JP2017524081A - Heat-sealable barrier paper - Google Patents

Abstract

The present invention relates to paper, which is a precoat layer comprising a fibrous base material, a binder, a plate-like filler having a form factor of at least 15 and a mixture of finer fillers, wherein A precoat layer, wherein the fine filler particles have a particle size of less than 2 μm for 80% by weight (measured according to ISO 13317-3 cedigraph method) and at least one coating layer applied to said precoat layer A water vapor transmission rate of at most 150 g / m2 / 24 hours and preferably less than 100 g / m2 / 24 hours, measured according to the ASTM F1249 standard under so-called tropical conditions of 38 ° C. and 90% relative humidity Have.

Description

  The present invention relates to the field of wrapping paper.

Plastic films are widely used in flexible packaging because they have the water vapor barrier properties required for proper storage of perishable products or products with limited shelf life.
Paper is a material made from fibers, generally cellulose fibers, and therefore of plant origin. These are naturally porous and permeable to gases, and as such cannot be used for this application.
However, it is known to combine paper and other materials (plastic, aluminum, etc.) to obtain the barrier properties necessary to package various products and especially perishable foods. In this case, the paper support is subjected to conversion operations, such as application of a coating layer made of polymer in dispersion, extrusion coating of molten polymer or plastic or aluminum film. Including lamination. The costs associated with this paper-based composite with barrier properties are increasing.
Document US 2 653 870 A describes a method for producing wrapping paper.
Packaging materials made from barrier paper produced online are described in patent application WO 2011/056130. On-line manufacturing is understood to mean manufacturing using a single manufacturing means that includes all the elements required to manufacture the paper.

However, the proposed barrier levels are limited to measurement conditions that are not so limited (these are temperature, ie 25 ° C., 75% relative humidity). This barrier level is measured by the water vapor transmission rate, and a weak barrier means a high water vapor transmission rate. In the literature, “tropical” conditions (ie, 38 ° C., 90% relative humidity) are more severe than temperature conditions, and as a result, the barrier measured under mild conditions is more It is known to be even lower.
The expression “barrier paper” should be understood to mean a non-porous paper comprising a fibrous base material covered with one or more layers, Intrusion of the water vapor into the packaging material in an amount that may sufficiently adversely affect the preservation of the product contained therein or the integrity of the product. Resist.

The present invention, 38 ° C. and of 90% relative humidity under a so-called tropical conditions, ASTM as measured according F1249 standard, higher even at 150g / m ^2/24 and preferably in 100g / m ^2/24 Of particular interest, but not exclusively, for water vapor barrier papers with sub-hour water vapor transmission rates.
It is advantageous that the barrier paper is likewise heat-sealable in order to allow the formation of the packaging material by sealing the paper to itself.
The production of heat-sealable paper includes, for example, a step of layering a heat-sealable polymer coating layer on a cellulosic support. Such a cover layer, when not dried, has a very strong tack and also prevents the various turns of the reel of paper from sticking to each other. It must be completely dry before being done.
The application of this coating layer is generally performed off-line during one or more processing steps, which gives good coverage and makes it impossible for the coating layer to excessively penetrate the fibrous support. Benefit from paper at ambient temperature at the time of the coating, and allow the reel width travel time in the oven to adapt to speeds of, for example, 200 m / min, resulting in exposure times to these heating means Is sufficient to dry completely to the depth of the heat-sealing coating layer.

Documents US 2004/121079 A1, WO 2010/052571 A2, US 2014/113080 A1 and WO 2009/112255 A1 disclose paper processed off-line.
Paper that provides a barrier to water vapor and, in some cases, is heat sealable, is generally produced during processing operations in the prior art described above, and conventionally has a coating layer of 10-30 g / m ² when dried. The coating layer may be applied in one or more thicknesses using various coating means (air knife, reverse gravure, Meyer rod or bar or any other coating method), or Deposited by applying one thick layer using a flow coat.
Thus, the off-line processing of the paper to give the paper a water vapor barrier and heat seal is an additional step in the manufacture of the paper, which significantly increases its cost and plastic film packaging Limit the development of paper in flexible packaging, which is advantageous to Accordingly, there is an economic need for improved productivity associated with the production of water vapor barrier and heat sealable paper.

The present invention relates to the development of paper that is provided with water vapor barrier and heat sealing properties during on-line production of paper. This barrier and heat-sealable paper can be used to make packaging materials by sealing the paper to itself.
The heat-sealable layer and more generally any heat-sealable or not applied to the fiber substrate, online or offline, independent of the method in which the heat-sealable layer is applied Face the problem of facilitating the deposition of the coating layer.
In general, it is desirable that the coating layer not penetrate too deeply into the fiber substrate, in order to reduce its amount applied to the paper if this layer is polymer based. Furthermore, less penetration of the coating layer makes it possible to produce the barrier film more easily.
The use of a Yankee cylinder is the primary solution for reducing surface porosity.
The second means to choose is the use of a calendar prior to any processing of the paper.
Another means to choose is to take measures to make the precoat layer present in order to reduce the porosity of the paper.
Another means to choose is to combine one or the other of the above selection means.
In forming the precoat layer, specific hydrophobic and highly film-forming latexes can be used.

However, the hydrophobicity of the precoat layer therefore presents problems with wettability during application of the coating layer when the coating layer is aqueous, especially in the case of an on-line process that uses high speed for the sheet May result in a non-uniform coating of the precoated fiber substrate with the coating layer. Furthermore, the surface energy of the precoat layer must be sufficiently different from that of the coating layer, while following well known rules for wettability in order to reduce the risk of wet defects.
As a result, there remains a need to adequately address the problems associated with applicability of the coating layer.
The present invention satisfies this need according to one aspect of the present invention, thanks to the following paper. The paper
-Fiber substrate;
A precoat layer comprising a binder and a mixture of platy filler (s) and fibers (s) having a form factor of at least 15, especially finer filler (s), the finer The filler particle size is less than 2 μm for 80% by weight (measured according to ISO 13317-3 SediGraph method);
-At least one coating layer applied to the precoat layer;
Hints, the paper is higher at 150g / m ^2/24 also and preferably less than at 100g / m ^2/24, the so-called tropical conditions of 38 ° C and 90% relative humidity, ASTM F1249 standard With water vapor permeability measured according to

In the precoat layer according to this aspect of the invention, the presence of a platy filler having a form factor of at least 15 and a finer, especially non-planar particulate filler, is independent of the hydrophobic or non-hydrophobic nature of the binder. Enables the achievement of relatively high barrier levels, the particle size of the finer filler being less than 2 μm for 80% by weight (measured according to ISO 13317-3 cedigraph method).
The platy fillers are, for example, according to the tortuosity imparted by the filler, as taught by the document: Imaries Technical Guide, Pigments for Paper, May 2008. Helps to increase its barrier effect. The presence of at least one finer, especially non-plate-like granular filler according to this aspect of the invention enhances this effect. One tentative explanation is that the filler will further hinder the movement of water molecules, especially around the plate-like particles, by sliding between the plate-like particles. Document: WO 2009/117040 A1 discloses a platy filler made of clay.
Because of the barrier effect associated with the particular choice of the filler present in the precoat layer, there is a greater degree of freedom with respect to the nature of the binder used.
It is therefore possible to use, inter alia, any papermaking binder that does not have specific barrier properties, which is a double water permeability, low water vapor transmission rate for the precoat layer, and good wettability for the coating layer. Allows you to gain benefits.

The present invention allows the precoat layer to have an enhanced barrier effect, which allows the amount of coating layer to be applied to be reduced, or for an equivalent amount of coating layer. It is possible to further increase the paper barrier level, which may prove useful for paper that must be leak-proof against water vapor. Due to this higher barrier capability of the precoated paper, the reduction in the amount of coating layer required makes it easier to dry and more easily coats this layer during online production of the paper. there is a possibility.
The paper of the present invention is preferably produced on a papermaking apparatus from a fiber substrate consisting of cellulose fibers and optionally synthetic fibers.
The cellulose fiber is generally a mixture of short fibers and long fibers.
Additives such as sizing agents, wet strength agents, retention agents or antifoaming agents can be added.
Similarly, the paper can also contain paper-making fillers such as titanium dioxide, kaolin, calcium carbonate and talc, among others.
The paper is preferably wrapping paper.

Another object of the present invention, suitable for making barrier paper according to the present invention, as defined above, according to the above criteria, at 150g / m ^2/24 be higher and preferably 100 g / m ² / Pre-coated paper with water vapor transmission rate of less than 24 hours. The precoated paper need not be calendared.
Another subject of the present invention is a precoat composition for producing paper according to the present invention, which comprises a binder in the form of a latex, a platy filler having a form factor of at least 15 and a finer filler. The particle size of the finer filler is less than 2 μm with respect to 80% by mass.
Another subject of the invention is a packaging material according to the invention, in particular containing paper that is heat sealed to itself, which packaging material comprises, for example, food products.
Another subject of the invention is a method for producing a paper according to the invention, in which a precoat treatment composition as defined above is applied to a fiber substrate.

Precoat layer The precoat layer may be the same as the coating layer, or may be a pigment layer as defined below.
The precoat layer preferably comprises a mixture of at least one latex and a filler, often also referred to as a “pigment”.
Document: US 4 018 647 A describes an example of a latex.
The latex according to the invention preferably has a Tg (glass transition temperature) measured according to the ASTM E1356 standard of 25 ° C. or less and more preferably 10 ° C. or less. The latex can be selected from latexes having the following chemical properties: styrene-butadiene, styrene-acrylic, acrylic, butyl acrylate, butyl acrylate / styrene / acrylonitrile, and more particularly styrene-butadiene emulsions. .
The amount of latex is preferably at least 15 parts when dried, preferably at least or even more than 25 parts per 100 parts filler, and even better 30, relative to the filler (100 parts) when dried. Part.
The filler is preferably constituted by a mixture of plate-like fillers and finer, especially non-plate-like fillers.
The plate filler is a particle in the form of a plate having a form factor (ratio between maximum length and thickness) of equal to or greater than 15, more preferably at least 40 and even more preferably at least 60. It is.

The precoat layer includes a binder, a plate-like filler having a form factor of at least 15 and a finer filler, in particular a mixture of non-plate-like fillers, and the size of the finer filler particles is 80% by mass. In contrast, it is less than 2 μm (measured according to ISO 13317-3 cedigraph method).
In order to include a mixture of platy fillers and finer fillers, the finer filler particle size is less than 2 μm for 80% by weight, and the platy filler particle size is, for example, It can be equal to or greater than 2 μm for 80% by weight. According to another example, less than 80% by weight of the plate-like particles may be less than 2 μm.
In other words, in order to include a finer filler than the plate-like filler, the finer filler is, according to the first example, more than the particle size of the plate-like filler in an equivalent weight distribution. Can also have a small granularity. According to a second example, the particles can have a greater mass distribution for particles of the same size than that of the platy filler.
The finer filler can be selected from any other pigment used in papermaking that meets the required size requirements.
The ratio of the plate-like filler to the whole filler can vary from 10% to 90%, preferably from 40% to 90%, and more preferably from 60% to 90%.

The plate-like filler can be selected from, for example, kaolin and talc, and mixtures thereof.
30% to 80% by weight of the plate-like particles can be of a size equal to or less than 2 μm (measured according to ISO 13317-3 cedigraph method).
The plate-like filler particles are particularly oriented substantially parallel to the surface of the support.
The finer filler particles can be selected from calcium carbonate, barium sulfate, silica, titanium dioxide, and mixtures thereof. They are characterized by a particle size as measured according to the ISO 13317-3 cedigraph method of less than 2 μm for 80% by weight.
Similarly, the finer filler is any other, including kaolin, having a particle size measured according to the ISO 13317-3 cedigraph method of less than 2 μm for sufficient fineness, especially 95% by weight. It can be selected from pigments.
The binder is preferably selected from the latexes described above, but other binders or auxiliary binders such as PVOH, starch, CMC, etc. can also be used. The binder may include a polymer having a chemical property that is not present in the coating layer.

Coating layer The polymer used to obtain the vapor barrier and heat sealability described above is preferably selected from polymers or copolymers based on PVdC (polyvinylidene chloride) or acrylic.
These polymers are applied as pure polymers or as a mixture with fillers. The term “pure” is understood to mean lacking particulate filler. Other products such as pH modifiers, rheology (e.g., viscosifying) rheological agents, antifoaming agents, wetting agents, etc. are optionally added to the polymer dispersion. be able to.
The use of fillers in the coating layer can be particularly helpful in reducing the risk of reel turns sticking together.

Production Preferably, the coating layer is applied on-line.
The invention makes it possible to achieve a good water vapor barrier level for a coating layer mass not exceeding 10 g / m ² when dried.
Despite the relatively high running speed of the paper imposed by industrial papermaking equipment, for example, around 400 m / min, online application of the composition to form the heat-sealable coating layer is Under the condition that sufficient drying capacity is used to dry the layer prior to the winding operation of the layer. In particular, the relatively low mass of the coating layer facilitates the online drying while providing sufficient barrier properties.
The online process makes it possible to increase productivity by eliminating handling operations related to the offline processing.
After drying the fiber substrate, the paper sheet can be transferred to a Yankee cylinder to improve the surface finish of the sheet and consequently the distribution of the first layer.
The sheet can then be processed in a size press or any other device of a similar type. In order to avoid excessive penetration of the precoat layer into the fibrous support, the pigment composition can be used in advance to perform “pore filling”.
This pore-filling composition has up to 20 parts binder upon drying, such as a latex with styrene-butadiene chemistry, and 20% upon drying against the above dry pigment. Up to part of an auxiliary binder, such as starch.
The composition preferably contains a filler, which generally has a dimension of less than 2 μm. These fillers can be chosen in particular from kaolin or calcium carbonate or mixtures thereof.

The precoat layer is applied to the support thus treated using any of the coating techniques that may be encountered in papermaking equipment. This may in particular be knife coating, gravure coating, reverse gravure coating or Mayer rod coating. The precoat layer is preferably deposited in a dry layer weight of between 4~12g / m ^2.
The precoat layer is then dried by one or more infrared ovens and / or one or more hot air ovens so that they do not contact.
Prior to application of the coating layer, it is not necessary to have a very high level of smoothness. A Bekk level of 150 seconds is sufficient (measured according to the ISO 5627 standard).
The water vapor barrier and heat sealable coating layer is applied by a coating method using any of the coating techniques that may be encountered in papermaking equipment. This can be, for example, knife coating, gravure coating, reverse gravure coating or Mayer rod coating. The coating layer is preferably deposited with a dry layer mass of at most 10 g / m ² .
This coating layer is then sufficient using one or more infrared furnaces and / or one or more hot air furnaces to prevent the turn from sticking on the take-up reel. To be dried.
Application can be performed on the opposite side to enhance the barrier properties and / or provide other functionality such as printability, curl correction, and the like.
The paper produced in this way can optionally be calendared online prior to its winding to reduce its surface roughness.
The final basis weight of the paper can be between 45~200g / m ^2.
38 ° C., at 90% relative humidity, barrier properties against water vapor measured according to ASTM F1249 standard, 150 g / m ² / less than 24 hours, and preferably less than at 100g / m ^2/24.

Example 1:
A fibrous support with a basis weight of 55 g / m ² is produced on a papermaking machine operating at 400 m / min. The papermaking apparatus includes a Yankee cylinder disposed in front of the size press.
The fibrous support is first polished, then 100 dry parts Amazon Premium type kaolin (Cadam) and a ratio of 20 dry parts to the dry kaolin (Merifilm) Using a pore-filling pigment composition comprising a mixture of 104 starch (Tate & Lyle) and a DL950 type latex (Dow), the substrate was pressed by a size press. Both sides are processed online. Overall, the applied treatment is 5 g / m ² when dry.
This is then used, using a Meyer rod coater, a mixture of platy fillers and finer granular fillers and a latex with a styrene-butadiene type chemistry of Tg = 7 ° C. (from Dow Chemical). Painted with a precoat formulation containing DL950) and dried in an infrared heating oven and then in a hot air oven without contact. It is then wound on a reel without any other processing. The dry weight of this applied precoat layer is 7 g / m ² and its formulation is given in the following table:

The particle size with respect to 97% by mass for Amazon Premium, measured according to ISO13317-3 cedigraph method, is less than 2 μm.
The shape factor of Capim NP particles is 28.
The barrier property to water vapor is measured by a Mocon Permatran 3/61 apparatus according to the ASTM F1249 standard at 38 ° C. and 90% relative humidity to determine the barrier contribution for this precoat layer. This is measured at at ^{334 ± 13g / m 2/24} . After applying the coating layer, the barrier property of less than at 150g / m ^2/24 is obtained.

Example 2:
The fibrous support is first polished, then 100 dry parts Amazon Premium type kaolin (Cadam) and a ratio of 20 dry parts to the dry kaolin (Merifilm) On-line treatment of both sides of the support by size press using a pore-filling pigment composition containing a mixture of 104 starch (Tate & Lyle) and DL950 type latex (Dow) To do. Overall, the applied treatment is 5 g / m ² when dry.
This is then used, using a Meyer rod coater, a mixture of platy fillers and finer granular fillers and a latex with a styrene-butadiene type chemistry of Tg = 7 ° C. (from Dow Chemical). Painted with a formulation containing DL950) and dried in an infrared heating furnace and then in a hot air oven without contact. It is then wound on a reel without any other processing. The dry weight of this applied precoat layer is 7 g / m ² and its formulation is given in the following table:

The particle size relative to 95% by weight according to Hydrocurve 95, measured according to the ISO13317-3 cedigraph method, is less than 2 μm.
The barrier property to water vapor is measured with a Mocon Permatran 3/61 apparatus according to ASTM F1249 at 38 ° C. and 90% relative humidity to determine the barrier contribution for this precoat layer. This is measured at at ^{315 ± 9g / m 2/24} . After applying the coating layer, the barrier property of less than at 150g / m ^2/24 is obtained.

Example 3:
Paper is produced online under the same conditions as in Example 1. However, following the deposition of the precoat layer, this was applied online with a coating layer consisting of a dispersion of PVdC copolymer (Diofan A297 from Solvay) and heated without infrared contact. Dry in an oven and then in a hot air oven. This was then wound on a reel without any other processing, but no coupling between the turns was observed. The dry mass of this coating layer is 6.5 g / m ² .
The barrier property to water vapor is measured by a Moperpermatlan 3/61 apparatus according to ASTM F1249 standard at 38 ° C. and 90% relative humidity. This is measured at at ^{21.0 ± 2.4g / m 2/24} .
The paper was then sealed on the surface covered with its coating layer on a laboratory heat sealing device at 110 ° C. under about 0.3 MPa (3 bar) for 0.5 seconds. By simulating it. Next, the force required to separate the paper bound to a sample with a width of 15 mm is subsequently measured under an angle of 90 degrees at a rate of 100 mm / min according to the Tappi T540 standard.
A sealing force of 3.5 N / 15 mm is obtained.
The invention is not limited to the described embodiments.

In short, the present invention can have one or more of the following advantageous features:
The mass of the coating layer does not exceed 10 g / m ² when dry, in particular strictly less than 10 g / m ² ;
The coating layer comprises or is constituted by a heat-sealing polymer;
The plate filler and the finer filler have the same properties;
The form factor of the platy filler particles is at least 40, more preferably at least 60;
The finer filler is a non-plate filler;
The finer filler is a plate-like filler;
The finer filler has a particle size of less than 2 μm, measured according to ISO 13317-3 cedigraph method for 95% by weight;
-The plate-like filler is an inorganic filler;
The finer filler is an inorganic filler;
The platy filler is selected from kaolin and talc and mixtures thereof;
The finer filler is selected from kaolin, calcium carbonate, barium sulfate, silica, titanium dioxide and mixtures thereof;
The finer filler is selected from kaolin;
The dry mass of the platy filler is between 3% and 58% of the total dry mass of the precoat layer, and the mass of the platy filler is preferably greater than the value of the finer filler;

The dry weight of the finer filler is between 3% and 58% of the total dry weight of the precoat layer;
The ratio of the platy filler expressed in dry mass to the total filler expressed in dry mass is between 10% and 90%, preferably between 40% and 90% and even more preferably Between 60% and 90%;
The binder has a glass transition temperature Tg of less than or equal to 25 ° C and more preferably less than 10 ° C;
The binder is selected from styrene-butadiene, styrene-acrylic, acrylic, butyl acrylate, latex with butyl acrylate / styrene / acrylonitrile chemistry and mixtures thereof;
The binder is selected from latexes with styrene-butadiene chemistry;
The binder is introduced in latex form;
The precoat layer comprises at least 15 parts, and preferably more than 25, and better still 30 parts dry binder, relative to the dry filler mass (100 parts);
The binder comprises a polymer with chemical properties not present in the coating layer;
The coating layer is substantially free of filler;
The coating layer is the only layer covering the precoat layer;
The coating layer comprises one or more polymers selected from PVdC-based or styrene-acrylic-based copolymers and mixtures thereof;
The amount of the precoat layer is less than or equal to 12 g / m ² on a dry mass basis;
The paper includes a printed layer on a surface of the support opposite to the surface having the precoat layer and the coating layer;
The support has two identical precoat layers on its opposite side;

The support has two precoat layers with different properties on its opposite side;
The pore-filling composition is applied to the support and the precoat layer is applied to the pore-filling composition, the pore-filling composition being preferably by size press or film press Applies;
The basis weight of the fiber substrate is between 25 and 180 g / m ² ;
The paper can be heat-sealed at about 0.3 MPa (3 bar) for 0.5 seconds, especially starting at 90 ° C., when the sealing is done with hot clamps;
Water vapor permeability of the barrier sheet is less than at 100g / m ^2/24;
• Between 30% and 80% by weight of plate-like particles with dimensions less than or equal to 2 μm (measured according to ISO 13317-3 cedigraph method);
・ The paper is a vertical wrapping machine of VFFS (Vertical Form, Fill and Seal) type, 40 bags / min along a longitudinal sealing line of 330 mm / bag Can be heat-sealed, especially to itself, at equal or higher production rates;
The paper, when its sealing is done with hot clamps under 0.5 bar (0.5 bar) for 0.5 seconds, under an angle of 90 degrees, according to the Tappi T540 standard, Can be heat sealed against itself with a sealing force equal to or exceeding 2 N / 15 mm as measured at a speed of 100 mm / min;
The temperature of the fiber substrate during application of the precoat layer is equal to or greater than 50 ° C .;
The temperature of the fiber substrate during application of the coating layer is equal to or greater than 70 ° C .;
- Final basis weight of the paper is between 45~200g / m ^2.
The expression “comprising a” is synonymous with “comprising at least one”.

Claims (37)

A fiber substrate;
A precoat layer comprising a binder, a plate-like filler having a form factor of at least 15 and a finer filler, especially a mixture of non-plate-like fillers, wherein the finer filler particles have a particle size of 80% by mass. In contrast, a precoat layer that is less than 2 μm (measured according to ISO 13317-3 cedigraph method)
At least one coating layer applied to the precoat layer;
A paper containing, in 38 ° C. and 90% relative humidity as measured according to ASTM F1249 standards in the so-called tropical conditions, up to 150g / m ^2/24 hours and preferably less than at 100g / m ^2/24 Paper with water vapor transmission rate. ^2. Paper according to claim 1, wherein the mass of the covering layer does not exceed 10 g / m < ² > when dried, in particular strictly less than 10 g / m < ² >.   The paper according to claim 2, wherein the coating layer contains a heat-sealable polymer or is further composed of a heat-sealable polymer.   The paper according to claim 1 or 2, wherein the plate-like filler and the finer filler have the same properties.   The paper according to any one of claims 1 to 4, wherein the shape factor of the plate-like filler particles is at least 40, more preferably at least 60.   The paper according to any one of claims 1 to 5, wherein the finer filler has a particle size of less than 2 m, measured according to ISO 13317-3 cedigraph method, with respect to 95% by weight.   The paper according to any one of claims 1 to 6, wherein the plate-like filler is an inorganic filler.   The paper according to any one of claims 1 to 7, wherein the finer filler is an inorganic filler.   The paper according to any one of claims 1 to 8, wherein the platy filler is selected from kaolin and talc and mixtures thereof.   The paper according to any one of claims 1 to 9, wherein the finer filler is selected from kaolin, calcium carbonate, barium sulfate, silica, titanium dioxide and mixtures thereof.   The paper according to any one of claims 1 to 10, wherein the finer filler is selected from kaolin.   The dry mass of the plate-like filler is 3% to 58% of the total dry mass of the precoat layer, and the mass of the plate-like filler is preferably larger than the mass of the finer filler. 11. The paper according to any one of 11 above.   The paper according to any one of claims 1 to 12, wherein a dry mass of the finer filler is 3% to 58% of a total dry mass of the precoat layer.   The ratio of the plate-like filler expressed by dry mass to the total of the filler expressed by dry mass is 10% to 90%, preferably 40% to 90%, and more preferably 60% to 90%. The paper according to any one of claims 1 to 13.   15. Paper according to any one of the preceding claims, wherein the binder has a glass transition temperature Tg of 25 [deg.] C or less and more preferably less than 10 [deg.] C.   16. The binder of any one of the preceding claims, wherein the binder is selected from styrene-butadiene, styrene-acrylic, acrylic, butyl acrylate, butyl acrylate / styrene / acrylonitrile latexes, and mixtures thereof. Paper as described in.   17. Paper according to any one of the preceding claims, wherein the binder is selected from latexes having styrene-butadiene chemistry.   Paper according to any one of the preceding claims, wherein the binder is introduced in latex form.   19. The precoat layer comprises at least 15 parts, and preferably more than 25 parts, and better still 30 parts binder when dry, relative to the weight of the filler (100 parts) when dry. The paper according to any one of the above.   The paper according to any one of claims 1 to 19, wherein the binder comprises a polymer having a chemical property that is not present in the coating layer.   The paper according to any one of claims 1 to 20, wherein the coating layer does not substantially contain a filler.   The paper according to any one of claims 1 to 21, wherein the coating layer is the only layer covering the precoat layer.   23. Paper according to any one of the preceding claims, wherein the coating layer comprises one or more polymers selected from PVdC based copolymers or styrene-acrylic based copolymers and mixtures thereof. . The amount of the precoat layer, on a dry weight is 12 g / m ² or less, the paper according to any one of claims 1 to 23.   The paper according to any one of claims 1 to 24, comprising a printed layer on a surface of the substrate that faces the surface having the precoat layer and the coating layer.   26. Paper according to any one of claims 1 to 25, wherein the substrate has two identical precoat layers on its opposing surfaces.   The paper according to any one of claims 1 to 25, wherein the substrate has two precoat layers having different properties on its opposing surfaces.   A pore-filling composition is applied to the substrate, and the precoat layer is applied to the pore-filling composition, and the pore-filling composition is preferably by size press or film press 28. A paper according to any one of the preceding claims, applied. The basis weight of the fibrous substrate is a 25~180g / m ^2, the paper according to any one of claims 1 to 28.   30. The heat-sealing property according to any one of claims 1 to 29, wherein the paper is heat-sealable, particularly starting at 90 [deg.] C., when sealing is performed by hot clamping at 0.3 MPa (3 bar) for 0.5 seconds. Paper according to item 1. The final basis weight of the paper, a 45~200g / m ^2, the paper according to any one of claims 1 to 30. A precoating treatment paper suitable for the manufacture of paper according to any one of claims 1 to 31, according to ASTM F1249 standards in 38 ° C. and 90% relative humidity, at 150g / m ^2/24 at maximum and preferably , precoating treatment paper having a water vapor transmission rate of less than at 100g / m ^2/24.   The precoated paper according to claim 32, which is not calendared.   The packaging material containing the paper of any one of Claims 1-33.   35. The packaging material of claim 34, wherein the paper is heat sealed to itself.   36. A packaging material according to any one of claims 34 and 35 comprising a food product.   34. A method of manufacturing a paper according to any one of claims 1 to 33, wherein the composition is applied to a fiber substrate, the composition having a latex form binder and at least 15 form factors. And a dispersion of a mixture of finer fillers, wherein the finer filler particles have a size of less than 2 μm with respect to 80% by mass.