EP3957488A1 - Heat-sensitive recording material and heat-sensitive recording layer and coating composition for its production, uses and methods - Google Patents

Abstract

A heat-sensitive recording layer is described, comprising organic color developers free from phenol groups, a coating composition for producing the heat-sensitive recording layer and a heat-sensitive recording material, in particular thermal paper, comprising the heat-sensitive recording layer. Furthermore, the use of the heat-sensitive recording layer for the production of the heat-sensitive recording material, a method for the production of the heat-sensitive recording material and the use of the heat-sensitive recording material in thermal paper applications are described. Because of its composition, the heat-sensitive recording material has particularly good recyclability and high environmental compatibility.

Description

The present invention relates to a heat-sensitive recording layer comprising organic color developers free from phenol groups, a coating composition for producing the heat-sensitive recording layer and a heat-sensitive recording material, in particular thermal paper, comprising the heat-sensitive recording layer. The present invention further relates to the use of the heat-sensitive recording layer for the production of the heat-sensitive recording material, a method for the production of the heat-sensitive recording material and the use of the heat-sensitive recording material in thermal paper applications. Because of its composition, the heat-sensitive recording material of the present invention has particularly good recyclability and high environmental compatibility.

Heat-sensitive recording materials (often also referred to as "thermal papers") have been known for many years and are very popular. This popularity is based, among other things, on the fact that the color-forming components are contained in the recording material itself, meaning that printers without toner and ink cartridges can be used. It is therefore no longer necessary to use toner or color cartridges, to stockpile, to change or to fill up. This innovative technology has become widespread in business life, particularly in public transport and in retail, where its flexible applicability in business transactions (at the "point-of-sale") is valued.

In the recent past, however, there has been increased discussion regarding the environmental compatibility of heat-sensitive recording materials and their ingredients, for example certain organic color developers (sometimes also referred to as "color acceptors"), but sometimes also of dye precursors with which the color developers react when heat is applied, forming a visually recognizable color. These discussions are closely followed by industry and especially by trade. For example, the well-known and extensively studied components "bisphenol-A" (corresponds to 2,2-bis-(4-hydroxyphenyl)-propane) and "bisphenol-S" (corresponds to 4,4'-dihydroxydiphenylsulfone) have recently become available in color developers ) increased in focus. These are often already being replaced by the substitutes Pergafast ^® 201 (corresponds to N- (4-methylphenylsulfonyl) -N '-(3-(4-methylphenylsulfonyloxy)phenyl)urea), "D8" (corresponds to 4-hydroxy-4'- isopropoxydiphenylsulfone), N -[2-(3-phenylureido)phenyl]benzenesulfonamide or N -{2-[(phenylcarbamoyl)amino]phenyl}benzenesulfonamide.

With the aim of improving heat-sensitive recording materials, especially when used as tickets or lottery tickets, with regard to their resistance to environmental influences such as heat, moisture and chemicals, the underlying chemistry and the production technology for producing such recording materials have been continuously developed. Efforts have also been made in the past to improve the environmental properties of heat-sensitive recording materials.

For example, to increase the resistance of a thermal printout (ie a heat-induced recording) obtainable on a heat-sensitive recording material to water, aqueous alcohol solutions and plasticizers in the document DE 10 2004 004 204 A1 proposed a heat-sensitive recording material whose heat-sensitive recording layer has conventional dye precursors and the combination of a phenolic color developer and a urea-urethane-based color developer.

In the document DE 10 2015 104 306 A1 describes a heat-sensitive recording material which comprises a carrier substrate and a heat-sensitive color-forming layer containing at least one color former and at least one phenol-free color developer, N-phenyl-N'[(phenylamino)sulfonyl]-urea,N-(4- methylphenyl)-N'[(4-ethylphenylamino)sulfonyl]urea, N-(4-ethoxycarbonylphenyl)-N'[(4-ethoxycarbonylphenylamino)sulfonyl]urea or structurally similar compounds can be used.

In the document JP 2014-218062 A describes a heat-sensitive recording material having a heat-sensitive recording layer containing at least a leuco dye and a color developer on a support. A mixture of 4,4'-bis(3-tosylureido)diphenylmethane and N-[2-(3-phenylureido)phenyl]benzenesulfonamide is used as the color developer.

In the document WO 2016/136203 A1 describes a crystalline form of N-(2-(3-phenylureido)-phenyl)benzenesulfonamide and the use of this crystalline form in a recording material.

subject of the document US 2005/0148467 A1 is a heat-sensitive recording material that contains at least the components of two color-forming systems to form an irreversible print image, one system being of the chelate type and the other being a conventional leuco-dye system.

The documents WO 2018/065328 A1 as WO 2018/065330 A1 each disclose a heat-sensitive recording material comprising a carrier substrate and a heat-sensitive recording layer, wherein the heat-sensitive recording layer comprises a color former and a color developer mixture.

The document WO 2019/166608 A1 describes a heat-sensitive recording material and color developer.

The document WO 2012/145456 A1 deals with a recording material.

However, there is a constant need for further and improved heat-sensitive recording materials for a wide variety of applications, it being possible for these to be produced at low production costs on account of high sales volumes in a dynamic market and they should therefore have a simple structure. Given this In view of the high sales and production volumes, increasing demands have recently also been made on the recyclability and, quite generally, on the environmental compatibility of heat-sensitive recording materials.

Another constant challenge is that a printed heat-sensitive recording material is exposed to a variety of different environmental influences, such as humidity, temperature extremes and/or chemicals, given its typical areas of application as tickets, entrance tickets, transport tickets, parking tickets and the like.

In addition to resistance to chemicals, heat-sensitive recording materials should therefore also have the highest possible resistance to thermal influences. On the one hand, it should be possible to print the heat-sensitive recording material in an energy-saving and easy way, for example in order to use less energy in mobile applications. On the other hand, the printed image should be preserved after printing and when exposed to heat, the printed image should fade as little as possible and the unprinted background should not discolor: this would make the print illegible. Thermal resistance is particularly important for parking tickets, which are stored behind the windshield after printing and are therefore exposed to high temperatures and direct sunlight in summer.

It was now a primary object of the present invention to provide a heat-sensitive recording material which has particularly good recyclability and high environmental compatibility while at the same time having excellent printability.

A further object of the present invention was to provide a heat-sensitive recording material which, in the printed state, has high resistance to environmental influences, such as moisture, heat, fat or fats and/or chemicals.

• K1) ein oder mehrere organische Farbstoffvorläufer, welche jeweils eine Fluoran-Struktur umfassen,
• K2) ein oder mehrere Phenolgruppen-freie organische Farbentwickler,
• K3) ein oder mehrere, vernetzte oder unvernetzte, polymere organische Bindemittel, vorzugsweise ausgewählt aus der Gruppe bestehend aus Stärke, unmodifizierten Polyvinylalkoholen, mit Carboxylgruppen modifizierten Polyvinylalkoholen, mit Silanolgruppen modifizierten Polyvinylalkoholen, Diaceton-modifizierten Polyvinylalkoholen, Acetoacetyl-modifizierten Polyvinylalkoholen, teil- und vollverseiften Polyvinylalkoholen, filmbildenden Acrylcopolymeren (vorzugsweise Alkylen/(Meth)Acrylsäure-Copolymeren und deren Gemischen;
• K4) ein oder mehrere, vorzugsweise synthetische, Amidwachse, welche jeweils einen Schmelzpunkt im Bereich von 80 °C bis 120 °C aufweisen,
• K5) ein oder mehrere partikuläre anorganische Pigmente (und/oder partikuläre anorganische Füllstoffe)
  und
• K6) ein oder mehrere Gleitmittel,

wobei die Summe der Komponenten K1) bis K6) ≥ 95 Massenprozent der Trockenmasse der wärmeempfindlichen Aufzeichnungsschicht ausmacht.Surprisingly, it has now been found that the primary object and other objects and/or sub-objects of the present invention are achieved by a heat-sensitive recording layer, preferably for the production of a heat-sensitive recording material, comprising:

• K1) one or more organic dye precursors, each of which comprises a fluoran structure,
• K2) one or more phenol group-free organic color developers,
• K3) one or more crosslinked or uncrosslinked, polymeric organic binders, preferably selected from the group consisting of starch, unmodified polyvinyl alcohols, polyvinyl alcohols modified with carboxyl groups, polyvinyl alcohols modified with silanol groups, diacetone-modified polyvinyl alcohols, acetoacetyl-modified polyvinyl alcohols, partially and fully hydrolyzed polyvinyl alcohols, film-forming acrylic copolymers (preferably alkylene/(meth)acrylic acid copolymers and mixtures thereof;
• K4) one or more, preferably synthetic, amide waxes, each of which has a melting point in the range from 80° C. to 120° C.,
• K5) one or more particulate inorganic pigments (and/or particulate inorganic fillers)
  and
• K6) one or more lubricants,

where the sum of the components K1) to K6) makes up ≧95 percent by weight of the dry weight of the heat-sensitive recording layer.

The invention as well as combinations of preferred parameters, properties and/or components of the present invention which are preferred according to the invention are defined in the appended claims. Preferred aspects of the present invention are also specified or defined in the following description and in the examples.

The composition of the above-mentioned heat-sensitive recording layer according to the invention makes it possible to use it to produce a heat-sensitive recording material, in particular a thermal paper, which has particularly good recyclability and high environmental compatibility.

For example, the heat-sensitive recording layer according to the invention contains no developers containing phenol groups, making it particularly suitable for the production of heat-sensitive recording material with good recyclability, since such heat-sensitive recording material causes little or no irreversible discoloration, for example in deinking systems. The heat-sensitive recording layer according to the invention and the heat-sensitive recording material according to the invention (see below) also come without classic organic sensitizer compounds (hereinafter referred to as "sensitizers") such as benzyl 2-naphthyl ether, 1,2-diphenoxyethane, 1,2-bis(3 -methylphenoxy)-ethane or 1-phenoxy-2-(4-methylphenoxy)ethane, which are increasingly regarded as unattractive from the point of view of environmental compatibility. Likewise, the heat-sensitive recording layer according to the invention preferably does not contain any organic hollow body pigments which could get into the environment as undesired "microplastics". Dyes which are potentially harmful to the environment or health, such as carbon black, can preferably be dispensed with entirely in the heat-sensitive recording layer according to the invention and in the heat-sensitive recording material according to the invention.

The above-mentioned heat-sensitive recording layer according to the invention preferably comprises exclusively components (or constituents) which, according to the " Award criteria for printing and press paper mainly made from waste paper", DE-UZ 72, January 2020 issue, version 1 , for the "Blue Angel" eco-label of the German Federal Ministry for the Environment, Nature Conservation and Nuclear Safety (hereinafter referred to as "Award Criteria Blue Angel DE-UZ 72") and the " Award criteria for graphic paper and cardboard made from 100% waste paper (recycled paper and cardboard)", DE-UZ 14a, January 2020 issue, version 2 , for which the aforementioned environmental label of the "Blue Angel" (hereinafter referred to as "award criteria Blue Angel DE-UZ 14a") are approved.

auch bekannt als struktureller Kern einer Anzahl organischer Farbstoffvorläufer, welche substituierte Derivate des Fluorans umfassen (auch bezeichnet als "Fluoran-Leukofarbstoffe" bzw. "Fluoran-Leukofarbstoffvorläufer"). Die vorstehend angegebene erfindungsgemäße wärmeempfindliche Aufzeichnungsschicht umfasst als Komponente K1) vorzugsweise ein oder mehrere organische Farbstoffvorläufer, welche als strukturellen Kern eine vorstehend angegebene, substituierte, Fluoran-Struktur der Formel I umfassen.The heat-sensitive recording layer according to the invention specified above comprises, as component K1), one or more organic dye precursors, each of which comprises a fluoran structure. The compound fluoran per se is known as a triarylmethane dye. However, the chemical structure of the fluoran is of formula I given below

also known as the structural core of a number of organic dye precursors, which include substituted derivatives of fluoran (also referred to as "fluorane leuco dyes" and "fluorane leuco dye precursors," respectively). The abovementioned heat-sensitive recording layer according to the invention preferably comprises as component K1) one or more organic dye precursors which comprise an abovementioned substituted fluoran structure of the formula I as the structural core.

The heat-sensitive recording layer according to the invention specified above comprises, as component K4), one or more, preferably synthetic, amide waxes which each have a melting point in the range from 80.degree. C. to 120.degree. These amide waxes are preferably synthetically produced waxes, which are preferably produced by reacting technical fatty acids, fatty acid esters and/or triacylglycerols with ammonia, monovalent amines, polyvalent amines and/or amino alcohols.

These one or more, preferably synthetic, amide waxes to be used according to the invention as component K4) act as or assume the function of a sensitizer known per se. A sensitizer used in a heat-sensitive recording layer is at least partially melted by the application of heat during printing. The at least partially melted sensitizer dissolves and/or lowers the melting point (or melting range) of the color former and color developer coexisting in a heat-sensitive recording layer, thereby facilitating or inducing a color-developing reaction. The sensitizer does not usually take part in the color development reaction itself.

In our own experiments it was found that an above-mentioned heat-sensitive recording layer according to the invention (or a heat-sensitive recording layer according to the invention, which is referred to as preferred in this text) or a heat-sensitive recording layer according to the invention (or a heat-sensitive recording layer according to the invention, which is referred to as preferred in this text is) a composition specified in this text, in addition to the one or more, preferably synthetic, amide waxes specified as component K4), each of which has a melting point in the range from 80 ° C to 120 ° C (or in addition to the one specified below as preferred or more, preferably synthetic, amide waxes, do not have to contain any further sensitizers as component K4)), in particular no "classical" sensitizers, in order to have the advantageous properties specified above or below.

The above-mentioned heat-sensitive recording layer according to the invention (or a heat-sensitive recording layer according to the invention, which is referred to as preferred in this text) preferably contains such sensitizers in a total amount of ≦1 percent by mass, based on the dry mass of the heat-sensitive recording layer, which are selected from the group "classical" sensitizers consisting of 1,2-bis(3-methylphenoxy)ethane, 1,2-diphenoxyethane, 1-phenoxy-2-(4-methylphenoxy)ethane, benzyl 2-naphthyl ether, 2-(2H-benzotriazole- 2-yl)-p-cresol, 2,2'-bis(4-methoxyphenoxy)diethyl ether, 4,4'-diallyloxydiphenylsulfone, 4-acetylacetophenone, 4-benzylbiphenyl, acetoacetic anilide, benzyl 4-(benzyloxy)benzoate, benzylparaben, Bis(4-chlorobenzyl) oxalate ester, bis(4-methoxyphenyl) ether, dibenzyl oxalate, dibenzyl terephthalate, dimethyl terephthalate, dimethyl sulfone, diphenyl adipate, diphenyl sulfone, p-benzylbiphenyl, phenylbenzene sulfonate ester, α,α' -Diphenoxyxyten and their mixtures. The inventive heat-sensitive recording layer specified above (or an inventive heat-sensitive recording layer which is designated as preferred in this text) particularly preferably contains no sensitizers selected from the above-specified group of “classic” sensitizers. Such preferred heat-sensitive recording layers according to the invention offer the advantage that (with a suitable selection of the other components) they can also be used safely, e.g. in the food sector, even if e.g. direct or indirect contact of the recording layer with the food cannot be ruled out.

The heat-sensitive recording layer according to the invention specified above comprises one or more particulate inorganic pigments as component K5). As is not unusual in the field of paper technology, the particulate inorganic pigments to be used according to the invention preferably not only or not primarily fulfill the function of dyes, but also at least or even predominantly fulfill the function of particulate fillers. If the particulate inorganic pigments to be used according to the invention at least also have the function of Dyes have, it is preferably white pigments. For more information on the particulate inorganic pigments to be used according to the invention, see also below.

The heat-sensitive recording layer according to the invention specified above preferably comprises organic hollow body pigments (in particular those as specified or defined in the document WO 2012/145456 A1 ) at most in a total amount of ≤ 1 percent by mass, based on the dry mass of the heat-sensitive recording layer. Particularly preferably, the above-mentioned heat-sensitive recording layer according to the invention (or a heat-sensitive recording layer according to the invention which is referred to as preferred in this text) contains no such organic hollow body pigments.

The heat-sensitive recording layer according to the invention specified above comprises one or more lubricants as component K6). In the context of the present invention, the term "lubricant" is understood to mean - as is customary in the paper industry - additives for plastic compositions containing fillers (such as coating colors or coating compositions), which preferably serve to make the fillers more easily gliding and the plastic compositions thus more easily deformable or to make it processable. The one or more lubricants of component K6) are preferably selected from the group consisting of metal soaps (preferably salts of fatty acids with a total number of carbon atoms in the range from ≧12 to ≦22 with metal ions with a single or double positive charge), wax dispersions, paraffin dispersions, sulfated oils and mixtures thereof. For further preferred configurations of component K6), see below.

In the heat-sensitive recording layer according to the invention specified above, the sum of the components K1) to K6) makes up ≧95 percent by weight of the dry weight of the heat-sensitive recording layer. "Dry mass" in the context of the present invention is preferably understood to mean the water- and moisture-free mass of a sample (here: the heat-sensitive recording layer according to the invention) measured (under laboratory conditions at 23° C. and 50% RH). For the purposes of the present invention, the dry mass is preferably determined—as is customary in the field—on the sample to be examined (here: the heat-sensitive recording layer according to the invention), which had been dried at 105° C. to constant weight before the determination. Methods for determining the dry matter of a sample are known to those skilled in the art:
For example, the dry mass of a sample (in particular a sample of the heat-sensitive recording layer according to the invention) can be determined for the purposes of the present invention by heating a sample of defined mass before drying (e.g. 1.5 g of the sample before drying) at 105° C. for five hours dries in the drying oven and then, after cooling to room temperature (in case of doubt to 23 °C) checks for constant weight (sample, e.g. by heating it up again and determining the mass again) in a manner known per se, whereby, of course, reabsorption of water during the cooling process must be avoided (desiccator ).

Likewise, the dry mass of a sample (in particular a sample of the heat-sensitive recording layer according to the invention) can be determined for the purposes of the present invention in a manner known per se using a moisture determination device, for example a halogen moisture determination device known per se, under the conditions specified above (105° C., heating to constant weight).

Preference is given to additionally comprising a heat-sensitive recording layer according to the invention as specified above (or a heat-sensitive recording layer according to the invention indicated as preferred in this text).
K7) one or more process auxiliaries, preferably selected from the group consisting of defoamers, biocides, dispersants and wetting agents,
preferably in a total amount of ≤ 5 percent by mass, particularly preferably in a total amount in the range from ≥ 0.1 to ≤ 3 percent by mass and more preferably in the range from ≥ 0.1 to ≤ 2 percent by mass, based on the dry mass of the heat-sensitive recording layer.

The one or more process auxiliaries K7) preferably serve to facilitate or enable the processing of a heat-sensitive recording layer according to the invention (or a coating composition according to the invention for producing a heat-sensitive recording layer according to the invention) in the industrial production process, in particular in the industrial process of paper production.

In some cases a heat-sensitive recording layer according to the invention as indicated above (or a heat-sensitive recording layer according to the invention indicated as preferred in this text) which additionally comprises one or more optical brighteners may be preferred. If a heat-sensitive recording layer according to the invention additionally comprises one or more optical brighteners, it is preferred if the heat-sensitive recording layer according to the invention contains this one or more optical brighteners in a total amount of ≦1 percent by mass, more preferably in a total amount of ≦0.75 percent by mass, based on the dry mass of the heat-sensitive recording layer. Particularly preferably, the above-mentioned heat-sensitive recording layer according to the invention (or a heat-sensitive recording layer according to the invention which is referred to as preferred in this text) contains no optical brighteners.

Preference is also given to a heat-sensitive recording layer according to the invention specified above (or a heat-sensitive recording layer according to the invention, which is referred to as preferred in this text), the sum of components K1) to K6) being ≧97 percent by mass, preferably ≧98 percent by mass, more preferably ≧98, 5 percent by mass that makes up the dry mass of the heat-sensitive recording layer,

where preferably (in cases in which the heat-sensitive recording layer according to the invention comprises a component K7) the sum of the components K1) to K7) makes up ≧99 percent by mass, particularly preferably 100 percent by mass, of the dry mass of the heat-sensitive recording layer.

• der eine oder mindestens einer der mehreren organischen Farbstoffvorläufer K1) ausgewählt ist aus der Gruppe bestehend aus 3-Diethylamino-6-methyl-7-anilinofluoran, 3-Diethylamino-6-methyl-7-(3'-methylphenylamino)fluoran, 3-(Diethylamino)-6-methyl-7-(3-methylphenylamino)fluoran (ODB-7), 3-Di-n-pentyl-amino-6-methyl-7-anilinofluoran, 3-Di-n-butylamino-7-(2-chloranilino)fluoran, 3-Diethylamino-7-(2-chloranilino) fluoran, 3-Diethylamino-6-methyl-7-xylidinofluoran, 3-Diethylamino-7-(2-carbomethoxyphenylamino)fluoran, 3-Pyrrolidino-6-methyl-7-anilinofluoran, 3-Pyrrolidino-6-methyl-7-(4-n-butyl-phenylamino)fluoran, 3-Piperidino-6-methyl-7-anilinofluoran, 3-N-Di-n-butylamino-6-methyl-7-anilinofluoran (ODB-2), 3-(N-Methyl-N-cyclohexyl)amino-6-methyl-7-anilinofluoran, 3-(N-Methyl-N-propyl)amino-6-methyl-7-anilinofluoran, 3-(N-Methyl-N-tetrahydrofurfuryl)amino-6-methyl-7-anilinofluoran), 3-(N-Ethyl-N-isoamyl) amino-6-methyl-7-anilinofluoran, 3-(N-Ethyl-N-tolyl)amino-6-methyl-7-anilinofluoran, 3-(N-Ethyl-N-tetrahydrofuryl)amino-6-methyl-7-anilinofluoran, 3-(N-Ethyl-N-isopentylamino)-6-methyl-7-anilinofluoran, 3-(N-Ethyl-4-toluidino)6-methyl-7-(4-toluidino)fluoran, 3-(N-Cyclopentyl-N-ethyl)amino-6-methyl-7-anilinofluoran und deren Gemischen,
  wobei vorzugsweise der eine oder mindestens einer der mehreren organischen Farbstoffvorläufer K1) ausgewählt ist aus der Gruppe bestehend aus 3-N-Di-n-butylamin-6-methyl-7-anilinofluoran (ODB-2), 3-(N-Ethyl-N-isopentylamino)-6-methyl-7-anilinofluoran und deren Gemischen,
  wobei ganz besonders bevorzugt der eine oder mindestens einer der mehreren organischen Farbstoffvorläufer K1) 3-N-Di-n-butylamin-6-methyl-7-anilinofluoran (ODB-2) ist;
  und/oder
• die ein oder mehreren organischen Farbstoffvorläufer K1) in einer Gesamtmenge im Bereich von ≥ 7 bis ≤ 18 Massenprozent, vorzugsweise von ≥ 8 bis ≤ 15 Massenprozent vorliegen, bezogen auf die Trockenmasse der wärmeempfindlichen Aufzeichnungsschicht.

Also preferred is a heat-sensitive recording layer according to the invention as indicated above (or a heat-sensitive recording layer according to the invention indicated as preferred in this text), wherein

• the one or at least one of the several organic dye precursors K1) is selected from the group consisting of 3-diethylamino-6-methyl-7-anilinofluoran, 3-diethylamino-6-methyl-7-(3'-methylphenylamino)fluoran, 3- (Diethylamino)-6-methyl-7-(3-methylphenylamino)fluoran (ODB-7), 3-Di-n-pentylamino-6-methyl-7-anilinofluoran, 3-Di-n-butylamino-7- (2-chloroanilino)fluoran, 3-diethylamino-7-(2-chloroanilino)fluoran, 3-diethylamino-6-methyl-7-xylidinofluoran, 3-diethylamino-7-(2-carbomethoxyphenylamino)fluoran, 3-pyrrolidino-6 -methyl-7-anilinofluoran, 3-pyrrolidino-6-methyl-7-(4-n-butyl-phenylamino)fluoran, 3-piperidino-6-methyl-7-anilinofluoran, 3-N-di-n-butylamino-6-methyl-7-anilinofluoran (ODB-2), 3-(N-methyl-N-cyclohexyl)amino-6- methyl-7-anilinofluoran, 3-(N-methyl-N-propyl)amino-6-methyl-7-anilinofluoran, 3-(N-methyl-N-tetrahydrofurfuryl)amino-6-methyl-7-anilinofluoran), 3 -(N-ethyl-N-isoamyl)amino-6-methyl-7-anilinofluoran, 3-(N-ethyl-N-tolyl)amino-6-methyl-7-anilinofluoran, 3-(N-ethyl-N- tetrahydrofuryl)amino-6-methyl-7-anilinofluoran, 3-(N-ethyl-N-isopentylamino)-6-methyl-7-anilinofluoran, 3-(N-ethyl-4-toluidino)6-methyl-7-( 4-toluidino)fluoran, 3-(N-cyclopentyl-N-ethyl)amino-6-methyl-7-anilinofluoran and mixtures thereof,
  where preferably the one or at least one of the several organic dye precursors K1) is selected from the group consisting of 3-N-di-n-butylamino-6-methyl-7-anilinofluoran (ODB-2), 3-(N-ethyl- N-isopentylamino)-6-methyl-7-anilinofluoran and mixtures thereof,
  very particularly preferably the one or at least one of the plurality of organic dye precursors K1) is 3-N-di-n-butylamino-6-methyl-7-anilinofluoran (ODB-2);
  and or
• the one or more organic dye precursors K1) are present in a total amount in the range from ≧7 to ≦18 percent by mass, preferably from ≧8 to ≦15 percent by mass, based on the dry mass of the heat-sensitive recording layer.

• die ein oder mehrere Phenolgruppen-freien organischen Farbentwickler K2) jeweils kein Phenol-Strukturelement der Formel II,
  
  umfassen,
  und/oder
  der eine oder mindestens einer der mehreren Phenolgruppen-freien organischen Farbentwickler K2) ausgewählt ist aus der Gruppe bestehend aus N-(4-Methylphenylsulfonyl)-N'-(3-(4-methylphenylsulfonyloxy)phenyl)harnstoff, 5-(N-3-Methylphenyl-sulfonylamido)-(N',N"-bis-(3-methylphenyl)-isophthalsäurediamid, N-[2-(3-Phenylureido) phenyl]benzolsulfonamid und deren Gemischen,
  und/oder
• die ein oder mehreren Phenolgruppen-freien organischen Farbentwickler K2) in einer Gesamtmenge im Bereich von ≥ 12 bis ≤ 35 Massenprozent, vorzugsweise von ≥ 15 bis ≤ 30 Massenprozent vorliegen, bezogen auf die Trockenmasse der wärmeempfindlichen Aufzeichnungsschicht.

Then, also preferred is a heat-sensitive recording layer according to the invention as specified above (or a heat-sensitive recording layer according to the invention indicated as preferred in this text), wherein

• the one or more phenol-free organic color developers K2) each have no phenol structural element of the formula II,
  
  include,
  and or
  the one or at least one of the several phenol group-free organic color developers K2) is selected from the group consisting of N- (4-methylphenylsulfonyl)-N'-(3-(4-methylphenylsulfonyloxy)phenyl)urea, 5-( N -3 -Methylphenylsulfonylamido)-(N',N"-bis-(3-methylphenyl)isophthalic acid diamide, N -[2-(3-phenylureido)phenyl]benzenesulfonamide and mixtures thereof,
  and or
• the one or more phenol group-free organic color developers K2) are present in a total amount in the range from ≧12 to ≦35 percent by mass, preferably from ≧15 to ≦30 percent by mass, based on the dry mass of the heat-sensitive recording layer.

The color developers which contain phenol groups and which are therefore preferably not used as phenol-group-free organic color developers K2) in an above-mentioned heat-sensitive recording layer according to the invention include, in particular, the known compounds bisphenol A (4,4'-propane-2,2 -diyldiphenol), bisphenol S (4,4'-sulfonyldiphenol), bisphenol AP (1,1-bis(4-hydroxyphenyl)-1-phenylethane CAS RN 1571-75-1 ), 4-[(4-Isopropoxyphenyl)sulfonyl]phenol (also known as "D8", CAS RN 95235-30-6 ), 4,4'-Methylenediphenol, 2,2'-Methylenediphenol, 4-[4'-[(1'-Methylethyloxy)phenyl]sulfonyl]phenol (also known as "D90", CAS RN 191680-83-8 ), 2,2'-diallyl-4,4'-sulfonyldiphenol (also known as "TGSA", CAS RN 41481-66-7 ) 4-4'-methylenebis(oxyethylenethio)diphenol (also known as "DD70", CAS RN 93589-69-6 ) and their mixtures.

sein oder umfassen (s.o.), welche auch unter der Bezeichnung "Pergafast 201" ( CAS-Nr. 232938-43-1 ) bekannt ist.In the above-mentioned heat-sensitive recording layer according to the invention, one or at least one of the several phenol-free organic color developers K2) can be the compound N- (4-methylphenylsulfonyl) -N '-(3-(4-methylphenylsulfonyloxy)phenyl)urea of the formula III

be or include (see above), which are also referred to as "Pergafast 201" ( CAS no. 232938-43-1 ) is known.

sein.In the above-mentioned heat-sensitive recording layer according to the invention, one or at least one of the several phenol-free organic color developers K2) can also contain the compound 5-(N-3-methylphenylsulfonylamido)-(N',N"-bis-(3-methylphenyl )-isophthalic acid diamide of the formula IV

be.

The compound 5-(N-3-methylphenylsulfonylamido)-(N',N''-bis-(3-methylphenyl)isophthalic acid diamide of the formula IV is known per se, for example from the document WO 2019/166608 A1 , and can be prepared using the methods given there. The compound of formula IV can exist in several different crystalline forms. These different crystalline forms may have different physical properties, which may have influences on a heat-sensitive recording layer containing such crystalline forms as a color developer. At least three different crystalline forms of the compound of the formula IV are currently known, which are referred to as the crystalline modification "α", as the crystalline modification "β" or as the crystalline modification "γ" (cf. WO 2019/166608 A1 , p. 8, lines 1 to 18 and p. 42, lines 24 to 44). The heat-sensitive recording layer of the present invention may be any individual of these three different crystalline forms of the compound of the formula IV (as component K2)) and mixtures thereof.

Also preferred is a heat-sensitive recording layer according to the invention as described above (preferably a heat-sensitive recording layer according to the invention, which is referred to as preferred in this text), wherein the compound of formula I comprises a crystalline form or wherein the compound of formula IV is present in a crystalline form,
where preferably
the or at least one crystalline form of the compound of formula IV has a melting point in the range from 195°C to 217°C, preferably from 200°C to 215°C, more preferably from 205°C to 213°C, as determined by differential thermal analysis (DSC).

Preferred is a heat-sensitive recording layer according to the invention as described above (preferably a heat-sensitive recording layer according to the invention, which is referred to in this text as preferred), wherein the compound of formula IV comprises a crystalline form or wherein the compound of formula IV is present in a crystalline form, wherein the crystalline form of the compound of formula I is the crystalline modification "α" as described in WO 2019/166608 A1 , p. 8, lines 9-13.

Preference is also given to a heat-sensitive recording layer according to the invention as described above (preferably a heat-sensitive recording layer according to the invention, which is referred to as preferred in this text), wherein the compound of the formula IV comprises a crystalline form or wherein the compound of the formula IV is present in a crystalline form, where the crystalline form of the compound of the formula IV has an X-ray powder diffractogram with diffraction reflections at °2θ values (+/- 0.2°) of 5.5, 6.1, 6.4, 12.1, 16.1, 16.8, 17.1, 18.3, 19.1, 19.9, 20.2, 21.4, 22.1, 22.7, 23.3, 24.3, 24.7, 25.0, 26.4, 27.7 and 29.3.

Preference is also given to a heat-sensitive recording layer according to the invention as described above (preferably a heat-sensitive recording layer according to the invention, which is referred to as preferred in this text), where the compound of the formula IV accounts for ≧95% by mass, preferably completely (to the extent of 100% by mass). , is present as the crystalline modification "α" (as described above), based on the total mass of the compound of formula IV present in the heat-sensitive recording layer.

sein.In the above-mentioned heat-sensitive recording layer according to the invention, one or at least one of the several organic color developers K2) free from phenol groups can also contain the compound N- [2-(3-phenylureido)phenyl]benzenesulfonamide of the formula V

be.

The compound N-[2-(3-phenylureido)phenyl]benzenesulfonamide of the formula V (synonym: N-{2-[(phenylcarbamoyl)amino]phenyl}benzenesulfonamide) is one, for example from EP 2 923 851 A1 , known compound, for example, under the name "NKK-1304". The compound of formula V can exist in several different crystalline forms. These different crystalline forms may have different physical properties, which may have influences on a heat-sensitive recording layer containing such crystalline forms as a color developer. The compound of the formula V, which is not differentiated according to polymorphic forms, is used in the literature CAS RN 215917-77-4 attributed.

At least three different crystalline forms of the compound of formula V are presently known, as detailed below. The heat-sensitive recording layer according to the invention can contain each of these three different crystalline forms of the compound of the formula V (as component K2)) and mixtures thereof.

The first of these crystalline forms of the compound of formula V has a melting point of about 158°C. This crystalline form was used in connection with heat-sensitive recording materials, for example, in the EP 2 923 851 A1 , described.

The second crystalline form of the compound of formula V has a melting point of about 175°C. For example, the compound of formula V, which is the crystalline form with a melting point of 175°C, has been described in the document WO 2018/065328 A1 .

The third crystalline form of the compound of the formula V has a melting point of about 160° C. to 162° C. and was described, for example, in document EP 3 263 553 A1 described.

Preference is given according to the invention to a heat-sensitive recording material in which the crystalline form of the compound of the formula V exhibits a (preferably endothermic) transition at a temperature between 170° C. and 178° C. ("second crystalline form of the compound of the formula VII"), preferably between 173 °C and 177 °C, particularly preferably between 174 °C and 176 °C, determined with the aid of differential thermal analysis (DSC), also known as "differential scanning calorimetry" (DKK), at a heating rate of 10 K/min.

At least the first and the second of the aforementioned crystalline forms of the compounds of formula V can also be distinguished from one another in the IR absorption spectrum. An absorption band in the IR spectrum at 3401±20 cm ^-1 is particularly characteristic of the crystalline form of the compound of the formula V used according to the invention. In the crystalline form of the compound of the formula V, which has a melting point of about 158° C., this band is not present, but rather a band at 3322 and 3229 cm ^-1 .

A heat-sensitive recording layer is also preferred according to the invention, the crystalline form of the compound of the formula V in the IR spectrum having absorption bands at 689±10 cm ^-1 , 731±10 cm ^-1 , 1653±10 cm ^-1 3364±20 cm ^-1 and 3401±20 cm ^-1 ("second crystalline form of the compound of formula V").

Preference is given according to the invention to a heat-sensitive recording material in which the IR absorption spectrum of the crystalline form of the compound of the formula V corresponds essentially to that in FIG. 1a), 2a) and/or 3a) of WO 2018/065328 A1 IR absorption spectrum shown coincides ("second crystalline form of the compound of formula V").

At least the first and the second of the aforementioned crystalline forms of the compound of the formula V can also be distinguished from one another in the X-ray powder diffractogram or diffraction diagram. A heat-sensitive recording material is preferred according to the invention, the crystalline form of the compound of the formula V having an X-ray powder diffractogram with reflections at °2θ values of 10.00±0.20, 11.00±0.20, 12.40±0.20, 13.80±0.20 and 15.00±0.20 ("second crystalline form of the compound of formula V").

According to the invention, preference is given to a heat-sensitive recording layer in which the crystalline form of the compound of the formula V has an X-ray powder diffractogram which essentially corresponds to that in FIG. 4b) of FIG WO 2018/065328 A1 shown X-ray powder diffraction pattern ("second crystalline form of the compound of formula V").

In the sense of this text, a compound of the formula V preferably describes the crystalline form which has an absorption band at 3401±20 cm ^-1 in the IR spectrum or has a melting point of 175° C. or has a transition at a temperature between 170 °C and 178 °C (determined by differential thermal analysis, at a heating rate of 10 K/min) or in the X-ray powder diffractogram diffraction reflections at °2θ values of at least 10.00±0.20, 11.00±0.20, 12 .40±0.20, 13.80±0.20 and 15.00±0.20 unless the presence of the other crystal structure is explicitly stated ("second crystalline form of the compound of formula V").

It goes without saying that the specification of a) the melting point, b) the diffraction reflections in the X-ray powder diffractogram or c) the absorption bands in the IR spectrum only serve to describe the crystalline form of a compound specified in this text and thus make it possible to describe this crystalline form distinguished from other crystalline forms of the compound. The specification of one of these measured variables is usually already sufficient to differentiate between the various crystalline forms. For a compound of the formula V, it is particularly preferred to indicate the absorption bands in the IR spectrum, since an IR spectrum can be measured very easily and with high reproducibility by a person skilled in the art and IR spectrometers are part of the basic equipment in a chemical laboratory.

Also preferred is a heat-sensitive recording layer according to the invention as described above (preferably a heat-sensitive recording layer according to the invention, which is referred to as preferred in this text), wherein the compound of formula V comprises a crystalline form or wherein the compound of formula V is in a crystalline form ( if the heat-sensitive recording layer comprises, for example, a color developer mixture, the color developer mixture comprising, in addition to a compound of the formula IV, at least one further organic color developer which comprises or is a compound of the formula V),
where preferably the or at least one crystalline form of the compound of formula II has an absorption band at 3401±20 cm ^-1 in the IR spectrum.

• einem Farbentwicklergemisch enthaltend eine vorstehend definierte Verbindung der Formel V (NKK-1304), wobei vorzugsweise die Verbindung der Formel V in einer kristallinen Form vorliegt, die im IR-Spektrum eine Absorptionsbande bei 3401±20 cm-1 aufweist, und eine vorstehend definierte Verbindung der Formel III (Pergafast 201),
  wobei vorzugsweise
  das Massenverhältnis zwischen der Verbindung der Formel V und der Verbindung der Formel III im Bereich von 0,5 : 99,5 bis 35 : 65 liegt, vorzugsweise im Bereich von 5 : 95 bis 30 : 70, besonders bevorzugt im Bereich von 15 : 85 bis 25 : 75 liegt;
  oder
  das Massenverhältnis zwischen der Verbindung der Formel V und der Verbindung der Formel III im Bereich von 99,5 : 0,5 bis 65 : 35 liegt, vorzugsweise im Bereich von 97 : 3 bis 85 : 15, besonders bevorzugt im Bereich von 95 : 5 bis 90 : 10 liegt;
  oder
  das Massenverhältnis zwischen der Verbindung der Formel V und der Verbindung der Formel III im Bereich von 0,5 : 99,5 bis 99,5 : 0,5 liegt, vorzugsweise im Bereich von 35 : 65 bis 65 : 35, weiter bevorzugt im Bereich von 40 : 60 bis 60 : 40 und besonders bevorzugt im Bereich von 45 : 55 bis 55 : 45 liegt;
  und
• einem Farbentwicklergemisch enthaltend eine vorstehend definierte Verbindung der der Formel IV, wobei vorzugsweise die Verbindung der Formel IV in der kristallinen Modifikation "α" (wie vorstehend definiert) vorliegt, und eine vorstehend definierte Verbindung der Formel V (NKK-1304), wobei vorzugsweise die Verbindung der Formel V in einer kristallinen Form vorliegt, die im IR-Spektrum eine Absorptionsbande bei 3401±20 cm-1 aufweist,
  wobei vorzugsweise
  das Massenverhältnis zwischen der Verbindung der Formel IV und der Verbindung der Formel V im Bereich von 5 : 95 bis 99,9 : 0,1 liegt, vorzugsweise von 10 : 90 bis 99 : 1, weiter bevorzugt von 30 : 70 bis 99 : 1 und besonders bevorzugt von 50 : 50 bis 98 : 2 liegt.

Preference is given in particular to a heat-sensitive recording layer according to the invention specified above (or a heat-sensitive recording layer according to the invention, which is referred to as preferred in this text), wherein the one or at least one of the several phenol-group-free organic color developers K2) is selected from the group consisting of

• a color developer mixture containing a compound of formula V (NKK-1304) as defined above, preferably wherein the compound of formula V is in a crystalline form having an absorption band at 3401±20 cm-1 in the IR spectrum, and a compound as defined above of formula III (Pergafast 201),
  where preferably
  the mass ratio between the compound of the formula V and the compound of the formula III is in the range from 0.5:99.5 to 35:65, preferably in the range from 5:95 to 30:70, particularly preferably in the range from 15:85 to 25:75;
  or
  the mass ratio between the compound of the formula V and the compound of the formula III is in the range from 99.5:0.5 to 65:35, preferably in the range from 97:3 to 85:15, particularly preferably in the range from 95:5 to 90:10;
  or
  the mass ratio between the compound of formula V and the compound of formula III is in the range from 0.5:99.5 to 99.5:0.5, preferably in the range from 35:65 to 65:35, more preferably in the range from 40:60 to 60:40 and more preferably in the range from 45:55 to 55:45;
  and
• a color developer mixture containing a compound of formula IV as defined above, preferably wherein the compound of formula IV is present in the crystalline modification "α" (as defined above), and a compound of formula V (NKK-1304) as defined above, preferably the A compound of the formula V is present in a crystalline form which has an absorption band at 3401±20 cm-1 in the IR spectrum,
  where preferably
  the mass ratio between the compound of formula IV and the compound of formula V is in the range from 5:95 to 99.9:0.1, preferably from 10:90 to 99:1, more preferably from 30:70 to 99:1 and most preferably from 50:50 to 98:2.

A color developer mixture comprising a compound of formula V (NKK-1304) as defined above, preferably wherein the compound of formula V is in a crystalline form having an absorption band at 3401±20 cm-1 in the IR spectrum, and a compound as defined above of the formula III (Pergafast 201), in the proportions defined above, and the advantages that can be achieved with this color developer mixture in a heat-sensitive recording layer or in a heat-sensitive recording material are described in the documents WO 2018/065328 A1 and WO 2018/065330 A1 , the contents of which are hereby expressly referred to in connection with the present invention.

• die ein oder mehreren polymeren organischen Bindemittel K3) in einer Gesamtmenge im Bereich von ≥ 7 bis ≤ 25 Massenprozent, vorzugsweise von ≥ 8 bis ≤ 20 Massenprozent vorliegen, bezogen auf die Trockenmasse der wärmeempfindlichen Aufzeichnungsschicht.
  und/oder
• das eine oder mindestens eines der mehreren polymeren organischen Bindemittel K3) ausgewählt ist aus der Gruppe bestehend aus Polyvinylalkohol und Stärke,
  wobei vorzugsweise das eine oder mindestens eines der mehreren polymeren organischen Bindemittel K3) Polyvinylalkohol ist.

Furthermore, it is also preferable to have a heat-sensitive recording layer according to the invention as indicated above (or a heat-sensitive recording layer according to the invention indicated as preferred in this text), wherein

• the one or more polymeric organic binders K3) are present in a total amount in the range from ≧7 to ≦25 percent by mass, preferably from ≧8 to ≦20 percent by mass, based on the dry mass of the heat-sensitive recording layer.
  and or
• the one or at least one of the several polymeric organic binders K3) is selected from the group consisting of polyvinyl alcohol and starch,
  where preferably one or at least one of the plurality of polymeric organic binders K3) is polyvinyl alcohol.

• die ein oder mehreren, vorzugsweise synthetischen, Amidwachse K4) ein oder mehrere Fettsäuremonoamide umfassen oder sind, welche jeweils einen Schmelzpunkt im Bereich von 80 °C bis 120 °C aufweisen,
  wobei vorzugsweise das eine oder mindestens eines der mehreren Amidwachse K4) ein Monoamid einer gesättigten Fettsäure ist, dessen Fettsäurerest eine Gesamtzahl von Kohlenstoffatomen im Bereich von ≥ 12 bis ≤ 20, vorzugsweise im Bereich von ≥ 14 bis ≤ 18, besonders bevorzugt im Bereich von ≥ 16 bis ≤ 18 aufweist;
  wobei besonders bevorzugt das eine oder mindestens eines der mehreren Amidwachse ausgewählt ist aus der Gruppe bestehend aus Laurinsäureamid, Myristinsäureamid, Palmitinsäureamid, Octadecanamid (Synonym: Stearinsäureamid, CAS RN 124-26-5 ), N-Methylolstearinsäureamid (Synonym: (N-(Hydroxymethyl)octadecanamid, CAS RN 3370-35-2 ) und deren Gemischen;
  wobei ganz besonders bevorzugt das eine oder mindestens eines der mehreren Amidwachse ausgewählt ist aus der Gruppe bestehend Octadecanamid, N-Methylolstearinsäureamid und deren Gemischen;
  und/oder
• die ein oder mehreren, vorzugsweise synthetischen, Amidwachse K4) in einer Gesamtmenge im Bereich von ≥ 10 bis ≤ 30 Massenprozent, vorzugsweise von ≥ 12,5 bis ≤ 25 Massenprozent, besonders bevorzugt von ≥ 15 bis ≤ 25 Massenprozent, ganz besonders bevorzugt von ≥ 16 bis ≤ 24 Massenprozent vorliegen, bezogen auf die Trockenmasse der wärmeempfindlichen Aufzeichnungsschicht;
  und/oder
• das Verhältnis der in der Trockenmasse der wärmeempfindlichen Aufzeichnungsschicht vorliegenden Gesamtmenge an ein oder mehreren Phenolgruppen-freien organischen Farbentwicklern K2) zur in der Trockenmasse derwärmeempfindlichen Aufzeichnungsschicht vorliegenden Gesamtmenge an ein oder mehreren, vorzugsweise synthetischen, Amidwachsen K4) im Bereich von 1 : 0,5, vorzugsweise im Bereich von 1 : 2, liegt.

Also preferred is an above-mentioned heat-sensitive recording layer according to the invention (or a heat-sensitive recording layer according to the invention, which is referred to as preferred in this text), wherein

• the one or more, preferably synthetic, amide waxes K4) comprise or are one or more fatty acid monoamides, each of which has a melting point in the range from 80° C. to 120° C.,
  where preferably one or at least one of the several amide waxes K4) is a monoamide of a saturated fatty acid whose fatty acid residue has a total number of carbon atoms in the range from ≧12 to ≦20, preferably in the range from ≧14 to ≦18, particularly preferably in the range from ≧ 16 to ≤ 18;
  particularly preferably one or at least one of the several amide waxes is selected from the group consisting of lauric acid amide, myristic acid amide, palmitic acid amide, octadecanamide (synonym: stearic acid amide, CAS RN 124-26-5 ), N-methylolstearic acid amide (synonym: (N-(hydroxymethyl)octadecanamide, CAS RN 3370-35-2 ) and their mixtures;
  very particularly preferably the one or at least one of the several amide waxes is selected from the group consisting of octadecanamide, N-methylolstearic acid amide and mixtures thereof;
  and or
• the one or more, preferably synthetic, amide waxes K4) in a total amount in the range from ≧10 to ≦30 percent by mass, preferably from ≧12.5 to ≦25 percent by mass, particularly preferably from ≧15 to ≦25 percent by mass, very particularly preferably from ≧ 16 to ≤ 24 percent by mass, based on the dry mass of the heat-sensitive recording layer;
  and or
• the ratio of the total amount of one or more phenol-group-free organic color developers K2) present in the dry matter of the heat-sensitive recording layer to the total amount of one or more, preferably synthetic, amide waxes K4) present in the dry matter of the heat-sensitive recording layer in the range of 1: 0.5, preferably in the range of 1:2.

In our own experiments, it was found that thermal printouts produced with a heat-sensitive recording layer according to the invention or with a heat-sensitive recording material according to the invention (see below) have particularly advantageous properties if the heat-sensitive recording layer used for this purpose contains the one or more amide waxes K4) (preferably the ones mentioned above as preferred designated one or more amide waxes K4) in the total amount indicated above (preferably in the total amounts indicated above as preferred). The particularly advantageous properties of the thermal printouts produced in this way include, in particular, high resistance to plasticizers, high resistance to lanolin, high resistance to water or aqueous ethanol solution, but also high climate resistance and high heat resistance. In this case, heat-sensitive recording materials produced with heat-sensitive recording layers according to the invention have a dynamic print density which is generally at least comparable to that of a conventional heat-sensitive recording material and in some cases even better. The dynamic print density of a heat-sensitive recording material (especially a thermal paper) indicates how quickly a heat-sensitive recording material can be printed on. The higher the dynamic print density, the faster a thermal printer can print on the heat-sensitive recording material with otherwise unchanged settings.

• das eine oder mindestens eines der mehreren anorganischen Pigmente K5) ausgewählt ist aus der Gruppe bestehend aus kalziniertem Kaolin, Kaolin, Kaolinit, Magnesiumsilikathydrat, Siliziumdioxid (umfassend Kieselsäure), Bentonit, Calciumcarbonat, Calciumsilkathydrat, Calciumaluminatsulfat, Aluminiumhydroxid, Aluminiumoxid, Böhmit und deren Gemische,
  wobei vorzugsweise das eine oder mindestens eines der mehreren anorganischen Pigmente K5) Calciumcarbonat ist;
  und/oder
• die ein oder mehreren anorganischen Pigmente K5) in einer Gesamtmenge im Bereich von ≥ 9 bis ≤ 50 Massenprozent, vorzugsweise von ≥ 10 bis ≤ 40 Massenprozent, besonders bevorzugt von ≥ 10 bis ≤ 35 Massenprozent, vorliegen, bezogen auf die Trockenmasse der wärmeempfindlichen Aufzeichnungsschicht.

It is also preferred a heat-sensitive recording layer according to the invention as indicated above (or a heat-sensitive recording layer according to the invention indicated as preferred in this text), wherein

• the one or at least one of the several inorganic pigments K5) is selected from the group consisting of calcined kaolin, kaolin, kaolinite, magnesium silicate hydrate, silicon dioxide (including silica), bentonite, calcium carbonate, calcium silicate hydrate, calcium aluminate sulfate, aluminum hydroxide, aluminum oxide, boehmite and mixtures thereof,
  where preferably the one or at least one of the plurality of inorganic pigments K5) is calcium carbonate;
  and or
• the one or more inorganic pigments K5) are present in a total amount in the range from ≧9 to ≦50 percent by mass, preferably from ≧10 to ≦40 percent by mass, particularly preferably from ≧10 to ≦35 percent by mass, based on the dry mass of the heat-sensitive recording layer.

• das eine oder mindestens eines der mehreren Gleitmittel K6) ausgewählt ist aus der Gruppe bestehend aus
  • Salzen von Fettsäuren, welche eine Gesamtzahl von Kohlenstoffatomen im Bereich von 14 bis 20 aufweisen, mit ein- oder zweiwertigen Metallkationen;
  • Paraffinwachsen, vorzugsweise mit einem Schmelz- oder Erweichungspunkt im Bereich von 45 °C bis 80 °C und
  • deren Gemischen;
  und/oder
• die ein oder mehreren Gleitmittel K6) in einer Gesamtmenge im Bereich von ≥ 1,5 bis ≤ 10 Massenprozent, vorzugsweise von ≥ 2 bis ≤ 8 Massenprozent, besonders bevorzugt von ≥ 2 bis ≤ 6 Massenprozent, vorliegen, bezogen auf die Trockenmasse der wärmeempfindlichen Aufzeichnungsschicht.

Also preferred is an above-mentioned heat-sensitive recording layer according to the invention (or a heat-sensitive recording layer according to the invention, which is referred to as preferred in this text), wherein

• the one or at least one of the several lubricants K6) is selected from the group consisting of
  • salts of fatty acids having a total number of carbon atoms ranging from 14 to 20 with mono- or divalent metal cations;
  • paraffin waxes, preferably having a melting or softening point in the range of 45°C to 80°C and
  • their mixtures;
  and or
• the one or more lubricants K6) are present in a total amount in the range from ≧1.5 to ≦10 percent by mass, preferably from ≧2 to ≦8 percent by mass, particularly preferably from ≧2 to ≦6 percent by mass, based on the dry mass of the heat-sensitive recording layer .

The present invention also relates to a coating composition for producing a heat-sensitive recording layer, comprising the components K1) to K6) defined above and preferably component K7) as above for the heat-sensitive recording layer according to the invention (or for a heat-sensitive recording layer according to the invention, which is referred to in this text as is designated preferred), defined,
preferably wherein the coating composition additionally comprises:
K8) one or more carrier liquids, preferably selected from the group consisting of (i) water, (ii) monohydric alcohols having a total number of carbon atoms in the range from 1 to 4 and (iii) mixtures of water with one or more monohydric alcohols with a Total number of carbon atoms ranging from 1 to 4.

The explanations given above for the heat-sensitive recording layer according to the invention apply accordingly, and vice versa, with regard to preferred embodiments of the inventive coating composition specified above and possible combinations of one or more aspects of the invention specified here above.

• einem Substrat, vorzugsweise einem Papiersubstrat, vorzugsweise aufweisend eine Vorderseite und eine der Vorderseite gegenüberliegende Rückseite
  und
• einer vorstehend beschriebenen, erfindungsgemäßen wärmeempfindlichen Aufzeichnungsschicht (oder einer erfindungsgemäßen wärmeempfindlichen Aufzeichnungsschicht, die in diesem Text als bevorzugt bezeichnet ist), welche auf zumindest einer der Seiten des Substrats angeordnet ist.

Furthermore, the present invention also relates to a heat-sensitive recording material, preferably thermal paper, comprising or consisting of

• a substrate, preferably a paper substrate, preferably having a front side and a back side opposite the front side
  and
• a heat-sensitive recording layer according to the invention as described above (or a heat-sensitive recording layer according to the invention referred to as preferred in this text) which is arranged on at least one of the sides of the substrate.

The explanations given above for the heat-sensitive recording layer according to the invention and/or for the coating composition according to the invention apply accordingly, and vice versa.

In our own tests, it was found that an above-mentioned heat-sensitive recording material according to the invention (or a heat-sensitive recording material according to the invention which is referred to as preferred in this text) enables thermal printouts with particularly advantageous properties. These particularly advantageous properties of such thermal printouts include, in particular, high resistance to plasticizers, high resistance to lanolin, high resistance to water or aqueous ethanol solution, but also high climate resistance and high heat resistance. In this case, heat-sensitive recording materials produced with heat-sensitive recording layers according to the invention have a dynamic print density which is generally at least comparable to that of a conventional heat-sensitive recording material and in some cases even better. It was also found in our own experiments that a heat-sensitive recording material according to the invention specified above (or a heat-sensitive recording material according to the invention which is referred to as preferred in this text)—even without a corresponding top layer—already has excellent scratch resistance.

• das wärmeempfindliche Aufzeichnungsmaterial eine oder mehrere (vorzugsweise eine), zwischen dem Substrat und der wärmeempfindlichen Aufzeichnungsschicht angeordnete, Zwischenschichten aufweist;
  und/oder
• die flächenbezogene Trockenmasse der wärmeempfindlichen Aufzeichnungsschicht im Bereich von ≥ 1,8 g/m² bis ≤ 2,5 g/m², vorzugsweise im Bereich von ≥ 2,0 g/m² bis ≤ 2,4 g/m², weiter bevorzugt im Bereich von ≥ 2,0 g/m² bis ≤ 2,3 g/m² und besonders bevorzugt im Bereich von ≥ 2,0 g/m² bis ≤ 2,20 g/m²liegt;
  oder die flächenbezogene Trockenmasse der wärmeempfindlichen Aufzeichnungsschicht im Bereich von ≥ 1,8 g/m² bis ≤ 2,3 g/m², vorzugsweise im Bereich von ≥ 1,9 g/m² bis ≤ 2,2 g/m², besonders bevorzugt im Bereich von ≥ 1,9 g/m² bis ≤ 2,15 g/m², liegt;
  und/oder
• das Substrat ein Papiersubstrat ist und das Papiersubstrat einen Anteil von ≥ 80 Massenprozent an Recyclingfasern enthält, bezogen auf die Gesamtmasse des lufttrockenen Papiersubstrats;
  und/oder
• das Substrat ein Papiersubstrat ist und das Papiersubstrat einen Anteil von ≤ 25 Massenprozent an Frischfasern enthält, bezogen auf die Gesamtmasse des lufttrockenen Papiersubstrats.

Preference is given to a heat-sensitive recording material according to the invention as specified above (or a heat-sensitive recording material according to the invention which is referred to as preferred in this text), wherein

• the heat-sensitive recording material has one or more (preferably one) intermediate layers arranged between the substrate and the heat-sensitive recording layer;
  and or
• the dry weight per unit area of the heat-sensitive recording layer is in the range from ≧1.8 g/m ² to ≦2.5 g/m ² , preferably in the range from ≧2.0 g/m ² to ≦2.4 g/m ² preferably in the range from ≥ 2.0 g/m ² to ≤ 2.3 g/m ² and particularly preferably in the range from ≥ 2.0 g/m ² to ≤ 2.20 g/m ² ;
  or the area-related dry mass of the heat-sensitive recording layer in the range from ≥ 1.8 g/m ² to ≤ 2.3 g/m ² , preferably in the range from ≥ 1.9 g/m ² to ≤ 2.2 g/m ² , more preferably in the range from ≧1.9 g/m ² to ≦2.15 g/m ² ;
  and or
• the substrate is a paper substrate and the paper substrate contains ≥ 80% by mass of recycled fibers, based on the total mass of the air-dried paper substrate;
  and or
• the substrate is a paper substrate and the paper substrate contains ≤ 25 percent by mass of fresh fibers, based on the total mass of the air-dried paper substrate.

If the heat-sensitive recording material according to the invention has one or more intermediate layers arranged between the substrate and the heat-sensitive recording layer, such an intermediate layer preferably comprises pigments and/or fillers. The pigments (or fillers) of such an intermediate layer are preferably inorganic pigments (or fillers), particularly preferably selected from the list consisting of calcined kaolin, silicon dioxide, bentonite, calcium carbonate, aluminum oxide and boehmite.

If inorganic pigments (or fillers) are integrated into the intermediate layer between the recording layer and the substrate, they can absorb and promote the components (eg waxes) of the heat-sensitive recording layer that have been liquefied by the heat of the thermal head during the formation of the typeface thus an even safer and faster functioning of the heat-induced recording.

It is particularly advantageous if the inorganic pigments (or fillers) of the intermediate layer have an oil absorption of at least 80 cm ³ /100 g and even better of 100 cm ³ /100 g, determined according to Japanese standard JIS K 5101. Calcined kaolin has proven particularly useful due to its large absorption reservoir in the cavities. Mixtures of several different types of inorganic pigments are also conceivable.

A heat-sensitive recording material is preferred according to the invention, the intermediate layer optionally containing, in addition to the inorganic pigments (or fillers), at least one binder, preferably based on a synthetic polymer, with styrene-butadiene latex giving particularly good results. The use of a synthetic binder with the admixture of at least one natural polymer, such as particularly preferably starch, represents a particularly suitable embodiment. In experiments with inorganic pigments, it was also found that a binder-pigment ratio within the intermediate layer of between 3:7 and 1:9, based in each case on the percentage by mass in the intermediate layer, represents a particularly suitable embodiment.

It is preferred according to the invention if the dry mass per unit area of an intermediate layer described above is in the range from 5 to 20 g/m ² , preferably in the range from 7 to 12 g/m ² .

In our own experiments, it was also found that an above-mentioned heat-sensitive recording material according to the invention (preferably a heat-sensitive recording material according to the invention, which is referred to as preferred in this text) also enables very good thermal prints if its heat-sensitive recording layer is only relatively thin (thickness ) is present and preferably the dry mass per unit area of the heat-sensitive recording layer is in the range from ≥ 1.8 g/m ² to ≤ 2.3 g/m ² , preferably in the range from ≥ 1.9 g/m ² to ≤ 2.2 g/ m ² , particularly preferably in the range from ≧1.9 g/m ² to ≦2.15 g/m ² . Such a variant of the present invention enables a particularly economical production of a heat-sensitive recording material with only a small consumption of material. Another advantage of such a variant is that that only relatively small amounts of waste arise when disposing of a heat-sensitive recording material. Since a heat-sensitive recording material according to the invention also largely or preferably exclusively contains components that meet the award criteria of the "Blue Angel" (see above), a heat-sensitive recording material according to the invention has a particularly good ecological balance sheet according to this variant.

For the purposes of the present invention, the mass of an "air-dry" paper substrate given above is determined under standard ambient conditions (23°C, 50% RH, 1013 hPa). A water content of the paper substrate of 10 percent by mass is assumed for an air-dried paper substrate--as is customary in the technical field.

The present invention also relates to the use of an above-described heat-sensitive recording layer according to the invention (or a heat-sensitive recording layer according to the invention, which is referred to as preferred in this text) for the production of a heat-sensitive recording material, preferably for the production of a heat-sensitive recording material according to the invention (or a heat-sensitive according to the invention recording material designated as preferred in this text).

With regard to preferred embodiments of the above-mentioned inventive use of a heat-sensitive recording layer according to the invention (or a heat-sensitive recording layer according to the invention, which is referred to as preferred in this text) and in this regard possible combinations of one or more aspects of the invention specified here above with each other, the above for the inventive heat-sensitive Recording layer and/or for the coating composition according to the invention and/or for the heat-sensitive recording material according to the invention in accordance with the explanations given in each case, and vice versa.

• V1) Herstellen oder Bereitstellen einer vorstehend beschriebenen, erfindungsgemäßen Beschichtungszusammensetzung (oder einer erfindungsgemäßen Beschichtungszusammensetzung, die in diesem Text als bevorzugt bezeichnet ist),
  wobei vorzugsweise
  • keine Phenolgruppen-haltigen organischen Farbentwickler eingesetzt werden, vorzugsweise keine Phenolgruppen-haltigen organischen Farbentwickler, welche ausgewählt sind aus der Gruppe bestehend aus Bisphenol A, Bisphenol S, Bisphenol AP, (4-[(4-lsopropoxyphenyl)sulfonyl]phenol, 4,4'-Methylendiphenol, 2,2'-Methylendiphenol, 4-[4'-[(1'-methylethyloxy)phenyl]sulfonyl]phenol, 2,2'-Diallyl-4,4'-sulfonyldiphenol, 4-4'-Methylenebis-(oxyethylenethio)diphenol und deren Gemischen;
    und/oder
  • keine organischen Sensibilisatoren eingesetzt werden, vorzugsweise keine organischen Sensibilisatoren eingesetzt werden, welche ausgewählt sind aus der Gruppe bestehend aus 1,2-Bis(3-methylphenoxy)ethan, 1,2-Diphenoxyethan, 1-Phenoxy-2-(4-methylphenoxy) ethan, Benzyl-2-naphthylether, 2-(2H-Benzotriazol-2-yl)-p-cresol, 2,2'-Bis(4-methoxyphenoxy)diethylether, 4,4'-Diallyloxydiphenylsulfon, 4-Acetylacetophenon, 4-Benzylbiphenyl, Acetoessigsäureanilid, Benzyl-4-(benzyloxy)benzoat, Benzylparaben, Bis(4-chlorbenzyl)oxalatester, Bis(4-methoxyphenyl)ether, Dibenzyloxalat, Dibenzylterephthtalat, Dimethylterephthalat, Dimethylsulfon, Diphenyladipat, Diphenylsulfon, p-Benzylbiphenyl, Phenylbenzolsulfonatester, α,α'-Diphenoxyxylen und deren Gemischen;
    und/oder
  • keine organischen Hohlkörperpigmente (vorzugsweise keine organischen Hohlkörperpigmente wie beschrieben im Dokument WO 2012/145456 A1 ) eingesetzt werden.
• V2) Herstellen oder Bereitstellen eines Substrats, vorzugsweise eines Papiersubstrats, vorzugsweise aufweisend eine Vorderseite und eine der Vorderseite gegenüberliegende Rückseite,
• V3) Aufbringen auf mindestens einer Seite des Substrats, oder auf mindestens einer Seite einer auf dem Substrat angeordneten Zwischenschicht, der Beschichtungszusammensetzung aus Schritt V1),
  vorzugsweise unter Verwendung einer Beschichtungsvorrichtung, wobei vorzugsweise die Beschichtungsvorrichtung ausgewählt ist aus der Gruppe bestehend aus Rollrakelstrichwerk, Messerstreichwerk, Vorhangbeschichter und Luftbürste;
• V4) Vorzugsweise Trocknen der in Schritt V3) aufgebrachten Beschichtungszusammensetzung unter Ausbildung einer wärmeempfindlichen Aufzeichnungsschicht,

vorzugsweise so dass ein erfindungsgemäßes wärmeempfindliches Aufzeichnungsmaterial resultiert.Furthermore, the present invention also relates to a method for the production of a heat-sensitive recording material, preferably for the production of a heat-sensitive recording material according to the invention described above (or a heat-sensitive recording material according to the invention, which is referred to as preferred in this text), at least comprising the steps:

• V1) preparing or providing a coating composition according to the invention as described above (or a coating composition according to the invention which is referred to as preferred in this text),
  where preferably
  • no organic color developers containing phenol groups are used, preferably no organic color developers containing phenol groups, which are selected from the group consisting of bisphenol A, bisphenol S, bisphenol AP, (4-[(4-isopropoxyphenyl)sulfonyl]phenol, 4,4 '-methylenediphenol, 2,2'-methylenediphenol, 4-[4'-[(1'-methylethyloxy)phenyl]sulfonyl]phenol, 2,2'-diallyl-4,4'-sulfonyldiphenol, 4-4'-methylenebis -(oxyethylenethio)diphenol and mixtures thereof;
    and or
  • no organic sensitizers are used, preferably no organic sensitizers are used, which are selected from the group consisting of 1,2-bis(3-methylphenoxy)ethane, 1,2-diphenoxyethane, 1-phenoxy-2-(4-methylphenoxy) ethane, benzyl 2-naphthyl ether, 2-(2H-benzotriazol-2-yl)-p-cresol, 2,2'-bis(4-methoxyphenoxy)diethyl ether, 4,4'-diallyloxydiphenyl sulfone, 4-acetylacetophenone, 4- Benzylbiphenyl, acetoacetic anilide, benzyl 4-(benzyloxy)benzoate, benzylparaben, bis(4-chlorobenzyl)oxalate ester, bis(4-methoxyphenyl)ether, dibenzyl oxalate, dibenzyl terephthalate, dimethyl terephthalate, dimethyl sulfone, diphenyl adipate, diphenyl sulfone, p-benzylbiphenyl, phenylbenzene sulfonate ester, α ,α'-diphenoxyxylene and mixtures thereof;
    and or
  • no organic hollow body pigments (preferably no organic hollow body pigments as described in the document WO 2012/145456 A1 ) are used.
• V2) producing or providing a substrate, preferably a paper substrate, preferably having a front side and a back side opposite the front side,
• V3) Application of the coating composition from step V1) to at least one side of the substrate, or to at least one side of an intermediate layer arranged on the substrate
  preferably using a coating device, wherein preferably the coating device is selected from the group consisting of knife coater, knife coater, curtain coater and air knife;
• V4) preferably drying the coating composition applied in step V3) to form a heat-sensitive recording layer,

preferably so that a heat-sensitive recording material according to the invention results.

With regard to preferred embodiments of the above-mentioned method according to the invention for the production of a heat-sensitive recording material and possible combinations of one or more aspects of the invention given here above with one another in this regard, the above apply to the heat-sensitive recording layer according to the invention and/or for the coating composition according to the invention and/or for the coating composition according to the invention heat-sensitive recording material and/or for the use according to the invention of a heat-sensitive recording layer according to the invention in accordance with the explanations given in each case, and vice versa.

Then the present invention also relates to the use of a heat-sensitive recording material according to the invention described above (or a heat-sensitive recording material according to the invention, which is referred to as preferred in this text) as a flight, train, ship or bus ticket, gambling receipt, parking ticket, label, receipt , self-adhesive label, medical chart paper, fax paper and/or barcode label.

With regard to preferred embodiments of the above-mentioned inventive use of a heat-sensitive recording material according to the invention and possible combinations of one or more aspects of the invention mentioned here above with one another, the above for the heat-sensitive recording layer according to the invention and/or for the according to the invention apply Coating composition and/or for the heat-sensitive recording material according to the invention and/or for the inventive use of a heat-sensitive recording layer according to the invention and/or for the process according to the invention for the production of a heat-sensitive recording material in accordance with the explanations given in each case, and vice versa.

Examples:

The examples given below are intended to describe and explain the invention in more detail without restricting its scope.

Example 1: Preparation of an interlayer paper substrate

A raw paper with a mass per unit area of 42 g/m ² was provided as the paper substrate. Using a coater, a coating composition for forming an intermediate layer having a basis weight (dry weight) of 9 g/m ² was applied on the front side of this paper substrate with a bar coater and dried conventionally. Water was used as the carrier liquid for the coating composition for forming an intermediate layer.

The components of the coating composition for forming an intermediate layer after drying on the paper substrate (dry weight, see above) and their amounts (in percent by mass based on the dry weight of the coating composition for forming the intermediate layer) are given below in Table 1: <u>Table</u> 1: Components of a coating composition for forming an intermediate layer component Total amount [mass%] Dispersant based on polysiloxane 0.2 - 0.8 strength 1 - 5 Calcined kaolin 65 - 85 Na carboxymethyl cellulose 0.3 - 1 ground calcium carbonate 2 - 10 Styrene butadiene copolymer dispersion 7 - 15

All components of the coating composition described above for forming an intermediate layer thus met the "award criteria for printing and press paper predominantly made from waste paper", DE-UZ 72, January 2020 edition, version 1, for the "Blue Angel" environmental label of the German Federal Ministry for the Environment , nature conservation and nuclear safety (hereinafter referred to as "Blue Angel award criteria DE-UZ 72") and the "Award criteria for graphic paper and cardboard made from 100% waste paper (recycled paper and cardboard)", DE-UZ 14a, January 2020 edition , Version 2, for the above-mentioned "Blue Angel" eco-label (hereinafter referred to as "Award Criteria Blue Angel DE-UZ 14a").

Example 2 Production of Coating Compositions According to the Invention

A coating composition according to the invention (for producing a heat-sensitive recording layer) was prepared by mixing together the ingredients listed below in Table 2, water being used as the carrier liquid. The components of the coating composition and their amounts (in percent by mass based on the dry weight of the coating composition) are given in Table 2 below: <u>Table</u> 2: Constituents of a coating composition according to the invention for producing a heat-sensitive recording layer component component Total amount [mass%] K1) 3-di-N-butylamino-6-methyl-7-anilinofluoran (ODB-2) 8 - 12 K2) N -(4-Methylphenylsulfonyl)- N' -(3-(4-methylphenylsulfonyloxy)phenyl)urea (Pergafast 201) 19 - 26 K3) Polyvinyl alcohol, degree of hydrolysis > 80% 10 - 18 K4) octadecanamide 17 K5) Calcium carbonate, finely divided, precipitated 21 - 32 K6) Paraffin wax, melting point in the range of 50 to 65 °C / zinc stearate 5 - 10 K7) Process aids (defoamers, biocides, dispersants, wetting agents) ≤ 0.7 K8) water ./.

According to our own assessment, all components of the coating composition described above for producing a heat-sensitive recording layer meet the "Award criteria for printing and press paper predominantly made from waste paper", DE-UZ 72, January 2020 edition, version 1, for the "Blue Angel" environmental label of the German Federal Ministry for the Environment, Nature Conservation and Nuclear Safety (hereinafter referred to as "Blue Angel award criteria DE-UZ 72") or the "Award criteria for graphic paper and cardboard made from 100% waste paper (recycled paper and cardboard)", DE-UZ 14a, January 2020 edition, version 2, for the above-mentioned eco-label "Blue Angel" (hereinafter referred to as "award criteria Blue Angel DE-UZ 14a").

Further coating compositions according to the invention were prepared in accordance with the preparation process described here above, with the amount of octadecanamide being varied in each case, while the proportion of the other components was not changed. The coating compositions prepared in this way, their abbreviations and the total amounts of octadecanamide used in each case (in percent by mass, based on the dry mass of the coating composition) in these coating compositions are given in Table 3 below. <u>Table</u> 3: Coating compositions according to the invention for producing heat-sensitive recording layers coating composition Total amount of octadecanamide [mass%] BSZE-1 14.0 BSZE-2 16.9 BSZE-3 19.7 BSZE-4 22.2 BSZE-5 24.6 BSZE-6 26.9

Example 3 Production of Heat-Sensitive Recording Layers According to the Invention and Heat-Sensitive Recording Materials According to the Invention

A coating composition according to the invention for the production of a heat-sensitive recording layer was provided (for production see Example 2 above) and a paper substrate which was coated on its front side with an intermediate layer (for production see Example 1 above).

Using a coating machine, the coating composition according to the invention was then applied to the intermediate layer of the paper substrate by means of a doctor blade to produce a heat-sensitive recording layer with a mass per unit area of 2.1 g/m ² (dry mass) and dried conventionally, resulting in a heat-sensitive recording layer according to the invention (arranged on the intermediate layer of the paper substrate) and also a heat-sensitive recording material according to the invention.

Further heat-sensitive recording layers or heat-sensitive recording materials were produced in accordance with the production process described here above, the coating compositions BSZE-1 to BSZE-6 according to the invention given above in Example 2, Table 3, being used in each case. The heat-sensitive recording materials produced in this way, their abbreviations and the coating compositions used in each case are given in Table 4 below. <u>Table</u> 4: Heat-sensitive recording materials according to the invention Heat-sensitive recording material Coating composition used WAME-1 BSZE-1 WAME -2 BSZE-2 WAME -3 BSZE-3 WAME -4 BSZE-4 WAME -5 BSZE-5 WAME -6 BSZE-6

Example 4: Production of a non-inventive heat-sensitive recording material (comparison)

A paper substrate coated on its front side with an intermediate layer (prepared as in Example 1) and a conventional coating composition not according to the invention for the production of a heat-sensitive recording layer were provided. The conventional coating composition, not according to the invention, for producing a heat-sensitive recording layer was produced by mixing the components listed in Table 5 below with each other, water being used as the carrier liquid. The components of the non-inventive coating composition and their amounts (in percent by mass based on the dry weight of the coating composition) are given below in Table 5: <u>Table</u> 5: Constituents of a non-inventive coating composition for producing a heat-sensitive recording layer component Total amount [mass%] 3-di-N-butylamino-6-methyl-7-anilinofluoran (ODB-2) 8 - 12 N -(4-Methylphenylsulfonyl)- N '-(3-(4-methylphenylsulfonyloxy)phenyl)urea (Pergafast ^® 201) 19 - 26 1,2-diphenoxyethane 9 - 15 methylol stearamide 2 - 5 Polyvinyl alcohol, degree of hydrolysis > 80% 14 - 20 Calcium carbonate, finely divided, precipitated 21 - 32 Paraffin wax, melting point in the range of 50 to 65 °C / zinc stearate 5 - 10 Process aids (defoamers, biocides, dispersants, wetting agents) 1.5 - 4 Optical brightener 1 - 2.5 water ./.

Analogously to the process given above in Example 3, the non-inventive coating composition for producing a heat-sensitive recording layer with a mass per unit area of 2.3 g/m ² (dry mass) was then applied to the intermediate layer of the paper substrate using a doctor blade and dried conventionally. so that a non-inventive heat-sensitive recording layer (located on the interlayer of the paper substrate) as well as a non-inventive heat-sensitive recording material (comparison) resulted. The heat-sensitive recording material not according to the invention is hereinafter referred to as "WAMV-1" for short.

Example 5: Determination of the heat resistance of heat-sensitive recording materials at 60 °C / 24 hours

For the metrological determination of the heat resistance of thermal printouts on the heat-sensitive recording materials WAME-1 to WAME-6 according to the invention (manufacture see Example 3) and the non-inventive comparative example WAMV-1, under laboratory conditions (23 ° C) each turned black on the heat-sensitive recording materials to be tested / white checkered thermal test prints created with a device of the GeBE Printerlab type.

After the creation of the black and white checkered thermal test prints, after a rest period of more than 5 minutes, the print density was determined with a spectral -Densitometer of the type TECHKON SpectroDens Advanced performed. The mean value ("before heating") was formed from the measured values for the black-colored areas ("image") and for the uncolored areas ("background").

The thermal test prints were then hung in a drying cabinet at 60 °C. After 24 hours, the thermal paper printouts were removed again, cooled to room temperature (23 °C) and the print density was again determined at three points each on the black colored areas and the uncolored areas of the thermal test printouts (averaging and densitometer as described above; " after heating").

The permanence of the print image in "%" determined under the test conditions corresponds to the quotient of the mean value formed of the print density of the colored areas "before heating" and after storage in the drying cabinet ("after heating"), multiplied by 100. The determined under the test conditions The contrast of the print image in "%" corresponds to the quotient of the mean value of the print density of the uncolored areas ("background") "before heating" and after storage in the drying cabinet ("after heating"), multiplied by 100.

The measurement results obtained in this way are listed in Table 6 below: <u>Table</u> 6: Durability of the print image of heat-sensitive recording materials before and after heating to 60 °C / 24 hours. Heat-sensitive recording material Durability of the print image [%] Contrast [%] WAME-1 97.0 96.2 WAME-2 95.8 95.3 WAME-3 95.0 94.5 WAME-4 95.3 95.1 WAME-5 96.5 95.7 WAME-6 94.8 93.9 WAMV-1 92.4 91.7

From the data given above in Table 6 it can be seen that a heat-sensitive recording material according to the invention (WAME-1 to WAME-6) - also in comparison to a conventional heat-sensitive recording material (WAMV-1) has excellent heat resistance of the printed image or background and thus permanent, very high-contrast printouts.

Example 6: Determination of the climatic stability of heat-sensitive recording materials at 40 °C/24 hours and 90% RH.

For the metrological determination of the climate resistance of thermal printouts on the heat-sensitive recording materials WAME-1 to WAME-6 according to the invention (production see Example 3) and the non-inventive comparative example WAMV-1, the print densities on the black were measured analogously to the specification given in Example 5 above colored areas ("image") and for the uncolored areas ("background") before and after storage in a climatic cabinet (at 40 °C and 90 % RH for 24 hours; instead of storage in a drying cabinet at 60 °C for 24 hours as determined in Example 5).

The measurement results thus obtained are listed in Table 7 below: <u>Table</u> 7: Durability of the print image of heat-sensitive recording materials before and after storage in a climate cabinet at 40 °C and 90 % RH for 24 hours. Heat-sensitive recording material Durability of the print image [%] Contrast [%] WAME-1 76.5 74.0 WAME-2 78.5 76.5 WAME-3 79.9 78.6 WAME-4 80.1 78.2 WAME-5 79.5 77.5 WAME-6 77.4 75.6 WAMV-1 74.5 73.1

It can be seen from the data given in Table 7 above that a heat-sensitive recording material according to the invention (WAME-1 to WAME-6) - also in comparison to a conventional heat-sensitive recording material (WAMV-1) - has excellent climate resistance of the printed image or background and thus enables permanent, high-contrast printouts even under the conditions of a humid climate.

Example 7: Determination of the resistance of heat-sensitive recording materials to lanolin (exposure time 10 minutes)

For the metrological determination of the resistance of thermal printouts on the heat-sensitive recording materials WAME-1 to WAME-6 according to the invention (manufacture see Example 3) and the non-inventive comparative example WAMV-1 to lanolin, black and white checkered designs were used on the heat-sensitive recording materials to be tested Thermal test prints were produced using an Atlantek 400 device from Printrex (USA), using a thermal head with a resolution of 300 dpi and an energy per unit area of 16 mJ/mm ² .

After the creation of the black/white checkered thermal test prints, after a rest period of more than 5 minutes, three areas each of the black-colored areas were and the uncolored areas of the thermal test prints, the print density was determined using a TECHKON SpectroDens Advanced densitometer - spectral densitometer. The mean value was formed from the respective measured values of the black-colored areas and the uncolored areas.

Then the created thermal proof of the heat-sensitive recording material to be tested was generously coated with lanolin by hand. After an exposure time of 10 minutes (23 °C, 50 % RH), the lanolin was carefully wiped off and the print density was again measured in three places each on the black colored areas and the uncolored areas of the thermal test prints using a densitometer TECHKON SpectroDens Advanced - spectral densitometer certainly. The mean value was formed from the respective measured values of the black-colored areas and the uncolored areas. The determined resistance of the thermal prints to lanolin in "%" corresponds to the quotient of the mean value of the print density formed before the lanolin treatment and after the lanolin treatment, multiplied by 100.

The measurement results thus obtained are listed in Table 8 below: <u>Table</u> 8: Resistance of the printed image of heat-sensitive recording materials to lanolin (exposure time 10 min.) Heat-sensitive recording material Durability of the print image [%] WAME-1 55.7 WAME-2 49.5 WAME-3 55.7 WAME-4 51.7 WAME-5 57.4 WAME-6 53.8 WAMV-1 52.6

From the data presented in Table 8 above, it can be seen that a heat-sensitive recording material according to the invention (WAME-1 to WAME-6) has at least one improvement over a conventional heat-sensitive recording material (WAMV-1). comparable - and in many cases even better - resistance of the printed image to lanolin.

Example 8: Determination of the resistance of heat-sensitive recording materials to water and aqueous ethanol solution (23 °C, 50% RH, 24 hours)

These tests are used to assess the resistance of an image produced on the heat-sensitive recording layer of heat-sensitive recording materials to water or to 25% (v/v) aqueous ethanol solution ("test liquids"). A drop of distilled water or the selected aqueous 25% ethanol solution was applied to the printed areas produced with the printer ATLANTEK Model 400-Thermal Response Test System with the energy level medium level 10. After 20 minutes exposure time, the excess test liquid is dabbed off with a filter paper or cotton cloth and the test sheet is then stored in a room climate (23 °C, 50 % relative humidity) for 24 hours. Before applying the respective test liquid and after the end of the storage time, the optical density of the printed areas and their difference were determined with the densitometer TECHKON SpectroDens Advanced - spectral densitometer (mean value from measurements on three printed areas).

The resistance of the thermal print image on a heat-sensitive recording material in "%" to water or aqueous ethanol solution corresponds to the quotient of the mean value of the print density formed before and after treatment with the respective test liquid, multiplied by 100.

The measurement results obtained as above are shown in Table 9 below: <u>Table</u> 9: Resistance of the printed image of heat-sensitive recording materials to water or aqueous ethanol solution Heat-sensitive recording material Resistance of the printed image to water [%] Resistance of the printed image to aqueous ethanol solution [%] WAME-1 92.1 84.7 WAME-2 90.9 86.2 WAME-3 92.7 87.5 WAME-4 92.5 87.5 WAME-5 92.2 85.9 WAME-6 92.4 85.7 WAMV-1 75.4 73.0

From the data given above in Table 9 it can be seen that a heat-sensitive recording material according to the invention (WAME-1 to WAME-6) - also in comparison to a conventional heat-sensitive recording material (WAMV-1) - has an excellent resistance of the printed image to water and aqueous ethanol solution and thus enables permanently stable and high-contrast printouts, even against the influences mentioned.

Example 9: Determination of the resistance of heat-sensitive recording materials to plasticizers of an adhesive film (23 °C, 50% RH)

These tests are used to assess the resistance of an image produced on the heat-sensitive recording layer of heat-sensitive recording materials to plasticizers contained in an adhesive film. A Tesa graphic adhesive film of the type "57331-0000 MPF" was applied to the printed surfaces produced with the printer ATLANTEK Model 400 -Thermal Response Test System with the energy level medium level 10 and it was measured with the densitometer TECHKON SpectroDens Advanced - spectral Densitometer before applying the graphic adhesive film and immediately after its application in each case the optical density of the printed areas and their difference (mean value from measurements on three printed areas).

The resistance of the thermal print image on a heat-sensitive recording material in "%" to plasticizers contained in a graphic adhesive film corresponds to the quotient of the mean value formed of the print density before application and after application of the graphic adhesive film, multiplied by 100.

The measurement results obtained as above are shown in Table 10 below: <u>Table</u> 10: Resistance of the printed image of heat-sensitive recording materials to plasticizers contained in a graphics adhesive film Heat-sensitive recording material Resistance of the printed image to plasticizers [%] WAME-1 54.2 WAME-2 57.1 WAME-3 62.0 WAME-4 65.1 WAME-5 66.1 WAME-6 66.0 WAMV-1 56.9

From the data given above in Table 10 it can be seen that a heat-sensitive recording material according to the invention (WAME-1 to WAME-6) has a print image durability which is at least comparable to that of a conventional heat-sensitive recording material (WAMV-1) and in many cases even improved compared to plasticizers contained in a graphic adhesive film.

Example 10 Determination of the dynamic print density (or the dynamic sensitivity) of heat-sensitive recording materials

The sensitivity of a heat-sensitive recording material (in particular a thermal paper) defines the degree of reaction at a certain energy input. It is usually shown in graphs that show the generated image density or optical density (OD) as a function of the energy or heat supplied. Optical density is a measure of the ratio between incident and reflected light. An optical density, specified in "Optical Density Units" (ODU), of approx. 1.1 is usually completely black for the human eye. Therefore, lower optical densities result in different shades of gray. A distinction is made between static and dynamic sensitivity (or static and dynamic pressure density).

The dynamic sensitivity (or dynamic print density) of a heat-sensitive recording material (in particular thermal paper) indicates how quickly a heat-sensitive recording material can be printed on. The higher the dynamic sensitivity, the faster a thermal printer can print on the heat-sensitive recording material with otherwise unchanged settings.

To determine the maximum dynamic print density of the heat-sensitive recording materials listed in Table 11 below, black and white checkered thermal test prints were created with a GeBE printer, with the heat-sensitive recording materials (see Table 11) being printed with an energy in the range from 3 to 16 mJ /mm ² were printed. Each thermal printout was then examined with a TECHKON ^® SpectroDens Advanced spectral densitometer. The measurement results obtained using a densitometer (as print density data in ODU) are given in Table 11 below against the corresponding energy inputs. <u>Table</u> 11: Dynamic sensitivity (print density) of heat-sensitive recording materials Heat-sensitive recording material Energy input [mJ/mm ² ] 3.22 4.62 6.07 7.49 8.88 10:32 11.74 13:17 14.57 16.00 WAME-1 (ODU) 0.06 0.14 0.34 0.64 0.80 0.95 1.03 1.09 1:11 1:11 WAME-2 (ODU) 0.06 0.15 0.39 0.66 0.88 1.02 1.07 1:11 1:13 1:12 WAME-3 (ODU) 0.06 0.16 0.39 0.67 0.88 1.02 1.09 1:13 1.14 1:12 WAME-4 (ODU) 0.05 0.15 0.41 0.71 0.91 1.04 1.09 1:13 1:15 1:11 WAME-5 (ODU) 0.06 0.16 0.41 0.73 0.91 1.04 1.10 1:13 1.14 1:12 WAME-6 (ODU) 0.06 0.17 0.43 0.70 0.90 1.00 1.08 1.10 1:11 1.08 WAMV-1 (ODU) 0.07 0.17 0.42 0.71 0.90 1.04 1.08 1.10 1.14 1:13

From the data given above in Table 11 it can be seen that a heat-sensitive recording material according to the invention (WAME-1 to WAME-6) has a dynamic print density which is at least comparable to a conventional heat-sensitive recording material (WAMV-1) and in some cases even improved .

Claims (15)

Heat-sensitive recording layer comprising: K1) one or more organic dye precursors, each of which comprises a fluoran structure, K2) one or more phenol group-free organic color developers, K3) one or more crosslinked or uncrosslinked polymeric organic binders, K4) one or more amide waxes, each of which has a melting point in the range from 80° C. to 120° C., K5) one or more particulate inorganic pigments
and K6) one or more lubricants, where the sum of the components K1) to K6) makes up ≧95 percent by weight of the dry weight of the heat-sensitive recording layer. A heat-sensitive recording layer according to claim 1 additionally comprising
K7) one or more process auxiliaries, preferably selected from the group consisting of defoamers, biocides, dispersants and wetting agents,
preferably in a total amount of ≤ 5 percent by mass, particularly preferably in a total amount in the range from ≥ 0.1 to ≤ 3 percent by mass and more preferably in the range from ≥ 0.1 to ≤ 2 percent by mass, based on the dry mass of the heat-sensitive recording layer. Heat-sensitive recording layer according to one of the preceding claims, wherein the sum of the components K1) to K6) ≥ 97 percent by mass, preferably ≥ 98 percent by mass, more preferably ≥ 98.5 percent by mass, of the dry mass of the heat-sensitive recording layer makes up,
the sum of the components K1) to K7) preferably making up ≧99% by mass, particularly preferably 100% by mass, of the dry mass of the heat-sensitive recording layer. Heat-sensitive recording layer according to any one of the preceding claims, wherein - the one or at least one of the several organic dye precursors K1) is selected from the group consisting of 3-diethylamino-6-methyl-7-anilinofluoran, 3-diethylamino-6-methyl-7-(3'-methylphenylamino)fluoran, 3 -(Diethylamino)-6-methyl-7-(3-methylphenylamino)fluoran (ODB-7), 3-Di-n-pentylamino-6-methyl-7-anilinofluoran, 3-Di-n-butylamino-7 -(2-chloroanilino)fluoran, 3-diethylamino-7-(2-chloroanilino)fluoran, 3-diethylamino-6-methyl-7-xylidinofluoran, 3-diethylamino-7-(2-carbomethoxyphenylamino)fluoran, 3-pyrrolidino- 6-methyl-7-anilinofluoran, 3-pyrrolidino-6-methyl-7-(4-n-butyl-phenylamino)fluoran, 3-piperidino-6-methyl-7-anilinofluoran, 3-N-di-n-butylamino -6-methyl-7-anilinofluoran (ODB-2), 3-(N-methyl-N-cyclohexyl)amino-6-methyl-7-anilinofluoran, 3-(N-methyl-N-propyl)amino-6- methyl-7-anilinofluoran, 3-(N-methyl-N-tetrahydrofurfuryl)amino-6-methyl-7-anilinofluoran), 3-(N-ethyl-N-isoamyl)amino-6-methyl-7-anilinofluoran, 3 -(N-ethyl-N-tolyl)amino-6-methyl-7-anilinofluoran, 3-(N-ethyl-N-tetrahydrofuryl)amino-6-methyl-7-anilinofluoran, 3-(N-ethyl-N-isopentylamino)-6-methyl-7-anilinofluoran, 3-(N-ethyl-4- toluidino)6-methyl-7-(4-toluidino)fluoran, 3-(N-cyclopentyl-N-ethyl)amino-6-methyl-7-anilinofluoran and mixtures thereof,
where preferably the one or at least one of the several organic dye precursors K1) is selected from the group consisting of the group consisting of 3-N-di-n-butylamino-6-methyl-7-anilinofluoran (ODB-2) 3-(N -ethyl-N-isopentylamino)-6-methyl-7-anilinofluoran and mixtures thereof;
and or - the one or more organic dye precursors K1) are present in a total amount in the range from ≧7 to ≦18 percent by mass, preferably from ≧8 to ≦15 percent by mass, based on the dry mass of the heat-sensitive recording layer. Heat-sensitive recording layer according to any one of the preceding claims, wherein - the one or more phenol-free organic color developers K2) each no phenol structural element of the formula II,

include,
and or
the one or at least one of the several phenol group-free organic color developers K2) is selected from the group consisting of N- (4-methylphenylsulfonyl)-N'-(3-(4-methylphenylsulfonyloxy)phenyl)urea, 5-( N -3 -Methylphenylsulfonylamido)-(N',N"-bis-(3-methylphenyl)isophthalic acid diamide, N -[2-(3-phenylureido)phenyl]benzenesulfonamide and mixtures thereof,
and or - the one or more phenol group-free organic color developers K2) are present in a total amount in the range from ≧12 to ≦35 percent by mass, preferably from ≧15 to ≦30 percent by mass, based on the dry mass of the heat-sensitive recording layer. Heat-sensitive recording layer according to any one of the preceding claims, wherein - the one or more polymeric organic binders K3) are present in a total amount in the range from ≧7 to ≦25 percent by mass, preferably from ≧8 to ≦20 percent by mass, based on the dry mass of the heat-sensitive recording layer;
and or - the one or at least one of the several polymeric organic binders K3) is selected from the group consisting of polyvinyl alcohol and starch,
where preferably one or at least one of the plurality of polymeric organic binders K3) is polyvinyl alcohol. Heat-sensitive recording layer according to any one of the preceding claims, wherein - the one or more amide waxes K4) comprise or are one or more fatty acid monoamides, each of which has a melting point in the range from 80° C. to 120° C.,
where preferably one or at least one of the several amide waxes K4) is a monoamide of a saturated fatty acid whose fatty acid residue has a total number of carbon atoms in the range from ≧12 to ≦20, preferably in the range from ≧14 to ≦18, particularly preferably in the range from ≧ 16 to ≤ 18;
wherein particularly preferably the one or at least one of the several amide waxes is selected from the group consisting of lauric acid amide, myristic acid amide, palmitic acid amide, octadecanamide, N-methylolstearic acid amide and mixtures thereof;
and or - the one or more amide waxes K4) in a total amount in the range from ≧10 to ≦30 percent by mass, preferably from ≧12.5 to ≦25 percent by mass, particularly preferably from ≧15 to ≦25 percent by mass particularly preferably from ≧16 to ≦24 percent by mass, based on the dry mass of the heat-sensitive recording layer;
and or - the ratio of the total amount of one or more phenol-group-free organic color developers K2) present in the dry matter of the heat-sensitive recording layer to the total amount of one or more amide waxes K4) present in the dry matter of the heat-sensitive recording layer in the range of 1: 0.5, preferably im range of 1:2. Heat-sensitive recording layer according to any one of the preceding claims, wherein - the one or at least one of the several inorganic pigments K5) is selected from the group consisting of calcined kaolin, kaolin, kaolinite, magnesium silicate hydrate, silicon dioxide, bentonite, calcium carbonate, calcium silicate hydrate, calcium aluminate sulfate, aluminum hydroxide, aluminum oxide, boehmite and mixtures thereof,
where preferably the one or at least one of the plurality of inorganic pigments K5) is calcium carbonate;
and or - the one or more inorganic pigments K5) are present in a total amount in the range from ≧9 to ≦50 percent by mass, preferably from ≧10 to ≦40 percent by mass, based on the dry mass of the heat-sensitive recording layer. Heat-sensitive recording layer according to any one of the preceding claims, wherein - the one or at least one of the several lubricants K6) is selected from the group consisting of - salts of fatty acids having a total number of carbon atoms ranging from 14 to 20 with mono- or divalent metal cations; - Paraffin waxes, preferably with a melting or softening point in the range from 45°C to 80°C and - their mixtures; and or - the one or more lubricants K6) are present in a total amount in the range from ≧1.5 to ≦10 percent by mass, preferably from ≧2 to ≦8 percent by mass, particularly preferably from ≧2 to ≦6 percent by mass, based on the dry mass of the heat-sensitive recording layer. Coating composition for producing a heat-sensitive recording layer, comprising components K1) to K6) and preferably component K7) as defined in any one of claims 1 to 9
and preferably additionally comprising
K8) one or more carrier liquids, preferably selected from the group consisting of (i) water, (ii) monohydric alcohols having a total number of carbon atoms in the range from 1 to 4 and (iii) mixtures of water with one or more monohydric alcohols with a Total number of carbon atoms ranging from 1 to 4. Heat-sensitive recording material, preferably thermal paper, comprising or consisting of - a substrate, preferably a paper substrate, preferably having a front side and a back side opposite the front side
and - a heat-sensitive recording layer according to any one of claims 1 to 9, which is arranged on at least one of the sides of the substrate. Heat-sensitive recording material according to claim 11, wherein - the heat-sensitive recording material has one or more intermediate layers arranged between the substrate and the heat-sensitive recording layer;
and or - the area-related dry mass of the heat-sensitive recording layer in the range from ≥ 1.8 g/m ² to ≤ 2.5 g/m ² , preferably in the range from ≥ 2.0 g/m ² to ≤ 2.4 g/m ² , more preferably in the range from ≧2.0 g/m ² to ≦2.3 g/m ² and particularly preferably in the range from ≧2.0 g/m ² to ≦2.2 g/m ² ;
and or - the substrate is a paper substrate and the paper substrate contains a proportion of ≥ 80% by mass of recycled fibers, based on the total mass of the air-dried paper substrate;
and or - the substrate is a paper substrate and the paper substrate contains ≤ 25 percent by mass of fresh fibers, based on the total mass of the air-dried paper substrate. Use of a heat-sensitive recording layer according to any one of claims 1 to 9 for the production of a heat-sensitive recording material, preferably for the production of a heat-sensitive recording material according to any one of claims 10 to 12. Process for the production of a heat-sensitive recording material, preferably for the production of a heat-sensitive recording material according to one of claims 10 to 12, at least comprising the steps: V1) producing or providing a coating composition according to claim 10,
where preferably - no organic color developers containing phenol groups are used, preferably no organic color developers containing phenol groups, which are selected from the group consisting of bisphenol A, bisphenol S, bisphenol AP, 4-[(4-isopropoxyphenyl)sulfonyl]phenol, 4,4 '-methylenediphenol, 2,2'-methylenediphenol, 4-[4'-[(1'-methylethyloxy)phenyl]sulfonyl]phenol, 2,2'-diallyl-4,4'-sulfonyldiphenol, 4-4'-methylenebis (oxyethylenethio)diphenol and mixtures thereof;
and or - no organic sensitizers are used, preferably no organic sensitizers are used which are selected from the group consisting of 1,2-bis(3-methylphenoxy)ethane, 1,2-diphenoxyethane, 1-phenoxy-2-(4-methylphenoxy). ) ethane, benzyl 2-naphthyl ether, 2-(2H-benzotriazol-2-yl)-p-cresol, 2,2'-bis(4-methoxyphenoxy)diethyl ether, 4,4'-diallyloxydiphenyl sulfone, 4-acetylacetophenone, 4 -Benzylbiphenyl, Acetoacetic anilide, Benzyl 4-(benzyloxy)benzoate, Benzylparaben, Bis(4-chlorobenzyl)o-xalate ester, Bis(4-methoxyphenyl)ether, Dibenzyl oxalate, Dibenzyl terephthalate, dimethyl terephthalate, dimethyl sulfone, diphenyl adipate, diphenyl sulfone, p-benzylbiphenyl, phenylbenzenesulfonate esters, α,α'-diphenoxyxylene and mixtures thereof;
and or - No organic hollow body pigments are used. V2) producing or providing a substrate, preferably a paper substrate, preferably having a front side and a back side opposite the front side, V3) Application of the coating composition from step V1) to at least one side of the substrate, or to at least one side of an intermediate layer arranged on the substrate
preferably using a coating device, wherein preferably the coating device is selected from the group consisting of knife coater, knife coater, curtain coater and air knife; V4) Preferably drying the coating composition applied in step V3) to form a heat-sensitive recording layer. Use of a heat-sensitive recording material according to one of Claims 10 to 12 as a plane, train, ship or bus ticket, gambling receipt, parking ticket, label, till receipt, self-adhesive label, medical chart paper, fax paper and/or barcode label.