Method of priming and coating

FIELD: paper industry.

SUBSTANCE: invention may be used to apply coatings onto paper or cardboard substrate, which is a precursor of finished paper, cardboard, fabric, sheet of fibre board. Substrate is brought in contact with primer supplied from source of primer. Electrostatic deposition of primer onto substrate is carried out by means of electrospinning.

EFFECT: invention provides for high uniformity of deposition, including hard-to-access uneven surfaces.

19 cl, 3 tbl, 41 dwg

 

The invention relates to a method of priming a substrate (base), which comprises bringing the substrate into contact with the primer, supplied from a source of primer and the deposition of the primer on the substrate. The invention also relates to a method for coating a substrate, which comprises bringing the substrate into contact with the primer, supplied from a source of primers, the deposition of the primer to the substrate and coating the primed substrate covering substance.

There are various ways to improve the adhesion between the substrate and the coating. Such methods include processing the surface roughened by mechanical means, remove weak boundary layers, minimizing stress, the use of amplifiers adhesion, the use of appropriate acid-base interactions, as well as providing favorable thermodynamic properties and use of moisture. Standard processing methods include the use of chemicals such as primers and solvents, the use of heat and flame, mechanical methods, plasma treatment, treatment by corona discharge and radiation. Each method can have multiple effects, which enhance adhesion.

An important method of improving adhesion between the substrate and its coating is priming. Priming means clicks the processing of the substrate with a primer coating (primer). Under the primer means a preliminary coating on the surfaces to be painted or finish any other way (see McGraw-Hill Dictionary of Scientific and Technical Terms (Dictionary of scientific and technical terms, McGraw-hill), 6 as amended, str and 1669).

Standard primers are adhesive organic matter, soluble in water and/or organic solvent, and is used for surface treatment of the substrate to improve its adhesion to the coating or adhesion of the coating. The following table shows the standard primers and adhesion and performance.

Table 1
The properties of standard primers
Adhesive propertiesPerformance specifications
The type of primerPaperMetalPolymer filmOperating temperatureHumidityChemical resistance
Shellacthe izkuyu excellentlowlowlowlow
The organic titanategoodgoodgoodsatisfactorysatisfactorysatisfactory
Polyurethanevery goodexcellentexcellentexcellentexcellentexcellent
Polyethyleniminevery goodgoodexcellentexcellentlowlow
Ethylenically acidexcellentexcellentsatisfactorySatisfactoryexcellentgood
Gradesexcellentsatisfactoryexcellentgoodvery goodsatisfactory

Traditional priming is carried out using conventional methods of application of the solution. Application of primer enhances adhesion between the substrate and the coating due to the increase in free energy (wettability) of the surface, induce chemical reactions between them and the removal of impurities that weaken the grip.

However, traditional priming has the disadvantage that it is difficult to obtain the exact mass of a coating layer that is appropriate for the specific primer. Uniform deposition is important for all primers. This applies especially to the case of rough surfaces, less accessible areas which are difficult to handle by conventional means priming.

These disadvantages are overcome by using a new method of priming the substrate, which comprises bringing the substrate into contact with the primer, supplied from a source of primers, and deposition of the primer on the substrate. The claimed method is essentially characterized in that the deposition is carried out electrostatically. Under the "deposition" podrazumeva the fast deposition of any material on the substrate. The term "electrostatically" refers to anything related to static electricity, such as electric charge of the subject (see McGraw-Hill Dictionary of Scientific and Technical Terms, 6th Ed., p.707).

Electrostatic coating methods known as such. However, the inventors have found that these methods, in particular, are suitable for the purposes of priming. Using electrostatic coating can easily obtain the exact mass of a coating layer that is suitable for any specific primers. In addition, by using electrostatic methods of priming is conveniently achieved in the least accessible areas of uneven surface of the substrate. Thus, a large part of the surface of the substrate will have adhesion, improved by priming.

Electrostatic coating methods can be divided into three groups: electrostatic spraying and electrospinning (electroprecizia), usually from a solution under the action of a constant electric field, as well as dry coating powder materials under the action of variable electric fields.

When spraying high-voltage electric field applied to the surface of the liquid, causing the emission of small charged droplets. This process is affected by the mass, charge and conservation of momentum. Thus, the su is basically a few options, influencing the process. The most important parameters are the physical properties of the liquid, the rate of fluid flow, the applied voltage, the geometrical characteristics of the used systems and dielectric strength environment. The main physical properties of the liquid are its electrical conductivity, surface tension and viscosity. Device for elektrorazpredelenie, as a rule, consists of a capillary, a nozzle of a high pressure rotary nozzle or atomizer, which moves the covering liquid, and flat collector supporting the coated substrate. Between capillary and plate creates an electric potential difference.

The potential difference between the plate and the end of the capillary, which serves to cover the liquid is several thousand volts, typically tens of kilovolts. The formed droplets are charged, but if necessary they can be neutralized in a variety of ways. Their size varies depending on conditions. Conditions elektrorazpredelenie, the most suitable for priming are discussed more fully below.

When electrospinning, as well as when elektrorazpredelenie use high-voltage electric field. Unlike elektrorazpredelenie, which are formed of solidified drops, electr when the spinning of the polymer melt or solution, skip through the nozzle in the millimeter range, the formed solid fibre. The resulting fibers are collected on a grounded or oppositely charged plate. Using electrospinning you can get fiber from certain polymers or polymer mixtures.

Electrospinning can be used to obtain ultrafine continuous fibers, the diameter of which ranges from nanometers to several micrometers. Small diameter provides small pore size, a large porosity and a large surface area and high ratio of length to diameter. The resulting products are typically non-woven cloth. Such a small size and non-woven form makes electrospraying fiber suitable for various applications.

When spinning the resulting fiber is affected by various parameters. These parameters can be divided into three main types, among which the parameters of the solution, the parameters of the method and the environmental parameters. To the properties of the solution are the concentration, viscosity, surface tension, conductivity and molecular weight, molecular weight distribution and structure of the polymer. The parameters of the method include the electric field, the distance from the nozzle to the collector and feed rate. Properties of the environment on the given temperature, humidity and air velocity in the spinning chamber. Conditions electrospinning, the most suitable for priming are discussed more fully below.

The dry coating method is similar to methods elektrorazpredelenie and electrospinning, except that the source material is in powder form. One of the latest inventions is to cover this type of paper. Drawing on paper coating dry method is an alternative to traditional pigment coating. This dry surface treatment (DST) paper and cardboard combines methods of coating and calendering. When the DST method of electrically charged powder particles sprayed on the surface of paper or cardboard. The particles form a layer on the surface of paper and attach to the paper under the influence of electrostatic forces. Final fixation occurring in the gap between the heated rollers which provides adhesion and makes the surface smooth.

Next, we discuss the most important technical features of the invention. The claimed method relates to electrostatic coating of the substrate. Preferably, the substrate is subject to priming, was a solid material such as wood, paper or composite material. The preferred type of substrate is cellulose or wood is a, containing <300 g/m2uncovered or covered type, obtained using a conventional wet methods of paper production. Most preferably, the solid material was paper. Under the paper is meant any felted or matted sheet containing as a main part of the fiber pulp.

In this context, "paper or paperboard substrate" refers to a precursor or of paper or cardboard or cloth or sheet of fibreboard, or to the products, such as roll, pipe, packet, container, tableware, case, tray etc. In the substrate base includes a base layer comprising cellulosic sheet or webs of cellulose fibers, with the specified base layer may have a coating, for example a polymer coating. These substrates also include a base paper for impregnating or impregnated paper, where the final product can be, for example, sheet products, impregnated phenolic, melamine resin and/or other polymers, and the final products of them. Of paper or paperboard substrate according to the invention can be formed in two or more layers or sheets of the same or different materials, processed together.

According to one of preferred embodiments of the invention, the electrostatic about ardenia, used in the coating according to the invention, is elektrorazpredelenie. When elektrorazpredelenie the primer is preferably first is in the form of liquid droplets dispersed in the gas phase. Drops can be either drops of molten primer, or, preferably, droplets of a solution of a primer material in the solvent. Typically, the average diameter of the liquid droplets is from 0.02 to 20 μm, preferably from 0.05 to 2 μm.

According to another preferred variant of the invention, the coating by electrostatic deposition according to the invention is electrospinning. When electrospinning at least part of the primer is in the form of fibers, dispersed in the gas phase. Fibers can be formed either from molten material primer, or, preferably, from drops of primer mixture in a solvent. In the formation of fibers primer using electrospinning the average diameter of the fibers is preferably from 0.05 to 5.0 μm, most preferably from 0.1 to 0.5 micron.

Electrostatic coating according to the invention may also be a combination of electrocapillary and electrospinning by which the substrate is formed as a solid droplets and solid fiber.

When using electrostatic deposition (sputtering, spinning, or both) from the solution, the content of the primer material in the solution is preferably from 5 to 50 wt.%, most preferably, from 20 to 45 wt.%. Preferably, the solution had a viscosity of 40 to 400 centipoise, most preferably from 50 to 200 centipoise. The solvent is chosen in accordance with the used primer, whereas that for good performance, its volatility should be low enough, and its conductivity must be suitable for electrostatic method. Preferred solvents are water and water/alcohol system.

As mentioned above in connection with the General description of the invention, the primer material can be a natural polymer, polysperchon, ORGANOMETALLIC compound and/or a synthetic polymer. Typically, the primer material is a synthetic polymer (Homo - or copolymer). According to one of the most effective ways of carrying out the claimed invention, the synthetic polymer is an acrylic copolymer, most preferably in the form of an aqueous emulsion. The thickness of the deposited material, as a rule, makes 0.002-0.05 g/m2preferably 0,006-of-0.02, and most preferably, about 0.01 g/m2. According to another preferred variant implementation, the primer p is ecstasy diethanolamine (DEAE), preferably, in the aquatic environment. The preferred thickness of deposited material is 0.02-0.5 g/m2more preferably, is 0.06 to 0.2, and most preferably, about 0.1 g/m2.

Most preferably, the primer solution also contained an additive for modifying the morphology of the particles of the primer on the substrate. The preferred additive is a polymer soluble in the solvent and compatible with the primer having a sufficiently high molecular weight to stabilize the method. Preferably, the polymeric additive, also suitable for electrostatic method. Examples of polymers suitable as additives in the inventive electrostatic methods, along with other are polyvinyl alcohol, polyethylene oxide and acrylic resin.

Electrostatic coating of the present invention preferably takes place by setting suitable for elektrorazpredelenie or electrospinning. The installation consists of the fume cupboard with minimized external interference, which is a design incorporating a metal plate to support the substrate and the loading area. A voltage source connected to the metal plate and the boot area. The electrostatic force, expressed as the voltage divided by the distance between the substrate is m and the source of the primer, squared, is, according to one of embodiments, from 0.02 to 4.0 In/mm2preferably, from 0.2 to 0.5 In/mm2. The electrostatic voltage is preferably from 10 to 50 kV, more preferably from 20 to 40 kV, and the distance between the source of the primer and the substrate preferably ranges from 100 to 1000 mm, more preferably from 200 to 500 mm

In addition to the above electrostatic method of priming the substrate the invention also relates to a method for coating a substrate, which comprises bringing the substrate into contact with the primer, supplied from a source of primers, the deposition of the primer to the substrate and coating the primed substrate covering substance. Specified deposition of the primer on the substrate is performed electrostatically.

The claimed method of the coating, thus, includes the electrostatic priming, followed immediately or at a later date should the coating. For the stage of priming using the same specifications as described above, so no need to repeat them here. However, during the transition from priming to coating the primed substrate is preferably treated in a flame, or, most preferably, in the corona discharge prior to application on the cover it is his substance.

Typically, the covering substance is a thermoplastic polymer. Since the most preferred substrate was paper, the preferred combination is a paper coating specified thermoplastic polymer. The best thermoplastic polymer is a polyolefin polymer such as a polymer of ethylene (Homo - or copolymer).

EXAMPLES

Experimental part

Further, the invention is illustrated by several examples, methods are described in detail below. Reference is made to the following drawings:

Figure 1 shows the setup for electrospinning according to one embodiments of the invention.

Figure 2 shows the boot area setup for electrospinning with Figure 1.

Figure 3 shows the boot area and plate collector installation for electrospinning with Figure 1.

Figure 4 shows a snapshot of the executed scanning electron microscope (hereinafter, picture SEM - Scanning Electron Microscope), paper covered P1, with increasing 3500×, Figa - weighing a cover layer of 0.1 g/m2, Figw - weight top layer of 0.01 g/m2.

Figure 5 shows a snapshot SEM paper covered P2, with increasing 750×, Figa - weighing a cover layer of 0.1 g/m2, Figw - weight top layer of 0.01 g/m2.

Figure 6 shows a snapshot SEM paper covered P3, with increasing 750×, Figa - weighing on the smooth layer of 0.1 g/m 2, Figw - weight top layer of 0.01 g/m2.

7 shows SEM picture of paper covered P5, with magnification 1500×, Figa - weighing a cover layer of 0.1 g/m2, Figw - weight top layer of 0.01 g/m2.

On Fig shows a snapshot SEM paper covered P6, with increasing 1500×, Figa - weighing a cover layer of 0.1 g/m2, Figw - weight top layer of 0.01 g/m2.

Figure 9 shows a snapshot SEM paper covered P7, with increasing 3500×, Figa - weighing a cover layer of 0.1 g/m2, Figw - weight top layer of 0.01 g/m2.

Figure 10 shows a snapshot SEM paper covered P11, with increasing 3500×, Figa - weighing a cover layer of 0.1 g/m2, Figw - weight top layer of 0.01 g/m2.

Figure 11 shows SEM picture of paper covered R, with increasing 1500×, Figa - weighing a cover layer of 0.1 g/m2, Figw - weight top layer of 0.01 g/m2.

On Fig shows a snapshot SEM paper covered P13, with increasing 1500×, Figa - weighing a cover layer of 0.1 g/m2, Figw - weight top layer of 0.01 g/m2.

On Fig shown coated with polyethylene (PE) film after the test for delamination, P1-P13 processing in the corona discharge.

On Fig shows the Board with a P3 after the test for delamination. Figa without processing in the corona discharge and FIGU - processing in the corona discharge.

On Fig the provided cardboard with the P5 after testing steaming. Figa without processing in the corona discharge and FIGU - processing in the corona discharge.

On Fig shown cardboard with P6 after the test for delamination and processing in the corona discharge. The increase was 1500×.

On Fig shown cardboard with P7 after the test for delamination and without treatment by corona discharge. The increase was 1500×.

On Fig shows SEM images after the test for delamination and without treatment by corona discharge; Figa - cardboard with P11, increase h; Figv - cardboard with R, magnification 1500×; and Figs - cardboard with P13, the magnification of 1500×.

On Fig shows a coating PE film after the test for delamination without treatment by corona discharge, P1-P13.

In this experimental work the priming was carried out on the installation electrospinning, such as the one shown in figure 1. The installation includes a fume cupboard, the walls of which, except the front wall, made of metal plate, to minimize internal and external electrical interference. The inner surface of the walls is covered with a fiberglass composite material. Used power supply is a high voltage power supply type BP 50 Simco. The power source can generate both positive and negative voltage 0-50 kV.

The installation also includes a boot area, imoudu the die plate and the needle. The needle is attached to filiere made of glass syringe with Luer tip cemented connection, the power source is attached to the metal connection of the needle. The boot area is shown in figure 2.

As a counter-electrode in the boot area has a square copper plate with a size of 400 mm × 400 mm × 1 mm, This plate collector that supports the substrate, based on a plastic rack. Plate collector and the boot area is shown in Figure 3. To the front of the plate collector attach the coated substrate. The substrate may be, for example, sheet metal or paper. In the conducted experiments the substrate was ion-coated paper quality STM, cardboard pulp, not containing wood with a density of 225 g/m2.

Suitable primers were chosen based on preliminary tests. These primers, designated as P1-P13, had a viscosity solution (Brookfield DV-II+), morphology (JEOL SEM T-100), surface energy (PISARA-equipment) and adhesion (test for delamination on Alwetron). In addition, examined the influence on the adhesion processing primed paper substrate in the corona discharge.

13 samples were tested, i.e. P1-P13. The symbols P1-P13 mean:

P1 → carboxymethylcellulose

P2 → dimer of alkylbetaine

P3 → polyethylenimine

P4 → polyvinyliden

P5 → polyvinyl sleep is t

P6 → emulsified acrylic copolymer

P7 → ethylene copolymer

P11 → polyvinyl alcohol, modified ethylene groups

R → diethanolamine (DEAE)

P13 → MSK/S20-C24-olefin

In → M20-C24-olefin

→ Ethylene copolymer

E → polyvinyliden

G → polyvinylacetal

N → diethanolamine (DEAE)

I → carbonylmethyl

The following results were obtained.

Results and discussion

The suitability of primers for elektrorazpredelenie or electrospinning

The respective compositions of the solutions of primers and parameters of the method were established experimentally. For each primer was tested several mortar compositions. All primers were sprayed or molded fiber through a needle of length 5 cm size 18G.

Primer P5, P6 and P11 were the most suitable without adding to the solution for spraying/spinning modifiers morphology. Primers P1, P2, P3, P7, R and P13 also meet the requirements, but they were necessary additives. Without additives they gave drops large and covered area was very small. With the introduction of additives covered area was significantly expanded, and the droplet size decreased.

Performance elektrorazpredelenie or electrospinning

Performance for each primer p is redstavlena in Table 2. The table also includes other properties used in the calculation of the rate of flow, namely, the weight of the solution, the content of the primers in the solution and the primer consumption. In addition, the table presents the time required to obtain the dry weight of a coating layer of 0.1 g/m2and 0.01 g/m2.

Table 2
Productivity and other properties of each primer
The time required priming
PrimerThe specific weight of the solution [g/ml]The content of the primers in solution [%]The solution flow rate [s/1 ml]Area [m2]Productivity [g/m2]to 0.01 g/m2to 0.1 g/m2
P11,02811,7050400,0491 0,0004921205
P20,91531,6762520,04910,0009411106
P31,035to 22.3527680,03140,00266428
P50,97315,0033000,04910,0009011111
P61,03745,2014100,09620,00346329
P71,04122,3320400,12000,0009511107
P111,0187,5018000,04520,0009411107
R0,98225,0019200,08550,00149767
P131,01122,3945620,03600,00138772

During the test, the flow was easy to see which of primers suitable for continuous priming, and which are not, without making any changes to the solution or method. Primers P2, P3, P6 and P13 were unsuitable for continuous priming, because they zahustovali at the end of the needle. But primers P1, P5, P7, P11 and R suited for continuous priming.

The time required priming is only approximate. When measuring performance, it was assumed that all the primer comes with a needle-to-plate collector. In practice, however, some particles of rollout over the plate, and some large drops may not fly as far. When the flow measurement process was first faster, then slowed down, because the level of the solution and the pressure in the needle decreased over time. Thus, the flow rate are averages. Coverage is determined visually, so they are approximate values.

The viscosity of the solutions primer and morphology primed cardboard

The viscosity of the used solutions of primers represented the viscosity Brookfield. The morphology of the precipitated particles primers was measured on the basis of the analysis of SEM images. SEM images presented in this section were chosen randomly. In addition to viscosity and morphology in this section shows, and other parameters of the method, such as the voltage and the working distance between the substrate and feeding capillary.

In the following experiments, each sample was processed separately.

Primer P1

The viscosity of the solution amounted to SDR 370. Although the viscosity was high, primer P1 was not formed fibers, and drops. The droplet size was 0.1-0.3 microns, voltage and working distance were equal to ±35 kV and 350 mm, respectively, while the diameter of the covered area 25 see SEM Picture layer P1 are presented in figure 4.

Primer P2

The viscosity of the solution amounted to SDR 170. And again, although the viscosity was before the ciently high, primer P1 was not formed fibers, and drops. The droplet size was 0.5-6 μm, the voltage and working distance were equal to ±30 kV and 450 mm, respectively, while the diameter of the covered area 25 see SEM Picture of the layer P2 is presented in figure 5.

Primer P3

The viscosity of the solution amounted to 215 SDR. In this case, although the viscosity of the solution was high enough, the primer gave the drops instead of fibers. The drops were very large, and the particle size was also wide. The droplet size was 1.2-17 μm, the voltage and working distance were equal to ±50 kV and 350 mm, respectively, while the diameter of the covered area 20 see SEM Picture layer P3 is presented on Fig.6.

Primer P5

The viscosity of the solution amounted to 193 SDR. And again, although the viscosity was high enough, the primer was not formed fibers, and drops. The droplet size was 0.2 to 1.5 μm, the voltage and working distance were equal to ±40 kV and 400 mm, and the diameter covered an area of 25 cm thick Layer of P5 presented on Fig.7.

Primer P6

The viscosity of the fluid was quite low: 90 SDR, as a consequence of the solution formed drops. The droplet size was 0.2-5 μm, voltage and working distance were equal to ±30 kV and 300 mm, respectively, while the diameter of the covered area 35 cm thick Layer of P6 shown in Fig.

Primer P7

The viscosity of the solution was 60 centipoise. Although the viscosity was low, primer, together the with the drops formed and fiber. The formation of fibers may have been caused by the use of additives. The diameter of the fibers was approximately 0.1 μm, the droplet size was 0.5-6 μm, and the voltage and working distance were equal to ±30 kV and 400 mm, respectively. The area covered by the soil, was very large. The primer covers the entire area of the plate collector. Layer P7 presented on Fig.9.

Primer P11

The viscosity of the solution amounted to SDR 110. Primer 11 formed only a thin fiber, including a number of grains. The diameter of the fibers was 0.4-0.1 ám, and the grain size of 0.8 to 1.4 microns. Voltage and working distance were equal to ±40 kV and 400 mm, respectively, while the diameter of the covered area was 24 cm thick Layer P11 represented at 11.

Primer R

The viscosity of the solution was 60 centipoise. Although the viscosity was low, primer along with drops formed and fiber. The formation of fibers may have been caused by the use of additives. The droplet size was 0.5-3 μm, and the diameter of the fibers of 0.1-0.4 μm. Voltage and working distance were equal to ±20 kV and 300 mm, respectively, and the direction of the electric field from negative potential to positive. The diameter of the covered area was 33 cm thick Layer of R presented on Fig.

Primer P13

The viscosity of the solution amounted to 310 SDR. Although the viscosity was high enough, the primer is formed ka what if instead of fibers. The droplet size was 0.2-2.5 μm, voltage and working distance were equal to ±30 kV and 250 mm, respectively, while the diameter of the covered area was 18 cm thick Layer P13 presented on Fig.

The surface energy

The critical value of the surface energy is shown in Diagram 1. These values of the surface energy compared with the magnitude of the surface energy of cardboard. The magnitude of the surface energy of all primers was less than the surface energy of cardboard. In the Diagram the sample By means of the cardboard, and samples P1-P13 - primers that were used during the preliminary tests.

The critical value of the surface energy primed cardboard shown on Diagram 2. Values of the critical surface energy of the coated paperboard was less than the magnitude of the surface energy of the cardboard. Values of the surface energy, calculated as the geometric mean, are given in Appendix 1.

To calculate the surface energy used by three liquid, which was the minimum number.

Adhesion of primers and methods of priming

Adhesion was measured using priming paper in the usual way (primer B-I) and according to the invention (primers P1-P13), extrusion coating is C low density polyethylene (LDPE) and finally, measuring the strength of adhesion between LDPE and paper. Primer-1, which was primed cardboard usual smearing, from a chemical point of view is similar to the primers P1-P13, respectively. When priming the anointing mass of the primer layer is obtained compared with the electrostatic method (>>0.1 g/m2).

The measurement results of adhesion primers B-I, caused by the anointing, is presented in figure 3. Primer B-I, caused by the smearing, gave a slight improvement in adhesion. Only primer N leads to improved adhesion in extrusion coating without processing in the corona discharge.

Chart 4 presents the adhesion of samples that have the mass of the primer layer is 0.1 g/m2and 0.01 g/m2. Priming was performed using electrostatic coating. In the case of primers P1-P13 to improve the adhesion required processing in the corona discharge. When the processing in the corona discharge is not applied, the adhesion was equal to zero for almost every primer. Primers P1, P6, P11 and P13, especially with the weight of the soil layer is 0.01 g/m2and R, especially with the weight of the soil layer of 0.1 g/m2significantly improve adhesion. Primer P7 with the mass of the top layer of 0.01 g/m2and primer P2 with the weight of a cover layer of 0.1 GM 2are also a good amplifiers adhesion.

Standard on both charts is covered with PE cardboard processing in the corona discharge and without using a primer.

Each primer has an individual weight of the coating layer, resulting in maximum adhesion.

Primer was attached to the cardboard and PE film, when extrusion coating used processing in the corona discharge. This fact is illustrated in Fig. The picture was taken after the test for delamination iodine on painted surfaces of polyethylene film. Only primers P3 and P6 with the weight of the soil layer of 0.1 g/m2joined the PE the film only partially.

When extrusion coating not used processing in the corona discharge, priming did not lead to increased adhesion, because it was not attached to the PE the film. On Fig shown PE film after the test for delamination. Some pulp is fixed on the surface of PE, but much of it is not attached to PE without processing in the corona discharge.

The following drawings show SEM images after the test for delamination. These SEM images were made from cardboard. Thus, when compared to the SEM images taken immediately after priming, these pictures show morphological changes after e is struinogo coating. The morphology of the P3 does not change, if the extrusion coating process does not use processing in the corona discharge. When used, the processing in the corona discharge, priming was distributed over the surface of the cardboard. On Pig picture on the right is made in the area which is not attached to the PE the film. Areas where the cardboard, primed P3, is attached to the PE the film look similar Fig.

Cardboard with primer P5 partially attached to the PE the film. The picture to the right on Fig made in the area where the cardboard is not attached to the PE. Morphology primer P5 varies slightly during the extrusion coating process, despite the use of processing in the corona discharge.

Morphology primed P6 changed during extrusion coating, if used processing in the corona discharge. P6 distributed over the surface of the cardboard. Fig made in the area where there is no attachment to PE. Perhaps the weight of the soil layer of 0.1 g/m2is excessively large, because the cardboard with P6 is not attached to PE properly.

Morphology P7 significantly changed by extrusion coating. The fiber is attached to the surface of the cardboard, little is distributed and possibly absorbed (Fig). Morphology of P8 in the extrusion coating process changes slightly (Fig).

Morphol the Gia P11, R and P13 significantly changed during extrusion coating (Fig). All these primers are attached to the surface of the cardboard, primers are distributed and may be absorbed into the surface of the cardboard.

Morphological changes in the extrusion process depend on the primers. Only the communication result with the use of primers that are already confirmed by testing for delamination, explains the fact that the treatment by corona discharge at the extrusion method significantly improves adhesion.

Conclusions

This work confirms that static methods of a coating suitable for priming. Achieved improved adhesion compared with standard padding with glazing. The smaller mass of the soil layer even give better adhesion than the large mass of the soil layer. However, preferably, the primers were processed in the corona discharge during the extrusion coating process for coating paper with polyethylene. The adhesion results show that each primer has an individual weight of the soil layer for maximum adhesion.

The correlation between the value of the surface energy and adhesion represented in figure 5-7. From these charts you can see that the low polarity leads to improved adhesion.

Figure 8 presents the particle size distribution for each of the primer. Based on the above it can be concluded that the particle size affect the adhesion. Thus, the primer R has a very good adhesive properties, because it has a low equivalent polarity and a small particle size. Perhaps the influence of particle size is based on the fact that the smaller particles are formed, the more adhesive areas have to the square on the surface of the cardboard.

In addition to the polarity of the primers and the size of the particles, the adhesion properties vary depending on the weight of the primer. Some better primer to enhance adhesion with the weight of the primer 0.01 g/m2than the mass of the primer 0.1 g/m2others better enhance adhesion when the mass of the primer 0.1 g/m2.

Appendix 1

The magnitude of the surface energy of cardboard in the form of a geometric mean of primers P1-R and primed cardboard

Component of variance [MJ/m2]Component polarity [MJ/m2] The share of polarityThe surface energy [MJ/m2]
Cardboard21,260,020,00121,28
P120,9631,410,60052,37
P222,0322,720,50844,75
P322,4921,730,49144,22
P422,820,350,47243,14
P522,9929,350,56152,34
P625,37at 8.360,24833,73
P726,566,650,200 33,21
R8of 28.278,640,23436,92
P923,2721,780,48345,05
P1024,399,380,27833,77
P1124,5225,750,51250,27
R25,27a total of 8.740,25734,01
P1318,5313,870,42832,4
R19,8121,350,51941,16
Primed 0.01 g/m2
P1212,080,090 results were 23.08
P220,961,970,08622,93
P323,170,330,01423,49
P5220,960,04222,96
P621,841,190,052to 23.03
P720,781,50,06722,27
P1123,140,690,02923,83
Rto 22.830,090,00422,93
P1322,640,610,02623,25
Primed 0.1 g/m2
P123,750,450,01924,2
P222,620,10,00422,73
P323,450,020,00123,47
P521,371,020,04622,39
P621,660,50,02322,17
P723,990,390,01624,38
R821,341,710,07423,06
P1123,710,230,01023,94
R22,89 00,00022,9
P1319,920,170,00820,09

1. Method of priming a paper or cardboard substrate, comprising bringing the substrate into contact with the primer, supplied from a source of primer and the deposition of the primer on the substrate, characterized in that it includes electrostatic deposition by electroprecizia.

2. The method according to claim 1, characterized in that at least part of the primer is in the form of fibers, dispersed in the gas phase.

3. The method according to claim 1 or 2, characterized in that the fibers are formed from a solution or emulsion primer material in a solvent or emulsion medium.

4. The method according to claim 2, characterized in that the average diameter of the fibers is from 0.05 to 1.0 μm, preferably from 0.1 to 0.5 micron.

5. The method according to claim 3, characterized in that the content of the primer material in the solution is from 5 to 50 wt.%, preferably from 20 to 45 wt.%.

6. The method according to claim 3, characterized in that the viscosity of the solution is from 40 to 400 centipoise, preferably from 50 to 200 centipoise.

7. The method according to claim 3, characterized in that the solvent is selected from water solvent system and, preferably, is own the th water or a mixture, containing water and alcohol.

8. The method according to claim 1, characterized in that the primer material selected from the group consisting of natural polymers, polyalcohol, ORGANOMETALLIC compounds and synthetic polymers.

9. The method of claim 8, wherein the primer material is a synthetic polymer, namely, Homo - or copolymer.

10. The method according to claim 9, characterized in that the synthetic polymer is an acrylic copolymer, preferably emulsified in an aqueous emulsion medium.

11. The method according to claim 10, characterized in that the acrylic polymer is precipitated on the substrate to a thickness of 0.002-0.05 g/m2preferably 0,006-0.02 g/m2most preferably about 0.01 g/m2.

12. The method according to claim 8, characterized in that the primer is diethanolamine.

13. The method according to item 12, characterized in that diethanolamine precipitated on the substrate to a thickness of 0.02-0.5 g/m2preferably 0.06 to 0.2 g/m2most preferably about 0.1 g/m2.

14. The method according to claim 1, characterized in that the primer also contains an additive for modifying the morphology of the particles of the primer on the substrate.

15. The method according to 14, characterized in that the additive is soluble polymer, preferably polietilenoksidnoy polymer.

16. The method according to claim 1, characterized in that electrostatic the Kai power, expressed as a voltage divided by the distance between the substrate and the source of the primer, squared, is from 0.02 to 4.0 In/mm2preferably, from 0.2 to 0.5 In/mm2.

17. The method according to item 16, wherein the electrostatic voltage is from 10 to 50 kV, preferably from 20 to 40 kV, and the distance between the source of the primer and the substrate is from 100 to 1000 mm, preferably from 200 to 500 mm, most preferably such that the electric field ranged from 1 to 4 kV/see

18. The method according to claim 1, characterized in that the coated substrate is subjected to processing in a flame or corona discharge prior to application on it covering substance.

19. The method according to p, characterized in that the coated substrate is subjected to processing in the corona discharge prior to application on it covering substance.



 

Same patents:

FIELD: pulp-and-paper industry, in particular production of multilayered cellulose product preferably paper or paperboard.

SUBSTANCE: claimed method includes filler application between at least two layers of moving fibrous material before bonding thereof with one another. In preferable embodiment inorganic filler is used optionally containing organic components. In the most preferable embodiment calcium sulfate is used.

EFFECT: paper with better optical characteristic such as whiteness and opacity without losses of mechanical properties.

42 cl, 7 dwg

FIELD: manufacture of a tub-sized paper or board sheet, applicable in wood-pulp and paper industry.

SUBSTANCE: the method consists in application at least on one side of the sheet of an aqueous compound of adhesive substance in amounts not exceeding 5 g/cu.m. The content of the solid substance in the applied adhesive compound makes up at least 15%. The aqueous compound is applied on one side of the sheet after its drying in a drying section of the machine for manufacture of paper or board. After that the adhesive compound is embedded in the sheet surface.

EFFECT: reduced power of the drying section of the machine for manufacture of paper or board and provided reduction of investments and reduction of the length of the paper-making line.

9 cl

FIELD: pulp-and-paper industry, in particular, production of paper and cardboard.

SUBSTANCE: method involves producing surface finished paper or cardboard Bw by applying aqueous solution Lw of surface finishing component W onto hydrophilic paper or cardboard sheet B, where W contains polyethylene glycol W1 with an average molar weight Mw≥1,500 or mixture of polyethylene glycol W1 and at least one additional finishing additive and/or receipt additive having concentration providing full water content in paper or cardboard in the range of 4-30 wt%; passing paper or cardboard sheet surface finished with aqueous solution Lw through smoothing rolls and drying. Substance for surface finishing of paper or cardboard is aqueous solution Lw of component W for surface treatment or component W and at least one non-finishing receipt additive F, wherein W contains polyethylene glycol W1 with an average molar weight Mw ≥ 1,500 and at least one additional finishing additive and/or receipt additive. Additive is selected from the group of antifoaming agents and agents for protecting from hazardous action of microorganisms, and finishing additive W3 containing at least one additive for increasing strength in wet state, with concentration of component W constituting ≥0.1 wt% and ≤ 70 wt%, and concentration of polyethylene glycol W1 constituting ≤50 wt%. Paper or cardboard is subjected to surface finishing process according to the above method. Method for producing of graphically treated paper or cardboard involves applying of at least one pattern of graphic paint onto paper base or cardboard base and drying. Base is surface finished paper Bw or surface finished cardboard Bw.

EFFECT: improved quality of paper and provision for avoiding of decrease in capacity and additional contamination of wastewater.

13 cl, 5 tbl, 11 ex

The invention relates to a method for impregnating decorative paper, intended for the manufacture of highly wear-resistant laminated flooring materials, in which the decorative paper is first moistened and thereby impregnate amenomori, and thus regulate the content of the resin

The invention relates to the pulp and paper industry, in particular the production of separator paper, which will find application in electrical industry for chemical current sources with an alkaline electrolyte

FIELD: pulp-and-paper industry, in particular, production of paper and cardboard.

SUBSTANCE: method involves producing surface finished paper or cardboard Bw by applying aqueous solution Lw of surface finishing component W onto hydrophilic paper or cardboard sheet B, where W contains polyethylene glycol W1 with an average molar weight Mw≥1,500 or mixture of polyethylene glycol W1 and at least one additional finishing additive and/or receipt additive having concentration providing full water content in paper or cardboard in the range of 4-30 wt%; passing paper or cardboard sheet surface finished with aqueous solution Lw through smoothing rolls and drying. Substance for surface finishing of paper or cardboard is aqueous solution Lw of component W for surface treatment or component W and at least one non-finishing receipt additive F, wherein W contains polyethylene glycol W1 with an average molar weight Mw ≥ 1,500 and at least one additional finishing additive and/or receipt additive. Additive is selected from the group of antifoaming agents and agents for protecting from hazardous action of microorganisms, and finishing additive W3 containing at least one additive for increasing strength in wet state, with concentration of component W constituting ≥0.1 wt% and ≤ 70 wt%, and concentration of polyethylene glycol W1 constituting ≤50 wt%. Paper or cardboard is subjected to surface finishing process according to the above method. Method for producing of graphically treated paper or cardboard involves applying of at least one pattern of graphic paint onto paper base or cardboard base and drying. Base is surface finished paper Bw or surface finished cardboard Bw.

EFFECT: improved quality of paper and provision for avoiding of decrease in capacity and additional contamination of wastewater.

13 cl, 5 tbl, 11 ex

FIELD: manufacture of a tub-sized paper or board sheet, applicable in wood-pulp and paper industry.

SUBSTANCE: the method consists in application at least on one side of the sheet of an aqueous compound of adhesive substance in amounts not exceeding 5 g/cu.m. The content of the solid substance in the applied adhesive compound makes up at least 15%. The aqueous compound is applied on one side of the sheet after its drying in a drying section of the machine for manufacture of paper or board. After that the adhesive compound is embedded in the sheet surface.

EFFECT: reduced power of the drying section of the machine for manufacture of paper or board and provided reduction of investments and reduction of the length of the paper-making line.

9 cl

FIELD: pulp-and-paper industry, in particular production of multilayered cellulose product preferably paper or paperboard.

SUBSTANCE: claimed method includes filler application between at least two layers of moving fibrous material before bonding thereof with one another. In preferable embodiment inorganic filler is used optionally containing organic components. In the most preferable embodiment calcium sulfate is used.

EFFECT: paper with better optical characteristic such as whiteness and opacity without losses of mechanical properties.

42 cl, 7 dwg

FIELD: paper industry.

SUBSTANCE: invention may be used to apply coatings onto paper or cardboard substrate, which is a precursor of finished paper, cardboard, fabric, sheet of fibre board. Substrate is brought in contact with primer supplied from source of primer. Electrostatic deposition of primer onto substrate is carried out by means of electrospinning.

EFFECT: invention provides for high uniformity of deposition, including hard-to-access uneven surfaces.

19 cl, 3 tbl, 41 dwg

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