EP2965919A1 - Transfer paper with a barrier layer and associated method of manufacturing - Google Patents

Abstract

The invention relates to a transfer paper (1) comprising: a reservoir layer (2), having an outer face (20) configured to receive a sublimable ink (5) and an inner face (22), and a barrier layer (3), applied on the inner face (22) of the reservoir layer (2), and configured to form a barrier to the vehicle of the sublimable ink (5), said barrier layer (3) comprising between 70 % and 100% by dry weight of cellulose fibers, preferably at least 80% by dry weight, the transfer paper (1) being characterized in that the reservoir layer comprises: at least 60% by dry weight of main pigments having a mean diameter of between 0.2 micrometers and 0.8 micrometers, and - At most 45% by dry weight of secondary pigments having an average diameter greater than the average diameter of the main pigments.

Description

FIELD OF THE INVENTION

The invention relates to the field of transfer paper.

BACKGROUND

Transfer paper is a complex used to reproduce an image or pattern on textiles composed of polyester or a blend of polyester and other fibers, or on hard substrates previously treated with a polyester-type varnish. The image or pattern to be reproduced is printed according to common printing techniques with aqueous sublimable inks. Typically, printing is done by inkjet technology. The image is then applied to its substrate, textile or hard, using a hot press. Under the effect of heat and pressure, the sublimable ink passes from the solid state to the gaseous state and penetrates directly into the mesh of the textile or into the varnish of the hard substrates.

After the transfer step, a portion of the ink is transferred into the textile or polyester varnish, while another part often remains on the printed face of the complex, which can not be reused and is difficult to recycle.

It should be noted that inkjet printing is a technique that responds to the concept of print on demand, with low series, in comparison with traditional textile printing techniques to frames.

In order to reduce the amount of non-transferred dyes during the transfer step, it has been proposed to apply a barrier layer opposite the face to be printed, adapted to limit the penetration depth of the pigments in the process. transfer paper. This barrier layer has made it possible to improve the transfer rate of the pigments on the substrate and to facilitate the application of the image on the substrate.

The document EP 1 102 682 proposes for example a transfer paper having, on the face to be printed, a water-soluble resin having porosity less than 25 mL / min. This paper has a satisfactory transfer rate and colorimetric rendering. However, the paper has a basis weight between 40 and 120 g / m ² , preferably between 60 g / m ² and 80 g / m ² , which represents a significant cost for manufacturers in terms of ink consumption and amount of waste from the transfer step.

SUMMARY OF THE INVENTION

An object of the invention is therefore to provide a new transfer paper having a basis weight lower than the paper usually marketed while having a transferability at least equivalent and a transfer speed at least equal or greater.

This new transfer paper will allow market manufacturers to significantly reduce the amount of waste at the end of the transfer stage, to reduce ink consumption, with at least equal reproduction quality.

Another object of the invention is to provide such a transfer paper, further having good machinability throughout the transfer process, that is to say a transfer paper capable of ensuring good support and a flattening on the glued carpet of the press during the transfer stage, and a catch without transfer or fouling of the carpet.

• une couche réservoir, présentant une face externe configurée pour recevoir une encre sublimable et une face interne, et
• une couche barrière, appliquée sur la face interne de la couche réservoir et configurée pour former une barrière au véhicule de l'encre sublimable, ladite couche barrière comprenant entre 70% et 100% en poids sec de fibres de cellulose, de préférence au moins 80% en poids sec,

le papier transfert étant caractérisé en ce que la couche réservoir comprend

• au moins 60% en poids sec de pigments principaux présentant un diamètre moyen compris entre 0.2 micromètres et 0.8 micromètres, et
• au plus 45% en poids sec de pigments secondaires présentant un diamètre moyen supérieur au diamètre moyen des pigments principaux.

For this, the invention proposes a transfer paper comprising:

• a reservoir layer, having an outer face configured to receive a sublimable ink and an inner face, and
• a barrier layer, applied on the inner face of the reservoir layer and configured to form a barrier to the vehicle of the sublimable ink, said barrier layer comprising between 70% and 100% by dry weight of cellulose fibers, preferably at least 80 % by dry weight,

the transfer paper being characterized in that the reservoir layer comprises

• at least 60% by dry weight of main pigments having an average diameter of between 0.2 micrometers and 0.8 micrometers, and
• at most 45% by dry weight of secondary pigments having an average diameter greater than the average diameter of the main pigments.

• les fibres de cellulose présentent une longueur moyenne de fibres comprise entre 0.4 mm et 0.9 mm, de préférence de l'ordre de 0.65 mm,
• les fibres de cellulose présentent un niveau de raffinage mesuré en degrés Schopper-Riegler compris entre 38°SR et 42°SR,
• les fibres de cellulose comprennent un mélange de fibres issues de bois résineux et/ou de feuillus,
• la couche barrière comprend en outre entre 3% et 15% en poids sec d'une charge minérale, typiquement entre 6% et 12% en poids sec, par exemple 9%,
• la couche barrière comprend en outre un agent de collage de type alkyl cétène dimère (AKD) ou anhydre alkylsuccénique (ASA) présentant une qualité de collage suivant le test COBB avec un temps de contact de 60 secondes inférieure à 20 g/m²,
• la couche barrière présente un grammage compris entre 30 g/m² et 40 g/m², typiquement entre 32 g/m² et 35 g/m², par exemple de l'ordre de 34 g/m²,
• les pigments principaux présentent un diamètre moyen compris entre 0.3 micromètres et 0.6 micromètres,
• les pigments principaux comprennent du carbonate de calcium précipité, par exemple du type aragonite, rhomboédrique, scalenoédrique ou prismatique, de préférence du type aragonite,
• le papier transfert comprend au plus 30% en poids sec de pigments secondaires, de préférence au plus 20% en poids sec,
• les pigments secondaires présentent un diamètre moyen compris entre 0.3 micromètres et 2 micromètres, de préférence entre 0.5 micromètres et 1.5 micromètres,
• les pigments secondaires comprennent du carbonate de calcium broyé ou du kaolin,
• la couche réservoir comprend au plus 15% en poids sec d'un liant, par exemple un liant à base d'amidon et/ou d'alcool polyvinylique,
• la couche réservoir présente un grammage compris entre 2 g/m² et 8 g/m², de préférence entre 3 g/m² et 6 g/m²,
• le papier transfert comprend en outre une couche d'adhésivage, fixée sur la couche barrière à l'opposé de la couche réservoir, ladite couche d'adhésivage étant configurée pour assurer une bonne machinabilité du papier transfert et comprenant un agent cohésif, par exemple des polysaccharides ou de l'alcool polyvinylique (PVA),
• la couche d'adhésivage présente un grammage compris entre 0.1 g/m² et 10 g/m², de préférence entre 0.3 g/m² et 0.6 g/m²,
• le papier transfert présente une porosité Bendtsen supérieure à 100 mL/min, de préférence supérieure à 125 mL/min, typiquement supérieure à 150 mL/min,
• le papier transfert présente un grammage compris entre 35 g/m² et 45 g/m², typiquement entre 38 g/m² et 40 g/m², par exemple 39 g/m², et
• le papier transfert présente un indice d'aptitude au transfert supérieur à 20, de préférence supérieur ou égal à 22.

Some preferred but non-limiting aspects of the transfer paper described above are as follows, taken individually or in combination:

• the cellulose fibers have an average fiber length of between 0.4 mm and 0.9 mm, preferably of the order of 0.65 mm,
• the cellulose fibers have a degree of refining measured in Schopper-Riegler degrees between 38 ° SR and 42 ° SR,
• the cellulose fibers comprise a mixture of fibers derived from softwood and / or hardwoods,
• the barrier layer further comprises between 3% and 15% by dry weight of a mineral filler, typically between 6% and 12% by dry weight, for example 9%,
• the barrier layer further comprises a ketene dimer (AKD) or anhydrous alkylsuccenic (ASA) type bonding agent having a quality of bonding according to the COBB test with a contact time of 60 seconds of less than 20 g / m ² ,
• the barrier layer has a basis weight of between 30 g / m ² and 40 g / m ² , typically between 32 g / m ² and 35 g / m ² , for example of the order of 34 g / m ² ,
• the main pigments have an average diameter of between 0.3 micrometers and 0.6 micrometers,
• the main pigments comprise precipitated calcium carbonate, for example of the aragonite, rhombohedral, scalenoedric or prismatic type, preferably of the aragonite type,
• the transfer paper comprises at most 30% by dry weight of secondary pigments, preferably at most 20% by dry weight,
• the secondary pigments have a mean diameter of between 0.3 micrometers and 2 micrometers, preferably between 0.5 micrometers and 1.5 micrometers,
• the secondary pigments comprise ground calcium carbonate or kaolin,
• the reservoir layer comprises at most 15% by dry weight of a binder, for example a binder based on starch and / or polyvinyl alcohol,
• the reservoir layer has a weight of between 2 g / m ² and 8 g / m ^2, preferably between 3 g / m ² and 6 g / m ^2,
• the transfer paper further comprises an adhesive layer, fixed on the barrier layer opposite the reservoir layer, said adhesive layer being configured to ensure good machinability of the transfer paper and comprising a cohesive agent, e.g. polysaccharides or polyvinyl alcohol (PVA),
• the adhesive layer has a basis weight of between 0.1 g / m ² and 10 g / m ² , preferably between 0.3 g / m ² and 0.6 g / m ² ,
• the transfer paper has a Bendtsen porosity greater than 100 ml / min, preferably greater than 125 ml / min, typically greater than 150 ml / min,
• the transfer paper has a basis weight of between 35 g / m ² and 45 g / m ² , typically between 38 g / m ² and 40 g / m ² , for example 39 g / m ² , and
• the transfer paper has a transferability index greater than 20, preferably greater than or equal to 22.

• former la couche barrière sur une machine à papier, et
• déposer la couche réservoir sur une face de la couche barrière, ladite couche réservoir comprenant :
• au moins 60% en poids sec de pigments principaux présentant un diamètre moyen compris entre 0.2 micromètres et 0.8 micromètres, et
• au plus 45% en poids sec de pigments secondaires présentant un diamètre moyen supérieur au diamètre moyen des pigments principaux.

According to a second aspect, the invention also proposes a method for manufacturing a transfer paper as described above, comprising the following steps:

• forming the barrier layer on a paper machine, and
• depositing the reservoir layer on one side of the barrier layer, said reservoir layer comprising:
• at least 60% by dry weight of main pigments having an average diameter of between 0.2 micrometers and 0.8 micrometers, and
• at most 45% by dry weight of secondary pigments having an average diameter greater than the average diameter of the main pigments.

• l'étape de formation de la couche barrière (3) comprend les sous-étapes suivantes : mettre les fibres de cellulose en dispersion aqueuse dans un pulpeur, et raffiner les fibres de cellulose afin d'obtenir un niveau de raffinage mesuré en degré Schopper-Riegler (°SR) compris entre 38°SR et 42°SR, et une longueur moyenne de fibres comprise entre 0.4 mm et 0.9 mm, préférentiellement de l'ordre de 0.65 mm,
• la sous-étape de raffinage des fibres de cellulose est réalisée en deux phases au cours desquelles : la dispersion aqueuse est raffinée dans une première boucle de raffinage comprenant un raffineur conique de type Claflin 202 à lames fibrillantes et d'un raffineur double disques Duo-flow 26 pouces à lames fibrillantes avec un recyclage de 20% et dans une deuxième boucle de raffinage comprenant deux raffineurs double disques Duo-flow 26 pouces à lames fibrillantes avec un recyclage de 10% de manière à obtenir un degré Schopper-Riegler compris entre 37°SR et 41°SR, typiquement de l'ordre de 39°SR, et un indice de longueur de fibres (FLI) compris entre 0.3 mm et 0.5 mm, de préférence de l'ordre de 0.4 mm, puis la dispersion de fibres de cellulose passe dans une boucle de raffinage de tête comprenant un raffineur conique de type Claflin 202 à lames coupantes afin d'obtenir une longueur moyenne de fibre de cellulose comprise entre 0.4 mm et 0.9 mm, préférentiellement 0.65 mm,
• le procédé comprend en outre une étape au cours de laquelle une couche d'adhésivage est déposée sur une autre face de la couche barrière, ladite couche d'adhésivage étant configurée pour assurer une bonne machinabilité du papier transfert et comprenant un agent cohésif, par exemple des polysaccharides ou de l'alcool polyvinylique (PVA),
• la couche réservoir est déposée à l'aide d'une size press, d'un système de transfert de couche par crayon doseur, d'une coucheuse à lame, d'un dispositif de couchage rideau,
• la couche réservoir et/ou la couche barrière est déposée en ligne sur la machine à papier, et
• la couche réservoir et/ou la couche barrière est imprimée hors ligne, par héliogravure, rotogravure, ou flexographie.

Some preferred but non-limiting aspects of the manufacturing method described above are as follows:

• the step of forming the barrier layer (3) comprises the following sub-steps: placing the cellulose fibers in aqueous dispersion in a pulper, and refining the cellulose fibers to obtain a degree of refining measured in Schopper-degree Riegler (° SR) between 38 ° SR and 42 ° SR, and an average fiber length of between 0.4 mm and 0.9 mm, preferably of the order of 0.65 mm,
• the sub-step of refining the cellulose fibers is carried out in two phases during which: the aqueous dispersion is refined in a first refining loop comprising a conical refiner of Claflin 202 type with fibrillating blades and a Duo double-disc refiner for 26 inches with fibrillating blades with 20% recycling and in a second refining loop including two 26-inch Duo-flow double-disc refiners with fibrillating blades with 10% recycling to achieve a Schopper-Riegler degree of between 37 ° SR and 41 ° SR, typically of the order of 39 ° SR, and a fiber length index (FLI) of between 0.3 mm and 0.5 mm, preferably of the order of 0.4 mm, and then the dispersion of fibers of cellulose passes through a refining loop head including a conical refiner type Claflin 202 cutting blades to obtain an average length of cellulose fiber between 0.4 mm and 0.9 mm, preferably 0. 65 mm,
• the method further comprises a step in which an adhesive layer is deposited on another side of the barrier layer, said adhesive layer being configured to ensure good machinability of the transfer paper and comprising a cohesive agent, for example polysaccharides or polyvinyl alcohol (PVA),
• the reservoir layer is deposited using a size press, a metering pencil layer transfer system, a blade coater, a curtain coating device,
• the reservoir layer and / or the barrier layer is deposited in line on the paper machine, and
• the reservoir layer and / or the barrier layer is printed offline, by gravure, rotogravure, or flexography.

According to a third aspect, the invention also proposes a method for transferring a pattern or an image using a transfer calender, characterized in that the pattern or image has been printed using sublimable ink on the outer face of a reservoir layer of a transfer paper as described above.

BRIEF DESCRIPTION OF THE DRAWINGS

• La figure 1 illustre une vue éclatée d'un exemple de réalisation d'un papier transfert conforme à l'invention, et
• La figure 2 est un organigramme représentant différentes étapes d'un exemple de réalisation du procédé de fabrication d'un papier transfert conforme à l'invention,
• Les Figures 3 à 5 sont des graphes représentant, pour différents papiers transferts, la densité optique dans les couleurs primaire (Fig. 3), la densité optique en trichromie, en bichromie et en aplat de noir (Fig. 4) et le mal uni et l'aptitude au transfert (Fig. 5).

Other features, objects and advantages of the present invention will appear better on reading the detailed description which follows, and with reference to the appended drawings given by way of non-limiting examples and in which:

• The figure 1 illustrates an exploded view of an exemplary embodiment of a transfer paper according to the invention, and
• The figure 2 is a flowchart showing various steps of an exemplary embodiment of the method of manufacturing a transfer paper according to the invention,
• The Figures 3 to 5 are graphs representing, for different transfer papers, the optical density in the primary colors ( Fig. 3 ), the optical density in three-color, two-color and black ( Fig. 4 ) and unified evil and transferability ( Fig. 5 ).

DETAILED DESCRIPTION OF AN EMBODIMENT

A transfer paper 1 according to the invention will now be described with reference to the accompanying figures.

This transfer paper 1 can be made online, that is to say on the paper machine, or offline, for example by printing. The transfer paper 1 is then able to be wound on a reel for storage purposes, then unrolled to be printed typically on a digital press and then applied hot by means of a transfer calender on a given substrate.

The substrate may also be a textile composed of polyester or a mixture of polyester and other fibers, or a hard substrate previously treated with a varnish such as a polyester varnish.

• une couche réservoir 2, présentant une face externe 20 configurée pour recevoir une encre sublimable 5 et une face interne 22, et
• une couche barrière 3, appliquée sur la face interne 22 de la couche réservoir 2, et configurée pour former une barrière au véhicule de l'encre sublimable 5.

The transfer paper 1 comprises:

• a reservoir layer 2, having an outer face 20 configured to receive a sublimable ink 5 and an inner face 22, and
• a barrier layer 3, applied on the inner face 22 of the reservoir layer 2, and configured to form a barrier to the vehicle of the sublimable ink 5.

The sublimable ink 5 comprises dyes and a vehicle which may in particular comprise glycol. In order to be ink jet printed, the sublimable ink 5 is preferably aqueous based.

In one embodiment, the transfer paper 1 further comprises an adhesive layer 4, fixed on the barrier layer 3 opposite the reservoir layer 2, to ensure good machinability of the transfer paper 1.

Barrier layer 3

The barrier layer 3 comprises between 70% and 100%, preferably at least 80% by dry weight, for example between 85% and 95% by dry weight, of cellulose fibers. Preferably, the cellulose fibers are derived from softwood and / or hardwood, corresponding respectively to long fibers (resinous) and short fibers (hardwood). By long fibers, cellulose fibers having a length of between 1.8 mm and 2.5 mm will be understood, while by short fibers, fibers having a length of between 0.3 mm and 1 mm will be understood.

For example, the cellulose fibers comprise a mixture of long fibers and short fibers.

The cellulose fibers may in particular be obtained in a conventional manner using a process known as "kraft" or "sulfate", in which the raw material (that is to say the pulp used for the manufacture of paper) is cooked under pressure at high temperature in the presence of chemical actives (usually sodium hydroxide (NaOH) and sodium sulphide (Na ₂ S)) to soften and remove lignin and retain only cellulose fibers. Such a manufacturing method is known per se and will not be further detailed here.

In one embodiment of the invention, these cellulose fibers are then dispersed in water in a pulper, and refined to obtain a sufficient cutting length, fibrillation and hydration level to form a barrier layer. 3 having sufficient mechanical characteristics to absorb voltages and titrations in unwinding and winding the coil.

For this, during a first sub-step, the aqueous dispersion of cellulose fiber can in particular pass into a first refining loop, called the main refining, which aims to achieve a level of refining measured in Schopper- Riegler (° SR) between 37 ° SR and 41 ° SR, preferably of the order of 39 ° SR, and a fiber length index (FLI), determining the state of shortening of the fibers, between 0.3 mm and 0.5 mm, preferably of the order of 0.4 mm. Then, during a second substep, the aqueous dispersion of cellulose fibers can pass into a second refining loop, called head refining, which aims to adjust the length of the cellulose fibers before they arrive on the forming table of a paper machine and obtain an average fiber length of between 0.4 mm and 0.9 mm, preferably of the order of 0.65 mm. The level of fiber refinement is also in the range of 38 ° SR to 42 ° SR.

For example, during the first substep, i.e. in the main refining, an aqueous dispersion of cellulose fibers at a temperature of concentration between 3.5 and 4%, preferably 3.7% can pass into a first refining loop comprising a Claflin 202 type conical refiner with fibrillating blades and a 26-inch Duo-flow double-finned refiner with fibrillating blades 20% and in a second refinery loop comprising two 26-inch Duo-flow double-disc refiners with fibrillating blades with a 10% recycling. The specific refining power required to obtain a Schopper-Riegler 39 ° SR degree and a FLI fiber length index of 0.4 mm is between 220 kwh / T and 280 kwh / T of cellulose fiber preferably 250 kWh / T of cellulose fiber.

During the second sub-step, the aqueous dispersion of cellulose fibers can then pass into the top refining loop consisting of a Claflin 202 type conical refiner with cutting blades to obtain an average fiber length between 0.4 mm and 0.9 mm, preferably 0.65 mm.

Cellulose fibers made from softwood and hardwood can be refined together or separately. Preferably, they are refined together.

With this composition based on cellulose fibers, the barrier layer 3 has sufficient mechanical characteristics to absorb tension and pulling unwinding and winding of the coil, and good breaking strength in the long sense and in the sense transverse. The Applicant has in particular found that it was then possible to reduce the weight of the transfer paper 1 without affecting its behavior during the transfer step sublimable ink 5. Indeed, it becomes possible to obtain a barrier layer 3 having a basis weight of between 30 g / m ² and 40 g / m ² , typically between 32 g / m ² and 35 g / m ² , for example of the order of 34 g / m ² .

The barrier layer 3 also has a high level of hydrophobicity enabling it to form a barrier to the vehicle of the sublimable ink 5, and a permeability sufficiently high to allow the temperature exchange with the substrate by transmitting the sublimation energy necessary for the sublimable ink 5 to pass from the solid state to the gaseous state during the dye transfer step of the sublimable ink 5 on the substrate.

The composition of the barrier layer 3 finally allows the attachment of the reservoir layer 2 and the adhesive layer 4, if necessary, guaranteeing the functionality of each of these layers.

In one embodiment, the barrier layer 3 further comprises between 3% and 15% by dry weight of a mineral filler, typically between 6% and 12% by dry weight.

For example, the barrier layer 3 may comprise of the order of 90% of cellulose fibers for 10% mineral filler, for example a mineral filler based on ground or precipitated calcium carbonate, Kaolin or any other type of pigment. titanium dioxide, talc, etc.

In order to confer a hydrophobic character to the barrier layer 3, it can also be treated with chemical compounds called alkyl ketene dimer bonding agents (AKD) or anhydrous alkylsuccenic acid (ASA) having a bonding quality according to the test COBB ₆₀ with a contact time of 60 seconds less than 25 g / m ² , preferably less than 20 g / m ² .

In one embodiment, the barrier layer 3 has an absolute humidity of between 4% and 8%, preferably between 5% and 7%. This moisture content gives good dimensional stability to the barrier layer 3, which allows the transfer paper 1 to absorb solid ink and therefore a high volume of ink per square meter during the printing step pattern or image on the outer face 20 of the reservoir layer 2.

The composition of the barrier layer thus obtained may then have a Bendtsen porosity (measured according to the NF Q 03-076 standard) greater than 300 ml / min.

The barrier layer 3 comprises, in a manner known per se, a rough face 30 (corresponding to the face facing the fabric of the papermaking machine), and a smooth face 32 (or felt face). In one embodiment, the inner face 22 of the reservoir layer 2 may be formed on the rough face 30 of the barrier layer 3. This is however not limiting, since the reservoir layer 2 could also be formed on its smooth face 32.

Tank layer 2

The reservoir layer 2 comprises at least 60% by dry weight of main pigments having a mean diameter of between 0.2 micrometers and 0.8 micrometers, preferably between 0.3 micrometers and 0.6 micrometers. The Applicant has in fact noticed that such a reservoir layer 2 made it possible to obtain a good transfer rate of the sublimable ink 5.

The main pigments may in particular comprise precipitated calcium carbonate, for example of the aragonite, rhombohedral, scalenohedral or prismatic type.

In one embodiment, the main pigments comprise precipitated calcium carbonate of the aragonite type.

Optionally, the reservoir layer 2 may further comprise secondary pigments having a mean diameter greater than the average diameter of the main pigments. The combination of the main pigments and the secondary pigments makes it possible to obtain a polydispersity of the pigments reducing the homogeneity of the particle size of the pigments in the reservoir layer 2 and improving the colorimetric density and the definition of the pattern after it is transferred onto the substrate. The Applicant has indeed found that the use of a transfer paper 1 having a reservoir layer 2 comprising only the main pigments could create phenomena of "poorly united", that is to say a poor uniformity of deposit resulting in a large percentage of non-inked area. It will be noted that the phenomena of unevenness are measured in the field of textile printing on solid areas of color converted to gray level and are expressed as a percentage of non-inked area.

In one embodiment, the reservoir layer 2 comprises at most 45% by dry weight of secondary pigments, typically at most 30% by dry weight, preferably at most 20% by dry weight. Moreover, the secondary pigments may in particular have a mean diameter of between 0.3 micrometers and 2 micrometers, preferably between 0.5 micrometers and 1.5 micrometers. The secondary pigments may in particular comprise ground calcium carbonate or kaolin.

In one embodiment, the reservoir layer 2 may further comprise a binder, for example based on starch and / or polyvinyl alcohol.

Preferably, the reservoir layer 2 comprises at most 15% of binder. For example, the reservoir layer 2 may comprise about 8% by dry weight of starch and 4% by dry weight of polyvinyl alcohol.

In order to fix the dyes of the sublimable ink 5 on the surface of the transfer paper 1, that is to say at the external face 20 of the reservoir layer 2, and thus to improve its transfer rate, the reservoir layer 2 may further comprise a cationic polymer. Since the dyes of the ink are anionic, they remain at the outer face 20 of the reservoir layer 2, while the vehicle of the ink is absorbed by the latter.

Typically, the cationic polymer may comprise diallyldimethylammonium polychloride (also known as polyDADMAC), typically between 3 and 5% by dry weight, for example 4.2%.

For example, the reservoir layer 2 may comprise of the order of 7% by dry weight of diallyldimethylammonium chloride.

It is then possible to obtain a reservoir layer 2 having a grammage of between 2 g / m ² and 8 g / m ² , preferably between 3 g / m ² and 6 g / m ² with good transferability.

In an exemplary embodiment, a transfer paper 1 comprising a reservoir layer 2 of a weight of between 3 g / m ² and 6 g / m ² comprising precipitated aragonite calcium carbonate with a mean diameter of between 0.3 micrometers and 0.6 micrometers , makes it possible to improve the reproduction of the primary colors with respect to a paper available on the market, with higher optical densities, especially in the yellow, and partly with higher optical density levels in two colors, in particular for the yellow-cyan mixture and the yellow-magenta mixture. This transfer paper 1 also makes it possible to reduce the ink level during the printing step, and therefore the ink consumption, in accordance with the current market requirements, and guarantees a better stability of the transfer paper 1 at the time of printing. printing thanks to a lower volume of ink per square meter.

Adhesive layer 4

The adhesive layer 4 is adapted to ensure the maintenance and the flattening of the transfer paper 1 on the glued mat of the press to avoid generating printing defects on the substrate during the transfer step. The adhesive layer 4 is furthermore configured to ensure a sufficient level of adhesion of the transfer paper 1 to the glued carpet, while preventing it from being fouled by the release of fibers, fine particles or fillers contained in the transfer paper 1 for to limit the need for renewal of the glue-in-place glue, which requires stopping the press.

For this purpose, the adhesive layer 4 may comprise a cohesive agent and bonding agents, conferring hydrophobic properties.

For example, the cohesive agent may comprise a hydrophilic binder, such as polysaccharides or polyvinyl alcohol (PVA), typically a hydrophilic starch-based binder.

In one embodiment, the dry ratio of sizing agent to starch may be from 0% to 5%, preferably from 2% to 4%.

It is then possible to obtain an adhesive layer 4 having a basis weight of between 0.1 g / m ² and 1.0 g / m ² , preferably between 0.3 g / m ² and 0.6 g / m ² .

Example of transfer paper 1

An example of transfer paper 1 according to the invention comprising a reservoir layer 2 comprising precipitated calcium carbonate, secondary pigments and a binder in the proportions indicated above makes it possible to improve the transfer rate by at least 10%. sublimable ink 5 based on water compared to a conventional transfer paper 1.

Furthermore, thanks in particular to the formulation of the barrier layer 3, it is possible to obtain a transfer paper 1 formed of the superposition of the adhesive layer 4, the barrier layer 3 and the reservoir layer, having a basis weight between 20 g / m ² and 50 g / m ² , preferably between 25 g / m ² and 45 g / m ² , more preferably between 30 g / m ² and 40 g / m ² , without reducing the productivity of the press.

• une couche réservoir 2 présentant :
  • * 71 % de carbonate de calcium précipité (en poids sec par rapport au poids sec de la couche totale) ayant un diamètre moyen de 0.4 micromètres,
  • * 12.5 % de kaolin (en poids sec par rapport à la couche réservoir 2) dont 81 % des particules en poids sec présentent un diamètre inférieur à 2 micromètres et
  • * 12.3% de liant (en poids sec par rapport à la couche réservoir 2), le liant comprenant 67 % d'amidon et 33% d'alcool polyvinylique (PVA)
  • * 4.2% de PolyDADMAC (en poids sec par rapport à la couche réservoir 2)
• une couche barrière 3 présentant :
  • * 92% de fibre de cellulose (en poids sec par rapport au poids sec de la couche barrière 3), les fibres de cellulose comprenant 17% de fibres de résineux et 83% de fibres de feuillus,
  • * 7% de carbonate de calcium précipité (en poids sec par rapport à la couche barrière 3) ayant un diamètre moyen de 1.4µm,
  • * 0.8% d'agent de collage (en poids sec par rapport à la couche barrière 3), l'agent de collage comprenant 12.5% d'anhydre alkylsuccénique (ASA) et 87.5% d'alkyl cétène dimère (AKD)
• une couche d'adhésivage 4 présentant :
  • * 94% d'amidon (en poids sec par rapport au poids sec de la couche d'adhésivage 4),
  • * 1.4% d'agent de collage de type alkyl cétène dimère (en poids sec par rapport au poids sec de la couche d'adhésivage 4)

présente les caractéristiques suivantes : Tableau 1 Papier conventionnel Papier transfert 1 de l'invention Grammage (g/m²) 64 39 Quantité d'encre déposée (g/m²) 4.1 4.2 Poids total après impression (g/m²) 68.1 43.2 Poids total après transfert (g/m²) 66 40.4 Quantité d'encre restituée (g/m²) 2.1 2.8 Taux de transfert de l'encre (%) 51% 67% Poids pour 10 000m² (kg) 640 390 Surface imprimée avec une tonne de papier (m²) 15 625 25 641 Aptitude transfert +++ +++ Consommation encre ++ + Vitesse transfert ++ +++ Thus, a transfer paper 1 comprising:

• a reservoir layer 2 having:
  • * 71% of precipitated calcium carbonate (in dry weight relative to the dry weight of the total layer) having an average diameter of 0.4 micrometers,
  • * 12.5% of kaolin (in dry weight with respect to the reservoir layer 2) of which 81% of the particles by dry weight have a diameter of less than 2 micrometers and
  • * 12.3% binder (dry weight relative to the reservoir layer 2), the binder comprising 67% starch and 33% polyvinyl alcohol (PVA)
  • * 4.2% PolyDADMAC (in dry weight compared to the reservoir layer 2)
• a barrier layer 3 having:
  • * 92% of cellulose fiber (in dry weight relative to the dry weight of the barrier layer 3), the cellulose fibers comprising 17% of softwood fibers and 83% of hardwood fibers,
  • * 7% of precipitated calcium carbonate (in dry weight relative to the barrier layer 3) having an average diameter of 1.4 μm,
  • * 0.8% of bonding agent (in dry weight relative to the barrier layer 3), the bonding agent comprising 12.5% of anhydrous alkylsuccenic (ASA) and 87.5% of alkyl ketene dimer (AKD)
• an adhesive layer 4 having:
  • * 94% of starch (in dry weight relative to the dry weight of the adhesive layer 4),
  • * 1.4% of alkyl ketene dimer bonding agent (in dry weight relative to the dry weight of the adhesive layer 4)

has the following characteristics: <u> Table 1 </ u> Conventional paper Transfer paper 1 of the invention Weight (g / m ² ) 64 39 Amount of ink deposited (g / m ² ) 4.1 4.2 Total weight after printing (g / m ² ) 68.1 43.2 Total weight after transfer (g / m ² ) 66 40.4 Quantity of ink returned (g / m ² ) 2.1 2.8 Ink transfer rate (%) 51% 67% Weight per 10,000m ² (kg) 640 390 Surface printed with one ton of paper (m ² ) 15,625 25,641 Transferability +++ +++ Ink consumption ++ + Transfer speed ++ +++

The transfer paper 1 described above therefore has a transfer rate greater than 16% compared with conventional paper, for a weight reduction of 39%. On the other hand, the paper surface that can be printed with one ton of transfer paper 1 according to the invention can be increased by 64% over conventional transfer paper 1.

It will be noted that the inevitable variability of the measurements, the tolerance of which, in particular as regards the basis weight of the paper, is of the order of ± 1 g / m ² . <u> Table 2 </ u> Target ( I _i target ) Low Conventional paper Transfer paper 1 of the invention Optical density of primary colors Cyan (C) 1.7 1.6 1.76 1.86 Magenta (M) 1.6 1.5 1.74 1.85 Yellow (J) 1.1 1 1.14 1.22 Black ( I ₁ ) 1.4 1.2 1.48 1.54 C x M x D (I ₂ ) 3 2.5 3.49 4.20 Optical Density in Duotone (CxJ) + (MxD) (I ₃ ) (C x J) 2.5 2.3 1.06 1.10 (M x D) 1.34 1.34 Optical density Flat black (I ₄ ) 1.5 1.4 1.60 1.52 Badly united (I ₅ ) 95 90 98.1 97.4

Table 2 compares the recovery of the image of the pattern according to several factors, including the optical density measured in the dark I ₁ and I ₂ primary colors 100% ink (the index _I2 corresponding to the product of the optical densities measured in yellow, magenta and cyan), the optical density measured on the black solid areas I ₄ composed of the addition of the three primary colors (Cyan, Magenta and Yellow), the optical density measured in two colors I ₃ (c that is, the sum of the optical density measured for Cyan and Yellow on the one hand and Magenta and Yellow on the other hand), the uniformity of deposit in percentage of inked area I ₅ (or the "unevenness", expressed as a percentage of inked area relative to the non-inked area) on flat areas of colors converted to gray level.

As can be seen in the table above, the transfer paper 1, which corresponds to the transfer paper 1 defined in Table 1, has values higher than the minimum threshold values defined for the parameters studied. Moreover, the restitution of the primary colors of the transfer paper 1 has been improved compared with conventional paper, with higher optical densities, especially in the yellow and partly by higher optical density levels in two colors, in particular for the paper. yellow-cyan mixture and the yellow-magenta mixture, despite the significantly reduced basis weight of the transfer paper 1 of the invention.

Optical density measurements were performed on various examples of transfer papers.

• * 71 % de carbonate de calcium précipité (en poids sec par rapport au poids sec de la couche totale) ayant un diamètre moyen de 0.4 micromètres,
• * 12.5 % de kaolin (en poids sec par rapport à la couche réservoir 2) dont 81 % des particules en poids sec présentent un diamètre inférieur à 2 micromètres
• * 12.3% de liant (en poids sec par rapport à la couche réservoir 2), le liant comprenant 67 % d'amidon et 33% d'alcool polyvinylique (PVA) et
• * 4.2% de PolyDADMAC (en poids sec par rapport à la couche réservoir 2).

Test No. 2 corresponds to the example of transfer paper according to the invention of Tables 1 and 2, comprising in particular in the reservoir layer 2:

• * 71% of precipitated calcium carbonate (in dry weight relative to the dry weight of the total layer) having an average diameter of 0.4 micrometers,
• * 12.5% of kaolin (in dry weight with respect to the reservoir layer 2) of which 81% of the particles by dry weight have a diameter of less than 2 micrometers
• * 12.3% of binder (in dry weight relative to the reservoir layer 2), the binder comprising 67% of starch and 33% of polyvinyl alcohol (PVA) and
• * 4.2% PolyDADMAC (in dry weight relative to the reservoir layer 2).

In this test No. 2, the pigments of the reservoir layer 2 therefore comprise 100 parts of dry pigments including 85 parts of main pigment and 15 parts of secondary pigments.

• * 58.5% de carbonate de calcium précipité (en poids sec par rapport au poids sec de la couche totale) ayant un diamètre moyen de 0.4 micromètres,
• * 25 % de kaolin (en poids sec par rapport à la couche réservoir 2) dont 81 % des particules en poids sec présentent un diamètre inférieur à 2 micromètres
• * 12.3% de liant (en poids sec par rapport à la couche réservoir 2), le liant comprenant 67 % d'amidon et 33% d'alcool polyvinylique (PVA) et
• * 4.2% de PolyDADMAC (en poids sec par rapport à la couche réservoir 2).

Test No. 1 corresponds to a second example of a transfer paper 1 according to the invention, the reservoir layer 2 of which comprises:

• * 58.5% of precipitated calcium carbonate (in dry weight relative to the dry weight of the total layer) having an average diameter of 0.4 micrometers,
• * 25% of kaolin (in dry weight relative to the reservoir layer 2) of which 81% of the particles by dry weight have a diameter of less than 2 micrometers
• * 12.3% of binder (in dry weight relative to the reservoir layer 2), the binder comprising 67% of starch and 33% of polyvinyl alcohol (PVA) and
• * 4.2% PolyDADMAC (in dry weight relative to the reservoir layer 2).

In this test No. 1, the pigments of the reservoir layer 2 therefore comprise 100 parts of dry pigments, of which 70 parts of the main pigment and 30 parts of secondary pigments.

• * 82.5% de carbonate de calcium précipité (en poids sec par rapport au poids sec de la couche totale) ayant un diamètre moyen de 0.4 micromètres,
• * 12.3% de liant (en poids sec par rapport à la couche réservoir 2), le liant comprenant 67 % d'amidon et 33% d'alcool polyvinylique (PVA) et
• * 4.2% de PolyDADMAC (en poids sec par rapport à la couche réservoir 2).

Test No. 3 is a comparative example in which the reservoir layer comprises only main pigments. Thus, the reservoir layer of test No. 3 comprises:

• * 82.5% of precipitated calcium carbonate (in dry weight relative to the dry weight of the total layer) having an average diameter of 0.4 micrometers,
• * 12.3% of binder (in dry weight relative to the reservoir layer 2), the binder comprising 67% of starch and 33% of polyvinyl alcohol (PVA) and
• * 4.2% PolyDADMAC (in dry weight relative to the reservoir layer 2).

In this test No. 3, the pigments of the reservoir layer 2 thus comprise 100 parts of dry pigments, of which 100 parts of main pigment.

It will be noted that the barrier layer 3 and the adhesive layer 4 are identical in the three tests.

The following results are then obtained: <u> Table 3 </ u> Test n ° 1 Test n ° 2 Test No. 3 (Comparative) Optical density in primary colors Cyan C 1.74 1.86 1.67 Magenta M 1.61 1.85 1.52 Yellow J 1.14 1.22 1.1 Black N 1.35 1.54 1.28 Optical density in two colors CxMxJ 3.2 4.2 2.83 CXM 0.98 1.1 0.97 MXJ 1.21 1.34 1.2 Optical density flat of black 1.37 1.52 1.4 Badly united 82.4 97.4 87.5 Ability to transfer 17.5 20.5 17.2

• la densité optique dans les couleurs primaire (Fig. 3) obtenue à l'aide d'un densitomètre de marque TECHKON R410e,
• la densité optique en trichromie, en bichromie et en aplat de noir (Fig. 4) obtenue obtenue à l'aide d'un densitomètre de marque TECHKON R410e,
• le mal uni (Fig. 5) et l'aptitude au transfert (voir ci-après) obtenus à l'aide d'un logiciel de traitement d'images, ici ImageJ.

The Figures 3 to 5 are graphs representing, on the abscissa, the number of the test, and on the ordinate (for each of the tests n ° 1 to 3):

• the optical density in the primary colors ( Fig. 3 ) obtained using a TECHKON R410e densitometer,
• the optical density in three-color, two-color and black ( Fig. 4 ) obtained using a TECHKON R410e densitometer,
• the united evil ( Fig. 5 ) and transferability (see below) obtained using an image processing software, here ImageJ.

These measurements show that the optical density in the primary colors, in particular for black, cyan and magenta, and in trichromium (CxMxY) is particularly improved when the reservoir layer 2 comprises at least 60% by dry weight (on the total weight of pigments) of a main pigment and at most 45% by dry weight (on the total weight of pigments) of a secondary pigment. Optical density, unevenness and transferability are further improved when the reservoir layer comprises 85% by dry weight (on the total weight of pigments) of the main pigment and 15% by dry weight (on the total weight of pigments ) of the secondary pigment (see Test No. 2).

The Applicant has developed an AT transfer aptitude index in order to qualify both the transfer rate of a transfer paper 1, the colorimetric density of the image or pattern on a given substrate and the definition of that image or pattern on that substrate. The AT transferability index thus defined groups the measurement of the optical density measured in the black I ₁ and the primary colors I ₂ to 100% of inking, the optical density measured on the black solid areas composed of the adding together the three primary colors I _4, the optical density measured duotone I _3, and the uniformity of deposited percentage of inked surface I ₅ (or "evil uni") on flat colors converted grayscale.

As part of the measurements made in Tables 2 and 3, the substrate is a fabric of 88g / m ² in satin weave, made of 100% polyester and printed on its matte surface. In addition, the pattern was printed on the outer face of the reservoir layer 2 using an EPSON WP-4015 DN printer with Rotech inks from Sawgrass, then transferred to the textile using a Promashirt TS-3838ME press. Finally, the optical density was measured using a TECHKON R410e densitometer, and the unevenness was measured using image processing: image-J.

Specifically, this AT proficiency index was defined as the sum of the average of the measured parameters relative to their respective target value multiplied by the reference transferability index (AT _ref ) and divided by the number of parameters taken into account: $$\mathrm{AT}T=\frac{1}{\mathrm{not}}\left({\displaystyle \underset{i=1}{\overset{\mathrm{not}}{\Sigma }}}\frac{I_i*\mathrm{AT}{T}_{\mathit{ref}}}{I_i\mathit{target}}\right)$$

In Table 2 above, the reference transferability index AT _ref was set at 20 and n = 5. Thus, for the mean of the unevenness of the transfer paper 1 of the invention: $$\frac{I_5*\mathrm{AT}{T}_{\mathit{ref}}}{I_5\mathit{target}}=\frac{97.4*20}{95}$$

This gives an AT transferability index of 19.8 for conventional paper, and 20.5 for example of transfer paper 1 of Table 2 (which also corresponds to Test No. 2). The transfer paper 1 according to the invention thus has, from a total point of view, better transfer characteristics than conventional paper, for less ink consumption and a much lower basis weight.

Manufacturing process S of the transfer paper 1

The transfer paper 1 can be made completely online, on a paper machine, or partly on a paper machine and partly offline.

In a first step S1, a barrier layer 3 is formed on a fabric of a paper machine. The barrier layer can be obtained from fibers having undergone the main refining and head substeps described above.

During a second step S2, a reservoir layer 2 is deposited on the barrier layer 3. In one embodiment, the inner face 22 of the reservoir layer 2 is applied to the coarser surface 30, which is rougher, of the barrier layer 3.

In a first embodiment, the deposition of the reservoir layer 2 can be carried out online on the paper machine on a coating station after passing the barrier layer 3 in a drying zone. Typically, the reservoir layer 2 can be deposited using a size press (that is to say a device comprising two cylinders forming between them a bath of sauce comprising the composition to be deposited), a system of layer transfer by metering pens (or "film press"), a blade coater or a curtain coating device.

Alternatively, in a second embodiment, the reservoir layer 2 may be deposited offline. Typically, in this form of In this embodiment, the reservoir layer 2 can be printed by gravure, rotogravure, flexography or coated by means of a size press, a press film, a coater or a curtain coating device.

During this step, the composition of the barrier layer 3 makes it possible to barrier the vehicle with the sublimable ink 5 and thus maintain the dyes in the reservoir layer 2, thereby improving the transfer rate of the transfer paper 1.

During a third step S3, an adhesive layer 4 may be deposited on the barrier layer 3, opposite the reservoir layer 2. In one embodiment, the adhesive layer 4 is applied to the felt side 32, which is smoother, of the barrier layer 3.

In a similar manner to the reservoir layer 2, the adhesive layer 4 can be deposited online on the paper machine, or offline.

Thus, in a first embodiment, the deposition of the adhesive layer 4 can be carried out online on the paper machine on a coating or coating station, after passage of the barrier layer 3 in the drying zone. . Typically, the adhesive layer 4 may be deposited using a size press, a press film, a coater or a curtain coating device.

Alternatively, in a second embodiment, the adhesive layer 4 may be deposited offline. Typically, in this embodiment, the adhesive layer 4 may be printed by rotogravure, rotogravure, flexography or coated by means of a size press, a press film, a coater or a coater. a curtain coating device.

It will of course be understood that the reservoir layer 2 and the adhesive layer 4 can be deposited simultaneously if the depositing device allows it. This is particularly possible when the reservoir layer 2 and the adhesive layer 4 is deposited (online or offline) using a size press, a press film or a coater blade.

Moreover, the adhesive layer 4 can indifferently be deposited on the barrier layer 3 after the reservoir layer 2, or prior to the deposition of the reservoir layer 2.

Finally, the reservoir layer 2 can be deposited in line while the adhesive layer 4 is deposited offline, or vice versa.

The outer face 20 of the transfer paper 1 can then be printed conventionally, typically using an ink jet printer. Since the reservoir layer 2 has a high transfer rate, it is possible, however, to reduce the amount of sublimable ink required to achieve the desired image or pattern as compared to conventional paper, while increasing the transfer speed and reducing the weight of the transfer paper 1.

Conventionally, the transfer of the sublimable ink 5 of the image or pattern carried by the reservoir layer 2 can then be carried out hot using a transfer calender.

For this, the outer face 20 of the reservoir layer 2, which corresponds to the printed face of the transfer paper 1, is applied to the face of the substrate to be printed by the transfer calender. Under the effect of the pressure and the temperature applied by the cylinder of the transfer calender, the sublimable ink 5 passes from the solid state to the gaseous state and penetrates into the substrate (namely in the mesh of the textile or in the varnish of the hard substrate). The transfer temperature range for the sublimable inks is usually between 170 ° C and 210 ° C, for a range of application pressure of the transfer paper 1 on the substrate between about 2.5 bar and 4.5 bar.

During this step, the transfer paper 1 of the invention ensures a good restitution of the image or pattern on the substrate with good productivity.

Once the image or pattern has been transferred onto the substrate, part of the sublimable ink that has not been transferred onto the substrate remains on the transfer paper 1. This transfer paper 1 is no longer usable. neither recyclable nor represents a waste to be eliminated by the industrialist. However, a transfer paper 1 according to the invention makes it possible to reduce the grammage by more than 30% in comparison with conventional papers, which makes it possible to reduce the amount of waste resulting from the transfer step.

Finally, the transfer paper 1 according to the invention has a Bendtsen porosity (measured according to the NF Q 03-076 standard) greater than 100 ml / min, preferably greater than 125 ml / min and more preferably greater than 150 ml / ml. min. Such porosity makes it possible to ensure productivity during the transfer, the level of permeability of the transfer paper 1 must be sufficiently high to promote the exchange of temperature with the textile and to provide the necessary sublimation energy to the ink to go from the solid state to the gaseous state. This high level of permeability is in particular allowed by the composition of the barrier layer 3

Claims (18)

Transfer paper (1) comprising: a reservoir layer (2), having an outer face (20) configured to receive a sublimable ink (5) and an inner face (22), and a barrier layer (3), applied on the inner face (22) of the reservoir layer (2), and configured to form a barrier to the vehicle of the sublimable ink (5), said barrier layer (3) comprising between 70 % and 100% by dry weight of cellulose fibers, preferably at least 80% by dry weight the transfer paper (1) being characterized in that the reservoir layer comprises: at least 60% by dry weight of main pigments having a mean diameter of between 0.2 micrometers and 0.8 micrometers, and - At most 45% by dry weight of secondary pigments having an average diameter greater than the average diameter of the main pigments. Transfer paper (1) according to claim 1, wherein the cellulose fibers have a degree of refining measured in Schopper-Riegler degrees between 38 ° SR and 42 ° SR. Transfer paper (1) according to one of claims 1 or 2, wherein the barrier layer (3) further comprises: between 3% and 15% by dry weight of a mineral filler, typically between 6% and 12% by dry weight, for example 9%, and / or an alkyl ketene dimer (AKD) or anhydrous alkylsuccenic (ASA) bonding agent having a quality of bonding according to the COBB test with a contact time of 60 seconds of less than 20 g / m ² Transfer paper (1) according to one of claims 1 to 3, wherein the barrier layer (3) has a basis weight of between 30 g / m ² and 40 g / m ² , typically between 32 g / m ² and 35 g / m ² , for example of the order of 34 g / m ² . Transfer paper (1) according to one of claims 1 to 4, wherein the main pigments have an average diameter of between 0.3 micrometers and 0.6 micrometers. Transfer paper (1) according to claim 5, in which the main pigments comprise precipitated calcium carbonate, for example of the aragonite, rhombohedral, scalenoedric or prismatic type, preferably of the aragonite type. Transfer paper (1) according to one of claims 5 or 6, wherein the reservoir layer comprises at most 30% by dry weight of secondary pigments, preferably at most 20% by dry weight. Transfer paper (1) according to claim 7, wherein the secondary pigments have a mean diameter of between 0.3 micrometers and 2 micrometers, preferably between 0.5 micrometers and 1.5 micrometers. Transfer paper (1) according to one of claims 7 or 8, wherein the secondary pigments comprise ground calcium carbonate or kaolin. Transfer paper (1) according to one of claims 1 to 9, wherein the reservoir layer (2) has a basis weight of between 2 g / m ² and 8 g / m ² , preferably between 3 g / m ² and 6 g / m ² . Transfer paper (1) according to one of claims 1 to 10, further comprising an adhesive layer (4), fixed on the barrier layer (3) opposite the reservoir layer (2), said layer adhesive layer (4) being configured to ensure good machinability of the transfer paper and comprising a cohesive agent, for example polysaccharides or polyvinyl alcohol (PVA). Transfer paper (1) according to claim 11, wherein the adhesive layer (4) has a basis weight of between 0.1 g / m ² and 10 g / m ² , preferably between 0.3 g / m ² and 0.6 g / m ² . Transfer paper (1) according to one of claims 1 to 12, having a Bendtsen porosity greater than 100 mL / min, preferably greater than 125 mL / min, typically greater than 150 mL / min. Transfer paper (1) according to one of claims 1 to 13, having a basis weight between 35 g / m ² and 45 g / m ² , typically between 38 g / m ² and 40 g / m ² , for example 39 g / m ^2. Transfer paper (1) according to one of claims 1 to 14, having a transferability index greater than 20, preferably greater than or equal to 22. Method of manufacturing (S) a transfer paper (1) according to one of claims 1 to 15, comprising the following steps: forming (S1) the barrier layer (3) on a paper machine, and depositing (S2) the reservoir layer (2) on one side of the barrier layer (3), said reservoir layer (2) comprising: at least 60% by dry weight of main pigments having a mean diameter of between 0.2 micrometers and 0.8 micrometers, and - At most 45% by dry weight of secondary pigments having an average diameter greater than the average diameter of the main pigments. Manufacturing method (S) according to claim 16, wherein the step (S1) for forming the barrier layer (3) comprises the following substeps: to put the cellulose fibers in aqueous dispersion in a pulper, and - refine the cellulose fibers in order to obtain a level of refining measured in Schopper-Riegler degree (° SR) between 38 ° SR and 42 ° SR, and an average fiber length (FLI) between 0.4 mm and 0.9 mm , preferably of the order of 0.65 mm. Manufacturing method (S) according to one of claims 16 to 17, further comprising a step in which an adhesive layer (4) is deposited on another face of the barrier layer (3), said layer of the adhesive (4) being configured to ensure good machinability of the transfer paper and comprising a cohesive agent, for example polysaccharides or polyvinyl alcohol (PVA).

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