HEAT-SENSITIVE RECORDING MATERIAL

Abstract

The present invention relates to a heat-sensitive recording material, wherein the color layer contains at least one removable dye, more particularly a dye that can be removed in the waste paper cycle; to a process for decoloring a heat-sensitive recording material in order to obtain a fibrous material mixture, comprising the steps of providing a mixture of the heat-sensitive recording material and at least one other paper type, more particularly at least one waste paper type, and subsequently decoloring the mixture in a deinking process in order to obtain a fibrous material mixture; to a fibrous material mixture obtained by means of said process; to a process for producing a recycled paper comprising the fibrous material mixture by compressing and dewatering the fibrous material mixture; and to a recycled paper which can be obtained by means of said process.

Claims

1. A heat-sensitive recording material comprising a web-like carrier material, a color layer on one side of the web-like carrier material, and a heat-sensitive layer on the color layer such that the color layer is at least partially covered, wherein the heat-sensitive layer is configured in such a way that it becomes translucent when exposed to localized heat, such that the underlying color layer becomes visible, characterized in that the color layer contains at least one removable dye, more particularly at least one dye which can be removed in the waste paper cycle.

2. The heat-sensitive recording material according to claim 1, characterized in that after reprocessing of the heat-sensitive recording material according to INGEDE method 11, the following scores are achieved according to the Assessment of Printed Product Recyclability, Deinkability Score: a) Luminosity Y maximum of 35 points, b) Color coefficient a* in the CIELAB system maximum of 20 points, c) Dirt specks A in the two different size classes A50 maximum of 15 points and A250 maximum of 10 points, d) Degree of dye elimination (ink elimination) IE maximum of 10 points, and e) Filtrate darkening Y maximum of 10 points, wherein the sum of all points is in the range from 0 to 100

3. The heat-sensitive recording material according to claim 1, characterized in that the at least one removable dye, more particularly removable in the waste paper cycle, is selected from the group comprising bleachable dyes, hydrophobic dyes, hydrophobizable dyes and/or magnetic dyes.

4. The heat-sensitive recording material according to claim 1, characterized in that the at least one removable dye, more particularly removable in the waste paper cycle, is selected from the group comprising carbon black pigments, alternative carbon black pigments, preferably with different particle sizes, morphologies, primary/secondary particle composition and/or surface chemistry, organic dyes, direct dyes, more particularly substantive dyes, reactive dyes, disperse dyes, pigment dyes, iron oxide, sulfur dyes, activated carbon as a dispersion, metal complex dyes, such as iron gall ink (iron(III) gallate), graphite, mica, combinations of carbon black pigments and dark pigments, more particularly dark pigments such as iron oxides, bio-based/food dyes, such as sepia black, caramel coloring or based on hydrothermally treated lignin, and/or printing inks for coloring (offset, (UV) flexo inks), and/or mixtures thereof.

5. The heat-sensitive recording material according to claim 1, characterized in that the color layer comprises at least one binder.

6. The heat-sensitive recording material according to claim 1, characterized in that the at least one removable dye is crosslinked and/or set with the binder.

7. The heat-sensitive recording material according to claim 1, characterized in that the heat-sensitive layer comprises at least one scattering particle having a glass transition temperature of 55 C. to 130 C., a melting temperature of less than 250 C. and/or an average particle size in the range from 0.1 to 2.5 m.

8. The heat-sensitive recording material according to claim 1, characterized in that the heat-sensitive layer comprises at least one 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.

9. The heat-sensitive recording material according to claim 1, characterized in that the heat-sensitive recording material has a residual moisture content from 2 to 14%.

10. The heat-sensitive recording material according to claim 1, characterized in that the heat-sensitive recording material has a surface whiteness of 35 to 60%.

11. The heat-sensitive recording material according to claim 1, characterized in that each layer applied to the web-like carrier material has on its upper side a Bekk smoothness which is at least as great as or greater than that of the respective underlying layer, the upper side in each case being the side on which the web-like carrier material does not lie.

12. The heat-sensitive recording material according to claim 1, characterized in that an insulating layer is present between the web-like carrier material and the color layer, wherein the insulating layer has a Bekk smoothness of more than 50 s or in that the color layer is both a color layer and an insulating layer, wherein the color layer, which is also an insulating layer, has a Bekk smoothness of more than 50 s.

13. The heat-sensitive recording material according to claim 1, characterized in that the heat-sensitive recording material is recyclable and has at least one of the following recyclability criteria: a) In an initial mixture consisting of 100% wood-free, uncoated copy paper with a dry toner printed on both sides and a coverage of 5% (CEN_TEST Master from EN 12281) per side, the addition of 1% heat-sensitive recording material only worsens the light reflectance value after flotation by a maximum of 6 points and the filtrate darkening by a maximum of 3 points compared to the floated initial mixture without heat-sensitive recording material; and/or b) in an initial waste paper mixture of newspapers/magazines (offset, uncoated) in a ratio of 60%/40%, the addition of 5% heat-sensitive recording material only worsens the light reflectance value after flotation by a maximum of 6 points and the filtrate darkening by a maximum of 3 points compared to the floated initial mixture without heat-sensitive recording material.

14. A process for decoloring a heat-sensitive recording material according to claim 1, with a web-like carrier material, a color layer on one side of the web-like carrier material and a heat-sensitive layer on the color layer, such that the color layer is at least partially covered, wherein the heat-sensitive layer is configured to become translucent when exposed to localized heat such that the underlying color layer becomes visible in order to obtain a fibrous material mixture, comprising the steps of Providing a mixture of the heat-sensitive recording material and at least one other paper type, more particularly at least one waste paper type; Decoloring the mixture in a deinking process in order to obtain a fibrous material mixture.

15. The process according to claim 14, characterized in that it comprises the following steps: i) Providing a mixture of the heat-sensitive recording material and at least one other paper type, wherein a specific quantity of the at least one other paper type, ii) Working up of a sample of the mixture according to INGEDE method 11, iii) Determining the following scores according to the Assessment of Printed Product Recyclability, Deinkability Score: a) Luminosity Y maximum of 35 points, b) Color coefficient a* in the CIELAB system maximum of 20 points, c) Dirt specks A in the two different size classes A50 maximum of 15 points and A250 maximum of 10 points, d) Degree of dye elimination (ink elimination) IE maximum of 10 points, and e) Filtrate darkening Y maximum of 10 points, wherein the sum of all points is in the range from 0 to 100, iv) Decoloring the mixture by a deinking process, provided that the sample of the mixture has reached a predetermined number of points, in order to obtain a fibrous material mixture; or Starting again with step i) with addition of an additional quantity of at least one paper type if the sample has not yet reached a predetermined number of points.

16. A fibrous material mixture obtainable by the process according to claim 14.

17. A process for producing a recycled paper comprising the steps of: Decoloring a heat-sensitive recording material according to the process according to claim 14 in order to obtain a fibrous material mixture, and Producing a recycled paper comprising the fibrous material mixture, preferably with the addition of additional primary fibrous material or secondary or waste paper fibrous material, comprising compressing and dewatering the fibrous material mixture optionally containing the additional primary fibrous material or secondary or waste paper fibrous material.

18. (canceled)

19. The heat-sensitive recording material according to claim 2, characterized in wherein no individual point is negative.

20. The heat-sensitive recording material according to claim 1, characterized in that the at least one removable dye, more particularly removable in the waste paper cycle, is selected from the group comprising: carbon black pigments up to 19% by weight, alternative carbon black pigments with different particle sizes, morphologies, primary/secondary particle composition and/or surface chemistry, bleachable organic dyes, substantive dyes, reactive dyes, organic and/or water insoluble disperse dyes, disperse pigment dyes, Fe304, sulfur dyes, activated carbon as a dispersion, iron gall ink (iron(III) gallate), graphite, mica, combinations of carbon black pigments and Fe304, sepia black, caramel coloring or based on hydrothermally treated lignin, (UV) flexo inks, and/or mixtures thereof.

21. The heat-sensitive recording material according to claim 1, characterized in that: the at least one removable dye is removable in the waste paper cycle and is crosslinked and/or set with the binder; the heat-sensitive layer comprises at least one polymer particle having a glass transition temperature of 55 C. to 130 C., a melting temperature of less than 250 C. and/or an average particle size in the range from 0.1 to 2.5 m; the heat-sensitive layer comprises a fatty acid and/or a fatty acid amide 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.; the heat-sensitive recording material has a residual moisture content from 3 to 18%; and an insulating layer having a Bekk smoothness of more than 100 s is present between the web-like carrier material and the color layer or the color layer has a Bekk smoothness of more than 100 s and is both a color layer and an insulating layer.

Description

DESCRIPTION OF THE FIGURES

[0533] The following figures schematically illustrate various layer structures for exemplary heat-sensitive recording materials according to the invention. The composition of the individual layers is to be understood as defined above for each layer.

[0534] 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.

[0535] FIG. 2: Heat-sensitive recording material with a web-like carrier material, an insulating layer applied thereto, a color layer applied to the insulating layer, and a heat-sensitive layer on the color layer.

[0536] FIG. 3: Heat-sensitive recording material with a web-like carrier material, a color layer applied thereto, which is also an insulating layer, and a heat-sensitive layer on the color layer.

[0537] FIG. 4: Heat-sensitive recording material with a web-like carrier material having a starch precoat on both sides, a color layer applied thereto, and a heat-sensitive layer on the color layer.

[0538] FIG. 5: Heat-sensitive recording material with a web-like carrier material, a color layer applied thereto, and a heat-sensitive layer on the color layer, wherein a protective layer is applied to the heat-sensitive layer.

[0539] FIG. 6: A heat-sensitive recording material with a web-like carrier material, an insulating layer applied thereto, a color layer applied to the insulating layer, and a heat-sensitive layer applied to the color layer, wherein a protective layer is applied to the heat-sensitive layer.

[0540] FIG. 7: Heat-sensitive recording material with a web-like carrier material, a color layer applied thereto, which is also an insulating layer, and a heat-sensitive layer on the color layer, wherein a protective layer is applied to the heat-sensitive layer.

[0541] FIG. 8: Heat-sensitive recording material comprising a web-like carrier material having a starch precoat on both sides, a color layer applied thereto, and a heat-sensitive layer on the color layer, wherein a protective layer is applied to the heat-sensitive layer.

[0542] FIG. 9: Heat-sensitive recording material with a web-like carrier material, an adhesive layer on the lower side, and a color layer applied to the other side of the web-like carrier material, and a heat-sensitive layer on the color layer, wherein a siliconized layer is applied to the heat-sensitive layer.

[0543] FIG. 10: Heat-sensitive recording material with a web-like carrier material, an adhesive layer on the lower side and an insulating layer applied to the other side of the web-like carrier material, a color layer applied to the insulating layer, and a heat-sensitive layer on the color layer, wherein a siliconized layer is applied to the heat-sensitive layer.

[0544] FIG. 11: Heat-sensitive recording material with a web-like carrier material, an adhesive layer on the lower side, and a color layer applied to the other side of the web-like carrier material, which is also an insulating layer, and a heat-sensitive layer on the color layer, wherein a siliconized layer is applied to the heat-sensitive layer.

[0545] FIG. 12: Heat-sensitive recording material with a web-like carrier material having a starch precoat on both sides, an adhesive layer on the lower side and a color layer applied to the other side of the web-like carrier material, and a heat-sensitive layer on the color layer, wherein a siliconized layer is applied to the heat-sensitive layer.

[0546] FIG. 13: Heat-sensitive recording material with a web-like carrier material having a starch precoat on both sides, an adhesive layer on the lower side, and a color layer applied to the other side of the web-like carrier material, and a heat-sensitive layer on the color layer, wherein a protective layer is applied to the heat-sensitive layer and a siliconized layer is applied thereon.

[0547] FIG. 14: Measurement of the dynamic sensitivity of heat-sensitive recording materials, wherein the carrier material has different Bekk smoothnesses. The dynamic sensitivity (optical density (ODU)) is shown as a function of the current energy E of three recording materials with different base papers:

[0548] A: Uncalendared, smoothness 210 Bekk [s], [0549] B: Calendared, line pressure 0.5 bar, smoothness 490 Bekk [s], [0550] C: Calendared, line pressure 210 bar, smoothness 1276 Bekk [s].

EXAMPLES

[0551] The invention is explained in more detail below with reference to several non-limiting examples:

[0552] Heat-sensitive recording materials according to the invention were prepared with the dyes and/or binders or binder concepts according to Tables 13 to 19 (comparative example and examples E1 to E39). These were produced according to the exemplary embodiment 2, wherein changes in the percentage of individual formulation components, such as the percentage of the dye, were balanced out using the inorganic pigment calcium carbonate.

[0553] For this purpose, the color layer was applied to the paper substrate on a paper coating machine using a curtain coater. After the application, the drying process of the respective coated paper carrier is carried out in the conventional manner without negatively affecting the properties of the heat-sensitive recording material according to the invention, such as the surface whiteness or paper whiteness of the heat-sensitive layer.

[0554] Then, in accordance to INGEDE Method 11, the scores also listed in Tables 13 to 19 were determined in accordance with the Assessment of Printed Product Recyclability, Deinkability Score and the heat-sensitive recording material was finally evaluated.

[0555] It was also tested whether the heat-sensitive recording material is recyclable and meets at least one of the following recyclability criteria: [0556] a) In an initial mixture consisting of 100% wood-free, uncoated copy paper with a dry toner printed on both sides and a coverage of 5% (CEN_TEST Master from EN 12281) per side, the addition of 1% heat-sensitive recording material only worsens the light reflectance value after flotation by a maximum of 6 points and the filtrate darkening by a maximum of 3 points compared to the floated initial mixture without heat-sensitive recording material; [0557] and/or [0558] b) in an initial waste paper mixture of newspapers/magazines (offset, uncoated) in a ratio of 60%/40%, the addition of 5% heat-sensitive recording material only worsens the light reflectance value after flotation by a maximum of 6 points and the filtrate darkening by a maximum of 3 points compared to the floated initial mixture without heat-sensitive recording material.

[0559] The result of the recyclability test is shown in Tables 13 to 19 in the column Assessment or Note, respectively.

[0560] The process for decoloring the heat-sensitive recording materials in order to obtain a fibrous material mixture comprised the steps: [0561] Providing a mixture of the heat-sensitive recording material and at least one other paper type, more particularly at least one waste paper type; [0562] Decoloring the mixture in a deinking process in order to obtain a fibrous material mixture.

[0563] Heat-sensitive recording materials according to the invention were prepared with the basic compositions according to Tables 1 to 12. Further examples and modifications of these compositions are listed in Tables 13 to 19.

[0564] In all examples, a paper substrate made of hardwood and softwood pulp with a specific basis weight of 41 or 58 g/m.sup.2 is used as the carrier material.

[0565] All indicated basis weights refer to the respective dried layer.

[0566] The dry contents (TG) of the respective coating formulations are adjusted by adding water as follows: Insulating layer (30%), color layer (26%), heat-sensitive layer (20%) and protective layer (10%).

[0567] The raw materials are used as a dispersion or solution with the following dry contents: Ropaque HP-1055 (21%), styrene butadiene latex (48%), dyes, more particularly according to tables 1 to 4 (generally 45%; for E1 the amount of dye was approximately halved), Ropaque OP-96 (30%), sodium metaborate tetrahydrate (2%), stearic acid amide wax (22%), silicon oxide (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%).

[0568] The quantities [% by weight] refer to the oven-dry state (ods).

1. Example 1

[0569] In exemplary embodiment 1, 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. Each application is followed in a conventional manner by the drying process of the respective coated paper substrate.

TABLE-US-00001 TABLE 1 Composition of the individual layers of the heat-sensitive recording material according to example 1. Example 1 (FIG. 3) Formulation Formulation Layer ingredient ingredient Quantity basis weight Trade name Chemical name Function % by wt.] Color layer Ropaque HP-1055, Styrene-acrylate Polymer 52.3 5.2 g/m.sup.2 Dow Co. copolymer particles Latex, Styron Co. Styrene-butadiene Binder 25.7 latex Dye Dye/color 21.2 pigment n.a. n.a. Rheology Balance additives Heat-sensitive Ropaque OP-96, Styrene-acrylate Polymer 35.1 layer Dow Co. copolymer particles 3.5 g/m.sup.2 Sodium metaborate Crosslinker 0.7 tetrahydrate Chukyo Co. Stearic acid Heat-sensitive 40.4 amide wax material Silicon oxide Inorganic 9.0 pigment Zinc stearate Lubricant/ 3.2 release agent Poval, Polyvinyl alcohol, Binder 8.3 Kuraray Co. highly saponified, high viscosity n.a. n.a. Rheology Balance additives n.a.: Common materials known to those skilled in the art.

[0570] In order to improve certain coating properties, additional components, more particularly rheology additives such as thickeners and/or surfactants, are added to the individual layers. The additional components are added in such quantities that the % by weight of the respective layer adds up to 100% by weight. The corresponding quantities are familiar to those skilled in the art.

2. Example 2

[0571] In exemplary embodiment 2, a starch precoat (0.5 g/m.sup.2) is applied to the front and back of the paper substrate on a paper machine using 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 and the heat-sensitive layer is applied using a curtain coater at a speed of 900 n/min. Each application is followed in a conventional manner by the drying process of the respective coated paper substrate.

TABLE-US-00002 TABLE 2 Composition of the individual layers of the heat-sensitive recording material according to example 2. Example 2 (FIG. 4) Formulation Formulation Layer ingredient ingredient Quantity basis weight Trade name Chemical name Function % by wt.] Color layer Calcined kaolin Inorganic pigment 48.2 7.0 g/m.sup.2 Precipitated Inorganic pigment 22.9 calcium carbonate, calcite type Latex, Styron Co. Styrene-butadiene Binder 8.6 latex Dye Dye/color pigment 19.0 n.a. n.a. Rheology additives Balance Heat-sensitive Ropaque OP-96, Styrene-acrylate Polymer particles 36.1 layer Dow Co. copolymer 3.5 g/m.sup.2 Sodium metaborate Crosslinker 0.5 tetrahydrate Chukyo Co. Stearic acid Heat-sensitive 40.4 amide wax material Silicon oxide Inorganic pigment 8.0 Zinc stearate Lubricant/release 3.9 agent Poval, Kuraray Co. Polyvinyl alcohol, Binder 10.3 highly saponified, high viscosity n.a. n.a. Rheology additives Balance n.a.: Common materials known to those skilled in the art.

[0572] In order to improve certain coating properties, additional components, more particularly rheology additives such as thickeners and/or surfactants, are added to the individual layers. The additional components are added in such quantities that the % by weight of the respective layer adds up to 100% by weight. The corresponding quantities are familiar to those skilled in the art.

3. Example 3

[0573] In exemplary embodiment 3, a starch precoat (0.5 g/m.sup.2) is applied to the front and back of the paper substrate on a paper machine using 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. To the starch-coated paper substrate with a color layer, the heat-sensitive layer and the protective layer are applied consecutively using a single and/or simultaneously using a double curtain coater at a speed of 900 m/min on a paper coating machine. Each application is followed in a conventional manner by the drying process of the respective coated paper substrate.

TABLE-US-00003 TABLE 3 Composition of the individual layers of the heat-sensitive recording material according to example 3. Example 3 (FIG. 8) Formulation Formulation Layer ingredient ingredient Quantity basis weight Trade name Chemical name Function % by wt. ] Color layer Calcined kaolin Inorganic pigment 52.2 7.0 g/m.sup.2 Precipitated calcium Inorganic pigment 16.9 carbonate, calcite type Latex, Styron Co. Styrene-butadiene Binder 12.6 latex Dye Dye/color 19.0 pigment n.a. n.a. Rheology additives Balance Heat-sensitive Ropaque OP-96, Styrene-acrylate Polymer particles 38.5 layer Dow Co. copolymer 3.5 g/m.sup.2 Ammonium zirconium Crosslinker 0.9 carbonate Chukyo Co. Stearic acid amide Heat-sensitive 51.0 wax material Poval, Kuraray Co. Polyvinyl alcohol, Binder 8.3 highly saponified, high viscosity n.a. n.a. Rheology additives Balance Protective Poval, Kuraray Co. Polyvinyl alcohol, Binder 75.0 layer highly saponified, 1.0 g/m.sup.2 high viscosity Silicon oxide Inorganic pigment 8.0 Zinc stearate Lubricant/release agent 4.0 Ammonium zirconium Crosslinker 11.0 carbonate n.a. n.a. Rheology additives Balance n.a.: Common materials known to those skilled in the art.

[0574] In order to improve certain coating properties, additional components, more particularly rheology additives such as thickeners and/or surfactants, are added to the individual layers. The additional components are added in such quantities that the % by weight of the respective layer adds up to 100% by weight. The corresponding quantities are familiar to those skilled in the art.

4. Example 4

[0575] In exemplary embodiment 4, 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. Each application is followed in a conventional manner by the drying process of the respective coated paper substrate.

TABLE-US-00004 TABLE 4 Composition of the individual layers of the heat-sensitive recording material according to example 4. Example 4 (FIG. 3) Formulation Formulation Layer ingredient ingredient Quantity basis weight Trade name Chemical name Function % by wt.] Color layer Ropaque HP-1055, Styrene-acrylate Polymer particles 47.2 7.5 g/m.sup.2 Dow Co. copolymer Kaolin Inorganic pigment 16.2 Latex, Styron Co. Styrene-butadiene Binder 12.8 latex Dye Dye/color pigment 23.3 n.a. n.a. Rheology additives Balance Heat-sensitive Plastic Pigment Styrene polymer Polymer particles 35.3 layer 756A, Trinseo LLC 4.0 g/m.sup.2 Chukyo Co. Stearic acid Heat-sensitive 30.8 amide wax material Latex, Styron Co. Styrene-butadiene Binder 10.3 latex Zinc stearate Lubricant/release 3.5 agent Precipitated calcium Inorganic pigment 6.0 carbonate, calcite type Silicon oxide Inorganic pigment 9.0 n.a. n.a. Rheology additives Balance n.a.: Common materials known to those skilled in the art.

[0576] In order to improve certain coating properties, additional components, more particularly rheology additives such as thickeners and/or surfactants, are added to the individual layers. The additional components are added in such quantities that the % by weight of the respective layer adds up to 100% by weight. The corresponding quantities are familiar to those skilled in the art.

5. Example 5

[0577] In exemplary embodiment 5, 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. Each application is followed in a conventional manner by the drying process of the respective coated paper substrate.

TABLE-US-00005 TABLE 5 Composition of the individual layers of the heat-sensitive recording material according to example 5. Example 5 (FIG. 1) Formulation Formulation Layer ingredient ingredient Quantity basis weight Trade name Chemical name Function % by wt.] Color layer Precipitated calcium Inorganic pigment 40.3 4.0 g/m.sup.2 carbonate, calcite type Latex, Styron Co. Styrene-butadiene Binder 16.9 latex Dye Dye/color pigment 42.4 n.a. n.a. Rheology additives Balance Heat-sensitive Chukyo Co. Stearic acid Heat-sensitive 72.3 layer amide wax material/lubricant 6.0 g/m.sup.2 Poval, Kuraray Co. Polyvinyl alcohol, Binder 12.8 highly saponified, high viscosity Precipitated calcium Inorganic pigment 5.5 carbonate, calcite type Silicon oxide Inorganic pigment 8.7 n.a. n.a. Rheology additives Balance n.a.: Common aids known to those skilled in the art.

[0578] In order to improve certain coating properties, additional components, more particularly rheology additives such as thickeners and/or surfactants, are added to the individual layers. The additional components are added in such quantities that the % by weight of the respective layer adds up to 100% by weight. The corresponding quantities are familiar to those skilled in the art.

6. Example 6

[0579] In exemplary embodiment 6, the insulating layer is applied to the paper substrate on a paper machine using 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 to the paper substrate provided with an insulating layer on a paper coating machine. Each application is followed in a conventional manner by the drying process of the respective coated paper substrate.

TABLE-US-00006 TABLE 6 Composition of the individual layers of the heat-sensitive recording material according to the example. Example 6 (FIG. 2) Formulation Formulation Layer ingredient ingredient Quantity basis weight Trade name Chemical name Function % by wt.] Insulating Ropaque HP-1055, Styrene-acrylate Polymer particles 41.1 layer 2.5- Dow Co. copolymer 3.0 g/m.sup.2 Precipitated calcium Inorganic pigment 39.9 carbonate, calcite type Poval, Kuraray Co. Polyvinyl alcohol, Binder 3.0 highly saponified, low viscosity Latex, Styron Co. Styrene-butadiene Binder 15.5 latex n.a. n.a. Rheology additives Balance Color layer Kaolin Inorganic pigment 67.4 3.5 g/m.sup.2 Poval, Kuraray Co. Polyvinyl alcohol, Binder 20.0 highly saponified, low viscosity Dye Dye/color pigment 12.0 n.a. n.a. Rheology additives Balance Heat-sensitive Ropaque OP-96, Styrene-acrylate Polymer particles 44.1 layer Dow Co. copolymer 3.5 g/m.sup.2 Sodium metaborate Crosslinker 0.9 tetrahydrate Chukyo Co. Stearic acid Heat-sensitive 34.4 amide wax material Silicon oxide Inorganic pigment 8.0 Zinc stearate Lubricant/release 3.9 agent Poval, Kuraray Co. Polyvinyl alcohol, Binder 8.3 highly saponified, high viscosity n.a. n.a. Rheology additives Balance n.a.: Common materials known to those skilled in the art.

[0580] In order to improve certain coating properties, additional components, more particularly rheology additives such as thickeners and/or surfactants, are added to the individual layers. The additional components are added in such quantities that the % by weight of the respective layer adds up to 100% by weight. The corresponding quantities are familiar to those skilled in the art.

[0581] It has been shown that using any mixture of scattering particles/polymer particles (e.g., styrene-acrylate copolymer) and inorganic pigment (e.g., calcined kaolin) in the insulating/color layer offers particular advantages in terms of improved barcode readability of the heat-sensitive recording material due to a high degree of fixation of the heat-sensitive layer on the color layer.

[0582] 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 quantities [% by wt.] in the oven-dry state (ods).

[0583] The following examples (examples 7 to 12) explain these embodiments in more detail without limiting their scope.

7. Example 7

[0584] In exemplary embodiment 7, 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. After each application, the drying process of the respective coated paper carrier is carried out in the usual manner without negatively affecting the properties of the heat-sensitive recording material according to the invention, such as the surface whiteness or paper whiteness of the heat-sensitive layer.

TABLE-US-00007 TABLE 7 Composition of the individual layers of the heat-sensitive recording material according to example 7. Example 7 (FIG. 3) Formulation Formulation Quant ty Layer ingredient ingredient % by basis weight Trade name Chemical name Function t.] Color layer Ropaque HP-1055, Styrene-acrylate Scattering particles/polymer 36.3 5.2 g/m.sup.2 Dow Co. copolymer particles Calcined kaolin Inorganic pigment 16.0 Latex, Styron Co. Styrene-butadiene Binder 25.7 latex Carbon black Dye/color pigment 21.2 n.a. n.a. Rheology additives Balance Heat-sensitive Ropaque OP-96, Styrene-acrylate Scattering particles/polymer 35.1 layer Dow Co. copolymer particles 3.5 g/m.sup.2 Sodium metaborate Crosslinker 0.7 tetrahydrate Chukyo Co. Stearic acid amide Heat-sensitive material 40.4 wax Silicon oxide Inorganic pigment 9.0 Zinc stearate Lubricant/release agent 3.2 Poval, Kuraray Co. Polyvinyl alcohol, Binder 8.3 highly saponified, high viscosity n.a. n.a. Rheology additives Balance n.a.: Common materials known to those skilled in the art. indicates data missing or illegible when filed

[0585] In order to improve certain coating properties, additional components, more particularly rheology additives such as thickeners and/or surfactants, are added to the individual layers. The additional components are added in such quantities that the % by weight of the respective layer adds up to 100% by weight. The corresponding quantities are familiar to those skilled in the art.

8. Example 8

[0586] In exemplary embodiment 8, 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. After each application, the drying process of the respective coated paper carrier is carried out in the usual manner without negatively affecting the properties of the heat-sensitive recording material according to the invention, such as the surface whiteness or paper whiteness of the heat-sensitive layer.

TABLE-US-00008 TABLE 8 Composition of the individual layers of the heat-sensitive recording material according to example 8. Example 8 (FIG. 4) Formulation Formulation Quantity Layer ingredient ingredient % by basis weight Trade name Chemical name Function t.] Color layer Ropaque HP-1055, Styrene-acrylate Scattering 16.0 7.0 g/m.sup.2 Dow Co. copolymer particles/polymer particles Calcined kaolin Inorganic pigment 42.2 Precipitated calcium Inorganic pigment 22.9 carbonate, calcite type Latex, Styron Co. Styrene-butadiene Binder 8.6 latex Carbon black Dye/color pigment 19.0 n.a. n.a. Rheology additives Balance Heat-sensitive Ropaque OP-96, Styrene-acrylate Scattering particles, 36.1 layer Dow Co. copolymer polymer particles 3.5 g/m.sup.2 Sodium metaborate Crosslinker 0.5 tetrahydrate Chukyo Co. Stearic acid amide Heat-sensitive 40.4 wax material Silicon oxide Inorganic pigment 8.0 Zinc stearate Lubricant/release 3.9 agent Poval, Kuraray Co. Polyvinyl alcohol, Binder 10.3 highly saponified, high viscosity n.a. n.a. Rheology additives Balance n.a.: Common materials known to those skilled in the art. indicates data missing or illegible when filed

[0587] In order to improve certain coating properties, additional components, more particularly rheology additives such as thickeners and/or surfactants, are added to the individual layers. The additional components are added in such quantities that the % by weight of the respective layer adds up to 100% by weight. The corresponding quantities are familiar to those skilled in the art.

9. Example 9

[0588] In exemplary embodiment 9, 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. After each application, the drying process of the respective coated paper carrier is carried out in the usual manner without negatively affecting the properties of the heat-sensitive recording material according to the invention, such as the surface whiteness or paper whiteness of the heat-sensitive layer.

TABLE-US-00009 TABLE 9 Composition of the individual layers of the heat-sensitive recording material according to example 9. Example 9 (FIG. 8) Formulation Formulation Quantity Layer ingredient ingredient % by basis weight Trade name Chemical name Function t.] Color layer Ropaque HP-1055, Styrene-acrylate Scattering 17.2 7.0 g/m.sup.2 Dow Co. copolymer particles/polymer particles Calcined kaolin Inorganic pigment 35.0 Precipitated calcium Inorganic pigment 16.9 carbonate, calcite type Latex, Styron Co. Styrene-butadiene Binder 12.6 latex Carbon black Dye/Color pigment 19.0 n.a. n.a. Rheology additives Balance Heat-sensitive Ropaque OP-96, Styrene-acrylate Scattering particles, 38.5 layer Dow Co. copolymer polymer particles 3.5 g/m.sup.2 Ammonium zirconium Crosslinker 0.9 carbonate Chukyo Co. Stearic acid amide Heat-sensitive material 51.0 wax Poval, Kuraray Co. Polyvinyl alcohol, Binder 8.3 highly saponified, high viscosity n.a. n.a. Rheology additives Balance Protective layer Poval, Kuraray Co. Polyvinyl alcohol, Binder 75.0 1.0 g/m.sup.2 highly saponified, high viscosity Silicon oxide Inorganic pigment 8.0 Zinc stearate Lubricant/release agent 4.0 Ammonium zirconium Crosslinker 11.0 carbonate n.a. n.a. Rheology additives Balance n.a.: Common materials known to those skilled in the art. indicates data missing or illegible when filed

[0589] In order to improve certain coating properties, additional components, more particularly rheology additives such as thickeners and/or surfactants, are added to the individual layers. The additional components are added in such quantities that the % by weight of the respective layer adds up to 100% by weight. The corresponding quantities are familiar to those skilled in the art.

10. Example 10

[0590] In exemplary embodiment 10, 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. After each application, the drying process of the respective coated paper carrier is carried out in the usual manner without negatively affecting the properties of the heat-sensitive recording material according to the invention, such as the surface whiteness or paper whiteness of the heat-sensitive layer.

TABLE-US-00010 TABLE 10 Composition of the individual layers of the heat-sensitive recording material according to example 10. Example 10 (FIG. 3) Formulation Formulation Quantity Layer ingredient ingredient % by basis weight Trade name Chemical name Function t.] Color layer Ropaque HP-1055, Styrene-acrylate Scattering 32.2 7.5 g/m.sup.2 Dow Co. copolymer particles/polymer particles Calcined kaolin Inorganic pigment 15.0 Kaolin Inorganic pigment 16.2 Latex, Styron Co. Styrene-butadiene Binder 12.8 latex Carbon black Dye/color pigment 23.3 n.a. n.a. Rheology additives Balance Heat-sensitive Plastic Pigment Styrene polymer Scattering 35.3 layer 756A, Trinseo LLC particles/polymer 4.0 g/m.sup.2 particles Chukyo Co. Stearic acid Heat-sensitive material 30.8 amide wax Latex, Styron Co. Styrene-butadiene Binder 10.3 latex Zinc stearate Lubricant/release agent 3.5 Precipitated Inorganic pigment 6.0 calcium carbonate, calcite type Silicon oxide Inorganic pigment 9.0 n.a. n.a. Rheology additives Balance n.a.: Common materials known to those skilled in the art. indicates data missing or illegible when filed

[0591] In order to improve certain coating properties, additional components, more particularly rheology additives such as thickeners and/or surfactants, are added to the individual layers. The additional components are added in such quantities that the % by weight of the respective layer adds up to 100% by weight. The corresponding quantities are familiar to those skilled in the art.

11. Example 11

[0592] In exemplary embodiment 11, 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. After each application, the drying process of the respective coated paper carrier is carried out in the usual manner without negatively affecting the properties of the heat-sensitive recording material according to the invention, such as the surface whiteness or paper whiteness of the heat-sensitive layer.

TABLE-US-00011 TABLE 11 Composition of the individual layers of the heat-sensitive recording material according to example 11. Example 11 (FIG. 1) Formulation Formulation Quantity Layer ingredient ingredient % by basis weight Trade name Chemical name Function t.] Color layer Ropaque HP-1055, Styrene-acrylate Scattering particles/polymer 15.3 4.0 g/m.sup.2 Dow Co. copolymer particles Calcined kaolin Inorganic pigment 14.7 Precipitated Inorganic pigment 28.3 calcium carbonate, calcite type Latex, Styron Co. Styrene-butadiene Binder 8.9 latex Carbon black Dye/color pigment 32.4 n.a. n.a. Rheology additives Balance Heat-sensitive Chukyo Co. Stearic acid amide Scattering particles/heat- 72.3 layer wax sensitive material/lubricant 6.0 g/m.sup.2 Poval, Kuraray Co. Polyvinyl alcohol, Binder 12.8 highly saponified, high viscosity Precipitated Inorganic pigment 5.5 calcium carbonate, calcite type Silicon oxide Inorganic pigment 8.7 n.a. n.a. Rheology additives Balance n.a.: Common aids known to those skilled in the art. indicates data missing or illegible when filed

[0593] In order to improve certain coating properties, additional components, more particularly rheology additives such as thickeners and/or surfactants, are added to the individual layers. The additional components are added in such quantities that the % by weight of the respective layer adds up to 100% by weight. The corresponding quanitites are familiar to those skilled in the art.

12. Example 12

[0594] In exemplary embodiment example 12, the insulating layer is applied to the paper substrate on a paper machine using 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 to the paper substrate provided with an insulating layer on a paper coating machine. After each application, the drying process of the respective coated paper carrier is carried out in the usual manner without negatively affecting the properties of the heat-sensitive recording material according to the invention, such as the surface whiteness or paper whiteness of the heat-sensitive layer.

TABLE-US-00012 TABLE 12 Composition of the individual layers of the heat-sensitive recording material according to example 12. Example 12 (FIG. 2) Formulation Quantity Layer ingredient Formulation ingredient % by basis weight Trade name Chemical name Function t.] Insulating layer Ropaque HP- Styrene-acrylate Scattering particles/polymer 41.1 2.5-3.0 g/m.sup.2 1055, Dow Co. copolymer particles Calcined kaolin Inorganic pigment 12.3 Precipitated calcium Inorganic pigment 25.6 carbonate, calcite type Poval, Kuraray Polyvinyl alcohol, Binder 3.0 Co. highly saponified, low viscosity Ammonium zirconium Crosslinker 2.0 carbonate Latex, Styron Styrene-butadiene Binder 15.5 Co. latex n.a. n.a. Rheology additives Balance Color layer Kaolin Inorganic pigment 61.2 3.5 g/m.sup.2 Poval, Kuraray Polyvinyl alcohol, Binder 20.0 Co. highly saponified, low viscosity Ammonium zirconium Crosslinker 6.2 carbonate Carbon black Dye/color pigment 12.0 n.a. n.a. Rheology additives Balance Heat-sensitive Ropaque OP-96, Styrene-acrylate Scattering particles/polymer 44.1 layer Dow Co. copolymer particles 3.5 g/m.sup.2 Sodium metaborate Crosslinker 0.9 tetrahydrate Chukyo Co. Stearic acid amide wax Heat-sensitive material 34.4 Silicon oxide Inorganic pigment 8.0 Zinc stearate Lubricant/release agent 3.9 Poval, Kuraray Polyvinyl alcohol, Binder 8.3 Co. highly saponified, high viscosity n.a. n.a. Rheology additives Balance n.a.: Common materials known to those skilled in the art. indicates data missing or illegible when filed

[0595] In order to improve certain coating properties, additional components, more particularly rheology additives such as thickeners and/or surfactants, are added to the individual layers. The additional components are added in such quantities that the % by weight of the respective layer adds up to 100% by weight. The corresponding quantities are familiar to those skilled in the art.

TABLE-US-00013 TABLE 13 Comparative example E1 E2 E3 Dye Carbon black [2.1% by Carbon black [1.1% by Carbon black/ Substantive dye* weight, based on weight, based on binder crosslinker recording material] recording material] concept B/K* Dye class Carbon Carbon Final blackening (optical 1.40 1.31 1.37 1.45 density) a) Luminosity Y (maximum of 30 30 max. 35 max. 35 35 points) b) Color coefficient a* in the 20 20 max. 20 max. 20 CIELAB system (maximum of 20 points) c) Dirt specks A in size 15 1 max. 15 max. 15 classes A50 (maximum of 15 points) d) Dirt specks A in size 10 20 max. 10 max. 10 classes and A250 (maximum of 10 points) e) Degree of dye elimination 10 10 max. 10 max. 10 (ink elimination) IE (maximum of 10 points) f) Filtrate darkening Y 10 0 max. 10 max. 10 (maximum of 10 points) Sum of points (score; 25 54 max. 100 max. 100 maximum of 100 points) Assessment Not suitable for deinking Suitable for deinking, Suitable for deinking, Suitable for deinking, without the addition of more particularly for more particularly for more particularly for waste paper or wood-free, recycling according to recycling according to recycling according to uncoated copy paper the recyclability the recyclability the recyclability criteria.sup.1 criteria.sup.1 criteria.sup.1 Remark *(Meth)acrylamide-acrylate *Pergasol Black 18 LNA copolymer of the core-shell type .sup.1Criteria for recyclability: a) In an initial mixture consisting of 100% wood-free, uncoated copy paper with a dry toner printed on both sides and a coverage of 5% (CEN_TEST Master from EN 12281) per side, the addition of 1% heat-sensitive recording material only worsens the light reflectance value after flotation by a maximum of 6 points and the filtrate darkening by a maximum of 3 points compared to the floated initial mixture without heat-sensitive recording material; and/or b) in an initial waste paper mixture of newspapers/magazines (offset, uncoated) in a ratio of 60%/40%, the addition of 5% heat-sensitive recording material only worsens the light reflectance value after flotation by a maximum of 6 points and the filtrate darkening by a maximum of 3 points compared to the floated initial mixture without heat-sensitive recording material.

TABLE-US-00014 TABLE 14 E4 E5 E6 E7 Dye Carbon black/ Carbon black/ Waterflexo/Aqualabel* Graphite Binder concept W* Binder concept (SK on 1/0- HK)* Dye class Carbon Final blackening (optical 1.44 1.49 1.45 0.66 density) a) Luminosity Y (maximum of max. 35 max. 35 max. 35 max. 35 35 points) b) Color coefficient a* in the max. 20 max. 20 max. 20 max. 20 CIELAB system (maximum of 20 points) c) Dirt specks A in size classes max. 15 max. 15 max. 15 max. 15 A50 (maximum of 15 points) d) Dirt specks A in size classes max. 10 max. 10 max. 10 max. 10 and A250 (maximum of 10 points) e) Degree of dye elimination max. 10 max. 10 max. 10 max. 10 (ink elimination) IE (maximum of 10 points) f) Filtrate darkening Y max. 10 max. 10 max. 10 max. 10 (maximum of 10 points) Sum of points (score; max. 100 max. 100 max. 100 max. 100 maximum of 100 points) Assessment Suitable for deinking, Suitable for deinking, more Suitable for deinking, Suitable for deinking, more particularly for particularly for recycling more particularly for more particularly for recycling according to according to the recyclability recycling according to the recycling according to the the recyclability criteria.sup.1 criteria.sup.1 recyclability criteria.sup.1 recyclability criteria.sup.1 Remark *Ethylene-acrylate *Styrene-butadiene latex *Process black HK/HR copolymer (double amount) and natural calcium carbonate .sup.1Criteria for recyclability: a) In an initial mixture consisting of 100% wood-free, uncoated copy paper with a dry toner printed on both sides and a coverage of 5% (CEN_TEST Master from EN 12281) per side, the addition of 1% heat-sensitive recording material only worsens the light reflectance value after flotation by a maximum of 6 points and the filtrate darkening by a maximum of 3 points compared to the floated initial mixture without heat-sensitive recording material; and/or b) in an initial waste paper mixture of newspapers/magazines (offset, uncoated) in a ratio of 60%/40%, the addition of 5% heat-sensitive recording material only worsens the light reflectance value after flotation by a maximum of 6 points and the filtrate darkening by a maximum of 3 points compared to the floated initial mixture without heat-sensitive recording material.

TABLE-US-00015 TABLE 15 E8 E9 E10 E11 Dye Sulfur dye/cassulfon* Iron gall ink RYB mixture, red, yellow, Iron oxide/Bayferrox blue pigment 306/Fe.sub.3O.sub.4 1:1:1/Pergalite pigments* Dye class Inorganic and/or organic Iron oxide/magnetic or pigment dyes magnetizable dyes/pigments Final blackening (optical 1.37 1.05 1.4 0.57 density) a) Luminosity Y (maximum of max. 35 max. 35 max. 35 max. 35 35 points) b) Color coefficient a* in the max. 20 max. 20 max. 20 max. 20 CIELAB system (maximum of 20 points) c) Dirt specks A in size classes max. 15 max. 15 max. 15 max. 15 A50 (maximum of 15 points) d) Dirt specks A in size classes max. 10 max. 10 max. 10 max. 10 and A250 (maximum of 10 points) e) Degree of dye elimination max. 10 max. 10 max. 10 9 (ink elimination) IE (maximum of 10 points) f) Filtrate darkening Y max. 10 max. 10 max. 10 9 (maximum of 10 points) Sum of points (score; max. 100 max. 100 max. 100 max. 98 maximum of 100 points) Assessment Suitable for deinking, more Suitable for deinking, more Suitable for deinking, Suitable for deinking, particularly for recycling particularly for recycling more particularly for more particularly for according to the according to the recycling according to the recycling according to the recyclability criteria.sup.1 recyclability criteria.sup.1 recyclability criteria.sup.1 recyclability criteria.sup.1 Remark *Cassulfon Black PM-S *Pergalite Yellow G-L; Deinking was carried out Red G-L; Blue R-LW by magnetic removal of the dye .sup.1Criteria for recyclability: a) In an initial mixture consisting of 100% wood-free, uncoated copy paper with a dry toner printed on both sides and a coverage of 5% (CEN_TEST Master from EN 12281) per side, the addition of 1% heat-sensitive recording material only worsens the light reflectance value after flotation by a maximum of 6 points and the filtrate darkening by a maximum of 3 points compared to the floated initial mixture without heat-sensitive recording material; and/or b) in an initial waste paper mixture of newspapers/magazines (offset, uncoated) in a ratio of 60%/40%, the addition of 5% heat-sensitive recording material only worsens the light reflectance value after flotation by a maximum of 6 points and the filtrate darkening by a maximum of 3 points compared to the floated initial mixture without heat-sensitive recording material.

TABLE-US-00016 TABLE 16 E12 E13 E14 E15 Dye Iron oxide black Carbon black [2.1% by Carbon black [2.1% by Carbon black [1.1% by suspension*/Fe.sub.3O.sub.4 weight, based on weight, based on weight, based on recording material] recording material] recording material] Dye class Iron oxide/magnetic or magnetizable dyes/pigments Final blackening (optical 0.61 1.4 1.4 1.31 density) a) Luminosity Y (maximum of max. 35 34 35 34 35 points) b) Color coefficient a* in the max. 20 18 20 20 CIELAB system (maximum of 20 points) c) Dirt specks A in size max. 15 10 12 15 classes A50 (maximum of 15 points) d) Dirt specks A in size max. 10 8 10 7 classes and A250 (maximum of 10 points) e) Degree of dye elimination 9 2 8 8 (ink elimination) IE (maximum of 10 points) f) Filtrate darkening Y 9 2 10 8 (maximum of 10 points) Sum of points (score; max. 98 74 95 92 maximum of 100 points) Assessment Suitable for deinking, more Suitable for deinking, more Suitable for deinking Suitable for deinking particularly for recycling particularly for recycling according to the recyclability according to the recyclability criteria.sup.1 criteria.sup.1 Remark Deinking was carried out by Mixture of max. 3% by Mixture of 0.1% by Mixture of 2.5% by magnetic removal of the dye weight comparative example weight comparative weight E1 and 97.5% by *Bayferrox 350 fl. and min. 97% by weight waste example and 99.9% by weight waste paper paper is suitable for deinking weight waste paper composition suitable for composition suitable for deinking deinking .sup.1Criteria for recyclability: a) In an initial mixture consisting of 100% wood-free, uncoated copy paper with a dry toner printed on both sides and a coverage of 5% (CEN_TEST Master from EN 12281) per side, the addition of 1% heat-sensitive recording material only worsens the light reflectance value after flotation by a maximum of 6 points and the filtrate darkening by a maximum of 3 points compared to the floated initial mixture without heat-sensitive recording material; and/or b) in an initial waste paper mixture of newspapers/magazines (offset, uncoated) in a ratio of 60%/40%, the addition of 5% heat-sensitive recording material only worsens the light reflectance value after flotation by a maximum of 6 points and the filtrate darkening by a maximum of 3 points compared to the floated initial mixture without heat-sensitive recording material.

TABLE-US-00017 TABLE 17 E16 E18 E19 E20 Dye Carbon black [1.1% by Carbon black [1.1% by RYB mixture, red, yellow, RYB mixture, red, yellow, weight, based on weight, based on blue pigment blue pigment recording material] recording materiall 1:1:1/Pergalite pigments 1:1:1/Pergalite pigments Dye class Final blackening (optical 1.31 1.31 1.4 1.4 density) a) Luminosity Y (maximum of 35 11 35 35 35 points) b) Color coefficient a* in the 20 20 20 20 CIELAB system (maximum of 20 points) c) Dirt specks A in size classes 15 15 15 15 A50 (maximum of 15 points) d) Dirt specks A in size classes 10 10 10 10 and A250 (maximum of 10 points) e) Degree of dye elimination 10 10 7 10 (ink elimination) IE (maximum of 10 points) f) Filtrate darkening Y 10 0 8 8 (maximum of 10 points) Sum of points (score; 95 66 95 98 maximum of 100 points) Assessment Suitable for deinking Suitable for deinking Suitable for deinking Suitable for deinking Remark Mixture of 5% by weight Mixture of 10% by weight Mixture of 2.5% by weight Mixture of 5% by weight E1 and 95% by weight E1 and 90% by weight E10 and 97.5% by weight E10 and 95% by weight waste paper composition waste paper composition waste paper composition waste paper composition suitable for deinking suitable for deinking suitable for deinking suitable for deinking

TABLE-US-00018 TABLE 18 E21 E24 E27 Dye RYB mixture, red, Carbon black/Binder Sulfur dye yellow, blue pigment concept W 1:1:1/Pergalite pigments Dye class Final blackening (optical 1.4 1.44 1.37 density) a) Luminosity Y (maximum of 35 32 35 35 points) b) Color coefficient a* in the 20 20 20 CIELAB system (maximum of 20 points) c) Dirt specks A in size classes 15 14 15 A50 (maximum of 15 points) d) Dirt specks A in size classes 10 8 10 and A250 (maximum of 10 points) e) Degree of dye elimination 10 8 6 (ink elimination) IE (maximum of 10 points) f) Filtrate darkening Y 7 6 6 (maximum of 10 points) Sum of points (score; 97 88 92 maximum of 100 points) Assessment Suitable for deinking Suitable for deinking Suitable for deinking Remark Mixture of 10% by Mixture of 2.5% by Mixture of 2.5% by weight E10 and 90% by weight E4 and 97.5% by weight E8 and 97.5% weight waste paper weight waste paper by weight waste paper composition suitable for composition suitable for composition suitable for deinking deinking deinking E32 E34 Dye Carbon black [2.1% by Carbon black [1.1% by weight, based on weight, based on recording material] recording material] Dye class Cartaren Black (alt. Cartaren Black (alt. Carbon black) Carbon black) Final blackening (optical 1.38 1.31 density) a) Luminosity Y (maximum of 22 29 35 points) b) Color coefficient a* in the 20 20 CIELAB system (maximum of 20 points) c) Dirt specks A in size classes 15 15 A50 (maximum of 15 points) d) Dirt specks A in size classes 10 10 and A250 (maximum of 10 points) e) Degree of dye elimination 10 10 (ink elimination) IE (maximum of 10 points) f) Filtrate darkening Y 4 5 (maximum of 10 points) Sum of points (score; 81 89 maximum of 100 points) Assessment Suitable for deinking Suitable for deinking Remark Mixture of 2.5% by Mixture of 5% by weight weight comparative of E1 with Cartaren example with Cartaren Black instead of carbon Black instead of carbon black or E34 and 95% black or E32 and 97.5% by weight of waste by weight waste paper paper composition composition suitable for suitable for deinking deinking

TABLE-US-00019 TABLE 19 E36 E37 E38 E39 Dye Carbon black [2.1% by Carbon black [1.6% by Carbon black [2.1% by Carbon black [2.1% weight, based on weight, based on weight, based on by weight, based on recording material] recording material] recording material] recording material] Dye class Final blackening (optical density) a) Luminosity Y (maximum of 35 35 35 35 35 points) b) Color coefficient a* in the 20 20 20 20 CIELAB system (maximum of 20 points) c) Dirt specks A in size 15 15 15 15 classes A50 (maximum of 15 points) d) Dirt specks A in size 10 10 10 10 classes and A250 (maximum of 10 points) e) Degree of dye elimination 4 3 2 8 (ink elimination) IE (maximum of 10 points) f) Filtrate darkening Y 10 10 10 10 (maximum of 10 points) Sum of points (score; 94 93 92 98 maximum of 100 points) Assessment Suitable for deinking Suitable for deinking Suitable for deinking Suitable for deinking Remark Mixture of 1% by Mixture of 1% by Mixture of 1% by weight Mixture of 1% by weight comparative weight E30 and 99% by comparative example and weight. according to example and 99% by weight copy paper 99% by weight copy embodiment 3 and weight copy paper paper 99% by weight copy paper

7. Testing of the Recyclability of the Heat-Sensitive Recording Materials of Examples E1 to E39

[0596] Examples E1 to E39 each met at least one of the following recyclability criteria: [0597] a) In an initial mixture consisting of 100% wood-free, uncoated copy paper with a dry toner printed on both sides and a coverage of 5% (CEN_TEST Master from EN 12281) per side, the addition of 1% heat-sensitive recording material only worsens the light reflectance value after flotation by 6 points and the filtrate darkening by 3 points compared to the floated initial mixture without heat-sensitive recording material; [0598] and/or [0599] b) in an initial waste paper mixture of newspapers/magazines (offset, uncoated) in a ratio of 60%/40%, the addition of 5% heat-sensitive recording material only worsens the light reflectance value after flotation by 6 points and the filtrate darkening by 3 points compared to the floated initial mixture without heat-sensitive recording material.