water, alcohol or water-alcohol mixtures, e.g. be poured from methyl alcohol, ethyl alcohol, isopropyl alcohol.
- Non-aqueous solvents are generally required for the silver salt layer and the leuco dye layer. Suitable solvents are e.g. Acetone, methyl ethyl ketone, tetrahydrofuran, dioxane, dichloromethane, carbon tetrachloride and ethyl acetate.
- the heat-sensitive recording materials according to the invention can e.g. can be written with a thermal head and deliver black and white images with high optical density (D-max> 2), good grayscale reproduction, high sharpness and good stability.
- the gradation is particularly suitable for halftone reproduction, especially in areas of lower density, e.g. for portrait reproduction of identification documents and in the field of medical diagnostics for the reproduction of images, e.g. generated by X-ray, ultrasound or nuclear magnetic resonance (NMR) signals.
- grade refers to the slope of a blackening curve, which represents the optical density (D) as a function value (ordinate) for linearly increasing amounts of heat on the abscissa. Different amounts of heat are applied to the thermographic material in adjacent areas, analogous to the production of a step wedge.
- the linear increase in heat is e.g. achieved by linearly increasing the heating time at various points in the recording material, the heating power (J) per unit time (s) being kept constant. Alternatively, the heating time can remain constant and instead the heating output can be increased linearly.
- a gradient corresponds to the slope at a single point on the density curve.
- the gamma value ( ⁇ ) is the maximum gradient of the blackening curve and usually corresponds to the gradient between the end of the foot and the beginning of the shoulder of the blackening curve.
- the recording material according to the invention is also particularly advantageous from an ecological point of view.
- a barrier layer made of polyvinyl alcohol (Moviol® 18/88) was applied from an aqueous solution at a rate of 2.50 g / m 2 .
- a leuco dye layer with the composition specified below was applied from a methyl ethyl ketone solution and dried: Leuco dye, Yamada Black® S 205 1.60 g / m 2 Poly (vinyl chloride-co-vinyl acetate) 9.60 g / m 2
- a developer layer with the following composition from a methanol solution was applied and dried: p-Hydroxybenzoic acid benzyl ester 2.25 g / m 2 Nitrocellulose 2.25 g / m 2 Tegoglide® 410 0.30 g / m 2
- a recording material with the following composition was prepared in accordance with the procedure described in Example 1.
- Silver salt layer Silver behenate 6.63 g / m 2 Polyvinyl butyral (Butvar® B79) 6.63 g / m 2 3,3,3 ', 3', - tetramethyl-5,6,5 ', 6', - tetrahydroxy-spiro-bis-indan 1.26 g / m 2 3,4-dihydro-2,4-dioxo-1,3,2H-benzoxazine 0.50 g / m 2 Barrier layer: Polyvinyl alcohol (Moviol®18 / 88) 3.50 g / m 2 Leuco dye layer: Leuco dye Pergascript® 2.40 g / m 2 Poly (vinyl chloride-co-vinyl acetate) 8.80 g / m 2 Developer layer: p-Hydroxybenzoic acid benzyl ester 3.75 g
- a recording material with the following composition was prepared in accordance with the procedure described in Example 1.
- Silver salt layer Silver behenate 6.63 g / m 2 Polyvinyl butyral (Butvar® B79) 6.63 g / m 2 3,3,3 ', 3', - tetramethyl-5,6,5 ', 6', - tetrahydroxy-spiro-bis-indan 1.26 g / m 2 3,4-dihydro-2,4-dioxo-1,3,2H-benzoxazine 0.50 g / m 2 Top layer: Nitrocellulose 1.25 g / m 2 Tegoglide® 410 0.30 g / m 2
- a test image with 16 shades of gray was written onto the recording materials of Examples 1 to 3 using a printer with a thermal head (Hitachi VY 100 video printer).
- the optical densities of the individual stages were measured in transmission and tabulated.
- Optical density step 2nd 4th 6 8th 10th 12th 14 16 example 1 0.16 0.32 0.48 0.67 1.44 3.67 4.16 4.38
- Example 2 0.14 0.3 0.48 0.69 1.5 3.85 4.22 4.44
- Example 3 0.04 0.04 0.04 0.07 0.68 2.89 3.08 3.14
- the table clearly shows that the materials according to the invention are particularly suitable for reproducing shades of gray, particularly in the area of low densities.
Abstract
Description
Die Erfindung betrifft ein wärmeempfindliches Aufzeichnungsmaterial auf Basis einer Kombination aus einem wärmeempfindlichen Silbersalz und einem säureempfindlichen Leukofarbstoff.The invention relates to a heat-sensitive recording material based on a combination of a heat-sensitive silver salt and an acid-sensitive leuco dye.
Das Wärmebildverfahren bzw. die Thermografie ist ein Aufnahmeprozeß, bei dem Bilder mit Hilfe von bildmäßig modulierter Wärmeenergie erzeugt werden. In der Thermografie sind zwei Konzepte bekannt:
- 1. Die direkte thermische Erzeugung eines sichtbaren Bildmusters durch bildmäßige Erwärmung eines Aufnahmematerials, das Substanzen enthält, die durch chemische oder physikalische Prozesse ihre Farbe oder optische Dichte ändern. Derartige Aufnahmematerialien und entsprechende Verfahren werden nachfolgend als "direkt thermisch" bezeichnet.
- 2. Der Thermofarbstofftransferdruck, wobei ein sichtbares Bildmuster durch Übertragung einer farbigen Substanz von einem bildmäßig erwärmten Donatorelement auf ein Rezeptorelement erzeugt wird. Bei dem Thermofarbstofftransferdruck wird ein Farbstoff-Donatorelement verwendet, das über eine Farbstoffbindemittelschicht verfügt, aus der durch Anwendung von Wärme in einem Muster, das normalerweise durch elektronische Datensignale erzeugt wird, eingefärbte Teile oder nur die Farbstoffmoleküle selbst auf ein mit ihr in Kontakt stehendes Aufnahmeelement übertragen werden.
- 1. The direct thermal generation of a visible image pattern by imagewise heating of a recording material which contains substances which change their color or optical density through chemical or physical processes. Such recording materials and corresponding methods are referred to below as "directly thermal".
- 2. The thermal dye transfer printing, wherein a visible image pattern is generated by transferring a colored substance from an imagewise heated donor element to a receptor element. Thermal dye transfer printing uses a dye-donor element that has a dye-binder layer from which colored parts or only the dye molecules themselves are transferred to a receiving element in contact with them by applying heat in a pattern that is normally generated by electronic data signals will.
Eine Übersicht der "direkt thermischen" Abbildungsverfahren ist z.B. in dem Buch "Imaging Systems" von Kurt I. Jacobson und Ralph E. Jacobson, erschienen bei The Focal Press, London und New York (1976), in Kapitel VII unter der Überschrift "7.1 Thermografie" enthalten. Bei der Thermografie werden Materialien eingesetzt, die im wesentlichen nicht licht- bzw. fotoempfindlich, sondern wärmempfindlich bzw. thermosensitiv sind. Die in den Bildbereichen aufgebrachte Wärme reicht aus, um eine sichtbare Veränderung in einem wärmeempfindlichen Aufnahmematerial hervorzurufen.An overview of the "direct thermal" imaging methods is, for example, in the book "Imaging Systems" by Kurt I. Jacobson and Ralph E. Jacobson, published by The Focal Press, London and New York (1976), in Chapter VII under the heading "7.1 Thermography "included. Thermography uses materials that are essentially not sensitive to light or photos, but are sensitive to heat or thermosensitive. The heat applied in the image areas is sufficient to cause a visible change in a heat-sensitive recording material.
Die meisten direkt thermografischen Aufnahmematerialien sind chemischer Art. Bei Erwärmung auf eine bestimmte Umwandlungstemperatur findet eine irreversible chemische Reaktion statt, wodurch ein farbiges Bild erzeugt wird.Most direct thermographic recording materials are chemical. When heated to a certain transition temperature, an irreversible chemical reaction takes place, which creates a colored image.
Eine große Vielzahl chemischer Systeme ist vorgeschlagen worden, von denen einige Beispiele auf Seite 138 des vorstehend genannten Buches von Kurt I. Jacobson et al. angegeben sind. An dieser Stelle wird die Herstellung eines Silbermetallbildes mit Hilfe einer thermisch induzierten Reduktion einer Silberseife beschrieben. Laut dem US-Patent 3.080.254 umfaßte ein typisches wärmeempfindliches Kopierpapier in der wärmeempfindlichen Schicht ein thermoplastisches Bindemittel, z.B. Ethylcellulose, ein wasserunlösliches Silbersalz, z.B. Silberstearat, sowie ein geeignetes organisches Reduktionsmittel, für das 4-Methoxy-1-hydroxy-dihydronaphthalin ein repräsentatives Beispiel ist. Die örtlich begrenzte Erwärmung des Aufzeichnungsmaterials im thermografischen Reproduktionsprozeß auf eine geeignete Umwandlungstemperatur im Bereich von 90 °C bis 150 °C verursacht eine sichtbare Veränderung in der wärmeempfindlichen Schicht. Die anfänglich weiße oder leicht farbige Schicht wird dunkler und erhält an der erwärmten Stelle ein bräunliches Aussehen. Zur Erzielung eines neutraleren Farbtons wird der wärmeempfindlichen Schicht eine heterocyclische organische Tonersubstanz, z.B. Phthalazinon, zugegeben.A wide variety of chemical systems have been proposed, some examples on page 138 of the above-mentioned book by Kurt I. Jacobson et al. are specified. At this point, the production of a silver metal image using a thermally induced reduction of a silver soap is described. According to U.S. Patent 3,080,254, a typical thermosensitive copy paper in the thermosensitive layer comprised a thermoplastic binder, e.g. Ethyl cellulose, a water-insoluble silver salt, e.g. Silver stearate and a suitable organic reducing agent, for which 4-methoxy-1-hydroxy-dihydronaphthalene is a representative example. The localized heating of the recording material in the thermographic reproduction process to a suitable transition temperature in the range from 90 ° C. to 150 ° C. causes a visible change in the heat-sensitive layer. The initially white or slightly colored layer becomes darker and acquires a brownish appearance when heated. To achieve a more neutral color tone, the heat sensitive layer is treated with a heterocyclic organic toner substance, e.g. Phthalazinone added.
Wärmeempfindliche Kopierpapiere, die eine Aufnahmeschicht mit einem im wesentlichen lichtunempfindlichen organischen Silbersalz und einem hydroxylaminartigen Reduktionsmittel in einem thermoplastischen Bindemittel wie z.B. Ethylcellulose und nachchloriertes Polyvinylchlorid aufweisen, sind in US-Patent 4.082.901 beschrieben. Bei Verwendung in thermografischen Aufnahmeverfahren mit Thermodruckköpfen sind die genannten Kopierpapiere nicht zur Reproduktion von Bildern mit einer relativ großen Anzahl von Graustufen geeignet, wie sie für die Halbtonreproduktion erforderlich sind.Heat-sensitive copier papers comprising a recording layer with a substantially light-insensitive organic silver salt and a hydroxylamine-like reducing agent in a thermoplastic binder such as e.g. Having ethyl cellulose and post-chlorinated polyvinyl chloride are described in U.S. Patent 4,082,901. When used in thermographic recording processes with thermal print heads, the copier papers mentioned are not suitable for reproducing images with a relatively large number of gray levels, as are required for halftone reproduction.
Laut dem vorstehend erwähnten Handbuch für Abbildungsmaterialien (Seiten 499 - 501) werden direkte Wärmeaufnahmeverfahren mit einem Leukofarbstoffsystem heute kommerziell genutzt.According to the above-mentioned manual for imaging materials (pages 499-501), direct heat absorption processes with a leuco dye system are used commercially today.
In einer von T. Usami und A. Shimura im Journal of Imaging Technology, Jg. 16, Nr. 6, Dezember 1990, S. 234 bis 237, beschriebenen Ausführungsform arbeitet ein bestimmtes Leukofarbstoffsystem auf einem transparenten Filmträger mit gekapselten Leukofarbstoffen in einer Aufnahmeschicht, die einen sog. "Entwickler" enthält (z.B. eine sauer reagierende Bisphenolverbindung, die in einem organischen Lösemittel gelöst und in einem wasserlöslichen Bindemittel dispergiert ist). Aus der Kurve der optischen Dichte in Abhängigkeit von der Temperatur (Bild 11 auf Seite 236) ist zu ersehen, daß die optische Dichte bei Temperaturen von etwa 130 °C nicht höher als 1,5 ist und nicht weiter ansteigt.In an embodiment described by T. Usami and A. Shimura in the Journal of Imaging Technology, vol. 16, no. 6, December 1990, pp. 234 to 237, a specific leuco dye system works on a transparent film support encapsulated leuco dyes in a recording layer which contains a so-called "developer" (for example an acid-reacting bisphenol compound which is dissolved in an organic solvent and dispersed in a water-soluble binder). From the curve of the optical density as a function of temperature (Figure 11 on page 236) it can be seen that the optical density at temperatures of around 130 ° C is not higher than 1.5 and does not increase further.
Weder direkte thermische Monoblatt-Aufnahmematerialien noch Zweiblatt-Thermofarbstofftransfer-Aufnahmematerialien (Farbstoffdonator- und Rezeptormaterialien), wie sie heute auf dem Markt sind, verfügen über die Fähigkeit, Bilder mit maximalen optischen Dichten über 2,5 und einer für die Halbtonreproduktion erforderlichen Gradation zu liefern.Neither direct mono-sheet thermal receivers nor two-sheet thermal dye transfer receivers (dye donor and receptor materials) on the market today have the ability to provide images with maximum optical densities above 2.5 and gradation required for halftone reproduction .
Bei bestimmten Anwendungen, z.B. im Bereich der medizinischen Diagnostik, müssen jedoch die vorstehenden Abbildungsmöglichkeiten gegeben sein, und direkt thermische Aufnahmematerialien sind dafür nur geeignet, wenn sie die vorstehend genannten sensitometrischen Eigenschaften hinsichtlich optischer Dichte und Gradation aufweisen.In certain applications, e.g. in the field of medical diagnostics, however, the above imaging options must be available, and direct thermal recording materials are only suitable for this if they have the aforementioned sensitometric properties with regard to optical density and gradation.
Nach der bisher unveröffentlichten EP-Anmmeldung 94 201 207.1 weist ein wärmeempfindliches Aufzeichnungsmaterial auf der gleichen Seite eines Trägermaterials, der sogenannten wärmeempfindlichen Seite, eine oder mehrere Bindemittelschichten auf die ein im wesentlichen lichtunempfindliches Metallsalz in Kombination mit mindestens einem organischen Reduktionsmittel sowie einen säureempfindlichen Leukofarbstoff in Kombination mit einer sauer reagierenden Verbindung, die als Farbstoffentwickler dient, enthalten. Die Materialien gemäß der EP-Anmmeldung 94 201 207 ergeben Bilder mit hoher optischer Dichte und guter Graustufenwiedergabe.According to the previously unpublished EP application 94 201 207.1, a heat-sensitive recording material on the same side of a carrier material, the so-called heat-sensitive side, has one or more binder layers on which an essentially light-insensitive metal salt in combination with at least one organic reducing agent and an acid-sensitive leuco dye in combination with an acidic compound that serves as a dye developer. The materials according to EP application 94 201 207 result in images with high optical density and good grayscale reproduction.
Aufgabe der vorliegenden Erfindung ist es, ein wärmeempfindliches Aufzeichnungsmaterial bereitzustellen, das Abbildungen mit hoher optischer Dichte, guter Graustufenwiedergabe und guter Stabilität liefert. Eine weitere Aufgabe der vorliegenden Erfindung ist die Bereitstellung eines Aufzeichnungsmaterials mit einem vereinfachtem Schichtaufbau, das in einfacher Weise durch Gießtechnologie herstellbar ist.It is an object of the present invention to provide a heat-sensitive recording material which provides images with high optical density, good grayscale reproduction and good stability. Another object of the present invention is to provide a recording material with a simplified layer structure which can be produced in a simple manner by means of casting technology.
Gegenstand der Erfindung ist ein wärmeempfindliches Bildaufzeichnungsmaterial, das auf einem Trägermaterial
- 1. mindestens eine Bindemittelschicht oder eine Abfolge von Bindemittelschichten mit einer wärmeempfindlichen bilderzeugenden Kombination aus einem organischen Silbersalz und einem organischen Reduktionsmittel für das organische Silbersalz, und
- 2. mindestens eine Bindemittelschicht oder eine Abfolge von Bindemittelschichten mit einer wärmeempfindlichen bilderzeugenden Kombination aus einem säureempfindlichen Leukofarbstoff und einer sauer reagierenden, als Entwickler für den Leukofarbstoff dienenden Verbindung
- 1. at least one binder layer or a sequence of binder layers with a heat-sensitive imaging combination of an organic silver salt and an organic reducing agent for the organic silver salt, and
- 2. at least one binder layer or a sequence of binder layers with a heat-sensitive image-forming combination of an acid-sensitive leuco dye and an acidic compound serving as a developer for the leuco dye
Unter "thermischer Wirkungsbeziehung" ist die Möglichkeit zu verstehen, daß die betreffenden die Bilddichte erhöhenden reaktiven Substanzen bei Einwirkung von Wärme miteinander in reaktiven Kontakt treten können, z. B. durch thermisch induzierte Diffusion oder dadurch, daß trennende Elemente wie beispielsweise Sperrschichten oder die Wände von eine Reaktionskomponente einhüllenden Mikrokapseln bei Einwirkung von Wärme durchlässig werden.Under "thermal effect relationship" is the possibility to understand that the relevant image density-increasing reactive substances can come into reactive contact with each other when exposed to heat, for. B. by thermally induced diffusion or in that separating elements such as barrier layers or the walls of a reaction component enveloping microcapsules become permeable when exposed to heat.
In einer bevorzugten Ausführungsform der Erfindung enthält das erfindungsgemäße wärmeempfindliche Aufzueichnungsmaterial auf einem Trägermaterial mindestens vier Schichten, nämlich
- 1. eine Bindemittelschicht mit einer wärmeempfindlichen bilderzeugenden Kombination aus einem organischen Silbersalz und einem organischen Reduktionsmittel für das organische Silbersalz (Silbersalzschicht),
- 2. eine Schicht mit einem wasser- oder alkohollöslichen Polymer,
- 3. eine Schicht mit einem Leukofarbstoff und einem Bindemittel für den Leukofarbstoff (Leukofarbstoffschicht), und
- 4. eine Schicht mit einem Entwickler für den Leukofarbstoff und einem wasser- oder alkohollöslichen Bindemittel (Entwicklerschicht),
- 1. a binder layer with a heat-sensitive imaging combination of an organic silver salt and an organic reducing agent for the organic silver salt (silver salt layer),
- 2. a layer with a water- or alcohol-soluble polymer,
- 3. a layer with a leuco dye and a binder for the leuco dye (leuco dye layer), and
- 4. a layer with a developer for the leuco dye and a water- or alcohol-soluble binder (developer layer),
Das Trägermaterial für das erfindungsgemäße wärmeempfindliche Aufnahmematerial ist vorzugsweise ein dünner flexibler Träger z.B. aus Papier, polyethylenbeschichtetem Papier oder transparenter Kunststoffolie, z.B. aus einem Celluloseester, z.B. Cellulosetriacetat, Polypropylen, Polycarbonat oder Polyester, z.B. Polyethylenterephthalat. Der Schichtträger kann Bogen-, Band- oder Bahnform haben und bei Bedarf mit einer Unterlage versehen sein, um die Haftung der darauf aufgebrachten wärmeempfindlichen Aufnahmeschicht zu verbessern. Die Schichtdicke des Trägers kann beispielsweise zwischen 10 und 2000 µm, vorzugsweise zwischen 50 und 500 µm liegen.The carrier material for the heat-sensitive recording material according to the invention is preferably a thin flexible carrier e.g. made of paper, polyethylene-coated paper or transparent plastic film, e.g. from a cellulose ester, e.g. Cellulose triacetate, polypropylene, polycarbonate or polyester, e.g. Polyethylene terephthalate. The layer support can have an arch, tape or web shape and, if necessary, be provided with a base in order to improve the adhesion of the heat-sensitive recording layer applied thereon. The layer thickness of the support can be, for example, between 10 and 2000 μm, preferably between 50 and 500 μm.
Das erfindungsgemäße Aufnahmematerial kann zur Herstellung von Durchsichts- und Aufsichtsbildern verwendet werden. Dies bedeutet, daß der Schichtträger transparent oder opak sein kann, im letzteren Fall weist der Schichtträger eine weiße, lichtreflektierende Oberfläche auf. Es wird z.B. ein Papierträger verwendet, der weiße, lichtreflektierende Pigmente enthalten kann, optional auch in einer Zwischenschicht zwischen einer Aufnahmeschicht und dem genannten Träger. Wird ein transparenter Schichtträger verwendet, kann der genannte Träger farblos oder farbig sein, z.B. blau getönt. Im Bereich der Hardcopy-Herstellung werden Aufnahmematerialien auf einem weißen, opaken Träger verwendet, während im Bereich der medizinischen Diagnostik vielfach Schwarzbild-Dias für die Betrachtung mit einem Lichtkasten angewandt werden.The recording material according to the invention can be used for the production of transparency and supervisory images. This means that the substrate can be transparent or opaque, in the latter case the substrate has a white, light-reflecting surface. For example a paper carrier is used which can contain white, light-reflecting pigments, optionally also in an intermediate layer between a receiving layer and said carrier. If a transparent layer support is used, the said support can be colorless or colored, e.g. tinted blue. In the field of hard copy production, recording materials on a white, opaque support are used, while in the field of medical diagnostics, black-screen slides are often used for viewing with a light box.
Erfindungsgemäß geeignete organische Silbersalze sind im wesentlichen lichtunempfindlich. Besonders geeignet sind Silbersalze von aliphatischen Carbonsäuren, die sogenannten Fettsäuren, bei denen die aliphatische Kohlenstoffkette vorzugsweise mindestens 12 C-Atome aufweist, z.B. Silberlaurat, Silberpalmitat, Silberstearat, Silberhydroxystearat, Silberoleat und Silberbehenat sowie gleichermaßen Silberdodecylsulfonat gemäß US-Patent 4.504.575 und Silberdi-(2-ethylhexyl)-sulfosuccinat gemäß der Europäischen Patentanmeldung 227 141.Organic silver salts suitable according to the invention are essentially insensitive to light. Silver salts of aliphatic carboxylic acids, the so-called fatty acids, in which the aliphatic carbon chain preferably has at least 12 carbon atoms, for example silver laurate, silver palmitate, silver stearate, silver hydroxystearate, silver oleate and silver behenate, and the like, are particularly suitable Silver dodecyl sulfonate according to US patent 4,504,575 and silver di (2-ethylhexyl) sulfosuccinate according to European patent application 227 141.
Geeignete organische Reduktionsmittel für die Reduktion des Silbersalzes sind organische Verbindungen mit mindestens einem aktiven Wasserstoffatom an O, N oder C, wie etwa bei aromatischen Di- und Trihydroxyverbindungen, z.B. Hydrochinon und substituierten Hydrochinonen, Catechol, Pyrogallol, Gallussäure und Gallate, Aminophenole, METOL (Handelsname), p-Phenylendiamine, Alkoxynaphthole, z.B. 4-Methoxy-1-naphthol gemäß US-Patent 3.094.417, Pyrazolidin-3-on-artige Reduktionsmittel, z.B. PHENIDONE (Handelsname), Pyrazolin-5-one, Indandion-1,3-Derivate, Hydroxytetronsäuren, Hydroxytetronimide, Hydroxylamin-Derivate (siehe z.B. US-Patent 4.082.901), Hydrazin-Derivate, Reductone und Ascorbinsäure; siehe auch US-Patente 3.074.809, 3.080.254, 3.094.417 und 3.887.378. Bevorzugt werden Catechol und Polyhydroxy-spiro-bis-indan-Verbindungen. Das Reduktionsmittel wird vorzugsweise in die wärmeempfindliche Bildschicht eingearbeitet, es kann aber ganz oder teilweise in eine angrenzende Schicht eingebettet sein, von wo es in die Schicht mit dem organischen Silbersalz diffundieren kann.Suitable organic reducing agents for the reduction of the silver salt are organic compounds with at least one active hydrogen atom on O, N or C, such as with aromatic di- and trihydroxy compounds, e.g. Hydroquinone and substituted hydroquinones, catechol, pyrogallol, gallic acid and gallates, aminophenols, METOL (trade name), p-phenylenediamines, alkoxynaphthols, e.g. 4-methoxy-1-naphthol according to U.S. Patent 3,094,417, pyrazolidin-3-one type reducing agents, e.g. PHENIDONE (trade name), pyrazolin-5-one, indanedione-1,3-derivatives, hydroxytetronic acids, hydroxytetronimides, hydroxylamine derivatives (see e.g. U.S. Patent 4,082,901), hydrazine derivatives, reductones and ascorbic acid; see also U.S. Patents 3,074,809, 3,080,254, 3,094,417 and 3,887,378. Catechol and polyhydroxy spiro-bis-indan compounds are preferred. The reducing agent is preferably incorporated into the heat-sensitive image layer, but it can be wholly or partially embedded in an adjacent layer, from where it can diffuse into the layer with the organic silver salt.
Als Bindemittel eignen sich in erster Linie natürliche, modifizierte natürliche oder synthetische Harze. z.B. Cellulosederivate wie etwa Ethylcellulose, Celluloseester, Carboxymethylcellulose, Stärke-Ether, Galactomannan, Polymere aus a,b-ethylenisch ungesättigten Verbindungen wie Polyvinylchlorid, nachchloriertes Polyvinylchlorid, Copolymere von Vinylacetat und Vinylidenchlorid, Copolymere aus Vinylchlorid und Vinylacetat, Polyvinylacetat und teilhydrolyisiertes Polyvinylacetat, Polyvinylalkohol, Polyvinylacetale aus Polyvinylalkohol, bei denen nur ein Teil der sich wiederholenden Vinylalkoholeinheiten mit einem Aldehyd, vorzugsweise Polyvinylbutyral, umgesetzt ist, Copolymere von Acrylnitril und Acrylamid, Polyacrylsäureester, Polymethacrylsäureester und Polyethylen oder Mischungen davon. Ein besonders geeignetes Bindemittel ist Polyvinylbutyral mit einer geringen Menge Vinylalkoholeinheiten, das unter der Handelsbezeichnung BUTVAR B79 von Monsanto USA vertrieben wird.Natural, modified natural or synthetic resins are primarily suitable as binders. e.g. Cellulose derivatives such as ethyl cellulose, cellulose esters, carboxymethyl cellulose, starch ether, galactomannan, polymers of a, b-ethylenically unsaturated compounds such as polyvinyl chloride, post-chlorinated polyvinyl chloride, copolymers of vinyl acetate and vinylidene chloride, copolymers of vinyl chloride and vinyl acetate, polyvinyl acetate and partially hydrolyzed polyvinyl vinyl vinyl acetate from polyvinyl alcohol, in which only a part of the repeating vinyl alcohol units is reacted with an aldehyde, preferably polyvinyl butyral, copolymers of acrylonitrile and acrylamide, polyacrylic acid esters, polymethacrylic acid esters and polyethylene or mixtures thereof. A particularly suitable binder is polyvinyl butyral with a small amount of vinyl alcohol units, which is sold under the trade name BUTVAR B79 by Monsanto USA.
Um einen neutralschwarzen Bildton mit Silber in den Bereichen höherer optischer Dichte und Neutralgrau in den Bereichen geringerer Dichte zu erhalten, können die reduzierbaren Silbersalze und die Reduktionsmittel vorteilhaft in Verbindung mit einer aus der Thermografie oder Foto-Thermografie bekannten sog. Tonersubstanz verwendet werden. Geeignete Tonersubstanzen sind die Phthalimide und Phthalazinone entsprechend den in US-Patent 4.082.901 beschriebenen allgemeinen Formeln. Weiterhin wird auf die in den US-Patenten 3.074.809, 3.446.648 und 3.844.797 beschriebenen Tonersubstanzen verwiesen. Besonders geeignete Tonersubstanzen sind auch die heterozyclischen Tonerverbindungen des Benzoxazindion- oder Naphthoxazindion-Typs.In order to obtain a neutral black image tone with silver in the areas of higher optical density and neutral gray in the areas of lower density, the reducible silver salts and the reducing agents can advantageously be used in conjunction with a so-called toner substance known from thermography or photo-thermography be used. Suitable toner substances are the phthalimides and phthalazinones according to the general formulas described in US Pat. No. 4,082,901. Reference is also made to the toner substances described in US Patents 3,074,809, 3,446,648 and 3,844,797. Particularly suitable toner substances are also the heterocyclic toner compounds of the benzoxazinedione or naphthoxazinedione type.
In der Silbersalzschicht liegt das Gewichtsverhältnis von Bindemittel zu organischem Silbersalz vorzugsweise zwischen 0,2 und 6. Diese Schicht hat vorzugsweise eine Dicke zwischen 8 µm und 32 µm.In the silver salt layer, the weight ratio of binder to organic silver salt is preferably between 0.2 and 6. This layer preferably has a thickness between 8 μm and 32 μm.
Die Schicht mit dem wasser- oder alkohollöslichen Polymer hat die Funktion einer Sperrschicht. Geeignete Polymere sind z.B. Polyvinylalkohol, teilverseiftes Polyvinylacetat, Polyvinylpyrrolidon, Polyethylenoxid, Polyethylenoxid-Polypropylenoxid-Copolymere, Celluloseester und Celluloseether. Besonders gut geeignet ist Polyvinylalkohol. Die Dicke der Sperrschicht beträgt 0,1 bis 10 µm, vorzugsweise 0,2 bis 5 µm.The layer with the water- or alcohol-soluble polymer has the function of a barrier layer. Suitable polymers are e.g. Polyvinyl alcohol, partially saponified polyvinyl acetate, polyvinyl pyrrolidone, polyethylene oxide, polyethylene oxide-polypropylene oxide copolymers, cellulose esters and cellulose ethers. Polyvinyl alcohol is particularly suitable. The thickness of the barrier layer is 0.1 to 10 μm, preferably 0.2 to 5 μm.
Für die Leukofarbstoffschicht besonders geeignet sind Leukofarbstoffe, die zur Klasse der Fluorane gehören, wie sie z.B. in EP-A-0 155796, in DE-A-35 34 594 und DE-A-43 29 133 sowie in den US-Patenten 3.957.288, 4.011.352 und 5.206.118 beschrieben sind.Particularly suitable for the leuco dye layer are leuco dyes belonging to the class of the fluoranes, such as those e.g. in EP-A-0 155796, in DE-A-35 34 594 and DE-A-43 29 133 as well as in US Patents 3,957,288, 4,011,352 and 5,206,118.
Die bevorzugten fluoranartigen Leukofarbstoffe haben die folgende allgemeine Formel (A):
- R1
- eine Mono- oder Dialkylaminogruppe in substituierter Form ist, z.B. substituiert mit einer Tetrahydrofurylgruppe,
- R2
- Wasserstoff, F, Cl, C1-C5-Alkyl, C1-C5-Alkoxy, Phenyl oder Benzyl ist,
- R3
- Wasserstoff, eine C1-C4-Alkylgruppe, eine Alkarylgruppe, eine Cycloalkylgruppe oder eine Arylgruppe ist, z.B. eine Phenylgruppe, und
- R4
- eine C1-C4-Alkylgruppe, eine Alkarylgruppe, eine Cycloalkylgruppe oder eine Arylgruppe ist, z.B. eine Phenylgruppe.
- R 1
- is a mono- or dialkylamino group in substituted form, for example substituted with a tetrahydrofuryl group,
- R 2
- Is hydrogen, F, Cl, C1-C5-alkyl, C1-C5-alkoxy, phenyl or benzyl,
- R 3
- Is hydrogen, a C1-C4 alkyl group, an alkaryl group, a cycloalkyl group or an aryl group, for example a phenyl group, and
- R 4
- is a C1-C4 alkyl group, an alkaryl group, a cycloalkyl group or an aryl group, for example a phenyl group.
Andere Leukofarbstoffe, die durch Reaktion mit einer Säure eine farbige Verbindung ergeben, sind Leuko-Kristallviolett, Leuko-Malachitgrün, Kristallviolettlakton, Benzoyl-Leuko-Methylenblau und die säureempfindlichen Leukofarbstoffverbindungen in der Klasse der Bisindophthalide und Carbazolylmethane, die in US-Patent 5.206.118 beschrieben sind.Other leuco dyes that form a colored compound upon reaction with an acid are leuco crystal violet, leuko malachite green, crystal violet lactone, benzoyl leuko methylene blue, and the acid sensitive leuco dye compounds in the bisindophthalide and carbazolylmethane class described in U.S. Patent 5,206,118 are described.
Als Bindemittel für die Leukofarbstoffschicht eignen sich die gleichen Bindemittel sie für die Silbersalzschicht. Besonders gut geeignet sind Vinylchlorid und Vinylidenchlorid Copolymerisate, wie z.B. Poly(Vinylchlorid-co-Vinylacetat).The same binders as for the silver salt layer are suitable as binders for the leuco dye layer. Vinyl chloride and vinylidene chloride copolymers, such as e.g. Poly (vinyl chloride-co-vinyl acetate).
Die genannten Bindemittel können in Verbindung mit Wachsen oder "Wärmelösemitteln", auch als "Thermo-Lösemittel" bezeichnet, eingesetzt werden, die die Reaktionsgeschwindigkeit der Farbstoffbildungsreaktion und der Bildsilber erzeugenden Redox-Reaktion bei erhöhten Temperaturen verbessern.The binders mentioned can be used in conjunction with waxes or "heat solvents" , also referred to as "thermal solvents", which improve the reaction rate of the dye formation reaction and the image-silver-producing redox reaction at elevated temperatures.
Der Begriff "Wärmelösemittel" im Sinne der vorliegenden Erfindung bezeichnet ein nicht hydrolysierbares organisches Material, das bei Temperaturen unter 50 °C eine feste Form hat, aber ab etwa 60 °C als Weichmacher für das Bindemittel dient, mit dem es sich in dem erwärmten Bereich verbindet und/oder dann als Lösemittel für mindestens einen der farbbildenden Reaktionspartner wirkt. Für diesen Zweck geeignet ist z.B. ein Polyethylenglykol mit einer mittleren relativen Molekülmasse zwischen 1.500 und 20.000 gemäß Beschreibung in US-Patent 3.347.675.Die Dicke der Leukofarbstoffschicht beträgt 2 bis 25 µm, vorzugsweise 4 bis 15 µm.The term "heat solvent" in the sense of the present invention denotes a non-hydrolyzable organic material which has a solid form at temperatures below 50 ° C, but from around 60 ° C serves as a plasticizer for the binder with which it is in the heated area connects and / or then acts as a solvent for at least one of the color-forming reactants. Suitable for this purpose is e.g. a polyethylene glycol having an average molecular weight between 1,500 and 20,000 as described in U.S. Patent 3,347,675. The thickness of the leuco dye layer is 2 to 25 µm, preferably 4 to 15 µm.
Geeignete Entwickler für den Leukofarbstoff sind elektronenaufnehmende oder sauer reagierende Verbindungen. Beispielhaft seien genannt: 1,3-bis-p-Hydroxycumylbenzol oder 1,4-bis-Cumylbenzol, p-Hydroxybenzoesäure-Butylester (PHBB) und Bisphenole wie z.B. 4,4'-Isopropylidendiphenol (Bisphenol A) sowie analoge Verbindungen, die im Journal of Imaging Technology, Jg. 16, Nr. 6, Dezember 1990, S. 235, sowie in DE-A- 35 34 594 und DE-A-43 29 133 beschrieben sind. Andere geeignete sauer reagierende Verbindungen, die als Entwickler für Leukofarbstoffe dienen, sind Monoester von aromatischen ortho-Carbonsäuren, die z.B. in US-Patent 4.011.352 beschrieben sind, insbesondere der Ethylhalbester der ortho-Phthalsäure.Suitable developers for the leuco dye are electron-accepting or acid-reacting compounds. Examples include: 1,3-bis-p-hydroxycumylbenzene or 1,4-bis-cumylbenzene, p-hydroxybenzoic acid butyl ester (PHBB) and bisphenols such as 4,4'-isopropylidenediphenol (bisphenol A) and analogues Compounds described in the Journal of Imaging Technology, vol. 16, No. 6, December 1990, p. 235, as well as in DE-A-35 34 594 and DE-A-43 29 133. Other suitable acid-reacting compounds which serve as developers for leuco dyes are monoesters of aromatic ortho-carboxylic acids, which are described, for example, in US Pat. No. 4,011,352, in particular the ethyl half-ester of ortho-phthalic acid.
Die Entwicklerschicht wird zweckmäßigerweise unter Verwendung solcher Lösungsmittel hergestellt, die für das Bindemittel der Leukofarbstoffschicht keine lösende Wirkung haben. Dementsprechend sind die in der Entwicklerschichtverwendeten Bindemittel wasser- oder alkohollöslich. Es kann sich dabei um modifizierte natürliche oder synthetische Polymere handeln. Als Beispiel seien Cellulosederivate, Polyvinylpyrrolidon und Copolymerisate aus Vinylpyrrolidon und Vinylacetat genannt. Ein bevorzugtes Bindemittel ist Nitrocellulose. Die Schichtdiche der Entwicklerschicht beträgt 1 bis 15 µm, vorzugsweise 3 µm bis 10 µm.The developer layer is expediently produced using solvents which have no solvent effect for the binder of the leuco dye layer. Accordingly, the binders used in the developer layer are water or alcohol soluble. These can be modified natural or synthetic polymers. Cellulose derivatives, polyvinylpyrrolidone and copolymers of vinylpyrrolidone and vinyl acetate may be mentioned as examples. A preferred binder is nitrocellulose. The layer thickness of the developer layer is 1 to 15 µm, preferably 3 µm to 10 µm.
Selbstverständlich kann das erfindungsgemäße Aufzeichnungsmaterial weitere für diesen Einsatzzweck bekannte Schichten enthalten. So kann es günstig sein, als oberste Schicht eine Abdeckschicht (topcoat) anzubringen. Eine übliche Dicke dieser Abdeckschicht beträgt 0.05 bis 2.5 µm.Of course, the recording material according to the invention can contain further layers known for this purpose. It can be beneficial to apply a top coat as the top layer. A common thickness of this cover layer is 0.05 to 2.5 µm.
Die Abdeckschicht kann Antihafteigenschaften haben, was sich z.B. durch die Verwendung von Polysiloxanen, Polysiloxan-Polyether-Blockcopolymerisaten oder Fluorpolymeren erreichen läßt. Auch Polyvinylalkohol ist als Abdeckschicht geeignet.The cover layer can have non-stick properties, e.g. can be achieved by using polysiloxanes, polysiloxane-polyether block copolymers or fluoropolymers. Polyvinyl alcohol is also suitable as a cover layer.
Für das Beschreiben des Bildmaterials mit einem Thermokopf hat es sich als günstig erwiesen, eine thermostabile Abdeckschicht anzubringen. Hierfür geeignete Polymere haben einen Erweichungspunkt oberhalb von 100 °C, vorzugsweise oberhalb von 130 °C. Gut geeignet ist Polycarbonat, insbesondere Homo- und Copolymere des Trimetylcyclohexylbisphenolpolycarbonats. Die letztgenannten Polymere führen zu Bildmaterialien mit besonders hohem Glanz und guter Bildschärfe. Eine Verschmutzung des Thermokopfes durch das Bildmaterial infolge von Verklebung oder Abrieb findet nicht statt. Ein zusätzlicher Vorteil dieser Polymere besteht in ihrer einfachen Verarbeitbarkeit, z.B. durch Gießen aus organischer Lösung.For writing the image material with a thermal head, it has proven to be advantageous to attach a thermostable cover layer. Polymers suitable for this have a softening point above 100 ° C., preferably above 130 ° C. Polycarbonate is particularly suitable, in particular homopolymers and copolymers of trimethylcyclohexylbisphenol polycarbonate. The latter polymers result in image materials with a particularly high gloss and good image sharpness. There is no contamination of the thermal head by the image material due to gluing or abrasion. An additional advantage of these polymers is their ease of processing, for example by casting from an organic solution.
Die Herstellung der erfindungsgemäßen Aufzeichnungsmaterialien kann mittels bekannter Technologien erfolgen. Günstig ist die Herstellung durch Gießen oder Rakeln. Die Schicht mit dem wasser- oder alkohollöslichen Polymer und die Entwicklerschicht können in einfacher Weise aus Wasser, Alkohol oder Wasser-Alkohol-Gemischen, z.B. aus Methylalkohol, Ethylalkohol, Isopropylalkohol gegossen werden. Für die Silbersalzschicht und die Leukofarbstoffschicht sind im allgemeinen nichtwäßrige Lösungsmittel notwendig. Geeignete Lösemittel sind z.B. Aceton, Methylethylketon, Tetrahydrofuran, Dioxan, Dichlormethan, Tetrachlormethan und Ethylacetat.The recording materials according to the invention can be produced using known technologies. Production by casting or knife coating is cheap. The layer with the water or alcohol soluble polymer and the developer layer can easily be made from water, alcohol or water-alcohol mixtures, e.g. be poured from methyl alcohol, ethyl alcohol, isopropyl alcohol. Non-aqueous solvents are generally required for the silver salt layer and the leuco dye layer. Suitable solvents are e.g. Acetone, methyl ethyl ketone, tetrahydrofuran, dioxane, dichloromethane, carbon tetrachloride and ethyl acetate.
Die erfindungsgemäßen wärmeempfindlichen Aufzeichnungsmaterialien können z.B. mit einem Thermokopf beschrieben werden und liefern Schwarz-Weiß-Bilder mit hoher optischer Dichte (D-max > 2), guter Graustufenwiedergabe, hoher Schärfe und guter Stabilität. Die Gradation ist, vor allem in Bereichen geringerer Dichte, für die Halbtonreproduktion gut geeignet, z.B. für die Porträt-reproduktion bei Ausweisdokumenten und im Bereich der medizinischen Diagnostik für die Wiedergabe von Bildern, die z.B. durch Röntgen-, Ultraschall- oder Kernspinresonanz- (NMR-) Signale erzeugt werden.The heat-sensitive recording materials according to the invention can e.g. can be written with a thermal head and deliver black and white images with high optical density (D-max> 2), good grayscale reproduction, high sharpness and good stability. The gradation is particularly suitable for halftone reproduction, especially in areas of lower density, e.g. for portrait reproduction of identification documents and in the field of medical diagnostics for the reproduction of images, e.g. generated by X-ray, ultrasound or nuclear magnetic resonance (NMR) signals.
Der Begriff "Gradation" bezieht sich auf die Steigung einer Schwärzungskurve, die die optische Dichte (D) als Funktionswert (Ordinate) zu linear steigenden Wärmemengen auf der Abszisse darstellt. Hierbei werden unterschiedliche Wärmemengen in aneinander angrenzenden Bereichen auf das thermografische Material aufgebracht, analog zur Herstellung eines Stufenkeils. Die lineare Wärmezunahme wird z.B. durch lineare Erhöhung der Erwärmungszeit an verschiedenen Stellen des Aufnahmematerials erzielt, wobei die Heizleistung (J) pro Zeiteinheit (s) konstant gehalten wird. Alternativ kann die Erwärmungszeit konstant bleiben und statt dessen die Heizleistung linear erhöht werden.The term "gradation" refers to the slope of a blackening curve, which represents the optical density (D) as a function value (ordinate) for linearly increasing amounts of heat on the abscissa. Different amounts of heat are applied to the thermographic material in adjacent areas, analogous to the production of a step wedge. The linear increase in heat is e.g. achieved by linearly increasing the heating time at various points in the recording material, the heating power (J) per unit time (s) being kept constant. Alternatively, the heating time can remain constant and instead the heating output can be increased linearly.
Definitionsgemäß ergeben alle Gradienten oder Steigungen der besagten Schwärzungskurve zusammen die Gradation des thermografischen Bildes. Ein Gradient entspricht der Steigung an einem einzelnen Punkt auf der Schwärzungskurve. Der Gammawert (γ) ist der maximale Gradient der besagten Schwärzungskurve und entspricht in der Regel dem Gradienten zwischen dem Ende des Fußes und dem Anfang der Schulter der Schwärzungskurve.By definition, all gradients or slopes of said blackening curve together result in the gradation of the thermographic image. A gradient corresponds to the slope at a single point on the density curve. The gamma value (γ) is the maximum gradient of the blackening curve and usually corresponds to the gradient between the end of the foot and the beginning of the shoulder of the blackening curve.
Auch das Einschreiben mit einem Infrarot-Laser ist möglich, in diesem Falle wird dem Aufzeichnungsmaterial ein Infrarotabsorber zugesetzt.It is also possible to write with an infrared laser, in which case an infrared absorber is added to the recording material.
Das erfindungsgemäße Aufzeichnungsmaterial ist auch aus ökologischer Sicht besonders vorteilhaft.The recording material according to the invention is also particularly advantageous from an ecological point of view.
Auf einer substrierten Polyethylenterephthalatunterlage mit einer Schichtdicke von 125 µm wurde mit Hilfe einer Rakel eine Silbersalzschicht mit nachfolgend angegebener Zusammensetzung aus einer Methylethylketon-Lösung aufgetragen und getrocknet:
Anschließend wurde aus wäßriger Lösung eine Sperrschicht aus Polyvinylalkohol (Moviol®18/88) mit einem Auftrag von 2,50 g/m2 aufgebracht.Subsequently, a barrier layer made of polyvinyl alcohol (Moviol® 18/88) was applied from an aqueous solution at a rate of 2.50 g / m 2 .
Darüber wurde eine Leukofarbstoffschicht mit der nachfolgend angegebenen Zusammensetzung aus einer Methylethylketon-Lösung aufgetragen und getrocknet:
Darüber wurde eine Entwicklerschicht mit nachfolgend angegebener Zusammensetzung aus einer Methanol-Lösung aufgetragen und getrocknet:
Entsprechend der in Beispiel 1 angegebenen Arbeitsweise wurde ein Aufnahmematerial mit nachfolgender Zusammensetzung angefertigt.A recording material with the following composition was prepared in accordance with the procedure described in Example 1.
Unterlage: substrierte Polyethylenterephthalatfolie mit einer Schichtdicke von 100 µm
Entsprechend der in Beispiel 1 angegebenen Arbeitsweise wurde ein Aufnahmematerial mit nachfolgender Zusammensetzung angefertigt.A recording material with the following composition was prepared in accordance with the procedure described in Example 1.
Unterlage: substrierte Polyethylenterephthalatfolie mit einer Schichtdicke von 100 µm
Auf die Aufnahmematerialien der Beispiele 1 bis 3 wurden mit Hilfe eines Printers mit Thermokopf (Hitachi VY 100 videoprinter) ein Testbild mit 16 Graustufen eingeschrieben. Die optischen Dichten der einzelnen Stufen wurden in Transmission gemessen und tabelliert.
Die Tabelle läßt klar erkennen, daß die erfindungsgemäßen Materialien, besonders im Bereich niedriger Dichten zur Wiedergabe von Graustufen gut geeignet sind.The table clearly shows that the materials according to the invention are particularly suitable for reproducing shades of gray, particularly in the area of low densities.
Claims (6)
Applications Claiming Priority (2)
| Application Number | Priority Date | Filing Date | Title |
|---|---|---|---|
| DE19536045 | 1995-09-28 | ||
| DE19536045A DE19536045A1 (en) | 1995-09-28 | 1995-09-28 | Heat-sensitive recording material |
Publications (3)
| Publication Number | Publication Date |
|---|---|
| EP0767403A2 true EP0767403A2 (en) | 1997-04-09 |
| EP0767403A3 EP0767403A3 (en) | 1997-07-30 |
| EP0767403B1 EP0767403B1 (en) | 2002-04-17 |
Family
ID=7773390
Family Applications (1)
| Application Number | Title | Priority Date | Filing Date |
|---|---|---|---|
| EP96114797A Expired - Lifetime EP0767403B1 (en) | 1995-09-28 | 1996-09-16 | Heat-sensitive recording material |
Country Status (4)
| Country | Link |
|---|---|
| US (1) | US5753587A (en) |
| EP (1) | EP0767403B1 (en) |
| JP (1) | JPH09109550A (en) |
| DE (2) | DE19536045A1 (en) |
Families Citing this family (6)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| WO1998012053A1 (en) | 1996-09-23 | 1998-03-26 | Media Solutions, Inc. | Direct thermal printable film and laminate |
| US6090747A (en) * | 1996-12-17 | 2000-07-18 | Labelon Corporation | Thermosensitive direct image-recording material |
| US6409328B1 (en) * | 1999-03-31 | 2002-06-25 | Fuji Photo Film Co., Ltd. | Method of forming images and material for image formation |
| DE602007009719D1 (en) * | 2006-12-07 | 2010-11-18 | Agfa Gevaert Nv | METHOD FOR PRODUCING AN INFORMATION SUPPORT |
| US8871994B2 (en) | 2010-12-10 | 2014-10-28 | Kimberly-Clark Worldwide, Inc. | Wetness sensor for use in an absorbent article |
| US11472214B1 (en) * | 2017-12-12 | 2022-10-18 | Gourgen AMBARTSOUMIAN | Shielded direct thermal label and methods |
Citations (3)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| US5196297A (en) * | 1985-12-16 | 1993-03-23 | Polaroid Corporation | Recording material and process of using |
| EP0599580A1 (en) * | 1992-11-20 | 1994-06-01 | Nippon Paper Industries Co., Ltd. | Thermal recording sheet |
| EP0680833A1 (en) * | 1994-05-02 | 1995-11-08 | Agfa-Gevaert N.V. | Recording material for direct thermal imaging |
Family Cites Families (2)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| JPS5581194A (en) * | 1978-12-14 | 1980-06-18 | Ricoh Co Ltd | Polychromic heat sensitive recording material |
| DE3540627A1 (en) * | 1984-11-15 | 1986-05-22 | Ricoh Co., Ltd., Tokio/Tokyo | TWO-COLOR HEAT-SENSITIVE RECORDING MATERIAL |
-
1995
- 1995-09-28 DE DE19536045A patent/DE19536045A1/en not_active Withdrawn
-
1996
- 1996-09-16 EP EP96114797A patent/EP0767403B1/en not_active Expired - Lifetime
- 1996-09-16 DE DE59609086T patent/DE59609086D1/en not_active Expired - Fee Related
- 1996-09-18 US US08/715,196 patent/US5753587A/en not_active Expired - Fee Related
- 1996-09-25 JP JP8272874A patent/JPH09109550A/en active Pending
Patent Citations (3)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| US5196297A (en) * | 1985-12-16 | 1993-03-23 | Polaroid Corporation | Recording material and process of using |
| EP0599580A1 (en) * | 1992-11-20 | 1994-06-01 | Nippon Paper Industries Co., Ltd. | Thermal recording sheet |
| EP0680833A1 (en) * | 1994-05-02 | 1995-11-08 | Agfa-Gevaert N.V. | Recording material for direct thermal imaging |
Also Published As
| Publication number | Publication date |
|---|---|
| DE59609086D1 (en) | 2002-05-23 |
| DE19536045A1 (en) | 1997-04-03 |
| EP0767403B1 (en) | 2002-04-17 |
| JPH09109550A (en) | 1997-04-28 |
| EP0767403A3 (en) | 1997-07-30 |
| US5753587A (en) | 1998-05-19 |
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