DE102016118587A1 - Packaging paper and process for its production - Google Patents

Abstract

The invention relates to a packaging paper with barrier properties, in particular against oily and greasy materials, prepared from a base paper with a basis weight between 15 g / m2 and 500 g / m2 and a porosity greater than 150 Gurley-s according to ISO 5636/5: 2013, with a Pulp mix of long fibers and short fibers, an ash content according to DIN 54370: 2007 less than 15% and one auxiliary. The invention is characterized in that the paper has on at least one surface a barrier layer which comprises at least one modified starch, a platelet-shaped pigment having an aspect ratio greater than 1:20, preferably greater than 1:40, in particular 1: 80, and a surface-hydrophobing agent is formed.

Description

The present invention relates to a packaging paper with increased barrier properties against oily and greasy materials and a method for its preparation.

Packaging papers having increased barrier properties against oily and greasy materials are known in the art. Since papers are inherently more porous, water, grease and oil impermeable, they must be provided with special measures for these barrier properties.

The required increased barrier property in the prior art is achieved either by extremely high milling of the fibers; grinding degrees of 90 ° SR (Schopper-Riegler) and more are chosen. This measure proves, however, because of the required high grinding energy, as expensive. Or the barrier property is achieved by applying a barrier coating using fluorocarbons. However, fluorocarbons are considered harmful to the environment as they have a long life and can hardly be degraded biologically.

Starting from this prior art, it is an object of the present invention, at least partially overcome or to improve the disadvantages of the prior art.

The object is achieved with a device according to claim 1 and an inventive method according to claim 16. Preferred embodiments and modifications are the subject of the dependent claims.

A packaging paper according to the invention is produced from a base paper having a basis weight of between 15 g / m ² and 500 g / m ² and a porosity greater than 150 gurley-s ISO 5636/5: 2013 , This shows a pulp mix of long fibers and short fibers, an ash content after DIN 54370: 2007 of less than 15% and a resource on.

The paper has on at least one surface a barrier layer which comprises at least one modified starch and a platelet-shaped pigment having an aspect ratio of greater than 1:20, preferably greater than 1:40, in particular 1:80, and a surface-hydrophobicizing agent is formed. The proportion of the platelet-shaped pigment in the line formulation is between 5% and 50%.

By aspect ratio is meant a ratio between the diameter and the thickness of the platelet-shaped pigment, according to the equation aspect ratio = ((D ₁ + D ₂ ) / 2) / d (Eq. 1)

D _{1 is} the thickness in the x-direction, D ₂ the thickness in the x-direction and d the thickness in the z-direction of the platelet-shaped pigment.

For the production of a packaging paper according to the invention can be selected from a wide range of raw papers. Thus, base paper with a basis weight between 15 g / m ² and 500 g / m ² can be used. Of course, for the selection of the base paper plays a significant role, for which applications the packaging paper produced according to the invention is determined.

According to the invention, a sufficiently strong, dense and less porous base paper is required. Its porosity should be greater than 150 Gurley-s after ISO 5636/5: 2013 , For this purpose, a pulp mix is used which on the one hand has a certain proportion of short fibers for closing the pores for the tightness; especially suitable are pulp fibers of eucalyptus, beech or birch or combinations thereof. For the formation of the suitable strength properties, a certain proportion of long fibers is used; especially pulp fibers from pine and spruce are suitable for this purpose. Preferably at low basis weights while a higher proportion of long fibers is used.

Furthermore, the base paper detects an ash content DIN 54370: 2007 less than 15% to achieve a certain degree of whiteness and to contribute to a balance of strength and density appropriate to the application.

A packaging paper according to the invention has a barrier layer ("bar") on at least one surface. The coating weight per surface is between 0.5 and 5 g / m ² . This layer is formed from a dispersion of modified starch and a platelet-shaped pigment pigments. In addition, depending on the desired modification, a surface-hydrophobing agent is added to the coating liquor (coating agent).

The pigment is added to the coating liquor in order to seal the pores present on the paper surface due to its geometrical, platelet-shaped form and to prevent penetration, in particular too low binder migration, of the remaining liquor constituents into the paper. The modified thickness of the coating liquor is in the form of nano-starch particles which are applied to the paper web when painted and to the pigments during drying connect. This forms a stable, pore-occlusive and very dense film on the at least one paper surface. This film, in combination with the special base paper, creates an extremely effective barrier against various liquids, especially oils, greases, solvents and water.

• • Der sog. "KIT-Test", nach TAPPI T 559 cm – 12 (TAPPI: Technical Association of the Pulp and Paper Industry) ;
• • DIN Fettdurchlässigkeitstest, nach DIN 53116 – 2003 ;
• • sog. "TAPPI-Terpentintest", nach TAPPI T 454 om – 15 ;
• • Test mit Hühnchen-Öl, sog. "Heiß-Öl-Test", nach einer firmeninternen Testmethode der Firma Drewsen, Stand 2016;
• • sog. "Nutella-Test", nach einer firmeninternen Testmethode der Firma Drewsen, Stand 2016.

The barrier is so well designed and effective that very high barrier values are achieved in all food packaging and barrier tests known and used in the paper industry. It is a considerable advantage of the paper according to the invention that very high barrier values are achieved throughout, ie in all the test methods carried out. A variety of tests were performed to measure and optimize the barrier effect. These tests include, for example, the following test procedures, which are based on market and / or customer requirements:

• • The so-called "KIT-Test", after TAPPI T 559 cm - 12 (TAPPI: Technical Association of the Pulp and Paper Industry) ;
• • DIN grease permeability test, after DIN 53116 - 2003 ;
• • so-called "TAPPI-turpentine test", according to TAPPI T 454 om - 15 ;
• • Test with chicken oil, so-called "hot oil test", according to an in-house test method of Drewsen, as of 2016;
• • so-called "Nutella test", according to a company-internal test method of Drewsen, as of 2016.

• • Brat-Öl in einem Becherglas mit Rührer auf ca. 50 °C erhitzen. Dabei kann als Brat-Öl handelsübliches Speiseöl – wie z.B. Sonnenblumenöl – verwendet werden, das frisch eine Viskosität von 18 bis 22 mPa·s, insbesondere 20 mPa·s bei 20° C aufweist.
• • 50 ml Öl abmessen (mittels eines Messzylinders).
• • Papiertuch in die Kunststoff-/Prüfschale legen. Zu untersuchendes, fettdichtes Papier ("Prüfling") auf Papiertuch legen.
• • Schwamm auf Prüfling legen und die abgemessene Ölmenge von 50 ml über den Schwamm langsam ausgießen.
• • Weiteren Prüfling auf den Schwamm legen und mit einer Metallplatte und einem 1 kg-Gewicht beschweren.
• • Öl-durchtränkten Schwamm 20 min einwirken lassen, danach Gewicht und Metallplatte entfernen.
• • Oberen und unteren Prüfling mit ölbenetzter Seite nach oben ablegen und überschüssiges Öl abwischen.
• • Beide Prüflinge visuell beurteilen, in Aufsicht und Durchsicht: – Bei guter oder hoher Öl-/Fettdichtigkeit sind keine oder nur wenige kleine (< 2 mm²) Öl-Durchschläge feststellbar. – Bei geringer Öl-/Fettdichtigkeit ist die Prüfzeit stufenweise zu verringern und die Zeit zu bestimmen, bei der noch keine Öldurchschläge erkennbar sind. Vorzugsweise werden, in Anlehnung an die Öl-Fettdichtigkeitsprüfung nach DIN, folgende zeitliche Abstände gewählt: 20 min, 10 min, 5 min, 1 min.

The so-called "hot oil test" has the following steps:

• • Heat the frying oil in a beaker with a stirrer to approx. 50 ° C. It can be used as frying oil commercial edible oil - such as sunflower oil - fresh has a viscosity of 18 to 22 mPa · s, in particular 20 mPa · s at 20 ° C.
• • Measure out 50 ml of oil (using a measuring cylinder).
• • Place the paper towel in the plastic / test tray. Place the greaseproof paper ("test piece") to be examined on paper towel.
• • Place the sponge on the sample and slowly pour out the measured amount of 50 ml over the sponge.
• • Place another test piece on the sponge and weigh it down with a metal plate and a 1 kg weight.
• • Leave oil-saturated sponge to act for 20 minutes, then remove weight and metal plate.
• • Place upper and lower test specimen with oil-wetted side up and wipe off excess oil.
• • Visually inspect both specimens, in supervision and inspection: - With good or high oil / grease tightness, no or only a few small (<2 mm ² ) oil punctures can be detected. - In the case of low oil / grease tightness, the test time should be gradually reduced and the time during which no oil punctures are discernible should be determined. Preferably, based on the oil-grease test according to DIN, the following time intervals are selected: 20 min, 10 min, 5 min, 1 min.

• • Weißes DIN A4-Blatt als Unterlage auf Tischplatte legen.
• • DIN A4-Muster des zu prüfenden Papiers darüberlegen.
• • Eine Fläche von ca. 5 × 5 cm mit einer Nuss-Nougat-Creme, beispielsweise der Marke Nutella, gut abdeckend bestreichen; der Aufstrich muss die Prüffläche vollständig bedecken.
• • Prüfling in festen Zeitabständen hochheben und Unterlage kontrollieren, ob Nutella- und/oder Fettdurchschläge erkennbar sind.
• • Visuelle Beurteilung der Durchschläge, in Aufsicht und Durchsicht: – Bei guter/hoher Öl-/Fettdichtigkeit sind keine oder nur einzelne, kleine (< 2 mm²)Öl-/Fett-Durchschläge feststellbar. – Bei geringer Öl-/Fettdichtigkeit sind großflächige Durchschläge zu erkennen. In diesem Fall ist die Prüfzeit anzugeben, bei der noch keine Durchschläge zu erkennen sind. Vorzugsweise werden folgende zeitliche Abstände gewählt: 10 min, 30 min, 60 min, 4 h, 24 h.

The so-called "Nutella test" has the following steps:

• • Place a white A4 sheet on the table top as a support.
• • Overlay A4 size pattern of the paper to be tested.
• • Cover an area of approx. 5 × 5 cm with a nut-nougat cream, such as the Nutella brand, covering well; the spread must completely cover the test area.
• • Lift the test specimen at fixed intervals and check the pad to see if it shows any grooving and / or grease punctures.
• • Visual assessment of punctures, in supervision and review: - With good / high oil / grease impermeability, no or only individual, small (<2 mm ² ) oil / grease punctures can be detected. - With low oil / grease tightness large-scale punctures can be seen. In this case, the test time must be indicated, at which no punctures are yet to be recognized. Preferably, the following time intervals are selected: 10 min, 30 min, 60 min, 4 h, 24 h.

For the above tests, the top and the screen side of the papers must be checked.

The mentioned tests were carried out with very good results. Furthermore, as a rule of thumb, the higher the coating weight of the coating, the higher the barrier effect.

This means that papers according to the invention are suitable for a very wide range of applications, wherever a barrier effect against natural or synthetic fats, oils and solvents or water or mixtures of these substances is required. Examples are vegetable fats, chocolate fats, animal fats such as chicken fats, but also greases, etc. Here, depending on the desired application, it can be selected from low to very high density.

Another advantage is that this excellent barrier effect against the substances mentioned using natural and biodegradable and recyclable auxiliaries, in particular without the use of fluorocarbons and / or synthetic binders is achieved.

Furthermore, according to a particularly preferred embodiment, the base paper has wet strength agents to ensure a certain wet strength during manufacture. Wet strength agents need to develop a firmer (preferably covalent) bond to the fibers that can not be displaced by water molecules. The wet strength agents used are usually polymers or polyfunctional compounds having reactive groups which react with the OH groups of the pulp fibers only under the drying conditions, thereby bridging a plurality of fibers with one another.

In one embodiment, the modified starch is a modified corn starch, in particular as the starch with the trade name biolatex ^®, manufactured by the company Ecosynthetix.

This has the advantage that - u.a. because of the appropriate ionization - when drying a very good connection with the pigments is achieved, resulting in a high density of the paper.

In one embodiment, the hydrophobing agent is an anionic surface sizing agent.

For example, anionic polymers find use, e.g. modified copolymers of styrene and maleic anhydride, copolymers of methacrylate and acrylate monomers, copolymers of styrene with acrylate / methacrylate monomers, polyurethane dispersions or copolymers and graft polymers of acrylonitrile.

In one embodiment, the pulp mix has a proportion between 0 to 70% long fibers and 30 to 100% short fibers, preferably a proportion between 10 to 60% long fibers and 40 to 90% short fibers and in particular a proportion of 50% long fibers and 50% short fibers on.

This has - depending on the application - the advantage that a balanced and requirement-specific ratio between strength and density is achieved for a paper according to the invention. For example, in the case of a paper according to the invention, with a grammage of 40 g / m ² , values for the wet breaking force are greater than or equal to 4.0 and 2.5 N / 15 mm and for the porosity values greater than 180 gurley. s achieved.

In one embodiment, the long fiber pulp is a spruce and / or pine sulphate pulp and the short fiber pulp is a eucalyptus, beech and / or birch sulphate pulp. Experiments showed that the combination of these substances in a paper according to the invention lead to very good results.

In one embodiment, the ash content is less than 15%, preferably less than 5% and in particular between 0% and 5%.

This has the advantage that said ash content contributes in a meaningful way to the tightness, but still does not lead to any limitation in the strength of the paper according to the invention.

In one embodiment, the weight per unit area of the base paper is preferably between 18 g / m ² and 400 g / m ² , in particular between 20 g / m ² and 300 g / m ² , preferably between 22 g / m ² and 250 g / m ² preferably between 25 g / m ² and 160 g / m ² , and in particular it is about 40 g / m ² . The basis weight of the selected base paper depends mainly on the required use.

In one embodiment, the at least one adjuvant is selected from a group comprising conditioning agents for pulp, cationic resin dispersion, kaolin slurries, polyamide wet strength resins, polyaluminum chloride, biopolymer and carboxymethylcellulose (CMC) with anionic charges.

The substances mentioned contribute to charge regulation and to a further increase in the strength properties.

In one embodiment, the porosity of the paper of the invention is preferably greater than 180 gurley-s and less than 25,000 gurley-s, more preferably greater than 200 gurley-s and less than 10,000 gurley-s, and more preferably about 5,000 gurley-s ,

This means that also the tightness against gases, e.g. Air, is significantly increased by the barrier layer according to the invention. For although the thickness of the barrier layer is small in comparison to the thickness of the paper arranged underneath, the barrier layer generally contributes significantly more to the impermeability of the paper according to the invention than the paper arranged underneath; This applies both to the impermeability to oils, greases, etc. and to the impermeability to gases.

In one embodiment, the weight ratio between the modified starch and the platelet-shaped pigments having an aspect ratio> 20 is greater than 50% starch and less than 50% pigments, more preferably greater than 65% starch and less than 35% pigments, and especially at 85% strength and 15% platelet-shaped pigments.

In this case, the weight ratio of the mixture of modified starch and platelet-shaped pigments - and thus u.a. also the resulting tightness of the paper - mainly from the required use.

In one embodiment, the barrier layer provides oil and greaseproofing DIN standard 53116 - 2003 , of at least level 5, more preferably of at least level 4 and in particular level 3 on.

In one embodiment, the barrier layer detects oil and grease impermeability Standard DIN EN ISO 16532-2: 2007 of at least 3 KIT, more preferably of at least 6 KIT and in particular of 12 KIT.

In one embodiment, the barrier layer has an oil and grease seal according to TAPPI standard of 60 s to 1800 s.

In one embodiment, the barrier layer has an oil and grease seal in accordance with the so-called "hot oil test" - which was explained above - from 1 min to 20 min.

In one embodiment, the barrier layer has an oil and greaseproofness according to the so-called "Nutella test" of 1 hour to 24 hours.

A particular advantage of the paper according to the invention is that it achieves excellent results in a large number of these tests, even if, as the width of the tests carried out shows, the tightness is tested against a number of quite heterogeneous fats, oils, solvents and / or water. This means that papers according to the invention are suitable for a very wide range of applications, wherever a barrier effect against natural or synthetic fats, oils and solvents or water or mixtures of these substances is required.

• • Bereitstellen eines Rohpapiers mit vorgegebenen Trockengehalt zwischen 2 % und 9 %, dessen Flächengewicht zwischen 15 g/m² und 500 g/m² und dessen Porosität größer als 150 Gurley-s ist mit einem Zellstoff-Mix aus Langfasern und Kurzfasern, einem Ascheanteil kleiner als 15 % und einem Hilfsmittel;
• • Bereitstellen eines Streichmittels mit mindestens einer modifizierten Stärke, einem plättchenförmigen Pigment mit einer aspect ratio von größer als 1:20, bevorzugt von größer als 1:40, insbesondere von 1:80, einem Oberflächen-Hydrophobierungsmittel und Wasser;
• • Auftragen des Striches auf das Rohpapier mittels eines Streichwerkes, eines Druckwerkes oder einer Streichmaschine;
• • Trocknen des Strichs auf dem Rohpapier.

A packaging paper according to the invention is produced in a method with the steps:

• • Providing a base paper with predetermined dry content between 2% and 9%, whose basis weight between 15 g / m ² and 500 g / m ² and whose porosity is greater than 150 Gurley-s with a pulp mix of long fibers and short fibers, an ash content less than 15% and an aid;
• Providing a coating agent with at least one modified starch, a platelet-shaped pigment having an aspect ratio of greater than 1:20, preferably greater than 1:40, in particular 1:80, a surface-water repellent and water;
• • application of the stroke on the base paper by means of a coating unit, a printing unit or a coating machine;
• • drying the line on the base paper.

For the production of a packaging paper according to the invention can be selected from a wide range of raw papers. Thus, base paper with a basis weight between 15 g / m ² and 500 g / m ² can be used. Of course, for the selection of the base paper plays a significant role, for which applications the packaging paper produced according to the invention is determined. According to the invention, a sufficiently strong, dense and less porous base paper is required. Here, the grinding of the raw paper plays a role, ie it is a raw paper with the highest possible specific grinding energy used.

A packaging paper according to the invention has a barrier layer ("bar") on at least one surface. For this purpose, a coating agent is provided, which is formed from a dispersion comprising: modified starch, platelet-shaped pigment, a surface-water repellent and water.

The said line is applied to the raw paper by means of a coating unit, a printing unit, a coating machine or by spraying. The method according to the invention can therefore be carried out on a large number of different types of paper machines.

Subsequently, the drying of the stroke takes place on the base paper.

The platelet-shaped pigment closes - due to its geometric, platelet-shaped form - the pores present on the paper surface. The modified thickness of the coating liquor is in the form of tiny nano-starch particles which combine with the platelet-shaped pigment during drying. This forms a stable, pore-occlusive and very dense film on the at least one paper surface. This film, especially in conjunction with the dense base paper, creates an effective barrier against various liquids, especially oils, fats, solvents and water.

In addition to the grinding of the base paper, the solids content and the temperature and viscosity of the coating liquor, the drying and the smoothing of the coated paper also play a role in the production process.

Further, according to a particularly preferred embodiment, the base paper used in the production has wet strength agent to ensure a certain wet strength during production. Wet strength agents need to develop a firmer (preferably covalent) bond to the fibers that can not be displaced by water molecules. The wet strength agents used are usually polymers or polyfunctional compounds having reactive groups which react with the OH groups of the pulp fibers only under the drying conditions, thereby bridging a plurality of fibers with one another.

In one embodiment, the solids content is after DIN EN 827: 2006 of the coating agent between 10% and 35%, preferably between 20% and 30%, and this is in particular about 28%. In one embodiment, the temperature of the size liquor is 30 to 60 ° C.

The drying of the coated paper should be done as quickly as possible. This is preferably done by means of contactless and then touching drying, for example by means of an air-turn dryer and / or infrared radiator and then by means of a dry cylinder. The smoothing should be carried out under the highest possible pressure. In this case, pressures with a line force of 30 to 300 kN / m, preferably from 80 to 120 kN / m used.

Furthermore, the best possible running behavior of the paper on the paper machine is desirable, which can be achieved in particular by uniform coating application and by a sufficient strength of the paper.

The platelet-shaped pigment is added to the coating liquor due to its geometric, platelet-shaped shape to close the pores present on the paper surface and to prevent penetration, in particular too far penetration, of the remaining liquor constituents in the paper. The modified thickness of the coating liquor is in the form of tiny nano-starch particles, which are applied to the paper web during coating and combine with the pigments during the drying pass. This forms a stable, pore-occlusive and very dense film on the at least one paper surface. This film, in conjunction with the dense base paper, provides an extremely effective barrier against various liquids, especially oils, greases, solvents and water.

In one embodiment, the coat application on the upper side and / or on the underside of the base paper is in each case between 0.1 and 7.0 g / m ² , preferably between 0.5 and 5.0 g / m ² , particularly preferably between 1, 0 to 4.0 g / m ² and especially between 1.5 and 3.0 g / m ² .

The thickness of the coating application depends considerably on the intended use of the packaging paper according to the invention. Thus, for a very high required barrier strength, the line will be made particularly thick. The thickness of the coating application is for example between 0.1 and 7 microns. If necessary, the line is also applied on both sides.

A packaging paper according to the invention has in principle a wide range of applications. Thus, these packaging papers can be used as barrier papers against oily and greasy materials, e.g. To beat or pack hot or cold foods such as meat, sausage, fish, cheese, snacks such as French fries or pizzas, but also East and vegetables, etc. in the store or directly after production. Since a wide range of base papers can be selected for the production of packaging papers according to the invention, these papers can be produced in a variety of forms, for example as simple paper sheets, foldable cartons or as thermoformable papers. In general, these papers are suitable for a wide range of applications, wherever a barrier effect against oils, solvent-oil mixtures, vegetable fats, chicken fats, chocolate fats, etc. is required. In addition, these papers can also be used for machine parts such as screws, gaskets, etc., which are either stored or shipped in oils, solvents, etc., or which are - e.g. during shipping - to be protected against water, grease, oils, solvents, etc.

The invention will be further explained below with reference to various experiments.

It should be noted that these examples include modifications or additions as they are immediately apparent to the person skilled in the art. Moreover, this preferred embodiment is not a limitation of the invention in the way that modifications and additions are within the scope of the present invention.

• • Der sog. "KIT-Test", nach TAPPI T 559 cm – 12 .
• • DIN Fettdurchlässigkeitstest, nach DIN 53116 – 2003 .
• • Der sog. "TAPPI-Terpentintest", nach TAPPI T 454 om – 15 .
• • Ein Test mit Hühnchen-Öl, der sog. "Heiß-Öl-Test", nach einer firmeninternen Testmethode der Firma Drewsen, Stand 2016.
• • Der sog. "Nutella-Test", nach einer firmeninternen Testmethode der Firma Drewsen, Stand 2016.

1 Figure 4 shows a table of experiments in which papers according to the invention, ie with fluoropolymer-free coating, and papers according to the prior art were tested. The following test methods were used:

• • The so-called "KIT-Test", after TAPPI T 559 cm - 12 ,
• • DIN grease permeability test, after DIN 53116 - 2003 ,
• • The so-called "TAPPI-turpentine test", according to TAPPI T 454 om - 15 ,
• • A test with chicken oil, the so-called "hot oil test", according to an in-house test method of Drewsen, as of 2016.
• • The so-called "Nutella-Test", after an in-house test method of Drewsen, as of 2016.

For all experiments basis weights between 31 and 70 g / m ² and thicknesses between 41 and 49 μm were used. The porosity of the raw papers was between 200 and 1,000 Gurley-s. The ash content was between 0 and 2%, with a sizing between 1.5 and 60.

• • Bei dem sog. "KIT-Test" werden – jeweils für Papiere mit niedrigem/mittlerem/hohem Fettdichtbereich – KIT Stufe 4/5/12 erreicht, wogegen Papiere nach dem Stand der Technik bei ähnlichen Flächengewicht und Strichauftrag KIT Stufe 2/5/8 erreichen.
• • Der DIN Fettdurchlässigkeitstest, nach DIN 53116 – 2003 , ergab die DIN-Stufen IV/IV – III/III – II, gegenüber Papieren nach dem Stand der Technik mit DIN-Stufen > V/V/IV – III.
• • Tests mit dem sog. "TAPPI-Terpentintest" ergaben die Werte 60–120/300–600/1200–1800, gegenüber Papieren nach dem Stand der Technik 30–60/60–300/600–1800 TAPPI-Sekunden.
• • Ein Test mit Hühnchen-Öl, der sog. "Heiß-Öl-Test", nach der oben spezifizierten Testmethode, ergab Werte von 5/5/15–20 Minuten, gegenüber Papieren nach dem Stand der Technik 1/5/20 Minuten.
• • Der sog. "Nutella-Test", nach der oben spezifizierten Testmethode, ergab Werte von 4/4/24 Stunden, gegenüber Papieren nach dem Stand der Technik 1/4/24 Stunden.

These tests show a clear difference from prior art papers:

• • The so-called "KIT test" achieves KIT level 4/5/12 for papers with a low / medium / high density range, whereas prior art papers have a similar basis weight and coating order. KIT Level 2/5 / Reach 8.
• • The DIN grease permeability test, after DIN 53116 - 2003 , gave the DIN levels IV / IV - III / III - II, compared to prior art papers with DIN levels> V / V / IV - III.
• • Tests with the so-called "TAPPI-turpentine test" gave the values 60-120 / 300-600 / 1200-1800, compared to prior art papers 30-60 / 60-300 / 600-1800 TAPPI-seconds.
• • A test with chicken oil, the so-called "hot oil test", according to the test method specified above, gave values of 5/5 / 15-20 minutes, compared to prior art papers 1/5/20 minutes ,
• • The so-called "Nutella test", according to the test method specified above, gave values of 4/4/24 hours compared to prior art papers 1/4/24 hours.

The measured values show that fluoropolymer-free papers according to the invention in each test at least reach the density values of prior art papers, in many cases even significantly above these values. Papers according to the invention therefore not only have the advantage of better environmental compatibility, but also regularly have higher tightness values for a wide range of applications.

QUOTES INCLUDE IN THE DESCRIPTION

This list of the documents listed by the applicant has been generated automatically and is included solely for the better information of the reader. The list is not part of the German patent or utility model application. The DPMA assumes no liability for any errors or omissions.

Cited non-patent literature

• ISO 5636/5: 2013 [0006]
• DIN 54370: 2007 [0006]
• ISO 5636/5: 2013 [0011]
• DIN 54370: 2007 [0012]
• TAPPI T 559 cm - 12 (TAPPI: Technical Association of the Pulp and Paper Industry) [0015]
• DIN 53116 - 2003 [0015]
• TAPPI T 454 om-15 [0015]
• DIN standard 53116 - 2003 [0039]
• Standard DIN EN ISO 16532-2: 2007 [0040]
• DIN EN 827: 2006 [0053]
• TAPPI T 559 cm - 12 [0062]
• DIN 53116 - 2003 [0062]
• TAPPI T 454 om-15 [0062]
• DIN 53116 - 2003 [0064]

Claims (19)

Packaging paper having barrier properties, in particular against oily and greasy materials, prepared from a base paper having a basis weight between 15 g / m ² and 500 g / m ² and a porosity greater than 150 Gurley-s according to ISO 5636/5: 2013, with a pulp Mix of long fibers and short fibers, an ash content according to DIN 54370: 2007 less than 15%, and an adjuvant, characterized in that the paper on at least one surface has a barrier layer, which consists of at least one modified starch, a platelet-shaped pigment with an aspect ratio greater than 1:20, preferably greater than 1:40, especially 1:80, and a surface water repellent is formed. Packaging paper according to claim 1, characterized in that the base paper further comprises a wet strength agent. Packaging paper according to claim 1 or 2, characterized in that the starch is a cationic potato starch and / or a modified corn starch, in particular a Biolatex. Packaging paper according to one of the preceding claims, characterized in that the hydrophobing agent is an anionic surface sizing agent. Packaging paper according to one of the preceding claims, characterized in that the pulp mix a proportion between 0 to 90% long fibers and 10 to 100% short fibers, preferably a proportion between 10 to 60% long fibers and 40 to 90% short fibers and in particular a share of 50% long fibers and 50% short fibers. Packaging paper according to one of the preceding claims, characterized in that the long-fiber pulp is a spruce and / or pine sulphate or sulphite pulp and the short fiber pulp is a eucalyptus, beech or birch sulphate or sulphite pulp. Packaging paper according to one of the preceding claims, characterized in that the ash content is less than 15%, preferably less than 5% and in particular between 0% and 5%. Packaging paper according to one of the preceding claims, characterized in that the basis weight preferably between 18 g / m ² and 400 g / m ² , in particular between 20 g / m ² and 300 g / m ² , preferably between 22 g / m ² and 250 g / m ² , more preferably between 25 g / m ² and 160 g / m ² and in particular about 40 g / m ² . Packaging paper according to one of the preceding claims, characterized in that the at least one auxiliary agent is selected from the group consisting of conditioning agents for pulp, cationic resin dispersion, kaolin slurries, polyamide wet strength resins, polyaluminum chloride, biopolymer and carboxymethylcellulose with anionic charges. Packaging paper according to one of the preceding claims, characterized in that the porosity preferably greater than 180 Gurley-s and less than 25,000 Gurley-s, more preferably greater than 200 Gurley-s and less than 10,000 Gurley-s, and in particular about 5,000 Gurley -s is. Packaging paper according to one of the preceding claims, characterized in that the weight ratio between the modified starch and the platelet-shaped pigment with an aspect ratio> 20 at more than 50% strength and less than 50% platelet-shaped pigment, more preferably at more than 65% strength and less than 35% platelet pigment, and especially 85% starch and 15% platelet pigment. Packaging paper according to one of the preceding claims, characterized in that the barrier layer has an oil and greaseproofness according to DIN standard 53116 - 2003 of at least stage 5, particularly preferably of stage 4 and in particular of stage 3. Packaging paper according to one of the preceding claims, characterized in that the barrier layer has an oil and grease seal according to TAPPI standard T 454 om - 15 of at least 60 s, particularly preferably from 60 to 600 s and in particular from 60 to 1800 s. Packaging paper according to one of the preceding claims, characterized in that the barrier layer has an oil and greaseproofness according to the so-called "hot oil test" of at least 1 minute, particularly preferably from 1 to 10 minutes and in particular from 1 to 20 minutes. Packaging paper according to one of the preceding claims, characterized in that the barrier layer has an oil and greaseproofness according to the so-called "Nutella test" of at least 1 hour, preferably of at least 24 hours. Method for producing a packaging paper according to one of the preceding claims, comprising the steps of: providing a base paper with a predetermined dry content of between 5% and 15%, whose basis weight is between 15 g / m ² and 500 g / m ² and whose porosity is greater than 150 gurley s is a pulp mix of long fibers and short fibers, an ash content of less than 15% and an adjuvant; - Providing a coating agent with at least one modified starch, a platelet-shaped pigment having an aspect ratio of greater than 1:20, preferably greater than 1:40, in particular 1:80, a surface-water repellent and water; - applying the line to the base paper by means of a coating unit, a printing unit, a coating machine or by spraying; - drying the line on the base paper. A method according to claim 16, characterized in that and the base paper further comprises a wet strength agent. A method according to claim 16 or 17, characterized in that the solids content according to DIN EN 827: 2006 of the coating composition is between 25% and 30%, preferably between 27.5% and 30% and in particular about 28%. A method according to claim 16, 17 or 18, characterized in that the coating application on the top and / or on the underside of the base paper in each case between 0.1 to 7.0 g / m ² , preferably between 0.5 to 5.0 g / m ² , more preferably between 1.0 to 4.0 g / m ² and in particular between 1.5 to 3.0 g / m ² .

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