JPS60116408A - Manufacture of aggregate veneer - Google Patents

Abstract

(57) [Summary] This bulletin contains application data before electronic filing, so abstract data is not recorded.

Description

[Detailed Description of the Invention] [Technical Field] The present invention belongs to the field of so-called veneer assembly technology, in which wood veneers are assembled to artificially reproduce the wood grain.

[Background technology] In the manufacturing method of laminated veneer, traditionally the material veneer is
Tree species with good stainability were selected and used (1). In other words, it is a porous material with relatively low specific gravity.
For example, South Sea wood was used. Wood made of such materials has a relatively large dimensional change rate, and therefore the laminated veneer obtained from this material also has a large dimensional change rate, which poses problems in terms of product quality.

In other words, after the laminated veneer has been pasted and processed, defects such as "scraping" may occur, or dry cracks may occur in the paint film applied to the laminated veneer after installation. It was thought that the cause of such defects was the large dimensional shrinkage rate of the veneer in the tangential direction.

Conventionally, in order to reduce the dimensional shrinkage in the tangential direction (T direction) of the veneer, there has been a method of pasting a backing material such as Japanese paper or non-woven fabric on the back side of the veneer (Japanese Patent Application Laid-open No. 105985/1985).
Furthermore, there is a method of penetrating resin into the inside of the veneer by thermally melting a Honmelt film (Japanese Patent Laid-Open No. 52-145506).
No.), method of impregnating and curing thermosetting resin (urea resin, phenol resin, etc.) liquid (JP-A-54-145202)
)It has been known.

Another known method is to impregnate the veneer with an aqueous solution of polyethylene glycol (2), and stabilize the dimensions through the hygroscopicity and bulk curing of the resin (Wood Utilization Chemistry, Kyofu Publishing Co., Ltd.). Written by Teruo Goto).

However, each of the above methods involves processing the veneer as a product, and has various drawbacks, such as causing color changes in the laminated veneer, and is not fully satisfactory as a processing method. Ta.

[Object of the Invention] An object of the present invention is to provide a method for efficiently modifying a veneer by subjecting the veneer to a dimensional stabilization treatment.

[Disclosure of the invention] The present invention provides a method for modifying a veneer in which a dimensional stabilization treatment is performed at the same time as coloring in the dyeing process of the material veneer, and is characterized by the treatment agent and treatment conditions. .

As the processing agent in this invention, in addition to the acid dye necessary for dyeing, polyethylene glycol and a heat-reactive water-soluble urethane resin are used.

(3) Regarding polyethylene glycol, the molecular weight is preferably about 1,500 to 4,000 in order to increase the effect of dimensional stabilization. In addition, the concentration of the treatment agent is preferably 50 to 60% polyethylene glycol and 10 to 20% heat-reactive urethane resin in terms of solid content, and the dye is used in an amount of less than a few percent at the concentration required for color toning. be done.

The above treatment agent is preferably applied at 150~150% per both sides of the veneer.
200g/♂ is applied, and after application, the veneer is heated and cured at 80° C. for 10 to 20 hours, making sure that the moisture in the veneer does not scatter. Here, heating curing means an operation in which the veneer is heated for a predetermined period of time without scattering the moisture contained in the veneer, and the temperature and time are arbitrary. For heating and curing, it is preferable to heat the veneer by wrapping it in a sheet, or to heat it in a heating tank with a structure that prevents moisture from evaporating.

In this way, each component is impregnated into the inside of the veneer. At this time, the heat-reactive urethane resin self-crosslinks within the veneer, and the O of the polyethylene glycol present within the veneer
Due to the reaction with the H group, (4) it becomes three-dimensional and is thought to play a role in improving the strength of the veneer itself.

In addition, in order to impregnate the veneer with the treatment agent, as described above, the polyethylene glycol and the king of reactive water-soluble polyurethane resins may be simultaneously blended into the dye solution and then impregnated into the veneer. Alternatively, polyethylene glycol and a reactive water-soluble polyurethane resin may be separately blended into a dye solution, and this may be sequentially applied to the veneer. Furthermore, a method in which the material veneer is impregnated with polyethylene glycol, a reactive water-soluble polyurethane resin, and a dye solution in sequence, that is, a method in which each treatment agent is impregnated alone, is also permitted.

For example, the moisture content of the dyed veneer obtained as above is 3
After adjusting to 0 to 50%, in a mold plate with an uneven curved surface,
Press with urethane adhesive (usually 30~
By repeating this operation a predetermined number of times, a laminate (flitch) is obtained, and this flitch is sliced in any direction to obtain a laminated veneer.

(5) Hereinafter, further explanation will be given based on examples.

Example 1 After washing Ius wood with rotary lace to one thickness in hot water, the following treatment was performed.

The processing agent had the following formulation.

Polyethylene glycol 50% (molecular weight: 4000) Water-soluble urethane resin 20% Acid dye (Suminol Miling Brown
3G) A treatment solution containing 0.8% water and 29.2% or more was applied to both sides of the veneer at a rate of 200 g/d on both sides. Wrap 30 coated veneers in a polyethylene sheet to prevent moisture from scattering, and
It was placed in a dryer at ℃ and cured for 20 hours. The moisture content of the obtained veneers was adjusted to 30 to 50%, and then 100 g/po of urethane adhesive was applied, and 50 veneers were laminated and pressed in a mold having an uneven curved surface. This operation was repeated five times at 30 minute intervals to obtain a flitch.

(6) Make the above flitch 0゜5 x m with the grains showing.
A laminated veneer was obtained by slicing it thickly.

The dimensional shrinkage rate (dimensional change rate per 1% moisture content) of the laminated veneer obtained through the same process by treating the laminated veneer obtained above with only dye using the conventional method, dyeing property (uniformity) The color difference between the surface and interior of the plate) and the tensile strength in the T direction were evaluated. The results were as shown in Table 1.

As shown in Table 1, the dyeability is almost unchanged compared to the conventional method.
Moreover, the appearance of the obtained laminated veneer was not much different from that of the conventional method, and significant improvements in physical properties were observed as shown in Table 1. A remarkable improvement effect was also observed in secondary processability and handling properties.

Example 2 After washing Ius wood with rotary lace to a thickness of 1 ++n in hot water, it was decolorized using hydrogen peroxide [H202], and after the decolorization was completed, it was washed in hot water to obtain a material veneer, (7) The following processing was performed. That is, the 50% solution of the water-soluble urethane resin used in Example 1, the 60% solution of polyethylene glycol, and the acid dye (Suminol Mi
A 0.8% solution of Ling Brown 3G) was prepared, and 100 g/I was applied to both sides of each veneer in the above order. Example 1 was applied to the veneer after the coating was completed.
A dyed veneer was obtained by heating and curing in the same manner as above. Next, this was processed into a laminated veneer in the same manner as in Example 1.

As in Example 1, a laminated veneer with significantly improved dimensional change rate and tensile strength was obtained.

[Effects of the Invention] When dyeing a material veneer, the present invention includes a step of impregnating the material veneer with a dye solution of a predetermined concentration, polyethylene glycol and a reactive water-soluble polyurethane resin, and then heating and curing it. It has been found that the effect of producing a laminated veneer with a small dimensional change rate and high tensile strength is achieved because it is characterized by a high tensile strength.

As a result, even in actual practical use, the ``graininess'' (8) has been improved and the effect of reducing dry cracks has been achieved.

Patent applicant: Matsushita Electric Works Co., Ltd. Representative Patent Attorney Toshimaru Takemoto (and 2 others) (9) -ri0

Claims (1)

[Claims] (1) In the manufacturing method of laminated veneer, which includes the process of dyeing the material veneer, applying an adhesive and pressing it between molds to obtain flitches, and slicing the material veneer, A method for manufacturing a laminated veneer, which includes the steps of impregnating a raw material veneer with a dye solution of a predetermined concentration and a reactive water-soluble polyurethane resin during dyeing, and then curing with heating.