JPH06328409A - Manufacture of decorative plywood - Google Patents

Abstract

PURPOSE:To manufacture a recess-free decorative plywood by a single process by a method wherein plywood having recesses is filled with putty made of a water-based urethane resin and, after that, an adhesive composition made of multivalent isocyanate compound is applied to the plywood under the state that the putty has not been cured yet. CONSTITUTION:By filling plywood with recesses with putty made of a water- based urethane resin, the defects are repaired. Then, by applying the specified adhesive composition to the resultant plywood under the state of the green putty, the decorative plywood is manufactured. Since the water-based resin as the putty is quickly tacky dried due to its continuity, the application of the adhesive composition to the resin is possible even under green state. As the adhesive composition, a water-based emulsion and a water-soluble polymer aqueous solution having thermal adhesion and foam properties are used. By means of the above-mentioned constitution, no separation of the putty develops and both the filling of the plywood having defects such as recesses in plywood and the adgesion bond of veneers can be carried out by a single process, resulting in facilitating the manufacturing of decorative plywood.

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a method for manufacturing decorative plywood. More specifically, the present invention relates to a method for manufacturing a decorative plywood in which a putty agent is filled in a base plate for secondary processing having a recess and the putty agent remains undried.

[0002]

2. Description of the Related Art Conventionally, when manufacturing decorative plywood using plywood, in order to obtain a smooth surface property, a good quality secondary processing base plate is selected and bonded using a coating machine such as a roll coater. The agent is applied and manufacturing is performed. Mainly used as adhesives are urea resins, amino resins such as melamine resins, vinyl acetate resins,
It is used as an aqueous emulsion of ethylene vinyl acetate resin, styrene-butadiene resin or the like, an aqueous latex adhesive, or a mixture of two or more thereof. After applying these adhesives, a printed plywood, a veneer, a plastic sheet and the like are bonded, and after the paper is processed, a polyester resin is processed to manufacture a decorative plywood.

However, when the surface of the secondary processing base plate (hereinafter, simply referred to as a base plate) has a defective portion such as a concave portion, the defective portion is formed even if an adhesive is applied using a coating machine such as a roll coater. Is not filled with adhesive. Even if it is filled, the decorative plywood after processing is thinned by the above-mentioned adhesive, and a recess is formed on the surface of the decorative plywood, so that a smooth decorative plywood cannot be obtained.

Therefore, when a base plate having a recess is used, it is usually necessary to manufacture the decorative plywood by repairing the recess with a putty and obtaining a smooth base plate by drying, polishing or the like. Also, even if a base plate without recesses is used, using an applicator such as a roll coater and applying an adhesive does not apply the adhesive to the conduit. It has a drawback that it affects the surface property and it is difficult to obtain a surface having good smoothness. Even if it is applied to the conduit, it becomes thin and defects appear on the surface of the decorative plywood over time.

[0005]

Usually, a base plate having a defective portion such as a recess is usually formed by filling the recess with a putty agent, repairing it, and drying and polishing the base plate to produce a decorative plywood. There is. The present invention manufactures a decorative plywood without performing such an operation. The present invention fills a concave portion having a defective portion with a putty agent, repairs it, fills the concave portion with a specific putty agent without performing drying, polishing, etc., and uses the adhesive composition in an undried state. In this way, it was found that a smooth decorative plywood can be obtained in one step.

[0006]

Means for Solving the Problems As a result of various studies aimed at solving the above-mentioned problems, the present inventors filled a recess on the surface of the base plate with a specific putty agent, and The present inventors have found a method for producing a decorative plywood which is made smoother by using the adhesive composition as it is in a dry state, and has a smooth surface of the base plate without defects such as recesses and conduits in one step.

That is, the present invention is (a) a method for producing a decorative plywood in which a plywood having a recess is filled with a putty agent made of an aqueous urethane resin and the adhesive composition is applied. (B) A method for producing a decorative plywood, which comprises filling a plywood having recesses with a putty agent made of a water-based urethane resin and applying the adhesive composition in the undried state to the filled putty agent. (C) A plywood having recesses is filled with a putty agent made of a water-based urethane resin, the adhesive composition is applied, and paper is pasted on the adhesive composition, and then the adhesive composition is applied. The present invention relates to a method for manufacturing a decorative plywood.

The present invention will be described in more detail below. The term “plywood having concave portions” as used in the present invention means plywood having defective portions such as cracks, worms, and unevenness on the surface of plywood. Further, the present invention also includes a plywood having recesses in which the recesses of these defective portions are once filled with a putty agent or the like and repaired, and then the filled and repaired portions are thinned. Further, it also includes a product to which a seal layer has been applied in advance in order to solve the problem that components such as tars of the base plate migrate to the surface of the decorative plywood.

The aqueous urethane resin used in the present invention is obtained from an isocyanate compound (A), a polyol having a carboxyl group and / or an amino acid (B), and a polyol (C). , A carboxyl group-containing urethane prepolymer (D) is reacted with a basic organic compound (E) and an extender (F) in the presence of a solvent and / or water, or, subsequently, under reduced pressure. By removing the solvent, a three-dimensional structure particle dispersion in which the particles are connected to each other than in a single particle dispersion is formed.

The urethane-based prepolymer used in the present invention is a compound of the following aliphatic, aromatic or alicyclic isocyanates, a polyol having a carboxyl group and / or an amino acid (B), and a polyol. A carboxyl group-containing urethane prepolymer having two or more isocyanate groups at the end, which is obtained by reacting with a group of compounds, is used.

In the above reaction, with isocyanates,
The proportion of the carboxyl group-containing polyols and / or amino acids (B) and the polyols is such that the isocyanate group content of the prepolymer (in terms of solid content) is 0.5.
It is adjusted to be 10%, preferably 1% to 4%. When the content of the isocyanate group is less than 0.5%, it is difficult to obtain three-dimensional structured particles in which the particles are connected to each other than in the single particle dispersion of the present invention, and when it exceeds 10%, the three-dimensional structured particles become water-soluble. Since it is not dispersed, the quick-drying aqueous resin solution as the three-dimensional structure particle dispersion of the present invention cannot be obtained.

In the above reaction, the amount of the polyol having a carboxyl group and / or the amino acid (B) is determined by the acid value (in terms of solid content) of the target quick-drying aqueous resin.
Is set to 10 or more, preferably 25 or more. When the acid value of the quick-drying aqueous resin becomes less than 10,
The three-dimensional structure particles are not dispersed in water, and the quick-drying aqueous resin solution as the three-dimensional structure particle dispersion of the present invention cannot be obtained. The above-mentioned carboxyl group-containing urethane-based prepolymer can be manufactured by the same known method as the so-called urethane-based prepolymer which is usually used for manufacturing a polyurethane resin.

As the above-mentioned isocyanate compound (A), for example, 1,4-tetramethylene diisocyanate, 1,6-hexamethylene diisocyanate, 2,
4,4-trimethylhexamethylene diisocyanate,
Aliphatic isocyanates such as 2,8-diisocyanate methyl caproate, 3-isocyanate methyl-3,
5,5-trimethylcyclohexyl isocyanate, dicyclohexylmethane-4,4'-diisocyanate,
Alicyclic diisocyanates such as methylcyclohexyl-2,4-diisocyanate, toluylene diisocyanate, diphenylmethane diisocyanate, 1,5-naphthene diisocyanate, diphenylmethylmethane diisocyanate, tetraalkyldiphenylmethane diisocyanate, 4,4'-dibenzyl diisocyanate,
One or a mixture of two or more of aromatic diisocyanates such as 1,3-phenylene diisocyanate, chlorinated diisocyanates, brominated diisocyanates, and polyisocyanate compounds that are adducts with water are used. Among the above polyisocyanates, aliphatic and alicyclic polyisocyanates are particularly preferable from the viewpoint of weather resistance and the like, and aliphatic polyisocyanates are more preferably used.

The carboxyl group-containing polyols and amino acids (B) to be used can be any of those which impart a branched carboxyl group to a linear prepolymer molecule, but the carboxyl group in the prepolymer can be used. In order to increase the group content, a low molecular weight one is preferable, and examples of the carboxyl group-containing polyols include 2,2-
Preferred examples of dimethylolpropionic acid and amino acids include glycine and serine. Further, the polyols used in the present invention are generally known polyols used in the production of urethane resins, for example, diethylene glycol, butanediol, hexanediol, neopentyl glycol, bisphenol A, cyclohexanedimethanol, and triamine. Methylolpropane, glycerin, pentaerythritol, polyethylene glycol,
Polypropylene glycol, polyester polyol,
One or a mixture of two or more of polycaprolactone, polytetramethylene ether glycol, polythioether polyol, polyacetal polyol, polybutadiene polyol, furandimethanol and the like can be mentioned. These polyols can be appropriately selected according to the purpose and application, and the required physical properties such as hardness and softness can be easily designed.

The production of the quick-drying aqueous resin for the three-dimensional structure particle dispersion of the present invention is carried out by dissolving or suspending the above carboxyl group-containing urethane prepolymer in the following solvent and / or water and mixing it with a basic organic compound. (React with carboxyl group to increase hydrophilicity) and the following extender is added dropwise, or basic organic compounds and extender are dissolved in a solvent and / or water, and a solution of urethane prepolymer is added dropwise. The urethane group prepolymer containing a carboxyl group is made hydrophilic by the method described above, and at the same time reacted with an extender, and then diluted with an appropriate amount of water to reduce the concentration of non-volatile components to 30 to 40% under reduced pressure. By performing dehydration and solvent removal until the formation, a quick-drying aqueous resin solution of a three-dimensional structure particle dispersion in which particles are connected to each other is obtained from a single particle dispersion.

At this time, the reaction temperature is 30 to 50 ° C., preferably 40 ° C. If the reaction temperature exceeds 50 ° C., the reaction becomes violent, the reaction with the extender cannot be controlled, and the reaction is runaway, which is dangerous. In the above reaction, the ratio of the extender to the prepolymer (extender / prepolymer) is 0.3 to 1.0, preferably 0.1.
4 to 0.9 is suitable. If the equivalent ratio of the extender to the prepolymer is less than 0.3, it is difficult to obtain particles having a three-dimensional structure in which the particles are connected to each other than the single particle dispersion of the present invention, and if it exceeds 1.0, unreacted particles do not react. The remaining extender causes a problem in weather resistance and stability of the cured resin, which is not preferable.

As the extender used in the present invention, water or diamines are suitable, and examples of the diamines include:
Ethylenediamine, diethylenetriamine, triethylenetetramine, propylenediamine, butylenediamine, hexamethylenediamine, cyclohexylenediamine, piperazine, 2-methylpiperazine, phenylenediamine, tolylenediamine, xylenediamine, α,
α'-methylenebis (2-chloroaniline) 3,3'-
Dichloro-α, α'-biphenyldiamine, 2,6-diaminopyridine, α, α'-diaminodiphenylmethane, m-xylenediamine, isophoronediamine, N
-Methyl-3,3'-diaminopropylamine, an adduct of diethylenetriamine and acrylate, or a hydrolysis product thereof, and the like.

As the basic organic compound for imparting hydrophilicity by reacting with a carboxyl group, any of known compounds can be used, and particularly preferred examples are dimethylethanolamine, diethylethanolamine,
Examples include triethylamine and the like. Further, as the solvent used for resin production, methyl ethyl ketone, methyl isobutyl ketone, ethyl acetate, toluene, xylene, isobutyl acetate, butyl acetate, acetone, dimethylformamide, N-methyl-2-pyrrolidone, diethylene glycol dimethyl ether and the like are suitable. is there.

The aqueous urethane resin obtained by the present invention is advantageously used as a coating composition, an impregnating composition, an adhesive composition and the like. For that purpose, the aqueous urethane resin is further treated with water. And / or it can be diluted with an organic solvent. The above-mentioned composition contains, if necessary, an organic solvent, a pigment, a dye, an emulsifier, a surfactant, a thickener, a heat stabilizer, a leveling agent, an antifoaming agent, a filler, an anti-settling agent, a UV absorber, an antioxidant. , A viscosity reducing agent, and other conventional ingredients may be included.

In a commercially available putty agent which is usually used, when the adhesive composition is overcoated with the putty agent filled in the recesses in an undried state, the putty agent filled in the recesses is rolled up by the adhesive composition. By using the putty agent comprising the aqueous urethane resin of the present invention, since the aqueous urethane resin is quick-drying, the surface layer of the putty agent filled in the recesses is quickly touch-dried, and even if it is in an undried state, In the step of, it becomes possible to apply the adhesive composition by a usual application method. Furthermore, since the water-based urethane resin of the present invention has a high degree of water resistance, the resulting decorative plywood has a high degree of water resistance as well, and is compact in terms of putting putty treatment equipment, and is manufactured at low cost. Because it is possible, it is economically advantageous.

The adhesive composition used in the present invention may be an ordinary adhesive, but it is more preferable that it has adhesiveness when heated and has foamability. An aqueous emulsion and / or an aqueous solution of a water-soluble polymer is mainly used for these adhesive compositions. Aqueous emulsions include vinyl acetate, acrylic ester, ethylene-
Vinyl acetate type, styrene-butadiene type, styrene-acrylic type, acrylic type acrylonitrile-butadiene type, water-based urethane resin and the like are mainly used. These are 1
Not limited to types, it is also possible to use two or more types together. The amount used is preferably 2 to 30% by weight in terms of solid content,
If it exceeds 30% by weight, the performance such as water resistance and solvent resistance is adversely affected, which is not preferable.

As the water-soluble polymer aqueous solution, a polymer aqueous solution of polyvinyl alcohol, carboxymethyl cellulose, hydroxymethyl cellulose or the like is used.
For example, polyvinyl alcohol is generally commercially available and has a saponification degree of 80 to 100 mol% and a polymerization degree of 300 to 2
The one of 500 is used. The amount used is preferably 1 to 25% by weight in terms of solid content. These are not limited to one type, and two or more types can be used in combination.

In the present invention, it is also possible to blend a thermosetting resin into the main component consisting of an aqueous emulsion and a water-soluble polymer aqueous solution. As the thermosetting resin, an amino resin and / or a modified amino resin which is a formaldehyde-based condensation resin can be used.

Amino resins are urea-formaldehyde condensation resins, melamine-formaldehyde condensation resins,
Examples include phenol-formaldehyde type condensation resins and urea-melamine-formaldehyde type condensation resins.

The modified amino resin means an amino resin obtained by modifying the terminal of the amino resin with a functional group such as an alkyl group, an imino group, a methylol-imino group, a carboxyl group and a butyl group. Further, an amino resin in which the terminal of an amino resin such as benzoguanamine resin or glycoluril resin is modified with an alkyl group, an imino group, a methylol-imino group, a carboxyl group, a butyl group or the like is also used.

These may be used alone or in combination of two or more. Further, as these modified amino resins, urea resin type, melamine resin type, or a mixture thereof may be used depending on the purpose. The blending amount of these is preferably 0.5 to 70% by weight in terms of solid content,
More preferably, 1 to 30% by weight is suitable.

As an effect of using the thermosetting resin, for example, when the base plate surface is finished with a solvent-based paint or the like and the solvent reaches the adhesive layer, the solvent resistance is improved. And the adhesive layer is less likely to be attacked.
Even when heat treatment such as heating is performed in the finishing step, the heat resistance of the adhesive layer is improved, and the adhesive layer is less likely to be damaged. The use of the thermosetting modified amino resin further enhances the solvent resistance and heat resistance. Further, when a high solid type is used as the non-volatile content, the non-volatile content of the compound also becomes a high non-volatile content, and the effect is further exhibited.

Further, these modified amino resins have excellent compatibility with various polymers and can improve the fluidity and wettability of the resin liquid. Then, it exerts an outstanding effect on the long-term storage stability of the resin liquid due to separation, aggregation, solidification, etc. of the resin liquid formulation which is the most problematic in practical use. The effect is that when it is used as an adhesive for sticking paper such as print paper, it penetrates well into the paper, prevents separation between papers, and improves the performance of plane tensile strength. Further, it is possible to use an aromatic sulfonic acid or phosphoric acid-based acid catalyst in combination therewith, and the curing time and the like can be adjusted by the addition amount.

In the present invention, the polyisocyanate compound is used as a crosslinking agent to exert the adhesive force and the foaming effect of the resin composition. These compounds include 4,4
-Diphenylmethane diisocyanate (MDI), 2,
4- or 2,6-tolylene diisocyanate (TD
I), 1,4-xylene diisocyanate, polymethylene polyphenyl polyisocyanate (polymeric MD
Aliphatic or aromatic diisocyanates such as I) are used.

To obtain the adhesive composition, a resin composition and a crosslinking agent are used. The mixing ratio of the resin composition and the crosslinking agent,
The crosslinking agent is preferably 0.1 to 30 parts by weight, more preferably 1 to 20 parts by weight, based on 100 parts by weight of the resin composition. If the amount of the cross-linking agent is less than 0.1 parts by weight, the base plate having the defective portion is not subjected to secondary processing to sufficiently supplement the defective portion of the base plate, and the physical properties of the secondary processed product in terms of performance such as strength and water resistance. Is inferior and is not preferable. When the amount of the cross-linking agent exceeds 30 parts by weight, the pot life is shortened and it is economically disadvantageous, which is not preferable.

Further, a foaming agent may be added to the resin composition, and it is particularly effective for a base plate having a large defective portion. Examples of the foaming agent used include carbonate compounds such as sodium carbonate, calcium carbonate, magnesium carbonate, ammonium carbonate and ammonium bicarbonate, and ammonium salts such as ammonium chloride, ammonium sulfide and ammonium nitrate.

Furthermore, it is also possible to use heat-expandable microcapsules containing a low-boiling substance. For example,
Microcapsules such as vinylidene chloride copolymer containing low boiling point gaseous substances such as propane, butane, and hexane. When heated, the gaseous substances expand, destroying the resin capsules and significantly increasing the volume by foaming. Refers to something with characteristics. The adhesive in the case of using the heat-expandable microcapsules encapsulating the low-boiling substance is not limited to the above-mentioned foaming adhesive, and is urea resin, vinyl acetate resin, urea-vinyl acetate resin, styrene-butadiene cocondensation. It is also used for resins.

Inorganic pigments and / or organic pigments are used in the aqueous urethane resin and resin composition of the present invention. As the inorganic pigment, titanium oxide, calcium carbonate, iron oxide, magnesium oxide, talc, clay, silica powder, bentonite, perlite, quick lime, slaked lime, kaolin, diatomaceous earth and the like are used.

Further, as the organic pigment, a plastic pigment or the like which contains styrene, acryl, styrene-acryl or the like as a main component, and polymerizes the obtained polymer to obtain a powder is also used. The characteristic of the organic pigment is that the fluidity of the adhesive solution is improved. Furthermore, when secondary processing such as polyester processing is performed, compatibility with the polyester resin is improved. These inorganic pigments and organic pigments may be used in combination. Furthermore, an antifoaming agent, a dispersant, a preservative, a foam stabilizer, etc. can be used when obtaining an adhesive composition.

In order to obtain a better surface property of the decorative plywood,
After the base plate having the concave portions is filled with the putty agent, the adhesive composition is applied and paper is applied. The paper used at this time is preferably a mixed paper having a basis weight of 23 to 100 g / m ² , titanium paper, Japanese paper, and the like. If the basis weight is less than 23 g / m ² , the crack resistance in the cold heat repetition test required for decorative plywood becomes poor, and if it exceeds 100 g / m ² , the inter-paper strength in the water resistance test decreases, which is economically disadvantageous. Is not preferable.

A knife coater, a comma coater or the like is used as an applicator for filling the putty agent made of the water-based urethane resin used in the present invention, and smoothes the surface by following the recesses of the base plate, that is, the surface defects. It is desirable to use a leveling applicator.

[0037]

EXAMPLES The present invention will now be described with reference to Examples and Comparative Examples in order to more specifically describe the present invention, but the present invention is not limited to these Examples. Hereinafter,% and parts represent% by weight and parts by weight, unless otherwise specified.

Example 1 In a 2000 ml four-necked flask equipped with a thermometer, a stirrer and a nitrogen inlet tube, 86.5 g of polycaprolactone having a molecular weight of 2000 and 53.4 g of neopentyl glycol,
Trimethylolpropane 4.3 g, dimethylolpropionic acid 17.9 g, N-methyl-2-pyrrolidone 34.5 g were charged, and while introducing nitrogen, the temperature was raised to 90 ° C. to dissolve the contents. . Then cool to 40 ° C., 72
g of acetone was added, and 137.8 g of tolylene diisocyanate was added dropwise over 1 hour when the internal temperature reached 30 ° C. After maintaining the internal temperature at 30 to 40 ° C. and performing the reaction for 8 hours, the mixture was diluted with 100.5 g of acetone. The NCO group content of the obtained prepolymer was 0.90%.

Deionized water 50 containing 10.7 g of dimethylethanolamine and 9.2 g of isophoronediamine.
4.4 g of the above prepolymer 50 was kept at 40 ° C.
An aqueous resin solution was obtained by adding 6.9 g dropwise and reacting. This aqueous resin solution is further subjected to reduced pressure acetone removal at 40 ° C. to finally obtain a nonvolatile content of 37.1%, pH 7.7,
An aqueous urethane resin having a viscosity of 200 cp / 25 ° C. was obtained. 400 parts of the obtained aqueous urethane resin and 60 calcium carbonate
0 part was mixed and stirred to prepare a putty agent.

Next, PVA (Kuraray PVA-117) 1
40 parts of a 5% aqueous solution and 40 parts of calcium carbonate were mixed and stirred, and dispersed by stirring. In addition, ethylene vinyl acetate resin (Sumikaflex S460 manufactured by Sumitomo Chemical Co., Ltd.)
20 parts were added and mixed and stirred to obtain a resin composition shown in Table 1. An adhesive composition was prepared by adding 1 part of MDI as a cross-linking agent to the resin composition. Using a base plate having a defective portion of the concave portion, the putty agent is filled in the concave portion with a knife coater, the adhesive composition is applied in an undried state, and the veneer is attached,
Bonding was performed under the following bonding conditions. As a result, although the base plate having the defective portion of the concave portion was used, there was no problem in the surface property, and the putty agent was applied to the adhesive composition in the undried state. There was no exfoliation of the agent. After that, as a result of a finished surface property and a dip peeling test, no abnormality was found. The results are shown in Table 3.

Adhesion conditions Putty agent application amount 4 to 5 g / 30 × 30 cm Foaming adhesive 8 to 10 g / 30 × 30 cm Veneer material type Mizunara Veneer thickness 0.25 mm Hot pressure temperature 110 to 120 ° C. Hot pressure pressure 6 kg / cm ² Veneer top coating urethane resin

Examples 2 to 3 The procedure of Example 1 was repeated, except that the resin composition shown in Table 1 was changed to 5 or 20 parts by weight of MDI as a crosslinking agent. The putty agent was not peeled off even though the adhesive composition was applied in the undried state. The results are shown in Table 3.

Example 4 In a 2000 ml four-necked flask equipped with a thermometer, a stirrer and a nitrogen inlet tube, 86.5 g of polycaprolactone having a molecular weight of 2000 and 53.4 g of neopentyl glycol,
Trimethylolpropane 4.3 g, dimethylolpropionic acid 17.9 g, N-methyl-2-pyrrolidone 34.5 g were charged, and while introducing nitrogen, the temperature was raised to 90 ° C. to dissolve the contents. . Then cool to 40 ° C., 72
g of acetone was added, and 137.8 g of tolylene diisocyanate was added dropwise over 1 hour when the internal temperature reached 30 ° C. After maintaining the internal temperature at 30 to 40 ° C. and performing the reaction for 8 hours, the mixture was diluted with 100.5 g of acetone. The NCO group content of the obtained prepolymer was 0.89%. To 482.9 g of deionized water containing 10.7 g of dimethylethanolamine, 506.9 g of the above prepolymer,
An aqueous resin solution was obtained by dropping and reacting at 40 ° C. This aqueous resin solution was further subjected to deacetone removal under reduced pressure at 40 ° C. to finally obtain a nonvolatile content of 37.3% and a pH of 7.
7, an aqueous urethane resin having a viscosity of 185 cp / 25 ° C. was obtained.

400 parts of the obtained aqueous urethane resin and 600 parts of calcium carbonate were mixed and stirred to obtain a putty agent. Next, using the adhesive composition of Example 1, using a base plate having a defective portion of a recess according to Example 1, a putty agent was filled with a knife coater, and the adhesive composition was left undried. It was applied, and a veneer was attached under the adhesion conditions of Example 1. The putty agent was not peeled off even though the adhesive composition was applied in a state where the putty agent thus filled was not dried. The results are shown in Table 3.

Example 5 Q4646B (polyester polyol manufactured by Mitsui Toatsu Kagaku Co., Ltd., molecular weight 500) was placed in a 2000 ml four-necked flask equipped with a thermometer, a stirrer and a nitrogen inlet tube.
4.4 g, trimethylolpropane 1.6 g, dimethylolpropionic acid 17.9 g, N-methyl-2-pyrrolidone 34.3 g, ethyl acetate 71.7 g, isophorone diisocyanate 126.1 g, 80 ° C
After reacting for 8 hours, 100 of ethyl acetate was added for dilution. The NCO group content of the obtained prepolymer was 1.8%. 506.0 g of the above prepolymer
Was neutralized with 13.3 g of triethylamine and then at 50 ° C.,
It was put into deionized water to obtain an aqueous resin solution. This aqueous resin solution was subjected to vacuum deethyl acetate removal at 50 ° C. to obtain an aqueous urethane resin having a nonvolatile content of 37.5%, pH 7.8 and a viscosity of 50 cp / 25 ° C.

400 parts of the obtained aqueous urethane resin and 600 parts of calcium carbonate were mixed and stirred to prepare a putty agent. Next, the adhesive composition of Example 1 was used, and according to Example 1, a base plate having a defective portion of a recess was used, and a putty agent was filled with a knife coater. The putty agent was not peeled off even though the adhesive composition was applied in a state where the putty agent thus filled was not dried. The results are shown in Table 3.

Example 6 An aqueous resin solution was obtained in the same manner as in Example 5, except that 14.0 g of DL-serine was used instead of dimethylolpropionic acid. This aqueous resin solution was subjected to reduced pressure ethyl acetate removal at 50 ° C. to obtain a nonvolatile content of 37.0%, pH 8.0 and a viscosity of 55 cp / 25 ° C.
An aqueous urethane resin was obtained. Obtained aqueous urethane resin 4
00 parts and 600 parts of calcium carbonate were mixed and stirred to prepare a putty agent. Next, using the adhesive composition of Example 1, using a base plate having a defective portion of a recess according to Example 1, a putty agent was filled with a knife coater, and the adhesive composition was left undried. It was applied, and a veneer was attached under the adhesion conditions of Example 1. The putty agent was not peeled off even though the adhesive composition was applied in a state where the putty agent thus filled was not dried. The results are shown in Table 3.

Example 7 An aqueous resin solution was obtained in the same manner as in Example 5, except that 19.5 g of D-lysine was used instead of dimethylolpropionic acid. This aqueous resin solution was subjected to vacuum deethyl acetate removal at 50 ° C. to obtain an aqueous urethane resin having a nonvolatile content of 37.3%, pH 8.0 and a viscosity of 53 cp / 25 ° C. Obtained aqueous urethane resin 40
0 part and 600 parts of calcium carbonate were mixed and stirred to obtain a putty agent. Next, using the adhesive composition of Example 1, Example 1
According to the above, a base plate having a defective portion of a concave portion was used, a putty agent was filled with a knife coater, the adhesive composition was applied in an undried state, and a veneer was attached under the adhesion conditions of Example 1. Although the filled putty agent was applied in the undried state, the putty agent was not peeled off. The result is
It shows in Table 3.

Example 8 Q4646B (polyester polyol manufactured by Mitsui Toatsu Kagaku Co., Ltd., molecular weight 500) was placed in a 2000 ml four-necked flask equipped with a thermometer, a stirrer and a nitrogen inlet tube.
4.4 g, trimethylolpropane 1.6 g, dimethylolpropionic acid 17.9 g, N-methyl-2-pyrrolidone 206.0 g, and isophorone diisocyanate 126.1 g were charged, and the mixture was heated at 80 ° C. for 8 hours. The reaction was carried out. The NCO group content of the obtained prepolymer was 1.7%.
Met. The above-mentioned prepolymer (379.9 g) was neutralized with triethylamine (13.3 g) and then put into deionized water at 50 ° C. to obtain an aqueous urethane resin. This water-based urethane resin has a nonvolatile content of 30.1%, a pH of 7.7 and a viscosity of 53.0.
It was cp / 25 ° C. Obtained aqueous urethane resin 40
0 part and 600 parts of calcium carbonate were mixed and stirred to obtain a putty agent. Next, using the adhesive composition of Example 1, Example 1
According to the above, a base plate having a defective portion of a concave portion was used, a putty agent was filled with a knife coater, the adhesive composition was applied in an undried state, and a veneer was attached under the adhesion conditions of Example 1. The putty agent was not peeled off even though the adhesive composition was applied in a state where the putty agent thus filled was not dried. The results are shown in Table 4.

Example 9 Using the putty agent and the adhesive composition of Example 1, a base plate having a defective portion of a concave portion was used, the putty agent was filled with a knife coater, and the adhesive agent was left undried. After applying the composition, paper was applied, and then veneer was applied. Then, bonding was performed under the bonding conditions of Example 1. As a result, although the base plate having the defective portion of the concave portion was used, there was no problem in the surface property, and the putty agent was applied to the adhesive composition in the undried state. There was no exfoliation of the agent. After that, as a result of a finished surface property and a dip peeling test, no abnormality was found. The results are shown in Table 4.

Example 10 Using the putty agent of Example 1, a base plate having defective concave portions was filled with the putty agent using a knife coater, and the urea-vinyl acetate resin adhesive was applied in an undried state. The coating was applied, and a veneer plate was applied, and adhered under the adhesion conditions of Example 1. as a result,
There was no problem in the surface property of the portion having the defective portion of the concave portion, and there was no peeling of the putty agent even though the adhesive composition was applied in a state where the putty agent was not dried. After that, as a result of a finished surface property and a dip peeling test, no abnormality was found. The results are shown in Table 4.

Examples 11 to 13 Examples 11 to 13 were carried out except that the addition amount of MDI was 5 parts and 5, 10, and 15 parts of the completely alkyl type urea resin (Cymel UFR65 manufactured by Mitsui Cyanamid Co., Ltd.) were used as shown in Table 2. Bonding was performed under the bonding conditions of Example 1. As a result, there is no problem in the surface property of the portion having the defective portion of the concave portion, and
The putty agent was not peeled off even though the adhesive composition was applied in the undried state. After that, as a result of a finished surface property and a dip peeling test, no abnormality was found. The results are shown in Table 4.

Reference Example 1 Using a high-quality base plate having no recessed concave portion, the same putty agent, adhesive composition and bonding conditions as in Example 1 were used for bonding. After that, as a result of a finished surface property and a dip peeling test, no abnormality was found. The results are shown in Table 4.

[0054]

[Table 1]

[0055]

[Table 2]

[0056]

[Table 3]

[0057]

[Table 4]

Comparative Example 1 400 parts of vinyl acetate resin having a solid content of 40% and 600 parts of calcium carbonate were mixed and stirred to obtain a putty agent. Using the putty agent, a base plate having a defective portion of a concave portion was filled with the putty agent using a knife coater, and the adhesive composition used in Example 1 was applied in an undried state, and Example 1 was used. Adhesion was performed under the following adhesion conditions. As a result, the putty agent filled in the recesses was partially wound up on the adhesive composition, and the putty agent was peeled off from the base plate, and sufficient surface properties could not be obtained. The results are shown in Table 5.

Comparative Example 2 300 parts of vinyl acetate resin having a solid content of 40% and a solid content of 70%
100 parts of the high-concentration urea resin of was mixed with 600 parts of calcium carbonate and stirred to obtain a putty agent. Using the putty agent, a base plate having a defective portion of a concave portion was filled with the putty agent using a knife coater, and the adhesive composition used in Example 1 was applied in an undried state, and Example 1 was used. Adhesion was performed under the following adhesion conditions. As a result, the putty agent filled in the recesses was partially wound up on the adhesive composition, and the putty agent was peeled off from the base plate, and sufficient surface properties could not be obtained. The results are shown in Table 5.

[0060]

[Table 5]

The evaluation method of the decorative plywood was as follows. Surface property of decorative plywood ⊚: The surface of the decorative plywood after processing is smooth and there are no irregularities in the defective portion. ◯: The surface of the decorative plywood after processing is smooth and there are no irregularities in the defective portion. Δ: The plate surface of the decorative plywood after processing is smooth, but there are some irregularities in the defective portion. Poor: The surface of the decorative plywood after processing is not smooth and there are irregularities in the defective portion.

Method 2 of dipping and peeling test of decorative plywood As test pieces, four pieces each having a square shape with a side of 75 mm are prepared from each sample plywood. The test piece is immersed in warm water of 70 ± 3 ° C. for 2 hours, and then dried at 60 ± 3 ° C. for 3 hours. ◯: No peeling of the surface of the decorative plywood. Δ: Slight peeling is observed on the plate surface of the decorative plywood. X: Peeling is recognized in the recess of the base plate of the decorative plywood.

[0063]

According to the present invention, a defective portion of a base plate having a defective portion of a recess, which has not been achieved by the prior art, is filled with a putty agent made of a water-based urethane resin, and the adhesive agent is left undried. After applying the composition, the filling of the base plate having a defective portion of the recess and the adhesion with the projecting plate is performed in one step,
The present invention has a great influence on the future production of decorative plywood in the aggravation of plywood circumstances.

Claims (8)

[Claims] 1. A method for producing a decorative plywood, which comprises filling a plywood having recesses with a putty agent made of a water-based urethane resin and applying an adhesive composition. 2. A method for manufacturing a decorative plywood, which comprises filling a plywood having recesses with a putty agent made of an aqueous urethane resin, and applying the adhesive composition in the undried state of the putty agent. 3. A plywood having recesses is filled with a putty agent made of a water-based urethane resin, the adhesive composition is applied, and paper is pasted on the adhesive composition, and then the adhesive composition is further applied. A method for producing a decorative plywood that is applied. 4. A carboxyl group-containing urethane prepolymer (wherein the aqueous urethane resin is obtained from an isocyanate compound (A), a carboxyl group-containing polyol and / or amino acid (B), and a polyol (C). The method according to claim 1, 2 or 3, wherein D) is reacted with a basic organic compound (E) and an extender (F) in the presence of a solvent and / or water. 5. A carboxyl group-containing urethane prepolymer (wherein the aqueous urethane resin is obtained from an isocyanate compound (A), a carboxyl group-containing polyol and / or amino acid (B), and a polyol (C). D) is reacted with a basic organic compound (E) and an extender (F) in the presence of a solvent and / or water, and then the solvent is removed under reduced pressure to remove particles from a single particle dispersion. The method according to claim 1, 2 or 3, which is a three-dimensional structured particle dispersion in which the above are connected. 6. The method according to claim 1, 2 or 3, wherein the adhesive composition comprises an aqueous emulsion and / or an aqueous solution of a water-soluble polymer and a polyvalent isocyanate compound as a crosslinking agent. 7. The adhesive composition comprises an aqueous emulsion and / or an aqueous solution of a water-soluble polymer, a modified amino resin, and a polyvalent isocyanate compound as a crosslinking agent.
Or the method described in 3. 8. The method according to claim 1, 2 or 3, wherein the adhesive composition comprises an aqueous emulsion and / or an aqueous solution of a water-soluble polymer, a thermosetting resin and a foaming agent.