JPH06270108A - Manufacture of timber having impregnated surface layer with resin - Google Patents

Abstract

PURPOSE:To manufacture a reformed timber whose strength, decay resistance, and abrasion resistance are improved, and whose characteristic as a timber is maintained. CONSTITUTION:A (meta)acrylate compound with molecular weight of 1000 or less containing 2-4 (meta)acryloyl groups in a molecular and an alkylene oxide unit (RO) (R represents 2-4C alkyl group) is made to infiltrate concentrically into only a surface layer of a timber without solvent. It is cured and fixed in the timber so as to form a WPC layer having low steam permeability on its surface layer. Then, the surface of the timber is further coated. Or, a pigment of 1wt.% or more is added to the acrylate compound. Further, the surface is heated and cured by far infrared radiation when resin is heated and cured.

Description

Detailed Description of the Invention

[0001]

FIELD OF THE INVENTION The present invention relates to a method for producing modified wood.

[0002]

2. Description of the Related Art Conventionally, a wood-plastic composite obtained by injecting a vinyl-based monomer or the like into wood and polymerizing and solidifying this resin in a material has been widely known as WPC. This WPC has been widely evaluated and recognized for its performance as a material having excellent dimensional stability, strength, decay resistance, wear resistance, etc.
A number of patents relating to manufacturing methods have been proposed so far.

[0003]

However, the conventional WPC
Although it has the above-mentioned characteristics, it has some disadvantages. In other words, general WPC needs to inject a large amount of resin liquid with respect to the weight of wood in order to exert its performance and advantages to a high degree, and the specific gravity increases due to this large amount of injected resin. With the addition of a different feel and the loss of some of the properties of wood, the image of modified wood is diminished. Furthermore, there is also a tendency to impair the material properties of wood, which is originally environmentally friendly.

Since it is necessary to inject a large amount of resin liquid,
It has the greatest practical difficulty of increasing cost, and is subject to great restrictions on its range of use, such as treating and using only the plywood surface plate except for the purpose of special high-grade products. Not even versatile. In addition, when only the surface layer of wood is treated by the conventional method, the WPC layer formed on the surface layer has a high water vapor permeability, so the untreated wood inside cannot be protected, and the dimensional stability is improved. , Performance such as decay resistance does not improve. Further, in the conventional impregnation method for the purpose of cost reduction, a solvent is used for the resin liquid. When using an organic solvent, there is a high risk that a flammable explosion may occur during work. When an aqueous solvent was used, it was necessary to heat and dry the wood, which deformed the wood, and the wood after molding could not be treated.

Therefore, the object of the present invention is to eliminate all the above-mentioned drawbacks, and to produce a modified wood which has improved strength, decay resistance and wear resistance, and which retains the characteristics as wood.

[0006]

Means for Solving the Problems As a result of earnest research for achieving the above object, the present inventors have found that (meta) is present in one molecule.
A (meth) acrylate compound having a molecular weight of 1000 or less and having 2 to 4 acryloyl groups and an alkylene oxide unit (RO) (R is an alkyl group having 2 to 4 carbon atoms) is injected into wood without solvent. When cured,
It was found that a WPC having a very low water vapor permeability is formed. Then, it was found that the method of adding 1% by weight or more of the pigment to the resin liquid is effective as a means for concentrating on the surface layer of the wood. Further, as a method for preventing the resin liquid injected at the time of heat curing of the resin from flowing out of the treatment layer, polymerization is performed by utilizing radiation or hot air drying is performed at 80 ° C.
It was found that it is effective to cure in an atmosphere of 200 ° C. for a short time, to cure from the front side by irradiation with far infrared rays, or to heat-cure by hot pressing.

That is, the production method according to claim 1 of the present invention has 2 to 4 (meth) acryloyl groups in one molecule, and has an alkylene oxide unit (RO) (R is 2 to 4 carbon atoms). Molecular weight 1000 having 1 alkyl group)
The following (meth) acrylate compound was solventlessly impregnated only in the surface layer of wood to form a WPC layer having low water vapor permeability on the surface layer by hardening and fixing in the material to form a WPC layer. It is characterized by painting the surface. The production method according to claim 2, wherein the molecule has 2 to 4 (meth) acryloyl groups in one molecule and has an alkylene oxide unit (RO) (R is an alkyl group having 2 to 4 carbon atoms) and a molecular weight of 1,000 or less. 1% by weight or more of pigment is added to the (meth) acrylate compound described above and solvent-free is concentrated and impregnated only on the surface layer of wood, and the material is cured and fixed in the material so that WPC has low water vapor permeability in the surface layer. After forming the layer, the surface of the wood is painted. According to the manufacturing method of claims 3 to 6, when the resin of claim 1 or 2 is cured and fixed in a material, it is polymerized by utilizing radiation or is dried by hot air in an atmosphere of 80 to 200 ° C. It is cured in a short time, is cured by irradiation with far infrared rays, or is heat-cured by hot pressing.

Two (meth) acryloyl groups are contained in one molecule.
Have 4 and alkylene oxide unit (RO)
(R is an alkyl group having 2 to 4 carbon atoms) having a molecular weight of 1
The 000 or less (meth) acrylate compound is an oligomer having an alkylene oxide unit of acrylic acid or methacrylic acid, such as trimethylolpropane PO-modified triacrylate (or methacrylate) and trimethylolpropane PO-modified diacrylate (or methacrylate). is there. 50% of low molecular weight monoacrylate (or methacrylate) having OH group or COOH group in this oligomer alone or in this oligomer
What was blended below was immersed under normal pressure, reduced pressure, increased pressure, reduced pressure-
The wood is injected and impregnated by a pressure method or the like, but in the injection from the mouth direction of the wood, the pigment is added in an amount of 1% by weight or more to suppress the excessive injection of the resin liquid. Furthermore, when it is necessary to promote the injectability in injection from other than the wood mouth, the above composition is used and no pigment is added.

After injecting the resin liquid using such a method, the resin liquid is polymerized by utilizing radiation or dried by hot air to obtain 80
Curing in an atmosphere of ℃ to 200 ℃ for a short time,
Alternatively, it is cured from the front side by irradiation with far infrared rays, or is heated and cured for 10 minutes by a heat press at 180 ° C. and 1 kgf / square centimeter. Such hot pressing prevents the resin liquid from flowing out from the surface layer and cures the resin quickly.

The modified wood thus obtained is a material that is expected to have improved strength, water resistance and light resistance, but one of the features that cannot be overlooked is that if a coating treatment is applied to this material, it will be a very simple work. Water resistance, moisture resistance, dryness resistance, and rot resistance are significantly improved. It is a particularly noteworthy feature of the present invention that the materials produced by such a method exhibit performance far superior to the properties of conventional modified wood.

[0011]

[Function] A WPC layer having low water vapor permeability is formed on the surface layer of wood, and the strength, water resistance,
There is an improvement in light resistance, and when a coating treatment is applied to this material, water resistance, moisture resistance, dryness resistance, and decay resistance are significantly improved.

[0012]

Example: For example, a block piece of cedar (60 × 25 × 90
mm), two acrylic oligomers (M310, TO-
1145, manufactured by Toagosei Kagaku Kogyo Co., Ltd.) was injected by a depressurization method and cured at 100 ° C. for 30 minutes, and then urethane coating was applied once to each treated material at a temperature of 20 ° C. and a relative humidity of 94. %, A moisture absorption test for 25 days was performed, and the results of measuring the hygroscopicity (MEE) and the dimensional stability (ASE) are shown in Table 2. As a comparative example, untreated material shown in Table 1 and a coated material obtained by applying only urethane coating, M5700 simple substance manufactured by Toagosei Co., Ltd. are injected by the depressurization method, and cured at 100 ° C. for 30 minutes. After that, the temperature of each treated material that was once coated with urethane was 20
A moisture absorption test was performed at 25 ° C. and a relative humidity of 94% for 25 days, and the results of measuring the hygroscopicity (MEE) and the dimensional stability (ASE) were classified into a surface layer WPC treated material and a surface layer WPC treated + paint treated material. Furthermore, M31 manufactured by Toagosei Co., Ltd.
0, TO-1145 simple substance was injected by the depressurization and pressurization method,
Moisture absorption (MEE) and dimensional stability (AS) of the surface layer WPC treated material cured at 100 ° C for 30 minutes at a temperature of 20 ° C and a relative humidity of 94% for 25 days were tested.
The result of measuring E) is shown in Table 1 as a comparative example. For the hygroscopicity and dimensional stability, the MEE and ASE values obtained by the following equations were adopted as the degree of improvement on the basis of the untreated material. MEE (%) = (weight increase rate of untreated material-weight increase rate of treated material) / (weight increase rate of untreated material) x 100% ASE (%) = (dimensional change rate of untreated material-treated material Dimensional change rate) / (dimensional change rate of untreated material) x 100%

Table 1 Comparative Example

[Table 1] Note) M5700: monofunctional oligoester acrylate, having OH group M310: trimethylolpropane PO-modified triacrylate TO-1145: trimethylolpropane PO-modified diacrylate Table 2 Examples

[Table 2] Note) M310: trimethylolpropane PO-modified triacrylate TO-1145: trimethylolpropane PO-modified diacrylate

From these results, it can be seen that the MEE and ASE values of the examples are larger than those of the comparative examples. Therefore, since the weight increase is small and the dimensional change is small in the case where the treatment of the example is performed, the resistance to moisture and dryness and the dimensional stability are better. Particularly in Comparative Example 5. , 6. Compared with Example 1. , 2. Has a high degree of improvement.

[0015]

The modified wood thus obtained has the effect of being a material that is expected to have improved strength, water resistance and decay resistance. Furthermore, water resistance, moisture resistance, dryness resistance, and rot resistance are remarkably improved by the extremely simple work of applying a coating, and the produced material has an effect of far surpassing the properties of conventional modified wood.

Claims (6)

[Claims] 1. An alkylene oxide unit (RO) having 2 to 4 acryloyl groups or methacryloyl groups in one molecule (R is an alkyl group having 2 to 4 carbon atoms).
A WPC layer having a low water vapor permeability was formed on the surface layer of wood by impregnating only the surface layer of wood with a solvent-free acrylate compound or methacrylate compound having a molecular weight of 1000 or less and hardening and fixing in the material. After that, a coating method is applied to the surface of the wood, which is a method for manufacturing resin-injected wood for the surface layer. 2. An alkylene oxide unit (RO) (R is an alkyl group having 2 to 4 carbon atoms) having 2 to 4 acryloyl groups or methacryloyl groups in one molecule.
1 wt% or more of pigment is added to an acrylate compound or methacrylate compound having a molecular weight of 1000 or less, which is impregnated only in the surface layer of wood without solvent, and is cured and fixed in the material so that the surface layer of water vapor A method for producing a surface layer resin-injected wood, which comprises forming a WPC layer having low permeability and then coating the surface of the wood. 3. The method for producing a surface layer resin-injected wood according to claim 1, wherein when the resin is hardened and fixed in the material, the resin is polymerized by utilizing radiation. 4. The surface layer resin according to claim 1, wherein when the resin is cured and fixed in the material, it is cured by hot air drying in an atmosphere of 80 ° C. to 200 ° C. for a short time. Manufacturing method of injected wood. 5. The method for producing a surface layer resin-injected wood according to claim 1, wherein the resin is cured by irradiation with far infrared rays when the resin is cured and fixed in the material. 6. The method for producing a surface layer resin-injected wood according to claim 1, wherein when the resin is hardened and fixed in the material, it is heated and hardened by hot pressing.