Water-based siloxane coating composition for wood materials and wood-based materials

Abstract

The present invention addresses the problem of providing: a water-based siloxane coating composition for wood materials and wood-based materials, which contains substantially no alcohol and is excellent in the permeability into wood materials and wood-based materials and the protection properties for wood materials and wood-based materials, can provide excellent textures of wood materials, and has excellent storage stability; and a use of the water-based siloxane coating composition. The problem can be solved by a coating composition for wood materials and wood-based materials, which comprises (a) a water-based siloxane compound having an amino group, (b) a water-based compound having an epoxy group or a polyol group, and a water-based solvent, in which the ratio of the mass A of the component (a) to the mass B of the component (b), i.e., A / B, is 0.08 to 14, the composition contains no alcohol or contains an alcohol at a content of 5% by mass or less, and the pH value of the composition is 7 or more.

Description

Waterborne siloxane coating composition for wood and wood-based materials

[0001] The present invention relates to a coating composition for wood and wood-based materials, and more specifically to an aqueous siloxane coating composition for wood and wood-based materials, which comprises an aqueous siloxane compound having an amino group, an aqueous compound having a specific functional group, and an aqueous solvent, and which can achieve excellent penetration into wood and wood-based materials, protection, wood texture, and storage stability without using alcohol or using a reduced amount of alcohol, and relates to uses of the aqueous siloxane coating composition for wood and wood-based materials.

[0002] Wood and wood-based materials are often coated to prevent scratches, waterproofing, stain resistance, etc., and various coating compositions have been proposed that offer excellent penetration and protection for wood and wood-based materials. While some of these coating compositions contain volatile organic solvents such as alcohols to improve penetration and storage stability, there is a strong demand for aqueous coating compositions that do not contain volatile organic solvents, in order to solve management and transportation problems associated with low flash points, and to improve the working environment and health. Various aqueous siloxane coating compositions containing amino or epoxy groups have been proposed as aqueous siloxane coating compositions that are substantially free of volatile organic solvents, and their application to wood has also been suggested (see, for example, References 1 to 4). However, no experimental results or data have been reported that demonstrate their effectiveness in actual use in coating wood or wood-based materials. Therefore, formulations and design guidelines for aqueous siloxane coating compositions suitable for coating wood or wood-based materials are unclear, even to those skilled in the art.

[0003] JP-A-2010-537016 JP-A-2011-246636 JP-A-2012-524162 JP-A-2014-515771

[0004] In view of the limitations of the prior art described above, an object of the present invention is to provide a coating composition for wood and wood materials that is substantially alcohol-free, and that has excellent penetration into wood and wood-based materials, protective properties, wood texture, and storage stability, and uses thereof.

[0005] As a result of extensive research, the present inventors have discovered that in an aqueous siloxane coating composition for wood and woody materials comprising (a) an aqueous siloxane compound having an amino group, (b) an aqueous compound having a specific functional group, and an aqueous solvent, by setting the ratio A / B of the mass A of component (a) to the mass B of component (b) and the pH of the coating composition within respective predetermined ranges, it is possible to achieve excellent penetration into wood and woody materials, protection, wood texture, and storage stability without using alcohol or while reducing the amount of alcohol used, and have completed the present invention. That is, the present invention relates to: [1] a coating composition for wood and woody materials comprising: (a) an aqueous siloxane compound having an amino group; (b) an aqueous compound having an epoxy group or a polyol group; and an aqueous solvent, wherein the ratio A / B of the mass A of component (a) to the mass B of component (b) is 0.08 to 14, the composition does not contain alcohol or the alcohol content is 5 mass% or less, and the pH of the composition is 7 or more. Note that the term "coating composition for wood and woody materials" as used herein is intended to be sufficient if it can be used for either wood coating or woody material coating, and both coating compositions usable only for wood coating and coating compositions usable only for wood material coating are included within the scope of the present invention.

[0006]

[0023] The following [2] to

[13] are all preferred aspects or embodiments of the present invention. [2] The coating composition for wood and wood materials according to [1], wherein the pH of the composition is 10 or higher. [3] The coating composition for wood and wood materials according to [1] or [2], wherein the pH of the composition is 13 or lower. [4] The coating composition for wood and wood materials according to any one of [1] to [3], wherein the solids content of the composition is 15.0 mass % to 50.0 mass %. [5] The coating composition for wood and wood materials according to any one of [1] to [4], wherein component (b) is an aqueous epoxy compound. [6] The coating composition for wood and wood materials according to any one of [1] to [5], which is capable of forming a coating layer having stain resistance. [7] A method for imparting stain resistance to wood or wood materials using the coating composition for wood and wood materials according to any one of [1] to [6]. [8] Coated wood or wood material having a coating layer formed by curing the coating composition for wood and wood materials according to any one of [1] to [6]. [9] The coated wood or wood material according to [8], wherein the wood is solid wood or the wood material contains solid wood.

[10] Furniture, building components, stationery, tableware, or sporting goods, having the coated wood or wood material according to [8] or [9].

[11] A method for manufacturing furniture, building components, stationery, tableware, or sporting goods, comprising a step of carrying out the method according to [7].

[12] A member having a coating layer formed by curing the coating composition for wood and wood materials according to any one of [1] to [6], and a substrate made of wood or wood material.

[13] The amount of coating layer applied is such that the amount of coating layer applied is 100 cm2 of the area of ​​the substrate. ２

[13] The element according to

[12] , wherein the weight is 0.01 to 1.0 g per unit area.

[0007] The present invention provides a coating composition for wood and wood materials that can achieve excellent penetration into wood and wood materials, protection, wood texture, and storage stability while using no alcohol or a reduced amount of alcohol, and various applications of coated wood or wood materials, etc. Because the coating composition does not use alcohol or uses only a small amount of alcohol, it is easy to manage and transport, and usually does not require consideration of the working environment or health.However, because it is excellent in penetration into wood and wood materials, protection, wood texture, storage stability, etc., it can be particularly suitably used in coating wood components used in furniture, building components, stationery, tableware, etc.

[0008] The present invention provides a coating composition for wood and woody materials, comprising: (a) an aqueous siloxane compound having an amino group; (b) an aqueous compound having an epoxy group or a polyol group; and an aqueous solvent, wherein the ratio A / B of the mass A of component (a) to the mass B of component (b) is 0.08 to 14; the composition contains no alcohol or the alcohol content is 5 mass% or less; and the pH of the composition is 7 or higher. That is, the coating composition for wood and woody materials of the present invention contains (a) the aqueous siloxane compound having an amino group and (b) the aqueous compound having an epoxy group or a polyol group in predetermined mass proportions. The coating composition for wood and woody materials of the present invention may consist solely of (a) the aqueous siloxane compound having an amino group and (b) the aqueous compound having an epoxy group or a polyol group, or it may contain other components in addition to (a) the aqueous siloxane compound having an amino group and (b) the aqueous compound having an epoxy group or a polyol group. The coating composition for wood and wood-based materials of the present invention contains an aqueous solvent such as water.

[0009] (a) Aqueous Siloxane Compound Having an Amino Group The aqueous siloxane compound having an amino group (a) used in the present invention is not limited to any particular compound as long as it has one or more amino groups and a siloxane skeleton. Here, "aqueous" means that when a 30% by weight solution of the siloxane compound having an amino group (a) as the solute is prepared using water as the solvent and stored at 25°C for one month, it can be visually confirmed that the dissolved state is stably maintained without precipitation or separation. To achieve affinity for water, the aqueous siloxane compound having an amino group (a) preferably has a polar group such as a hydroxyl group. The aqueous siloxane compound having an amino group (a) may have one amino group or two or more amino groups. The amino group may be a primary amino group, a secondary amino group, or a tertiary amino group. When the aqueous siloxane compound having an amino group (a) has two or more amino groups, all of the amino groups may be from the same series, or a combination of amino groups from different series. From the viewpoints of reactivity during coating formation, wood protection, storage stability, etc., it is preferable that (a) the amino group-containing aqueous siloxane compound has two or more amino groups. From the viewpoints of availability, cost, storage stability, etc., it is preferable that it has two to four amino groups, and for example, so-called diaminosiloxanes having two amino groups can be preferably used.

[0010] Specific examples of diaminosiloxanes that can be preferably used as component (a) in the present invention include those represented by the following general formula (1): HN-Z-(SiR0) m -SiR2-Z-NH2-(1) (wherein R is independently a hydroxy group, an unsubstituted or substituted hydrocarbon group having 1 to 10 carbon atoms, or an alkoxy group, alkenoxy group, or cycloalkoxy group having 1 to 8 carbon atoms; Z is independently a single bond, or an unsubstituted or substituted divalent hydrocarbon group having 1 to 8 carbon atoms which may contain an ether bond in the chain; and m is an integer of 1 to 100), and in the compound represented by general formula (1), -NH ２and compounds in which one or both of the R groups are replaced with a secondary or tertiary amino group. From the viewpoint of not using alcohol or reducing the amount of alcohol used, it is preferable that at least one R in formula (1) is a hydroxy group. Furthermore, from the viewpoint of facilitating the alcohol content of the coating composition for wood and woody materials of the present invention to be 5% by mass or less, it is preferable that the weight of alcohol that can be liberated from component (a) is 5% or less based on the weight of the entire compound. In formula (1), m is preferably 1 to 7, and particularly preferably 1 to 3. In formula (1), Z is preferably a single bond or an alkyl group having 1 to 3 carbon atoms, and particularly preferably a single bond.

[0011] More specific examples of diaminosiloxanes that are preferably used as component (a) in the present invention include 1,3-diamino-1,1,3,3-tetrahydroxydisiloxane, 1,3-bis(3-aminopropyl)-1,1,3,3-tetrahydroxydisiloxane, 1,3-bis(4-aminobutyl)-1,1,3,3-tetrahydroxydisiloxane, 1,3-bis(4-aminophenoxy)-1,1,3,3-tetrahydroxydisiloxane, and 1,3-bis(N-phenyl-3-aminopropyl)-1,1,3,3-tetrahydroxydisiloxane.

[0012] When an aqueous siloxane compound having more than two amino groups is used as component (a) in the present invention, preferred examples of the compound include the above-mentioned diaminosiloxanes in which one or both of the amino groups have been substituted with an ethylenediamine group, an aminoethyl-3-aminopropyl group, a 3-ureidopropyl group, etc. These aqueous siloxane compounds having amino groups (a) may be used alone or in combination of two or more.

[0013] (b) Aqueous Compound Having Epoxy Group or Polyol Group The aqueous compound having (b) epoxy group or polyol group has at least one group selected from the group consisting of epoxy groups and polyol groups. Here, "polyol group" refers to a group in which two or more hydrogen atoms constituting a hydrocarbon group are substituted with hydroxyl groups. The presence of a polyol group can more effectively contribute to the realization of the effects of the present invention, such as suppressing deterioration in texture, such as fluffing, of wood or wood-based materials after washing with running water, due to the two or more water absorption functions of the polyol group. The hydrocarbon group in the polyol group is not particularly limited, but alkyl groups, vinyl groups, allyl groups, etc. are preferred, and alkyl groups are particularly preferred. The number of hydroxyl groups in the polyol group is also not particularly limited, but 2 to 8 are preferred, and 2 is particularly preferred. It is particularly preferred that the polyol group is an alkylene glycol group. Here, "alkylene glycol group" refers to a functional group in which two hydroxyl groups are substituted on an alkyl chain, and specific examples include those represented by the following general formula (2): -CH(OH)CH ２ OH-(2) is an example of a functional group having a structure represented by the formula: (b) The aqueous compound having an epoxy group or a polyol group may be a compound having no repeating units, or a so-called polymer or oligomer having repeating units. From the viewpoint of wood protection, etc., a so-called polymer or oligomer having repeating units is preferred, and from the viewpoints of cost, storage stability, etc., a compound having no repeating units is preferred.

[0014] (b) The aqueous compound having an epoxy group or a polyol group may have one epoxy group or polyol group, or two or more epoxy groups or polyol groups. When the aqueous compound has two or more epoxy groups or polyol groups, all of the epoxy groups or polyol groups may be epoxy groups, all of the polyol groups may be polyol groups, or a combination of epoxy groups and polyol groups may be present.

[0015] (bi) Aqueous siloxane compound having epoxy group or polyol group The aqueous siloxane compound having epoxy group or polyol group that is preferably used as component (b) in the present invention is only required to be an aqueous compound having one or more epoxy group and / or one or more polyol group and having a siloxane skeleton, and there are no other limitations.(bi) Aqueous siloxane compound having epoxy group or polyol group is particularly preferably used as component (b) from the viewpoints of affinity with (a) aqueous siloxane compound having amino group, protection for wood, storage stability, etc.

[0016] (bi) The aqueous siloxane compound having an epoxy group or a polyol group may have one epoxy group or a polyol group, or may have two or more epoxy groups or polyol groups. When having two or more epoxy groups or polyol groups, all of them may be epoxy groups, all of them may be polyol groups, or may have a combination of epoxy groups and polyol groups. From the viewpoints of reactivity during coating formation, protection for wood, wood texture, etc., it is preferable that (bi) the aqueous siloxane compound having an epoxy group or a polyol group has a total of two or more epoxy groups and / or polyol groups. From the viewpoints of availability, cost, storage stability, etc., it is preferable that it has a total of two to four epoxy groups and / or polyol groups.

[0017] (bi) Preferred examples of the aqueous siloxane compound having an epoxy group or a polyol group include the above-mentioned diaminosiloxane, preferably a diaminosiloxane having a structure represented by formula (1), in which the amino group has been substituted with an epoxy group or a polyol group.

[0018] (bii) Epoxy Compounds (b) The aqueous compound having an epoxy group or a polyol group preferably has an epoxy group, i.e., is preferably an epoxy compound (bii). The epoxy compound (bii) may have one epoxy group or two or more epoxy groups.

[0019] (bii) Examples of preferred compounds as the epoxy compound include ethylene glycol diglycidyl ether, polyethylene glycol diglycidyl ether, and phenol (EO). ５ Examples of suitable epoxy compounds include glycidyl ether, 2-ethylhexyl glycidyl ether, phenyl glycidyl ether, 2-phenylphenol glycidyl ether, p-tert-butylphenyl glycidyl ether, N-glycidyl phthalimide, sorbitol polyglycidyl ether, glycerol polyglycidyl ether, diglycerol polyglycidyl ether, polyglycerol polyglycidyl ether, and trimethylolpropane polyglycidyl ether. (bii) The epoxy equivalent of the epoxy compound is not particularly limited, but is preferably from 80 g / eq. to 1,000 g / eq., and more preferably from 100 g / eq. to 600 g / eq.

[0020] Coating Composition for Wood and Wood-Based Materials The coating composition for wood and wood-based materials of the present invention contains the above-mentioned (a) aqueous siloxane compound having an amino group and (b) aqueous compound having an epoxy group or a polyol group, and has a ratio A / B of 0.08 to 14, where A is the mass of component (a) to B is the mass of component (b). Here, the mass A of the aqueous siloxane compound having an amino group is the mass of the aqueous siloxane compound having an amino group itself. Therefore, when the aqueous siloxane compound having an amino group is provided dissolved or dispersed in a solvent such as water, the mass of the aqueous siloxane compound having an amino group itself is calculated from the solids content, and this is used as mass A to calculate the ratio A / B. When multiple types of component (a) are contained in the coating composition, the sum of the masses of those components (a) is taken as mass A. Similarly, the mass B of the (b) aqueous compound having epoxy groups or polyol groups is the mass of the (b) aqueous compound having epoxy groups or polyol groups itself, and therefore, when the (b) aqueous compound having epoxy groups or polyol groups is provided dissolved or dispersed in a solvent such as water, the mass of the (b) aqueous compound having epoxy groups or polyol groups itself is calculated from the solid content ratio, etc., and this is used to calculate the ratio A / B as mass B. When multiple types of (b) components are contained in the coating composition, mass B is the sum of the masses of those (b) components.

[0021] When the ratio A / B is within the range of 0.08 to 14 and other technical features of the present invention are included, the coating composition for wood and wood materials of the present invention can achieve excellent penetration into wood and wood materials, protective properties, wood texture, storage stability, etc. From the viewpoint of more effectively achieving these desirable technical effects, the ratio A / B is preferably within the range of 0.2 to 12, more preferably within the range of 1 to 10, even more preferably within the range of 2 to 8, and particularly preferably within the range of 4 to 6. The ratio A / B can be adjusted as appropriate by, for example, adjusting the mixing ratio of the respective starting materials when producing the coating composition.

[0022] The coating composition for wood and wood-based materials of the present invention contains an aqueous solvent such as water. The aqueous solvent in this embodiment refers to a solvent selected from water, various solvents having affinity for water, and mixed solvents thereof. It is preferable to use water or a mixed solvent containing 50% or more by mass of water as the aqueous solvent. Preferred examples of solvents having affinity for water include inorganic acids such as hydrochloric acid, sulfuric acid, phosphoric acid, and polyphosphoric acid, or aqueous solutions thereof; organic acids such as formic acid, acetic acid, propionic acid, and lactic acid, or aqueous solutions thereof; and aqueous solutions of inorganic acid salts such as zinc chloride, calcium chloride, and magnesium chloride. These may be used alone or in combination of two or more.

[0023] The coating composition for wood and woody materials of the present invention does not contain alcohol, or if it does contain alcohol, the alcohol content is 5% by mass or less. By being alcohol-free or containing 5% by mass or less, the coating composition for wood and woody materials of the present invention is easy to manage and transport, and generally does not require measures to protect the working environment or health when used, making it highly practically convenient. The alcohol content is preferably 3% by mass or less, more preferably 1% by mass or less, and particularly preferably 0.5% by mass or less. The alcohol content can be measured, for example, by gas chromatography or headspace gas chromatography in accordance with JIS K5601. When measured by headspace gas chromatography, for example, if the peak of the organic solvent detected in the measurement is 5%, the alcohol content is 5% by mass or less. Alternatively, the alcohol content of the coating composition for wood and woody materials of the present invention may be measured for each of the above components (a) and (b) using the above method or the like, and the alcohol content of the coating composition for wood and woody materials of the present invention may be calculated based on the alcohol content of each component.

[0024] The coating composition for wood and woody materials of the present invention preferably contains not only alcohol but also no VOCs (volatile organic compounds) at all, or the total VOC content is 5% by mass or less. By containing no VOCs at all or a total VOC content of 5% by mass or less, the coating composition for wood and woody materials of this embodiment is easier to manage and transport, and requires less work environment and health measures when used, making it even more practically convenient. The total VOC content is more preferably 3% by mass or less, even more preferably 1% by mass or less, and particularly preferably 0.5% by mass or less.

[0025] The coating composition for wood and wood materials of the present invention has a pH of at least 7. By having a pH of at least 7 and other technical features of the present invention, the coating composition for wood and wood materials of the present invention can achieve excellent penetration into wood and wood materials, protection, wood texture, storage stability, and the like, without using VOCs such as alcohol or using a reduced amount of such VOCs.

[0026] From the viewpoint of more effectively achieving these favorable technical effects, the pH of the coating composition for wood and wood materials of the present invention is preferably 10 or higher, more preferably 10 or higher and 13 or lower, and particularly preferably 11 to 12. By having a pH of 10 or higher, the coating composition for wood and wood materials of this embodiment exhibits excellent penetration into wood and wood materials and can maintain even higher stain resistance even against repeated staining.

[0027] The pH of the coating composition for wood and woody materials of the present invention can be measured using a glass electrode pH meter or the like, more specifically, by the method described in the Examples of the present application. The pH of the coating composition for wood and woody materials of the present invention can be appropriately adjusted by adjusting the type and amount of each component, such as (a) an aqueous siloxane compound having an amino group, (b) an aqueous compound having an epoxy group or a polyol group, and an aqueous solvent. Furthermore, the pH of the coating composition for wood and woody materials can be adjusted by using various additives, such as a pH adjuster, as needed.

[0028] There are no particular restrictions on the solids content of the coating composition for wood and woody materials of the present invention, and it may be set appropriately depending on the manner and conditions of use and storage of the coating composition, and the properties of each component, such as (a) the aqueous siloxane compound having an amino group, (b) the aqueous compound having an epoxy group or a polyol group, and the aqueous solvent. From the viewpoints of wood protection, storage stability, etc., the solids content is preferably 15.0 to 50.0 mass%, more preferably 20.0 to 40.0 mass%, particularly preferably 25.0 to 35.0 mass%, and most preferably 25.0 to 30.0 mass%.

[0029] Other Components In addition to (a) an aqueous siloxane compound having an amino group, (b) an aqueous compound having an epoxy group or a polyol group, and an aqueous solvent, the coating composition for wood and woody materials of the present invention may contain other components such as conventional coating additives, provided that the addition does not contradict the objectives of the present invention. Examples of other components include preservatives, coloring pigments, extender pigments, pigment dispersants, surface conditioners, antifoaming agents, thickeners, curing catalysts, surfactants, antisettling agents, softeners, plasticizers, reactive diluents, antifreeze agents, antiskinning agents, and pH adjusters. Antioxidants, ultraviolet inhibitors, antifoaming agents, etc. may also be added.

[0030] Wood and Wood-Based Materials The wood and wood-based materials to which the coating composition for wood and wood-based materials of the present invention can be applied are not particularly limited, and may be sawn lumber (solid wood), processed wood made from processed wood chips or fibers, or recycled wood made from wood powder solidified with resin. Examples of processed and recycled wood include plywood, laminated wood, glued laminated lumber, particle board, and MDF. The wood species is also not particularly limited, and various types of wood, such as cypress, cedar, Japanese cypress, oak, paulownia, zelkova, and sawara, may be used alone or in combination of two or more types. Furthermore, the part of the wood is not particularly limited, and the coating composition of the present invention can be applied to various parts, such as straight grain, cross grain, sapwood, red wood, and cross grain. The coating composition for wood and wood materials of the present invention has excellent stain resistance and excellent penetration into wood and / or wood materials, so it can be used on compressed wood, which is generally difficult for coating agents to penetrate, and it is also of great practical value in that it can relatively easily form a coating layer with excellent stain resistance on compressed wood.

[0031] Coated Wood or Wood-Based Materials By applying the coating composition for wood and wood materials of the present invention to wood or wood materials and curing it, a coating (layer) is formed on the wood or wood material, and coated wood or wood-based materials can be produced. Heating is not essential for curing, but heating can shorten the curing time. More specifically, the coating composition for wood and wood-based materials of the present invention can be applied to the surface of wood or wood-based materials by methods such as dipping, spray coating, roll coating, brush coating, etc. A coating (layer) may be formed by a single application, or by repeated application two or more times. When a coating (layer) is formed by repeated application two or more times, the coating composition may be cured after application and then further application, or the application may be repeated without curing, and the coating composition may be cured after all applications have been completed. There is no particular limit to the amount of coating of the coating composition for wood and wood-based materials to be applied, but it is recommended to apply a coating amount of the composition to a surface of 100 cm of wood or wood-based material. ２The amount of application is preferably 0.01 g to 1.0 g, and particularly preferably 0.1 g to 0.5 g, per 100 cm of wood or wood-based material. ２ If the amount is less than 0.01 g per unit area, it is difficult to achieve stain resistance, and if it exceeds 1.0 g, it is difficult to obtain the texture of wood or wood materials. A coating amount within the above range indicates even better penetration into wood and wood materials. Penetration into wood and wood materials can also be evaluated visually after dropping onto wood or wood materials, and more specifically, it can be evaluated, for example, by the method described in the examples of this application.

[0032] There are no particular limitations on the thickness of the coating (layer) after hardening, and it can be set appropriately depending on the purpose of the coating, the required physical properties, the manner in which the coated wood or wood material is used, etc., but it is preferably 30 μm or less, and particularly preferably 15 μm or less.

[0033] The coating composition for wood and wood materials of the present invention has excellent penetration into wood and wood materials and can form a coating layer that is excellent in stain resistance, protection, wood texture, etc., so the coated wood or wood material of one embodiment of the present invention is particularly suitable for use in applications where wood or wood materials are widely used and require protection by coating, from the standpoint of aesthetics, texture, etc., such as furniture, building components, stationery, tableware, sporting goods, etc.

[0034] The present invention will be described in more detail below with reference to examples and comparative examples, but the present invention is not limited thereto in any way.

[0035] In the following Examples and Comparative Examples, physical properties and characteristics were evaluated using the following methods. The ratio A / B of the mass A of component (a) to the mass B of component (b) was calculated by determining the mass A of component (a) from the amount of solids in component (a) used, and determining the mass B of component (b) from the amount of solids in component (b) used. pH of Coating Composition: The pH of the samples prepared as coating compositions in each Example and Comparative Example was measured using pH test paper (manufactured by MACHEREY-NAGEL). Solids and Nonvolatiles: The samples prepared as coating compositions in each Example and Comparative Example were dried at 105°C for 1 hour and their heating residues were measured in accordance with Japanese Industrial Standard JIS K5601-1-2, Heat Residue Test Method for Paint Components. Alcohol Content: The alcohol content of each component used to prepare the coating composition in each Example and Comparative Example was measured by gas chromatography in accordance with Japanese Industrial Standard JIS K5601, and the alcohol content of the entire coating composition was calculated based on the results. Solution Appearance: The appearance (transparency and fluidity) of the samples prepared as coating compositions in each Example / Comparative Example was visually observed. Storage Stability: The coating compositions of each Example / Comparative Example were prepared and stored at 25°C for one month after preparation. The storage stability was evaluated according to the following criteria: Good: No change from the state immediately after preparation, transparency and fluidity were maintained. Bad: Change from the state immediately after preparation, transparency and fluidity were not maintained. Penetration: One drop of the coating composition obtained in each Example and Comparative Example was applied to an MDF (medium density fiber) board or solid wood using a dropper, and the degree of penetration into the MDF board or solid wood was visually evaluated as Good for rapid penetration, Fair for penetration after several minutes, and Bad for almost no penetration. Application Amount: The coating composition obtained in each Example and Comparative Example was applied to a 10 x 10 x 1 cm MDF (medium density fiber) board or solid wood to the extent that no liquid pooled, and then dried at room temperature for 24 hours. The same procedure was repeated the next day and the day after, for a total of three coating and drying operations. After the third drying, the weight of the coated MDF board or solid wood was measured, and the area (100 cm ２The amount of application was calculated by adding (g) to the initial weight per unit area. Anti-fouling properties (water-based marker) After the third drying, marks were drawn arbitrarily on the coated surface of the coated MDF board or solid wood with a water-based marker, and the surface was rinsed with running water. Those that were rinsed away without leaving any visible staining were rated as ⊚, those that left almost no staining, those that left slight staining, and those that could hardly be rinsed away were rated as ◯, △, and ×, respectively. Furthermore, the same procedure was repeated four times after the wood surface had dried. Anti-fouling properties (permanent marker) After the third drying, marks were drawn arbitrarily on the coated surface of the coated MDF board or solid wood with a water-based marker, and the surface was wiped with ethanol. Those that were rinsed away without leaving any visible staining were rated as ⊚, those that left slight staining, and those that could hardly be wiped away were rated as △, and ×, respectively. Appearance (wood texture) After the third drying, arbitrary marks were made on the coating surface of the coated MDF board or solid wood with a water-based marker, and the wood texture was judged after rinsing with running water. Those that maintained the wood texture were rated as ◯ (pass), and those that lost the wood texture (whitening of the coating surface, fuzziness, etc. occurred) were rated as × (fail).

[0036] Example 1 The aqueous siloxane coating composition of Example 1 was prepared by adding 1 part by mass (solids basis) of (a-1) amino group-containing aqueous siloxane (Shin-Etsu Silicone KBP-90, manufactured by Shin-Etsu Chemical Co., Ltd.) as component (a) to 1 part by mass (solids basis) of (b-1) alkylene glycol group-containing aqueous siloxane (Shin-Etsu Silicone X-12-1098, manufactured by Shin-Etsu Chemical Co., Ltd.) as component (b). The obtained aqueous siloxane coating composition was used to evaluate the solution appearance and storage stability, and a coating film was formed on a 10 x 10 x 1 cm MDF board according to the above-mentioned method, and the coating amount, permeability, stain resistance, and appearance (woody texture) were evaluated. The results are shown in Table 1.

[0037] (Examples 2 to 17, Comparative Examples 1 to 15) Aqueous siloxane coating compositions were prepared in the same manner as in Example 1, except that the components and / or amounts used were changed to those shown in Table 1, Table 2, or Table 3. Using the obtained aqueous siloxane coating compositions, the solution appearance and storage stability were evaluated, and a coating film was formed on an MDF board measuring 10 x 10 x 1 cm according to the above-mentioned method, and the permeability, stain resistance, and appearance (wood texture) were evaluated. The results are shown in Table 1, Table 2, or Table 3.

[0038] The details of each component used in the above Examples and Comparative Examples and shown in Tables 1, 2 and 3 are as follows: (a) Aqueous siloxane compounds having amino groups: (a-1) Amino group-containing aqueous siloxane Shin-Etsu Silicone KBP-90 manufactured by Shin-Etsu Chemical Co., Ltd. (a-2) Ethylenediamino group-containing aqueous siloxane Shin-Etsu Silicone KBP-64 manufactured by Shin-Etsu Chemical Co., Ltd.

[0039] (b) Aqueous compounds having an epoxy group or a polyol group (b-1) Alkylene glycol group-containing aqueous siloxane Shin-Etsu Silicone X-12-1098 manufactured by Shin-Etsu Chemical Co., Ltd. (b-2) Epoxy group-containing aqueous siloxane Dynasylan HYDROSIL 2926 manufactured by Evonik (b-3) Ethylene glycol diglycidyl ether, bifunctional type, epoxy equivalent 113 g / eq., Denacol EX-810 manufactured by Nagase ChemteX Corporation (b-4) Polyethylene glycol diglycidyl ether, bifunctional type, epoxy equivalent 268 g / eq., Denacol EX-830 manufactured by Nagase ChemteX Corporation (b-5) Polyethylene glycol diglycidyl ether, bifunctional type, epoxy equivalent 551 g / eq. Nagase ChemteX Corporation Denacol EX-861 (b-6) Phenol (EO) ５Glycidyl ether, monofunctional type, epoxy equivalent 400 g / eq., manufactured by Nagase ChemteX Corporation: Denacol EX-145 (b-7) Sorbitol polyglycidyl ether, multifunctional type, epoxy equivalent 173 g / eq., manufactured by Nagase ChemteX Corporation: Denacol EX-614B

[0040] (c) Aqueous compounds having neither epoxy groups nor polyol groups: (c-1) Trimethylammonium chloride group-containing aqueous siloxane, manufactured by Shin-Etsu Chemical Co., Ltd., Shin-Etsu Silicone X-12-1126; (c-2) Carboxyl group-containing aqueous siloxane, manufactured by Shin-Etsu Chemical Co., Ltd., Shin-Etsu Silicone X-12-1135.

[0041]

[0042]

[0043]

[0044] (Examples 18 to 23) Using the aqueous siloxane coating compositions prepared in Examples 1, 3, 4, 5, 2, or 9, respectively, a coating film was formed on cypress wood in the same manner as in Example 1, except that cypress wood was used as the coating object instead of the MDF board, and the coating amount, permeability, and antifouling properties were evaluated. Furthermore, using the same aqueous siloxane coating composition, a coating film was formed on oak wood in the same manner as in Example 1, except that oak wood was used as the coating object instead of the MDF board, and the coating amount, permeability, and antifouling properties were evaluated. The results are shown in Table 4.

[0045] It is clear that the coating composition for wood and woody materials of the present invention is a suitable coating composition with excellent permeability and stain resistance even for various solid woods, which are typical types of wood.

[0046] The coating composition for wood and woody materials of the present invention is easy to manage and transport, has little impact on the working environment and health, and is excellent in permeability to wood and woody materials, protective properties, wood texture, storage stability, etc., and is therefore highly applicable in various fields of industries such as architecture, construction, and furniture manufacturing.

Claims

1. (a) an aqueous siloxane compound having an amino group, (b) an aqueous compound having an epoxy group or a polyol group, Aqueous solvent and A coating composition for wood and wood-based materials, comprising: The ratio A / B of the mass A of component (a) to the mass B of component (b) is 0.08 to 14. The composition does not contain alcohol, or its alcohol content is 5% by mass or less. The above-mentioned coating composition for wood and wood-based materials, wherein the pH of the composition is 7 or higher.

2. The coating composition for wood and wood-based materials according to claim 1, wherein the pH of the composition is 10 or higher.

3. The coating composition for wood and wood-based materials according to claim 1 or 2, wherein the pH of the composition is 13 or less.

4. The coating composition for wood and wood-based materials according to claim 1 or 2, wherein the solid content of the composition is 15.0% by mass to 50.0% by mass.

5. (b) The coating composition for wood and wood-based materials according to claim 1 or 2, wherein component (b) is an aqueous epoxy compound.

6. A coating composition for wood and wood-based materials according to claim 1 or 2, which can form a coating layer having stain-resistant properties.

7. A method for imparting stain resistance to wood or wood-based materials using the coating composition for wood and wood-based materials described in claim 1 or 2.

8. Coated wood or wood material having a coating layer which is a cured coating composition for wood and wood-based materials according to claim 1 or 2.

9. The coated wood or wood material according to claim 8, wherein the wood is solid wood, or the wood material contains solid wood.

10. Furniture, building materials, stationery, tableware, or sporting goods having the coated wood or wood-based material described in claim 8.

11. A method for manufacturing furniture, building materials, stationery, tableware, or sporting goods, comprising the step of carrying out the method described in claim 7.

12. A component comprising a coating layer which is a cured coating composition for wood and wood-based materials according to claim 1 or 2, and a base material composed of wood or wood-based material.

13. The amount of the coating layer applied is per 100 cm² of the substrate area. ２ The component according to claim 12, wherein the amount is 0.01 to 1.0 g per unit.