RU2285618C2 - Printing base and printing method - Google Patents

Abstract

FIELD: polygraphy.

SUBSTANCE: one invention from a group is related to printing base, being a substrate with oleophilic surface, having Gurley-Hill porosity value greater than 5000s/100ml, while printing paint, imprinted on such base, has offset value of printing paint IGT with delay time 30s, equal to more than 0,60 printing density units. Another invention is related to printing method, which is performed in at least one printing section with use of substrate, having oleophilic surface and being not porous with Gurley-Hill porosity value over 5000s/100ml, and carrier of pigment of printing paint, having value of offset of printing paint IGT with delay time 30s, equal to more than 0,60 printing density units.

EFFECT: improved quality of printing, improved quality of folding, decreased static electricity.

2 cl, 6 dwg, 3 tbl

Description

The invention relates to a printed base, which is a surface-treated paper used in offset printing with heat setting. The invention also relates to a printing method in which a printed substrate with a treated surface is subjected to offset printing with heat setting.

State of the art

Paper with suitable surface properties is printed using an offset printing method with heat setting. In this printing method, the printed element is transferred from the printing form through the offset web onto paper, which is fed to the offset printing machine with heat setting in the form of a continuous ribbon. The transfer of the printing ink element, consisting of various proportions of pigment, binder, solvent and additives, by the offset method is based on the transfer of printing ink from a smooth offset web. Ink is transferred onto the web from the printing plate, where the ink adheres to the oleophilic regions after wetting the hydrophilic regions of the printing plate with a wetting solution. The wetting solution contains treated tap water, a spray, a wetting agent and other additives. You can also use a printing plate that works on the principle of dry offset printing (also called waterless offset printing). In dry offset printing on a printing plate, there is a silicon layer that prevents the printing ink from sticking to areas of the printing plate that do not contain an image. After transferring the printing ink onto the paper, the ink is dried using heated air to evaporate most of the solvent contained therein. At the same time, the wetting solution transferred from the offset web and most of the moisture in the paper evaporate. After drying, the paper tape is cooled in cooling rollers after the ink film has solidified to provide further processing of the printed paper.

Certain properties of the paper used in the thermal setting offset printing method are required. Paper with suitable properties for this printing method is known, for example, from EP 539271 and publication GB 2047568. These sources disclose the use of calcium carbonate pigment CaCO ₃ to optimize paper porosity.

The printing method itself is described, for example, in published German patent DE 3207463.

In prior art, printing papers have been developed taking into account the position that the paper must be porous to some extent so that it can absorb the wetting solution transferred from the offset web to the paper and to simplify the removal of moisture from the paper when drying the paper in a dryer.

1. The invention

The aim of this invention is to provide a new type of printing substrate, which has a surface structure suitable for offset printing method with heat setting. To meet the requirements for a printed basis, the printed substrate has the characteristics presented in the claims.

An object of the present invention is also to provide a thermal fixation offset printing method in which paper is fed in the form of a continuous ribbon into one or more printing sections of a printing machine for transferring printing ink onto paper, after which most of the ink solvent is evaporated in a dryer using hot air to drying the ink; and creating ink that is easy to dry in the dryer.

The surface of the substrate is non-porous and oleophilic. This definition means that the oil displaces the wetting solution on the surface of the paper. The required properties of the paper are ensured by suitable paper processing, in particular by coating and subsequent finishing. In order to eliminate the problems associated with the transfer of printing ink and drying, the printing substrate is different from the printing papers currently used in the method of offset printing with heat setting, in which the surface is porous and absorbing water. The printing substrate according to the invention makes it possible to dry the printing ink as a surface phenomenon. The printing ink used also differs from the conventional printing ink currently used in the thermofix offset printing method, since the ink solvent evaporates faster at a lower air temperature in the dryer (lower oil content and / or boiling at a low temperature and poor solvent retention by a binder inks providing fast solvent removal), which simplifies drying of the printing ink. The non-porous surface of the paper allows the use of easily drying and fast-fixing printing ink (there are no problems associated with fast fixing of printing ink; see definition of fixing of printing ink in section 3.1). The combination of a non-porous surface of the paper and an easily drying ink makes it possible to use lower air temperatures in the dryer, while the moisture content in the paper remains high and the ink solvent evaporates. In addition, surface properties reduce the amount of wetting solution transferred to the paper (oleophilic non-porous surface repels the wetting solution and prevents its penetration into the paper structure).

The printing substrate according to the invention makes it possible to optimize the wetting solution used in the heat-setting offset printing method, so that its wetting agent is preferably non-alcoholic.

The invention provides a significant improvement in print quality, which is based on the fact that drying can be performed at a final temperature of the tape below 100 ° C, measured on the tape immediately after the dryer. With such a low drying temperature, on the one hand, the rapid removal of moisture is prevented, and on the other hand, the moisture content after drying is higher than in known solutions. This is an advantage because the rapid removal of moisture leads to roughness and waviness of the fibers, which reduces the gloss and uniformity of the print. The advantages of a higher moisture content after drying are improved print quality and parameters in the folding unit after drying. In addition to this, the folding parameters are improved, since paper better tolerates folding with a higher moisture content, and the likelihood of cracking is reduced. A higher moisture content also reduces static electricity, which is an advantage for the finishing process. It is also easier for the printer to handle printed paper, since there is no need for wrapping paper, since the moisture content of the paper is close to equilibrium with the moisture content in the air.

Advantages of the invention for paper manufacturers are an increased moisture content, lower strength requirements and increased manufacturing efficiency. The moisture content may be higher since the moisture of the paper does not evaporate during drying and there is no problem of paper bubble inherent in the method of offset printing with heat setting. Since there is no danger of paper bubbling, paper strength can be reduced, which makes it possible to use a cheaper base paper composition and eliminates the need for sizing. A decrease in sizing makes it possible to increase the manufacturing speed due to improved water removal. The use of a printing substrate according to the invention, with a composition also suitable for the intaglio printing method, allows to cut off the finished rolls of the paper machine for both intaglio printing and offset printing methods with heat setting for high print quality, which reduces the amount of paper waste and improves production efficiency.

Non-porous paper improves throughput and printability. Since the paper does not absorb the wetting solution from the printing sections, there is no change in paper size and no problems arise, for example, with case mismatch or fan discrepancies. There is no ink fixation, since there are no pores in the printing substrate. Therefore, there are no problems associated with the fixing of printing ink, such as mottling, contamination of letters or uneven distribution. This improves the print result and makes it possible to print longer because it requires less washing of the printed sheet.

The new printing concept is more environmentally friendly, since the use of a non-alcoholic type wetting solution reduces VOC emissions and requires less energy due to lower air temperature during the drying process. The solvent content of the printing ink is low.

The printed substrate according to the invention meets the following conditions:

1) the value of the curing of the IGT printing ink with a delay time of 30 s is more than 0.60 and

2) the value of the Gurley Hill permeability test for air is more than 5000 s / 100 ml. The set-off value is a measure of the capillary absorption of the paper surface. The IGT measurement result gives the value of the speed of fixing the ink, which correlates with the porosity of the surface of the paper;

3) the bonding build-up time when measuring ISIT is preferably more than 100 s for printing ink, which has stability in measuring the bonding time of a Tack-0-Scope printing ink T _max = 270-300 s. This sustainability result can be achieved, for example, using the well-known Sun Challenge printing ink. The ISIT measurement result gives the value of the speed of fixing the ink, which correlates with the porosity of the surface of the paper.

The stability of the ink when measuring bonding with the Tack-0-Scope provides less than 200 s. The printed substrate is preferably coated paper or surface-treated paper or paperboard that contains lamellar pigments as a coating pigment. The surface properties of the paper can be further adjusted by selecting the type of coating pigment and latex (coating binder) and their amount. The shape factor of the plate pigment particles, which is the ratio of the diameter of the pigment particles to the thickness of the pigment particles, is more than 2, preferably more than 4. The shape factor is preferably more than 4 to provide a non-porous surface. The pigment used in the coating paint is therefore preferably talc as the sole pigment or a combination of kaolin and talc. The large shape factor of the plate talc is preferably greater than 25 and has a positive effect on reducing the porosity of the paper surface. Similarly, the softer the latex used (low T _g , where T _g is the glass transition temperature) and the more latex is used compared to the amount of pigment, the more closed (non-porous) the surface is. Crosslinking the latex binder also improves surface closure.

The following is a detailed description of the invention in relation to some examples of execution, which do not limit the use of the invention.

2. Paper

The base paper in paper according to the invention is an ordinary LWC base paper with an ash content of 12% and a fiber blend of 40% chemical pulp and 60% mechanical pulp (TMP). The basis weight is about 36 g / m ² and the density is about 660 kg / m ³ . The paper is coated with the following components:

Talc (C 10X0 or C 15) Pigment Kaolin (Supragloss 95) Pigment Latex with a copolymer of butadiene and styrene Latex binder (Rhodopas 388) Starch (Raisamyl 302) Binder Latex with a copolymer of maleic anhydride and styrene (Raisaprint D100 or D200) Regulation of surface chemical properties Calcium Stearate (Raisacoat 50) Calendaring Supplement Optiblank NF Optical brightener Glyoxal Stapler

The solids content in the coating paint is 58% at a pH of 7.5. The value of T _g Rhodopas 388 is 0 ° C, which is the lowest value of Tg compared to the latexes commonly used in a coating ink for an offset printing method with heat setting. Surface closure can be improved with a T _g value of less than 5 ° C.

Various formulations of topcoat for paper, according to the invention, are presented in table 1 (in wt.%).

Table 1
Topcoat Formulations Coating paints one 2 3 four 5 6 8 C 10X0 70 70 40 70 70 C15 70 one hundred Supragloss thirty thirty thirty 60 thirty thirty Rhodopas 388 10 fifteen 10 10 10 10 10 Raisamyl 302 2 3 3 3 3 3 3 D200 3 3 3 3 3 D100 one Raisacoat 50 0.5 0.5 0.5 0.5 0.5 0.5 0.5 Optiblank 0.2 0.2 0.2 0.2 0.2 0.2 0.2 Glyoxal 0.2 0.2 0.2 0.2 0.2 0.2 0.2 * D100 was boiled with starch.

The paper was coated using a doctor blade (Opticoat-Jet). The upper (rougher) side of the base paper with a weight of 36 g / m ^{2 was} covered first. The target amount of coating weight was 12 g / m on both sides (coating 12 + 12 g / m ² ). The target final moisture content was 5.3% before calendaring.

The tape was dried after coating with infrared dryers and air tape dryers.

Coated paper was wound into rolls. The rolls were subjected to supercalendering, so that the upper side abutted against the first cooled roller.

The conditions of supercalendering were as follows:

Temperature

up: 120 ° C In the middle: 110 ° C at the bottom: 90 ° C Contact Zone Load 320 kN / m Speed 500 m / min Number of Contact Zones 9

The properties of the final coated paper are shown in Table 2.

Numbers refer to the numbers of topcoats and the corresponding numbers of samples.

table 2
Finished Coated Paper Properties One meas. Topcoats / Finish 1/2 5/8 6/10 3/12 8/18 4/22 Physical Properties: Base Weight g / m ² 59.8 61.7 61.7 62.7 62.7 63.7 Amount of topcoat g / m ² 9.7 12.0 13.1 12.6 12.8 12.7 Thickness μm 48 49 49 48 48 48 Density kg / m ³ 1239 1262 1265 1298 1302 1319 Volume dm ³ / kg 0.81 0.79 0.78 0.77 0.77 0.76 Surface Properties: Roughness PPS 10ts ^* ) μm 0.96 1.05 1,04 1,07 0.93 1.10 Roughness PPS 10ws ^** ) μm 0.99 1.01 0.91 0.91 0.73 1.10 Gloss ts ^* ) % 63.0 65.7 63.3 59,4 65,2 49.1 Gloss ws ^** ) % 58.6 67.2 64.5 59.3 65.0 48.6 Optical properties: Whiteness Eirepho ws ^** ) % 74.5 73.3 73,4 71.7 73.6 72.9 Brightness ws ^** ) % 78.0 77.6 77,2 76,2 77.1 76,4 Opacity ws ^** ) % 91.3 91.0 91.0 90.2 91.5 89.6 Dominant wavelength ws ^** ) nm 573 574 573 574 573 573 Excitation purity ws ^** ) % 3.2 3.9 3,5 4.4 3.4 3.4 Porosity and Absorption Properties
Paint absorption NP ws ^** ) 27.3 17.4 18,4 18.1 20.1 27.3 Paint absorption K&N ws ^** ) 2.7 1.3 1.3 1,5 1,5 3.4 Printing suitability: Surface strength IGT ws ^** ) m / s 0.50 0.60 0.66 0.65 0.65 0.58 Surface strength IGT wsrd ^** ) m / s 0.53 0.63 0.75 0.78 0.78 0.68 Surface Strength IGTwsard ^**** ) m / s 0.48 0.58 0.58 0.53 0.53 0.48 ^* ts = top side.
^** ws = back.
^*** wsrd = back when measured in the direction of travel.
^**** wsard = reverse side when measured against the direction of travel.

A small value in the K&N ink absorption test (in each case less than 4%) already shows that the surfaces of the papers in question are very closed and not absorbent.

In comparative tests, the following commercial and well-known offset printing papers with heat setting were used:

Sco UPM Max 56 g / m ² Lwco UPM Cote 60 g / m ² Lwco UPM Ultra 70 g / m ² Lwco UPM Ultra M 70 g / m ² MWC UPM Star 100 g / m ² Wfc UPM Art 100 g / m ²

SCO is a heat cured offset printing paper, LWCO is a light weight coated paper for a heat setting offset printing method, MWC is a medium weight coated paper for a heat setting offset printing method, and WFC is a woodless coated paper for use in a heat setting offset printing method. . The properties of known papers were investigated using methods described below.

The closed surface is also suitable for an offset printing method with heat setting and for an intaglio printing method for various types of paper and paperboard.

3. Methods

The significance of the test method lies in its ability to characterize the porosity of the surface of the paper regardless of the volume of the paper or the thickness or surface roughness. Absorption methods are best suited to characterize the surface of the paper, since absorption capacity and porosity are dependent on each other. The set-off value at a 30-second delay time measured by the IGT printing suitability tester is over 0.60, the ISIT bond buildup measurement method and K&N ink absorption test are based on capillary absorption and therefore the effect of paper volume is eliminated. The surface roughness affects the K&N test result and therefore these results are fundamental. The Gurley Hill air permeability test values are used in conjunction with the set-off values for a delay time of 30 seconds to separate porous uncoated papers from coated papers with a closed surface according to the invention.

3.1. Curing time with a delay time of 30 s, the need for ink and printing gloss when testing the suitability for printing using the IGT tester

The set-off value is a measure of the speed at which ink is fixed on paper. When the ink is fixed, the ink film on the paper hardens, because capillary forces cause the pore surface to absorb the solvent component of the ink for offset printing. The fastening speed of printing ink is high for microporous coating of the paper surface and low for closed, non-porous paper surfaces, as well as for uncoated paper, which contains large pores that cannot create large capillary forces.

Ink demand is a measure of the amount of printing ink needed for a particular print density. Print density is the ability of a printed image to absorb and reflect light, and it correlates with color brightness or the degree of dark color distinguished by the human eye. Low ink consumption is preferred for good print quality.

Ink gloss is a measure of print quality. High print density can only be achieved with high print gloss.

3.1.1. Introduction

This method describes the procedures that are used when using the IGT printability tester in preparation for printing on paper. IGT printability testers are manufactured by IGT Testers Systems b.v., Amsterdam, The Netherlands. This method measures the following properties of printed paper:

a) the set-off value at a delay time of 30 s, which correlates with the fixation speed of the printing ink and the porosity of the surface,

b) the need for ink, which means the amount of printing ink needed for a specific print density (see paragraph 3.1);

c) the gloss of printing, which is the gloss of printing ink, measured with a certain amount of printing ink.

Attention - it is necessary to carefully approach the comparison of the results of printing performed in different laboratories or using different suitability testers for printing, see paragraph 10.

3.1.2. References

This method makes references to the following Scandinavian SCAN methods performed by the Scandinavian Testing Secretariat:

SCAN-G1 Pulp, paper and paperboard - Reflection index - General measurement procedure (ISO 2469),

SCAN-P2 Papers and Boards - Sample Preparation for Testing (EN 20187, ISO 187),

SCAN-P8 Papers and Boards - Opacity and Y-values, light scattering and light absorption coefficients (C / 2 °) (ISO 2471),

SCAN-P9 Paper and Cardboard - Identification of machines and cross directions (EN 20187, ISO 187),

SCAN-P 10 Papers and Boards - Reverse Identification,

SCAN-P36 Papers and Cardboards - Evaluation of Test Print.

3.1.3. Definitions

For the purposes of this method, the following definitions are used:

3.1.3.1. Print Density, D. The decimal logarithm of the ratio of the Y-value of unprinted paper to the light reflectance of the print when it is placed above a stack of unprinted paper.

3.1.3.2. The amount of tearing at a delay time of 30 s.

The ability of printing ink to transfer from a newly printed surface to another surface with which the print is brought into contact under the influence of perpendicular directional amplification without shear. The set-off value is estimated as the decimal logarithm of the ratio of the Y-value of the receiving surface to the light reflectance of the area smeared by transferring ink when the paper is placed over the stack of receiving paper. The delay time for measuring the set-off value is 30 s from ink transfer to the set-off contact. The set-off value for a delay time of 30 s is indicated in units of print density.

Note: The receiving paper may be standard paper or a sheet of paper to be tested. Other print quality definitions are given in SCAN-P36.

3.1.4. Operating principle

A cylindrical printing plate consisting of a disk coated with a plastic coating rubber is coated with printing ink in a printing ink application section. The paper or cardboard to be printed is mounted on a cylindrical sector. Printing is performed under standard conditions.

The amount of ink transferred onto the paper is calculated by weighing the printing disk before and after printing.

When determining the set-off value, the fresh print is brought into contact with clean receiving paper in the second strip of the printed contact at normal pressure without a shift 30 seconds after printing.

3.1.5. Device

3.1.5.1. A suitability tester for printing, consisting of a printed section with two adjustable stripes of printed contact.

3 1.5.1.1 The printing section includes a sector driven by the engine, which rotates at a constant and adjustable speed with pressure against the printing disk, and when measuring the amount of setting, also with pressure against the second disk. The clamping force between the printing disc and the sector is ensured by an adjustable spring. You can also adjust the delay time used to measure the set-off value.

Note 1: It is important that the instrument is properly calibrated. The device manufacturer supplies accessories for calibrating both speed and force.

3.1.5.1.2. A cylindrical printing disk made of aluminum, with a diameter of 68 mm and a width of 32 or 50 mm, coated with plastic rubber (to prevent absorption of ink carriers), which has a shore hardness A of about 85 °. The width of the disk must match the width of the sector. The disc should be light enough to weigh on an analytical balance with an accuracy of 0.1 mg.

Note 2: Rubber ages with use over time, and discs must be stored in the dark at room temperature.

3.1.5.2. Section for applying printing ink to form a uniform film of printing ink on a printing disk.

3.1.5.3. An analytical balance with an accuracy of at least 0.1 mg.

3.1.5.3. Ink pipette or other suitable device for transferring a suitable amount of ink to a printing ink applicator.

3.1.5.5. Printing ink. Standard lithographic offset ink used by Michael Huber, Munich, Germany was used. The trade name of the printing ink in German is “Wegschlagtestfarbe” and in English “Setting Test Ink”, the number of printing ink is 520068, the lot number used in the tests is 00122615.

Note 3: Due to the fact that the printing ink is made from natural starting materials, it is not possible to have exactly constant ink properties from batch to batch. Therefore, test results may also vary, so that appropriate correction of the test conditions is necessary, see clause 10.2.

3.1.5.6. Solvent for cleaning purposes. Suitable are single petroleum ether or white spirit followed by purification with petroleum ether.

Note 4: Do not use cleaning fluids containing surfactants or non-volatile components.

3.1.5.7. Paper for curing. The method used spill-coated New Ojo paper manufactured by Oji Paper, Japan.

3.1.6. Sampling and test preparation

The sampling procedure is not fixed in this method. It must be ensured that the test sections taken represent the resulting sample. Samples are prepared in accordance with SCAN-P2 and held in the prepared atmosphere during testing.

Note 1: Since ink viscosity is temperature dependent, temperature control is as important as humidity control for this test.

Test specimens are cut into a size suitable for a printability tester. Typically, you should cut the strips of the test pieces in the machine direction (see SCAN-P9) to simulate tape offset printing. The print direction should be indicated in the report. The lines should not have wrinkles or wrinkles. The side to be printed must be marked.

Note 2: For subsequent evaluation, at least five bands are required in accordance with SCAN-P36.

3.1.7. Procedure

3.1.7.1. Test conditions

3.1.7.1.1. Temperature. If the equipment has an internal temperature controller, it is necessary to ensure that the test equipment, printing ink application section, and printing disc and test material are held at the correct temperature (23 ± 0.5 ° C).

3.1.7.1.2. Printed disk. Select a disk with a plastic coated rubber surface that matches the sector width (see clause 3.1.5.1.3). For contact with the purpose of killing, use the same type of disk as for printing.

3.1.7.1.3. Drawing ink on a printing disk. Ink is introduced into the ink unit and ink is applied to the printing disc in accordance with the manufacturer's instructions.

3.1.7.1.4. Print pressure. The printing force is set to 650 N for a printing disk with a width of 50 mm and 415 N for a printing disk with a width of 32 mm to provide a linear load of 13 ± 1 kN / m. If it is necessary to measure the amount of curing, it is necessary to use the same linear load in the second strip of the printed contact.

3.1.7.1.5. Print speed. The print speed is set to 1.0 m / s. Note: If there is a risk of plucking paper, use the following procedure. A piece of plastic tape is attached to the areas on the paper where the cylinder stops in front of the printing disc during printing, since the risk of plucking in these places is maximum. This must be indicated in the report.

3.1.7.1.6. Delay time. The delay time between ink transfer and curing is 30 s.

3.1.7.2. Test procedure. The front end of the test piece is attached to the sector. Set the test piece so that it lies flat against the sector, and fix the other end of the test sample. Fasten a strip of paper for mashing on the second printing disk and install the disk on the second shaft. Printed ink disk is weighed and mounted on a shaft. The printed disk is brought into contact with the sector and the test sample is printed. Remove the printed disk and immediately weigh. After transferring the printing ink, the press is pressed against the coated paper for a curing time after a delay of 30 s. The printed test specimen and spill-coated curing paper are retained for optical measurement after 24 ± 2 hours. The bands must be saved for later measurement in accordance with SCAN-P 36.

It is necessary to print a total of four test samples with four different amounts of printing ink. First, the lowest amount of printing ink is printed, and then the amount of printing ink is increased stepwise, so that the new printing ink is continuously supplied to the printing ink application section. After each series of tests, i.e. After four times printing, the ink section should be cleaned.

Note 2: After cleaning the printing disk with solvent, wipe the surface dry and allow sufficient time for the solvent to evaporate.

Four amounts of printing ink should be selected so as to cover the range of the amount of printing ink on paper from 0.7 g / m ² to at least 2.0 g / m ² . Print properties are determined by evaluating the print density in a tool that meets the requirements of SCAN-G1 (see SCAN-P 36).

3.1.8. Calculations

3.1.8.1. Determining the amount of printing ink on paper

The mass transfer of printing ink per unit area for each test sample is calculated by the formula:

where W denotes transferred printing ink in grams per square meter;

G1 is the mass of the printed disk before printing in grams with an accuracy of 0.1 g;

G2 - mass of the printed disk after printing in grams with an accuracy of 0.1 g;

A is the printing area in square meters, while the printing area is equal to the surface area of the printing disk.

3.1.8.2. Determination of the need for printing ink

The results are displayed on a graph where the amount of printing ink on the paper is plotted on the X-axis, and the print density of the printed paper on the Y-axis. A curve is constructed for four quantities of printing ink and corresponding print densities. The need for ink is interpolated from the curve at the point where the amount of ink on the paper is 1.50 g / m ² .

3.1.8.3. Determination of the set-off value at a delay time of 30 s

The results are displayed on a graph where the amount of printing ink on the paper is plotted on the X-axis, and the print density is plotted on the Y-axis by curing on coated spill paper for curing. A curve is built for four quantities of printing ink and the corresponding print densities due to curing. The set-off value at a delay time of 30 s is interpolated from the curve at the point where the amount of printing ink on the paper is 1.50 g / m ² .

3.1.8.4. Gloss Definition Print

The results are displayed on the graph, where the amount of printing ink on the paper is plotted on the X axis, and the print gloss on the sample is plotted on the Y axis. A curve is plotted for four quantities of printing ink and corresponding print gloss values. The print gloss is interpolated from the curve at the point where the amount of printing ink on the paper is 1.50 g / m.

3.1.9. Report

The test report shall contain a reference to this SCAN test method, as well as the following data:

(a) the time and place of the test;

(b) identification of the test material;

(c) design and type of plate;

(d) the type and name of ink used, including the manufacturer and lot number;

(e) the amount of printing ink transferred per unit area for each test sample with an accuracy of 0.1 g / m ² ;

(f) the type and weight of the paper used for laundering;

(g) the time delay before setting;

(h) the time at which printing was performed for each test sample;

(i) any deviations from this method that may affect the results.

3.1.10. Reproducibility

The properties of the 520068 printing ink used in the tests may vary from batch to batch. In order to obtain comparable results between laboratories and batches of printing ink, it is necessary to carry out the following correction of the test conditions.

It is necessary to use the same coated paper and used printing ink of lot 00122615 and used printing ink of new lot. Perform printing on paper with printing ink in accordance with the test method using both inks. If the set-off values for the two inks are different, then the delay time from ink transfer to the set-off contact should be changed so that the set-off value for the delay time of 30 s is the same for both inks with an accuracy of ± 0.03 units of print density. If the set-off value for a new batch is greater than that of the reference set, then the delay time from transferring the paint to the contact of the set-off should be increased, and if the set-off value is less, the delay time should be reduced.

Note: All changes in the conditions of test printing should be noted in the report.

3.2. ISIT Bonding Extension Method

3.2.1. Operating principle

Papers are tested using the ISIT method, which shows the buildup time of ink bonding, which correlates with the fixing speed of the ink. The amount of time obtained using an ISIT test device to determine the effect of printing ink - surface ("ISIT device"), manufactured by SeGam Ltd, UK. First, a controlled amount of printing ink is transferred to the test paper, and after a predetermined time, the bond of the printing ink is measured. The rate of increase in ink bonding after ink transfer is correlated with the ink fixation rate, which depends on the surface pore structure. The ink curing speed is low for non-porous surfaces and high for microporous paper coatings.

For the preparation and transfer of printing ink, a commercial IGT printing unit and an IGT printing disk are used. Ink transfer procedures are similar to those used in the IGT method for determining the set-off value at a delay time of 30 s (see clause 3.1.7). The bonding of printing ink on paper is measured using a special device, which consists of a solenoid, a coil spring, a load cell and a contact disk. The contact disk is pressed against the printing ink on the paper using electromagnetic force. The contact disk is separated from the print (printing ink on paper) by the tensile force of the coil spring. A tensile sensor mounted between the contact disk and the coil spring generates a load-dependent signal, which is recorded as the measured bond strength. After measurement, the contact disk and printing are interchanged, so that the next contact between the disk and the printing ink on the paper occurs between the clean contact disk and the intact surface of the printing ink. The extension of the tensile force necessary to separate the layer of printing ink is measured automatically, so that the contact disk is sequentially separated from the print, and each individual separation is recorded.

3.2.2. Bonding time

The test results are a function of the bonding of the ink (the Y axis is the bond on the paper) depending on the time the ink is fixed (the X axis is the time), and the time for the bonding is the time from the moment the ink was transferred onto the paper until the maximum bonding is reached see the graph in figure 1. In practice, the amount of bonding is the force necessary to separate the contact disk from the printing ink layer on the printed base. This method can be used to separate the various properties of the surface of the paper when the same printing ink is used, but different papers. The longer the time for maximum bonding for the same printing ink, the more non-porous (closed) the surface is, as can be seen in figure 1.

3.3.1. Test conditions for ISIT bonding method

Test conditions for the ISIT bonding method are as follows:

Ink amount applied 100 mm ³ Amount of paint transferred 1.4 g / m ² for paints Sun challenge 1.5 g / m ² for the ink Sicpa Mediatech Ultra Fast Paint leveling time 5 s in rollers + 5 s with disk Paint leveling speed 0.7 m / s One press and washing of rollers Ink transfer pressure 15 kN / m Print disk 20 mm, rubber surface Disk Contact Time 0.5 s Disc contact pressure 8 (without dimension) Contact Disc Separation Speed 5 (without dimension) Time intervals between print and 1.9 s, 7.7 s, 13.3 s, 19.0 s, 39.6 s, 60.3 s, 80.9 s, contact 121.6 s, 162.3 s, 203.0 s, 303.6 s, 404.2 s, 504.8 s

3.4. K&N Ink Absorption Test

Papers were tested using the K&N Ink Absorption Test. The following is a description of this method.

3.4.1. Operating principle

Test ink was distributed on paper for a predetermined time. Color density is a measure of the absorbency of paper. The value of the reflection coefficient was measured.

3.4.2. General information

First, a layer of test printing ink was distributed on paper on a paper surface. Part of the printing ink that did not absorb into the paper was removed and the reflectance of the ink coated paper was measured using an Elrepho color measuring device. The absorption properties of both sides of the paper were measured separately, and two tests were performed on each side. The test ink was distributed on the side to be tested.

3.4.3. K & N Printing Ink

K&N inks were used in most cases with coated grades of paper (ink absorption time 2 min).

- The sample was cut into 4 pieces of size 8 × 25 cm, so that the long side was in the machine direction.

- The test pieces of paper were placed on a glass plate so that two pieces were placed with the top of the paper up and two pieces with the bottom of the paper up.

- Printing ink was distributed on paper over an area of about 5 × 8 cm, and the remainder of the test paper was left clean. It is recommended that you use protective paper over a clean area of the test paper.

- K&N printing ink was thoroughly mixed in a can. A layer of paint that covers the surface of the paper was spread on paper and the timer was immediately started.

- Absorption of printing ink occurred within 2 minutes, after which excess ink was removed from the surface of the paper with a spatula and then a cloth.

Removal was continued until there was a change in the luminosity of the ink-printed area, usually 5-6 times.

- The amount of printing ink should be large enough so that it is not possible to absorb all the printing ink into paper.

- The test pieces of paper were hung in a line so that there were no obstacles to drying the printing ink. The reflection coefficient was measured after 2 hours. The measurement time was recorded.

3.4.4. Settings for color measurement

1. Turn on the power.

2. Before starting the measurement, wait for 5 minutes while the warning lamp is on.

3. Checked the presence of a gray filter: the sign on the shutter should be visible. To measure the reflection coefficient:

1. Reset the sensor to zero

- the filter switch was moved to position 12,

- adjusted the indicator to zero using a zero setting potentiometer; pressed the control button and again adjusted the zero point.

2. Turn on the filter 10 using the filter switch

- filmed the internal standard.

3. The sensor was adjusted by a value of 100 on a clean area of the test print

- a stack of test paper was placed on a carrier plate, while the paper on top was paper with printed ink; the stack of paper and the test paper were always on the same side;

- a clean area of the test paper was installed under the measuring hole and a value of 100 was set on the measuring drum;

- the sensor was first adjusted to zero only by rotating the drum, and then again using the adjustment button.

4. Measurement of the reflection coefficient of the printed area

- the area with the printed ink of the test segment was moved under the measuring hole;

- the indicator was first adjusted to zero only by turning the measuring drum, and then again using the adjustment button.

The magnitude of the reflection coefficient was directly indicated as a number on the measuring drum. Reading was performed with an accuracy of 0.1 units. In the same way, the value of the reflection coefficient for each test paper was measured. One measurement was performed for the test paper.

3.4.5. Calculation of the result

The value of K & N = 100% is the measured value of the reflection coefficient in%.

3.5. Gurley Hill Air Permeability Test

The Gurley Hill value is measured in accordance with T536-88 standard. A large value means that the paper is not porous if it takes a long time for 100 ml of gas to pass through the paper.

4. Printing inks

Ink can best be characterized with respect to paper porosity using the amount of stability that is obtained from the measurement of bonding using the Tack-0-Scope device, which is a well-known method in the printing ink industry. When measured with Tack-0-Scope, the ink bonding, which is a measure of the force required to split the ink layer, increases from the point in time when the ink solvent begins to evaporate until it reaches its maximum level, after which bonding begins to decline as the ink begins to dry. For fast-drying ink, which is preferred for the method of offset printing with heat setting, according to the invention, the value of T _max is small.

Measurement conditions during the test using the Test-0-Scope device:

Ink amount 0.4 g Stabilization time 30 s Stabilization speed 100 m / min Test speed 200 m / min Temperature 25 ° C

5. Results

The results relate to the color of the coating and the number of paper samples specified in clause 2.

5.1. The amount of curing at a delay time of 30 s, the need for printing ink and printing gloss, measured using an IGT printing suitability tester

The results of measuring the set-off value at a delay time of 30 s are shown in table 3.

Printing ink: printing ink for bonding testing by Michael Huber, Munich, No. 520068, batch No. 00122615

Time and place: UPM-Kymmene Rauma Mills, 3/15/2002

The set-off values at a delay time of 30 s for papers according to the invention are more than 0.80, for known uncoated papers 0.79 and for known papers coated less than 0.40. The magnitude of the need for printing ink (in table 3 "The amount of ink on paper") for papers according to the invention and known coated papers is more than 1.50, and for known uncoated papers, more than 2.0. The gloss values for printing for papers according to the invention, and for MWC and WFC papers are more than 70%, for known uncoated papers - less than 60%, for LWCO papers - more than 65%. The change in print gloss (print gloss - paper gloss in table 3) is more than 5% for papers according to the invention, 7.6% for known uncoated papers, less than 3% for LWCO papers and 0% for MWC and FWC papers.

5.2. Gurley Hill Air Permeability

Gurley Hill (G-H) Air Permeability Measurement Results:

Paper according to the invention: G-H, s / 100 ml Cover color 3 / sample 12 31690 Cover color 5 / sample 8 13990 Cover color 6 / sample 10 40260 Famous papers: G-H, s / 100 ml UPM Cote 60g / m ² (LWCO) 3140 UPM Max 56 g / m ² (SCO) 360 UPM Star 100 g / m ² (MWC) 3430 UPM Ultra 70 g / m ² (LWCO) 2370 UPM Cote 100 g / m ² (WFC) 2240

The paper according to the invention has a much lower permeability to air.

5.3. ISIT Bonding

ISIT bond buildup curves and ISIT bond buildup times for three known papers and for one paper (cover color 3 / sample 12), according to the invention, for Sun Challenge printing ink are shown in FIG. According to the invention, the ISIT bond fastening time is over 400 s, while the known time is less than 50 s for known papers.

ISIT bond buildup curves and ISIT bond buildup times for two known papers and for two papers (coating color 5 / sample 8 and coating color 6 / sample 10) according to the invention for Sun Challenge printing ink are shown in FIG. 3. The ISIT bond buildup time for paper according to the invention is more than 300 s, while the time for known uncoated paper is less than 136 s, and for known coated paper less than 25 s.

ISIT bond buildup curves and ISIT bond buildup times for three known papers and for one paper (cover color 3 / sample 12), according to the invention, for SICPA Mediatech Ultra Fast printing ink are shown in FIG. According to the invention, the ISIT bond fastening time is over 200 s, while the known time is clearly less than 10 s.

ISIT bond buildup curves and ISIT bond buildup times for two known papers and for two papers (coating color 5 / sample 8 and coating color 6 / sample 10) according to the invention for SICPA Mediatech Ultra Fast printing ink are shown in FIG. According to the invention, the ISIT bond fastening time is more than 150 s, while the known time values are less than 25 s.

ISIT bond buildup curves and ISIT bond buildup times for a single known paper for both Sun Challenge printing ink and SICPA Mediatech Ultra Fast ink are shown in FIG. 6. The time value for known paper is less than 10 s.

5.4. K&N Ink Absorption Test and Gurley Hill Porosity

For four papers according to the invention, and for two known papers, the following K&N ink absorption test results were obtained.

  K&N Cover color 3 / sample 12 1.5 Cover color 5 / sample 8 1.3 Cover color 6 / sample 10 1.3 UPM Cote 60g / m ² (LWCO) 7.7 UPM Ultra 70 g / m ² (LWCO) 15,5

Papers according to the invention have a much lower absorption of printing ink.

5.5. Printing ink

1. Sun Challenge

The T _max value for Sun Challenge inks was 286 s, and for SICPA Mediatech Ultra Fast inks, the values were between 100 and 150 s.

Printing ink
Color Tone
The consignment SICPA Mediatech Ultra Fast Sun challenge
Cyan 3925-02
95364 Yellow
2300K
183480 Magenta
5000K
183481 Cyanogen
67000K
183482 The black
9000K
183483 Bonding (100 m / min) 128 120 112 120 169 Stability (200 m / min) The beginning 153 128 118 130 176 Mach 164 132 121 138 196 Stability T _max (s) 150 s 108 s 101 s 145 s 286 s

5.6. findings

Papers according to the invention have a clearly more closed surface than known papers. SICPA Mediatech Ultra Fast printing ink loses solvent much faster than Sun Challenge printing ink, and is therefore preferable for low temperature drying in offset curing.

Based on the test results, it can be argued that the known UPM Max 56 g / m ² (SCO) coated paper has a long ISIT binder build-up time of more than 100 s and a large IGT cure time of 0.50 units with a delay time of 30 s. print density, because UPM Max paper capillary suction is small due to the large pore radius of uncoated paper, which follows from the value of permeability for air according to Gurley Hill, which is clearly less than 1000 s. You can identify the difference between uncoated porous supercalendered papers and coated non-porous papers using the Gurley Hill method of measuring air permeability.

6. Printing method

The following are the parameters of the method of offset printing with heat setting, designed for paper, according to the invention:

Typewriter: Albert Frankenthal A 101-S Print speed: 6.2 m / s Printing ink: ICPA Mediatech Ultra Fast Wetting Solution: 3% alcohol-free supplement SICPA Sol, 97% water Drying: The final temperature of the tape 95 ° C Dryer Length: 8 m

The final temperature of the tape after the dryer of the printing machine is maintained at less than 115 ° C and preferably 100 ° C.

The printed product can also be printed using similar printing ink under other printing conditions and using other starting materials in the printing process.

The following is the data of another paper according to the invention, which can be used in addition to the offset printing method with heat setting also in the intaglio method. The steps for making paper are the same as above, but the coating composition is as follows:

Talc (C 10X0) 60 pieces Kaolin (Supragloss 95) 40 pieces CMC (FinnFix 10) 0.8 parts Maleic anhydride copolymer and styrene (Raisaprint D100) 1 part Calcium Stearate (Raisacoat 50) 0.5 parts Optical Brightener (Optiblank NF) 0.2 parts

The solids content in the cover color is 59% at pH 8.0. The target coating weight is 10 + 10 g / m ² . The target moisture content is 5.5%. The base papers were LWC base papers containing 40% chemical pulp and 60% mechanical pulp (wood pulp), and the weight of the base papers was 43 and 41 g / m ² . At first, the smoother side (upper side) was coated. Calendering temperatures (upper, middle, lower) were 100 ° C, 90 ° C and 80 ° C.

The paper meets the requirements for offset printing paper with heat setting, but in addition to this also the requirements for gravure printing paper with respect to smoothness and compressibility, taking into account the composition of the coating. For this purpose, starch was removed from the composition, and the latex was replaced by softer (T _g -20 ° C).

The following is the data of the third paper according to the invention, which is more reminiscent of SC calendula paper. The steps for making paper are the same as above, but the coating composition is as follows:

Latex SB (Rhodopas SB3 88) 100 pieces Talc (C 10X0) 100 pieces

The solids content in the cover color is 20% at pH 7.8, and the coating method is a two-way Sym Sizer method. The target coating weight is 2 + 2 g / m ² . The target moisture content is 5.3%. The base paper was typical SC paper with an ash content of 30% and a fiber blend of 20% chemical pulp and 80% mechanical pulp. The weight of the base paper was 56 g / m ² . Calendering temperatures (upper, middle, lower) were 100 ° C, 90 ° C and 80 ° C.

The paper can be coated with various coatings and various calendaring methods can be used, and the base paper can be composed of different starting materials. Coating recipes can be used to cover cardboard with the possibility of using the offset printing method with heat setting. The drawings and the description attached to them serve only to explain the idea of the invention. The details of the invention, for example pigments, compositions, coating binders, coating and calendaring methods, uncoated paper, for example SC paper or paperboard, may vary within the scope of the claims.

Claims (15)

1. The printing substrate, which is a substrate with an oleophilic surface having a Gurley-Hill permeability of more than 5000 s / 100 ml, and the IGT value of the curing of the printing ink printed on the substrate, with a delay time of 30 s, amounting to more than 0.60 density units print. 2. The printing base according to claim 1, characterized in that the ISIT bond buildup time is more than 100 s for ink, the stability of which when measuring the bond using the Tack-0-Scope device is between 270 and 300 s. 3. The printing base according to claim 1, characterized in that the bonding build-up time is more than 200 s, preferably more than 250 s, with the specified ink, and the IGT curing value at a delay time of 30 s is preferably more than 0.70 print density units . 4. The printing base according to any one of claims 1 to 3, characterized in that it is paper or cardboard having a coating or surface finish. 5. The printing base according to claim 4, characterized in that the coating is made of pigment material. 6. The printing base according to claim 5, characterized in that the pigment is lamellar. 7. The printing base according to claim 6, characterized in that the pigment shape factor, which is the ratio of diameter to thickness, is more than 2 and preferably more than 4. 8. The printing base according to claim 7, characterized in that the pigment is a pure talc or a mixture of talc and kaolin. 9. The printing base according to claim 1, characterized in that it is made with the possibility of use for offset printing with heat setting. 10. The printing method, consisting in the fact that it is carried out in at least one printing section using a substrate having an oleophilic surface and being non-porous, characterized by a Gurley Hill permeability of more than 5000 s / 100 ml, and a pigment carrier or printing ink, which has an ICT ink curing value at a holding time of 30 seconds in excess of 0.60 units of print density. 11. The method according to claim 10, characterized in that the substrate is a tape of paper or cardboard with a treated surface, and it is served through at least one printing section. 12. The method according to claim 10, characterized in that the build-up time of the ISIT bond of the printed substrate is more than 100 s for ink, the stability of which when measuring the bond with the Tack-0-Scope device is between 270 and 300 s. 13. The method according to any one of paragraphs.10-12, characterized in that it is carried out by offset printing with heat setting. 14. The method according to any one of paragraphs.10-12, characterized in that the final temperature of the tape after the dryer of the printing press is maintained at a level of less than 115 ° C and preferably less than 100 ° C. 15. The method according to any one of paragraphs.10 and 11, characterized in that the stability of the printing ink when measuring bonding using a Tack-0-Scope device is less than 200 s.