Coloration method

Abstract

To provide a coloration method for certainly causing coloration of zinc in wood or in a woody material.SOLUTION: A coloration method for causing coloration of an infiltration label component containing zinc in wood or a woody material includes: a pH adjustment step for adjusting the pH of a surface of the wood or a surface of the woody material to 5 or more; and a coating step for coating a color reagent on the surface of the wood or the surface of the woody material after the pH adjustment step. In the coloration method, a content of the zinc in the wood or the woody material is 0.001 kg / m3 to 0.5 kg / m3.SELECTED DRAWING: None

Description

Technical Field

[0001] The present invention relates to a coloring method that can be used for quality inspection of wood or wood materials that have been preserved with a wood preservative that protects the wood from organisms that cause wood deterioration.

Background Art

[0002] For the purpose of protecting wood from pests and decay fungi, which are organisms that cause wood deterioration, preservation treatment using a wood preservative has been carried out.

[0003] The preservation treatment is performed by subjecting wood or wood materials such as lumber, glued laminated timber, and laminated veneer lumber (LVL) (hereinafter, wood and wood materials may be referred to as "wood etc.") to pressure injection treatment of a wood preservative. Sufficient infiltration of the wood preservative into the interior of wood etc. affects the quality of wood etc.

[0004] Therefore, as one of the inspection methods for confirming the quality of wood etc. after the preservation treatment, an inspection is carried out in which the infiltration area of the wood preservative infiltrated into the interior of wood etc. is colored using an appropriate reagent, and the infiltration degree of the wood preservative is measured.

[0005] There are wood preservatives that are active ingredients for preserving wood and exhibit vivid color development by reacting with a coloring reagent. On the other hand, there are also wood preservatives that do not contain such an active ingredient that exhibits color development and contain an active ingredient that does not exhibit color development. For such wood preservatives, a coloring agent (for example, Patent Document 1) or a labeling component that exhibits color development is separately added.

[0006] For example, as a labeling component that can be added to a wood preservative, zinc components such as zinc acetate can be mentioned. The zinc component forms a complex with good color development by reacting with a coloring reagent such as dithizone or PAN. Therefore, by utilizing this reaction to color the zinc component, it becomes possible to confirm the infiltration area of the wood preservative in wood etc.

Prior Art Documents

Patent Document

[0007]

Patent Document 1

Summary of the Invention

Problems to be Solved by the Invention

[0008] However, the zinc component used as a labeling component has a problem that it is difficult to cause a color reaction with a color - forming reagent such as dithizone or PAN due to the influence of acid components contained in wood and adsorption to lignin, and it may be difficult to clearly color the infiltration area of the wood preservative. Therefore, when coloring zinc contained in the infiltration area of a wood preservative such as preserved wood, the infiltration area may not be correctly colored due to the influence of the chemical properties of the wood.

[0009] An object of the present invention is to provide a coloring method capable of surely coloring zinc in wood or woody materials, paying attention to the above - mentioned problems.

Means for Solving the Problems

[0010] The inventors of the present invention have variously studied means for solving the above problems. As a result, before applying a color - forming reagent to wood or the like after preservation treatment with a wood preservative containing zinc, by adjusting the surface pH of the wood or the like so that the surface pH becomes 5 or more, it has been found that zinc reacts with the color - forming reagent to develop color even under conditions where color development does not occur when this adjustment is not made.

[0011] To solve the above problems, the coloring method of the present invention is a coloring method for coloring zinc in wood or woody materials, including a pH adjustment step of adjusting the pH of the surface of the wood or the surface of the woody material to 5 or more, and an application step of applying a color - forming reagent to the surface of the wood or the surface of the woody material after the pH adjustment step. The zinc content in the wood or the woody material is 0.001 kg / m3 ~0.5 kg / m 3 is as follows.

[0012] The tree species of the wood or woody material may be at least one selected from larch, Scots pine, whitewood, balsam fir, balsam poplar, SPF, bay laurel, Japanese larch, cypress, sugi, Dahurian larch, and southern yellow pine.

[0013] The wood or woody material may be impregnated with an impregnation labeling component containing at least one or more zinc compounds.

[0014] The color reagent may contain at least one or more selected from dithizone, PAN, PAR, Nitro-PAPS, 5-Br-PAPS, and Zincon.

Advantages of the Invention

[0015] According to the present invention, a coloring method capable of surely coloring zinc in wood or a woody material can be provided.

Embodiments for Carrying Out the Invention

[0016] Hereinafter, the coloring method according to the present invention will be described. Note that the present invention is not limited to the following examples. The coloring method of the present invention is a coloring method for coloring zinc in wood or a woody material, and includes a pH adjustment step and a coating step described below.

[0017] [Wood, Woody Material] Examples of the tree species of wood include conifers and broad-leaved trees, and are not particularly limited. For example, larch, Scots pine, whitewood, balsam fir, balsam poplar, SPF, bay laurel, Japanese larch, cypress, sugi, Dahurian larch, and southern yellow pine can be mentioned, and at least one selected from these can be used. Examples of the woody material include those obtained by sawing these woods, glued laminated timber, and laminated veneer lumber (LVL).

[0018] The wood and woody materials contain zinc. As long as it is wood or the like containing zinc, it is not particularly limited. For example, those preserved with a wood preservative containing zinc can be mentioned. More specifically, it is a wood preservative that does not contain an active ingredient that exhibits color development by reaction with a color-developing reagent and contains an active ingredient that does not exhibit color development, and uses a wood preservative containing zinc as an infiltration labeling component that exhibits color development, and wood or woody materials preserved by pressure injection treatment or the like can be mentioned.

[0019] The wood or woody material may be one infiltrated with an infiltration labeling component containing at least one or more zinc compounds. The wood or woody material may contain only one type of zinc component, or may contain those adjusted with two or more types in an appropriate mass ratio.

[0020] The zinc content in the wood or woody material is 0.001 kg / m 3 ~0.5 kg / m 3 That is. When the zinc content is less than 0.001 kg / m 3 , it may not develop color sufficiently to be visually recognized even if the pH adjustment step is performed. Also, if the zinc content is 0.5 kg / m 3 , sufficient color development can be obtained. If the zinc content is more than this, the cost as a color development method increases and it is not economical.

[0021] [pH Adjustment Step] The pH adjustment step is a step of adjusting the pH of the surface of the wood or the surface of the woody material to 5 or more. For example, the surface pH can be adjusted by applying an alkaline aqueous solution such as an aqueous sodium hydroxide solution, an aqueous sodium acetate solution, or an aqueous ammonia solution to the surface of the wood or the woody material. Also, the surface pH can be adjusted by using a buffer solution with a pH of 5 or more. Since the pH only needs to be 5 or more, the upper limit of the pH is not particularly limited. However, since it becomes more difficult to handle as the alkaline aqueous solution or buffer solution approaches strong alkali, considering the safety aspect of the color development method, for example, pH 10 can be set as the upper limit.

[0022] When the zinc content in wood or woody materials is as low as 0.001 kg / m 3 ~0.5 kg / m 3 it may be difficult to develop color. As a cause, the acid contained in wood or the like may slow down the reaction between zinc and the color-developing reagent. Wood is known to be acidic. For example, the heartwood of untreated Douglas fir is known to have a particularly low pH of 3 to 4, and the heartwood of Betula platyphylla is said to have a pH of 4 to 5. Therefore, in consideration of the fact that the pH of the wood surface itself is low, a pH adjustment step is performed to reduce the activity of the acid in the wood. By performing the pH adjustment step and then the coating step in the subsequent process, zinc can be colored even with a small amount of zinc.

[0023] [Coating step] The coating step is a step of applying a color-developing reagent to the surface of the wood or woody material after the pH adjustment step. The method of applying the color-developing reagent is not particularly limited. For example, the color-developing reagent can be dissolved in a solvent to prepare a solution with a adjusted concentration of the color-developing reagent, and then the color-developing reagent can be applied to the surface of wood or the like with a brush, a brush, a roller, etc. that has been impregnated with the solution.

[0024] The color-developing reagent is not particularly limited as long as it is a reagent capable of developing color for zinc. For example, at least one kind of color-developing reagent selected from dithizone (1,5-diphenylthiocarbazone dithizone), PAN (1-(2-pyridylazo)-2-naphthol), PAR (4-(2-pyridylazo)resorcinol), Nitro-PAPS (2-(5-nitro-2-pyridinylazo)-5-[propyl(3-sulfopropyl)amino]phenol), 5-Br-PAPS (2-(5-bromo-2-pyridylazo)-5-(N-propyl-N-sulfopropylamino)phenol sodium), and Zincon (2-[5-(2-hydroxy-5-sulfophenyl)-3-phenyl-1-formazyl]benzoic acid monosodium salt) can be used. The color-developing reagent may contain only one kind of these components, or may contain a preparation of two or more kinds in an appropriate mass ratio.

[0025] [Storage treatment step] The color development method of the present invention may include a storage treatment step as a pre-step of the above pH adjustment step and coating step. For example, a wood preservative that does not contain an active ingredient that exhibits color development by reaction with a color developing reagent and contains an active ingredient that does not exhibit color development, and that contains zinc as an infiltration labeling component that exhibits color development, is used. A step of subjecting wood or a woody material to a storage treatment by applying, spraying, dipping, pressure injection treatment, or the like of this wood preservative can be mentioned.

Example

[0026] Hereinafter, the present invention will be described more specifically using examples, but the present invention is not limited to the following examples at all.

[0027] [Experimental Example 1] As the wood to be tested, larch, Scots pine, whitewood, balsam fir, white spruce, SPF, Japanese cypress, lodgepole pine, Japanese cypress, sugi, Dahurian larch, and southern yellow pine were used, and a plurality of 3 cm × 3 cm × 2 mm wood pieces were prepared from these sawn timbers. The wood pieces were all immersed in a solution of aliphatic hydrocarbon in which zinc 2-ethylhexanoate was dissolved, and then cured for 1 month in a well-ventilated upper room to obtain test specimens.

[0028] After curing, the test specimens were coated with a color developing solution on their surfaces to confirm the color development state of zinc. The color development was divided into Comparative Example 1 in which the color developing solution was directly applied to the surface of the test specimen without performing the pH adjustment step, and Test Example 1 in which the color developing solution was applied after adjusting the pH of the test specimen surface to 5.

[0029] In Test Example 1, the pH of the test specimen surface was adjusted by spraying a 0.01 M aqueous sodium hydroxide solution on the test specimen surface.

[0030] 〈Color developing solution〉 As the color developing solution, an acetone solution containing 0.01% by mass of dithizone (0.01% dithizone-acetone color developing solution) was used.

[0031] For specimens that did not show coloration, in order to confirm the amount of zinc contained, the specimens were wet-decomposed using sulfuric acid and hydrogen peroxide solution, and then the zinc contained in the solution after wet decomposition was measured using an atomic absorption spectrophotometer.

[0032] Test Example 1: After adjusting the specimen surface to pH 5, a 0.01% dithizone-acetone coloring solution was applied. Comparative Example 1: A 0.01% dithizone-acetone coloring solution was directly applied to the specimen surface.

[0033] The discrimination of the coloration state was carried out visually, and the discrimination criteria were as follows. ○: Colored. ×: The same color as when the coloring solution was applied to a specimen that had not been treated with zinc, that is, no coloration occurred. △: Although coloration occurred, the specimen contained regions that could be discriminated according to the × discrimination criteria in part.

[0034] Tables 1 to 4 show the results of discriminating the coloration states when the zinc content in the specimen was 0.0001 kg / m 3 , 0.0005 kg / m 3 , 0.001 kg / m 3 , 0.5 kg / m 3 .

[0035]

Table 1

[0036]

Table 2

[0037]

Table 3

[0038]

Table 4

[0039] From the results of Tables 1 to 4, when the zinc content in the specimen is 0.001 kg / m 3 , 0.5 kg / m 3 , in Test Example 1 where the surface of the specimen was adjusted to pH 5 and then a 0.01% dithizone-acetone coloring solution was applied, zinc reacted with the coloring reagent and the surface of the specimen was colored as a result.

[0040] [Experimental Example 2] As the wood to be tested, Japanese larch, Scots pine, whitewood, balsam fir, beech, SPF, hinoki, Japanese cedar, sugi, Dahurian larch, southern yellow pine were used, and a plurality of 3 cm × 3 cm × 2 mm wood pieces were prepared from these sawn timbers. The wood pieces were all immersed in a solution of aliphatic hydrocarbon in which zinc 2-ethylhexanoate was dissolved, and then cured in a well-ventilated upper room for 1 month to obtain specimens.

[0041] After curing, the specimens were coated with a coloring solution on their surfaces to confirm the coloring state of zinc. The coloring was divided into Comparative Examples 2 to 7 in which the coloring solution was directly applied to the surface of the specimen without performing a pH adjustment step, and Test Examples 2 to 7 in which the coloring solution was applied after adjusting the pH of the specimen surface to 5.

[0042] In Test Examples 2 to 7, the pH of the specimen surface was adjusted by spraying a 0.01 M aqueous sodium hydroxide solution onto the specimen surface.

[0043] 〈Coloring solution〉 As the coloring solution, an acetone solution containing 0.01% dithizone (0.01% dithizone-acetone coloring solution) was used for Test Example 2 and Comparative Example 2, an acetone solution containing 0.05% PAN (0.05% PAN-acetone coloring solution) was used for Test Example 3 and Comparative Example 3, an acetone solution containing 0.05% PAR (0.05% PAR-acetone coloring solution) was used for Test Example 4 and Comparative Example 4, an aqueous solution containing 0.05% Nitro-PAPS (0.05% Nitro-PAPS-water coloring solution) was used for Test Example 5 and Comparative Example 5, an aqueous solution containing 0.05% 5-Br-PAPS (0.05% 5-Br-PAPS-water coloring solution) was used for Test Example 6 and Comparative Example 6, and a 0.01M sodium hydroxide aqueous solution containing 0.01% Zincon (0.01% Zincon-water (pH 12) coloring solution) was used for Test Example 7 and Comparative Example 7.

[0044] For the test specimens that did not show coloring, in order to confirm the amount of zinc contained, the test specimens were wet-decomposed using sulfuric acid and hydrogen peroxide water, and then the zinc contained in the solution after wet decomposition was measured using an atomic absorption photometer.

[0045] Test Example 2: After adjusting the pH of the test specimen surface to 5, the 0.01% dithizone-acetone coloring solution was applied. Test Example 3: After adjusting the pH of the test specimen surface to 5, the 0.05% PAN-acetone coloring solution was applied. Test Example 4: After adjusting the pH of the test specimen surface to 5, the 0.05% PAR-acetone coloring solution was applied. Test Example 5: After adjusting the pH of the test specimen surface to 5, the 0.05% Nitro-PAPS-water coloring solution was applied. Test Example 6: After adjusting the pH of the test specimen surface to 5, the 0.05% 5-Br-PAPS-water coloring solution was applied. Test Example 7: After adjusting the pH of the test specimen surface to 5, the 0.01% Zincon-water (pH 12) coloring solution was applied.

[0046] Comparative Example 2: The 0.01% dithizone-acetone coloring solution was directly applied to the test specimen surface. Comparative Example 3: A 0.05% PAN-acetone coloring solution was directly applied to the surface of the test specimen. Comparative Example 4: A 0.05% PAR-acetone coloring solution was directly applied to the surface of the test specimen. Comparative Example 5: A 0.05% Nitro-PAPS-water coloring solution was directly applied to the surface of the test specimen. Comparative Example 6: A 0.05% 5-Br-PAPS-water coloring solution was directly applied to the surface of the test specimen. Comparative Example 7: A 0.01% Zincon-water (pH 12) coloring solution was directly applied to the surface of the test specimen.

[0047] (Criteria for judging the coloring state) The criteria for judging the coloring state were the same as in Experimental Example 1.

[0048] Tables 5 to 8 show the results of judging the coloring state when the zinc content in the test specimen was 0.0001 kg / m 3 , 0.0005 kg / m 3 , 0.001 kg / m 3 , 0.5 kg / m 3 .

[0049] [Table 5]

[0050] [Table 6]

[0051] [Table 7]

[0052] [Table 8]

[0053] From the results in Tables 5 to 8, when the zinc content in the test specimen was 0.001 kg / m 3 , 0.5 kg / m 3In the case of Examples 2 to 7 where the surface of the specimen was adjusted to pH 9 and then the coloring solution was applied, zinc reacted with the coloring reagent, resulting in the coloring of the surface of the specimen.

[0054] [Experimental Example 3] As the wood to be tested, Japanese larch, Scots pine, whitewood, balsam fir, Sitka spruce, SPF, Japanese cypress, Siberian larch, Japanese cedar, sugi, Dahurian larch, southern yellow pine were used, and a plurality of 3 cm × 3 cm × 2 mm wood pieces were prepared from these sawn timbers. The wood pieces were all immersed in a solution of aliphatic hydrocarbon in which zinc neodecanoate was dissolved, and then cured in a well-ventilated upper room for one month to obtain specimens.

[0055] After curing, the specimens were coated with a coloring solution on their surfaces to confirm the coloring state of zinc. The coloring was divided into Comparative Example 8 in which the coloring solution was directly applied to the surface of the specimen without performing a pH adjustment step, and Test Example 8 in which the pH of the surface of the specimen was adjusted to 5 and then the coloring solution was applied.

[0056] The pH of the surface of the specimen in Test Example 8 was adjusted by spraying a 0.01 M aqueous sodium hydroxide solution on the surface of the specimen.

[0057] 〈Coloring solution〉 As the coloring solution, an acetone solution containing 0.01% by mass of dithizone (0.01% dithizone-acetone coloring solution) was used.

[0058] For specimens that did not show coloring, in order to confirm the amount of zinc contained, the specimens were wet-decomposed using sulfuric acid and hydrogen peroxide solution, and then the zinc contained in the solution after wet decomposition was measured using an atomic absorption spectrophotometer.

[0059] Test Example 8: The surface of the specimen was adjusted to pH 5 and then the 0.01% dithizone-acetone coloring solution was applied. Comparative Example 8: The 0.01% dithizone-acetone coloring solution was directly applied to the surface of the specimen.

[0060] (Criteria for judging the coloring state) The criteria for determining the coloring state were the same as in Experimental Example 1.

[0061] Tables 9 to 12 show the results of determining the coloring state when the zinc content in the test piece was 0.0001 kg / m 3 , 0.0005 kg / m 3 , 0.001 kg / m 3 , 0.5 kg / m 3 .

[0062] [Table 9]

[0063] [Table 10]

[0064] [Table 11]

[0065] [Table 12]

[0066] From the results of Tables 9 to 12, when the zinc content in the test piece was 0.001 kg / m 3 , 0.5 kg / m 3 , in Test Example 8 where the surface of the test piece was adjusted to pH 5 and then the 0.01% dithizone-acetone coloring solution was applied, the zinc reacted with the coloring reagent and the surface of the test piece was colored.

[0067] [Experimental Example 4] As the wood to be tested, larch, Scots pine, whitewood, balsam fir, white spruce, SPF, Japanese cypress, Siberian larch, Japanese cypress, sugi, Dahurian larch, and southern yellow pine were used, and a plurality of 3 cm × 3 cm × 2 mm wood pieces were prepared from these sawn timbers. The wood pieces were all immersed in a solution of aliphatic hydrocarbon in which zinc neodecanoate was dissolved, and then cured in a well-ventilated upper room for one month to obtain test specimens.

[0068] After curing, the test specimens were coated with a coloring solution on their surfaces to confirm the coloring state of zinc. The coloring was divided into Comparative Examples 9 to 14 in which the coloring solution was directly applied to the surface of the test specimen without performing a pH adjustment step, and Test Examples 9 to 14 in which the coloring solution was applied after adjusting the pH of the test specimen surface to 9.

[0069] The pH of the test specimen surface in Test Examples 9 to 14 was adjusted by spraying a 0.01 M aqueous sodium hydroxide solution on the test specimen surface.

[0070] 〈Coloring Solution〉 As the coloring solution, for Test Example 9 and Comparative Example 9, an acetone solution containing 0.01% by mass of dithizone (0.01% dithizone-acetone coloring solution) was used; for Test Example 10 and Comparative Example 10, an acetone solution containing 0.05% by mass of PAN (0.05% PAN-acetone coloring solution) was used; for Test Example 11 and Comparative Example 11, an acetone solution containing 0.05% by mass of PAR (0.05% PAR-acetone coloring solution) was used; for Test Example 12 and Comparative Example 12, an aqueous solution containing 0.05% by mass of Nitro-PAPS (0.05% Nitro-PAPS-aqueous coloring solution) was used; for Test Example 13 and Comparative Example 13, an aqueous solution containing 0.05% by mass of 5-Br-PAPS (0.05% 5-Br-PAPS-aqueous coloring solution) was used; for Test Example 14 and Comparative Example 14, a 0.01 M aqueous sodium hydroxide solution containing 0.01% by mass of Zincon (0.01% Zincon-aqueous (pH 12) coloring solution) was used.

[0071] For the specimens that did not show coloration, in order to confirm the amount of zinc contained, the specimens were wet-decomposed using sulfuric acid and hydrogen peroxide solution, and then the zinc contained in the solution after wet decomposition was measured using an atomic absorption spectrophotometer.

[0072] Test Example 9: After adjusting the pH of the specimen surface to 9, a 0.01% dithizone-acetone coloring solution was applied. Test Example 10: After adjusting the pH of the specimen surface to 9, a 0.05% PAN-acetone coloring solution was applied. Test Example 11: After adjusting the pH of the specimen surface to 9, a 0.05% PAR-acetone coloring solution was applied. Test Example 12: After adjusting the pH of the specimen surface to 9, a 0.05% Nitro-PAPS-water coloring solution was applied. Test Example 13: After adjusting the pH of the specimen surface to 9, a 0.05% 5-Br-PAPS-water coloring solution was applied. Test Example 14: After adjusting the pH of the specimen surface to 9, a 0.01% Zincon-water (pH 12) coloring solution was applied.

[0073] Comparative Example 9: A 0.01% dithizone-acetone coloring solution was directly applied to the specimen surface. Comparative Example 10: A 0.05% PAN-acetone coloring solution was directly applied to the specimen surface. Comparative Example 11: A 0.05% PAR-acetone coloring solution was directly applied to the specimen surface. Comparative Example 12: A 0.05% Nitro-PAPS-water coloring solution was directly applied to the specimen surface. Comparative Example 13: A 0.05% 5-Br-PAPS-water coloring solution was directly applied to the specimen surface. Comparative Example 14: A 0.01% Zincon-water (pH 12) coloring solution was directly applied to the specimen surface.

[0074] (Criteria for Discriminating the Coloring State) The criteria for discriminating the coloring state were the same as in Experimental Example 1.

[0075] In Tables 13 to 16, the zinc content in the specimen is 0.0001 kg / m 3 , 0.0005 kg / m3 、 0.001 kg / m 3 、 0.5 kg / m 3 shows the results of discriminating the coloring states in the case of.

[0076] [Table 13]

[0077] [Table 14]

[0078] [Table 15]

[0079] [Table 16]

[0080] From the results of Tables 13 to 16, the zinc content in the specimen is 0.001 kg / m 3 、 0.5 kg / m 3 In the case of, in Test Examples 9 to 14 where the surface of the specimen was adjusted to pH 9 and then the coloring solution was applied, zinc reacted with the coloring reagent and the surface of the specimen was colored.

[0081] [Experimental Example 5] As the wood to be tested, larch, Scots pine, whitewood, balsam fir, spruce, SPF, Japanese cypress, lodgepole pine, Japanese cypress, cedar, black lodgepole pine, and southern yellow pine were used, and a plurality of 3 cm × 3 cm × 2 mm wood pieces were prepared from these sawn timbers. The wood pieces were all immersed in an aqueous zinc acetate solution and then cured in a well-ventilated upper room for one month to obtain specimens.

[0082] After the health preservation, the test specimens were examined for the color development state of zinc by applying a coloring solution to their surfaces. The color development was divided into Comparative Example 15 in which the coloring solution was directly applied to the surface of the test specimen without performing a pH adjustment step, and Test Example 15 in which the coloring solution was applied after adjusting the pH of the surface of the test specimen to 5.

[0083] In Test Example 15, the pH of the surface of the test specimen was adjusted by spraying a 0.01 M aqueous sodium hydroxide solution onto the surface of the test specimen.

[0084] 〈Coloring solution〉 As the coloring solution, an acetone solution containing 0.01% by mass of dithizone (0.01% dithizone-acetone coloring solution) was used.

[0085] For the test specimens that did not show color development, in order to confirm the amount of zinc contained, the test specimens were wet-decomposed using sulfuric acid and hydrogen peroxide water, and then the zinc contained in the solution after wet decomposition was measured using an atomic absorption spectrophotometer.

[0086] Test Example 15: After adjusting the surface of the test specimen to pH 5, a 0.01% dithizone-acetone coloring solution was applied. Comparative Example 15: A 0.01% dithizone-acetone coloring solution was directly applied to the surface of the test specimen.

[0087] (Criteria for judging the color development state) The criteria for judging the color development state were the same as in Experimental Example 1.

[0088] Tables 17 to 20 show the results of judging the color development state when the zinc content in the test specimen was 0.0001 kg / m 3 , 0.0005 kg / m 3 , 0.001 kg / m 3 , 0.5 kg / m 3 .

[0089]

Table 17

[0090]

Table 18

[0091] [Table 19]

[0092] [Table 20]

[0093] From the results of Tables 17 to 20, when the zinc content in the specimen was 0.001 kg / m 3 , 0.5 kg / m 3 , in Test Example 15 where the surface of the specimen was adjusted to pH 5 and then a 0.01% dithizone-acetone coloring solution was applied, zinc reacted with the coloring reagent and the surface of the specimen was colored as a result.

[0094] [Experimental Example 6] As the wood to be tested, larch, Scots pine, whitewood, balsam fir, white spruce, SPF, cypress, lodgepole pine, Japanese cypress, Japanese cedar, Dahurian larch, and southern yellow pine were used, and a plurality of 3 cm × 3 cm × 2 mm wood pieces were prepared from these sawn timbers. The wood pieces were all immersed in an aqueous zinc acetate solution and then cured in a well-ventilated upper room for 1 month to obtain specimens.

[0095] After curing, the specimens were coated with a coloring solution on their surfaces to confirm the coloring state of zinc. The coloring was divided into Comparative Examples 16 to 21 in which the coloring solution was directly applied to the surface of the specimen without performing a pH adjustment step, and Test Examples 16 to 21 in which the coloring solution was applied after adjusting the pH of the surface of the specimen to 9.

[0096] In Test Examples 16 to 21, the pH of the surface of the specimen was adjusted by spraying a 0.01 M aqueous sodium hydroxide solution on the surface of the specimen.

[0097] 〈Coloring Solution〉 As the coloring solution, an acetone solution containing 0.01% by mass of dithizone (0.01% dithizone-acetone coloring solution) was used for Test Example 16 and Comparative Example 16, an acetone solution containing 0.05% by mass of PAN (0.05% PAN-acetone coloring solution) was used for Test Example 17 and Comparative Example 17, an acetone solution containing 0.05% by mass of PAR (0.05% PAR-acetone coloring solution) was used for Test Example 18 and Comparative Example 18, an aqueous solution containing 0.05% by mass of Nitro-PAPS (0.05% Nitro-PAPS-aqueous coloring solution) was used for Test Example 19 and Comparative Example 19, an aqueous solution containing 0.05% by mass of 5-Br-PAPS (0.05% 5-Br-PAPS-aqueous coloring solution) was used for Test Example 20 and Comparative Example 20, and a 0.01 M aqueous sodium hydroxide solution containing 0.01% by mass of Zincon (0.01% Zincon-aqueous (pH 12) coloring solution) was used for Test Example 21 and Comparative Example 21.

[0098] For the test specimens that did not show coloration, in order to confirm the amount of zinc contained, the test specimens were wet-decomposed using sulfuric acid and hydrogen peroxide water, and then the zinc contained in the solution after wet decomposition was measured using an atomic absorption spectrophotometer.

[0099] Test Example 16: After adjusting the pH of the test specimen surface to 9, a 0.01% dithizone-acetone coloring solution was applied. Test Example 17: After adjusting the pH of the test specimen surface to 9, a 0.05% PAN-acetone coloring solution was applied. Test Example 18: After adjusting the pH of the test specimen surface to 9, a 0.05% PAR-acetone coloring solution was applied. Test Example 19: After adjusting the pH of the test specimen surface to 9, a 0.05% Nitro-PAPS-aqueous coloring solution was applied. Test Example 20: After adjusting the pH of the test specimen surface to 9, a 0.05% 5-Br-PAPS-aqueous coloring solution was applied. Test Example 21: After adjusting the pH of the test specimen surface to 9, a 0.01% Zincon-aqueous (pH 12) coloring solution was applied.

[0100] Comparative Example 16: A 0.01% dithizone-acetone coloring solution was directly applied to the surface of the test specimen. Comparative Example 17: A 0.05% PAN-acetone coloring solution was directly applied to the surface of the test specimen. Comparative Example 18: A 0.05% PAR-acetone coloring solution was directly applied to the surface of the test specimen. Comparative Example 19: A 0.05% Nitro-PAPS-water coloring solution was directly applied to the surface of the test specimen. Comparative Example 20: A 0.05% 5-Br-PAPS-water coloring solution was directly applied to the surface of the test specimen. Comparative Example 21: A 0.01% Zincon-water (pH 12) coloring solution was directly applied to the surface of the test specimen.

[0101] (Criteria for judging the coloring state) The criteria for judging the coloring state were the same as in Experimental Example 1.

[0102] Tables 21 to 24 show the results of judging the coloring state when the zinc content in the test specimen was 0.0001 kg / m 3 , 0.0005 kg / m 3 , 0.001 kg / m 3 , 0.5 kg / m 3 .

[0103]

Table 21

[0104]

Table 22

[0105]

Table 23

[0106]

Table 24

[0107] From the results of Tables 21 to 24, when the zinc content in the specimen was 0.001 kg / m 3 , 0.5 kg / m 3 , in Test Examples 16 to 21 where the surface of the specimen was adjusted to pH 9 and then the coloring solution was applied, zinc reacted with the coloring reagent and the surface of the specimen was colored as a result.

[0108] [Experimental Example 7] As the wood to be tested, larch, Scots pine, whitewood, balsam fir, spruce, SPF, Japanese cypress, larches, Japanese cedar, sugi, Dahurian larch, southern yellow pine were used, and a plurality of 3 cm × 3 cm × 2 mm wood pieces were prepared from these sawn timbers. The wood pieces were all immersed in a solution of aliphatic hydrocarbon in which zinc naphthenate was dissolved, and then cured in a well-ventilated upper room for 1 month to obtain specimens.

[0109] For the specimens after curing, the coloring solution was applied to the surface to confirm the coloring state of zinc. The coloring was divided into Comparative Example 22 in which the coloring solution was directly applied to the surface of the specimen without performing the pH adjustment step, and Test Example 22 in which the coloring solution was applied after adjusting the pH of the specimen surface to 5.

[0110] The pH of the specimen surface in Test Example 22 was adjusted by spraying a 0.01 M aqueous sodium hydroxide solution on the specimen surface.

[0111] 〈Coloring Solution〉 As the coloring solution, an acetone solution containing 0.01% by mass of dithizone (0.01% dithizone-acetone coloring solution) was used.

[0112] For the specimens that did not show coloring, in order to confirm the amount of zinc contained, the specimens were wet-decomposed using sulfuric acid and hydrogen peroxide solution, and then the zinc contained in the solution after wet decomposition was measured using an atomic absorption spectrophotometer.

[0113] Test Example 22: After adjusting the specimen surface to pH 5, the 0.01% dithizone-acetone coloring solution was applied. Comparative Example 22: A 0.01% dithizone-acetone coloring solution was directly applied to the surface of the test specimen.

[0114] (Criteria for judging the coloring state) The criteria for judging the coloring state were the same as in Experimental Example 1.

[0115] Tables 25 to 28 show the results of judging the coloring state when the zinc content in the test specimen was 0.0001 kg / m 3 , 0.0005 kg / m 3 , 0.001 kg / m 3 , 0.5 kg / m 3 .

[0116] [Table 25]

[0117] [Table 26]

[0118] [Table 27]

[0119] [Table 28]

[0120] From the results in Tables 25 to 28, when the zinc content in the test specimen was 0.001 kg / m 3 , 0.5 kg / m 3 , in Test Example 22 where the surface of the test specimen was adjusted to pH 5 and then a 0.01% dithizone-acetone coloring solution was applied, zinc reacted with the coloring reagent and the surface of the test specimen was colored.

[0121] [Experimental Example 8] As the wood to be tested, Japanese larch, Scots pine, whitewood, balsam fir, balsam poplar, SPF, Japanese cypress, larch, Japanese cedar, sugi, Dahurian larch, and southern yellow pine were used, and a plurality of 3 cm × 3 cm × 2 mm wood pieces were prepared from these sawn timbers. The wood pieces were all immersed in a solution of aliphatic hydrocarbon in which zinc naphthenate was dissolved, and then cured in a well-ventilated upper room for one month to obtain test specimens.

[0122] For the cured test specimens, a coloring solution was applied to the surface to confirm the coloring state of zinc. The coloring was divided into Comparative Examples 23 to 28 in which the coloring solution was directly applied to the surface of the test specimen without performing a pH adjustment step, and Test Examples 23 to 28 in which the coloring solution was applied after adjusting the pH of the test specimen surface to 9.

[0123] The pH of the test specimen surface in Test Examples 23 to 28 was adjusted by spraying a 0.01 M aqueous sodium hydroxide solution onto the test specimen surface.

[0124] 〈Coloring Solution〉 As the coloring solution, an acetone solution containing 0.01% by mass of dithizone (0.01% dithizone-acetone coloring solution) was used for Test Example 23 and Comparative Example 23, an acetone solution containing 0.05% by mass of PAN (0.05% PAN-acetone coloring solution) was used for Test Example 24 and Comparative Example 24, an acetone solution containing 0.05% by mass of PAR (0.05% PAR-acetone coloring solution) was used for Test Example 25 and Comparative Example 25, an aqueous solution containing 0.05% by mass of Nitro-PAPS (0.05% Nitro-PAPS-water coloring solution) was used for Test Example 26 and Comparative Example 26, an aqueous solution containing 0.05% by mass of 5-Br-PAPS (0.05% 5-Br-PAPS-water coloring solution) was used for Test Example 27 and Comparative Example 27, and a 0.01 M aqueous sodium hydroxide solution containing 0.01% by mass of Zincon (0.01% Zincon-water (pH 12) coloring solution) was used for Test Example 28 and Comparative Example 28.

[0125] For the specimens that did not show coloration, in order to confirm the amount of zinc contained, the specimens were wet-decomposed using sulfuric acid and hydrogen peroxide solution, and then the zinc contained in the solution after wet decomposition was measured using an atomic absorption spectrophotometer.

[0126] Test Example 23: After adjusting the pH of the specimen surface to 9, a 0.01% dithizone-acetone coloring solution was applied. Test Example 24: After adjusting the pH of the specimen surface to 9, a 0.05% PAN-acetone coloring solution was applied. Test Example 25: After adjusting the pH of the specimen surface to 9, a 0.05% PAR-acetone coloring solution was applied. Test Example 26: After adjusting the pH of the specimen surface to 9, a 0.05% Nitro-PAPS-water coloring solution was applied. Test Example 27: After adjusting the pH of the specimen surface to 9, a 0.05% 5-Br-PAPS-water coloring solution was applied. Test Example 28: After adjusting the pH of the specimen surface to 9, a 0.01% Zincon-water (pH 12) coloring solution was applied.

[0127] Comparative Example 23: A 0.01% dithizone-acetone coloring solution was directly applied to the specimen surface. Comparative Example 24: A 0.05% PAN-acetone coloring solution was directly applied to the specimen surface. Comparative Example 25: A 0.05% PAR-acetone coloring solution was directly applied to the specimen surface. Comparative Example 26: A 0.05% Nitro-PAPS-water coloring solution was directly applied to the specimen surface. Comparative Example 27: A 0.05% 5-Br-PAPS-water coloring solution was directly applied to the specimen surface. Comparative Example 28: A 0.01% Zincon-water (pH 12) coloring solution was directly applied to the specimen surface.

[0128] (Criteria for judging the coloring state) The criteria for judging the coloring state were the same as in Experimental Example 1.

[0129] In Tables 29 to 32, the zinc content in the specimen is 0.0001 kg / m 3 , 0.0005 kg / m3 , 0.001 kg / m 3 , 0.5 kg / m 3 shows the result of discriminating the coloring state in the case of.

[0130]

Table 29

[0131]

Table 30

[0132]

Table 31

[0133]

Table 32

[0134] From the results of Tables 29 to 32, when the zinc content in the specimen is 0.001 kg / m 3 , 0.5 kg / m 3 , in Test Examples 23 to 28 where the surface of the specimen was adjusted to pH 9 and then the coloring solution was applied, zinc reacted with the coloring reagent and the surface of the specimen was colored.

Industrial Applicability

[0135] From the above results, when examining the color development property of zinc in wood using various tree species, zinc compounds, and coloring reagents, the zinc content in wood is 0.001 kg / m 3 to 0.5 kg / m 3 , and by performing the pH adjustment step, zinc could be made to react. Therefore, according to the present invention, zinc in wood and the like can be surely colored, so it is industrially useful.

Claims

Claim 1 A color development method for coloring zinc in wood or woody materials, comprising: a pH adjustment step of adjusting the pH of the surface of the wood or the surface of the woody material to 5 or more; a coating step of applying a color development reagent to the surface of the wood or the surface of the woody material after the pH adjustment step. The zinc content in the wood or the woody material is 0.001 kg / m ３ to 0.5 kg / m ３ This is the coloring method. Claim 2 The color development method according to claim 1, wherein the tree species of the wood or the woody material is at least one selected from the group consisting of larch, Scots pine, whitewood, balsam fir, white spruce, SPF, hemlock, Siberian larch, cypress, cedar, dahurian larch, and southern yellow pine. Claim 3 The color development method according to claim 1, wherein the wood or the woody material is impregnated with an impregnation labeling component containing at least one or more zinc compounds. Claim 4 The color development method according to claim 1, wherein the color development reagent contains at least one or more selected from the group consisting of dithizone, PAN, PAR, Nitro-PAPS, 5-Br-PAPS, and zincon.

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