JPS5842411A - Stabilizing treatment method for size of woody material - Google Patents

Abstract

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

Description

[Detailed description of the invention] The present invention relates to dimensional stabilization of wood-based materials.

As is well known, wood materials exhibit considerable elasticity, and this elasticity is derived 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 depending on conditions such as the tree species and place of production, but in some cases it can reach 30% or more and in some cases it can reach 150% or more. 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., #1 is almost constant and is typically 12 to 15%. Furthermore, the state where the cell membrane is saturated with bound water and does not contain free water before reaching the air-dry state 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, at the moisture content of the fiber saturation point -F, wood does not expand or contract regardless of its increase or decrease, but 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 where it has the least expansion and contraction under normal usage conditions, that is, in a state where it has been dried to an air-dry state. However, the moisture content fluctuates in response to changes in the equilibrium moisture content at the location of use, and therefore still expands and contracts considerably.
The occurrence of deformation, warping, cracking, etc. is an important issue in the field of wood processing, and is also a difficult issue to solve due to the inherent 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 satisfactory in terms of performance and economy. I'm not getting the results I want. Among these treatment methods, the one that is currently attracting the most attention is the polyether injection treatment method, but in this method, the polyethers themselves have large hydrophilic properties. Therefore, it has a high hygroscopicity and is a liquid or semi-solid of low molecular weight that can be used for dimensional stabilization of wood.Therefore, it gives a wet feel to the surface of treated wood materials and is easy to cause contamination and is usually used. exudate over time in the condition. Furthermore, when it comes into contact with water, it easily dissolves out, reducing its dimensional stabilizing effect.

As a result of continuing intensive research to eliminate these drawbacks, the inventor of the present invention discovered that when polyethers and specific substances are used together, the desired purpose can be achieved. The invention was completed. That is, the present invention relates to a method for dimensional stabilizing wood materials, which comprises heating a mixture of polyethers and a substance that is solid at room temperature to liquefy it, and impregnating the wood material with the mixture.

In the present invention, a mixture of a substance that is solid at room temperature and a polyether is liquefied by heating at a temperature of usually about 40 to 180°C, and the mixture is impregnated into a wood material and then cooled and solidified. It can be immobilized in materials, suppress leaching, elution, and moisture absorption of polyethers, and provide dimensional stability.

Examples of polyethers used in the present invention include polyethylene glycol and polyethylene glycol, and these can also be used in combination.

The substance that is solid at room temperature used in the present invention is 40
A substance is used that is liquid at about 180° C. but becomes solid by crystallization, solidification, etc. when brought to room temperature. Preferred specific examples include solid paraphytes, 0 plants, 0 animals, 0 petroleum, microcrystalline wax, stearic acid, acetanilide, urea, dimethylurea, ethylene urea, dimethyl isophthalate, dimethyl terephthalate, lauric acid, Adhihisic acid, sulfamic acid acid,
; Zinc stearate, benzoic acid, trimethylic acid, ester gum, maleic anhydride, zinc oleic acid, lithic acid, sebacic acid, myristic acid, valmitic acid, chirecipis stearamide, methic acid 0-cystea amide, oleic acid amide, stearic acid amide, methyrecipitate stear amide, ma 0. ．． '
Acid % carnauba wax, acysulanilic acid, α-naphthylaminic acid, α-naphthol, butylcatechol, acetoacetic acid-olyanilide, P-anisidine, magnesium acetate, phthalic anhydride, sodium acetate,
Polyethylene with a molecular weight of approximately 500 to 5000, molecular weight approximately 2
00 to 5000 polyester, molecular weight approximately 600 to 3
000 petroleum resin, polyethylene having a molecular weight of approximately 300 to 5000, naphthalic acid, P-dichlorobethicene, etc., which may be used alone or in combination of two or more.

In the present invention, when liquefying a mixture of a substance that is solid at room temperature and polyethers, the mixture of the above-mentioned solid substance and polyethers is heated at a temperature higher than the melting point of the solid substance, usually 40 to 18
It may be thermally melted by heating to about 0°C. In the present invention, when impregnating wood materials with the liquefied material, there are no particular restrictions on the impregnation method; normal pressure, reduced pressure, pressurization, reduced pressure.
Various means such as pressurization can be effectively applied, such as a method in which a wood material is immersed in a melted mixture of a substance that is solid at room temperature and a polyether, and impregnated at a pressure of usually 50 kg/cr4 or less. The ratio of polyethers to solids is 2 to 50% by weight of polyether, preferably 5 to 20% by weight.
It is about % by weight.

Examples of wood materials used in the present invention include wood, fiberboard, particle board, and plywood.

Wood is fir, shinoshi, f1 larch, spruce,
pine, togasakura, hemlock,]tsuP mashi, agathis, maple, hasinoshi, hippo, zusu, ash, yurino +, seven reshi, ha] sena ko, nishi, keya +, seshi, ri ℃, cus ,
Examples include Shinanoshi, Rawashi, Shiri, Shioji, Joshikoshi, Zeruton, Prai, Nemunoshi, Gomunoshi, Pescicilciter, Calophyllum, Taushi, Karishi, Pupishika.

Wood materials treated with the dimensional stabilization method of the present invention not only have improved hygroscopicity without giving the surface a wet feel, but also greatly improve the elution and leaching of polyethers,
As a result, surface contamination is eliminated, and the dimensions of furniture, buildings, etc. constructed using the wood material can be stabilized.

The present invention will be specifically explained below by giving Examples and Comparative Examples.

Example 1 In a mixed melt of 50% by weight of stearic acid, 40% by weight of rosefish (melting point 70°C) and 10% by weight of polyethylene glycol (average molecular weight 200) heated and melted at 95°C in a pressurized container, fiber direction fibers were added. After soaking the paulownia cut in the fin, radial direction 30113+, tangential direction 30iu+, 9”f
/ cni for 3 hours, the impregnation material was drained out and cooled to fix the mixed melt in the paulownia wood (the impregnated amount of the mixed melt is based on the volume of paulownia wood). 0.64t
/ctl).

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 using the following formula. In order to confirm the extent to which the moisture absorption, hygroscopicity, and wet feel were improved, the amount of elution, moisture absorption, and wet feel were calculated using the following formulas and methods. The test results are shown in Table 1. Good results were obtained.

<Shrinkage rate and anti-shrinkage rate> Dimensions were measured after the test piece was left in a desiccator adjusted to a temperature of 25°C and relative humidity of 85% for 30 days, and then adjusted to a temperature of 25°C and relative humidity of 30%. desiccator
The dimensions after being left in the container for 30 days were measured and calculated using the following formula.

L work: Dimension L2 at temperature 25°C and relative humidity 85°C (equilibrium moisture content 18%): Dimension Do at temperature 25°C and relative humidity 30°C (equilibrium moisture content 6%): Shrinkage rate of untreated material ( %) D: Shrinkage rate of treated material (excellent) <Dissolution> The test piece was placed at a temperature of 25℃ and a relative humidity of 50℃ (equilibrium water content 9%).
) and then left in a desiccator adjusted to 10 days and weighed, then immersed in water at a temperature of 25°C for 8 hours, and then placed in a desiccator adjusted to a temperature of 25°C and relative humidity of 5°C.
The weight was measured after being left in the container for 10 days, and the weight was calculated using the following formula.

Elution amount -W□-'2 (mg) W□: Weight before immersion at a temperature of 25°C and relative humidity of 50% (mq) W2: Weight after immersion at a temperature of 25°C and relative humidity of 50% (η) <Hygroscopicity> The test piece was placed at a temperature of 25℃ and a relative humidity of 30℃ (equilibrium moisture content 6q).
6) After being left for 10 days in a desiccator adjusted to 60 Moisture absorption amount - F3 - F4 (η) W3: Weight at temperature 25℃, relative humidity 85% (■) Wl: Temperature 25℃, relative humidity 30% Weight (■) <Feel of wetness> The test piece was placed at a temperature of 25℃ and relative humidity of 30℃ (equilibrium moisture content of 6%).
) The degree of wetness after being left in a desiccator for 10 days was evaluated by a sensory test.
After being left in a desiccator adjusted to 5° C. and a relative humidity of 85° (equilibrium moisture content 18%) for 10 days, the degree of wet feeling was similarly evaluated by a sensory test.

◯ mark: Wetting sensation not observed △ mark: Wetting sensation is weak × mark: Wetting sensation is strong The following examples and comparative examples were also calculated based on this calculation formula and method.

Comparative Example l In a mixed melt of 10% by weight of polyethylene/thalicol (average molecular weight 200) and 90% by weight of water heated and melted at 95°C in a pressurized container, the fiber direction was 30ul, the radial direction was 30u1, and the tangential direction was 30tmx. After soaking the cut paulownia 9 K9
/c! After impregnation under pressure for 3 hours at normal pressure, the impregnated material was taken out, cooled, and left in a room at a temperature of 25°C and relative humidity of 50 cm (equilibrium moisture content: 9%) to dry. (The amount of impregnation of the mixed melt was 0-639/cr! based on the volume of paulownia wood).

The test results are shown in Table 1.

Example 2 15% by weight of polysilyl (average molecular weight 400), 40% by weight of dimethyl isophthalate, and 35% by weight of dimethyl isophthalate (average molecular weight 400) heated and melted at 110°C in a heating container. After immersing paulownia cut in the fiber direction 5UI% radial direction 30m and tangential direction 30m into the mixed melt of 5Ky/a/
After pressure impregnation for 2 hours at normal pressure, the impregnated material was taken out and cooled to fix the mixed melt in the paulownia wood (the impregnated amount of the mixed melt was 0.6Of per the volume of paulownia). /-).

The test results are shown in Table 1. Good results were obtained.

Comparative Example 2 In a mixed melt of 15% by weight polydurohireclicol (average molecular weight 400) and 85% by weight water heated and melted at 110°C in a pressurized container, 511 mm in the fiber direction and 30 wm in the radial direction were mixed.
, 5~/ml after soaking paulownia cut in a tangential direction of 30 m
After being impregnated under pressure for 2 hours at normal pressure, the impregnated material was taken out and cooled at a temperature of 25°C and relative humidity of 50% (equilibrium moisture content of 9 cm).
The paulownia wood was left to stand in a room for drying, and the paulownia wood was impregnated with polysiloxane (the impregnated amount of the mixed melt was 0 to 60 f/ca relative to the volume of paulownia wood).

The test results are shown in Table 1.

Example 3 Fibers were added to a mixed melt of 10% by weight of oleic acid amide, 60% by weight of stearic acid amide, and 30% by weight of polyethylene, . 5 directions, 30m in radial direction
, after soaking paulownia cut in the tangential direction 30y 7 Kg/
After pressure impregnation with crA 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 mixed melt was 0.61 r/w with respect to the volume of paulownia). cJ).

The test results are shown in Table 1. Good results were obtained.

Comparative Example 3 In a mixed melt of 30% by weight of polyethylene glycol (average molecular weight 600) and 70% by weight of water heated and melted at 100°C in a pressurized container, fiber direction 511J11 radial direction 3
After soaking paulownia cut in 30m in tangential direction, 7K
After pressure impregnation for 4 hours at normal pressure, the impregnated material was taken out, cooled, and left in a room at a temperature of 25°C and a relative humidity of 50% (equilibrium moisture content of 9g), dried, and made into polyethylene glycol. was impregnated into paulownia wood (the amount of impregnation of the mixed melt was 0.629/CJ based on the volume of paulownia wood).

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.

Table 1 (that's all) 65

Claims (1)

[Claims] ■ A method for dimensional stabilizing wood materials, which is characterized by impregnating wood materials with polyethers and substances that are solid at room temperature.