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
  • B41M5/423—Intermediate, backcoat, or covering layers characterised by non-macromolecular compounds, e.g. waxes

Definitions

• This invention relates to a heat-sensitive recording material having high sensitivity and excellent capability to run through a facsimile machine, and which exhibits no substantial fogging when stored at high temperature.
• Recording materials employing an electron donative dye precursor (referred to herein as a "color former") and an electron accepting compound (referred to herein as a “developer”) are well known for use in such applications as pressure-sensitive recording paper, heat-sensitive recording paper, light-sensitive pressure-sensitive recording paper, electro conductive heat-sensitive recording paper and the like.
• JP-B as used herein means an "examined Japanese patent publication”
• JP-A-57-179836 the term “JP-A” as used herein means an "unexamined published Japanese patent application”
• JP-A-60-123556 and JP-A-60-123557.
• an object of the present invention is to provide a heat-sensitive recording material having a high sensitivity and excellent capability to run through a facsimile machine, and which exhibits substantially no background fogging at high storage temperatures.
• a heat-sensitive recording material comprising a support having thereon at least one layer, at least one layer of which is a heat-sensitive recording layer comprising a binder, a color former and a developer, the color-former reacts with the developer to form a color
• the heat-sensitive recording layer and/or a layer adjacent to the heat-sensitive color developing layer contains at least one compound selected from the group consisting of succinate-containing compounds represented by formulae (I), (II) and (III): wherein R1 and R2, which may be the same or different, each represents hydrogen or an alkyl group having from 1 to 20 carbon atoms (which may be substituted); and X1 and X2, which may be the same or different, each represents hydrogen, an alkali metal, an ammonium or amine group (containing or not containing a substituent), which ammonium or amine group forms a salt with an acid group of the succinate.
• the alkyl group represented by R1 and R2 preferably contains 1 to 8 carbon atoms, and is preferably a hydrogen atom or a lower alkyl group.
• Specific examples of the alkyl group represented by R1 or R2 include a methyl, ethyl, propyl, butyl and pentyl group.
• Sodium and potassium are preferred as the alkali metal represented by X1 or X2, and triethanolamine and monoethanolamine are preferred as the amino group represented by X1 or X2.
• the compound represented by formulae (I) to (III) for use in the present invention is preferably in the form of an alkali metal salt, more preferably in the form of a potassium salt.
• the compound represented by formulae (I) to (III) is added to the heat-sensitive recording layer and/or a layer adjacent to the heat sensitive recording layer in an amount of preferably from 5 to 200% by weight, more preferably from 10 to 100% by weight, based on the content of the color former.
• An undercoat layer, a protecting layer and/or the like layer may be provided in the heat-sensitive recording material of the present invention and a layer adjacent to the heat-sensitive layer may contain at least one compound selected from succinic compounds represented by formulae (I), (II) and (III).
• a color former, a developer and a heat-fusible compound are disperseed in the presence of a water-soluble binder.
• the binder for use in the present invention is preferably selected from compounds which dissolve in water at 25°C in an amount of 5% by weight or higher.
• Such compounds include polyvinyl alcohol, methyl cellulose, carboxymethyl cellulose, starch or a starch derivative including modified starch, gelatin, gum arabic, casein, a hydrolyzate of a styrene-maleic anhydride copolymer, a carboxy-modified polyvinyl alcohol, a polyacrylamide resin, a saponified product of a vinyl acetate-polyacrylic acid copolymer and the like.
• binders may be used not only for the purpose of dispersion but also for the improvement of film strength for the latter purpose, a latex type synthetic polymer binder may be used together with the above described binders.
• Useful latex type binders include a copolymer of styrene and butadiene, a copolymer of vinyl acetate, a copolymer of acrylonitorile and butadiene, a copolymer of methyl acrylate and butadiene, polyvinylidene chloride and the like. These binders may also be applied to an undercoat layer.
• the binder is generally used in an amount of from 5 to 20% by weight based on the total weight of solid content.
• the color former for use in the present invention may be selected from triarylmethane compounds, diphenylmethane compounds, xanthene compounds, thiazine compounds, spiropyran compounds and the like.
• Useful examples of these compounds are disclosed, for example, in 1P-A-55-227253 which include: triarylmethane compounds such as 3,3′-bis(p-dimethyl-aminophenyl)-6-dimethylamino phthalide, 3,3′-bis(p-dimethylaminophenyl) phthalide, 3-(p-dimethylaminophenyl)-3-(1,3 dimethylindole-3-yl) phthalide and 3-(p-dimethyl-aminophenyl)-3-(2-methylindole-3-yl) phthalide; diphenylmethane compounds such as 4,4′-bis-dimethylamino-benzhydrin benzyl ether, N-halophenyl leucoa
• the color former is contained in the heat-sensitive recording layer in an amount of preferably from 0.1 to 2 g/m2, more preferably from 0.2 to 1.0 g/m2.
• the developer for use in the present invention is preferably selected from phenolic compounds, salicylic acid derivatives and polyvalent metal salts thereof.
• Useful examples of these compounds include: phenolic compounds such as 2,2′-bis(4-hydroxyphenyl)propane, 4-t-butylphenol, 4-phenylphenol, 4-hydroxydiphenoxide, 1,1′-bis(3-chloro-4-hydroxyphenyl)cyclohexane, 1,1′-bis(4-hydroxyphenyl)cyclohexane, 1,1′-bis (3-chloro-4-hydroxyphenyl)-2-ethylbutane, 4,4′-sec-isooctylidenediphenol, 4,4′-sec-butylidenediphenol, 4-tert-octylphenol, 4-p-methylphenyl-phenol, 4,4′methylcyclohexylidene phenol, 4,4′-isopentylidene phenol and benzyl p-hydroxybenzoate; salicylic acid
• the developer is contained in the heat-sensitive recording layer in an amount of from 50 to 800% by weight, more preferably from 100 to 500% by weight, based on the content of the color former. An amount of less than 50% by weight would cause insufficient color development and the addition of more than 800% by weight would not provide a proportionally greater effect.
• a heat fusible compound may be included in the heat-sensitive recording layer.
• the heat fusible compound include benzyl p-benzyloxybenzoate, ⁇ -naphthyl-benzyl ether, stearic acid amide, stearylurea, p-benzyl-biphenyl, di(2-methylpehnoxy)ethane, di(2-methoxyphenoxy) ethan, ⁇ -naphthol-(p-methylbenzyl) ether, ⁇ -naphthylbenzyl ether, 1,4-butanediol-p-methylphenyl ether, 1,4-butanediol-p-isopropylphenyl ether, 1,4-butanediol-p-tert-octylphenyl ether, 1-phenoxy-2-(4-ethylphen
• the heat fusible compounds may be used alone or in combination thereof.
• the heat fusible compound is used in an amount of from 10 to 200% by weight, more preferably from 20 to 150% by weight, based on the content of the developer.
• Pigments for use in the present invention include calcium carbonate, barium sulfate, lithophone, agalmatolite, kaolin, silica, amorphous silica, aluminum hydroxide or the like.
• the heat-sensitive recording material of the present invention may include other commonly employed additives such as a metallic soap, a wax material, a surfactant, an antistatic agent, an ultraviolet ray absorption agent, an antifoaming agent, a conductive agent, a fluorescent dye and the like.
• Useful metallic soaps include metal salts of higher fatty acids such as zinc stearate, calcium stearate and aluminum stearate.
• Useful materials include a paraffin wax, a microcrystalline wax, a carnauba wax, methylolstearoamide, a polyethylene wax, a polystyrene wax, a fatty acid amide wax and the like either alone or in combination thereof.
• Useful surfactants include an alkali metal salt of sulfosuccinic acid and a fluorine-containing surfactant.
• an anti-decoloring agent to the heat-sensitive color developing layer is desirable for the purpose of preventing decoloring of image printed parts and thereby improving preservation of a formed image.
• Phenolic compounds, especially hindered phenol compounds, may be effective as the anti-decoloring agent.
• Such compounds include 1,1,3-tris(2-methyl-4-hydroxy-tert-butylphenyl)-butane, 1,1,3-tris(2-ethyl-4-hydroxy-tert-butylphenyl)-butane, 1,1,3-tris(3,5-di-tert-butyl-4-hydroxyphenyl)butane, 1,1,3-tris(2-methyl-4-hydroxy-5-tert-butylphenyl)propane, 2,2′-methylene-bis(6-tert-butyl-4-methylphenol), 2,2′-methylene-bis(6-tert-butyl-4-ethylphenol), 4,4′-butylidene-bis(6-tert-butyl-3-methylphenol) and 4,4′-thio-bis(3-methyl-6-tert-butylphenol).
• the phenolic compound is preferably used in an amount of from 1 to 200% by weight, more preferably from 5 to 50% by weight, based on the content
• Useful supports include paper, synthetic paper or various bases, and an undercoat layer is preferably coated on the support prior to applying the coating solution for the recording layer to obtain a high smoothness.
• the heat-sensitive recording layer thus coated on a support is then dried and subjected to calendering treatment, etc., prior to practical use.
• a pigment dispersion was prepared by dispersing 80 g of a commercially available calcined kaolin (Ancylex 93, tradename, manufactured by Engelhard Corp.) in 160 g of a 0.5% aqueous solution of sodium hexametaphosphate using a homogenizer.
• the thus prepared pigment dispersion was mixed with 16 g of a styrene-butadiene latex (SN 307, tradename, manufactured by Sumitomo Nogatac Co., Ltd., solid content : 48%) and 24 g of a 10% aqueous solution of polyvinyl alcohol (PVA-117, tradename, manufactured by Kuraray Co., Ltd.) to obtain a coating liquid for use in providing an undercoat layer.
• PVA-117 polyvinyl alcohol
• PVA-105 polyvinyl alcohol
• a mixture of 40 g of bisphenol-A, 40 g of naphthylbenzyl ether and 400 g of a 10% aqueous solution of polyvinyl alcohol (PvA-105, tradename, manufactured by Kuraray Co., Ltd.) was treated in a ball mill for 24 to 48 hours to obtain a dispersion of particles having mean particle size of 1.0 ⁇ m.
• a pigment dispersion was prepared by dispersing 80 g of calcium carbonate (Univer, tradename, manufactured by Shiraishi Kogyo Co., Ltd.) in 160 g of a 0.5% aqueous solution of sodium hexametaphosphate.
• a heat-sensitive recording material was prepared by repeating the procedure of Example 1, except that 10 g of the compound represented by formula (I) wherein R1 was hydrogen and X1 and X2 were both potassium was replaced by 10 g of a compound represented by formula (II) wherein R1 was hydrogen, R2 was an n-pentyl group and X1 and X2 were potassium.
• a heat-sensitive recording material was prepared by repeating the procedure of Example 1, except that 10 g of the compound represented by formula (I) wherein R1 was hydrogen and X1 and X2 were both potassium was replaced by 10 g of a compound represented by formula (III) wherein R1 and R2 were n-butyl and X1 and X2 were potassium.
• a heat-sensitive recording material was prepared by repeating the procedure of Example 1, except that 10 g of the compound represented by formula (I) in which R1 was hydrogen and X1 and X2 were both potassium was replaced by 25 g of a commercially available 40% aqueous solution of alkenyl succinate (SizePine 5300, tradename, manufactured by Arakawa Kagaku Co., Ltd., which is a mixture of compounds of formulae (I) to (III) wherein R1 and R2 represented a mixture of alkyl groups having a total of 6 to 9 carbon atoms, and X1 and X2 were both potassium).
• SizePine 5300 tradename, manufactured by Arakawa Kagaku Co., Ltd.
• a heat-sensitive recording material was prepared by repeating the procedure of Example 3, except that the alkenyl succinate was removed from the heat-sensitive recording layer and 10 g of the same alkenyl potassium succinate as used in Example 3 was added to the coating liquid for the undercoat layer.
• a heat-sensitive recording material was prepared by repeating the procedure of Example 3, except that the potassium salt of alkenyl succinate in the heat-sensitive recording layer was replaced by the triethanolamine salt.
• a heat-sensitive recording material was prepared by repeating the procedure of Example 3, except that the addition amount of the potassium salt of the alkenyl succinate was reduced from 10 g to 1.6 g.
• a heat-sensitive recording material was prepared by repeating the procedure of Example 3, except that the amount of the potassium salt of the alkenyl succinate was increased from 10 g to 24 g.
• a heat-sensitive recording material was prepared by repeating the procedure of Example 1, except that the potassium salt of alkenyl succinate was not added to the coating liquid for the heat-sensitive recording layer.
• Each of the thus prepared heat-sensitive recording materials was subjected to a surface treatment using a low pressure calender.
• Printing on the thus treated sheet of paper was carried out by using an experimental apparatus for heat-sensitive printing, equipped with a thermal head and a pressure roll (100 kg/cm2) attached directly to the thermal head (KLT-216-8MPD1, tradename, manufactured by Kyocera Corp.). Pressure rolling conditions of 24 V head voltage and 10 ms pulse cycle with the pulse width of 0.8, 1.0 and 1.2.
• Print density on the thus printed paper was measured using a Macbeth reflection density meter, model RD-918.
• the present invention provides a heat-sensitive recording material having a high sensitivity and an excellent facsimile running capacity and which exhibits substantially no fogging of the background during storage at high temperature

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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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Publications (1)

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ID=11898773

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Cited By (4)

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Citations (5)

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• 1990
  • 1990-01-25 JP JP2015795A patent/JP2618063B2/ja not_active Expired - Fee Related
• 1991
  • 1991-01-25 EP EP91300589A patent/EP0439369A1/fr not_active Withdrawn

Patent Citations (5)

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