DE102021116478A1 - Composition of a primer and a printing press - Google Patents

Abstract

The invention relates to a composition of a primer, the primer having at least one solvent, the primer having at least one binder, the primer having at least one inorganic or organic salt, the primer having at least one surfactant, the primer having at least one first pigment has, wherein the at least one first pigment has an average pore volume of at least 4 cm3/g (four cubic centimeters per gram) and/or of a maximum of 35 cm3/g (thirty-five cubic centimeters per gram), the primer having at least one second pigment, wherein the at least one second pigment has a different chemical composition than the at least one first pigment, the at least one second pigment being in the form of resin and/or wax and/or polyethylene and/or polypropylene. The invention also relates to a printing machine.

Description

The invention relates to a composition of a primer and a printing machine according to the features of claims 1 and 3.

In the industrial application of inkjet processes for the production of, for example, additionally individualized, mass-printed products on substrates with non-standardized surfaces, e.g. B. different materials and / or types of paper, the color or ink drops spread very differently. The substrate surface influences the spread of the drop, for example from two to five times the diameter of the original drop. In order to counter such effects and to distribute the pigments on the surface homogeneously without losing the reflectance of the pigments of a printing fluid in the paper, a wide variety of methods are known that are based on chemical, chemical-physical or purely physical interaction between the color or ink and a optionally based precoated substrate. In addition to varying the droplet size and thus the water content of the pressure fluid, there is also the option of precoating.

With one-sided precoating, i.e. applying primer to a web to be printed using an application roller working against a counter-roller, there is a risk that fluid will build up on the application roller outside the track width covered by the web, which fluid will run into the area covered by the web during operation and the web is contaminated in the edge area on its back. To prevent the fluid from being carried over into the machine on the reverse side, this problem is solved in practice by additional rear dryers for the edges. This problem becomes even more serious when different printing material or web widths are to be applied and then printed by one and the same application device.

through the DE 10 2017 211 843 A1 discloses an inkjet printing machine for industrial use with an inline pretreatment upstream of the printing substrate in the path of the printing unit, for example an application device upstream of the first printing point, by means of which a substance mixture can be or is applied to the printing substrate during operation before printing.

the US 10,906,349 B2 discloses a method of making a printed paper layer. Water-based inks are applied to the paper substrate using an inkjet printer. Before applying the inks, the paper substrate is coated with a layer containing a pigment with a pore volume of 0.5 to 3 ml/g.

The object of the invention is to provide a primer composition and a printing machine.

The object is achieved according to the invention by the features of claim 1 and 3, respectively.

The advantages that can be achieved with the invention consist in particular in creating a primer which ensures optimal application behavior of a subsequently applied printing fluid on a printing material.

Advantageously, at least one cleaning agent is additionally or alternatively created. A method for cleaning the printing press advantageously prevents open systems, in particular within an application device and/or a printing unit, from becoming infested with mold, algae and/or the like in the printing press. The at least one cleaning agent is advantageously compatible with a primer and/or printing fluid, which is preferably transferred through the cleaned printing unit and/or application device.

Advantageously, losses in quality due to contamination on the back of the printing material and/or in the machine are avoided. In a particularly advantageous embodiment, this can also be achieved for varying web widths. Additional drying devices can be omitted.

Advantageously, at least one printing material designed as decorative paper or decorative foil is created, advantageously with optimal application behavior of a printing fluid that is subsequently applied after a primer.

Further advantages can be seen from the following description.

Exemplary embodiments of the invention are shown in the drawings and are described in more detail below.

• 1 ein Ausführungsbeispiel für eine Druckmaschine mit einer Vorrichtung zur Vorbehandlung;
• 2 Ausführungen für die Vorrichtung zur Vorbehandlung a) in Seitenansicht und b) in Draufsicht.

Show it:

• 1 an embodiment of a printing machine with a device for pretreatment;
• 2 Designs for the device for pretreatment a) in side view and b) in top view.

A printing material processing and/or printing material processing machine, in particular a printing press, in particular a web-fed printing press, has at least one or more, for example at least two, printing units 01 through which at least one, for example web-shaped, printing material 02, for example a printing material web 02, on one or both sides , preferably in the inkjet process, is printable and/or is printed. The at least one printing unit 01 is preferably embodied as an inkjet printing unit 01. The at least one printing substrate 02 is preferably processed in the printing press. In addition, the printing material processing and/or printing material processing machine, in particular a printing press, in particular a web-fed printing press, preferably has a printing material template 03, for example a roll changer 03, a downstream product receptacle 04, which is provided by further processing or, as shown by way of example, by a rewinder 04, or is designed, for example, as a delivery and preferably at least one dryer 06 arranged downstream of the respective printing unit 01 in the printing substrate path. At least one coating unit is preferably arranged downstream of the at least one printing unit 01, more preferably also the at least one dryer 06, which preferably coats, for example water-based coating or printing coating or UV coating or functional coating, onto the printing substrate 02 printed by the at least one printing unit 01 raises. At least one further dryer 06 is arranged downstream of the at least one coating unit, for example.

A printing press designed as a web-fed printing press is described in more detail below. Corresponding details can, however, also be transferred to other printing presses, for example sheet-fed printing presses, i.e. the processing of sheet-type printing materials 02, provided they do not conflict with this. The printing substrate path is defined by at least one element guiding printing substrate 02, preferably by at least one cylinder and/or at least one roller, with printing substrate 02 running around the at least one guiding element. Alternatively, for example, the printing material path is horizontal, in particular if the guiding element is designed as at least one conveyor belt or conveyor rollers arranged in a row.

The printing press is preferably used as a production line for processing printing materials 02, preferably for producing folding boxes and/or for producing packaging and/or for producing decorative products, such as laminates, more preferably for producing intermediate products whose end products are folding boxes and/or Packaging and/or decorative products are formed. Printing substrate 02 is preferably designed as decorative paper or decorative foil or paper or cardboard or corrugated cardboard or cardboard. At least one printing material 02 embodied as decorative paper or decorative foil is preferably produced by means of a method, preferably by means of the printing press.

The at least one printing substrate 02 is preferably paper, in particular a paper web. According to DIN 6730, paper is a flat material consisting essentially of fibers, mostly of vegetable origin, which is formed by draining a fibrous suspension on a sieve. This creates a fiber felt that is then dried. The mass per unit area of paper is preferably at most 225 g/m ² .

Alternatively, for example, the at least one printing substrate 02 is cardboard or corrugated cardboard or cardboard; the printing press is then preferably designed as a sheet-fed printing press and the printing substrate is sheet-shaped. According to DIN 6730, cardboard is a flat material consisting essentially of fibers of plant origin, which is formed by dewatering a fibrous suspension on one or between two screens. The fiber structure is compacted and dried. Cardboard is preferably made from cellulose by gluing or pressing together. Cardboard is preferably designed as solid cardboard or corrugated cardboard. Preferably the basis weight of paperboard is over 225 g/m ² . In the foregoing and in the following, the term board refers to a paper fabric that is preferably coated on one side and has a mass per unit area of at least 150 g/m ² and at most 600 g/m ² . Cardboard preferably has high strength relative to paper.

The printing unit 01, which is preferably designed as an inkjet printing unit 01, has at least one print head 07 for single-color printing, and for multi-color printing a plurality of print heads 07 arranged one behind the other in the direction of substrate transport, for example at least four print heads 07 arranged one behind the other for four-color printing, each with one or more nozzles for the controlled release of the printing fluid, preferably the ink. The at least one printing unit 01 embodied as an inkjet printing unit preferably works according to the drop-on-demand method, with droplets of printing fluid being generated in a targeted manner as required, for example by means of at least one piezoelectric element. When a voltage is applied, the piezo element preferably reduces a volume filled with printing ink by a specific proportion at high speed, as a result of which individual drops are preferably ejected. In multi-color printing, the print heads 07 arranged one behind the other preferably one of the colors cyan, magenta, yellow, black, red, green, blue or special colors. The at least one inkjet printing unit 01 of the printing press preferably applies the at least one printing fluid to the at least one printing substrate 02.

In the foregoing and below, a printing fluid refers to inks, printing inks and/or varnishes, as well as other materials, which are transferred to a printing substrate 02 by the printing press, preferably by the at least one printing unit 01 or by the at least one coating unit of the printing press, and/or are transferrable. The printing fluid, preferably in a finely structured form and/or not just over a large area, creates a texture on the printing material that is preferably visible and/or perceptible by sensory impressions and/or detectable by machine. Inks and printing inks are preferably solutions or dispersions of at least one colorant in at least one solvent. Examples of suitable solvents are water and/or organic solvents. Inks are relatively low viscosity printing fluids and inks are relatively high viscosity printing fluids. Inks have no binder or relatively little binder, while printing inks preferably contain a relatively large amount of binder and more preferably other auxiliaries. Colorants are, for example, pigments and/or dyes, pigments being insoluble in the respective solvent, while dyes are soluble in the respective solvent. In particular, inks that have dyes as colorants preferably have no binder. Alternatively or additionally, the pressure fluid is designed, for example, as a pressure fluid that crosslinks under UV light. Lacquers are, for example, water-based or designed as UV lacquers, ie crosslinked by UV radiation. Preferably, the paint applied by the at least one paint unit is colorless.

The dry weight of the application quantity of the applied printing fluid, preferably printing fluid applied to the at least one printing substrate 02 by the at least one printing unit 01, in particular ink or printing ink, more preferably ink or printing ink containing pigments, is a maximum of 8 g/m ² (eight grams per square meter), preferably at most 6 g/m ² (six grams per square meter), more preferably at most 4 g/m ² (four grams per square meter), more preferably at most 3 g/m ² (three grams per square meter), further preferably not more than 1 g/m ² , for example not more than 0.8 g/m ² . Preferably additionally or alternatively, the dry weight of the application quantity of the applied printing fluid, preferably printing fluid applied to the at least one printing substrate 02 by the at least one printing unit 01, in particular ink or printing ink, more preferably ink or printing ink containing pigments, is at least 0.01 g /m ² (zero point zero one gram per square meter), preferably at least 0.1 g/m ² (zero point one gram per square meter), more preferably at least 0.2 g/m ² (zero point two grams per square meter), more preferably at least 0.9 g/m ² (zero point nine grams per square meter).

A device for pretreatment 08, in particular an application device 08, for inline precoating, in particular over the entire surface, of the printing substrate 02 to be printed on only downstream is preferably arranged upstream of the at least one or first printing unit 01 in the printing substrate path. The printing press has the at least one device for pretreatment 08, which is arranged upstream of the at least one inkjet printing unit 01 and is preferably embodied as an application device 08. This applies a fluid, a so-called primer or precoating, to the printing substrate 02 on the side to be printed downstream in an inline process. The at least one application device 08 is designed to apply at least one primer to the at least one printing substrate 02. The at least one application device 08 of the printing press, which is arranged upstream of the at least one inkjet printing unit 01, preferably applies at least one primer to the at least one printing substrate 02. In contrast to printing in a printing unit 01 with text or image content using appropriately structured print patterns, precoating relates to the pre-treatment, in particular over a large area, of the printing substrate 02 without visible text or image information or content, i.e. not the printing of the desired print image. Printing substrate 02 is preferably provided with primer on at least one side covering at least 60%, preferably at least 80%, of the surface of this side.

The primer, also known as a primer, precoating or precoat fluid, for example, which is preferably applied by the at least one application unit 08, is preferably a fluid and/or is preferably used as an adhesion promoter for a printing fluid, in particular paint, applied downstream of the application unit 08 in the transport direction /or printing ink and/or ink, and additionally or alternatively it is used to adjust the surface tension of the respective printing substrate 02. Advantageously, the application of a primer to the printing substrate 02 before the printing fluid of the at least one printing unit 01 enables a reduction in the application quantity of the printing fluid. The reason for this is preferably that the primer makes it possible to achieve a desired color location within the color space is made easier and/or that stronger contrasts of the individual colors on the printing material 02 are achieved through the primer.

The application device 08 preferably has at least one pair of rollers, namely a fluid-carrying roller 09, for example forme roller 09, which receives the fluid to be applied from a supply device and via the printing substrate 02 to be applied, for example printing substrate web 02, against a roller 11 that represents an abutment, for example a counter roller 11 is employed or employable. The counter-roller 11 is preferably designed as an impression roller 11 and has, for example, a hard and/or unyielding surface, for example made of metal or hard plastic, as the effective outer surface. For example, it is deliberately not designed as a flexible, that is to say elastic and/or compressible, layer such as a rubber coating or a soft lining would be, for example.

In order to prevent a build-up of fluids that may get onto the counter roller 11 next to the rolling section of the printing material 02, the application device 08 comprises means 12 that counteract the build-up of fluid on the counter roller or impression roller 11; 16

In a first embodiment (see for example 2 the solid lines), the application device 08 comprises means 12, through which precoat fluid that has reached the lateral surface of the impression roller 11 next to the rolling section of the printing material onto the counter-roller 11 can be removed from the lateral surface. For this purpose, it comprises as a means 12 at least one doctor blade 12, possibly continuous across the width, which can be or is placed on the surface of counter-roller 11 at least in a longitudinal section of counter-roller 11 that encompasses the peripheral rolling line of a printing material edge. In the first embodiment, however, the means 12 counteracting the build-up of fluid on the counter-roller 11 are preferably two part-width squeegees 12, i.e. less than a quarter of the width of the usable cylinder length, for example, one of which encompasses the rolling line of one of the two printing material edges Longitudinal section of the counter-roller 11 are adjustable or employed on the surface.

In the case of two squeegees 12, these are preferably arranged to be axially movable, that is to say movable in a direction parallel to the course of the roller axis of rotation R11, and/or movable by motor. During operation, the amounts of fluid that may have reached the area of the run-off lines of the edges of the printing material on the outer surface of the counter-roller 11 are scraped off by the doctor blade 12 and collected, for example, in a suitable container 13 . In this first embodiment, the fluid can in principle be supplied via a supply device of any design in order to apply a sufficient quantity of fluid, in particular precoat fluid or primer, to the lateral surface of the forme roller 09.

In another, for example in 2 In the embodiment indicated by dashed lines, the application device 08 comprises - instead of or in addition to the above first means 12 - means 16, by means of which the width of the fluid supply in the supply device to the forme roller 09 can be adapted to a printing material width B02. For this purpose, the fluid is preferably supplied via a supply device comprising at least one chambered doctor blade 14, which comprises a doctor blade chamber that can be varied with respect to its effective width. For this purpose, the means 16 counteracting the above-mentioned build-up of fluid on the counter-roller 11 are preferably provided which laterally delimit the doctor chamber and are arranged to be axially movable and/or movable by a motor.

The fluid, in particular primer, can also be applied directly from chamber doctor blade 14 to forme roller 09, but as shown, it is preferably transferred from chamber doctor blade 14 to forme roller 09 via a further roller 17, for example anilox roller 17.

A dryer 18 is preferably provided downstream of the application unit 08 in the printing material path, which is arranged upstream of the printing unit 01 arranged downstream of the application unit 08 and/or is designed to act, preferably only, on the side of the printing material previously exposed to the fluid. For example, a hot air heater or a radiation source, for example a UV or preferably IR radiation source, is provided on that side of the printing material path on which the fluid-carrying roller 09 of the application device 08 is provided upstream.

An application device 08 according to the first and/or second embodiment can in principle be provided in any machine that treats printing materials 02, in particular different types of printing presses, but is preferably in the printing material path of a printing press that has already been mentioned above - in particular an industrial printing press - with at least one working according to the inkjet process Printing unit 01 provided.

The printing substrate 02 is preferably treated with the at least one primer, preferably after it has been processed in the printing press. Printing substrate 02 is preferably additionally applied over the at least one primer, preferably after it has been processed in the printing press preferably along a direction starting from the surface of the printing material outwards to the primer, that is to say as a preferably external application, is acted upon by the at least one printing fluid. Printing substrate 02 is preferably in the form of decorative paper or decorative film, preferably after it has been processed in the printing press. Preferably alternatively, the printing substrate 02 is designed as an intermediate product for the production of packaging, preferably folding boxes, preferably after it has been processed in the printing press.

For example, when producing decorative products, in particular laminates, the printing press is preferably followed by further processing of the printed product, for example as an additional processing machine or as at least one additional unit connected to the printing press. The printed printing substrate 02 is preferably treated with at least one impregnating resin, which preferably places the printing fluid in a resin bath. Printing substrate 02 is preferably arranged on a substrate, preferably as the top layer on the substrate, and is pressed with it, for example, and is preferably bonded to it under high pressure and/or at elevated temperature. If the at least one primer has been applied to the printing substrate 02 before the printing substrate 02 is printed with printing fluid, bleeding of the printing fluid into the resin bath during the impregnation is preferably prevented or minimized.

The composition of the primer in particular affects the properties of printing substrate 02, such as drying of the printing fluid and/or moisture content and/or pH value and/or cut quality and/or porosity and/or effective surface area of printing substrate 02, and additionally or alternatively on the printability of the printing substrate 02, i.e. properties that influence the running and the speed of the printing substrate 02 during processing in the printing press, such as tear strength and/or moisture elongation and/or breaking load and/or blistering and/or mechanical elongation, and in addition or alternatively on the printability of the printing substrate 02, i.e. in particular properties that influence the, for example optical, quality of the printed product, such as acceptance of the printing fluid and/or color coordinates obtained and/or gloss and/or smoothness and/or uniformity of the surface and/or or absorbency and/ or lightfastness.

Advantageously, the application of the primer to the printing substrate 02 does not change its fiber structure. In particular, the effective surface of printing substrate 02, which is preferably uneven due to the printing substrate fibers and/or the surface of which has a larger surface area than a smooth surface of the same size, remains. The primer is preferably designed to coat the fibers of the printing material. The primer preferably does not form a continuous top layer covering the surface of printing substrate 02. In particular, the porosity of printing substrate 02 is retained after exposure to the primer and/or is minimally changed compared to before exposure, preferably reduced by a maximum of 25%, preferably by a maximum of 10%. This advantageously allows air to exit the pores of the printing material 02 after the printing material 02 has been printed with printing fluid. This is particularly important in the case of subsequent impregnation with impregnation resin, since the remaining air significantly degrades the quality of the impregnated printing material 02 and leads to cracks, for example.

The primer preferably has at least one solvent. The primer is preferably water-based. The at least one solvent is preferably water. For example, at least 25%, preferably at least 50%, of which at least 20% is formed by water accounts for the proportion of solvent comprising at least water. The solvent fraction is formed solely by water, for example, or has at least one other co-solvent, for example ethylene glycol and/or ethanol and/or toluene and/or butyl acetate. Based on 100% by weight (one hundred percent by weight) of the primer, this preferably has at least 25% by weight, preferably at least 40% by weight, more preferably at least 50% by weight, more preferably at least 65% by weight, of water. Additionally or alternatively, based on 100% by weight of the primer, the primer preferably has at most 80% by weight, preferably at most 77% by weight, of water.

The primer preferably has at least one, preferably organic, binder, in particular at least one polymer P, for example at least one hydrocarbon polymer. The at least one binder preferably binds at least one pigment of the primer, preferably so that the printing substrate 02 to which the primer has been applied releases little dust and/or the pigment remains in its position. The at least one binder is preferably a hydrophilic or hydrophobic material, preferably hydrophilic. The binder is preferably based on saccharides, polyglycosides, polyvinyl alcohol, small molecules, polyurethane, polyamide and/or resin. The at least one binder is preferably at least one starch, one gelatine, one latex, one vinyl acetate(s). ethylene copolymer, a carboxymethyl cellulose, a polyethylene/polypropylene glycol, a saccharide and/or cellulosic solubles or insolubles. For example, the at least one binder is at least one styrenic polymer, a halohydrocarbon polymer, a vinyl polymer, a polyvinyl alcohol, a fluorinated or non-fluorinated acrylic polymer, a synthetic or natural rubber, a polyether copolymer or their copolymers. For example, the at least one binder is a mixture of two or more of the substances mentioned. Based on 100% by weight (one hundred percent by weight) of the primer, this preferably has at least 2% by weight (two percent by weight), preferably at least 4% by weight, and additionally or alternatively a maximum of 15% by weight (fifteen percent by weight), preferably a maximum of 10% by weight .%, more preferably at most 7.5% by weight, of binder. The primer preferably has a ratio of the at least one pigment to the at least one binder of at least 11/89, preferably at least 20/70, more preferably at least 25/65, preferably during and/or after it is applied to the printing substrate 02. and/or at most 89/11, preferably at most 70/20, more preferably at most 65/25. The at least one pigment to the at least one polymer preferably has a relative ratio of at least 0.5, preferably at least 0.9, more preferably at least 1.3, more preferably at least 2.1, and/or at most 6 5, preferably not more than 5.3, more preferably not more than 4.0, more preferably not more than 3.5.

The primer preferably has at least one preferably inorganic or organic salt. The at least one salt is preferably a precipitating agent. The at least one salt is preferably at least a monovalent or divalent or trivalent salt of an inorganic or organic substance, for example metal-based or alternatively metal-free. For example, the at least one salt includes polydadmac (polydiallyldimethylammonium chloride), polyamine, and/or alumina. Based on 100% by weight (one hundred percent by weight) of the primer, this preferably has at least 2% by weight (two percent by weight), preferably at least 4% by weight, more preferably at least 6% by weight, and additionally or alternatively a maximum of 20% by weight ( twenty percent by weight), preferably at most 18% by weight, more preferably at most 15% by weight, more preferably at most 12% by weight of salt. The at least one salt preferably prevents the at least one printing fluid from spreading relative to its printing position to other printing fluid points and/or into the interior of printing substrate 02, in particular to an undesirable extent.

The primer preferably has at least one humectant. The at least one humectant is preferably glycerin. Alternatively, for example, the at least one humectant is glycol or a mixture of glycerin and glycol. Based on 100% by weight (one hundred percent by weight) of the primer, this preferably has at least 0.5% by weight (zero point five percent by weight), preferably at least 2% by weight, preferably at least 2.5% by weight, for example 3% by weight, and/or a maximum of 10% by weight, preferably a maximum of 8% by weight, more preferably a maximum of 5% by weight, preferably a maximum of 4.5% by weight, of humectant. The at least one humectant preferably prevents rapid evaporation of the at least one solvent, in particular water, which preferably prevents the primer from clumping. Preferably, in the case of subsequent impregnation of printing substrate 02, i.e. following impregnation after printing, with at least one impregnating resin, the humectant preferably reacts with this impregnating resin and is preferably incorporated into its crosslinking structure.

The primer preferably has at least one biocide. The at least one biocide preferably has at least one isothiazole, for example benzisothiazolinone or methylisothiazolinone or a mixture of the substances mentioned. Based on 100% by weight (one hundred percent by weight) of the primer, this preferably has at least 0.01% by weight (zero point zero one percent by weight), preferably at least 0.04% by weight, more preferably at least 0.05% by weight preferably at least 0.09% by weight, for example 0.1% by weight, and/or at most 0.2% by weight, preferably at most 0.18% by weight, more preferably at most 0.16% by weight, more preferably at most 0.15% by weight, more preferably at most 0.12% by weight, of biocide. The at least one biocide preferably has a microbicidal and/or fungicidal effect and/or is a preservative.

The primer preferably has at least one defoamer, preferably at least one surfactant designed as a defoamer, preferably a surface-active substance, and/or at least one component for optimizing the viscosity. The at least one defoamer preferably prevents foam formation in the printing press and/or spattering during processing of the primer. The at least one surfactant preferably reduces the surface tension and/or supports the dispersing, i.e. the homogenization of substances and/or their mixing, and/or stabilizes the dispersing and/or increases the wetting of the primer on the printing substrate 02 and/or increases the Wetting of the primer in the at least one application device 08. In addition, the at least one surfactant preferably increases the wetting of the at least one printing fluid on printing substrate 02. For example, the at least one surfactant and/or the at least one defoamer is configured as at least one polyether or at least one siloxane or at least one polyether-siloxane copolymer. Based on 100% by weight (one hundred percent by weight) of the primer, this preferably has at least 0.1% by weight (zero point one percent by weight), preferably at least 0.25% by weight, for example 0.3% by weight, and/or at most 2.3% by weight, preferably at most 1.8% by weight, more preferably at most 1.5% by weight, for example 1.5% by weight, more preferably at most 0.5% by weight, of defoamer and/or surfactant and/or viscosity optimization component.

The primer preferably has at least one pigment. The primer preferably has at least one first pigment and/or at least one second pigment. The at least one pigment, preferably the at least one first pigment and/or the at least one second pigment, is preferably a solid and/or poorly soluble or not soluble in water. The at least one pigment is preferably finely distributed within the primer, in particular in the at least one solvent. The at least one second pigment is preferably of a different chemical type, in particular of a different chemical composition, than the at least one first pigment.

The at least one pigment, in particular the at least one first pigment, is preferably porous. The average pore volume, also called “pore volume” below, of the at least one pigment is preferably determined by means of mercury diffusion, for example alternatively by means of gas adsorption (for example with nitrogen), preferably according to DIN ISO 9277:2014-01. The particle size distribution and thus preferably the mean particle size of the at least one pigment is preferably determined by means of static or dynamic light scattering, preferably laser diffraction, preferably according to ISO 13320:2020, or for example by means of a grindometer. The shape of the particles of the at least one pigment is preferably determined using image analysis methods, in particular by recording an image of the particles and evaluating it.

The at least one first pigment of the primer preferably comprises at least 0.5% by weight (zero point five percent by weight), preferably at least 1% by weight, for example 1% by weight, more preferably based on 100% by weight (one hundred percent by weight) of the primer at least 4.5% by weight and/or a maximum of 20% by weight (twenty percent by weight), preferably a maximum of 16% by weight, more preferably a maximum of 14% by weight, more preferably a maximum of 10% by weight, for example 10% by weight or 6 wt%, up.

The at least one first pigment of the primer is preferably inorganic and/or a porous solid. The at least one first pigment is preferably a hydrophilic or hydrophobic material, preferably hydrophilic. The at least one first pigment preferably has silicon dioxide (SiO ₂ ). The silicon dioxide is preferably fumed silicon dioxide, preferably synthetically produced, amorphous silicon dioxide, for example Orisil 100, Orisil 200, Orisil 250, Orisil 300, Orisil 380, Aerosil 100, Aerosil 200, Aerosil 250, Aerosil 300, and/or or Aerosil 380. More preferably, the at least one first pigment additionally or alternatively has calcium carbonate (CaCO ₃ ). The calcium carbonate is preferably synthetically produced calcium carbonate. The calcium carbonate preferably has different particle sizes and/or pore volumes. Preferably, the calcium carbonate is screenings of natural grist. For example, the at least one first pigment additionally has bentonite, talc, titanium dioxide and/or kaolin. For example, the at least one first pigment is a mixture of two or more of the substances mentioned, preferably a mixture of at least silicon dioxide and calcium carbonate. For example, the mixture additionally contains bentonite, talc, titanium dioxide (TiO ₂ ), barium titanate (BaTiO ₃ ) and/or kaolin. The at least one first pigment preferably has at least one colored component or at least one component with a coloring effect, preferably at least one component designed as a whitening agent, in particular titanium dioxide (TiO ₂ ) and/or barium titanate (BaTiO ₃ ). A whitening agent is preferably a colored pigment, especially white. The mixture of silicon dioxide with calcium carbonate preferably increases the pore volume of the primer applied to printing substrate 02 compared to the pore volume obtained solely through silicon dioxide. The at least one first pigment preferably guarantees uniform color behavior on different surfaces of printing substrates 02, with the color space preferably being kept constant.

The at least one first pigment preferably has a pore volume, in particular an average pore volume, of greater than 3 cm ³ /g (three cubic centimeters per gram), preferably at least 4 cm ³ /g, more preferably at least 4.5 cm ³ /g, more preferably at least 10 cm ³ /g, more preferably at least 12 cm ³ /g. Preferably additionally or alternatively, the at least one first pigment has a maximum pore volume of 35 cm ³ /g (thirty-five cubic centimeters per gram), preferably at most 20 cm ³ /g, more preferably at most 15 cm ³ /g. This pore volume preferably enables optimized absorption of the printing fluid by the primer applied to printing substrate 02. Wetting according to Wenzel preferably takes place, with fine structuring of a surface, such as a porous surface, increasing the existing hydrophilicity or hydrophobicity of the surface. Particularly in the case of a hydrophilic pigment, preferably at least the at least one first pigment and/or preferably the at least one second pigment, its wetting, preferably wetting with printing fluid, advantageously determined by contact angle measurement, is thus enhanced by the high porosity. The spread of the printing fluid on the printing material is preferably optimized by the pore volume of the at least one first pigment, preferably additionally by the pore volume of the at least one second pigment. This preferably reduces the amount of primer to be applied in order to obtain a desired color location and/or contrast with the subsequently applied printing fluid.

The at least one first pigment preferably has an average particle size of at least 0.02 μm (zero point zero two microns), preferably at least 0.03 μm, more preferably at least 0.1 μm, more preferably at least 1 μm, more preferably from at least 10 µm. Preferably additionally or alternatively, the at least one first pigment has an average particle size of not more than 70 μm (seventy micrometers), preferably not more than 50 μm, more preferably not more than 45 μm, more preferably not more than 30 μm. For example, the average particle size is between 41 μm and 45 μm.

For example, the at least one pigment, preferably at least the at least one first pigment, more preferably additionally or alternatively the at least one second pigment, has a Mohs hardness of at least 1, preferably at least 3, more preferably greater than 3, for example 4, and preferably additionally or alternatively of a maximum of 15, preferably of a maximum of 10, more preferably of a maximum of 5. The at least one first pigment preferably has a Mohs hardness of greater than 3.

The Mohs hardness is determined by comparing several materials, in particular using the Mohs scale. Materials with a Mohs hardness of 1 to 2 are preferably soft, materials with a Mohs hardness of 3 to 5 are preferably medium and materials with a Mohs hardness of 6 or greater are preferably hard. The at least one first pigment preferably has a Vickers hardness of at least 189 HV. For example, the at least one first pigment has at least one edge on its surface. For example, the shape of the at least one first pigment deviates from an ideal sphere, in particular the at least one first pigment has shape anisotropy, ie at least two axes of different lengths. Advantageously, the effect of the pore volume, in particular the improved spread of the pressure fluid, is further supported by the hardness and/or shape of the pigment.

The at least one second pigment of the primer is preferably at least 1% by weight (one percent by weight), preferably at least 3% by weight, more preferably at least 3.5% by weight, more preferably based on 100% by weight (one hundred percent by weight) of the primer at least 4% by weight, for example 4.5% by weight, and/or a maximum of 10% by weight (ten percent by weight), preferably a maximum of 8% by weight, more preferably a maximum of 6.5% by weight, more preferably a maximum of 5% by weight. %, on. Alternatively, for example, the primer only has the at least one first pigment, ie not the at least one second pigment.

The at least one second pigment of the primer is preferably inorganic and/or a porous solid. The at least one second pigment is preferably a hydrophilic or hydrophobic material, preferably hydrophilic. The at least one second pigment preferably contains calcium carbonate (CaCO ₃ ) and/or titanium dioxide (TiO ₂ ). For example, the at least one second pigment additionally has bentonite, talc or kaolin. Alternatively, for example, the second pigment comprises a mixture of the substances mentioned. The at least one second pigment is preferably poorly water-soluble or not water-soluble. Alternatively, for example, the at least one second pigment of the primer is organic. The at least one organic second pigment preferably contains resin, wax, polyethylene and/or polypropylene or a mixture of these substances.

The at least one second pigment preferably has a pore volume of at least 2 cm ³ /g (two cubic centimeters per gram), preferably at least 3 cm ³ /g (three cubic centimeters per gram), more preferably greater than 3 cm ³ /g, preferably of at least ⁴ cc/g, more preferably at least 4.5 ^cc /g. Preferably additionally or alternatively, the at least one second pigment has a pore volume of at most 35 cm ³ /g (thirty-five cubic centimeters per gram), preferably at most 25 cm ³ /g, more preferably at most 20 cm ³ /g, more preferably at most 15 cm ³ / g, more preferably not more than 10 cm ³ /g, for example 12 cm ³ /g. The at least one second pigment preferably has an average particle size of at least 0.03 μm (zero point zero three microns), preferably at least 0.1 μm, more preferably at least 1 μm, more preferably at least 2 μm, more preferably at least 5 μm, more preferably of at least 10 µm. Preferably additionally or alternatively, the at least one second pigment has an average particle size of not more than 70 μm (seventy micrometers), preferably not more than 50 μm, more preferably not more than 45 μm, more preferably not more than 30 μm. For example, the average particle size is between 41 μm and 45 μm. The mean particle size is preferably at most 25 μm (twenty-five micrometers), preferably at most 20 μm, more preferably at most 15 μm. Preferably, in particular with an average particle size of at most 15 μm, the at least one second pigment has a maximum particle size of the sieve residue of less than 0.1% at 60 μm. More preferably, the at least one second pigment has an average particle size of between 1.5 μm and 5 μm, with a weight proportion of a maximum particle size of greater than 41 μm of the sieve residue preferably having less than 2%.

The wet weight of the primer applied to printing substrate 02 is preferably at least 0.1 g/m ² (zero point one gram per square meter), preferably at least 0.5 g/m ² , more preferably at least 1 g/m ² , more preferably at least 3 g/m ² , more preferably at least 3.2 g/m ² , more preferably at least 4.8 g/m ² . Additionally or alternatively, the wet weight of the primer applied to printing substrate 02 is preferably at most 18 g/m ² , preferably at most 8 g/m ² , more preferably at most 7 g/m ² , more preferably at most 6 g/m ² at most 5.5 g/m ² , more preferably at most 3 g/m ² , more preferably at most 1 g/m ² . The mass of the primer is preferably sufficient to achieve an optimal application of printing fluid and/or to obtain a desired color locus and/or contrast with the subsequently applied printing fluid. The wet weight is preferably determined by determining the theoretical application volume of the primer, preferably by means of a theoretical scoop volume of the printing unit 01, in particular the anilox roller 17, and/or converted therefrom. The theoretical application volume is preferably at least 1/3 (one third), preferably at least 1/2 (one half) and/or preferably at most 2/3 (two thirds) of the theoretical scoop volume. Additionally or alternatively, the wet weight is preferably determined by weighing. For example, a stretch of known length of printing substrate 02 is printed with the at least one primer and the amount of the at least one primer used on the printed area is calculated. Additionally or alternatively, the wet weight is calculated back, preferably according to DIN EN ISO 3251, using the dry content and/or the dry application.

The printing substrate 02 to which the at least one primer has been applied preferably has an average air resistance of no more than 28 seconds, preferably no more than 26 seconds, more preferably no more than 23 seconds. The printing substrate 02 to which the at least one primer has been applied preferably has an average air resistance of 18 seconds to 23 seconds. More preferably, the average air resistance of the printing substrate 02 to which the at least one primer has been applied is the same as or lower than the average air resistance of the printing substrate 02 to which no primer has been applied. The air resistance of the printing substrate 02 to which no primer has been applied is preferably at least 22 seconds, for example 22 to 24 seconds seconds. Advantageously, the average air resistance of the printing substrate 02 to which primer has been applied allows better impregnation compared to printing substrate 02 that has not been applied, since resin and/or printing fluid that is applied later can penetrate the printing substrate 02, in particular paper, more easily. The mean air resistance is preferably determined using the Gurley method (Tappi T460). A Gurley Densometer measures the time required for a specified volume of air, for example 25 cm ³ (twenty-five cubic centimeters) to 300 cm ³ , to flow through a standard area of the material under test under light, uniform pressure. Air pressure is supplied by an inner cylinder of specified diameter and weight that sits freely within an outer cylinder that is partially filled with oil and serves as an air seal. The sample material is held between clamp plates with a circular opening area of 1.0 square inches as standard, or alternatively 0.25 or 0.1 square inches.

According to a first exemplary embodiment, the at least one primer, preferably referred to below as the first primer, preferably has the following composition: The first primer preferably has 76.6% by weight (seventy-six point six percent by weight), preferably with an error limit of ±5, of water as a solvent. The first primer preferably comprises 1% by weight (one percent by weight), preferably to within ±3%, of preferably silica as the first pigment. The first pigment of the first primer preferably has a pore volume of at least 10 cm ³ /g (ten cubic centimeters per gram), preferably at least 12 cm ³ /g, and/or at most 35 cm ³ /g, preferably at most 20 cm ³ /g. g, up. The first pigment of the first primer preferably has an average particle size of at least 0.03 μm (zero point zero three micrometers) and/or of 30 µm (thirty microns) maximum. The first primer preferably comprises 10% by weight (ten percent by weight), preferably to within ±4%, of organic or inorganic salts. The first primer preferably comprises 4.5 wt% (four point five wt%), preferably to within ±2% of the binder. The first primer preferably has 4.5% by weight (four point five percent by weight), preferably with an error limit of ±4, of at least one second pigment, for example calcium carbonate. The first primer preferably has 3% by weight (three percent by weight), preferably with an error limit of ±2, of humectant, preferably glycerin. The first primer preferably comprises 0.1% by weight (zero point one percent by weight), preferably to within ±0.05% of the biocide, preferably isothiazole. The first primer preferably has 0.3% by weight (zero point three percent by weight), preferably with an error limit of ±0.2, of defoamer and/or surfactant and/or at least one component for optimizing viscosity, preferably siloxane or at least one polyether siloxane copolymer. The wet weight of the first primer applied to printing substrate 02 is preferably at least 1 g/m ² (one gram per square meter), preferably at least 3 g/m ² , more preferably at least 3.2 g/m ² , more preferably at least 4.8 g/m ² , and/or preferably at most 8 g/m ² , preferably at most 6 g/m ² , more preferably at most 5.5 g/m ² .

According to a second exemplary embodiment, the at least one primer, preferably referred to below as the second primer, preferably has the following composition: The second primer preferably has 76.6% by weight (seventy-six point six percent by weight), preferably with an error limit of ±5, of water as a solvent. The second primer preferably comprises 1% by weight (one percent by weight), preferably to within ±3%, of silica as at least a first pigment. The at least one first pigment of the second primer preferably has a pore volume of at least 3 cm ³ /g (three cubic centimeters per gram), preferably at least 4 cm ³ /g, more preferably at least 4.5 cm ³ /g, and/or of at most 10 cm ³ /g, preferably at most 5.5 cm ³ /g, for example 5 cm ³ /g. The at least one first pigment of the second primer preferably has an average particle size of at least 0.03 μm (zero point zero three microns) and/or at most 45 μm (forty-five microns), for example at least 41 μm and/or at most 45 μm , on. The second primer preferably comprises 10% by weight (ten percent by weight), preferably to within ±4%, of organic or inorganic salts. The second primer preferably comprises 4.5% by weight (four point five percent by weight), preferably to within ±2% of the binder. The second primer preferably has 4.5% by weight (four point five percent by weight), preferably with an error limit of ±4, of at least one second pigment, for example calcium carbonate or titanium dioxide. The at least one second pigment of the second primer preferably has a pore volume of at least 4 cm ³ /g (four cubic centimeters per gram) and/or at most 35 cm ³ /g. The second primer preferably has 3% by weight (three percent by weight), preferably with an error limit of ±2, of humectant, preferably glycerin. The second primer preferably comprises 0.1 wt% (zero point one wt%), preferably to within ±0.05% of biocide, preferably isothiazole. The second primer preferably has 0.3% by weight (zero point three percent by weight), preferably with an error limit of ±0.2, of defoamer and/or surfactant and/or at least one component for optimizing viscosity, preferably siloxane or at least one polyether siloxane copolymer. The wet weight of the second primer applied to printing substrate 02 is preferably at least 1 g/m ² (one gram per square meter), preferably at least 3 g/m ² , more preferably at least 3.2 g/m ² , more preferably at least 4.8 g/m ² , and/or preferably at most 8 g/m ² , preferably at most 6 g/m ² , more preferably at most 5.5 g/m ² .

According to a third exemplary embodiment, the at least one primer, hereinafter preferably referred to as the third primer, preferably has the following composition: The third primer preferably has at least 50% by weight (fifty percent by weight) and/or a maximum of 79% by weight, preferably 72.6% by weight .% (seventy-two point six percent by weight), preferably to within ±7% of water as the solvent. The third primer preferably comprises 6% by weight (six percent by weight), preferably to within ±3%, of at least one mixture of at least silicon dioxide and calcium carbonate as at least one first pigment. The at least one first pigment of the third primer preferably has a pore volume of at least 3 cm ³ /g (three cubic centimeters per gram), preferably at least 4 cm ³ /g, more preferably at least 4.5 cm ³ /g, and/or of at most 35 cm ³ /g (thirty-five cubic centimeters per gram), preferably at most 10 cm ³ /g, more preferably at most 5.5 cm ³ /g, for example 5 cm ³ /g. The first pigment of the third primer preferably has an average particle size of silicon dioxide of at least 0.03 µm (zero point zero three micrometers) and additionally or alternatively of at most 30 µm (thirty micrometers) and/or of calcium carbonate of at least 0.1 µm ( zero point one micrometer) and additionally or alternatively of a maximum of 45 µm (five and forty microns). The third primer preferably comprises 13% (thirteen percent by weight), preferably to within ±6% by weight, of organic or inorganic salts. The third primer preferably has 5% by weight (five percent by weight), preferably with an error limit of ±3.2, of binder, preferably saccharide-, polyglyco-, polyvinyl alcohol-, small molecule-, polyurethane-, polyamide-, and/or Resin based on. The third primer preferably has 4.5% by weight (four point five percent by weight), preferably with an error limit of ±4, of at least one second pigment, for example calcium carbonate or titanium dioxide. The at least one second pigment of the third primer preferably has a pore volume of at least 4 cm ³ /g (four cubic centimeters per gram) and/or at most 35 cm ³ /g. The third primer preferably has 3% by weight (three percent by weight), preferably with an error limit of ±2.5, of humectant, preferably glycerin. The third primer preferably comprises 0.1 wt% (zero point one wt%), preferably to within ±0.06% of biocide, preferably isothiazole. The third primer preferably has 0.3% by weight (zero point three percent by weight), preferably with an error limit of ±0.2, of defoamer and/or surfactant and/or at least one component for optimizing viscosity, preferably siloxane or at least one polyether siloxane copolymer. The applied quantity preferably has a dry weight of the applied printing fluid, preferably printing fluid applied to the at least one printing substrate 02 by the at least one printing unit 01, of no more than 3 g/m ² (three grams per square meter), preferably no more than 2 g/m ² , more preferably at most 1 g/m ² , for example at most 0.8 g/m ² , and preferably additionally or alternatively at least 0.01 g/m ² (zero point zero one gram per square meter), preferably at least 0.1 g/m ² , preferably for optimal print fluid application. With the color density remaining the same, a saving of at least 6%, preferably at least 15%, for example up to 40%, in the required application quantity of printing fluid is preferably achieved. Printing substrate 02 to which the at least one third primer and preferably also at least one printing fluid is applied is preferably configured as decorative paper or decorative film.

According to a fourth exemplary embodiment, the at least one primer, hereinafter preferably referred to as the fourth primer, preferably has the following composition: The fourth primer preferably has at least 40% by weight (forty percent by weight) and/or a maximum of 79% by weight, preferably 74.1% by weight .% (seventy-four point one percent by weight), preferably to within ±12% of water as the solvent. The fourth primer preferably has 4.5% by weight (four point five percent by weight), preferably with an error limit of ±3, of at least one mixture of at least silicon dioxide and calcium carbonate as at least one first pigment. The at least one first pigment of the fourth primer preferably has a pore volume of at least 3 cm ³ /g (three cubic centimeters per gram), preferably at least 4 cm ³ /g, more preferably at least 4.5 cm ³ /g, and/or of at most 10 cm ³ /g, preferably at most 5.5 cm ³ /g, for example 5 cm ³ /g. The at least one first pigment of the fourth primer preferably has an average particle size of silicon dioxide of at least 0.03 μm (zero point zero three microns) and additionally or alternatively of a maximum of 30 μm (thirty microns) and/or of calcium carbonate of at least 0.1 µm (zero point one micron) and additionally or alternatively by a maximum of 45 µm (forty-five microns). The fourth primer preferably has 9% by weight (nine percent by weight), preferably with an error limit of ±7, of organic or inorganic salts, of which, for example, 2% by weight with an error limit of ±2 are polymer-based salts. The fourth primer preferably comprises 4.5 wt% (four point five wt%), preferably to within ±2% of the binder. The at least one second pigment is preferably in the form of resin and/or wax and/or polyethylene and/or polypropylene. The fourth primer preferably has 3.5% by weight (three point five percent by weight), preferably with an error limit of ±3, of at least one second pigment, preferably resin and/or wax and/or polyethylene and/or polypropylene. The at least one second pigment of the fourth primer preferably has a particle size of at least 0.03 μm (zero point zero three microns) and/or at most 30 μm (thirty microns). The fourth primer preferably has 2% by weight (two percent by weight), preferably with an error limit of ±2, of humectant, preferably glycerin. The fourth primer preferably comprises 0.1 wt% (zero point one wt%), preferably within ±0.09% error, of biocide, preferably isothiazole. The fourth primer preferably has 0.3% by weight (zero point three percent by weight), preferably with an error limit of ±0.2, of defoamer and/or surfactant and/or at least one component for optimizing viscosity, preferably siloxane or at least one polyether siloxane copolymer. The wet weight of the fourth primer applied to printing substrate 02 is preferably at least 0.3 g/m ² (zero point three grams per square meter), preferably at least 1 g/m ² (one gram per square meter), more preferably at least 2.5 g /m ² , and/or preferably at most 5 g/m ² , preferably at most 3.5 g/m ² . The fourth primer preferably gives printing substrate 02 an improved abrasion resistance. In particular, it is preferable that the second pigment increases the slipperiness of an object applied thereto. For example, the at least one second pigment, in particular in the case of a resin, acts as an adhesion promoter between the surface of the printing substrate 02 and another layer arranged over the primer, for example a laminate, or the printing fluid applied after the primer has been applied, in particular ink or varnish. The end product of the printing substrate 02 to which the at least one fourth primer and preferably also at least one printing fluid has been applied is preferably packaging and/or a folding box.

According to a fifth exemplary embodiment, the at least one primer, hereinafter preferably referred to as the fifth primer, preferably has the following composition: The fifth primer preferably has at least 25% by weight (twenty-five percent by weight) and/or a maximum of 70% by weight, preferably 51.9% by weight .% (fifty-one point nine percent by weight), preferably to within ±12% of water as the solvent. The at least one first pigment preferably has silicon dioxide and/or calcium carbonate or a mixture thereof. The fifth primer preferably has 10% by weight (ten percent by weight), preferably to within ±4%, of silicon dioxide and/or calcium carbonate as at least one first pigment. The at least one first pigment of the fifth primer preferably has a pore volume of at least 3 cm ³ /g (three cubic centimeters per gram), preferably at least 4 cm ³ /g, more preferably at least 4.5 cm ³ /g, more preferably at least at least 10 cm ³ /g, and/or at most 35 cm ³ /g, preferably at most 25 cm ³ /g, more preferably at most 15 cm ³ /g. The at least one first pigment of the fifth primer preferably has an average particle size of silicon dioxide of at least 0.03 μm (zero point zero three microns) and additionally or alternatively of a maximum of 30 μm (thirty microns) and/or of calcium carbonate of at least 0.1 µm (zero point one micron) and additionally or alternatively by a maximum of 45 µm (forty-five microns). The at least one first pigment preferably has a Mohs hardness of greater than 3, for example 4. For example, the at least one first pigment has at least one edge on its surface. The fifth primer preferably comprises 12% by weight (twelve percent by weight), preferably to within ±6%, of organic or inorganic salts. The fifth primer preferably comprises 7% by weight (seven percent by weight), preferably to within ±4%, of binder, preferably saccharide, polyglycoside, polyvinyl alcohol, small molecule, polyurethane, polyamide, and/or resin base, on. The fifth primer has at least one second pigment, preferably 4.5% by weight (four point five percent by weight), preferably with an error limit of ±4, of at least one second pigment, for example calcium carbonate or titanium dioxide. The at least one second pigment of the fifth primer preferably has a particle size of at least 0.1 μm (zero point one micron) and/or at most 45 μm (forty-five microns). The at least one second pigment preferably has a Mohs hardness of at least 1 and preferably additionally up to a maximum of 5, for example 4. The at least one second pigment of the fifth primer preferably has a pore volume of at least 2 cm ³ /g (two cubic centimeters per gram), preferably at least 3 cm ³ /g, more preferably at least 4 cm ³ /g (four cubic centimeters per gram), and /or at most 35 cm ³ /g (thirty-five cubic centimeters per gram), preferably at most 25 cm ³ /g, more preferably at most 15 cm ³ /g, more preferably at most 10 cm ³ /g. The fifth primer preferably has 3% by weight (three percent by weight), preferably with an error limit of ±2, of humectant, preferably glycerin. The fifth primer preferably comprises 0.1% by weight (zero point one percent by weight), preferably to within ±0.08% of the biocide, preferably isothiazole. The fifth primer preferably has 1.5% by weight (one point five percent by weight), preferably with an error limit of ±0.8, of defoamer and/or surfactant and/or at least one component for optimizing viscosity, preferably siloxane or at least one polyether siloxane copolymer. The fifth primer preferably has at least one base, for example sodium hydroxide, preferably 30% sodium hydroxide, preferably for stabilizing the at least one pigment. The fifth primer preferably comprises 10% (ten percent) by weight caustic, preferably to within ±10% error. The fourth primer preferably gives printing substrate 02 improved abrasion resistance. With the color density remaining the same, a saving of at least 6%, preferably at least 15%, for example up to 40%, in the required application quantity of printing fluid is preferably achieved.

According to a sixth exemplary embodiment, the at least one primer, hereinafter preferably referred to as the sixth primer, preferably has the following composition: The sixth primer preferably has 73.1% by weight (seventy-three point one percent by weight), preferably with an error limit of ±7, of water as a solvent. The at least one first pigment is preferably silicon dioxide. The sixth primer preferably comprises 1% by weight (one percent by weight), preferably to within ±3%, of silica as at least a first pigment. The at least one first pigment of the sixth primer preferably has a pore volume of at least 4 cm ³ /g (four cubic centimeters per gram), preferably at least 4.5 cm ³ /g, more preferably at least 10 cm ³ /g, more preferably at least 12 cm ³ /g, and/or of at most 35 cm ³ /g, preferably at most 20 cm ³ /g, more preferably at most 15 cm ³ /g. The at least one first pigment of the sixth primer preferably has an average particle size of at least 0.03 μm (zero point zero three microns) and/or at most 45 μm (forty-five microns), preferably at most 30 μm. The sixth primer preferably comprises 13% (ten percent) by weight, preferably to within ±6%, of organic or inorganic salts. The sixth primer preferably comprises 5 wt.% (five percent by weight), preferably to within ±3.2% of binder. The sixth primer preferably has at least one second organic or inorganic pigment, preferably of a different chemical composition than the at least one first pigment. The at least one second pigment is preferably calcium carbonate or titanium dioxide, for example alternatively resin and/or wax and/or polyethylene and/or polypropylene. The sixth primer preferably has 4.5% by weight (four point five percent by weight), preferably with an error limit of ±4, of at least one second pigment, for example calcium carbonate or titanium dioxide. The at least one second pigment of the sixth primer preferably has a pore volume of at least 4 cm ³ /g (four cubic centimeters per gram) and/or at most 35 cm ³ /g. The sixth primer preferably has 3% by weight (three percent by weight), preferably with an error limit of ±2.5, of humectant, preferably glycerin. The sixth primer preferably comprises 0.1% by weight (zero point one percent by weight), preferably to within ±0.05% of the biocide, preferably isothiazole. The sixth primer preferably has 0.3% by weight (zero point three percent by weight), preferably with an error limit of ±0.2, of defoamer and/or surfactant and/or at least one component for optimizing viscosity, preferably siloxane or at least one polyether siloxane copolymer. The wet weight of the sixth primer applied to printing substrate 02 is preferably at least 0.1 g/m ² (zero point one gram per square meter), preferably at least 0.5 g/m ² , and/or preferably at most 18 g/m ² , preferably at most 7 g/m ² , more preferably at most 5.5 g/m ² , more preferably at most 3 g/m ² , more preferably at most 1 g/m ² . The applied quantity preferably has a dry weight of the applied printing fluid, preferably printing fluid applied to the at least one printing substrate 02 by the at least one printing unit 01, of no more than 3 g/m ² (three grams per square meter), preferably no more than 1 g/m ² , for example of a maximum of 0.8 g/m ² , and preferably additionally or alternatively of at least 0.01 g/m ² (zero point zero one gram per square meter), preferably at least 0.1 g/m ² , preferably for optimal printing fluid application on. With the color density remaining the same, a saving of at least 6%, preferably at least 15%, for example up to 40%, in the required application quantity of printing fluid is preferably achieved.

The at least one primer, hereinafter preferably referred to as the seventh primer, preferably has the following composition according to a seventh embodiment: The seventh primer preferably has at least 40% by weight (forty percent by weight) and/or a maximum of 79% by weight, preferably 65.9% by weight .% (sixty-five point nine percent by weight), preferably to within ±1%, of water as the solvent. Preferably, the at least one pigment of the seventh primer is colored. The at least one pigment is preferably silicon dioxide, calcium carbonate, titanium dioxide and/or barium titanate and/or a mixture of at least two of the substances mentioned. The seventh primer preferably has 12% by weight (twelve percent by weight), preferably with an error limit of ±7, of at least one mixture of at least silicon dioxide, calcium carbonate, titanium dioxide and/or barium titanate as at least one, preferably first, pigment. The at least one first pigment preferably has a coloring effect, for example as a whitening agent, and/or is colored, in particular after the printing substrate 02 has been exposed to the primer. The at least one preferably first pigment of the seventh primer preferably has a pore volume of at least 3 cm ³ /g (three cubic centimeters per gram), preferably at least 4 cm ³ /g, more preferably at least 4.5 cm ³ /g, more preferably of at least 10 cm ³ /g, and/or at most 35 cm ³ /g, preferably at most 20 cm ³ /g, preferably at most 15 cm ³ /g, for example 15 cm ³ /g. The at least one preferably first pigment of the seventh primer preferably has an average particle size of at least 0.03 μm (zero point zero three micrometers) and additionally or alternatively of a maximum of 45 μm (forty-five micrometers), for example silicon dioxide of at least 0.03 μm ( zero point zero three micrometers) and additionally or alternatively of a maximum of 30 µm (thirty micrometers) and/or of calcium carbonate of at least 0.1 µm (zero point one micrometer) and additionally or alternatively of a maximum of 45 µm (forty five micrometers). The seventh primer preferably comprises 10% by weight (ten percent by weight), preferably to within ±6%, of organic or inorganic salts. The seventh primer preferably comprises 4 wt% (four percent by weight), preferably to within ±3.5% of binder. The seventh primer preferably has 5% by weight (five percent by weight), preferably with an error limit of ±3, of humectant, preferably glycerin. The seventh primer preferably comprises 0.1% by weight (zero point one percent by weight), preferably to within ±0.06% of the biocide, preferably isothiazole. The seventh primer preferably has 0.4% by weight (zero point four percent by weight), preferably with an error limit of ±0.3, of defoamer and/or surfactant and/or at least one component for optimizing viscosity, preferably siloxane or at least one polyether siloxane copolymer. The seventh primer preferably has at least one adhesion promoter, preferably calcium hydroxide, for example in a concentration of 0.1% by weight (zero point one percent by weight) to a maximum of 5% by weight, preferably 2.6% by weight with an error limit of ±2. 5, on. The adhesion promoter preferably improves the adhesion of the at least one pigment on the printing substrate 02. Color differences between different printing substrates 02, in particular different batches of paper, are preferably leveled out relative to one another, preferably by means of a coloring primer, in particular a whitening primer, using the seventh primer. The seventh primer is preferably a coloring primer for the printing substrate 02. The opacity of the primer is preferably retained by means of the seventh primer even after the printing substrate 02 has been pressed and/or laminated. The at least one, preferably the first, pigment preferably guarantees uniform color behavior on different surfaces, with the color space preferably being kept constant. A color space of the subsequently applied printing fluid is preferably shifted by the seventh primer compared to the color space of a printing fluid application without a seventh primer. Preferably, the dry weight of the application quantity of printing fluid applied to the at least one printing substrate 02 by the at least one printing unit 01 is no more than 6.5 g/m ² (six point five grams per square meter), preferably no more than 3 g/m ² , for example a maximum of 0.8 g/m ² , and/or at least 0.1 g/m ² , preferably at least 0.2 g/m ² , preferably sufficient for optimal printing fluid application. With the color density remaining the same, a saving of at least 6%, preferably at least 15%, for example up to 40%, in the required application quantity of printing fluid is preferably achieved. The wet weight of the seventh primer applied to printing substrate 02 is preferably at least 0.5 g/m ² (zero point five grams per square meter), preferably at least 1 g/m ² , more preferably at least 3 g/m ² , and/or preferably at most 16 g/m ² , preferably at most 6 g/m ² , more preferably at most 5 g/m ² .

The printing press, preferably at least the at least one application device 08 and/or the at least one printing unit 01, preferably has at least one cleaning agent. The at least one cleaning agent preferably prevents open systems of the printing press, for example at least one print head tray and/or at least one tray containing the primer, of application unit 08 from becoming infested with algae and/or mold. The printing machine is preferably cleaned, in particular with the at least one cleaning agent. Advantageously, the at least one application device 08 and/or the at least one printing unit 01 is rinsed with the at least one cleaning agent, preferably before filling with primer or printing fluid. The at least one printing unit 01 and/or the at least one application device 08 preferably has at least one supply line and at least one discharge line for the cleaning agent. At least the at least one pressure chamber of the at least one printing unit 01, preferably inkjet printing unit 01, and/or at least chamber doctor blade 14, preferably also forme roller 09 and/or anilox roller 17, of the at least one application device 08 is preferably rinsed with the at least one cleaning agent . The at least one cleaning agent is preferably used for cleaning when using water-based pressure fluids and/or water-based primers and/or water-based paints. The at least one printing fluid and/or the at least one primer is preferably water-based, in particular when the at least one cleaning agent is used.

The at least one cleaning agent preferably has solvents, preferably water, more preferably osmosis water or distilled water or deionized water. The electrical conductivity of the solvent is preferably at least 3 µS/cm (three microsiemens per centimeter), preferably at least 5 µS/cm, more preferably at least 15 µS/cm, and/or at most 100 µS/cm, preferably at most 50 µS/cm, more preferably at most 30 μS/cm, for example 20 μS/cm. The at least one cleaning agent preferably has at least one biocide. The at least one cleaning agent preferably has water as the solvent and the at least one biocide. The at least one biocide preferably has at least one isothiazole, for example benzisothiazolinone, in particular 1,2benzisothiazol-3(2H)-one, or methylisothiazolinone, in particular 2-methyl-2H-isothiazol-3-one, or a mixture of the substances mentioned. The at least one cleaning agent preferably has at least 0.001% by weight (zero point zero zero one percent by weight), preferably at least 0.01% by weight, and/or at most 0.7% by weight, preferably at most 0.2% by weight Biocide, for example 0.1 % by weight with an error limit of ±0.06, of biocide. The percentage by weight of the cleaning agent remaining in addition to the percentage by weight of the biocide is preferably accounted for by the at least one solvent, preferably water. For example, the at least one cleaning agent has at least one surfactant, preferably at least one nonionic surfactant, in addition to the at least one solvent and the at least one biocide. The at least one surfactant preferably has lauryl sulfate and/or at least one polymer, for example at least one epoxide and/or having at least one methyl group, and/or at least one ether, for example oxirane, 2-methyl-, polymer with oxirane, mono[2 -methoxy-4-(2 propen-1-yl)phenyl] ether and/or poly(oxyethylene)(oxypropylene) glycol monoallyl ether. The at least one cleaning agent preferably has a maximum of 0.5% by weight (zero point five percent by weight), preferably a maximum of 0.3% by weight, more preferably a maximum of 0.2% by weight, of surfactant.

The cleaning agent is advantageously compatible with the at least one primer and/or the at least one printing fluid. In particular, the at least one primer is mixed with the cleaning agent or the at least one printing fluid is mixed with the cleaning agent, preferably without precipitation or flocculation of the components thereof. This is advantageous since components of the printing press can become clogged with precipitated or flocculated components.

Reference List

01

Printing unit, inkjet printing unit

02

Printing material, printing material web

03

Printing material template, roll changer

04

Product intake, rewinder

05

-

06

dryer

07

printhead

08

Device for pre-treatment, application device

09

roller, applicator roller

10

-

11

Roller, backing roller, impression roller

12

Medium, squeegee

13

container

14

chamber doctor blade

15

-

16

medium, waterproofing

17

roller, anilox roller

18

dryer

R11

Roller axis of rotation (11)

B02

substrate width

QUOTES INCLUDED IN DESCRIPTION

This list of the documents cited by the applicant was 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.

Patent Literature Cited

• DE 102017211843 A1 [0004]
• US 10906349 B2 [0005]

Claims (3)

Composition of a primer, the primer having at least one solvent, the primer having at least one binder, the primer having at least one inorganic or organic salt, the primer having at least one surfactant, the primer having at least one first pigment, the at least one first pigment has an average pore volume of at least 4 cm ³ /g (four cubic centimeters per gram) and/or at most 35 cm ³ /g (thirty-five cubic centimeters per gram), the primer having at least one second pigment, the at least a second pigment is of a different chemical composition than the at least one first pigment, wherein the at least one second pigment is formed as a resin and/or wax and/or polyethylene and/or polypropylene. composition after claim 1 , characterized in that the primer has at least one humectant and / or that the primer has at least one biocide. Printing press, the printing press having at least one inkjet printing unit (01), the printing press having at least one application device (08) arranged upstream of the at least one inkjet printing unit (01), the at least one application device (08) having at least one printing substrate (02) with at least one primer according to claim 1 or 2 is formed acting.

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