EP4420887B1 - Support d'enregistrement thermosensible - Google Patents

Support d'enregistrement thermosensible

Info

Publication number
EP4420887B1
EP4420887B1 EP23305230.7A EP23305230A EP4420887B1 EP 4420887 B1 EP4420887 B1 EP 4420887B1 EP 23305230 A EP23305230 A EP 23305230A EP 4420887 B1 EP4420887 B1 EP 4420887B1
Authority
EP
European Patent Office
Prior art keywords
layer
thermosensitive
group
recording medium
thermosensitive recording
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.)
Active
Application number
EP23305230.7A
Other languages
German (de)
English (en)
Other versions
EP4420887A1 (fr
Inventor
Gaku KOHARA
Florian VILLAIN
Current Assignee (The listed assignees may be inaccurate. Google has not performed a legal analysis and makes no representation or warranty as to the accuracy of the list.)
Ricoh Co Ltd
Original Assignee
Ricoh Co Ltd
Priority date (The priority date 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 date listed.)
Filing date
Publication date
Application filed by Ricoh Co Ltd filed Critical Ricoh Co Ltd
Priority to EP23305230.7A priority Critical patent/EP4420887B1/fr
Priority to ES23305230T priority patent/ES3059935T3/es
Priority to PCT/JP2024/005023 priority patent/WO2024176910A1/fr
Priority to CN202480014195.7A priority patent/CN120677070A/zh
Priority to JP2025536177A priority patent/JP7838712B2/ja
Priority to KR1020257031169A priority patent/KR20250145121A/ko
Publication of EP4420887A1 publication Critical patent/EP4420887A1/fr
Application granted granted Critical
Publication of EP4420887B1 publication Critical patent/EP4420887B1/fr
Active legal-status Critical Current
Anticipated expiration legal-status Critical

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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
    • B41M5/333—Colour developing components therefor, e.g. acidic compounds
    • B41M5/3333—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
    • B41M5/30—Thermography ; Marking by high energetic means, e.g. laser otherwise than by burning, and characterised by the material used using chemical colour formers
    • B41M5/323—Organic colour formers, e.g. leuco dyes
    • 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
    • B41M5/323—Organic colour formers, e.g. leuco dyes
    • B41M5/327—Organic colour formers, e.g. leuco dyes with a lactone or lactam ring
    • B41M5/3275—Fluoran 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
    • B41M5/30—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
    • B41M5/3377—Inorganic compounds, e.g. metal salts of organic acids
    • 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
    • B41M5/44—Intermediate, backcoat, or covering layers characterised by the macromolecular compounds
    • B—PERFORMING OPERATIONS; TRANSPORTING
    • B41—PRINTING; LINING MACHINES; TYPEWRITERS; STAMPS
    • B41M—PRINTING, DUPLICATING, MARKING, OR COPYING PROCESSES; COLOUR PRINTING
    • B41M2205/00—Printing methods or features related to printing methods; Location or type of the layers
    • B41M2205/04—Direct thermal recording [DTR]
    • B—PERFORMING OPERATIONS; TRANSPORTING
    • B41—PRINTING; LINING MACHINES; TYPEWRITERS; STAMPS
    • B41M—PRINTING, DUPLICATING, MARKING, OR COPYING PROCESSES; COLOUR PRINTING
    • B41M2205/00—Printing methods or features related to printing methods; Location or type of the layers
    • B41M2205/38—Intermediate layers; Layers between substrate and imaging layer
    • B—PERFORMING OPERATIONS; TRANSPORTING
    • B41—PRINTING; LINING MACHINES; TYPEWRITERS; STAMPS
    • B41M—PRINTING, DUPLICATING, MARKING, OR COPYING PROCESSES; COLOUR PRINTING
    • B41M2205/00—Printing methods or features related to printing methods; Location or type of the layers
    • B41M2205/40—Cover layers; Layers separated from substrate by imaging layer; Protective layers; Layers applied before imaging

Definitions

  • the present invention relates in one of its aspects to a thermosensitive recording medium.
  • the present invention relates to food packaging comprising the thermosensitive recording medium.
  • Thermosensitive recording mediums which use a colorant system wherein a dye, such as a leuco dye, in one layer of the medium reacts, upon the application of heat, with another component, a so-called "developer", in order to give rise to a coloured product.
  • a dye such as a leuco dye
  • developer another component
  • phenols can successfully be used as developers in thermal paper.
  • N-phenylureido-phenyl-benzenesulfonamides have been proposed, for example in EP 2 923 851 , JP-2015-150764 EP3670205 and WO 2021/215470 , as non-phenol developers in this context.
  • N-phenylureido-phenyl-benzenesulfonates are proposed in JP-7-177569 and proposed in combination with diphenylsulfone compounds or non-phenol compounds in JP-2021-100798 .
  • N,N'-di-[arylsulfonyloxy)phenyl]urea compounds are proposed in JP-7-146147 and JP-2022-067451 .
  • several structures of non-phenol developers have been proposed, for example in EP3395583 and EP3677569 .
  • thermosensitive colouring layer of a thermosensitive recording medium when using an N-phenylureido-phenyl-benzenesulfonamide as a colour developer in the thermosensitive colouring layer of a thermosensitive recording medium, a dynamic sensitivity is still not achieved at the same level as bis-phenol type developers.
  • Several countermeasures such as combination with a sensitizer or other developers have been proposed to improve this problem, but it is difficult to keep higher heat resistance while improving the dynamic sensitivity.
  • thermosensitive recording mediums are converted into labels through a digital printing process. In this field, due to its printing process through heating rolls, extremely high heat resistance such as resistance above 110°C is desirable. When a thermosensitive recording medium with not enough heat resistance is processed in digital printing machines, undesirable colour developing may occur. It is difficult to simultaneously resolve this compatibility problem of dynamic sensitivity and at the same provide very high heat resistance.
  • thermosensitive recording medium achieving a good dynamic sensitivity and a good plasticizer resistance, oil resistance and alcohol resistance of the printed image.
  • high heat resistance of background up to 110°C is also achieved.
  • thermosensitive recording medium comprising at least:
  • the at least 20% of hollow particles the undercoat layer preferably has a hollow ratio at 80% or more.
  • the hollow ratio of hollow particles of the undercoat layer may be at least 85%, or at least 90%.
  • thermosensitive colouring layer preferably further comprises 1,3-diphenylurea. This has been found to be a useful stabilizer (preservability-improving agent) in the context of the present invention.
  • the present invention relates to a consumer product package to which a thermosensitive recording medium of the invention has been attached or incorporated.
  • a thermosensitive recording medium of the invention may be converted into a label, for example by lamination, die-cutting and pre-printing, and then put onto the food packaging.
  • the consumer product package may be partially or fully transparent, flexible or rigid, and may contain one or more perishable food items, such as delicatessen products or box lunches.
  • the support layer (which may also be called “substrate”) in the thermosensitive recording medium of the present invention is suitably selected depending on the intended purpose without any particular restriction. It is possible for this support layer to be transparent or non-transparent.
  • Possible supports may include supports made of wood-free paper, recycled pulp (containing 50% or more of recycled pulp), synthetic paper, polyethylene films, and laminated paper.
  • the thickness of a paper layer varies depending on the composition of the layer and intended use of the thermosensitive recording materials and cannot be specified flatly, but it is preferably 30 ⁇ m to 250 ⁇ m, more preferably 50 ⁇ m to 200 ⁇ m.
  • a transparent support may also be used in the form of a polymeric material present in the form of a thin film.
  • the total light transmittance of the transparent film is preferably at least 60%, more preferably at least 70% and most preferably at least 90%.
  • Preferred films show a haze value less than 3.
  • the transparent film may also be coloured.
  • the thickness of the transparent film is preferably from 20 ⁇ m to 100 ⁇ m, more preferably 40 ⁇ m to 70 ⁇ m.
  • Film materials to be used in the transparent support may be selected from the group consisting of: ionomer film (IO), polyethylene film (PE), poly(vinyl chloride) film (PVC), poly(vinylidene chloride) film (PVDC), poly(vinyl alcohol) film (PVA), polypropylene film (PP) including biaxially oriented (bi-oriented) polypropylene (BOPP), polyester film, poly(ethylene terephthalate) film (PET), polyethylene naphthalate) film (PEN), polycarbonate film (PC), polystyrene film (PS), polyacrylonitrile film (PAN), ethylene-vinyl acetate copolymer film (EVA), ethylene-vinyl alcohol copolymer film (EMAA), nylon film (NY), polyamide film (PA), triacetyl cellulose film (TAC), norbornane film (NB), and Arton film.
  • IO ionomer film
  • PE polyethylene film
  • PVC poly(vinyl
  • undercoat is understood by the skilled person to refer to the layer between the support and thermosensitive colouring layer.
  • under layer may also be used synonymously with “undercoat layer” by skilled persons in the field.
  • the undercoat layer will normally contain a binder resin.
  • the binder resin to be used in an undercoat layer either of a water-dispersible resin or a water-soluble resin may be used. Specific examples thereof include conventionally known water-soluble polymers, and aqueous polymer emulsions.
  • the water-soluble polymer that may be used in the binder resin in an undercoat layer may be suitably selected depending on the intended purpose without any restriction.
  • examples thereof include polyvinyl alcohol, starch and derivatives thereof, cellulose derivatives such as methoxy cellulose, hydroxy ethyl cellulose, carboxy methyl cellulose, methyl cellulose and ethyl cellulose, polyvinyl pyrrolidone, alkali salts of styrene-maleic anhydride copolymers, alkali salts of isobutylene-maleic anhydride copolymers, alginate soda, gelatin and casein. These may be used alone or in combination.
  • a particularly preferred binder material for an undercoat layer of the present invention is polyvinyl alcohol.
  • the aqueous polymer emulsion that may be used in the binder resin in an undercoat layer may be suitably selected depending on the intended purpose without any restriction.
  • examples thereof include latexes of, for example, styrene-butadiene copolymers; and emulsions of, for example, vinyl acetate resins, acryl-based resins and polyurethane resins. These may be used alone or in combination.
  • particularly preferred embodiment consists in the combination of polyvinyl alcohol as binder material and styrene-butadiene copolymer added as an aqueous polymer emulsion.
  • An inorganic filler may be used or may be omitted from an undercoat layer if an undercoat layer is used in the thermosensitive recording medium of the present invention.
  • examples thereof include aluminum hydroxide, calcium carbonate, aluminum oxide, zinc oxide, titanium dioxide, silica, barium sulfate, talc, kaolin, alumina and clay. These may be used alone or in combination.
  • aluminum hydroxide, calcium carbonate, kaolin and clay are preferable in terms of liquid properties in a coating liquid, stability of dispersed particles, and water solubility.
  • the undercoat layer comprises inorganic filler which has an oil absorption property of 60 g/100 g or less. Such a low oil absorption property is preferable in terms of liquid properties as mentioned above.
  • a particularly preferred inorganic filler for the undercoat layer in this respect is non-calcined kaolin, preferable in this context to calcined kaolin.
  • thermosensitive recording medium In undercoat layers of a thermosensitive recording medium according to present invention, hollow particles are used.
  • the hollow ratio given as a percentage (%) is the (inner diameter of a hollow particle / outer diameter of the hollow particle) x 100.
  • Each of such hollow particles may have a shell made of a thermoplastic resin and contain therein air or other gas, typically with a volume average particle diameter of 1 ⁇ m to 10 ⁇ m, most commonly having a thermoplastic resin as a shell, made from polystyrene, polyvinyl chloride, polyvinylidene chloride, polyvinyl acetate, polyacrylic esters and polymethacrylic esters (polymethacrylates), polyacrylonitrile, and polybutadiene, and copolymer resins thereof.
  • a thermoplastic resin made from polystyrene, polyvinyl chloride, polyvinylidene chloride, polyvinyl acetate, polyacrylic esters and polymethacrylic esters (polymethacrylates), polyacrylonitrile, and polybutadiene, and copolymer resins thereof.
  • the at least 20% of hollow particles the undercoat layer preferably has a hollow ratio at 80% or more.
  • the hollow ratio of hollow particles of the undercoat layer may be at least 85%, or at least 90%.
  • a total pigment ratio (the inorganic filler and the organic filler) in the undercoat layer is from at least 20% by weight to at most 80% by weight with respect to the total dry weight of the undercoat layer.
  • the deposition amount thereof is appropriately 0.4 g/m 2 to 10 g/m 2 , more preferably 0.6 g/m 2 to 4 g/ m 2 .
  • the thickness of an undercoat layer in the present invention varies depending on the composition of the layer and intended use of the thermosensitive recording materials and cannot be specified flatly, but it is preferably 0.5 ⁇ m to 15 ⁇ m, more preferably 0.8 ⁇ m to 6 ⁇ m.
  • thermosensitive colouring layer is situated over the support layer, and the thermosensitive colouring layer contains a leuco dye and a developer.
  • an undercoat layer is/are present between the support layer and the thermosensitive colouring layer.
  • thermosensitive colouring layer contains a colorant system wherein a dye, such as a leuco dye, in one layer of the medium reacts, upon the application of heat, with another component, a so-called "developer”, in order to give rise to a coloured product.
  • a dye such as a leuco dye
  • the leuco dye is a compound exhibiting electron donation properties, and may be used singly or in combination of two or more species. However, the leuco dye itself is a colourless or light-coloured dye precursor, and commonly known leuco compounds can be used.
  • the leuco compounds include triphenylmethane phthalide compounds, triarylmethane compounds, fluoran compounds, phenothiazine compounds, thiofluoran compounds, xanthen compounds, indophthalyl compounds, spiropyran compounds, azaphthalide compounds, chlormenopirazole compounds, methyne compounds, rhodamine anilinolactum compounds, rhodamine lactuam compounds, quinazoline compounds, diazaxanthen compounds, bislactone compounds.
  • specific examples of such compounds are as follows:
  • the amount of the leuco dye contained in the thermosensitive colouring layer is preferably 3% by mass to 30% by mass, with respect to the total mass of the thermosensitive colouring layer taken as 100%.
  • various electron accepting materials are known to be able to react with the aforementioned leuco dye at the time of heating so as to develop colours, such as phenolic compounds, organic or inorganic acidic compounds and esters or salts thereof.
  • the thermosensitive colouring layer comprises at least two types of colour developer.
  • the three types of colour developer among which at least two, or indeed all three, are present in the thermosensitive colouring layer of a thermosensitive recording medium of the present invention correspond most preferably to compounds having an N-phenylureido-phenyl-benzenesulfonamide structure, an N-phenylureido-phenyl-oxy-sulfonyl-aryl structure, or an N,N'-di-([arylsulfonyloxyl]-phenyl)urea structure.
  • R 1 to R 3 each independently represent a hydrogen atom, a halogen atom, a C1-C6 alkyl group, a C1-C6 alkoxyl group, or a C1-C6 fluoroalkyl group.
  • Such developers can be prepared according to methods of synthesis disclosed for example in EP 2 923 851 .
  • the aromatic ring attached to the SO 2 group in formula (1) above has either no (R 1 ) substituents, or one Me group or one CI group, or -NHAc or -OMe.
  • the middle ring above has Me groups as possible (R 3 ) substituents.
  • the aromatic ring attached via the urea group may show a -OMe, -F, -CF 3 , CI, as well as CH 3 (Me) substituent.
  • thermosensitive colouring layer of the thermosensitive recording medium of the invention comprises a developer having the following formula (4):
  • Colour developers of type (2) have an N-phenylureido-phenyl-oxysulfonyl-aryl structure: wherein, in formula (2), R 3 is a hydrogen atom, a halogen atom, a nitro group, an amino group, an alkyl group, an alkoxy group, an aryloxy group, an alkylcarbonyloxy group, an arylcarbonyloxy group, an alkylcarbonylamino group, an arylcarbonylamino group, an alkylsulfonylamino group, an arylsulfonylamino group, a monoalkylamino group, a dialkylamino group, or an arylamino group.
  • R 3 is a hydrogen atom, a halogen atom, a nitro group, an amino group, an alkyl group, an alkoxy group, an aryloxy group, an alkylcarbonyloxy group, an arylcarbonyloxy group, an al
  • Such developers can be prepared according to methods of synthesis disclosed for example in EP 3 395 583 .
  • R 3 is a methyl group.
  • Colour developers of type (3) have an N,N'-di-([arylsulfonyloxyl]-phenyl)urea structure: wherein, in formula (3), R represents an alkyl group and n represents an integer ranging from 0 to 3. Such developers can be prepared according to methods of synthesis disclosed for example in EP 3 677 569 . Most preferably in the present invention, the colour developer of formula (3) has a structure wherein each (R)n system is constituted by a single methyl group in the para position with respect to the -SO 2 -O- group.
  • the mixing ratio of the developer(s) to the leuco dye(s) is such that the developer(s) is (are) preferably 0.5 parts by mass to 10 parts by mass, more preferably 1 part by mass to 5 parts by mass, relative to 1 part by mass of the leuco dye(s).
  • various other known developers can optionally be used as long as the effects of the present invention are not impaired.
  • These other developers are color developers including various electron-accepting compounds and oxidants capable of coloring the leuco dye. Examples thereof include 4,4'-isopropylidene bisphenol, 4,4'-isopropylidene bis(o-methylphenol), 4,4'-secondary butylidene bisphenol, 4,4'-isopropylidene bis(2-tert-butylphenol), zinc p-nitrobenzoate, 1,3,5-tris(4-tert-butyl-3-hydroxy-2,6-dimethylbenzyl)isocyanurate, 2,2-(3,4'-dihydroxydiphenyl)propane, bis(4-hydroxy-3-methylphenyl) sulfide, 4' ⁇ 6-(p-methoxyphenoxy)ethoxy ⁇ sal icylate, 1,7-bis(4-hydroxyphenylthio)-3,5-dioxaheptan
  • thermosensitive colouring layer of the thermosensitive recording medium the following urea urethane and D90 commercial products may also be considered:
  • the combined mass of other developer(s), not being those of formula (1), (2) or (3) is less than 2 parts by mass, relative to 1 part by mass of the leuco dye(s) in the thermosensitive colouring layer, more preferably less than 0.5 parts by mass relative to 1 part by mass of the leuco dye(s) in the thermosensitive colouring layer.
  • stabilizers can optionally be used as long as the effects of the present invention are not impaired.
  • these stabilizers are hindered phenol compounds or hindered amine compounds.
  • the latter type of electron-accepting compounds have relatively low colouring ability, and may be optionally added to the thermosensitive recording layer as an auxiliary additive. Specific examples thereof include:
  • thermosensitive coloring layer other materials customarily used in thermosensitive recording materials, such as a binder, a filler, a sensitizer, a crosslinking agent, a pigment, a surfactant, a fluorescent whitening agent and a lubricant.
  • the binder may be used if necessary in order to improve the adhesiveness and coatability of the layer.
  • the binder is suitably selected depending on the intended purpose without any restriction.
  • Specific examples of the binder resin include starches, hydroxyethyl cellulose, methyl cellulose, carboxy methyl cellulose, gelatin, casein, gum arabic, polyvinyl alcohols, salts of diisobutylene-maleic anhydride copolymers, salts of styrene-maleic anhydride copolymers, salts of ethylene-acrylic acid copolymers, salts of styrene-acryl copolymers and salt emulsions of styrene-butadiene copolymers.
  • the filler is suitably selected depending on the intended purpose without any restriction.
  • examples thereof include inorganic pigments such as calcium carbonate, aluminum oxide, zinc oxide, titanium dioxide, silica, aluminum hydroxide, barium sulfate, talc, kaolin, alumina and clay, and commonly known organic pigments.
  • inorganic pigments such as calcium carbonate, aluminum oxide, zinc oxide, titanium dioxide, silica, aluminum hydroxide, barium sulfate, talc, kaolin, alumina and clay, and commonly known organic pigments.
  • acidic pigments such as silica, alumina and kaolin are preferable, with silica being particularly preferable from the viewpoint of developed color density.
  • Calcined kaolin is preferable in the framework of the present invention.
  • thermosensitive colouring layer of a thermosensitive recording medium it is preferred to use inorganic fillers which have a high oil absorption such as 80 g/100g or more.
  • inorganic fillers which have a high oil absorption such as 80 g/100g or more.
  • suitable fillers in this context for the thermosensitive colouring layer are calcined kaolin, or amorphous silica.
  • thermoplastic materials are commonly added as a sensitivity improving agent (sensitizers).
  • sensitizers no sensitizer is added to the thermosensitive colouring layer.
  • the absence of any sensitizer may in particular allow an increase in heat resistance, for example as measured at 110°C.
  • a sensitizer may improve the colouring effect in some instances by melting under the effect of heat and thereby providing a temporary solvent facilitating reaction between the leuco dye and developer.
  • the thermoplastic material not be added, or a compound having a melting point of 90°C or higher be selected.
  • sensitizers include: (1) fatty acids such as stearic acid, and behenic acid; (2) fatty acid amides, such as stearic acid amide, and palmitic acid amide; (3) metal salts of fatty acids, such as zinc stearate, aluminum stearate, calcium stearate, zinc palmitate, and zinc behenate; (4) sensitizers with N-octadecyl chains such as N-octadecylcarbamoyl-p-methoxycarbonylbenzene, N-octadecylcarbamoylbenzene; (5) polyphenyl hydrocarbons such as p-benzylbiphenyl, terphenyl, triphenylmethane; (6) benzyloxy derivatives, benzoates and napthates such as benzyl p-benzyloxy benzoate, ⁇ -benzyloxynaphthalene, phenyl ⁇ -naph
  • the thermosensitive colouring layer may in particular not comprise a compound known in the field of thermosensitive recording media as a sensitizer, such as compounds containing aryloxy groups (such as phenoxy, tolyloxy groups) and alkoxy groups, oxaate groups and benzyloxy groups. It is of particular interest for the thermosensitive colouring layer thus not to contain sensitizers of the types indicated in groups 6, 9, 10 and 11 indicated above. The absence of such sensitizers may in particular allow an increase in heat resistance, for example as measured at 110°C.
  • a sensitizer such as compounds containing aryloxy groups (such as phenoxy, tolyloxy groups) and alkoxy groups, oxaate groups and benzyloxy groups.
  • the colouring layer can be formed by commonly known methods. To avoid reaction between components of the thermosensitive colouring layer, in preferred embodiments, dispersion is carried out separately and then liquids are mixed. Grinding with a binder and other components is performed typically so as to have a particle diameter of 0.2 ⁇ m to 3 ⁇ m, preferably 0.2 ⁇ m to 1 ⁇ m by using a disperser such as a ball mill, an Atriter or a sand mill.
  • a disperser such as a ball mill, an Atriter or a sand mill.
  • the resultant dispersion is mixed, if necessary, together with a filler and a hot-meltable material (sensitizer) dispersion liquid in accordance with a predetermined formulation, to thereby prepare a coating liquid of a thermosensitive colouring layer, followed by applying the thus-prepared coating liquid onto a support.
  • a hot-meltable material (sensitizer) dispersion liquid in accordance with a predetermined formulation, to thereby prepare a coating liquid of a thermosensitive colouring layer, followed by applying the thus-prepared coating liquid onto a support.
  • the thickness of the thermosensitive colouring layer varies depending on the composition of the thermosensitive colouring layer and intended use of the thermosensitive recording materials and cannot be specified flatly, but it is preferably 1 ⁇ m to 50 ⁇ m, more preferably 2 ⁇ m to 20 ⁇ m.
  • At least one protective layer is provided over the thermosensitive layer in the present invention.
  • Several different protective layers can be overlaid on each other to focus respectively more on matching or barrier properties.
  • At least one protective layer in the thermosensitive recording medium of the present invention may appropriately comprise particles of wax, preferably with an average particle size of at least 0.05 and at most 2.0 ⁇ m. Where there is more than one protective layer, it is solely the uppermost protective layer, the one furthest removed from the thermosensitive colouring layer and on the surface exposed to the outside, which may appropriately contain wax particles. In preferred embodiments, where the uppermost protective layer contains wax particles, the underlying protective layers may contain do not contain wax particles.
  • the value is as obtained in a method to measure average particle size, in the form of the median size (D 50 ), as measured by laser diffraction using a Laser Diffraction Particle Size Distribution Analyzer. This measurement can be carried out for example by the LA-950 machine produced by the company HORIBA LA-950.
  • the melting point of the wax if wax particles are used in the protective layer / uppermost protective layer is at least 80°C and at most 200°C. More preferably, the wax melting point is at least 90°C and at most 130°C, most preferably at least 100°C and at most 120°C.
  • the wax particle size is at least 0.1 ⁇ m and at most 0.5 ⁇ m.
  • the particles of wax constitute at least 2.0 wt.% and at most 20 wt.% with respect to 100 wt.% constituted by all the components of the protective layer taken as a whole, more preferably at least 5.0 wt.% and at most 10 wt.% with respect to 100 wt.% constituted by all the components of the protective layer taken as a whole.
  • the wax material of the wax particles in the present invention may be polyethylene wax, salts of higher fatty acids such as zinc stearate and calcium stearate, montanate wax, carnauba wax, paraffin wax, ester wax and metal salts thereof; higher fatty acid amides, higher fatty acid esters, animal wax, vegetable wax, mineral wax, and petroleum wax.
  • a particularly preferred wax material for the wax particles of a protective layer of the thermosensitive recording medium of the present invention is polyethylene wax. Low density or high density polyethylene wax particles may be used.
  • the protective layer(s) typically contain(s) at least a binder, and each of the protective layer(s) may contain an inorganic filler and a surfactant.
  • the binder of (each of) the protective layer(s) is suitably selected depending on the intended purpose without any restriction, it being possible to use the same binder in each protective layer or a different binder in separate protective layers.
  • binders that may be used in the protective layer(s) include polyvinyl alcohol, modified polyvinyl alcohol, starch and derivatives thereof, cellulose derivatives, polyvinylpyrrolidone, polyethyleneimine, alginate soda, gelatin and casein. Acrylic binders may also be used.
  • Hydrophobic resins that may be used as binders in the protective layer(s) include ones typically provided as aqueous emulsions during preparation of the protective layer(s), such as urethane resins, epoxy resins, vinyl acetate (co)polymers, vinylidene chloride (co)polymers, vinyl chloride (co)polymers, and styrene-butadiene copolymers.
  • a particularly preferred binder material for the protective layer of the present invention is polyvinyl alcohol.
  • the thickness of the protective layer(s) varies preferably from 0.2 ⁇ m to 10 ⁇ m, more preferably from 0.5 ⁇ m to 5 ⁇ m. In non-limiting exemplary embodiments for this invention, a protective layer of thickness 2.5 ⁇ m when dry can be used. In the event that several protective layers are applied, lower individual thicknesses for each one will be required. A preferred maximum cumulative thickness for the sum of all protective layers is 10 ⁇ m for the dried final product.
  • the inorganic filler in the protective layer(s), if used, is suitably selected depending on the intended purpose without any restriction.
  • the inorganic filler include aluminum hydroxide, calcium carbonate, aluminum oxide, zinc oxide, titanium dioxide, silica, barium sulfate, talc, kaolin, alumina and clay. These may be used alone or in combination.
  • aluminum hydroxide, and calcium carbonate are particularly preferable because the protective layer containing such inorganic filler is provided with excellent abrasion resistance with respect to a thermal head when printing is performed for a long period of time.
  • the amount of the inorganic filler in the protective layer(s) is suitably selected depending on the intended purpose without any restriction.
  • the amount of the inorganic filler depends on types of the filler, but it is preferably 50 parts by mass to 500 parts by mass, relative to 100 parts by mass of the binder resin.
  • a first protective layer is laid down on the thermosensitive colouring layer, and whilst it contains a binder such as polyvinyl alcohol (PVA), it does not contain wax particles.
  • a second protective layer may be laid down on the first protective layer, the second protective layer thus not being in direct contact with the thermosensitive colouring layer, the second protective layer containing wax particles and possibly filler such as inorganic filler.
  • a method for forming the first, second or subsequent protective layer is suitably selected depending on the intended purpose without any restriction. Examples thereof include blade coating, roll coating, wire bar coating, die coating, and curtain coating. Such methods can be used to apply other layers of the thermosensitive recording medium of the present invention, such as the undercoat layer(s).
  • Curtain coating is a preferred method for applying protective layer(s) in the present invention and can also be used to apply the thermosensitive colouring layer.
  • thermosensitive recording medium may contain a back layer containing a pigment, a binder resin, and preferably a crosslinking agent.
  • the back layer if present, is to be disposed on the surface of the support layer opposite to the surface thereof where the thermosensitive layer is disposed, or where the undercoat layer between the support and the thermosensitive layer is situated, if such an undercoat layer is present.
  • the back layer may further contain other components such as a filler, a lubricant, and an antistatic agent.
  • the binder resin either of a water-dispersible resin or a water-soluble resin can be used. Specific examples thereof include conventionally known water-soluble polymers, and aqueous polymer emulsions.
  • the water-soluble polymer is suitably selected depending on the intended purpose without any restriction.
  • examples thereof include polyvinyl alcohol, starch and derivatives thereof, cellulose derivatives such as methoxy cellulose, hydroxy ethyl cellulose, carboxy methyl cellulose, methyl cellulose and ethyl cellulose, polyvinyl pyrrolidone, alkali salts of styrene-maleic anhydride copolymers, alkali salts of isobutylene-maleic anhydride copolymers, alginate soda, gelatin and casein. These may be used alone or in combination.
  • the aqueous polymer emulsion is suitably selected depending on the intended purpose without any restriction.
  • examples thereof include latexes of, for example, styrene-butadiene copolymers; and emulsions of, for example, vinyl acetate resins, acryl-based resins (e.g. acrylic acid-acrylic acid ester copolymer latexes), (meth)acrylamide-based resins, and polyurethane resins. These may be used alone or in combination.
  • the crosslinking agent is suitably selected depending on the intended purpose without any restriction.
  • examples thereof include polyvalent amine compounds such as ethylene diamine; polyvalent aldehyde compounds such as glyoxal, glutalaldehyde and dialdehyde; dihydrazide compounds such as dihydrazide adipate and dihydrazide phthalate; polyamide-epichlorohydrin compounds; water-soluble methylol compounds (urea, melamine and phenol); multifunctional epoxy compounds; multivalent metal salts (e.g., Al, Ti, Zr and Mg); titanium lactate; and boric acid.
  • polyvalent amine compounds such as ethylene diamine
  • polyvalent aldehyde compounds such as glyoxal, glutalaldehyde and dialdehyde
  • dihydrazide compounds such as dihydrazide adipate and dihydrazide phthalate
  • polyamide-epichlorohydrin compounds such as dihydrazide a
  • the amount of the crosslinking agent varies depending on the amounts and types of functional groups of the crosslinking agent, but it is preferably 0.1 parts by mass to 100 parts by mass, more preferably 1 part by mass to 100 parts by mass, relative to 100 parts by mass of the binder resin.
  • an inorganic filler or an organic filler may be used.
  • the inorganic filler include carbonates, silicates, metal oxides and sulfate compounds.
  • the organic filler include silicone resins, cellulose resins, epoxy resins, nylon resins, phenol resins, polyurethane resins, urea resins, melamine resins, polyester resins, polycarbonate resins, styrene resins, polyethylene resins, and formaldehyde resins.
  • the antistatic agent may, for example, be selected from commonly used ion-conducting antistatic agents and electron-conducting antistatic agents.
  • the ion-conducting antistatic agents include inorganic salts such as sodium chloride; anionic polymers such as sodium polystyrenesulfonate; and resins containing quaternary ammonium salts that are electrolyte cations.
  • the electron-conducting antistatic agents include conductive metal compounds such as conductive tin and antimony oxide; and conductive polymers such as polyaniline.
  • polystyrene sulfonic acid salts in particular, react with aziridine, thereby improving water resistance obtained by means of cross-linkage.
  • salts which have copolymerized with maleic acid are effective in that they have antistatic properties and also improve water resistance.
  • a method for forming the back layer is suitably selected depending on the intended purpose without any restriction.
  • the back layer is preferably formed by applying a coating liquid of the back layer to a support.
  • the coating method is suitably selected depending on the intended purpose without any restriction. Examples thereof include blade coating, roll coating, wire bar coating, die coating, and curtain coating.
  • the thickness of the back layer is suitably selected depending on the intended purpose without any restriction. It is preferably 0.1 ⁇ m to 10 ⁇ m, more preferably 0.5 ⁇ m to 5 ⁇ m.
  • a viscous layer also called an adhesive layer, may be provided in the thermosensitive recording medium of the present invention.
  • Such a viscous layer is however not required in the present invention, but instead is only optional.
  • a viscous layer may be provided on a surface of the support layer, or backing layer (back layer), opposite to the surface over which the protective layer is formed.
  • the viscous layer may, for example, help to attach the thermosensitive recording medium to a food package in a typical application of the present invention.
  • the thermosensitive recording medium of the invention can thus be provided with an adhesive surface attached to the support or backing layer, which is useful in order to provide a label which has an adhesive layer.
  • a releasable liner may then be attached to the adhesive layer, to be removed before final attachment to a product to be labelled.
  • the viscous layer may also provide antistatic properties.
  • the method for forming the viscous layer is not particularly limited. Examples of the method include common coating methods and laminating methods.
  • the average thickness of the viscous layer is not particularly limited, may be appropriately selected depending on the intended purpose, and is preferably 0.1 ⁇ m or greater but 20 ⁇ m or less.
  • the material of the viscous layer is not particularly limited and may be appropriately selected depending on the intended purpose.
  • Examples of the material of the viscous layer include urea resins, melamine resins, phenol resins, epoxy resins, vinyl acetate-based resins, vinyl acetate-acrylic-based copolymers, ethylene-vinyl acetate copolymers, acrylic-based resins, polyvinyl ether-based resins, vinyl chloride-vinyl acetate-based copolymers, polystyrene-based resins, polyester-based resins, polyurethane-based resins, polyamide-based resins, chlorinated polyolefin-based resins, polyvinyl butyral-based resins, acrylic acid ester-based copolymers, methacrylic acid ester-based copolymers, natural rubbers, cyano acrylate-based resins, and silicone-based resins.
  • thermosensitive recording medium of the invention is in the form of a silicone linerless (SLL) label.
  • An image recording method may be used for recording an image on the thermosensitive recording medium of any of the embodiments of the present invention using an image recording unit, which is any one of a thermal head and a laser.
  • the thermal head is suitably selected depending on the intended purpose without any restriction regarding the shape, structure and size thereof.
  • the laser may be selected depending on the intended purpose without any restriction.
  • a CO 2 laser which emits light having a wavelength of 9.3 ⁇ m to 10.6 ⁇ m may be used.
  • a satisfactory laser print image can be obtained without using a photothermal conversion agent such as a phthalocyanine pigment.
  • Other laser types may be used, such as FLDA (Fiber Laser Diode Array).
  • thermosensitive recording medium was created in accordance with the following steps. 1) A coating liquid for an undercoat layer was applied over a substrate, and thereby the undercoat layer (having 2 g/m 2 as dry mass) was created. In this example, a wood free paper, having a basic weight of about 60 g/m 2 , was used. The prescription of the coating liquid for the undercoat layer is below.
  • the compound of general formula (2) mentioned above has the specific structure: [ Liquid D1 ] Filler dispersion liquid 1 Calcined Kaolin 1) 32 parts 10% itaconic-modified polyvinyl alcohol aqueous solution 2) 32 parts Water 36 parts 1) Ansilex 93 from BASF, Oil absorption: 105 ⁇ 120 g/100g 2) From Kuraray, Itaconic-modified polyvinyl alcohol
  • thermosensitive colouring layer (Liquid E1].
  • thermosensitive colouring layer [Liquid E1] was uniformly applied to undercoat layer to thereby form a thermosensitive colouring layer.
  • the coating amount of the thermal layer was such as to produce a dye coating weight of 0.4 g/m 2 on a dry basis, then dried, to thereby form a thermosensitive colouring layer.
  • Coating liquids (a first coating liquid and a second coating liquid) for a double-layered protective layer were applied over the thermosensitive colouring layer so that a lower protective layer formed of the first coating liquid is present below an upper protective layer formed of the second coating liquid, and thereby the double-layered protective layer was created over the thermal recording layer.
  • the upper and lower protective layers had thickness of 1 g/m 2 and 1 g/m 2 respectively on a dry basis.
  • the prescription of the coating liquids for the double-layered protective layer are below; they were then dried.
  • samples were aged at 50°C during 48 h. Further to this process, samples were calendered at 20 kgF, before proceeding with quality evaluation.
  • thermosensitive recording medium was prepared according to Example 1, except where changes are indicated in following Table 1.
  • Amorphous silica 32 parts 10% itaconic-modified polyvinyl alcohol aqueous solution 2) 32 parts Water 36 parts 1) Mizukasil P-527 from Mizusawa Industrial Chemicals, Ltd, Oil absorption: 140 ⁇ 180 g/100g 2) From Kuraray, Itaconic-modified polyvinyl alcohol
  • Example 1 different combination of colour developers were compared in Examples 1 to 3.
  • a combination of three different types of colour developer is tested in Example 4.
  • Examples 5 to 12 test the effects of ratios between two different types of colour developers.
  • Example 13 tests the effect of another type of inorganic filler in the thermosensitive colouring layer.
  • thermosensitive recording medium was prepared according to Example 1, except where a [Liquid I] below was added to prepare a coating liquid of a thermosensitive colouring layer [Liquid E3].
  • thermosensitive recording medium was prepared according to Example 1, except where changes are indicated in following Table 1.
  • Fine spherical hollow plastic particles 1) 26 parts Large spherical hollow plastic particles 2) 7 parts Latex of styrene/butadiene copolymer 3) 10 parts 10% aqueous polyvinyl alcohol solution 4) 7 parts Water 50 parts 1) AF-1055 from Dow, copolymer resin based on styrene/acryl, solid content: 26.5%, average particle diameter: 1 ⁇ m, hollow rate : 55% 2) R-500 from Matsumoto Yushi-Seiyaku Co., Ltd., solid content: 33.0%, hollow rate : 90% 3) solid content : 50.0% 4) Fully hydrolysed PVA
  • Fine spherical hollow plastic particles 1) 24 parts Large spherical hollow plastic particles 2) 10 parts Latex of styrene/butadiene copolymer 3) 10 parts 10% aqueous polyvinyl alcohol solution 4) 6 parts Water 50 parts 1) AF-1055 from Dow, copolymer resin based on styrene/acryl, solid content: 26.5%, average particle diameter: 1 ⁇ m, hollow rate : 55% 2) R-500 from Matsumoto Yushi-Seiyaku Co., Ltd., solid content: 33.0%, hollow rate : 90% 3) solid content : 50.0% 4) Fully hydrolysed PVA
  • Spherical hollow plastic particles 1 25 parts Large spherical hollow plastic particles 2) 11 parts Latex of styrene/butadiene copolymer 3) 11 parts 10% aqueous polyvinyl alcohol solution 4) 7 parts Water 46 parts 1) AF-1570 from Dow, copolymer resin based on styrene/acryl, solid content: 17.5%, average particle diameter: 1.6 ⁇ m, hollow rate : 65% 2) R-500 from Matsumoto Yushi-Seiyaku Co., Ltd., solid content: 33.0%, hollow rate : 90% 3) solid content : 50.0% 4) Fully hydrolysed PVA
  • Spherical hollow plastic particles 1) 48 parts Latex of styrene/butadiene copolymer 2) 10 parts 10% aqueous polyvinyl alcohol solution 3) 6 parts Water 36 parts 1) AF-1570 from Dow, copolymer resin based on styrene/acryl, solid content: 17.5%, average particle diameter: 1.6 ⁇ m, hollow rate : 65% 2) solid content : 50.0% 3) Fully hydrolysed PVA
  • Fine spherical hollow plastic particles 1) 12 parts Large spherical hollow plastic particles 2) 10 parts Non calcined Kaolin 3) 3 parts Latex of styrene/butadiene copolymer 4) 10 parts 10% aqueous polyvinyl alcohol solution S) 6 parts Water 59 parts 1) AF-1055 from Dow, copolymer resin based on styrene/acryl, solid content: 26.5%, average particle diameter: 1 ⁇ m, hollow rate : 55% 2) R-500 from Matsumoto Yushi-Seiyaku Co., Ltd., solid content: 33.0%, hollow rate : 90% 3) UW-90 4) solid content : 50.0% 5) Fully hydrolysed PVA
  • Spherical hollow plastic particles 1 20 parts Large spherical hollow plastic particles 2) 9 parts Non calcined Kaolin 3) 3 parts Latex of styrene/butadiene copolymer 4) 9 parts 10% aqueous polyvinyl alcohol solution 5) 6 parts Water 53 parts 1) AF-1570 from Dow, copolymer resin based on styrene/acryl, solid content: 17.5%, average particle diameter: 1.6 ⁇ m, hollow rate : 65% 2) R-500 from Matsumoto Yushi-Seiyaku Co., Ltd., solid content: 33.0%, hollow rate : 90% 3) UW-90 4) solid content : 50.0% 5) Fully hydrolysed PVA
  • thermosensitive recording medium was prepared according to Example 1, except where changes are indicated in following Table 1.
  • three types of sensitizer were added respectively in thermosensitive colouring layer liquid.
  • Bis(4-methyl benzyl) oxalate 1) 32 parts 10% itaconic-modified polyvinyl alcohol aqueous solution 2) 32 parts Water 36 parts 1) HS-3520 from Dainippon Ink & Chemicals 2) From Kuraray, Itaconic-modified polyvinyl alcohol
  • Reference Example 1 here corresponds to Example 21 with KS-232 added, and Reference Example 2 corresponds to Example 17 with KS-232 added.
  • Reference Example 3 corresponds to Example 2 with KS-232 added,
  • Reference Example 4 corresponds to Example 21 with HS-3520 added, and
  • Reference Example 5 corresponds to Example 1 with Stearamide added.
  • thermosensitive recording medium was prepared according to Example 1, except where changes are indicated in following Table 1.
  • another type of colour developer was combinined with [Liquid C1] and [Liquid C2] respectively in thermosensitive colouring layer liquid.
  • N-(p-toluenesulfonyl)-N'-(3-(p-toluenesulfonyloxy)phenyl)urea 1) 32 parts 10% itaconic-modified polyvinyl alcohol aqueous solution 2) 32 parts Water 36 parts 1) Pergafast 201 from SOLENIS 2) From Kuraray, Itaconic-modified polyvinyl alcohol
  • Pergafast 201 has the following structure:
  • thermosensitive recording medium in Comparative Examples 8 to 10, in each case, a thermosensitive recording medium was prepared according to Example 1, except where changes are indicated in following Table 1. Thus, three types of undercoat layer liquid [Liquid A12], [Liquid A13] and [Liquid A14] below were tested.
  • Fine spherical hollow plastic particles 1) 36 parts Latex of styrene/butadiene copolymer 2) 10 parts 10% aqueous polyvinyl alcohol solution 3) 6 parts Water 48 parts 1) AF-1055 from Dow, copolymer resin based on styrene/acryl, solid content: 26.5%, average particle diameter: 1 ⁇ m, hollow rate : 55% 2) solid content : 50.0% 3) Fully hydrolysed PVA
  • Fine spherical hollow plastic particles 1) 24 parts Non calcined Kaolin 2) 3 parts Latex of styrene/butadiene copolymer 3) 10 parts 10% aqueous polyvinyl alcohol solution 4) 6 parts Water 57 parts 1) AF-1055 from Dow, copolymer resin based on styrene/acryl, solid content: 26.5%, average particle diameter: 1 ⁇ m, hollow rate : 55% 2) UW-90 3) solid content : 50.0% 4) Fully hydrolysed PVA
  • Non calcined Kaolin 10 parts Latex of styrene/butadiene copolymer 2) 10 parts 10% aqueous polyvinyl alcohol solution 3) 6 parts Water 74 parts 1) UW-90 2) solid content : 50.0% 3) Fully hydrolysed PVA
  • thermosensitive recording medium in Comparative Examples 11 to 14, in each case, a thermosensitive recording medium was prepared according to Example 1, except where changes are indicated in following Table 1. Thus, each developer dispersion liquid was used without combining with others.
  • thermosensitive recording medium was prepared according to Example 1, except where changes are indicated in following Table 1.
  • undercoat layer liquid [Liquid A15] was used instead of [Liquid A1].
  • Fine spherical hollow plastic particles 1) 33 parts Spherical hollow plastic particles 2) 22 parts Latex of styrene/butadiene copolymer 3) 2 parts 10% aqueous polyvinyl alcohol solution 4) 9 parts Water 34 parts 1) AF-1055 from Dow, copolymer resin based on styrene/acryl, solid content: 26.5%, average particle diameter: 1 ⁇ m, hollow rate : 55% 2) AF-1570 from Dow, copolymer resin based on styrene/acryl, solid content: 17.5%, average particle diameter: 1.6 ⁇ m, hollow rate : 65% 3) Solid content : 50.0% 4) Fully hydrolysed PVA
  • thermosensitive recording medium was prepared according to Example 1, except where changes are indicated in following Table 1.
  • thermosensitive colouring layer
  • Barcode decodability was assessed as follows: A ZEBRA 110Xi4 printer was used to print picket type barcodes (bars are printed parallelly to the printing direction) using applied energy of +15 at a printing speed of 304 mm per sec (12 inches per sec). The barcode was read with a barcode verifier (MICROSCAN LVS-9580, available from OMRON corporation) to evaluate its decodability. The results were recorded according to ANSI symbol grades. The value is preferably higher (Maximum 4.0).
  • the value is preferably 90% or higher.
  • the value is preferably 90% or higher.
  • the value is preferably 70% or higher.
  • Anchorage level of the layer was assessed as follows: A piece of scotch tape (NICHIBAN CT405AP-18) was applied on a surface of each sample. The tape was repeeled in three steps below.
  • the anchorage level was evaluated according to the rank below.
  • SBR Styrene-Butadiene Resin
  • Dev for Developer
  • Pig for Pigment
  • "Ratio” in Table 1a to 1d stands for dry ratio by mass.
  • Pig ratio in Undercoat gives total pigment ratio (the inorganic filler and the organic filler) in the undercoat layer by weight with respect to the total dry weight of the undercoat layer.
  • Hollow in Pig gives dry ratio of hollow particles in the underlayer by weight with respect to the total dry weight of the pigments in the undercoat layer.
  • >60% hollow” and “>80% hollow give ratio of the hollow particles which has hollow ratio higher than 60% and 80% respectively, with respect to the total dry weight of the hollow particles in the undercoat layer.

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

Claims (15)

  1. Support d'enregistrement thermosensible comprenant au moins :
    - une couche de support,
    - une sous-couche au-dessus de la couche de support,
    - une couche colorante thermosensible au-dessus de la sous-couche,
    - une couche protectrice au-dessus de la couche colorante thermosensible,
    dans lequel
    - la sous-couche comprend au moins un type de particules creuses plastiques à titre de charges organiques, les particules creuses plastiques comprenant au moins 20 %, en masse par rapport à la masse totale de toutes les particules creuses, de particules creuses qui ont un rapport de creux de 60 % ou plus, le rapport de creux étant un rapport en pourcentage du diamètre intérieur des particules creuses au diamètre extérieur des particules creuses ; et
    - la couche colorante thermosensible comprend un colorant leuco et au moins deux types de révélateurs chromogènes choisis parmi les formules générales (1), (2) et (3) : dans lequel,
    - dans la formule (1), chacun de R1 à R3 représente indépendamment un atome d'hydrogène, un atome d'halogène, un groupe alkyle en C1 à C6, un groupe alcoxy en C1 à C6, un groupe fluoroalkyle en C1 à C6;
    - dans la formule (2), R3 est un atome d'hydrogène, un atome d'halogène, un groupe nitro, un groupe amino, un groupe alkyle, un groupe alcoxy, un groupe aryloxy, un groupe alkylcarbonyloxy, un groupe arylcarbonyloxy, un groupe alkylcarbonylamino, un groupe arylcarbonylamino, un groupe alkylsulfonylamino, un groupe arylsulfonylamino, un groupe monoalkylamino, un groupe dialkylamino, ou un groupe arylamino ;
    - dans la formule (3), R représente un groupe alkyle et n représente un entier situé dans la plage allant de 0 à 3.
  2. Support d'enregistrement thermosensible selon la revendication 1, dans lequel les au moins 20 % de particules creuses ont un rapport de creux de 80 % ou plus.
  3. Support d'enregistrement thermosensible selon la revendication 1 ou 2, dans lequel la couche colorante thermosensible comprend du N-[2-(3-phényluréido)phényl]benzènesulfonamide à titre de révélateur chromogène.
  4. Support d'enregistrement thermosensible selon la revendication 3, dans lequel la couche colorante thermosensible comprend du N-[2-(3-phényluréido)phényl]benzènesulfonamide et un composé de formule générale (2) à titre de révélateurs chromogènes.
  5. Support d'enregistrement thermosensible selon l'une quelconque des revendications 1 à 4, dans lequel la couche colorante thermosensible comprend en outre de la 1,3-diphénylurée.
  6. Support d'enregistrement thermosensible selon l'une quelconque des revendications 1 à 5, dans lequel la sous-couche comprend une charge inorganique qui a une propriété d'absorption d'huile de 60 g/100 g ou moins.
  7. Support d'enregistrement thermosensible selon l'une quelconque des revendications 1 à 6, dans lequel la proportion totale de pigments, combinant la charge inorganique et la charge organique, dans la sous-couche est d'au moins 20 % en poids à au plus 80 % en poids par rapport au poids sec total de la sous-couche.
  8. Support d'enregistrement thermosensible selon l'une quelconque des revendications 1 à 7, dans lequel le révélateur chromogène (1) est présent dans la couche colorante thermosensible et répond à la formule (4) suivante :
  9. Support d'enregistrement thermosensible selon l'une quelconque des revendications 1 à 8, dans lequel le révélateur chromogène (2) est présent dans la couche colorante thermosensible et a une structure dans laquelle le groupe -O-SO2-(phényl)-para-R3 est en position méta par rapport au substituant -NH-CO-NH-phényle, et R3 = méthyle.
  10. Support d'enregistrement thermosensible selon l'une quelconque des revendications 1 à 9, dans lequel le révélateur chromogène de formule (3) est présent dans la couche colorante thermosensible et chaque système (R)n est constitué d'un seul groupe méthyle en position para par rapport au groupe -S02-O-.
  11. Support d'enregistrement thermosensible selon l'une quelconque des revendications 1 à 10, dans lequel la couche colorante thermosensible comprend au moins un type de charge inorganique qui a une propriété d'absorption d'huile de 80 g/100 g ou plus.
  12. Support d'enregistrement thermosensible selon l'une quelconque des revendications 1 à 11, dans lequel la couche colorante thermosensible ne comprend pas de sensibilisateur.
  13. Support d'enregistrement thermosensible selon l'une quelconque des revendications 1 à 12, dans lequel la couche colorante thermosensible ne comprend pas de sensibilisateur sous la forme d'un dérivé benzyloxy, d'un sensibilisateur oxalate, d'un sensibilisateur alcoxy ou aryloxy, et/ou d'un sensibilisateur alcool.
  14. Conditionnement alimentaire comprenant le support d'enregistrement thermosensible selon l'une quelconque des revendications 1 à 13.
  15. Utilisation du support d'enregistrement thermosensible selon l'une quelconque des revendications 1 à 13 dans le conditionnement alimentaire.
EP23305230.7A 2023-02-22 2023-02-22 Support d'enregistrement thermosensible Active EP4420887B1 (fr)

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EP23305230.7A EP4420887B1 (fr) 2023-02-22 2023-02-22 Support d'enregistrement thermosensible
ES23305230T ES3059935T3 (en) 2023-02-22 2023-02-22 Thermosensitive recording medium
PCT/JP2024/005023 WO2024176910A1 (fr) 2023-02-22 2024-02-14 Support d'impression thermosensible
CN202480014195.7A CN120677070A (zh) 2023-02-22 2024-02-14 热敏记录介质
JP2025536177A JP7838712B2 (ja) 2023-02-22 2024-02-14 感熱性記録媒体
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JP2015150764A (ja) 2014-02-13 2015-08-24 王子ホールディングス株式会社 感熱記録体
KR102493552B1 (ko) 2015-12-25 2023-01-30 닛뽄 가야쿠 가부시키가이샤 감열 기록 재료
FI3677569T3 (fi) 2017-08-31 2025-07-04 Sanko Co Ltd N,n'-diaryyliureajohdannainen, menetelmä sen valmistamiseksi ja sitä käyttävä lämpöherkkä tallennusmateriaali
JP6865656B2 (ja) * 2017-08-31 2021-04-28 三光株式会社 感熱記録材料
JP7127684B2 (ja) * 2018-06-29 2022-08-30 王子ホールディングス株式会社 感熱記録体
EP3670205B1 (fr) 2018-12-19 2021-02-17 Ricoh Company, Ltd. Support d'enregistrement thermosensible
JP7342320B2 (ja) 2019-04-04 2023-09-12 エルジー・ケム・リミテッド エステル系組成物の製造方法及び製造システム
JP7422536B2 (ja) * 2019-12-24 2024-01-26 日本化薬株式会社 感熱記録材料
CN115515796B (zh) * 2020-04-23 2025-12-05 王子控股株式会社 热敏记录体
JP7491181B2 (ja) * 2020-10-20 2024-05-28 王子ホールディングス株式会社 感熱記録体
ES3028248T3 (en) 2020-12-28 2025-06-18 Sanko Co Ltd Colour developer, thermal recording material, and coating material for thermal recording layers
JP7146147B1 (ja) * 2021-03-19 2022-10-03 日本製紙株式会社 感熱記録体
JP7794064B2 (ja) 2022-04-07 2026-01-06 王子ホールディングス株式会社 感熱記録体

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CN120677070A (zh) 2025-09-19
WO2024176910A1 (fr) 2024-08-29
JP7838712B2 (ja) 2026-04-01

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