text: Decorative impregnated paper used for printing by ink-jet printing method, method for its obtaining, and application
  D21H19/26 - Aminoplasts
  The present invention relates to decorative impregnated paper, which integriruetsa thermally curable resin for impregnating and which can be printed by using the methods of inkjet printing, after printing impregnated decorative paper can pressoffice directly with woody material to form a laminate.
  Decorative paper required for the production of decorative laminates, which are used as building materials in the manufacture of furniture and interiors. Decorative laminates mainly include so-called high pressure laminates (HPL) and low pressure laminates (LPL). To obtain high pressure laminate decorative paper in printed or not printed state is impregnated with resin and pressed together with one or several layers of sheets of Kraft paper impregnated with phenolic resin (inner layers), in press for lamination at a temperature of from about 110 to 170°C and a pressure of from 5.5 to 11 MPa. Then laminate (HPL), thus obtained, is glued or pasted to the substrate material, such as MDF or particleboard. Laminate low pressure get by pressing printed or not printed decorative paper, impregnated the Mola, directly from the plate of the substrate at a temperature of from 160 to 200°C and a pressure of from 1.25 to 3.5 MPa.
  The surface finish of the material may be of a visual nature (with associated staining) and/or physical nature (by coating on the surface of the slab with the appropriate functionality and structure). Decorative paper can be produced with printed pattern or not. For this purpose, printed or not printed decorative paper usually integriruetsa synthetic resins in a single-stage or multi-stage method, then dried, and the resin is still chemically active, and then permanently pressed in the hot condition together with the substrate material with the formation of sheets or rolled products. The resin cures during the pressing. This curing receive not only binding to the plate, but this paper is completely sealed, chemically and physically.
  The printing pattern is usually carried out by way of gravure printing. In particular, at the time of receipt of printed patterns, which are common on the market, this printing technology has the advantage of printing large quantities of paper at high machine speeds.
  However, the method of gravure printing should be evaluated as not being economically EF is unbiased for smaller quantities and relatively inadequate print quality in the case of complex design. Among the printing technologies that meet the requirements of flexibility and quality, method of inkjet printing (ink jet printing) is becoming increasingly important.
  To make decorative paper suitable for printing by means of ink jet printing, it is covered by one or more functional layers for receiving ink and fixation of the dyes. This decorative paper, which can be run printing method inkjet printing, is described in DE 19916546 A1.
  Suitable for inkjet printing decorative paper may be impregnated with thermosetting resin after printing, and then pressoffice in a hot condition. Because often printed on paper only in the form of leaf length up to several meters linear, for example, 3.5 m, impregnation in the impregnation system is often impossible. In this case, the sheet is pressed between layers of the resin coating paper. During the process of pressing the resin penetrates into the decorative paper and cures. The result is a laminate of good quality. However, compared to the system of impregnating this procedure does not guarantee that the decorative paper is evenly impregnated through and through. As a consequence, this method does not achieve complete sealing of the paper.
  During the pressing of decorative paper between layers of paper, it is regirovannyy resin, is privileged to have merged only decorative paper that has been printed. If printing is performed on the decorative paper into a roll, and then impregnate, there are losses of material, caused by breaks in the systems transients printing and cutting and adjustment processes. For this reason, you lose the high quality material.
  The present invention is the creation of decorative paper that does not have the disadvantages described above.
  This problem is solved by using impregnated decorative paper that contains impregnated base paper (decorative base paper) and a layer for receiving ink, and the base paper contains a resin for impregnation in an amount of from 40 to 250 wt.% with respect to the base weight of the paper base, and after drying, the impregnated decorative paper has a residual moisture, which is at least 3.5 wt.%, and spreading, constituting more than 0.4%, measured at a pressure of 180 bar and a temperature of 143±2°C.
  In a specific embodiment of the present invention, the amount of resin for impregnation is 80-125 wt.% with respect to the base weight of the paper base.
  Residual moisture decorative paper after drying is preferably from 5 to 8.5%.
  The result is in accordance with h is a worthwhile invention is achieved, in particular, if the decorative base paper first internally integriruetsa, pre-dried and only then covered with one or several layers for receiving ink in the coating process and dried. In this case, it should be noted that after pre-drying internally impregnated to the core base paper and drying the finished impregnated decorative paper resin for impregnating not cures and, therefore, remains chemically active.
  The term "not cured" in the sense of the present invention means that the resin for impregnating has a degree of cross-linkage at most 65%, preferably at most 30%. The way to determine the degree of cross-linkage is described in detail in the text below.
  The method of obtaining impregnated decorative paper in accordance with the present invention has the following stages:
  (a) obtaining a decorative base paper with a weight of 30 to 200 g/m2,
  (b) internal impregnation of decorative paper base thermally curable resin for impregnating in an amount of from 40 to 250 wt.% with respect to the base weight of the paper base,
  (c) pre-drying internally impregnorium paper, and the temperature of the drying regulate in such a way that the paper has a moisture content of 9 to 20 and the resin is not cured, and consequently, it is still chemically active,
  (d) coating on pre-dried, internally impregnated paper at least one layer for receiving ink,
  (e) drying internally impregnated decorative paper, provided with at least one layer for receiving ink, to a residual moisture content ranging from 3.5 to 8.5%, where the resin is cross stitched at most to the extent of cross-linkage 30% and for this reason is still chemically active, and the resulting dried impregnated decorative paper is spreading more than 0.4%, measured at a pressure of 180 bar and a temperature of 143±2°C.
  Internal impregnation can be carried out off-line in the standard system for impregnating or in-line inside a paper machine using the normal nodes coating.
  In another embodiment of the present invention, the layer for receiving ink can also be applied to internally impregnated paper without pre-drying.
  In yet another embodiment of the present invention, the layer for receiving the dye may also be applied to the impregnated resin paper with multiple impregnation (conventional impregnated decorative paper).
  In a specific embodiment, the present invention decorative impregnare the fair paper has chemical activity 2 to 3 minutes at a temperature of 140°C and a pressure of 25 bar.
  Decorative impregnated paper, thus obtained, can slide into a roll in the specified system or be separated into leaves. Then on decorative paper can be applied to the high-quality print using different methods of inkjet printing. After the printing paper is pressed while hot on the stove wood-based or form a laminate in the press for coating. For this purpose impregnated with resin paper (lining) as a layer composite, or any other adhesive layer is no longer required. However, impregnated with resin lining can be used additionally, if this is desirable. Impregnated by resin molding can be applied as a protective layer before pressing. However, the printed product can also first be sealed with varnish.
  Decorative base paper, which can be used in accordance with the present invention is a paper that is not subjected to any sizing in the mass or surface sizing. It essentially consists of cellulose, pigments and fillers and conventional additives. Conventional additives can be an additive to impart strength in the wet state, the retaining additives and reinforcing additives. Decorative base paper differs from the usual boom and a much higher proportion of filler or pigment content and the lack of any padding in the mass or surface sizing, which is normal to the paper.
  Pulp softwood pulp hardwood or a mixture of both types of cellulose can be used for decorative base paper. Is the preferred use of 100% cellulose solid wood. However, you can also use a mixture of pulp, soft wood/hard wood, with a ratio of 5:95 to 50:50, in particular from 10:90 to 30:70. The base paper may be obtained on clinocerinae paper machine or paper machine from American dryer. For this purpose, the cellulose mixture having the consistency of paper pulp from 2 to 5 wt.%, can refinerias to sagasti from 10 to 45°SR. When mixing fillers and/or pigments in the tank, color pigments and/or dyes, and also additives to provide strength in the wet state, such as polyamide/polianinova epichlorhydrine resin, cationic polyacrylates, modified melamine formaldehyde resin or carinsurance starches, may be added in amounts conventional for the production of decorative paper, and thoroughly mixed with the pulp mixture.
  The fillers and/or pigments may be added in an amount up to 55 wt.%, in particular, from 10 to 45 wt.% in relation to the weight of cellulose. Appropriate pigments and fill and represent for example, titanium dioxide, talc, zinc sulfide, kaolin, aluminum oxide, calcium carbonate, aluminum oxide, aluminum silicate and magnesium or mixtures thereof.
  Material high consistency obtained in the tank for mixing, can be mixed to the consistency of paper pulp about 1%. If necessary, you can add additional excipients, such as retaining additives, protivovspenivayushchie additives, dyes, and other above-mentioned excipients or mixtures thereof. This material is a low consistency passes through the headbox of the paper machine wire section. Formed fibrous mass, and after dehydration receive a base paper, which is then optionally dried. The mass of the obtained paper can range from 30 to 200 g/m2.
  Depending on the applications and requirements for quality decorative base paper used in accordance with the present invention, can represent the following:
  smooth, that is, having the smoothness according bekku more than 80 s,
  neotragini less than 80 s,
  ironed with American dryer or by using the calender, not pre-impregnated or pre-impregnated with synthetic resin,
  very breathable (air permeability Gurley neither is e 20/10 ml) or dense (air permeability Gurley above 20 C/10 ml) or even in the case of pre-impregnated dense, with permeability to air Gurley above 200 C/10 ml
  Decorative paper in accordance with the present invention can be dyed. For staining can be used inorganic colored pigments such as the oxides, hydroxides and hydrates, metal oxides, sulfides, sulfates, chromates and molybdates metals or mixtures thereof, and organic colored pigments and/or dyes, such as carbonyl dyes (e.g., quinones, chinagreen), cyanine dyes, azo dyes, azomethines and but, phthalocyanines or dioxazine. Especially preferred are mixtures of inorganic color pigments and organic colored pigments or dyes. The amount of color pigment/mixture of pigments or dye/mixture of dyes may be from 0.0001 to 5 wt.% in relation to the mass of pulp, depending on the type of substance.
  All receiving layers can be used as a layer for receiving ink. In this case they mostly contain hydrophilic coating containing a water-soluble or dispersible polymers in water.
  Layer for receiving ink may optionally contain fillers, pigments, substances, fixing the dyes, such as Quaternary salts of polyamine and other excipients normally used in such layers. The corresponding Quaternary salt of paliam the Deposit is polydiallyldimethyl chloride.
  In a preferred embodiment of the present invention, the layer for receiving ink contains a pigment and binder in the quantitative ratio of from 10:90 to 90:10. The amount of pigment in the layer for receiving ink is preferably from 5 to 80 wt.% and, in particular, from 10 to 60 wt.% in relation to the dry weight of the layer.
  The pigment can be any pigment commonly used in materials for inkjet printing, and, in particular, aluminum oxide, aluminum hydroxide, boemite and silicon dioxide (such as precipitiously or pyrogene generated silicon dioxide).
  The binder may be a water-soluble and/or dispersible in water, a polymer, e.g. polyvinyl alcohol, polyvinylpyrrolidone, polyvinyl acetate, starch, gelatin, carboxymethyl cellulose, copolymer ethylene/vinyl acetate, copolymers of styrene/esters of acrylic acid or mixtures thereof. Polyvinyl alcohol having a degree of saponification of from 88 to 99%, can be used as the polyvinyl alcohol.
  In a specific embodiment of the present invention, the layer for receiving paint can be painted. The dyeing may be carried out using the same colour pigments and/or dyes used for coloring paper base. The amount (concentration) of a color pigment and/or is of rasites layer for receiving ink in relation to the dry layer for receiving the dye preferably is approximately 45-75%, in particular, from 45 to 65% of a color pigment and/or dye in the paper bases with respect to the cellulose (absolutely dry).
  Mass for applying a layer for receiving ink can be from 2 to 25 g/m2in particular from 3 to 20 g/m2but preferably from 4 to 15 g/m2. Layer for receiving ink can be applied using conventional methods of application, such as application with a roller, the application of the slit-like nozzle, means of gravure printing, or plotting in the clamp between the rollers, curtain coating, spraying or dispensing roller.
  The appropriate resin for impregnating represent a resin for impregnation, usually used in this technical field, in particular melamine-formaldehyde resin, urea resin, phenol resin, polyacrylate, copolymers of ester of acrylic acid/styrene, and mixtures thereof. Especially suitable for use are the so-called "slow" resin for impregnation, which have time turbidity more than 4.5 minutes. While turbidity is a time after which the resin at a temperature of 100°C shows the first turbidity, which indicates the beginning of the polymerization reaction.
  Resin for impregnation is used in an amount of from 40 to 250 wt.%, preferably from 0 to 125 wt.% with respect to the base weight of the decorative base paper.
  The suspension of cellulose were prepared by boiling the pulp mixture of 80 wt.% eucalyptus pulp and 20 wt.% sulphate pulp pine with consistency paper pulp 5% to sagasti 33°SR. That was followed by the addition of 1.8 wt.% epichlorhydrine resin as additives to impart strength in the wet state. This pulp suspension was brought to pH 6.5 to 7 by using aluminum sulfate. Then to the pulp suspension was added a mixture of 40 wt.% titanium dioxide and 5 wt.% talc, 0.11 wt.% retaining additives and 0.03 wt.% protivovspenivayushchie additives and received decorative base paper having a basic weight of 81 g/m2and the ash content of about 32 wt.% Mass specification is relative to the cellulose.
  At the next stage to prepare the mixture for the coating layer for receiving ink having the following composition:
  Beamit 10 wt.%
  Polyvinyl alcohol 5 wt.%
  Salt of Quaternary polyamine 1 wt.%
  The obtained decorative base paper was subjected to a "slow" resin in the first stage conventional systems impregnating decorative paper and after a phase of penetration, was loaded and then only moderately pressed, so that a small film of the resin remained on the surface of the paper. the quality of the resin used pure melamine-formaldehyde resin, having a solid content of products 51% and time turbidity 4.5 minutes.
  Internally impregnated paper was dried to a moisture content of 12%. The base weight of the paper after impregnation was 139 g/m2.
  Pre-dried impregnated to the core paper is then covered by a layer for receiving ink for inkjet printing, described in detail above, with the mass application of 6 g/m2and were dried to the final moisture content of 6.3%.
  The dried impregnated decorative paper had a base weight of 140 g/m2and the thickness of 133 ám.
  The chemical activity of the resin for impregnation in the dried impregnated decorative paper was 2.5 minutes the Degree of cross-linkage was equal to 29%.
  Spreading impregnated decorative paper in accordance with the present invention was 1.2%.
  Decorative impregnated paper, obtained in accordance with Example 1, was adictivos on an inkjet printer (HP 2500 with pigmented inks) and divided into sheets DIN A4. These sheets were placed on the wood particle Board, covered with foil lining paper having a basic weight of 35 g/m2that is impregnated with resin to 116 g/m2) and extruded in a hot condition. The pressing was carried out at a temperature of 140°C and a pressure of 25 bar.
  The pulp suspension prigot lively by boiling 100 wt.% eucalyptus pulp at a consistency paper pulp 5% to sagasti 33°SR. That was followed by the addition of 1.8 wt.% epichlorhydrine resin as an additive to impart strength in the wet state. Then this pulp slurry was brought to pH 6.5-7 using aluminum sulfate. Then added to the pulp slurry a mixture of 36 wt.% titanium dioxide and 5 wt.% talc, 0.11 wt.%. retaining additives and 0.03 wt.% protivovspenivayushchie agent, and received a decorative base paper having a basic weight of about 80 g/m2and the ash content of about 30 wt.% Mass specification is relative to the cellulose.
  The obtained decorative paper was subjected to a "slow" resin in the first stage conventional systems impregnating decorative paper and after a phase of penetration was loaded and then only moderately pressed (as in example 1). The resin was a pure melamine-formaldehyde resin having a solids content of products 51% and time dimness of 5.5 minutes. Internally impregnated paper was dried to a moisture content of 13%. The base weight of the paper after impregnation was 162 g/m2.
  Pre-dried internally impregnated paper is then covered with a layer for receiving ink for inkjet printing, are described in detail above, with the mass application of 7 g/m2and dried to the final moisture content of 6.5%.
  The dried impregnated decorative the Umag had a base weight of 160 g/m 2and the thickness of 149 μm. The chemical activity of the resin for impregnation in the dried impregnated decorative paper was 3.5 minutes, the Degree of cross-linkage was 26%. Spreading impregnated decorative paper was 1.5%.
  Decorative impregnated paper in accordance with Example 2 was printed on an inkjet printer (HP 2500 with pigmented paint) and was divided into sheets of DIN A4. These sheets were placed on the wood particle Board, covered with foil lining, as in example 1 and extruded in a hot condition. The pressing was carried out at a temperature of 140°C and a pressure of 25 bar.
  Laminated plate obtained by using decorative papers in accordance with the present invention, showed properties of high-quality melamine coating. They differed closed surface, which did not contain bubbles and discoloration in the study with water vapor. The surface was also resistant to the action of chemicals in accordance with the standards EN 438 for laminated plates.
  Procedure in accordance with the present invention additionally have the following advantages:
  Even short periods of blade length in multiple linear meters can be fully impregnated through and through. Usually when industrial impregnation of synthetic resin of at least the floor is th length of the system of impregnation is used as the control plot to install and monitor settings, that means in numbers from 50 to 100 meters
  Because decorative paper in accordance with the present invention is printed only after internal impregnating cloth paper, expensive and sensitive seal is not exposed to hazards from the process of impregnation.
  - When printing water-based paints for printing paper product in accordance with the present invention becomes less wavy because of the swelling, because the structure of the paper is stabilized with resin.
  - Given the rigidity, it is easier to provide a press impregnated paper than in the case of reimpregnation base paper during normal pressing between two layers of paper, impregnated with resin.
  - Eliminated technological stage, when compared with the method with subsequent impregnation, resulting in significant economic benefit.
  - The manufacturer of the laminate can be individually print each batch required decorative paper without the need of owning one's own equipment for impregnation. For this purpose the equipment for inkjet printing can be installed near the press for laminate. By eliminating the link between printing and impregnation General logistics for the product is improved and the use of the material is optimized.
  Used methods investigated is I
  The study of the spreading of the impregnated material
  Spreading examined by determining the behavior of the spreading of the resin of the coating resin for impregnating decorative paper impregnated material). For this purpose, five disks with a diameter of 4 cm, cut out the stamp from the sample impregnated material. They squeeze between the aluminium foil for 5 min (precision press Wickert und Sonne, 120×120 cm, pre-pressure: 46 bar/12 seconds, the main pressure: 180 bar/12 seconds at 143±2°C). After the process of compression of the disc-shaped laminate is cooled and weighed (initial weight). After removal of the resin, which spreads from the disk (amount of resin located on the side surface of the workpiece), the laminate is again weighed (final weight). The difference between the initial and final weight, referred to the weight of the initial disc-shaped laminate, gives the spreading of the impregnated material.
  Flow =Initial weight (g) - final weight (g)× 100
  The chemical activity of the resin
  Chemical activity represents the minimum pressing time required at a specific temperature (for example, 140°C), during which the surface is cured so that the contamination using the dye Rhodamine b can easily be removed is water.
  The degree of cross-linkage of the resin
  The degree of cross-linkage is the number of resin for impregnation, which cannot be dissolved from the sample after immersion for 35 min in DMF (dimethylformamide) at room temperature.
  Residual moisture impregnated material
  For this purpose, cut a circular samples (F 40 mm) and the first condition at 23°C and 50% humidity environment and weighed. The weighted sample is dried for 5 minutes in a drying Cabinet at 160°C. the Residual moisture content is calculated as follows:
  Residual moisture (%)=
  =Initial weight (g) - final weight (g)
  This study is used to determine the behavior of the curing time impregnated decorative paper.
  For this purpose, cut stamp several circular samples with a diameter of 4 see Then these samples are placed between the shiny sides of an aluminum film (thickness 0.030 mm) and the package placed in the middle of a heated press (Wickert und Sonne, square extrusion 120 mm × 120 mm, setting the initial pressure bar 46 within 12 seconds, the setting of the main pressure 180 bar within 12 seconds, the temperature setting of 140°C). Press include and run the program pressing. The curing time at which alchanii is from 20 to 600 seconds in steps of 5 seconds (in the beginning) to 120 seconds (at the end).
  When the program pressing ends of the investigated samples immediately cooled between two sheets to stop the curing reaction.
  After cooling to 5 to 65°C test specimens are immersed for three minutes in a 0,025% aqueous solution of Rhodamine In at 95°C and then for 15 seconds in cold water. After drying, soft paper towels samples of paste on the transparent film after increasing time compression. Evaluation is done visually in relation to the reference sample. The value of the chemical activity is achieved when the analyzed samples are colored only minimally, and at longer time compression can be achieved more change.
  The degree of cross-linkage
  The study used to determine the degree of curing of impregnated materials.
  For this purpose, cut out the stamp of the analyzed samples, with an area of 100 cm2and weighed (corresponding to the mass of the sample before extraction"). Then, test specimens are immersed in N,N-dimethylformamide (DMF) (100 cm2drives 100 ml). After the exposure time from 30 to 35 min at room temperature, the analyzed samples are removed, placed on a blotting paper and then dried in a drying Cabinet at 120°C for 90 min After cooling, the analyzed samples are weighed is (corresponds to the mass of the sample after extraction").
  The dissolved fraction (g) = initial weight (g) - final weight (g)
  The dissolved fraction (%) = dissolved fraction (g)/initial weight (g) × 100
  Cross stitched fraction (%) = final weight (g)/initial weight (g) × 100
  Initial weight (g) = weight of sample before extraction" (d) base weight base paper (g/m2) × sample area (cm2)/10000
  Final mass (g) = weight of sample after extraction" (d) base weight base paper (g/m2) × sample area (cm2)/10000.
  1. Decorative impregnated paper materials decorative coatings, which contains the impregnated base paper and a layer for receiving ink, wherein the base paper contains a resin for impregnation in an amount of from 40 to 250 wt.% in relation to the weight of base paper, after drying, the impregnated decorative paper has a residual moisture, which is at least 3.5 wt.%, and spreading, constituting more than 0.4%, measured at a pressure of 180 bar and a temperature of 143±2°C.
  2. Decorative impregnated paper according to claim 1, characterized in that the resin for impregnation is contained in an amount of from 80 to 125 wt.% in relation to the weight of the paper base.
  3. Decorative impregnated paper according to claim 1 or 2, characterized in that the resin for impregnation is particularly the melamine-formaldehyde resin, urea resin, acrylate resin, or a mixture of these resins.
  4. Decorative impregnated paper according to claim 1, characterized in that the resin for impregnation is still reactive after drying, the impregnated decorative paper.
  5. Decorative impregnated paper according to claim 1, characterized in that the layer for receiving ink contains a pigment and binder in the quantitative ratio of from 10:90 to 90:10.
  6. Decorative impregnated paper according to claim 5, characterized in that the binder layer for receiving the dye is a water-soluble and/or dispersible in water the polymer.
  7. Decorative impregnated paper according to claim 5, characterized in that the pigment may be an aluminum oxide, aluminum hydroxide, boemite and/or silicon dioxide.
  8. Decorative impregnated paper according to claim 1, characterized in that the mass of a coating layer for receiving ink ranges from 2 to 25 g/m2.
  9. A method of obtaining a compressed impregnated decorative paper, characterized in that
  (a) decorative base paper obtained from a weight of 30 to 200 g/m2internally impregnorium resin for impregnating in an amount of from 40 to 250 wt.% with respect to the base weight of the paper base,
  (b) internally impregnated paper pre-dried, at this rate is the temperature of drying is set that paper has a moisture content from 9%to 20%, and the resin is only partially condensed and not completely polymerized and for this reason is still chemically active,
  (c) pre-dried paper is covered with at least one layer for receiving ink,
  (e) internally impregnated decorative paper, provided with at least one layer for receiving ink impregnated decorative paper), dried to a residual moisture content ranging from 3.5 to 8.5%, while the resin is subjected to cross-linking of at most up to the degree of cross-linkage 30% and for this reason is still chemically active, and dried impregnated decorative paper is spreading, constituting more than 0.4%, measured at a pressure of 180 bar and a temperature of 143±2°C.
  10. The method according to claim 9, characterized in that the resin for impregnation is a melamine-formaldehyde resin, urea resin, acrylate resin, or a mixture of these resins.
  11. The method according to claim 9, characterized in that the mass for applying a layer for receiving ink ranges from 2 to 25 g/m2.
  12. The application of the decorative coating paper according to claim 1 to obtain a laminated fibrous materials and laminates of all kinds.
  SUBSTANCE: item is arranged in the form of rectangular sheet, has the first parallel edges in the first direction and the second edges in the second direction, perpendicular to the first direction. Item comprises at least two layers attached together by binder applied in the form of fixing pattern between layers. Fixing pattern is the pattern of fixing of increased size and comprises fixing elements arranged along the first group of irregular wave-like lines of fixing, passing from one parallel edge to the other at the first angle, making from 20° to 70°, to the first direction, and along the second group of irregular wave-like fixing lines passing from one parallel edge to the other at the second angle, making from 110° to 160°, in the first direction. The first and second groups of irregular wave-like fixing lines cross to form a grid. Fixed area of surface makes from 0.6% to 6.0% of item area.