RU2015887C1 - Method for production of wallboards with finished surface - Google Patents

Abstract

FIELD: wood-working. SUBSTANCE: method includes preparation of aminoformaldehyde impregnating resin with reduced content of melamine in presence of modifying additions. Resin is prepared in medium with variable acidity. Board are molded at temperature reduced by 20-30 C. Used as modifying additives are monobasic and/or polyatomic alcohols (e.g., butanol-1, ethyleneglycol). EFFECT: higher efficiency. 4 cl, 1 tbl

Description

 The invention relates to the woodworking industry and can be used in the manufacture of chipboards in the manufacture of finished boards.

 A known method of producing wood boards with a finished surface, including the preparation of aminoformaldehyde impregnating resin, impregnating resin with a texture paper to obtain a sheet of decorative material, laying it on the surface to be trimmed, followed by pressing, using urea-urea-formaldehyde resin MMPC as an urea condensation product and melamine with formaldehyde, obtained in a slightly alkaline environment in the presence of urotropine.

 A disadvantage of the known solution is the increased consumption of melamine in the manufacture of an impregnating resin, insufficient stability of the resin, insufficient durability of the coatings, a significant pressing temperature in the manufacture of coated panels.

The problem solved by this invention is the manufacture of an impregnating resin with a low content of melamine, increasing the stability of the resin, improving its quality characteristics and, as a result, the characteristics of the outer layer of finished wood boards: the crack resistance of coatings based on film materials increases due to an increase in the elasticity of cured polymers, the durability of the coatings increases due to the reduction of shrink stress, the exclusion of surface-active substances from the composition of the impregnating solution in (SAW), because this function is performed by modifying agent administered in the manufacture of the impregnating resin, and finally, the possibility of reducing the pressing temperature trim wallboard 20-30 ^{° C} as compared to the traditional one.

The task is ensured by the fact that in the method of producing plates with a finished surface, including the preparation of an aminoformaldehyde impregnating resin, impregnating a resin of a texture paper to obtain a sheet material, laying it on a surface to be trimmed, followed by pressing, an aminoformaldehyde resin is obtained at a molar ratio of urea: formaldehyde: melamine, equal to 1.0: 1.5 - 1.8: 0.05 - 0.2, in the presence of modifying additives in an amount of 0.01 - 0.035 mol, while the preparation of the impregnating resin produced out in a medium with variable acidity, and pressing is carried out the temperature is lowered to 20-30 ^{° C,} and in that the modifying agent is used as mono- and / or polyhydric alcohols and in that the modifying agent is used as butanol 1, as well as the fact that ethylene glycol is used as a modifying additive.

In the technical and patent literature, no sources of information have been found that describe a technical solution similar to the claimed one, therefore, the proposed solution meets the criteria of the invention of "novelty." No technical solutions have been found in the literature that use the aminoformaldehyde resin obtained at a molar ratio of urea: formaldehyde: melamine equal to 1.0: 1.5 - 1.8: 0.05 - 0.2 in the presence of modifying additives in an amount 0,01-0,035 mol, wherein the preparation of the impregnating resin is carried out in a medium with variable acidity, trim and molding wood boards is carried out with decreasing temperature at 20-30 ^C. Therefore, the proposed solution has the inventive level.

The technological process for the production of an impregnating aminoformaldehyde resin (for example, SP-50) consists of the following stages. A 37% formalin solution was charged into the reflux reactor, and a pH of 8.0-8.4 was adjusted with a 33% sodium hydroxide solution. Then urea is charged. Include heating the reactor and heated to 18-20 ° ^C. By the reaction exotherm temperature of the mixture rises to 55-60 ^C. At the temperature not above 60 ^{° C} the mixture was incubated for 30 min. After the exposure is completed, a modifying additive, for example, butanol, is introduced into the reactor, after which the pH must be at least 7. Melamine is charged into the reactor with the vacuum pump turned on. The reaction temperature is maintained at 60-65 ^{° C} for 30 min. After closure shutter pH of the reaction mixture was adjusted to 5.5-6 (ammonium chloride) include heating the reactor (raising the temperature at 3-4 ° ^C). Due to the exotherm the reaction temperature was raised to 80-85 ° ^C. After reaching a temperature of 80-85 ^{° C} every 15-20 min control miscibility with water, which when the 1: 1000 control is performed every 5 min. Upon reaching the miscibility with water of 1: 1.5-2 mixture was cooled to 60-65 ^{° C} and then through the hatch while the vacuum pump was charged with urea. After that, the mixture is cooled to 30 ^about With using vacuum recirculation. In this case, urea in the second stage is loaded in an amount of 8-25% of its total amount.

 The table shows the specific ratios of the starting components in moles for the manufacture of an impregnating amino formaldehyde resin.

Similarly, with a reduced amount of melamine, in comparison with the known solutions, the AFBP resin is made, which is also successfully used for the manufacture of finished wood boards. At the same time, finished wood boards can be obtained both when laying sheet decorative material on a particleboard carpet, followed by pressing and obtaining a finished plate in one pressing cycle, and when laying sheet decorative material on a finished particleboard calibrated, for example, 16 mm thick, group P-1 , P-2 according to GOST 10632-89 and then also produce hot pressing at a reduced temperature of 20-30 ^{° C,} followed by cooling.

In the first case, i.e. in case of particle boards trimmed in one pressing cycle (simultaneously with the plate manufacturer), the compacting pressure is 1.0-2.0 MPa, the pressing temperature is 160 ± ²⁰ ° C, and the duration of the pressing cycle corresponds to the pressing chipboards. In the second case, when facing finished wood chipboards, the assembly of a package for single-floor pressing is performed by laying sheet decorative material obtained by impregnating resin with texture paper and then drying the resulting decorative decorative material on a pre-calibrated particle board. The package is loaded into the press. Matte press pads and compensating asbestos mats are permanently fixed in the press. Baling (Veneering) is conducted at a temperature of 150-180 ^{° C,} pressure 1.8-2.0 MPa and overmolding duration 35-90 seconds.

Assembling a package for multi-storey lamination (pressing in a multi-storey press) is as follows. A compensating asbestos mat is laid on the transport pallet, then a press gasket, then a sheet of decorative material, then a particle board (or a particle board for multi-level pressing of particle boards with their simultaneous decoration), then a decorative sheet material (to obtain plates finished on both sides), then a press pad and an asbestos mat on top of the bag. Next, the package is loaded into the press from movable whatnots and pressed. Compression mode ready for wrapping plates in the press-rise as follows: the maximum pressure - 1.8-2.0 MPa, initial temperature of 60-110 ^{° C,} maximum temperature 160 ± 10 ^{° C,} the cooling temperature is 80-110 ° ^C. The duration of lamination: the total cycle is 7 minutes, the duration at maximum temperature is 1 - 2.5 minutes.

 The use of the claimed invention allows to obtain impregnating resins with increased stability, the shelf life of such resins is at least 20 days (increases by several times compared with the prototype), which is due to the content of a chemically active modifier in the resin, while excluding from the composition of the impregnating solution during paper impregnation Surfactant. The use of modifying additives helps to increase the elasticity of cured polymers, which increases the crack resistance of coatings based on such film materials in comparison with the prototype, as well as the durability of the coatings due to a decrease in shrink stresses. In addition, the manufacture of impregnating resins requires significantly lower melamine consumption compared to the prototype. Finally, pressing can be carried out at a reduced temperature.

Claims (4)

1. METHOD FOR PRODUCING WOODBOARDS WITH FINISHED SURFACE, including the preparation of an amine formaldehyde impregnating resin, the impregnation of a resin with a texture paper to produce a sheet of finishing material, laying it on the surface to be finished, followed by pressing, characterized in that the amine formaldehyde resin is obtained by molar carbide: 1.0: 1.5 - 1.8: 0.05 - 0.2 in the presence of modifying additives in an amount of 0.01 - 0.035 mol, while the preparation of the impregnating resin is carried out in medium e with variable acidity, and pressing is carried out with a decrease in temperature by 20 - 30 ^o C.  2. The method according to claim 1, characterized in that mono-and / or polyhydric alcohols are used as a modifying additive.  3. The method according to claim 2, characterized in that butanol-1 is used as a modifying additive.  4. The method according to claim 2, characterized in that ethylene glycol is used as a modifying additive.

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