MX2007016207A

MX2007016207A - Aldehyde capture material and process for production of plywood with the same

Info

Publication number: MX2007016207A
Application number: MXMX/A/2007/016207A
Authority: MX
Inventors: Ishimoto Kenichi; Shirakami Yukio; Shimada Nobuyuki; Mabuchi Tomoyuki; Takeuchi Toshiya; Ikeda Takashi
Original assignee: Ipposha Oil Industries Co Ltd
Priority date: 2005-07-06
Filing date: 2007-12-17
Publication date: 2008-10-03

Abstract

[PROBLEMS]To provide an aldehyde capture material to be used in producing plywood by using veneers and a formaldehyde adhesive, which is not lowered in the capturing power even when the resulting plywood is subjected to surface grinding and which exerts a high capturing power for formaldehyde;a process for the production of plywood with the material;and plywood obtained by the process. [MEANS FOR SOLVING PROBLEMS]A powdery aldehyde capture material containing at least one aldehyde-capturing compound which is solid at ordinary temperatures and has the property of generating an acid gas such as sulfurous acid gas on being heated;and a process for production of plywood which comprises incorporating the above aldehyde capture material into an adhesive or veneers and producing plywood through hot pressing by the use of the adhesive and the veneers.

Description

A DEPURATOR FOR ALDEHYDES AND A MANUFACTURING METHOD FOR USING THE SAME Field of the Invention The present invention relates to a formaldehyde scrubber that captures aldehydes, such as formaldehyde and the like, and more particularly, the present invention relates to an aldehyde scavenger used to inhibit the generation of aldehydes from woody panels manufactured using formaldehyde-based woody and binding materials.

Description of the Related Art In the manufacture of woody panels such as chipboard, plywood, woody fiber panels and the like, sometimes, the formaldehyde-based binders (phenol resins, urea resins, melamine resins) and similar, they are used as binders. In this case, free formaldehyde derived from formaldehyde-based binders is emitted into the atmosphere from woody panels, causing damage to the environment and health. Conventionally, as a means to solve this problem, the usual practice employs urea, sulfite and coating hydrazides, on a surface of the panels i woody, preparing a so-called debugger for formaldehyde, which reacts with formaldehyde and captures it (captures it) (see Patent Document 1 and Patent Document 2). In this case, a scrubber for formaldehyde is usually diluted in water and the like, followed by a coating with a spray or roller. After being coated with the formaldehyde scrubber, the woody panels are stored in piles and delivered. Patent Document 1: Japanese Patent Publication Available to the Public No. Hei 11-240002 Patent Document 2: Japanese Patent Publication Available to the Public No. 2002-331504 Meanwhile, it is usual for woody panels to be supplied with lightly sanded surfaces after coating with an aldehyde scrubber, in order to improve the aesthetic appearance of the surfaces, and to obtain the required thickness. However, when the surfaces are sanded, particularly in the case where the sanding thickness is large, there are few purifiers for aldehydes present on the surface of a woody panel, and as a result, a capture property of formaldehyde decreases or is lost by the means mentioned above. As a means to solve this problem, a method is proposed to decrease the formaldehyde emissions, adding sodium sulfite or urea as the components of formaldehyde capture in woody materials (Patent document 3). Patent Document 3: Japanese Patent Publication Available to the Public No. Hei 10-119010 Description of the Invention Problem to be solved by the Invention However, with respect to patent document 3, since sodium sulfite or urea which is a capture component of formaldehyde is a solid, reactions with formaldehyde are reactions solid-gas. Thus, formaldehyde is captured on the surfaces of the particles of formaldehyde capture components. In other words, since a woody panel is studded with the scrubbers as a filter, free formaldehyde can not be completely captured. Particularly, considering that the JIS standard (International Standardization Act) was recently revised, which narrows the restrictions on formaldehyde emissions, by the above means, a capture property of the aldehyde is not satisfactory to prepare a woody panel under a evaluation F "which is not susceptible to restriction Therefore, the object of the present invention is to provide a scavenger for aldehyde with a property of capture not diminished by surface sanding and with an excellent capture property of formaldehyde. In addition, the object of the present invention is to provide a method of manufacturing a woody panel using the aldehyde scavenger and the woody panel.

Means to solve the problem by means of the Invention In order to solve the problem, as a result of extensive studies, the inventors have found that as a purifier for aldehydes, by using a scrubber for aldehydes comprising solid compounds to capture the aldehydes, which is a powder at room temperature, and it has a property of generating an acid gas, in particular, sulfurous acid gas, by heating, as the essential components, an excellent purification property of the aldehydes can be obtained. The inventors have also found that by adding in addition the compounds having a property of generating a basic gas, by heating, or basic compounds to the aldehyde scrubber, in addition to obtaining a purifying property of the aldehydes, the acid gas generated in excess can be removed . The inventors have also found that when the compounds having a property of generating the basic gas have a higher initial decomposition temperature with Because of the heat of the compounds to capture the aldehydes, the compounds having a property of generating the basic gas do not inhibit a purifying property of the aldehydes of the compounds to capture the aldehydes.

Effect of the Invention A aldehyde scavenger of the present invention can substantially eliminate free aldehydes in accordance with aldehyde emissions, such as formaldehyde, from woody materials in a hot press forming process, since an acid gas is generated which has a property of capturing the aldehyde from the aldehyde scavenger. By this, a good evaluation (F * -fc k) can now be obtained, even with a woody panel made using formaldehyde-based binders. The woody panels of chipboard, MDF, plywood and the like, manufactured using these, can capture the aldehydes with a high capture efficiency and in addition, the surface of the woody panels has an excellent aesthetic appearance. Further, when the compounds which generate the basic gas such as urea by heating are further added to an aldehyde scrubber of the present invention, the excessively generated acid gas can also be removed and the odor at the time of the hot press is inhibited. . Further, the acid gas and the basic gas such as sulfurous acid gas and ammonia gas, generated by heating, produce ammonium sulfite, by reacting in a gaseous state. Since ammonium sulfide binds to a whole woody panel, it has the effect of capturing the free aldehydes generated in small amounts, even after cooling a woody panel. In addition, when a compound having a property of generating the basic gas has a higher temperature of thermal decomposition compared to that of the aldehyde capture compound, in the initial initial stage of heating, the effective capture of aldehydes becomes more initial and by raising the temperature further, the chances of the reactions of the basic gas capturing the excess acid gas increase, and therefore, the competition of the reactions between the acid gas and the free aldehydes and the reactions between the gas acid and basic gas are inhibited. In other words, in the present invention, the basic gas almost does not inhibit the property of capture of aldehydes that the acid gas itself. On the other hand, when a basic compound is added, although the effect of drastically reducing the acid gas concentration can not be expected in the hot press formation process, as observed in the compound that has a property of generating the basic gas , the acid gas can captured in the long term, which is generated in a small amount, even after the woody panel has been manufactured. In addition, since a woody panel made by the method of the present invention can also develop the capture effect of the aldehydes emitted again from inside the woody panel when heated during the bonding process by an aldehyde scavenger of the present invention which remains inside the woody panel in the case of the gluing of a decorative sheet on a woody panel surface, a woody panel can be obtained with a decorative sheet glued with preferred properties. Further, when a woody panel is made using an aldehyde scrubber of the present invention with an added water repellent agent, or by using a woody material binding device consisting of at least formaldehyde-based binders, an aldehyde scrubber includes compounds for capture aldehydes, and a water repellent agent, even when a scrubber for aldehydes with a high hygroscopic property is used, since a water repellent agent that is a powder or granular at room temperature, melts in the press forming process hot and has an effect of imparting a protective barrier to all woody materials, it can prevent the woody panel manufactured from absorbing water and increase in size. By this, a woody panel with a good evaluation F "can be manufactured, inhibiting the emission of aldehydes and in addition, the aesthetic appearance of the woody panel is excellent, avoiding the water absorption and the increase in size, and the cracking thereof.

Brief explanation of the drawings [Figure 1] A schematic perspective view showing an apparatus that measures a resting angle of powdered samples.

Explanation of reference numbers 1 A container for measuring an angle of repose 2 opening door in an upper portion 3 side lid T An angle of repose The best mode for carrying out the invention (Debugger for aldehydes) The present invention relates to with an aldehyde scrubber used to make a woody panel, when added to, or dispersed in binders based on formaldehyde or woody materials, and its property is powdered under ambient temperature. When its property is liquid, the effect that the present invention has can not be expected and even when its property is solid, in the case where it is not a powder, but is a pooled mass whose average particle size exceeds 5 mm, it is difficult to achieve a uniform dispersion in the woody materials, and therefore, it is not appropriate. In addition, ambient temperature refers to 25 ° C by strict definition, although sometimes it can be used in a more general meaning. It is preferable that the aldehyde scavenger of the present invention be a powder and that not less than 70% by weight of the particles contained in the powder aldehyde scavenger have a particle size of not more than 2 mm. In a liquid aldehyde scrubber, when added before the hot press formation of the woody materials, the aldehyde scavenger is introduced into the woody materials without intermediate space and the union is inhibited, since the junction points between a splinter of wood and a binder, one between a binder and a wood chip, are less numerous. In addition, when the hot press is applied after adding the liquid aldehyde scrubber, the vapor pressure inside the woody panel is increased and the woody panel bursts and therefore, a desired woody panel can not be formed. In addition, when a woody panel is manufactured using a powder aldehyde scrubber, in which particles with a size of not less than 2 mm are present, in excess of 70% of the particles contained in the powder, it is likely that traces of particles appear on the surface of the product as white spots. In order to make such particles contained in not less than 70% by weight of the powders composed of particles whose particle size is not greater than 2 mm, for example, the scrubber for aldehyde powder is sieved with a sieve, whose opening is 2 mm, leaving it therefore, composed of not less than 70% of particles that pass through the screen. In all the powder, the assessment of the proportion of particles whose particle size is not greater than 2 mm can be made by, for example, a device for measuring the particle size distribution, including a sonic vibration method with a device of automatic measurement of sieving "RPS-85C" (manufactured by SEISHIN ENTERPRISE CO., LTD.). In a powder aldehyde scrubber of the present invention, it is preferable that the angle of repose is small. An angle of repose is an index to know about the property of the powders and refers to a maximum angle formed between an inclined plane and a horizontal plane in a state where the stacked powders are stably maintained. An angle of repose is determined by the particle shapes or the resistance between the particles caused by the sticky surfaces of the particle, however, in an aldehyde scrubber of the present invention, when an angle of repose as an index is small, the powders are smooth, whereas when an angle of repose as an index is large, the powders are sticky. To be specific, in a powder aldehyde scrubber of the present invention, an angle of repose is preferably not greater than 65 ° and moreover, preferably, not greater than 60 °. When a resting angle is too large, the powders probably become sticky as mentioned above and each of the particles binds and is likely to become bulky particles, making these particles difficult to handle. The specific measurement methods of the angle of repose are described in the Examples that are mentioned later.

(Compounds for capturing aldehydes) The aldehyde scavenger includes at least one or more compounds to capture aldehydes that are solid at room temperature, and the compounds for capturing aldehydes generate an acid gas upon heating. As a specific acidic gas, the sulfurous acid gas and the hydrogen sulfide gas can be used. The compounds generating the acid gas generate the sulfurous acid gas and the hydrogen sulfide gas by heating the reaction as follows. The explanation takes the sodium acid sulfite as a compound to generate the sulfurous acid gas by heating, and taking the sodium acid sulfite as a compound to generate the hydrogen sulfide gas by heating. 2NaHS03? (Heating)? Na2S03 + H20 + S02t 2NaHS? (heating)? Na2S + H2st By the reaction mentioned above, it is assumed that the mechanism of purification of the aldehydes during the process in hot press by the acid gas generated from the compounds to capture the aldehydes, follows the following chemical reaction.

(In the case of sulphurous acid gas) HCHO + S02 + H20 + HOCH2SO3H (unstable acid is formed).

HOCH2S03H + Na2S03? HOCH2S03Na + NaHS03 (In the case of hydrogen sulfide gas) H2S + HOCH2OH? HOCH2SH + H20 Since the aforementioned reaction occurs in a gaseous state during the hot press forming process, the aldehydes can be effectively removed. As examples of compounds for capturing aldehydes having a property of generating the sulfurous acid gas by heating, bisulfite, such as sodium acid bisulfite, is preferable. Like others, pyrosulfite, dithionite and the like are preferred. As examples of the classes of salts, metal salts such as sodium salt, potassium salt, magnesium salt and the like, amine salt, such as monoethanol amine and the like, and ammonium salt, are considered. On the other hand, as examples of the compounds for capturing the aldehydes having a property of generating the hydrogen sulfide gas, the hydrogen sulfide and the like, such as the sodium acid sulfide and the like can be exemplified. Although it is necessary for a aldehyde scrubber of the present invention to include at least one compound to capture the aldehydes, two or more compounds can be used to capture the aldehydes. In addition, such The compounds can be used together with other known compounds to capture the aldehydes. Among them, when such compounds for capturing the aldehydes are sodium sulfite, potassium sulfite or hydrazides, a synergistic effect is generated without canceling a purification property of the aldehydes from one another, and in addition, a property that eliminates odor is improved. . As mentioned above, when other compounds are included, it is preferable that the content of the compounds to capture the aldehydes be from 5 to 95% with respect to the total amount of the aldehyde scavenger. In the case where it is necessary to more strictly define the compound term having a property to generate an acid gas, it is when the acid gas is sulfurous acid gas that can be strictly defined as follows. In other words, it refers to a compound with the generation of a concentration of the sulfurous acid gas of the compound to capture the aldehydes of not less than 500 ppm when heated to 140 ° C or a compound that generates the sulfurous acid gas with an initial decomposition temperature of not more than 250 ° C, and preferably not greater than 200 ° C. This is because when the sulfuric acid gas concentration is generated, it is too low, a property to capture the aldehydes is not enough. This is also due to the fact that when a compound has a Initial decomposition temperature which is too high, it is considered that a satisfactory amount of the sulfurous acid gas is not generated, even at a temperature of around 200 ° C, when the joint is made during the hot press forming process. On the other hand, in the case of a compound whose concentration of the sulfurous acid gas generated by heating exceeds 50%, it is not preferable since the compound decomposes easily even when it is solid at room temperature, has a strong odor and is difficult to manage. With respect to a method for the generation of a concentration of sulfurous acid gas at the time of heating, since there is no measurement method established, for example, by JIS and the like, the measurement was made under the following method explained to continuation. In addition, the measurement of an initial decomposition temperature was carried out under the following conditions.

(Measurement of sulfuric acid gas concentration) Device and test instrument: The test device is used for corrosion on the heat transfer surface described in JIS K2234-1994. However, the portion corresponding to a test piece of the metal was manufactured by SUS 304 to prepare a heating plate. Test method: 1.0 g of the sample is placed in the upper portion of a glass cell and sealed, followed by heating the corresponding portion to a metal test piece by a heater at a selected temperature. After reaching the selected temperature, the temperature was maintained for 30 minutes, allowing the sulfurous acid gas to be generated from the sample, followed by the opening of the plug of the upper portion of a test device, thereby measuring the concentration of the sulfurous acid gas through a gas detection tube. For the information, a glass cell with an internal diameter of 40 mm and a total length of 530 mm is used. As a gas detection tube, a gas measurement device of the type of a gas detection tube (sulfur dioxide), manufactured by GASTEK CORPORATION and based on JIS K0804-1998, was used.

(Initial decomposition temperature) The thermal decomposition was done by TG (TG / DTA6200 / manufactured by SEIKO instruments Inc.) and the initial decomposition temperature was extrapolated. The heat condition is as follows. Temperature range: 30 to 300 ° C.

Speed of elevation of the temperature: 10 ° C / minute. The result of the above test is shown in Table 1. With respect to sodium acid sulfite, the concentration with 0.1 g of a sample was also measured in a supplementary manner. As shown in Table 1, sodium acid sulfite, sodium pyrosulfite, potassium acid sulfite, potassium pyrosulfite, magnesium sulphite, zinc sulphite and aluminum sulfite are recognized as compounds with a concentration that generates the gas of the sulphurous acid of not less than 500 ppm when heated to a temperature of 140 ° C or compounds that generate sulfurous acid gas and have an initial decomposition temperature of not more than 250 ° C. On the other hand, it was recognized that sodium sulfite and calcium sulfite do not satisfy the above requirement and are compounds that do not generate the acid gas in the present invention.

(Table 1) (Compounds that generate the basic gas by heating) Although the aldehyde scrubber of the present invention comprises the compounds for capturing the aldehydes as the essential components, it is preferable that the aldehyde scrubber of the present invention further comprises a compound having a property of generating a basic gas by heating. In order to capture sufficient amount of aldehydes, it is preferable to comprise compounds to capture the aldehydes, so that the acid gas is generated excessively to some degree by heating. However, under such a condition, the unreacted acid gas remains, causing odor at the time of heat treatment, and therefore, the unreacted acid gas is preferably removed as much as possible. Here, when a compound that has a property to generate a basic gas is included, the unreacted acid gas is extinguished by reacting it with the generated basic gas. In a aldehyde scavenger of the present invention, the ratio of a compound for capturing the aldehydes / a compound having a property of generating a basic gas by heating, is preferably from 5/95 to 95/5 and in a more preferred manner. preferred, from 10/90 to 90/10. When the ratio of a compound to capture the aldehydes is very small, the formaldehyde emitted from a woody panel can not be completely reduced and when the ratio of a compound that has a property of generating a basic gas by heating is very small, the acid gas it can not be extinguished. The mechanism in which the compound having the property of generating the basic gas by heating captures the unreacted sulphurous acid gas, for example, is supposed to follow the next chemical reaction. The explanation takes urea as a compound that has a property of generating a basic gas by heating, as an example. In this case, the basic gases generated are ammonia. NH2CONH2 + H20? (heating)? 2NH3 + C02 2NH3 + S02 + H20? (NH4) 2S03 During heating, since the aforesaid gas reacts in the gaseous state, the unreacted sulphurous acid gas can be effectively removed. As mentioned above, the representative examples of basic gases are ammonia. As the ammonia generating compounds by heating, ammonium sulfite, urea and its derivatives and hydrazides can be exemplified. As urea and its derivatives, urea and compounds having a urea bond are exemplified and apart from these, methyl urea, ethyl urea, dimethyl urea, diethyl urea, guanyl urea, acetyl urea, thio urea, cyclic urea condensates such as ethylene urea, allantoin and the like, and non-cyclic urea condensates, such as urea dimer, including biuret and the like. As hydrazides, a mohohydrazide compound having a hydrazide group in a molecule, a dihydrazide compound having two hydrazide groups in a molecule, and polyhydrazide compounds having no hydrazide can be exemplified. less than three hydrazide groups in one molecule. As specific examples of a monohydrazide compound, an alkylhydrazide compound, such as lauryl acid hydrazide, salicylic acid hydrazide, formhydrazide, acetohydrazide, propionic acid hydrazide, naphthoic acid hydrazide and the like can be exemplified. As specific examples of the hydrazide compound, the dibasic acid dihydrazide compound can be exemplified such as carbodihydrazide, oxalic acid dihydrazide, malonic acid dihydrazide, succinic acid dihydrazide, adipic acid dihydrazide, azelaic acid dihydrazide, sebacic acid dihydrazide, dedecandioic acid dihydrazide, maleic acid dihydrazide, fumaric acid dihydrazide, tartaric acid dihydrazide, malic acid dihydrazide, isophthalic acid dihydrazide, terephthalic acid dihydrazide, dimeric acid dihydrazide and the like. As specific examples of the polyhydrazide compounds, polyacrylic acid hydrazide and the like can be exemplified. In addition, compounds having a property of generating a basic gas by heating may be combinations of two or more compounds. As specific examples, a method to generate ammonia can be exemplified by mixing and adding solid ammonium chloride and solid aluminum hydroxide to the woody materials and using steam generated in the hot press forming process. 3 H4C1 + Al (OH) 3? AlCl3 3¾0 + H3t When it is necessary to more strictly define the compound term having a property to generate a basic gas, it refers to the compound having a concentration of the basic gas generated from the compound that is not less than 500 ppm when heated to a temperature of 140 ° C or the compound that generates the basic gas, where the initial decomposition temperature is not higher than 300 ° C. In addition, the initial decomposition temperature is preferably also not greater than 250 ° C. This is because when the concentration of the basic gas generation is too low, the unreacted sulfuric acid gas can not be completely extinguished. In addition, this is because when an initial decomposition temperature is too high, it is assumed that a compound does not completely generate basic gas even at a temperature of about 200 ° C at the junction by the aforementioned heating process (process of hot press training). On the other hand, there is no specific upper limit of the concentration of the basic gas generation and it can be used even when it becomes 100% at a temperature of 140 ° C.

With respect to the method of measuring the concentration of the generation of the basic gas when it is heated, since there is no measurement method established for example, by JIS and the like, it was decided to use the method which is the same to measure the concentration of the sulfurous acid gas as mentioned above. However, the tube for gas detection must be changed to an appropriate detection tube for the generated basic gases, such as ammonia and the like. The condition for an initial decomposition temperature is adjusted to be the same as when measuring the initial decomposition temperature of the sulfuric acid gas mentioned above. The result of the above test is shown in Table 2. As shown in Table 2, urea, carbodihydrazide and ammonium sulfite are recognized as the compound with the ammonium concentration of not less than 500 ppm when heated to 140 ° C. Further, although the ammonium concentration of the ethylene urea, the adipic acid dihydrazide and the dodecandioic acid dihydrazide is 0 ppm, the initial decomposition temperature is recognized to be less than 300 ° C. In addition, since it was recognized that an initial decomposition temperature of urea, ethylene urea and carbodihydrazide is less than 250 ° C, it was recognized that these can be used in a preferred manner. as compounds having a property of generating a basic gas by heating.

(Table 2) In addition, the concentration of the sulfurous acid gas and the concentration of the ammonia gas when 1 g of sodium acid sulfite and 1 g of urea are mixed was measured by the same method. The result is shown in Table 3.

(Table 3) (Basic Compounds) In a aldehyde scavenger of the present invention, the basic compounds can be further included. When only the basic compounds are added to an aldehyde scavenger of the present invention, unlike when the compounds having a property of generating a basic gas by heating, the unreacted acid gas can not be captured efficiently in the formation process In hot press, however, after forming a woody panel, a small amount of the acid gas generated over a long term of the remaining compounds to capture the aldehydes, can be safely captured. Therefore, in the present invention, by adding both of the compounds having a property of generating a basic gas by heating and the basic compounds, a synergistic effect of capturing the acid gas can be obtained. The basic compounds that can be used in the present invention are not specifically limited, as long as they are basic materials that react with the acid gas generated. To be specific, gaseous basic compounds such as ammonia and sulfur dioxide can be exemplified. similar, liquid basic compounds such as alkanolamine and the like, the solid basic compounds such as sodium hydroxide, calcium hydroxide, aluminum hydroxide and the like. Among them, solid basic compounds are preferred from the point of view of ease of handling.

(Solid base compounds) As the specific solid base compounds, the oxides or hydroxides of calcium, aluminum, zinc or magnesium can be exemplified and in addition, sodium aluminate, alkylamines and polyamine can also be used. Among these, the divalent or trivalent metal oxides, such as calcium oxide, aluminum oxide, zinc oxide, magnesium oxide, calcium hydroxide, aluminum hydroxide and the like or compounds whose basicity is relatively weak, such as metal hydroxides are preferred. Strong basic compounds, such as sodium hydroxide and the like, are not preferred, since they probably do not inhibit the curing of a binder based on formaldehyde. In addition, the basic organic compounds that melt with heat | at the time of formation with heating are also not preferred, since they probably cause the inhibition of curing, penetrating the woody materials.

(Liquid basic compounds) As the basic liquid compounds, organic alkylamine compounds, such as monoethanol amine, triethanolamine, ethylene diamine, diethylene triamine, oleyl amine, and the like, can be exemplified. In a aldehyde scrubber of the present invention, the weight ratio of the compounds for capturing the aldehydes / basic compounds is preferably 5/95 to 95/5 and more preferably 10/90 to 90/10. When the ratio of the compounds to capture the aldehydes is too small, the formaldehyde emitted from a woody panel can not be completely reduced, and when the ratio of the basic compounds is too small, the acid gas can not be removed.

(Water repellent agents) Since a scrubber for aldehydes with the aforementioned composition includes compounds with a high water absorbability, such as sodium acid sulfite or sodium pyrosulfite as the compounds for capturing the aldehydes, there is a disadvantage that A woody panel made of a woody material added as a compound to capture aldehydes will probably absorb water and increase in size. Therefore, when adding a Water repellent agent to a aldehyde scrubber of the aforementioned composition, it can be avoided that the woody panel absorbs water and increases in size. As the water repellent agents that can be used in the present invention, known water repellent agents that are solid at room temperature can be used. As specific examples of preferred water repellent agents, waxes, silicones, metal salts of higher fatty acids and the like can be exemplified. As the waxes, the natural waxes represented by carnauba wax, candelilla wax, ozokerite, ceresin, paraffin wax and microcrystalline wax and synthetic waxes represented by polyethylene wax, polypropylene wax, are exemplified. o-olefin wax, Fischer-Tropsch wax and the synthetic fatty acid ester. In addition, oxidized waxes such as natural or synthetic oxidized waxes, hydrogenated oils and fats such as hydrogenated tallow waxes or hydrogenated castor waxes, modified wax derivatives such as modified natural or synthetic waxes and the like are also exemplified. In addition, waxes containing olefin and maleic anhydride, waxes containing olefin and acrylic acid, waxes containing vinyl acetate or waxes such as those of higher alcohols, amide of fatty acid, polyether and the like, can also be used. As the silicones, for example, the modified dimethyl silicone oil is exemplified and as the metal salt of a higher fatty acid, for example, calcium stearate, zinc stearate and aluminum stearate are exemplified. Among them, water repellent agents with a melting point of 40 to 140 ° C are preferred, and water repellents with a melting point of 50 to 120 ° C are more preferred. The reason is that the waterproof effect can be easily obtained since they solidify after they are melted with heat by the hot press at the time of manufacture of a woody panel and are dispersed in all woody materials. As the preferred specific examples, natural waxes such as carnauba wax, ozokerite, paraffin wax and microcrystalline wax, synthetic waxes such as polyethylene wax, and hydrogenated oils and fats such as wax may be exemplified. Hydrogenated tallow, castor wax and the like can be exemplified. Although these can be used alone, they can also be used in combinations. The water repellent agents used in the present invention are preferably powders or granules, and a particle size is preferably not greater than 3 mm. and preferably, not greater than 2 mm. The reason is that when a particle size is large, it is difficult to evenly disperse the particles in the woody materials and it will probably remain white spots on a woody panel surface. When the water-repellent agents are used when included in an aldehyde scrubber, the ratio is preferably 5 to 80% by weight with respect to the total amount of the aldehyde scrubber and most preferably 10 to 60% by weight. weight. When the ratio is very small, the water absorption and the size increase of a woody panel can not be completely inhibited and on the other hand, when the relation is too large, the purification property of the aldehydes, which is the original effect of a purifier for aldehydes, decreases. In order to include the water repellent agents in a scrubber for aldehydes, mixing them with other components such as the compounds for capturing the aldehydes mentioned below by a known method is sufficient. In an aldehyde scrubber of the present invention, instead of mechanically mixing the solid compounds to capture the aldehydes and solid water repellent agents, when the water repellent agents are mixed with the compounds to capture the aldehydes and cooled after hot melt water repellent agents, part or all of the surface of the compounds to capture the aldehydes is coated with the water repellent agents. The water-repellent agents coated with the compounds to capture the aldehydes, in addition to the effect of inhibiting water absorption and the increase in size in the preparation of the woody panel mentioned above, when an aldehyde scrubber of the present invention and a binder based In formaldehyde are added to the woody materials, during the time until the woody materials are provided for a hot press forming process, the binder based on formaldehyde and the compounds for the aldehydes are in contact together, thus avoiding degradation of the union property. On the other hand, at the time of hot press formation, since the water repellent agents are hot melted and liquefied, and therefore, they release the compounds to capture the aldehydes, formaldehyde emissions from a woody panel after Hot press training can be inhibited effectively.

(Anti-caking agents) In an aldehyde scrubber of the present invention, for the purpose of preventing the agglutination of water repellent particles and making the angle of repose more small at the time of production and storage of products, in other words, in order to improve the flow at the time of using the products, anti-caking agents are included. As specific anticaking agents, carbonate, such as sodium carbonate, calcium carbonate, magnesium carbonate and the like, can be exemplified as silicate such as amorphous silica, calcium silicate, magnesium silicate and aluminosilicate such as natural zeolite, synthetic zeolite and the similar. Among them, zeolite or bentonite is preferable. The reason is that a more effective anti-caking effect can be obtained. Although these compounds can be used alone as mentioned above, two or more can also be used in combinations. The content ratio of the anti-caking agent is preferably 0.1 to 10% by weight with respect to the total amount of the aldehyde scavenger and more preferably 0.5 to 5% by weight. When the ratio of the content is too small, the binding of the particles can not be effectively avoided and the absorption of water and the enlargement of the woody panel can not be avoided either. On the other hand, when the content is very large, the selected effect can not be improved and the cost is high, after all. (Other additives) In the composition of the aldehyde scavenger of the present invention, apart from the aforementioned compounds, as required, additives such as antioxidants, preservatives, colorants, anti-rust agents and the like may be contained.

(Method of manufacture) Among the powder aldehyde scavenger of the present invention, regardless of the method of manufacturing the aldehyde scavenger comprising at least one compound for capturing aldehydes, a water repellent agent and an anti-caking agent, wherein the Water repellent agent includes particles that cover a part or all of a surface of a compound to capture aldehydes, by going through processes (1) to (5), a high manufacturing yield is available. (1) A hot melt process of a water repellent agent (2) A process of dripping or spraying a hot melt water repellent in a state higher than the melting point of the water repellent agent. at 20 ° C, while stirring and mixing the compounds to capture the aldehydes after the process (1) (3) A process for cooling a mixture obtained in the process (2), while stirring and mixing (4) A process of also adding an anti-caking agent at the time when the mixture is cooled to a temperature that is lower than the melting point of the water repellent agent by 10 to 50 ° C in the process (3) (5) A sieving process to obtain a scrubber for aldehyde powder, sifting the mixture obtained in the process (4) (Process (1)) In order to drip or spray a water repellent agent to a compound for capturing aldehydes, process (1) of the present invention is a process for hot melting the water repellent agent. As the heater used for hot melt, a publicly known heater can be used.

(Process (2)) Although the process (2) of the manufacturing method of the present invention is a process for dripping or spraying a water-repellent agent that is hot-melted in the process (1) to a compound for capturing aldehydes, The temperature for dripping or spraying is adjusted to be higher than the melting point of the water repellent agent by 1 to 20 ° C. For example, a temperature to drip or spray using paraffin wax whose melting point is 55 ° C as A water repellent agent is adjusted to be 56 to 75 ° C. In addition, it is preferable to drip or spray at a temperature that is higher than the melting point of a water repellent agent by 5 to 10 ° C. When the drip or spray temperature is too low, a water repellent agent solidifies and locks in a tube. On the other hand, when the drip or spray temperature is very high, since the temperature in a granulator rises, the cooling time is prolonged, causing an additional loss of energy and increasing the adhesion to the inner surface of a granulator. In addition, as mentioned above, in order to control the temperature at the time of dripping or spraying within a prescribed range, it is preferable to control the temperature of the parts of the system to a spray nozzle or a drip port that sprays or drips the water-repellent agents melted from a tank in which a water repellent agent to be dripped or sprayed is stored. When dripping or spraying, in particular, by spraying the water-repellent agent to the compounds to capture the aldehydes, while controlling a temperature range at the time of dripping or spraying the water-repellent agent in the present process, a scrubber for aldehydes powder with a better effect to avoid the inhibition of the union, with an increased probability that the particles Generated compounds in which the water repellent agent is coated with a particle surface of the compounds to capture the aldehydes. In order to make a scrubber for aldehydes with few unbalanced components, it is preferable to drip or spray the compounds to capture the aldehydes that are the components to be added or sprayed while stirring.

(Process (3)) The process (3) of the manufacturing method of the present invention is the process of cooling a mixture obtained in the process (2), while stirring and mixing. By cooling, a hot melt water repellent agent solidifies again.

(Stirring) As a treatment condition for stirring in the processes (2) and (3), it is preferable to stir under the condition of the stirring number of Froude, as defined in the following formula (i) is the number of Froude Fr not less than 0.1 and less than less than 5.0. Fr = V / [(R xg) 0-5] (i) In formula (i), V represents the circumferential velocity [m / s] of one end of the tip of a stirring blade, R represents a rotating radius [m] of the agitation blade and g represents the gravitational acceleration [m / s2]. By controlling the Froude Fr number within the above range, even when a viscous water repellent agent is selected, it can be uniformly added to a compound to capture aldehydes. When the number of Froude Fr at the time of adding a water-repellent agent is too small, the particles come together and it is possible that bulky particles are generated. In addition, the particles adhere to the inside surface of a granulator, causing too much loading and therefore, it is not preferred. On the other hand, when the Froude Fr number is too large, or when the stirring speed is too high, since the temperature in the granulator rises caused by the heat of friction by agitation, the cooling time is prolonged and a loss of energy is caused, and therefore, it is not preferred.

(Process (4)) The process (4) of the manufacturing method of the present invention is a process of adding an anti-caking agent to the moment when the mixture is cooled to the temperature lower than the melting point of the water repellent agent by 10 to 50 ° C in the process (3). For example, when using paraffin wax whose melting point is 55 ° C as a water repellent agent, an anti-caking agent is added to the moment when the mixture cools from 5 to 45 ° C. Furthermore, it is more preferable to add an anti-caking agent at the time when the mixture is cooled to the temperature which is lower than the melting point of the water repellent agent by 20 to 30 ° C. When an anti-caking agent is added before cooling by the process (3), the anti-caking agent is taken into the mixture, which does not contribute to the improvement in flowability and anti-caking property. Therefore, an anti-caking agent is added after the process (3), in which a water repellent agent in the mixture solidifies. In addition, by restricting the temperature range to add an anti-caking agent to a certain range, particles with a small size can easily be obtained with one step.

(Process (5)) The process (5) of the manufacturing method of the present invention is the sieving process in which a scrubber for aldehyde powder is obtained by sieving the mixture obtained in the process (4). In the aldehyde scavenger of the present invention, since not less than 70% by weight of the particles included in the powder aldehyde scavenger, preferably having a particle size of not more than 2 mm, it is preferable to use a sieve whose opening is of 2 mm, the sieving with another opening is possible, naturally and can be finished appropriately considering the objective quality of the woody panels and in particular, considering the balance of the aesthetic quality and the production efficiency of a scrubber for aldehydes of the present invention. Although it is possible to spray an aldehyde scavenger obtained in the process (4) before sieving it and to re-pulverize the remaining powders in a sieve, therefore again screening, in many cases, in a powder aldehyde scavenger obtained through the processes (1) to (4) mentioned above, even without any spraying process, not less than 70% by weight of the particles included with a step can obtain a particle size of not more than 2 mm in high yield.

(Granulation methods and devices) The processes (1) to (4) mentioned above can be carried out by granulation methods of the agitated type, can be used granulation methods with tamboreación, granulation methods with extrusion, granulation methods with crushing, methods granulation with spray drying and as commercial names of specific devices, HIGH SPEED MIXER, HENSHEL MIXER, NEW-GRA MACHINE, SCHUGI CONTINUOUS GRANULATOR, LODIGE MIXER, PLOUGHSHA E MIXER, RIBBON SHAPED SCREW MIXER, SPARTAN GRANULATOR, CONTINUOUS "PUG MIXER" and TURBULIZER (granulation methods of the agitated type), and as specific devices, horizontal cylinder mixers (granulation methods with tamboreación), extruders kneaded, continuous horizontal kneaders, sealed devices for compaction (kneading and extrusion methods), countercurrent spray drying column (granulation methods with spray drying) and the like. The sieving in the process (5) mentioned above can be carried out using oscillators, vibrating screens and the like. In addition, the grinding of powders can be done using mechanical mills, hammer mills, barbed mills and the like.

(Method of manufacturing a woody panel 1) The manufacture of woody panels using formaldehyde-based binders generally involves processes of adding formaldehyde-based binders to a woody material (process of adding binders), followed by the process of bonding woody materials applying pressure and heating (hot press forming process). In the manufacture of a woody panel using the aldehyde scrubber of this invention, before the process of adding binders, the aldehyde scavenger can be used when included in binders based on formaldehyde, and can also be used by adding it to the side of the woody materials to be joined before or after adding the binders or at the same time that the binders are added. To cite specific manufacturing examples, for example, in the manufacture of agglomerate panels (hereinafter abbreviated as PB), woody materials crushed relatively finely for the surface layers are used, while the woody materials crushed relatively thicker ones are used for the central layers. After spraying a binder based on formaldehyde into the woody materials for the surface layers, the aforementioned aldehyde scavenger is added and dispersed. In the same way, a binder and a scrubber for aldehydes are added to the woody materials for the central layers. Although the aldehyde scavenger added to the surface layers and the aldehyde scavenger added to the core layers may be identical or different, the aldehyde scavenger used for the surface layers desirably does not diminish the aesthetic appearance of a panel woody. On the other hand, an aldehyde scrubber used for the central layers desirably has a high purification property for the aldehydes. Although the order of addition of a scavenger for aldehydes is not specifically restricted and the scavenger for aldehydes can be added directly to a binder or can be added before, after and at the same time a binder is added, from the process point of view , a scrubber is added more desirably sooner or later or at the same time a binder is added in the woody materials. When the unreacted acid gas is going to be captured by the compounds that have a property of generating a basic gas by heating or by the basic compounds (hereinafter, both of them called "basicity compounds"), a scrubber for aldehydes mixed with compounds for capturing the aldehydes with one or two or more of the "basicity compounds" can be manufactured, followed by the addition of these to the woody materials, or the compounds for capturing the aldehydes and the "basicity compounds" can be added to woody materials separately. In addition, "basicity compounds" may be added before, after or at the same time as a binder based on formaldehyde is added or coated. In the manufacture of the woody panels formed of a plurality of layers, such as agglomerate panels, between a plurality of layers, addition to the woody materials of an optionally selected layer or woody materials of a plurality of layers (a part or all). In addition, the "basicity compounds" can be placed between the layers. In addition, the compounds for capturing the aldehydes and the "basicity compounds" can be used by adding them to other layers or by adding them between the layers. After that, laminated layers of the upper surface-core layers-layers of the rear surface, the materials are heated. At the time of heating, heating is usually carried out by applying pressure (hot pressing). Through hot pressing, the woody materials join and become woody panels. In general woody panels, which do not utilize a aldehyde scrubber of the present invention, a large amount of aldehydes, including free formaldehyde, is generated in this hot press process, and the aldehyde that can not be captured remains in the woody panel , and therefore, even after cooling, the aldehydes are generated little by little. In woody panels using an aldehyde scrubber of the present invention, since an acid gas is generated during the hot press forming process, such a problem does not occur. In other words, it is necessary that a scrubber for aldehydes be used for the method of making a woody panel in this invention, to generate enough acid gas to capture the aldehydes generated. Although the temperature and time for a hot press process are appropriately determined by the quality of a woody panel and the productivity in general, when a scrubber for aldehydes of the present invention is used, in order to obtain the effect, a hot press forming temperature is preferably 100 to 300 ° C, and most preferably 140 to 250 ° C. When the temperature is too low, the amount that is generated from the acid gas is small, and therefore, a satisfactory amount of formaldehyde and the like can not be captured. On the other hand, when the temperature is too high, a quality decreases, for example, a surface of a woody panel is burned and the like. In addition, the time for hot press training is preferably not less than 60 seconds and more preferably, not less than 90 seconds. When the time for formation is too short, the temperature inside the woody panel rises unlikely, and the effect of this scavenger for aldehydes deteriorates. The temperature inside a woody panel at the time of hot dam formation is preferably not less than 60 ° 0 in the central portion in the thickness direction and most preferably not less than 80 ° C. In addition, it is more preferably, not less than 100 ° C.

In addition, in the manufacture of a medium density fiber (DF), the aforementioned aldehyde scavenger can be added and a woody panel can be manufactured in the same way. The additional content of an aldehyde scrubber to the woody materials in the manufacture of a woody panel is from 0.1 to 20.0% by weight, and preferably from 0.5 to 10% by weight and furthermore, preferably from 1.0 to 20% by weight. 7.0% by weight. When the additional content is less than 0.1% by weight, a selected purifying property can not be obtained and when the additional content exceeds 20.0% by weight, the aesthetic appearance of the surface of a woody panel decreases and the value as a product is affected, thereby causing the cost of production to rise. Further, when the compounds for capturing the aldehydes and the "basicity compounds" are added to the woody materials separately, the total additional content of these compounds to the woody materials is from 0.1 to 20% by weight, preferably from 0.1 to 20% by weight. 0.5 to 10% by weight, and also, preferably, from 1 to 7% by weight. When the additional content of these compounds is very small, the capture effect of the aldehydes and the effect of reducing the acid gas can not be obtained. On the other hand, when additional content is too much, the aesthetic appearance of the surface of a woody panel is also affected and the strength decreases, thereby decreasing value as a product, thereby causing the cost of production to rise. The weight ratio of the compounds for capturing aldehydes / "basicity compounds" is preferably 5/95 to 95/5 and more preferably 10/90 to 90/10. When the ratio of the compounds to capture the aldehydes is very small, the formaldehyde emitted from the woody panel can not be reduced sufficiently, and when the ratio of the "basicity compounds" is very small, the acid gas can not be removed. For the aldehyde scavenger, in addition to the compounds for capturing the aldehydes, when the compounds having a property of generating a basic gas by heating are selected and added as "basicity compounds", and when the compounds having a property of generating a basic gas by heating have a higher initial decomposition temperature than the compounds to capture the aldehydes, in the previous heating process, since the reaction of the acid gas and the free aldehydes generated from the woody materials takes precedence in the first Initial stage of warming, effective capture of aldehydes is available. Then, when additional heating is applied, gradually, the reaction in which the basic gas Capture the excess acid gas becomes advantageous. Thus, since the hot press forming process can be divided into a hot press forming process in the initial stage, in which acid gas and free aldehydes react and a hot press forming process in the later stage, in which acid gas and basic gas react, competition in both reactions can be inhibited. In other words, in the method of manufacturing a woody panel in the present invention, the basic gas inhibits almost does not inhibit the property of the aldehydes that the acid gas has. In addition, according to the method of manufacturing a woody panel of the present invention, a woody panel with inhibited emissions of aldehydes can be obtained, but in addition, compounds with an aldehyde capture property can be coated in the woody panel obtained from through the process mentioned above as an aqueous solution as well. For example, in the manufacture of an agglomerate panel (here abbreviated later as PB), in a woody panel manufactured by adding the compounds to capture the aldehydes that are solid at room temperature to the core layers, and adding only the "basicity compounds" "to the surface layers, there may be the case where the effect of capturing the aldehydes on the woody panel surface layers is not satisfactory to some degree and in such a case, it is effective to coat the aqueous solution on the surface or both surfaces of the woody panel. Applicable compounds for the coating include sulfite, bisulfite, urea and its derivatives and hydrazides. Among these, sodium acid sulfite, potassium acid sulfite, ammonium acid sulfite, sodium pyrosulfite, potassium pyrosulfite, sodium sulfite, potassium sulfite, ammonium sulfite, urea, ethylene urea, carbodihydrazide and acid dihydrazide Adipic are preferred. These compounds may be used alone or in combinations of two or more thereof dissolved in water.

(Method of manufacturing a woody panel 2, when using water repellent agents) When the aforementioned aldehyde scrubber or a device for bonding woody materials of the present invention is used, a woody panel with low water absorption can be manufactured and increase in the size of the woody panel, with good superficial aesthetic appearance and with an inhibited aldehyde generating amount. As a manufacturing process, it comprises at least one process of adding a formaldehyde-based binder, an aldehyde scavenger that includes compounds to capture the aldehydes that are powdered or granular at room temperature, and a water repellent agent that is in powder or granular at room temperature, for woody materials and a hot press forming process, to prepare a woody panel by heating, applying pressure to the woody materials and joining the woody materials. As mentioned above, when each of the formaldehyde-based binder, a aldehyde scavenger and a water-repellent agent can be dispersed in woody materials, they can be added separately to the woody materials or they can be added to the woody materials with two or three of them mixed in advance. However, when a water repellent agent is included in an aldehyde scavenger beforehand to prepare the state of the aldehyde scavenger of the present invention, it is advantageous in that it is easier to add and disperse and that the operation can be saved, that it must be done correctly before the hot press training process. To cite a specific example of manufacture, when an agglomerate panel (hereinafter abbreviated as PB) is manufactured, for example, the relatively fine crushed woody materials are used for the surface layers, while the crushed woody materials of relatively thicker way are used for the central layers. After spraying formaldehyde-based binders into the materials Woody for the surface layers, the aforementioned aldehyde scavenger including a water repellent agent is added and dispersed. Similarly, a scrubber for aldehydes is added to the woody materials for the core layers. Although the aldehyde scavenger added to the surface layers and the aldehyde scavenger added to the core layers may be identical or different, the aldehyde scavenger used for the surface layers desirably does not affect the aesthetic appearance of the surface of a woody panel. On the other hand, a scrubber for aldehydes used for the central layers, desirably has a high purifying property for the aldehydes. Although the order of adding a scrubber for aldehydes that includes a water repellent agent is not specifically restricted, and the scrubber for aldehydes can be added directly to a binder or can be added before, after and at the same time a binder is added , from the process point of view, an aldehyde scrubber that includes a water repellent agent is added more desirably sooner or later or at the same time a binder is added to the woody materials. After that, laminates in the layers of the upper surface-middle layers-layers of the back surface, the materials are hot pressed (hot press forming process). Through a hot press, the woody materials are joined and a woody panel is manufactured. Although the general heating temperature is about 200 ° C, it is not specifically limited to this temperature. When the hot press forming process is carried out without a water-repellent agent present, a highly hygroscopic aldehyde scavenger acts as a water-absorbing agent and a woody panel absorbs water, thereby causing the size increase of a woody panel , the beginning of cracks and diminishing the aesthetic appearance of a surface. When a scrubber for aldehydes or a binding equipment of woody materials of the present invention is used for a woody panel, even after forming in a hot press, since a water-repellent agent which is hot-melt and dispersed prevents absorption of water from a woody panel, such a problem does not occur. In addition, when a medium density fiberboard (MDF) is manufactured, a woody panel can be manufactured by adding the aldehyde scrubber or equipment to join the woody materials in the same way. The additional content of an aldehyde scavenger in the manufacture of a woody panel to the woody materials is from 0.1 to 20.0% by weight, preferably from 0.5 to 10% by weight, and even more preferably, from 1.0 to 7.0. % in weigh.

The reason is that when the additional content is less than 0.1% by weight, a selected purifying property can not be obtained and on the other hand, when the additional content exceeds 20.0% by weight, the aesthetic appearance of a woody panel surface becomes worse, and the value as a product decreases, causing the cost of production to rise. The additional ratio of adding the water repellent agent and a scrubber for aldehydes to the woody materials is preferably 5/95 to 80/20 (weight ratio) and 10/90 to 60/40 (weight ratio) it is even more preferable. When the ratio is very large, the amount of one becomes excessive and the excessive portion does not contribute to the improvement of the quality of a woody panel and is wasted.

(Method for making woody panels with attached decorative sheets) The woody panels obtained through the above process have a preferred property as woody panels with decorative sheets attached. In many cases, woody panels with decorative glued sheets are used for indoor uses. Woody panels with decorative glued sheets are made by coating adhesives on a woody panel surface or by coating the adhesives on a surface of a decorative sheet, and then adhering both of them. Here, the decorative sheets are generally adhered by binding with heating and pressure, and at this stage, a woody panel is heated again and the formaldehyde remaining in the woody panel or formaldehyde is generated arising from the hydrolysis of a binder and emissions of formaldehyde from a woody panel are increased, which has been considered a problem. In this regard, in a woody panel obtained through the above process, an aldehyde scrubber of the present invention added at the time of making a woody panel remains in the woody panel, and since the aldehyde scrubber develops a scrubbing property again together With heating at the time of adhering the decorative sheets, the emissions of the aldehydes can be reduced. As the kinds of decorative sheets, for example, there are decorative paper sheets, decorative plastic sheets, decorative wooden sheets and the like. Furthermore, although the adhesives used to glue the adhesive sheets are not specifically limited and the binders based on formaldehyde, acrylic resins, vinyl chloride resins, diallyl phthalate resins and the like, which do not contain formaldehyde, can be used, They are generally used as adhesives. Decorative sheets can stick on a woody panel surface or they can stick on both surfaces. In addition, the adhesives may be coated on a surface of a woody panel or on a back surface of the decorative sheets, or on both surfaces on the bonded surfaces. The temperature of the process at the time of gluing the decorative sheets is not less than 60 ° C, preferably, it is not less than 70 ° C, and even more preferably, it is not less than 80 ° C. In addition, from the point of view of the purifying effect of the aldehydes, although there is no specific limitation for the upper limit of the temperature, in the case of pasting the decorative leaves, some problems may appear, such as the staining of the decorative leaves. and the like, and therefore, from this point of view, the upper limit of the temperature is preferably not greater than 160 ° and still more preferably not greater than 140 °. The time for the bonding process is the time required for the adhesives to cure and is generally from 10 seconds to 20 minutes. Since the formaldehyde emissions generated at the time of gluing these decorative sheets are less compared to those generated at the time of forming a woody panel as described above, when the temperature of the process is relatively low as 60 ° C, a satisfactory effect of reducing emissions of formaldehyde, by means of an aldehyde scavenger of the present invention, which remains in the woody panel.

(Example) Hereinafter, with reference to Examples and Comparative Examples, the present invention will be described in greater detail, however, the present invention is in no way restricted to the following Examples. In each Example, the parts and the% are on a mass basis, unless otherwise indicated.

(Example 1) (Manufacture of a woody panel) Woody raw materials, such as pieces of wood and the like, were crushed by a chipformer and sieved with a sieve whose opening is 1.7 mm, thus preparing the materials woody ones that pass through the opening as woody materials for the surface layers and woody materials that do not pass through the opening as the woody materials for the core layers. The woody materials for sieving were dried in a dryer with hot air at a temperature of 90 ° C, making the humidity no greater than 3%. Then, urea resin (nonvolatile content of 65%, urea: formaldehyde = 1: 1.2 mole) was used as a binder, with 55% wax emulsion, ammonium chloride as a curing agent and water, were mixed by 20 parts, 1 part, 0.5 parts and 2 parts, respectively (hereinafter, called mixture A). With respect to the 100 parts of woody materials for the surface layers, 25 parts of the mixture A were added by spraying and mixed uniformly. After that, 5 parts of powdered sodium acid sulfite as scavengers for aldehydes are added thereto and mixed, thus preparing the materials for the surface layers. Similarly, with respect to the 100 parts of the woody materials for the central layers, 15 parts of the mixture A and 5 parts of acid sodium sulfite powder as the aldehyde scavengers were added to them, preparing the materials for the central layers. Next, 250 parts of the materials for the back surface layers, 650 parts of the core layers and 250 parts of materials for the top surface layers were dispersed in the form of a 30 cm square in series, followed by the sandwich of the same between heating plates at 200 ° C and the hot pressing with a pressure of 40 kgf / cm2 for 90 seconds, obtaining therefore a woody panel with a thickness of 15.2 rare and with a density of 0.77 g / cm2.

(Evaluation) The formaldehyde emissions from the woody panels obtained by the aforementioned methods were captured and measured by a desiccating method based on a test method for agglomerate boards (JIS A 5908: 2003) and for the Determination of the emission of formaldehyde from construction boards (JIS A 1460: 2001). Sulfur dioxide gas emissions from a woody panel were captured and measured as follows. Sulfuric acid gas was captured in the same manner as in the test for formaldehyde emissions, except that 100 ppm of NaOH water was used, as capture water. The sulfurous acid gas becomes sodium sulfite and sodium sulfate in the capture water. To measure the concentration, an anion chromatograph manufactured by Nihon dionex K.K. was used, and the concentration was measured as the sulphite ion and the sulfate ion, and the fusion as the sulfurous acid gas was calculated from each concentration. The odor was evaluated by olfactory evaluation of the intensity of the odor arising from an aldehyde scrubber that was generated at the time of the hot press and the quality was determined. These results are shown in Table 4. In Table 4, the signs in the odor section mean the following.

Smell: ® for good (no smell) OR for light smell ? for odor x for relatively strong odor xx for strong odor (Examples 2 to 13, Comparative Examples 1 to 8) A woody panel was made based on the same method as in Example 1, except that the classes of the compounds for capturing the aldehydes were modified from those of Example 1, by preparing both a scavenger for aldehydes, and the evaluation was made as in Example 1. Here, all the compounds for capturing aldehydes are powdered. In addition, the same evaluation was done by changing the amount of a debugger for aldehydes to be added. The results are shown in Table 4 (Examples 2 to 13) and Table 5 (Comparative Examples 1 to 8).

[Table 4] [Table 5] Next, as reference examples, the same types of experiments were performed with respect to a liquid aldehyde scavenger. The manufacture of a woody panel was attempted by the same method as in Example 1, except that the sodium acid sulfite powder exposed in Example 1 was changed to aqueous solutions of sodium acid sulfite with the concentration set forth in Table 6 (Comparative Examples 9 and 10). However, under the condition of Comparative Examples 9 and 10, the woody materials do not bind and the woody panels can not be manufactured.

[Table 6] (Examples 14 to 23) Next, the results of an aldehyde scavenger including both the sulfurous acid gas generating compound by heating and the gas generating compound by heating are shown in Table 7 (Examples 14 to 2. 3) . Here, a debugger for aldehydes to be used was mixed uniformly beforehand, followed by fabrication of a woody panel by the same method as in Example 1.

[Table 7] (Examples 24 to 29, Comparative Examples 11 to 14) Next, the result of adding bisulfite as a compound having a property of generating an acid gas (sulphurous acid gas) by heating and sodium sulfite compounds, sulfite potassium or hydrazide, as the compounds with the property of capturing the aldehydes are publicly known, to a scrubber for aldehydes, is shown in Table 8 (Examples 24 to 29) and Comparative Examples (Comparative Examples 11 to 14) using two or more publicly known compounds with a property of capturing the aldehydes in a mixture, instead of using the compounds that generate the acid gas by heating, are shown in Table 9. Here, a scrubber for aldehydes to be used was mixed uniformly in advance, followed by the manufacture of a woody panel by the same method as in Example 1.

[Table 8] [Table 9] (Example 30) Next, a woody panel was made with the same method as in Example 1, except that a compound for capturing aldehydes was modified to be a compound for capturing aldehydes which is sodium acid sulfide, which generates the hydrogen sulfide by heating, and the same evaluation was made as in Example 1. The result is shown in Table 10.

[Table 10] (Examples 31 to 33) Next, a woody panel was manufactured by the same method as in Example 14 and evaluated in the same manner as in Example 14, except that instead of ammonium sulfite which is a compound that generates a basic gas by heating, the solid basic compounds (aluminum hydroxide, calcium hydroxide and calcium oxide) were used and that the ratio of the composition of the solid basic compounds to sodium acid sulfite was changed to 70/30. The results are shown in Table 11.

[Table 11] (Examples 34 to 37, Comparative Examples 15 to 16) A woody panel manufactured was evaluated by adding a powder aldehyde scavenger of the present invention only to the core layers of woody materials, formed by the same hot press forming process as in Example 1, followed by coating with the compounds with a property of capturing the aldehydes on both surfaces of a woody panel, as an aqueous solution and drying at room temperature. The result is shown in Table 12. Furthermore, as a comparison, the evaluation was also done on a woody panel manufactured by the same process, but using sodium sulfite, that is, the compounds that do not generate the sulfurous acid gas by heating , as a scrubber for aldehyde powder to the core layer. The result is shown in Table 13.

[Table 12] [Table 13] (Example 38) On a surface of a woody panel manufactured in Example 1, commercially available, bonded to work with wood (manufactured by Konishi Co. (Ltd., type without formaldehyde) was coated with 200 g / m2 followed by bonding of a decorative plastic sheet, therefore hot pressing at a temperature of 60 ° C for 5 minutes.The formaldehyde emissions of this woody panel with a decorative sheet stuck were measured (Examples 39 to 43, Comparative Examples 17 to 18) A woody panel with a glued decorative sheet was made by the same method as in Example 38, except that the woody panel to be used and the temperature of the bonding process were changed, and evaluated in the same manner as in Example 38 These results are shown in Table 14 (Examples 39 to 43) and Table 15 (Comparative Examples 17 to 18).

[Table 14] [Table 15] From the results of Tables 4 to 15 above, it is found that an aldehyde scavenger that uses the compounds to capture the aldehydes, which has a property of generating an acid gas (sulfurous acid gas, hydrogen sulfide gas) by heating , can greatly improve the property of the formaldehyde generated from an agglomerate panel compared to the use of known debuggers. Furthermore, when the "basicity compounds" are included therein, it is found that the scrubber can reduce the remaining acid gas and that the odor at the time of hot press formation can also be reduced. In addition, by combining the compounds of sodium sulfite, potassium sulfite and hydrazides, it was found that the odor at the time of manufacture can be improved. In addition, it was found that in a aldehyde scrubber of the present invention, the compositions of the surface layers and the core layers can be changed and used in combinations In addition, it was found that a woody panel obtained by the manufacturing method of the present invention develops a high purifying property of the aldehydes emitted during the process of gluing the decorative sheet.

(Examples 44 to 48 Evaluation of the coefficient of expansion of the thickness by water absorption) (Example 44) (Manufacture of woody panels) Woody raw materials such as pieces of wood and the like were crushed by a chip former and sifted with a sieve whose opening is 1.7 mm, thus preparing the woody materials that pass through the opening as the woody materials for the surface layers and the woody materials that do not pass through the opening as the woody materials for the central layers. The woody materials for sieving were dried in a dryer with hot air at a temperature of 90 ° C, making the humidity no greater than 3%. Then, urea resin (non-volatile content of 65%, urea: formaldehyde = 1: 1.2 mole) was used as a binder, with 55% wax emulsion, ammonium chloride as a curing agent and water, mixed by 20 parts, 1 part, 0.5 parts and 2 parts, respectively (here later, called mixture A). With respect to the 100 parts of woody materials for the surface layers, 25 parts of the mixture A were added by spraying and mixed uniformly. After that, 5 purifying parts for aldehyde powder including sodium acid sulfite (compounds for capturing the aldehydes) and paraffin waxes (water repellent agents) mixed with the ratio shown in Table 16, were added thereto, preparing Therefore, the materials for the layers of the surface. Similarly, with respect to the 100 parts of the woody materials for the core layers, 15 parts of the mixture A and 5 parts of the aldehyde scavengers were added thereto, preparing the materials for the core layer. Next, 250 parts of the materials for the back surface layer, 650 parts of the core layer and 250 parts of materials for the top surface layer were dispersed in the form of a 30 cm square in series, followed by the sandwich of the same between heating plates at 200 ° C and the hot pressing with a pressure of 40 kgf / cm2 for 90 seconds, thus obtaining a woody panel with a thickness of 15.2 mm and with a density of 0.77 g / cm2.

Here, the paraffin waxes (melting point 55 ° C) were ground in advance and those sieved with a sieve with an opening of 2 mm were used.

(Evaluation) In addition to evaluating the points that are the same as in Example 1, the coefficient of expansion of the thickness was measured by the absorption of water. The formaldehyde emissions and the coefficient of expansion of the thickness by water absorption were measured based on a test method for particle boards (JIS A 5908: 2003) and for the Determination of the emission of formaldehyde in construction boards (JIS A 1460 : 2001).

(Examples 45 to 48) A woody panel was made by the same method as in Example 44, except that the classes of the compounds for capturing the aldehydes or the water repellent agents have been changed, thus preparing a scrubber for aldehydes and the same evaluation was carried out as in the Example.

(Example 49) As an example without added water-repellent agent, the coefficient of expansion of the thickness was measured by water absorption in a woody panel manufactured in the Example 1. The results of Examples 44 to 49 as mentioned so far, are shown in Table 16. [Table 16] (Examples 50 to 57; Evaluation of resting angles) (Example 50) 79 parts of powdered sodium pyrosulfite (manufactured by DAITO CHEMICAL CO., LTD., Average particle size 173 μt?) Was placed in a mixer of trade name HIGH SPEED MIXER (manufactured by FUKAE POWTEC CO., LTD) and 20 parts of PARVA 1320, which is a paraffin wax with a melting point of 55 ° C (manufactured by Exon Mobil Co., Ltd) was melted in hot, followed by sodium pyrosulfite spray at a state of 65 ° C, thus granulating under the condition of granulation with a stirring number of Froude Fr of 1.1. At this time, the temperature of the powders was raised to 48 ° C. Then, the powders were cooled to 40 ° C, while maintaining the condition with a stirring number of Froude Fr of 1.1, followed by obtaining a scrubber for aldehydes and having confirmed that the temperature of the samples obtained reached a temperature of cooling (40 ° C), 1 part of CARPREX® # 67 (manufactured by DLS JAPAN), which is silica, was added. Finally, in a mechanical mill (manufactured by DALTON CO., LTD), the maximum particle size was adjusted to 3 mm, returning the particles with a particle size exceeding 3 mm to the granulator, followed by grinding and sieving , thus obtaining a scrubber for aldehydes of Example 50.

(Examples 51 to 57) A scrubber for aldehydes of Examples 51 to 57 was obtained by the same procedure as in Example 50, except that the raw material classes and the composition ratio were changed to those described in Table 17.

(Evaluation; Measurement of the angles of rest) The resting angles were measured in the Examples 50 to 57 that were obtained. For measurement, a rectangular container 1 was used as shown in Figure 1, with an opening door 2 in the upper portion, a side cover 3 in the short side. In addition, the width of the opening door 2 is 10 cm (longitudinal: ai) by 3 cm (horizontal: a2), and the height a3 is 10 cm, and the side cover 3 can be opened from the base portion and its size is 3 cm (horizontal: b2) by 8 cm (height: b3). First, approximately 280 cm3 of the powder samples were carefully placed from the opening port 2 of the upper portion of a container with the side cover 3 closed. Next, the side cover 3 was opened carefully with the container 1 held horizontally and after the powder samples flowed, the angle of a surface of the powder at the time when the powder samples stopped flowing and the angle T was defined as a resting angle of the samples. With respect to the aldehyde scrubber in Examples 50 to 57, the condition of composition of the raw materials and the manufacturing condition changed, and the powder properties obtained were organized in Table 17.

[Table 17] XI) Urea powder; industrial urea (powder: average particle diameter 264 μ:?, manufactured by Mitsui Chemicals Inc.) X'2) Paraffin wax; PARVAN 1320 (manufactured by Exon Mobil Co., Ltd) • X-3) Polyethylene; HI- AX 410P (manufactured by Mitsui Chemicals Inc.) X-4) Silica; CARPREX® # 67 (manufactured by DLS JAPAN) X-5) Zeolite; Toyobuilder® (manufactured by TOSOH CORPORATION) (Examples 58 to 62 s evaluation of the appearance of woody panels) Woody raw materials such as pieces of wood and the like were crushed by a chipformer and sieved with a sieve whose opening is 1.7 mm, preparing for both the woody materials that pass through the opening and the woody materials for the surface layers and the woody materials that do not pass through the opening as the woody materials for the core layers. The woody materials for sieving were dried in a dryer with hot air at a temperature of 90 ° C, making the humidity no greater than 3%. Next, urea resin was used (content of no volatile of 65%, urea: formaldehyde = 1: 1.2 moles) as a binder, with 55% wax emulsion, ammonium chloride as a curing agent and water, were mixed by 20 parts, 1 part, 0.5 parts and 2 parts , respectively (here later, called mixture A). On the other hand, an aldehyde scavenger manufactured in Example 50 was screened for each particle size by sieves with an aperture of 3 mm, 2 mm, 1 mm and 0.5 mm, respectively, thereby preparing an aldehyde scavenger of the Examples 58 to 62. The correspondence of the number of the Examples and the sieved powders is shown in Table 18. 25 parts of the mixture A were added by spraying to 100 parts of the woody materials for the surface layers and mixed in a uniform. Next, 5 parts of the sieved aldehyde scrubber were added and mixed, thereby preparing the materials for the surface layers. Likewise, 15 parts of the mixture A and 3 parts of the aldehyde scavengers manufactured by Example 50 were added to 100 parts of the woody materials, thus preparing the materials for a core layer. Next, 250 parts of the materials for a back layer, 650 parts of a core layer and 250 parts of the materials for the top surface layer, are dispersed in the form of a square of 30 cm in series, followed by the sandwiching of the same between the heating plates at 200 ° C and the hot pressing with a pressure of 40 kgf / cm2 for 90 seconds, thus obtaining a woody panel with a thickness of 15.2 mm and with a density of 0.77 g / cm2. With respect to the woody panel prepared by the above, the flexural strength, the resistance to separation, the coefficient of expansion of the thickness by absorption of water, formaldehyde emissions and appearance thereof were tested. Formaldehyde emissions, flexural strength, resistance to separation and water absorption and size increase were measured based on a test method for chipboard (JIS A 5908: 2003) and the determination of the emission of formaldehyde of construction boards (JIS A 1460: 2001). In addition, with respect to the appearance test, a surface of a woody panel obtained after the hot press formation was visually observed and the evaluation was made by verifying the presence of white spots, sizes, quantities and the like. The evaluation criteria are as follows. ®: good (no white spots discovered) OR: few fine white spots uncovered ?: many fine white spots or few larger white spots discovered x: many large white spots The previous woody panel test and the result are shown in Table 18.

[Table 18] Industrial Applicability A aldehyde scrubber of the present invention has industrial applicability as additives to be added to woody or binding materials in the bonding of woody materials with formaldehyde-based binders. In addition, the method of manufacturing a woody panel of the present invention has industrial applicability as the method of manufacturing agglomerate panels, plywood and woody fiber panels with few formaldehyde emissions.

Claims

WHAT IS REQUIRED IS: 1. An aldehyde scavenger used to aggregate or disperse in woody or binding materials, where the aldehyde scavenger is powdered at room temperature, the aldehyde scavenger includes at least one or more compounds to capture the aldehyde scavengers. aldehydes that are solid at room temperature, and the compounds to capture the aldehydes generate an acid gas by heating.
2. The aldehyde scavenger according to claim 1, wherein among the compounds for capturing the aldehydes, the acid gas generated by heating is sulfurous acid gas.
3. The aldehyde scavenger according to claim 1, wherein the acid gas generated from the compounds for capturing the aldehydes is the sulfurous acid gas and the concentration of the sulfurous acid gas generation is not less than 500 ppm when heated to a temperature of 140 ° C.
4. The aldehyde scavenger according to claim 1, wherein the acid gas generated from the compounds for capturing the aldehydes is sulfurous acid gas and the Initial decomposition temperature of the compounds to capture the aldehydes is not greater than 250 ° C.
5. The aldehyde scavenger according to claim 1, wherein the compounds for capturing the aldehydes are compounds that are either bisulfite, pyrosulfite and dithionite.
6. The aldehyde scavenger according to claim 1, wherein the compounds for capturing the aldehydes are either sodium acid sulfite, potassium acid sulfite, sodium pyrosulfite, potassium pyrosulfite, magnesium sulphite, zinc sulphite or aluminum sulfite.
7. The aldehyde scavenger according to claim 1, wherein the compounds for capturing the aldehydes are contained in 5 to 95% by weight with respect to the total amount of the aldehyde scavenger.
8. An aldehyde scavenger used to aggregate or disperse into woody or binding materials, where the aldehyde scavenger is powdered at room temperature and the aldehyde scavenger comprises compounds to capture the aldehydes that are solid at room temperature, which generate an acidic gas by heating and compounds that have a property of generating a basic gas by heating.
9. The aldehyde scavenger according to claim 8, wherein among the compounds having the property of generating the basic gas, the basic gas generated is ammonia.
10. The aldehyde scrubber according to claim 8, wherein the basic gas generated from the compounds having the property of generating the basic gas is ammonia gas and the concentration of the ammonia gas generation is not less than 500 ppm when heated to a temperature of 140 ° C.
11. The aldehyde scavenger according to claim 8, wherein the basic gas generated from the compounds having the property of generating the basic gas is ammonia gas and the initial decomposition temperature of the compounds having the property of generating the basic gas is not greater than 250 ° C.
12. The aldehyde scavenger according to claim 8, wherein the compounds having the property of generating the basic gas are any of urea, ethylene urea, ammonium sulfite or carbodihydrazide.
13. The aldehyde scavenger according to claim 8, wherein the initial thermal decomposition temperature of the compounds having the property of generating the basic gas by heating is higher by not less than 10 ° C than the initial temperature of the compounds to be captured. the aldehydes that have a property of generating the acid gas.
14. The aldehyde scavenger according to claim 8, wherein the weight ratio of the compounds for capturing the aldehydes and the compounds having the property of generating the basic gas is from 5/95 to 95/5.
15. An aldehyde scavenger used to aggregate or disperse into woody or binder materials, where the aldehyde scavenger is powdered at room temperature, the aldehyde scavenger includes compounds to capture the aldehydes that are solid at room temperature, which generate acid gas through heating and basic compounds.
16. The aldehyde scavenger according to claim 15, wherein the basic compounds are the compounds selected from the group of calcium oxides or hydroxides, aluminum, zinc or magnesium, sodium aluminate, alkyl amines and polyamine.
17. The aldehyde scavenger according to claim 15, wherein the weight ratio of the compounds for capturing the aldehydes and the basic compounds is from 5/95 to 95/5.
18. The aldehyde scavenger according to claim 1, which includes at least one of the compounds selected from the group of sodium sulfite, potassium sulfite and hydrazides, in addition to the compounds for capturing the aldehydes.
19. A woody panel made with the aldehyde scrubber according to claim 1, added to the woody materials.
20. A method for making a woody panel, comprising the process of: allowing a powder aldehyde scavenger including compounds to capture the aldehydes that are solid at room temperature and having a property of generating an acidic gas, is contained in the binders based on formaldehyde; add formaldehyde-based binders including an aldehyde scavenger obtained by the process to the woody materials; Y capture the aldehydes generated from the formaldehyde-based resin binders by the acid gas generated from the compounds to capture the aldehydes, together with a woody panel with the woody materials bonded by hot pressing of the woody materials with the binders obtained by the process .
21. A method for manufacturing a woody panel comprising the process of: adding the binders of the formaldehyde-based resin to the woody materials; allow a powder aldehyde scavenger, which includes the compounds to capture the aldehydes that are solid at room temperature and which have the property of generating the acid gas, to be dispersed and contained in the woody materials; and capture the aldehydes generated from the binders of the formaldehyde-based resin by the acid gas generated from the compounds to capture the aldehydes together with a woody panel with the woody materials bonded by hot pressing of the woody materials to which they are added the binders obtained through the two processes (regardless of the order of the process).
22. A method for manufacturing a woody panel, comprising the process of: adding the binders of the formaldehyde-based resin to the woody materials; allow a powder aldehyde scavenger that includes the compounds to capture the aldehydes that are solid at room temperature and that have a property of generating the acid gas, to be dispersed and contained in the woody materials; allowing compounds that have a property of generating a basic gas by heating to be dispersed and contained in the woody materials; capture the aldehydes generated from the binders of the formaldehyde-based resin by the acid gas generated from the compounds to capture the aldehydes, together with the woody panel with the woody materials bonded by hot pressing of the woody materials to which the binders obtained through the three processes (regardless of the order of the process); and remove the additional acid gas by the basic gas after the process.
23. A method for manufacturing a woody panel comprising the process of: adding binders of the formaldehyde-based resin to the woody materials; allow a powder aldehyde scavenger that includes the compounds to capture the aldehydes that are solid at room temperature and that have a property of generating the acid gas, to be dispersed and contained in the woody materials; allow the basic compounds to be dispersed and contained in the woody materials, the process of capturing the aldehydes generated from the binders of the formaldehyde-based resin by the acid generated from the compounds to capture the aldehydes together with a woody panel with the woody materials united by hot pressing of the woody materials, to which are added the binders obtained in the three processes (regardless of the order of the process); and remove the additional acid gas by the basic compounds after the process.
24. A woody panel, comprising the process of: adding a scrubber for aldehydes according to claim 1 to the woody materials to which the binders of the formaldehyde-based resin are applied prior to hot-press forming; and heating for at least 60 seconds at a temperature ranging from 100 to 300 ° C.
25. A woody panel, wherein a solution comprising one or more compounds selected from the group of sulfite, hydrogen sulfide, urea and its derivatives, hydrazides, is coated on at least one surface of a woody panel by adding a scrubber for aldehyde powder , which includes compounds for capturing the aldehydes that are solid at room temperature, which have a property of generating the acid gas by heating.
26. A method for removing aldehydes, comprising the process of: removing the aldehydes generated from woody materials by reaction with an acid gas generated from the aldehyde scavenger by heating the woody materials to which the resin based binders are added in formaldehyde and an aldehyde scavenger according to claim 1.
27. A method to eliminate the aldehydes and an acid gas, which comprises the process of: removing the acid gas generated from the woody materials by reacting with the acid gas generated from the aldehyde scrubber by heating the woody materials to which the resin binders based on formaldehyde and a scavenger for aldehydes according to claim 8; and removing the additional acid gas generated by the reaction with the basic gas.
28. A method for removing aldehydes and acid gas, which comprises the process of: removing the acid gas generated from woody materials by reacting with the acid gas generated from the aldehyde scrubber by heating the woody materials to which the binders of the formaldehyde-based resin and an aldehyde scavenger according to claim 15; and removing the additional acid gas generated by the reaction with the basic compounds contained in the aldehyde scavenger.
29. A method for manufacturing a woody panel glued with a decorative sheet, comprising the process of: coating an adhesive on at least one surface and / or a surface of the decorative sheet of a woody panel made by adding a scrubber for aldehyde powder including compounds for capturing aldehydes that are solid at room temperature, which generate an acid gas by heating to woody materials; Y paste a decorative sheet at a temperature of 60 to 160 ° C.
30. A woody panel glued with a decorative sheet obtained by a method of manufacturing a woody panel glued with a decorative sheet according to claim 29.
31. A purifier for aldehydes used to aggregate to or be dispersed in woody or binding materials, where the aldehyde scavenger is powdered at room temperature, the aldehyde scavenger includes compounds to capture the aldehydes that are solid at room temperature, which generate an acid gas by heating and water repellent agents that are solid at room temperature.
32. The aldehyde scrubber according to claim 31, wherein the water repellent agents are waxes with a melting point of 40 to 140 ° C.
The aldehyde scrubber according to claim 31, wherein the water repellent agents are any of carnauba waxes, ozokerite, castor waxes, paraffin waxes, microcrystalline waxes, hydrogenated oils or polyethylene waxes.
34. The aldehyde scavenger according to claim 31, wherein the water repellent agents are paraffin waxes or hydrogenated oils and fats.
35. The aldehyde scrubber according to claim 31, wherein the water repellent agents are contained from 5 to 80% by weight in the aldehyde scrubber.
36. An equipment for joining woody materials used in the manufacture of a woody panel, adhering the woody materials, wherein the equipment is constituted at least of binders of the formaldehyde-based resin, a scrubber for aldehydes according to claim 1, and a repellent agent to powdered water that includes one or more water repellent agents that are solid at room temperature.
37. The equipment for joining woody materials according to claim 36, wherein the water repellent agents are waxes with a melting point of 40 to 140 ° C.
38. The equipment for joining woody materials according to claim 36, wherein the water repellent agents are any of carnauba waxes, ozokerite, waxes of Castor, paraffin waxes, microcrystalline waxes, oils and hydrogenated fats or polyethylene waxes.
39. The equipment for bonding woody materials as set forth in claim 36, wherein the water repellent agents are paraffin waxes or are hydrogenated oils and fats.
40. The woody panel made with at least the aldehyde scrubber according to claim 1 and the water repellent agents which are solid at room temperature.
41. A method for making a woody panel, comprising: the addition process of adding a binder based on formaldehyde, the compounds to capture the aldehydes that are solid at room temperature, which has the property of generating the acid gas by heating, and agents water repellents that are solid at room temperature to woody materials; and the hot pressing process of heating the woody materials with applied pressure, joining the woody materials, thus forming a woody panel.
42. The method for manufacturing a woody panel according to claim 41, wherein the addition ratio of the water repellent agent and the compounds to capture the aldehydes added to woody materials in the addition process is 5/95 to 80/20 (weight ratio). •
43. An aldehyde scrubber that is powder at room temperature, which includes at least one or more compounds that are solid at room temperature that have the property of generating the acid gas by heating, one or more water repellent agents that are solid at temperature environment, and one or more anti-caking agents.
44. The aldehyde scavenger according to claim 43, wherein the anticaking agents are the compounds selected from the group of carbonate compounds, silicate compounds and aluminosilicate compounds.
45. The aldehyde scavenger according to claim 43, wherein not less than 70% by weight of the particles contained in the powder aldehyde scavenger have a particle diameter of not more than 2 mm.
46. A method for making an aldehyde scavenger that is powder at room temperature, which includes one or more compounds to capture the aldehydes, which are solid at room temperature, which have a property of generating the acid gas by heating, one or more agents water repellents that are solid at room temperature, and one or more anti-caking agents, wherein the method comprises: (1) the process of melting the water repellent agents; (2) the process of dripping or spraying molten water repellent agents at a state higher than their melting point by 1 to 20 ° C, while stirring and mixing the compounds to capture the aldehydes after the process (1); (3) the process of cooling the mixture obtained by process (2), while stirring and mixing; (4) the process of adding in addition the anti-caking agents at the point where the mixture is cooled to the temperature lower than a melting point of the water repellent agents by 10 to 50 ° C in the process (3); and (5) the sieving process of sifting the mixture obtained by the process (4), thereby obtaining the debugger for aldehyde powder.
47. The method for manufacturing an aldehyde scavenger according to claim 46, wherein the stirring treatment is carried out under the condition that the Froude Fr number is not less than 0.1 and less than 5.0, defined by the following formula (i) in the stirring and mixing of processes (2) and (3). Fr = V / [(R x g) 0 5] (i) (in formula (i), V represents the circumferential velocity [m / s] at the tip end of a stirring blade, R represents a radius of rotation [m] of the stirring blade and g represents the gravitational acceleration.
48. A woody panel obtained by adding at least one binder based on formaldehyde and a purifier for aldehydes according to claim 43 to the woody materials, followed by the application of the hot press formation in the woody materials.