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
• • 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
  • B41M5/40—Thermography ; Marking by high energetic means, e.g. laser otherwise than by burning, and characterised by the material used characterised by the base backcoat, intermediate, or covering layers, e.g. for thermal transfer dye-donor or dye-receiver sheets; Heat, radiation filtering or absorbing means or layers; combined with other image registration layers or compositions; Special originals for reproduction by thermography
  • B41M5/42—Intermediate, backcoat, or covering layers
• • 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
  • B41M5/40—Thermography ; Marking by high energetic means, e.g. laser otherwise than by burning, and characterised by the material used characterised by the base backcoat, intermediate, or covering layers, e.g. for thermal transfer dye-donor or dye-receiver sheets; Heat, radiation filtering or absorbing means or layers; combined with other image registration layers or compositions; Special originals for reproduction by thermography
  • B41M5/42—Intermediate, backcoat, or covering layers
  • B41M5/423—Intermediate, backcoat, or covering layers characterised by non-macromolecular compounds, e.g. waxes
• • 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
  • B41M5/40—Thermography ; Marking by high energetic means, e.g. laser otherwise than by burning, and characterised by the material used characterised by the base backcoat, intermediate, or covering layers, e.g. for thermal transfer dye-donor or dye-receiver sheets; Heat, radiation filtering or absorbing means or layers; combined with other image registration layers or compositions; Special originals for reproduction by thermography
  • B41M5/42—Intermediate, backcoat, or covering layers
  • B41M5/426—Intermediate, backcoat, or covering layers characterised by inorganic compounds, e.g. metals, metal salts, metal complexes
• • 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
  • B41M5/40—Thermography ; Marking by high energetic means, e.g. laser otherwise than by burning, and characterised by the material used characterised by the base backcoat, intermediate, or covering layers, e.g. for thermal transfer dye-donor or dye-receiver sheets; Heat, radiation filtering or absorbing means or layers; combined with other image registration layers or compositions; Special originals for reproduction by thermography
  • B41M5/42—Intermediate, backcoat, or covering layers
  • B41M5/44—Intermediate, backcoat, or covering layers characterised by the macromolecular compounds

Definitions

• This invention relates to a heat-sensitive recording material, and more particularly to a heat-sensitive recording material having on a support a coloring layer containing an electron donating colorless dye and an electron accepting compound.
• Recording material using an electron - donating colorless dye and an electron-accepting compound is already well known, e.g., as pressure-sensitive recording papers, heat-­sensitive recording papers, light- and pressure-sensitive recording papers, electro heat-sensitive recording papers, heat-sensitive transfer papers, etc., as described in British Patent 2,140,449, U.S.
• Patents 4,480,052, 4,436,920, JP-B-60-­23992 (the term “JP-B” as used herein means an "examined published Japanese patent application"), and JP-A-57-179836, 60-123556, and 60-123557, (the term “JP-A” as used herein means an "unexamined published Japanese patent application"), and particularly in terms of heat-sensitive recording materials in JP-B-43-4160 and 45-14039.
• the object of this invention is, therefore, to provide a heat-sensitive recording material having a high sensitivity and excellent running property.
• a heat-sensitive recording material having, on a support (1) a heat-sensitive coloring layer containing at least an electron-donating colorless dye, and an electron-accepting compound, a compound represented by formula (I), wherein R1, R2, R3 and R4 each represents a hydrogen atom, an alkyl group having 1 to 4 carbon atoms, an alkoxy group having 1 to 4 carbon atoms, or a halogen atom, preferably chlorine, bromine or fluorine, more preferably chlorine, and a pigment, wherein the pigment is calcium carbonate having an oil absorption by JIS method K-5101 of not more than 60 ml/100 g, and (2) a water-soluble polymer layer containing at least an inorganic pigment having an oil absorption by JIS method K-5101 of at least 50 ml/100 g, a wax, and a metal soap formed on the heat-sensitive coloring layer.
• a heat-sensitive coloring layer containing at least an electron-donating colorless dye, and an electron-accepting compound, a compound represented
• JIS Japanese Industrial Standard
• the water-soluble polymer layer to be formed on the heat-sensitive coloring layer may be coated separately from the coloring layer or immediately after coating the composition (solution) for the coloring layer.
• the components of the upper layer may diffuse into the heat-sensitive coloring layer or mix with the components of the heat-sensitive coloring layer, but at least 50% of the components of the upper layer remain in the upper layer.
• Specific examples of the compound of formula (I) for use in this invention include 4′-methoxyphenyl-4-methyl-benzyl ether, 4′-methylphenyl-4-methoxybenzyl ether, 4′-methoxyphenyl-­4-chlorobenzyl ether, 4′-ethoxyphenyl-4-chlorobenzyl ether, 4′-­chlorophenyl-4-methoxybenzyl ether and 3′-methyl-4′-­chlorophenyl-4-methoxybenzyl ether.
• the aforesaid compound can be used with a compound disclosed, for example, in JP-A-58-57989 or 58-87094.
• Typical examples of such a compound are aromatic ethers, aromatic esters, aliphatic amides, and aliphatic ureides.
• water-soluble polymer binder used for the coloring and upper layers in this invention examples include polyvinyl alcohol (including carboxy-denatured, itaconic acid-­denatured, maleic acid-denatured, and silica-denatured polyvinyl alcohols), methyl cellulose, carboxymethyl cellulose, starches (including denatured starches), gelatin, gum arabic, casein, the hydrolyzed product of a styrene-maleic acid copolymer, polyacrylamide and saponification product of a vinyl acetate-polyacrylic acid copolymer.
• polyvinyl alcohol including carboxy-denatured, itaconic acid-­denatured, maleic acid-denatured, and silica-denatured polyvinyl alcohols
• methyl cellulose carboxymethyl cellulose
• starches including denatured starches
• gelatin gum arabic
• casein the hydrolyzed product of a styrene-maleic acid copolymer
• the binder is used not only for dispersing, but also for improving the strength of the coated layer.
• a latex series binder of a synthetic polymer can be used together therewith, such as a styrene-butadiene copolymer, a vinyl acetate copolymer, an acrylonitrile-butadiene copolymer, a methyl acrylate-butadiene copolymer or poly­vinylidene chloride, in an amount of not more than 200 % by weight of the water-soluble polymer.
• a suitable crosslinking agent for the binder may be used.
• the pigment used for the heat-sensitive coloring layer in this invention calcium carbonate having an oil absorption by JIS method K-5101 of not more than 60 ml/100 g is used, and the amount of the pigment is generally in the range of 0.02 to 1.0% by weight, and preferably 0.05 to 0.6% by weight based on the weight of the solid component of the compound represented by formula (I) being used.
• the compound of formula (I) has a high selectivity for pigment and the compound does not show a high sensitivity effect with pigments other than the aforesaid pigment.
• a water-soluble polymer layer containing an inorganic pigment having an oil absorption by JIS method K-5101 of at least 50 ml/100 g, a wax, and a metal soap is formed on the heat-sensitive coloring layer, whereby the running property of the heat-sensitive recording material can be improved with the high sensitivity effect by the compound of formula (I).
• Examples of the metal soap used in this invention include higher fatty acid metal salts such as zinc stearate, calcium stearate, and aluminum stearate.
• wax for use in this invention examples include paraffin wax, microcrystalline wax, carnauba wax, methylol stearoamide, polyethylene wax, polystyrene wax, methylol stearoamide, polyethylene wax, polystyrene wax, and a fatty acid series wax. They can be used singly or as a mixture thereof.
• inorganic pigments which have hitherto been used for heat-sensitive recording materials, such as calcium carbonate, aluminum hydroxide, talc, kaolin, burned kaolin. or silica, each having an oil absorption by JIS method K-5101 of at least 50 ml/100 g.
• the electron donating colorless dye, the electron accepting compound, and the compound represented by formula (I) are dispersed in a ball mill, a sand mill, etc., together with an aqueous solution (generally 0.2 to 15 wt%) of a water-­soluble polymer such as polyvinyl alcohol, to sizes of less than 3 microns in diameter.
• the compound of formula (I) may be dispersed alone or together with the electron donating colorless dye and/or the electron accepting compound after adding the compound of formula (I) thereto or formed into an eutectic mixture with each followed by dispersing.
• the calcium carbonate used for the heat-sensitive recording layer may be dispersed in a ball mill, a sand mill, a kady mill, a homogenizer, etc., together with a surface active agent, a dispersing agent, a water-soluble polymer, etc.
• the aforesaid dispersions and calcium carbonate (or the dispersion thereof) are mixed with each other, and, if desired, a surface active agent, a binder, a metal soap, a wax, an antioxidant, a ultraviolet absorbent, etc., may be added to the mixture to provide a coating composition for the heat-sensitive recording layer.
• the inorganic pigment having an oil absorption by JIS method K-5101 of at least 50 ml/100 g used for the upper layer in this invention may be dispersed similarly to the case of dispersing calcium carbonate for the coating composition of the heat-sensitive recording layer described above.
• a wax, a metal soap, and a water-soluble polymer After mixing the inorganic pigment or the dispersion thereof with a wax, a metal soap, and a water-soluble polymer, to the mixture may be added a surface active agent, an additional binder, an additional metal soap, an additional wax, an antioxidant, a ultraviolet absorbent, etc. to provide the coating composition for the upper layer.
• the coating composition for the heat-sensitive recording layer and the coating composition for the upper layer thus obtained may be simultaneously or separately coated on a wood-free paper, a wood-free paper having a subbing layer, a synthetic paper, a plastic film, etc., followed by drying, and it is preferred that they are coated on a wood-free paper having a subbing layer, followed by drying.
• the heat-­sensitive recording material is obtained.
• aforesaid compounds include triarylmethane series compounds such as 3,3-bis(p-­dimethylaminophenyl)-6-dimethylaminophthalide, 3,3-bis(p-­dimethylaminophenyl)phthalide, 3-(p-dimethylaminophenyl)-3-­(1,3-dimethylindol-3-yl)phthalide, 3-(p-dimethylaminophenyl)-3-­(2-methylindol-3-yl)-phthalide, etc.; diphenylmethane series compounds such as 4,4′-bis-dimethylaminobenzhydrin benzyl ether, N-halophenyl-leucoauramine, N-2,4,5-trichlorophenyl-­leucoauramine; xanthene series compounds such as rhodamine-B-anilinolactam, rhodamine(p-nitrino)l
• phenolic compounds, or salicylic acid compounds and the polyvalent metal salts thereof are preferred.
• phenolic compounds such as 2,2′-­bis(4-hydroxyphenyl)propane(bisphenol A), 4-t-butylphenol, 4-­phenylphenol, 4-hydroxydiphenoxide, 1,1′-bis(3-chloro-4-­hydroxyphenyl)cyclohexane, 4,4′-sec-butylidenediphenol, 4-p-­methylphenylphenol, 4,4′-methylcyclohexylidenephenol, 1,1′-­bis(3-chloro-4-hydroxyphenyl)-2-ethylbutane, 1,1′-bis(4-­hydroxyphenyl)-cyclohexane, 4,4′-sec-isooctylidenediphenol, 4,4′-isopentylidenephenol, benzyl p-hydroxybenzoate, etc.; salicylic acid derivatives such as 4-pentadecylsalicylic acid, 3,5-di( ⁇ -methyl)-2-ethylbutane, 1,1′
• the amount of the electron-accepting compound being used is preferably from 50 to 800% by weight, and more preferably from 100 to 500% by weight of the amount of the electron donating colorless dye.
• the amount is less than 50% by weight, coloring may be insufficient, and if the amount is over 800% by weight, a further effect is not obtained.
• the compounds disclosed in JP-A-58-­57989, 58-87094, etc. can be further used as a sensitizer in addition to the compound represented by formula (I).
• the heat-sensitive recording material may further contain a surface active agent, an antistatic agent, a ultraviolet absorbent, an anti-oxidant, a deforming agent, an electric conductive agent, a fluorescent dye, a coloring dye, etc.
• a decolorization inhibitor may be added to the heat-sensitive coloring layer.
• the decolorization inhibitor phenol compounds, and in particular hindered phenol compounds, are effectively used.
• the amount of the phenolic compound is preferably from 1 to 200% by weight, and more preferably from 5 to 50% by weight based on the amount of the electron accepting compound.
• a back coat layer may be formed on the surface of the support of the heat-sensitive recording material opposite to the side carrying the heat-sensitive recording layer.
• any materials which are conventionally used for back coat layers of heat-sensitive recording materials can be used.
• Each of 20 g of 2-anilino-3-methyl-6-dibutylamino­fluoran as an electron donating colorless dye, 20 g of bisphenol A as electron accepting compound, and 20 g of 4′-­ethoxyphenyl-4-chlorobenzyl ether as a sensitizer was dispersed for about 24 hours in a ball mill together with 100 g of an aqueous solution of 5% polyvinyl alcohol (PVA-105, trademark for product made by Kuraray Co., Ltd.) to a mean grain size of less than 1.5 ⁇ m in each case to provide each dispersion.
• PVA-105 polyvinyl alcohol
• the dispersions thus prepared were mixed with each other in mixing ratio of 5 g of the dispersion of the electron donating colorless dye, 10 g of the dispersion of the electron accepting compound, 10 g of the dispersion of the sensitizer, and 5 g of the dispersion of calcium carbonate, to provide a coating composition for a heat-sensitive coloring layer.
• the coating composition was coated on a wood-free paper by a coating bar at a dry weight of 5 g/m2 and dried for one minute at 50°C to form a heat-sensitive colorless layer.
• the coating composition for the upper layer was coated on the heat-sensitive coloring layer using a coating bar at a dry weight of 0.5 g/m2, and dried for one minute at 50°C to provide a heat-sensitive recording paper.
• Example 2 By following the same procedure as in Example 1 except that the amount (10 g) of the dispersion of calcium carbonate which was used in the coating composition for the heat-­sensitive coloring layer was reduced to 5 g, a heat-sensitive recording material was prepared.
• Example 2 By following the same procedure as in Example 1, except that aluminum hydroxide (HAIJIRAITO H42, oil absorption 30 ml/100 g, trademark for product made by Showa Denko K.K.) was used in place of the calcium carbonate (Unibur 70) which was used in the coating composition for the heat-sensitive coloring layer, a heat-sensitive recording paper was prepared.
• aluminum hydroxide HAIJIRAITO H42, oil absorption 30 ml/100 g, trademark for product made by Showa Denko K.K.
• Example 2 By following the same procedure as in Example 1, except that the paraffin wax emulsion in the coating composition for the upper layer was omitted, a heat-sensitive recording paper was prepared.
• Example 2 By following the same procedure as in Example 1, except that the emulsion of zinc stearate in the coating composition for the upper layer was omitted, a heat-sensitive recording paper was prepared.
• Each of the heat-sensitive recording papers (materials) thus prepared was printed at a pulse width of 1.0 ms. by means of a heat-sensitive printout experimental apparatus manufactured by Kyocera Corporation using a press roll at a head potential of 24 V and pulse cycle of 10 ms., and the printout density thereof was measured by a Macbeth reflection densitomer RD-918.
• printout of 50% in black ratio was performed on each sample using a Facsimile UF-22 machine, manufactured by Matsushita Graphic Communication Systems, Inc., after which head staining and sticking were evaluated.
• the head staining and sticking were evaluated by the following standard.
• Table 1 Example Coloring Density Head Stain Sticking Example 1 1.38 A A Example 2 1.42 B A Example 3 1.37 A A Comparison Example 1 1.40 X X Comparison Example 2 1.20 B A Comparison Example 3 1.18 B B Comparison Example 4 1.25 B B Comparison Example 5 1.20 X A Comparison Example 6 1.40 A X Comparison Example 7 1.40 X B Comparison Example 8 1.40 X X
• the heat-sensitive recording papers of this invention show a good coloring density even using low energy and are excellent in running properties.

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• Physics & Mathematics (AREA)
• Optics & Photonics (AREA)
• Chemical & Material Sciences (AREA)
• Chemical Kinetics & Catalysis (AREA)
• General Chemical & Material Sciences (AREA)
• Heat Sensitive Colour Forming Recording (AREA)

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• 1989
  • 1989-07-13 JP JP1181290A patent/JPH0345380A/ja active Pending
• 1990
  • 1990-07-11 EP EP19900307584 patent/EP0408339A3/en not_active Withdrawn

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