JPS5912463B2 - Manufacturing method of decorative veneer board - Google Patents

Description

Detailed Description of the Invention 25 The present invention involves thinly cutting a natural tree to obtain a real root, cutting it to a fixed size, impregnating it with a water-soluble thermosetting resin or a mixture of a thermoplastic resin and a thermosetting resin, and drying it. After applying a hydrophilic adhesive on the impregnated paper (hereinafter referred to as lining impregnated paper), the roots were lined up without any gaps and temporarily fixed, and the roots were lightly pressed with a 30mm hot press and lined with the lining impregnated paper. Obtain a sheet of the lining seed roots (hereinafter referred to as lining seed root), overlay paper (hereinafter referred to as overlay paper) impregnated and dried with a transparent thermosetting resin on the upper surface of the lining seed root, and thermosetting resin on the back side. Core paper (hereinafter referred to as core paper) that has been impregnated and dried for 35 minutes is layered, and then a synthetic resin film or metal foil is layered in contact with the overlay paper and heat-pressed, and after decompression, the synthetic resin film is Alternatively, the present invention relates to a method for manufacturing a decorative veneer board using a natural wood veneer obtained by peeling off a metal foil.

In known melamine decorative boards, printed paper imitating the grain of natural wood is used for surface decoration, but the surface is flat and lacks a three-dimensional appearance, and in order to give it a three-dimensional appearance, the wood grain is embossed. Attempts have been made to express the unevenness of wood, but this is far from the natural grain of natural wood.

Furthermore, attempts have been made to manufacture melamine decorative laminates using natural wood veneers, but the molding of melamine decorative laminates took place in the 40s.
Because the process is carried out under high pressure of more than kg/d, the veneer used is compressed so strongly that the unevenness on the surface disappears, and there is no difference in appearance from using printing paper, which is an advantage of using expensive natural veneer. Moreover, the veneer used tends to crack easily, which is a serious problem in practical use. An object of the present invention is to provide a method for manufacturing a veneer decorative board that utilizes a veneer cut from natural wood, takes advantage of the natural grain of the veneer, and does not cause cracks in the veneer. The present invention involves cutting natural wood veneers to a thickness of 0.5m71t or less, cutting them to a specified size, and then temporarily fixing the veneers by arranging them on a backing impregnated paper using a hydrophilic adhesive without any gaps. do.

Temporary fixing is performed by lining up the projecting plates without any gaps and pressing them lightly. Next, the veneer temporarily fixed with the impregnated backing paper is hot pressed using a hot press to tightly fix the veneer to the impregnated backing paper to obtain a backing veneer. At this time, hot pressing is carried out under conditions that prevent the curing of the resin and adhesive in the backing impregnated paper as much as possible, and is determined by the properties of the resin used, impregnation, and drying conditions, but at a temperature of 80 to 130. °C, pressure 1-5 kg
/CTLl time ranges from 5 to 300 seconds. Next, layer one overlay paper on the top surface of the backing veneer, one core paper on the back side, and then add a layer of 10 to 200μ thick paper in contact with the overlay paper.
This is a method for producing a veneer decorative board that reveals the grain and conduit recesses of natural wood veneer, which is characterized by stacking synthetic resin films or metal foils and hot-pressing them, and then peeling off the synthetic resin films or metal foils. In the present invention, the use of a backing impregnated paper impregnated with a water-soluble thermosetting resin or a mixture of a water-soluble thermoplastic resin and a thermosetting resin is used between the veneers in the subsequent heat-pressing process. This is to prevent the veneer from shrinking and elongating and breaking due to changes in humidity, since the seams do not shift and the lining impregnated paper is inserted between the veneer and the core paper.

That is, since the impregnated backing paper is made by impregnating it with a water-soluble resin, the paper absorbs the impregnation and is dried and fixed in a state where the fibers, which have particularly large dimensional expansion and contraction, are elongated to the maximum extent in the orthogonal direction. Therefore, in the next step, a hydrophilic adhesive was applied to the surface of the impregnated backing paper, a wet veneer with a moisture content above the fiber saturation point was layered, and even if it was temporarily fixed, the dimensions of the impregnated backing paper remained stable with almost no change. It will be done. In the subsequent third step of heat-pressing the veneer that has been temporarily fixed to tightly fix it to the impregnated backing paper, the veneer that has been temporarily fixed to the impregnated backing paper is inserted between the hot plates and left for about 30 minutes until it is hot-pressed. For ~60 seconds, the moisture in the veneer, adhesive, and backing impregnated paper keep the dimensions of the veneer and impregnated paper stable.

Further, during thermocompression bonding, the veneer and the impregnated backing paper shrink at the same time to the same extent, so that misalignment of the seam between the veneers can be prevented. When backing impregnated paper impregnated with a water-insoluble resin is used, the dimensions of the impregnated paper will be in a state of shrinkage compared to the original paper dimensions, contrary to the case where the paper is impregnated with a water-soluble resin.

When a hydrophilic adhesive is applied to the surface of this impregnated backing paper and the veneers are then temporarily attached, the impregnated backing paper absorbs the moisture in the adhesive and gradually stretches, creating a gap at the seam of the temporarily attached veneers. let In addition, the adhesive's viscosity increases rapidly as moisture is absorbed by the impregnated paper, which sometimes causes various problems in terms of work, such as the adhesive's ability to temporarily hold the veneer together. Also,
When the veneer is heat-pressed in direct contact with the core paper without using an impregnated backing paper, the veneer may elongate or contract due to the difference in dimensional change rate due to changes in humidity between the veneer and the core paper. However, by interposing the backing paper between the veneer and the core paper, the elongation or contraction strain that occurs in the veneer is absorbed by the impregnated backing paper, and the veneer does not crack. prevent it from occurring.

Furthermore, in the present invention, a synthetic resin film with a thickness of 10 to 200 μm or a metal foil with a thickness of 10 to 200 μm is laminated in contact with an overlay paper, and the obtained product is further hot-pressed by a conventional method with or without a cushion material. The surface of the decorative veneer board shows a beautiful finish with the grain of the natural wood veneer and conduit recesses intact.

Heat and pressure conditions are temperature 130-150℃, pressure 30-80kg.
/CTIl time of 30 to 60 minutes is appropriate. By using the above-mentioned synthetic resin film or metal foil, the synthetic resin film or metal foil can be easily deformed during hot pressing, and the overlay paper in contact with it can be formed along the grain of the surface of the backing veneer and the conduit recess. By pressing and hardening, and then peeling off the synthetic resin film or metal foil, a veneer decorative board is obtained which shows the wood grain and conduit recesses of the veneer as they are, and has a natural and beautiful appearance rich in three-dimensional appearance. As described above, the decorative veneer manufactured by the method of the present invention has excellent physical and chemical performance without causing cracks on the surface of the veneer, and the wood grain and conduit recesses of natural veneer are directly displayed on the surface. It is useful as furniture, construction materials, etc.
In the present invention, the veneer used in the first step has a thickness of 0.5
mm or less and above the wood fiber saturation point, that is, the water content is 25% or more.

The paper used for the backing impregnated paper in the second step has a thickness of 2~
The thermoplastic resin used is acrylic resin, and the thermosetting resins are phenol resin, melamine resin, and acetoguanamine resin, and the resins are dissolved and used for impregnation and drying.

The hydrophilic adhesives used to temporarily secure and adhere the veneer to the impregnated backing paper are hydrophilic adhesives such as urethane resins, epoxy resins, melamine resins, phenolic resins, urea resins, and the like. In the case of hydrophobic adhesives, it is difficult to temporarily fix the adhesive to the veneer and to apply it to the surface of the impregnated paper. The paper used for the overlay paper in the fourth step has a thickness of 1 to 4
These are ordinary manila hemp paper and alpha cellulose paper for impregnation, and the resins include melamine resin, benzoguanamine resin, acetoguanamine resin, diallyl phthalate resin, etc. One core paper has a thickness of 8 to 10 mil.
Ordinary kraft paper for impregnation is used, and the resin used is phenolic resin. The synthetic resin film in the fifth step is a polypropylene, nylon, tetron or polycarbonate film with a thickness of 10 to 200 μm, and the metal foil is an aluminum foil with a thickness of 10 to 200 μm, and the metal foil is backed with paper on the back side. Foil is used as well.

The veneer decorative board manufactured by the method of the present invention is JISK
-6902 test results are JISK-6903LD-
It has performance that passes the general decorative board standard of GP-1.2.

This will be explained in detail below using examples.

However, the present invention is not limited to the examples. The parts shown in the examples are parts by weight. Example 1 0.25m7 with moisture content adjusted to 30%! L thickness zelkova veneer veneer width 20CT! L1 length 190? cut into
A 5 mils thick paper is impregnated with a resin liquid dissolved in a phenol resin, and a hydrophilic urethane resin adhesive is uniformly applied to the entire surface of the dried impregnated paper at a rate of 100 g/w, then lined up without any gaps and temporarily fixed.

Temporary fixing is done by lightly pressing the veneer against a sticky adhesive. Next, the zelkova veneer temporarily fixed to the impregnated backing paper is hot-pressed in a pot press for 25 seconds at a temperature of 120 to 125°C and a pressure of 4k9/CTil to tightly fix the zelkova veneer to the impregnated backing paper, forming a sheet-like backing veneer. I got it. After that, 10 mils thick kraft paper impregnated with phenol resin and dried, 5 pieces of core paper, the above-mentioned backing veneer and 4 ml thick.
An overlay paper impregnated with melamine resin and dried is successively superimposed on mils α-cellulose paper. Furthermore, a commercially available polyethylene terephthalate film with a thickness of 50 μm was superimposed on a piece of overlay paper, and after being hot-pressed using a hot press at a temperature of 150°C and a pressure of 80 kg/CTil for 30 minutes using cushion boards on the top and bottom, it was cooled under pressure to room temperature. After releasing the pressure, peel off the polyethylene terephthalate film. The obtained decorative board had a thickness of 1.13 m71 L, and the grain of natural wood and concave portions of the conduit portion were exposed on the surface, and it had an elegant taste peculiar to a veneer. This one is JISK-69
03, passed the LD-GP-1.2 standard. Example
2 Cut a 0.5U1-thick veneer veneer with a moisture content of 30% or more into a width of 20CfL and a length of 190cTn, and impregnate the paper with a resin solution of melamine resin dissolved in water to a 2mils thickness. 120 g/m” of hydrophilic epoxy resin adhesive on dry impregnated paper impregnated with 130% and volatile content 4%.
After applying, line them up without any gaps and temporarily fix them.

Temporary fixing is performed by lightly pressing the veneer using the adhesive properties of the adhesive applied to the impregnated paper. Next, the shioji veneer temporarily fixed to the above-mentioned backing impregnated paper was heated to 100 to 110℃.
The veneer was hot-pressed at a pressure of 3 kg/CTII for 30 seconds to closely fix the veneer to the impregnated backing paper to obtain a sheet-like backing veneer. After that, 5 core sheets of 10mils thick kraft paper impregnated with phenolic resin and dried, a veneer for the backing of the paperboard,
A sheet of overlay paper impregnated with benzoguanamine resin and dried was layered one after another on α-cellulose paper with a thickness of 4 mils, a polypropylene film with a thickness of 20μ was layered on top of the overlay sheet, and cushion paper was used as the bottom layer at a temperature of 13.
After hot pressing at 0° C. and a pressure of 80 kg/d for 30 minutes, the polypropylene film was peeled off after being cooled under pressure to room temperature and depressurized. The obtained decorative board had a thickness of 1.2311 mm, and had the unique elegance of a veneer with natural wood grain and conduit recesses on the surface. This product passed JISK-6903 and LD-GP-1.2.
Example 3 A 0.311 thick cedar veneer veneer whose moisture content was adjusted to 35% was cut into pieces of 20 cm wide and 190 crfL long, and this was coated with a resin solution prepared by dissolving acetoguanamine resin in water on paper with a thickness of 3 miIs. 95% hydrophilic melamine resin adhesive on dried impregnated paper with an impregnation rate of 150% and a volatile content of 4%.
After applying g/a, line them up without any gaps and temporarily fix them.

Claims (1)

[Claims] 1. The first step of cutting natural wood to a thickness of 0.5 mm or less and cutting the wood veneer with a thickness above the wood fiber saturation point to a specified size. Water-soluble thermosetting resin or water-soluble thermoplastic resin and thermosetting resin are used for backing. After applying a hydrophilic adhesive to the surface of the impregnated paper that has been impregnated with a resin mixture and dried, the veneers are lined up without any gaps and temporarily fixed.The second step is to heat-press the veneers that have been temporarily fixed to the impregnated paper. The third step is to obtain a sheet in which the backing veneer is closely fixed to the impregnated backing paper.The upper surface of the backing veneer is impregnated with a transparent thermosetting resin, and the dried overlay paper and the back side are coated with a moderate amount of thermosetting resin. The fourth step is to layer several sheets of impregnated and dried core paper, and the fifth step is to layer a synthetic resin film or metal foil with a thickness of 10 to 200 μm in contact with the overlay paper. A method for manufacturing a veneer decorative board, comprising a sixth step of obtaining a decorative board showing the wood grain and conduit recesses, and a seventh step of peeling off the synthetic resin film or metal foil after depressurization.