Composition, binder composition for wood materials, method of using the binder composition, method of manufacturing the composition, and wood board

Abstract

The present invention provides a composition that offers excellent stability during manufacturing and enables the molding of molded products with high strength. [Solution] The composition of the present invention comprises a polymer having a carboxyl group and / or a carboxylic acid base, and a water-soluble oxazoline compound. The polymer has 50 to 100% by mass of constituent units derived from unsaturated monocarboxylic acid (salt) and 0 to 50% by mass of other constituent units, and a weight-average molecular weight of 1,000 to 100,000. The water-soluble oxazoline compound has two or more oxazoline groups in one molecule. The molar ratio of the carboxyl group and / or carboxylic acid base to the oxazoline group is 10 to 300.

Description

Technical Field

[0001] The present invention relates to a composition, a binder composition for a wood material, a method for using the binder composition, a method for manufacturing the composition, and a wood board. More specifically, the present invention relates to a composition, a binder composition for a wood material, a method for using the composition, a method for manufacturing the composition, and a wood board in which a plurality of wood pieces are integrally molded with a binder.

Background Art

[0002] Wood boards are known to be manufactured by integrally molding a plurality of wood pieces with a composition such as a binder composition. Thus, when molding a molded article, a composition such as a binder composition or an adhesive composition is used. Generally, such a composition is a thermosetting resin produced by a condensation reaction with formaldehyde, such as water-soluble urea, melamine resin, or phenol resin, used alone or in combination of a plurality. However, these compositions cause problems in terms of work and health in use due to the gas and irritating odor of free formaldehyde released from the composition, and are cited as one of the causes of sick house syndrome indoors.

[0003] Therefore, in recent years, molded articles such as wood boards using binders that do not generate a formaldehyde odor have been developed (see, for example, Patent Document 1).

Prior Art Documents

Patent Documents

[0004]

Patent Document 1

Summary of the Invention

Problems to be Solved by the Invention

[0005] However, the wood-based board disclosed in Patent Document 1 had the problem of being weaker in strength compared to conventional wood-based boards using binders that generate formaldehyde. Therefore, the composition used for molding molded products is required to be able to produce molded products with superior strength. Furthermore, such a composition is required to be able to be manufactured stably, such as by not generating aggregates during manufacturing.

[0006] Therefore, an object of the present invention is to provide a composition that allows for the molding of molded products having excellent stability during manufacturing and high strength. Another object of the present invention is to provide a binder composition for wood-based materials that allows for the molding of wood-based molded products having excellent stability during manufacturing and high strength. Another object of the present invention is to provide a method for using a binder composition to manufacture wood-based boards having high strength. Another object of the present invention is to provide a method for manufacturing a composition that has excellent stability during manufacturing. Another object of the present invention is to provide wood-based boards having high strength. [Means for solving the problem]

[0007] The present invention comprises a polymer having a carboxyl group and / or a carboxylic acid base, and a water-soluble oxazoline compound. The above polymer has 50-100% by mass of unsaturated monocarboxylic acid (salt)-derived constituent units and 0-50% by mass of other constituent units, and a weight-average molecular weight of 1,000-100,000. The above water-soluble oxazoline compound has two or more oxazoline groups in one molecule, The present invention provides a composition in which the molar ratio of the carboxyl group and / or carboxylic acid base to the oxazoline group is 10 to 300.

[0008] The above unsaturated monocarboxylic acid (salt) preferably includes (meth)acrylic acid (salt).

[0009] Furthermore, the present invention relates to a binder composition for wood materials comprising a polymer having a carboxyl group and / or a carboxylic acid base and a water-soluble oxazoline compound. The above polymer has 50-100% by mass of unsaturated monocarboxylic acid (salt)-derived constituent units and 0-50% by mass of other constituent units, and a weight-average molecular weight of 1,000-100,000. The above water-soluble oxazoline compound has two or more oxazoline groups in one molecule, The present invention provides a binder composition for wood materials, wherein the molar ratio of the carboxyl group and / or carboxylic acid base to the oxazoline group is 10 to 300.

[0010] Furthermore, the present invention relates to a method of using a binder composition for wood materials, which involves mixing the binder composition with multiple wood materials and using it to manufacture wood boards by press molding. The above binder composition comprises a polymer having a carboxyl group and / or a carboxylic acid base, and a water-soluble oxazoline compound. The above polymer has 50-100% by mass of unsaturated monocarboxylic acid (salt)-derived constituent units and 0-50% by mass of other constituent units, and a weight-average molecular weight of 1,000-100,000. The above water-soluble oxazoline compound has two or more oxazoline groups in one molecule, The present invention provides a method for using a binder composition in which the molar ratio of the carboxyl group and / or carboxylic acid base to the oxazoline group is 10 to 300.

[0011] Furthermore, the present invention relates to a method for producing a composition comprising a polymer having a carboxyl group and / or a carboxylic acid base and a water-soluble oxazoline compound. The above polymer has 50-100% by mass of structural units derived from unsaturated monocarboxylic acid (salt) and 0-50% by mass of other structural units, and a weight-average molecular weight of 1,000-100,000. The above water-soluble oxazoline compound has two or more oxazoline groups in one molecule, The present invention provides a method for producing a composition, comprising adding a solution of a water-soluble oxazoline compound with a solid content concentration of 5 to 25% by mass to a solution of the above polymer with a solid content concentration of 15 to 60% by mass.

[0012] Furthermore, the present invention relates to a wood-based board in which multiple wood pieces are molded and integrated with a binder. The above binder includes a crosslinked polymer having a crosslinked structure in which a polymer containing a carboxyl group and / or a carboxylate salt is crosslinked with a water-soluble oxazoline compound. The above polymer has 50-100% by mass of structural units derived from unsaturated monocarboxylic acid (salt) and 0-50% by mass of other structural units, and a weight-average molecular weight of 1,000-100,000. The above water-soluble oxazoline compound has two or more oxazoline groups in one molecule, The present invention provides a wood-based board in which the molar ratio of the carboxyl group and / or carboxylic acid base to the oxazoline group is 10 to 300. [Effects of the Invention]

[0013] The composition of the present invention allows for the molding of molded products that exhibit excellent stability during manufacturing and high strength. Furthermore, the binder composition for wood materials of the present invention allows for the molding of wood-based molded products that exhibit excellent stability during manufacturing and high strength. Moreover, the method of using the binder composition of the present invention allows for the production of wood-based boards with high strength. Furthermore, the method of manufacturing the composition of the present invention allows for the production of compositions that exhibit excellent stability during manufacturing. In addition, the wood-based board of the present invention has high strength. [Modes for carrying out the invention]

[0014] [Composition] The composition of the present invention comprises at least a polymer having a carboxyl group and / or a carboxylic acid base, and a water-soluble oxazoline compound. In this specification, the carboxyl group and / or carboxylic acid base may be referred to as "carboxylic acid (salt)," and the same applies to other cases where "(salt)" is appended. Furthermore, the polymer having the carboxyl group and / or carboxylic acid base, i.e., the polymer having the carboxylic acid (salt), may be referred to as "the polymer of the present invention." The above composition may contain only one polymer of the present invention, or it may contain two or more polymers.

[0015] (Polymer of the present invention) The polymer of the present invention contains at least a structural unit derived from an unsaturated monocarboxylic acid (salt). The polymer of the present invention may contain only one kind or two or more kinds of structural units derived from an unsaturated monocarboxylic acid (salt).

[0016] Examples of the unsaturated monocarboxylic acid in the above-mentioned unsaturated monocarboxylic acid (salt) include (meth)acrylic acid (acrylic acid and / or methacrylic acid), carboxyethyl (meth)acrylate, carboxypentyl (meth)acrylate, etc. In addition, examples of the unsaturated monocarboxylic acid also include unsaturated monocarboxylic acids having a hydroxy group such as α-hydroxyacrylic acid and α-hydroxymethylacrylic acid. Among them, from the viewpoint of a high curing rate during molding, a high crosslink density after molding, and higher strength, (meth)acrylic acid is preferable. That is, as the above-mentioned unsaturated monocarboxylic acid (salt), (meth)acrylic acid and / or its salt ((meth)acrylic acid (salt)) is preferable.

[0017] Examples of the salt in the unsaturated monocarboxylic acid salt include monovalent metal salts such as alkali metal salts (lithium salt, sodium salt, potassium salt, rubidium salt, cesium salt, etc.); divalent metal salts such as alkaline earth metal salts (calcium salt, magnesium salt, etc.); quaternary ammonium salts, amine salts, substituted amine salts or double salts thereof, etc.

[0018] The content ratio of the structural unit derived from the unsaturated monocarboxylic acid (salt) in the polymer of the present invention is 50 to 100% by mass, preferably 60 to 100% by mass, more preferably 70 to 100% by mass, still more preferably 80 to 100% by mass, and particularly preferably 90 to 100% by mass with respect to the total amount of 100% by mass of the structural units derived from the monomer components constituting the polymer of the present invention.

[0019] The polymer of the present invention may contain other structural units other than the structural units derived from unsaturated monocarboxylic acids (salts) (that is, structural units derived from other monomer components other than unsaturated monocarboxylic acids (salts)). The polymer of the present invention may contain only one kind of the above other structural units, or may contain two or more kinds.

[0020] Examples of the other monomer components include unsaturated dicarboxylic acids (salts) such as itaconic acid, maleic acid, fumaric acid, crotonic acid, and acid anhydrides thereof; sulfonic acid-based monomers such as 3-allyloxy-2-hydroxypropanesulfonic acid, (meth)allylsulfonic acid, isoprenesulfonic acid, vinylsulfonic acid, styrenesulfonic acid, and salts thereof; amino group-containing monomers such as vinylpyridine, vinylimidazole, dimethylaminoethyl (meth)acrylate, dimethylaminopropyl (meth)acrylate, diallylamine, diallyldimethylamine, and quaternized products and salts thereof; N-vinyl-based monomers such as N-vinylpyrrolidone, N-vinylformamide, N-vinylacetamide, N-vinyl-N-methylformamide, N-vinyl-N-methylacetamide, N-vinyl oxazolidone; amide group-containing monomers such as (meth)acrylamide, N,N-dimethyl (meth)acrylamide, N-isopropyl (meth)acrylamide; unsaturated alcohol-based monomers such as 3-(meth)allyloxy-1,2-dihydroxypropane, 3-allyloxy-1,2-dihydroxypropane, (meth)allyl alcohol, isoprenol; polyalkylene glycol-based monomers having a structure in which an alkylene oxide is added to the unsaturated alcohol-based monomers; (meth)acrylic acid alkyl ester-based monomers such as butyl (meth)acrylate, 2-ethylhexyl (meth)acrylate, dodecyl (meth)acrylate; hydroxy group-containing (meth)acrylic acid alkyl esters such as 2-hydroxyethyl (meth)acrylate, 4-hydroxybutyl (meth)acrylate; vinylaryl-based monomers such as styrene, indene, vinylaniline; alkenes such as isobutylene, octene; vinyl carboxylates such as vinyl acetate, vinyl propionate, and the like.

[0021] Among the other monomer components mentioned above, alkyl (meth)acrylates containing hydroxyl groups are preferred, from the viewpoint of forming an esterification reaction with carboxylic acids during molding, resulting in a higher crosslink density and greater strength after molding.

[0022] The content of the above-mentioned other constituent units in the polymer of the present invention is 0 to 50% by mass, preferably 0 to 40% by mass, more preferably 0 to 30% by mass, even more preferably 0 to 20% by mass, and particularly preferably 0 to 10% by mass, based on 100% by mass of the total amount of constituent units derived from the monomer components constituting the polymer of the present invention.

[0023] The weight-average molecular weight of the polymer of the present invention is 1,000 to 100,000, more preferably 1,500 to 60,000, even more preferably 2,000 to 30,000, even more preferably 2,500 to 20,000, even more preferably 3,000 to 15,000, and particularly preferably 3,500 to 10,000. When the weight-average molecular weight is 1,000 or more, the flexural strength of the molded product obtained using the above composition as a binder composition is high. When the weight-average molecular weight is 100,000 or less, aggregates are less likely to form and the stability during manufacturing is excellent. The weight-average molecular weight can be measured using GPC with polyacrylic acid as a standard substance, and specifically can be measured by the method described in the examples.

[0024] The polymer of the present invention preferably has a neutralization rate of carboxyl groups by metal salts of 20% or less, more preferably 10% or less, even more preferably 5% or less, even more preferably 1% or less, and particularly preferably 0%. Since the structure neutralized by the metal salt (e.g., -COONa) does not contribute to the crosslinking of the polymer, when the neutralization rate is 20% or less, the crosslinking of the polymer by water-soluble oxazoline compounds proceeds easily, resulting in a higher crosslink density after molding and higher flexural strength. The above neutralization rate is a ratio (mol%) to 100 mol% of the total amount of constituent units derived from the carboxylic acid (salt).

[0025] Examples of the above-mentioned metal salts include monovalent metal salts such as alkali metal salts (lithium salts, sodium salts, potassium salts, rubidium salts, cesium salts, etc.) and divalent metal salts such as alkaline earth metal salts (calcium salts, magnesium salts, etc.).

[0026] The content of the polymer of the present invention in the composition of the present invention is preferably 50% by mass or more, more preferably 55% by mass or more, and even more preferably 60% by mass or more, based on 100% by mass of the total solid content of the composition of the present invention. Furthermore, the above content is preferably 99% by mass or less, more preferably 97% by mass or less, and even more preferably 95% by mass or less.

[0027] (Water-soluble oxazoline compound) The water-soluble oxazoline compound is a compound that is water-soluble and has two or more oxazoline groups in one molecule. During molding, the oxazoline groups of the water-soluble oxazoline compound react with the carboxylic acid (salt) of the polymer of the present invention to act as a crosslinking agent, forming a crosslinked structure within the molded product. By using the above water-soluble oxazoline compound as a crosslinking agent, aggregate formation is less likely, stability during manufacturing is excellent, and the molded product obtained using the above composition as a binder composition has high flexural strength. The above water-soluble oxazoline compound may be used alone or two or more types may be used.

[0028] The above-mentioned water-soluble oxazoline compound is not particularly limited as long as it is generally considered water-soluble, but specifically, it is an oxazoline compound that dissolves at least 0.01 g in 100 g of water at 25°C.

[0029] The oxazoline group equivalent of the above water-soluble oxazoline compound is preferably 2 to 25 mmol / g, more preferably 2.5 to 20 mmol / g, and even more preferably 3 to 15 mmol / g. When the oxazoline group equivalent is 2 mmol / g or more, the flexural strength of the molded article obtained using the above composition as a binder composition is higher. When the oxazoline group equivalent is 25 mmol / g or less, aggregates are less likely to form, resulting in better stability during manufacturing.

[0030] The above water-soluble oxazoline compound is preferably a high-molecular-weight compound. The weight-average molecular weight of the above water-soluble oxazoline compound is preferably 10,000 to 200,000, and more preferably 20,000 to 150,000. If the weight-average molecular weight is 10,000 or more, the flexural strength of the molded product obtained using the above composition as a binder composition will be higher. If the weight-average molecular weight is 200,000 or less, aggregates are less likely to form, and the stability during manufacturing is better. The weight-average molecular weight can be measured using GPC with polystyrene as the standard substance, for example, under the following conditions. [Measurement conditions] • Measuring device: Manufactured by Tosoh Corporation, Part number: HLC-8320GPC • Detector: RI • Column: TSKgel SuperMultiporeHZ-M [Manufactured by Tosoh Corporation] Column temperature: 40°C ·Flow rate: 0.18mL / min Calibration curve: Standard polystyrene • Eluent: Tetrahydrofuran containing 1% by mass of triethylamine

[0031] The above-mentioned water-soluble oxazoline compound is used not as an emulsion, but as a solution dissolved in an aqueous solvent, mixed with the polymer of the present invention, etc. As the aqueous solvent, from the viewpoint of efficiently exhibiting high flexural strength of the molded product, an aqueous solvent with a boiling point of 110°C or lower is preferred, and most preferably water. The content ratio of the above aqueous solvent (especially an aqueous solvent with a boiling point of 110°C or lower) in the solvent contained in the above solution is preferably 50% by mass or more, more preferably 70% by mass or more, even more preferably 90% by mass or more, particularly preferably 95% by mass or more, and may also be 100% by mass, based on the total amount of the above solvent (100% by mass).

[0032] In the composition of the present invention, the molar ratio [carboxylic acid (salt) / oxazoline group] of the carboxylic acid (salt) in the polymer of the present invention to the oxazoline group of the water-soluble oxazoline compound is 10 to 300, preferably 12 to 200, and more preferably 15 to 100. When the molar ratio is 10 or more, the proportion of oxazoline groups is appropriate, making it less likely for aggregates to form and resulting in better stability during manufacturing. When the molar ratio is 300 or less, the proportion of oxazoline groups is sufficient, resulting in higher flexural strength of molded articles obtained using the above composition as a binder composition.

[0033] (Neutralizing agent) The composition of the present invention may contain a neutralizing agent for neutralizing the carboxylic acid (salt) in the polymer of the present invention. Furthermore, in the composition of the present invention, the carboxylic acid (salt) in the polymer of the present invention may be neutralized by the neutralizing agent. That is, the polymer of the present invention may have a structure in which at least a portion of the carboxyl group and / or carboxylic acid base in the polymer having the carboxylic acid (salt) is neutralized with an alkanolamine. By using a neutralizing agent, the pH of the composition of the present invention can be adjusted, and the applicability of the composition of the present invention can be improved. The neutralizing agent may be used alone or in combination of two or more types.

[0034] Examples of the neutralizing agents mentioned above include volatile bases and non-volatile bases.

[0035] Examples of the volatile bases mentioned above include ammonia, monomethylamine, dimethylamine, trimethylamine, n-butylamine, and triethylamine. In this specification, "volatile base" means a base with a boiling point of less than 100°C at 1 atmosphere.

[0036] The above-mentioned volatile base acts as a pH adjuster in the composition of the present invention and volatilizes during molding. This facilitates the crosslinking of the above-mentioned water-soluble oxazoline compound during molding.

[0037] In the composition of the present invention, the molar ratio of the volatile base to the carboxylic acid (salt) in the polymer of the present invention [volatile base / carboxylic acid (salt)] is preferably 0 to 150, more preferably 0 to 100, and even more preferably 0 to 70.

[0038] Examples of non-volatile bases include alkali metal hydroxides such as sodium hydroxide and potassium hydroxide; alkaline earth metal hydroxides such as calcium hydroxide; alkali metal carbonates such as sodium bicarbonate and sodium carbonate; alkanolamines such as monoethanolamine and diethanolamine; and tributylamine and cyclohexylamine. In this specification, "non-volatile base" means a base with a boiling point of 100°C or higher at 1 atmosphere.

[0039] The above neutralizing agent may contain the above alkanolamine (sometimes referred to as "alkanolamine A") having two or more hydroxyl groups in one molecule. Alkanolamine A acts as a neutralizing agent and also acts as a crosslinking agent for the polymer of the present invention. The number of hydroxyl groups is preferably 2 to 4, more preferably 2 to 3, and even more preferably 2.

[0040] Examples of the above-mentioned alkanolamine A include alkanolamines having two hydroxyl groups, such as diethanolamine, diisopropanolamine, methyldiethanolamine, and methyldiisopropanolamine; alkanolamines having three hydroxyl groups, such as triethanolamine, triisopropanolamine, diethanolisopropanolamine, diisopropanolethanolamine, and tris(2-hydroxybutyl)amine; and alkanolamines having four hydroxyl groups, such as tetrahydroxyethylethylenediamine and N,N,N',N'-tetrakis(2-hydroxypropyl)ethylenediamine. In addition, alkanolamines in which some of these alkanolamines are bonded to a polymer (for example, polymers having a triisopropanolamine backbone) are also included.

[0041] Among the above alkanolamine A, diethanolamine is preferred from the viewpoint of having a fast curing rate during molding, a high crosslink density after molding, and higher strength.

[0042] In the composition of the present invention, the molar ratio [non-volatile base / carboxylic acid (salt)] of the non-volatile base (particularly alkanolamine A) to the carboxylic acid (salt) in the polymer of the present invention is preferably 0 to 60, more preferably 0 to 45, and even more preferably 0 to 40.

[0043] In the composition of the present invention, the molar ratio of the total of the volatile base and the non-volatile base (particularly alkanolamine A) to the carboxylic acid (salt) in the polymer of the present invention [(volatile base + non-volatile base) / carboxylic acid (salt)] is preferably 0 to 150, more preferably 0 to 100, and even more preferably 0 to 50.

[0044] The composition of the present invention may contain other components in addition to those described above. Examples of these other components include resin components other than the polymer of the present invention, and other than water-soluble oxazoline compounds and neutralizing agents, crosslinking agents, curing accelerators, plasticizers, inorganic or organic fillers, colorants (pigments, dyes), thickeners, dispersants, wetting agents, defoaming agents, antiseptics and antifungal agents, rust inhibitors, water repellents, and solvents. As for the solvent, an aqueous medium is preferred, and more preferably water, from the viewpoint of excellent environmental suitability, excellent solubility and dispersibility of the polymer of the present invention, and excellent coatability. Each of these other components may consist of only one or two or more.

[0045] The compositions of the present invention may also contain other crosslinking agents besides the water-soluble oxazoline compound and alkanolamine A. Examples of the other crosslinking agents include: a) ethylene glycol, diethylene glycol, triethylene glycol, propylene glycol, dipropylene glycol, tripropylene glycol, 1,3-propanediol, 2,2-methyl-1,3-propanediol, 2-butyl-2-ethyl-1,3-propanediol, 1,3-butanediol, 1,4-butanediol, 2-methyl-2,4-butanediol, 1,5-pentanediol, 3-methyl-1,5-pentanediol, 2-methyl-2,4-pentanediol, 1,6-hexanediol, 1,4-cyclohexanediol, 2-ethyl-1,3-hex Examples include aliphatic polyols such as sandiol, 2-hydroxymethyl-2-methyl-1,3-propanediol, 2-ethyl-2-hydroxymethyl-2-methyl-1,3-propanediol, 1,2,6-hexanetriol, and 2,2-bis(hydroxymethyl)-2,3-propanediol; sugars such as glucose, fructose, mannitol, sorbitol, and maltitol; and polyester polyols which are esters of the above aliphatic polyols with carboxylic acids such as phthalic acid, adipic acid, and azelaic acid; polyethylene glycol; polypropylene glycol; and polyhydric alcohols such as acrylic resin polyols.

[0046] Other crosslinking agents mentioned above include aliphatic epoxy compounds such as propanediol diglycidyl ether, butanediol diglycidyl ether, pentanediol diglycidyl ether, hexanediol diglycidyl ether, neopentyl glycol diglycidyl ether, glycerol triglycidyl ether, trimethylolpropane triglycidyl ether, polyethylene glycol polyglycidyl ether, polypropylene polyglycidyl ether, cyclohexanediol diglycidyl ether, sorbitol polyglycidyl ether, adipic acid diglycidyl ester, azelaic acid diglycidyl ester, tetrahydrophthalic acid diglycidyl ester, and hexahydrophthalic acid diglycidyl ester; and aromatic epoxy compounds such as bisphenol A diglycidyl ether, bisphenol F diglycidyl ether, cresol phenol polyglycidyl ether, novolac phenol polyglycidyl ether, and phthalic acid diglycidyl ester (particularly glycidyl ethers and glycidyl esters).

[0047] Other crosslinking agents include components of the non-volatile bases that function as crosslinking agents. Examples of non-volatile bases that function as crosslinking agents include ethylenediamine, diethylenetriamine, triethylenetetramine, tetraethylenepentamine, pentaethylenehexamine, 1,2-diaminopropane, 1,3-diaminopropane, 1,4-diaminobutane, 1,6-diaminohexane, 3,3'-iminobis(propylamine), 3-(methylamino)propylamine, 3-(dimethylamino)propylamine, 3-(ethylamino)propylamine, 3-(butylamino)propylamine, N-methyl-3,3'-iminobis(propylamine), polyethyleneimine and other aliphatic polyamines; phenylenediamine, o-tolidine, m-toluylenediamine, m-xylylenediamine, dianisidine, diaminodiphenyl ether, 1 Examples include aromatic polyamines such as ,4-diaminoanthraquinone, 3,3'-dimethyl-4,4'-diaminobiphenyl, 4,4'-diaminobenzanilide, and 4,4'-diamino-3,3'-diethyldiphenylmethane; heterocyclic amines such as piperazine, 2-methylpiperazine, 1-(2-aminoethyl)piperazine, 2,5-dimethylpiperazine, cis-2,6-dimethylpiperazine, bis(aminopropyl)piperazine, 1,3-di(4-piperidyl)propane, 3-amino-1,2,4-triazole, and 1-aminoethyl-2-methylimidazole; and compounds containing an amino group or imino group, such as polyamine polyols obtained by adding alkylene oxides such as ethylene oxide or propylene oxide to the above polyamines. Other examples include polyalkylene polyamines, polyamide polyamines, polyalkylene imine alkylene oxides, and polyvinylamines, which have four or more nitrogen atoms. The above-mentioned other crosslinking agents may be used individually or in combination of two or more.

[0048] The content of the above-mentioned other crosslinking agents is preferably 10% by mass or less, more preferably 5% by mass or less, more preferably 3% by mass or less, even more preferably 1% by mass or less, even more preferably 0.5% by mass or less, and particularly preferably 0.1% by mass or less, based on the total amount of crosslinking agents (100% by mass) in the composition of the present invention.

[0049] The composition of the present invention can be dissolved in water and used as an aqueous solution. The pH of the aqueous solution of the composition of the present invention (composition aqueous solution) is preferably 0.5 or higher, more preferably 0.8 or higher, and even more preferably 1.0 or higher. When the pH is 0.5 or higher, the bending strength of the molded product obtained using the composition as a binder composition is higher. The pH is, for example, 7.0 or lower, preferably 6.5 or lower, and more preferably 6.0 or lower. When the pH is 7.0 or lower, aggregates are less likely to form, resulting in better stability during manufacturing.

[0050] The solid content concentration of the aqueous solution of the above composition is preferably 15% by mass or more, more preferably 17% by mass or more, even more preferably 20% by mass or more, and particularly preferably 25% by mass or more. When the solid content concentration is 15% by mass or more, the flexural strength of the molded product obtained using the above composition as a binder composition becomes higher. From the viewpoint of preventing the formation of aggregates and providing better stability during manufacturing, the solid content concentration is preferably 50% by mass or less, and more preferably 45% by mass or less.

[0051] The viscosity of the aqueous solution of the above composition is preferably 500 mPa·s or less, more preferably 400 mPa·s or less, and even more preferably 350 mPa·s or less. When the viscosity is 500 mPa·s or less, aggregates are less likely to form, resulting in better stability during manufacturing. From the viewpoint of excellent handling, the viscosity is, for example, 1 mPa·s or more. The viscosity is the viscosity at 25°C and can be measured using a B-type viscometer. The rotor and rotation speed are appropriately selected according to the viscosity range.

[0052] (Method of manufacturing the composition) The composition of the present invention can be produced by mixing the polymer of the present invention with the above-mentioned water-soluble oxazoline compound and, if necessary, a neutralizing agent and other components. Alternatively, by adding and mixing the polymer of the present invention and the neutralizing agent in a solvent, a polymer having a structure in which the carboxylic acid (salt) of the polymer of the present invention is neutralized by the neutralizing agent can be produced in the composition of the present invention. The composition of the present invention can be produced as an aqueous solution by mixing the composition of the present invention with water, or by adding and mixing the various components constituting the composition of the present invention with water.

[0053] In the above manufacturing method, when mixing the polymer of the present invention with the water-soluble oxazoline compound, a solution of the polymer of the present invention (sometimes referred to as "the polymer solution of the present invention") is mixed with a solution of the water-soluble oxazoline compound. At this time, a solution of the water-soluble oxazoline compound with a solid content of 5 to 25% by mass is added to a solution of the polymer of the present invention with a solid content of 15 to 60% by mass. By adding in this manner, the generation of aggregates during mixing can be suppressed.

[0054] The polymer solution of the present invention may contain a neutralizing agent. By adding a neutralizing agent to the polymer solution of the present invention before adding the aqueous solution of the water-soluble oxazoline compound, the pH before adding the aqueous solution of the water-soluble oxazoline compound can be adjusted. From the viewpoint of suppressing the formation of aggregates between the polymer of the present invention and the water-soluble oxazoline compound, the neutralization rate of the carboxylic acid (salt) in the polymer solution of the present invention is preferably 0 to 60 mol%, more preferably 0 to 55 mol%, and even more preferably 0 to 50 mol%, based on 100 mol% of the total amount of the carboxylic acid (salt).

[0055] The viscosity of the polymer solution of the present invention is preferably 500 mPa·s or less, more preferably 400 mPa·s or less, and even more preferably 350 mPa·s or less. When the viscosity is 500 mPa·s or less, mixing efficiency is good and the formation of aggregates can be further suppressed. From the viewpoint of excellent handling, the viscosity is, for example, 1 mPa·s or more. The viscosity is the viscosity at 25°C and can be measured using a B-type viscometer. The rotor and rotation speed are appropriately selected according to the viscosity range.

[0056] The temperature at which the polymer solution of the present invention is mixed with the solution of the water-soluble oxazoline compound is preferably 10 to 50°C, and more preferably 15 to 40°C. When the temperature is 10°C or higher, the viscosity of the polymer solution of the present invention can be lowered, the mixing efficiency is improved, and the formation of aggregates can be further suppressed. When the temperature is 50°C or lower, the rapid reaction between the polymer of the present invention and the water-soluble oxazoline compound can be suppressed, and the formation of aggregates can be further suppressed.

[0057] The other components mentioned above may be added to either or both of the polymer solution of the present invention and the water-soluble oxazoline compound solution, or they may be added to the mixture after adding the water-soluble oxazoline compound solution to the polymer solution of the present invention. The above additions are not particularly limited and can be carried out, for example, at room temperature. The above method for producing the composition makes it possible to produce a composition with excellent stability during production.

[0058] The composition of the present invention has excellent stability during manufacturing and can be used to mold molded products having high strength. For this reason, the composition of the present invention can be preferably used as a binder composition for materials used to mold molded products. In particular, the composition of the present invention is preferably a binder composition for molding wood-based materials to obtain wood-based molded products (binder composition for wood-based materials). The above binder composition for wood-based materials is a composition that forms a binder that binds multiple wood-based materials together in a wood-based molded product. The above binder composition for wood-based materials has excellent stability during manufacturing and can be used to mold wood-based molded products having high strength. An example of the above wood-based molded product is a wood-based board.

[0059] [Method of using the binder composition] Wood-based molded products such as wood-based boards can be manufactured using the above-described binder composition. In the above-described method of use, the binder composition (preferably an aqueous solution of the composition) is mixed with multiple wood-based materials and used to manufacture wood-based molded products by press molding. According to the above-described method of use of the binder composition, wood-based molded products such as wood-based boards with high strength can be manufactured.

[0060] The above-mentioned wood-based materials can be known or conventional wood chips used in wood-based molded products such as wood-based boards. Examples of wood-based materials include coniferous trees such as pine, cedar, and cypress, and broad-leaved trees such as lauan, kapur, and poplar. Only one type of wood-based material may be used, or two or more types may be used.

[0061] Wood chips are obtained by grinding the woody material into granules using a known grinding device (chipper), such as a hammer mill, pin mill, or jet mill. The particle size (maximum diameter) of the wood chips is, for example, 0.5 to 5 mm.

[0062] The shape of the wood material is not particularly limited, but examples include chips, flakes, wafers, strands, and fibers.

[0063] The moisture content of the above wood material is preferably 1% by mass or more, and more preferably 3% by mass or more, based on 100% by mass of the total amount of wood material. When the moisture content is 1% by mass or more, the applicability of the binder composition is superior. From the viewpoint of ease of removal during molding, the moisture content is preferably 20% by mass or less, and more preferably 15% by mass or less. The moisture content can be determined from the formula (m1-m0)×100 / m0 in accordance with JIS A 5905 (2003) 6.4. Here, m1 is the mass (g) of the wood material before drying, and m0 is the mass (g) of the wood material when it reaches a constant weight in an air dryer at 103°C.

[0064] In the above method of use, specifically, the binder composition and a plurality of the above wood materials are first mixed to impregnate the wood materials with the binder composition (preferably an aqueous solution of the composition) and prepare the mixture. The wood materials may be dried before mixing to adjust the moisture content as needed. After mixing, the solvent that may be contained in the binder composition may be evaporated as needed to adjust the solid content concentration and prepare the mixture. The mixing ratio of the binder composition and the wood materials is not particularly limited, but the mass ratio of the wood materials to the solid content of the binder composition [wood materials / solid content of binder composition] is preferably 70 / 30 to 99 / 1, more preferably 75 / 25 to 98 / 2, even more preferably 80 / 20 to 97 / 3, even more preferably 85 / 15 to 96 / 4, and particularly preferably 90 / 10 to 95 / 5. When the above mass ratio is 70 / 30 or higher, the wood texture is good, the appearance is good, and the workability tends to be excellent. When the above mass ratio is 99 / 1 or lower, the bending strength tends to be excellent.

[0065] Next, the above mixture is subjected to press molding. Specifically, the above mixture is spread into a mold for a wood-based molded product, and then heated and pressurized to form a board, thereby manufacturing the wood-based molded product. The following description will explain the manufacturing method as an example when the wood-based molded product is a fiberboard made of wood (when the wood material is fibrous wood chips). Before molding the above mixture by heating and pressurizing, the above mixture is pre-formed into a mat-like material. The forming method is not particularly limited, but examples include wet forming and dry forming (air forming). When using the wet forming method, it is necessary to thoroughly dry the mat-like material before molding.

[0066] Examples of equipment used in the wet forming method include long-wire papermaking machines (Ford linear machines) and cylinder papermaking machines. On the other hand, examples of equipment used in the dry forming method include forming machines equipped with gravitational or suction filters, or Levanite filters.

[0067] The molding conditions for forming a mat-like material into a plate are not particularly limited, but the molding temperature is preferably 130 to 270°C, more preferably 150 to 250°C, the molding pressure is preferably 1 to 6 MPa, more preferably 3 to 5 MPa, and the molding time is preferably 1 to 20 minutes, more preferably 5 to 15 minutes. If the molding temperature is 130°C or higher, sufficient durability and water resistance are achieved. If the molding temperature is 270°C or lower, deterioration of the wood material can be suppressed, a decrease in strength can be suppressed, and sufficient durability and water resistance are achieved. If the molding pressure is 1 MPa or higher, sufficient durability and water resistance are achieved. If the molding pressure is 6 MPa or lower, high fiber strength can be maintained. If the molding time is 1 minute or more, sufficient durability and water resistance are achieved. If the molding time is 20 minutes or less, deterioration of the wood material can be suppressed, a decrease in strength can be suppressed, and sufficient durability and water resistance are achieved.

[0068] Examples of equipment used for molding include hot presses equipped with a pressurizing section, a heating plate, etc. After the molding process, further treatments such as heat treatment or oil immersion may be performed to improve physical properties such as water resistance.

[0069] As described above, wood-based molded products such as wood-based boards can be manufactured using the above-mentioned binder composition.

[0070] [Wood board] The wood-based board described above is formed by molding and integrating multiple wood pieces with a binder. The wood-based board of the present invention has high strength.

[0071] The above binder includes a polymer having a crosslinked structure (crosslinked polymer) formed by crosslinking the polymer of the present invention in the binder composition with the water-soluble oxazoline compound during molding. Specifically, the above crosslinked polymer has a crosslinked structure formed when the carboxylic acid (salt) in the polymer of the present invention reacts with the oxazoline group of the water-soluble oxazoline compound, resulting in the polymer of the present invention being crosslinked by the water-soluble oxazoline compound. Alternatively, the above crosslinked polymer may have a structure in which the carboxylic acid (salt) of the polymer of the present invention is neutralized with alkanolamine A.

[0072] The above-mentioned binder may contain other components in addition to those described above. These other components include those known or commonly used in binders for wood-based boards, and are examples of other components that the above-mentioned composition may contain. One or more of these other components may be used.

[0073] The preferred content ratio of the structural portion derived from the polymer of the present invention in the above binder is the same as the preferred content ratio of the polymer of the present invention relative to the total amount of solids in the composition of the present invention. Similarly, the preferred content ratio of the structural portion derived from the water-soluble oxazoline compound in the above binder is the same as the preferred content ratio of the water-soluble oxazoline compound relative to the total amount of solids in the composition of the present invention. Furthermore, the preferred content ratio of the structural portion derived from the non-volatile base in the above binder is the same as the preferred content ratio of the non-volatile base relative to the total amount of solids in the composition of the present invention. Moreover, the molar ratio of the structural portion derived from the carboxylic acid (salt) in the polymer of the present invention to the structural portion derived from the oxazoline group of the water-soluble oxazoline compound [carboxylic acid (salt) / oxazoline group] in the above binder, and the molar ratio of the structural portion derived from the non-volatile base to the structural portion derived from the carboxylic acid (salt) in the polymer of the present invention [non-volatile base / carboxylic acid (salt)] are also the same.

[0074] The bending strength of the wood-based board of the present invention is preferably 6.5 MPa or higher, more preferably 7.5 MPa or higher, and even more preferably 8.5 MPa or higher. The higher the bending strength, the better the strength, and there is no particular upper limit. The upper limit of the bending strength is, for example, 20 MPa. The bending strength can be measured by a three-point bending test using a universal material testing machine with a test piece span of 50 mm and a deformation speed of 1.5 mm / min on a wood-based board measuring 80 mm in length and 20 mm in width. [Examples]

[0075] The present invention will be described in more detail below with reference to examples, but the present invention is not limited to these examples. Unless otherwise specified, "parts" means "parts by mass" and "%" means "percent mass".

[0076] <Measurement conditions (GPC) for the weight-average molecular weight (10,000 or less) of carboxyl group-containing polymers> Equipment: HLC-8320GPC manufactured by Tosoh Corporation Detector: RI Column: TSK-GEL G3000PWXL manufactured by Tosoh Corporation (connected in series, 2 columns) Column temperature: 40 °C Flow rate: 0.5 mL / min Sample solution injection volume: 10 μL (sample concentration: 0.5 mass%) Calibration curve: Prepared using polyacrylic acid standards (Mp = 1250, 2925, 7500, 16000, 36200, 43100) and sodium acetate (Mp = 94) manufactured by Polymer Standards Service, and creating a cubic equation based on Mp and elution time Eluent: A solution prepared by diluting a mixture of sodium dihydrogen phosphate dodecahydrate / disodium hydrogen phosphate dihydrate (34.5 g / 46.2 g) to 5000 g with pure water

[0077] <Measurement conditions (GPC) for the weight average molecular weight of the carboxy group-containing polymer (when exceeding 10,000)>[ Apparatus: HLC-8320GPC manufactured by Tosoh Corporation Detector: RI Column: TSKgel GMPWXL manufactured by Tosoh Corporation (connected in series, 2 columns) Column temperature: 40 °C Flow rate: 1 mL / min Sample solution injection volume: 20 μL (sample concentration: 0.5 mass%) Calibration curve: Prepared using polyacrylic acid standards (Mp = 1200, 2925, 7500, 16000, 36200, 43100, 73600, 115000, 143000, 321000, 532000, 724000, 1020000, 1390000) manufactured by Polymer Standards Service, and creating a cubic equation based on Mp and elution time Eluent: (60.84 mM aqueous sodium carbonate solution + 60.84 mM aqueous sodium hydrogen carbonate solution) / acetonitrile = 83.74 / 16.26 (mass ratio)

[0078] <pH measurement>[ The pH of the aqueous composition solution and the polymer solution was measured under the following conditions.[ Apparatus: "pH METER D-52" manufactured by Horiba, Ltd.[ Electrodes: Glass electrodes Temperature: 25℃

[0079] <Viscosity measurement> The viscosity of the aqueous composition solution and the polymer solution was measured under the following conditions. Equipment: B type viscometer Temperature of the aqueous solution during measurement: 25℃ Rotor and rotational speed: Selected appropriately based on viscosity.

[0080] <Measurement of solid content concentration> 1.0 g of the sample was weighed into an aluminum dish, diluted with 1.0 g of pure water, and spread evenly. This was dried in a 130°C oven for 1 hour, then cooled in a desiccator, and the mass was weighed after drying. The solid content (non-volatile content) concentration was calculated from the mass difference before and after drying. Unless otherwise specified, the solid content concentration measured using the above procedure was used as the concentration of the polymer solution and the aqueous composition solution.

[0081] <Manufacturing Example 1> 720.0 g of pure water was pre-charged into a 2.5 L stainless steel separable flask equipped with a stirrer, reflux condenser, and thermometer, and the temperature was raised to the boiling point under stirring. Then, under stirring, 1000.0 g of 80% acrylic acid (hereinafter referred to as AA) aqueous solution, 56.9 g of 45% sodium hypophosphate monohydrate (hereinafter referred to as SHP) aqueous solution, and 53.3 g of 15% sodium persulfate (hereinafter referred to as NaPS) aqueous solution were added dropwise separately to the system under reflux at the boiling point. The entire amounts of the 80% AA aqueous solution, 45% SHP aqueous solution, and 15% NaPS aqueous solution were added continuously at a constant dropping rate from 0 to 180 minutes. After all dropwise addition was complete, the mixture was matured for another 30 minutes under reflux conditions to complete the polymerization. By adjusting with pure water, a polymer solution with a solid content of 45%, viscosity of 200 mPa·s, and pH of 1.2 was obtained, containing a polymer (carboxyl group-containing polymer) with a weight-average molecular weight of 10,000.

[0082] <Manufacturing Example 2> 720.0g of pure water was pre-charged into a 2.5L stainless steel separable flask equipped with a stirrer, reflux condenser, and thermometer, and the temperature was raised to the boiling point under stirring. Then, under stirring, 800.0g of 80% AA aqueous solution, 160.0g of 2-hydroxyethyl methacrylate (hereinafter referred to as HEMA), 56.9g of 45% SHP aqueous solution, and 53.3g of 15% NaPS aqueous solution were added dropwise separately to the system under reflux at the boiling point. The total amounts of the 80% AA aqueous solution, HEMA, 45% SHP aqueous solution, and 15% NaPS aqueous solution were added continuously at a constant dropping rate from 0 to 180 minutes. After all dropwise addition was complete, the mixture was matured for another 30 minutes under reflux conditions to complete the polymerization. By adjusting with pure water, a polymer solution with a solid content of 45%, viscosity of 185 mPa·s, and pH of 1.6 was obtained, containing a polymer (carboxyl group-containing polymer) with a weight-average molecular weight of 10,000.

[0083] <Manufacturing Example 3> 720.0 g of pure water was pre-charged into a 2.5 L stainless steel separable flask equipped with a stirrer, reflux condenser, and thermometer, and heated to its boiling point under stirring. Then, under stirring, 1000.0 g of 80% AA aqueous solution, 142.2 g of 45% SHP aqueous solution, and 53.3 g of 15% NaPS aqueous solution were added dropwise, separately, to the system under reflux at the boiling point. The entire amounts of the 80% AA aqueous solution, 45% SHP aqueous solution, and 15% NaPS aqueous solution were added continuously at a constant dropping rate from 0 to 180 minutes. After all additions were completed, the system was matured for another 30 minutes under reflux at the boiling point to complete the polymerization, and then adjusted with pure water to obtain a polymer solution with a solid content of 45%, viscosity of 50 mPa·s, and pH of 1.7, containing a polymer (carboxyl group-containing polymer) with a weight-average molecular weight of 1,500.

[0084] <Manufacturing Example 4> 720.0g of pure water was pre-charged into a 2.5L stainless steel separable flask equipped with a stirrer, reflux condenser, and thermometer, and the temperature was raised to the boiling point under stirring. Then, under stirring, 1000.0g of 80% AA aqueous solution, 8.9g of 45% SHP aqueous solution, and 49.6g of 15% NaPS aqueous solution were added dropwise, separately, to the system under reflux at the boiling point. The entire amounts of the 80% AA aqueous solution, 45% SHP aqueous solution, and 15% NaPS aqueous solution were added continuously at a constant dropping rate from 0 to 180 minutes. After all additions were completed, the system was matured for another 30 minutes under reflux at the boiling point to complete the polymerization, and then adjusted with pure water to obtain a polymer solution with a solid content of 40%, viscosity of 1,600 mPa·s, and pH of 1.4, containing a polymer (carboxyl group-containing polymer) with a weight-average molecular weight of 90,000.

[0085] <Manufacturing Example 5> 720.0g of pure water was pre-charged into a 2.5L stainless steel separable flask equipped with a stirrer, reflux condenser, and thermometer, and heated to its boiling point under stirring. Then, under stirring, 400.0g of 80% AA aqueous solution, 400.0g of HEMA, 56.9g of 45% SHP aqueous solution, and 53.3g of 15% NaPS aqueous solution were added dropwise, separately, to the system under reflux at the boiling point. The entire amounts of the 80% AA aqueous solution, HEMA, 45% SHP aqueous solution, and 15% NaPS aqueous solution were added continuously at a constant dropping rate from 0 to 180 minutes. After all additions were completed, the system was matured for another 30 minutes under reflux at the boiling point to complete the polymerization, and then adjusted with pure water to obtain a polymer solution with a solid content of 45%, viscosity of 180 mPa·s, and pH of 1.7, containing a polymer (carboxyl group-containing polymer) with a weight-average molecular weight of 10,000.

[0086] <Manufacturing Example 6> 720.0 g of pure water was pre-charged into a 2.5 L stainless steel separable flask equipped with a stirrer, reflux condenser, and thermometer, and the temperature was raised to the boiling point under stirring. Then, under stirring, 1000.0 g of 80% AA aqueous solution, 5.9 g of 45% SHP aqueous solution, and 49.6 g of 15% NaPS aqueous solution were added dropwise, separately, to the system under reflux at the boiling point. The entire amounts of the 80% AA aqueous solution, 45% SHP aqueous solution, and 15% NaPS aqueous solution were added continuously at a constant dropping rate from 0 to 180 minutes. After all additions were completed, the system was matured for another 30 minutes under reflux at the boiling point to complete the polymerization, and then adjusted with pure water to obtain a polymer solution with a solid content of 35%, viscosity of 980 mPa·s, and pH of 1.0, containing a polymer (carboxyl group-containing polymer) with a weight-average molecular weight of 140,000.

[0087] <Manufacturing Example 7> 400.0 g of pure water was pre-charged into a 2.5 L stainless steel separable flask equipped with a stirrer, reflux condenser, and thermometer, and the temperature was raised to the boiling point under stirring. Then, under stirring, 1000.0 g of 80% AA aqueous solution, 71.1 g of 45% SHP aqueous solution, and 66.7 g of 15% NaPS aqueous solution were added dropwise, separately, to the system under reflux at the boiling point. The entire amounts of the 80% AA aqueous solution, 45% SHP aqueous solution, and 15% NaPS aqueous solution were added continuously at a constant dropping rate over 0 to 180 minutes. After all additions were completed, the system was matured for another 30 minutes under reflux at the boiling point to complete the polymerization, and then adjusted with pure water to obtain a polymer solution with a solid content of 65%, viscosity of 3,800 mPa·s, and pH of 1.2, containing a polymer (carboxyl group-containing polymer) with a weight-average molecular weight of 10,000.

[0088] <Examples 1-13, Comparative Examples 1-5> According to the formulations shown in Tables 1 and 2, the polymer was weighed in a container, and the neutralizing agent, oxazoline group-containing compound, and adjusted water were added in that order while stirring in the polymer solution at room temperature to obtain an aqueous solution of the binder composition (composition aqueous solution). Using the obtained composition aqueous solution, wood-based boards were manufactured according to the "Method for Manufacturing Wood-Based Boards" described below, and evaluated according to the "Evaluation Method" described later. The results are shown in Tables 1 and 2.

[0089] In the table, "carboxyl group-containing polymer" indicates the mass of the polymer solution obtained in each production example. Also, "80% diethanolamine" in the table refers to diethanolamine diluted with pure water to adjust to 80%. Furthermore, the oxazoline group-containing compounds in the table are as follows. Epocross WS-300: Product name "Epocross WS-300", manufactured by Nippon Shokubai Co., Ltd., water-soluble oxazoline compound, solid content concentration 10%, oxazoline group equivalent 7.7 mmol / g, weight-average molecular weight 120,000 Epocross WS-700: Product name "Epocross WS-700", manufactured by Nippon Shokubai Co., Ltd., water-soluble oxazoline compound, solid content concentration 25%, oxazoline group equivalent 4.5 mmol / g, weight-average molecular weight 40,000 Epocross K-2035E: Product name "Epocross K-2035E", manufactured by Nippon Shokubai Co., Ltd., emulsion-type oxazoline compound, solid content concentration 40%, oxazoline group equivalent 1.8 mmol / g

[0090] (Manufacturing method for wood-based boards) Wood chips were placed in a hot air dryer at 80°C for 24 hours to obtain wood chips with a moisture content of 5-10%. The moisture content of the wood chips can be calculated using the formula (m1-m0)×100 / m0, in accordance with JIS A 5905 (2003) 6.4. Here, m1 is the mass (g) of the wood chips before drying, and m0 is the mass (g) of the wood chips when they reach a constant weight after being placed in an air dryer at 103°C.

[0091] Next, 15 parts of the aqueous composition solution obtained in each example were added to 45 parts of dried wood chips while stirring, impregnating the wood chips with the aqueous composition solution. The impregnated chips were laid out in a 100 x 100 mm mold and heated and compressed using a hot press at a pressure of 3 MPa and a temperature of 200°C for 10 minutes, resulting in a density of approximately 0.5-0.6 g / cm³. 3 We also fabricated wood-based boards with a thickness of 8-10 mm.

[0092] (Bending strength test of wood-based boards) After cutting the fabricated wood-based boards to a length of 80 mm and a width of 20 mm, a three-point bending test was performed using a universal material testing machine (manufactured by Instron) under the conditions of a specimen span of 50 mm and a deformation speed of 1.5 mm / min to obtain the bending strength. The boards were then evaluated based on the following evaluation criteria. [Evaluation Criteria] ◎: 8.5 MPa or higher ○: 7.5 MPa or higher, less than 8.5 MPa △: 6.5 MPa or higher, less than 7.5 MPa ×: Less than 6.5 MPa

[0093] (Manufacturing stability of the binder composition) Regarding the manufacturing stability of the binder composition, the presence or absence of aggregate formation when the binder composition was compounded at room temperature was visually confirmed. [Evaluation Criteria] ◎: No aggregates have formed; the liquid is clear. ○: Opaque liquid with no aggregates formed. ×: Aggregates are formed

[0094] [Table 1] [Table 2]

[0095] As shown in Tables 1 and 2, the binder compositions of the examples exhibited excellent stability during manufacturing, and the resulting wood-based boards were judged to have high flexural strength. On the other hand, when the oxazoline group-containing compound was not included (Comparative Example 1), and when the constituent units derived from unsaturated monocarboxylic acid (salt) in the carboxyl group-containing polymer were less than 50% by mass (Comparative Example 2), the flexural strength was evaluated as inferior. When the weight-average molecular weight of the carboxyl group-containing polymer was large (Comparative Example 3), and when an emulsion type with a solid content concentration of 40% was used as the oxazoline group-containing compound (Comparative Example 5), aggregates were formed during compounding, and the stability during manufacturing was evaluated as inferior. Furthermore, when a composition was prepared by adding a water-soluble oxazoline compound to a polymer solution with a solid content concentration exceeding 60% by mass (Comparative Example 4), aggregates were formed during compounding.

Claims

1. The polymer comprises a polymer having a carboxyl group and / or a carboxylic acid base, and a water-soluble oxazoline compound. The polymer has 50 to 100% by mass of constituent units derived from unsaturated monocarboxylic acid (salt) and 0 to 50% by mass of other constituent units, and a weight-average molecular weight of 1,000 to 100,000. The aforementioned water-soluble oxazoline compound has two or more oxazoline groups in one molecule, A composition in which the molar ratio of the carboxyl group and / or carboxylic acid base to the oxazoline group is 10 to 300.

2. The composition according to claim 1, wherein the unsaturated monocarboxylic acid (salt) comprises (meth)acrylic acid (salt).

3. A binder composition for wood materials comprising a polymer having a carboxyl group and / or a carboxylic acid base and a water-soluble oxazoline compound, The polymer has 50 to 100% by mass of constituent units derived from unsaturated monocarboxylic acid (salt) and 0 to 50% by mass of other constituent units, and a weight-average molecular weight of 1,000 to 100,000. The aforementioned water-soluble oxazoline compound has two or more oxazoline groups in one molecule, A binder composition for wood materials, wherein the molar ratio of the carboxyl group and / or carboxylic acid base to the oxazoline group is 10 to 300.

4. This describes a method for using a binder composition for wood materials, which is mixed with multiple wood materials and used to manufacture wood boards by press molding. The binder composition comprises a polymer having a carboxyl group and / or a carboxylic acid base, and a water-soluble oxazoline compound. The polymer has 50 to 100% by mass of constituent units derived from unsaturated monocarboxylic acid (salt) and 0 to 50% by mass of other constituent units, and a weight-average molecular weight of 1,000 to 100,000. The aforementioned water-soluble oxazoline compound has two or more oxazoline groups in one molecule, A method for using a binder composition, wherein the molar ratio of the carboxyl group and / or carboxylic acid base to the oxazoline group is 10 to 300.

5. A method for producing a composition comprising a polymer having a carboxyl group and / or a carboxylic acid base and a water-soluble oxazoline compound. The polymer has 50 to 100% by mass of structural units derived from unsaturated monocarboxylic acid (salt) and 0 to 50% by mass of other structural units, and a weight-average molecular weight of 1,000 to 100,000. The aforementioned water-soluble oxazoline compound has two or more oxazoline groups in one molecule, A method for producing a composition, comprising adding a solution of the water-soluble oxazoline compound with a solid content concentration of 5 to 25% by mass to a solution of the polymer with a solid content concentration of 15 to 60% by mass.

6. It is a wood-based board in which multiple pieces of wood are molded together with a binder. The binder comprises a crosslinked polymer having a crosslinked structure in which a polymer containing a carboxyl group and / or a carboxylate salt is crosslinked with a water-soluble oxazoline compound. The polymer has 50 to 100% by mass of structural units derived from unsaturated monocarboxylic acid (salt) and 0 to 50% by mass of other structural units, and a weight-average molecular weight of 1,000 to 100,000. The aforementioned water-soluble oxazoline compound has two or more oxazoline groups in one molecule, A wood-based board in which the molar ratio of the carboxyl group and / or carboxylic acid base to the oxazoline group is 10 to 300.

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