KR20210043374A - Aqueous thermosetting composition for adhesive - Google Patents

Abstract

The present invention relates to an aqueous thermosetting adhesive composition which contains a phenol-formaldehyde resin, reducing sugar, and amino acid, wherein the total amount of the reducing sugar and the amino acid and the phenol-formaldehyde resin are mixed in a weight ratio of 1 : 2 to 5. An objective of the present invention is to provide a thermosetting adhesive composition which is environmentally friendly due to a small amount of formaldehyde emission.

Description

Aqueous thermosetting adhesive composition {AQUEOUS THERMOSETTING COMPOSITION FOR ADHESIVE}

The present invention relates to a water-based thermosetting adhesive composition that is environmentally friendly and has excellent mechanical properties due to a small amount of formaldehyde emission of the prepared cured product.

Phenol-aldehyde resins have a variety of commercial uses, and resins having a molar ratio of phenol to various aldehydes are known in the industry. In particular, phenol-aldehyde resol resins, that is, resins formed by condensing phenol with aldehydes in the presence of an alkali catalyst, have been applied to a wide variety of industrial fields among phenol-aldehyde resins. The phenol-aldehyde resol resin has a property of curing by heat, and is often used as a binder that is cured by applying pressure or heat after being applied to a substrate. As such phenol-aldehyde resol resin, a phenol-formaldehyde resol resin is typical, and the phenol-formaldehyde resol resin is used as a binder for artificial boards, chipboard products, fiber products or laminate products.

However, the substrate treated with the phenol-formaldehyde resol resin has a problem of releasing formaldehyde to the surroundings during processing, storage, and curing. Formaldehyde has a foul odor and is known to cause various diseases when exposed to the human body. Accordingly, there is a need to reduce the concentration of free formaldehyde in the resin and to reduce the amount of formaldehyde released into the surrounding environment during processing of such resins.

As an alternative to this, U.S. Patent No. 5,538,761 (Patent Document 1) discloses a phenol-formaldehyde resin prepared by reacting phenol and formaldehyde under alkaline conditions. However, the phenol-formaldehyde prepared by the method of Patent Document 1 has a limitation in controlling the amount of formaldehyde released, and when the composition is acidified, the stability of the binder solution may be degraded, resulting in a problem of poor storage performance.

In addition, U.S. Patent No. 7,854,980 (Patent Document 2) discloses a thermosetting organic resin composed of a trifunctional monomeric acid, a reducing sugar, and ammonia. The thermosetting organic resin of Patent Document 2 basically does not emit formaldehyde since it does not use a raw material containing formaldehyde, but there is a limitation in that the mechanical properties of the manufactured product are insufficient compared to the use of a phenol-formaldehyde binder.

Accordingly, there is a need for research and development on a thermosetting adhesive composition that is environmentally friendly due to low formaldehyde emission and excellent mechanical properties of the prepared cured product.

US Patent No. 5,538,761 (published on July 23, 1996) US Patent No. 7,854,980 (published on April 1, 2010)

Accordingly, the present invention is environmentally friendly due to a small amount of formaldehyde emission, and an object of the present invention is to provide a thermosetting adhesive composition having excellent mechanical properties such as water resistance, cutability, and tensile strength.

The present invention includes a phenol-formaldehyde resin, a reducing sugar and an amino acid,

It provides an aqueous thermosetting adhesive composition comprising the total amount of the reducing sugar and the amino acid and the phenol-formaldehyde resin in a weight ratio of 1: 2 to 5.

In addition, the present invention provides a fibrous material bound using an aqueous thermosetting adhesive composition.

The water-based thermosetting adhesive composition according to the present invention is eco-friendly due to its low amount of formaldehyde emission, and the fibrous material bound by using it has excellent water resistance, cutting processability, water immersion and tensile strength, and a low dust rate, making it a conventional phenol-formaldehyde resol resin. It has similar or superior mechanical properties to the bound fibrous material.

Hereinafter, the present invention will be described in detail.

In the present invention, the "weight average molecular weight" of the resin can be measured by a method well known in the art, for example, it can represent a value measured by the method of GPC (gel permeation chromatograph).

Water-based thermosetting adhesive composition

The aqueous thermosetting adhesive composition according to the present invention comprises a phenol-formaldehyde resin, a reducing sugar and an amino acid.

Phenol-formaldehyde resin

Phenol-formaldehyde resin is the main resin of the adhesive composition and serves to impart adhesiveness and mechanical properties to the composition.

The phenol-formaldehyde resin is a condensation product of a phenol compound and a formaldehyde compound, and may be prepared from, for example, a resin composition containing a phenol compound and a formaldehyde compound. Specifically, the phenol-formaldehyde resin may be a compound produced by condensation reaction of a phenol compound and formaldehyde in a molar ratio of 1:1.2 to 2.6, or 1:1.3 to 2.2. When the reaction molar ratio of the phenol compound and formaldehyde is out of the above range, there is a problem that the amount of formalin released is increased.

At this time, the phenolic compound refers to a phenyl compound containing at least one hydroxy group (OH), for example, phenol, cresol, xylenols, cumylphenol, nonylphenol, butylphenol, phenylphenol, ethylphenol , Octylphenol, amylphenol, naphthol, resorcinol, bisphenol A, bisphenol F, bisphenol C, catechol, hydroquinone, pyrogallol, ursiol, eugenol, tannin, ligrin, etc., or mixtures thereof It can be used, and in the industry, phenol is most commonly used in terms of economics, etc., but is not limited thereto.

In addition, the resin composition may further include a polymerization catalyst and an amide compound. The polymerization catalyst can be used without particular limitation as long as it can be used in the production of a phenol-formaldehyde resol resin in general, and examples thereof include triethylamine, lime (CaO), and hydroxides of alkali metals or alkaline earth metals. have. The hydroxide may be, for example, sodium hydroxide, potassium hydroxide, calcium hydroxide or barium hydroxide. Further, the polymerization catalyst may be included in the resin composition in an amount of 0.5 to 30 parts by weight, or 10 to 25 parts by weight based on 100 parts by weight of the phenol compound. When the content of the polymerization catalyst is out of the above range, there is a problem in that it is not easy to control the polymerization reaction rate.

The amide-based compound is a formaldehyde catcher, and can be used without particular limitation as long as it can be used in the production of a phenol-formaldehyde resol resin, for example, urea, thiourea, melamine, benzoguanamine, and dish. Andiamide, etc. are mentioned. Further, the amide-based compound may be included in the resin composition in an amount of 5 to 80 parts by weight, or 20 to 60 parts by weight based on 100 parts by weight of the phenol compound. When the content of the amide compound is less than the above range, the formaldehyde catcher performance is deteriorated, and when the content of the amide compound is too large, physical properties and water resistance are deteriorated due to an excessive amount of unreacted substances.

The total amount of reducing sugars and amino acids to be described later to the phenol-formaldehyde resin may be included in a weight ratio of 1: 2 to 5, or 1: 2 to 4.5. When it exceeds the above range, that is, when an excessive amount of phenol-formaldehyde resin is included, there is a problem in that the amount of formaldehyde emission increases, and when it is less than the above range, there is a problem that the strength characteristics of the prepared adhesive are poor.

Reducing sugar

The reducing sugar is an auxiliary resin of the composition and serves to reduce the amount of formaldehyde released from the composition.

The reducing sugar refers to an aldose or ketose saccharide that may contain an aldehyde group or have an aldehyde structure by isomerization, and may have 3 or more carbon atoms, for example. Specifically, the reducing sugar may include one or more selected from the group consisting of monosaccharides and disaccharides such as glucose, maltose, fructose, galactose, lactose, cellobiose, genthiobiose, luteinose, and glycealdehyde.

In addition, the reducing sugar may be included in the composition in an amount of 5 to 40 parts by weight, or 10 to 40 parts by weight based on 100 parts by weight of the phenol-formaldehyde resin. If the content of the reducing sugar is out of the above range, the effect of reducing the amount of formaldehyde emission may be insignificant or the strength of the product may decrease.

amino acid

Amino acids are auxiliary resins and play a role in reducing the amount of formaldehyde released in the composition.

The amino acid refers to a compound containing at least one amino group and one carboxyl group in one molecule, for example, glycine, alanine, valine, leucine, isoleucine, threonine, serine, cysteine, methionine, aspartic acid, asparagine, glutamic acid. , Diiodotyrosine, lysine, arginine, histidine, phenylalanine, tyrosine, tryptophan, proline, oxyproline, glutamine, and sulfates thereof.

In addition, the amino acid may be included in the composition in an amount of 1 to 20 parts by weight, or 1 to 15 parts by weight based on 100 parts by weight of the phenol-formaldehyde resin. If the amino acid content is out of the above range, the effect of reducing the amount of formaldehyde emission may be insignificant or the strength of the product may decrease.

Metal cation complex

The composition may further include a metal cation complex compound. The metal cation complex compound serves to cure the composition after the adhesive composition is applied to the fibrous material as a chelating agent and a condensation catalyst, and serves to adjust the water resistance of the fibrous material bound by using the same.

In this case, the metal cation complex compound may be an ammonium salt. Specifically, the metal cation complex compound is ammonium aluminum (III) sulfate, ammonium cobalt (II) thiocyanate, ammonium cobalt (II) sulfate, ammonium cobalt (II) phosphate, ammonium copper (II) sulfate, ammonium copper (II) Carbonate, ammonium nickel(II) sulfate, ammonium nickel(II) phosphate, ammonium manganese(II) sulfate, ammonium manganese(III) diphosphate, ammonium manganese(II) phosphate, ammonium zinc(II) sulfate, ammonium zinc(II) Phosphate, ammonium zinc(II) carbonate, ammonium iron(II) sulfate, ammonium iron(III) sulfate, ammonium iron(III) citrate, ammonium iron(II) phosphate, ammonium iron(III) phosphate, ammonium aluminum(III) ) Phosphate, ammonium aluminum (III) carbonate, ammonium zirconium (IV) sulfate, ammonium zirconium (IV) phosphate and ammonium zirconium (IV) carbonate, and at least one selected from the group consisting of hydrates thereof.

In addition, the metal cation complex may be included in the composition in an amount of 0.1 to 5 parts by weight, or 0.1 to 3 parts by weight based on 100 parts by weight of the phenol-formaldehyde resin. If the content of the metal cation complex is out of the above range, the formation of a complex by coordination bonds is insufficient, or ionic substances become excessive, resulting in poor water resistance of the product or adversely affecting product properties such as strength.

additive

The adhesive composition may further include at least one selected from the group consisting of a pH adjusting agent, a coupling agent, an acid catalyst, a curing agent, and a solvent.

In this case, the additive may be included in the composition in an amount of 100 to 1,000 parts by weight, or 300 to 800 parts by weight based on 100 parts by weight of the phenol-formaldehyde resin.

The pH modifier plays a role of imparting solution stability by adjusting the pH of the adhesive composition. At this time, the pH modifier may be used without particular limitation as long as it is commonly used in the adhesive composition, and examples include aqueous ammonia, sodium hydroxide, potassium hydroxide, sodium carbonate, potassium carbonate, silane, amino alcohol, polyamine, etc. I can. The pH modifier may be included in the composition in an amount of 0 to 5 parts by weight, or 0 to 3 parts by weight based on 100 parts by weight of the phenol-formaldehyde resin.

The coupling agent serves to increase the interfacial adhesion between the fibrous material and the adhesive composition. The coupling agent may be used without particular limitation as long as it is commonly used in the adhesive composition, and may be, for example, an organosilicon compound. The organosilicon compound may be, for example, an amino silane. In addition, the coupling agent may be included in the composition in an amount of 0.1 to 1 parts by weight, or 0.1 to 0.5 parts by weight based on 100 parts by weight of the phenol-formaldehyde resin.

The acid catalyst serves to accelerate the condensation reaction in the adhesive composition. The acid catalyst may be used without particular limitation as long as it is commonly used in the adhesive composition, and examples thereof include ammonium sulphate, ammonium sulphate, ammonium paratoluene sulfonate, and ammonium citric salt. In addition, the acid catalyst may be included in the composition in an amount of 1 to 20 parts by weight, or 1 to 10 parts by weight based on 100 parts by weight of the phenol-formaldehyde resin.

The curing agent serves to improve the mechanical properties of the cured product. The curing agent may be used without particular limitation as long as it is commonly used in the adhesive composition, and may be, for example, an aliphatic epoxy compound. In addition, the curing agent may be included in the composition in an amount of 0.1 to 5 parts by weight, or 0.1 to 3 parts by weight based on 100 parts by weight of the phenol-formaldehyde resin.

The solvent plays a role in controlling the viscosity and drying properties of the composition. At this time, the solvent may be water, and specifically, may include at least one selected from the group consisting of deionized water, pure water, ultrapure water, and distilled water. In addition, the solvent may be included in the composition in an amount of 100 to 900 parts by weight, or 350 to 800 parts by weight based on 100 parts by weight of the phenol-formaldehyde resin.

The water-based thermosetting adhesive composition according to the present invention as described above is ^{eco-friendly because the amount of formaldehyde emission is less than 0.008 mg/m 3} ·hr, and the fibrous material bound using this is excellent in water resistance, cutting processability, water immersion and tensile strength. And because of its low dust rate, it has similar or superior mechanical properties to fibrous materials bound with conventional phenol-formaldehyde resins.

Fibrous material

Further, the fibrous material according to the present invention is bound using the aqueous thermosetting adhesive composition as described above.

At this time, the fibrous material to be bound may include inorganic fibers (eg, rock wool, glass wool, ceramic fibers, etc.), or organic fibers such as fibers obtained from natural and synthetic resins, but is not limited thereto. In addition, the fibrous material may be a short fiber or a medium fiber.

In addition, the fibrous material may be bonded by spraying or applying a water-based thermosetting adhesive composition to the fibrous material and then thermally curing the adhesive composition. At this time, the thermal curing may be performed at 120° C. or higher, 120 to 300° C., or 150 to 250° C., and when heat-treated at a temperature of 120° C. or higher, mail occurring in an amadori intermediate between the aldehyde group of the reducing sugar and the amine group of the amino acid Various curing reactions such as Maillard reaction, self-amide reaction of amino acid carboxylic acid group and amine group, ester reaction of reducing sugar hydroxy group and amino acid carboxylic acid group, condensation reaction of methylol group and hydroxy, self-condensation reaction between methylol group, etc. This occurs, and through this, a water-insoluble polymer is formed, so that it can be used as an adhesive having very excellent physical properties such as water resistance.

Further, the bound fibrous material may include 1 to 20 parts by weight, or 2 to 15 parts by weight of an aqueous thermosetting adhesive composition based on 100 parts by weight of the raw fibrous material.

In addition, the fibrous material may have an emission amount of formaldehyde of 0.008 mg/m ³ ·hr or less, or 0.006 mg/m ³ ·hr or less.

The fibrous material according to the present invention as described above has excellent water resistance, cut processability, water immersion, tensile strength, weather resistance and moldability, and is eco-friendly because of its low dust rate and low amount of formaldehyde emission.

Hereinafter, the present invention will be described in more detail through examples. However, these examples are only intended to aid understanding of the present invention, and the scope of the present invention is not limited to these examples in any sense.

[Example]

Example 1. Preparation of adhesive composition

345.3 kg of phenol and 417 kg of 37 wt% formaldehyde were put into the reaction vessel, and 62.8 kg of 33 wt% sodium hydroxide was added dropwise. Thereafter, the mixture was stirred at 60° C. for 5 hours, cooled to 35° C., and 120.1 kg of a 50% by weight urea aqueous solution was added to prepare a phenol-formaldehyde resin.

156.5 kg of the prepared phenol-formaldehyde resin, 30 kg of glucose (D-glucose) (solid content: 91% by weight) as a reducing sugar, 8.7 kg of solid lysine neutralized with sulfuric acid as an amino acid (solid content: 98% by weight), Ammonium aluminum sulfate (AASD) 0.3kg, glycerin triglycidyl ether (JSI, EJ-300) (solid content: 99% by weight) 0.3kg as a hardener, silane coupling agent (A-1100 from Momentive) 0.5kg, sulfuric acid as an acid catalyst 14.6 kg of ammonium sulphate (solid content: 98% by weight) and 789.1 kg of water were added to the container and stirred for 30 minutes. Thereafter, the pH was adjusted to 8 to 9 using aqueous ammonia, and further stirred for 10 minutes to prepare an adhesive composition. The solid content of the prepared adhesive composition was 12.4% by weight.

Examples 2 to 5.

An adhesive composition was prepared in the same manner as in Example 1, except that the contents of each component described in Table 1 were used.

Ingredients (parts by weight) Example 1 Example 2 Example 3 Example 4 Example 5 Phenol-form
Aldehyde resin
Composition phenol 345.3 345.3 345.3 286 230 Formaldehyde 417 417 417 493.3 497.3 Sodium hydroxide 62.8 62.8 62.8 52 41.8 Urea 120.1 120.1 120.1 120.1 120.1 Number of moles of formaldehyde
/Number of moles of phenol 1.4 1.4 1.4 2 2.5 glue
Composition Phenol-formaldehyde resin 156.5 118.8 169.5 156.5 156.5 glucose 30 45.5 26.0 30.4 30.4 Lysine sulfate 8.7 13.9 7.9 8.7 8.7 AASD 0.3 0.5 0.2 0.3 0.3 Hardener 0.3 0.3 0.3 0.3 0.3 Silane coupling agent 0.5 0.5 0.5 0.5 0.5 Acid catalyst 14.6 11.1 15.1 14.6 14.6 water 789.1 809.4 780.5 788.7 788.7 Gross weight 1000.0 1000.0 1000.0 1000.0 1000.0 Solid content (%) 12.4% 12.4% 12.5% 12.4% 12.2%

Comparative Examples 1 to 7.

An adhesive composition was prepared in the same manner as in Example 1, except that the contents of each component described in Table 2 were used.

Ingredients (parts by weight) Comparative Example 1 Comparative Example 2 Comparative Example 3 Comparative Example 4 Comparative Example 5 Comparative Example 6 Comparative Example 7 Phenol-formaldehyde
Suzy
Composition phenol 345.3 345.3 345.3 419.4 212.5 - 345.3 Formaldehyde 417 417 417 361.7 557.5 - 417 Sodium hydroxide 62.8 62.8 62.8 76.3 38.6 - 62.8 Urea 120.1 120.1 120.1 120.1 120.1 - 120.1 Number of moles of formaldehyde / Number of moles of phenol 1.4 1.4 1.4 1.0 3.0 - 1.4 Adhesive composition Phenol-formaldehyde resin 205.7 164.1 48 230.3 230.3 - 250 glucose - 31.9 73.6 - - 93.2 30 Lysine sulfate 11.4 - 22.4 - - 28.9 8.7 AASD 0.4 0.3 0.8 - - 1.0 0.3 Hardener 0.3 0.3 0.3 0.3 0.3 0.3 0.3 Silane coupling agent 0.5 0.5 0.5 0.5 0.5 0.5 0.5 Acid catalyst 19.1 15.3 4.4 21.0 21.0 - 14.6 water 762.6 787.6 850 747.9 747.9 876.1 695.6 Gross weight 1000.0 1000.0 1000.0 1000.0 1000.0 1000.0 1000.0 Solid content (%) 12.3% 12.1% 12.3% 12.3% 12.3% 12.4% 12.6%

Experimental example. Binding of fibrous materials using water-based adhesive composition

After passing the high-temperature glass material through a spinner to form fibers at a rate of 2,100 kg per hour, the adhesive composition of the Example and Comparative Example was sprayed at an amount of 16 L/min on the glass fibers coming down to the cotton thread, and then subjected to a drying process. Insulation was obtained. Physical properties were measured by the following method for the prepared glass-surface insulating material, and the results are shown in Table 3.

(1) Resin adhesion rate

To measure the content of the adhesive composition in the bound fibrous material, a sample of 100 mm (width) x 100 mm (length) x 50 mm (thickness) of glass wool was prepared, and then heat-treated at 500° C. for 1 hour in an oven to measure weight loss before and after.

(2) compression ratio

Three specimens (250mmX250mmX100mm, width X length X thickness) were taken as samples from the glass-surface insulation prepared as described above. The dimensions of the specimen were taken by cutting in half in the thickness direction and in the vertical direction, taking into account the uniform collecting surface. After binding the specimen to a jig for measuring the compressibility, it was placed in the center of a universal testing machine. Afterwards, the compressed displacement was measured under a load of 40 kgf, and the arithmetic mean value was taken by measuring three times. At this time, the compression ratio was calculated by Equation 1 below, and the lower the compression ratio, the better the strength of the product.

[Equation 1]

Compression rate (%) = [(initial thickness-compression displacement)/initial thickness]x100

(3) water absorption

Three samples were prepared by cutting the glass-surface insulation material into a size of 254mmX254mmX100mm (length X width X thickness), and the weight (W1) was accurately measured up to 0.01 g. After that, water at room temperature was filled in a water bath from the bottom to 10 steps (30 mm per 1 step), and a sample was put, and then the screen (square mesh wire mesh) was fixed to come to 7 steps from the bottom. (If the sample does not fix the square mesh wire due to buoyancy, a weight of 2 kg or more was applied to fix the square mesh wire mesh.)

The screen was fixed so that it did not float in water, and water was absorbed into the sample for 15 minutes. After 15 minutes, the sample was taken out, and one corner was held with a fingertip and held vertically for 150±5 seconds to allow water droplets to fall. Thereafter, the sample was placed on a pre-weighed silver plate (W2), and then the weight (W3) was accurately measured up to 0.01 g, and the average value of the weights of the three samples was taken. Thereafter, the absorption rate was calculated by the following equation (2), and it was determined that the water resistance was lower as the absorption rate was higher.

[Equation 2]

Absorption rate (%) = [(W3-W2)/W1] X 100

(4) Formaldehyde emission amount

According to the small chamber method specified in KS M ISO 16000 and KS M 1998, the glass wool insulation was left in a small chamber, and then the chamber air on the 7th day was collected, and the collected air was analyzed by HPLC (liquid chromatography). The specific test method followed the method set by the Air Purification Association.

(5) Dust rate

The glass-surface insulation was cut to prepare four samples each having a width of 1.5 cm and a width of 10 cm. After measuring the weight of the sample before measuring the dust rate, the sample was placed in a dust rate meter and shaken back and forth, left and right at a speed of 1 m/min. It was left in the dust rate meter for 10 minutes per sample, and the weight of the sample was weighed after the tester was stopped. At this time, the dust rate was calculated by Equation 3 below.

[Equation 3]

Dust rate = [(Weight after measurement/Weight before measurement)-1]Х100

Resin adhesion rate (%) Compression rate (%) Water absorption (%) Formaldehyde emission amount
(mg/m ³ hr) Dust rate (%) (goal) 5±1 below 10 - 0.008 or less 1.0 or less Example 1 4.8 8.5 423 0.004 One Example 2 4.9 9.1 716 0.002 0.9 Example 3 5 8.4 371 0.006 One Example 4 4.8 8.5 412 0.005 One Example 5 5.1 8.2 402 0.006 0.9 Comparative Example 1 5.3 9.7 483 0.006 1.5 Comparative Example 2 4.7 9.8 477 0.006 1.4 Comparative Example 3 5.1 10.7 978 0.002 1.5 Comparative Example 4 4.3 11.1 541 0.001 1.4 Comparative Example 5 5.3 8.7 388 0.01 1.1 Comparative Example 6 5.1 12.2 950 N.D. One Comparative Example 7 5 8 380 0.012 0.9

As shown in Table 3, the fibrous materials bound with the compositions of Examples 1 to 5 were excellent in water resistance, cutting processability, water immersion and tensile strength, low dust rate, and low formaldehyde emission.

On the other hand, Comparative Example 1 containing no reducing sugar and Comparative Example 2 containing no amino acid had a high dust generation rate. In addition, the fibrous material bound with the composition of Comparative Example 5 in which the condensation reaction ratio of phenol and formaldehyde is 1:3, and Comparative Example 7 containing an excess of phenol-formaldehyde resin based on the total amount of reducing sugar and the amino acid The large amount of aldehyde emission has deteriorated eco-friendliness. In addition, Comparative Example 4 in which the condensation reaction ratio of phenol and formaldehyde is 1:1, Comparative Example 6 not containing a phenol-formaldehyde resin, and a small amount of phenol-formaldehyde resin based on the total amount of the reducing sugar and the amino acid. The fibrous material bound with the composition of Comparative Example 3 had high compressibility and water absorption.

Claims (7)

Contains phenol-formaldehyde resin, reducing sugar and amino acids,
An aqueous thermosetting adhesive composition comprising the total amount of the reducing sugar and the amino acid and the phenol-formaldehyde resin in a weight ratio of 1: 2 to 5. The method according to claim 1,
The phenol-formaldehyde resin is a compound produced by condensation reaction of a phenol compound and formaldehyde in a molar ratio of 1:1.2 to 2.6, an aqueous thermosetting adhesive composition. The method according to claim 1,
The composition comprises 100 parts by weight of a phenol-formaldehyde resin, 5 to 40 parts by weight of reducing sugar and 1 to 20 parts by weight of amino acids. The method according to claim 1,
The composition further comprises a metal cation complex compound, aqueous thermosetting adhesive composition. The method of claim 4,
The composition comprises 0.1 to 5 parts by weight of a metal cation complex compound based on 100 parts by weight of a phenol-formaldehyde resin, an aqueous thermosetting adhesive composition. A fibrous material bound using the aqueous thermosetting adhesive composition of claims 1 to 5. The method of claim 6,
The fibrous material is a fibrous material having an emission amount of formaldehyde of 0.008 mg/m ³ ·hr or less.