AU690497B1 - Adhesive, adhesive for pressed lignocellulose board, pressed lignocellulose board and production processes thereof - Google Patents

Description

AUSTRALIA

Patents Act COMPLETE SPECIFICATION

(ORIGINAL)

Class Int. Class Application Number: Lodged: Complete Specification Lodged: Accepted: Published: Priority Related Art: Name of Applicant: Mitsui Toatsu Chemicals, Incorporated Actual Inventor(s): Yasuhiro Matsuzaka Hitoshi Watanabe Takashi Nagou Hisashi Hokonohara Naohiro Murata Ryuji Haseyama Address for Service: PHILLIPS ORMONDE FITZPATRICK Patent and Trade Mark Attorneys 367 Collins Street Melbourne 3000 AUSTRALIA Invention Title: ADHESIVE, ADHESIVE FOR PRESSED LIGNOCELLULOSE BOARD, PRESSED LIGNOCELLULOSE BOARD AND PRODUCTION PROCESSES THEREOF Our Ref: 504600 POF Code: 1566/1719 The following statement is a full description of this invention, including the best method of performing it known to applicant(s): -1- ADHESIVE, ADHESIVE FOR PRESSED LIGNOCELLULOSE BOARD, PRESSED LIGNOCELLULOSE BOARD AND PRODUCTION PROCESSES

THEREOF

BACKGROUND OF THE INVENTION 1. Field of the Invention This invention relates to an adhesive, particularly an adhesive for hot-pressed board formed mainly of lignocellulose and preparation process thereof.

2. Description of the Related Art Pressed boards formed mainly of lignocellulose are called "particle board" when the lignocellulose is in the form of ligneous chips. In addition to the particle board, there are a wafer board for which large-sized chips are used and an oriented strand board (OSB) in which slender chips (strands) are arranged in a row. In the case of lignified Sfibers, they are produced as a board such as an insulation board, a medium-density fiber board (MDF) or hardboard.

These boards are used as floor materials, wall materials, door materials, soundproof materials, adiabatic materials, core materials for tatami, furniture members or automobile members.

As an adhesive or binder for the production of a particle board, a wafer board, an OSB, a fiber board such as hard board, an MDF or insulation board, a chaff board formed from chaffs or a kaoliang board formed from kaoliang e e stalks (which will be hereinafter called "board", collectively), thermosetting resins such as urea resin, melamine resin, urea melamine resin, phenol melamine resin and phenol resin (which will hereinafter be called "formalin-base resin adhesive", collectively) have so far been used widely.

The formalin-base resin adhesive features that its exhibits excellent adhesion even at a low cost and hardens in a comparatively short time. Formalin which is emitted from the hot-pressed products adhered by the formalin-base resin adhesive is regarded as a problem from the environmental viewpoint. An improvement with a view to reducing the emitted amount of formalin has been proposed but satisfactory results have not yet been attained.

On the other hand, the use of an isocyanate-base adhesive has been proposed as an adhesive which is a non-formalin base and imparts excellent physical properties to the board in Japanese Patent Laid-Open Nos.

131538/1982 and 147567/1982, U.S. Patent Nos. 3557263, 3636199, 3870665, 3919017 and 3930110 and the like.

S

When a lignocellulose material is hot pressed using an organic polyisbcyanate as an adhesive, the adhesive 1. 0e sticks to a platen owing to its excellent adhesion, which a*.

impairs the pressed product, thereby causing a marked SaS* damage to the commodity value of the product and in addition, requires much labor to remove the deposit from

I

the platen.

The use of an additive to the organic polyisocyanate has therefore been studied in order to improve the releasability from the metal of the platen, thereby overcoming the above-described problem. For example, proposed as an additive to the organic polyisocyanate are an alkyl phosphate or pyrophosphate (Japanese Patent Publication No. 018068/1989), a sulfonated compound (Japanese Patent Publication No. 038309/1991), a wax and a liquid ester (Japanese Patent Publication No.

054390/1990), an aliphatic carboxylic acid (Japanese Patent Laid-Open No. 36430/1983), a polysiloxane compound (Japanese Patent Laid-Open No. 86205/1986), an aliphatic acid polymer Patent Nos. 4772442 and 4933232) and the like. But they have not yet bring about sufficient results.

In addition, proposed is a method of applying a releasing agent directly to a platen prior to hot pressing, which is effected by the formation of a release layer by using a metal soap (Japanese Patent Laid-Open No.

34026/1996), by using a high-boiling-point polyol (German u Patent No. 1653178), by using a polysiloxane film having e*e a functional group (European Patent No. 135992), by covering with polytetrafluoroethylene Patent No.

4374791) or the like. Such a method is not sufficient.

In some board plants, an organic polyisocyanate-base adhesive is used only for the inside layer which is not

V

9 o brought into contact with a platen and a conventional formalin base resin is used for the surface layer which is brought into contact with the platen.

In addition to the above-described methods, disclosed in Japanese Patent Laid-Open Nos. 30306/1985, 34026/19996 and 78049/1997) is a method in which a metallic salt of an aliphatic carboxylic acid is used in combination with an MDI adhesive for the production of a board. This method is however accompanied with the drawbacks such as inferior stability of the adhesive composition and pressing time which cannot be shortened. Accordingly, the method is not a sufficient solution which satisfies the object of the present invention.

The methods so far described are accompanied with various problems such as low solubility of a metallic salt of an aliphatic carboxylic acid, wax, alkyl phosphate or polysiloxane in an organic polyisocyanate and inferior releasability, so that they are not suited for use in the practical production site. At present, therefore, they are not satisfactory in anyone of the process, economy and physical properties.

An object of the present invention is to provide a novel adhesive and also a method for producing, at a low cost, a high-quality board which method overcomes the

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problems in the process and physical properties which could not been satisfied by prior method, and permits the S II production without depositing an organic polyisocyanate adhesive on a platen.

The present inventors have carried out an extensive investigation with a view to overcoming the above problems and as a result, found an adhesive, particularly an adhesive for a hot pressed board formed mainly of lignocellulose, a hot pressed board produced using said adhesive and production processes thereof.

It has been found that the use of a polyether polyol and/or polyester polyol containing in its molecule a nitrogen atom derived from an amine compound residue makes it possible to adjust the reactivity of the adhesion composition reduces pressing time and improves the dispersibility of the internal releasing agent when a specific metallic salt of a saturated or an unsaturated carboxylic acid is used as the internal releasing agent; and that because the above-described adjustment of the reactivity has a synergistic effect on the releasability, said adhesive is suited as an adhesive for a hot pressed board which does not deposit on a platen upon hot pressing and exhibits good productivity even if the using amount of the internal releasing agent is small, without using an 9* external releasing agent leading to the completion of the present invention.

SUMMARY OF THE INVENTION The present inventors have conducted an extensive investigation with a view to overcoming the above-described problems, leading to the completion of the invention. In the present invention, there is thus provided an adhesive which comprises an aqueous emulsion containing (A) an organic isocyanate compound and a polyether polyol and/or polyester polyol, said component being contained in an amount of 1 to 70 parts by weight relative to 100 parts by weight of said component and said polyether polyol and/or polyester polyol being an amine polyol which has a hydroxyl number of 24 to 800 mg KOH/g and contains in its molecule a nitrogen compound.

BRIEF DESCRIPTION OF THE PREFERRED EMBODIMENTS The present invention also embraces the following inventions and embodiments to An adhesive as described in wherein said 00.0 polyether polyol has been obtained by adding an alkylene oxide to one or more compounds selected from triethanolamine, diethanolamine, monoethanolamine, 0 orthotoluenediamine, metatoluenediamine, diphenylmethanediamine and 0 polyphenylpolymethylenepolyamine, said alkylene oxide containing an ethylene oxide in an amount of 5 to 70 parts by weight relative to 100 parts by weight of the polyether polyol.

I An adhesive as described in or wherein the organic isocyanate compound is polymethylene polyphenyl polyisocyanate.

An adhesive as described in any one of to wherein the polyether polyol and/or polyester polyol (B) contains a nitrogen atom in an amount of 0.1 to 12.0 wt.% based on the total weight; contains 2 to 8 functional groups; and has recurring units (-CH2CH2-O-) in an amount of 5 to 70 based on the weight of the component An adhesive as described in any one of to wherein the polyether polyol and/or polyester polyol is contained in an amount of 1 to 70 wt.% based on the organic isocyanate compound and further contained a metallic salt of a saturated and/or unsaturated aliphatic carboxylic acid having 8 to 28 carbon atoms is contained in an amount of 1 to 150 parts by weight relative to 100 parts by weight of the component An adhesive as described in wherein the a

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metallic salt of a saturated and/or unsaturated aliphatic carboxylic acid having 8 to 28 carbon atoms is an aqueous emulsion.

An adhesive as described in any one of to wherein the adhesive is an adhesive for lignocellulose.

A process for producing an adhesive as described in any one of to which comprises emulsifying water, the organic isocyanate compound and the polyether a. eg o polyol and/or polyester polyol A process for producing an adhesive as described in which further comprises mixing a metallic salt of a saturated and/or unsaturated aliphatic carboxylic acid having 8 to 28 carbon atoms.

A process for producing a pressed lignocellulose board, which comprises mixing an adhesive as described in any one of to with a lignocellulose material, and then subjecting the resulting mixture to hot pressing.

A pressed lignocellulose board obtained by the process according to An adhesive for a pressed lignocellulose board as described in any one of wherein the metallic salt (C) of a saturated and/or unsaturated aliphatic carboxylic acid having 8 to 28 carbon atoms is at least one salt selected from those composed of octylic acid, lauric acid, myristic acid, palmitic acid, stearic acid, oleic acid, linolic acid, linoleic acid, arachic acid, lignoceric acid or behenic acid; and zinc, iron, aluminum, calcium, zirconium, magnesium, barium, nickel, copper or cobalt.

The present invention will hereinafter be described more specifically.

0 The adhesive according to the present invention is comprised of an organic isocyanate compound, a polyether polyol and/or polyester polyol, and water; or comprised of an organic isocyanate compound, a polyether polyol and/or polyester polyol, water and a metallic salt of a saturated or unsaturated aliphatic carboxylic acid having 8 to 28 carbon atoms. The adhesive is particularly useful for a pressed lignocellulose board.

The pressed lignocellulose board in the present invention is obtained by applying, to a lignocellulose material,, an adhesive comprising an organic isocyanate compound, a polyether polyol and/or polyester polyol and water and optionally a metallic salt of a saturated or unsaturated aliphatic carboxylic acid having 8 to 28 carbon atoms and then subjecting the resulting material to hot press.

Examples of the lignocellulose material include strand chips, dust chips and flake chips which are used for the production of a particle board, wafer board or OSB; fibers used for hard board, MDF or insulation board; and agricultural products such as kaoliang stalk, bagasse and chaff. The above-exemplified materials can be used either singly or in combination.

As the organic isocyanate compound any substance having an isocyanate group can be used in the present invention. Specific examples include tolylene 4*40 diisocyanate, 4,4'-diphenylmethane diisocyanate, hexamethylene diisocyanate, xylene diisocyanate, isophorone diisocyanate, norbornene diisocyanate and polymethylene polyphenyl polyisocyanate (polymeric MDI), 44 and these isocyanate compounds modified with a compound having at least one active hydrogen. Among them, polymeric MDI is preferred from the economical viewpoint.

As the polyether polyol or polyester polyol usable in the present invention, those having 2 to 8 functional groups, having a hydroxyl number (OHv) of 24 to 800 mg KOH/g and containing in its molecule a nitrogen compound are preferred. In addition, a polyether polyol or polyester polyol contains 2 to 8 functional groups and has recurring units: -CH 2 -CH2-O- in an amount of 5 to 70 wt.%, more preferably 10 to 60 wt.% relative to the weight of the component Contents of the above-described ethylene oxide greater than 5% bring about good emulsifying property, while contents smaller than 70% bring about good compatibility.

The proportion of the nitrogen atom in the polyether polyol and/or polyester polyol is preferably 0.1 to 12.0 more preferably from 1.0 to 10.0 Proportions greater than 0.1 wt.% permit effective emulsification.

00 oe 0 When the proportion is smaller than 12.0 on the other hand, the reaction is appropriate and the adhesive produced easily.

The polyether polyol usable in the present invention is prepared by adding, in a conventional manner for the production of a polyol, an alkylene oxide having in its molecule an epoxy group such as ethylene oxide, propylene oxide, butylene oxide or styrene oxide to, as an initiator, a low-molecular compound having at least two active hydrogen atoms in the absence of a catalyst or presence of a catalyst such as a hydroxide of an alkali metal or a tertiary amine.

Examples of the initiator include amine initiators and non-amine initiators. Exemplary amine initiators include ethanolamines such as monoethanolamine, diethanolamine and triethanolamine and amines such as ethylenediamine, diethylenetriamine, orthotolylenediamine, metatolylenediamine, 4,4'-diphenylmethanediamine, 2,4'diphenylmethanediamine and polymethylpolyphenylpolyamine. They are used either singly or in combination.

Exemplary non-amine initiators include sucrose, alcohols such as glycerin, pentaerythritol, sorbitol, trimethylol propane, diglycerin, propylene glycol, S* dipropylene glycol, diethylene glycol, ethylene glycol, 1,4-butanediol and 1,2-butanediol, and phenols such as Shydroquinone, bisphenol A and novolak.

In the present invention, the above-exemplified amine initiators are preferred. It is also possible to use the amine initiator in combination with any one of the above-exemplified non-amine initiator.

SThe polyester polyol can be obtained by the addition

S*

i reaction between an acid anhydride and alcohol, polycondensation reaction between a polycarboxylic acid and an alcohol or the addition of an alkylene oxide to an acid.

Examples of the acid anhydride include maleic anhydride, succinic anhydride, trimellitic anhydride, pyromellitic anhydride, itaconic anhydride, phthalic anhydride, glutaric anhydride, glutaconic anhydride, diglycolic anhydride, citraconic anhydride, diphenic anhydride and toluylic anhydride. Examples of the polycarboxylic acid include maleic acid, terephthalic acid, dimethylterephthalic acid, isophthalic acid, fumaric acid, oxalic acid, malonic acid, glutaric acid, adipic acid, pimelic acid, suberic acid, azelaic acid, sebacic acid, citric acid and trimellitic acid.

Illustrative of the alcohol usable in the present invention include alcohols, phenols and alkylene oxide adducts exemplified above.

4* In the present invention, the metallic salt of a o e 4 saturated or unsaturated aliphatic carboxylic acid having 8 to 28 carbon atoms as the component can contain as its acid component any acid having mono-, di- or trifunctional groups. Among them, linear aliphatic monocarboxylic acids having 12 to 22 carbon atoms are preferred. Specific examples include octylic acid, lauric acid, myristic acid, palmitic acid, stearic acid, oleic 4 acid, linolic acid, linoleic acid, arachic acid, lignoceric acid and behenic acid. Examples of the metal component include zinc, iron, aluminum, calcium, zirconium, magnesium, barium, nickel, copper and cobalt. At least one acid component and at least one metal component, each selected from.the above-exemplified ones, can be used in combination. In other words, it is possible to use metallic salts of a carboxylic acid either singly or in combination, said salt being composed of an acid component selected from the group consisting of preferred carboxylic acids and a metal component selected from the group consisting of the above preferred metals.

Specific examples of the metallic salt include salts of zinc, iron, aluminum, calcium, zirconium, magnesium or barium with an aliphatic carboxylic acid such as octylic acid, lauric acid, myristic acid, palmitic acid, stearic acid, oleic acid or behenic acid. The aliphatic carboxylic acid may contain mono, di or tri functional groups, but linear aliphatic monocarboxylic acids having 12 to 22 carbon atoms are preferred.

The metallic salt of a saturated or unsaturated aliphatic carboxylic acid having 8 to 28 carbon atoms as the component may exist as is in the adhesive of the present invention. It may be added in the form of a metallic salt or added in the separate forms as an aliphatic carboxylic acid and a metal compound.

The metallic salt of a saturated or unsaturated aliphatic carboxylic acid having 8 to 28 carbon atoms as the component may be used in the form emulsified by an emulsifier as needed. Here, anyone of emulsifiers commonly used can be used. Specific examples include anionic surfactants such as aliphatic acid soap, rosin soap, alkyl sulfonate, alkylbenzene sulfonate, dialkylarylsulfonate, alkyl sulfosuccinate, polyoxyethylene alkyl sulfate and polyoxyethylene alkylarylsulfonate, surfactant such as polyoxyethylene alkyl ether, polyoxyethylene alkylaryl ether, polyoxyethylene sorbitan fatty acid ester, oxyethylene oxypropylene block copolymer. The present invention is not limited by the above-exemplified surfactants. These surfactants may be used either singly or in combination.

In addition, it is possible to use an emulsion stabilizer as needed. No particular limitation is imposed V a.

''seo* on the stabilizer insofar as it can stabilize the metallic

S**

salt of a saturated or unsaturated aliphatic carboxylic acid having 8 to 28 carbon atoms, the component or 0* Semulsified product thereof. Examples of the usable emulsion stabilizer include natural high-molecular compounds and synthetic high-molecular compounds permitting the formation of a protective colloid, such as gelatin, gum arabic, carboxymethyl cellulose and polyvinyl alcohol.

0o S e

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The metallic salt of a saturated or unsaturated aliphatic carboxylic acid having 8 to 28 carbon atoms as the component may be added to any one of an organic isocyanate compound, polyether polyol and water; or may be added to an adhesive composed of an organic isocyanate compound, polyether polyol and water.

Concerning the mixing ratio of the organic isocyanate compound with the polyether polyol and/or polyester polyol it is preferred that the active hydrogen equivalent is 0.02 to 1.2 per isocyanate equivalent of the organic polyisocyanate. Equivalents greater than 0.02 permit the conversion of the organic polyisocyanate into water, while those smaller than 1.2 impart the resulting board with good physical properties.

An adhesive for the production of a pressed lignocellulose board, which adhesive is comprised of (A) an organic isocyanate compound, a polyether polyol S" and/or polyester polyol, optionally a metallic salt of S S a saturated or unsaturated aliphatic carboxylic acid having 8 to 28 carbon atoms and water is prepared as follows.

In the present invention, no particular limitation is imposed on the water emulsifying method of the organic isocyanate compound and the mixing method of the Smetallic salt of a saturated or unsaturated aliphatic carboxylic acid having 8 to 28 carbon atoms. For- example, three components, that is, the organic isocyanate compound Is at the polyether polyol and/or polyester polyol and water may be mixed or emulsified at high velocity at the same time. It is also possible to add the polyether polyol and/or polyester polyol to water to dissolve the former in the latter and then mix the organic isocyanate compound with the resulting solution at high velocity to emulsify them; or to mix the polyether polyol and/or polyester polyol and the organic isocyanate compound and then add the resulting mixture in water while stirring at high velocity to emulsify them.

It is also possible to mix the four components, that is, the organic isocyanate compound the polyether polyol and/or polyester polyol the metallic salt (C) of a saturated or unsaturated aliphatic carboxylic acid having 8 to 28 carbon atoms and water at the same time at 9* high velocity, thereby emulsifying them; to disperse the metallic salt of a saturated or unsaturated aliphatic carboxylic acid having 8 to 28 carbon atoms in water in advance, add the polyether polyol and/or polyester polyol to the resulting dispersion to dissolve the former in the latter, and then mix the organic isocyanate compound with the resulting solution at high velocity, thereby emulsifying them; to mix the polyether polyol and/or polyester polyol with the metallic salt of a Ssaturated or unsaturated aliphatic carboxylic acid having 8 to 28 carbon atoms, mix the resulting mixture with water, and then add the organic isocyanate compound to the resulting mixture while stirring at high velocity, thereby emulsifying them; to add the metallic salt of a saturated or unsaturated aliphatic carboxylic acid having 8 to 28 carbon atoms to the organic isocyanate compound add the resulting mixture to a mixture of water and the polyether polyol and/or polyester polyol thereby emulsifying them; to mix the polyether polyol and/or polyester polyol the organic isocyanate compound (A) and the metallic salt of a saturated or unsaturated aliphatic carboxylic acid having 8 to 28 carbon atoms and to add the resulting mixture to water while stirring at high velocity, thereby emulsifying them; or to dissolve the polyether polyol and/or polyester polyol in water, mix the resulting solution with the organic isocyanate compound and emulsify them, and then mix the resulting emulsion with the metallic salt of a saturated or unsaturated aliphatic carboxylic acid having 8 to 28 carbon atoms.

It is possible to add a surfactant and/or emulsion stabilizer in each step within an extent not impairing the object of the present invention. No particular limitation is imposed on the mixing manner. Either batch system or continuous system can be employed. For mixing, a homogenizer, static mixer or the like can be used.

SThe amount c water to be used differs with -the water content of the lignocellulose material. Water may be added in an amount permitting the uniform mixing of an adhesive with the lignocellulose material. Preferred is 1 to 300 wt.% of the amount of the adhesive.

The polyether polyol and/or polyester polyol is added in an amount ranging from 1 to 70 parts by weight, preferably 5 to 50 parts by weight, per 100 parts by weight of the organic isocyanate compound Amounts greater than 1 part by weight permit the provision of a stabile water emulsion, while those smaller than 70 parts by weight impart the resulting board with good physical properties.

The using ratio of the aqueous emulsion comprised of the organic isocyanate compound and the polyether polyol and/or polyester polyol to the lignocellulose material preferably falls within a range of from 2:100 to 30:100, more preferably from 3:100 to 20:100 in terms of the weight ratio of the effective ingredients of the

SC

components and to the lignocellulose material. When

C

the amount of the effective ingredient is greater than 2 parts by weight per 100 parts by weight of the lignocellulose material, the resulting adhesive serve as an adhesive. When the amount of the effective ingredients is smaller than 30 parts by weight, on the other hand, the resulting board have sufficient physical properties.

In the present invention, the metallic salt of a saturated or unsaturated aliphatic carboxylic acid having 8 to 28 carbon atoms is used preferably in an amount of 1 to 150 parts by weight per 100 parts by weight of the polyether polyol and/or polyester polyol with 5 to parts by weight being more preferred. When the amount of the component is greater than 1 part by weight, the resulting adhesive exert sufficient releasing effects and does not tend to deposit on a platen upon hot pressing. When the amount is smaller than 150 parts by weight, sufficient releasability is obtained.

In the present invention, it is desired that a lignocellulose material is uniformly mixed with an adhesive comprised of an organic isocyanate compound a polyether polyol and/or polyester polyol and water and optionally a metallic salt of a saturated or unsaturated aliphatic carboxylic acid having 8 to 28 carbon atoms by spraying the adhesive into a blender or by using a similar apparatus. If necessary, the adhesive may be diluted with a solvent or water into a solution. From the viewpoint of economy and safety, the adhesive in the aqueous solution form is preferred.

In the production process of the pressed lignocellulose board according to the present invention, the mixture. of the adhesive and the lignocellulose material is subjected to hot pressing after formed into a mat. The mixture can be formed into a mat composed of a single layer e or plural layers. After forming but prior to hot pressing, the mixture formed into a mat may be subjected to prepressing; The content of the adhesive may be changed according to need. Pre-pressing can be carried out after lamination or prior to lamination according to need. At this time, it is possible to form the mat with plural layers by using the adhesive of the present invention only for the outer layer contiguous with a platen and another adhesive, which is inferior in releasability, for the inner layer.

Described specifically, it is possible to form as the outermost layer a lignocellulose layer containing the adhesive of the present invention and as the inner layer also the lignocellulose layer containing the adhesive of the present invention or a lignocellulose layer containing another adhesive. The inner lignocellulose layer may be composed of a single layer or plural layers. According to need, pre-pressing can be carried out after lamination or prior to lamination.

The lignocellulose layer containing the adhesive of the present invention as the outermost layer can be formed at the time when the mixture of the adhesive and the lignocellulose material is formed into a mat.

Alternatively, it is possible to form a lignocellulose layer containing the adhesive of the present invention on a bottom platen, stack a lignocellulose layer containing another adhesive over the first layer and then, stack 06 0 another lignocellulose layer containing the adhesive of the present invention over the second layer. These three layers can be formed at the same time.

In order to allow heat penetrate into the materials to be pressed, either hot pressing with flat platens or curved platens can be employed. From the viewpoint of the continuous productivity and low cost, pressing with flat platens is preferred. The hot pressing may be carried out in a continuous or multi-stage manner.

According to need, it is also possible to apply an external releasing agent to a portion which is bought into contact with the adhesive of the present invention upon pressing into a board, such as press platen.

It is particularly effective when no internal releasing agent is used. Releasability can also be improved by using the external releasing agent in combination with As external releasing agent, those used generally for molding or forming, particularly those used upon reaction injection molding of urethane and injection molding of 6* general purpous thermoplastic resin.

f6.o Specific examples include fluorine containing releasing agent such as fluorine compound containing wax, fluorine containing surfactant, fluorine containing hydrocarbon oligomer wax; hydrocarbon or its derivative containing releasing agent such as hydrocarbon wax, polyethylene wax; carnaba wax, montan wax; silicon containing wax such as polysiloxane, polysiloxane -e -r a oligomer.

After hot pressing, the surface of the outermost layer of the board may be subjected to polished finish into a desired thickness.

The lignocellulose layer removed by polishing can be used again as a lignocellulose material after sufficiently loosened.

In the present invention, it is possible to use in combination an antioxidant, ultraviolet absorber, plasticizer, silane coupling agent, POVAL, metal catalyst, external releasing agent, synthetic rubber latex and/or acrylic emulsion within an extent not impairing the intended advantages of the present invention.

Examples The present invention will hereinafter be described in further detail by examples. It should however be borne in mind that the present invention is not limited to or by these examples. Evaluation results of Examples and a. Comparative Examples are shown below in Tables 1 to 2. All designations of "part" or "parts" and mean part or parts by weight and wt.% unless otherwise specifically indicated.

The conditions common to the production of a board employed in the comparison of performances are shown below: Raw material: dust chips or lignified fibers (water ai content: which will hereinafter be called "chips") Composition of the board: single layer (dust chips) or three layers (lignified fibers) Thickness of the board (except the polished portion): mm Water content of the mat: 16% Hot pressing temperature: 180°C Pressing pressure: 35 kg/cm 2 Pressing time: 2.5 min Set density: 700 kg/m 3 Evaluation Test 1. Dry Flexural strength The pressed sample was cut into a test piece of mm wide and 275 mm long (spun: 225 mm) and a flexural test was conducted in accordance with "Particle board JIS-A- 5908". The results are shown as bending strength.

2. Wet flexural strength (Test A) As in the above method, a test piece was cut out from the pressed sample. The test piece was then immersed in warm water of 70+3 0 C for 2 hours, and then in water of the normal temperature for one hour. The flexural test of the test piece was conducted without drying. The results are indicated as wet flexural strength.

3. Wet flexural strength (Test B) "As in the above method, a test piece was cut out from the pressed sample. The test piece was then immersed in boiling water for 2 hours, and then in water of the normal temperature for one hour. The flexural test of the test I, I piece was conducted without drying. The results are indicated as wet flexural strength.

4. Releasability test The adhesion condition of chips to a steel-made platen was visually observed after hot pressing. That operation was repeated 30 times at the maximum and the number of times until the adhesion was confirmed was recorded.

Synthetic judgment The production ease and physical properties of a pressed board were judged synthetically. They were judged by the following four ranks: 0: A board can be produced without problems and physical properties are good.

A: A board can be produced but physical properties are not good.

X: A board can be produced but is accompanied with the problems such as emission of odor.

XX: A board cannot be produced.

Example 1 e !In an SUS autoclave, 60 g (1 mole) of ethylenediamine (EDA) as initiator were charged, followed by purging with nitrogen. Then, 504 g (9 moles) of propylene oxide (PO) were charged and they were reacted at 110°C for 4 hours.

After degassing, 0.3 g of KOH as a catalyst followed by purging with nitrogen and KOH was solved at 90 110 0 C and 396 g (9 mole) of ethylene oxide (EO) were added, followed by the reaction at 110 0 C for 4 hours. The polyol so obtained was purified in a manner known per se in the art, whereby a propylene oxide (PO)/ethylene oxide block copolymer PPG (ethylene oxide content: 43%, hydroxyl number: 230 mg KOH/g) was obtained.

In water, 14.8 parts of- the polyether polyol so obtained were dissolved in 117 parts of water. To the resulting solution, 59.2 parts of polymeric MDI ("Cosmonate M-200", trade name; product of Mitsui Toatsu Chemicals Inc.) were charged under high-speed stirring to emulsify them. Five minutes later, the resulting aqueous emulsion was spray-coated to 820 parts of dust chips in a blender through a spray gun.

On a steel-made platen which had been coated with a fluorine surfactant ("Moldspat W823", trade name; product *9 *b of Asahi Glass Co., Ltd.), as an external releasing agent, and dried, the emulsion-sprayed dust chips followed by blending with blender, the obtained mixture were placed and formed uniformly into a 30 cm x 30 cm square, followed by covering with another steel-made platen coated with the same external releasing agent. Under the above-described conditions, hot pressing was carried out. It took minutes from the beginning of emulsification to the S* beginning of hot pressing. After hot pressing, the adhesion condition to the steel-made platen was observed but no adhesion was observed. The hot-pressed board was provided for use in the measurement of physical properties. Even after the above operation for producing a pressed board was repeated 50 times with the same platen, no deposit was observed on the steel-made platen.

Example 2 In a similar manner to Example 1 except for the use of a polyether polyol having a hydroxyl number of 447 mg KOH/g which was prepared by changing PO/EO ratio 4 mol, a pressed board was obtained. Even after the operation for producing a pressed board was repeated 50 times, no deposit was observed on the steel-made platen.

Example 3 In a similar manner to Example 1 except for the use of a polyol (ethylene oxide content: 50%, hydroxyl number: 452 mg KOH/g) obtained using as an initiator a 5:1 (molar ratio) mixture of orthotoluenediamine (OTD) and glycerin

C

a pressed board was obtained. Even after the operation for producing a pressed board was repeated 50 times, no dep it was observed on the steel-made platen.

Example 4 In a similar manner to Example 1 except for the use of a polyether polyol (ethylene oxide content: hydroxyl number: 449 mg KOH/g) obtained using as an initiator metatoluenediamine (MTD), a pressed board was obtained. Even after the operation for producing a pressed LII=ILe~board was repeated 50 times, no deposit was observed on the steel-made platen.

Example In a similar manner to Example 1 except for the use of a polyol (ethylene oxide content: 40%, hydroxyl number: 452 mg KOH/g).obtained using as an initiator 4,4'diphenylmethanediamine (MDA),'a pressed board was obtained. Even after the operation for producing a pressed board was repeated 50 times, no deposit was observed on the steel-made platen.

Example 6 In a similar manner to Example 1 except for the use of a polyether polyol (ethylene oxide content: hydroxyl number: 280 mg KOH/g) obtained using as an initiator orthotoluenediamine (OTD), a pressed board was obtained. Even after the operation for producing a pressed 99 board was repeated 50 times, no deposit was observed on the steel-made platen.

*o *9 Example 7 In a similar manner to Example 1 except for the use of a polyether polyol (ethylene oxide content: hydroxyl number: 280 mg KOH/g) obtained using as an h initiator monoethanolamine (MEOA), a pressed board was obtained. Even after the operation for producing a pressed board was repeated 50 times, no deposit was observed on the steel-made platen.

Example 8 In a similar manner to Example except for the use of a polyether polyol (ethylene oxide content: hydroxyl number: 713 mg KOH/g) obtained using as an initiator triethanolamine (TEOA), a pressed board was obtained. Even after the opexation for producing a pressed board was repeated 50 times, no'deposit was observed on the steel-made platen.

Example 9 In a similar manner to Example 1 except for the use of a polyether polyol (ethylene oxide content: hydroxyl number: 280 mg KOH/g) obtained using as an initiator a 1:1 (molar ratio) mixture of orthotoluenediamine (OTD) and monoethanolamine (MEOA', a pressed board was obtained. Even after the operation for producing a pressed board was repeated 50 times, no deposit was observed on the steel-made platen.

Example *0 In a similar manner to Example 1 except for the use of a polyester polyol which had been synthesized by esterifying 17.4 parts of the polyol used in Example 1 with 2.5 parts of phthalic anhydride at 220 0 C for 15 hours, a pressed board was obtained. Even after the operation for producing a pressed board was repeated 50 times, no deposit S was observed on the steel-made platen.

Example 11 In a similar manner to Example 1 except that the amounts of the propylene oxide/ethylene oxide block copolymer PPG (ethylene oxide amount: 40%, hydroxyl number: 252 mg KOH/g), which had been obtained by using as an initiator ethylenediamine, as a polyether polyol and polymeric MDI.were changed to 17.8 parts and 71.1 parts, respectively; lignified fibers were used instead of dust chips; and the pressed bc .rd was formed to have three layers in which the resin content of the surface layer was 8% and the core layer was 4% and the forming ratio of the surface layer, core layer and surface layer was 25:50:25 an MDF was prepared. Even after the operation for producing a pressed board was repeated 50 times, no deposit was observed on the steel-made platen.

99*e Example 12 In a similar manner to Example 11 except for the use of a polyether polyol having a hydroxyl number of 450 mg KOH/g, an MDF was formed. Even after the operation for producing a pressed board was repeated 50 times, no deposit was observed on the steel-made platen.

Example 13 In a similar manner to Example 11 except for the use of a polyether polyol (ethylene oxide content: hydroxyl number: 452 mg KOH/g) obtained by using as an initiator a 5:1 (molar ratio) mixture of orthotoluenediamine (OTD) and glycerin an MDF was formed. Even after the operation for producing a pressed board was repeated 50 times, no deposit was observed on the steel-made platen.

Example 14 In a similar manner to Example 11 except for the use of a polyether polyol (ethylene oxide content: hydroxyl number: 449 mg KOH/g) obtained using as an initiator metatoluenediamine (MTD), an MDF was formed.

Even after the operation for producing a pressed board was repeated 50 times, no deposit was observed on the steel-made platen.

Example In a similar manner to Example 11 except for the use of a polyether polyol (ethylene oxide content: hydroxyl number: 452 mg KOH/g) obtained using as an initiator 4,4'-diphenylmethanediamine (MDA), an MDF was formed. Even after the operation for producing a pressed board was repeated 50 times, no deposit was observed on the steel-made platen.

Example 16 In a similar manner to Example 11 except for the use of a polyether polyol (ethylene oxide content: hydroxyl number: 280 mg KOH/g) obtained by using as an eC initiator orthotoluenediamine (OTD), an MDF was formed.

Even after the operation for producing a pressed board was repeated 50 times, no deposit was observed on the steel-made platen.

Example 17 In a similar manner to Example 11 except for the use of a polyether polyol (ethylene oxide content: hydroxyl number: 280 mg KOH/g) obtained by using as an initiator monoethanolamine (MEOA), an MDF was formed. Even after the operation for producing a pressed board was repeated 50 times, no deposit was observed on the steel-made platen.

Example 18 In a similar manner to Example 11 except for the use of a polyether polyol (ethylene oxide content: hydroxyl number: 713 mg KOH/g) obtained by using as an oo initiator triethanolamine (TEOA), an MDF was formed. Even after the operation for prodiucing a pressed board was repeated 50 times, no deposit was observed on the steel-made platen.

Example 19 In a similar manner to Example 11 except for the use of a polyether polyol (ethylene oxide content: hydroxyl number: 280 mg KOH/g) obtained by using as an initiator a 1:1 (molar ratio) mixture of orthotoluenediamine (OTD) and monoethanolamine (MEOA), an MDF was formed. Even after the operation for producing a pressed board was repeated 50 times, no deposit was-observed on the steel-made platen.

Comparative Example 1 In a similar manner to Example 1 except for the use of a polyether polyol (ethylene oxide content: hydroxyl number: 450 mg KOH/g) obtained by using as an initiator glycerin, the emulsion-coated dust chips so obtained were pressed into a board. Under those conditions, however, the dust chips so pressed did not solidify and with the removal of the pressing pressure, the board collapsed noisily. It was therefore impossible to conduct evaluation of the physical properties of the pressed board.

Comparative Example 2 In a similar manner to Example 1 except that a polyether polyol (ethylene oxide content: 40%, hydroxyl r number: 450 mg KOH/g) obtained using as an initiator glycerin was used instead and 1.0 part of triethylenediamine (TEDA) was used as an urethanating catalyst upon emulsification, the dust chips so coated were pressed into a board. Five minutes after emulsification, however, the emulsion foamed and thickened. After hot pressing, the pressed board so obtained was not uniform and *e partially chipped so that it had an uneven surface. It was therefore impossible to carry out evaluation of the physical properties of the board. It has been found from the above result that when an amine catalyst was used in a pressed product so obtained was not satisfactory.

Comparative Example 3 In a similar manner to Example 1 except that a polyol (ethylene oxide content: 40%, hydroxyl number: 450 mg KOH/g) obtained using as an initiator glycerin was used instead and 0.5 part of triethylenediamine was used as an urethanating catalyst upon emulsification, the dust chips so coated were pressed into a board. Five minutes after emulsification, no appare;; change occurred in the emulsion and it was subjected to hot pressing. During hot pressing or after hot pressing, however, the resulting board emitted an amine odor presumably derived from the catalyst, which lowered the commodity value and also worsened the working environment.

Comparative Example 4 In a similar manner to Example 1 except for the use of an aqueous emulsion type adhesive, which had been t o obtained by emulsifying a self-emulsifying type polymeric MDI ("UR-4000", trade name; product of Mitsui Toatsu Chemical Inc.) in water while high-speed stirring, instead of the aqueous emulsion type adhesive obtained from polymeric MDI and the polyether polyol, a pressed board was *o 0 *00. obtained. It has been understood that the pressed product had good physical properties but inferior to that obtained S. in Example 1.

Comparative Example A polyether polyol (containing nitrogen atoms in an amount of 18.9%) having a hydroxyl number of 1516 mg KOH/g I~ I was treated as in Example 1. Upon preparation of the adhesive, however, the adhesive composition foamed and a portion of it precipitated so that it was impossible to apply it to the dust chips. Accordingly, the subsequent operation for the production of a pressed board was not carried out.

Example In 117 parts of water were added 14.8 parts of a propylene oxide/ethylene oxide block copolymer PPG (ethylene oxide content: 43%, hydroxyl number: 230 mg KOH/g) obtained employing as an initiator ethylenediamine (EDA) which had been used in Example 1, and 6.0 parts of zinc stearate (St-Zn) as an internal releasing agent. In the resulting mixture, 59.2 parts of polymeric MDI ("Cosmonate M-200", trade name; product of Mitsui Toatsu Chemicals Inc.) were charged under high-speed stirring, .9 .o o0 whereby they were emulsified. Five minutes later, the aqueous emulsion so obtained was spray coated to 820 parts of dust chips in a blender by a spray gun. On a dried steel-made platen, dust chips coated with the aqueous .9°9 emulsion were placed and formed uniformly into a 30 cm x cm square, followed by covering with another steel-made platen. The dust chips so coated were hot pressed under the above-described conditions. It took 20 minutes from the beginning of emulsification to the beginning of hot pressing. After hot pressing, the adhesion condition to the steel-made platen was observed but no deposit was observed. The board after hot pressing was used for the comparison of physical properties. Even after the above operation for producing a pressed board was repeated times by using the same platen, no deposit was observed on the steel-made platen.

The present example used component as a internal releasing agent, the releasability of a board and an adhesive was excellent without using an external releasing agent. The similar results were shown in examples 22 to 38.

Example 21 In a similar manner to Example 20 except for the use of a polyether polyol having a hydroxyl number of 450 mg KOH/g, a pressed board was obtained. Even after the operation for producing a pressed board was repeated times, no deposit was observed on the steel-made platen.

Lxample 22 In a similar manner to Example 20 except for the use of a polyether polyol (ethylene oxide content: o* *hydroxyl number: 447 mg KOH/g) obtained using as an initiator metatoluenediamine (MTD), a pressed board was i obtained. Even after the operation for producing a pressed was repeated 50 times, no deposit was observed on the steel-made platen.

Example 23 ii In a similar manner to Example 20 except for the use of a polyether polyol (ethylene oxide content: hydroxyl number: 452 mg KOH/g) obtained using as an initiator a 5:1 (molar ratio) mixture of orthotoluenediamine (OTD) and glycerin a pressed board was obtained.. Even after the operation for producing a pressed board was repeated 50 times, no deposit was observed on the steel-made platen.

Example 24 In a similar manner to Example 20 except for the use of a polyether polyol (ethylene oxide content: hydroxyl number: 255 mg KOH/g) obtained using as an initiator metatoluenediamine (MTD) a pressed board was obtained. Even after the operation for producing a pressed board was repeated 50 times, no deposit was observed on the steel-made platen.

Example In a similar manner to Example 20 except for the use of a polyether polyol (ethylene oxide content: hydroxyl number: 452 mg KOH/g) obtained using as an initiator 4,4'-diphenylmethanediamine (MDA), a pressed board was obtained. Even after the operation for producing a pressed board was repeated 50 times, no deposit was observed on the steel-made platen.

Example 26 In a similar manner to Example 20 except for the use of a polyether polyol (ethylene oxide content: hydroxyl number: 280 mg KOH/g) obtained using as an initiator orthotoluenediamine (OTD), a pressed board was obtained. Even after the operation for producing a pressed board was repeated 50 times, no deposit was observed on the steel-made platen.

Example 27 In a similar manner to Example 20 except for the use of a polyether polyol (ethylene oxide content: hydroxyl number: 713 mg KOH/g) obtained using as an initiator triethanolamine (TEOA), a pressed board was obtained. Even after the operation for producing a pressed board was repeated 50 times, no deposit was observed on the steel-made platen.

•Example 28 In a similar manner to Example 20 except for the use *e of a polyether polyol (ethylene oxide content: hydroxyl number: 280 mg KOH/g) obtained using as an o' initiator a 1:1 (molar ratio) mixture of orthotoluenediamine (OTD) and monoethanolamine (MEOA), a pressed board was obtained. Even after the operation for producing a pressed board was repeated 50 times, no deposit 0. was observed on the steel-made platen.

Example 29 In a similar manner to Example 20 except for the use of a polyester polyol synthesized by esterifying 17.4 parts of the polyol used in Example 1 with 2.5 parts of phthalic anhydride at 220 0 C for 15 hours, a pressed board was obtained. Even after the operation for producing a pressed board was repeated 50 times, no deposit was observed on the steel-made platen.

Example A propylene oxide/ethylene oxide block copolymer PPG (ethylene oxide content: 43%, hydroxyl number: 230 mg KOH/g) used in Example 1 and 6.0 parts of zinc stearate (St-Zn) as an internal releasing agent were emulsified in 3 times the amount of water by using a nonionic surfactant.

In a similar manner to Example 20 except that the polyol so obtained was used in an amount of 17.8 parts, polymeric MDI was used in an amount of 71.1 parts, ligrified fibers were used instead of dust chips, and a pressed board was formed to have three layers in which the content of the resin of the surface layer was 8% to and the core layer was 4% and the forming ratio of the surface layer, core layer and surface layer was 25:50:25 an MDF was produced. Even after the operation for producing a pressed board was @0 .repeated 50 times, no deposit was observed on the steel-made platen.

*0 Example 31 In a similar manner to Example 30 except for the use of a polyether polyol having a hydroxyl number of 450 mg KOH/g, an MDF was obtained. Even after that operation for producing a pressed board was repeated 50 times, no deposit was observed on the steel-made platen.

Example 32 In a similar manner to Example 30 except for the use of a polyether polyol (ethylene oxide content: hydroxyl number: 447 mg KOH/g) obtained using as an initiator metatoluenediamine (MTD), an MDF was produced.

Even after the above operation for producing a pressed board was repeated 50 times, no deposit was observed on the steel-made platen.

Example 33 In a similar manner to Example 30 except for the use of a polyether polyol (ethylene oxide content: hydroxyl number: 452 mg KOH/g) obtained using as an "0 initiator a 5:1 (molar ratio) mixture of orthotoluenediamine (OTD)/glycerin an MDF was formed.

Even after the above operation for producing a pressed board was repeated 50 times, no deposit was observed on the steel-made platen.

Example 34 In a similar manner to Example 30 except for the use of a polyether polyol (ethylene oxide content: he

S.

hydroxyl number: 255 mg KOH/g) obtained using as an initiator metatoluenediamine (MTD) an MDF was formed. Even after the operation for producing an MDF was repeated times, no deposit was observed on the steel-made platen.

Example In a similar manner to Example 30 except for the use of a polyether polyol (ethylene oxide content: hydroxyl number: 452 mg KOH/g) obtained using as an initiator 4,4'-diphenylmethanediamine (MDA), an MDF was produced. Even after the above operation for producing a pressed board was repeated 50 times, no deposit was observed on the steel-made platen.

Example 36 In a similar manner to Example 30 except for the use of a polyether polyol (ethylene oxide content: hydroxyl number: 280 mg KOH/g) obtained using as an initiator orthotoluenediamine(OTD), an MDF was formed.

Even after the above operation for producing a pressed board 0" was repeated 50 times, no deposit was observed on the 4 steel-made platen.

44 Example 37 In a similar manner to Example 30 except for the use of a polyether polyol (ethylene oxide content: 6 hydroxyl number: 713 mg KOH/g) obtained using as an initiator triethanolamine (TEOA), an MDF was formed. Even after the above operation for producing an MDF was repeated r 50 times, no deposit was observed on the steel-made platen.

Example 38 In a similar manner to Example 30 except for the use of a polyether polyol (ethylene oxide content: i I hydroxyl number: 280 mg KOH/g) obtained using as an initiator a 1:1 (molar ratio) mixture of orthotoluenediamine (OTD)/monoethanolamine (MEOA), an MDF was produced. Even after the above operation for producing a pressed board was repeated 50 times, no deposit was observed on the steel-made platen.

Throughout the description -and claims of the specification g the word "comprise" and variations of the word, such as "comprising" and "comprises" is not intended to exclude *other additives, components, integers or steps.

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Lignocellulose Material Isocyanate Polyol or Polyester Water Releasing Agent Catalyst Kind Parts Water Kind Parts Initiator Hydroxyl Nitrogen EO Content Parts Parts External Internal Kind Content Number Content, (mg KOH/g) (wt. (Wt. Kind Kind (Amount) Example 1 Dust Chip820 M-2 00 59. 2 EDA 230 3. 1 43 14. 8 117 Fluorine-- Example 2 Dust Chip820 M-2 00 59. 2 EDA 450 5. 5 50 14. 8 117 Fluorine Example 3 Dust Chip 8 2 0 M-2 00 59 2 OTD/G 452 4. 9 50 14. 8 117 Fluorine-. Example 4 Dust Chip820 M-200 59. 2 MTD 449 5. 6 40 14. 8 117 Fluorine Example 5 Dust Chip820 M-2 0 0 59. 2 MDA 452 5. 6 40 14. 8 117 Fluorine----- Example 6 Dust Chip 8 2 0 M-2200 59. 2 OTD 280 3. 5 40 14. 8 1.17 Fluorine Example 7 Dust Chip820 M-2 0 0 59. 2 MEOA 280 3. 1 60 14. 8 117 Fluorine---- Example 8 Dust Chip820 M-2 00 59. 2 TEOA 713 11. 9 40 14. 8 117 Fluorine--- Example 9 Dust Chip 8 2 0 M-2 00 59. 2 OTDMEOA 2 8 0 3. 3 45 14. 8 117 Fluorine----- Example 10 Dust Chip820 M-2 00 59. 2 Ester 180 2. 7 35 17. 4 11 7 Fluorine Example 11 Lignified ber820 M-2 00 71. 1 EDA 230 3. 1 43 17. 8 117 Fluorine Example 12 U4nfied Fiber8 2 0 M-2 00 71. 1 EDA 450 5. 5 50 17. 8 117 Fluorine Example 13 LignifiedFiber8 2 0 M-2 00 71. 1 OTD IG 452 4. 9 50 17. 8 117 Fluorine Example 14 ugnifiedber8 2 0 M-2 00 71. 1 MTD 449 5. 6 40 17. 8 117 Fluorine Example 15 LUgified iber8 20 M-2 00 71. 1 MDA 452. 5. 6 40 17. 8 117 Fluorine------ Example 16 TU£nifiedPiber8 2 0 M-2 00 71. 1 OTD 280 0 3. 5 40 17. 8 117 Fluorine Example 17 gnifiedFiber 8 2 0 M-2 00 71. 1 MEOA 28 0 3. 1 60 17. 8 117 Fluorine Example 18 ignified Fber 8 2 0 M-2 00 71. 1 TEOA 713 11. 9 40 17. 8 117 Fluorine Example 19 lignifiedFiber8 2 0 M-2 00 71. 1 OTD/MEOA 2 8 0 3. 3 45 17. 8 17 Fluorine- Comp. Ex. 1 DustChip820 M-200 59. 2 G 450 0. 0 40 14. 8 1 1 7 Fluorine Comp. Ex. 2 Dust Chip 8 20 M-2 00 59. 2 G 450 0. 0 40 14. 8 117 Fluorine-- TEDALO Comp. Ex. 3 Dust Chip 8 20 M-2 00 59. 2 G 450 0 0 40 14. 8 17 Fluorine-- Comp. Ex. 4 Dust Chip 8 2 0 UR-4000 74. 0 1 17 Fluorine____ Comp. Ex. 5 Dust Chip 8 20 M-2 00 59. 2 EDA 1516 18. 9 40 14. 8 117 Fluorine----- Cs S .ce a.

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c e 0 be *ce *eo* c Ce s I x Table 2 Lignocellulose Material Isocyanate Polyol or Polyester Water Releasing Agent Catalyst Kind Parts Water Kind Parts Initoator Hydroxyl Nitrogen EO Content Parts Parts External Internal Kind Content Number Content (mg KOH/g) (wt. (wt. Kind Kind z (Amount) Example 20 Dust Chip 8 2 0 M-2 0 0 59. 2 EDA 2 3 0 3. 1 43 14. 8 117 St-Zn 6 Example 21 Dust Chip 8 2 0 M-2 200 59. 2 EDA 4 5 0 5. 5 50 14. 8 117 st-Zn 6 Example22 Dust Chip820 M-2 0 5 9. 2 ITD 447 5. 5 40 14. 8 117 St-Zn 6 Example 23 Dust Chip 8 2 0 M-200 59. 2 OTD/G 452 4. 9 50 14. 8 117 StZn 6 Example 24 Dust Chip 8 2 0 M-2 0 0 59. 2 MTD 25 5 3. 2 40 14. 8 117 St-Z 6-- Example 25 Dust Chip 8 2 0 M-2 0 0 59. 2 MDA 4 5 2 5. 6 40 14. 8 117 St-Zn 6 Example 2 6 Dust Chip 8 2 0 M-2 0 0 59. 2 OTD 28 0 3. 5 40 14. 8 117 StZn 6 Example 27 Dust Chip 8 2 0 M-2 00 5 9. 2 TEOA 7 1 3 11. 9 40 14. 8 117 St-Zn 6 Example 28 Dust Chip 8 2 0 M-2 0 0 59. 2 OTD/HEOA 2 8 0 3. 3 4 5 1 4 8 1 1 7 St-Zn 6 Example 29 DustChip 8 2 0 M-2 0 0 59. 2 Ester 180 2. 7 35 17. 4 1 17 St-Zn 6 Example 30 Lifieda Fiber 8 2 0 M-2 0 0 7 1. 1 EDA 2 3 0 3. 1 43 17. 8 1 7 St-Zn 6 Example 31 Ligified iber 8 2 0 M- 200 71. 1 EDA 4 5 0 5. 5 50 17. 8 117 St-Zn 6 Example 32 Llgnifiediber 8 2 0 M-2 0 0 71. 1 H TD 447 5. 5 40 17. 8 1 17 St-Zn 6 Example 33 LUjified Fiber 8 2 0 M- 200 71. 1 OTD IG 452 4. 9 50 17. 8 1 17 St-Zn 6 Examplea34 ignifiedFiber820 M-200 71. 1 MTD 255 5. 6 40 17. 8 117 St-Zn 6 Example 35 Lgpified Fiber 8 2 0 M-2 0 0 7 1. 1 MDA 4 5 2 5. 6 40 17. 8 11 7 St-Zn 6 Example 36 LignifiedFiber 8 2 0 M-2 0 0 7 1. 1 OTD 2 8 0 3. 5 40 17. 8 1 1 7 St-Zn 6 Example 37 LinifiedFiber 8 2 0 M-2 0 7 1. 1 TEOA 7 1 3 11. 9 40 17. 8 1 17 St-Zn 6 Example38 LigifiedFiber 8 2 0 M-2 0 0 7 1. 1 OTDAMEOA 2 8 0 3. 3 45 17. 8 117 St-Za 6 0*e

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S S S.C S S US U .5* .e S *O S Table 3 Density Water Dry Flexural Wet Flexural Wet Flexura. Peel elasable Snhei Content Strength Strength A Strength B Srreqenc Odoteti /m 3 Nm 2 Nm 2 Nm 2 /ren 2 Tmeqny Oo Judgment Example 1 0. 692 8. 8 26. 2 19. 6 15. 6 0. 56, >50 None 0 Example 2 0. 7 01 8. 9 27. 1 19. 2 15. 7 0. 54 >560 None 0 Example 3 0. 69 1 9. 0 23. 2 18. 2 15. 0 0. 49 50 N~one 0 Example 4 0. 70 1 9. 0 26. 3 19. 0 16. 0 0. 52 0 None Example 5 0. 689 8. 9 26. 1 19. 0 16. -3 50 50 None Q Example 6 0. 701 8. 9 26. 2 16. 9 13. 5 0. 48 50 None 0 Example 7 0. 695 8. 9 24. 2 17. 1 12. 6- 0. 47 50 None0 Exml8 0. 699 8. 9 23. 9 16. 9 12. 8 0. 50 50 None 0 Example 9 0. 7 07 9. 0 23. 2 19. 0 1 3. 8 0. 51 >5 0 None0 ExamplelO0 0. 721 8. 8 23. 9 18. 2 14 .5 5 oe0 Example 11 0. 689 8. 9 43. 2 21. 0 18. 5 0. 49 50 N~one 0 Examplel12 0. 704 7. 8 46. 4 22. 3 19. 1 0. 72 50 None 0 Example 13 0. 695 7. 7 42. 9 22. 0 18. 6 0. 65 50 None 0 Examplel14 0. 7 13 8. 0 40. 2 22. 8 18.- 3 0. 72 50 None 0 Example 15 0. 706 7. 9 44. 3 23. 1 18. 9 0. 69 50 None 0 Example 16 0. 7 02 1 42. 9 23. 8 18. 5 0. 65 50 None 0 Example 17 0. 689 7. 6 41.. 0 22. 2 19. 0 0. 65- >50 None 0 Example 18 0. 7 11 7. 5 3.9. 8 23. 7 18. 2 0. 68 >0 Nn xape9 0. 703 8. 1 42. 5 22. 3 18. .8 0. 71 50 None 0 Comp. Ex. I Physical properties were not masured because of puncture upon releasing. X X Comp. Ex. 2 Physical properties of the board were not evaluated because it had unevenness on its surface. Amsine Odor x x Comp. Ex. 3 0. 697 9. 0 19. 8 9. 8 8. 0 0. 51 50 Amine Odor X .Comp. Ex. 4 0. 706 8. 9 16. 8 9. 8 7. 7 0. 5 1 50 None A Comp. Ex. 5 Because of the foaming and precipitation of the sdhesive composition. X X it could not be applied to dust chips.

@0 0* .0* 0 0 0 *0 0 @0 0 0 0* 0 *e Table 4 .1 Density Water Nr Flexural Wet Flexural Wet Flexural Peel Releasable Synthetic Content trength Stegth A Strength B Strength Frequency Odr ugen g/CM I N/mm 2 N/mm 2 N/mm 2 N/rfmm 2 Timeodr Jgmn Example 20 0. 692 8. 8 26. 2 1 9. 6 1 6. 6 0. 57 >50 None 0 Example 21 0. 701 8. 9 27. 1 19. 2 15. 7 0. 58 50 None 0 Example 22 0. 689 9. 2 25. 7 18. 8 15. 7 0. 53 50 None 0 Example 23 0. 69 1 9. 0 23. 2 1 8. 2 14. 9 0. 49 50 None 0 Example 24 0. 695 9. 1 26. 2 19. 1 15. 1 54 50 None 0 Example 25 0. 701 9. 0 26. 3 1 9. 0 1 6. 0 0. '61 50 None 0 Example 2 6 0. 711 8. 9 23. 2 18. 3 15. 4 0. -58 50 None 0 Example 27 0. 709 8. 8 24. 1 18. 5 16, 7 0. 55 >560 None 0 Example 28 0. 708 8. 7 23. 7 18. 7 16. 0 0. 53 50 None 0 Example 29 0 704 9. 1 24. 6 18. 9 16. 0 0. 55 50 None 0 Example 30 0. 697 9. 0 42. 4 23. 2 18. 6 0. 72 50 None 0 Example 31 0. 702 8. 9 41. 9 22. 9 18. 2 0. 69 >560 None 0 Example 3 2 0. 721 9. 1 40. 9 22. 9 17. 9 0. 63 50 None 0 Example 33 0. 706 8. 9 41. 7 22. 9 18. 4 0. 76 50 None 0 Example 34 0. 7 11 8. 8 39. 9 21. 7 18. 4 0. 80 50 None 0 Example 3 5 0. 717 8. 9 40. 4 24. 3 17. 6 0. 78 50 None 0 Example 36 0. 700 9. 0 41. 1 23. 4 18. 6 0. 69 5 0 None 0 Example 37 0. 702 8 41. 3 22. 6 18. 8 0. 66 50 None 0 Example 38 0. 709 8. 7 41. 5 22. 9 18. 9 0. 65 50 None 0

Claims (12)

1. An adhesive which comprises an aqueous emulsion containing an organic isocyanate compound and a polyether polyol and/or polyester polyol said component being contained in an amount of 1 to 70 parts by weight per 100 parts by weight of said component said polyether polyol and/or polyester polyol being an amine polyol which has a hydroxyl number of 24 to 800 mg KOH/g and contains in its molecule a nitrogen compound.

2. An adhesive according to claim 1, wherein said polyether polyol has been obtained by adding an alkylene oxide to one or more compounds selected from triethanolamine, diethanolamine, monoethanolamine, orthotoluenediamine, metatoluenediamine, diphenylmethanediamine and polyphenylpolymethylenepolyamine, said alkylene oxide containing an ethylene oxide in an amount of 5 to 70 parts by weight based on the weight of the polyether polyol.

3. An adhesive according to claim 1 or 2, wherein the organic isocyanate compound is polymethylene polyphenyl polyisocyanate.

4. An adhesive according to any one of claims 1 to 3, wherein the polyether polyol and/or polyester polyol (B) contains a nitrogen atom in an amount of 0.1 to 12.0 wt.% based on the total weight; contains 2 to 8 functional groups; and has recurring units (-CH2CH 2 in an amount of 5 to 70 based on the weight of the component An adhesive according to any one of claims 1 to 4, wherein the polyether polyol and/or polyester polyol (B) is contained in an amount of 1 to 70 parts by weight relative to 100 parts by weight of the organic isocyanate compound and further comprising the metallic salt of a saturated and/or unsaturated aliphatic carboxylic acid having 8 to 28 carbon atoms is contained in an amount of 1 to 150 parts by weight relative to 100 parts by weight of the component *°o

6. An adhesive according to claim 5, wherein the metallic salt of a saturated and/or unsaturated aliphatic carboxylic acid having 8 to 28 carbon atoms is in the form of an aqueous emulsion. 9* 0

7. An adhesive according to any one of claims 1 to 6, wherein the adhesive is an adhesive for lignocellulose. C*

8. A process for preparing an adhesive according to any one of claims 1 to 7, which comprises emulsifying water, L ~11~1 an organic isocyanate compound and a polyether polyol and/or polyester polyol

9. A process for preparing an adhesive according to claim 8, which further comprises mixing a metallic salt (C) of a saturated and/or unsaturated aliphatic carboxylic acid having 8 to 28 carbon atoms. o.

10. A process for producing a pressed lignocellulose board, which comprises mixing an adhesive as claimed in any one of claims 1 to 6 with a lignocellulose material, and then subjecting the resulting mixture to hot pressing. C

11. A pressed lignocellulose board obtained by the process according to claim o

12. An adhesive according to claim 1 substantially as hereinbefore described with reference to any one of the examples.

13. A process according to claim 8 substantially as hereinbefore described with reference to any one of the examples. DATED: 3 December 1997 PHILLIPS ORMONDE FITZPATRICK Attorneys for: MITSUI TOATSU CHEMICALS, INCORPORATED I ABSTRACT In a process for producing a board by using an isocyanate adhesive according to the present invention, a stable emulsion can be obtained by using an amine polyol, which has been obtained by the addition of an alkylene oxide to an amine compound, or a polyester polyol contained in its molecule a nitrogen compound upon emulsification of an organic polyisocyanate in water. The use of the aqueous emulsion so obtained or the aqueous emulsion further containing a metallic salt of an aliphatic carboxylic acid having 2 to 28 carbon atoms as an adhesive, particularly, as an adhesive for a lignocellulose material brings about an improvement in the physical properties of the resulting pressed board including strength, shortens the pressing time and heightens the releasability. It is therefore an industrial method suited for the effective production of a high-quality pressed lignocellulose board at a low cost. o* 9 I I r I p -"CI