JP2002069417A - Adhesive composition for hot press molded article of lignocellulosic material, and hot press molded article using the same and its manufacturing method - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide an adhesive composition for a hot press molded article of lignocellulosic material capable of improving physical properties of the lignocellulosic molded article, and solving a problem of achieving both securing a pot-life of an adhesive formulation liquid and decreasing a hot press time. SOLUTION: The problem is solved by the adhesive composition for hot press molded article of lignocellulose based material comprising an organic polyisocyanate (A), and a catalyst (B) consisting of a complex of formic acid (and if necessary an aliphatic monocarboxylic acid having 2 to 20 carbon atoms) and an aliphatic tertiary amine.

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to an adhesive composition for hot-pressed lignocellulosic material, a hot-pressed product using the same, and a method for producing the same.

[0002]

2. Description of the Related Art A hot-pressed product (particle board, MDF) of a lignocellulosic material such as wood chips and wood fibers.
Conventionally, formalin-based adhesives such as urea resin, melamine resin, urea melamine resin, phenol resin, and phenol melamine resin have been used as adhesives for boards called medium density fiberboards and the like. However, in view of improving the housing environment and improving safety in terms of health,
For example, there is a need to reduce formalin released from adhesives as seen in the problem of sick house syndrome.

As an adhesive capable of coping with the above problem, an organic polyisocyanate adhesive which is a non-formalin adhesive has been used. This is because, in addition to the characteristic that the organic polyisocyanate does not originally contain formalin in its structure, it further has excellent adhesive properties, hot water resistance and the like. However, when an organic polyisocyanate is used as an adhesive for the hot-pressed article, it is said that the pot life after the compounding of the adhesive is relatively short and there are many problems in workability. Further, in order to further improve the physical properties and productivity, the use of a catalyst increases the effect, but on the other hand, the pot life is further shortened, and practical use has been difficult.

In order to solve such a problem, it has been attempted to add a so-called temperature-sensitive catalyst to an adhesive of a lignocellulosic material. For example, JP
In JP-A-55016, those obtained by reacting an amine compound and a phosphorus-based acidic ester in substantially equivalent amounts are used. In Japanese Patent Publication No. 2000-504051, an ammonium salt of an amine and malonic acid is used.

[0005]

DISCLOSURE OF THE INVENTION The present invention solves the problems of improving the physical properties of a lignocellulose-based molded article, and ensuring both the working life of an adhesive compounding liquid and the shortening of hot press time. An object of the present invention is to provide an adhesive composition for a hot-pressed product of a material.

[0006]

Means for Solving the Problems The present inventors have conducted intensive studies to solve the above-mentioned problems, and as a result, the present inventors have found that the use of a complex comprising formic acid and an aliphatic tertiary amine as a catalyst solves the above-mentioned problems. They have found what they can do and have completed the present invention.

That is, the present invention provides the following (1) to
This is shown in (7). (1) An adhesive composition for a hot-press molded article of a lignocellulosic material, comprising an organic polyisocyanate (A) and a catalyst (B) comprising a complex of formic acid and an aliphatic tertiary amine. .

(2) Organic polyisocyanate (A),
And a catalyst (B) comprising a complex of formic acid, an aliphatic monocarboxylic acid having 2 to 20 carbon atoms, and an aliphatic tertiary amine. Composition.

(3) In the catalyst (B), the molar ratio between the carboxyl group and the amino group is 0.1: 1 to 1: 1. Or the adhesive composition for a hot-pressed article of (2).

(4) An active hydrogen group-containing compound (C)
The adhesive composition for a hot-pressed article according to any one of the above (1) to (3), comprising:

(5) Further, a wax emulsion (D)
The adhesive composition for a hot-pressed molded article according to any one of the above (1) to (4), comprising:

(6) The composition is obtained by applying the adhesive composition for a hot-pressed article according to any one of the above (1) to (5) to a lignocellulose-based material and then hot pressing. Hot pressed body.

(7) A hot-press forming method characterized in that the hot-pressing is performed after applying the adhesive composition for a hot-pressed body according to any one of the above (1) to (5) to a lignocellulosic material. How to make the body.

[0014]

BEST MODE FOR CARRYING OUT THE INVENTION The constituent components of the adhesive composition for a lignocellulosic material of the present invention for hot-press molding are described below.

As the organic polyisocyanate (A),
For example, diphenylmethane diisocyanate (hereinafter referred to as M
DI), a mixture of MDI and an MDI-based polynuclear condensate (hereinafter, referred to as polymeric MDI), liquid MDI
(Carbodiimide-modified MDI), polyisocyanate alone or two or more such as tolylene diisocyanate, xylylene diisocyanate, trimethylene xylylene diisocyanate, isophorone diisocyanate, hexamethylene diisocyanate, naphthalene diisocyanate, hydrogenated diphenylmethane diisocyanate, hydrogenated xylylene diisocyanate And dimer (uretdione-modified) or trimer (isocyanurate-modified) by adding a catalyst to the polyisocyanate.

Also, the above-mentioned organic polyisocyanate,
An active hydrogen group-containing compound to be described later is converted into an isocyanate (hereinafter referred to as NCO) group and an active hydrogen group (AH) having an equivalent ratio (NCO / AH) of 1.5 to 500, preferably 2.0 to 400. An NCO group-terminated prepolymer obtained by a known method so as to fall within the range can also be suitably used as the component (A).

Examples of the active hydrogen group-containing compound include low molecular weight monols, low molecular weight polyols, low molecular weight amino alcohols, low molecular weight monoamines, low molecular weight polyamines, hydroxyl group containing polyethers, hydroxyl group containing polyesters,
Examples include hydroxyl group-containing polycarbonates.

Examples of low molecular monols include methanol, ethanol, propanol, butanol, octanol, lauryl alcohol and the like.

The low molecular polyols include ethylene glycol, diethylene glycol, triethylene glycol, 1,2-propanediol, 1,3-propanediol, dipropylene glycol, 1,2-butanediol and 1,3-butanediol. , 1,4-butanediol, 1,6-hexanediol, cyclohexane-1,
4-diol, cyclohexane-1,4-dimethanol, hydrogenated bisphenol A, glycerin, trimethylolpropane, pentaerythritol, diglycerin and the like.

Examples of low molecular weight amino alcohols include monoethanolamine, diethanolamine, triethanolamine, N-methylethanolamine, N-methyldiethanolamine, N-ethylethanolamine, N-ethylethanolamine and N-ethylethanolamine.
n-butylethanolamine, Nn-butyldiethanolamine, N- (β-aminoethyl) ethanolamine, N- (β-aminoethyl) isopropanolamine and the like.

The low molecular weight monoamines include ethylamine, propylamine, butylamine, diethylamine,
Examples include dibutylamine, aniline, N-methylaniline and the like.

Examples of low molecular weight polyamines include tetramethylenediamine, hexamethylenediamine, tolylenediamine, 4,4'-diaminodiphenylmethane, 3,3 '
-Dimethyl-4,4'-diaminodicyclohexylmethane, diethyltriamine, dibutyltriamine, dipropylenetriamine and the like.

The hydroxyl group-containing polyethers include low molecular weight monols, low molecular weight polyols, low molecular weight amino alcohols, low molecular weight monoamines, low molecular weight polyamines, phenol, alkyl-substituted phenols, bisphenol A, and thiols alone. Or, using a mixture as an initiator, ethylene oxide, propylene oxide, alkylene oxides such as butylene oxide, epoxides such as styrene oxide, cyclic ethers such as tetrahydrofuran alone or in combination, and obtained by addition polymerization by a known method. Are included.

Examples of the hydroxyl group-containing polyesters and hydroxyl group-containing polyamide-esters include the above-mentioned low-molecular polyols, low-molecular amino alcohols and low-molecular polyamines alone or in combination with oxalic acid, malonic acid, succinic acid and glutaric acid. , Adipic acid, azelaic acid, sebacic acid, maleic acid, fumaric acid, o-phthalic acid, i-phthalic acid, t
And those obtained by polycondensation with a polycarboxylic acid such as phthalic acid or trimellitic acid by a known method.

The hydroxyl group-containing polycarbonates include
A single or a mixture of the low-molecular polyols, dimethyl carbonate, dialkyl carbonate such as diethyl carbonate, diaryl carbonate such as diphenyl carbonate, ethylene carbonate, alkylene carbonate such as propylene carbonate, polycondensation with a known method. Obtained ones are listed.

In the present invention, the preferred component (A) is
Preferred is a type having good compatibility with the catalyst (B) and the active hydrogen group-containing compound (C), etc. In particular, those selected from polymeric MDI and NCO-terminated urethane prepolymers obtained by modifying polymeric MDI with hydroxyl-containing polyethers are preferred. preferable.

The catalyst (B) is a complex of formic acid and an aliphatic tertiary amine. The reason for the complexation is to adjust the catalytic activity of the tertiary amine. Examples of the aliphatic tertiary amines include linear aliphatic tertiary monoamines such as triethylamine and tripropylamine, and cyclic rings such as triethylenediamine, hexamethylenetetramine, piperidine, pyrrolidine, N, N'-dimethylpiperazine, and N-methylmorpholine. Linear aliphatic polyamines such as aliphatic tertiary monoamines, N, N, N ', N'-tetramethylethylenediamine, N, N, N', N'-tetramethylhexamethylenediamine;
N, N-dialkylalkanolamines such as N-dimethylethanolamine, N-alkyldialkanolamines such as N-methyldiethanolamine, trialkanolamines such as triethanolamine, N, N,
N'-trimethylaminoethylethanolamine, N,
N, N ', N'-tetramethylhydroxypropylenediamine and the like. The aliphatic tertiary amines preferred in the present invention have 10 or less carbon atoms, and particularly preferred are triethylamine and triethylenediamine.

In the present invention, an aliphatic monocarboxylic acid having 2 to 20 carbon atoms other than formic acid can be used in combination in order to more precisely adjust the catalytic activity. As aliphatic monocarboxylic acids having 2 to 20 carbon atoms, acetic acid, propionic acid, butyric acid, isobutyric acid,
Valeric acid, isovaleric acid, caproic acid, caprylic acid, octylic acid, capric acid, lauric acid, myristic acid, barmitic acid, stearic acid, acrylic acid, methacrylic acid, oleic acid, lactic acid and the like. Preferred in the present invention are those having 5 to 15 carbon atoms, and particularly preferred are caprylic acid, octylic acid, lauric acid, myristic acid and balmitic acid.

When an aliphatic monocarboxylic acid other than formic acid is used in combination, the molar content of formic acid in the acid component (the number of moles of formic acid /
(Mol number of formic acid + mol number of aliphatic monocarboxylic acid other than formic acid)) is preferably 50 mol% or more, particularly 60 to 90 mol%.
Molar% is preferred.

The complex of formic acid (and a monocarboxylic acid other than formic acid) and an aliphatic tertiary amine as the catalyst (B) used in the present invention was equipped with a stirrer, a thermometer, a cooler and a nitrogen gas inlet tube. After charging the aliphatic tertiary amine to the reactor,
At a temperature of 10 to 70 ° C., formic acid (and a monocarboxylic acid other than formic acid) is gradually added dropwise while stirring while paying attention to heat generation, and is reacted to form unreacted formic acid (and a monocarboxylic acid other than formic acid). By reacting until completely reacted. It is preferable to add water, an organic solvent, an active hydrogen group-containing compound in a liquid state at room temperature, or the like before charging the acid, since heat generation can be reduced and the catalyst can be easily charged during the production of a molded article.

In this case, the molar ratio between the carboxyl group and the amino group is such that carboxyl group: amino group = 0.1: 1 to 1:
1, especially carboxyl group: amino group = 0.2
~ 0.9 is preferred. If the carboxyl group is too small, the effect of suppressing the catalytic activity is insufficient, and the curing reaction becomes too fast, so that the hot-pressed molded product reacts and solidifies before hot pressing with a hot plate, and a normal molded product cannot be obtained. On the other hand, if the amount is too large, the catalytic activity is excessively suppressed and the curing reaction becomes insufficient, so that it takes a long time for hot pressing to achieve the desired physical properties, and the productivity is deteriorated.

In the present invention, it is preferable to use an active hydrogen group-containing compound (C) in combination with the above-mentioned organic polyisocyanate (A) because higher physical properties can be achieved. Examples of the active hydrogen group-containing compound (C) include those used to obtain the above-mentioned NCO group-terminated prepolymer.

Further, as the component (C), polyoxyalkylene polyamines having an oxyalkylene structure in the molecule can be mentioned. For example, as polyoxypropylene diamine, Jeffamine D-2000 (Huntsman Specialty Chemicals) Available from Techslim TR-5050 (manufactured by Huntsman Specialty Chemicals, Inc., amine equivalent: about 193) and polyoxypropylene triamine.
0), Jeffamine T-403 (manufactured by Huntsman Specialty Chemicals, amine equivalent: about 160) and the like.

In the present invention, it is not preferable to use the wax emulsion (D) in combination, since the molded body immediately after molding and the hot plate become intimate and the productivity is improved.

Examples of the wax component of the wax emulsion include natural waxes such as paraffin wax, montan wax, carnauba wax and rice wax, and synthetic waxes such as paraffin wax derivatives, montan wax derivatives, hardened castor oil, and stearamide. Emulsions may be mentioned.
Among them, paraffin-based wax, montanic acid-based wax and derivatives thereof are particularly preferable because they exhibit good mold release properties and, as a secondary effect, give a good effect on the hot water resistance of the hot-pressed product.

The melting point of the wax component is 40 to 160 ° C. If the melting point of the wax component is less than 40 ° C., it tends to evaporate and evaporate under the normal hot-pressing temperature of 100 to 200 ° C., making it difficult to exhibit mold release properties. On the other hand, when the melting point is 160 ° C. or more, the hot pressing temperature is 2 ° C.
Even under the condition of 00 ° C., the temperature inside the molded body does not always rise to that temperature within the molding time, so that the wax component is less likely to move to the surface of the molded body,
The mold release property from the hot plate cannot be exhibited. Also, it is difficult to obtain a stable wax emulsion.

Further, the wax component contains a component having a number average molecular weight of 100 to 1,000 in terms of polystyrene as a peak area ratio of at least 80% by gel permeation chromatography (GPC). In the case where the component having a peak area ratio of GPC of 80% or more in the wax component has a number average molecular weight of less than 100, the component easily evaporates and vaporizes under the condition of a normal hot pressing temperature of 100 to 200 ° C., It is difficult to exhibit releasability. Further, when the number average molecular weight of this component is 1,000 or more, the stability of the wax emulsion is deteriorated and the compatibility with the organic polyisocyanate compound is reduced, and the melting point is relatively high as described below. As a result, the wax component hardly transfers heat to the surface of the molded body, so that the wax component cannot exhibit releasability from the hot platen. When the component having a number average molecular weight of 100 to 1,000 is less than 80% in terms of the peak area ratio of GPC, the stability of the wax emulsion deteriorates and the compatibility with the organic polyisocyanate compound decreases. Since the melting point is relatively high, the wax component is less likely to move to the surface of the molded body, and the mold release property from the hot plate cannot be exhibited.

For emulsification of the wax component, a known emulsifier can be used. Examples of such emulsifiers include surfactants such as alkyl sulfonates, alkylbenzene sulfonates, and dialkylaryl sulfonates, and surfactants such as esters with fatty acids such as polyoxyethylene alkyl ethers and polyoxyethylene aryl ethers. Agents.

The solid content of the wax emulsion is 10 to
Those having 60% by mass are preferred, and those having 15 to 55% by mass are particularly preferred.

In the present invention, a surfactant can be used. Examples of the surfactant include those obtained by condensing an alkylene oxide such as ethylene oxide and propylene oxide with at least one organic compound containing active hydrogen. Examples of the organic compound containing at least one active hydrogen include the aforementioned low-molecular monols, low-molecular polyols,
Low-molecular-weight amino alcohols, low-molecular-weight monoamines, low-molecular-weight polyamines, phenol, alkyl-substituted phenol, bisphenol A, thiol alone or as a mixture, ethylene oxide, propylene oxide, alkylene oxides such as butylene oxide,
Epoxysides such as styrene oxide, and cyclic ethers such as tetrahydrofuran alone or in combination, and those obtained by addition polymerization by a known method are exemplified.

Examples of the surfactant include silicone surfactants, for example, various siloxane polyalkylene oxide block copolymers. Specifically, L-5340 manufactured by Nippon Unicar, B-8451, B-840 manufactured by Te Goldschmidt
7 and the like.

In the present invention, a formalin condensation resin can be used in combination. As the formalin condensation resin, urea resin, melamine resin, urea melamine co-condensation resin, phenol resin, phenol melamine co-condensation resin and the like can be used in combination.

The adhesive composition of the present invention may further contain, if necessary, inorganic fillers such as cement, blast furnace slag, gypsum, calcium carbonate, clay, aluminum hydroxide, antimony trioxide, quicklime, slaked lime, bentonite and the like. , A leveling agent, a flame retardant, an anti-aging agent, a heat resistance imparting agent, an antioxidant, and the like can be appropriately adjusted in amount.

Generally, the adhesive composition of the present invention is generally used as a two-part mixed type adhesive in which components other than the organic polyisocyanate (A) are previously mixed.

The hot-pressed article of the present invention is obtained by curing a lignocellulosic material with the above-mentioned adhesive composition. As the lignocellulose-based material, a particle board, an oriented strand board (OS
B) Strand chips, dust chips, flake chips, and hard chips, which are wood chips used in wafer boards, laminated veneer lumbar (LVL), laminated strand lumbar (LSL), parallel strand lumbar (PSL), and the like. Fiber used for board, medium density fiberboard (MDF), insulation board, etc., kollang stalk, bagasse, rice hull, hemp, straw, grass, reed, coconut and tree, rubber tree, corn, sawdust, etc. No. These may be used alone or in combination of two or more.

The amount of the organic polyisocyanate (A) added is 2 to 50% by mass based on the lignocellulosic material.
And more preferably 4 to 30% by mass.

The amount of the catalyst (B) is preferably from 0.01 to 5% by mass, more preferably from 0.03 to 3% by mass, based on the organic polyisocyanate (A). (B)
If the amount of the component is less than the lower limit, the curing reaction is too slow, so that the heat pressure is insufficient and the physical properties of the molded body are likely to be insufficient. Alternatively, the heat and pressure time must be increased, and the productivity tends to decrease. If the upper limit is exceeded, the content of the catalyst in the adhesive composition is increased, resulting in low physical properties due to a kind of plasticity effect,
Over time, the adhesive bond deteriorates, causing deterioration in physical properties and poor durability.

When the active hydrogen group-containing compound (C) is used in combination, the amount of (C) is preferably from 0.3 to 50% by mass, more preferably from 1 to 50% by mass, based on the lignocellulosic material.
３０30% by mass.

When a wax emulsion is used in combination, the amount of the wax emulsion is preferably from 0.3 to 10% by mass, more preferably from 0.5 to 8% by mass, based on the solid content of the lignocellulosic material. .

When a surfactant is used in combination, the amount of the surfactant to be added is 0.0 to the organic polyisocyanate (A).
5 to 5% by mass is preferred.

When a formalin condensed resin is used in combination, the compounding amount of the formalin condensed resin is represented by a mass ratio in terms of solid content,
Organic polyisocyanate / formalin condensation resin = 5 /
95-95 / 5 is preferred, and especially 10 / 90-90 / 1.
0 is preferred.

Regarding the method for producing a hot-pressed article of the present invention,
It is described below. First, the above-mentioned adhesive composition is applied to a lignocellulosic material. As the coating method, an organic polyisocyanate (A), a catalyst (B), and, if necessary, an active hydrogen compound (C), a wax emulsion (D), a surfactant and a formalin condensation resin are used as the above various lignocellulose. They may be used by mixing them immediately before application to the system material, or may be used by separately applying each component other than (A) and (B) and, if necessary, other than the above (A) and (B). At this time, a mixed system to which water is added may be used.

When the production is carried out in a continuous line, the catalyst (B) and, if necessary, the components other than the components (A) and (B), and the pre-mixture in which water is previously mixed, are mixed with a static mixer. After continuously mixing with the organic polyisocyanate (A), it is applied to the lignocellulose-based material.

After the adhesive composition has been applied, it is formed on a hot plate and hot pressed. This hot pressing condition can be applied to all known molding conditions. Preferred hot pressing conditions are: temperature: 100-250 ° C., pressure: 1-10 MP
a, time (per 1 mm thickness): 6 to 30 seconds, temperature: 150 to 230 ° C., pressure: 2 to 5 MPa,
Time (per 1 mm thickness): 6 to 15 seconds is particularly preferred.

[0055]

As described above, by using the adhesive composition of the present invention, it is possible to prevent shortening of the pot life of the adhesive composition during hot-press molding of lignocellulosic materials such as wood chips and wood fibers. Thus, it is possible to obtain a homogeneous and high-performance hot-pressed product with high productivity. Furthermore, by using an active hydrogen group-containing compound, the physical properties of the hot-pressed body are further improved, and by using a wax emulsion, adhesion to the hot platen surface can be prevented, and a lignocellulosic material having excellent physical properties Can be obtained.

[0056]

EXAMPLES Next, the adhesive composition for hot-pressed lignocellulose-based material of the present invention, the hot-pressed product using the same, and a method for producing the same will be described in more detail with reference to examples. However, the present invention is not limited to only such examples. “%” Is “% by mass” unless otherwise specified.
Is shown.

[Synthesis of Organic Polyisocyanate (A)] Production Examples 1-5 A stirrer, a thermometer, a cooler and a nitrogen gas inlet tube were attached.
Using a reactor having a capacity of 2,000 ml, the raw materials shown in Table 1 were charged, and the temperature was raised to 80 ° C. and reacted for 3 hours to obtain organic polyisocyanates A-1 to A-3. A
-4 and A-5 used polymeric MDI as it was. Table 1 shows the types, amounts and analytical values of the raw materials.

[0058]

[Table 1]

In Table 1, PMDI-1: polymeric MDI NCO content = 31.1% MDI content in polymeric MDI = 42% PMDI-2: polymeric MDI NCO content = 30.1% MDI content in polymeric MDI = 30% MPEG-700: methoxypolyethylene glycol number average molecular weight = 700 average functional group = 1 PPG-200: poly (oxypropylene) polyol number average molecular weight = 200 average functional group = 2 PEG-2000: poly (oxyethylene) polyol number Average molecular weight = 2,000 Average number of functional groups = 2

[Synthesis of Catalyst (B)] Production Examples 6 to 14 A stirrer, a thermometer, a cooler and a nitrogen gas inlet tube were attached.
Aliphatic tertiary amine and DPG in 100 ml reactor
Was charged. Next, the acid charged in the dropping funnel was gradually dropped, and the mixture was stirred uniformly, and the catalysts B-1 to B-4, B-
6 to B-9 were obtained. B-5 was made without DPG. Table 2 shows the types and amounts of the raw materials.

[0061]

[Table 2]

In Production Examples 6 to 14 and Table 2, TEDA: triethylenediamine TEA: triethylamine DPG: dipropylene glycol COOH: carboxyl group tN: tertiary amino group

[Preparation and Evaluation of Adhesive Composition] Examples 1 to 15, Comparative Examples 1 to 5 Organic polyisocyanates A-1 to A-5 in Table 1, catalysts B-1 to B-9 in Table 2, An adhesive composition for a hot-press molded article of a lignocellulose material was obtained by combining water, an active hydrogen group-containing compound, a wax emulsion, a surfactant, and a formalin condensation-based resin adjusted to have a predetermined mat moisture content. Particle board using this adhesive composition,
A medium density fiberboard was prepared and evaluated. Tables 3 and 4 show the amounts of each adhesive composition and the evaluation results.

[0064]

[Table 3]

[0065]

[Table 4]

In Tables 3 and 4, EG: ethylene glycol AEETA: N- (β-aminoethyl) ethanolamine EDAET: ethylenediamino-N, N, N ', N'
-Tetraethanol WE-1: a montanic acid-based wax emulsion (solid content = 30%, melting point = 78 ° C., number average molecular weight 100)
WE-2: paraffinic wax emulsion (solid content = 30%, melting point = 78 ° C., number average molecular weight 100)
(* Number average molecular weight is measured by GPC, in terms of polystyrene) B-8407: T-Goldschmidt silicone surfactant UMR: Urea melamine co-condensation resin (mol Ratio = 1.
5, solid content = 50%)

[Method of Forming Hot-Pressed Body] Molding conditions Board size: 40 cm × 40 cm Board thickness: 15 mm Set density: 720 kg / m ³ Product water content: 9% Matt water content: 14% Hot platen (press) temperature: 200 ° C. Hot platen (press) pressure: 3 MPa (surface pressure) Hot platen (press) time: 150 seconds (however, only Comparative Example 5 has 2
25 seconds)

Molding Method With respect to the preparation of the hot-pressed molded articles described in Tables 3 and 4, the particleboards (Examples 1 to 10 and Comparative Examples 1 to 4) obtained by using the wood chips of the conifers are described in the following ( 1)
And medium-density fiberboards (Examples 11 to 15 and Comparative Example 5) obtained using wood fibers were prepared by the following method (2).

(1) Method of preparing particle board (Examples 1 to 10, Comparative Examples 1 to 4) Wood chips of conifers in the amounts shown in Tables 3 and 4 were mixed with a stirring blade to a volume of about 0.5 m ^3. And a mixture of various components in the amounts shown in Tables 3 and 4 and water for the water content of the mat were spray-applied thereto with mixing and stirring for about 5 minutes. Thereafter, the wood chip to which the adhesive composition has been applied is taken out, weighed so that the density of the molded body after molding becomes the set density, formed on an iron plate so as to have the board size, and further formed into the same shape. Was placed on top and hot pressed under the above conditions. In Comparative Example 1, since the release property was poor, a release agent was applied to the iron plate to prepare a physical property measurement board.

(2) Method of Making Medium Density Fiberboard (Example 1)
1 to 15, Comparative Example 5) Wood chips of conifers were digested using a pressurized refiner (fibrillator) to a cooking pressure of 0.7 so that the amount shown in Table 4 was obtained.
It was defibrated (fibrillated) under the conditions of MPa and digestion temperature = 150 ° C. The mixture was passed through a pipe, and a mixture of various components in the amounts shown in Table 4 and water for mat moisture content were simultaneously added to the pipe, and dried with a flash dryer until the mat moisture content was reached. . Thereafter, the wood fiber to which the adhesive composition has been applied is taken out, weighed so that the density of the molded body after molding becomes a set density, and formed on a stainless steel plate with a forming molding apparatus so as to have the board size. Then, a stainless steel plate having the same shape was placed thereon, and hot-pressed under the above conditions. In Comparative Example 5, since there was no catalyst, the molding was performed by extending the pressing time to 225 seconds.

(3) Evaluation method [Measurement of pot life] The organic polyisocyanate and the catalyst in the amounts described in Examples 1 to 15 and Comparative Examples 1 to 5 were mixed, and the same mass was added to the organic polyisocyanate. Was added, and the gelation time of the mixed solution at 25 ° C. was measured. When the mixture time was 3 hours or more, “OK” was judged, and when less than 3 hours, “NO” was judged. [Confirmation of Releasability] An iron plate (SPCC-SB) manufactured by Nippon Test Panel was placed on the upper and lower sides of the board, and the releasability was confirmed during the molding. [Measurement of Physical Properties] Regarding the various physical property values of the molded articles of Examples 1 to 10 and Comparative Examples 1 to 4 in Tables 3 and 4, JIS A-
Measured according to 5908, Examples 11 to 15, Comparative Example 5
For various physical property values of the molded article of JIS A-590
5 was measured.

The particle board (Examples 1 to 10) in the examples shown in Table 3 and the medium density fiberboard (Examples 11 to 15) in the examples shown in Table 4 exhibited good physical properties. However, the particle board in Comparative Example (Comparative Examples 1 to 5)
The value of 4) was lower than that of the comparative example as a whole, and the medium-density fiberboard (Comparative Example 5) in the comparative example was particularly poor in the water absorption thickness expansion coefficient.

Claims (7)

[Claims] 1. An adhesive for a hot-pressed lignocellulose material, comprising an organic polyisocyanate (A) and a catalyst (B) comprising a complex of formic acid and an aliphatic tertiary amine. Composition. 2. A catalyst comprising an organic polyisocyanate (A) and a catalyst (B) comprising a complex of formic acid, an aliphatic monocarboxylic acid having 2 to 20 carbon atoms, and an aliphatic tertiary amine. An adhesive composition for a hot-pressed product of a lignocellulosic material. 3. The catalyst (B) wherein the molar ratio of carboxyl group to amino group is such that carboxyl group: amino group = 0.
The adhesive composition for a hot-pressed product according to claim 1, wherein the ratio is 1: 1 to 1: 1. 4. The adhesive composition for a hot-pressed product according to claim 1, further comprising an active hydrogen group-containing compound (C). 5. The adhesive composition for a hot-pressed product according to claim 1, further comprising a wax emulsion (D). 6. A hot-press obtained by applying the adhesive composition for a hot-pressed article according to claim 1 to a lignocellulosic material and then hot-pressing. Molded body. 7. A hot-press molded article characterized by applying the hot-press molded article adhesive composition according to any one of claims 1 to 5 to a lignocellulosic material, followed by hot pressing. Production method.