KR100543652B1 - Dimensional stability method of wood product - Google Patents

Abstract

The present invention relates to a processing and processing method of wood processed products, including a dimensional stabilization method for suppressing the expansion and contraction caused by the absorption and dehumidification of the moisture of the wood as a natural material.

In the present invention, by using an acid anhydride as a wood dimensional stabilizer, the existing treatment method is minimized by minimizing the dimensional deformation of the product by inhibiting the expansion and contraction of the wood produced when the wood-based material is exposed to moisture or heat. Overcoming the fatal shortcomings of lacking durability, and by using thermosetting resins as wood processing agents in addition to the dimensional stabilizer and controlling the conditions such as time and temperature of the treatment process, the physical properties and aesthetics of the processed product can be improved.

Wood, dimensional stability, acetic anhydride, succinic anhydride, maleic anhydride, phthalic anhydride, polyglycerol methacrylate (PGMA), polypropyleneglycerol (PPGMA) methacylate)

Description

Dimensional stability method of wood product

1 is a schematic diagram showing the coupling mechanism of the hydroxyl group present in the acid anhydride and wood according to the present invention,

Figure 2 is a process chart of the processed wood according to an embodiment of the present invention,

Figure 3 is a processing step of the wood processing product according to another embodiment of the present invention,

4a and 4b are SEM (scanning electron microscope) photographs of untreated wood cell walls and wood cell walls treated with PPGMA,

Figure 5 is a graph showing the dimensional stability results through the durability test of the processed Walnut (Walnut) species in accordance with the present invention (AA in the following figure shows an acetic anhydride, UT untreated group),

6 is a graph showing the results of the dimensional stability through the durability test of oak (Oak) species treated according to the present invention,

Figure 7 is a graph showing the dimensional stability results through the durability test of the cherry (Cherry) species treated according to the present invention,

8 is a graph showing the results of the dimensional stability through the durability test of the beech (Beech) species processed according to the present invention,

9 is a graph showing the results of the dimensional stability through the durability test of the maple (Maple) species processed according to the present invention,

The present invention relates to a dimensional stabilization processing method of wood processed products, and more particularly, once the wood treated once ensures durability and is not dissolved or eluted again in water, which can secure the dimensional stability of wood by moisture and heat. A dimension stabilization treatment method.

In the case of processed products using wood, even if the wood is cut and processed to a certain size, if the humidity conditions are different, the moisture and dehumidification of the moisture of the natural wood will expand and contract the wood, causing the length and volume to change. However, these changes have a negative impact on quality in the processing of sophisticated wood products.

Moreover, wood processing materials other than solid wood, such as Particle Board (PB), Medium Density Fiberboard (MDF), High Density Fiberboard (HDF), High Pressure Laminate (HPL), Low Pressure Laminate (LPL), OSB (Oriented) When using materials such as strand board, veneer, plywood, corrugated board, paper, etc., or when using heterogeneous materials such as PVC, sponge, and plastic other than wood, When exposed to overheating, unstable and nonuniform phenomena occur due to different dimensional behavior, and when the degree is severe, it may be bent or squashed up, down, left and right.

To date, various dimensional stabilization methods have been tried to suppress or eliminate dimensional instability due to shrinkage and expansion of wood. The most widely used method is to use a wooden cell wall bulking effect by impregnating a polyethylene glycol compound into the wood as a representative treatment method.

Another method is the WPC (Wood Polymer Composite) method for filling the lumen of wood cells to increase the strength of wood while suppressing dimensional instability.

However, the limitations of these treatment methods have a major drawback that they do not secure the durability of wood dimensional stability.

In more detail, a method for securing wood dimension stability using a polyethylene glycol compound may have a volume effect of swelling the wood cell wall, but this is only a temporary phenomenon. That is, the hydrophilic compound of the polyethylene glycol system may temporarily have a volume effect of swelling the wood cell wall, but when the treated wood specimen is immersed in hot or cold water again, the hydrophilic compound of the polyethylene glycol system is hot water or By dissolving and eluting in cold water, the wood cell walls are returned to their original state and the dimensional stability of the wood is instability.

Another wood dimensional stabilization method, the WPC process, also poses problems with durability. That is, even if the lumen in the wood cells is filled with other materials, when the treated specimen is immersed in hot or cold water, it gradually dissolves and dissolves in hot or cold water, and eventually has a defect of returning the wood to its original state.

These dimensional stabilization treatments may seem to secure the dimensional stability of wood temporarily due to moisture and heat, but the durability test shows that the effect is negligible.

The present invention is to solve the dimensional instability that may appear during the processing of wood composite products, it is possible to minimize the dimensional deformation by inhibiting the expansion and contraction of wood when wood-based products are exposed to moisture or heat Its purpose is to provide a method for dimensional stabilization of woodworking articles.

Another object of the present invention is to provide a processing method of wood processed products that can improve the overall physical properties and aesthetics of wood processed products with dimensional stabilization.

In order to achieve the above object, the present invention in the processing of wood-based processed products including wood for the purpose of improving the physical properties including wood size stabilization, acid anhydride and its derivatives, PGMA (Polyglycerol methacrylate), PPGMA (Polypropyleneglycerol methacrylate) It provides a method for dimensional stabilization of wood processed products, characterized in that the wood processing of wood products using a wood processing agent comprising at least one wood dimensional stabilizer selected from.

Wood dimensional stabilizer in the present invention serves to acetylate and esterify the hydroxyl groups present in woods. The hydroxyl groups present in acetylated and esterified woods by wood dimensional stabilizers are essentially blocked from binding to water molecules, resulting from the expansion and contraction of wood when wood products are exposed to moisture or heat. It is possible to minimize the dimensional deformation.

The acid anhydride used as the wood dimensional stabilizer in the present invention is selected from acetic anhydride, maleic anhydride, phthalic anhydride, succinic anhydride. The use concentration and the combination of the wood dimensional stabilizer mentioned above can be controlled in various ways, preferably acetic anhydride and succinic anhydride and PGMA or PPGMA in combination.

In the present invention, the wood processing agent including the wood dimensional stabilizer is preferably treated to the wood processing product by impregnation, and can be replaced by various similar processes such as humidification, suction, spray or injection in addition to the impregnation process. .

The processing process of wood processed products according to the present invention includes reaction, depressurization, hardening and drying steps, by varying the processing conditions of each step can induce a variety of surface color and a variety of physical properties, each Some of the processes may be added, omitted or modified.

For example, when the reaction time is 3 hours or less and the reaction temperature is 90 ° C. or less, it does not significantly affect the color change of the wood surface, but when the reaction time is 3 hours or more and the reaction temperature is 90 ° C. or more, the color change of the wood surface is affected. Get mad. The reaction time can be selected within the range of 15 minutes to 72 hours, the reaction temperature is 50 ℃ to 200 ℃, the drying time is 30 seconds to 72 hours, the curing time is 30 seconds to 72 hours, the decompression conditions The larger the value, the shorter the decompression time, the better the treatment effect than the undecompressed one, and the reaction is carried out until the acid anhydride penetrates into the wood and stops foaming.

Thermosetting resin selected from epoxy resin, phenol resin, acrylic resin, melamine resin, polyurethane resin, unsaturated polyester resin, diallyl phthalate resin in addition to the dimensional stabilizer as a wood processing agent in the present invention; Filler selected from calcium carbonate, talc, titanium oxide, silica, glass powder, and silicon dioxide; Flame retardants selected from phosphate esters, halogenated hydrocarbons, antimony oxides, aluminum hydroxides, phosphate compounds, and dicyandiamides; Benzoyl peroxide, acetyl peroxide, dilauryl peroxide, di-tert-butyl peroxide, cumyl hydroperoxide, Peroxide initiators such as hydrogen peroxide and potassium persulfate, azo compound initiators, pyrolysis initiators of silver alkyls initiators, oxidation of persulfates, hydroperoxides, reduction initiators, X-rays, alpha particles, An initiator selected from initiators using gamma rays or the like can be further used. In addition, a catalyst selected from potassium acetate, sodium acetate, urea and ammonium sulfate may be further used for acetylation.

The object of the processing method according to the present invention is a wood processed product including wood, wherein the wood includes all wood materials such as solid wood, plywood, veneer, PB, MDF, HDF, HPL, LPL, OSB, corrugated paper and paper. . In the present invention, the wood processed products to be processed are not only various interior materials, exterior materials and decorative materials including wood floor, ondol floor, and reinforced floor, but also composite processing of synthetic materials other than natural materials such as plastic, PVC, sponge, styrofoam, etc. on wood. Includes all one product.

The present invention has solved the important problem of the insufficiency of various conventional treatment methods attempted to solve the dimensional instability of wood due to moisture and heat. Once treated, semi-permanent swelling and shrinkage of wood due to moisture and heat Can be suppressed.

Hereinafter, the present invention will be described in detail with reference to the accompanying drawings and examples.

Figure 1 is a schematic diagram showing the coupling mechanism of the acid anhydride and the hydroxyl group present in the timber according to the present invention, showing the principle of wood size stabilization according to the present invention. Specifically, wood dimensional stabilization method using a dimensional stabilizer such as an acid anhydride according to the present invention is to acetylate and esterify the hydroxyl group present in the wood, if such a reaction is made, even if the wood is exposed to water again the hydroxyl group in the wood Since is substituted, the bond with the water molecule is fundamentally blocked. In addition, the hydroxyl group which is not substituted in the wood can be more reliably blocked from combining with water molecules by combining with PGMA and PPGMA of Formula 1, and this reaction principle ensures durability, which is the biggest drawback of the conventional dimensional stabilization method. Will be. The mechanism by which each acid anhydride is esterified with the hydroxyl group of wood is shown in Scheme 1.

2 is a process chart of the processed wood according to an embodiment of the present invention, including cutting, pretreatment, filtration, drying, reaction, post-treatment, drying, impregnation, decompression, hardening and drying process. Referring to the treatment process of Figure 2, the wood sample is first cut to a certain size and then subjected to pretreatment, filtered and dried in running water. The dried specimen is reacted by immersing it in an acid anhydride solution. After the reaction, the specimen is dried and dried. The treated specimen is impregnated with PGMA solution or PPGMA solution, and then subjected to reduced pressure to change to actual pressure when bubbles of the solution no longer occur, and then cured and dried.

3 is a process chart of a wood processed product according to another embodiment of the present invention, and includes drying, reaction, post-treatment, drying, impregnation, depressurization, curing, and drying. In detail, the treatment process of Figure 3, first to dry the wood specimens to dry condition and then immersed in the acid anhydride solution to react, and after the reaction is carried out to dry after the post-treatment. The specimen treated in this process is impregnated with PGMA solution or PPGMA solution, and then subjected to reduced pressure to change to actual pressure when bubbles of the solution no longer occur, and then hardened and dried.

In the following examples, oak, beech, walnut, cherry, maple, and birch were selected as the wood species of the test specimen, and acetic anhydride, succinic anhydride, phthalic anhydride, and maleic anhydride were used as dimension stabilizers. The effect was further enhanced by using PGMA and PPGMA.

Example 1 Treatment Process Using Maleic Anhydride, Succinic Anhydride, Phthalic Anhydride and Xylene

After the wood specimens were cut to 80 × 80 × 5 mm in size according to the process of FIG. 2, pretreated to react for 8 hours with ethanol / toluene (1/2 v / v), followed by filtration and drying in running water ( 105 ° C., 12 h). The dried specimen was immersed in maleic anhydride / xylene (1/9 v / v) solution, phthalic anhydride / xylene (1/9 v / v) solution, and succinic anhydride / xylene (1/9 v / v) solution. It reacted (105 degreeC, 12h). At this time, the specimens were treated alone in one of the three solutions, and each of the three solutions was carried out individually. After the reaction was completed, a post treatment was performed for 8 hours with ethanol / toluene (1/2 v / v), followed by drying (105 ° C., 12 h). The specimen treated in this process was impregnated with PGMA solution or PPGMA solution, and then subjected to reduced pressure to change to actual pressure for one hour at the time when the bubble no longer occurred, and then cured and dried (105 ° C., 12 h). .

Example 2 Treatment Process Using Maleic Anhydride, Succinic Anhydride, Phthalic Anhydride and Acetone

3, after drying the wood specimens (105 ℃, 12h) to dry condition, maleic anhydride / acetone (10 g / 100 mL) solution, phthalic anhydride / acetone (10 g / 100 mL) solution, The specimen was immersed in a succinic anhydride / acetone (10 g / 100 mL) solution and then left at room temperature until the acetone was completely volatilized. At this time, the specimens were treated alone in one of the three solutions, and each of the three solutions was carried out individually. After completion of the reaction, the reaction was washed with acetone again, and then dried (105 ° C., 12 h). The specimen treated in this process was impregnated with PGMA solution or PPGMA solution, and then subjected to reduced pressure to change to actual pressure for one hour at the time when the bubble no longer occurred, and then cured and dried (105 ° C., 12 h). .

Example 3 Treatment Process Using Acetic Anhydride

3, the wooden specimen was dried (105 ° C., 12 h) in a dry state, immersed in an acetic anhydride solution, and then depressurized to change to actual pressure for an hour when bubbles were no longer generated. After filtration, ethanol was subjected to post-treatment, curing and drying (105 ° C., 12 h). The specimen treated in this process was impregnated with PGMA solution or PPGMA solution, and then subjected to reduced pressure to change to actual pressure for one hour at the time when the bubble no longer occurred, and then cured and dried (105 ° C., 12 h). .

5 to 9 are walnut trees (Fig. 5), oak (Fig. 6), cherry (Fig. 7), beech (Fig. 8), maple (Fig. 9) species treated with acetic anhydride according to the present invention, respectively. It is a graph showing the results of the dimensional stability through the durability test.

5 to 9, it can be seen that the dimensional strain width of the treated species according to the present invention is within 4 mm, the dimensional stability is superior to the untreated group having a dimensional strain width of 6 mm or more. Also, when acetic anhydride and PPGMA were mixed, the dimensional stability was more excellent. In addition, dimensional stability was maintained despite repeated tests.

When processed by the dimensional stabilizer and the dimensional stabilization method of the present invention, the dimensional instability that may appear during processing wood composite products to eliminate the expansion and contraction of the wood generated when exposed to moisture or heat products made of wood By suppressing it, the dimensional deformation can be minimized, and the limitation of the existing treatment methods, namely, the long-term exposure to moisture, which is a critical disadvantage of insufficient durability due to dissolution, dissolution by water, and return to its original state It is possible to semi-permanently suppress the swelling and shrinkage of wood as a single treatment by solving the problem.

In this way, wood dimensional stabilization that suppresses swelling and shrinkage of wood due to moisture and heat is possible, thereby processing wood-related products such as solid wood, plywood, veneer, PB, MDF, HDF, HPL, LPL, OSB, corrugated paper, and paper. It is possible to solve the dimensional instability that occurs in the first place, and to solve the problems such as bending and cracking caused by dimensional imbalance when using plastic materials such as PVC, styrofoam, sponge and other release materials in combination. In addition, by using thermosetting resins as wood processing agents in addition to dimensional stabilizers and controlling conditions such as the time and temperature of the processing process, the aesthetics of the processed products can be adjusted and the physical properties can be improved for additional product processing. Can be obtained.

Claims (14)

In processing wood processed products including woods for the purpose of improving the physical properties including wood size stabilization, It includes wood dimensional stabilization treatment of wood processed products, which is characterized by processing wood of wood processed products using at least one wood dimensional stabilizer selected from acid anhydride and its derivatives, polyglycerol methacrylate (PGMA) and polypropylene glycerol methacrylate (PPGMA). Processing method. The processing method of claim 1, wherein the wood dimensional stabilizer comprises acetylation and esterification of hydroxyl groups present in woods. The wood grain of claim 1, wherein the acid anhydride is selected from acetic anhydride, maleic anhydride, phthalic anhydride, and succinic anhydride. Processing method including stabilization treatment. 2. The processing method according to claim 1, wherein the wood dimensional stabilizer is used in combination with acetic anhydride, polyglycerol methacrylate (PGMA) and polypropylene glycerol methacrylate (PPGMA). The processing method according to claim 1, wherein the wood dimensional stabilizer is treated by impregnation, humidification, depressurization, spraying or injection. The process according to claim 1, wherein the treatment process includes a reaction, reduced pressure, curing and drying step, reaction time 15 minutes to 72 hours, reaction temperature 50 ℃ to 180 ℃, drying time 30 seconds to 72 hours, curing time 30 seconds to 72 hours, the decompression time and the degree of decompression is a processing method including the wood dimensional stabilization treatment of the wood-worked product, characterized in that the processing range until the acid anhydride penetrates into the wood to stop the foaming. The method of claim 1, wherein the wood dimensional stabilizer further comprises a thermosetting resin selected from epoxy resin, phenol resin, acrylic resin, melamine resin, polyurethane resin, unsaturated polyester resin, diallyl phthalate resin. A processing method comprising wood dimensional stabilization of wood processed products. The process according to claim 1, further comprising a filler selected from calcium carbonate, talc, titanium oxide, silica, glass powder, and silicon dioxide as the wood dimensional stabilizer. Way. The wood dimensional stabilization treatment of wood processing products according to claim 1, further comprising a flame retardant selected from phosphate esters, halogenated hydrocarbons, antimony oxides, aluminum hydroxides, phosphate compounds, and dicyandiamides. Processing method comprising. The method of claim 1, wherein benzoyl peroxide, acetyl peroxide, dilauryl peroxide, di-tert-butyl peroxide as a peroxide initiator in the wood dimensional stabilizer. tert-butyl peroxide, cumyl hydroperoxide, hydrogen peroxide, potassium persulfate; Azo compound initiators; Pyrolysis initiators of silver alkyls initiators; Initiators for oxidation and reduction of persulfate or hydroperoxide; An initiator selected from among initiators using X-rays, alpha particles or gamma rays, A processing method comprising wood dimensional stabilization treatment of wood processed products, characterized in that it further uses a catalyst selected from potassium acetate, sodium acetate, urea and ammonium sulfate. Wood processed products comprising wood processed according to the method of any one of claims 1 to 10. According to claim 11, The timber is solid wood, plywood, veneer, Particle Board (PB), Medium Density Fiberboard (MDF), High Density Fiberboard (HDF), High Pressure Laminate (HPL), Low Pressure Laminate (LPL), OSB (Oriented Strand Board), woodworking, characterized in that the cardboard or paper. 12. The wood processed product according to claim 11, wherein the wood processed product is an interior material, an exterior material or a decorative material including solid wood floor, ondol floor, and reinforced floor. 12. The wood processed product according to claim 11, wherein the wood processed product is a product obtained by complex processing of a synthetic polymer comprising a plastic, PVC, a sponge, and styrofoam on the processed wood.

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