DE1519154B - Process for priming wood-based materials - Google Patents

Description

The invention relates to the use of effect-improving primers for priming of wood-based materials in a manufacturing process for imitation wood decorations by printing.

It is used in the wood processing industry, e.g. B. in furniture production and manufacturing from radio or television housings the various wood materials, such as plywood, blockboard or chipboard, which in many cases is not pressed with expensive precious wood veneers, but with others materials made of wood are coated.

With the help of indirect gravure printing, you have both tried different carrier materials, such as inexpensive veneers, fibreboard or plywood with any decor, for example to print a wood imitation of natural fine wood veneer surfaces. For this purpose, the Initially, raw materials mostly colored by pickling.

Such a means for staining or coloring wooden surfaces with visible preservation of the wood structure, the production of pastel shades by incorporating pigment particles (titanium dioxide) Permitted into the wood pores is known from the German Auslegeschrift 1146 244. The penetration of the Mordant in the wood fabric can be achieved by adding a wetting agent and the adhesive strength by adding an adhesive, for example of the vinyl acetate and vinyl propionate type. For the subsequent printing is the pickled substrate by applying a primer, for example based on nitrocellulose. However, this way of working does not give satisfactory results, and the print doesn't look real. By applying such a primer, the grown The structure of the wood is obscured and intimate contact between the printing ink and the wood is disturbed, as the Primer all that contains organic solvents that swell and dissolve vinyl compounds and let the other stain dyes "bleed out" so that especially when the wood material needs to be lightened a concealment of the wood structure and a loss of the natural depth effect of the wood grain entry. Due to these circumstances, the imitation print appears very conspicuous and unnatural. The printing of wood-based materials is becoming more and more widely used only find when the print imitations of natural fine wood veneer surfaces are also recognized by the viewer can be perceived as appearing natural. This is surprisingly achieved by the Use of primers

a) Urea - formaldehyde condensation products, melamine - formaldehyde condensation products , Phenol-formaldehyde condensation products, cresol-formaldehyde condensation products

products, polyacrylic or polymethacrylic acid resins or alkyd resins in water-soluble form;

b) water-soluble cellulose derivatives as thickeners;

c) optionally inorganic and / or organic Pigments, pigment dyes and / or transparent inorganic, organic pigments and / or soluble dyes and / or soluble heavy metal salts;

d) optionally water-soluble plasticizers;
e) Water as a solvent and diluent, if appropriate

f) additional alcohols, glycols and / or glycol ethers or other compatible water-miscible organic solvents;
g) where appropriate, additionally higher polyhydric alcohols as plasticizers;

for priming wood-based materials. The wood-based materials pretreated in this way are then used in the usual way In single or multi-color printing with a wood imitation decor, which, for example, has the appearance of a Reproduces wood grain pattern, printed. By using the primer according to the invention all disadvantages described above are largely eliminated, since in a single operation the re-coloring of the wood immediately together with the coating of the wood-based material with a Priming is done.

The binders can be contained in the claimed primer individually or as a mixture being. Your job is to remove the dyes, pigments, pigments and heavy metal salts on the wood fiber or to be fixed to the subsurface.

The thickeners should regulate the viscosity of the batch and the processable Adjust consistency. Instead of the cellulose derivatives, other customary thickeners can also be used will. In addition, they can also contain wetting agents and what are known as pigment distributors being.

The main solvent and diluent is water. It can be the only solvent present being; but sometimes it is useful to have a water

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soluble organic solvent, e.g. B. contain an aiko. In the context of this registration, protection

hol, glycols and / or glycol ethers. The only for the use of the claimed

Particularly good wood friendliness of the primer according to the invention, but not the primer used in accordance with the agent itself, is based on the ' ¹ heard. The use of the primers results in the presence of water. I 5 end products that are compared to the known one

The wood-based materials to be printed can be fur- '; significant improvement of the pressure on the wooden kidney grille, Plywood, also have any veneer materials. A major advantage of the Coated blockboard, chipboard, hard- Invention consists in the fact that the claimed green fiber boards or other materials. Such diermittel of the subsequently applied printing ink Wood-based materials are guaranteed to have good penetration for open-pore processing and thus an intimate one suitable. They can also be used to create closed-cell contact with the wood-based material and create the wood effect be generated. Closed-pore effects largely retain the character of the material. Because of can be used on non-veneered materials such as chipboard - the good penetration possibility of the printing ink Hardboard and the like are produced. there is a sharply drawn design, while the

The primer can be used with the usual primers known in the 15 up to now, even with a proper paint technique applied application methods on the setting of the printing mechanism a squeezing of the Wood materials are applied. A particularly stressful one is never entirely to be avoided. Another pre-expedient and advantageous application method is part of the primers used according to the invention rolling on with roller coating machines, what is it like that now the dyeing and preparation for example in the furniture industry for job 20 for the application of printing ink in a single work of Lacquering or matting or in the sheet metal aisle takes place, namely by applying the beemballagenindustrie For rolling on primers that have been exposed to canned food. For that surprise can varnish are common. the effect is only guaranteed by such primers

For the open-pore treatment, the one whose binder content is water-soluble is particularly suitable. Roller application of the primer on veneers or 25 Surprisingly increased, especially with roller veneers Materials suitable and secures the application that in the claimed primer closing veneer print a distinctive, contrasting water only very briefly the moisture rich Pore emphasis and an excellent degree of depth of the wood-based material. After a short time effect of the overall picture. Time can be used on the materials treated in this way

The selection of the pigments, pigment dyes, and the print colors set on them continued soluble or transparent dyes or the be. Despite the quick drying is about one soluble heavy metal salts, continuous work depends on the long period of time Basic color of the wood-based material and the herzu- possible because a thickening or a change providing shade. How to use z. B. only the consistency of the claimed primer soluble or transparent dyes, if one of 35 can hardly be observed in the application machine. light wood materials to darker open-pore The possibilities for the inventive effects wants to get. Darker, open-pore designs are extremely versatile. If accessory materials you give a lighter tint, for example, lighter wood-based materials in the basic shade, such as through the use of appropriate pigments. For closed abachi, limba or walnut sapwood veneers in open-pored Effects are soluble dyes and 40 porous effect with a rosewood or teak pigments appropriately combined. But it is also or walnut decor should be provided, possible, only giving appropriate colorations, the process is carried out in such a way that initially To use pigments. the veneer surfaces using the usual roller

The one with the green paint application machine used according to the invention, once with the primer

Wood-based material treated with an agent can already be rolled according to composition 1. The deeper

a short time with the special pores lying on the veneer print experience a stronger coloring and

Matched inks can be printed. This emphasizes this. After a short drying time

usually done in indirect gravure printing. But takes 1 to 2 minutes at room temperature

other printing processes are also possible. The printing then immediately the single or multi-color printing,

color layer can be achieved by a suitable coating, 50 which leads to the desired veneer motifs. the

such as B. a clear lacquer or a coating with a veneer print is characterized by a

Varnishes based on unsaturated polyester - natural depth effect and a sharp reproduction

resins are protected. tion of the grain including the accentuated pore.

On suitable carrier materials, such as hard fiber

plates, the printing ink layer can also be the veneer motif to be achieved with a 55, z. B. plywood

Baked-in lacquer can be coated and baked. with Macore veneer layer, which is covered with an open

The stain-like primer and printing ink-porous walnut decor should be provided

layer do not require a separate burn-in. expediently proceed in such a way that the Macoro-

The basic materials and processing methods veneer surface first the primer of the are known per se. Thus, the German patent 60 has composition 2 by means of the usual roller lacquer writing 838 215 a method for the production of stable, application machine is rolled on. Due to the Aqueous dispersions of soluble phenolic resins for pigment content are in this case a certain spreading purpose and for the production of wood gluing, contamination of the starting material cannot be avoided, gen to the content. The German patent specification 752 336, however, remains due to the composition of the Finally, describes paints on top of the primer and their rolling onto the wood layer Aqueous emulsions of artificial high molecular weight even largely obtained. After organic compounds that act as an emulsifier poly- drying of the applied layer is carried out by the monovinyl alcohol or its still water-soluble derivatives or flour color printing, which leads to the desired nut

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tree decor leads. Good penetration is made possible for the print and the veneer design appears this is particularly sharply drawn.

Closed-pore effects can also be advantageously achieved. For example, natural-colored wood fiber hardboards To provide a teak motif, the procedure is that first on the wood fiber hardboard the primer of composition 1 or 3 or 5 in the corresponding yellowish Clay is rolled on once by means of the usual roller coating machine. After drying takes place Immediately afterwards the single or multi-color print, which results in the desired teak decor. Unless there is is desired, the corresponding pore can then be embossed with the help of an embossing roller. It is also possible to cover the printing ink layer with a clear varnish to protect it. For example, to make wood fiber hardboard with a lighter, closed-pore walnut, maple or To obtain a cherry tree motif, the work is carried out in such a way that the primer 2 or 4 is either applied in the casting process or rolled on with the roller coating machine.

In this case, the primer is opaque and gives the subsequent print a particularly evenly spreading and coloring base. After drying, the single or multi-color printing takes place, which results in a very clear and sharply drawn decor. The print can be covered with a clear coat. Other wood-based materials, e.g. B. non-veneered blockboard, which also has a closed-pore wood decor, z. B. want to get a walnut or maple ίο decor by printing, are first filled with a filler or with a roller spatula or leveled to achieve a completely flat surface. This is followed by the procedure that the primer of composition 2 or 4 is applied. After drying, this layer is then printed with the desired decor in single or multi-color printing. Panels are obtained whose surfaces show a clear and sharp wood decor.
The composition of the primers 1 to 5 used, for example, is shown in the table below. The figures given each mean parts by weight.

Urea-formaldehyde condensation product soluble in water

Melamine-formaldehyde condensation product soluble in water

Phenol-formaldehyde condensation product soluble in water

Water soluble polymethacrylate resin

Medium oil castor alkyd resin, acid number 50 to 70, neutralized with alkali

Carboxymethyl cellulose Na salt

Methyl cellulose

water

Ethyl alcohol

Ethyl glycol

Pigments:

Zinc sulfide

Iron oxide red

Iron oxide yellow

Iron oxide black

Soluble dyes in a brownish-yellow shade

glycerin

Wetting agents

until 50

0.5 to 1.5
until 50
until 5

0.2 to 0.5
0.2 to 0.5

30 to 20
20 to 10

0.5 to 1.5
30 to 60
5 to 10

20 to 30
0.1 to 0.3

Ibis 2
0.1 to 0.5

0.5 to 1.0
0.5 to 1.0

30 to 20

20 to 10

0.5 to 1.5

30 to 60
5 to 10

0.2 to 0.5
0.2 to 0.5

50 to 40

5 to 10

30 to 60
5 to 10

20 to 30
0.1 to 0.4

Ibis 2
0.1 to 0.5

0.2 to 0.5

30 to 60

50 to 80

0.2 to 0.5
0.2 to 0.5

Claims (1)

Claim: Use of primers a) Urea - formaldehyde condensation products, melamine - formaldehyde condensation products, Phenol-formaldehyde condensation products, Cresol - formaldehyde condensation products, polyacrylic or polymethacrylic acid resins or alkyd resins in water-soluble form; b) water-soluble cellulose derivatives as thickeners; c) where appropriate, inorganic and / or organic pigments, pigment dyes and / or transparent inorganic, organic pigments and / or soluble dyes and / or soluble heavy metal salts; d) optionally water-soluble plasticizers; e) Water as a solvent and diluent, if appropriate f) additional alcohols, glycols and / or glycol ethers or other compatible ones water-miscible organic solvents; g) optionally, in addition, higher polyhydric alcohols as plasticizers; for priming wood-based materials in a manufacturing process for wood imitation decorations by printing.