EP4355582A2 - Wärmeempfindliche aufzeichnungsmaterialien - Google Patents

Wärmeempfindliche aufzeichnungsmaterialien

Info

Publication number
EP4355582A2
EP4355582A2 EP22738538.2A EP22738538A EP4355582A2 EP 4355582 A2 EP4355582 A2 EP 4355582A2 EP 22738538 A EP22738538 A EP 22738538A EP 4355582 A2 EP4355582 A2 EP 4355582A2
Authority
EP
European Patent Office
Prior art keywords
heat
layer
recording material
sensitive
sensitive 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.)
Pending
Application number
EP22738538.2A
Other languages
German (de)
English (en)
French (fr)
Inventor
Dr. Timo STALLING
Dr. Uwe BRASCH
Dominik HOFERER
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.)
Koehler Innovation and Technology GmbH
Original Assignee
Koehler Innovation and Technology GmbH
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 Koehler Innovation and Technology GmbH filed Critical Koehler Innovation and Technology GmbH
Publication of EP4355582A2 publication Critical patent/EP4355582A2/de
Pending legal-status Critical Current

Links

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
    • B41M5/40—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
    • B41M5/41—Base layers supports or substrates
    • 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
    • B41M5/36—Thermography ; Marking by high energetic means, e.g. laser otherwise than by burning, and characterised by the material used using a polymeric layer, which may be particulate and which is deformed or structurally changed with modification of its' properties, e.g. of its' optical hydrophobic-hydrophilic, solubility or permeability properties
    • B41M5/363—Thermography ; Marking by high energetic means, e.g. laser otherwise than by burning, and characterised by the material used using a polymeric layer, which may be particulate and which is deformed or structurally changed with modification of its' properties, e.g. of its' optical hydrophobic-hydrophilic, solubility or permeability properties using materials comprising a polymeric matrix containing a low molecular weight organic compound such as a fatty acid, e.g. for reversible recording
    • 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
    • B41M5/36—Thermography ; Marking by high energetic means, e.g. laser otherwise than by burning, and characterised by the material used using a polymeric layer, which may be particulate and which is deformed or structurally changed with modification of its' properties, e.g. of its' optical hydrophobic-hydrophilic, solubility or permeability properties
    • B41M5/366—Thermography ; Marking by high energetic means, e.g. laser otherwise than by burning, and characterised by the material used using a polymeric layer, which may be particulate and which is deformed or structurally changed with modification of its' properties, e.g. of its' optical hydrophobic-hydrophilic, solubility or permeability properties using materials comprising a polymeric matrix containing a polymeric particulate material, e.g. hydrophobic heat coalescing particles
    • 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
    • B41M5/44—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
    • B41M2205/36—Backcoats; Back layers
    • 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 to heat-sensitive recording materials, in particular heat-sensitive recording materials for direct thermal printing.
  • Heat-sensitive recording materials are known in principle, with a basic distinction being made between two different types of heat-sensitive recording materials, in particular for direct thermal printing:
  • Type 1 Heat-sensitive recording material in which the printed image is generated by local, heat-induced, chemical reaction in an ink layer, e.g. between color former (e.g. a leuco dye) and color developer (e.g. bisphenol A or a phenol-free alternative).
  • color former e.g. a leuco dye
  • color developer e.g. bisphenol A or a phenol-free alternative
  • the color layer also contains a heat-sensitive solvent (solvent) that melts when heated (e.g. long-chain aliphatic alcohols, amides, esters or carboxylic acids), so that the color reaction of the color former and color developer is enabled.
  • the colored layer can contain heat-sensitive sensitizers.
  • Type 2 Heat-sensitive recording material in which the print image is created by making a heat-sensitive cover layer translucent through the local action of heat, eg by means of a direct thermal printer so that an underlying layer of paint becomes visible.
  • This technology is described and interpreted differently in the prior art, and such a heat-sensitive recording material is obtained through partly different compositions, porosities and materials of the cover layer, is optimized for direct thermal printing and is explained in more detail below.
  • the top coat should cover the underlying paint coat as well as possible. This is essentially achieved through light scattering (scattering particles) and light absorption.
  • the top layer should have the highest possible contrast to the underlying color layer in order to create a printed image that can be read by the human eye and/or a machine (scanner) (e.g. white/black or blue/yellow).
  • a machine e.g. white/black or blue/yellow.
  • the cover layer should have heat sensitivity that is as sufficient as possible, so that it becomes translucent as a result of local exposure to heat, in particular by means of conventional direct thermal printers.
  • recording materials of type 1 and type 2 should be usable and the printer settings should be comparable, in particular print head temperature and printer speed.
  • the present invention relates to heat-sensitive recording materials of type 2 described above.
  • GB 997289 describes for the first time a recording material for direct thermal printing, comprising a carrier material, an ink layer and a heat-sensitive top layer, the heat-sensitive top layer becoming translucent as a result of the local action of heat by means of a direct thermal printer, so that the color layer underneath is visible and thus a printed image is produced.
  • US Pat. No. 6,043,193 describes a heat-sensitive recording material comprising a substrate and an opaque recording layer applied to it and contained in a hydrophilic binder dispersed hollow spherical beads, the beads having an average diameter of 0.2 ⁇ m to 1.5 ⁇ m and a void volume of 40% to 90%.
  • US 6133342 describes a heat-sensitive recording material comprising a colorant and an opaque polymeric material whose opacity changes essentially irreversibly and renders the colorant more visible when exposed to heat.
  • WO 2015/119964 A1 discloses an oriented multilayer film for printing, comprising an extruded outer layer, an extruded inner pigment layer, and an extruded image-reproduction layer, which lies between the outer layer and the inner pigment layer, the image-reproduction layer comprising a cavity layer with a collapsible layer structure wherein multiple voids are dispersed, multiple voids being formed by orienting the multilayer, the extruded image display layer and the collapsible layered structure being in an uncollapsed state which is substantially opaque to hide the pigment layer beneath.
  • US 2010/245524 A describes a heat-sensitive recording material comprising a heat-sensitive substrate with an opaque polymer which is sensitive to the application of heat and pressure and which, when heated to a predetermined temperature and under the action of a predetermined pressure, causes the opaque polymer becomes transparent, and a color material arranged with respect to the substrate in a way that it is obscured by the opaque polymer prior to application of the predetermined heat and pressure and thereafter becomes visible.
  • US 2011/172094 A discloses a recording material comprising: a) a support having a surface impregnated with a colorant or coated with a coating containing a pigment or a dye and placed thereon , b) a layer comprising polymeric particles having a core-shell structure and, when dry, hollow to scatter visible light, the particles having an inner first polymeric shell having a Tg of 40°C to 130°C and a outer second polymeric shell having a Tg of -55°C to 50°C, wherein the Tg of the outer polymeric shell is lower than that of the inner polymeric shell.
  • US 2011/251060 A describes a heat-sensitive recording material consisting of a colorant and a flexible carrier substrate, the heat-sensitive recording material also consisting of a heat-sensitive layer, the heat-sensitive layer consisting of a binder, a large number of organic hollow sphere pigments and a thermal solvent and wherein the heat-sensitive layer is disposed on the colorant.
  • the thermosensitive layer may be provided with a barrier layer and a protective layer.
  • WO 2012/145456 A1 describes a heat-sensitive recording material optimized for conventional direct thermal printing, which includes: a) a carrier in the form of a sheet-like structure containing at least one colored surface and arranged thereon, b) a layer containing polymer particles with a Core-shell structure wherein the particles have an outer first polymeric shell with a calculated Tg of 40°C to 130°C, the particles when dry contain at least one void space, and from 1% by weight to 90 % by weight, based on the weight of the polymer particles, of an opacity reducer having a melting point of from 45°C to 200°C, the colored surface having sufficient color density to visually stand out from the surface of the subsequent layer dispersed thereon, the opacity reducer an aromatic oxalic acid ester, an aromatic ethylene glycol ether, 1,2-diphenyloxyethane, dibenzyl oxalate, dibenzyl ter ephthalate, benzylbiphenyl, benz
  • WO 2013/152287 A1 describes a heat-sensitive recording material with a two-layer, monoaxially oriented film, comprising a first layer comprising an opaque polymer based on beta-nucleated propylene, and a second layer comprising a dark pigment.
  • a heat-sensitive recording material comprising a heat-sensitive layer arranged on a colored solid support substrate, the heat-sensitive layer comprising single-phase scattering polymer particles, each of which has a center, a surface, a refractive index at the center thereof, the differs in a refractive index at the surface thereof and has a continuous refractive index gradient, wherein the heat-sensitive layer further includes heat-deformable particles and a binder.
  • a web-shaped heat-sensitive recording material is described with at least one first layer and a second layer at least partially covering the first layer, the first layer having an intense color at least facing the second layer and the second layer having hollow body pigments which are used to form a Typeface can be melted by locally limited heat treatment, which is characterized in that the second layer also has one or more fatty acids and one or more heat-sensitive sensitizers in addition to the hollow body pigments.
  • a web-shaped, heat-sensitive recording material is described with at least one first layer and a second layer at least partially covering the first layer, the first layer having an intensive coloring at least facing the second layer and the second layer having hollow body pigments which are used to form a Character image can be melted by locally limited heat treatment, which is characterized in that the recording material has at least one protective layer at least partially covering the second layer.
  • the printed image is produced in that a heat-sensitive top layer becomes translucent through the local action of heat using a direct thermal printer, the top layer comprising fusible hollow body pigments.
  • the printed image is produced in that a heat-sensitive top layer becomes translucent through the local action of heat by means of a direct thermal printer, the top layer comprising softenable or dissolvable hollow body pigments.
  • an acceptable, gray recording material can be obtained with the following characteristics: whiteness of 56% or 52% with or without UV component, optical density (unprinted) of 0.33 ODU, optical density (printed) of 1 .22 ODU and contrast of 0.89 ODU (thermal head 300 dpi, 16 mJ/mm 2 )
  • the feature of the top layer is specified in particular, which comprises hollow body pigments that can be manipulated to form a typeface and at least one fatty acid, namely stearic acid and/or palmitic acid or stearic acid amide and/or methylstearic acid amide.
  • a recording material comprising: a release liner base material layer, an optional adhesive layer, a label base layer, a thermal insulation layer (thermal insulating layer) arranged over the label base layer, an ink layer arranged over the thermal insulation layer ( thermal insulation layer), wherein the ink layer comprises at least one color, a top coat disposed over the printed ink layer, and a top coat layer disposed over the top coat, wherein the top coat comprises an acrylic-based composition that scatters light contains particles that cause the topcoat to be opaque in a first state and transparent in a second state, wherein at least one of heat and pressure is applied from a printhead that causes the topcoat to change from the first state to the second state transitions, thereby allowing the at least one color of the ink layer to be visible through the cover layer.
  • WO 2019/183471 A1 discloses a recording medium comprising a substrate, the substrate participating in the first scattering particles having a melting point, comprising a first solid light-scattering layer, and the first light-scattering layer as close as possible to a plurality of second solid scattering particles, wherein the second solid scattering particles have a lower melting point than the first melting point of the second solid scattering particles, and wherein the first light-scattering layer is porous and the second scattering particles during melting of the solid, the first solid scattering particles being arranged around the to fill space between the recording medium.
  • WO 2019/219391 A1 describes a heat-sensitive recording material comprising a carrier substrate that is black or colored on at least one side and a thermoresponsive layer on the at least one black or colored side of the carrier substrate, the thermoresponsive layer comprising nanoparticles of at least one cellulose ester.
  • WO 2021/055719 A1 describes a heat- or pressure-sensitive recording material comprising a layer of an opaque material, color material which is arranged on a first side of the layer of opaque material, the layer of opaque material covering the color material, wherein the opaque material in an opaque state comprises a plurality of irregular and/or odd shaped opaque polymeric particles defining voids therebetween and having different shapes and/or different sizes, and further wherein the opaque material is configured such that upon application of a sufficient temperature and/or sufficient pressure to change from an opaque state to a transparent state to reveal the colored material beneath the opaque material.
  • WO 2021/062230 A1 describes a recording medium comprising a substrate, a first light-scattering layer which is carried by the substrate and contains first scattering particles with a first melting point, and a plurality of second scattering particles proximate to the first light scattering layer, the second scattering particles having a second melting point lower than the first melting point, the first light scattering layer being porous and the second scattering particles being arranged to form spaces between the first scattering ones upon melting to fill particles, and wherein the first scattering particles comprise perforated particles disclosed.
  • heat-sensitive recording materials are in need of improvement, particularly with regard to their functionality, their sustainability and their economic production.
  • the present invention addresses this need.
  • a heat-sensitive recording material according to claim 1 by a heat-sensitive recording material according to claim 21, by a heat-sensitive recording material according to claim 41, by a heat-sensitive recording material according to claim 64, by a heat-sensitive recording material according to claim 65 and/or by a heat-sensitive recording material solved according to claim 85.
  • first, second, etc. may be used herein to describe various elements, these elements are not intended to be limited by those terms. These terms are only used to distinguish one element from another.
  • a first object or step could be referred to as a second object or step, and similarly a second object or step could be referred to as a first object or step.
  • the first object or step and the second object or step are both objects or steps, but they are not to be considered the same object or step.
  • the terms “includes”, “comprises” and/or “comprising” can also mean “consisting of”, ie the presence or addition of one or more other features, steps, operations, elements, components and/or or groups will be excluded.
  • the term “including” can also mean “exclusive”.
  • the present invention relates to a heat-sensitive recording material, comprising a web-shaped base material, a color layer on one side of the web-shaped base material and a heat-sensitive layer on the color layer, so that the color layer is at least partially covered, the heat-sensitive layer being configured in such a way that this becomes translucent through the local effect of heat, so that the underlying color layer becomes visible, which is characterized in that the carrier material on the side on which the color layer is applied has a Bekk smoothness of greater than 20 s, the Bekk smoothness according to DIN 53107 (2016).
  • Such a heat-sensitive recording material has the advantage of high dynamic sensitivity.
  • the carrier material preferably has a Bekk smoothness of greater than 30 s, particularly preferably greater than 50 s.
  • the color layer preferably has a Bekk smoothness of greater than 50 s, more preferably greater than 100 s and very particularly preferably greater than 150 s.
  • the heat-sensitive layer preferably has a Bekk smoothness of greater than 100 s, particularly preferably greater than 250 s.
  • the carrier material preferably has a Bekk smoothness of 20 to 400 s, particularly preferably 30, on the side to which the color layer is applied to 300 s and most preferably from 50 to 200 s. Most preferred is a Bekk smoothness of 50 to 150 s.
  • the color layer preferably has a Bekk smoothness of 50 to 400 s, more preferably 100 to 250 s, and most preferably 150 to 250 s on the side on which the heat-sensitive layer is coated.
  • the heat-sensitive layer preferably has a Bekk smoothness of from 100 to 1000 s, particularly preferably from 250 to 800 s, on the side on which the color layer does not lie.
  • each layer applied to the web-shaped carrier material has a Bekk smoothness on its upper side, i.e. on the side on which the web-shaped carrier material does not lie, which is at least as great as or greater than that of the respective underlying layer.
  • each layer applied to the substrate sheet has a Bekk smoothness of at least 5% (percentage increase) on its top surface, i.e., the side not bearing the substrate sheet, over the underlying layer.
  • Each layer applied to the web-shaped carrier material preferably has a Bekk smoothness of at least 5 s (absolute increase) on its upper side, i.e. on the side on which the web-shaped carrier material is not located, compared to the respective underlying layer.
  • the web-shaped carrier material is not limited.
  • the carrier material in web form comprises paper, synthetic paper and/or a plastic film.
  • the carrier material preferably has a basis weight of 30 to 100 g/m 2 , in particular 40 to 80 g/m 2 .
  • the carrier material in web form of the heat-sensitive recording material according to the invention preferably comprises at least one black or colored side, which is achieved by applying a colored layer.
  • the term "colored page" means that the page is a color other than white or black.
  • the heat-sensitive recording material comprises at least one side colored so that it is not white.
  • the at least one black or colored side has several different colors, also in combination with the color black.
  • the at least one colored layer on one side of the web-shaped carrier material is preferably characterized in that the colored layer comprises at least one pigment and/or one dye and preferably a binder.
  • the pigments and/or dyes include various organic and inorganic pigments, dyes and/or carbon black. These can be used alone or in any mixture.
  • the pigment, the dye and/or the carbon black are each preferably contained in the color layer in an amount of 2 to 50% by weight, particularly preferably 10 to 35% by weight, based on the total solid content of the color layer.
  • Soot is generally understood to mean a black, powdery solid which, depending on the quality and use, consists of 80% to 99.5% carbon and can be obtained, for example, through the incomplete combustion and/or thermal cracking of hydrocarbons.
  • the binder is contained in the color layer preferably in an amount of
  • the colored layer preferably has a basis weight of 1 to 10 g/m 2 , in particular 3 to 8 g/m 2 .
  • the colored layer preferably has a thickness of 1 to 10 gm, in particular 2 to 8 gm.
  • the heat-sensitive recording material is characterized in that the heat-sensitive layer comprises at least one scattering particle, in particular a polymer particle, with a glass transition temperature of -55 to 130°C, preferably of 40 to 80°C.
  • the heat-sensitive recording material is characterized in that the heat-sensitive layer comprises at least one scattering particle, in particular a polymer particle, with a core/fill structure, the scattering particles, in particular the polymer particles, being selected from the group consisting of (i) scattering particles, in particular polymer particles, with an outer shell having a glass transition temperature of 40 °C to 80 °C and (ii) scattering particles, in particular polymer particles, having an inner shell with a glass transition temperature of 40 °C to 130 °C and an outer one Shell having a glass transition temperature of -55°C to 50°C, wherein the glass transition temperature of the outer shell is preferably lower than that of the inner shell.
  • the scattering particles in particular the polymer particles, being selected from the group consisting of (i) scattering particles, in particular polymer particles, with an outer shell having a glass transition temperature of 40 °C to 80 °C and (ii) scattering particles, in particular polymer particles, having an inner shell with a glass transition temperature of 40 °
  • the heat-sensitive recording material is characterized in that the heat-sensitive layer contains at least one scattering particle, in particular a polymer particle, with a melting point of less than 250°C, preferably from 0°C to 250°C.
  • the heat-sensitive recording material is characterized in that the heat-sensitive layer has at least one scattering particle, in particular a polymer particle, with a mean particle size ranging from 0.1 to 2.5 gm, preferably from 0.2 to 0.8 gm.
  • the heat-sensitive recording material is characterized in that the heat-sensitive layer contains at least one scattering particle, in particular a polymer particle, with a glass transition temperature of -55 to 130 °C, preferably from 40 to 80 °C, and with an average particle size in the range from 0.1 to 2.5 pm, preferably from 0.2 to 0.8 pm.
  • the heat-sensitive layer contains at least one scattering particle, in particular a polymer particle, with a glass transition temperature of -55 to 130 °C, preferably from 40 to 80 °C, and with an average particle size in the range from 0.1 to 2.5 pm, preferably from 0.2 to 0.8 pm.
  • the heat-sensitive recording material is characterized in that the heat-sensitive layer comprises at least one scattering particle, in particular a polymer particle, with a core/shell structure, the scattering particles, in particular the polymer particles, being selected from the group consisting of (i) scattering particles, in particular polymer particles, with an outer shell having a glass transition temperature of 40 °C to 80 °C and (ii) scattering particles, in particular polymer particles, having an inner shell with a glass transition temperature of 40 °C to 130 °C and an outer one shell with a glass transition temperature of -55 °C to 50 °C, the glass transition temperature of the outer shell being preferably lower than that of the inner shell, and having an average particle size in the range of 0.1 to 2.5 ⁇ m, preferably 0, 2 to 0.8 pm.
  • the scattering particles in particular the polymer particles, being selected from the group consisting of (i) scattering particles, in particular polymer particles, with an outer shell having a glass transition temperature of 40 °C to 80 °C and (
  • the heat-sensitive recording material is characterized in that the heat-sensitive layer contains at least one scattering particle, in particular a polymer particle, with a melting point of less than 250° C., preferably from 0° C. to 250° C., and with an average particle size in the range from from 0.1 to 2.5 pm, preferably from 0.2 to 0.8 pm.
  • the heat-sensitive layer contains at least one scattering particle, in particular a polymer particle, with a melting point of less than 250° C., preferably from 0° C. to 250° C., and with an average particle size in the range from from 0.1 to 2.5 pm, preferably from 0.2 to 0.8 pm.
  • a glass transition temperature or a melting point of less than 250° C. was recognized as advantageous. No direct thermal printing is possible above temperatures of 250 °C, since the temperature-time window is outside the printer specification. An average particle size in the range from 0.1 to 2.5 ⁇ m is advantageous since particles of this size scatter visible light and the color layer is thus covered as far as possible.
  • the average particle size can be determined using a Beckman Coulter device (laser diffraction, Fraunhofer method).
  • the scattering particles in particular the polymer particles, are preferably crystalline, partially crystalline and/or amorphous.
  • the glass transition temperatures mentioned above relate to partially crystalline or amorphous scattering particles, in particular polymer particles.
  • the melting temperatures relate to crystalline scattering particles, in particular polymer particles, or to the crystalline portion of the scattering particles, in particular polymer particles.
  • the primary property of the scattering particles is the scattering of light in the visible range of light.
  • the secondary property is sensitivity to heat.
  • the polymer particles preferably comprise thermoplastic polymers.
  • the polymer particles preferably comprise polymers resulting from the polymerisation of one or more monomers selected from the group consisting of acrylonitrile, styrene, butadiene, benzyl methacrylate, phenyl methacrylate, ethyl methacrylate, divinylbenzene, 2-hydroxyethyl methacrylate, cyclohexyl methacrylate, 2-methylstyrene, 3-methylstyrene, 4 -methylstyrene, alpha-methylstyrene, beta-methylstyrene, acrylamide, methacrylamide, methacrylonitrile, hydroxypropyl methacrylate, methoxystyrene, N-acrylylglycine amide and/or N-methacrylylglycine amide and/or their derivatives are selected.
  • the polymer particles can be polymerized using a variety of ethylenically unsaturated monomers.
  • nonionic monoethylenically unsaturated monomers include styrene, vinyl toluene, ethylene, vinyl acetate, vinyl chloride, vinylidene chloride, acrylonitrile, (meth)acrylamide, various (Ci-C2o)-alkyl or (C3-C2o)-alkenyl esters of (meth)acrylic acid, inclusive methyl acrylate (MA), methyl methacrylate (MMA), Ethyl (meth)acrylate, butyl (meth)acrylate, 2-hydroxyethyl (meth)acrylate, 2- ethylhexyl (meth)acrylate, benzyl (meth)acrylate, lauryl (meth)acrylate, oleyl (meth)acrylate, palmityl (meth) acrylate and stearyl (meth)acrylate.
  • acrylic esters such as MMA, EA, BA, and styrene are preferred monomers for polymerization and formation of the shell of the polymer particles.
  • Difunctional vinyl monomers such as divinylbenzene, allyl methacrylate, ethylene glycol dimethacrylate, 1,3-butanediol dimethacrylate, diethylene glycol dimethacrylate,
  • Trimethylolpropane trimethacrylate and the like can also be copolymerized to form a crosslinked outer shell as described in US Patent Application 2003-0176535 A1.
  • the polymer particles preferably comprise (meth)acrylonitrile copolymers, polyvinyl chloride, polyvinylidene chloride, polystyrene, styrene acrylate, styrene-(meth)acrylate copolymers, polyacrylonitrile, polyacrylic acid esters or mixtures of at least two of these.
  • the strength and durability of the polymer particles can be influenced by the crosslinking of polymer chains.
  • the scattering particles in particular the polymer particles, can be present in the form of closed polymer particles, open polymer particles and/or solid particles, which can each have a regular or irregular shape.
  • Hollow spherical polymer particles or polymer particles with a core/shell structure can be mentioned as examples of closed hollow body particles.
  • Ropaque HP-1055, Ropaque OP-96 and Ropaque TH-1000 can be mentioned as examples of hollow spherical polymer particles or polymer particles with a core/shell structure.
  • cup-shaped polymer particles in particular, can be mentioned as examples of polymer particles.
  • the shell these have the same materials as the closed polymer particles, in particular the closed hollow spherical polymer particles.
  • open polymer particles which can be mentioned are polymer particles in the form of a lattice cage, such as are described in WO 2021/062230 A1.
  • Polyethylene, polystyrene and cellulose ester can be mentioned as examples of solid particles.
  • the scattering particles mentioned above, in particular the polymer particles, can have a regular or irregular shape.
  • the polymer particles are spherical solid particles, preferably irregularly shaped, and/or spherical hollow particles, both preferably in the form of droplets.
  • These preferably include polystyrene, for example Plastic Pigment 756A from Trinseo LLC., and Plastic Pigment 772HS from Trinseo LLC., polyethylene, for example Chemipear 10 W401 from Mitsui Chemical Inc., to hollow spherical particles (HSP)/spherical hollow pigments, for example Ropaque TH-500EF from The Dow Chemical Co., modified polystyrene particles, e.g.
  • Joncryl 633 from BASF Corp., 1,2-diphenoxyethane (DPE), ethylene glycol m-tolyl ether (EGTE) and/or diphenylsulfone (DPS) . These can be used alone or in any mixture. These polymer particles preferably have an average particle size of 0.2 ⁇ m, 0.3 ⁇ m, 0.4 ⁇ m, 0.45 ⁇ m, 0.75 ⁇ m or 1.0 ⁇ m.
  • DPE 1,2-diphenoxyethane
  • EGTE ethylene glycol m-tolyl ether
  • DPS diphenylsulfone
  • the scattering particles are preferably present in the heat-sensitive layer in an amount of 20% to 60% by weight, preferably 30% to 50% by weight, based on the solid content of the heat-sensitive layer contain.
  • the heat-sensitive layer comprises at least one heat-sensitive material having a melting temperature in the range from 40 to 200°C, preferably from 80 to 140°C, and/or a Glass transition temperature in the range from 40 to 200°C, preferably from 80 to 140°C.
  • the heat-sensitive layer comprises at least one heat-sensitive material having an average particle size of 0.2 to 4.0 ⁇ m, preferably 0.5 to 2.0 ⁇ m.
  • the heat-sensitive material also preferably contributes to the opacity (covering power) of the heat-sensitive layer, for example by absorbing and/or also scattering light. It is assumed that the heat-sensitive material quickly melts locally as a result of the local effect of heat from the thermal print head of the direct thermal printer, resulting in a local "softening" of the polymer particles and thus a local reduction in opacity (reduction in opacity), so that the cover layer translucent and the underlying color layer becomes visible.
  • the heat-sensitive material can also be referred to as a sensitizer or a thermal solvent.
  • the heat-sensitive material comprises one or more fatty acids such as stearic acid, behenic acid or palmitic acid, one or more fatty acid amides such as stearamide, behenamide or palmitamide, an ethylene-bis-fatty acid amide such as N,N'-ethylene-bis-stearic acid amide or N, N'-ethylene-bis-oleic acid amide, one or more fatty acid alkanolamides, in particular hydroxymethylated fatty acid amides such as N-(flydroxymethyl)stearamide, N-hydroxymethyl palmitamide, hydroxyethyl stearamide, one or more waxes such as polyethylene wax, candelilla wax, carnauba wax or montan wax, one or more carboxylic acid esters such as dimethyl terephthalate, dibenzyl terephthalate, benzyl 4-benzyloxybenzoate, di-(4-methylbenzyl) oxalate, di-(4-chlor
  • Stearamide is preferred because it has an advantageous price/performance ratio.
  • the heat-sensitive material is preferably present in the heat-sensitive layer in an amount of from about 10 to about 80% by weight, more preferably from about 25 to about 60% by weight, based on the total solids content of the heat-sensitive layer.
  • lubricants or release agents can also be present in the heat-sensitive layer.
  • Such lubricants or release agents are present in particular when there is no protective layer or no further layer on the heat-sensitive layer.
  • These agents are preferably fatty acid metal salts, such as zinc stearate or calcium stearate, or else behenate salts, synthetic waxes, e.g. B. in the form of fatty acid amides, such as. B. stearic acid amide and behenic acid amide, fatty acid alkanolamides, such as. B. stearic acid methylolamide, paraffin waxes of different melting points, ester waxes of different molecular weights, ethylene waxes, propylene waxes of different flavors and / or natural waxes, such as. B. carnauba wax or montan wax. These can be used alone or in any mixture.
  • Zinc stearate is preferred because it has an advantageous price/performance ratio.
  • the lubricant or release agent is present in the heat-sensitive layer preferably in an amount of about 1 to about 10% by weight, more preferably in an amount of about 3 to about 6% by weight, based on the total solids content of the heat-sensitive layer shift before.
  • At least one binder is present in the heat-sensitive layer.
  • This is preferably water-soluble starches, starch derivatives, starch-based biolatices of the EcoSphere type, methyl cellulose, flydroxyethyl cellulose, Carboxymethyl cellulose, gelatin, casein, partially or fully saponified polyvinyl alcohols, chemically modified polyvinyl alcohols, ethylene-vinyl alcohol copolymers, sodium polyacrylates, styrene-maleic anhydride copolymers, ethylene-maleic anhydride copolymers, styrene-butadiene copolymers, acrylamide-(meth)acrylate copolymers, acrylamide -Acrylate-methacrylate terpolymers, polyacrylates, poly(meth)acrylic acid esters, acrylate-butadiene copolymers, polyvinyl acetates and/or acrylonitrile-butadiene copoly
  • Partially or partially hydrolyzed polyvinyl alcohols are preferred because they have an advantageous price/performance ratio.
  • the binder is preferably present in the heat-sensitive layer in an amount of from 1 to 30% by weight, preferably from 5 to 20% by weight, based on the total solids content of the heat-sensitive layer.
  • the binder is preferably present in crosslinked form in the heat-sensitive layer, the optimum degree of crosslinking of the binder occurring in the drying step of the coating process in the presence of a crosslinking agent (crosslinking agent).
  • crosslinking agent crosslinking agent
  • the crosslinking agents can be polyvalent aldehydes such as glyoxal, dialdehyde starch, glutaraldehyde, possibly mixed with boron salts (borax), salts or esters of glyoxylic acid, crosslinking agents based on ammonium zirconium carbonate, polyamidoamine-epichlorohydrin Flarze (PAE-Flarze), adipic acid dihydrazide (AFID), boric acid or its salts, polyamines, epoxy resins, formaldehyde oligomers, cyclic flame substances, methylolurea, melamine-formaldehyde oligomers, etc. These can be used alone or in any mixture.
  • PAE-Flarze polyamidoamine-epichlorohydrin Flarze
  • AFID adipic acid dihydrazide
  • boric acid or its salts polyamines, epoxy resins, formaldehyde oligomers,
  • Ammonium zirconium carbonate and polyamidoamine-epichlorohydrin resin are particularly preferred for reasons of food conformity.
  • Self-crosslinking binders such as specially modified polyvinyl alcohols or acrylates, enable crosslinking without any crosslinking agents thanks to the reactive, crosslinkable groups that are already built into the binder polymer.
  • the crosslinking agent is preferably in an amount of about 0.01 to about 25.0% by weight, particularly preferably in an amount of about 0.05 to about 15.0% by weight, based on the total solids content of the color layer. before.
  • the heat-sensitive layer contains pigments. These pigments are preferably different from the pigments of the color layer.
  • the use of these has the advantage, among other things, that they can fix the chemical melt produced in the thermal printing process on their surface.
  • the surface whiteness and opacity of the heat-sensitive layer and its printability with conventional printing inks can also be controlled via pigments.
  • pigments are inorganic pigments of both synthetic and natural origin, preferably clays, precipitated or natural calcium carbonates, aluminum oxides, aluminum hydroxides, silicic acids, precipitated and pyrogenic silicic acids (e.g. Aerodisp types), diatomaceous earths, magnesium carbonates, talc, kaolin, Titanium oxide, bentonite, but also organic pigments such as flea pigments with a styrene/acrylate copolymer wall or flan/formaldehyde condensation polymers. These can be used alone or in any mixture.
  • inorganic pigments of both synthetic and natural origin preferably clays, precipitated or natural calcium carbonates, aluminum oxides, aluminum hydroxides, silicic acids, precipitated and pyrogenic silicic acids (e.g. Aerodisp types), diatomaceous earths, magnesium carbonates, talc, kaolin, Titanium oxide, bentonite, but also organic pigments such as flea pigments with a styrene/acrylate copoly
  • Calcium carbonates, aluminum hydroxides and pyrogenic silicic acids are preferred, since they enable the heat-sensitive recording materials to have particularly advantageous performance properties with regard to their subsequent printability with commercially available printing inks.
  • the pigments are preferably present in the heat-sensitive layer in an amount of from about 2 to about 50% by weight, more preferably in an amount of from about 5 to about 20% by weight, based on the total solids content of the heat-sensitive layer.
  • the heat-sensitive layer can also contain carbon black components and/or dyes/color pigments.
  • optical brighteners can be incorporated into the heat-sensitive color-forming layer. These are preferably stilbenes.
  • the heat-sensitive layer may further contain inorganic oil-absorbing white pigments.
  • inorganic oil-absorbing white pigments examples include natural or calcined kaolin, silica, bentonite, calcium carbonate, aluminum hydroxide, particularly boehmite, and mixtures thereof.
  • the inorganic oil-absorbing white pigments are preferably present in the heat-sensitive layer in an amount of about 2 to about 50% by weight, more preferably in an amount of about 5 to about 20% by weight, based on the total solids content of the heat-sensitive layer .
  • rheological aids such as e.g. As thickeners and / or surfactants to add.
  • the other components are each preferably present in customary amounts known to those skilled in the art.
  • the heat-sensitive layer preferably has a basis weight of 1 to 8 g/m 2 , in particular 2 to 6 g/m 2 .
  • the heat-sensitive layer preferably has a thickness of 1 to 10 ⁇ m, in particular 2 to 8 ⁇ m.
  • the heat-sensitive recording material is preferably characterized in that there is an insulating layer between the web-shaped carrier material and the colored layer.
  • the heat-sensitive recording material is preferably characterized in that the colored layer simultaneously represents a colored layer and an insulating layer.
  • Such an insulating layer or a colored layer which is both a colored layer and an insulating layer, causes a reduction in heat conduction through the heat-sensitive recording material.
  • the local application of heat using a direct thermal printer is more efficient and a higher thermal printer speed is possible.
  • the top layer becomes translucent more quickly due to the amount of heat introduced and the sensitivity is thus improved.
  • the insulating layer or the colored layer which is both a colored layer and an insulating layer, preferably has a Bekk smoothness of greater than 50 s, particularly preferably greater than 100 s and very particularly preferably from 100 to 250 s.
  • the insulating layer or the colored layer which is both a colored layer and an insulating layer, preferably comprises a heat-insulating material.
  • the heat-sensitive recording material having an insulating layer or a colored layer which is also an insulating layer has a lower thermal conductivity than a heat-sensitive recording material which does not have an insulating layer or a colored layer which is also an insulating layer.
  • the thermally insulating material preferably comprises kaolin, more preferably calcined kaolin and mixtures thereof.
  • the heat-insulating material can also comprise fleaball pigments, in particular fleaball pigments comprising styrene-acrylate copolymer.
  • fleaball pigments in particular fleaball pigments comprising styrene-acrylate copolymer.
  • These hollow sphere pigments preferably have a glass transition temperature of 40 to 80° C. and/or an average particle size of 0.1 to 2.5 ⁇ m.
  • the heat-insulating material is preferably present in the insulating layer in an amount of about 20 to about 80% by weight, more preferably in an amount of about 40 to about 60% by weight, based on the total solids content of the insulating layer.
  • the heat-insulating material is preferably present in an amount of about 30 to about 70% by weight, more preferably in an amount of about 40 to about 60% by weight, based on the total solids content of the paint layer, which is at the same time a paint layer and an insulating layer, in this.
  • the binder is preferably present in crosslinked form in the insulating layer and/or color layer, with the optimal degree of crosslinking of the binder being established in the drying step of the coating process in the presence of a crosslinking agent (crosslinking agent).
  • crosslinking agent crosslinking agent
  • the crosslinking agents can be polyvalent aldehydes such as glyoxal, dialdehyde starch, glutaraldehyde, possibly mixed with boron salts (borax), salts or esters of glyoxylic acid, crosslinking agents based on ammonium zirconium carbonate, polyamidoamine-epichlorohydrin Resins (PAE resins), adipic acid dihydrazide (AHD), boric acid or its salts, polyamines, epoxy resins, formaldehyde oligomers, cyclic ureas, methylolurea, melamine formaldehyde oligomers, etc. m. act. These can be used alone or in any mixture.
  • PAE resins polyamidoamine-epichlorohydrin Resins
  • AHD adipic acid dihydrazide
  • boric acid or its salts polyamines, epoxy resins, formaldehyde oligomers, cycl
  • Ammonium zirconium carbonate and polyamidoamine-epichlorohydrin (PAE) resins are particularly preferred for reasons of food conformity.
  • Self-crosslinking binders such as specially modified polyvinyl alcohols or acrylates, enable crosslinking without any crosslinking agents thanks to the reactive, crosslinkable groups that are already built into the binder polymer.
  • the crosslinking agent is preferably in an amount of about 0.01 to about 25.0% by weight, particularly preferably in an amount of about 0.05 to about 15.0% by weight, based on the total solids content of the insulating or color layer, before.
  • the insulating layer preferably has a basis weight of 1 to 5 g/m 2 , in particular 2 to 4 g/m 2 .
  • the insulating layer preferably has a thickness of 1 to 10 gm, in particular 2 to 8 gm.
  • the colored layer which is both a colored layer and an insulating layer, preferably has a basis weight of 1 to 10 g/m 2 , in particular 3 to 8 g/m 2 .
  • the colored layer which is both a colored layer and an insulating layer, preferably has a thickness of 1 to 12 gm, in particular 4 to 8 gm.
  • the heat-sensitive recording material is preferably characterized in that directly on at least one side of the web-shaped carrier material, preferably directly on both sides of the web-shaped carrier material, a layer comprising starch (starch coating) and/or modifications thereof (modified starches), is available.
  • the starch coat is preferably applied in an amount of 0.1 to 3, particularly preferably 0.2 to 1.5 g/m 2 .
  • a line of starch on the side of the web-shaped carrier material on which the color layer is present has the advantage that the web-shaped carrier material is closed and the flattening of the color layer is improved and penetration of the color layer into the web-shaped carrier material can be reduced or prevented.
  • a line of starch on the side of the web-shaped carrier material on which the color layer is not present has the advantage that the color layer can be reduced or prevented from striking through the web-shaped carrier material.
  • the layer comprising starch preferably has a Bekk smoothness greater than 20 s, more preferably greater than 50 s, and most preferably from 50 to 200 s.
  • the heat-sensitive recording material is preferably characterized in that a protective layer is provided on the heat-sensitive layer.
  • the protective layer preferably has a Bekk smoothness of greater than 200 s, preferably greater than 400 s and very particularly preferably from 400 s to 1500 s. Most preferred is a Bekk smoothness of 400 to 1300 s.
  • This protective layer preferably comprises at least one binder and at least one pigment, particularly preferably an inorganic pigment.
  • Suitable binders include water-soluble starches, starch derivatives, starch-based biolatices of the EcoSphere type, methyl cellulose, hydroxyethyl cellulose, carboxymethyl cellulose, partially or fully hydrolyzed polyvinyl alcohols, chemically modified polyvinyl alcohols such as acetoacetyl, diacetone, carboxy, silanol-modified polyvinyl alcohols, or styrene maleic anhydride copolymers, Styrene-butadiene copolymers, acrylamide (meth)acrylate copolymers, acrylamide-acrylate-methacrylate terpolymers, polyacrylates, poly(meth)acrylic esters, acrylate-butadiene copolymers, polyvinyl acetates and/or acrylonitrile-butadiene copolymers. These can be used alone or in any mixture.
  • Suitable inorganic pigments include inorganic pigments of both synthetic and natural origin, preferably clays, precipitated or natural calcium carbonates, aluminum oxides, aluminum hydroxides, silicic acids, precipitated and pyrogenic silicic acids (e.g. Aerodisp types), diatomaceous earths, magnesium carbonates, talc, kaolin, Titanium oxide, bentonite but also organic pigments such as hollow pigments with a styrene / acrylate copolymer wall or urea/formaldehyde condensation polymers. These can be used alone or in any mixture.
  • inorganic pigments of both synthetic and natural origin, preferably clays, precipitated or natural calcium carbonates, aluminum oxides, aluminum hydroxides, silicic acids, precipitated and pyrogenic silicic acids (e.g. Aerodisp types), diatomaceous earths, magnesium carbonates, talc, kaolin, Titanium oxide, bentonite but also organic pigments such as hollow pigments with a styrene
  • Suitable organic pigments include hollow pigments having a styrene/acrylate copolymer wall or urea/formaldehyde condensation polymers. These can be used alone or in any mixture.
  • the binder is preferably present in the protective layer in an amount of from about 40 to about 90% by weight, more preferably in an amount of from about 50 to about 80% by weight, based on the total solids content of the protective layer.
  • the pigment is preferably present in the protective layer in an amount of from about 5 to about 40% by weight, more preferably in an amount of from about 10 to about 30% by weight, based on the total solids content of the protective layer.
  • the binder is preferably present in crosslinked form in the protective layer, the optimum degree of crosslinking of the binder occurring in the drying step of the coating process in the presence of a crosslinking agent (crosslinking agent).
  • crosslinking agent crosslinking agent
  • the crosslinking agents can be polyvalent aldehydes such as glyoxal, dialdehyde starch, glutaraldehyde, possibly mixed with boron salts (borax), salts or esters of glyoxylic acid, crosslinking agents based on ammonium zirconium carbonate, polyamidoamine-epichlorohydrin Resins (PAE resins), adipic acid dihydrazide (AHD), boric acid or its salts, polyamines, epoxy resins, formaldehyde oligomers, cyclic ureas, methylolurea, melamine formaldehyde oligomers, etc. m. act. These can be used alone or in any mixture.
  • PAE resins polyamidoamine-epichlorohydrin Resins
  • AHD adipic acid dihydrazide
  • boric acid or its salts polyamines, epoxy resins, formaldehyde oligomers, cycl
  • Ammonium zirconium carbonate and polyamidoamine-epichlorohydrin (PAE) resins are particularly preferred for reasons of food conformity.
  • Self-crosslinking binders such as specially modified polyvinyl alcohols or acrylates, enable crosslinking without any crosslinking agents thanks to the reactive, crosslinkable groups that are already built into the binder polymer.
  • the crosslinker is preferably present in an amount of from about 0.01 to about 25.0, more preferably in an amount of from about 0.05 to about 15.0, based on the total solids content of the color coat.
  • the crosslinker is preferably present in an amount of from about 0.01% to about 25.0% by weight. more preferably in an amount of from about 0.05 to about 15.0% by weight. based on the total solids content of the protective layer.
  • the protective layer also preferably comprises at least one lubricant or at least one release agent.
  • These agents are preferably fatty acid metal salts, such as zinc stearate or calcium stearate, or else behenate salts, synthetic waxes, e.g. B. in the form of fatty acid amides, such as. B. stearic acid amide and behenic acid amide, fatty acid alkanolamides, such as. B. stearic acid methylolamide, paraffin waxes of different melting points, ester waxes of different molecular weights, ethylene waxes, propylene waxes of different flavors and / or natural waxes, such as. B. carnauba wax or montan wax.
  • synthetic waxes e.g. B. in the form of fatty acid amides, such as. B. stearic acid amide and behenic acid amide, fatty acid alkanolamides, such as. B. stearic acid methylolamide, paraffin waxes of different melting points, ester waxes of different mole
  • the lubricant or release agent is preferably present in an amount of from about 1% to about 30% by weight, more preferably in an amount of from about 2% to about 20% by weight, based on the total solids content of the protective layer.
  • optical brighteners preferably stilbenes
  • the protective layer In order to control the surface whiteness of the heat-sensitive recording material according to the invention, optical brighteners, preferably stilbenes, can be incorporated into the protective layer.
  • the protective layer preferably has a basis weight of 0.3 to 5.0 g/m 2 , in particular 1.0 to 3.0 g/m 2 .
  • the protective layer preferably has a thickness of 0.3 to 6.0 ⁇ m, in particular 0.5 to 2.0 ⁇ m.
  • the use of a protective layer has the advantage that the recording material is better protected from external influences.
  • the heat-sensitive recording material is preferably characterized in that an adhesive layer is present on the side of the carrier material in web form on which the color layer is not located.
  • the adhesive layer preferably comprises at least one adhesive, preferably a heat-activatable adhesive, in particular a pressure-sensitive adhesive.
  • the adhesive preferably the heat-activatable adhesive and in particular the pressure-sensitive adhesive, is particularly preferably an adhesive based on rubber and/or acrylate.
  • the adhesive layer preferably has a weight per unit area of from 1 to 40 g/m 2 , in particular from 12 to 25 g/m 2 .
  • the heat-sensitive recording material is preferably characterized in that a siliconized separating layer is present on the heat-sensitive layer.
  • siliconized release layer and "siliconized layer” are to be understood synonymously in the sense of "cover with a layer of silicone”. These layers preferably consist of silicone or comprise at least 90% by weight, preferably at least 95% by weight and particularly preferably at least 99 wt.
  • the siliconized separating layer preferably has a Bekk smoothness of greater than 400 s, particularly preferably greater than 800 s and very particularly preferably from 800 to 2000 s. If a protective layer, in particular as defined above, is present on the heat-sensitive layer, the siliconized release layer is preferably present on this protective layer.
  • the heat-sensitive recording material is preferably characterized in that a diffusion layer is formed between the siliconized layer and the underlying layer, preferably the heat-sensitive layer.
  • This diffusion layer is preferably formed by diffusing at least parts of the siliconized separating layer over a large area into the upper region of the underlying layer, with preferably 5 to 50% by weight, particularly preferably 6 to 45% by weight and in particular 7 to 40% by weight of the siliconized separating layer diffuse into the upper area of the underlying layer.
  • a diffusion layer is described, for example, in EP 3 221 153 A1.
  • a siliconized release layer is preferably present when an adhesive layer is also present as described above.
  • the presence of a siliconized release layer on the heat-sensitive layer and an adhesive layer on the web-shaped base material on the side where the ink layer is not located has the advantage that the heat-sensitive recording material can be used as a linerless heat-sensitive recording material.
  • Carrierless means that the (self-adhesive) heat-sensitive recording material according to the invention is not applied to a carrier material but is wound onto itself. This has the advantage that the production costs can be further reduced, more running meters per roll can be realized, no disposal effort for the disposal of the liner is necessary and more labels can be transported per specific loading space volume.
  • At least one platelet-shaped pigment is contained in the heat-sensitive layer or in the layer that lies directly below the siliconized separating layer.
  • the at least one platelet-shaped pigment is preferably selected from the group consisting of kaolin, Al(OH) 3 and/or talc.
  • kaolin is particularly preferred.
  • coated kaolin is very particularly preferred. Such is available, for example, under the trade name Kaolin ASP 109 (BASF, Germany).
  • the main advantage of using these platelet-shaped pigments, in particular kaolin, is that the heat-sensitive layer or the layer that lies directly below the siliconized separating layer can be siliconized very easily.
  • Platelet-shaped pigment is understood as meaning a pigment in which the ratio of diameter to thickness is about 7 to 40:1, preferably about 15 to 30:1.
  • the particle size of the platelet-shaped pigment is preferably adjusted in such a way that at least about 70%, preferably at least about 85%, of the particles have a particle size of about ⁇ 2 ⁇ m (Sedigraph).
  • the pH of the flaky pigment in aqueous solution is preferably 6 to 8.
  • the at least one platelet-shaped pigment is in the heat-sensitive color-forming layer or in the layer that lies directly below the siliconized release layer, preferably in an amount of about 5 to about 60% by weight, particularly preferably in an amount of about 15 to about 55% by weight, based on the total solids content of the respective layer.
  • the heat-sensitive recording material is preferably characterized in that the siliconized separating layer comprises at least one siloxane, preferably a poly(organo)siloxane, in particular an acrylic poly(organo)siloxane.
  • the siliconized release layer comprises a mixture of at least two siloxanes.
  • a mixture of at least two acrylic poly(organo)siloxanes is preferred.
  • the heat-sensitive recording material is preferably characterized in that the siliconized separating layer contains at least one polysilicon acrylate, which was preferably formed by condensation of at least one silicon acrylate.
  • the siliconized release layer is preferably anhydrous. It is also preferred that the siliconized separating layer does not contain any Pt catalysts.
  • the siliconized separating layer preferably contains an initiator, particularly preferably a photoinitiator. This is used for radical curing of the silicone.
  • the siliconized separating layer can preferably contain other additives, such as matting agents and/or adhesion additives.
  • the siliconized separating layer preferably has a basis weight of 0.3 to 5.0 g/m 2 , in particular 1.0 to 3.0 g/m 2 .
  • the siliconized separating layer preferably has a thickness of 0.3 to 6.0 ⁇ m, in particular 0.5 to 2.0 ⁇ m.
  • the heat-sensitive recording material is preferably characterized in that the heat-sensitive recording material has a residual moisture content of 2 to 14%, preferably 2 to 12% and very particularly preferably 3 to 10%. A residual moisture content of 3 to 8% is most preferred.
  • the residual moisture can be determined as described in connection with the examples.
  • the opacity in the heat-sensitive layer is not only due to the scattering particles, especially the polymer particles themselves, but also by the air trapped between the scattering particles, in particular the polymer particles (open porosity). Moisture entering these "pores” displaces air and reduces opacity. This can result in a grayer material, which is not preferred.
  • the heat-sensitive recording material is preferably characterized in that the heat-sensitive recording material has a surface whiteness of 35 to 60%, in particular 45 to 50%.
  • Residual moisture in the specified range has the advantage that, after printing, there is a high relative print contrast with advantageous application properties, such as better readability.
  • the surface whiteness (paper whiteness) can be determined according to ISO 2470-2 (2008) with an Elrepho 3000 spectrophotometer.
  • the heat-sensitive recording material is preferably characterized in that the contrast of places where the heat-sensitive layer has become translucent due to the local effect of heat to places where the heat-sensitive layer has not become translucent due to the local effect of heat , 40 to 80%, in particular from 50 to 70%.
  • This contrast can be calculated by taking the difference between the optical density of the background and the typeface.
  • the optical density (n.d.) is measured, for example, using a densitometer.
  • All of the layers mentioned above can be formed in one or more layers.
  • the heat-sensitive recording material according to the invention can be obtained using known production methods.
  • the present invention also relates to a manufacturing method for a heat-sensitive recording material as described above. It is preferred to obtain the heat-sensitive recording material according to the invention using a process in which (aqueous) suspensions, comprising the starting materials of the individual layers, are applied successively to the web-shaped carrier material, the (aqueous) application suspensions having a solids content of 8 to 50% by weight. %, preferably from 10 to 40% by weight, and are applied using the curtain coating method at an operating speed of the coater of at least 200 m/min.
  • This method is particularly advantageous from an economic point of view and due to the uniform application over the web-shaped carrier material.
  • Embodiments of the method according to the invention are also conceivable, in which a “double curtain” is used. This means that two successive layers are applied directly one after the other. The application is carried out so immediately after one another that the first applied layer has not yet dried before the next layer is applied. The two layers are therefore preferably applied “wet on wet”.
  • the aqueous, deaerated application suspension has a viscosity of about 100 to about 1000 mPas (Brookfield, 100 rpm, 20° C.). If the value falls below about 100 mPas or the value of about 1000 mPas is exceeded, this leads to poor runnability of the coating composition on the coating unit.
  • the viscosity of the aqueous, deaerated application suspension is particularly preferably about 200 to about 500 mPas.
  • the viscosities of successive coating compositions in the double curtain should decrease from bottom to top. Improperly adjusted coatings increase the likelihood of heeling at the curtain impact point, as well as the occurrence of "wetting failures".
  • the surface tension of the aqueous application suspension can be reduced to about 25 to about 70 mN/m, preferably to about 35 to about 60 mN/m (measured based on the standard for bubble pressure tensiometry (ASTM D 3825-90) , as described below). Better control over the coating process is obtained by determining the dynamic surface tension of the coating color and adjusting it by selecting the appropriate surfactant and determining the required amount of surfactant.
  • the dynamic surface tension is measured using a bubble pressure tensiometer.
  • the maximum internal pressure of a gas bubble that is formed in a liquid via a capillary is measured.
  • the internal pressure p of a spherical gas bubble (Laplace pressure) depends on the Young-Laplace equation depends on the radius of curvature r and the surface tension o:
  • the radius of the capillary is determined using a reference measurement made with a liquid of known surface tension, usually water. If the radius is then known, the surface tension can be calculated from the maximum pressure pmax. Since the capillary is immersed in the liquid, the hydrostatic pressure pO, which results from the immersion depth and the density of the liquid, must be subtracted from the measured pressure (this is done automatically with modern measuring instruments). This results in the following formula for the bubble pressure method:
  • the measured value corresponds to the surface tension at a specific surface age, the time from the start of bubble formation to the occurrence of the pressure maximum.
  • the generation speed of the bubbles By varying the generation speed of the bubbles, the dependence of the surface tension on the surface age can be recorded, resulting in a curve in which the surface tension is plotted against time.
  • the individual layers can be formed on-line or off-line in a separate coating process.
  • the following method steps are preferably carried out.
  • the web-shaped carrier material is preferably calendered in a first cylinder.
  • This one-sided or two-sided high level of smoothness which is produced by this process technology, already gives the web-shaped carrier material an advantage. Additional calendering by a downstream calender, preferably before a first coating device, can further improve the smoothness and/or is used for good profiling.
  • a starch coat as defined above, is applied, this is preferably done using a film press before the color layer is applied using a blade coater.
  • the thickness on the back is particularly advantageous in order to prevent the blade coater from penetrating the coating color.
  • the insulating layer if present, is applied in the same way.
  • the siliconized layer if present, is also applied in the same way.
  • the protective layer can also be printed on.
  • Protective layers which can be cured by means of actinic radiation are particularly suitable in terms of processing technology and with regard to their technological properties.
  • actinic radiation means UV or ionizing radiation such as electron beams.
  • the heat-sensitive layer is preferably applied by means of curtain coating, as described above.
  • LAS dampening unit LAS Liquid Applicator System
  • a film of water is applied to the less coated side and then dried. As a result, the so-called flatness is obtained again. If the water film is applied, the surface will deteriorate somewhat.
  • a preferred option for protecting the surface would be a steam humidifier.
  • steam is blown on instead of water applied.
  • the surface is not damaged in this way. This is very well suited for applications where the highest surface quality must be achieved.
  • Another possibility would be a spray dampener, in which a water mist is applied.
  • All of the layers mentioned above can be formed in one or more layers.
  • the present invention also relates to a heat-sensitive recording material which can be obtained using the process described above.
  • the present invention also relates to the use of a heat-sensitive recording material as described above as a roll of receipts, as a roll of adhesive labels, also in the cold and deep-freeze sector, and as a roll of tickets.
  • a heat-sensitive recording material as described above as a roll of receipts, as a roll of adhesive labels, also in the cold and deep-freeze sector, and as a roll of tickets.
  • these have a functional side and/or back (with color, multicolored, black/grey) and can be pre-printed.
  • the rolls mentioned are preferably available in typical widths and lengths.
  • the present invention relates to a heat-sensitive recording material, comprising a color layer on one side of the web-like carrier material and a heat-sensitive layer on the color layer, so that the color layer is at least partially covered, the heat-sensitive layer being designed in such a way that it is The effect of heat becomes translucent so that the color layer underneath becomes visible, which is characterized in that the heat-sensitive recording material has a residual moisture content of 2 to 14%, preferably 2 to 12% and particularly preferably 3 to 10%. A residual moisture content of 3 to 8% is most preferred.
  • Residual moisture in the specified range has the advantage that, after printing, there is a high relative print contrast with advantageous application properties, such as better readability.
  • the residual moisture can be determined as described in connection with the examples.
  • the opacity in the heat-sensitive layer is generated not only by the scattering particles, in particular the polymer particles, but also by the air trapped between the scattering particles, in particular the polymer particles (open porosity). Moisture entering these "pores” displaces air and reduces opacity. This can result in a grayer material, which is not preferred.
  • the heat-sensitive recording material is preferably characterized in that the heat-sensitive recording material has a surface whiteness of 35 to 60%, in particular 45 to 50%.
  • the surface whiteness (paper whiteness) can be determined according to ISO 2470-2 (2008) with an Elrepho 3000 spectrophotometer.
  • the heat-sensitive recording material is preferably characterized in that the contrast between places where the heat-sensitive layer has become translucent due to the local effect of heat and places where the heat-sensitive layer has not become translucent due to the local effect of heat is from 40 to 80%, in particular from 50 to 70%.
  • This contrast can be calculated by taking the difference between the optical density of the background and the typeface.
  • the optical density (n.d.) is measured, for example, using a densitometer.
  • the carrier material preferably has a Bekk smoothness of greater than 20 s, particularly preferably greater than 30 s and very particularly preferably greater than 50 s.
  • the colored layer preferably has a Bekk smoothness of greater than 50 s, more preferably greater than 100 s and very particularly preferably greater than 150 s.
  • the heat-sensitive layer preferably has a Bekk smoothness of greater than 100 s, particularly preferably greater than 150 s.
  • the support material preferably has a Bekk smoothness of 20 to 400 s, particularly preferably 30 to 300 s and very particularly preferably 50 to 200 s on the side to which the colored layer is applied. Most preferred is a Bekk smoothness of 50 to 150 s.
  • the color layer preferably has a Bekk smoothness of 50 to 400 s, more preferably 100 to 250 s, and most preferably 150 to 250 s on the side on which the heat-sensitive layer is coated.
  • a heat-sensitive recording material has the advantage of high dynamic sensitivity.
  • each layer applied to the web-shaped carrier material has a Bekk smoothness on its upper side, i.e. on the side on which the web-shaped carrier material does not lie, which is at least as great as or greater than that of the respective underlying layer.
  • each layer applied to the substrate sheet has a Bekk smoothness of at least 5% (percentage increase) on its top surface, i.e., the side not bearing the substrate sheet, over the underlying layer.
  • each layer applied to the substrate sheet has a Bekk smoothness of at least 5% (absolute increase) on its upper side, i.e., on the side on which the substrate sheet does not lie, compared to the underlying layer.
  • the web-shaped carrier material is not limited.
  • the carrier material in web form comprises paper, synthetic paper and/or a plastic film.
  • the carrier material preferably has a basis weight of 30 to 100 g/m 2 , in particular 40 to 80 g/m 2 .
  • the carrier material in web form of the heat-sensitive recording material according to the invention preferably comprises at least one black or colored side, which is achieved by applying a colored layer.
  • the term "colored side” is understood to mean that the side has a color other than white or black.
  • the heat-sensitive recording material comprises at least one side that is colored in such a way that it is not white.
  • the at least one black or colored side has several different colors also in combination with the color black.
  • the at least one colored layer on one side of the web-shaped carrier material is preferably characterized in that the colored layer comprises at least one pigment and/or one dye and preferably a binder.
  • the pigments and/or dyes include various organic and inorganic pigments, dyes and/or carbon black. These can be used alone or in any mixture.
  • the pigment, the dye and/or the carbon black are each preferably contained in the color layer in an amount of 2 to 50% by weight, particularly preferably 10 to 35% by weight, based on the total solid content of the color layer.
  • the binder is preferably contained in the color layer in an amount of 2 to 40% by weight, particularly preferably 10 to 30% by weight, based on the total solids content of the color layer.
  • the colored layer preferably has a basis weight of 1 to 10 g/m 2 , in particular 3 to 8 g/m 2 .
  • the colored layer preferably has a thickness of 1 to 10 ⁇ m, in particular 2 to 8 ⁇ m.
  • the heat-sensitive recording material is characterized in that the heat-sensitive layer comprises at least one scattering particle, in particular a polymer particle, with a glass transition temperature of -55 to 130°C, preferably of 40 to 80°C.
  • the heat-sensitive recording material is characterized in that the heat-sensitive layer comprises at least one scattering particle, in particular a polymer particle, with a core/shell structure, the scattering particles, in particular a polymer particle, being selected from the group consisting of ( i)
  • Scattering particle in particular a polymer particle, with an outer polymer shell with a glass transition temperature of 40 °C to 80 °C and (ii) scattering particle, in particular a polymer particle, with an inner shell with a glass transition temperature of 40 °C to 130 °C and an outer shell having a glass transition temperature of -55°C to 50°C, the glass transition temperature of the outer shell preferably being lower than that of the inner shell.
  • the heat-sensitive recording material is characterized in that the heat-sensitive layer contains at least one scattering particle, in particular a polymer particle, with a melting point of less than 250°C, preferably from 0°C to 250°C.
  • the heat-sensitive recording material is characterized in that the heat-sensitive layer contains at least one scattering particle, in particular a polymer particle, with an average particle size in the range from 0.1 to 2.5 ⁇ m, preferably from 0.2 to 0.8 ⁇ m , includes.
  • the heat-sensitive recording material is characterized in that the heat-sensitive layer contains at least one scattering particle, in particular a polymer particle, with a glass transition temperature of from -55 to 130° C., preferably from 40 to 80° C. and having an average particle size ranging from 0.1 to 2.5 gm, preferably from 0.2 to 0.8 gm.
  • the heat-sensitive recording material is characterized in that the heat-sensitive layer comprises at least one scattering particle, in particular a polymer particle, with a core/shell structure, the scattering particles, in particular a polymer particle, being selected from the group consisting of ( i)
  • Scattering particle in particular a polymer particle, having an outer shell with a glass transition temperature of 40°C to 80°C and (ii) scattering particle, in particular a polymer particle, having an inner shell with a glass transition temperature of 40°C to 130°C and an outer one shell with a glass transition temperature of -55 °C to 50 °C, the glass transition temperature of the outer shell being preferably lower than that of the inner shell, and having an average particle size in the range of 0.1 to 2.5 ⁇ m, preferably 0, 2 to 0.8 pm.
  • the heat-sensitive recording material is characterized in that the heat-sensitive layer contains at least one scattering particle, in particular a polymer particle, with a melting point of less than 250° C., preferably from 0° C. to 250° C., and with an average particle size in the range from from 0.1 to 2.5 pm, preferably from 0.2 to 0.8 pm.
  • the heat-sensitive layer contains at least one scattering particle, in particular a polymer particle, with a melting point of less than 250° C., preferably from 0° C. to 250° C., and with an average particle size in the range from from 0.1 to 2.5 pm, preferably from 0.2 to 0.8 pm.
  • a glass transition temperature or a melting point of less than 250° C. was recognized as advantageous. No direct thermal printing is possible above temperatures of 250 °C, since the temperature-time window is outside the printer specification.
  • An average particle size in the range from 0.1 to 2.5 ⁇ m is advantageous since particles of this size scatter visible light and the colored layer is thus covered as far as possible.
  • the average particle size can be determined using a Beckman Coulter device (laser diffraction, Fraunhofer method).
  • the scattering particles, in particular the polymer particles are preferably crystalline, partially crystalline and/or amorphous.
  • the glass transition temperatures mentioned above relate to partially crystalline or amorphous scattering particles, in particular polymer particles.
  • the melting temperatures relate to crystalline scattering particles, in particular polymer particles, or to the crystalline portion of the scattering particles, in particular polymer particles.
  • the primary property of the scattering particles is the scattering of light in the visible range of light.
  • the secondary property is sensitivity to heat.
  • the polymer particles preferably comprise thermoplastic polymers.
  • the polymer particles preferably comprise polymers resulting from the polymerization of one or more monomers selected from the group consisting of acrylonitrile, styrene, butadiene, benzyl methacrylate, phenyl methacrylate, ethyl methacrylate, divinylbenzene, 2-hydroxyethyl methacrylate, cyclohexyl methacrylate, 2-methylstyrene, 3-methylstyrene, 4 -methylstyrene, alpha-methylstyrene, beta-methylstyrene, acrylamide, methacrylamide, methacrylonitrile, hydroxypropyl methacrylate, methoxystyrene, N-acrylylglycine amide and/or N-methacrylylglycine amide and/or their derivatives are selected.
  • the polymer particles can be polymerized using a variety of ethylenically unsaturated monomers.
  • nonionic monoethylenically unsaturated monomers include styrene, vinyl toluene, ethylene, vinyl acetate, vinyl chloride, vinylidene chloride, acrylonitrile, (meth)acrylamide, various (Ci-C2o)-alkyl or (C3-C2o)-alkenyl esters of (meth)acrylic acid, inclusive Methyl acrylate (MA), methyl methacrylate (MMA), ethyl (meth)acrylate, butyl (meth)acrylate, 2-hydroxyethyl (meth)acrylate, 2- ethylhexyl (meth)acrylate, benzyl (meth)acrylate, lauryl (meth)acrylate, oleyl (meth)acrylate, palmityl (meth)acrylate and stearyl (meth)acryl
  • acrylic esters such as MMA, EA, BA, and styrene are preferred monomers for polymerization and formation of the shell of the polymer particles.
  • Difunctional vinyl monomers such as divinylbenzene, allyl methacrylate, ethylene glycol dimethacrylate, 1,3-butanediol dimethacrylate, diethylene glycol dimethacrylate, Trimethylolpropane trimethacrylate and the like can also be copolymerized to form a crosslinked outer shell as described in US Patent Application 2003-0176535 A1.
  • the polymer particles preferably comprise (meth)acrylonitrile copolymers, polyvinyl chloride, polyvinylidene chloride, polystyrene, styrene acrylate, styrene-(meth)acrylate copolymers, polyacrylonitrile, polyacrylic acid esters or mixtures of at least two of these.
  • the strength and durability of the polymer particles can be influenced by the crosslinking of polymer chains.
  • the polymer particles can be in the form of closed polymer particles, open polymer particles and/or solid particles, each of which can have a regular or irregular shape.
  • Hollow spherical polymer particles or polymer particles with a core/shell structure can be mentioned in particular as examples of closed hollow body particles.
  • Ropaque HP-1055, Ropaque OP-96 and Ropaque TH-1000 can be mentioned as examples of hollow spherical polymer particles or polymer particles with a core/shell structure.
  • cup-shaped polymer particles in particular, can be mentioned as examples of open polymer particles.
  • the shell these have the same materials as the closed polymer particles, in particular the closed hollow spherical polymer particles.
  • open polymer particles which can be mentioned are polymer particles in the form of lattice cages, as are described in WO 2021/062230 A1.
  • Polyethylene, polystyrene and cellulose esters can be mentioned as examples of solid particles.
  • the scattering particles mentioned above in particular a polymer particle, can have a regular or irregular shape.
  • the polymer particles are spherical solid particles, preferably irregularly shaped, and/or spherical hollow particles, both preferably in the form of droplets.
  • These preferably include polystyrene, for example Plastic Pigment 756A from Trinseo LLC., and Plastic Pigment 772HS from Trinseo LLC., polyethylene, for example Chemipear 10 W401 from Mitsui Chemical Inc., to hollow spherical particles (HSP)/spherical hollow pigments, for example Ropaque TH-500EF from The Dow Chemical Co., modified polystyrene particles, e.g.
  • Joncryl 633 from BASF Corp., 1,2-diphenoxyethane (DPE, also known by the name diphenoxyethane), ethylene glycol m-tolyl ether (EGTE) and /or diphenylsulfone (DPS). These can be used alone or in any mixture. These polymer particles preferably have an average particle size of 0.2 ⁇ m, 0.3 ⁇ m, 0.4 ⁇ m, 0.45 ⁇ m, 0.75 ⁇ m or 1.0 ⁇ m.
  • DPE 1,2-diphenoxyethane
  • EGTE ethylene glycol m-tolyl ether
  • DPS diphenylsulfone
  • the scattering particles are preferably present in the heat-sensitive layer in an amount of 20% to 60% by weight, preferably 30% to 50% by weight, based on the solid content of the heat-sensitive layer contain.
  • the heat-sensitive layer comprises at least one heat-sensitive material having a melting temperature in the range from 40 to 200°C, preferably from 80 to 140°C, and/or a
  • Glass transition temperature in the range from 40 to 200°C, preferably from 80 to 140°C.
  • the heat-sensitive layer comprises at least one heat-sensitive material having an average particle size of 0.2 to 4.0 ⁇ m, preferably 0.5 to 2.0 ⁇ m.
  • the heat-sensitive material also preferably contributes to the opacity (covering power) of the heat-sensitive layer, for example by absorbing and/or also scattering light. It is assumed that the heat-sensitive material quickly melts locally as a result of the local effect of heat from the thermal print head of the direct thermal printer, resulting in a local "softening" of the polymer particles and thus a local reduction in opacity (reduction in opacity), so that the cover layer translucent and the underlying color layer becomes visible.
  • the heat-sensitive material can also be referred to as a sensitizer or a thermal solvent.
  • the heat-sensitive material comprises one or more fatty acids such as stearic acid, behenic acid or palmitic acid, one or more fatty acid amides such as stearamide, behenamide or palmitamide, an ethylene-bis-fatty acid amide such as N,N'-ethylene-bis-stearic acid amide or N, N'-ethylene-bis-oleic acid amide, one or more fatty acid alkanolamides, in particular hydroxymethylated fatty acid amides such as N-(flydroxymethyl)stearamide, N-hydroxymethyl palmitamide, hydroxyethyl stearamide, one or more waxes such as polyethylene wax, candelilla wax, carnauba wax or montan wax, one or more carboxylic acid esters such as dimethyl terephthalate, dibenzyl terephthalate, benzyl 4-benzyloxybenzoate, di-(4-methylbenzyl) oxalate, di-(4-chlor
  • Stearamide is preferred because it has an advantageous price/performance ratio.
  • the heat-sensitive material is preferably present in an amount of from about 10% to about 80% by weight, more preferably in an amount of from about 25% to about 80% 60% by weight based on the total solid content of the heat-sensitive layer in the heat-sensitive layer.
  • lubricants or release agents can also be present in the heat-sensitive layer.
  • Such lubricants or release agents are present in particular when there is no protective layer or no further layer on the heat-sensitive layer.
  • These agents are preferably fatty acid metal salts, such as zinc stearate or calcium stearate, or else behenate salts, synthetic waxes, e.g. B. in the form of fatty acid amides, such as. B. stearic acid amide and behenic acid amide, fatty acid alkanolamides, such as. B. stearic acid methylolamide, paraffin waxes of different melting points, ester waxes of different molecular weights, ethylene waxes, propylene waxes of different flavors and / or natural waxes, such as. B. carnauba wax or montan wax. These can be used alone or in any mixture.
  • Zinc stearate is preferred because it has an advantageous price/performance ratio.
  • the lubricant or release agent is present in the heat-sensitive layer preferably in an amount of about 1 to about 10% by weight, more preferably in an amount of about 3 to about 6% by weight, based on the total solids content of the heat-sensitive layer layer before.
  • At least one binder is present in the heat-sensitive layer.
  • This is preferably water-soluble starches, starch derivatives, starch-based biolatices of the EcoSphere type, methyl cellulose, flydroxyethyl cellulose, carboxymethyl cellulose, gelatin, casein, partially or fully hydrolyzed polyvinyl alcohols, chemically modified polyvinyl alcohols, ethylene-vinyl alcohol copolymers, sodium polyacrylates, styrene-maleic anhydride Copolymers, ethylene-maleic anhydride copolymers, styrene-butadiene copolymers, acrylamide-(meth)acrylate copolymers, acrylamide-acrylate-methacrylate terpolymers, polyacrylates, poly(meth)acrylic acid esters, acrylate-butadiene copolymers, polyvinyl acetate and/or acrylonitrile -butadiene copolymers.
  • the binder is preferably present in the heat-sensitive layer in an amount of from 1 to 30% by weight, preferably from 5 to 20% by weight, based on the total solids content of the heat-sensitive layer.
  • the binder is preferably present in crosslinked form in the heat-sensitive layer, the optimum degree of crosslinking of the binder occurring in the drying step of the coating process in the presence of a crosslinking agent (crosslinking agent).
  • crosslinking agent crosslinking agent
  • the crosslinking agents can be polyvalent aldehydes such as glyoxal, dialdehyde starch, glutaraldehyde, possibly mixed with boron salts (borax), salts or esters of glyoxylic acid, crosslinking agents based on ammonium zirconium carbonate, polyamidoamine-epichlorohydrin Flarze (PAE-Flarze), adipic acid dihydrazide (AFID), boric acid or its salts, polyamines, epoxy resins, formaldehyde oligomers, cyclic flame substances, methylolurea, melamine-formaldehyde oligomers, etc. These can be used alone or in any mixture.
  • PAE-Flarze polyamidoamine-epichlorohydrin Flarze
  • AFID adipic acid dihydrazide
  • boric acid or its salts polyamines, epoxy resins, formaldehyde oligomers,
  • Ammonium zirconium carbonate and polyamidoamine-epichlorohydrin resin are particularly preferred for reasons of food conformity.
  • Self-crosslinking binders such as specially modified polyvinyl alcohols or acrylates, enable crosslinking without any crosslinking agents thanks to the reactive, crosslinkable groups that are already built into the binder polymer.
  • the crosslinking agent is preferably in an amount of about 0.01 to about 25.0% by weight, particularly preferably in an amount of about 0.05 to about 15.0% by weight, based on the total solids content of the color layer. before.
  • the heat-sensitive layer contains pigments. These pigments are preferably different from the pigments of the color layer.
  • the use of these has the advantage, among other things, that they can fix the chemical melt produced in the thermal printing process on their surface.
  • the surface whiteness and opacity of the heat-sensitive layer and its printability with conventional printing inks can also be controlled via pigments.
  • pigments are inorganic pigments of both synthetic and natural origin, preferably clays, precipitated or natural calcium carbonates, aluminum oxides, aluminum hydroxides, silicic acids, precipitated and pyrogenic silicic acids (e.g. Aerodisp types), diatomaceous earths, magnesium carbonates, talc, kaolin, Titanium oxide, bentonite, but also organic pigments such as hollow pigments with a styrene/acrylate copolymer wall or urea/formaldehyde condensation polymers. These can be used alone or in any mixture.
  • inorganic pigments of both synthetic and natural origin preferably clays, precipitated or natural calcium carbonates, aluminum oxides, aluminum hydroxides, silicic acids, precipitated and pyrogenic silicic acids (e.g. Aerodisp types), diatomaceous earths, magnesium carbonates, talc, kaolin, Titanium oxide, bentonite, but also organic pigments such as hollow pigments with a styrene/acrylate copolymer
  • Calcium carbonates, aluminum hydroxides and pyrogenic silicic acids are preferred, since they enable the heat-sensitive recording materials to have particularly advantageous performance properties with regard to their subsequent printability with commercially available printing inks.
  • the pigments are preferably present in the heat-sensitive layer in an amount of from about 2 to about 50% by weight, more preferably in an amount of from about 5 to about 20% by weight, based on the total solids content of the heat-sensitive layer.
  • the heat-sensitive layer can also contain carbon black components and/or dyes/color pigments.
  • optical brighteners can be incorporated into the heat-sensitive color-forming layer. These are preferably stilbenes.
  • the heat-sensitive layer may further contain inorganic oil-absorbing white pigments.
  • inorganic oil-absorbing white pigments include natural or calcined kaolin, silica, bentonite, calcium carbonate, aluminum hydroxide, especially boehmite, and/or mixtures thereof.
  • the inorganic oil-absorbing white pigments are preferably present in the heat-sensitive layer in an amount of about 2 to about 50% by weight, more preferably in an amount of about 5 to about 20% by weight, based on the total solids content of the heat-sensitive layer .
  • rheological aids such as e.g. As thickeners and / or surfactants to add.
  • the other components are each preferably present in customary amounts known to those skilled in the art.
  • the heat-sensitive layer preferably has a basis weight of 1 to 8 g/m 2 , in particular 2 to 6 g/m 2 .
  • the heat-sensitive layer preferably has a thickness of 1 to 10 ⁇ m, in particular 2 to 8 ⁇ m.
  • the heat-sensitive recording material is preferably characterized in that there is an insulating layer between the web-shaped carrier material and the colored layer.
  • the heat-sensitive recording material is preferably characterized in that the colored layer simultaneously represents a colored layer and an insulating layer.
  • Such an insulating layer or a colored layer which is both a colored layer and an insulating layer, causes a reduction in heat conduction through the heat-sensitive recording material.
  • the local application of heat using a direct thermal printer is more efficient and a higher thermal printer speed is possible.
  • the top layer is through the The amount of heat introduced shines through more quickly and the sensitivity is thus improved.
  • the insulating layer or the colored layer which is both a colored layer and an insulating layer, preferably has a Bekk smoothness of greater than 50 s, particularly preferably greater than 100 s and most preferably from 100 to 250 s.
  • the insulating layer or the colored layer which is both a colored layer and an insulating layer, preferably comprises a heat-insulating material.
  • the heat-sensitive recording material having an insulating layer or a colored layer which is also an insulating layer has a lower thermal conductivity than a heat-sensitive recording material which does not have an insulating layer or a colored layer which is also an insulating layer.
  • the thermally insulating material preferably comprises kaolin, more preferably calcined kaolin and mixtures thereof.
  • the heat-insulating material can also comprise fleaball pigments, in particular fleaball pigments comprising styrene-acrylate copolymer.
  • These flea bead pigments preferably have a glass transition temperature of 40 to 80° C. and/or an average particle size of 0.1 to 2.5 ⁇ m.
  • the heat-insulating material is preferably present in the insulating layer in an amount of about 20 to about 80% by weight, more preferably in an amount of about 40 to about 60% by weight, based on the total solids content of the insulating layer.
  • the thermally insulating material is preferably present in an amount of about 30 to about 70% by weight, particularly preferably in an amount of about 40 to about 60% by weight, based on the total solids content of the color layer, which is a color layer and an insulating layer at the same time.
  • the binder is preferably present in crosslinked form in the insulating layer and/or color layer, with the optimal degree of crosslinking of the binder being established in the drying step of the coating process in the presence of a crosslinking agent (crosslinking agent).
  • crosslinking agent crosslinking agent
  • the crosslinking agents can be polyvalent aldehydes such as glyoxal, dialdehyde starch, glutaraldehyde, possibly mixed with boron salts (borax), salts or esters of glyoxylic acid, crosslinking agents based on ammonium zirconium carbonate, polyamidoamine-epichlorohydrin resins (PAE resins), adipic acid dihydrazide (AFID), boric acid or its salts, polyamines, epoxy resins, formaldehyde oligomers, cyclic flames, methylolurea, melamine-formaldehyde oligomers, and others. m. act. These can be used alone or in any mixture.
  • Ammonium zirconium carbonate and polyamidoamine-epichlorohydrin resin are particularly preferred for reasons of food conformity.
  • Self-crosslinking binders such as specially modified polyvinyl alcohols or acrylates, enable crosslinking without any crosslinking agents thanks to the reactive, crosslinkable groups that are already built into the binder polymer.
  • the crosslinking agent is preferably in an amount of about 0.01 to about 25.0% by weight, particularly preferably in an amount of about 0.05 to about 15.0% by weight, based on the total solids content of the insulating or color layer, before.
  • the insulating layer preferably has a basis weight of 1 to 10 g/m 2 , in particular 2 to 8 g/m 2 .
  • the insulating layer preferably has a thickness of 2 to 8 gm, in particular 4 to 6 gm.
  • the colored layer which is both a colored layer and an insulating layer, preferably has a basis weight of 1 to 10 g/m 2 , in particular 3 to 8 g/m 2 .
  • the colored layer which is both a colored layer and an insulating layer, preferably has a thickness of 1 to 10 gm, in particular 4 to 8 gm.
  • the heat-sensitive recording material is preferably characterized in that directly on at least one side of the web-shaped carrier material, preferably directly on both sides of the web-shaped carrier material, a layer comprising starch (starch coating) and/or modifications thereof (modified starches), is available.
  • the starch coat is preferably applied in an amount of 0.1 to 3, particularly preferably 0.2 to 1.5 g/m 2 .
  • a line of starch on the side of the web-shaped carrier material on which the color layer is present has the advantage that the web-shaped carrier material is closed and the flattening of the color layer is improved and penetration of the color layer into the web-shaped carrier material can be reduced or prevented.
  • a line of starch on the side of the web-shaped carrier material on which the color layer is not present has the advantage that the color layer can be reduced or prevented from striking through the web-shaped carrier material.
  • the layer comprising starch preferably has a Bekk smoothness greater than 20 s, more preferably greater than 50 s, and most preferably from 50 to 200 s.
  • the heat-sensitive recording material is preferably characterized in that a protective layer is provided on the heat-sensitive layer.
  • the protective layer preferably has a Bekk smoothness of greater than 200 s, particularly preferably greater than 400 s and very particularly preferably from 400 to 1500 s. Most preferred is a Bekk smoothness of 400 to 1300 s.
  • This protective layer preferably comprises at least one binder and at least one pigment, particularly preferably an inorganic pigment.
  • Suitable binders include water-soluble starches, starch derivatives, starch-based biolatices of the EcoSphere type, methyl cellulose, hydroxyethyl cellulose, carboxymethyl cellulose, partially or fully hydrolyzed polyvinyl alcohols, chemically modified polyvinyl alcohols such as acetoacetyl, diacetone, carboxy, silanol-modified polyvinyl alcohols, or styrene maleic anhydride copolymers, Styrene-butadiene copolymers, acrylamide (meth)acrylate copolymers, acrylamide-acrylate-methacrylate terpolymers, polyacrylates, poly(meth)acrylic esters, acrylate-butadiene copolymers, polyvinyl acetates and/or acrylonitrile-butadiene copolymers. These can be used alone or in any mixture.
  • Suitable inorganic pigments include inorganic pigments of both synthetic and natural origin, preferably clays, precipitated or natural calcium carbonates, aluminum oxides, aluminum hydroxides, silicic acids, precipitated and pyrogenic silicic acids (e.g. Aerodisp types), diatomaceous earths, magnesium carbonates, talc, kaolin, Titanium oxide, bentonite, but also organic pigments such as hollow pigments with a styrene/acrylate copolymer wall or urea/formaldehyde condensation polymers. These can be used alone or in any mixture.
  • inorganic pigments of both synthetic and natural origin, preferably clays, precipitated or natural calcium carbonates, aluminum oxides, aluminum hydroxides, silicic acids, precipitated and pyrogenic silicic acids (e.g. Aerodisp types), diatomaceous earths, magnesium carbonates, talc, kaolin, Titanium oxide, bentonite, but also organic pigments such as hollow pigments with a styrene/
  • Suitable organic pigments include hollow pigments having a styrene/acrylate copolymer wall or urea/formaldehyde condensation polymers. These can be used alone or in any mixture.
  • the binder is preferably in an amount of about 40 to about 90% by weight, more preferably in an amount of about 50 to about 80% by weight, based on the total solids content of the protective layer, in the protective layer.
  • the pigment is preferably present in the protective layer in an amount of from about 5 to about 40% by weight, more preferably in an amount of from about 10 to about 30% by weight, based on the total solids content of the protective layer.
  • the binder is preferably present in crosslinked form in the protective layer, the optimum degree of crosslinking of the binder occurring in the drying step of the coating process in the presence of a crosslinking agent (crosslinking agent).
  • crosslinking agent crosslinking agent
  • the crosslinking agents can be polyvalent aldehydes such as glyoxal, dialdehyde starch, glutaraldehyde, possibly mixed with boron salts (borax), salts or esters of glyoxylic acid, crosslinking agents based on ammonium zirconium carbonate, polyamidoamine-epichlorohydrin resins (PAE resins), adipic acid dihydrazide (AFID), boric acid or its salts, polyamines, epoxy resins, formaldehyde oligomers, cyclic flames, methylolurea, melamine-formaldehyde oligomers, and others. m. act. These can be used alone or in any mixture.
  • Ammonium zirconium carbonate and polyamidoamine-epichlorohydrin resin are particularly preferred for reasons of food conformity.
  • Self-crosslinking binders such as specially modified polyvinyl alcohols or acrylates, enable crosslinking without any crosslinking agents thanks to the reactive, crosslinkable groups that are already built into the binder polymer.
  • the crosslinker is preferably present in an amount of from about 0.01 to about 25.0, more preferably in an amount of from about 0.05 to about 15.0, based on the total solids content of the color coat.
  • the protective layer also preferably comprises at least one lubricant or at least one release agent.
  • These agents are preferably fatty acid metal salts such as zinc stearate or calcium stearate, or behenate salts, synthetic waxes such.
  • the lubricant or release agent is preferably present in an amount of from about 1% to about 30% by weight, more preferably in an amount of from about 2% to about 20% by weight, based on the total solids content of the protective layer.
  • the protective layer preferably has a basis weight of 0.3 to 5.0 g/m 2 , in particular 1.0 to 3.0 g/m 2 .
  • optical brighteners preferably stilbenes
  • the protective layer In order to control the surface whiteness of the heat-sensitive recording material according to the invention, optical brighteners, preferably stilbenes, can be incorporated into the protective layer.
  • the protective layer preferably has a thickness of 0.5 to 6.0 ⁇ m, in particular 0.5 to 2.0 ⁇ m.
  • the use of a protective layer has the advantage that the recording material is better protected from external influences.
  • the heat-sensitive recording material is preferably characterized in that an adhesive layer is present on the side of the carrier material in web form on which the color layer is not located.
  • the adhesive layer preferably comprises at least one adhesive, preferably a heat-activatable adhesive, in particular a pressure-sensitive adhesive.
  • the adhesive preferably the heat-activatable adhesive and in particular the pressure-sensitive adhesive, is particularly preferably an adhesive based on rubber and/or acrylate.
  • the adhesive layer preferably has a basis weight of 10 to 40 g/m 2 , in particular 12 to 25 g/m 2 .
  • the heat-sensitive recording material is preferably characterized in that a siliconized separating layer is present on the heat-sensitive layer.
  • siliconized release layer and "siliconized layer” are to be understood synonymously in the sense of "cover with a layer of silicone”. These layers preferably consist of silicone or comprise at least 90% by weight, preferably at least 95% by weight and particularly preferably at least 99 wt.
  • the siliconized separating layer preferably has a Bekk smoothness of greater than 400 s, particularly preferably greater than 800 s and very particularly preferably from 800 to 2000 s.
  • the siliconized release layer is preferably present on this protective layer.
  • the heat-sensitive recording material is preferably characterized in that a diffusion layer is formed between the siliconized layer and the underlying layer, preferably the heat-sensitive layer.
  • This diffusion layer is preferably formed by diffusing at least parts of the siliconized separating layer over a large area into the upper region of the underlying layer, with preferably 5 to 50% by weight, particularly preferably 6 to 45% by weight and in particular 7 to 40% by weight of the siliconized separating layer diffuse into the upper area of the underlying layer.
  • a diffusion layer is described, for example, in EP 3 221 153 A1.
  • a siliconized release layer is preferably present when an adhesive layer is also present as described above.
  • the presence of a siliconized release layer on the heat-sensitive layer and an adhesive layer on the web-shaped base material on the side where the ink layer is not located has the advantage that the heat-sensitive recording material can be used as a linerless heat-sensitive recording material.
  • Carrierless means that the (self-adhesive) heat-sensitive recording material according to the invention is not applied to a carrier material but is wound onto itself. This has the advantage that the production costs can be further reduced, more running meters per roll can be realized, no disposal effort for the disposal of the liner is necessary and more labels can be transported per specific loading space volume.
  • a siliconized separating layer it is preferred that at least one platelet-shaped pigment is contained in the heat-sensitive layer or in the layer that lies directly below the siliconized separating layer.
  • the at least one platelet-shaped pigment is preferably selected from the group consisting of kaolin, Al(OH) 3 and/or talc.
  • kaolin is particularly preferred.
  • coated kaolin is very particularly preferred. Such is available, for example, under the trade name Kaolin ASP 109 (BASF, Germany).
  • the main advantage of using these platelet-shaped pigments, in particular kaolin, is that the heat-sensitive layer or the layer that lies directly below the siliconized separating layer can be siliconized very easily.
  • Platelet-shaped pigment is understood as meaning a pigment in which the ratio of diameter to thickness is about 7 to 40:1, preferably about 15 to 30:1.
  • the particle size of the platelet-shaped pigment is preferably adjusted in such a way that at least about 70%, preferably at least about 85%, of the particles have a particle size of about ⁇ 2 ⁇ m (Sedigraph).
  • the pH of the flaky pigment in aqueous solution is preferably 6 to 8.
  • the at least one platelet-shaped pigment is in the heat-sensitive color-forming layer or in the layer that lies directly below the siliconized release layer, preferably in an amount of about 5 to about 60% by weight, particularly preferably in an amount of about 15 to about 55% by weight, based on the total solids content of the respective layer.
  • the heat-sensitive recording material is preferably characterized in that the siliconized separating layer comprises at least one siloxane, preferably a poly(organo)siloxane, in particular an acrylic poly(organo)siloxane.
  • the siliconized release layer comprises a mixture of at least two siloxanes.
  • a mixture of at least two acrylic poly(organo)siloxanes is preferred.
  • siloxanes available under the trade names TEGO®RC902 and TEGO®RC711 (Evonik, Germany).
  • the heat-sensitive recording material is preferably characterized in that the siliconized separating layer contains at least one polysilicon acrylate, which was preferably formed by condensation of at least one silicon acrylate.
  • the siliconized release layer is preferably anhydrous. It is also preferred that the siliconized separating layer does not contain any Pt catalysts.
  • the siliconized separating layer preferably contains an initiator, particularly preferably a photoinitiator. This is used for radical curing of the silicone. This is very particularly preferably the TEGO® photoinitiator A18 (from Evonik, Germany).
  • the siliconized separating layer can preferably contain other additives, such as matting agents and/or adhesion additives.
  • the siliconized separating layer preferably has a basis weight of 0.3 to 5.0 g/m 2 , in particular 1.0 to 3.0 g/m 2 .
  • the siliconized separating layer preferably has a thickness of 0.3 to 6.0 gm, in particular 0.5 to 2.0 gm.
  • All of the layers mentioned above can be formed in one or more layers.
  • the heat-sensitive recording material according to the second aspect of the present invention can be obtained by the manufacturing method described in connection with the first aspect.
  • the present invention also relates to a heat-sensitive recording material which can be obtained using the process described above.
  • the present invention also relates to the use of a heat-sensitive recording material as described above as a roll of receipts, as a roll of adhesive labels, also in the cold and deep-freeze sector, and as a roll of tickets.
  • a heat-sensitive recording material as described above as a roll of receipts, as a roll of adhesive labels, also in the cold and deep-freeze sector, and as a roll of tickets.
  • these have a functional side and/or back (with color, multicolored, black/grey) and can be pre-printed.
  • the rolls mentioned are preferably available in typical widths and lengths.
  • the present invention relates to a heat-sensitive recording material, comprising a web-shaped base material, a color layer on one side of the web-shaped base material and a heat-sensitive layer on the color layer, so that the color layer is at least partially covered, the heat-sensitive layer being configured in such a way that this becomes translucent through the local effect of heat, so that the color layer underneath becomes visible, characterized in that the heat-sensitive layer contains 10 to 90% by weight, preferably 20 to 60% by weight, in particular from 30% by weight to 50 wt 60% by weight of a heat-sensitive material having a melting temperature in the range from 40 to 200°C and/or a glass transition temperature in the range from 40 b is 200°C and 1 to 30% by weight, preferably 5 to 20% by weight, of a binder.
  • Such a heat-sensitive recording material is distinguished in particular with regard to its functionality, its environmental properties (sustainability) and/or its economic availability (simple and inexpensive) and in particular by the advantageous combination of these three properties.
  • the heat-sensitive recording material is characterized in that the heat-sensitive layer comprises at least one scattering particle, in particular a polymer particle, with a glass transition temperature of -55 to 130°C, preferably of 40 to 80°C.
  • the heat-sensitive recording material is characterized in that the heat-sensitive layer comprises at least one scattering particle, in particular a polymer particle, with a core/fill structure, the scattering particles, in particular the polymer particles, being selected from the group consisting of (i) scattering particles, in particular polymer particles, with an outer shell having a glass transition temperature of 40 °C to 80 °C and (ii) scattering particles, in particular polymer particles, having an inner shell with a glass transition temperature of 40 °C to 130 °C and an outer one Shell with a glass transition temperature of -55 °C to 50 °C, where the Glass transition temperature of the outer shell is preferably lower than that of the inner shell.
  • the scattering particles in particular the polymer particles, being selected from the group consisting of (i) scattering particles, in particular polymer particles, with an outer shell having a glass transition temperature of 40 °C to 80 °C and (ii) scattering particles, in particular polymer particles, having an inner shell with a glass transition temperature of 40
  • the heat-sensitive recording material is characterized in that the heat-sensitive layer contains at least one scattering particle, in particular a polymer particle, with a melting point of less than 250°C, preferably from 0°C to 250°C.
  • the heat-sensitive recording material is characterized in that the heat-sensitive layer contains at least one scattering particle, in particular a polymer particle, with a glass transition temperature of -55 to 130 °C, preferably from 40 to 80 °C, and with an average particle size in the range from 0.1 to 2.5 pm, preferably from 0.2 to 0.8 pm.
  • the heat-sensitive layer contains at least one scattering particle, in particular a polymer particle, with a glass transition temperature of -55 to 130 °C, preferably from 40 to 80 °C, and with an average particle size in the range from 0.1 to 2.5 pm, preferably from 0.2 to 0.8 pm.
  • the heat-sensitive recording material is characterized in that the heat-sensitive layer comprises at least one scattering particle, in particular the polymer particles, with a core/shell structure, the scattering particles, in particular the polymer particles, being selected from the group consisting of (i) scattering particles, in particular polymer particles, with an outer shell having a glass transition temperature of 40 °C to 80 °C and (ii) scattering particles, in particular polymer particles, having an inner shell with a glass transition temperature of 40 °C to 130 °C and an outer one Shell with a glass transition temperature of -55 °C. to 50°C, the glass transition temperature of the outer shell being preferably lower than that of the inner shell, and with an average particle size in the range from 0.1 to 2.5 ⁇ m, preferably from 0.2 to 0.8 ⁇ m.
  • the heat-sensitive recording material is characterized in that the heat-sensitive layer contains at least one scattering particle, in particular a polymer particle, with a melting point of less than 250° C., preferably from 0° C. to 250° C., and with an average particle size in the range from 0.1 to 2.5 pm, preferably from 0.2 to 0.8 pm.
  • a glass transition temperature or a melting point of less than 250° C. was recognized as advantageous. No direct thermal printing is possible above temperatures of 250 °C, since the temperature-time window is outside the printer specification.
  • An average particle size in the range from 0.1 to 2.5 ⁇ m is advantageous since particles of this size scatter visible light and the colored layer is thus covered as far as possible.
  • the average particle size can be determined using a Beckman Coulter device (laser diffraction, Fraunhofer method).
  • the scattering particles in particular the polymer particles, are preferably crystalline, partially crystalline and/or amorphous.
  • the glass transition temperatures mentioned above relate to partially crystalline or amorphous scattering particles, in particular polymer particles.
  • the melting temperatures relate to crystalline scattering particles, in particular polymer particles, or to the crystalline portion of the scattering particles, in particular polymer particles.
  • the polymer particles are preferably closed flake particles, in particular hollow spherical polymer particles, open flake particles, in particular polymer particles in the form of lattice cages, and/or solid particles, in particular irregularly shaped polymer particles.
  • the primary property of the scattering particles is the scattering of light in the visible range of light.
  • the secondary property is sensitivity to heat.
  • the polymer particles preferably comprise thermoplastic polymers.
  • the polymer particles preferably comprise polymers resulting from the polymerisation of one or more monomers selected from the group consisting of acrylonitrile, styrene, butadiene, benzyl methacrylate, phenyl methacrylate, ethyl methacrylate, divinylbenzene, 2-hydroxyethyl methacrylate, cyclohexyl methacrylate, 2-methylstyrene, 3-methylstyrene, 4 -methylstyrene, alpha- methyl styrene, beta-methyl styrene, acrylamide, methacrylamide, methacrylonitrile, hydroxypropyl methacrylate, methoxy styrene, N-acrylylglycine amide and/or N-methacrylylglycine amide and/or derivatives thereof.
  • monomers selected from the group consisting of acrylonitrile, styrene, butadiene, benzyl
  • the polymer particles can be polymerized using a variety of ethylenically unsaturated monomers.
  • nonionic monoethylenically unsaturated monomers include styrene, vinyl toluene, ethylene, vinyl acetate, vinyl chloride, vinylidene chloride, acrylonitrile, (meth)acrylamide, various (Ci-C2o)-alkyl or (C3-C2o)-alkenyl esters of (meth)acrylic acid, inclusive Methyl acrylate (MA), methyl methacrylate (MMA), ethyl (meth)acrylate, butyl (meth)acrylate, 2-hydroxyethyl (meth)acrylate, 2- ethylhexyl (meth)acrylate, benzyl (meth)acrylate, lauryl (meth)acrylate, oleyl (meth)acrylate, palmityl (meth)acrylate and stearyl (meth)acryl
  • acrylic esters such as MMA, EA, BA, and styrene are preferred monomers for polymerization and formation of the shell of the polymer particles.
  • Difunctional vinyl monomers such as divinylbenzene, allyl methacrylate, ethylene glycol dimethacrylate, 1,3-butanediol dimethacrylate, diethylene glycol dimethacrylate,
  • Trimethylolpropane trimethacrylate and the like can also be copolymerized to form a crosslinked outer shell as described in US Patent Application 2003-0176535 A1.
  • the polymer particles preferably comprise (meth)acrylonitrile copolymers, polyvinyl chloride, polyvinylidene chloride, polystyrene, styrene acrylate, styrene-(meth)acrylate copolymers, polyacrylonitrile, polyacrylic acid esters or mixtures of at least two of these.
  • the strength and durability of the polymer particles can be influenced by the crosslinking of polymer chains.
  • the scattering particles in particular the polymer particles, can be present in the form of closed scattering particles, in particular polymer particles, in particular hollow body particles, open scattering particles, in particular polymer particles, and/or solid particles, each of which can have a regular or irregular shape.
  • Hollow spherical polymer particles or polymer particles with a core/shell structure can be mentioned in particular as examples of closed hollow body particles.
  • Ropaque HP-1055, Ropaque OP-96 and Ropaque TH-1000 can be mentioned as examples of hollow spherical polymer particles or polymer particles with a core/shell structure.
  • cup-shaped polymer particles in particular, can be mentioned as examples of open polymer particles.
  • the shell these have the same materials as the closed polymer particles, in particular the closed hollow spherical polymer particles.
  • open polymer particles which can be mentioned are polymer particles in the form of a lattice cage, such as are described in WO 2021/062230 A1.
  • Polyethylene, polystyrene and cellulose esters can be mentioned as examples of solid particles.
  • the scattering particles mentioned above, in particular the polymer particles, can have a regular or irregular shape.
  • the polymer particles are spherical solid particles, preferably irregularly shaped, and/or spherical hollow particles, both preferably in the form of droplets.
  • These preferably include polystyrene, for example Plastic Pigment 756A from Trinseo LLC., and Plastic Pigment 772HS from Trinseo LLC., polyethylene, for example Chemipear 10 W401 from Mitsui Chemical Inc., to hollow spherical particles (HSP)/spherical hollow pigments, for example Ropaque TH-500EF from The Dow Chemical Co. to modified polystyrene particles, for example Joncryl 633 from BASF Corp.
  • polystyrene for example Plastic Pigment 756A from Trinseo LLC.
  • Plastic Pigment 772HS from Trinseo LLC.
  • polyethylene for example Chemipear 10 W401 from Mitsui Chemical Inc.
  • HSP hollow spherical particles
  • Ropaque TH-500EF from
  • DPE 1,2- diphenoxyethane
  • EGTE ethylene glycol m-tolyl ether
  • DPS diphenyl sulfone
  • These polymer particles preferably have an average particle size of 0.2 ⁇ m, 0.3 ⁇ m, 0.4 ⁇ m, 0.45 ⁇ m, 0.75 ⁇ m or 1.0 ⁇ m.
  • the scattering particles are preferably present in the heat-sensitive layer in an amount of 20% to 60% by weight, preferably 30% to 50% by weight, based on the solid content of the heat-sensitive layer contain.
  • the heat-sensitive layer comprises at least one heat-sensitive material having a melting temperature in the range from 40 to 200°C, preferably from 80 to 140°C, and/or a
  • Glass transition temperature in the range from 40 to 200°C, preferably from 80 to 140°C.
  • the heat-sensitive layer comprises at least one heat-sensitive material having an average particle size of 0.2 to 4.0 ⁇ m, preferably 0.5 to 2.0 ⁇ m.
  • the heat-sensitive material also preferably contributes to the opacity (covering power) of the heat-sensitive layer, for example by absorbing and/or also scattering light. It is assumed that the heat-sensitive material quickly melts locally as a result of the local effect of heat from the thermal print head of the direct thermal printer, resulting in a local "softening" of the polymer particles and thus a local reduction in opacity (reduction in opacity), so that the cover layer translucent and the underlying color layer becomes visible.
  • the heat-sensitive material can also be referred to as a sensitizer or a thermal solvent.
  • the heat-sensitive material comprises one or more fatty acids such as stearic acid, behenic acid or palmitic acid, one or more fatty acid amides such as stearamide, behenamide or palmitamide, an ethylene-bis-fatty acid amide such as N,N'-ethylene-bis-stearic acid amide or N, N'-ethylene-bis-oleic acid amide, one or more fatty acid alkanolamides, in particular Hydroxymethylated fatty acid amides such as N-(hydroxymethyl)stearamide, N-hydroxymethylpalmitamide, hydroxyethylstearamide, one or more waxes such as polyethylene wax, candelilla wax, carnauba wax or montan wax, one or more carboxylic acid esters such as dimethyl terephthalate, dibenzyl terephthalate, benzyl 4-benzyloxybenzoate, di-( 4-methylbenzyl)oxalate, di-(4-chlorobenzyl)ox
  • Stearamide is preferred because it has an advantageous price/performance ratio.
  • the heat-sensitive material is preferably present in the heat-sensitive layer in an amount of about 10 to about 80% by weight, more preferably in an amount of about 25 to about 60% by weight, based on the total solids content of the heat-sensitive layer.
  • At least one binder is present in the heat-sensitive layer.
  • This is preferably water-soluble starches, starch derivatives, starch-based biolatices of the EcoSphere type, methyl cellulose, flydroxyethyl cellulose, carboxymethyl cellulose, gelatin, casein, partially or fully hydrolyzed polyvinyl alcohols, chemically modified polyvinyl alcohols, ethylene-vinyl alcohol copolymers, sodium polyacrylates, styrene-maleic anhydride Copolymers, ethylene-maleic anhydride copolymers, styrene-butadiene copolymers, acrylamide-(meth)acrylate copolymers, acrylamide-acrylate-methacrylate terpolymers, polyacrylates, poly(meth)acrylic acid esters, acrylate-butadiene copolymers, polyvinyl acetate and/or acrylonitrile -butadiene copolymers.
  • the binder is preferably present in the heat-sensitive layer in an amount of from 1 to 30% by weight, preferably from 5 to 20% by weight, based on the total solids content of the heat-sensitive layer.
  • the binder is preferably present in crosslinked form in the heat-sensitive layer, the optimum degree of crosslinking of the binder occurring in the drying step of the coating process in the presence of a crosslinking agent (crosslinking agent).
  • crosslinking agent crosslinking agent
  • the crosslinking agents can be polyvalent aldehydes such as glyoxal, dialdehyde starch, glutaraldehyde, possibly mixed with boron salts (borax), salts or esters of glyoxylic acid, crosslinking agents based on ammonium zirconium carbonate, polyamidoamine-epichlorohydrin resins (PAE resins), adipic acid dihydrazide (AFID), boric acid or its salts, polyamines, epoxy resins, formaldehyde oligomers, cyclic flames, methylolurea, melamine-formaldehyde oligomers, and others. m. act. These can be used alone or in any mixture.
  • Ammonium zirconium carbonate and polyamidoamine-epichlorohydrin resin are particularly preferred for reasons of food conformity.
  • Self-crosslinking binders such as specially modified polyvinyl alcohols or acrylates, enable crosslinking without any crosslinking agents thanks to the reactive, crosslinkable groups that are already built into the binder polymer.
  • the crosslinker is preferably present in an amount of from about 0.01 to about 25.0, more preferably in an amount of from about 0.05 to about 15.0, based on the total solids content of the color coat.
  • the heat-sensitive recording material is preferably characterized in that the heat-sensitive recording material has a residual moisture content of 2 to 14%, preferably from 2 to 12% and most preferably from 3 to 10%. A residual moisture content of 3 to 8% is most preferred.
  • Residual moisture in the specified range has the advantage that, after printing, there is a high relative print contrast with advantageous application properties, such as better legibility.
  • the residual moisture can be determined as described in connection with the examples.
  • the opacity in the heat-sensitive layer is generated not only by the scattering particles, particularly the polymer particles, but also by the air trapped between the scattering particles, particularly the polymer particles (open porosity). Moisture entering these "pores” displaces air and reduces opacity. This can result in a grayer material, which is not preferred.
  • the heat-sensitive recording material is preferably characterized in that the heat-sensitive recording material has a surface whiteness of 35 to 60%, in particular 45 to 50%.
  • the surface whiteness (paper whiteness) can be determined according to ISO 2470-2 (2008) with an Elrepho 3000 spectrophotometer.
  • the heat-sensitive recording material is preferably characterized in that the contrast of places where the heat-sensitive layer has become translucent due to the local effect of heat to places where the heat-sensitive layer has not become translucent due to the local effect of heat , 40 to 80%, in particular from 50 to 70%.
  • the carrier material preferably has a Bekk smoothness of greater than 20 s, particularly preferably greater than 30 s and very particularly preferably greater than 50 s.
  • the color layer preferably has a Bekk smoothness of greater than 50 s, more preferably greater than 100 s and very particularly preferably greater than 150 s.
  • the heat-sensitive layer preferably has a Bekk smoothness of greater than 100 s, particularly preferably greater than 250 s.
  • the support material preferably has a Bekk smoothness of from 20 to 400 s, particularly preferably from 30 to 300 s and very particularly preferably from 50 to 200 on the side to which the colored layer is applied. Most preferred is a Bekk smoothness of 50 to 150 s.
  • the color layer preferably has a Bekk smoothness of 50 to 400 s, more preferably 100 to 250 s, and most preferably 100 to 250 s on the side on which the heat-sensitive layer is coated.
  • Such a heat-sensitive recording material has the advantage of high dynamic sensitivity.
  • each layer applied to the web-shaped carrier material has a Bekk smoothness on its upper side, ie on the side on which the web-shaped carrier material does not lie, which is at least as great as or greater than that of the respective underlying layer.
  • Each layer applied to the web-like carrier material preferably has a Bekk smoothness of at least 5% (percentage increase) on its upper side, ie on the side on which the web-shaped carrier material is not located, compared to the respective underlying layer.
  • Each layer applied to the web-shaped carrier material preferably has a Bekk smoothness of at least 5 s (absolute increase) on its upper side, i.e. on the side on which the web-shaped carrier material is not located, compared to the respective underlying layer.
  • lubricants or release agents can also be present in the heat-sensitive layer.
  • Such lubricants or release agents are present in particular when there is no protective layer or no further layer on the heat-sensitive layer.
  • These agents are preferably fatty acid metal salts, such as zinc stearate or calcium stearate, or else behenate salts, synthetic waxes, e.g. B. in the form of fatty acid amides, such as. B. stearic acid amide and behenic acid amide, fatty acid alkanolamides, such as. B. stearic acid methylolamide, paraffin waxes of different melting points, ester waxes of different molecular weights, ethylene waxes, propylene waxes of different flavors and / or natural waxes, such as. B. carnauba wax or montan wax. These can be used alone or in any mixture.
  • Zinc stearate is preferred because it has an advantageous price/performance ratio.
  • the lubricant or release agent is present in the heat-sensitive layer preferably in an amount of about 1 to about 10% by weight, more preferably in an amount of about 3 to about 6% by weight, based on the total solids content of the heat-sensitive layer shift before.
  • the heat-sensitive layer contains pigments. These pigments are preferably different from the pigments of the color layer. The use of these has the advantage, among other things, that they can fix the chemical melt produced in the thermal printing process on their surface. Also, the pigments can Surface whiteness and opacity of the heat-sensitive layer and its printability with conventional inks can be controlled.
  • pigments are inorganic pigments of both synthetic and natural origin, preferably clays, precipitated or natural calcium carbonates, aluminum oxides, aluminum hydroxides, silicic acids, precipitated and pyrogenic silicic acids (e.g. Aerodisp types), diatomaceous earths, magnesium carbonates, talc, kaolin, Titanium oxide, bentonite, but also organic pigments such as hollow pigments with a styrene/acrylate copolymer wall or urea/formaldehyde condensation polymers. These can be used alone or in any mixture.
  • inorganic pigments of both synthetic and natural origin preferably clays, precipitated or natural calcium carbonates, aluminum oxides, aluminum hydroxides, silicic acids, precipitated and pyrogenic silicic acids (e.g. Aerodisp types), diatomaceous earths, magnesium carbonates, talc, kaolin, Titanium oxide, bentonite, but also organic pigments such as hollow pigments with a styrene/acrylate copolymer
  • Calcium carbonates, aluminum hydroxides and pyrogenic silicic acids are preferred, since they enable the heat-sensitive recording materials to have particularly advantageous performance properties with regard to their subsequent printability with commercially available printing inks.
  • the pigments are preferably present in the heat-sensitive layer in an amount of from about 2 to about 50% by weight, more preferably in an amount of from about 5 to about 20% by weight, based on the total solids content of the heat-sensitive layer.
  • the heat-sensitive layer can also contain carbon black components and/or dyes/color pigments.
  • optical brighteners can be incorporated into the heat-sensitive color-forming layer. These are preferably stilbenes.
  • the heat-sensitive layer may further contain inorganic oil-absorbing white pigments.
  • inorganic oil-absorbing white pigments examples include natural or calcined kaolin, silica, bentonite, calcium carbonate, aluminum hydroxide, especially boehmite, and/or mixtures thereof.
  • the inorganic oil-absorbing white pigments are preferably present in the heat-sensitive layer in an amount of about 2 to about 50% by weight, more preferably in an amount of about 5 to about 20% by weight, based on the total solids content of the heat-sensitive layer .
  • rheological aids such as e.g. As thickeners and / or surfactants to add.
  • the other components are each preferably present in customary amounts known to those skilled in the art.
  • the heat-sensitive layer preferably has a basis weight of 1 to 8 g/m 2 , in particular 2 to 6 g/m 2 .
  • the heat-sensitive layer preferably has a thickness of 1 to 10 ⁇ m, in particular 2 to 8 ⁇ m.
  • the web-shaped carrier material is not restricted.
  • the carrier material in web form comprises paper, synthetic paper and/or a plastic film.
  • the carrier material preferably has a basis weight of 30 to 100 g/m 2 , in particular 40 to 80 g/m 2 .
  • the carrier material in web form of the heat-sensitive recording material according to the invention preferably comprises at least one black or colored side, which is achieved by applying a colored layer.
  • the term "colored side” is understood to mean that the side has a color other than white or black.
  • the heat-sensitive recording material comprises at least one side that is colored in such a way that it is not white.
  • the at least one black or colored side has several different colors, also in combination with the color black.
  • the at least one color layer on one side of the web-shaped carrier material is preferably characterized in that the color layer comprises at least one pigment and/or a dye and preferably a binder.
  • the pigments and/or dyes include various organic and inorganic pigments, dyes and/or carbon black. These can be used alone or in any mixture.
  • the pigment, the dye and/or the carbon black are each preferably contained in the color layer in an amount of 2 to 50% by weight, particularly preferably 10 to 35% by weight, based on the total solid content of the color layer.
  • the binder is preferably contained in the color layer in an amount of 2 to 40% by weight, particularly preferably 10 to 30% by weight, based on the total solids content of the color layer.
  • the colored layer preferably has a basis weight of 1 to 10 g/m 2 , in particular 3 to 8 g/m 2 .
  • the colored layer preferably has a thickness of 1 to 10 ⁇ m, in particular 2 to 8 ⁇ m.
  • the heat-sensitive recording material is preferably characterized in that between the web-shaped carrier material and the color layer an insulating layer is present.
  • the heat-sensitive recording material is preferably characterized in that the colored layer simultaneously represents a colored layer and an insulating layer.
  • Such an insulating layer or a colored layer which is both a colored layer and an insulating layer, causes a reduction in heat conduction through the heat-sensitive recording material.
  • the local application of heat using a direct thermal printer is more efficient and a higher thermal printer speed is possible.
  • the top layer becomes translucent more quickly due to the amount of heat introduced and the sensitivity is thus improved.
  • the insulating layer or the colored layer which is simultaneously a colored layer and an insulating layer, preferably has a Bekk smoothness of greater than 50 s, particularly preferably greater than 100 s and very particularly preferably from 100 s to 250 s.
  • the insulating layer or the colored layer which is both a colored layer and an insulating layer, preferably comprises a heat-insulating material.
  • a heat-sensitive recording material with an insulating layer or a colored layer which is also an insulating layer preferably has a lower thermal conductivity than a heat-sensitive recording material which does not have an insulating layer or a colored layer which is also an insulating layer.
  • the thermally insulating material preferably comprises kaolin, more preferably calcined kaolin and mixtures thereof.
  • the heat-insulating material can also comprise hollow sphere pigments, in particular hollow sphere pigments comprising styrene-acrylate copolymer.
  • These hollow sphere pigments preferably have a glass transition temperature of 40 to 80° C. and/or an average particle size of 0.1 to 2.5 ⁇ m.
  • the heat-insulating material is preferably present in the insulating layer in an amount of about 20 to about 80% by weight, more preferably in an amount of about 40 to about 60% by weight, based on the total solids content of the insulating layer.
  • the heat-insulating material is preferably present in an amount of about 30 to about 70% by weight, more preferably in an amount of about 40 to about 60% by weight, based on the total solids content of the paint layer, which is at the same time a paint layer and an insulating layer, in this.
  • the binder is preferably present in crosslinked form in the insulating layer and/or color layer, with the optimal degree of crosslinking of the binder being established in the drying step of the coating process in the presence of a crosslinking agent (crosslinking agent).
  • crosslinking agent crosslinking agent
  • the crosslinking agents can be polyvalent aldehydes such as glyoxal, dialdehyde starch, glutaraldehyde, possibly mixed with boron salts (borax), salts or esters of glyoxylic acid, crosslinking agents based on ammonium zirconium carbonate, polyamidoamine-epichlorohydrin Resins (PAE resins), adipic acid dihydrazide (AHD), boric acid or its salts, polyamines, epoxy resins, formaldehyde oligomers, cyclic ureas, methylolurea, melamine formaldehyde oligomers, etc. m. act. These can be used alone or in any mixture.
  • PAE resins polyamidoamine-epichlorohydrin Resins
  • AHD adipic acid dihydrazide
  • boric acid or its salts polyamines, epoxy resins, formaldehyde oligomers, cycl
  • Ammonium zirconium carbonate and polyamidoamine-epichlorohydrin (PAE) resins are particularly preferred for reasons of food conformity.
  • Self-crosslinking binders such as specially modified polyvinyl alcohols or acrylates, enable crosslinking without any crosslinking agents thanks to the reactive, crosslinkable groups that are already built into the binder polymer.
  • the crosslinking agent is preferably in an amount of about 0.01 to about 25.0% by weight, particularly preferably in an amount of about 0.05 to about 15.0% by weight, based on the total solids content of the insulating or color layer, before.
  • the insulating layer preferably has a basis weight of 1 to 5 g/m 2 , in particular 2 to 4 g/m 2 .
  • the insulating layer preferably has a thickness of 1 to 10 ⁇ m, in particular 2 to 8 ⁇ m.
  • the colored layer which is both a colored layer and an insulating layer, preferably has a basis weight of 1 to 12 g/m 2 , in particular 4 to 8 g/m 2 .
  • the colored layer which is both a colored layer and an insulating layer, preferably has a thickness of 2 to 10 ⁇ m, in particular 4 to 8 ⁇ m.
  • the heat-sensitive recording material is preferably characterized in that directly on at least one side of the web-shaped carrier material, preferably directly on both sides of the web-shaped carrier material, there is a layer comprising starch (starch coating) and modifications thereof (modified starches). .
  • the starch coat is preferably applied in an amount of 0.1 to 3, particularly preferably 0.2 to 1.5 g/m 2 .
  • a line of starch on the side of the web-shaped carrier material on which the color layer is present has the advantage that the web-shaped carrier material is closed and the flattening of the color layer is improved and penetration of the color layer into the web-shaped carrier material can be reduced or prevented.
  • a line of starch on the side of the web-shaped carrier material on which the color layer is not present has the advantage that the color layer can be reduced or prevented from striking through the web-shaped carrier material.
  • the layer comprising starch preferably has a Bekk smoothness greater than 20s, more preferably greater than 50s, and most preferably from 50s to 200s.
  • the heat-sensitive recording material is preferably characterized in that a protective layer is provided on the heat-sensitive layer.
  • the protective layer preferably has a Bekk smoothness of greater than 200 s, particularly preferably greater than 400 s and very particularly preferably from 400 to 1500 s. Most preferred is a Bekk smoothness of 400 to 1300 s.
  • This protective layer preferably comprises at least one binder and at least one pigment, particularly preferably an inorganic pigment.
  • Suitable binders include water-soluble starches, starch derivatives, starch-based biolatices of the EcoSphere type, methyl cellulose, flydroxyethyl cellulose, carboxymethyl cellulose, partially or fully hydrolyzed polyvinyl alcohols, chemically modified polyvinyl alcohols such as acetoacetyl, diacetone, carboxy, silanol-modified polyvinyl alcohols, or styrene maleic anhydride copolymers, Styrene-butadiene copolymers, acrylamide (meth)acrylate copolymers, acrylamide-acrylate-methacrylate terpolymers, polyacrylates, poly(meth)acrylic esters, acrylate-butadiene copolymers, polyvinyl acetates and/or acrylonitrile-butadiene copolymers. These can be used alone or in any mixture.
  • Suitable inorganic pigments include inorganic pigments, both synthetic and natural, preferably clays, precipitated or natural calcium carbonates, aluminum oxides, aluminum hydroxides, silicic acids, precipitated and pyrogenic silica (e.g. Aerodisp types), diatomaceous earth, magnesium carbonate, talc, kaolin, titanium oxide, bentonite, but also organic pigments such as hollow pigments with a styrene/acrylate copolymer wall or urea/formaldehyde condensation polymers. These can be used alone or in any mixture.
  • inorganic pigments both synthetic and natural, preferably clays, precipitated or natural calcium carbonates, aluminum oxides, aluminum hydroxides, silicic acids, precipitated and pyrogenic silica (e.g. Aerodisp types), diatomaceous earth, magnesium carbonate, talc, kaolin, titanium oxide, bentonite, but also organic pigments such as hollow pigments with a styrene/acrylate copolymer wall or
  • Suitable organic pigments include such as hollow pigments having a styrene/acrylate copolymer wall or urea/formaldehyde condensation polymers. These can be used alone or in any mixture.
  • the binder is preferably present in the protective layer in an amount of from about 40 to about 90% by weight, more preferably in an amount of from about 50 to about 80% by weight, based on the total solids content of the protective layer.
  • the pigment is preferably present in the protective layer in an amount of from about 5 to about 40% by weight, more preferably in an amount of from about 10 to about 30% by weight, based on the total solids content of the protective layer.
  • the binder is preferably present in crosslinked form in the protective layer, the optimum degree of crosslinking of the binder occurring in the drying step of the coating process in the presence of a crosslinking agent (crosslinking agent).
  • crosslinking agent crosslinking agent
  • the crosslinking agents can be polyvalent aldehydes such as glyoxal, dialdehyde starch, glutaraldehyde, possibly mixed with boron salts (borax), salts or esters of glyoxylic acid, crosslinking agents based on ammonium zirconium carbonate, polyamidoamine-epichlorohydrin Resins (PAE resins), adipic acid dihydrazide (AHD), boric acid or salts thereof, polyamines, epoxy resins, formaldehyde oligomers, cyclic ureas, methylolurea, melamine formaldehyde oligomers, etc. These can be used alone or in any mixture. Ammonium zirconium carbonate and polyamidoamine-epichlorohydrin (PAE) resins are particularly preferred for reasons of food conformity.
  • PAE polyamidoamine-epichlorohydrin
  • Self-crosslinking binders such as specially modified polyvinyl alcohols or acrylates, enable crosslinking without any crosslinking agents thanks to the reactive, crosslinkable groups that are already built into the binder polymer.
  • the crosslinker is preferably present in an amount of from about 0.01 to about 25.0, more preferably in an amount of from about 0.05 to about 15.0, based on the total solids content of the color coat.
  • the protective layer also preferably comprises at least one lubricant or at least one release agent.
  • These agents are preferably fatty acid metal salts, such as zinc stearate or calcium stearate, or else behenate salts, synthetic waxes, e.g. B. in the form of fatty acid amides, such as. B. stearic acid amide and behenic acid amide, fatty acid alkanolamides, such as. B. stearic acid methylolamide, paraffin waxes of different melting points, ester waxes of different molecular weights, ethylene waxes, propylene waxes of different flavors and / or natural waxes, such as. B. carnauba wax or montan wax.
  • synthetic waxes e.g. B. in the form of fatty acid amides, such as. B. stearic acid amide and behenic acid amide, fatty acid alkanolamides, such as. B. stearic acid methylolamide, paraffin waxes of different melting points, ester waxes of different mole
  • the lubricant or release agent is preferably present in an amount of from about 1% to about 30% by weight, more preferably in an amount of from about 2% to about 20% by weight, based on the total solids content of the protective layer.
  • optical brighteners preferably stilbenes
  • the protective layer In order to control the surface whiteness of the heat-sensitive recording material according to the invention, optical brighteners, preferably stilbenes, can be incorporated into the protective layer.
  • the protective layer preferably has a basis weight of 0.3 to 5.0 g/m 2 , in particular 1.0 to 3.0 g/m 2 .
  • the protective layer preferably has a thickness of 0.3 to 6.0 ⁇ m, in particular 0.5 to 2.0 ⁇ m.
  • the use of a protective layer has the advantage that the recording material is better protected from external influences.
  • the heat-sensitive recording material is preferably characterized in that an adhesive layer is present on the side of the carrier material in web form on which the color layer is not located.
  • the adhesive layer preferably comprises at least one adhesive, preferably a heat-activatable adhesive, in particular a pressure-sensitive adhesive.
  • the adhesive preferably the heat-activatable adhesive and in particular the pressure-sensitive adhesive, is particularly preferably based on rubber and/or acrylate.
  • the adhesive layer preferably has a basis weight of 10 to 40 g/m 2 , in particular 12 to 25 g/m 2 .
  • the heat-sensitive recording material is preferably characterized in that a siliconized separating layer is present on the heat-sensitive layer.
  • siliconized release layer and "siliconized layer” are to be understood synonymously in the sense of "cover with a layer of silicone”. These layers preferably consist of silicone or comprise at least 90% by weight, preferably at least 95% by weight and particularly preferably at least 99 wt.
  • the siliconized separating layer preferably has a Bekk smoothness of greater than 400 s, particularly preferably greater than 800 s and very particularly preferably from 800 to 2000 s. If a protective layer, in particular as defined above, is present on the heat-sensitive layer, the siliconized release layer is preferably present on this protective layer.
  • the heat-sensitive recording material is preferably characterized in that a diffusion layer is formed between the siliconized layer and the underlying layer, preferably the heat-sensitive layer.
  • This diffusion layer is preferably formed by diffusing at least parts of the siliconized separating layer over a large area into the upper region of the underlying layer, with preferably 5 to 50% by weight, particularly preferably 6 to 45% by weight and in particular 7 to 40% by weight of the siliconized separating layer diffuse into the upper area of the underlying layer.
  • a diffusion layer is described, for example, in EP 3 221 153 A1.
  • a siliconized release layer is preferably present when an adhesive layer is also present as described above.
  • the presence of a siliconized release layer on the heat-sensitive layer and an adhesive layer on the web-shaped base material on the side where the ink layer is not located has the advantage that the heat-sensitive recording material can be used as a linerless heat-sensitive recording material.
  • Carrierless means that the (self-adhesive) heat-sensitive recording material according to the invention is not applied to a carrier material but is wound onto itself. This has the advantage that the production costs can be further reduced, more running meters per roll can be realized, no disposal effort for the disposal of the liner is necessary and more labels can be transported per specific loading space volume.
  • At least one platelet-shaped pigment is contained in the heat-sensitive layer or in the layer that lies directly below the siliconized separating layer.
  • the at least one platelet-shaped pigment is preferably selected from the group consisting of kaolin, Al(OH) 3 and/or talc.
  • kaolin is particularly preferred.
  • coated kaolin is very particularly preferred. Such is available, for example, under the trade name Kaolin ASP 109 (BASF, Germany).
  • the main advantage of using these platelet-shaped pigments, in particular kaolin, is that the heat-sensitive layer or the layer that lies directly below the siliconized separating layer can be siliconized very easily.
  • Platelet-shaped pigment is understood as meaning a pigment in which the ratio of diameter to thickness is about 7 to 40:1, preferably about 15 to 30:1.
  • the particle size of the platelet-shaped pigment is preferably adjusted in such a way that at least about 70%, preferably at least about 85%, of the particles have a particle size of about ⁇ 2 ⁇ m (Sedigraph).
  • the pH of the flaky pigment in aqueous solution is preferably 6 to 8.
  • the at least one platelet-shaped pigment is in the heat-sensitive color-forming layer or in the layer that lies directly below the siliconized release layer, preferably in an amount of about 5 to about 60% by weight, particularly preferably in an amount of about 15 to about 55% by weight, based on the total solids content of the respective layer.
  • the heat-sensitive recording material is preferably characterized in that the siliconized separating layer comprises at least one siloxane, preferably a poly(organo)siloxane, in particular an acrylic poly(organo)siloxane.
  • the siliconized release layer comprises a mixture of at least two siloxanes.
  • a mixture of at least two acrylic poly(organo)siloxanes is preferred.
  • the heat-sensitive recording material is preferably characterized in that the siliconized separating layer contains at least one polysilicon acrylate, which was preferably formed by condensation of at least one silicon acrylate
  • the siliconized release layer is preferably anhydrous. It is also preferred that the siliconized separating layer does not contain any Pt catalysts.
  • the siliconized separating layer preferably contains an initiator, particularly preferably a photoinitiator. This is used for radical curing of the silicone.
  • the siliconized separating layer can preferably contain other additives, such as matting agents and/or adhesion additives.
  • the siliconized separating layer preferably has a basis weight of 0.3 to 5.0 g/m 2 , in particular 1.0 to 3.0 g/m 2 .
  • the siliconized separating layer preferably has a thickness of 0.5 to 6.0 ⁇ m, in particular 0.5 to 2.0 ⁇ m.
  • All of the layers mentioned above can be formed in one or more layers.
  • the heat-sensitive recording material of the present invention according to the third aspect can be obtained by the manufacturing method described in connection with the first aspect.
  • the present invention also relates to a heat-sensitive recording material which can be obtained using the process described above.
  • the present invention also relates to the use of a heat-sensitive recording material as described above as a roll of receipts, as a roll of adhesive labels, also in the cold and deep-freeze sector, and as a roll of tickets.
  • a heat-sensitive recording material as described above as a roll of receipts, as a roll of adhesive labels, also in the cold and deep-freeze sector, and as a roll of tickets.
  • these have a functional side and/or back (with color, multicolored, black/grey) and can be pre-printed.
  • the rolls mentioned are preferably available in typical widths and lengths.
  • the present invention relates to a heat-sensitive recording material, comprising a web-shaped base material, an insulating layer on one side of the web-shaped base material, a colored layer on the insulating layer and a heat-sensitive layer on the colored layer, so that the colored layer is at least partially covered, the heat-sensitive layer is designed in such a way that it becomes translucent when exposed to local heat, so that the color layer underneath becomes visible.
  • the present invention relates to a heat-sensitive recording material, comprising a web-shaped base material, a layer that is both a color layer and an insulating layer on one side of the web-shaped base material, and a heat-sensitive layer on the color layer, so that the color layer at least is partially covered, the heat-sensitive layer being designed in such a way that it becomes translucent when exposed to local heat, so that the color layer underneath becomes visible.
  • Such an insulating layer or a colored layer which is both a colored layer and an insulating layer, causes a reduction in heat conduction through the heat-sensitive recording material.
  • the local application of heat using a direct thermal printer is more efficient and a higher thermal printer speed is possible.
  • the top layer becomes translucent more quickly due to the amount of heat introduced and the sensitivity is thus improved.
  • the heat-sensitive recording material with an insulating layer or a colored layer which is also an insulating layer has a lower thermal conductivity than a heat-sensitive recording material which does not have an insulating layer or a colored layer which is also an insulating layer.
  • the insulating layer or the colored layer which is both a colored layer and an insulating layer, preferably comprises a heat-insulating material.
  • the thermally insulating material preferably comprises kaolin, more preferably calcined kaolin and mixtures thereof.
  • the heat-insulating material can also comprise fleaball pigments, in particular fleaball pigments comprising styrene-acrylate copolymer.
  • These flea bead pigments preferably have a glass transition temperature of 40 to 80° C. and/or an average particle size of 0.1 to 2.5 ⁇ m.
  • the heat-insulating material is preferably present in the insulating layer in an amount of about 20 to about 80% by weight, more preferably in an amount of about 40 to about 60% by weight, based on the total solids content of the insulating layer.
  • the heat-insulating material is preferably present in an amount of about 30 to about 70% by weight, more preferably in an amount of about 40 to about 60% by weight, based on the total solids content of the paint layer, which is at the same time a paint layer and an insulating layer, in this.
  • the insulating layer or the colored layer which is both a colored layer and an insulating layer, preferably has a Bekk smoothness of greater than 50 s, particularly preferably greater than 100 s and very particularly preferably from 100 to 250 s.
  • the binder is preferably present in crosslinked form in the insulating layer and/or color layer, with the optimum degree of crosslinking of the binder in the drying step of the coating process in the presence of a crosslinking agent (crosslinking agent).
  • crosslinking agent crosslinking agent
  • the crosslinking agents can be polyvalent aldehydes such as glyoxal, dialdehyde starch, glutaraldehyde, possibly mixed with boron salts (borax), salts or esters of glyoxylic acid, crosslinking agents based on ammonium zirconium carbonate, polyamidoamine-epichlorohydrin Resins (PAE resins), adipic acid dihydrazide (AHD), boric acid or its salts, polyamines, epoxy resins, formaldehyde oligomers, cyclic ureas, methylolurea, melamine formaldehyde oligomers, etc. m. act. These can be used alone or in any mixture.
  • PAE resins polyamidoamine-epichlorohydrin Resins
  • AHD adipic acid dihydrazide
  • boric acid or its salts polyamines, epoxy resins, formaldehyde oligomers, cycl
  • Ammonium zirconium carbonate and polyamidoamine-epichlorohydrin (PAE) resins are particularly preferred for reasons of food conformity.
  • Self-crosslinking binders such as specially modified polyvinyl alcohols or acrylates, enable crosslinking without any crosslinking agents thanks to the reactive, crosslinkable groups that are already built into the binder polymer.
  • the crosslinking agent is preferably in an amount of about 0.01 to about 25.0% by weight, particularly preferably in an amount of about 0.05 to about 15.0% by weight, based on the total solids content of the insulating or color layer, before.
  • the insulating layer preferably has a basis weight of 1 to 5 g/m 2 , in particular 2 to 4 g/m 2 .
  • the insulating layer preferably has a thickness of 1 to 10 ⁇ m, in particular 2 to 8 ⁇ m.
  • the colored layer which is both a colored layer and an insulating layer, preferably has a basis weight of 1 to 10 g/m 2 , in particular 3 to 8 g/m 2 .
  • the colored layer which is both a colored layer and an insulating layer, preferably has a thickness of 1 to 12 ⁇ m, in particular 4 to 8 ⁇ m.
  • the heat-sensitive recording material is preferably characterized in that the heat-sensitive recording material has a residual moisture content of 2 to 14%, particularly preferably 2 to 12% and very particularly preferably 3 to 10%. A residual moisture content of 3 to 8% is most preferred.
  • Residual moisture in the specified range has the advantage that, after printing, there is a high relative print contrast with advantageous application properties, such as better readability.
  • the residual moisture can be determined as described in connection with the examples.
  • the opacity in the heat-sensitive layer is generated not only by the scattering particles, particularly the polymer particles, but also by the air trapped between the scattering particles, particularly the polymer particles (open porosity). Moisture entering these "pores” displaces air and reduces opacity. This can result in a grayer material, which is not preferred.
  • the heat-sensitive recording material is preferably characterized in that the heat-sensitive recording material has a surface whiteness of 35 to 60%, in particular 45 to 50%.
  • the surface whiteness (paper whiteness) can be determined according to ISO 2470-2 (2008) with an Elrepho 3000 spectrophotometer.
  • the heat-sensitive recording material is preferably characterized in that the contrast of places where the heat-sensitive layer has become translucent due to the local effect of heat to places where the heat-sensitive layer has not become translucent due to the local effect of heat , 40 to 80%, in particular from 50 to 70%.
  • This contrast can be calculated by taking the difference between the optical density of the background and the typeface. The optical density (n.d.) is measured, for example, using a densitometer.
  • the carrier material preferably has a Bekk smoothness of greater than 20 s, particularly preferably greater than 30 s and very particularly preferably greater than 50 s.
  • the color layer preferably has a Bekk smoothness of greater than 50 s, more preferably greater than 100 s and very particularly preferably greater than 150 s.
  • the heat-sensitive layer preferably has a Bekk smoothness of greater than 100 s, particularly preferably greater than 250 s.
  • the support material preferably has a Bekk smoothness of 20 to 400 s, particularly preferably 50 to 300 s and very particularly preferably 50 to 200 s on the side to which the colored layer is applied. Most preferred is a Bekk smoothness of 50 to 150 s.
  • the color layer preferably has a Bekk smoothness of 50 to 400 s, more preferably 100 to 250 s, and most preferably 150 to 250 s on the side on which the heat-sensitive layer is coated.
  • the heat-sensitive layer preferably has a Bekk smoothness of from 100 to 1000 s, particularly preferably from 250 to 800 s, on the side on which the color layer does not lie.
  • the Bekk smoothness is determined according to DIN 53107 (2016).
  • Such a heat-sensitive recording material has the advantage of high dynamic sensitivity. It is advantageous to already present a smooth web-like carrier material and to maintain this smoothness over the individual coatings. The smoother the substrate is built up from below, the better the final smoothness and thus the sensitivity of the end product.
  • each layer applied to the web-shaped carrier material has a Bekk smoothness on its upper side, i.e. on the side on which the web-shaped carrier material does not lie, which is at least as great as or greater than that of the respective underlying layer.
  • each layer applied to the substrate sheet has a Bekk smoothness of at least 5% (percentage increase) on its top surface, i.e., the side not bearing the substrate sheet, over the underlying layer.
  • each layer applied to the substrate sheet has a Bekk smoothness of at least 5% (absolute increase) on its upper side, i.e., on the side on which the substrate sheet does not lie, compared to the underlying layer.
  • the web-shaped carrier material is not limited.
  • the carrier material in web form comprises paper, synthetic paper and/or a plastic film.
  • the carrier material preferably has a basis weight of 30 to 100 g/m 2 , in particular 40 to 80 g/m 2 .
  • the carrier material in web form of the heat-sensitive recording material according to the invention preferably comprises at least one black or colored side, which is achieved by applying a colored layer.
  • the term "colored side" is understood to mean that the side has a color other than white or black.
  • the heat-sensitive recording material comprises at least one side that is colored in such a way that it is not white.
  • the at least one black or colored side has several different colors, also in combination with the color black.
  • the at least one colored layer on one side of the web-shaped carrier material is preferably characterized in that the colored layer comprises at least one pigment and/or one dye and preferably a binder.
  • the pigments and/or dyes include various organic and inorganic pigments, dyes and/or carbon black. These can be used alone or in any mixture.
  • the pigment, the dye and/or the carbon black are each preferably contained in the color layer in an amount of 2 to 50% by weight, particularly preferably 10 to 35% by weight, based on the total solid content of the color layer.
  • the binder is preferably contained in the color layer in an amount of 2 to 40% by weight, particularly preferably 10 to 30% by weight, based on the total solids content of the color layer.
  • the colored layer preferably has a basis weight of 1 to 10 g/m 2 , in particular 3 to 8 g/m 2 .
  • the colored layer preferably has a thickness of 1 to 10 ⁇ m, in particular 2 to 8 ⁇ m.
  • the heat-sensitive recording material is characterized in that the heat-sensitive layer comprises at least one scattering particle, in particular a polymer particle, with a glass transition temperature of -55 to 130°C, preferably 40 to 80°C.
  • the heat-sensitive recording material is characterized in that the heat-sensitive layer comprises at least one scattering particle, in particular a polymer particle, with a core/shell structure, the scattering particles, in particular the polymer particles, being selected from the group consisting of (i) scattering particles, in particular polymer particles, with an outer shell having a glass transition temperature of 40 °C to 80 °C and (ii) scattering particles, in particular polymer particles, having an inner shell with a glass transition temperature of 40 °C to 130 °C and an outer one Shell having a glass transition temperature of -55°C to 50°C, wherein the glass transition temperature of the outer shell is preferably lower than that of the inner shell.
  • the scattering particles in particular the polymer particles, being selected from the group consisting of (i) scattering particles, in particular polymer particles, with an outer shell having a glass transition temperature of 40 °C to 80 °C and (ii) scattering particles, in particular polymer particles, having an inner shell with a glass transition temperature of 40 °
  • the heat-sensitive recording material is characterized in that the heat-sensitive layer contains at least one scattering particle, in particular a polymer particle, with a melting point of less than 250°C, preferably from 0°C to 250°C.
  • the heat-sensitive recording material is characterized in that the heat-sensitive layer contains at least one scattering particle, in particular a polymer particle, with an average particle size in the range from 0.1 to 2.5 ⁇ m, preferably from 0.2 to 0.8 ⁇ m , includes.
  • the heat-sensitive recording material is characterized in that the heat-sensitive layer contains at least one scattering particle, in particular a polymer particle, with a glass transition temperature of -55 to 130 °C, preferably from 40 to 80 °C, and with an average particle size in the range from 0.1 to 2.5 pm, preferably from 0.2 to 0.8 pm.
  • the heat-sensitive layer contains at least one scattering particle, in particular a polymer particle, with a glass transition temperature of -55 to 130 °C, preferably from 40 to 80 °C, and with an average particle size in the range from 0.1 to 2.5 pm, preferably from 0.2 to 0.8 pm.
  • the heat-sensitive recording material is characterized in that the heat-sensitive layer comprises at least one scattering particle, in particular a polymer particle, with a core/shell structure, the scattering particles, in particular the polymer particles, being selected from the group consisting of from (i) scattering particles, in particular polymer particles, with an outer shell with a glass transition temperature of 40 ° C to 80 ° C and (ii) scattering particles, in particular polymer particles, with an inner shell with a glass transition temperature of 40 ° C to 130 ° C and a outer shell with a glass transition temperature of -55 °C to 50 °C, wherein the glass transition temperature of the outer shell is preferably lower than that of the inner shell, and with an average particle size in the range of 0.1 to 2.5 pm, preferably from 0 .2 to 0.8 pm.
  • the scattering particles, in particular the polymer particles being selected from the group consisting of from (i) scattering particles, in particular polymer particles, with an outer shell with a glass transition temperature of 40 ° C to
  • the heat-sensitive recording material is characterized in that the heat-sensitive layer contains at least one scattering particle, in particular a polymer particle, with a melting point of less than 250° C., preferably from 0° C. to 250° C., and with an average particle size in the range from from 0.1 to 2.5 pm, preferably from 0.2 to 0.8 pm.
  • the heat-sensitive layer contains at least one scattering particle, in particular a polymer particle, with a melting point of less than 250° C., preferably from 0° C. to 250° C., and with an average particle size in the range from from 0.1 to 2.5 pm, preferably from 0.2 to 0.8 pm.
  • a glass transition temperature or a melting point of less than 250° C. was recognized as advantageous. No direct thermal printing is possible above temperatures of 250 °C, since the temperature-time window is outside the printer specification.
  • An average particle size in the range from 0.1 to 2.5 ⁇ m is advantageous since particles of this size scatter visible light and the colored layer is thus covered as far as possible.
  • the average particle size can be determined using a Beckman Coulter device (laser diffraction, Fraunhofer method).
  • the scattering particles in particular the polymer particles, are preferably crystalline, partially crystalline and/or amorphous.
  • the glass transition temperatures mentioned above relate to partially crystalline or amorphous scattering particles, in particular polymer particles.
  • the melting temperatures relate to crystalline scattering particles, in particular polymer particles, or to the crystalline portion of the scattering particles, in particular polymer particles.
  • the scattering particles are preferably closed hollow body particles, in particular hollow spherical polymer particles, open hollow body particles, in particular polymer particles in the form of lattice cages, and/or solid particles, in particular irregularly shaped polymer particles.
  • the primary property of the scattering particles is the scattering of light in the visible range of light.
  • the secondary property is sensitivity to heat.
  • the polymer particles preferably comprise thermoplastic polymers.
  • the polymer particles preferably comprise polymers resulting from the polymerization of one or more monomers selected from the group consisting of acrylonitrile, styrene, butadiene, benzyl methacrylate, phenyl methacrylate, ethyl methacrylate, divinylbenzene, 2-hydroxyethyl methacrylate, cyclohexyl methacrylate, 2-methylstyrene, 3-methylstyrene, 4 -methylstyrene, alpha-methylstyrene, beta-methylstyrene, acrylamide, methacrylamide, methacrylonitrile, hydroxypropyl methacrylate, methoxystyrene, N-acrylylglycine amide and/or N-methacrylylglycine amide and/or their derivatives are selected.
  • the polymer particles can be polymerized using a variety of ethylenically unsaturated monomers.
  • nonionic monoethylenically unsaturated monomers include styrene, vinyl toluene, ethylene, vinyl acetate, vinyl chloride, vinylidene chloride, acrylonitrile, (meth)acrylamide, various (Ci-C2o)-alkyl or (C3-C2o)-alkenyl esters of (meth)acrylic acid, inclusive Methyl acrylate (MA), methyl methacrylate (MMA), ethyl (meth)acrylate, butyl (meth)acrylate, 2-hydroxyethyl (meth)acrylate, 2- ethylhexyl (meth)acrylate, benzyl (meth)acrylate, lauryl (meth)acrylate, oleyl (meth)acrylate, palmityl (meth)acrylate and stearyl (meth)acryl
  • acrylic esters such as MMA, EA, BA and styrene are preferred monomers to polymerize and form the shell of the polymer particles.
  • Difunctional vinyl monomers such as divinylbenzene, allyl methacrylate, ethylene glycol dimethacrylate, 1,3-butanediol dimethacrylate, diethylene glycol dimethacrylate,
  • Trimethylolpropane trimethacrylate and the like can also be copolymerized to form a crosslinked outer shell as described in US Patent Application 2003-0176535 A1.
  • the polymer particles preferably comprise (meth)acrylonitrile copolymers, polyvinyl chloride, polyvinylidene chloride, polystyrene, styrene acrylate, styrene-(meth)acrylate copolymers, polyacrylonitrile, polyacrylic esters or mixtures of at least two of these.
  • the strength and durability of the polymer particles can be influenced by the crosslinking of polymer chains.
  • the scattering particles in particular the polymer particles, can be present in the form of closed polymer particles, open polymer particles and/or solid particles, which can each have a regular or irregular shape.
  • Hollow spherical polymer particles or polymer particles with a core/shell structure can be mentioned in particular as examples of closed hollow body particles.
  • Ropaque HP-1055, Ropaque OP-96 and Ropaque TH-1000 can be mentioned as examples of hollow spherical polymer particles or polymer particles with a core/shell structure.
  • cup-shaped polymer particles in particular, can be mentioned as examples of open polymer particles.
  • the shell these have the same materials as the closed polymer particles, in particular the closed hollow spherical polymer particles.
  • open polymer particles which can be mentioned are polymer particles in the form of a lattice cage, as described in WO 2021/062230 A1.
  • Polyethylene, polystyrene and cellulose esters can be mentioned as examples of solid particles.
  • the above polymer particles may be regular or irregular in shape.
  • the polymer particles are spherical solid particles, preferably irregularly shaped, and/or spherical hollow particles, both preferably in the form of droplets.
  • These preferably include polystyrene, for example Plastic Pigment 756A from Trinseo LLC., and Plastic Pigment 772HS from Trinseo LLC., polyethylene, for example Chemipear 10 W401 from Mitsui Chemical Inc., to hollow spherical particles (HSP)/spherical hollow pigments, for example Ropaque TH-500EF from The Dow Chemical Co., modified polystyrene particles, e.g.
  • Joncryl 633 from BASF Corp., 1,2-diphenoxyethane (DPE), ethylene glycol m-tolyl ether (EGTE) and/or diphenylsulfone (DPS) . These can be used alone or in any mixture. These polymer particles preferably have an average particle size of 0.2 ⁇ m, 0.3 ⁇ m, 0.4 ⁇ m, 0.45 ⁇ m, 0.75 ⁇ m or 1.0 ⁇ m.
  • DPE 1,2-diphenoxyethane
  • EGTE ethylene glycol m-tolyl ether
  • DPS diphenylsulfone
  • the polymer particles are preferably contained in the heat-sensitive layer in an amount of from 20% to 60% by weight, preferably from 30% to 50% by weight, based on the solid content of the heat-sensitive layer.
  • the heat-sensitive layer comprises at least one heat-sensitive material having a melting temperature in the range from 40 to 200°C, preferably from 80 to 140°C, and/or a
  • the heat-sensitive layer comprises at least one heat-sensitive material having an average particle size of 0.2 to 4.0 ⁇ m, preferably 0.5 to 2.0 ⁇ m.
  • the heat-sensitive material also preferably contributes to the opacity (covering power) of the heat-sensitive layer, for example by absorbing and/or also scattering light. It is assumed that the heat-sensitive material quickly melts locally as a result of the local effect of heat from the thermal print head of the direct thermal printer, resulting in a local "softening" of the polymer particles and thus a local reduction in opacity (reduction in opacity), so that the cover layer translucent and the underlying color layer becomes visible.
  • the heat-sensitive material can also be referred to as a sensitizer or a thermal solvent.
  • the heat-sensitive material comprises one or more fatty acids such as stearic acid, behenic acid or palmitic acid, one or more fatty acid amides such as stearamide, behenamide or palmitamide, an ethylene-bis-fatty acid amide such as N,N'-ethylene-bis-stearic acid amide or N, N'-ethylene-bis-oleic acid amide, one or more fatty acid alkanolamides, in particular hydroxymethylated fatty acid amides such as N-(flydroxymethyl)stearamide, N-hydroxymethyl palmitamide, hydroxyethyl stearamide, one or more waxes such as polyethylene wax, candelilla wax, carnauba wax or montan wax, one or more carboxylic acid esters such as dimethyl terephthalate, dibenzyl terephthalate, benzyl 4-benzyloxybenzoate, di-(4-methylbenzyl) oxalate, di-(4-chlor
  • the heat-sensitive material is preferably present in the heat-sensitive layer in an amount of from about 10 to about 80% by weight, more preferably from about 25 to about 60% by weight, based on the total solids content of the heat-sensitive layer.
  • lubricants or release agents can also be present in the heat-sensitive layer.
  • Such lubricants or release agents are present in particular when there is no protective layer or no further layer on the heat-sensitive layer.
  • These agents are preferably fatty acid metal salts, such as zinc stearate or calcium stearate, or else behenate salts, synthetic waxes, e.g. B. in the form of fatty acid amides, such as. B. stearic acid amide and behenic acid amide, fatty acid alkanolamides, such as. B. stearic acid methylolamide, paraffin waxes of different melting points, ester waxes of different molecular weights, ethylene waxes, propylene waxes of different flavors and / or natural waxes, such as. B. carnauba wax or montan wax. These can be used alone or in any mixture.
  • Zinc stearate is preferred because it has an advantageous price/performance ratio.
  • the lubricant or release agent is present in the heat-sensitive layer preferably in an amount of about 1 to about 10% by weight, more preferably in an amount of about 3 to about 6% by weight, based on the total solids content of the heat-sensitive layer shift before.
  • At least one binder is present in the heat-sensitive layer.
  • This is preferably water-soluble starches, starch derivatives, starch-based biolatices of the EcoSphere type, methyl cellulose, flydroxyethyl cellulose, carboxymethyl cellulose, gelatin, casein, partially or fully hydrolyzed polyvinyl alcohols, chemically modified polyvinyl alcohols, ethylene-vinyl alcohol copolymers, sodium polyacrylates, styrene-maleic anhydride -copolymers, Ethylene-maleic anhydride copolymers, styrene-butadiene copolymers, acrylamide-(meth)acrylate copolymers, acrylamide-acrylate-methacrylate terpolymers, polyacrylates, poly(meth)acrylic acid esters, acrylate-butadiene copolymers, polyvinyl acetates and/or acrylonitrile-butadiene copo
  • Partially or partially hydrolyzed polyvinyl alcohols are preferred because they have an advantageous price/performance ratio.
  • the binder is preferably present in the heat-sensitive layer in an amount of from 1 to 30% by weight, preferably from 5 to 20% by weight, based on the total solids content of the heat-sensitive layer.
  • the binder is preferably present in crosslinked form in the heat-sensitive layer, the optimum degree of crosslinking of the binder occurring in the drying step of the coating process in the presence of a crosslinking agent (crosslinking agent).
  • crosslinking agent crosslinking agent
  • the crosslinking agents can be polyvalent aldehydes such as glyoxal, dialdehyde starch, glutaraldehyde, possibly mixed with boron salts (borax), salts or esters of glyoxylic acid, crosslinking agents based on ammonium zirconium carbonate, polyamidoamine-epichlorohydrin Flarze (PAE-Flarze), adipic acid dihydrazide (AFID), boric acid or its salts, polyamines, epoxy resins, formaldehyde oligomers, cyclic flame substances, methylolurea, melamine-formaldehyde oligomers, etc. These can be used alone or in any mixture.
  • PAE-Flarze polyamidoamine-epichlorohydrin Flarze
  • AFID adipic acid dihydrazide
  • boric acid or its salts polyamines, epoxy resins, formaldehyde oligomers,
  • Ammonium zirconium carbonate and polyamidoamine-epichlorohydrin resin are particularly preferred for reasons of food conformity.
  • Self-crosslinking binders such as specially modified polyvinyl alcohols or acrylates, enable crosslinking without any crosslinking agents thanks to the reactive, crosslinkable groups that are already built into the binder polymer.
  • the crosslinking agent is preferably in an amount of about 0.01 to about 25.0% by weight, particularly preferably in an amount of about 0.05 to about 15.0% by weight, based on the total solids content of the color layer. before.
  • the heat-sensitive layer contains pigments. These pigments are preferably different from the pigments of the color layer.
  • the use of these has the advantage, among other things, that they can fix the chemical melt produced in the thermal printing process on their surface.
  • the surface whiteness and opacity of the heat-sensitive layer and its printability with conventional printing inks can also be controlled via pigments.
  • pigments are inorganic pigments of both synthetic and natural origin, preferably clays, precipitated or natural calcium carbonates, aluminum oxides, aluminum hydroxides, silicic acids, precipitated and pyrogenic silicic acids (e.g. Aerodisp types), diatomaceous earths, magnesium carbonates, talc, kaolin, Titanium oxide, bentonite, but also organic pigments such as flea pigments with a styrene/acrylate copolymer wall or flan/formaldehyde condensation polymers. These can be used alone or in any mixture.
  • inorganic pigments of both synthetic and natural origin preferably clays, precipitated or natural calcium carbonates, aluminum oxides, aluminum hydroxides, silicic acids, precipitated and pyrogenic silicic acids (e.g. Aerodisp types), diatomaceous earths, magnesium carbonates, talc, kaolin, Titanium oxide, bentonite, but also organic pigments such as flea pigments with a styrene/acrylate copoly
  • Calcium carbonates, aluminum hydroxides and pyrogenic silicic acids are preferred, since they enable the heat-sensitive recording materials to have particularly advantageous performance properties with regard to their subsequent printability with commercially available printing inks.
  • the pigments are preferably present in the heat-sensitive layer in an amount of from about 2 to about 50% by weight, more preferably in an amount of from about 5 to about 20% by weight, based on the total solids content of the heat-sensitive layer.
  • the heat-sensitive layer can also contain carbon black components and/or dyes/color pigments.
  • optical brighteners can be incorporated into the heat-sensitive color-forming layer can be installed. These are preferably stilbenes.
  • the heat-sensitive layer may further contain inorganic oil-absorbing white pigments.
  • inorganic oil-absorbing white pigments examples include natural or calcined kaolin, silica, bentonite, calcium carbonate, aluminum hydroxide, especially boehmite, and/or mixtures thereof.
  • the inorganic oil-absorbing white pigments are preferably present in the heat-sensitive layer in an amount of about 2 to about 50% by weight, more preferably in an amount of about 5 to about 20% by weight, based on the total solids content of the heat-sensitive layer .
  • rheological aids such as e.g. As thickeners and / or surfactants to add.
  • the other components are each preferably present in customary amounts known to those skilled in the art.
  • the heat-sensitive layer preferably has a basis weight of 1 to 8 g/m 2 , in particular 2 to 6 g/m 2 .
  • the heat-sensitive layer preferably has a thickness of 1 to 10 ⁇ m, in particular 2 to 8 ⁇ m.
  • the heat-sensitive recording material is preferably characterized in that directly on at least one side of the web-shaped carrier material, preferably directly on both sides of the web-shaped carrier material, a layer comprising starch (starch coating) and/or modifications thereof (modified starches), is available.
  • the starch coat is preferably applied in an amount of 0.1 to 3, particularly preferably 0.2 to 1.5 g/m 2 .
  • a line of starch on the side of the web-shaped carrier material on which the color layer is present has the advantage that the web-shaped carrier material is closed and the adhesion of the color layer is improved and penetration of the color layer into the web-shaped carrier material can be reduced or prevented.
  • a line of starch on the side of the web-shaped carrier material on which the color layer is not present has the advantage that the color layer can be reduced or prevented from striking through the web-shaped carrier material.
  • the layer comprising starch preferably has a Bekk smoothness greater than 20 s, more preferably greater than 50 s, and most preferably from 50 to 200 s.
  • the heat-sensitive recording material is preferably characterized in that a protective layer is provided on the heat-sensitive layer.
  • the protective layer preferably has a Bekk smoothness of greater than 200 s, particularly preferably greater than 400 s and very particularly preferably from 400 to 1500 s.
  • a Bekk smoothness of 400 to 1300 s is most preferred.
  • This protective layer preferably comprises at least one binder and at least one pigment, particularly preferably an inorganic pigment.
  • Suitable binders include water-soluble starches, starch derivatives, starch-based Biolatices of the EcoSphere type, methyl cellulose, hydroxyethyl cellulose, carboxymethyl cellulose, partially or fully saponified polyvinyl alcohols, chemically modified polyvinyl alcohols such as acetoacetyl, diacetone, carboxy, silanol-modified polyvinyl alcohols, or Styrene-maleic anhydride copolymers, styrene-butadiene copolymers, acrylamide (meth)acrylate copolymers, acrylamide-acrylate-methacrylate terpolymers, polyacrylates, poly(meth)acrylic esters, acrylate-butadiene copolymers, polyvinyl acetates and/or acrylonitrile-butadiene copolymers. These can be used alone or in any mixture.
  • Suitable inorganic pigments include inorganic pigments of both synthetic and natural origin, preferably clays, precipitated or natural calcium carbonates, aluminum oxides, aluminum hydroxides, silicic acids, precipitated and pyrogenic silicic acids (e.g. Aerodisp types), diatomaceous earths, magnesium carbonates, talc, kaolin, Titanium oxide, bentonite, but also organic pigments such as hollow pigments with a styrene/acrylate copolymer wall or urea/formaldehyde condensation polymers. These can be used alone or in any mixture.
  • inorganic pigments of both synthetic and natural origin, preferably clays, precipitated or natural calcium carbonates, aluminum oxides, aluminum hydroxides, silicic acids, precipitated and pyrogenic silicic acids (e.g. Aerodisp types), diatomaceous earths, magnesium carbonates, talc, kaolin, Titanium oxide, bentonite, but also organic pigments such as hollow pigments with a styrene/
  • Suitable organic pigments include hollow pigments having a styrene/acrylate copolymer wall or urea/formaldehyde condensation polymers. These can be used alone or in any mixture.
  • the binder is preferably present in the protective layer in an amount of from about 40 to about 90% by weight, more preferably in an amount of from about 50 to about 80% by weight, based on the total solids content of the protective layer.
  • the pigment is preferably present in the protective layer in an amount of from about 5 to about 40% by weight, more preferably in an amount of from about 10 to about 30% by weight, based on the total solids content of the protective layer.
  • the binder is preferably present in crosslinked form in the protective layer, the optimum degree of crosslinking of the binder occurring in the drying step of the coating process in the presence of a crosslinking agent (crosslinking agent).
  • crosslinking agent crosslinking agent
  • the crosslinkers can be polyvalent aldehydes, such as glyoxal, dialdehyde starch, glutaraldehyde, optionally in a mixture with boron salts (borax). Salts or esters of glyoxylic acid, ammonium zirconium carbonate-based crosslinkers, polyamidoamine-epichlorohydrin resins (PAE resins), adipic acid dihydrazide (AHD), boric acid or its salts, polyamines, epoxy resins, formaldehyde oligomers, cyclic ureas, methylolurea, melamine formaldehyde oligomers, etc. These can be used alone or in any mixture.
  • PAE resins polyamidoamine-epichlorohydrin resins
  • AHD adipic acid dihydrazide
  • boric acid or its salts polyamines, epoxy resins, formaldehyde oligomers, cyclic ureas
  • Ammonium zirconium carbonate and polyamidoamine-epichlorohydrin (PAE) resins are particularly preferred for reasons of food conformity.
  • Self-crosslinking binders such as specially modified polyvinyl alcohols or acrylates, enable crosslinking without any crosslinking agents thanks to the reactive, crosslinkable groups that are already built into the binder polymer.
  • the crosslinking agent is preferably in an amount of about 0.01 to about 25.0% by weight, particularly preferably in an amount of about 0.05 to about 15.0% by weight, based on the total solids content of the color layer. before.
  • the protective layer also preferably comprises at least one lubricant or at least one release agent.
  • These agents are preferably fatty acid metal salts, such as zinc stearate or calcium stearate, or else behenate salts, synthetic waxes, e.g. B. in the form of fatty acid amides, such as. B. stearic acid amide and behenic acid amide, fatty acid alkanolamides, such as. B. stearic acid methylolamide, paraffin waxes of different melting points, ester waxes of different molecular weights, ethylene waxes, propylene waxes of different hardnesses and / or natural waxes, such as. B. carnauba wax or montan wax.
  • synthetic waxes e.g. B. in the form of fatty acid amides, such as. B. stearic acid amide and behenic acid amide, fatty acid alkanolamides, such as. B. stearic acid methylolamide, paraffin waxes of different melting points, ester waxes of
  • the lubricant or release agent is preferably present in an amount of from about 1% to about 30% by weight, more preferably in an amount of from about 2% to about 20% by weight, based on the total solids content of the protective layer.
  • optical brighteners preferably stilbenes
  • the protective layer preferably has a basis weight of 0.3 to 5.0 g/m 2 , in particular 1.0 to 3.0 g/m 2 .
  • the protective layer preferably has a thickness of 0.3 to 6.0 gm, in particular 0.5 to 2.0 gm.
  • the use of a protective layer has the advantage that the recording material is better protected from external influences.
  • the heat-sensitive recording material is preferably characterized in that an adhesive layer is present on the side of the carrier material in web form on which the color layer is not located.
  • the adhesive layer preferably comprises at least one adhesive, preferably a heat-activatable adhesive, in particular a flat adhesive.
  • the adhesive preferably the heat-activatable adhesive and in particular the pressure-sensitive adhesive, is particularly preferably an adhesive based on rubber and/or acrylate.
  • the adhesive layer preferably has a basis weight of 10 to 40 g/m 2 , in particular 12 to 25 g/m 2 .
  • the heat-sensitive recording material is preferably characterized in that a siliconized separating layer is present on the heat-sensitive layer.
  • siliconized release layer and "siliconized layer” are to be understood synonymously in the sense of "cover with a layer of silicone”. These layers preferably consist of silicone or comprise at least 90% by weight, preferably at least 95% by weight and particularly preferably at least 99 wt.
  • the siliconized separating layer preferably has a Bekk smoothness of greater than 400 s, particularly preferably greater than 800 s and very particularly preferably from 800 to 2000 s.
  • the siliconized release layer is preferably present on this protective layer.
  • the heat-sensitive recording material is preferably characterized in that a diffusion layer is formed between the siliconized layer and the underlying layer, preferably the heat-sensitive layer.
  • This diffusion layer is preferably formed by diffusing at least parts of the siliconized separating layer over a large area into the upper region of the underlying layer, with preferably 5 to 50% by weight, particularly preferably 6 to 45% by weight and in particular 7 to 40% by weight of the siliconized separating layer diffuse into the upper area of the underlying layer.
  • a diffusion layer is described, for example, in EP 3 221 153 A1.
  • a siliconized release layer is preferably present when an adhesive layer is also present as described above.
  • the presence of a siliconized release layer on the heat-sensitive layer and an adhesive layer on the web-shaped base material on the side where the ink layer is not located has the advantage that the heat-sensitive recording material can be used as a linerless heat-sensitive recording material.
  • Carrierless means that the (self-adhesive) heat-sensitive recording material according to the invention is not applied to a carrier material but is wound onto itself. This has the advantage that the production costs can be further reduced, more running meters per roll can be realized, no disposal effort for the disposal of the liner is necessary and more labels can be transported per specific loading space volume.
  • a siliconized separating layer it is preferred that at least one platelet-shaped pigment is contained in the heat-sensitive layer or in the layer that lies directly below the siliconized separating layer.
  • the at least one platelet-shaped pigment is preferably selected from the group consisting of kaolin, Al(OH) 3 and/or talc.
  • kaolin is particularly preferred.
  • coated kaolin is very particularly preferred. Such is available, for example, under the trade name Kaolin ASP 109 (BASF, Germany).
  • the main advantage of using these platelet-shaped pigments, in particular kaolin, is that the heat-sensitive layer or the layer that lies directly below the siliconized separating layer can be siliconized very easily.
  • Platelet-shaped pigment is understood as meaning a pigment in which the ratio of diameter to thickness is about 7 to 40:1, preferably about 15 to 30:1.
  • the particle size of the platelet-shaped pigment is preferably adjusted in such a way that at least about 70%, preferably at least about 85%, of the particles have a particle size of about ⁇ 2 ⁇ m (Sedigraph).
  • the pH of the flaky pigment in aqueous solution is preferably 6 to 8.
  • the at least one platelet-shaped pigment is in the heat-sensitive color-forming layer or in the layer that lies directly below the siliconized release layer, preferably in an amount of about 5 to about 60% by weight, particularly preferably in an amount of about 15 to about 55% by weight, based on the total solids content of the respective layer.
  • the heat-sensitive recording material is preferably characterized in that the siliconized separating layer comprises at least one siloxane, preferably a poly(organo)siloxane, in particular an acrylic poly(organo)siloxane.
  • the siliconized release layer comprises a mixture of at least two siloxanes. A mixture of at least two acrylic poly(organo)siloxanes is preferred.
  • siloxanes available under the trade names TEGO®RC902 and TEGO®RC711 (Evonik, Germany).
  • the heat-sensitive recording material is preferably characterized in that the siliconized separating layer contains at least one polysilicon acrylate, which was preferably formed by condensation of at least one silicon acrylate.
  • the siliconized release layer is preferably anhydrous. It is also preferred that the siliconized separating layer does not contain any Pt catalysts.
  • the siliconized separating layer preferably contains an initiator, particularly preferably a photoinitiator. This is used for radical curing of the silicone.
  • the siliconized separating layer can preferably contain other additives, such as matting agents and/or adhesion additives.
  • the siliconized separating layer preferably has a basis weight of 0.1 to 5.0 g/m 2 , preferably 0.3 to 5.0 g/m 2 , in particular 1.0 to 3.0 g/m 2 or 0 2 to 2.0 g/m 2 .
  • the siliconized separating layer preferably has a thickness of 0.1 to 6.0 ⁇ m, preferably 0.3 to 6.0 ⁇ m, in particular 0.5 to 2.0 ⁇ m or 0.2 to 1.5 ⁇ m.
  • the application of a siliconized separating layer leads to improved resistance properties due to its hydrophobic character heat-sensitive recording material to hydrophilic agents such. As alcohols or water.
  • the siliconized separating layer is therefore suitable as a protective layer.
  • All of the layers mentioned above can be formed in one or more layers.
  • the heat-sensitive recording material according to the fourth and fifth aspects of the present invention can be obtained by the manufacturing method described in connection with the first aspect.
  • the present invention also relates to a heat-sensitive recording material which can be obtained using the process described above.
  • the present invention also relates to the use of a heat-sensitive recording material as described above as a roll of receipts, as a roll of adhesive labels, also in the cold and deep-freeze sector, and as a roll of tickets.
  • a heat-sensitive recording material as described above as a roll of receipts, as a roll of adhesive labels, also in the cold and deep-freeze sector, and as a roll of tickets.
  • these have a functional side and/or back (with color, multicolored, black/grey) and can be pre-printed.
  • the rolls mentioned are preferably available in typical widths and lengths.
  • the present invention relates to a heat-sensitive recording material, comprising a web-shaped base material, a color layer on one side of the web-shaped base material and a heat-sensitive layer on the color layer, so that the color layer is at least partially covered, the heat-sensitive layer being configured in such a way that this becomes translucent through the local effect of heat, so that the color layer underneath becomes visible, characterized in that the heat-sensitive layer contains or consists of scattering particles, in particular a heat-sensitive material (as scattering particles), in particular a scattering particle, in particular a heat-sensitive material (as Scatter particles) selected from the group of biopolymers, modified biopolymers, fats, natural waxes, semi-synthetic waxes and / or synthetic waxes.
  • Such a heat-sensitive recording material is characterized in particular by the fact that sustainable raw materials are used.
  • biopolymers include natural biopolymers such as proteins, peptides, nucleic acids, ⁇ -polysaccharides, ⁇ -polysaccharides, lipids, polyhydroxyalkanuates, cutin, sulberin and/or lignin.
  • Regenerated fibers such as viscose and cellophane and celluloid as well as thermoplastic starch can be mentioned as examples of native polymers.
  • bio-based polymers are polylactides, polyhydroxybutyrates, lignin-based thermoplastics and/or epoxy acrylates based on oils, in particular linseed oil and palm oil.
  • Polyester polyvinyl alcohol, polybutylene adipate terephthalate, polybutylene succinate, polycaprolactone and/or polyglycolide can be mentioned as an example of degradable, petroleum-based polymers.
  • modified biopolymers include e.g. B. the esters of cellulose and / or lignin. These can be used alone or as mixtures.
  • Suitable examples of fats include, for example, fats based on saturated and/or unsaturated fatty acids, such as butyric acid, lauric acid, myristic acid, palmitic acid, stearic acid, arachidic acid, lauroleic acid, myrstolic acid, palmitoleic acid, oleic acid, linoleic acid, linolenic acid, gadoleic acid and/or arachidonic acid.
  • saturated and/or unsaturated fatty acids such as butyric acid, lauric acid, myristic acid, palmitic acid, stearic acid, arachidic acid, lauroleic acid, myrstolic acid, palmitoleic acid, oleic acid, linoleic acid, linolenic acid, gadoleic acid and/or arachidonic acid.
  • Suitable examples of natural waxes include, for example, carnauba wax, candelilla wax and/or montan wax.
  • Suitable examples of synthetic waxes include, for example, (hydro)carbon waxes, polyolefin waxes, HD-PE waxes, PE waxes, EVA waxes, polyester waxes, polyethylene glycol waxes, PTFE waxes, fluorine waxes, Fischer-Tropsch waxes, synthetic fatty acid esters and/or reconstituted waxes. These can be used alone or as mixtures.
  • Suitable examples of partially synthetic waxes include, for example, stearic acid amide wax and/or palmitic acid amide wax. These can be used alone or as a mixture.
  • waxes from the group of animal waxes, vegetable waxes, mineral waxes and/or microwaxes is also conceivable.
  • biopolymers, the modified biopolymers, the fats, the natural waxes, the partially synthetic waxes and the synthetic waxes can be used alone or as mixtures.
  • the heat-sensitive recording material is preferably characterized in that the scattering particles, preferably the heat sensitive material is selected from amide waxes, stearic acid amide waxes, palmitic acid amide waxes or combinations thereof.
  • Such amide waxes are used because they have an advantageous price/performance ratio.
  • the heat-sensitive recording material is preferably characterized in that the scattering particles, preferably the heat-sensitive material, are present in an amount of 5 to 100% by weight, preferably 40 to 100% by weight and particularly preferably 40 to 95% by weight % based on the total weight of the heat-sensitive layer.
  • the heat-sensitive recording material is preferably characterized in that the scattering particles, preferably the heat-sensitive material, have a melting point in the range from 30 to 250°C, preferably in the range from 40 to 200°C.
  • a melting temperature of less than 250 °C was found to be advantageous; direct thermal printing is not possible above temperatures of 250 °C, since the temperature-time window is outside the printer specifications.
  • the heat-sensitive recording material is preferably characterized in that the scattering particles, preferably the heat-sensitive material, comprise at least one binder and/or at least one pigment.
  • This binder is preferably water-soluble starches, starch derivatives, starch-based biolatices of the EcoSphere type, methyl cellulose, hydroxyethyl cellulose, carboxymethyl cellulose, gelatin, casein, partially or fully hydrolyzed polyvinyl alcohols, chemically modified polyvinyl alcohols, ethylene-vinyl alcohol copolymers, sodium polyacrylates , Styrene-maleic anhydride copolymers, ethylene-maleic anhydride copolymers, styrene-butadiene copolymers, acrylamide (meth)acrylate copolymers, acrylamide-acrylate-methacrylate terpolymers, polyacrylates, poly(meth)acrylic acid esters, acrylate-butadiene copolymers, polyvinyl acetates and/or acrylonitrile butadiene copolymers. These can be used alone or in any mixture
  • Partially or partially hydrolyzed polyvinyl alcohols are preferred because they have an advantageous price/performance ratio.
  • the binder is preferably present in the heat-sensitive layer in an amount of from 1 to 30% by weight, preferably from 5 to 20% by weight, based on the total solids content of the heat-sensitive layer.
  • the binder is preferably present in crosslinked form in the heat-sensitive layer, the optimum degree of crosslinking of the binder occurring in the drying step of the coating process in the presence of a crosslinking agent (crosslinking agent).
  • crosslinking agent crosslinking agent
  • the crosslinking agents can be polyvalent aldehydes such as glyoxal, dialdehyde starch, glutaraldehyde, possibly mixed with boron salts (borax), salts or esters of glyoxylic acid, crosslinking agents based on ammonium zirconium carbonate, polyamidoamine-epichlorohydrin resins (PAE resins), adipic acid dihydrazide (AFID), boric acid or its salts, polyamines, epoxy resins, formaldehyde oligomers, cyclic flames, methylolurea, melamine-formaldehyde oligomers, and others. m. act. These can be used alone or in any mixture.
  • Ammonium zirconium carbonate and polyamidoamine-epichlorohydrin resin are particularly preferred for reasons of food conformity.
  • Self-crosslinking binders such as specially modified polyvinyl alcohols or acrylates, enable crosslinking without any crosslinking agents thanks to the reactive, crosslinkable groups that are already built into the binder polymer.
  • the crosslinking agent is preferably in an amount of about 0.01 to about 25.0% by weight, particularly preferably in an amount of about 0.05 to about 15.0% by weight, based on the total solids content of the color layer. before.
  • the heat-sensitive layer contains pigments. These pigments are preferably different from the pigments of the color layer. The use of these has the advantage, among other things, that they can fix the chemical melt produced in the thermal printing process on their surface. The surface whiteness and opacity of the heat-sensitive layer and its printability with conventional printing inks can also be controlled via pigments.
  • pigments are inorganic pigments of both synthetic and natural origin, preferably clays, precipitated or natural calcium carbonates, aluminum oxides, aluminum hydroxides, silicic acids, precipitated and pyrogenic silicic acids (e.g. Aerodisp types), diatomaceous earths, magnesium carbonates, talc, kaolin, Titanium oxide, bentonite, but also organic pigments such as hollow pigments with a styrene/acrylate copolymer wall or urea/formaldehyde condensation polymers. These can be used alone or in any mixture.
  • inorganic pigments of both synthetic and natural origin preferably clays, precipitated or natural calcium carbonates, aluminum oxides, aluminum hydroxides, silicic acids, precipitated and pyrogenic silicic acids (e.g. Aerodisp types), diatomaceous earths, magnesium carbonates, talc, kaolin, Titanium oxide, bentonite, but also organic pigments such as hollow pigments with a styrene/acrylate copolymer
  • Calcium carbonates, aluminum hydroxides and pyrogenic silicic acids are preferred, since they enable the heat-sensitive recording materials to have particularly advantageous performance properties with regard to their subsequent printability with commercially available printing inks.
  • the pigments are preferably present in the heat-sensitive layer in an amount of from about 2 to about 50% by weight, more preferably in an amount of from about 5 to about 20% by weight, based on the total solids content of the heat-sensitive layer.
  • the heat-sensitive layer can also contain carbon black components and/or dyes/color pigments.
  • optical brighteners can be incorporated into the heat-sensitive color-forming layer. These are preferably stilbenes.
  • the heat-sensitive layer may further contain inorganic oil-absorbing white pigments.
  • inorganic oil-absorbing white pigments include natural or calcined kaolin, silica, bentonite, calcium carbonate, aluminum hydroxide, especially boehmite, and/or mixtures thereof.
  • the inorganic oil-absorbing white pigments are preferably present in the heat-sensitive layer in an amount of about 2 to about 50% by weight, more preferably in an amount of about 5 to about 20% by weight, based on the total solids content of the heat-sensitive layer .
  • rheological aids such as e.g. As thickeners and / or surfactants to add.
  • the other components are each preferably present in customary amounts known to those skilled in the art.
  • the heat-sensitive layer preferably has a basis weight of 1 to 8 g/m 2 , in particular 2 to 6 g/m 2 .
  • the heat-sensitive layer preferably has a thickness of 1 to 10 ⁇ m, in particular 2 to 8 ⁇ m.
  • the heat-sensitive recording material is preferably characterized in that the heat-sensitive recording material has a residual moisture content of 2 to 14%, preferably 2 to 12% and very particularly preferably 3 to 8%. A residual moisture content of 5 to 8% is most preferred.
  • Residual moisture in the specified range has the advantage that, after printing, there is a high relative print contrast with advantageous application properties, such as better legibility.
  • the residual moisture can be determined as described in connection with the examples. It is assumed that the opacity in the heat-sensitive layer is generated not only by the scattering particles, especially the polymer particles, but also by the air trapped between the scattering particles, especially the polymer particles (open porosity). Moisture entering these "pores" displaces air and reduces opacity. This can result in a grayer material, which is not preferred.
  • the heat-sensitive recording material is preferably characterized in that the heat-sensitive recording material has a surface whiteness of 35 to 60%, in particular 45 to 50%.
  • the surface whiteness (paper white) can be determined according to ISO 2470-2 (2008) with an Elrepho 3000 spectrophotometer.
  • the heat-sensitive recording material is preferably characterized in that the contrast of places where the heat-sensitive layer has become translucent due to the local effect of heat to places where the heat-sensitive layer has not become translucent due to the local effect of heat , 40 to 80%, in particular from 50 to 70%.
  • This contrast can be calculated by taking the difference between the optical density of the background and the typeface.
  • the optical density (n.d.) is measured, for example, using a densitometer.
  • the carrier material preferably has a Bekk smoothness of greater than 20 s, particularly preferably greater than 30 s and very particularly preferably greater than 50 s.
  • the color layer preferably has a Bekk smoothness of greater than 50 s, more preferably greater than 100 s and very particularly preferably greater than 150 s.
  • the heat-sensitive layer preferably has a Bekk smoothness of greater than 100 s, particularly preferably greater than 250 s.
  • the support material preferably has a Bekk smoothness of 20 to 400 s, particularly preferably 50 to 300 s and very particularly preferably 50 to 200 s on the side to which the colored layer is applied. Most preferred is a Bekk smoothness of 50 to 150 s.
  • the color layer preferably has a Bekk smoothness of 50 to 400 s, more preferably 100 to 250 s, and most preferably 150 to 250 s on the side on which the heat-sensitive layer is coated.
  • the heat-sensitive layer preferably has a Bekk smoothness of from 100 to 1000 s, particularly preferably from 250 to 800 s, on the side on which the color layer does not lie.
  • the Bekk smoothness is determined according to DIN 53107 (2016).
  • Such a heat-sensitive recording material has the advantage of high dynamic sensitivity.
  • each layer applied to the web-shaped carrier material has a Bekk smoothness on its upper side, i.e. on the side on which the web-shaped carrier material does not lie, which is at least as great as or greater than that of the respective underlying layer.
  • Each layer applied to the web-shaped carrier material preferably has a Bekk smoothness of at least 5% (percentage increase) compared to the respective underlying layer on its upper side, ie on the side on which the web-shaped carrier material lies.
  • Each layer applied to the web-shaped carrier material preferably has a Bekk smoothness of at least 5% (absolute increase) compared to the respective underlying layer on its upper side, ie on the side on which the web-shaped carrier material is not located.
  • the web-shaped carrier material is not limited.
  • the carrier material in web form comprises paper, synthetic paper and/or a plastic film.
  • the carrier material preferably has a basis weight of 30 to 100 g/m 2 , in particular 40 to 80 g/m 2 .
  • the carrier material in web form of the heat-sensitive recording material according to the invention preferably comprises at least one black or colored side, which is achieved by applying a colored layer.
  • the term "colored side” is understood to mean that the side has a color other than white or black.
  • the heat-sensitive recording material comprises at least one side that is colored in such a way that it is not white.
  • the at least one black or colored side has several different colors, also in combination with the color black.
  • the at least one colored layer on one side of the web-shaped carrier material is preferably characterized in that the colored layer comprises at least one pigment and/or one dye and preferably a binder.
  • the pigments and/or dyes include various organic and inorganic pigments, dyes and/or carbon black. These can be used alone or in any mixture.
  • the pigment, the dye and/or the carbon black are each preferably contained in the color layer in an amount of 2 to 50% by weight, particularly preferably 10 to 35% by weight, based on the total solid content of the color layer.
  • the binder is preferably contained in the color layer in an amount of 2 to 40% by weight, particularly preferably 10 to 30% by weight, based on the total solids content of the color layer.
  • the colored layer preferably has a basis weight of 1 to 10 g/m 2 , in particular 3 to 8 g/m 2 .
  • the colored layer preferably has a thickness of 1 to 10 ⁇ m, in particular 2 to 8 ⁇ m.
  • the heat-sensitive recording material is preferably characterized in that there is an insulating layer between the web-shaped carrier material and the colored layer.
  • the heat-sensitive recording material is preferably characterized in that the colored layer simultaneously represents a colored layer and an insulating layer.
  • Such an insulating layer or a colored layer which is both a colored layer and an insulating layer, causes a reduction in heat conduction through the heat-sensitive recording material.
  • the local application of heat using a direct thermal printer is more efficient and a higher thermal printer speed is possible.
  • the top layer becomes translucent more quickly due to the amount of heat introduced and the sensitivity is thus improved.
  • less dye is required, which results in improved recyclability in the material cycle, especially in the waste paper cycle (easier deinkability, separation of dye and carrier material components).
  • the insulating layer or the colored layer which is both a colored layer and an insulating layer, preferably has a Bekk smoothness of greater than 50 s, preferably greater than 100 s and very preferably from 100 to 250 s.
  • the insulating layer or the colored layer which is both a colored layer and an insulating layer, preferably comprises a heat-insulating material.
  • a heat-sensitive recording material with an insulating layer or a colored layer which is also an insulating layer preferably has a lower thermal conductivity than a heat-sensitive recording material which does not have an insulating layer or a colored layer which is also an insulating layer.
  • the thermally insulating material preferably comprises kaolin, more preferably calcined kaolin and mixtures thereof
  • the heat-insulating material can also comprise fleaball pigments, in particular fleaball pigments comprising styrene-acrylate copolymer.
  • These flea bead pigments preferably have a glass transition temperature of 40 to 80° C. and/or an average particle size of 0.1 to 2.5 ⁇ m.
  • the heat-insulating material is preferably present in the insulating layer in an amount of about 20 to about 80% by weight, more preferably in an amount of about 40 to about 60% by weight, based on the total solids content of the insulating layer.
  • the heat-insulating material is preferably present in an amount of about 30 to about 70% by weight, more preferably in an amount of about 40 to about 60% by weight, based on the total solids content of the paint layer, which is at the same time a paint layer and an insulating layer, in this.
  • the binder is preferably present in crosslinked form in the insulating layer and/or color layer, with the optimal degree of crosslinking of the binder being established in the drying step of the coating process in the presence of a crosslinking agent (crosslinking agent).
  • the crosslinking agents can be polyvalent aldehydes such as glyoxal, dialdehyde starch, glutaraldehyde, possibly mixed with boron salts (borax), salts or esters of glyoxylic acid, crosslinking agents based on ammonium zirconium carbonate, polyamidoamine-epichlorohydrin resins (PAE resins), adipic acid dihydrazide (AFID), boric acid or its salts, polyamines, epoxy resins, formaldehyde oligomers, cyclic flames, methylolurea, melamine-formaldehyde oligomers, and others. m. act. These can be used alone or in any mixture.
  • Ammonium zirconium carbonate and polyamidoamine-epichlorohydrin resin are particularly preferred for reasons of food conformity.
  • Self-crosslinking binders such as specially modified polyvinyl alcohols or acrylates, enable crosslinking without any crosslinking agents thanks to the reactive, crosslinkable groups that are already built into the binder polymer.
  • the crosslinking agent is preferably in an amount of about 0.01 to about 25.0% by weight, particularly preferably in an amount of about 0.05 to about 15.0% by weight, based on the total solids content of the insulating or color layer, before.
  • the insulating layer preferably has a basis weight of 1 to 5 g/m 2 , in particular 2 to 4 g/m 2 .
  • the insulating layer preferably has a thickness of 1 to 10 ⁇ m, in particular 2 to 8 ⁇ m.
  • the colored layer which is both a colored layer and an insulating layer, preferably has a basis weight of 1 to 10 g/m 2 , in particular 3 to 8 g/m 2 .
  • the colored layer, which is both a colored layer and an insulating layer preferably has a thickness of 1 to 12 gm, in particular 4 to 8 gm.
  • the heat-sensitive recording material is preferably characterized in that directly on at least one side of the web-shaped carrier material, preferably directly on both sides of the web-shaped carrier material, a layer comprising starch (starch coating) and/or modifications thereof (modified starches), is available.
  • the starch coat is preferably applied in an amount of 0.1 to 3, particularly preferably 0.2 to 1.5 g/m 2 .
  • a line of starch on the side of the web-shaped carrier material on which the color layer is present has the advantage that the web-shaped carrier material is closed and the flattening of the color layer is improved and penetration of the color layer into the web-shaped carrier material can be reduced or prevented.
  • a line of starch on the side of the web-shaped carrier material on which the color layer is not present has the advantage that the color layer can be reduced or prevented from striking through the web-shaped carrier material.
  • the layer comprising starch preferably has a Bekk smoothness greater than 20 s, more preferably greater than 50 s, and most preferably from 50 to 200 s.
  • the heat-sensitive recording material is preferably characterized in that a protective layer is provided on the heat-sensitive layer.
  • the protective layer preferably has a Bekk smoothness of greater than 200 s, particularly preferably greater than 400 s and very particularly preferably from 400 to 1500 s.
  • a Bekk smoothness of 400 to 1300 s is most preferred. This is on the side of the heat-sensitive layer on which the color layer does not lie.
  • This protective layer preferably comprises at least one binder and at least one pigment, particularly preferably an inorganic pigment.
  • Suitable binders include water-soluble starches, starch derivatives, starch-based biolatices of the EcoSphere type, methyl cellulose, hydroxyethyl cellulose, carboxymethyl cellulose, partially or fully hydrolyzed polyvinyl alcohols, chemically modified polyvinyl alcohols such as acetoacetyl, diacetone, carboxy, silanol-modified polyvinyl alcohols, or styrene maleic anhydride copolymers, Styrene-butadiene copolymers, acrylamide (meth)acrylate copolymers, acrylamide-acrylate-methacrylate terpolymers, polyacrylates, poly(meth)acrylic esters, acrylate-butadiene copolymers, polyvinyl acetates and/or acrylonitrile-butadiene copolymers. These can be used alone or in any mixture.
  • Suitable inorganic pigments include inorganic pigments of both synthetic and natural origin, preferably clays, precipitated or natural calcium carbonates, aluminum oxides, aluminum hydroxides, silicic acids, precipitated and pyrogenic silicic acids (e.g. Aerodisp types), diatomaceous earths, magnesium carbonates, talc, kaolin, Titanium oxide, bentonite, but also organic pigments such as hollow pigments with a styrene/acrylate copolymer wall or urea/formaldehyde condensation polymers. These can be used alone or in any mixture.
  • inorganic pigments of both synthetic and natural origin, preferably clays, precipitated or natural calcium carbonates, aluminum oxides, aluminum hydroxides, silicic acids, precipitated and pyrogenic silicic acids (e.g. Aerodisp types), diatomaceous earths, magnesium carbonates, talc, kaolin, Titanium oxide, bentonite, but also organic pigments such as hollow pigments with a styrene/
  • Suitable organic pigments include hollow pigments having a styrene/acrylate copolymer wall or urea/formaldehyde condensation polymers. These can be used alone or in any mixture.
  • the binder is preferably present in the protective layer in an amount of from about 40 to about 90% by weight, more preferably in an amount of from about 50 to about 80% by weight, based on the total solids content of the protective layer.
  • the pigment is preferably present in the protective layer in an amount of from about 5 to about 40% by weight, more preferably in an amount of from about 10 to about 30% by weight, based on the total solids content of the protective layer.
  • the binder is preferably present in crosslinked form in the protective layer, the optimum degree of crosslinking of the binder occurring in the drying step of the coating process in the presence of a crosslinking agent (crosslinking agent).
  • crosslinking agent crosslinking agent
  • the crosslinking agents can be polyvalent aldehydes such as glyoxal, dialdehyde starch, glutaraldehyde, possibly mixed with boron salts (borax), salts or esters of glyoxylic acid, crosslinking agents based on ammonium zirconium carbonate, polyamidoamine-epichlorohydrin resins (PAE resins), adipic acid dihydrazide (AFID), boric acid or its salts, polyamines, epoxy resins, formaldehyde oligomers, cyclic flames, methylolurea, melamine-formaldehyde oligomers, and others. m. act. These can be used alone or in any mixture.
  • Ammonium zirconium carbonate and polyamidoamine-epichlorohydrin resin are particularly preferred for reasons of food conformity.
  • Self-crosslinking binders such as specially modified polyvinyl alcohols or acrylates, enable crosslinking without any crosslinking agents thanks to the reactive, crosslinkable groups that are already built into the binder polymer.
  • the crosslinker is preferably present in an amount of from about 0.01 to about 25.0, more preferably in an amount of from about 0.05 to about 15.0, based on the total solids content of the color coat.
  • the protective layer also preferably comprises at least one lubricant or at least one release agent.
  • These agents are preferably fatty acid metal salts such as zinc stearate or calcium stearate, or behenate salts, synthetic waxes such.
  • the lubricant or release agent is preferably present in an amount of from about 1% to about 30% by weight, more preferably in an amount of from about 2% to about 20% by weight, based on the total solids content of the protective layer.
  • optical brighteners preferably stilbenes
  • the protective layer In order to control the surface whiteness of the heat-sensitive recording material according to the invention, optical brighteners, preferably stilbenes, can be incorporated into the protective layer.
  • the protective layer preferably has a basis weight of 0.3 to 5.0 g/m 2 , in particular 1.0 to 3.0 g/m 2 .
  • the protective layer preferably has a thickness of 0.3 to 6.0 ⁇ m, in particular 0.5 to 2.0 ⁇ m.
  • the use of a protective layer has the advantage that the recording material is better protected from external influences.
  • the heat-sensitive recording material is preferably characterized in that an adhesive layer is present on the side of the carrier material in web form on which the color layer is not located.
  • the adhesive layer preferably comprises at least one adhesive, preferably a heat-activatable adhesive, in particular a pressure-sensitive adhesive.
  • the adhesive preferably the heat-activatable adhesive and in particular the pressure-sensitive adhesive, is particularly preferably an adhesive based on rubber and/or acrylate.
  • the adhesive layer preferably has a basis weight of 10 to 40 g/m 2 , in particular 12 to 25 g/m 2 .
  • the heat-sensitive recording material is preferably characterized in that a siliconized separating layer is present on the heat-sensitive layer.
  • siliconized release layer and "siliconized layer” are to be understood synonymously in the sense of "cover with a layer of silicone”. These layers preferably consist of silicone or comprise at least 90% by weight, preferably at least 95% by weight and particularly preferably at least 99 wt.
  • the siliconized separating layer preferably has a Bekk smoothness of greater than 400 s, particularly preferably greater than 800 s and very particularly preferably from 800 to 2000 s.
  • the siliconized release layer is preferably present on this protective layer.
  • the heat-sensitive recording material is preferably characterized in that a diffusion layer is formed between the siliconized layer and the underlying layer, preferably the heat-sensitive layer.
  • This diffusion layer is preferably formed by diffusing at least parts of the siliconized separating layer over a large area into the upper region of the underlying layer, with preferably 5 to 50% by weight, particularly preferably 6 to 45% by weight and in particular 7 to 40% by weight of the siliconized separating layer diffuse into the upper area of the underlying layer.
  • a diffusion layer is described, for example, in EP 3 221 153 A1.
  • a siliconized release layer is preferably present when an adhesive layer is also present as described above.
  • the presence of a siliconized release layer on the heat-sensitive layer and an adhesive layer on the web-shaped base material on the side where the ink layer is not located has the advantage that the heat-sensitive recording material can be used as a linerless heat-sensitive recording material.
  • Carrierless means that the (self-adhesive) heat-sensitive recording material according to the invention is not applied to a carrier material but is wound onto itself. This has the advantage that the production costs can be further reduced, more running meters per roll can be realized, no disposal effort for the disposal of the liner is necessary and more labels can be transported per specific loading space volume.
  • a siliconized separating layer it is preferred that at least one platelet-shaped pigment is contained in the heat-sensitive layer or in the layer that lies directly below the siliconized separating layer.
  • the at least one platelet-shaped pigment is preferably selected from the group consisting of kaolin, Al(OH) 3 and/or talc.
  • kaolin is particularly preferred.
  • coated kaolin is very particularly preferred. Such is available, for example, under the trade name Kaolin ASP 109 (BASF, Germany).
  • the main advantage of using these platelet-shaped pigments, in particular kaolin, is that the heat-sensitive layer or the layer that lies directly below the siliconized separating layer can be siliconized very easily.
  • Platelet-shaped pigment is understood as meaning a pigment in which the ratio of diameter to thickness is about 7 to 40:1, preferably about 15 to 30:1.
  • the particle size of the platelet-shaped pigment is preferably adjusted in such a way that at least about 70%, preferably at least about 85%, of the particles have a particle size of about ⁇ 2 ⁇ m (Sedigraph).
  • the pH of the flaky pigment in aqueous solution is preferably 6 to 8.
  • the at least one platelet-shaped pigment is in the heat-sensitive color-forming layer or in the layer that lies directly below the siliconized release layer, preferably in an amount of about 5 to about 60% by weight, particularly preferably in an amount of about 15 to about 55% by weight, based on the total solids content of the respective layer.
  • the heat-sensitive recording material is preferably characterized in that the siliconized separating layer comprises at least one siloxane, preferably a poly(organo)siloxane, in particular an acrylic poly(organo)siloxane.
  • the siliconized release layer comprises a mixture of at least two siloxanes.
  • a mixture of at least two acrylic poly(organo)siloxanes is preferred.
  • siloxanes available under the trade names TEGO®RC902 and TEGO®RC711 (Evonik, Germany).
  • the heat-sensitive recording material is preferably characterized in that the siliconized separating layer contains at least one polysilicon acrylate, which was preferably formed by condensation of at least one silicon acrylate.
  • the siliconized release layer is preferably anhydrous. It is also preferred that the siliconized separating layer does not contain any Pt catalysts.
  • the siliconized separating layer preferably contains an initiator, particularly preferably a photoinitiator. This is used for radical curing of the silicone.
  • the siliconized separating layer can preferably contain other additives, such as matting agents and/or adhesion additives.
  • the siliconized separating layer preferably has a basis weight of 0.3 to 5.0 g/m 2 , in particular 1.0 to 3.0 g/m 2 .
  • the siliconized separating layer preferably has a thickness of 0.3 to 6.0 gm, in particular 0.5 to 2.0 gm.
  • All of the layers mentioned above can be formed in one or more layers.
  • the heat-sensitive recording material according to the sixth aspect of the present invention can be obtained by the manufacturing method described in connection with the first aspect.
  • the present invention also relates to a heat-sensitive recording material which can be obtained using the process described above.
  • the present invention also relates to the use of a heat-sensitive recording material as described above as a roll of receipts, as a roll of adhesive labels, also in the cold and deep-freeze sector, and as a roll of tickets.
  • a heat-sensitive recording material as described above as a roll of receipts, as a roll of adhesive labels, also in the cold and deep-freeze sector, and as a roll of tickets.
  • these have a functional side and/or back (with color, multicolored, black/grey) and can be pre-printed.
  • the rolls mentioned are preferably available in typical widths and lengths.
  • a particularly preferred first embodiment comprises a heat-sensitive recording material with a web-shaped base material, an ink layer applied thereto and a heat-sensitive layer on the ink layer.
  • the carrier material in web form comprises a paper.
  • the colored layer comprises at least one pigment and/or one dye and preferably a binder.
  • the heat-sensitive layer includes the above embodiments.
  • a particularly preferred second embodiment comprises a heat-sensitive recording material with a web-shaped base material, an insulating layer applied thereto, an ink layer applied on the insulating layer and a heat-sensitive layer on the ink layer.
  • the web-shaped carrier material comprises paper.
  • the insulating layer comprises a thermally insulating material, preferably kaolin, more preferably calcined kaolin and mixtures thereof, or fleaball pigments, particularly fleaball pigments comprising styrene-acrylate copolymer.
  • the colored layer comprises at least one pigment and/or one dye and preferably a binder.
  • the heat-sensitive layer comprises the above embodiments.
  • a particularly preferred third embodiment comprises a heat-sensitive recording material with a web-like carrier material, an ink layer applied thereto, which is at the same time an insulating layer, and a heat-sensitive layer on the ink layer.
  • the web-shaped carrier material comprises paper.
  • the colored layer which is at the same time an insulating layer, comprises a heat-insulating material, preferably kaolin, particularly preferably calcined kaolin and mixtures thereof, or fleaball pigments, in particular fleaball pigments comprising styrene-acrylate copolymer.
  • a heat-insulating material preferably kaolin, particularly preferably calcined kaolin and mixtures thereof, or fleaball pigments, in particular fleaball pigments comprising styrene-acrylate copolymer.
  • the heat-sensitive layer includes the above embodiments.
  • a particularly preferred fourth embodiment comprises a heat-sensitive recording material with a web-shaped carrier material which has a thickness mark on both sides, an ink layer applied thereto and a heat-sensitive layer on the ink layer.
  • the sheet-like carrier material comprises paper.
  • the colored layer comprises at least one pigment and/or one dye and preferably a binder.
  • the heat-sensitive layer includes the above embodiments.
  • a particularly preferred fifth embodiment comprises a heat-sensitive recording material having a web-shaped base material, an ink layer applied thereto and a heat-sensitive layer on the ink layer, with a protective layer being applied on the heat-sensitive layer.
  • the web-shaped carrier material comprises paper.
  • the colored layer comprises at least one pigment and/or one dye and preferably a binder.
  • the heat-sensitive layer includes the above embodiments.
  • the protective layer comprises at least one binder and at least one pigment, particularly preferably an inorganic pigment.
  • a particularly preferred sixth embodiment comprises a heat-sensitive recording material comprising a web-shaped base material, an insulating layer applied thereon, a colored layer applied on the insulating layer and a heat-sensitive layer on the colored layer, with a protective layer being applied on the heat-sensitive layer.
  • the web-like carrier material comprises paper.
  • the insulating layer comprises a thermally insulating material, preferably kaolin, more preferably calcined kaolin and mixtures thereof, or sphere pigments, in particular sphere pigments comprising styrene-acrylate copolymer.
  • the colored layer comprises at least one pigment and/or one dye and preferably a binder.
  • the heat-sensitive layer includes the above embodiments.
  • the protective layer preferably comprises at least one binder and at least one pigment, particularly preferably an inorganic pigment.
  • a particularly preferred seventh embodiment comprises a heat-sensitive recording material with a web-shaped base material, a color layer applied thereto, which is also an insulating layer, and a heat-sensitive layer on the color layer, with a protective layer being applied on the heat-sensitive layer.
  • the web-shaped carrier material comprises paper.
  • the colored layer which is at the same time an insulating layer, comprises a heat-insulating material, preferably kaolin, particularly preferably calcined kaolin and mixtures thereof, or fleaball pigments, in particular fleaball pigments comprising styrene-acrylate copolymer.
  • a heat-insulating material preferably kaolin, particularly preferably calcined kaolin and mixtures thereof, or fleaball pigments, in particular fleaball pigments comprising styrene-acrylate copolymer.
  • the heat-sensitive layer includes the above embodiments.
  • the protective layer preferably comprises at least one binder and at least one pigment, particularly preferably an inorganic pigment.
  • a particularly preferred eighth embodiment comprises a heat-sensitive recording material with a web-shaped base material which has a starch coating on both sides, an ink layer applied thereto and a heat-sensitive layer on the ink layer, with a protective layer being applied on the heat-sensitive layer.
  • the web-shaped carrier material comprises paper.
  • the colored layer comprises at least one pigment and/or one dye and preferably a binder.
  • the heat-sensitive layer includes the above embodiments.
  • the protective layer preferably comprises at least one binder and at least one pigment, particularly preferably an inorganic pigment.
  • a particularly preferred ninth embodiment comprises a heat-sensitive recording material with a web-shaped base material, an adhesive layer on the underside and a color layer applied to the other side of the web-shaped base material and a heat-sensitive layer on the color layer, with a siliconized layer being applied to the heat-sensitive layer.
  • the adhesive layer comprises an adhesive, preferably a thermosetting adhesive, in particular a flat adhesive.
  • the web-shaped carrier material comprises paper.
  • the colored layer comprises at least one pigment and/or one dye and preferably a binder.
  • the heat-sensitive layer includes the above embodiments.
  • the siliconized layer comprises at least one siloxane, preferably a poly(organo)siloxane.
  • a particularly preferred tenth embodiment comprises a heat-sensitive recording material with a web-shaped support material, an adhesive layer on the underside and an insulating layer applied to the other side of the web-shaped support material, an ink layer applied on the insulating layer and a heat-sensitive layer on the ink layer, wherein on the heat-sensitive layer a siliconized layer is applied.
  • the adhesive layer comprises an adhesive, preferably a thermosetting adhesive, in particular a pressure-sensitive adhesive.
  • the web-shaped carrier material comprises paper.
  • the insulating layer comprises a heat-insulating material, preferably kaolin, particularly preferably calcined kaolin and mixtures thereof, or hollow sphere pigments, in particular hollow sphere pigments comprising styrene-acrylate copolymer.
  • the colored layer comprises at least one pigment and/or one dye and preferably a binder.
  • the heat-sensitive layer includes the above embodiments.
  • the siliconized layer comprises at least one siloxane, preferably a poly(organo)siloxane.
  • a particularly preferred eleventh embodiment comprises a heat-sensitive recording material with a web-shaped carrier material, an adhesive layer on the underside and an ink layer applied to the other side of the web-shaped carrier material, which is at the same time an insulating layer and a heat-sensitive layer on the ink layer, wherein on the heat-sensitive layer a siliconized layer is applied.
  • the adhesive layer comprises an adhesive, preferably a thermosetting adhesive, in particular a pressure-sensitive adhesive.
  • the web-shaped carrier material comprises paper.
  • the colored layer which is at the same time an insulating layer, comprises a heat-insulating material, preferably kaolin, particularly preferably calcined kaolin and mixtures thereof, or hollow sphere pigments, in particular hollow sphere pigments comprising styrene-acrylate copolymer.
  • the heat-sensitive layer includes the above embodiments.
  • the siliconized layer comprises at least one siloxane, preferably a poly(organo)siloxane.
  • a particularly preferred twelfth embodiment comprises a heat-sensitive recording material with a web-shaped base material which has a starch mark on both sides, an adhesive layer on the underside and an ink layer applied to the other side of the web-shaped base material and a heat-sensitive layer on the ink layer, wherein on the heat-sensitive Layer a siliconized layer is applied.
  • the adhesive layer comprises an adhesive, preferably a thermosetting adhesive, in particular a flat adhesive.
  • the web-like support material comprises paper.
  • the colored layer comprises at least one pigment and/or one dye and preferably a binder.
  • the heat-sensitive layer includes the above embodiments.
  • the siliconized layer comprises at least one siloxane, preferably a poly(organo)siloxane.
  • a particularly preferred thirteenth embodiment comprises a heat-sensitive recording material with a web-shaped base material which has a starch mark on both sides, an adhesive layer on the underside and an ink layer applied to the other side of the web-shaped base material and a heat-sensitive layer on the ink layer, wherein on the heat-sensitive layer is a protective layer and a siliconized layer is applied thereon.
  • the adhesive layer comprises an adhesive, preferably a thermosetting adhesive, in particular a pressure-sensitive adhesive.
  • the web-like support material comprises paper.
  • the colored layer comprises at least one pigment and/or one dye and preferably a binder.
  • the heat-sensitive layer includes the above embodiments.
  • the protective layer preferably comprises at least one binder and at least one pigment, more preferably an inorganic pigment.
  • the siliconized layer comprises at least one siloxane, preferably a poly(organo)siloxane
  • a particularly preferred fourteenth embodiment comprises a heat-sensitive recording material with a web-shaped base material, an ink layer applied thereto and a heat-sensitive layer on the ink layer, wherein the heat-sensitive layer comprises only a wax.
  • the web-like carrier material comprises paper.
  • the colored layer comprises at least one pigment and/or one dye and preferably a binder.
  • the one to thirteen embodiments mentioned in relation to the heat-sensitive layer in the preferred embodiments described above include in particular the following embodiments:
  • the heat-sensitive layer comprises at least one polymer particle having a glass transition temperature of from -55° to 130°C, preferably from 40° to 80°C.
  • the heat-sensitive layer comprises at least one polymer particle having a core/shell structure, the polymer particles being selected from the group consisting of (i) polymer particles having an outer polymer shell having a glass transition temperature of 40° to 800°C and (ii) polymer particles having an inner polymer shell having a glass transition temperature of 40° to 130°C and an outer polymer shell having a glass transition temperature of -55° to 50°C, the glass transition temperature of the outer polymer shell preferably being lower than that of the inner polymer shell.
  • the heat-sensitive layer comprises at least one polymer particle with a melting point of less than 250°C, preferably from 0° to 250°C.
  • the heat-sensitive layer comprises at least one polymer particle with an average particle size in the range from 0.1 to 2.5 mm.
  • BA has the heat-sensitive layer of any heat-sensitive recording material according to the invention, as described above under aspects 1 to 6, in particular one of the following heat-sensitive recording materials according to the invention according to claim 41 or claim 85
  • Heat-sensitive recording material comprising a web-shaped base material, a color layer on one side of the web-shaped base material and a heat-sensitive layer on the color layer, so that the color layer is at least partially covered, the heat-sensitive layer being designed in such a way that it becomes translucent as a result of the local action of heat , so that the color layer underneath becomes visible, characterized in that the heat-sensitive layer contains 10 to 90% by weight of scattering particles, in particular polymer particles with an average particle size in the range from 0.1 to 2.5 ⁇ m, 10 to 80% by weight of a heat-sensitive material having a melting temperature in the range from 40 to 200°C and/or a glass transition temperature in the range from 40 to 200°C and 1 to 30% by weight - % of a binder included.
  • Heat-sensitive recording material comprising a web-shaped base material, a color layer on one side of the web-shaped base material and a heat-sensitive layer on the color layer, so that the color layer is at least partially covered, the heat-sensitive layer being designed in such a way that it becomes translucent as a result of the local action of heat , so that the color layer underneath becomes visible, characterized in that the heat-sensitive layer contains or consists of scattering particles, in particular a heat-sensitive material as scattering particles, in particular a heat-sensitive material selected from the group of biopolymers, modified biopolymers, fats, natural waxes , the partially synthetic waxes and/or the synthetic waxes, with partially synthetic waxes being preferred. at least one of the following characteristics or any combination of the following characteristics:
  • the scattering particles preferably have at least one of the following features: a) scattering particle is a wax which has a melting point in the range from 60 °C to 180 °C, in particular an amide wax, b) scattering particle is a fatty acid, in particular stearic acid and/or palmitic acid, c) scattering particle is a polybutylene succinate (PBS), d) scattering particle is a polybutylene succinate adipate (PBSA) e)
  • the total amount of scattering particles is in the range from a) 10 to ⁇ 40% by weight or b) 40 to 78% by weight, in particular 44 to 73% by weight, more preferably in the range from 50 to 67% by weight. -% or c) > 78 to 90% by weight, based on the dry weight of the heat-sensitive layer
  • the binder comprises at least one polymeric binder.
  • the heat-sensitive layer comprises at least one inorganic pigment as an additional scattering particle.
  • the heat-sensitive layer contains essentially no (color) developers or leuco compounds.
  • the average particle size of the scattering particles and the additional scattering particles is preferably in the range from 0.1 to 2.5 ⁇ m.
  • the average particle size D(4.3) of the scattering particles is therefore preferably in the range from 0.1 to 2.5 ⁇ m or the particle diameter D50 of the scattering particles is preferably in the range from 0.1 to 2.5 ⁇ m, preferably 0.8 to 2.0 pm, more preferably 1.0 to 1.8 pm, more preferably in the range 1.2 to 1.6 pm.
  • the quantitative ratio between the wax as scattering particles, in particular the amide wax, and the inorganic pigment preferably has a value in the range from 2:8 to 9:1, preferably from 2.5:7.5 to 7.5:2.5 , more preferably from 0.3:0.7 to 0.7:0.3.
  • a high wax content has a beneficial effect on the dynamic sensitivity and on the optical density (OD773), with an optimum in some examples at a ratio of preferably 6.5:3.5 could be achieved.
  • the binder is preferably present in a total amount ranging from 1 to 30% by weight, preferably from 2 to 20% by weight, more preferably from 4 to 16.5% by weight, based on the dry weight of the heat-sensitive layer.
  • the inorganic pigment is preferably present in a total amount of between 18 and 50%, preferably between 22 and 45%, more preferably between 25 and 39% by weight, based on the dry weight of the heat-sensitive layer , before.
  • the amide wax is preferably a monoamide of a saturated fatty acid, the fatty acid residue of which has a total number of carbon atoms ranging from 14 to 20, preferably ranging from 16 to 18, particularly preferably the amide wax is stearamide (stearic acid amide, octadecanoic acid amide).
  • the dry mass per unit area of the heat-sensitive layer is in particular in the range from 2 g/m 2 to 15 g/m 2 , preferably in the range from 2.5 g/m 2 to 12 g/m 2 , particularly preferably in the range from 3 g/m m 2 to 10 g/m 2 .
  • the inorganic pigment is preferably selected from the group consisting of calcined kaolin, natural kaolin, kaolinite, magnesium silicate hydrate, silicon dioxide, bentonite, calcium carbonate, calcium silicate, in particular calcium silicate hydrate, calcium aluminate sulphate, aluminum hydroxide, aluminum oxide and boehmite.
  • the inorganic pigment preferably has a particle diameter d50 in the range from 0.2 to 2.0 ⁇ m, preferably from 0.8 to 2.0 ⁇ m, more preferably from 1.0 to 1.8 ⁇ m, more preferably in the range from 1.2 until 1.6 pm on.
  • the one or more polymeric binders are preferably selected from the group consisting of starch, modified starch, polyvinyl alcohol and/or modified polyvinyl alcohol.
  • the scattering particles are preferably a fatty acid, in particular stearic acid and/or palmitic acid, which presumably form hydrogen bonds with the polar binder, in particular with polyvinyl alcohol or modified polyvinyl alcohol, which surprisingly results in a has a positive influence on the print contrast and the optical density of the resulting heat-sensitive recording materials.
  • the heat-sensitive recording materials according to the invention preferably have an optical density (OD773) of at least 1.10 +/- 2%, preferably at least 1.15 +/- 2%, particularly preferably of 1.20 +/- - 2% and more preferably 1.25 +/- 2%, with a basis weight of the heat-sensitive layer preferably less than 7 g/m 2 , preferably less than 6 g/m 2 , more preferably less than 5 g/m m 2 and more preferably less than 4 g/m 2 .
  • OD773 optical density
  • the heat-sensitive recording material according to the invention comprising the heat-sensitive layer can preferably be used as a receipt (roll), adhesive label (roll), ticket (roll), temperature indicator, security paper, admission ticket, receipt, self-adhesive label, ticket, TITO ticket (ticket-in, ticket-out ), plane, train, ship or bus ticket, parking ticket, label, gambling receipt, sales receipt, bank statement, medical and/or technical chart paper, fax paper or security paper.
  • the color layers according to Examples 1 to 5 were then applied conventionally to the smooth side of the carrier material (paper web) on a conventional coating machine using carbon black as the dye/color pigment dried and smoothed so that a Bekk smoothness of the paint layer of> 100 s is obtained.
  • the heat-sensitive layers two suspensions, a wax suspension and a pigment suspension, were prepared and then mixed in the ratios given in the table below to obtain the required coating compositions.
  • the coating composition was produced on the basis of the solution described in EP 3957489 A1. Deviating from this, both the wax and the pigment were present in a particle size distribution in order to be suitable as scattering particles and as additional scattering particles.
  • composition of the pigment dispersion Component Amount [otro, %] Amount [abt. g]
  • composition of the wax dispersion Component Amount [otro, %] Amount [abt. g]
  • composition of the coating compositions :
  • Example BAI 70% / 30%
  • Example BA2 50% / 50%
  • Example BA3 40% / 60%
  • Example BA5 With a fixed ratio of calcium silicate hydrate (pigment) to stearic acid amide (scattering particles) of 4:6 and 3:7, the proportion of polyvinyl alcohol (binder) in the coating composition was varied in the range from 4% to 30%.
  • these coating compositions for the production of heat-sensitive layers with a basis weight of 3, 3.5, 4, 5, 6 and 7 g/m 2 were applied to the color layer by means of a doctor blade, dried conventionally after application and smoothed , so that a Bekk smoothness of > 100 s is obtained.
  • these coating compositions for the production of heat-sensitive layers with a weight per unit area of 2, 3, 3.5, 4, 5, 6 and 7 g/m 2 were applied to the colored layer by means of conventional curtain coating using a conventional coating device. conventionally dried and smoothed after application, so that a Bekk smoothness of> 100 s is obtained, with essentially the same results being achievable as with coating using a roller blade coater.
  • the drying in particular that of the carrier material and of all layers, in particular the heat-sensitive recording layer, was carried out in such a way that the residual moisture content of the heat-sensitive recording material is in the range from 2% to 14%.
  • examples BA3 to BA5 (with a binder content of 20% or more) showed an excellent optical density (OD773) of at least 1.15 ODU with an energy input of 7.73 mJ/mm 2 (optical density, OD773) and with energy inputs >7 .73 mJ/mm 2 of > 1.15 ODU and this even with economical and particularly environmentally friendly basis weights of the heat-sensitive layer from 3 g/m 2 .
  • the heat-sensitive recording materials according to the invention which have an optical density (OD773) of at least 1.15 after thermal printing, can be used in commercially available thermal printers using the usual printing parameters (printing speed, temperature of the print head, energy input) and thereby meet all the essential requirements of the print image to be achieved (readability of the print image or barcode readability).
  • the amount of calcium silicate hydrate used was partially or completely replaced by calcium carbonate.
  • the heat-sensitive recording materials obtained in this way also showed comparably good results in terms of dynamic sensitivity, also in terms of relative print contrast and optical density (OD773).
  • the amount of stearic acid amide used was partially or fully replaced by polybutylene succinate (PBS) or polybutylene succinate adipate (PBSA) or replaced by mixtures of PBS and PBSA.
  • PBS polybutylene succinate
  • PBSA polybutylene succinate adipate
  • the heat-sensitive recording materials obtained in this way also showed comparably good results in terms of dynamic sensitivity and also in terms of optical density (OD773) and relative print contrast.
  • paper webs made from bleached and ground hardwood and coniferous wood pulp with a basis weight of 41 and 58 g/m 2 were produced on a Fourdrinier paper machine as web-like carrier material with the addition of usual additives in usual quantities and coated with usual front and back coatings (single or paper webs coated on both sides), in particular provided with conventional starch-based primers (starch layer) and produced with a Bekk smoothness on at least one side of greater than 20 s.
  • These coats on the front and back improve the application and adhesion of the other layers, e.g. the insulating layer or the color layer, or on the opposite side of the adhesive layer or a print layer, e.g. a print layer as backside printing of the heat-sensitive recording material with conventional color printing processes for advertising or informational purposes (e.g. "This receipt is environmentally friendly").
  • these heat-sensitive layers were provided with a) protective layers, b) siliconized release layers or c) protective layers and siliconized release layers on top of the protective layers.
  • the heat-sensitive recording materials provided with a siliconized separating layer were provided with an adhesive layer on the back and further processed and rolled into commercially available rolls for adhesive labels, e.g. for use in direct contact with food, provided that of course all materials, raw materials and processes were previously certified and approved accordingly as thermal printer adhesive labels in fruit and vegetable, cheese, fish, meat or sausage departments in supermarkets.
  • the heat-sensitive recording materials according to the invention have excellent storability of the unprinted and unprinted heat-sensitive recording materials (for measurement method, see the section on storability), even under extreme conditions, e.g. as a parking ticket printed with a thermal printer in the summer heat in the car interior stored for several hours (T max x 60 °C), the printed image of the parking ticket remains very legible.
  • FIG. 1 Heat-sensitive recording material with a web-like carrier material, a color layer applied thereto and a heat-sensitive layer on the color layer.
  • FIG. 2 Heat-sensitive recording material with a web-shaped carrier material, an insulating layer applied thereto, a colored layer applied to the insulating layer and a heat-sensitive layer on the colored layer.
  • FIG. 3 Heat-sensitive recording material with a web-like carrier material, a color layer applied thereto, which is at the same time an insulating layer, and a heat-sensitive layer on the color layer.
  • FIG. 4 Heat-sensitive recording material with a web-shaped carrier material which has a thickness mark on both sides, a color layer applied thereto and a heat-sensitive layer on the color layer.
  • FIG. 5 Heat-sensitive recording material with a web-like base material, a color layer applied thereto and a heat-sensitive layer on the color layer, with a protective layer being applied on the heat-sensitive layer.
  • FIG. 6 Heat-sensitive recording material with a web-shaped carrier material, an insulating layer applied thereto, a colored layer applied to the insulating layer and a heat-sensitive layer on the colored layer, a protective layer being applied to the heat-sensitive layer.
  • FIG. 7 Heat-sensitive recording material with a web-like base material, a color layer applied thereto, which is also an insulating layer, and a heat-sensitive layer on the color layer, with a protective layer being applied to the heat-sensitive layer
  • FIG. 8 Heat-sensitive recording material with a web-shaped carrier material which has a starch mark on both sides, a color layer applied thereto and a heat-sensitive layer on the color layer, with a protective layer being applied to the heat-sensitive layer.
  • Figure 9 Heat-sensitive recording material with a web-shaped carrier material, an adhesive layer on the underside and a color layer applied to the other side of the web-shaped carrier material and a heat-sensitive layer on the color layer, with a siliconized layer being applied to the heat-sensitive layer.
  • Figure 10 Heat-sensitive recording material with a web-shaped carrier material, an adhesive layer on the underside and an insulating layer applied to the other side of the web-shaped carrier material, a color layer applied to the insulating layer and a heat-sensitive layer on the color layer, with a siliconized layer being applied to the heat-sensitive layer is.
  • Figure 11 Heat-sensitive recording material with a sheet-like base material, an adhesive layer on the underside and one on the other Side of the web-shaped carrier material applied color layer, which is an insulating layer at the same time and a heat-sensitive layer on the color layer, wherein a siliconized layer is applied to the heat-sensitive layer.
  • Figure 12 Heat-sensitive recording material with a web-shaped carrier material that has a starch mark on both sides, an adhesive layer on the underside and a color layer applied to the other side of the web-shaped carrier material and a heat-sensitive layer on the color layer, with a siliconized layer on the heat-sensitive layer is upset.
  • Figure 13 Heat-sensitive recording material with a web-shaped base material which has a starch mark on both sides, an adhesive layer on the underside and a color layer applied to the other side of the web-shaped base material and a heat-sensitive layer on the color layer, with a protective layer and a protective layer on the heat-sensitive layer a siliconized layer is applied to it.
  • FIG. 14 Measurement of the dynamic sensitivity of heat-sensitive recording materials, the base material having different Bekk smoothnesses.
  • the dynamic sensitivity (optical density (ODU)) is shown as a function of the energization energy E of three recording materials with different base papers:
  • Heat-sensitive recording materials according to the invention were produced with the compositions shown in Tables 1 to 6.
  • a paper substrate made from deciduous and coniferous wood pulp with a basis weight of 41 or 58 g/m 2 is used as the carrier material.
  • the dry contents (TG) of the respective layer formulations are adjusted as follows by adding water: insulating layer (30%), color layer (26%), heat-sensitive layer (20%) and protective layer (10%).
  • the raw materials used are used as a dispersion or as a solution with the following solids content: Ropaque HP-1055 (21%), styrene butadiene latex (48%), carbon black (45%), Ropaque OP-96 (30%), sodium -Metaborate tetrahydrate (2%), stearic acid amide wax (22%), silica (28%), zinc stearate (35%), polyvinyl alcohol (high viscosity) (10%), calcined kaolin (45%), precipitated calcium carbonate (58%), ammonium zirconium carbonate (9%), polyvinyl alcohol (low viscosity) (7%) and kaolin (75%).
  • the color layer and the heat-sensitive layer are applied consecutively by a single and/or simultaneously by a double curtain coater to the paper substrate on a paper coating machine at a speed of 900 m/min.
  • the drying process takes place in the usual way, without the properties of the heat-sensitive recording material according to the invention, such as, for example, Surface whiteness or paper whiteness of the heat-sensitive layer to negatively affect the coated paper support in each case.
  • Table 1 Composition of the individual layers of the heat-sensitive recording material according to example 1.
  • na Customary materials known to those skilled in the art.
  • Example 2 In order to improve certain coating properties, the individual layers are given additional components, in particular rheological aids such as e.g. As thickeners and / or surfactants added.
  • the other components are added in amounts such that the weight percent of the respective layer adds up to 100 weight percent. The corresponding amounts are familiar to the person skilled in the art. 2.
  • Example 2 Example 2:
  • Example 2 a starch primer (0.5 g/m 2 ) is applied to the front and back of the paper substrate on a paper machine by a film press at a speed of 800 m/min.
  • the color layer is applied to the starch-coated paper substrate using a blade coater and the heat-sensitive layer is applied using a curtain coater at a speed of 900 m/min.
  • the drying process takes place in the usual way, without influencing the properties of the heat-sensitive recording material according to the invention, such as, for example, the surface whiteness or paper whiteness of the heat-sensitive layer negative, of the coated paper support in each case.
  • Table 2 Composition of the individual layers of the heat-sensitive recording material according to example 2.
  • na Customary materials known to those skilled in the art.
  • the individual layers are given additional components, in particular rheological aids such as e.g. As thickeners and / or surfactants added.
  • rheological aids such as e.g. As thickeners and / or surfactants added.
  • the other components are added in amounts such that the weight percent of the respective layer adds up to 100 weight percent. The corresponding amounts are familiar to the person skilled in the art.
  • a starch primer (0.5 g/m 2 ) is applied to the front and back of the paper substrate on a paper machine by a film press at a speed of 800 m/min.
  • the color layer is applied to the starch-coated paper substrate on a paper coating machine using a blade coater at a speed of 600 m/min.
  • the heat-sensitive layer and the protective layer are applied consecutively to the starch-coated paper substrate provided with a color layer using a single and/or simultaneously using a double curtain coater at a speed of 900 m/min.
  • the drying process takes place in the usual way, without influencing the properties of the heat-sensitive recording material according to the invention, such as, for example, the surface whiteness or paper whiteness of the heat-sensitive layer negative, of the coated paper support in each case.
  • Table 3 Composition of the individual layers of the heat-sensitive recording material according to example 3.
  • na Customary materials known to those skilled in the art.
  • the individual layers are given additional components, in particular rheological aids such as e.g. As thickeners and / or surfactants added.
  • rheological aids such as e.g. As thickeners and / or surfactants added.
  • the other components are added in amounts such that the weight percent of the respective layer adds up to 100 weight percent. The corresponding amounts are familiar to the person skilled in the art.
  • the color layer and the heat-sensitive layer are applied consecutively by a single and/or simultaneously by a double curtain coater to the paper substrate on a paper coating machine at a speed of 900 m/min.
  • the drying process takes place in the usual way, without influencing the properties of the heat-sensitive recording material according to the invention, such as, for example, the surface whiteness or paper whiteness of the heat-sensitive layer negative, of the coated paper support in each case.
  • Table 4 Composition of the individual layers of the heat-sensitive recording material according to example 4.
  • na Customary materials known to those skilled in the art.
  • the individual layers are given additional components, in particular rheological aids such as e.g. As thickeners and / or surfactants added.
  • rheological aids such as e.g. As thickeners and / or surfactants added.
  • the other components are added in amounts such that the weight percent of the respective layer adds up to 100 weight percent. The corresponding amounts are familiar to the person skilled in the art.
  • the color layer and the heat-sensitive layer are applied consecutively by a single and/or simultaneously by a double curtain coater to the paper substrate on a paper coating machine at a speed of 900 m/min.
  • the drying process takes place in the usual way, without influencing the properties of the heat-sensitive recording material according to the invention, such as, for example, the surface whiteness or paper whiteness of the heat-sensitive layer negative, of the coated paper support in each case.
  • Table 5 Composition of the individual layers of the heat-sensitive recording material according to example 5.
  • na Usual tools known to those skilled in the art.
  • the individual layers are given additional components, in particular rheological aids such as e.g. As thickeners and / or surfactants added.
  • the other components are added in amounts such that the weight percent of the respective layer adds up to 100 weight percent. The corresponding amounts are familiar to the person skilled in the art.
  • the insulating layer (insulator layer) is applied to the paper substrate on a paper machine by a film press at a speed of 800 m/min.
  • the color layer and the heat-sensitive layer are applied consecutively by a single and/or simultaneously by a double curtain coater at a speed of 900 m/min on a paper coating machine.
  • the drying process takes place in the usual way, without influencing the properties of the heat-sensitive recording material according to the invention, such as, for example, the surface whiteness or paper whiteness of the heat-sensitive layer negative, of the coated paper support in each case.
  • Table 6 Composition of the individual layers of the heat-sensitive recording material according to example 6.
  • na Customary materials known to those skilled in the art.
  • the individual layers are given additional components, in particular rheological aids such as e.g. As thickeners and / or surfactants added.
  • rheological aids such as e.g. As thickeners and / or surfactants added.
  • the other components are added in amounts such that the weight percent of the respective layer adds up to 100 weight percent. The corresponding amounts are familiar to the person skilled in the art.
  • the mixing ratio between scattering particles/polymer particles and inorganic pigment is preferably in the range from 8:1 to 1:8, particularly preferably in the range from 4:1 to 1:4, based on the stated amounts [wt. %] in the oven-dried state (otro).
  • the color layer and the heat-sensitive layer are applied consecutively by a single and/or simultaneously by a double curtain coater to the paper substrate on a paper coating machine at a speed of 900 m/min.
  • the drying process takes place in the usual way, without adversely affecting the properties of the heat-sensitive recording material according to the invention, such as, for example, the surface whiteness or paper whiteness of the heat-sensitive layer, of the coated paper support in each case.
  • Table 7 Composition of the individual layers of the heat-sensitive recording material according to Example 7.
  • na Customary materials known to those skilled in the art.
  • the individual layers are given additional components, in particular rheological aids such as e.g. As thickeners and / or surfactants added.
  • rheological aids such as e.g. As thickeners and / or surfactants added.
  • the other components are added in amounts such that the weight percent of the respective layer adds up to 100 weight percent. The corresponding amounts are familiar to the person skilled in the art.
  • the color layer and the heat-sensitive layer are applied consecutively by a single and/or simultaneously by a double curtain coater to the paper substrate on a paper coating machine at a speed of 900 m/min.
  • the drying process takes place in the usual way, without adversely affecting the properties of the heat-sensitive recording material according to the invention, such as, for example, the surface whiteness or paper whiteness of the heat-sensitive layer, of the coated paper support in each case.
  • Table 8 Composition of the individual layers of the heat-sensitive recording material according to Example 8.
  • na Customary materials known to those skilled in the art.
  • the individual layers are given additional components, in particular rheological aids such as e.g. As thickeners and / or surfactants added.
  • rheological aids such as e.g. As thickeners and / or surfactants added.
  • the other components are added in amounts such that the weight percent of the respective layer adds up to 100 weight percent. The corresponding amounts are familiar to the person skilled in the art.
  • the color layer and the heat-sensitive layer are applied consecutively by a single and/or simultaneously by a double curtain coater to the paper substrate on a paper coating machine at a speed of 900 m/min.
  • the drying process takes place in the usual way, without adversely affecting the properties of the heat-sensitive recording material according to the invention, such as, for example, the surface whiteness or paper whiteness of the heat-sensitive layer, of the coated paper support in each case.
  • Table 9 Composition of the individual layers of the heat-sensitive recording material according to Example 9.
  • na Customary materials known to those skilled in the art.
  • the individual layers are given additional components, in particular rheological aids such as e.g. As thickeners and / or surfactants added.
  • rheological aids such as e.g. As thickeners and / or surfactants added.
  • the other components are added in amounts such that the weight percent of the respective layer adds up to 100 weight percent. The corresponding amounts are familiar to the person skilled in the art.
  • the color layer and the heat-sensitive layer are applied consecutively by a single and/or simultaneously by a double curtain coater to the paper substrate at a speed of 900 m/min on a paper coating machine.
  • the drying process takes place in the usual way, without adversely affecting the properties of the heat-sensitive recording material according to the invention, such as, for example, the surface whiteness or paper whiteness of the heat-sensitive layer, of the coated paper support in each case.

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  • Physics & Mathematics (AREA)
  • Optics & Photonics (AREA)
  • Heat Sensitive Colour Forming Recording (AREA)
EP22738538.2A 2021-06-18 2022-06-17 Wärmeempfindliche aufzeichnungsmaterialien Pending EP4355582A2 (de)

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US20240278592A1 (en) 2024-08-22
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WO2022262908A3 (de) 2023-03-23

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