JP2002105425A - Adhesive for use in manufacturing odorless wood board - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide an odorless wood board used for building materials, etc., wherein the amount of formaldehyde emitted from the wood board is decreased. SOLUTION: This adhesive for use in manufacturing an odorless wood board is obtained by adding a salt made from an amino compound and an acidic material to an adhesive for a wood board comprising (a) a powder of a melamine compound and/or a melamine resin, and (b) an aqueous solution of an amino group-containing compound.

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to an adhesive for an odorless wood board which is excellent in strength and water resistance, in which the amount of formaldehyde released from the wood board used for building materials and the like is small.

[0002]

2. Description of the Related Art As an adhesive for a wood board, a so-called formaldehyde-based resin obtained by co-condensing with urea-based, melamine-based, phenol-based, etc. formaldehyde has excellent adhesiveness, water resistance and use. It is used because of its simplicity and low cost. However, since these resins release a small amount of formaldehyde after bonding, wood boards, storage furniture, etc. using these resins,
It has been pointed out that formaldehyde is released into the atmosphere at a later date and may cause health problems such as headache, nausea, eye irritation and skin damage to the human body. For this reason, a formaldehyde generation prevention measure is demanded.

[0003] As a resin, a so-called amino resin using urea or melamine, in particular, emits more formaldehyde than other resins, and is regarded as a problem. These resins are weak to acids and are said to undergo hydrolysis by the acids to release formaldehyde.

[0004] As a method for preventing the generation of formaldehyde, a method of lowering the reaction molar ratio of formaldehyde or addition of a formaldehyde trapping agent has been performed. However, as the molar ratio decreases, the stability of the adhesive becomes lower. There were problems such as deterioration of storage stability and time required for curing. Further, a method of reducing the formaldehyde emission by performing a chemical or physical treatment after the plate making has been performed, but it has a disadvantage in cost and has not been widely used.

[0005] Under such circumstances, there has been a demand for an adhesive for a wooden board that can reduce formaldehyde odor while maintaining the same adhesiveness and curability as before.

[0006]

SUMMARY OF THE INVENTION In view of the above situation, the present invention expresses conventional properties such as adhesiveness, curability, water resistance and the like, and reduces the amount of radiated formaldehyde in an amino resin adhesive. An object of the present invention is to provide an odorless wood board adhesive which gives a reduced wood board.

[0007]

Means for Solving the Problems The inventors of the present invention have conducted intensive studies to solve the above-mentioned problems, and as a result, it has been found that melamine-based compounds and melamine-based resins having good adhesiveness are present in the form of particles in an adhesive. The particles are allowed to remain at the bonding interface without penetrating the wood and harden, thereby exhibiting adhesiveness, and the compound having an amino group penetrates the wood together with the water in the adhesive, and The excess amino groups contained in the resin serve as a trapping agent for the formaldehyde that is released, making it possible to reduce the amount of formaldehyde that is released from the wooden board to be made, and to achieve both adhesion and low formaldehyde emission It was found that an agent was obtained, and the present invention was completed.

That is, the present invention provides a melamine compound and / or
Or an adhesive comprising a melamine resin (a), a compound (b) having an amino group, and an acidic substance or a salt (c) comprising an amino compound and an acidic substance, wherein the particles of the component (a) are used. An odorless wooden board-making adhesive characterized by being an aqueous solution comprising:

[0009]

BEST MODE FOR CARRYING OUT THE INVENTION The melamine compounds (component (a)) used in the present invention include monomethylol melamine, dimethylol melamine, trimethylol melamine, tetramethylol melamine, pentamethylol melamine, hexamethylol melamine, and tetrahexanol melamine. And mixtures thereof, and one or more of these can be used. Among them, monomethylolmelamine, dimethylolmelamine, trimethylolmelamine, tetramethylolmelamine, pentamethylolmelamine, and hexamethylolmelamine are preferred.

As a method for synthesizing these melamine compounds, formaldehyde and melamine are heated and refluxed under alkaline conditions at an arbitrary molar ratio for about 20 minutes, and a reaction product obtained is added to cooled methanol. As a result, the melamine compound is precipitated, and a reaction solution containing particles of the melamine compound is obtained. The reaction solution is filtered and dried to obtain a melamine compound powder.

Examples of the alkaline substance that renders the reaction system alkaline in the synthesis of the melamine compound include sodium hydroxide, potassium hydroxide, calcium hydroxide, barium hydroxide, ammonia, and various amines.

Examples of the melamine resin (component (a)) used in the present invention include resins synthesized with melamine such as melamine resin, urea / melamine resin, and melamine / phenol co-condensation resin. More than one kind can be used, and among them, melamine resin, urea-melamine resin, and melamine-phenol co-condensation resin are preferable.

Method for obtaining melamine resin used in the present invention
Is manufactured by a known synthesis method, and melamine and e
Lumaldehyde and various monomers such as urea and phenol
And alkaline, formaldehyde (F) and amine
No group (-NH_Two) Is F / -NH _Two= 0.3-2.2
And obtained by heating and refluxing for 30 minutes or more.
The acidic substance is added to the reaction
A reaction solution containing the lamin resin particles is obtained. In addition,
The reaction solution was added to cooled methanol and the resulting precipitate
The material is filtered, dried, or sprayed
The melamine resin powder is obtained by the rye.

As the alkaline substance for making the reaction system alkaline in the synthesis of the melamine resin, the same alkaline substances as described above can be used. The acidic substance is an inorganic or organic acid such as hydrochloric acid, formic acid, maleic acid, and paratoluenesulfonic acid.

In the synthesis of the melamine resin, the molar ratio is
When F / -NH ₂ is less than 0.3, the adhesive strength is not exhibited. When F / -NH ₂ exceeds 2.2, the amount of formaldehyde emission increases.

In the case where the component (a) is used as an emulsion, a dispersion stabilizer such as polyvinyl alcohol (PVA) can be added to a reaction solution obtained by heating and refluxing each of the components to obtain a small particle size very easily. And the storage stability of the emulsion is also improved.
PVA is preferably a partially saponified type having a molecular weight of 1,000 or more. The degree of saponification of PVA is desirably about 60 to 95 mol%.

An important characteristic of the emulsion particles is that they are insoluble in normal temperature water but soluble in hot water. This prevents the particles from penetrating the veneer, leaving it at the bonding interface, and when hot pressing is performed,
The particles melt and cure to adhere the veneer.

The melamine compound and / or melamine resin used in the present invention has a solid content of 10% in the total amount of the adhesive.
８０80% by weight, preferably 1
If it is less than 0% by weight, the adhesive strength may not be sufficiently exhibited, and if it is more than 80% by weight, the viscosity may be high and the workability may be deteriorated.

The compound (b) having an amino group used in the present invention includes ureas such as urea, thiourea, ethylene urea, methyl urea, ethyl urea, dimethyl urea, diethyl urea, acetyl urea, methanolamine, ethanolamine Alcoholamines such as ethylenediamine, propylenediamine, hexamethylenediamine, etc .; hydrazines such as hydrazine, methylhydrazine, hydrazinobenzoic acid, etc .; alkylamines such as dimethylamine, diethylamine, isopropylamine, butylamine, and ammonia. , Melamine, benzoguanamine, setguanamine, dicyanodiamide, guanidine carbonate, alanine, morpholine, guanine, piperazine, various proteins, various vitamins and the like. Iodine is preferable. These are used alone or in combination of two or more.

The compound (b) having an amino group used in the present invention is used as a solid component in the adhesive (component (a) 10).
It is preferably contained in an amount of 10 to 400 parts by weight with respect to 0 parts by weight. If the amount is less than 10 parts by weight, no effect of reducing the amount of formaldehyde emission is not recognized, and if it exceeds 400 parts by weight, the adhesive strength is reduced.

The acidic substance used in the present invention includes hydrochloric acid,
Preferred are inorganic acids such as sulfuric acid, nitric acid, phosphoric acid, carbonic acid and paratoluenesulfonic acid, and organic acids such as formic acid, acetic acid, citric acid and maleic acid. Among them, sulfuric acid, hydrochloric acid, nitric acid, carbonic acid, phosphoric acid,
Citric acid, formic acid, acetic acid, and maleic acid are preferred, and hydrochloric acid and sulfuric acid are particularly preferred. These are used alone or in combination of two or more.

The salt comprising an amino compound and an acidic substance used in the present invention is formed by mixing the above-mentioned compound (b) having an amino group with the above acidic substance, and these may be used alone or in combination of two or more. Used in combination. Among them, ammonia, melamine, alcoholamines, diamines, hydrazines and alkylamines are preferable as the compound having an amino group used for the salt. Particularly preferred is ammonia.

The acidic substance and the salt (c) comprising the amino compound and the acidic substance function as a so-called curing agent, and the amino compound dissociated in the adhesive reacts with free formaldehyde to generate hydrochloric acid. Reduces the pH and cures the adhesive.

The acidic substance used in the present invention, or the salt (c) comprising an amino compound and an acidic substance, is used as a solid component in the adhesive in an amount of 0.01 to 0.01% based on the melamine compound and / or melamine resin (a). It is preferably contained in a proportion of 10 parts by weight. If it is less than 0.01 part by weight, the amount of generated acid is not sufficient, curing does not proceed, and both the adhesive strength and the amount of formaldehyde emission deteriorate. If it exceeds 10 parts by weight, on the contrary, the amount of generated acid increases, and the acid remains in the resin after curing, so that the resin is easily decomposed, and the adhesive strength,
The amount of formaldehyde emission deteriorates.

The odorless wood board adhesive of the present invention can be obtained by mixing the component (a) and the component (b) with an acidic substance or a salt (c) composed of an amino compound and an acidic substance. In this case, when the powder particles of the component (a) are used, water is mixed with the mixture of the components (a), (b), and (c), and the emulsion of the component (a) or the component (a) is used.
In the case of using a reaction solution containing the particles of (a), the components (b) and (c) may be powders. Mixing may be performed by a usual method, and the order of addition is not particularly limited, but mixing is preferably performed immediately before use.

In addition to the above components, the odorless wood board adhesive of the present invention may further comprise, if necessary, a filler, a bulking agent such as flour, a preservative, a coloring agent, and a curing agent such as ammonium chloride and ammonium sulfate. And other additives can be added.

The obtained odorless wood board adhesive is a white emulsion, at least the component (a) is present in the form of particles, the viscosity is 20 to 4000 mPa · s, and the solid content is 30 to 80 weight. %, But is stable at normal temperature, does not cause agglomeration or the like by the addition of water, and has no problem in cleaning equipment using an adhesive.

The odorless wood board adhesive of the present invention can be used in the same manner as the conventional adhesive, and can be applied to wood in the same manner as the conventional one.

The odorless wood board adhesive of the present invention can be used mainly for plywood, and is molded by a known apparatus and method.

[0030]

EXAMPLES Hereinafter, the present invention will be described in detail with reference to examples, but the present invention is not limited to these examples.

[Synthesis Example 1] (Synthesis of hexamethylolmelamine) A reaction flask equipped with a reflux condenser, a thermometer, a stirrer, and a dropping funnel was charged with 50 parts by weight of melamine, 37% formaldehyde 19
After 4.5 parts by weight and 2 parts by weight of 20% NaOH were charged and heated under reflux for 20 minutes, the reaction product was added to cooled methanol while still hot. The precipitate was filtered and dried to obtain hexamethylolmelamine (abbreviated as H1). The molar ratio of formaldehyde (F) and the amino group of the amino compound _{(-NH 2) (F / -NH} 2) = 2.0

[Synthesis Example 2] (Synthesis of Melamine Resin Powder) The same apparatus as in Synthesis Example 1 was charged with 143 parts by weight of melamine, 194.5 parts by weight of 37% formaldehyde, and 2 parts by weight of 20% NaOH. While still hot, the reaction was added into cooled methanol. The precipitate was filtered and dried to obtain a melamine resin powder (abbreviated as H2). F / -N
H ₂ = 0.7

[Synthesis Example 3] (Synthesis of Melamine Resin Emulsion) In the same apparatus as in Synthesis Example 1, 143 parts by weight of melamine, 194.5 parts by weight of 37% formaldehyde, 20 parts by weight of polyvinyl alcohol (manufactured by Kuraray, trade name PVA217S), 20% NaOH
2 parts by weight were charged, heated under reflux for 90 minutes, and then cooled. 3 mol / L hydrochloric acid is gradually added dropwise to the above reaction solution, and the pH of the system
Was adjusted to 5.5 to obtain a uniform white emulsion (abbreviated as E1). The molar ratio (F / -NH ₂ ) of formaldehyde (F) to the amino group (—NH ₂ ) of the amino compound is 0.7, and the resin solid content (RC) is 66%.

[Synthesis Example 4] (Synthesis of Melamine Resin Emulsion) In the same apparatus as in Synthesis Example 1, melamine 50 parts by weight, 37% formaldehyde 194.5 parts by weight, polyvinyl alcohol (manufactured by Kuraray, trade name PVA217S) 20 parts by weight, 20 parts by weight % NaOH 2 parts by weight, and after heating under reflux for 20 minutes, 3 mol
/ L hydrochloric acid was gradually added dropwise to adjust the pH in the system to 5.5, and the system was further refluxed for 20 minutes. After cooling the reaction, a homogeneous white emulsion (abbreviated as E2) was obtained. F / -NH ₂ = 2.0 Resin solids (RC) = 54%

[Synthesis Example 5] (Synthesis of urea-melamine resin emulsion) In the same apparatus as in Synthesis Example 1, urea 16 parts by weight, melamine 143 parts by weight, 37% formaldehyde 194.5 parts by weight, polyvinyl alcohol (Kuraray, trade name) PVA217S) 20 parts by weight, 20
% NaOH 2 parts by weight was charged, heated under reflux for 90 minutes, and then cooled. 3 mol / L hydrochloric acid was gradually dropped into the reaction solution to adjust the pH of the system to 5.5, and a uniform white emulsion (E3
Abbreviated). F / -NH ₂ = 0.6, resin solid content (RC)
= 67%, Melamine modification rate 57% (in solids)

Examples 1 and 2 Ammonium chloride was mixed with 20 parts by weight of H1 obtained in Synthesis Example 1, 50 parts by weight of urea, 16 parts by weight of flour (red flowers) and 59 parts by weight of water in the proportions shown in Table 1. Then, each adhesive was adjusted. The adhesive obtained above was applied to a 1.3 mm-thick Rawan veneer in an amount of 165 g / m ^{2 on} one side, and the pressure was adjusted to 1.0 MPa.
After cooling at 20 ° C for 20 minutes, heat and pressure at 120 ° C for 78 seconds.
A plywood layer was made.

Examples 3 and 4 Ammonium chloride was blended with 20 parts by weight of H1 obtained in Synthesis Example 1, 20 parts by weight of urea, 16 parts by weight of flour (red flowers) and 29 parts by weight of water in the proportions shown in Table 1. Then, each adhesive was adjusted. Except for these, the same operation as in Examples 1 and 2 was performed to prepare a three-layer plywood.

Examples 5 and 6 Ammonium chloride was blended in the proportions shown in Table 1 with 20 parts by weight of H1 obtained in Synthesis Example 1, 10 parts by weight of urea, 16 parts by weight of flour (red flowers) and 29 parts by weight of water. Then, each adhesive was adjusted. Except for these, the same operation as in Examples 1 and 2 was performed to prepare a three-layer plywood.

Comparative Example 1 In a formulation, 40 parts by weight of H1 obtained in Synthesis Example 1 and urea 2
A three-layer plywood was prepared in the same manner as in Examples 1 and 2, except that the parts by weight of water, 72 parts by weight of water, and ammonium chloride were as shown in Table 1.

Comparative Example 2 In the formulation, 40 parts by weight of H1 obtained in Synthesis Example 1 and 20 parts of urea were added.
A three-layer plywood was prepared in the same manner as in Examples 1 and 2, except that the proportions of 0 parts by weight, 200 parts by weight of water, and ammonium chloride were as shown in Table 1.

Comparative Examples 3 and 4 Three-layer plywood was prepared in the same manner as in Examples 1 and 2, except that the composition containing only ammonium chloride was changed as shown in Table 1.

Examples 7 and 8 2.7 mol /% of 20 parts by weight of H2 obtained in Synthesis Example 2, 50 parts by weight of urea, 16 parts by weight of flour (red flower) and 59 parts by weight of water.
L-hydrochloric acid was blended in the ratio shown in Table 2 to prepare each adhesive. Except for this, the same operation as in Examples 1 and 2 was performed to prepare a three-layer plywood.

Comparative Example 5 In the formulation, 40 parts by weight of H2 obtained in Synthesis Example 2 and urea 2
A three-layer plywood was prepared in the same manner as in Examples 1 and 2, except that the blending of parts by weight, 62 parts by weight of water, and 2.7 mol / L hydrochloric acid was shown in Table 2 and the respective adhesives were adjusted.

Comparative Example 6 In the composition, 40 parts by weight of H2 obtained in Synthesis Example 2 and urea 20
Table 2 shows the composition of 0 parts by weight, 200 parts by weight of water, and 2.7 mol / L hydrochloric acid, and a three-layer plywood was prepared in the same manner as in Examples 1 and 2, except that the respective adhesives were adjusted.

Comparative Examples 7 and 8 Three layers of plywood were prepared in the same manner as in Examples 7 and 8, except that the composition containing only 2.7 mol / L hydrochloric acid was as shown in Table 2.

Examples 9 and 10 Ammonium sulfate was added to 100 parts by weight of E1 obtained in Synthesis Example 3, 165 parts by weight of urea, 16 parts by weight of flour (red flowers) and 40 parts by weight of water, in the proportions shown in Table 3. The respective adhesives were adjusted. Except for this, the same operation as in Examples 1 and 2 was performed to prepare a three-layer plywood.

Examples 11 and 12 Ammonium sulfate was added to 100 parts by weight of E1 obtained in Synthesis Example 3, 66 parts by weight of urea, 16 parts by weight of flour (red flowers), and 20 parts by weight of water in the proportions shown in Table 3. The respective adhesives were adjusted. Except for this, the same operation as in Examples 1 and 2 was performed to prepare a three-layer plywood.

Examples 13 and 14 Ammonium sulfate was added to 100 parts by weight of E1 obtained in Synthesis Example 3, 33 parts by weight of urea, 16 parts by weight of flour (red flower) and 10 parts by weight of water in the proportions shown in Table 3. The respective adhesives were adjusted. Except for this, the same operation as in Examples 1 and 2 was performed to prepare a three-layer plywood.

Comparative Example 9 In the formulation, 40 parts by weight of E1 obtained in Synthesis Example 3 and urea 1.
Table 3 shows the composition of 3 parts by weight, 2 parts by weight of water and ammonium sulfate.
Except for adjusting the adhesives
A three-layer plywood was prepared in the same manner as in Examples 1 and 2.

Comparative Example 10 In the composition, 40 parts by weight of E1 obtained in Synthesis Example 3 and urea 13
Three layers of plywood were prepared in the same manner as in Examples 1 and 2, except that the proportions of 2 parts by weight, 60 parts by weight of water and ammonium sulfate were set to the proportions shown in Table 3 and the respective adhesives were adjusted.

Comparative Examples 11 and 12 Three-layer plywood was prepared in the same manner as in Examples 9 and 10, except that the proportion of ammonium sulfate alone was changed to the proportions shown in Table 3.

Examples 15 and 16 0.5 mol of E2 obtained in Synthesis Example 4 was added to 100 parts by weight, 54 parts by weight of urea, 16 parts by weight of flour (red flower) and 20 parts by weight of water.
/ L sulfuric acid was blended at the ratios shown in Table 4 to prepare respective adhesives. Except for this, the same operation as in Examples 1 and 2 was performed to prepare a three-layer plywood.

Comparative Example 13 In the composition, 40 parts by weight of E2 obtained in Synthesis Example 4 and urea 1
A three-layer plywood was prepared in the same manner as in Examples 1 and 2, except that the proportions of parts by weight, water 10 parts by weight, and 0.5 mol / L sulfuric acid were set to the proportions shown in Table 4 and the respective adhesives were adjusted. did.

Comparative Example 14 In the formulation, 40 parts by weight of E2 obtained in Synthesis Example 4 and 10 parts of urea were
A mixture of 8 parts by weight, 60 parts by weight of water, and 0.5 mol / L sulfuric acid was set to the ratio shown in Table 4 and all the adhesives were adjusted. Created.

Comparative Examples 15 and 16 Three-layer plywood was prepared in the same manner as in Examples 15 and 16, except that the composition containing only 0.5 mol / L sulfuric acid was changed to that shown in Table 1.

Examples 17 and 18 50% formic acid was added to 100 parts by weight of E3 obtained in Synthesis Example 5, 29 parts by weight of urea, 16 parts by weight of flour (red flower) and 20 parts by weight of water at the ratio shown in Table 5. Was blended, and each adhesive was adjusted. Except for this, the same operation as in Examples 1 and 2 was performed to prepare a three-layer plywood.

Comparative Example 17 60 parts by weight of E3 obtained in Synthesis Example 5, 1.7 parts by weight of urea,
A three-layer plywood was prepared in the same manner as in Examples 1 and 2, except that the addition amount of 0% formic acid was set as shown in Table 5 and the respective adhesives were adjusted.

Comparative Example 18 60 parts by weight of E3 obtained in Synthesis Example 5, 140 parts by weight of urea, and 100 parts of water
The parts by weight and the amount of 50% formic acid to be added are shown in Table 5,
A three-layer plywood was prepared in the same manner as in Examples 1 and 2, except that the respective adhesives were adjusted.

Comparative Examples 19 and 20 Three layers of plywood were prepared in the same manner as in Examples 17 and 18, except that the proportion of only 50% formic acid was changed as shown in Table 5.

Comparative Example 23 Urea melamine resin (M, manufactured by Sumitomo Bakelite Co., Ltd.)
A-216K, JAS standard F-2 passed, resin content 60%)
100 parts by weight, 16 parts by weight of flour (red flower), 9 parts by weight of water, and 1 part by weight of ammonium chloride were mixed to prepare an adhesive. Except for this, the same operation as in Examples 1 and 2 was performed to prepare a three-layer plywood.

The amount of formaldehyde emission and adhesion of the plywood thus prepared were measured by the following methods, and the results are shown in Tables 1 to 6. 1) Dispersed formaldehyde concentration of adhesive According to the JAS measurement method, a sample of the plywood coated with the adhesive was left in a desiccator at 20 ° C. for 24 hours to be absorbed in pure water, and the color was fixed at 415 nm by the acetylacetone method.
The concentration was measured using the absorbance at Those with 5 ppm or less are called F2 and those with 0.5 ppm or less are called F1. 2) Adhesive strength The adhesive strength test of the plywood was measured according to the normal adhesive strength test of the JAS measuring method. The pass value is 0.7 MPa or more. 3) Wood breakage ratio After the adhesion test, the wood damage ratio on the bonding surface was visually observed. Larger numbers are better. 4) One-class immersion peel test Measured according to the one-class immersion peel test of the JAS measurement method.

[0062]

[Table 1]

[0063]

[Table 2]

[0064]

[Table 3]

[0065]

[Table 4]

[0066]

[Table 5]

[0067]

[Table 6]

As can be seen from Tables 1 to 6, Examples are superior to Comparative Examples in adhesion and low formaldehyde emission.

[0069]

The adhesive for producing odorless wood board of the present invention has a reduced formaldehyde emission while maintaining the conventional properties such as adhesiveness, curability and water resistance as compared with conventional amino resin adhesives. A reduced wood board can be provided.

 ──────────────────────────────────────────────────続 き Continued on the front page F term (reference) 2B200 AA03 BA03 BA19 CA13 DA04 EE15 HA05 HA08 HA18 4J040 EB111 EB131 EB171 FA092 HA086 HA196 HA216 HA226 HA256 HA286 HB24 HC02 HC04 HC08 HC09 HC15 HC19 HC25 JA03 LA11 MA08 MB05

Claims (9)

[Claims] 1. An adhesive comprising a melamine compound and / or a melamine resin (a), a compound having an amino group (b), and an acidic substance or a salt (c) comprising an amino compound and an acidic substance. An odorless wood board-forming adhesive, which is an aqueous solution containing particles of the component (a). 2. The adhesive for odorless wooden boards according to claim 1, wherein said component (a) is an emulsion. 3. The melamine compound is one or more selected from the group consisting of hexamethylolmelamine, pentamethylolmelamine, tetramethylolmelamine, trimethylolmelamine, dimethylolmelamine, and monomethylolmelamine. Odorless wood board adhesive. 4. The odorless wood board adhesive according to claim 1, wherein the melamine-based resin is at least one selected from the group consisting of melamine resins, urea-melamine resins, and melamine-phenol co-condensation resins. . 5. The odorless wood board-forming adhesive according to claim 1, wherein the compound (b) having an amino group is urea. 6. The acidic substance is sulfuric acid, hydrochloric acid, nitric acid, carbonic acid,
The odorless wood board adhesive according to claim 1, which is at least one selected from the group consisting of phosphoric acid, citric acid, formic acid, acetic acid, and maleic acid. 7. The salt comprising an amino compound and an acidic substance comprises at least one selected from the group consisting of ammonia, melamine, alcoholamines, diamines, hydrazines and alkylamines, and an acidic substance. The adhesive for odorless wooden board making according to claim 1, which is a salt. 8. The compound (b) having an amino group is a melamine compound and / or a melamine resin (a) in solid content.
The odorless wood board adhesive according to any one of claims 1 to 7, wherein the adhesive is contained in a ratio of 10 to 400 parts by weight with respect to 100 parts by weight. 9. The method according to claim 9, wherein the salt (c) comprising the acidic substance or the amino compound and the acidic substance is used in a solid content with respect to 100 parts by weight of the melamine compound and / or the melamine resin (a).
The odorless wood board adhesive according to any one of claims 1 to 8, wherein the adhesive is contained in a proportion of 0.01 to 10 parts by weight.