JPS61223077A - Powdery composition for bonding wood - Google Patents

Abstract

PURPOSE:To provide the titled composition containing specific amounts of powdery melamine resin and powder of partially or completely saponified ethylene-vinyl acetate copolymer (EVA), giving an adhesive liquid by the addition of water to the powdery mixture, and suitable for the bonding of wood pieces. CONSTITUTION:The objective composition contains (A) 100pts.(wt.) of the powder of methylolated melamine or its precondensate derived from melamine and formaldehyde and (B) 20-200pts. of an at least partially saponified EVA (preferably having a vinyl acetate content of 75-90wt% and a saponification degree of >=60mol% based on the whole vinyl acetate). EFFECT:Excellent storage stability, initial adhesivity and adhesive strength under normal condition and in wet state.

Description

[Detailed description of the invention] [Industrial application field] In the present invention, it is not made into an adhesive solution by adding water as it is.

Concerning powder compositions for use in wood bonding;
In detail, the methylolated product of melamine and formaldehyde obtained by combining melamine and formaldehyde (%) - 1st is the powder of the initial condensate (
100 parts by weight of at least partially saponified rt+ethylene-vinyl acetate copolymer (hereinafter abbreviated as rFiVAJ) powder;
200 parts by weight, the powdery composition obtained by the present invention is stable over a long period of time, and is suitable for wood bonding is a composition that can be made into an adhesive liquid by directly adding water to the powdered composition, and exhibits excellent initial adhesion and hardens at room temperature or by heating.

[Conventional technology]

Conventional Melamine resin adhesives have many characteristics such as excellent adhesiveness and do not exhibit the red or brown color seen with phenolic resin adhesives, so they are used for bonding materials such as wood. However, in liquid form, the storage stability period is relatively short, and in some cases it is made into powder form by spray drying, etc. for convenient handling, but powdered melamine resin is highly hygroscopic and requires careful storage. and usually requires heating at 70°C or higher for curing.
At temperatures below 50° C., even if the effect of the curing accelerator is strengthened, the curing is insufficient and the water resistance is significantly reduced, making it very difficult to achieve good adhesion at room temperature. Also, if a curing accelerator is added in advance, there is a risk that the curing will progress and solidify due to moisture absorption, so it is customary to prepare a curing accelerator separately and add it at the time of use, which makes the work cumbersome. was.

In addition, various attempts have been made to modify amino resin adhesives such as melamine resin1, for example,
Japanese Patent Publication No. 44-22304 describes improvements in dimensional stability, impact resistance, and cracking resistance when used as molding materials for melamine resins, area resins, and phenolic resins, as well as improvements when used as decorative laminates. In order to improve the brittleness and lack of flexibility of the Ethylene content 30-70 (mol)%
We propose a method for producing a thermosetting co-condensed resin characterized by mixing saponified ethylene-vinyl acetate copolymers to form a solution containing 0.5 to 50% water and reacting with acidity. has been done. However, this proposal does not include molding materials in which α-cellulose, wood flour, etc. are blended with the thermosetting co-condensed resin, or laminates made by impregnating impregnated paper for laminates with the thermosetting co-condensed resin. Only disclosing manufacturing information;
No suggestion is disclosed regarding wood adhesive applications, and the alcoholic solution of the thermosetting co-condensed resin disclosed in this proposal has the disadvantage of a relatively short storage stability period.

Furthermore, Japanese Patent Publication No. 44-10855 describes the inherent heat resistance, chemical resistance, and flame retardancy of amino resins.

To obtain an amino-based resin liquid which is extremely useful in adhesives and other fields, which has excellent temporary adhesion and low viscosity increase at low temperatures, without sacrificing any of the advantages of other materials such as weather resistance and rapid thermosetting. A method for producing an amine resin liquid with improved properties, which comprises reacting an amino compound and an aldehyde in the presence of a saponified copolymer of a vinyl ester and an unsaturated carboxylic acid or its ester. is suggesting.

JP-A No. 50-58134 discloses a melamine resin adhesive that has a high rate of increase in adhesive sap as an adhesive for wood, has excellent initial adhesion, adhesive strength, and water washability, and has a long usable life. To prepare a glue solution, a melamine resin adhesive modified with a crotonic acid/polyvinyl alcohol copolymer obtained by condensation reaction of melamine and aldehydes in the presence of a crotonic acid/polyvinyl alcohol copolymer, or a melamine resin adhesive modified with this and Yulya resin Add sap p to the adhesive mixture.
A curing agent and a pH buffering agent are added while adjusting H to be 6.4 or less, preferably 6.8 or less, and one or more types of extenders, fillers, water, etc. are added and the paste is made by stirring. We have proposed a method for preparing a crotonic acid Φ polyvinyl alcohol copolymer-modified melamine resin adhesive liquid, which is characterized by
No. 3 acrolein content 111-15 mol%, saponification degree 6
A method for producing an amine resin composition, characterized by reacting an amine compound with an aldehyde in the presence of 0 mol% or more of acrolein-modified polyvinyl alcohol, JP-A-1983
-41354 (Production method of amine resin composition by adding low saponification degree polyvinyl alcohol during the reaction)
, JP-A-53-41392 (Production method of amine resin composition by condensation reaction of amino compound and aldehyde in the presence of sulfonated polyvinyl alcohol) and JP-A-53-41392
-41393 (method for producing an amino resin adhesive in which an amino compound and an aldehyde are reacted in the presence of acetalized polyvinyl alcohol), but these are based on a condensation reaction system of an amine compound and an aldehyde, that is, water as the basis. The reaction system was carried out in a liquid state, and the storage stability was poor.

In addition, Japanese Patent Publication No. 44-23437 discloses that an ethylene-vinyl acetate copolymer with an ethylene content of 50 mol% or more is used to improve water resistance, heat resistance, and chemical resistance without reducing adhesiveness. Periodic table 1st to group 2nd row and below,
A mixture of selected compounds from oxides, hydroxides, and salts of elements of groups ① to 3rd row of groups V and below, and oxides, hydroxides, and salts of elements of groups ① to 4th column of groups An adhesive composition containing 30% by weight of a melamine thermosetting prepolymer (II) is proposed. However, the proposed adhesive composition is melt-kneaded in a rubber roll mill or the like at 100 to 150°C and used in the form of a lump or film. Preheat to 100℃ or higher, preferably about 130℃, and press the adhesive block or film in between.
It is heat treated at 150° C. or higher, which is completely different from the present invention, and therefore its adhesive strength is not as good as that of the present invention.

Furthermore, like the present invention, JP-B No. 55-21791 is stable for a long period of time, and when used for bonding wood, it can be made into an adhesive liquid as it is or by adding water, or it can be used at room temperature or by heating. As an adhesive composition that cures and exhibits excellent adhesive properties, a saponification degree of 9 is added to 100 parts by weight of a methylolated product of melamine obtained by reacting melamine and formaldehyde, or an initial charge powder.
50 to 200 parts by weight of partially saponified polyvinyl alcohol powder having a content of 0 mol% or less, and an appropriate amount of powder if necessary.
This paper proposes a powder composition for wood adhesive, which is characterized by being uniformly mixed with or without addition of a curing accelerator. However, when water is added to the proposed adhesive powder composition to form an adhesive solution, a relatively long period of stirring is required in order to obtain a completely uniformly dissolved solution, and the viscosity of the adhesive solution In many cases, the temperature becomes extremely high, making coating difficult, especially at low temperatures such as in winter. Moreover, the initial adhesive strength cannot be said to be sufficient.

[Problem that the invention seeks to solve]

Therefore, in order to solve the various problems mentioned above, the present inventors conducted studies and found that at least partially saponified E
VA powder is mixed with powdered melamine resin to form a powder composition, and when water is added to this powder composition and stirred, it dissolves easily to form an adhesive solution, and this adhesive solution can bond the wood to each other. In tests used for adhesion, even at room temperature, such as 20°C to 30°C without any particular heating, initial adhesion, normal adhesive strength, and water-resistant adhesive strength were all superior to melamine resin alone. I have come to discover that it shows gender.

[Structure of the invention]

The present invention provides powder 100 of a methylolated product of melamine or an initial charge obtained from melamine and formaldehyde.
20 to 200 parts by weight of at least partially saponified ethylene-vinyl acetate copolymer powder.

゛ The adhesive liquid obtained by adding water to the powder composition for adhesion of wood according to the present invention and stirring the mixture exhibits good adhesion even at room temperature without any particular heating in the adhesion test between pieces of wood as described above. Although the reason is not clear, polyvinyl alcohol (r, hereinafter abbreviated as PVAJ) is often added as a protective colloid during the polymerization of the EVA powder, and to improve water dispersibility after polymerization. Due to the presence of acidic components such as curing accelerators in water, the hydroxyl groups of BVA and the hydroxyl groups generated when the BVA is saponified,
It is presumed that when it reacts with the methylol groups in the melamine resin component and becomes three-dimensional, it is sufficiently cured even at room temperature, resulting in excellent performance such as water resistance. That is, by using the composition of the present invention, powdered melamine resin, which has conventionally been difficult to use at room temperature, can be used.
It has an excellent adhesive effect even at room temperature, making it possible to bond wood at room temperature. Of course, heat curing during adhesion is also possible, without any adverse effect on performance.

Furthermore, the composition of the present invention should have excellent performance. Conventionally, powdered melamine resins do not have storage stability when mixed with highly hygroscopic melamine or hardening accelerators, and are typically mixed at the time of use. However, in the case of a non-inventive composition, even if a hardening agent is mixed in advance, a storage-stable single powder adhesive composition can be obtained.

Furthermore, when using a commercially available at least partially saponified EVA powder in preparing the composition of the present invention, the BVA
Aqueous powder solutions are often acidic and do not necessarily require the addition of a curing accelerator.

Curing accelerators include ammonium salts of organic or inorganic acids such as ammonium paratoluenesulfonate and ammonium chloride; organic acids such as phthalic anhydride and tartaric acid; etc.; however, they are generally unnecessary in heat bonding; Although it is necessary for adhesive curing at a relatively low temperature such as room temperature, the amount used varies depending on the composition and the type of curing accelerator selected.

The melamine resin used here contains 1.5 to 6 moles of formaldehyde per 1 mole of melamine.

It is called a methylolated product or an initial condensate of melamine, which is heated to a pH of 7 or higher and made into a powder by a method such as spray drying after reaction.

Note that so-called melamine cocondensates, in which a part of melamine is replaced with urea, benzoguanamine phenol, resorcinol, etc., may also be used. Further, although formalin is usually used as the formaldehyde, it is also possible to use a substance that reacts substantially as formaldehyde, such as paraform or methyl formalin.

What is at least partially saponified EVA powder?

The vinyl acetate content in the ethylene-vinyl acetate copolymer is generally 50 to 95% by weight, preferably 6%.
5 to 90% by weight, particularly preferably 75 to 90% by weight, and the degree of saponification exceeds 10 mol S based on the total number of moles of vinyl acetate, preferably 40 mol% or more, particularly preferably 60 EVA powder with a mol% or more content that can be easily dispersed simply by mixing with water and stirring. When the vinyl acetate content is in the range of 65 to 90% by weight, both normal and water-resistant adhesive strength are excellent when used as the adhesive of the present invention, and when the vinyl acetate content is less than 65% by weight, the normal adhesive strength is poor. There is a tendency to decrease, 90%
When the amount increases, the water-resistant adhesive strength tends to decrease.

The method for producing the EVA powder is not particularly limited, but for example, vinyl acetate in an aqueous medium in the presence of PVA with or without an ionic and/or nonionic emulsifier, Emulsion polymerization is carried out under pressure with ethylene together with other unsaturated monomers as necessary, and the BVA polymer is appropriately precipitated from the resulting BVA emulsion and dried.
Prepare an alcohol solution such as methanol, saponify it by adding a caustic alkali such as caustic soda, or an alkali metal alcoholade, etc., then dilute with alcohol such as methanol to an appropriate viscosity and solid content, and make it into a powder by spray drying etc. It is preferable from the viewpoint of ease of dispersion in water and viscosity when dispersing in water.

Even if commercially available EVA has a vinyl acetate content within the range specified by the present invention, the EVA can be made into an alcohol solution in the same manner as above, saponified, and then partially saponified PVA can be added to the alcohol solution of the saponified BVA. It is also possible to add and mix a hydrous alcohol solution, an ionic emulsifier and/or a nonionic emulsifier, etc., and then form a powder by spray drying or the like in the same manner as above. , in which case partially saponified PVA, ionic emulsifiers and/or nonionic emulsifiers can also be added before the saponification step.

Furthermore, commercially available saponified BVA can also be used as long as it has a vinyl acetate content within the range specified by the present invention and a degree of saponification within the specified range. However, in this case as well, as above, partially saponified PVA, an ionic emulsifier and/or a nonionic emulsifier are added and made into a powder by spray drying etc., which has poor water dispersibility when used as an adhesive. It is preferable.

Examples of unsaturated monomers other than quaternary vinyl and ethylene include linear or branched vinyl carboxylates having 3 to 18 carbon atoms such as vinyl propionate, vinyl caproate, and vinyl versatate; methyl acrylate, ethyl Acrylates of aliphatic alcohols having 1 to 18 carbon atoms such as acrylate, butyl acrylate, 2-ethylhexyl acrylate, octyl acrylate, and stearyl acrylate; 1 to 18 carbon atoms such as methyl methacrylate, ethyl methacrylate, butyl acrylate, and stearyl acrylate methacrylates of aliphatic alcohols;
Monovalent or divalent α, β-unsaturated carboxylic acids such as acrylic acid, methacrylic acid, itaconic acid, maleic anhydride, crotonic acid: α, β such as acrylamide, methacrylamide, etc.
-Amides of unsaturated carboxylic acids; crosslinking monomers such as N-methylolacrylamide, glycidyl acrylate, and 2-hydroxyethyl methacrylate; and other monomers such as acrylonitrile and vinyl chloride.

When copolymerizing the unsaturated monomers, the amount of ethylene copolymerized is about 5 to 40% by weight based on the copolymer, and the minimum film forming temperature of the emulsion of the copolymer is 0°C or lower. It is preferable that there be.

When the above copolymer is produced by emulsion polymerization, the degree of saponification is 80 to 92%, preferably 86% as a colloid.
1 of ~89% partially saponified Pv (4% aqueous solution with a viscosity of 3 to 35 cps at 20°C, preferably)
Use one species or two or more species.

The total amount thereof is preferably 5 to 20% by weight, preferably 10 to 15% by weight, based on the total weight of the comonomer. Outside, above P
It is preferable to use 50 to 90% by weight of V during polymerization.

Moreover, ionic and/or nonionic emulsifiers can be used together with the PVA.

Examples of ionic emulsifiers include alkylphenyl sulfonates having 8 to 18 carbon atoms such as sodium dodecylbenzenesulfonate; alkyl sulfates having 10 to 18 carbon atoms such as sodium lauryl sulfate; sodium dimectyl sulfosuccinate; Mono- or dialkyl sulfosuccinate having 8 to 18 carbon atoms: polyoxyethylene alkyl (having 8 to 18 carbon atoms)
18) Sulfate; Examples include polyoxyethylene alkyl (8 to 18 carbon atoms) phenol sulfate. Nonionic emulsifiers include polyoxyethylene alkyl (8 to 18 carbon atoms) ether; polyoxyethylene alkyl (8 to 18 carbon atoms) phenol ether; polyoxyethylene fatty acid (8 to 18 carbon atoms) ester. ;
Examples include polyoxyethylene/polyoxypropylene block polymers. (9) Instead of the ionic emulsifier or in combination with the ionic emulsifier, a "reactive emulsifier" such as vinyl sulfonic acid that is copolymerizable with vinyl acetate, ethylene, and the unsaturated monomers mentioned above can also be used.

As the polymerization initiator, common radical initiators, such as persulfates such as potassium persulfate, hydrogen peroxide, water-soluble or hydrophilic peroxides such as t-butyl hydroperoxide, etc. may be used alone or in various forms. Can be used in redox form in combination with reducing agents.

The amount of gVA powder to be used as described above for powdered melamine resin is 2 parts by weight of EVA powder per 100 parts by weight of melamine resin.
0 to 200 parts by weight, preferably 50 to 150 parts by weight. EVA powder is 201! If the amount is less than 1 part, the adhesive after blending will have strong hygroscopicity, making it difficult to store for a long period of time, and the EV
If the amount of A powder exceeds 200 parts by weight, the results tend to be unsatisfactory in terms of normal state and water-resistant adhesive strength.

The composition according to the present invention has excellent storage stability as described above, but if wood flour, kaolin, fillers such as silicic anhydride, etc. are added at the same time, the composition of the present invention will not be as stable as when water is added during use. This may be effective in preventing moisture absorption during storage, and the additional addition of such materials also belongs to the embodiments of the present invention. Furthermore, when the composition of the present invention is dissolved in water and used, the above-mentioned fillers or flour can be added or blended as desired depending on the purpose of use, and there is no problem in use.

Thus, the powder composition according to the present invention, which has excellent adhesion performance even at low temperatures such as room temperature, has the natural advantages of a powder, such as storage and transportation efficiency and ease of handling, in addition to its storage stability. In addition, there is no need to measure and prepare hardening accelerators, etc., and it can be used extremely simply by simply adding water. Moreover, when adhering, it can be cured not only by heating but also at room temperature, and has excellent adhesive performance such as water resistance after curing. Furthermore, the adhesive film has many properties such as being light-colored or white and containing a small amount of free formalin.

The conventional applications have been greatly expanded, and there are many benefits to the users.

〔Test method〕

Initial adhesive strength, normal adhesive strength, water resistant adhesive strength of the present invention,
Hot water resistant adhesive strength etc. are measured by the following method.

(1) Initial adhesive strength: Approximately 250 f/W of adhesive applied at room temperature of 20°C? Clamping pressure approximately 10kg/c++! After pressing the prototype plate for 15 minutes and then removing the pressure, lean it diagonally so that the angle with the floor is 60 degrees. Observe the peeling state after 30 minutes and calculate the non-peeling area ratio (%).
Measure.

(11) Ordinary adhesive strength A plywood test piece obtained by pressing at a room temperature of 20°C with an applied amount of adhesive of about 25,097 d and a clamping pressure of about 10 kf/- for 1 day, removing the pressure, and leaving it at room temperature for 7 days was JI8 K. -Measure according to the method shown in Compression Shear Adhesive Strength of No. 6804.

<Il+) Water resistant adhesive strength A plywood test piece prepared by the method of (11) was immersed in water at room temperature for 2 hours.
After immersing for 4 hours, the measurement is performed in the same manner as when wet (11).

(1v) Hot water resistant adhesive strength A test piece of plywood prepared by the method of (11) was heated to 60°C ± 3°C.
After soaking in warm water for 3 hours, the measurement is carried out in the same manner as when wet (11).

(V) Adhesive strength after 3 months of adhesive packaging Each powdered adhesive composition was placed in a 4-layer kraft paper bag with a polyethylene inner bag, sealed, and left in a room at 20°C x 65% RH for 3 months. Using the above (+) ~ (1v
) Measure the adhesive strength using the same method.

(vl) Special plywood immersion peeling test At a room temperature of 20°C, the amount of adhesive applied is approximately 2009/lr? , After pressing for 15 minutes at a pressing pressure of about 10 kf/-, immediately apply hot pressure
The plywood prototype was made under the conditions of okf/d, 120℃ x 3 minutes.
After leaving it in a room at 0°C x 65% fLH for 3 days, the adhesive strength was measured according to the immersion peel test specified in the Japanese Agricultural Standards for special plywood.

The test results in (1) to (vl) above are shown as the average value of 10 test pieces, and the numbers in parentheses indicate the xylem breakage rate (%).
) is shown.

〔Example〕

Next, in order to explain the present invention more specifically, Reference Examples, Examples, and Comparative Examples are shown, but the present invention is not limited to these Examples.

Reference Example A-1 37% formalin 2449 (3 mol) was adjusted to pH 9.5 with soda carbonate, then melamine 126f (1 mol) was added, gradually heated, and anti-coring spray dried at 80°C for about 50 minutes. , obtain powdered melamine resin.

Reference Example A-2 37% formali 74B79 (6 mol) was adjusted to pH 9.0 with soda carbonate, and then melamine 126t (1 mol) was added.
The mixture was gradually heated to 80° C. for 60 minutes, and then the core was removed and dried to obtain a powdered melamine resin.

Reference Example B 1100 parts by weight of deionized water was charged into a pressurized reactor equipped with a stirrer and a temperature control device, and then 2 parts by weight of anhydrous sodium acetate was added.
1 part by weight, 1 part by weight of sodium lauryl sulfate, 8 k polyoxyethylene nonylphenol ether with about 30 moles of ethylene oxide added, part by SA, degree of saponification about 88%
After adding and dissolving 1 part of pvAx0011Lt having an average molecular weight of about 500, 5.5 parts of a 1.2% by weight ammonium persulfate aqueous solution was added thereto, and the internal pressure was maintained at 20 atmospheres with ethylene.

When heat generation starts, maintain the internal temperature at 80℃ and reduce the ethylene pressure to 2.
765 parts by weight of vinyl acetate and 1
．． A 2% by weight aqueous ammonium persulfate solution is added sequentially over 5 and 6 hours, respectively. Obtained] 13
The VA emulsion had a solid content of about 50% by weight, an ethylene content of about 15% by weight, a residual monomer content of about 0.5% by weight or less, and a minimum film forming temperature of 0° C. or less.

The EVA polymer was separated from the BVA emulsion thus obtained by salting out, thoroughly washed with water, dried, and then dissolved in methanol to obtain a 30% by weight methanol solution.

For 1000 parts by weight of the above hiVA methanol solution, 1
When 110 parts by weight of 0% by weight caustic soda methanol solution was added and anodization was carried out for 1.5 hours, the degree of saponification of the FiVA was approximately 86 mol%. Partially saponified EVA in powder form was obtained by appropriately spray-drying this saponified EVA methanol solution.

Examples 1 to 4, Comparative Examples 1 to 3 Ammonium chloride as a curing accelerator and BVA powder of Reference Example B were mixed with the powdered melamine resin of Reference Example A-1 to prepare a powder adhesive composition. A predetermined amount of water was added to the powdered adhesive composition and thoroughly stirred to obtain an adhesive liquid, and the cover materials were bonded to each other at room temperature of 20°C. The test for glued plywood was carried out as described above [
Test method]. The test results are shown in Table 1.

According to the test results shown in aX, powder melamine resin A-110
The powdered compositions of Examples 1 to 4 had adhesion at room temperature at 20° C. of Comparative Example 1 containing powdered melamine resin-1 alone and BVA The adhesive strength was significantly superior to that of Comparative Example 2 using Powder B alone, indicating that it can be used satisfactorily even at room temperature. In addition, in Comparative Example 3 using only PVA powder, it was not possible to obtain the excellent adhesive strength as obtained in Examples 1 to 4.

Also, the adhesive strength after 3 months of manufacture is not much different from that immediately after manufacture.

The powdered compositions of Examples 1 to 4 are stable in storage over a long period of time.

Examples 5 to 8, Comparative Examples 4 to 6 The powdered melamine resin of Reference Example A-2, tartaric acid as a hardening accelerator, wood flour and kaolin as fillers, and Reference Example Bf)g
VA powder was mixed to obtain a powder adhesive composition, and a predetermined amount of water was added to this to form an adhesive liquid, and lauan materials were bonded together at room temperature of 20°C. The results are shown in Table 2.

According to the test results shown in Table 2, powder melamine resin A-2100
The powdered compositions of Examples 5 to 8 were mixed with 50 to 200 parts by weight of FtVA powder B based on the weight part, and the adhesion at room temperature at 30°C was as follows: Comparative example in which only 100 parts by weight of powder melamine resin A-2 was used. The adhesive strength was significantly superior to that of Comparative Example 5 in which only 100 parts by weight of BVA powder B and BVA powder B were used, indicating that it can be used satisfactorily even at room temperature. In Comparative Example 6, in which only PV powder was used in the zooit portion, excellent initial adhesion as obtained in Examples 5 to 8 could not be obtained. In addition, the adhesive strength after 3 months of manufacture was not much different from that immediately after manufacture, and in Examples 5-
It can be seen that the powder composition of No. 8 is stable when stored for a long period of time.

Examples 9 to 12 A powder composition shown in Table 3 was prepared in the same manner as in Examples 1 to 4, and a predetermined amount of water was added to the powder composition and thoroughly stirred to prepare an adhesive solution.1. Veneer (Walnut thickness 0
．． 25■) and plywood (lauan thickness 3m+) were bonded. After leaving it at room temperature for 3 days, an adhesion test was conducted in accordance with the immersion peeling test specified in the Japanese Agricultural Standards for Special Plywood, and the results shown in Table 3 were obtained.

Example 9 in the case of heat bonding according to the test results shown in Table 3
As shown in items 1 to 12, it was shown that excellent adhesive strength was obtained not only when a curing accelerator was added, but also when the curing accelerator was not added.

Claims (1)

[Claims] 1. It contains 100 parts by weight of a powder of a methylolated product or an initial condensate of melamine obtained from melamine and formaldehyde, and 20 to 200 parts by weight of an at least partially saponified ethylene-vinyl acetate copolymer powder. Powder composition for wood adhesion.