DE102009044430A1 - Coating color for improving the quality and running properties of printing substrates and production method of the coating color - Google Patents

Abstract

The present invention relates to a coating color for coating a printing medium such as paper, cardboard and cardboard, which has water, at least one pigment, at least one binder, electrolytic components and at least two additives. The coating color is characterized in that it has at least one high molecular weight polyether as a first additive and at least one polyfunctional alcohol and / or a low molecular weight polyether and / or a micellar fatty acid dispersion as a second additive, and wherein the first and second additives contain the electrolytic components of the The coating color is at least partially restricted in its movement in the aqueous phase of an electrical double layer of the pigment and leads to an increase in the discharge time in the dried coating layer. The invention also encompasses a method for producing the coating color.

Description

The present invention relates to a paint for painting a print substrate such as paper, paperboard and cardboard and a method for producing the paint.

In the prior art, coating colors for the production of coated printing media are known. Coating paints essentially consist of a pigment or pigment mixture dispersed in water with the aid of a dispersing agent and binders, as well as certain amounts of additives.

The manufacturers of coated papers for offset and gravure printing are facing massive cost pressure due to the increasing competition with electronic media and must look for ways to further reduce the manufacturing costs of the products.

To stay competitive, paper manufacturers need to optimize the cost structure of their entire manufacturing process. In addition to improving the optical properties of the papers, the printing industry is increasingly demanding an increase in efficiency and production through improved printability and runnability in gravure printing and offset printing.

The effort to achieve improved efficiencies in process manufacturing, as well as the attempt to maintain the previous printability and verdruckbarkeitseigenschaften the papers has meant that more and more different sometimes very expensive materials such. As talc be used in the production of papers. Especially for the production of so-called lightweight, coated papers (so-called LWC and ULWC papers) for gravure printing u. a. Talcum used as a pigment.

Talcum as a pigment reduces the adhesive and sliding friction coefficients of the coated paper and slows the discharge rate at electrostatic charge. In the paper industry, therefore, the coefficient of static friction and sliding friction is included in quality control. New studies have shown, however, that the mechanism of action of talc to avoid core placements especially by increasing the surface and volume resistance d. H. is significantly determined by a higher charge and slow discharge of the paper. However, high electrolyte contents or high conductivity have a counterproductive effect on the preferred properties of talc.

In addition, talc is much more expensive compared to conventionally used gravure kaolins and has additional disadvantages of less whiteness, very poor dispersibility, and unfavorable rheological behavior when processed on the coater. Processing problems such as streaking when applying the coating to the raw paper are very common, resulting in a higher proportion of non-salable paper.

Among other things, the use of talcum was important in the prior art in order to avoid so-called core plots when unwinding very wide and large rolls in the gravure printing machine. Kernplatzer or Kreppfalten in the LWC offset arise when it comes to unwinding to sudden positional shifts, wherein the extensibility of the paper is exceeded and it comes to local tears or LWC offset to Kreppfalten or bursting of the web. Kernplatzer lead in the gravure printing machine to a web break. Above all, however, the residual amounts of paper on the unwound roll are no longer printable, so that the residual roll must be fed to the broke. This results in significant economic losses.

Also, the influence of moisture in the calendering is known, gloss and smoothness increase with higher humidity, whiteness and opacity, specific volume, capillarity, Be and Verdruckbarkeitsverhalten (core burst, Kreppfalten) deteriorate. The possibilities of increasing the gloss, in particular by changing the recipe and changing the input moisture, must be considered carefully before the calendering. D. H. be considered holistically to avoid adverse effects. So it makes no sense in the production of LWC offset paper, the gloss increase on a line weight increase or by increasing the input moisture content implement, if you already have blister problems or Kreppfaltenprobleme. High humidity causes a high conductivity and low surface resistance, which can lead to rapid discharge processes and thus to Kreppfalten.

The object of the present invention is to at least partially reduce or remedy the disadvantages known in the prior art and, in particular, to provide a coating color which is cost-effective to produce due to the saving of raw materials and, moreover, improved Has paper properties and printability properties and can be processed at high machine speeds.

The above object is achieved by a coating paint as claimed in claim 1. The method for producing this coating color according to claim 12 solves the above object, wherein preferred embodiments of the invention are the subject of the respective subclaims.

The coating composition according to the invention for painting a printing carrier, such as paper, cardboard and cardboard, comprises as constituents at least water, pigment and a binder, wherein, moreover, the coating color has in particular electrolytic constituents and at least two additives. At least one high molecular weight polyether is used as the first additive according to the present invention for the coating color and at least one polyfunctional alcohol and / or a low molecular weight polyether and / or a micellar fatty acid dispersion as the second additive, the first and second additive containing the electrolytic constituents of the coating color, in particular their movement and mobility in the aqueous phase of an electric double layer of the pigment limits and thereby leads to an extension of the discharge time in the dried line.

In the context of the present invention, the term "pigment" refers in particular to minerals which are, for example, kaolin, chalk, talc, calcium carbonates, titanium dioxide, aluminum hydroxides, bentonites, barium sulphates, synthetic fillers or plastic particles, dyes, combinations thereof and the like.

Binders according to the present invention are in particular polymers understood which in particular natural binders such as starch, casein, soy protein, cellulose ethers, vegetable proteins of other origin, synthetic binders especially in dispersion form, as well as in water-soluble form and basis of styrene-butadiene, styrene (meth ) Acrylate esters, vinyl acetate-ethylene, vinyl acetate acrylate esters, vinyl acetate and polyvinyl alcohols, combinations thereof, and the like.

In addition, according to the present invention as the electrolytic constituents in particular salts such as sodium chloride, calcium chloride, ammonium salts, hardening components in water, especially water-soluble polyelectrolytes such as natural and / or synthetic components such as carboxymethylcellulose (CMC), acrylic acid, methacrylic acid, fumaric acid, itanconic acid , Combinations thereof and the like understood.

The first additive according to the present invention is selected from a group consisting of high molecular weight polyethers such as straight-chain or branched high molecular weight polyethylene glycols, high molecular weight polypropylene glycols straight-chain or branched, mixtures of polyethylene glycols with polypropylene glycol, ethylene oxide / propylene oxide polyethers, reaction products of polyethylene glycol with bisphenol A diglycidic ethers, ester and ether products, associative thickeners on HEUR (Hydrophobicly Modified Ethoxylated Urethane) base, crown ethers, cyclic ethers, combinations thereof and the like understood.

According to a further, particularly preferred embodiment, the corresponding high molecular weight polyethers used as the first additive have in particular a molecular weight which is greater than 20,000 g / mol or preferably between 20,000 g / mol and 1,000,000 g / mol, particularly preferred between 20,000 g / mol and 50,000 g / mol and in particular about 35,000 g / mol.

According to the present invention, in particular, the second additive is selected from a group which comprises, inter alia, low molecular weight polyethylene glycols which are straight-chain or branched, low molecular weight polypropylene glycols which are straight-chain or branched, mixtures of polyethylene glycol and polypropylene glycol, ethylene oxide / propylene oxide polyethers, reaction products of polyethylene glycol and bisphenol A diglycidic ethers, as well as polyfunctional glycidyl ethers based on polyfunctional alcohols, micellar fatty acid dispersion (C ₁₂ to C ₂₁ ), for example stearic acid dispersions prepared using ammonia, organic armines or polymeric bases such as polydimethylethyl methacrylate as neutralizing component, Co Polymers of polyglycol methacrylates with acrylic acid or with methacrylic acid, N-vinylpyrrolidone, or N-vinyl lactam copolymers with hydroxyethyl or Polyglykolmethycrylaten, fatty acid amines, Aminopolyglykole, Kombi From these and the like.

According to a particularly preferred embodiment, the second additives have a molecular weight which is in particular less than 20,000 g / mol. Preferably, the molecular weight of the second additive between 100 g / mol and less than 20,000 g / mol, preferably between 1,500 g / mol and less than 20,000 g / mol, more preferably between 3,000 g / mol and less than 20,000 g / mol and in particular at 4,000 g / mol or at about 10,000 g / mol.

According to a particularly preferred embodiment, the coating color according to the invention is further characterized in that the limited mobility of the electrolytic constituents is achieved in particular by an increase in the surface and / or volume resistance of the coating or coated paper and / or the conductivity in the dried coating layer is reduced.

According to a further particularly preferred embodiment, the coating color according to the invention comprises further constituents such as, for example, optical brighteners, dyes, rheological aids, combinations thereof and the like.

The coating composition of the invention reduces by the use of the first and second additive in particular the mobility of the electrolytic components - preferably in the dried line - in that advantageously the electrolytic components by absorption on the pigment and / or by immobilization and / or fixation and / or Complexation be bound at least temporarily.

In this case, the first and / or the second additive in particular non-ionic property, wherein according to a further particularly preferred embodiment, the first and / or second additive may be weakly anionic or weakly cationic equipped.

According to a further, particularly preferred embodiment, the total amount of first and / or second additives which are added to the coating color in relation to the total pigment content is between 0.05 and 2.5 parts, preferably between 0.1 and 1.5 parts, and especially preferably between 0.15 and 1 part.

According to a further particular preferred embodiment of the present invention, the coating color according to the invention is prepared in such a way that it can be used in particular for processing with applicators such as, for example, film presses, curtain coater, spray application, roller coating method, blade coating method, blade coater, speed coater, Massey's method, flooded nip, combinations thereof and the like are known in the art.

According to a further particularly preferred embodiment, the coating color is used for a printing substrate, as used in particular in the processing in offset, gravure printing, inkjet, flexographic printing, laser printing, screen printing, high-pressure, combinations thereof and the like.

The object of the present invention is also achieved by a process for the production of a coating color which comprises at least the following steps: presentation of a pigment dispersion, which is initially introduced as a finished pigment dispersion or prepared as a corresponding pigment dispersion, ie a dispersion preferably of the pigment and water and optionally a dispersant is prepared in a corresponding container. In this submitted pigment dispersion according to the inventive method, the addition of the first additive, which is in particular a high molecular weight polyether and in particular with respect to the first additive further determined. In addition, a second additive is added, which is in particular a polyfunctional alcohol and / or a low molecular weight polyether and / or a micellar fatty acid dispersion and is more precisely determined with respect to the second additive.

In addition to the addition of the first and second additives, according to the process of the invention further components such as binders, CMC, synthetic thickeners, polyvinyl alcohols, starch, optical brighteners, calendering aids, combinations thereof and in the same are added before the corresponding coating color is completely dispersed.

According to a further, particularly preferred embodiment, the first and second additive is added as a mixture of the pigment or the pigment dispersion, wherein, as already stated above, the pigment is introduced as a finished pigment dispersion or the pigment is directly prepared as a dispersion in water.

According to a further, particularly preferred, embodiment of the method according to the invention, the proportion of the second additive increases with increasing molecular weight in relation to the proportion of the first additive.

According to a further preferred embodiment, the coating color to be produced in accordance with the above method is adjusted to a pH value which is preferably between 7.5 and 8.8 and in particular between 8.5 and 8.7 by the addition of an alkali or an acid ,

In particular, polyethers and micellar stearic acid dispersions adsorb on the pigment surface. The ions fixed in the electric double layer are restricted or complexed by the adsorption in their mobility, whereby the discharge rate is reduced by static charge

In particular, the use of the additives according to the invention results in improved printability and printability properties both in low and offset printing.

For example, the use of the additives according to the invention in gravure papers results in improved gloss, higher opacity, low color penetration and shine, and fewer missing halftone dots. Also occur in the settlement of broad roles core placer near the sleeve, which almost inevitably occur in papers that contain no talc, are avoided.

When using the additives according to the invention in coated offset papers a higher Ratserpunktschärfe is achieved in addition to higher gloss. The cleaning and washing intervals at the press can be significantly reduced. The occurrence of Kreppfalten the winder, which is due to sudden shift position due to low friction coefficients, can be avoided by the use of additives.

When using only low molecular weight polyethylene glycols in the coating color, however, massive printability problems were observed. These show in a fading of the ink (mainly cyan) after prolonged storage of the coated papers. Polyethylene glycol is a so-called linear crown ether. Linear crown ethers can adopt a cyclic conformation to complex metal ions, as in 1 represented, so that z. B. alkali metal ions can be complexed in the resulting cavity. The high molecular weight polyethylene glycol acts as a so-called "podand". The fading of the ink film can be explained by a diffusion of the low molecular weight polyethylene glycols into the ink film and the complexing there of the central atom of the phthalocyanine-based pigments.

In particular, low molecular weight polyethylene glycols can also be used as a carrier for optical brighteners, as well as stabilizers and lubricants in coating colors.

Of particular note is also the large increase in high shear viscosity with all its adverse effects associated with ammonium stearate as an additive.

Table 7 illustrates combinations of the first with the second additive. For example, in the above variations 1 and 2, a high molecular weight polyether was used in combination with a low molecular weight polyether. Thus, in Variation 1, a high molecular weight polyether having a molecular weight of 50,000 g / mol was used, the proportion of the second additive relative to the total amount of polyether used being 1-10% at low molecular weight (1,000 g / mol). 30% (10,000 g / mol) increased.

Variant 2 shows the use of a high molecular weight polyether having a molecular weight of 30,000 g / mol and the proportion of the second additive in relation to the total amount of polyether used of 0.5 to 5% with a molecular weight of 1000 g / mol up to 10-15 % or 15-20% when using a second polyether having a molecular weight of 10,000 g / mol.

The invention will be explained with reference to individual embodiments, wherein expressly pointed out that this does not limit the invention, but the embodiments only serve to understand the present invention and that of course also modifications and adaptations as the skilled person would make in the sense of the present Invention lie.

The measurements of the loading and unloading behavior of the coated papers were carried out with the Static Charge Analyzer, model 276A from Monroe Electronics. The degree of charge of the samples is characterized by the field strength emanating from the samples due to their charge. Three measuring points located below the rotating measuring plate record the field strength of the charged samples and conduct the trace continues to a writer. The recorder records the measured voltage over time. There are curves with the in 2 illustrated basic course, which are evaluated manually. The decay of the maximum charging voltage can be approximately described by an exponential function. U0 is the maximum charging voltage that can be transferred to the paper. To characterize the discharge different time constants can be used, their definition 2 is apparent. It should be noted that the height of the determined discharge times only give an indication of the particular embodiment, ie the discharge times can not be compared with other embodiments because of different measurement conditions.

Embodiment 1

Prevention of core spot locations when winding large rolls for LWC gravure papers by influencing the electrostatic charges. In these first investigations, it was to be determined to what extent selected additives influence the electrostatic discharge process. The base paper used was a wood-containing intaglio coating paper with a basis weight of 46 g / m ² . A high-performance dispersing device was used to produce the coating color. A self-thickening SB-TD binder (Dow-Chemical) as well as polyethylene glycol with different molecular weights (Clariant) as well as micellar stearic acid dispersion and stearylamine were introduced with stirring into the TD-kaolin slurry (AKW-Hirschau). The pH was adjusted with NaOH. The products used are described in detail in the company documents. The solids content was after DIN ISO 787 Part 2, the pH after DIN ISO 787 part 9, the low shear viscosity according to Brookfield at 100 rev / min after DIN ISO 2555 certainly. The coating colors were applied by means of a motorized hand doctor blade (Erichsen K Control Coater) to wood-containing base paper with an application rate of 10 g / m ² . The thus-coated paper is calendered in a laboratory calender under the following conditions. Roll surface temperature: 95 ° C Line force: 200 N / mm Speed: 10 m / min Number of passes 4

Table 1 shows the influence of the different coating compositions on the electrostatic charge when winding large rolls for LWC gravure, with which also corresponding core place places can be avoided or reduced. With hydrophobicized kaolin, emulsified triethoxyalkysilane, zeolite, etc., the desired discharge time of the practice in practice with 15-30 parts of talc between 0.8-0.9 sec (see Example 2) discharge time could not be achieved. However, z. B. a combination of z. As PEG and zeolite to support the reduction of conductivity conceivable.

The test results according to Table 1 show that the desired deceleration of the discharge time can best be achieved with high molecular weight PEG and micellar stearic acid dispersion and mixtures thereof. In contrast, a 4000 MW PEG has no effect on the discharge process. It has already been mentioned that low molecular weight PEG is used as antistatic agent, i. H. contributes to the discharge acceleration. From the investigations also shows that electrolytes z. B. NaCl also cause a strong discharge acceleration and that a pH reduction and consequent reduction of Na + ion concentration already has a positive effect on the discharge process.

Embodiment 2

Prevent core pitches when winding large rolls for LWC gravure without using talcum. The aim of this series of experiments was to determine to what extent high-molecular-weight PEG can replace the talc used in practice to avoid core sites with regard to the required surface resistance and the discharge time. Finntalc C 10 (Mondo Minerals) was used as the coating talc and ammonium stearate by Schill and Seilacher. The base paper used was a 46 g / m ² wood-containing base paper. To prepare the coating colors and measurement of the rheological properties, application by hand wringer and calendering and the discharge times, the methods mentioned in Example 1 were used. The coating is 10 g / m ² . The measurements of the sliding friction coefficient were based on DIN 53 119-1 executed. The surface and volume resistivity measurements were made using a Terra-Ohm meter from Eltex.

It can be seen from the tests according to Table 2 that the parameters which are important for the avoidance of core bursts, such as surface resistance and discharge times with PEG, are in the same range as with the 15-30 parts talc used in practice. The sliding and static friction coefficient is not changed by PEG. In fact, a reduced coefficient of sliding friction tends to lead to core bursts.

Embodiment 3

Influence of certain additives on the quality properties and prevention of core bursts of LWC-TD papers. In this series of tests, in addition to the water retention, high shear viscosity and discharge time, especially the paper and print quality properties with the various additives should be included in the test results. In addition, the following products were used or applied to the pigments and additives and methods mentioned in Example 1 and 2. Brazilian kaolin 90% <2 μm (Imerys), ground calcium carbonate (GCC 70% <2 μm) marble-based (Omya) alkaline swellable thickener based on butyl acrylate-acrylic acid Ethyl acrylate polymers (Alco Inc) Shear viscosity Rotational viscometer on cylinder / cup basis with defined gap. The water retention is measured by applying a defined coating color sample to a metal electrode. Filter paper is placed on the coating color sample and thereupon a counterelectrode designed as a weight. The time is measured in seconds until a certain current flow is achieved due to the impregnation of the filter paper with coating color serum. Generally, the longer the measured time, the higher the water retention of the coating color. A good water retention capacity of the coating color is a prerequisite for a perfect processing of coating colors, since too rapid dewatering of the coating film applied to the paper web on the metering element, the so-called doctor blade, leads to the formation of stripes. The test coats are applied to a h 'containing 36 g / m ² raw paper on a test machine, at a speed of 120 / m / min. The coating weight was 8-9 g / m ² on both sides. The coated papers were then calendered on a laboratory calender at a roll temperature of 90 ° C and a contact pressure of 150 kN / m with two nips per side.

Determination methods for paper and printability evaluation: determination of opacity according to 53 146/3; whiteness ISO 2470 , PPS roughness ISO 8791-4 . Smoothness to Bekk DIN 53107/7 ; Paper gloss 75 ° / 75 °; Printing gloss Tappi 75 ° / 75 °; Gravure tests IGT Heliotest (missing halftone dots / cm ² ). However, in the presence of ammonium stearate, the high shear viscosity increases sharply with both high molecular weight PEG and stearin micelles (V4 and V5). However, significant advantages in smoothness, gloss and printability development are achieved compared to the standard formulations (V1 and V2).

In addition, slower discharge times compared to the standard (V2) without talcum result. From this example according to Table 3 shows that can be improved with the additives used both the paper and printability properties (less missing halftone dots / cm ² ) and at the same time the talc can be replaced without Kernplatzerprobleme.

Embodiment 4

Deceleration of unloading time to avoid crepe creases when wrapping offset coated papers. This series of experiments was intended to clarify whether the additives successfully used in gravure printing are also effective with regard to the discharge time, even with offset formulations with different binder contents. The pigments and binders used were a ground calcium carbonate (GCC) from Omya, kaolin (Imerys), SB binder (BASF), PVA-4-98 (Kuraray), OBA (Clariant). The base paper used was a 46 g / m ² wood-containing base paper. To prepare the coating colors and measurement of the rheological properties, application by hand wringer and calendering and the discharge times, the methods mentioned in Example 1 were used.

The coating is 10 g / m ² . The investigations according to Table 4 show that the high molecular weight PEG products and the stearic acid dispersion are also fully effective in offset formulations with respect to a discharge time delay, while the low molecular weight PEG z. B. V2 MG 2000 rather adversely affect the discharge, ie lead to a faster discharge of the papers.

Embodiment 5

Influence of various additives on the quality properties and formation of crepe creases of coated offset papers. These investigations should shed light on the influence of the described additives on the electrical and electrostatic property changes Paper quality properties with respect to smoothness and gloss development. As raw paper and raw materials used 4 are described in the embodiment. The preparation of the coating color, application, calendering and electrical surface resistance and discharge time are shown in the embodiment 1 and 2. The paper test in the embodiment 3.

The test results according to Table 5 confirm on the one hand the positive influence of the additives on the surface and volume resistance and discharge process (high surface and volume resistance and slower discharge of the papers result in a smooth running behavior (with regard to Kreppfalten) and a significant increase in gloss and smoothness like this This also provides the opportunity to create moderate calendering conditions with the advantages already mentioned.

Embodiment 6

Use of low-cost raw materials in offset LWC without sacrificing quality through the use of high molecular weight PEGs. In this example, the use of the additives described economic benefits such. B. use of inexpensive Grobkaolin, calcium carbonate and binder savings are developed without loss of quality. The pigments and binders used were GCC 95% <2 μm, GCC 90% <2 μm (Omya), Feinstkaolin 98% <2 μm (Imerys), Grobkaolin 70% <2 μm (AKW) and SB-Binder (BASF). The experiments were carried out under the same experimental conditions and their evaluation as in Embodiment 3.

Tabelle 2 Komponente Teile V1 V2 V3 V4 Pigment: TD-Kaolin (75% < 2 μm) 100 70 50 100 Streichtalkum (Finntalc C 10) - 30 50 - Binder und Additive: - - - - TD-Latex (selbstverd. SB) 4,6 4,6 4,6 4,6 Ca-Stearat 0,7 0,7 0,7 - PEG (V10 aus Beispiel 1) - - - 0,6 Feststoffgehalt % 46,5 46,8 46,4 46,0 Viskosität (Brookf. RN/20°C/100 Rpm/mPa·s) 450 690 950 420 pH-Wert 9,0 9,0 9,0 9,0 Strichgewicht g/m² 10,0 10,0 10,0 10,0 Gleitreibungskoeffizient G 0,36 0,30 0,29 0,35 Oberflächenwiderstand 10⁸ Ohm 5,1 7,0 8,2 6,85 Entladungszeit sec. (t3) 0,60 0,85 1,10 0,95 Tabelle 3 Komponente Teile V1 V2 V3 V4 V5 Pigment: TD-Kaolin (75 < μm) 60 95 95 95 95 Brasilianisches Kaolin (90% < 1 μm) 20 - - - - Calciumcarbonat (GCC 70% < 2 μm) 5 5 5 5 5 Finntalc C 10 15 - - - - Binder und Additive: Ammomiumstearat 0,8 0,8 - 0,4 0,6 SB-Binder 5,0 5,0 5,0 5,0 5,0 alkaliquellbarer Verdicker 0,15 0,15 0,15 0,15 0,15 PEG-Mischung (V10 Beispiel 1) - - 0,8 - PEG-Mischung (V10 Beispiel 1) - - - 0,4 - Micellare Stearinsäuredispersion - - - - 0,15 FG % 56,9 56,7 56,7 56,8 56,5 pH-Wert 8,9 8,5 8,5 8,5 8,5 Viskosität (Brookf. RN/20°C/100 Rpm/mPa·s) 580 640 640 620 610 Hochscherviskosität 4390 sec^–1 mPa·s 138 140 79 230 235 Wasserretention sec. 27,0 26,0 28,0 26,5 25,0 Weißgrad ISO % 73,5 72,8 73 72,8 72,7 Opazität % 87,7 87,4 87,4 87,2 87,3 PPS-Rauhheit μm 0,9 0,75 0,65 0,68 0,63 Glätte Bekk sec 1800 1850 3100 3000 2850 Papierglanz TAPPT 75° 50 53 63 59,1 58,2 Druckglanz TAPPT 75° (Vollton) 29 30 34 33,3 34,0 Fehlende Rasterpunkte 1/cm² 140 110 55 48,5 53,5 Gleitreibungskoeffizient G 0,31 0,36 0,37 0,36 0,36 Entladungszeit sec (t3) 1,75 1,27 1,80 1,60 1,85 Tabelle 4 Komponente Teile V1 V2 V3 V5 V6 Pigment: GCC (90% < 2 μm) 80 80 80 80 80 Kaolin (98% < 2 μm) 20 20 20 20 20 Binder + Additive: Styrol-Butadien-Latex (Tg 2°C) 11 11 11 11 11 PVA (4-98) 0,4 0,4 0,4 0,4 0,4 CMC (Caboxylmethylcellulose) 0,5 0,5 0,5 0,5 0,5 Calciumstearat 0,3 - - - 0,15 OBA-Stilbentetrasulfonsäureaufheller 0,6 0,6 0,6 0,6 0,6 PEG (MG 2000) - 0,7 - - - PEG (MG 4000) - - 0,7 - - PEG Mischung (siehe V10 Beispiel 1) - - - 0,7 - Micellare Stearinsäuredispersion - - - - 0,15 Feststoffgehalt (%) 70,5 69,7 69,8 70,6 69,5 Viskosität (Brookf. RN/20°C/100 Rpm/mPa·s) 2200 2050 2100 2300 2350 pH-Wert 8,8 8,8 8,8 8,8 8,8 Strichgewicht (g/m²) 10,0 10,0 10,0 10,0 10,0 Entladungszeit sec (t3) 0,6 0,55 0,60 0,95 0,85 Tabelle 5 Komponente Teile V1 V2 V3 V4 Pigment: GCC (90% < 2 μm) 70 70 70 70 Kaolin (98% < 2 μm) 30 30 30 30 Binder + Additive: Styrol-Acrylat-Latex (Tg 27°C) 9 9 9 9 PVA 4-98 3 3 3 3 OBA (Tetrasulfo-Typ) 0,5 0,5 0,5 0,5 NaCl - 2 - - PEG (MG 4000) - - 0,7 - PEG (Mischung siehe V10 Beispiel 1) - - - 0,7 Feststoffgehalt % 66,5 65,5 66,5 66,0 Viskosität (Brookf. RTV/20°C/100 Rpm/mPa·s) 1150 1150 800 1200 pH-Wert 9,0 9,0 8,6 8,6 Strichgewicht g/m² 10,0 10,0 10,0 10,0 Weißgrad R 457 mit UV 100,6 100,5 100,5 100,9 Glanz 44,0 39,5 43,5 50,5 Glätte (PPS) μm 2,10 2,2 2,1 1,90 elektrischer Oberflächenwiderstand (10⁸ Ohm) 3,0 0,56 3,0 5,8 elektrischer Durchgangswiderstand (10⁸ Ohm) 3,5 0,95 3,6 6,2 Entladezeit sec (t3) 0,45 0,30 0,42 0,85 elektr. LF (ms/cm) der Streichfarbe 4,1 15,5 - - Tabelle 6 Komponente Teile V1 V2 V3 Pigment: GCC 95% < 2 μm 70 70 - Feinstkaolin 98% < 2 μm 30 - - Grobkaolin 70% < 2 μm - 30 - GCC 90% < 2 μm - - 100 Binder + Additive: Carboxylmethylzellulose 0,5 0,3 0,1 PVOH 4-98 0,5 0,3 0,2 SB-Latex 10,0 9,0 7,0 OBA-Stilbentetrasulfonsäureaufheller 0,8 0,8 0,8 Calciumstearat 0,8 - - PEG-Mischung (siehe V10 Beispiel 1) - 0,8 0,8 FG % 68 68 73 pH-Wert 8,7 8,8 8,6 Viskosität (Brookf. RTV/20°C/10 Rpm/mPa·s) 1620 1500 1450 Viskosität (Brookf. RTV/20°C/100 Rpm/mPa·s) 710 790 720 WRV sec 45 47 36 Hochscherviskosität mPas·s 85 80 75 Strichauftrag g/m² 11,0/12,3 11,5/12,0 10,9/12,5 Weißgrad ohne UV % 86,4 86,0 87,5 Weißgrad mit UV % 91,0 90,5 92,3 Opazität % 92,5 93,0 92,7 Glätte Bekk FS sec 1200 1300 1270 Glätte Bekk WS sec 1150 1250 1300 Glanz TAPPT 75°FS 58 62 60 TAPPI 75°WS 57 63 61 IGT Rupfwerte FS cm/sec m.V. > 100 > 100 > 100 IGT Rupfwerte WS cm/sec m.V. > 100 > 100 > 100 In the present example according to Table 6, the finely divided kaolin is replaced by a much coarser kaolin. In addition to economic benefits, rheological improvements and a higher gloss value than with the standard finely divided kaolin are achieved. If kaolin is completely replaced by GCC, the solids content can be drastically increased and higher gloss achieved with coarser GCC than the standard. Since coarser pigments have a lower binder requirement, binders can also be saved. Due to the higher solids content of V3 and the lower binder penetration into the base paper, the binder savings are even more pronounced.

Table 2 component parts V1 V2 V3 V4 Pigment: TD kaolin (75% <2 μm) 100 70 50 100 Scrapbooking (Finntalc C 10) - 30 50 - Binders and additives: - - - - TD latex (self-diluted SB) 4.6 4.6 4.6 4.6 Ca stearate 0.7 0.7 0.7 - PEG (V10 from Example 1) - - - 0.6 Solids content% 46.5 46.8 46.4 46.0 Viscosity (Brooks RN / 20 ° C / 100 Rpm / mPa · s) 450 690 950 420 PH value 9.0 9.0 9.0 9.0 Line weight g / m ² 10.0 10.0 10.0 10.0 Coefficient of sliding friction G 0.36 0.30 0.29 0.35 Surface resistance 10 ⁸ ohms 5.1 7.0 8.2 6.85 Discharge time sec. (T3) 0.60 0.85 1.10 0.95 Table 3 component parts V1 V2 V3 V4 V5 Pigment: TD kaolin (75 μm) 60 95 95 95 95 Brazilian kaolin (90% <1 μm) 20 - - - - Calcium carbonate (GCC 70% <2 μm) 5 5 5 5 5 Finntalc C 10 15 - - - - Binders and additives: Ammomiumstearat 0.8 0.8 - 0.4 0.6 SB-Binder 5.0 5.0 5.0 5.0 5.0 alkali-swellable thickener 0.15 0.15 0.15 0.15 0.15 PEG mixture (V10 example 1) - - 0.8 - PEG mixture (V10 example 1) - - - 0.4 - Micellar stearic acid dispersion - - - - 0.15 FG% 56.9 56.7 56.7 56.8 56.5 PH value 8.9 8.5 8.5 8.5 8.5 Viscosity (Brooks RN / 20 ° C / 100 Rpm / mPa · s) 580 640 640 620 610 High shear viscosity 4390 sec ^-1 mPa · s 138 140 79 230 235 Water retention sec. 27.0 26.0 28.0 26.5 25.0 Whiteness ISO% 73.5 72.8 73 72.8 72.7 Opacity% 87.7 87.4 87.4 87.2 87.3 PPS roughness μm 0.9 0.75 0.65 0.68 0.63 Smoothness Bekk sec 1800 1850 3100 3000 2850 Paper gloss TAPPT 75 ° 50 53 63 59.1 58.2 Printing gloss TAPPT 75 ° (full tone) 29 30 34 33.3 34.0 Missing halftone dots 1 / cm ² 140 110 55 48.5 53.5 Coefficient of sliding friction G 0.31 0.36 0.37 0.36 0.36 Discharge time sec (t3) 1.75 1.27 1.80 1.60 1.85 Table 4 component parts V1 V2 V3 V5 V6 Pigment: GCC (90% <2 μm) 80 80 80 80 80 Kaolin (98% <2 μm) 20 20 20 20 20 Binder + additives: Styrene butadiene latex (Tg 2 ° C) 11 11 11 11 11 PVA (4-98) 0.4 0.4 0.4 0.4 0.4 CMC (carboxymethylcellulose) 0.5 0.5 0.5 0.5 0.5 calcium stearate 0.3 - - - 0.15 OBA Stilbentetrasulfonsäureaufheller 0.6 0.6 0.6 0.6 0.6 PEG (MW 2000) - 0.7 - - - PEG (MW 4000) - - 0.7 - - PEG mixture (see V10 Example 1) - - - 0.7 - Micellar stearic acid dispersion - - - - 0.15 Solids content (%) 70.5 69.7 69.8 70.6 69.5 Viscosity (Brooks RN / 20 ° C / 100 Rpm / mPa · s) 2200 2050 2100 2300 2350 PH value 8.8 8.8 8.8 8.8 8.8 Line weight (g / m ² ) 10.0 10.0 10.0 10.0 10.0 Discharge time sec (t3) 0.6 0.55 0.60 0.95 0.85 Table 5 component parts V1 V2 V3 V4 Pigment: GCC (90% <2 μm) 70 70 70 70 Kaolin (98% <2 μm) 30 30 30 30 Binder + additives: Styrene acrylate latex (Tg 27 ° C) 9 9 9 9 PVA 4-98 3 3 3 3 OBA (tetrasulfone type) 0.5 0.5 0.5 0.5 NaCl - 2 - - PEG (MW 4000) - - 0.7 - PEG (mixture see V10 Example 1) - - - 0.7 Solids content% 66.5 65.5 66.5 66.0 Viscosity (Brookfield RTV / 20 ° C / 100 Rpm / mPa · s) 1150 1150 800 1200 PH value 9.0 9.0 8.6 8.6 Line weight g / m ² 10.0 10.0 10.0 10.0 Whiteness R 457 with UV 100.6 100.5 100.5 100.9 shine 44.0 39.5 43.5 50.5 Smoothness (PPS) μm 2.10 2.2 2.1 1.90 electrical surface resistance (10 ⁸ ohms) 3.0 0.56 3.0 5.8 electrical volume resistance (10 ⁸ ohms) 3.5 0.95 3.6 6.2 Discharge time sec (t3) 0.45 0.30 0.42 0.85 elec. LF (ms / cm) of the coating color 4.1 15.5 - - Table 6 component parts V1 V2 V3 Pigment: GCC 95% <2 μm 70 70 - Very fine kaolin 98% <2 μm 30 - - Coarse kaolin 70% <2 μm - 30 - GCC 90% <2 μm - - 100 Binder + additives: carboxymethylcellulose 0.5 0.3 0.1 PVOH 4-98 0.5 0.3 0.2 SB latex 10.0 9.0 7.0 OBA Stilbentetrasulfonsäureaufheller 0.8 0.8 0.8 calcium stearate 0.8 - - PEG mixture (see V10 Example 1) - 0.8 0.8 FG% 68 68 73 PH value 8.7 8.8 8.6 Viscosity (Brooks RTV / 20 ° C / 10 Rpm / mPa · s) 1620 1500 1450 Viscosity (Brookfield RTV / 20 ° C / 100 Rpm / mPa · s) 710 790 720 WRV sec 45 47 36 High shear viscosity mPas · s 85 80 75 Line application g / m ² 11.0 / 12.3 11.5 / 12.0 10.9 / 12.5 Whiteness without UV% 86.4 86.0 87.5 Whiteness with UV% 91.0 90.5 92.3 Opacity% 92.5 93.0 92.7 Smoothness Bekk FS sec 1200 1300 1270 Smoothness Bekk WS sec 1150 1250 1300 Gloss TAPPT 75 ° FS 58 62 60 TAPPI 75 ° WS 57 63 61 IGT picking values FS cm / sec mV > 100 > 100 > 100 IGT pickup values WS cm / sec mV > 100 > 100 > 100

Table 7

Variation 1: Polyether MW g / mol % dry % dry % dry 5 × 10 ⁴ 90-99 80-90 70-80 1 × 10 ⁴ 20-30 5 × 10 ³ 10-20 1 × 10 ³ 1-10 total 100 100 100 Variation 2: Polyether MW g / mol % dry % dry % dry % dry 3 × 10 ⁴ 95-99.5 90-95 85-90 80-85 1 × 10 ⁴ 10-15 15-20 5 × 10 ³ 5-10 1 × 10 ³ 0.5-5 total 100 100 100 100

QUOTES INCLUDE IN THE DESCRIPTION

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

Cited non-patent literature

• DIN ISO 787 part 2, [0043]
• DIN ISO 787 part 9, [0043]
• DIN ISO 2555 [0043]
• DIN 53 119-1 [0046]
• ISO 2470 [0049]
• ISO 8791-4 [0049]
• DIN 53107/7 [0049]

Claims (18)

A coating paint for painting a print substrate such as paper, paperboard and cardboard, which comprises water, at least one pigment, at least one binder, electrolytic constituents and at least two additives, characterized in that the coating color comprises, as a first additive, at least one high molecular weight polyether and one second additive comprises at least one polyfunctional alcohol and / or a low molecular weight polyether and / or a micellar fatty acid dispersion, and wherein the first and second additive at least partially restricts the electrolytic constituents of the coating color as they move in the aqueous phase of an electrical double layer of the pigment Extension of the discharge time in the dried coating layer leads. Coating paint according to claim 1, characterized in that there is an increase in the surface and / or volume resistance and / or a reduction in the conductivity in the dried coating layer. Coating paint according to one of the above claims, characterized in that the coating color further components, such as. As optical brighteners, dyes and rheological aids, combinations thereof and the like. Coating paint according to one of the above claims, characterized in that the pigment is selected from a group of materials which include minerals such as kaolins, talc, calcium carbonates, titanium dioxide, aluminum hydroxides, bentonites, barium sulfates, synthetic fillers, dyes, combinations thereof and the like, and / or the binder is selected from a group which comprises in particular natural binders, such as starch, casein, soy proteins, cellulose ethers, vegetable proteins of other origin, synthetic binders in dispersion form and water-soluble form based on styrene-butadiene, styrene- (meth) acrylate esters, vinylacetate Ethylene, vinyl acetate acrylate esters, vinyl acetate and polyvinyl alcohols, combinations thereof and the like, and / or the electrolytic constituents are selected from a group which in particular comprises ionogenic constituents such as salts, for example sodium chloride, calcium chloride, ammonium salts, hardening constituents in water, in particular water-soluble polyelectrolytes, such as natural and / or synthetic constituents, for example carboxymethylcellulose, acrylic acid, methacrylic acid, fumaric acid, itanconic acid, Combinations thereof and the like. Coating paint according to one of the preceding claims, characterized in that the first additive is selected in particular from a group which high molecular weight polyethers such as high molecular weight polyethylene glycols straight or branched, high molecular weight polypropylene glycols straight or branched, mixtures of polyethylene glycols with polypropylene glycols, ethylene oxide / propylene oxide polyethers, reaction product of polyethylene glycols with bisphenol A diglyzidethern, esters and ether products, HEUR associative thickeners, crown ethers, cyclic ethers, combinations thereof and the like, wherein in particular the first additive has a molecular weight which is greater than 20,000 g / mol or preferably between 20,000 g / mol and 1,000,000 g / mol, more preferably between 20,000 g / mol and 50,000 g / mol and in particular about 35,000 g / mol lies. Coating paint according to one of the preceding claims, characterized in that the second additive is selected in particular from a group which low molecular weight polyethylene glycols straight-chain or branched, low molecular weight polypropylene glycols straight-chain or branched, mixtures of polyethylene glycols with polypropylene glycols, ethylene oxide / propylene oxide polyethers, reaction product of polyethylene glycols with Bisphenol A diglycidic ethers, and polyfunctional glycidyl ethers based on polyfunctional alcohols, micellar fatty acid dispersions (C ₁₂ to C ₂₁ ), for example stearic acid dispersions, which are prepared using ammonia, organic amines or polymeric bases, such as polydimethylethyl methacrylate as neutralizing component, Polymers of polyglycol methacrylates with acrylic acid or methacrylic acid, N-vinylpyrrolidone, or N-vinyllactam copolymers with hydroxyethyl or Polyglykolmethycrylaten, fatty acid amines, Aminopolyglykole, Combinations thereof and the like, wherein in particular the second additive has a molecular weight which is less than 20,000 g / mol or preferably between 100 g / mol and less than 20,000 g / mol, preferably between 1,500 g / mol and less than 20,000 g / mol, especially preferably between 3,000 g / mol and smaller 000 g / mol and in particular about 4,000 g / mol or about 10,000 g / mol. Coating paint according to one of the preceding claims, characterized in that they are additives which limit the mobility of the electrolytic constituents of the coating color, preferably the dried coating color, in particular by adsorption on the pigment and / or immobilization and / or fixation and / or complex formation. Coating paint according to one of the preceding claims, characterized in that the first and / or second additive is non-ionic or weakly anionic or weakly cationic. Coating paint according to one of the preceding claims, characterized in that between 0.05 and 2.5 parts of the first and / or second additive or additive mixture based on the total pigment content, preferably between 0.1 and 1.5 parts, particularly preferably between 0, 15 and 1.0 parts are used. A coating composition according to any one of the preceding claims for processing with an applicator such as a film press, curtain coater, spray coating, roller coating, knife coating, blade coater, speed coater, Massey method, flooded nip and the like. Use of a coating color according to at least one of the preceding claims for producing a printing substrate, in particular for a printing substrate, which is processed in offset, gravure, inkjet, flexographic, laser, screen, high-pressure, combinations thereof and the like. Method for producing a coating color comprising the steps: - Presentation of a pigment dispersion, Addition of the first additive according to claim 5, Addition of the second additive according to claim 6, Addition of further components such as, for example, binders, CMC, synthetic thickeners, polyvinyl alcohol, starch, optical brighteners, calendering aids, combinations thereof and the like, - dispersing the coating color. A method for producing the coating color according to claim 12, characterized in that in particular between the addition of the first and the second additive, an adjustment of the pH of the coating color mixture between 7.5 to 8.8, preferably between 8.5 and 8.7. A process for the preparation of the coating color according to one of claims 12 or 13, characterized in that the pigment and / or the pigment dispersion is predispersed with at least one of the two additives. A process for producing the coating color according to any one of claims 12 to 14, characterized in that the first and second additive is added as a mixture of the pigment and / or the pigment dispersion. A method for producing the coating color according to one of claims 12 to 15, characterized in that the proportion of the second additive increases with increasing molecular weight in relation to the proportion of the first additive. A process for producing a coating color according to at least one of claims 1 to 10 with a process according to at least one of claims 12 to 16.

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