JP6896268B2 - How to protect outdoor wood-based materials and wood-based materials protected by that method - Google Patents

Description

The present invention relates to a method for protecting an outdoor wood-based material and a wood-based material protected by the method.

Conventionally, as a method of protecting a wood material used outdoors, there is a method of applying a wood protective paint on the surface of the wood material, and the wood protective paint includes (a) a wood antiseptic and antifungal agent and (b). It contains a wood insect repellent, (c) a coating film-forming component, (d) at least one pigment selected from the group consisting of red iron oxide, yellow iron oxide and carbon black, and (e) a solvent. (For example, see Patent Document 1), or a wood-based paint composition using an oil-based solvent containing a synthetic resin and an additive and containing a solvent component having a pungent odor to a foul odor such as toluene and xylene. In some products, limonene is blended as a solvent component in an amount of 5% by weight or more (preferably 5 to 30% by weight) based on the total weight of the composition (see, for example, Patent Document 2).

Further, by dehemicellulose treatment of lignocellulosic, hemicellulose and lignin which are the causes of discoloration and a part of the extracted component are removed or reduced, and the weather resistance of lignocellulosic is improved. Further, there is a method of accelerating the graft polymerization reaction between an anti-ultraviolet material such as an ultraviolet absorber or an ultraviolet stabilizer and a lignocellulosic material by performing a dehemicellulose treatment (see, for example, Patent Document 3).

However, in the method of protecting wood materials with these wood protective paints, when using colorants such as pigments and dyes, the appearance of the wood materials to be protected, such as the grain and color tone, is larger than the original appearance of the wood materials. There was a problem that it would be different. Further, in the method of using a transparent wood protective paint, there is a problem that when exposed outdoors for a long period of time, the coating film deteriorates over time and the appearance is suddenly changed such as peeling. By dehemicellulose treatment of lignocellulosic, hemicellulose and lignin which are the causes of discoloration and a part of the extracted components are removed or reduced, and the weather resistance of lignocellulosic is improved. Furthermore, the manufacturing process is complicated and special equipment is required for the method of promoting the graft polymerization reaction between the anti-ultraviolet material such as an ultraviolet absorber or an ultraviolet stabilizer and the lignocellulosic material by performing the dehemicellulose treatment. There was a problem of

Japanese Unexamined Patent Publication No. 2005-145909 JP-A-2009-167310 JP-A-2002-283306

The problem to be solved is a simple protection method for wood-based materials used for buildings, etc., which naturally deteriorates over a long period of time without major changes in appearance such as grain and color tone of the wood-based materials. It is a point to provide.

The present invention is a wood-based material used outdoors, and a water-repellent agent is applied to the surface of the wood-based material after applying a wood surface protectant containing an ultraviolet absorber and a light stabilizer and not containing a binder. The most important feature is to apply and dry.

According to the method for protecting an outdoor wood-based material of the present invention, there is an advantage that a simple method of coating and drying can cause natural deterioration for a long period of time without a large change in the appearance of the wood-based material to be protected. ..

The method for protecting an outdoor wood-based material of the present invention is to apply a water-repellent agent to the surface of the wood-based material after applying a wood surface-protecting agent containing an ultraviolet absorber and a light stabilizer and not containing a binder. It is done by drying.

The wood-based materials are not only those that use coniferous trees such as cedar, pine, hinoki, and ichii, and broad-leaved trees such as cherry, zelkova, beech, kunugi, and nara as they are, but also plywood and single board that are industrially processed from these natural trees. Includes laminated boards (LVL), laminated lumber, orthogonal laminated boards (Cross Laminated Timber, CLT) and the like.

It is necessary that the wood surface protectant contains an ultraviolet absorber and a light stabilizer and does not contain a binder.

The wood surface protectant needs to be applied to the surface of the wood material.

The ultraviolet absorbers are 2- (2'-hydroxy-5'-methylphenyl) benzotriazole and 2- (2'-hydroxy-3'-tert-butyl-5'-methylphenyl) -5-chlorobenzotriazole. , 2- (2'-Hydroxy-3', 5'-di-tert-amylphenyl) benzotriazole, 2- (2'-hydroxy-5'-tert-octylphenyl) benzotriazole, 2,2'-methylenebis [6- (2H-benzotriazole-2-yl) -4-tert-octylphenol], 6- (2-benzotriazolyl) -4-tert-octyl-6'-tert-butyl-4'-methyl- 2,2'-Methylenebisphenol, 2- (2H-benzotriazole-2-yl) -4,6-bis (1-methyl-1-phenylethyl) phenol, 2,2'-methylenebis [6- (2H) -Benzotriazole-2-yl) -4- (1,1,3,3-tetramethylbutyl) phenol], 2-methylenebis [6- (2H-benzotriazole-2-yl) -4- (1,1) , 3,3-Tetramethylbutyl) phenol], 2- (2H-benzotriazole-2-yl) -p-cresol, 2- (5-chloro-2H-benzotriazole-2-yl) -6-tert- Benzotriazole-based ultraviolet absorbers such as butyl-4-methylphenol, 2- (4,6-diphenyl-1,3,5-triazine-2-yl) -5- [2- (2-ethylhexanoyloxy) Triazine-based UV absorbers such as ethoxy] phenol, 2,4,6-tris (2-hydroxy-4-hexyloxy-3-methylphenyl) -1,3,5-triazine, [2-hydroxy-4- (octyloxy) ) Phenyl] (phenyl) Metanon and other benzophenone-based ultraviolet absorbers, benzoate-based ultraviolet absorbers, iron oxide, titanium oxide and the like can be mentioned. These may be used as they are, or may be diluted with water, alcohol, an organic solvent or the like before use. Of these, it is preferable to use an oil-soluble ultraviolet absorber, more preferably a triazine-based ultraviolet absorber, and 2- (4,6-bis (2,4 dimethylphenyl) -1,3,5- Triazine-2-yl) -5-hydroxyphenyl, tooxylan "(C10-C16 mainly C12-C13 alkyloxy) methyl] Reaction product with oxylan, benzenepropanoic acid 3- (2H-benzotriazole-2-yl) -5- (1,1-dimethylethyl) -4-hydroxy C7-9 side chain and linear alkyl ester, 2,4,6-tris (2-hydroxy-4-hexyloxy-3-methylphenyl) -1 , 3,5-Triazine is most preferred, especially 2- (4,6-bis (2,4 dimethylphenyl) -1,3,5-triazine-2-yl) -5-hydroxyphenyl, tooxylan " Reaction product with (C10-C16 mainly C12-C13 alkyloxy) methyl] oxylane and benzenepropanoic acid 3- (2H-benzotriazole-2-yl) -5- (1,1-dimethylethyl) -4- Since the hydroxy C7-9 side chain and the linear alkyl ester are colorless and transparent, the change in appearance when applied to wood is the smallest.

Examples of the photostabilizer include bis (2,2,6,6-tetramethyl-4-piperidyl) sebacate, bis (1,2,2,6,6-pentamethyl-4-piperidyl) sebacate, and tetrakis (1,2,2,6,6-pentamethyl-4-piperidyl) sebacate. 1,2,2,6,6-pentamethyl-4-piperidyl) butane-1,2,3,4-tetracarboxylate, tetrakis (2,2,6,6-tetramethyl-4-piperidyl) butane-1 , 2,3,4-tetracarboxylate, bis (1,2,2,6,6-pentamethyl-4-piperidyl) sebacate, bis (2,2,6,6-tetramethyl-4-piperidyl) sebacate, Bis (1-undecanoxy-2,2,6,6-tetramethylpiperidine-4-yl) carbonate, 1,2,2,6,6-pentamethyl-4-piperidyl methacrylate, 2,2,6,6-tetra Methyl-4-piperidyl methacrylate, bis (1,2,2,6,6-pentamethyl-4-piperidyl) [[3,5-bis (1,1-dimethylethyl) -4-hydroxyphenyl] methyl] butylmalo Examples thereof include hindered amine-based light stabilizers such as Nate. These may be used as they are, or may be diluted with water, alcohol, an organic solvent or the like before use. Of these, it is preferable to use an oil-soluble light stabilizer, bis (1,2,2,6,6-pentamethyl-4-piperidyl) sebacate, methyl 1,2,2,6,6-pentamethyl-. It is more preferable to use a sebacate hindered amine-based light stabilizer such as 4-piperidyl sebacate.

It is necessary to use the ultraviolet absorber and the light stabilizer in combination. By using an ultraviolet absorber and a light stabilizer in combination, changes in appearance such as grain and color tone of wood-based materials can be suppressed.

The UV absorber and light stabilizer are preferably dissolved in alcohol. By dissolving the UV absorber and the light stabilizer in alcohol, the UV absorber and the light stabilizer can be deeply penetrated into the surface of the wood material.

The amount of the ultraviolet absorber applied is preferably ² to 50 g / m 2, more preferably 3 to 25 g / m ² , and most preferably 5 to 20 g / m ² .

The amount of the light stabilizer applied is preferably 0.2 to 20 g / m ² , more preferably 1.5 to 15 g / m ² , and most preferably 5 to 10 g / m ² .

It is preferable to use the ultraviolet absorber and the light stabilizer as a mixture. By using both in combination, the outdoor durability (discoloration resistance) is superior as compared with the case where they are individually applied separately.

The mixing ratio of the ultraviolet absorber to 100 parts by mass of the light stabilizer is preferably 300 parts by mass or more, more preferably 500 parts by mass or more, and most preferably 800 parts by mass or more. The mixing ratio of the UV absorber and the light stabilizer has a greater effect on the outdoor durability (particularly the change in color tone) of the wood material than the amount of the UV absorber and the light stabilizer applied. It has the best outdoor durability when mixed with.

The alcohol content is preferably 20 to 500 parts by mass, more preferably 50 to 300 parts by mass, and most preferably 80 to 200 parts by mass with respect to 100 parts by mass of the total of the ultraviolet absorber and the light stabilizer.

The alcohol preferably has 1 to 5 carbon atoms, and more preferably 1 to 3 carbon atoms. Examples of alcohols having 1 to 5 carbon atoms include methanol (1 carbon atom), ethanol, ethylene glycol (2 carbon atoms), propanol, isopropyl alcohol, propylene glycol (3 carbon atoms), butanol (4 carbon atoms), and pentanol. (5 carbon atoms) and the like. Since the alcohol has 1 to 5 carbon atoms, the ultraviolet absorber and the light stabilizer can be deeply penetrated into the wood surface. Further, the alcohol may be diluted with water before use.

The binder is for fixing an ultraviolet absorber and a light stabilizer to the surface of a wood-based material, and examples thereof include synthetic resins and monomers that cause graft polymerization. The present invention needs to be free of the binder.

By applying the water-repellent agent, it is possible to suppress the infiltration of water into the wood-based material and suppress the cracking and deformation of the wood-based material.

The water repellent needs to be applied after the ultraviolet absorber and the light stabilizer are applied to the surface of the wood material. With such a configuration, the elution of the ultraviolet absorber and the light stabilizer with water (for example, rainwater) can be suppressed, so that the long-term durability (particularly discoloration resistance) of the wood material is excellent.

Examples of the water repellent include silicone-based water repellents such as silicone resins, silane-based water repellents such as silane monomers and silane dimers, and fluororesin-based water repellents such as fluororesins. Of these, it is preferable to use a fluorine-based water repellent, and it is more preferable to use a fluorine-based water repellent having a perfluoroalkyl group. These may be used as they are, or may be diluted or emulsified with water, alcohol, an organic solvent or the like. An example of a fluorine-based water repellent having a perfluoroalkyl group is shown in [Chemical Formula 1].

ここで、Ｒ_１、Ｒ_２、Ｒ_３はアルキル基、Ｃ_６Ｆ_１３はパーフルオロアルキル基、Ｘ，Ｙは非フッ素側鎖である。パーフルオロ基の炭素数及びフッ素数は任意である。

Here, R ₁ , R ₂ , and R ₃ are alkyl groups, C ₆ F ₁₃ is a perfluoroalkyl group, and X and Y are non-fluorine side chains. The number of carbon atoms and the number of fluorines of the perfluoro group are arbitrary.

The perfluoroalkyl group refers to an alkyl group in which part or all of hydrogen in the alkyl group is replaced with fluorine. Of these, an alkyl group in which all hydrogen of the alkyl group is replaced with fluorine is preferable, the number of carbon atoms of the alkyl group is more preferably 2 to 10, and the number of carbon atoms of the alkyl group is 5 to 8. Is the most preferable.

The portion other than the monomer unit having a perfluoroalkyl group is preferably a (meth) acrylic skeleton. Since the portion other than the monomer unit having a perfluoroalkyl group is a (meth) acrylic skeleton, it has excellent weather resistance.

The amount of the water repellent applied is preferably 1 to 50 g / m ^{2 in terms of non-volatile content, more preferably 2} to 35 g / m 2, and most preferably 5 to 15 g / m ² .

After applying the water repellent agent, a hydrophilic agent may be applied. With such a configuration, when used outdoors, dirt adhering to the surface of the wood-based material is easily washed away by rainwater, so that it is excellent in stain resistance.

The hydrophilic agent can be used arbitrarily. For example, a colloidal silica solution, a silicic acid compound such as sodium silicate and potassium silicate, an alkoxysilicate, a quaternary ammonium salt, a quaternary ammonium salt-containing polymer and the like can be mentioned.

The hydrophilic agent is preferably used in the form of an aqueous solution. By using it in the form of an aqueous solution, the surface can be made hydrophilic without dissolving and flowing out the ultraviolet absorber and the light stabilizer coated on the wood surface.

The ultraviolet absorber, light stabilizer and water repellent configured as described above are used as follows.
First, 2,4,6-tris (2-hydroxy-4-hexyloxy-3-methylphenyl) -1,3,5-triazine as an ultraviolet absorber and bis (1,2) as a light stabilizer. , 2,6,6-pentamethyl-4-piperidyl) sebacate, methyl 1,2,2,6,6-pentamethyl-4-piperidyl sebacate with 150 parts by mass of UV absorber and 100 parts by mass of light stabilizer. It is dissolved in 400 parts by mass of isopropyl alcohol as an alcohol in a ratio to prepare a mixed solution of an ultraviolet absorber and a light stabilizer as a wood surface protectant.

Subsequently, the wood surface protective agent is applied to the surface of a cedar lumber having a width of 200 mm, a length of 1000 mm, and a thickness of 20 mm as a wood material at an application amount of 44 g / m ² , and left at room temperature for 16 hours to dry. After that, an emulsion obtained by emulsifying a fluorine-based water repellent having a perfluoroalkyl group as a water repellent (alkyl group having 6 carbon atoms, 13 fluorines, acrylic skeleton and methacryl skeleton other than perfluoroalkyl group) in water. (Non-volatile content 40%) is applied at an application amount of 100 g / m ² and dried.

The wood-based material is not limited to sugi, and can be set arbitrarily. Examples thereof include coniferous trees such as Sugi, larch, cypress and Japanese yew, and broad-leaved trees such as cherry, zelkova, beech, oak and oak.

The wood-based material is not limited to the formulation and can be arbitrarily set. For example, plywood, single plate laminated board (LVL), laminated lumber, orthogonal laminated board (cross laminated timber, CLT) and the like can be mentioned.

The drying may be natural drying or forced drying using hot air, far infrared rays, or the like.

As the wood surface protective agent, additives used in ordinary paints can be used. For example, preservatives, antifoaming agents, pH adjusters, antifreeze agents, algae preventive agents, thickeners and the like can be mentioned.

The water repellent may be used as it is, dissolved in alcohol or an organic solvent, or emulsified in water or the like and applied.

The dried sugi lumber surface-treated as described above is used as the outer wall of the building.

The sugi lumber as a wood-based material has the effect of the present invention as long as it is exposed to wind, rain and sunlight in addition to the outer wall of the building. For example, wood decks, pillars, beams, eaves, verandas, moss-roofing, tokusa-roofing, tochi-roofing and other roofing materials, carports, fences, window frames, sashes, fences, signboards and other building materials, bridges. Civil engineering materials such as, chairs used outdoors such as outdoor stadiums and campgrounds, furniture such as desks, interior and exterior of vehicles such as automobiles and trains, electric poles, shoes, bags, glasses, etc. Further, even if it is an interior, it can be arbitrarily used as long as it is a part affected by sunlight and water. For example, floors (especially near windows), inner walls, blinds and the like.

Sugi lumber as a wood-based material constructed as described above can be manufactured by painting at a construction site without special equipment, and even if it is used as an outer wall material of a building, the grain and color tone, etc. It is not accompanied by a sudden change in appearance, has few cracks due to water absorption, and can be slowly deteriorated over a long period of time.

Hereinafter, the present invention will be described with reference to Examples and Comparative Examples. In the test, a wood surface protective agent was applied to the surface of a sugi lumber of 50 mm × 150 mm × 10 mm in thickness, and after leaving it at room temperature for 16 hours, a water repellent was applied and left at room temperature for another 16 hours to prepare a test piece. .. Subsequently, the test piece was subjected to the general paint test method specified in JIS K5600-7-6: 2002-Part 7: Long-term durability of the coating film-Section 6: Outdoor exposure and weather resistance in accordance with the horizontal surface. It was installed at a height of 45 cm from the ground at an angle of 45 degrees and exposed outdoors for 6 months and 18 months toward the south surface. The exposed place is Gifu City, Gifu Prefecture. The evaluation was performed by comparing the appearance with the unexposed test piece, and those with almost no change in appearance were evaluated as ◎, those that had not been incinerated but had a change in appearance were ○, those with a slight change in color and painted. Those in which the film was lifted were marked with Δ, those in which the appearance was incinerated and those in which the coating film was peeled off were marked with x. In addition, the test specimens that had been exposed to the outdoors for 18 months were repainted with the same specifications to evaluate the repainting suitability. Those that were easy to repaint and had a small change in appearance were marked with 〇, those that were easy to repaint but had a change in appearance were marked with Δ, and those that required peeling of the old coating film at the time of repainting were marked with x. Table 1 shows the compositions of the wood surface protectant, water repellent, and hydrophilic agent used in the test and the test results.

In the table, UVA / HALS indicates the mass ratio of the mass of the ultraviolet absorber divided by the mass of the hindered amine-based light stabilizer. In the table, the ultraviolet absorber A is 2- (4,6-bis (2,4-dimethylphenyl) -1,3,5-triazine-2-yl) -5-hydroxyphenyl, tooxylan "(C10-). C16 is mainly a reaction product with C12-C13 alkyloxy) methyl] oxylane, and the ultraviolet absorber B is benzenepropanoic acid, 3- (2H-benzotriazole-2-yl) -5- (1,1-dimethylethyl). ) -4-Hydroxy ・ C7-9 side chain and linear alkyl ester, and the ultraviolet absorber C is 2- (2,4-dihydroxyphenyl) -4,6-bis- (2,4-dimethylphenyl)- It is a reaction product of 1,3,5-triazine and (2-ethylhexyl) -glycidate, and the photostabilizer A is bis (1,2,2,6,6-pentamethyl-4-piperidyl). ) Sevacate, the photostabilizer B is bisdecanoate (2,2,6,6-tetramethyl-1- (octyloxy) -4-piperidinyl) ester, 1,1-dimethylethylhydroperoxide and octane. Reaction product of.

Claims (1)

A method for protecting an outdoor wood-based material in which a wood surface-protecting agent is applied to the surface of the wood-based material and then a water-repellent agent is applied and dried. The total concentration of the agents is an alcohol solution of 17% by mass to 57% by mass, and the alcohol solution contains an ultraviolet absorber having a mass ratio of 3 to 20 times the mass ratio of the light stabilizer and does not contain a binder. A characteristic method of protecting wood-based materials for outdoor use.