EP3775374B1 - Wrapping paper with use indicator for aerosol generating articles - Google Patents

Description

FIELD OF THE INVENTION

The invention relates to an aerosol generating article in which the aerosol generating material is heated to release an aerosol but the aerosol generating material is not combusted. The aerosol-generating article comprises a wrapping paper to which a substance is applied over the entire surface or in partial areas, which causes a change in the optical properties of the wrapping material and thus indicates that the aerosol-generating article has been used. In particular, the wrapping paper of the aerosol-generating article according to the invention is designed in such a way that its color changes irreversibly, at least in some areas, when it is heated, with special consideration being given to the fact that the air permeability of the wrapping material is little impaired. The invention also relates to a method for producing such a wrapping paper.

BACKGROUND AND PRIOR ART

Aerosol generating articles are known in the art which comprise an aerosol generating material and a paper encasing the aerosol generating material to form a typically cylindrical rod. The aerosol-generating material is a material that releases an aerosol when exposed to heat, the aerosol-generating material only being heated but not burned. In many cases, the aerosol-generating article also includes a filter capable of filtering components of the aerosol, which is wrapped by a filter wrapping paper and another wrapping paper connecting the filter and the wrapped rod of aerosol-generating material.

In the intended use of an aerosol-generating article, it is common for the aerosol-generating material to be heated but not burned. This heating can be done, for example, by an external device into which the aerosol-generating article is inserted, or by a heat source attached to one end of the aerosol-generating article, which is activated to use the article, for example by lighting it. In many cases, there are several aerosol generating articles in a package and often, after use, the used aerosol generating article is returned to the package with the unused aerosol generating articles. However, since the aerosol-generating material is only heated and not burned, the used aerosol-generating article differs from the unused aerosol-generating article optically not or only very little. In any case, the consumer cannot quickly decide which of the aerosol generating articles are used and which are not yet used.

WO 2014/202319 A1 discloses a cigarette paper which contains at least one burnt salt whose concentration c(x) varies along a direction x of the cigarette paper. For the location-dependent concentration c(x) on an interval of length L, the following applies to all x from the interval [o, L]: f ( x ) - Δ c ≤ c ( x ) ≤ f ( x ) + Δ c. In this case, 3 cm≦L≦11 cm, f(x) is a function which is monotonic over the interval [o,L] but not constant over the entire interval, and Δ c ≦1% by weight, preferably ≦0.7% by weight. %, particularly preferably ≦0.5% by weight, very particularly preferably ≦0.3% by weight and particularly preferably ≦0.15% by weight and Δc >0% by weight, based in each case on the mass of the cigarette paper.

WO 2014/037073 A1 discloses a cigarette paper to which is applied a composition in the form of a pattern having a Tamura coarseness of at most 0.22 mm, preferably at most 0.20 mm. The absolute difference in whiteness according to ISO 2470-1 between a surface of the cigarette paper to which the composition is applied over the entire surface and a surface of the cigarette paper to which the composition is not applied is at least 25% in the dried state of the composition, preferably at least 35% and more preferably at least 40%, and at most 60%, preferably at most 55%. Furthermore, the opacity according to ISO 2471 of a surface of the cigarette paper to which this composition is applied over the entire surface is higher in the dried state of the composition than the opacity of a surface to which this composition is not applied.

SUMMARY OF THE INVENTION

The invention is based on the object of providing a wrapping paper for an aerosol-generating article which optically changes irreversibly during or shortly after use of the aerosol-generating article, so that the aerosol-generating article can be easily recognized as being used. Aerosol-generating articles within the meaning of this invention are rod-shaped articles that comprise an aerosol-generating material and a wrapping paper that encloses the aerosol-generating material, with the aerosol-generating material only being heated and not burned when used as intended. In any case, typical aerosol-generating materials are heated without combustion if the aerosol-generating material is heated to a maximum temperature of 400°C.

This object is achieved by a wrapping paper for an aerosol generating article according to claim 1, an aerosol generating article comprising this wrapping paper according to claim 2 and a method for producing a wrapping paper according to claim 10 according to the invention. Advantageous developments are specified in the dependent claims.

The inventors have found that this problem can be solved by a wrapping paper to which a specific composition is applied over the entire surface or in partial areas, which causes an irreversible color change in the wrapping paper when heated by accelerating the thermal degradation of the cellulose in the wrapping paper. This color change can be used to tell a used aerosol generating article from an unused one with the naked eye.

It should be noted that thermochromic inks which show a color change when heated above a certain temperature are already known in the prior art, but are deliberately not used in the present invention. One reason for this is that the color change of thermochromic inks is often reversible, disappearing as the aerosol generating article cools. In contrast to this, the degradation of the cellulose in the wrapping paper according to the invention is in fact irreversible and thus allows reliable identification of the used aerosol-generating article, even if it has been used for a long time. In addition, the temperature at which the color change occurs in known thermochromic colors is comparatively low, so that storing the unused aerosol-generating article at a higher temperature, for example in a parked vehicle in summer, can also cause a color change, so that an unused article could be mistaken for a used one. In addition, when the aerosol-generating article is heated, temperatures of up to 400°C are reached for several minutes, and at such temperatures thermochromic colors can already partially thermally degrade so that they lose their function.

Furthermore, depending on the construction of the aerosol generating article, air should flow through the wrapping paper into the aerosol generating material during use. However, a thermochromic ink applied to the wrapping paper can significantly reduce the air permeability of the wrapping paper, which is why it is often not possible to apply a sufficient amount of such inks to the wrapping paper without impairing the function of the article.

Finally, the substances that can be used for wrapping papers for aerosol generating articles are severely restricted by legal regulations in many countries, so that thermochromic inks, even if they could be used from a technical point of view, often cannot be used.

A particular inventive effect of the invention, deviating from the behavior known from thermochromic paints, is that the applied substance does not change its color itself, but causes a color change in the cellulose in the wrapping paper.

The wrapping paper must comprise pulp fibers, with the pulp fibers being present in the wrapping paper in an amount of at least 50% by mass of the wrapping paper. This amount of pulp fibers is at least necessary to make the color change clearly visible.

The wrapping paper has an average air permeability of at least 0 cm ³ /(cm ² .min.kPa) and at most 200 cm ³ /(cm ² .min.kPa). The air permeability is measured according to ISO 2965:2009 using a measuring head with an opening area of 2 mm × 15 mm, with the mean air permeability being determined from ten measurements at randomly selected positions on the wrapping paper.

The composition applied to the wrapping paper must contain at least one substance that accelerates the thermal degradation of the cellulose to bring about the color change and a binder to bind said substance on or in the paper fix. The substance that accelerates the thermal degradation of cellulose is suitable for causing an irreversible color change in the wrapping paper that is visible to the naked eye when the wrapping paper is heated to a temperature of at least 130 °C for 5 minutes due to the thermal degradation of cellulose in the paper.

When the wrapping paper has an air permeability of more than 10 cm ³ /(cm ² .min.kPa), it is important that the air can flow evenly over the surface of the wrapping paper, so that large areas of low air permeability are avoided. Such areas of low air permeability can result from the application of the composition.

Adequate air permeability is ensured according to the invention in that the composition is applied only to partial areas of the wrapping paper, the partial areas covering at least 0.5% and at most 70% of the area of the wrapping paper. This limits the extent of the total area over which the air permeability is affected, but also ensures that the area is large enough for the color change to be clearly visible.

In addition, the homogeneity of the air permeability is ensured according to the invention in that the sub-areas are designed in a suitable manner and arranged on the wrapping paper, the suitable design or arrangement of these sub-areas for the purposes of the invention being assessed on the basis of two criteria, of which at least one must be fulfilled. According to the first criterion, if the mean air permeability of the wrapping paper is at least 10 cm ³ /(cm ² min kPa) and at most 20 cm ³ /(cm ² min kPa), the standard deviation of the air permeability should be at most 6 cm ³ / (cm ² ·min·kPa) and shall be, when the average air permeability of the wrapping paper is at least 20 cm ³ /(cm ² ·min·kPa) and at most 200 cm ³ /(cm ² ·min·kPa), the coefficient of variation of air permeability must not exceed 30%.

To determine the standard deviation and the coefficient of variation of the air permeability, a measuring head with an opening area of 2 mm × 15 mm is used and the standard deviation and the coefficient of variation are determined from ten measurements on areas that are close together but do not overlap, so that the mean value and the standard deviation are formed an area of about 300 mm ² is used. The coefficient of variation is then the quotient of the standard deviation and the mean and is expressed as a percentage. The average used in this calculation is not generally consistent with the average air permeability described above correspond, which is determined from measurements on ten randomly selected positions.

berechnet wird und D_max = 12 mm und Dmin = 6 mm betragen.As an alternative or in addition to specifying the scattering parameters of the air permeability, it is also sufficient according to a second criterion if, with an average air permeability of at least 10 cm ³ /(cm ² min kPa) and at most 200 cm ³ /(cm ² min kPa ) the partial areas in which the composition is applied to the wrapping paper are designed in such a way that each imaginary circle with a diameter of D mm on the wrapping paper contains at least one area in which the composition is not applied, the diameter of the circle being D in mm from the mean air permeability x in cm ³ /(cm ² min kPa). $$D=D_{\mathit{Max}}-\frac{\left(D_{\mathit{Max}}-D_{\mathit{at\; least}}\right)\cdot \left(x-10\right)}{190}$$

is calculated and D _max = 12 mm and D min = 6 mm.

The effect of this formula is that when the average air permeability is low, for example 10 cm ³ /(cm ² ·min·kPa), the circle can have a relatively large diameter of 12 mm and the partial areas can therefore have coarser structures. This is possible because at low air permeability the influence of the sub-areas to which the substance is applied is less significant. With high air permeability, for example 200 cm ³ /(cm ² min kPa), the circle may only have a relatively small diameter of 6 mm and the partial areas must therefore have a finer structure so that the air continues to flow homogeneously through the surface of the wrapping paper .

• das Zellstofffasern umfasst, wobei mindestens 50% der Masse des Umhüllungspapiers durch Zellstofffasern gebildet werden,
• das eine mittlere Luftdurchlässigkeit von mindestens 0 cm³/(cm²·min·kPa) und höchstens 200 cm³/(cm²·min·kPa) aufweist, gemessen mit einem Messkopf mit 2 mm × 15 mm nach ISO 2965:2009 an zehn zufällig ausgewählten Positionen,
• auf das eine Zusammensetzung aufgetragen ist, die eine den thermischen Abbau von Zellulose beschleunigende Substanz und ein Bindemittel umfasst, und

wobei für den Fall, dass die mittlere Luftdurchlässigkeit des Umhüllungspapiers 10 cm³/(cm²·min·kPa) oder mehr beträgt, die besagte Zusammensetzung lediglich in Teilbereichen aufgetragen ist, die mindestens 0,5% und höchstens 70% der Fläche des Umhüllungspapiers überdecken,
und wobei die genannten Teilbereiche in diesem Fall, d. h. wenn die mittlere Luftdurchlässigkeit des Umhüllungspapiers mindestens 10 cm³/(cm²·min·kPa) beträgt, so auf dem Umhüllungspapier angeordnet sind, dass mindestens eines der beiden folgenden Kriterien (1), (2) erfüllt ist:

1. (1) wenn die mittlere Luftdurchlässigkeit des Umhüllungspapiers mindestens 10 cm³/(cm²·min·kPa) und höchstens 20 cm³/(cm²·min·kPa) beträgt, dann beträgt die Standardabweichung der Luftdurchlässigkeit höchstens 6 cm³/(cm²·min·kPa) und wenn die mittlere Luftdurchlässigkeit des Umhüllungspapiers mindestens 20 cm³/(cm²·min·kPa) und höchstens 200 cm³/(cm²·min·kPa) beträgt, dann beträgt der Variationskoeffizient der Luftdurchlässigkeit höchstens 30%, oder
2. (2) die Teilbereiche, auf die die Zusammensetzung aufgetragen ist, sind so gestaltet, dass jeder gedachte Kreis mit einem Durchmesser von D mm auf dem Umhüllungspapier mindestens einen Bereich enthält, in dem die Zusammensetzung nicht aufgetragen ist, wobei der Durchmesser D in mm aus der mittleren Luftdurchlässigkeit x in cm³/(cm²·min·kPa) durch $$D=D_{\mathit{max}}-\frac{\left(D_{\mathit{max}}-D_{\mathit{min}}\right)\cdot \left(x-10\right)}{190}$$
   
   berechnet wird, wobei D_max = 12 mm und Dmin = 6 mm betragen.

In summary, the inventors have invented a wrapping paper for aerosol generating articles,

• which comprises cellulose fibers, with at least 50% of the mass of the wrapping paper being formed by cellulose fibers,
• which has an average air permeability of at least 0 cm ³ /(cm ² min kPa) and not more than 200 cm ³ /(cm ² min kPa), measured with a 2 mm × 15 mm measuring head according to ISO 2965:2009 ten randomly selected positions,
• to which is applied a composition comprising a substance accelerating the thermal degradation of cellulose and a binder, and

in the event that the average air permeability of the wrapping paper is 10 cm ³ /(cm ² min kPa) or more, said composition is applied only in partial areas covering at least 0.5% and at most 70% of the area of the wrapping paper cover,
and wherein in this case, ie if the average air permeability of the wrapping paper is at least 10 cm ³ /(cm ² min kPa), the said partial areas are arranged on the wrapping paper in such a way that at least one of the two following criteria (1), ( 2) is fulfilled:

1. (1) if the mean air permeability of the wrapping paper is at least 10 cm ³ /(cm ² min kPa) and at most 20 cm ³ /(cm ² min kPa), then the standard deviation of the air permeability is at most 6 cm ³ /( cm ² min kPa) and if the average air permeability of the wrapping paper is at least 20 cm ³ /(cm ² min kPa) and at most 200 cm ³ /(cm ² min kPa), then the coefficient of variation of the air permeability is at most 30%, or
2. (2) the portions to which the composition is applied are designed such that each imaginary circle of diameter D mm on the wrapping paper contains at least one area where the composition is not applied, the diameter D being in mm the average air permeability x in cm ³ /(cm ² min kPa). $$D=D_{\mathit{Max}}-\frac{\left(D_{\mathit{Max}}-D_{\mathit{at\; least}}\right)\cdot \left(x-10\right)}{190}$$
   
   is calculated, where D _max = 12 mm and D min = 6 mm.

The mean air permeability x is determined as the mean value of ten measurements at randomly selected positions on the wrapping paper. The individual measurement is carried out according to ISO 2965:2009 using a measuring head with an aperture area of 2 mm × 15 mm. Thus, the measurement ignores the fact that the aperture area typically can simultaneously include areas to which the composition is applied and areas to which it is not applied.

For the determination of the standard deviation and the coefficient of variation of the air permeability, ten measurements are also carried out according to ISO 2965:2009 with a measuring head with an opening area of 2 mm × 15 mm, but the measurements are carried out on areas that are close to each other but not overlapping, so that the formation of the mean and the standard deviation, an area of about 300 mm ² is used. The coefficient of variation is then the quotient of the standard deviation and the mean of the measured values determined in this way and is expressed as a percentage. The individual measuring surfaces are preferably arranged in such a way that their longer side, ie the 15 mm long side, is adjacent to one another or is parallel to one another at a small distance, preferably at most 2 mm.

Typical wrapping papers not according to the invention for aerosol-generating articles with a naturally homogeneous air permeability over the entire surface have a coefficient of variation measured in this way of at most 15%. On the other hand, wrapping papers with a composition applied to larger areas can achieve coefficients of variation in air permeability of 50% to 80%. This applies in particular when the composition is film-forming and thus closes the pores of the wrapping paper or the composition is applied in the form of bands several mm wide.

The wrapping paper preferably has a basis weight of at least 15 g/m ² , particularly preferably at least 18 g/m ² and very particularly preferably at least 20 g/m ² . Such a basis weight gives the wrapping paper a tensile strength which is favorable for the further processing of the wrapping paper into an aerosol-generating article.

The wrapping paper preferably has a basis weight of at most 100 g/m ² , particularly preferably at most 60 g/m ² and very particularly preferably at most 45 g/m ² . The basis weight of the wrapping paper is preferably not so high that restoring forces can make it difficult to wrap the aerosol generating material in the manufacture of the aerosol generating article.

The basis weight of the wrapping paper includes the applied composition and can be measured according to ISO 536:2012.

The wrapping paper contains pulp fibres, the pulp fibers making up at least 50% of the mass of the wrapping paper and preferably at least 60% of the mass of the wrapping paper and more preferably at least 65% of the mass of the wrapping paper. The cellulose fibers are necessary so that the effect of the substance that accelerates the thermal degradation of the cellulose can also be easily recognized visually by means of the color change.

The pulp fibers are derived from one or more plants selected from the group consisting of conifers, deciduous trees, spruce, pine, fir, beech, birch, eucalyptus, flax, hemp, jute, ramie, abaca, sisal, kenaf and cotton. The cellulose fibers can also be fibers made from regenerated cellulose, such as Tencel ^™ fibers, Lyocell ^™ fibers, viscose fibers or Modal ^™ fibers, in whole or in part.

Preferably, the pulp fibers are at least partially bleached because the white color of the bleached pulp fibers makes the color change more readily apparent. The proportion of unbleached Pulp fibers, which usually have a light brown to dark brown color, should preferably make up at most 50% of the mass of the pulp fibers.

The wrapping paper according to the invention can also contain one or more fillers. The total amount of fillers is preferably at most 40%, particularly preferably at least 10% and at most 38% and very particularly preferably at least 20% and at most 35% of the mass of the wrapping paper. The proportion of fillers can favorably influence the air permeability, color and opacity of the wrapping paper, so that a color change when the aerosol-generating article made from it is heated becomes more easily recognizable.

The filler or fillers are preferably white, water-insoluble particles and can particularly preferably be selected from the group consisting of calcium carbonate, magnesium carbonate, magnesium oxide, magnesium hydroxide, aluminum hydroxide, talc, kaolin and titanium dioxide.

The wrapping paper can also contain other substances that are necessary for the production of the wrapping paper or that give the wrapping paper other special properties. Such substances can be, for example, pigments, dyes, sizing agents, starch, retention aids or processing aids, and the type and amount can be selected by the person skilled in the art on the basis of his experience.

Outside of the areas to which the composition has been applied, the wrapping paper preferably does not contain any substances that accelerate the degradation of the cellulose, or only in an amount that is 0.5% by weight of the wrapping paper, more preferably 0.25% by weight of the wrapping paper and most preferably not exceeding 0.1% of the mass of the wrapping paper per area. Higher levels of these substances would make the color change of the wrapping paper more difficult to see compared to the areas where said composition was applied.

A composition comprising a binder and a substance that accelerates the thermal degradation of cellulose is applied over the entire surface or in partial areas of the wrapping paper.

The amount of binder applied to portions of the wrapping paper should be rather small because the binder reduces air permeability and increases the coefficient of variation of air permeability. The amount of binder applied in partial areas of the wrapping paper is therefore preferably at most 15%, particularly preferably at most 10% and most preferably at most 5% of the mass of the wrapping paper per area.

The binder is preferably selected from the group consisting of starch, starch derivatives, cellulose derivatives, carboxymethyl cellulose, alginates, pectins, polyvinyl alcohol, guar and gum arabic or mixtures thereof.

The substance accelerating the thermal degradation of cellulose is particular in the areas of the wrapping paper where the composition containing it is applied, in an amount of at least 0.2 g/m ² and at most 8.0 g/m ² preferably at least 0.3 g/m ² and at most 7.0 g/m ² and very particularly preferably at least 0.5 g/m ² and at most 5.0 g/m ² . The amount of the substance that accelerates the thermal degradation of cellulose is selected here in such a way that a color change can be seen particularly well, especially with the naked eye even under poor lighting conditions.

Alternatively and preferably, the amount of substance applied, which accelerates the thermal degradation of the cellulose, can also be characterized in relation to the amount of cellulose fibers contained in the wrapping paper. This proportion is important because, according to the invention, the substance is intended to act on the pulp fibers. The ratio of the amount of said substance in g/m ² based on the area on which the composition containing it is applied and the amount of cellulose fibers in the wrapping paper in g/m ² is preferably at least 0.05 and at most 0.45 , more preferably at least 0.06 and at most 0.30 and most preferably at least 0.07 and at most 0.25. The most favorable ratio in each case will depend on the specific substance that accelerates the thermal degradation of the cellulose.

The substance that accelerates the thermal degradation of cellulose is one or more of the chemical compounds selected from the group consisting of citrates, malates, tartrates, acetates, nitrates, succinates, fumarates, gluconates, glycolates, lactates, oxylates, salicylates, α- Hydroxycaprylates, bicarbonates, carbonates, chlorides, polyphosphates, phosphonates and phosphates and particularly preferably one or more of the chemical compounds selected from the group consisting of trisodium citrate, tripotassium citrate, monoammonium phosphate, sodium acetate, potassium acetate, sodium bicarbonate, potassium bicarbonate, sodium carbonate, potassium carbonate, sodium tartrate, potassium sodium tartrate, Potassium formate, sodium formate, sodium nitrate and potassium nitrate. The substance is very particularly preferably one or more of the chemical compounds selected from the group consisting of tripotassium citrate, monoammonium phosphate, sodium bicarbonate, sodium acetate and potassium carbonate. The very particularly preferred chemical compounds bring about a particularly marked change in the color of the cellulose, since they promote the formation of char particularly well.

If the average air permeability of the wrapping paper is at least 10 cm ³ /(cm ² ·min·kPa) and at most 200 cm ³ /(cm ² ·min·kPa), then the portions where said composition is applied are so designed that they account for at least 0.5% and at most 70%, preferably at least 1% and at most 60%, particularly preferably at least 1% and at most 20% and very particularly preferably at least 1% and at most 10% of the surface of the wrapping paper.

• (3) wenn die mittlere Luftdurchlässigkeit des Umhüllungspapiers größer als 10 cm³/(cm²·min·kPa) und kleiner als 20 cm³/(cm²·min·kPa) ist, dann beträgt die Standardabweichung der Luftdurchlässigkeit höchstens 6 cm³/(cm²·min·kPa), bevorzugt höchstens 5,5 cm³/(cm²·min·kPa) und besonders bevorzugt höchstens 5 cm³/(cm²·min·kPa) und wenn die mittlere Luftdurchlässigkeit des Umhüllungspapiers mindestens 20 cm³/(cm²·min·kPa) und höchstens 200 cm³/(cm²·min·kPa) beträgt, dann beträgt der Variationskoeffizient der Luftdurchlässigkeit höchstens 30%, bevorzugt höchstens 27,5% und besonders bevorzugt höchstens 25%, oder
• (4) die Teilbereiche, auf die die Zusammensetzung aufgetragen ist, sind so gestaltet, dass jeder gedachte Kreis mit einem Durchmesser von D mm auf dem Umhüllungspapier mindestens einen Bereich enthält, in dem die Zusammensetzung nicht aufgetragen ist, wobei der Durchmesser D in mm aus der mittleren Luftdurchlässigkeit x in cm³/(cm²·min·kPa) durch $$D=D_{\mathit{max}}-\frac{\left(D_{\mathit{max}}-D_{\mathit{min}}\right)\cdot \left(x-10\right)}{190}$$
  
  berechnet wird und wobei D_max = 12 mm und D_min = 6 mm, bevorzugt D_max = 10 mm und D_min = 5 mm und besonders bevorzugt D_max = 8 mm und D_min = 4 mm und ganz besonders bevorzugt D_max = 6 mm und D_min = 3 mm betragen.

If the mean air permeability of the wrapping paper is at least 10 cm ³ /(cm ² min kPa) and at most 200 cm ³ /(cm ² min kPa), then the partitions shall also be designed so that at least one of the following two Criteria (3), (4) are met:

• (3) if the mean air permeability of the wrapping paper is more than 10 cm ³ /(cm ² min kPa) and less than 20 cm ³ /(cm ² min kPa), then the standard deviation of the air permeability is at most 6 cm ³ /(cm ² min kPa), preferably at most 5.5 cm ³ /(cm ² min kPa) and more preferably at most 5 cm ³ /(cm ² min kPa) and when the average air permeability of the wrapping paper is at least 20 cm ³ /(cm ² min kPa) and at most 200 cm ³ /(cm ² min kPa), then the coefficient of variation of the air permeability is at most 30%, preferably at most 27.5% and more preferably at most 25% , or
• (4) the portions to which the composition is applied are designed such that each imaginary circle of diameter D mm on the wrapping paper contains at least one area where the composition is not applied, the diameter D being in mm the average air permeability x in cm ³ /(cm ² min kPa). $$D=D_{\mathit{Max}}-\frac{\left(D_{\mathit{Max}}-D_{\mathit{at\; least}}\right)\cdot \left(x-10\right)}{190}$$
  
  is calculated and where D _max = 12 mm and D _min = 6 mm, preferably D _max = 10 mm and D _min = 5 mm and more preferably D _max = 8 mm and D _min = 4 mm and most preferably D _max = 6 mm and D _min = 3 mm.

If the average air permeability of the wrapping paper is at least 0 cm ³ /(cm ² ·min·kPa) and at most 10 cm ³ /(cm ² ·min ·kPa), the composition can be applied over the entire surface or in partial areas. When ordering in partial areas the partial areas in which the composition is applied to the wrapping paper are preferably designed in such a way that each imaginary circle with a diameter of 12 mm, particularly preferably with a diameter of 10 mm and very particularly preferably with a diameter of 8 mm on the wrapping paper is at least contains an area where the composition is not applied.

If the average air permeability of the wrapping paper is at least 0 cm ³ /(cm ² min kPa) and at most 10 cm ³ /(cm ² min kPa) and the composition is applied only in partial areas, then the partial areas in which said composition is applied in such a way that it is preferably at least 0.5% and at most 70%, more preferably at least 1% and at most 60%, most preferably at least 1% and at most 20% and in particular at least 1% and at most 10 % of the area of the wrapping paper.

The smaller the area to which the composition is applied, the less the air permeability of the wrapping paper is affected in its mean value and its coefficient of variation, but on the other hand it also makes the individual sub-areas where the color change is visible smaller and thus becomes more difficult to detect that the aerosol generating article made from it has already been used.

The criteria (3) and (4) are not equivalent in their effect, which means that the fulfillment of one criterion does not necessarily entail the fulfillment of the other, but each is sufficient in itself to obtain a wrapping paper according to the invention, which works well on aerosol generating articles. The same applies to criteria (1) and (2) mentioned above.

The aerosol-generating article according to the invention is rod-shaped and comprises an aerosol-generating material and the wrapping paper according to the invention, the wrapping paper encasing the aerosol-generating material and the aerosol-generating material being only heated but not burned when the aerosol-generating article is used as intended.

In a preferred embodiment of the aerosol generating article, the aerosol generating material is heated to a maximum temperature of at least 120°C and at most 500°C and more preferably to a maximum temperature of at least 200°C and at most 400°C.

In a preferred embodiment, the aerosol-generating article additionally contains a filter.

• A - Bereitstellen eines Umhüllungsbasispapiers,
• B - Auftragen einer Zusammensetzung auf das Umhüllungsbasispapier, und
• C - Trocknen des in Schritt B erhaltenen Umhüllungspapiers, wobei
• das nach Schritt C erhaltene Umhüllungspapier Zellstofffasern umfasst, wobei mindestens 50% der Masse des Umhüllungspapiers durch Zellstofffasern gebildet werden, und
• das nach Schritt C erhaltene Umhüllungspapier eine mittlere Luftdurchlässigkeit von mindestens 0 cm³/(cm²·min·kPa) und höchstens 200 cm³/(cm²·min·kPa) aufweist, gemessen mit einem Messkopf mit 2 mm × 15 mm nach ISO 2965:2009, und
• in Schritt B eine Zusammensetzung aufgetragen wird, die eine den thermischen Abbau von Zellulose beschleunigende Substanz und ein Bindemittel umfasst, und die, wenn die mittlere Luftdurchlässigkeit des in Schritt C erhaltenen Umhüllungspapiers mindestens 10 cm³/(cm²·min·kPa) und höchstens 200 cm³/(cm²·min·kPa) beträgt, in Schritt B in Teilbereichen aufgetragen wird, die mindestens 0,5% und höchstens 70% der Fläche des Umhüllungspapiers überdecken,
• und wobei das in Schritt C erhaltene Umhüllungspapier, wenn die mittlere Luftdurchlässigkeit des in Schritt C erhaltenen Umhüllungspapiers mindestens 10 cm³/(cm²·min·kPa) und
• höchstens 200 cm³/(cm²·min·kPa) beträgt, mindestens eines der beiden folgenden Kriterien (1), (2) erfüllt:
  1. (1) wenn die mittlere Luftdurchlässigkeit des in Schritt C erhaltenen Umhüllungspapiers mindestens 10 cm³/(cm²·min·kPa) und höchstens 20 cm³/(cm²·min·kPa) beträgt, dann beträgt die Standardabweichung der Luftdurchlässigkeit höchstens 6 cm³/(cm²·min·kPa) und wenn die mittlere Luftdurchlässigkeit des in Schritt C erhaltenen Umhüllungspapiers mindestens 20 cm³/(cm²·min·kPa) und höchstens 200 cm³/(cm²·min·kPa) beträgt, dann beträgt der Variationskoeffizient der Luftdurchlässigkeit höchstens 30%, oder
  2. (2) die Teilbereiche, auf die in Schritt B die Zusammensetzung aufgetragen wird, sind so gestaltet, dass jeder gedachte Kreis mit einem Durchmesser von D mm auf dem Umhüllungspapier mindestens einen Bereich enthält, in dem die Zusammensetzung nicht aufgetragen wird, wobei der Durchmesser D in mm aus der mittleren Luftdurchlässigkeit x in cm³/(cm²·min·kPa) des nach Schritt C erhaltenen Umhüllungspapiers durch $$D=D_{\mathit{max}}-\frac{\left(D_{\mathit{max}}-D_{\mathit{min}}\right)\cdot \left(x-10\right)}{190}$$
     
     berechnet wird und D_max = 12 mm und D_min = 6 mm betragen.

The wrapping paper according to the invention can be produced by a method according to the invention, which comprises the following steps AC:

• A - providing a wrapper base paper,
• B - applying a composition to the wrapping base paper, and
• C - drying the wrapping paper obtained in step B, wherein
• the wrapping paper obtained after step C comprises cellulose fibres, with at least 50% of the mass of the wrapping paper being constituted by cellulose fibres, and
• the wrapping paper obtained after step C has an average air permeability of at least 0 cm ³ /(cm ² min kPa) and at most 200 cm ³ /(cm ² min kPa), measured with a 2 mm × 15 mm measuring head ISO 2965:2009, and
• in step B a composition is applied which comprises a substance accelerating the thermal degradation of cellulose and a binder, and which, if the average air permeability of the wrapping paper obtained in step C is at least 10 cm ³ /(cm ² min kPa) and at most 200 cm ³ /(cm ² min kPa), is applied in step B in partial areas that cover at least 0.5% and at most 70% of the surface of the wrapping paper,
• and wherein the wrapping paper obtained in step C, when the average air permeability of the wrapping paper obtained in step C is at least 10 cm ³ /(cm ² ·min·kPa) and
• is at most 200 cm ³ /(cm ² min kPa), meets at least one of the following two criteria (1), (2):
  1. (1) if the mean air permeability of the wrapping paper obtained in step C is at least 10 cm ³ /(cm ² min kPa) and at most 20 cm ³ /(cm ² min kPa), then the standard deviation of the air permeability is at most 6 cm ³ /(cm ² min kPa) and when the average air permeability of the wrapping paper obtained in step C is at least 20 cm ³ /(cm ² min kPa) and at most 200 cm ³ /(cm ² min kPa). , then the coefficient of variation of air permeability is at most 30%, or
  2. (2) the sub-areas to which the composition is applied in step B are designed such that each imaginary circle of diameter D mm on the wrapping paper contains at least one area where the composition is not applied, the diameter being D in mm from the mean air permeability x in cm ³ /(cm ² .min.kPa) of the wrapping paper obtained after step C $$D=D_{\mathit{Max}}-\frac{\left(D_{\mathit{Max}}-D_{\mathit{at\; least}}\right)\cdot \left(x-10\right)}{190}$$
     
     is calculated and D _max = 12 mm and D _min = 6 mm.

With regard to the properties and components of the wrapping paper obtained after step C, the same necessary, preferred, particularly preferred and very particularly preferred value ranges and properties apply as have already been mentioned for the wrapping paper according to the invention. This applies in particular to the basis weight, the standard deviation and the coefficient of variation of the air permeability, the type and amount of the pulp fibers, the type and amount of the fillers and the design of the sub-areas in which the composition is applied, for example with regard to their proportion of the total area of the wrapping paper and the choice of the parameters D _max and D _min .

The composition applied in step B comprises a substance accelerating the thermal degradation of cellulose, a binder and a solvent, the solvent preferably being water.

The substance in the composition of step B that accelerates the thermal degradation of cellulose is a chemical compound or a mixture of two or more chemical compounds, and preferentially dissolves in the solvent of the composition.

The substance contained in the composition of step B, which accelerates the thermal degradation of the cellulose, is preferably one or more of the chemical compounds selected from the group consisting of citrates, malates, tartrates, acetates, nitrates, succinates, fumarates, gluconates, glycolates, Lactates, oxylates, salicylates, α-hydroxycaprylates, bicarbonates, carbonates, chlorides, polyphosphates, phosphonates and phosphates and particularly preferably one or more of the chemical compounds selected from the group consisting of trisodium citrate, tripotassium citrate, monoammonium phosphate, sodium acetate, potassium acetate, sodium bicarbonate, potassium bicarbonate, Sodium carbonate, potassium carbonate, sodium tartrate, potassium sodium tartrate, potassium formate, sodium formate, sodium nitrate and potassium nitrate. The substance is very particularly preferably one or more of the chemical compounds selected from the group consisting of tripotassium citrate, monoammonium phosphate, sodium bicarbonate, sodium acetate and potassium carbonate.

The composition applied to the wrapping base paper in step B contains the substance that accelerates the thermal degradation of cellulose in an amount of preferably at least 3% and at most 30%, more preferably at least 4% and at most 25% and very particularly preferably at least 5% and at most 20%, in each case based on the mass of the composition.

The binder in the composition of step B is preferably selected from the group consisting of starch, starch derivatives, cellulose derivatives, carboxymethyl cellulose, alginates, pectins, polyvinyl alcohol, guar and gum arabic or mixtures thereof.

The composition applied to the wrapping base paper in step B contains the binder in an amount of preferably at least 0.1% and at most 15%, more preferably at least 0.3% and at most 12% and most preferably at least 0.5% % and at most 10%, in each case based on the amount of the composition. The amount of binder also depends on the requirements of the application process in step B, in particular with regard to the viscosity of the composition.

On drying in step C, the solvent is largely removed from the composition and the dried composition applied is then in an amount of preferably at least 0.2 g/m ² and at most 8 g/m ² , more preferably at least 0.5 g/m ² and at most 6 g/m ² and most preferably at least 1 g/m ² and at most 5 g/m ² applied based on the area to which the composition was actually applied.

The application in step B can be carried out by various methods, with printing and spraying being preferred and gravure printing or flexographic printing being very particularly preferred.

The drying process in step C can be accomplished by a variety of methods, preferably exposure to one or more heated cylinders, exposure to hot air, infrared radiation, microwave radiation, and combinations thereof.

In a particularly preferred embodiment of the method according to the invention, after step C it also comprises the additional steps D and E, wherein in step D water is applied over the entire surface of the wrapping paper obtained in step C and in step E the wrapping paper from step D is dried, very particularly preferably by contact with one or more heated cylinders. When applying the composition in step B, especially when the solvent contains water, wrinkles may appear after drying in step C. Steps D and E of this particularly preferred embodiment of the method according to the invention allow such creases to be significantly reduced or avoided altogether.

BRIEF DESCRIPTION OF THE FIGURE

1

shows an example of a wrapping paper and the positions where the ten measurements to determine the standard deviation and the coefficient of variation of the air permeability can be made.

DESCRIPTION OF THE PREFERRED EMBODIMENT

Some preferred embodiments of wrapping papers according to the invention are described below.

As the wrapping base paper in step A of the method of the present invention, two papers referred to as wrapping base paper A and wrapping base paper B were used.

Covering base paper A had a basis weight of 29 g/m ² and contained 69% wood pulp fibers and 31% precipitated calcium carbonate as a filler. The percentages relate here to the mass of the wrapping base paper. The wood pulp fibers were a mixture of pulp fibers derived from conifers and deciduous trees. Casing base paper A had an average air permeability of 60.1 CU, where the air permeability was measured according to ISO 2965:2009 with a measuring head having an aperture area of 2 mm × 15 mm at ten randomly selected positions and an average value was calculated from these ten measurements.

Casing base paper B had a basis weight of 24 g/m ² and contained 71% wood pulp fibers and 29% precipitated calcium carbonate as a filler. The percentages relate here to the mass of the wrapping base paper. The wood pulp fibers were a mixture of pulp fibers derived from conifers and deciduous trees. Coverstock base paper B had an average air permeability of 74.8 CU, where the air permeability was measured according to ISO 2965:2009 with a probe having an aperture area of 2 mm × 15 mm at ten randomly selected positions and an average value was calculated from these ten measurements.

On the wrapping base papers A and B, various compositions were applied in portions in the form of a pattern of intersecting 1.5 mm wide lines by gravure printing so that the portions to which the composition was applied accounted for about 40% of the area of the wrapping base paper.

The amount of the composition applied in the partial areas was 30 g/m ² for wrapping base paper A and 25 g/m ² for wrapping base paper B based on the area to which the composition was actually applied.

Thereafter, the wrapping papers were dried according to step C of the method according to the invention.

The parameters of the wrapping papers relevant to the production are given in Table 1. The column "No." indicates the wrapping paper number, the "BP" column indicates which wrapping base paper was used for manufacture. Under the "Composition" column are the binder and the substance that accelerates the thermal degradation of the cellulose in % based on the mass of the composition. The type of binder is indicated, where "CMC" means carboxymethyl cellulose and "St" means starch. The nature of the substance is also indicated, with "TKZ" meaning tripotassium citrate, "MAP" meaning monoammonium phosphate, "NaAc" meaning sodium acetate and "KCrb" meaning potassium carbonate. Under the "wrapping paper" column are the amounts of binder and the substance accelerating the thermal degradation of cellulose in g/m ² and in % based on the basis weight of the wrapping paper, as well as the ratio "V" of the amount of said substance in g/ m ² to the amount of cellulose fibers in the wrapping paper in g/m ² . composition wrapping paper binder substance binder substance V No. bp % kind % kind gsm ² % gsm ² % 1 A 0.71 CMC 5.0 TKZ 0.21 0.69 1.50 4.88 0.07 2 A 0.68 CMC 8.7 TKZ 0.20 0.64 2.61 8.20 0.13 3 A 0.70 CMC 10.0 TKZ 0.21 0.65 3.00 9:31 0.15 4 A 0.65 CMC 12.0 TKZ 0.20 0.59 3.60 10.98 0.18 5 A 0.63 CMC 14.8 TKZ 0.19 0.56 4.44 13.20 0.22 6 A 0.71 CMC 5.0 MAP 0.21 0.69 1.50 4.88 0.07 7 A 0.68 CMC 8.7 MAP 0.20 0.64 2.61 8.20 0.13 8th A 0.70 CMC 10.0 MAP 0.21 0.65 3.00 9:31 0.15 9 A 0.65 CMC 12.0 MAP 0.20 0.59 3.60 10.98 0.18 10 A 0.63 CMC 14.8 MAP 0.19 0.56 4.44 13.20 0.22 11 A 0.70 CMC 5.0 NaAc 0.21 0.68 1.50 4.88 0.07 12 A 0.70 CMC 10.0 NaAc 0.21 0.65 3.00 9:31 0.15 13 B 0.75 CMC 10.0 crb 0.19 0.70 2.50 9.37 0.15 14 B 0.75 CMC 25.0 crb 0.19 0.62 6.25 20.53 0.37 15 B 0.70 CMC 30.0 crb 0.18 0.55 7.50 23.68 0.44 16 B 5.00 st 8.0 crb 1.25 4.59 2.00 7.34 0.12 17 B 5.00 st 25.0 crb 1.25 3.97 6.25 19.84 0.37 18 B 5.00 CMC 25.0 crb 1.25 3.97 6.25 19.84 0.37

As for the wrapper base papers A and B, the air permeability was measured at ten random positions according to ISO 2965:2009 with a measuring head having an opening area of 2 mm × 15 mm, and the mean value was calculated therefrom. For the wrapping papers 1 to 12, which were made from the wrapping base paper A, the average air permeability was between 42 cm ³ /(cm ² · min · kPa) and 48 cm ³ /(cm ² · min · kPa), while the average Air permeability for the wrapping papers 13 to 18 made of the wrapping base paper B was between 50 cm ³ /(cm ² ·min·kPa) and 55 cm ³ /(cm ² ·min·kPa).

To test criteria (1) or (3), the coefficient of variation of air permeability was determined according to ISO 2965:2009 using a measuring head with an opening area of 2 mm × 15 mm. The measurement method is based on 1 explained. On the wrapping paper 1 in figure 1 The composition is plotted in the form of crossing lines 2 and the measuring head with an opening area of 2 mm × 15 mm was placed on ten adjacent positions 3a to 3j, with each position being offset by 3 mm so that there is a gap between the surfaces was of 1 mm. Air permeability was measured at each of positions 3a to 3j. From this, the mean and the standard deviation were determined and the coefficient of variation was calculated. For the wrapping papers 1 to 12, which were made from the wrapping base paper A, the coefficients of variation were between 10% and 15%, and for the wrapping papers 13 to 18, which were made from the wrapping base paper B, the coefficients of variation were between 12% and 17%. whereby criteria (1) and (3) are met.

To test criteria (2) and (4), the diameter of the imaginary circle was determined for each of the wrapping papers 1 to 18 on the basis of the measured average air permeability.

bis $$D=12-\frac{\left(12-6\right)\cdot \left(48-10\right)}{190}=\mathrm{10,8}\mathit{mm}.$$

For the wrapping papers 1 to 12, which were made from the wrapping base paper A, a diameter based on an average air permeability of 42 cm ³ /(cm ² ·min·kPa) to 48 cm ³ /(cm ² ·min·kPa) resulted of the circle of $$D=12-\frac{\left(12-6\right)\cdot \left(42-10\right)}{190}=11.0\mathit{mm}$$

until $$D=12-\frac{\left(12-6\right)\cdot \left(48-10\right)}{190}=10.8\mathit{mm}.$$

bis $$D=12-\frac{\left(12-6\right)\cdot \left(55-10\right)}{190}=\mathrm{10,6}\mathit{mm}.$$

The wrapping papers 13 to 18 made from the wrapping base paper B were found to have a diameter of 50 cc/(cm ² .min.kPa) to 55 ^cc /(cm ² .min.kPa ⁾ based on an average air permeability of the circle of $$D=12-\frac{\left(12-6\right)\cdot \left(50-10\right)}{190}=10.7\mathit{mm}$$

until $$D=12-\frac{\left(12-6\right)\cdot \left(55-10\right)}{190}=10.6\mathit{mm}.$$

The pattern with 1.5 mm wide crossing lines apparently meets the requirements of criteria (2) and (4) and thus these criteria are met for all wrapping papers 1-18.

The wrapping papers 1 to 18 were heated at 130°C for 5 minutes. Color changes on the wrapping papers 1, 3, 6, 8, 11, 12, 13 and 17 were discernible after just one minute. After 5 minutes, all the wrapping papers according to the invention showed a clear, irreversible color change to yellowish shades in the areas in which the composition was applied, and to light brown to dark brown shades with prolonged heating, which clearly differs from the color that has not changed or has hardly changed outside of this Sub-areas could be distinguished.

According to the state of the art, aerosol-generating articles were produced from the wrapping papers, which were heated up in a heater as intended. After removing the aerosol-generating articles from the heater, a clear color change was also observed in the printed areas, so that used and unused aerosol-generating articles could be clearly distinguished from one another.

Claims (15)

1. Wrapping paper for aerosol-generating articles, which comprises pulp fibers, wherein at least 50% of the mass of the wrapping paper is formed by pulp fibers,

   which has a mean air permeability of at least 10 cm³/(cm²·min·kPa) and at most 200 cm³/(cm²·min·kPa), measured with a 2 mm × 15 mm measuring head in accordance with ISO 2965:2009 at ten randomly selected positions,

   and to which a composition is applied which comprises a substance accelerating the thermal decomposition of cellulose and a binder, wherein the substance accelerating the thermal decomposition of cellulose is capable of causing an irreversible color change of the wrapping paper due to the thermal decomposition of cellulose in the paper which is discernible by the naked eye upon heating the wrapping paper to a temperature of at least 130°C for 5 min,

   wherein said composition is only applied in sections which cover at least 0.5% and at most 70% of the surface of the wrapping paper,

   wherein the substance accelerating the thermal decomposition of cellulose is present in an amount of at least 0.2 g/m² and at most 8 g/m² in those areas of the wrapping paper, in which said composition containing said substance is applied,

   wherein the substance accelerating the thermal decomposition of cellulose is one or more of the chemical compounds selected from the group consisting of citrates, malates, tartrates, acetates, nitrates, succinates, fumarates, gluconates, glycolates, lactates, oxylates, salicylates, α-hydroxy caprylates, hydrogen carbonates, carbonates, chlorides, polyphosphates, phosphonates and phosphates

   and wherein said sections are in this case arranged on the wrapping paper such that furthermore, at least one of the following criteria (1), (2) is fulfilled:

   (1) if the mean air permeability of the wrapping paper is at most 20 cm³/(cm²·min·kPa), then the standard deviation of the air permeability is at most 6 cm³/(cm²·min·kPa), wherein the standard deviation is determined from ten measurements with said 2 mm × 15 mm measuring head on non-overlapping areas located close to each other, and
   if the mean air permeability of the wrapping paper is at least 20 cm³/(cm²·min·kPa) and at most 200 cm³/(cm²·min·kPa), then the coefficient of variation of the air permeability is at most 30%, wherein the coefficient of variation is defined as the quotient of said standard deviation and the mean value of the ten measurements from which the standard deviation is determined,

   (2) the sections to which the composition is applied are shaped such that each imaginary circle with a diameter of D mm on the wrapping paper contains at least one area to which the composition has not been applied, wherein the diameter D in mm is calculated from the mean air permeability x in cm³/(cm²·min·kPa) by $$D=D_{\mathit{max}}-\frac{\left(D_{\mathit{max}}-D_{\mathit{min}}\right)\cdot \left(x-10\right)}{190}$$

   

   wherein D_max = 12 mm and D_min = 6 mm, wherein the mean air permeability x corresponds to said mean value from ten measurements at randomly selected positions on the wrapping paper.
2. Rod-shaped, aerosol-generating article which comprises an aerosol-generating material and a wrapping paper, wherein the wrapping paper wraps the aerosol-generating material and wherein during the intended use of the aerosol-generating article, the aerosol-generating material is only heated, but not burnt, wherein the wrapping paper either has a

   mean air permeability of at least o cm³/(cm²·min·kPa) and less than 10 cm³/(cm²·min·kPa), measured with a 2 mm × 15 mm measuring head in accordance with ISO 2965:2009 at ten randomly selected positions,

   wherein said wrapping paper comprises pulp fibers,

   wherein at least 50% of the mass of the wrapping paper is formed by pulp fibers,

   and to which a composition is applied which comprises a substance accelerating the thermal decomposition of cellulose and a binder, wherein the substance accelerating the thermal decomposition of cellulose is capable of causing an irreversible color change of the wrapping paper due to the thermal decomposition of cellulose in the paper which is discernible by the naked eye upon heating the wrapping paper to a temperature of at least 130°C for 5 min,

   wherein the substance accelerating the thermal decomposition of cellulose is present in an amount of at least 0.2 g/m² and at most 8 g/m² in those areas of the wrapping paper, in which said composition containing said substance is applied,

   wherein the substance accelerating the thermal decomposition of cellulose is one or more of the chemical compounds selected from the group consisting of citrates, malates, tartrates, acetates, nitrates, succinates, fumarates, gluconates, glycolates, lactates, oxylates, salicylates, α-hydroxy caprylates, hydrogen carbonates, carbonates, chlorides, polyphosphates, phosphonates and phosphates

   or is a wrapping paper according to claim 1.
3. Wrapping paper according to claim 1, or rod-shaped, aerosol-generating article according to claim 2, wherein the wrapping paper has a basis weight of at least 15 g/m², preferably of at least 18 g/m² and particularly preferably of at least 20 g/m², and/or which has a basis weight of at most 100 g/m², preferably of at most 60 g/m² and particularly preferably of at most 45 g/m².
4. Wrapping paper according to claim 1 or 3, or rod-shaped, aerosol-generating article according to claim 2 or 3, wherein the wrapping paper, in which the pulp fibers of the wrapping paper make up at least 60% of the mass of the wrapping paper and preferably at least 65% of the mass of the wrapping paper, wherein
   the pulp fibers are preferably sourced from one or more plants selected from the group consisting of coniferous trees, deciduous trees, spruce, pine, fir, beech, birch, eucalyptus, flax, hemp, jute, ramie, abaca, sisal, kenaf and cotton, and/or wherein at least a portion of the pulp fibers is bleached, wherein the proportion of unbleached pulp fibers, if present, is preferably at most 50% of the mass of the pulp fibers.
5. Wrapping paper according to one of claims 1 or 3 to 4, or rod-shaped, aerosol-generating article according to one of claims 2 to 4, wherein the wrapping paper contains one or more fillers, wherein the total amount of filler makes up at most 40%, preferably at least 10% and at most 38% and particularly preferably at least 20% and at most 35% of the mass of the wrapping paper, wherein
   the fillers are preferably formed by white, water-insoluble particles and are preferably selected from the group consisting of calcium carbonate, magnesium carbonate, magnesium oxide, magnesium hydroxide, aluminum hydroxide, talc, kaolin, titanium dioxide.
6. Wrapping paper according to one of claims 1 or 3 to 5, or rod-shaped, aerosol-generating article according to one of claims 2 to 5, wherein the wrapping paper does not contain substances accelerating the decomposition of the cellulose outside the sections to which the composition has been applied, or solely in an amount which does not exceed 0.5% of the mass of the wrapping paper, preferably 0.25% of the mass of the wrapping paper and particularly preferably 0.1% of the mass of the wrapping paper per unit area, and/or

   wherein the amount of binder which is applied in sections of the wrapping paper is at most 15%, preferably at most 10% and particularly preferably at most 5% of the mass of the wrapping paper per unit area, and/or

   in which the binder is selected from the group consisting of starch, starch derivatives, cellulose derivatives, carboxy methyl cellulose, alginates, pectins, polyvinyl alcohol, guar, gum Arabic or mixtures thereof.
7. Wrapping paper according to one of claims 1 or 3 to 6, or rod-shaped, aerosol-generating article according to one of claims 2 to 6, wherein the substance accelerating the thermal decomposition of cellulose is contained in the areas of the wrapping paper to which the composition containing has been applied in an amount of at least 0.3 g/m² and at most 7.0 g/m² and preferably of at least 0.5 g/m² and at most 5.0 g/m², and/or in which the ratio of the amount of the substance accelerating the thermal decomposition of cellulose in g/m² with respect to the area to which the composition containing it has been applied and the amount of pulp fibers in the wrapping paper in g/m² is at least 0.05 and at most 0.45, preferably at least 0.06 and at most 0.30 and particularly preferably at least 0.07 and at most 0.25, and/or
   wherein the substance accelerating the thermal decomposition of cellulose is one or more of the chemical compounds selected from the group consisting of trisodium citrate, tripotassium citrate, monoammonium phosphate, sodium acetate, potassium acetate, sodium hydrogen carbonate, potassium hydrogen carbonate, sodium carbonate, potassium carbonate, sodium tartrate, potassium sodium tartrate, potassium formate, sodium formate, sodium nitrate and potassium nitrate, wherein the substance is particularly preferably one or more of the chemical compounds selected from the group consisting of tripotassium citrate, monoammonium phosphate, sodium hydrogen carbonate, sodium acetate and potassium carbonate.
8. Wrapping paper according to claim 1 or one of claims 3 to 7, or rod-shaped, aerosol-generating article according to one of claims 2 to 7, wherein, in the case in which the mean air permeability of the wrapping paper is at least 10 cm³/(cm²·min·kPa) and at most 200 cm³/(cm²·min·kPa), the sections to which said composition is applied are shaped such that they make up at least 1% and at most 60%, preferably at least 1% and at most 20% and particularly preferably at least 1% and at most 10% of the surface of the wrapping paper, and/or wherein
   in the case in which the mean air permeability of the wrapping paper is at least 10 cm³/(cm²·min·kPa) and at most 200 cm³/(cm²·min·kPa), the sections are shaped such that at least one of the following two criteria (3), (4) is fulfilled:

   (3) if the mean air permeability of the wrapping paper is greater than 10 cm³/(cm²·min·kPa) and less than 20 cm³/(cm²·min·kPa), then the standard deviation of the air permeability is at most 5.5 cm³/(cm²·min·kPa), and preferably at most 5 cm³/(cm²·min·kPa), and if the mean air permeability of the wrapping paper is at least 20 cm³/(cm²·min·kPa) and at most 200 cm³/(cm²·min·kPa), then the coefficient of variation of the air permeability is 27.5% and preferably at most 25%, or

   (4) the sections to which the composition is applied are shaped such that each imaginary circle with a diameter of D mm on the wrapping paper contains at least one area to which the composition is not applied, wherein the diameter D in mm is calculated from the mean air permeability x in cm³/(cm²·min·kPa) by $$D=D_{\mathit{max}}-\frac{\left(D_{\mathit{max}}-D_{\mathit{min}}\right)\cdot \left(x-10\right)}{190}$$

   

   and wherein D_max = 10 mm and D_min = 6 mm, preferably D_max = 8 mm and D_min = 4 mm, particularly preferably D_max = 6 mm and D_min = 3 mm.
9. A rod-shaped material according to claims 2 to 7, in which, in the case in which the mean air permeability of the wrapping paper is at least o cm³/(cm²·min·kPa) and at most 10 cm³/(cm²·min·kPa), the composition is applied to the entire surface or in sections, wherein, in the case of an application in sections, the sections to which the composition is applied to the wrapping paper are preferably shaped such that each imaginary circle with a diameter of 12 mm, preferably with a diameter of 10 mm and particularly preferably with a diameter of 8 mm on the wrapping paper contains at least one area to which the composition has not been applied, and/or

   in the case in which the mean air permeability of the wrapping paper is at least o cm³/(cm²·min·kPa) and at most 10 cm³/(cm²·min·kPa) and the composition is only applied in sections, the sections to which said composition is applied are shaped such that they preferably make up at least 0.5% and at most 70%, preferably at least 1% and at most 60%, particularly preferably at least 1% and at most 20% and in particular at least 1% and at most 10% of the surface of the wrapping paper, and/or

   in which during the intended use, the aerosol-generating material is heated to a maximum temperature of at least 120°C and at most 500°C and preferably to a maximum temperature of at least 200°C and at most 400°C, and/or which contains a filter.
10. Process for manufacturing a wrapping paper for aerosol-generating articles, comprising the steps A to C:

    A - providing a base wrapping paper,

    B - applying a composition to the base wrapping paper, and

    C - drying the wrapping paper obtained in step B, wherein

    the wrapping paper obtained after step C comprises pulp fibers, wherein at least 50% of the mass of the wrapping paper is formed by pulp fibers, and the wrapping paper obtained after step C has a mean air permeability of at least 10 cm³/(cm²·min·kPa) and

    at most 200 cm³/(cm²·min·kPa), measured with a 2 mm × 15 mm measuring head in accordance with ISO 2965:2009, and

    in step B, a composition is applied which comprises a substance accelerating the thermal decomposition of cellulose and a binder, wherein the substance accelerating the thermal decomposition of cellulose is capable of causing an irreversible color change of the wrapping paper due to the thermal decomposition of cellulose in the paper which is discernible by the naked eye upon heating the wrapping paper to a temperature of at least 130°C for 5 min,

    wherein the substance accelerating the thermal decomposition of cellulose is one or more of the chemical compounds selected from the group consisting of citrates, malates, tartrates, acetates, nitrates, succinates, fumarates, gluconates, glycolates, lactates, oxylates, salicylates, α-hydroxy caprylates, hydrogen carbonates, carbonates, chlorides, polyphosphates, phosphonates and phosphates,

    wherein the composition is applied only in sections which cover at least 0.5% and at most 70% of the surface of the wrapping paper,

    wherein in which during drying in step C, a solvent is substantially removed from the composition and the applied dried composition is afterwards present in an amount of at least 0.2 g/m² and at most 8 g/m², respectively with respect to the area to which the composition was actually applied,

    and wherein the wrapping paper obtained in step C fulfills at least one of the following criteria (1), (2):

    (1) if the mean air permeability of the wrapping paper obtained in step C is at least 10 cm³/(cm²·min·kPa) and at most 20 cm³/(cm²·min·kPa), then the standard deviation of the air permeability is at most 6 cm³/(cm²·min·kPa); and
    if the mean air permeability of the wrapping paper obtained in step C is at least 20 cm³/(cm²·min·kPa) and at most 200 cm³/(cm²·min·kPa), then the coefficient of variation of the air permeability is at most 30%, or

    (2) the sections to which the composition is applied in step B are shaped such that every imaginary circle with a diameter of D mm on the wrapping paper contains at least one area to which the composition is not applied, wherein the diameter D in mm is calculated from the mean air permeability x in cm³/(cm²·min·kPa) of the wrapping paper obtained after step C by $$D=D_{\mathit{max}}-\frac{\left(D_{\mathit{max}}-D_{\mathit{min}}\right)\cdot \left(x-10\right)}{190}$$

    

    and wherein D_max = 12 mm and D_min = 6 mm.
11. Process according to claim 10, in which the composition applied in step B comprises a substance accelerating the thermal decomposition of cellulose, a binder and a solvent, wherein the solvent is preferably water.
    wherein the substance accelerating the thermal decomposition of cellulose in the composition of step B preferably is a chemical compound or a mixture of two or more chemical compounds and dissolves in the solvent of the composition.
12. Process according to claim 10 or 11, in which the substance accelerating the thermal decomposition of cellulose contained in the composition of step B is one or more of the chemical compounds selected from the group consisting of trisodium citrate, tripotassium citrate, monoammonium phosphate, sodium acetate, potassium acetate, sodium hydrogen carbonate, potassium hydrogen carbonate, sodium carbonate, potassium carbonate, sodium tartrate, potassium sodium tartrate, potassium formate, sodium formate, sodium nitrate and potassium nitrate, wherein the substance is particularly preferably one or more of the chemical compounds selected from the group consisting of tripotassium citrate, monoammonium phosphate, sodium hydrogen carbonate, sodium acetate and potassium carbonate, and/or
    in which the composition which is applied to the base wrapping paper in step B contains the substance accelerating the thermal decomposition of cellulose in an amount of at least 3% and at most 30%, preferably at least 4% and at most 25% and particularly preferably at least 5% and at most 20%, respectively with respect to the mass of the composition.
13. Process according to one of claims 10 to 12, in which the binder in the composition of step B is selected from the group consisting of starch, starch derivatives, cellulose derivatives, carboxy methyl cellulose, alginates, pectins, polyvinyl alcohol, guar, gum Arabic or mixtures thereof.
14. Process according to one of claims 10 to 13, in which the composition which is applied to the wrapping paper in step B contains the binder in an amount of at least 0.1% and at most 15%, preferably at least 0.3% and at most 12% and particularly preferably at least 0.5% and at most 10%, each with respect to the amount of composition, and/or
    in which during drying in step C, a solvent is substantially removed from the composition and the applied dried composition is afterwards present in an amount of at least 0.5 g/m² and at most 6 g/m² and preferably at least 1 g/m² and at most 5 g/m², respectively with respect to the area to which the composition was actually applied.
15. Process according to one of claims 10 to 14, in which the application of the composition in step B is carried out by printing or spraying, preferably by rotogravure printing or flexographic printing,

    and/or in which the drying process in step C is carried out by contact with one or more heated cylinders, by contact with hot air, by infra-red radiation, microwave radiation or combinations thereof,

    and/or in which the process comprises further additional steps D and E following step C, wherein in step D, water is applied to the entire surface of the wrapping paper obtained in step C and in step E, the wrapping paper from step D is dried, preferably by contact with one or more heated cylinders.

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