JP2006028366A - Formaldehyde scavenger and woody material - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To provide a formaldehyde scavenger suppressing release of formaldehyde in high efficiency for long period without influenced by production, storage and working conditions of the formaldehyde scavenger. <P>SOLUTION: The formaldehyde scavenger contains a hydrazine-based compound and a carboxylic acid compound as active ingredients. The woody material contains the formaldehyde scavenger containing the hydrazine-based compound and the carboxylic acid compound as active ingredients. <P>COPYRIGHT: (C)2006,JPO&NCIPI

Description

  The present invention relates to a formaldehyde scavenger and a wood material, and more particularly to a formaldehyde scavenger which prevents formaldehyde emission due to a formaldehyde-based adhesive used in the production of a wood material and a wood material with a low formaldehyde emission. .

Formaldehyde adhesives and the like are sometimes used for the production of wood materials. In such a case, the formaldehyde released due to the formaldehyde-based adhesive is diffused from the woody material, harms the environment and health, and is a social problem as a sick house syndrome that reacts sensitively to chemical substances. For this reason, a composition for removing formaldehyde has been proposed. As a specific example thereof, an aldehyde such as formaldehyde comprising a hydrazine compound and a weak acid metal salt such as a carboxylic acid metal salt or a borate metal salt is used. Deodorant compositions for removal are known.
JP 2000-152979 A

  However, although the above-mentioned composition removes aldehydes such as formaldehyde, it cannot be said that the removal effect is still sufficiently high, and considering the above-mentioned social problems, further improvement in the removal effect is desired. . It is also desired that the removal effect is stably exhibited without being affected by the production, storage or use conditions of the composition.

  The present invention has been made in view of the above circumstances, and its purpose is to capture formaldehyde with high efficiency and long-term suppression of formaldehyde emission without being affected by the production, storage, and use conditions of the formaldehyde scavenger. It is to provide an agent.

  As a result of various studies, the present inventors have surprisingly found that formaldehyde scavengers containing hydrazine-based compounds and carboxylic acid compounds as active ingredients have a high efficiency and long-term emission of formaldehyde caused by formaldehyde-based adhesives. Suppress.

  The present invention has been completed based on the above findings, and the gist of the present invention resides in a formaldehyde scavenger characterized by comprising a hydrazine compound and a carboxylic acid compound as active ingredients.

  And the 2nd summary of this invention exists in the woody material characterized by containing the above-mentioned formaldehyde scavenger.

  The formaldehyde scavenger of the present invention not only suppresses formaldehyde generated from the material for a long period of time, but also stably exhibits the formaldehyde scavenging effect without being affected by the production, storage, and use conditions of the formaldehyde scavenger. it can. Moreover, since the wooden material containing the formaldehyde scavenger of the present invention has less formaldehyde emission, it is possible to prevent the occurrence of problems such as sick house syndrome.

  Hereinafter, the present invention will be described in detail. In addition, description of the component requirement described below is an example (representative example) of the embodiment of this invention, and is not specified by these content.

  The formaldehyde scavenger of the present invention contains a hydrazine compound and a carboxylic acid compound as active ingredients.

(A) Hydrazine compounds:
The hydrazine compound used in the present invention is not particularly limited as long as it is a compound capable of generating hydrazine by decomposition or the like. Specifically, hydrazides having —NHNH ₂ group, monohydrazide compound having one hydrazide group in the molecule, dihydrazide compound having two hydrazide groups in the molecule, 3 or more in the molecule A polyhydrazide compound having a hydrazide group may be mentioned.

(1) Monohydrazide compound:
The monohydrazide compound is, for example, a compound represented by the following formula (I).

  In the formula (I), the alkyl group represented by R usually includes an alkyl group having 1 to 12 carbon atoms, preferably 1 to 6 carbon atoms, and specifically includes a methyl group, an ethyl group, an n-propyl group, Examples include linear alkyl groups such as n-pentyl group and n-hexyl group. The alkyl group may have a substituent, and examples of the substituent include a halogen atom such as chlorine and a hydroxyl group.

  Examples of the aryl group represented by R include an aryl group having 6 or more carbon atoms, and specifically include a phenyl group and a naphthyl group. The aryl group may have a substituent, and examples of the substituent include a halogen atom such as chlorine, a hydroxyl group, a methyl group, an ethyl group, an n-propyl group, and an iso-propyl group. .

  Examples of the hydrazide compound of the formula (I) include acetohydrazide, propionic acid hydrazide, naphthoic acid hydrazide, salicylic acid hydrazide and the like.

(2) Dihydrazide compound:
The dihydrazide compound is a compound represented by the following formula (II).

  In the formula (II), the alkylene group represented by A is usually an alkylene group having 1 to 12 carbon atoms, preferably 2 to 10 carbon atoms, and specifically includes a methylene group, an ethylene group, a trimethylene group, and a tetramethylene group. And linear alkylene groups such as a pentamethylene group, a hexamethylene group, a heptamethylene group, and an octamethylene group. The alkylene group may have a substituent, and examples of the substituent include a halogen atom such as chlorine and a hydroxyl group.

  The arylene group represented by A is usually an arylene group having 6 or more carbon atoms, and specifically includes a phenylene group, a biphenylene group, a naphthylene group, and the like.

  Specific examples of the dihydrazide compound of the formula (II) include carbohydrazide, oxalic acid dihydrazide, malonic acid dihydrazide, succinic acid dihydrazide, adipic acid dihydrazide, azelaic acid dihydrazide, sebacic acid dihydrazide, dodecane-2 acid dihydrazide, maleic acid Examples include dihydrazide and fumaric acid dihydrazide.

(3) Polyhydrazide compound:
As the polyhydrazide compound, polyacrylic acid hydrazide or the like can be used.

  Of the hydrazide compounds, dihydrazide compounds are preferred in view of formaldehyde scavenging ability and operability. Of these, dibasic acid dihydrazides such as sebacic acid dihydrazide and adipic acid dihydrazide are more preferable.

  The lower limit of the molecular weight of the hydrazine-based compound used in the present invention is usually 30, preferably 50, and the upper limit is usually 500, preferably 400. The hydrazine compounds can be used alone or as a mixture of two or more.

(B) Carboxylic acid compound:
The carboxylic acid compound used in the present invention is a compound having a carboxyl group, and the number of carboxyl groups is usually 1 to 4, preferably 1 to 3.

  Specific examples of carboxylic acid compounds include saturated carboxylic acids such as oxalic acid, succinic acid, adipic acid, tartaric acid, citric acid, malonic acid and malic acid, unsaturated carboxylic acids such as fumaric acid, and aromatics such as phthalic acid. Group carboxylic acid. Of these, succinic acid, phthalic acid, and adipic acid are preferred, and adipic acid is particularly preferred from the viewpoints of solubility, operability, safety, and economy.

  The lower limit of the molecular weight of the carboxylic acid compound used in the present invention is usually 50, preferably 60, and the upper limit is usually 500, preferably 400 or less.

  Further, the lower limit value of the acid dissociation constant (pKa) of the carboxylic acid compound used in the present invention is usually 1, preferably 2, and the upper limit value thereof is usually 6, preferably 5.5. When the acid dissociation constant exceeds 6, or when the acid dissociation constant is less than 1, the pH value varies greatly, which is not preferable.

  The acid dissociation constant (pKa) of the carboxylic acid compound is, for example, oxalic acid: 1.04 (dissociation stage: 3.82), succinic acid: 4.00 (dissociation stage: 5.24), adipic acid: 4.26. (Dissociation stage: 5.03), phthalic acid: 2.89 (dissociation stage: 5.50), tartaric acid: 2.82 (dissociation stage: 3.96), citric acid: 2.90 (dissociation stage: 4. 34), fumaric acid: 2.85 (dissociation stage: 4.10), malonic acid: 2.65 (dissociation stage: 5.28), malic acid: 3.24 (dissociation stage: 4.71). In addition, the acid dissociation index pKa and the value of the dissociation stage were referred to the chemical manual edited by the Chemical Society of Japan (published by Maruzen).

  The lower limit of the carboxylic acid compound in the formaldehyde scavenger is usually 0.0005 parts by weight, preferably 0.001 parts by weight, with respect to 1 part by weight of the hydrazine compound, and the upper limit is usually 0.1 parts by weight. Parts, preferably 0.05 parts by weight. When the amount is less than 0.0005 part by weight, a high scavenging effect of formaldehyde cannot be obtained. Moreover, when it exceeds 0.1 weight part, while a solubility deteriorates, there exists a problem which does not enter into a desired pH range when it is set as aqueous solution.

  In the formaldehyde scavenger of the present invention, by containing a hydrazine compound and a carboxylic acid compound, formaldehyde generated from the material can be suppressed for a long period of time. This is presumed that the carboxylic acid compound promotes the reaction with formaldehyde.

(C) Additive The formaldehyde scavenger of the present invention may contain additives such as urea and rust inhibitor. Urea can improve the formaldehyde scavenging ability and can stabilize the pH value when it is made into an aqueous solution. The lower limit of the amount of urea added is usually 0.2 parts by weight, preferably 0.5 parts by weight, with respect to 1 part by weight of the hydrazine compound, and the upper limit is usually 4 parts by weight, preferably 2 parts by weight. It is. When the addition amount of urea exceeds 4 parts by weight, the effect of improving the formaldehyde scavenging ability is saturated, so there is no point in adding beyond this. Moreover, when it is less than 0.2 parts by weight, the effect of improving the formaldehyde scavenging ability is not exhibited.

  Examples of the rust inhibitor include azole compounds having usually 2 to 3 N atoms as heteroatoms. Specifically, 2-methylimidazole, 2-ethylimidazole, 3,5-dimethylpyrazole, benzopyrazole, benzimidazole, 1,2,4-triazole, 3-amino-1,2,4-triazole, benzotriazole , Tolyltriazole, 1-hydroxybenzotriazole and the like.

  The rust inhibitor has an effect of preventing corrosion of the metal member of the production facility. The lower limit of the addition amount of the rust inhibitor is usually 0.0005 parts by weight, preferably 0.001 parts by weight, with respect to 1 part by weight of the hydrazide compound, and the upper limit is usually 10 parts by weight, preferably 3 parts by weight. It is. When the addition amount exceeds 10 parts by weight, the effect of improving the formaldehyde scavenging ability is saturated, so there is no point in adding beyond this.

  The formaldehyde scavenger of the present invention is usually used as an aqueous solution mixed and dissolved in water, but is not limited thereto. The lower limit of the concentration of formaldehyde scavenger in the aqueous solution (concentration of hydrazine compound and carboxylic acid compound) is usually 1% by weight, preferably 2% by weight, and the upper limit is usually 20% by weight, preferably 10%. % By weight.

  The pH value of the aqueous solution of formaldehyde scavenger is usually 9 or less, preferably 5-9. When the pH value exceeds 9, the plywood is contaminated with alkali, and there is a risk of lowering the bonding performance when performing secondary bonding.

  The formaldehyde scavenger is usually stored as an aqueous solution or powder, but is preferably stored at the lowest possible temperature.

  As a method for applying or impregnating a wooden material with the aqueous solution of the formaldehyde scavenger of the present invention, a known application or impregnation method is applied, and examples thereof include application or impregnation methods such as brush coating, roller coating, dipping method and spray coating. Applied. Of these, spray coating is preferred. The application or impregnation treatment is applied to one or both sides of the wood material. In particular, when coated on both sides, the formaldehyde scavenging effect is large and preferable.

The lower limit of the coating amount of the woody material (as solid content of formaldehyde scavenger) are per surface usually 0.01 g / m ² of wood ^material, preferably 0.1 g / m ^2, its upper limit, usually 100 g / m ² , preferably 50 g / m ² .

  The formaldehyde scavenger of the present invention is usually used for a material that diffuses formaldehyde, but the material is not particularly limited. When the formaldehyde scavenger of the present invention is used for a wood material, a high scavenging effect can be obtained. Examples of the wood material include wood boards such as lumber, collected lumber, plywood or OSP, particle board, and fiber board.

  These wood materials are usually produced using an adhesive as described in JP-A No. 2004-155863 and JP-A No. 2003-31718. Examples of the adhesive used include urea resin, melamine resin, and phenol resin. In particular, when urea resin or melamine resin is used, it is considered that a large amount of formaldehyde is diffused. Even when an adhesive containing no formaldehyde is used, formaldehyde may be emitted from the wood material itself.

  Accordingly, it is preferable to apply or impregnate the woody material with a formaldehyde scavenger. Application or impregnation of the formaldehyde scavenger of the present invention to the wood material is performed on wood chips or wood fibers in the production process of the wood material. Moreover, you may mix | blend with the adhesive agent used. When mix | blending with an adhesive agent, it mix | blends normally with the form of aqueous solution.

  Hereinafter, the present invention will be described more specifically with reference to examples. However, the present invention is not limited to the description of the following examples unless the gist of the present invention is exceeded.

  Adipic acid dihydrazide as a formaldehyde catcher component, urea, and adipic acid as a carboxylic acid compound were dissolved in water at 25 ° C. to prepare an aqueous formaldehyde scavenger solution. The concentration of adipic acid dihydrazide in the aqueous solution is 5% by weight, the concentration of urea is 8% by weight (corresponding to 1.6 parts by weight with respect to 1 part by weight of the hydrazine compound), and the concentration of adipic acid is 0.05% by weight. % (Corresponding to 0.01 part by weight relative to 1 part by weight of the hydrazine compound). Subsequently, the following test was carried out after storage at a temperature of 25 ° C. for 48 hours.

(1) Test piece adjustment:
A commercially available 20 mm particle board (35 cm × 35 cm) was sprayed uniformly on both sides with a formaldehyde scavenger aqueous solution at a rate of 22.2 g / m ² using an atomizer. Samples were dried at room temperature and each sample was sealed with a plastic bag and left for 1 week and 1 month. After standing, 8 pieces of (15 cm × 5 cm) rectangular test pieces were cut out from each sample.

(2) Formaldehyde collection and quantitative operation:
The formaldehyde emission amount was measured in accordance with JIS A 1460 (testing method for formaldehyde emission amount of building boards), a method described in the so-called desiccator method. The results are shown in Table 1.

Comparative Example 1:
A formaldehyde scavenger aqueous solution was obtained in the same manner as in Example 1 except that adipic acid was not added. After storage at a temperature of 25 ° C. for 48 hours, the amount of formaldehyde diffused was measured by the test method described above.

Comparative Example 2:
The test piece which does not process a formaldehyde scavenger composition was prepared, and the amount of formaldehyde emission was measured by the above-mentioned test method.

  From the above results, the formaldehyde emission amount of Example 1 to which the formaldehyde scavenger of the present invention was applied is 0.09 mg / L, which is smaller than that of Comparative Examples 1 and 2.

Claims (3)

  A formaldehyde scavenger comprising a hydrazine compound and a carboxylic acid compound as active ingredients.   The formaldehyde scavenger according to claim 1, wherein the acid dissociation constant of the carboxylic acid compound is 1-6.   A woody material comprising the formaldehyde scavenger according to claim 1 or 2.