JPS6260241B2 - - Google Patents

Description

[Detailed description of the invention]

FIELD OF INDUSTRIAL APPLICATION The present invention relates to a method for dimensional stabilizing treatment of wood materials. Prior Art and its Problems As is well known, wood materials exhibit considerable elasticity, and the elasticity originates from the original structural organization of these materials and their moisture content. For example, water contained in the inner cell lumen and intercellular spaces of wood tissue is called free water or free water, and water adsorbed to cell membranes is called bound water or adsorbed water. Wood immediately after being felled, ie, green wood, contains bound water and free water. The moisture content varies considerably depending on the tree species, production area, etc., and approximately
In some cases, the increase is more than 30%, and in some cases it is even more than 150%. When raw materials are left to dry naturally or are artificially dried to a similar state, the moisture content decreases to an air-dried state. In the process of drying wood, first free water is released and then some of the adsorbed water is released. This is determined by the tree species and the temperature and humidity of the area where it is left to dry. Although there are some differences depending on the equilibrium moisture content, etc., it is almost constant and is typically 12 to 15%. Furthermore, the state where the cell membrane is saturated with bound water and contains no free water before air-drying is called the fiber saturation point, and the water content is generally approximately constant at around 28%. The relationship between moisture content and elasticity of wood is as follows. That is, when the moisture content is above the fiber saturation point, wood does not expand or contract regardless of its increase or decrease, but when it is below the fiber saturation point, it expands or contracts in proportion to the increase or decrease in the moisture content. Wood materials are widely used as constituent materials for furniture such as cupboards, chests of drawers, dressing tables, and buildings. However, one of its main drawbacks is its considerable stretchability, ie its lack of dimensional stability. Therefore, it is used as a constituent material in a state in which it has the least expansion and contraction under normal usage conditions, that is, in a state that has been dried to an air-dry state. However, the moisture content may fluctuate in response to changes in the equilibrium moisture content of the location where it is used, resulting in considerable expansion and contraction, resulting in deformation, distortion, cracking, etc.
This is an important issue in the field of wood processing, and it is also a difficult issue to solve due to the unique properties of wood materials. For this reason, various methods of dimensional stabilization have been considered. Namely, methods using high-temperature heat treatment, methods using synthetic resin injection, formalization treatment using formaldehyde, acetylation treatment using acetyl groups, polyether injection treatment, etc., are known, but none of them are effective in terms of performance or economy. Satisfactory results have not been obtained. Among these treatment methods, the one that is currently attracting the most attention is the polyether injection treatment method.
In this method, polyethers themselves have high hydrophilicity and therefore have high hygroscopicity, and low molecular weight ones that can be used for dimensional stabilization of wood are liquid or semi-solid. It imparts a wet feel to the surface of treated wood, tends to cause contamination, and leaches over time under conditions of normal use. Furthermore, when it comes into contact with water, it easily dissolves out, reducing its dimensional stabilizing effect. Means for Solving the Problems The present inventor has continued to conduct intensive research to eliminate these drawbacks, and has found that when polyethers and specific substances are used together, the desired purpose can be achieved. The present invention was finally completed based on this discovery. That is, the present invention comprises (i) 15 to 30% by weight of polyethylene glycol and/or polypropylene glycol, and (ii) solid wax, ethylene urea, palmitic acid amide, oleic acid amide, stearic acid amide, acetanilide, p-anisidine,
At least one of maleic anhydride, dimethyl isophthalate, dimethyl terephthalate, naphthalene, α-naphthol, benzoic acid, 4-t-butylcatechol, and paradichlorobenzene 85-70
% by weight to liquefy the mixture and impregnate the wood material with the liquefied mixture. In the present invention, a mixture of a specific substance that is solid at room temperature and polyethers is usually heated at about 40 to 180°C to liquefy it, impregnated into a wood material, and then cooled and solidified. It can be immobilized in wood materials, suppressing leaching, elution and moisture absorption of polyethers, and imparting dimensional stability. Examples of polyethers used in the present invention include polyethylene glycol and polypropylene glycol, and these may also be used in combination. In the present invention, solid paraffin, vegetable wax, animal wax, solid wax such as carnauba wax, microcrystalline wax, ethylene urea, palmitic acid amide, and olein are used in combination with polyethers. Acid amide, stearamide, acetanilide, p
- Anisidine, maleic anhydride, dimethyl isophthalate, dimethyl terephthalate, naphthalene, α
- At least one of naphthol, benzoic acid, 4-t-butylcatechol and paradichlorobenzene is used. All of the above-mentioned substances used in combination with polyethers in the present invention are liquid at about 40 to 180°C, but become solid by crystallization, solidification, etc. when brought to room temperature. Therefore, when liquefying a mixture of each of the above substances and polyethers, the mixture of the above substances and polyethers is heated to a temperature above the melting point of the substance, usually about 40 to 180°C to melt it. good. In the present invention, when impregnating a wood material with the liquefied material, there is no particular restriction on the impregnation method, and various means such as normal pressure, reduced pressure, pressurization, reduced pressure-pressure, etc. can be effectively applied. For example, a method can be exemplified in which a wood material is immersed in the above-mentioned melted mixture of a substance that is solid at room temperature and a polyether, and impregnated at a pressure of usually 50 kg/cm ² or less. The ratio of polyethers to the above substances that are solid at room temperature is 15 to 30.
% by weight, the latter 85-70% by weight. Examples of wood materials used in the present invention include wood, fiberboard, particle board, plywood, and the like. Woods include fir, cypress, cedar, larch, spruce, pine, togasakura, hemlock, koyamaki, agathis, maple, alder,
Birch, beech, ash, lily tree, magnolia, cottonwood, elm, zelkova, sen, ash, camphor, linden, lauan, thorn, shioji, jiyonkon, zelton, ply, elm tree, rubber tree, pencil cedar, carophyllum, town, quince, bubinger etc. can be exemplified. Effects of the Invention Wood materials treated with the dimensional stabilization method of the present invention do not give a wet feel to the surface, and not only have improved hygroscopicity, but also greatly improve the dissolution and leaching of polyethers. As a result, surface contamination is eliminated, and the dimensions of furniture, buildings, etc. constructed with the wood material can be stabilized. Examples The present invention will be specifically described below with reference to Examples and Comparative Examples. Example 1 In a mixture containing 20% by weight of polyethylene glycol (average molecular weight 1540), 65% by weight of microcrystalline wax, and 15% by weight of ethylene urea, which was heated and melted at 110°C in a pressurized container, 5 mm in the fiber direction,
Paulownia cut 30mm in the radial direction and 30mm in the tangential direction was immersed, impregnated under pressure at 7 kg/cm ² for 3 hours, then brought to normal pressure, the impregnated material was removed and cooled, and the mixed melt was fixed in the paulownia wood. (The amount of impregnation of the mixture was 0.60 g/cm ³ based on the volume of paulownia). In order to confirm the degree of dimensional stabilization of the wood material obtained in this way, the shrinkage rate and anti-shrinkage rate were calculated based on the following formula. In order to confirm the extent to which the moisture absorption, moisture absorption, and wet feel were improved, the elution amount, moisture absorption, and wet feel were calculated based on the following formulas and methods. As shown in Table 1, good test results were obtained. <Shrinkage rate and anti-shrinkage rate> Measure the dimensions after leaving the test piece in a desiccator adjusted to a temperature of 25℃ and a relative humidity of 85% for 30 days, and then place it in a desiccator adjusted to a temperature of 25℃ and a relative humidity of 30%. The dimensions were measured after being left in a desiccator for 30 days, and calculated using the following formula. Shrinkage rate = L ₁ - L ₂ / L ₁ × 100 L ₁ : At a temperature of 25°C and relative humidity of 85% (equilibrium moisture content of 18
%) Dimension L ₂ : Temperature 25℃, relative humidity 30% (equilibrium moisture content 6
%) Dimensions Anti-shrinkage rate = D _p - D / D _p × 100 D _p : Shrinkage rate of untreated material (%) D: Shrinkage rate of treated material (%) <Dissolution> The test piece was heated at a temperature of 25°C. The sample was left in a desiccator adjusted to relative humidity 50% (equilibrium moisture content 9%) for 10 days and weighed, then immersed in water at a temperature of 25°C for 8 hours, and then returned to a temperature of 25°C and relative humidity of 50%. The sample was left in an adjusted dessicator for 10 days, the weight was measured, and the weight was calculated using the following formula. Elution amount = W ₁ - W ₂ (mg) W ₁ : Weight (mg) at temperature 25℃ and relative humidity 50% before immersion (mg) W ₂ : Weight (mg) at temperature 25℃ and relative humidity 50% after immersion ) <Hygroscopicity> The test piece was left in a desiccator adjusted to a temperature of 25°C and a relative humidity of 30% (equilibrium moisture content 6%), and then its weight was measured.
After being left in a desiccator adjusted to 85% (equilibrium moisture content 18%) for 24 hours, the weight was measured and calculated using the following formula. Moisture absorption = W ₃ - W ₄ (mg) W ₃ : Weight at temperature 25℃ and relative humidity 85% (mg) W ₄ : Weight at temperature 25℃ and relative humidity 30% (mg) <Feel of wetness> The test piece was left in a desiccator adjusted to a temperature of 25℃ and a relative humidity of 30% (equilibrium moisture content 6%) for 10 days, and then the degree of wetness was evaluated by a sensory test. Humidity 85% (equilibrium moisture content 18
The degree of wet feeling after being left in a desiccator adjusted to %) for 10 days was similarly evaluated by a sensory test. 〇 Mark: Wetting feeling not observed △ mark: Wetting feeling is weak × mark: Wetting feeling is strong In addition, calculations were made based on this formula and method in the following Examples and Comparative Examples as well. Comparative Example 1 5 mm in the fiber direction, 30 mm in the radial direction, and 30 mm in the tangential direction in an aqueous solution containing 20% by weight of polyethylene glycol (average molecular weight 1540) heated to 110°C in a pressurized container.
Paulownia cut into 30 mm pieces was immersed and impregnated under pressure at 7 kg/cm ² for 3 hours, then the pressure was reduced to normal pressure, the impregnated material was taken out, and the room temperature was 25°C and relative humidity was 50% (equilibrium moisture content 9%).
The paulownia wood was left to dry (the amount of polyethylene glycol impregnated was 0.59 g/cm ³ based on the volume of paulownia wood).
The test results are shown in Table 1. Example 2 15% by weight of polypropylene glycol (average molecular weight 400), 10% by weight of microtalistaline wax, 40% by weight of dimethyl isophthalate and dimethyl terephthalate heated and melted at 110°C in a heating container.
After immersing paulownia cut into a 35% by weight mixed melt at 5 mm in the fiber direction, 30 mm in the radial direction, and 30 mm in the tangential direction, the material was impregnated under pressure at 5 kg/cm ² for 2 hours, and then the impregnation material was reduced to normal pressure. It was taken out and cooled, and the mixed melt was fixed in the paulownia wood (the amount of the mixed melt impregnated was 0.60 g/cm ³ based on the volume of paulownia). As shown in Table 1, good test results were obtained. Comparative Example 2 Paulownia wood cut into 5 mm in the fiber direction, 30 mm in the radial direction, and 30 mm in the tangential direction in a mixed melt of 15% by weight of polypropylene glycol (average molecular weight 400) and 85% by weight of water heated and melted at 110°C in a pressurized container. After soaking, the material was impregnated under pressure at 5 kg/cm ² for 2 hours, then the impregnated material was removed from normal pressure and cooled at a temperature of 25°C and relative humidity of 50%.
The paulownia wood was left in a room with an equilibrium water content of 9% and dried to impregnate the paulownia wood with polypropylene glycol (the impregnated amount of the mixed melt was 0.60 g per paulownia volume).
^cm3 ). The test results are shown in Table 1. Example 3 10% by weight of oleic acid amide, 60% by weight of stearamide and polyethylene glycol (average molecular weight
600) In a 30% by weight mixed melt, fiber direction 5
After soaking the paulownia cut into 30 mm in the radial direction and 30 mm in the tangential direction, the paulownia wood was impregnated with a pressure of 7 kg/cm ² for 4 hours, then the impregnated material was removed from normal pressure and cooled, and the mixed melt was fixed in the paulownia material. (The amount of impregnation of the mixed melt was 0.61 g/cm ³ based on the volume of paulownia). As shown in Table 1, good test results were obtained. Comparative Example 3 30% by weight of polyethylene glycol (average molecular weight 600) and water heated and melted at 100°C in a pressurized container
After immersing paulownia cut into a 70% by weight mixed melt at 5 mm in the fiber direction, 30 mm in the radial direction, and 30 mm in the tangential direction, the material was impregnated under pressure at 7 kg/cm ² for 4 hours, and then reduced to normal pressure. Take it out and cool it to a temperature of 25℃ and relative humidity.
It was left in a room at 50% (equilibrium moisture content 9%) and dried to impregnate the paulownia wood with polyethylene glycol (the impregnated amount of the mixed melt was 0.62 g per paulownia volume).
^cm2 ). The test results are shown in Table 1. Comparative Example 4 The test results of untreated paulownia used as a wood material are shown in Table 1. Example 4 50% by weight of carnauba wax, 10% by weight of acetanilide, p-
5 mm in the fiber direction, 30 mm in the radial direction, and 30 mm in the tangential direction in a mixture consisting of 20% by weight of anisidine, 5% by weight of polypropylene glycol (average molecular weight 400), and 15% by weight of polyethylene glycol (average molecular weight 1540).
Paulownia cut into 30 mm pieces was immersed and impregnated under pressure at 9 kg/cm ² for 4 hours, then brought to normal pressure, the impregnated material was taken out and cooled, and the mixed molten material was fixed in the paulownia wood (mixed molten material). The amount of material impregnated was 0.62 g/cm ³ based on the volume of paulownia). The test results were good as shown in Table 1. Comparative Example 5 5% by weight polypropylene glycol (average molecular weight 400) and 15% by weight polyethylene glycol (average molecular weight 1540) heated to 110°C in a pressurized container.
5 mm in the fiber direction, 30 mm in the radial direction,
Paulownia cut 30mm in the tangential direction was immersed and impregnated at 9 kg/cm ² for 4 hours before being brought to normal pressure.The impregnated material was removed, and the room temperature was 25°C and relative humidity was 50% (equilibrium moisture content 9%).
The mixture was left to dry (the amount of impregnation of the mixture was 0.61 g/cm ³ based on the volume of paulownia). The test results are shown in Table 1. Example 5 Naphthalene heated and melted at 100°C in a pressurized container
60% by weight, 10% by weight of dimethyl terephthalate and 30% by weight of polyethylene glycol (average molecular weight 600), 5mm in the fiber direction and 30% in the radial direction.
mm, paulownia cut 30mm in the tangential direction, soaked, 7Kg/
After pressure impregnation at cm ² for 4 hours, the pressure was reduced to normal pressure, the impregnated material was taken out and cooled, and the mixed melt was fixed in the paulownia wood (the impregnated amount of the mixture was 0.61 per paulownia volume).
g/ ^cm3 ). The test results were good as shown in Table 1. Example 6 60% by weight of p-dichlorobenzene, 10% by weight of stearamide, polyethylene glycol (average molecular weight
600) fiber direction 5 in a mixture consisting of 30% by weight
Paulownia cut into 30 mm, radial direction, and tangential direction 30 mm was immersed and impregnated under pressure at 7 kg/cm ² for 4 hours, then brought to normal pressure, the impregnated material was taken out, cooled, and the mixed melt was poured into the paulownia wood. It was fixed (the amount of the mixture impregnated was 0.62 g/cm ³ based on the volume of paulownia). The test result is the first
As shown in the table, the results were good. Example 7 4-t- heated and melted at 110°C in a pressurized container
In a mixture consisting of 20% by weight of butylcatechol, 25% by weight of α-naphthol, 30% by weight of maleic anhydride, 10% by weight of microcrystalline wax and 15% by weight of polypropylene glycol (average molecular weight 400), 5 mm in the fiber direction and 5 mm in the radial direction. 30mm, tangential
Paulownia cut into 30 mm pieces was immersed and impregnated under pressure at 5 kg/cm ² for 2 hours, then brought to normal pressure, the impregnated material was taken out and cooled, and the mixed melt was fixed in the paulownia material (the amount of impregnation of the mixture was 0.60 g/cm ³ based on the volume of paulownia). The test results were good as shown in Table 1. Example 8 Benzoic acid heated and melted at 110°C in a pressurized container
20% by weight, 60% by weight of microcrystalline wax, polyethylene glycol (average molecular weight 1540)
Paulownia wood cut into 5 mm in the fiber direction, 30 mm in the radial direction, and 30 mm in the tangential direction is immersed in a mixture consisting of 20% by weight,
After pressure impregnation at 7Kg/ ^cm2 for 3 hours, normal pressure was removed.
The impregnating material was taken out and the mixed molten material was fixed in the paulownia wood (the impregnated amount of the mixed molten material was 0.62% of the volume of paulownia wood).
g/ ^cm3 ). The test results were good as shown in Table 1.

[Table] Example 9 A mixed melt of 20% by weight of polypropylene glycol (average molecular weight 700) and 80% by weight of palmitic acid amide heated and melted at 95°C in a pressurized container contains 5 mm in the fiber direction, 30 mm in the radial direction, and 30 mm in the tangential direction. Paulownia cut into 30 mm pieces was immersed and impregnated under pressure at 9 Kgf/cm ³ for 3 hours.The impregnated material was then removed from the atmosphere and cooled to fix the mixed molten material in the paulownia wood. The amount of impregnation of the mixed melt was 0.62 g/cm ³ based on the volume of paulownia. The test results are shown in Table 2. Comparative example 6 Polypropylene glycol (average molecular weight 700)
Polypropylene glycol was impregnated into paulownia wood in the same manner as in Example 9 except that a 20% by weight aqueous solution was used. The test results are shown in Table 2. Example 10 A mixture of 70% by weight dimethyl terephthalate and 30% by weight polyethylene glycol (average molecular weight 600) heated and melted at 85°C in a pressurized container was cut into 5 mm in the fiber direction, 30 mm in the radial direction, and 30 mm in the tangential direction. The paulownia wood was soaked and impregnated under pressure at 7 Kgf/cm ³ for 4 hours, then the pressure was reduced to normal pressure, the impregnation material was taken out, and the mixed melt was fixed in the paulownia material. The amount of the mixed melt impregnated into the paulownia wood was 0.60 g/cm ³ based on the volume of the paulownia wood. The test results are shown in Table 2. Example 11 A mixed melt consisting of 15% by weight of polypropylene glycol (average molecular weight 400) and 85% by weight of naphthalene heated and melted at 110°C in a pressurized container was cut into 5 mm in the fiber direction, 30 mm in the radial direction, and 30 mm in the tangential direction. The paulownia wood was immersed and impregnated under pressure at 5 kgf/cm ³ for 2 hours, and then the pressure was reduced to normal. The impregnated material was taken out and cooled, and the mixed melt was fixed in the paulownia wood. The amount of impregnation of the mixed melt was 0.60 g/cm ³ based on the volume of paulownia. The test results are shown in Table 2.

【table】

Claims (1)

[Scope of Claims] 1 (i) 15 to 30% by weight of polyethylene glycol and/or polypropylene glycol, and (ii) solid wax, ethylene urea, palmitic acid amide, oleic acid amide, stearic acid amide, acetanilide, p-anisidine ,
At least one of maleic anhydride, dimethyl isophthalate, dimethyl terephthalate, naphthalene, α-naphthol, benzoic acid, 4-t-butylcatechol, and paradichlorobenzene 85-70
% by weight to liquefy the mixture and impregnate the wood material with the liquefied mixture.