KR102188400B1 - Method for eco friendly particle board and eco friendly particle board manufactured therefrom - Google Patents

Abstract

The present invention provides: a method of manufacturing an eco-friendly particle board capable of securing water resistance and productivity while being eco-friendly because the amount of formaldehyde emission is extremely low; and an eco-friendly particle board manufactured therefrom.

Description

Manufacturing method of eco-friendly particle board and eco-friendly particle board manufactured therefrom {METHOD FOR ECO FRIENDLY PARTICLE BOARD AND ECO FRIENDLY PARTICLE BOARD MANUFACTURED THEREFROM}

The present invention relates to a method of manufacturing an eco-friendly particle board and an eco-friendly particle board manufactured therefrom.

Conventional particle boards are obtained by crushing wood and applying an adhesive to wood chips obtained by shredding, followed by thermocompression molding. In general, the particle board is widely used as a finishing material for interior and exterior walls of a building, a partition material, a decorative material, and kitchen furniture because of its low manufacturing cost, simple construction, and physical properties that do not degrade strength.

In general, in the manufacture of wood based building materials such as medium-density fiberboard (MDF), plywood, floorboard, and particle board, wax is added to increase water resistance. Because of the water resistance of the wax itself, a small amount of wax added in the manufacture of wood-based building materials improves dimensional stability such as moisture absorption and thickness expansion rate of the produced wood-based building material, but its effects are temporary and limited.

In addition, at present, urea-formaldehyde resin adhesives are widely used as adhesives for the manufacture of wood-based building materials, and these urea-formaldehyde resin adhesives have the advantage of good adhesion and low cost, on the other hand, manufactured wood-based construction materials. It is difficult to secure the water resistance of the product, so there is a physical disadvantage that it is easily expanded and destroyed when contacted with water.

In addition, as the raw material of the particle board is mainly recycled wood, water resistance is lowered, and the resin curing time of the water-repellent resin is slowed, resulting in a decrease in productivity. A problem occurs.

Furthermore, since wood-based building materials including particle boards have a wide surface area and are in constant contact with indoor air on this surface, indoor air quality to which the corresponding building material is applied (Indoor air quality) It can have a major effect on the evaluation of air quality), and it also emits various kinds of pollutants into the air.

In the case of wood-based building materials, volatile organic compounds (VOC), formaldehyde, etc., due to the influence of urea-formaldehyde-based resin and wood itself, which are blended in the manufacturing process It can be emitted in large quantities. In the case of formaldehyde, it can cause asthma or eye irritating, and it has the potential to cause various diseases such as cancer due to long term exposure.

The present invention was conceived in consideration of the above circumstances, and is eco-friendly, with extremely low formaldehyde emission, and a method of manufacturing an eco-friendly particle board capable of securing water resistance and productivity, and an eco-friendly particle board manufactured therefrom. Its purpose is to provide.

In order to solve the above problems, the present invention provides a step of manufacturing wood chips by cutting a wood material with a crusher, drying the wood chips, and classifying the dried wood chips by size and weight, and Separating into, forming a mixture by independently mixing an adhesive composition, a formaldehyde scavenger composition, and a curing accelerator on the surface chip and the core chip, respectively, Forming a mat by laminating a chip mixture layer for a surface layer, a chip mixture layer for an intermediate layer, and a chip mixture layer for a surface layer in that order, and forming a particle board by hot-pressing the laminated mat, wherein the adhesive composition comprises: It provides a method of manufacturing an eco-friendly particle board having a molar ratio of 1.3 to 2.5: 1 of formaldehyde and (NH ₂ ) ₂ .

In addition, the present invention provides an eco-friendly particle board comprising a condensation polymer of urea and formaldehyde and the curing accelerator, as manufactured by the above manufacturing method.

When the method for manufacturing an eco-friendly particle board according to the present invention is used, compared to the prior art, the amount of formaldehyde emission is extremely low and water resistance can be secured, thereby improving physical properties. Can be obtained.

1 is a procedure drawing for a method of manufacturing an eco-friendly particle board according to an embodiment of the present invention.

Hereinafter, various embodiments of the present invention will be described with reference to the accompanying drawings. The present invention is not limited to specific embodiments, and it should be understood that various modifications, equivalents, and/or alternatives of the embodiments of the present invention are included. In connection with the description of the drawings, similar reference numerals may be used for similar elements.

In this document, expressions such as "have", "may have", "include", or "may contain" are the presence of corresponding features (eg, elements such as numbers, functions, actions, or parts). And does not exclude the presence of additional features.

In this document, expressions such as "A or B", "at least one of A or/and B", or "one or more of A or/and B" may include all possible combinations of items listed together. . For example, “A or B”, “at least one of A and B”, or “at least one of A or B” includes (1) at least one A, (2) at least one B, Or (3) it may refer to all cases including both at least one A and at least one B.

The expression "Configured to" used in this document is, for example, "Suitable for", "Having the capacity to" depending on the situation. It can be used interchangeably with ", "Designed to", "Adapted to", "Made to", or "Capable of". The term "configured to (or set) to" does not necessarily mean only "specifically designed to".

Terms used in this document are only used to describe a specific embodiment, and may not be intended to limit the scope of other embodiments. Singular expressions may include plural expressions unless the context clearly indicates otherwise. Terms used herein, including technical or scientific terms, may have the same meaning as commonly understood by one of ordinary skill in the technical field described in this document. Among the terms used in this document, terms defined in a general dictionary may be interpreted as having the same or similar meaning as the meaning in the context of the related technology, and unless explicitly defined in this document, they may be interpreted in an ideal or excessively formal meaning. It is not interpreted. In some cases, even terms defined in this document cannot be interpreted to exclude embodiments of the present document.

In addition, each step of the process according to the present invention is not limited to being in a complete time-series order, and the invention is described in an easy-to-understand manner according to the order applied to the general particle board manufacturing process, and the process sequence of the invention is required. Of course, it is possible to change or modify according to, and the preparation of the compositions to be described later may be performed separately as an individual process.

The embodiments disclosed in this document are presented for description and understanding of the disclosed and technical content, and do not limit the scope of the present invention. Therefore, the scope of this document should be construed as including all changes or various other embodiments based on the technical idea of the present invention.

An embodiment of the present invention will be described with reference to FIG. 1, the step of manufacturing wood chips by cutting the wood material with a crusher (S10), drying the wood chips (S20), the dried wood chips The step of dividing by size and weight into a chip for a surface layer and a chip for an intermediate layer (S30), an adhesive composition and a formaldehyde scavenger composition independently of the surface chip and the middle layer chip, respectively And forming a mixture by mixing a curing accelerator (S40), forming a mat by laminating in the order of a chip mixture layer for a surface layer, a chip mixture layer for an intermediate layer, and a chip mixture layer for a surface layer (S50), Including the step (S60) of manufacturing a particle board by hot-pressing the laminated mat, wherein the adhesive composition is an eco-friendly particle board having a molar ratio of formaldehyde and (NH ₂ ) ₂ of 1.3 to 2.5: 1 It provides a method of manufacturing.

Hereinafter, a method of manufacturing such an eco-friendly particle board will be described in detail for each step.

In the manufacture of eco-friendly particle boards, the step of manufacturing wood chips by cutting the wood material with a crusher (S10) is a process of selecting the type of wood material and crushing and classifying the selected wood material into a shape of a chip.

Among the wooden materials, raw logs may be included, and the logs are natural materials, such as Merbau, Burckella, Bangkirai, and Malas. Malas), Kwila, etc. Tropical hardwood; Fast growing species such as Radiata pine, Eucalyptus, and Acacia; Korean red pine, Korean pine, Ulleungdo white pine, Black pine, Japanese yew, Temple juniper, Southern Japanese hemlock, globular tree It may include at least one selected from the group consisting of Temperate softwood and hardwood such as (Korean fir), Needle fir, and Dahurian larch.

Also, depending on the material, recycled wood may be used. The composition of recycled wood is composed of industrial waste wood or general waste wood, industrial waste wood is mainly waste wood from construction sites, and general waste wood is mainly waste wood from everyday life products such as furniture.

It may also contain agricultural residues such as bagasse, rice husks, rice straw, and the like.

These wood materials are crushed to a certain size to form wood chips. In this case, solid wood or wood materials are cut into sizes of 200 µm to 2 cm in width and 200 µm to 2 cm in length with a crusher, and those that are larger than the standard size are cut into standard sizes, and those that are less than the standard size are cut into a screen. It passes through and removes to form wood chips of certain sizes (Certain sizes).

In manufacturing an eco-friendly particle board, the step of drying the wood chips (S20) is a process of lowering the moisture content in order to form a mixture in the subsequent step.

Specifically, the wood chips may be subjected to acid-base chemical treatment in order to meet the condition of a constant acidity, and then transferred to a dryer and dried at 150 to 250°C.

In the manufacture of an eco-friendly particle board, the step (S30) of dividing the dried wood chips by size and weight and classifying them into a surface chip and a middle layer chip (S30) includes transferring the dried wood chips to a sorter to determine the size of the wood chips and It is sorted into surface chip and intermediate chip by weight. In general, the surface layer chip is divided into 200㎛∼2.0㎜, and the middle layer chip is divided into 2.0㎜ or more.

In the manufacture of eco-friendly particle boards, an adhesive composition, a formaldehyde scavenger composition, and a curing accelerator are each independently mixed with the surface chip and the intermediate chip to form a mixture. In step S40, the adhesive composition, the formaldehyde collector composition, and the curing accelerator may be formed through separate processes, and then mixed.

The adhesive composition may include a urea derived monomer and a formaldehyde derived monomer.

Here, the adhesive composition may have a molar ratio of formaldehyde and (NH ₂ ) ₂ of 1.3 to 2.5:1. If the molar ratio of formaldehyde and (NH ₂ ) _{2 in} the adhesive composition is less than 1.3:1, the crosslinking degree of the resin is significantly lowered, which is not preferable in terms of decrease of properties, and formaldehyde If the molar ratio of and (NH ₂ ) ₂ is greater than 2.5:1, the free formaldehyde content increases rapidly, which is not preferable because it is difficult to reduce formaldehyde emission reduction.

The molar ratio of formaldehyde and (NH ₂ ) ₂ is reacted (Reacted), unreacted (Unreacted) and remaining formaldehyde in the adhesive composition of the present invention, or formaldehyde-derived monomer and urea when reacted. In the case of reaction, it means the number of moles of (NH ₂ ) ₂ groups in the urea-derived monomer, and as a result, the molar ratio of the urea relative to the total amount of formaldehyde added in the manufacturing process of the adhesive composition (NH ₂ ) _It means the molar ratio of the total amount of ₂ groups

The adhesive composition is a first raw material input step of preparing a mixture by adding a urea derived monomer, a formaldehyde derived monomer, and a curing accelerator, and a mixture through the raw material input step The first acidity control step of adding a catalyst to the mixture (pH control), the first condensation polymerization step of reacting by heating the mixture that has undergone the first acidity control step (condensation polymerization), the first condensation polymerization A second raw material input step of injecting urea into the polymer (Condensate) passed through the step, a second condensation polymerization step of reacting the polymer through the second raw material input step, and the polymer prepared through the second condensation polymerization step It can be manufactured through a cooling step of cooling.

The raw material input step is a step of preparing a mixture by introducing urea, formaldehyde, and a curing accelerator into a reactor having a temperature of 20 to 40°C, and formaldehyde and urea-derived (NH ₂ ) introduced into the reactor _It is preferable that the molar ratio of 2 be 2 to 4.

In this case, the content of the curing accelerator is preferably 1:0.02 to 0.06 as a weight ratio of the adhesive composition including a urea derived monomer and a formaldehyde derived monomer.

If the weight ratio of the adhesive composition and the curing accelerator is less than 1:0.02, it is not preferable because the curing accelerating effect is weak, and if it exceeds 1:0.06, it is not preferable in that it is difficult to control the degree of polymerization in the condensation polymerization step. .

The formaldehyde is commercially available, and it is preferable to use one having a concentration of 37% to 50% in percent concentration.

The primary acidity control step is a step of adjusting the pH to 9.5 to 10.5 using a catalyst of alkali metal or alkaline earth metal hydroxide and borax in the mixture through the raw material input step. to be.

The alkali metal or alkaline earth metal hydroxide is lithium hydroxide, sodium hydroxide, potassium hydroxide, magnesium hydroxide, and calcium hydroxide. Calcium hydroxide) may contain one or more selected from the group consisting of.

In the second raw material input step and the second condensation polymerization step, after adjusting the pH of the reactant through the first condensation polymerization step to 4 to 6, the molar ratio of formaldehyde/urea is added to be 1.3 to 2.5, and then 90 to 100 This is a step of heating for 90 to 100 minutes at a temperature of °C.

The cooling step is a step of cooling the polymer prepared through the second condensation polymerization step, and a viscosity adjusting step is performed so that the viscosity of the polymer is 150 to 250 cps while maintaining a temperature of 70 to 80°C in the second condensation polymerization step. Then, after adjusting the pH of the polymer to 7 to 8, the temperature of the reactor is cooled to 25°C to stop condensation polymerization. When the cooling step is completed, an adhesive composition containing urea formaldehyde resin is prepared.

The curing accelerator is converted into heterocyclic glycoluril type compounds by reacting glyoxal type compounds with urea, and then hydroxy alkyl urea compounds, carboxylic acid compounds. It includes prepolymers obtained by reacting compounds (Carboxylic acid type compounds).

Specifically, the prepolymer may be a compound represented by the following Chemical Formula 5 or an isomer thereof. The isomer includes both cis and trans forms.

[Formula 5]

Here, R is an alkyl group having 1 to 5 carbon atoms, and n is an integer of 1 to 10.

The hydroxy alkyl urea compounds are urea compounds containing a hydroxy alkyl group having 1 to 5 carbon atoms, and specifically, hydroxymethyl urea, bis (hydroxymethyl) urea, tris (hydroxy Methyl) urea, tetrakis (hydroxymethyl) urea, bis (hydroxyethyl) urea, tris (hydroxyethyl) urea, and tetrakis (hydroxyethyl) urea containing at least one selected from the group consisting of urea I can.

The glyoxal-based compound is selected from the group consisting of glyoxal, sodium glyoxylate, glycoluril, tetramethylol glycoluril, and compounds of Formulas 1 to 4 below. It may contain one or more.

[Formula 1]

[Formula 2]

[Formula 3]

[Formula 4]

The carboxylic acid-based compound may include one or more selected from the group consisting of formic acid, acetic acid, maleic acid, and adipic acid.

The preparation of the curing accelerator is according to an embodiment of the present invention, after mixing 10 to 15 parts by weight of urea, 15 to 30 parts by weight of water, and 5 to 10 parts by weight of the glyoxal compound of Formula 4, and adjusting the pH to 1.5 to 2.5, After the first reaction was completed for 20 to 40 minutes by heating the temperature to 90 to 100° C., 20 to 50 parts by weight of bis(hydroxymethyl)urea and 20 to 50 parts by weight of water were mixed and the pH was adjusted to 6 to 8, After cooling the temperature to 40 to 60° C., 10 to 25 parts by weight of maleic acid is gradually added for 30 to 50 minutes to complete the secondary reaction. Thereafter, the pH of the reactor may be adjusted to 8 to 9 and then cooled to 25° C. to obtain a curing accelerator. Regarding the manufacture of urea-formaldehyde resin, which is an adhesive composition, in European Patent EP0062389A1, the formaldehyde/amino group molar ratio is set to 1.0 to 1.2, and the melamine content is set to 3% by weight. After charging, 1st condensation polymerization was performed at pH5, and 2nd condensation polymerization was performed at pH8 after melamine was added, and then 2nd urea ) And cooled. In this case, although the amount of formaldehyde released is small, there is a disadvantage in that productivity is lowered and cost is increased. International Publication WO2012-001154 A1 has a formaldehyde/urea/melamine molar ratio of 1.2/1.0/0.07, and after splitting the primary urea (1st urea), pH5.6 to 7.2, temperature 90 to 92 First condensation polymerization is performed at °C, and then secondary condensation polymerization is performed at a pH of 4.5 to 5.5 and a temperature of 80 to 82 °C. After the pH was adjusted to 9 to 10, melamine and borax were added, followed by tertiary condensation polymerization, and a second urea (2nd urea) was added at a temperature of 70° C. and cooled. In this case, the physical properties are excellent, but there is a disadvantage in that the resin manufacturing method is complex and the particle board productivity is lowered.

In addition, the prior art (Existing technology) to modify the urea-formaldehyde resin (Urea formaldehyde resin) containing melamine as an adhesive composition to improve (Improvement) water resistance (Existing technology) is productivity (Productivity) There was a problem that significantly declined (Significant decline).

However, according to an embodiment of the present invention, the hardening accelerator is a strong alkaline methylolation reaction using a hydroxide and borax of an alkali metal or alkaline earth metal as a catalyst. In the urea-formaldehyde resin produced through ), various methylol urea chemical species can be made to increase the reactivity of the urea-formaldehyde resin. In addition, by using a curing accelerator containing glyoxal derivatives, a 3D structure is created inside the urea-formaldehyde resin through a number of functional groups, improving the water resistance of the final particle board. I can make it. In addition, by hydrolysis of the formaldehyde derivative in the adhesive composition applied to the particle board, it prevents excessively emit of formaldehyde in the final adhesive composition. As one functional group can increase reactivity with a nucleophilic compound, it can significantly improve the productivity of the particle board.

In particular, the use of the glyoxal-based compound of Formula 4 having 4 functional groups has higher hydrolytical stability and reactivity, so that the inherent effects of the present invention can be more preferably secured.

The formaldehyde scavenger composition may include urea, ammonium salt compounds, polyphenol compounds, and carboxylic acid compounds.

The ammonium salt compounds include at least one selected from the group consisting of ammonium carbonate, ammonium chloride, ammonium sulfate, and ammonium nitrate. I can.

The polyphenol compounds are from the group consisting of tannic acid, lignin sulfonic acid, lignin alkali, catechin, quercetin, and flavanone. It may include one or more selected types.

The carboxylic acid compounds are oxalic acid, adipic acid, maleic acid, citric acid, ascorbic acid, and tartaric acid. , Succinic acid and glutaric acid may be one containing at least one selected from the group consisting of (Glutaric acid).

The formaldehyde collector composition is a 1st raw material feeding step in which urea and polycarboxylic acid are charged into a reactor to prepare a mixture. Reaction step of reacting by heating the mixture through the first raw material input step, polyphenol, and ammonium salt in the reactant through the reaction step the addition (add) secondary material In step ^{(2 nd raw material feeding step)} , which may be to include a cooling step of cooling the reaction product passed through the input stage the secondary material (cooling step).

Here, the first raw material input step may be mixing 45 to 90 parts by weight of water, 10 to 45 parts by weight of urea, and 1 to 15 parts by weight of polycarboxylic acid.

The reaction step may be heating the mixture through the first raw material input step to a temperature of 65 to 75 ℃ heating for 30 to 35 minutes.

The second raw material input step and cooling step may be cooling to 25° C. after adding 1 to 5 parts by weight of polyphenol and 1 to 5 parts by weight of ammonium salt to the reactant after the reaction step.

The polycarboxylic acid is oxalic acid, adipic acid, maleic acid, citric acid, ascorbic acid, tartaric acid, and succinic acid. (Succinic acid) and glutaric acid (Glutaric acid) may be one containing at least one selected from the group consisting of. Preferably, it may be adipic acid from the viewpoint of excellent pH stability and ability to promote formaldehyde trapping action.

The polyphenol is at least one selected from the group consisting of tannic acid, lignin sulfonic acid, lignin alkali, catechin, quercetin, and flavanone. It may be included. Preferably, it may be lignin sulfonic acid from the viewpoint of excellent water solubility and formaldehyde trapping ability.

The ammonium salt may include at least one selected from the group consisting of ammonium carbonate, ammonium chloride, ammonium sulfate, and ammonium nitrate. It may be preferably ammonium sulfate from the viewpoint of safe handling and not causing pollution.

In the manufacture of an eco-friendly particle board, the step of drying and molding the mixture (S40) is to further improve the adhesion of the adhesive by drying the mixture in which the wood fiber, the plastic prepolymer composition, and the collector composition are mixed, and the drying method and There is no time limit.

In the manufacture of an eco-friendly particle board, the step of forming a mat by laminating the surface chip mixture layer, the intermediate chip mixture layer, and the surface chip mixture layer in this order (S50) is a mixture for surface chips mixed in the previous step. After forming the first layer, the first layer is formed again with the mixture for multilayer chips on the layer, and the last layer is formed with the mixture for surface chips, and as a result, a mat is formed by laminating with a surface layer-intermediate layer-surface layer.

The weight ratio of the surface layer, which is the two layers constituting the particle board, may be 40 wt% to 45 wt%, and the intermediate layer may be 55 wt% to 60 wt% based on the total weight of the particle board. The total moisture content of the mat is maintained at the same level as that of the existing particle board, but the surface moisture content is relatively higher than the middle layer moisture content, so that heat transfer to the middle layer can be accelerated during the subsequent hot-pressing process, and due to the low moisture content of the middle layer, the spring The phenomenon of spring back can be reduced.

In the manufacture of eco-friendly particle board, the step of manufacturing a particle board by hot-pressing the laminated mat (S50) is formed into a particle board by thermal compression at a temperature of 200 to 250°C with a pressure of 30 to 50 kg/cm ² As a step, the thickness of the eco-friendly particle board manufactured therefrom is preferably 1.2 to 35mm, but is not necessarily limited.

In such a method of manufacturing an eco-friendly particle board, a cooling process may be optionally included, and a step of cutting the formed eco-friendly particle board may be included, and an eco-friendly particle board may be used in a certain size according to the purpose of use. It is cut with, but does not limit the shape of the foundation.

In addition, the step of polishing the surface of the cut eco-friendly particle board may be further included, and the surface of the eco-friendly particle board may be sanded to have a higher aesthetic feel or texture.

By passing through the above process, the eco-friendly particle board according to an embodiment of the present invention in each process can easily manufacture an eco-friendly particle board so that the amount of formaldehyde emission can be significantly reduced while increasing water resistance. .

According to another embodiment of the present invention, an eco-friendly particle board obtained through the manufacturing method as described above is provided.

Specifically, the eco-friendly particle board may include a condensation polymer of urea and formaldehyde and the curing accelerator.

Hereinafter, examples will be described in detail to illustrate the present invention in detail. However, the embodiments according to the present invention may be modified in various forms, and the scope of the present invention should not be construed as being limited to the embodiments described below. Embodiments of the present invention are provided to more completely describe the present invention to those of ordinary skill in the art.

Preparation Examples, Examples and Comparative Examples

Manufacturing example

In the following preparation examples, the cloud point is the time (Time) of the point at which one drop of resin added to a large amount of water at 20° C. is no longer directly dissolved and indicates turbidity. Defined as (Defined).

Preparation of adhesive composition A

As a percentage concentration, 870 g of 37% formalin, 215 g of 1st urea, and 30 g of a curing accelerator A were charged to a 2L reactor, while heating to 30°C. The pH of the reactor was adjusted to pH 10 with a concentration of 2M magnesium hydroxide and borax, and the temperature was raised to 96°C, followed by reaction for 45 minutes. When sufficiently reacted, 280 g of the secondary urea (2nd urea) was added, and the concentration of the reactant was adjusted to pH 4.7 with 2M concentration of formic acid, and the reaction was carried out for 100 minutes while maintaining 96°C. While proceeding the reaction (Proceeding), after checking the cloud point (Check), the pH of the reaction product was adjusted to pH 7.5 with 2M NaOH. The resin with the cloud point checked was cooled to 25°C to terminate the reaction. The molar ratio of formaldehyde/urea in the adhesive composition was 1.3:1.

Preparation of adhesive composition B

As a percentage concentration, 870 g of 37% formalin, 215 g of 1st urea, and 30 g of a curing accelerator A were charged to a 2L reactor, while heating to 30°C. The pH of the reactor was adjusted to pH 10 with a concentration of 2M magnesium hydroxide and borax, and the temperature was raised to 96°C, followed by reaction for 45 minutes. When fully reacted, 215g of secondary urea (2nd urea) is added. The pH was adjusted to 4.7 with 2M concentration of formic acid and reacted for 100 minutes while maintaining 96°C. While proceeding the reaction (Proceeding), after checking the cloud point (Check), the pH of the reaction product was adjusted to pH 7.5 with 2M NaOH. The resin with the cloud point checked was cooled to 25°C to terminate the reaction. The molar ratio of formaldehyde/urea in the adhesive composition was 1.5:1.

Preparation of adhesive composition C

As a percentage concentration, 870 g of 37% formalin, 215 g of 1st urea, and 30 g of a curing accelerator A were charged to a 2L reactor, while heating to 30°C. The pH of the reactor was adjusted to pH 10 with a concentration of 2M magnesium hydroxide and borax, and the temperature was raised to 96°C, followed by reaction for 45 minutes. When fully reacted, 165g of secondary urea (2nd urea) is added. The pH was adjusted to 4.7 with 2M concentration of formic acid and reacted for 100 minutes while maintaining 96°C. While proceeding the reaction (Proceeding), after checking the cloud point (Check), the pH of the reaction product was adjusted to pH 7.5 with 2M NaOH. The resin with the cloud point checked was cooled to 25°C to terminate the reaction. The molar ratio of formaldehyde/urea in the adhesive composition was 1.7:1.

Preparation of adhesive composition D

As a percentage concentration, 870 g of 37% formalin, 215 g of 1st urea, and 30 g of a curing accelerator A were charged to a 2L reactor, while heating to 30°C. The pH of the reactor was adjusted to pH 10 with a concentration of 2M magnesium hydroxide and borax, and the temperature was raised to 96°C, followed by reaction for 45 minutes. If enough reaction, while adding 125g of secondary urea (2nd urea). The pH was adjusted to 4.7 with 2M concentration of formic acid and reacted for 100 minutes while maintaining 96°C. While proceeding the reaction (Proceeding), after checking the cloud point (Check), the pH of the reaction product was adjusted to pH 7.5 with 2M NaOH. The resin with the cloud point checked was cooled to 25°C to terminate the reaction. The molar ratio of formaldehyde/urea in the adhesive composition was 1.9:1.

Preparation of adhesive composition E

As a percentage concentration, 870 g of 37% formalin, 215 g of 1st urea, and 30 g of a curing accelerator A were charged to a 2L reactor, while heating to 30°C. The pH of the reactor was adjusted to pH 10 with a concentration of 2M magnesium hydroxide and borax, and the temperature was raised to 96°C, followed by reaction for 45 minutes. When fully reacted, 92g of secondary urea (2nd urea) is added. The pH was adjusted to 4.7 with 2M concentration of formic acid and reacted for 100 minutes while maintaining 96°C. While proceeding the reaction (Proceeding), after checking the cloud point (Check), the pH of the reaction product was adjusted to pH 7.5 with 2M NaOH. The resin with the cloud point checked was cooled to 25°C to terminate the reaction. The molar ratio of formaldehyde/urea in the adhesive composition was 2.1:1.

Preparation of adhesive composition F

As a percentage concentration, 870 g of 37% formalin, 215 g of 1st urea, and 30 g of a curing accelerator A were charged to a 2L reactor, while heating to 30°C. The pH of the reactor was adjusted to pH 10 with a concentration of 2M magnesium hydroxide and borax, and the temperature was raised to 96°C, followed by reaction for 45 minutes. When fully reacted, 65g of secondary urea (2nd urea) is added. The pH was adjusted to 4.7 with 2M concentration of formic acid and reacted for 100 minutes while maintaining 96°C. While proceeding the reaction (Proceeding), after checking the cloud point (Check), the pH of the reaction product was adjusted to pH 7.5 with 2M NaOH. The resin with the cloud point checked was cooled to 25°C to terminate the reaction. The molar ratio of formaldehyde/urea in the adhesive composition was 2.3:1.

Preparation of adhesive composition G

As a percentage concentration, 870 g of 37% formalin and 215 g of 1st urea were charged to a 2L reactor and heated to 30°C. The pH of the reactor was adjusted to pH 10 with a concentration of 2M magnesium hydroxide and borax, and the temperature was raised to 96°C, followed by reaction for 45 minutes. When fully reacted, 280g of secondary urea (2nd urea) is added. The pH was adjusted to 4.7 with 2M concentration of formic acid and reacted for 100 minutes while maintaining 96°C. While proceeding the reaction (Proceeding), after checking the cloud point (Check), the pH of the reaction product was adjusted to pH 7.5 with 2M NaOH. The resin having a cloud point (Checked) was cooled to 25°C to terminate the reaction. The molar ratio of formaldehyde/urea in the adhesive composition was 1.3:1.

Preparation of adhesive composition H

As a percentage concentration, 870 g of 37% formalin and 215 g of 1st urea were charged to a 2L reactor and heated to 30°C. The pH of the reactor was adjusted to pH 10 with a concentration of 2M magnesium hydroxide and borax, and the temperature was raised to 96°C, followed by reaction for 45 minutes. When fully reacted, 65g of secondary urea (2nd urea) is added. The pH was adjusted to 4.7 with 2M concentration of formic acid and reacted for 100 minutes while maintaining 96°C. While proceeding the reaction (Proceeding), after checking the cloud point (Check), the pH of the reaction product was adjusted to pH 7.5 with 2M NaOH. The resin with the cloud point checked was cooled to 25°C to terminate the reaction. The molar ratio of formaldehyde/urea in the adhesive composition was 2.3:1.

Preparation of adhesive composition I

As a percent concentration, 870 g of 37% formalin was added to the reactor and the temperature was raised to 30°C. The pH of the reactant was adjusted to pH 5 with 2M HCl, 293 g of urea was added, the temperature was raised to the boiling point, and reacted for 50 minutes. After checking the cloud point, the pH of the reaction product was adjusted to pH 8 with 2M NaOH, and 35 g of melamine was added, and the reaction product was reacted for 30 minutes at the boiling point while maintaining the pH of the reaction product at pH 8. After checking the cloud point, 275 g of urea was added and then cooled to 25°C. The molar ratio of the adhesive composition was 1.05:1.

Preparation of adhesive composition J

As a percent concentration, 870 g of 37% formalin was added to the reactor and the temperature was raised to 30°C. After adding 250 g of urea, it was completely dissolved. The pH of the reactant was adjusted to pH 5.6 to 7.2 with a catalyst (formic acid), 54 g of urea was added, and the temperature was raised to 90 to 92°C to react. After sufficiently reacting, the mixture was cooled to 80 to 82°C, and the pH was adjusted to 4.5 to 5.5 with sulfuric acid (% concentration 2%). After adding 35 g of melamine, adjusting the pH of the reactant to pH 9 to 10 with borax and caustic soda (% concentration 4%), reacting at 80° C., and then adding 270 g of urea to the reactor, 65 to 70° C., pH 8 to The reaction was continued at 8.5. Then cooled to 20 to 30 ℃. The molar ratio of the adhesive composition was 1.2:1.

Preparation of formaldehyde trapping agent composition A'

15 parts by weight of urea and 5 parts by weight of adipic acid were mixed with water, heated to 65° C., and then reacted for 30 minutes. When sufficiently reacted, 1 part by weight of lignin sulfonic acid and 1 part by weight of ammonium sulfate were added, and when dissolution was completed (Completed), the reaction was terminated by cooling to 25°C (Terminated). ).

Preparation of formaldehyde trapping agent composition B'

46.87 parts by weight of urea and 3.13 parts by weight of hydroxyamine hydrochloride were mixed in 30° C. water and dissolved

Preparation of formaldehyde trapping agent composition C'

Water 60.4 parts by weight, Urea 36.9 parts by weight, 75% Phosphoric acid 1.1 parts by weight, Dipotassium phosphate 0.8 parts by weight, Diammonium phosphate 0.21 parts by weight Mixed and dissolved.

Cure Accelerator Composition Ⅰ

After mixing 12.5 parts by weight of urea, 24.2 parts by weight of water and 7.6 parts by weight of the glyoxal compound of Formula 4, the mixture is heated to 98°C. Thereafter, the pH was adjusted to 2.1 with nitric acid (70%) and heated for 30 minutes, followed by mixing 30.2 parts by weight of bis(hydroxymethyl)urea and 29.4 parts by weight of water, and adjusting the pH to 7.5 with caustic soda (25%). Cool to 50°C. Thereafter, 19.8 parts by weight of maleic acid was gradually added for 45 minutes to react, and then the pH was adjusted to 8.6 with caustic soda (25%) and cooled to 25°C.

Curing accelerator composition Ⅱ

After mixing 12.5 parts by weight of urea, 24.2 parts by weight of water and 7.6 parts by weight of the glyoxal compound of Formula 2, the mixture is heated to 98°C. Thereafter, the pH was adjusted to 2.1 with nitric acid (70%) and heated for 30 minutes, followed by mixing 30.2 parts by weight of bis(hydroxymethyl)urea and 29.4 parts by weight of water, and adjusting the pH to 7.5 with caustic soda (25%). Cool to 50°C. Thereafter, 19.8 parts by weight of maleic acid was gradually added for 45 minutes to react, and then the pH was adjusted to 8.6 with caustic soda (25%) and cooled to 25°C.

Examples and Comparative Examples

<Particle board manufacturing conditions>

Preparation of the particle board was performed under the following conditions, and the adhesive composition, the formaldehyde collector composition, and the curing accelerator were used by combining the compositions prepared in the above-described Preparation Example as shown in Table 1 below.

Board thickness: 9mm

Adhesive use (Resin content): 80kg/m3 (based on resin solids)

Press temperature: 190℃

Press time: 180 seconds

Scavenger content: 10~50kg/m3 (adjusted based on final molar ratio of 0.85, final molar ratio 0.85, based on solid content of scavenger, solid)

Remark Adhesive composition
(Adhesive composition) Hardening accelerator
(Curing accelerator composition) Formaldehyde
Collector composition
(Formaldehyde scavenger composition) Example 1 Composition A Composition I Composition A’ Example 2 Composition B Composition I Composition A’ Example 3 Composition C Composition I Composition A’ Example 4 Composition D Composition I Composition A’ Example 5 Composition E Composition I Composition A’ Example 6 Composition F Composition I Composition A’ Example 7 Composition A Composition Ⅱ Composition A’ Example 8 Composition F Composition Ⅱ Composition A’ Comparative Example 1 Composition G - Composition A’ Comparative Example 2 Composition H - Composition A’ Comparative Example 3 Composition A Composition I Composition A’ (resin mixing) Comparative Example 4 Composition F Composition I Composition A’ (resin mixing) Comparative Example 5 Composition I - Composition B’ Comparative Example 6 Composition J - Composition C’

Test example

Examples 1 to 8 and Comparative Examples 1 to 6 were repeated three times as in the conditions of Tables 2 and 3 below, and the results are described.

KS F 3104 Particle Board
Quality standards
(180 type, U type, E0 type),
EN321-V313 Peel strength* (MPa)
> 0.3 Flexural strength* (MPa)
>18 Formaldehyde emission amount* (mg/L)
<0.5 Thickness expansion rate*
(24h, %)
<12 V313
Peel strength* (MPa)
Example 1 One 0.32 18.8 0.33 10.9 0.10 2 0.38 18.7 0.29 11.0 0.06 3 0.33 18.8 0.28 12.3 0.05 Example 2 One 0.31 18.0 0.27 11.4 0.04 2 0.34 17.9 0.35 12.0 0.10 3 0.34 19.3 0.31 12.0 0.10 Example 3 One 0.40 18.7 0.26 10.4 0.08 2 0.34 19.7 0.33 11.3 0.11 3 0.43 18.3 0.37 11.6 0.11 Example 4 One 0.42 19.3 0.45 9.9 0.20 2 0.45 18.7 0.33 10.4 0.11 3 0.39 19.3 0.45 10.3 0.11 Example 5 One 0.46 20.1 0.50 8.9 0.09 2 0.50 18.2 0.44 9.0 0.20 3 0.45 19.6 0.41 10.3 0.22 Example 6 One 0.49 21.3 0.39 9.0 0.11 2 0.60 19.8 0.44 7.6 0.23 3 0.47 19.2 0.48 9.5 0.23 Example
7 One 0.31 18.1 0.39 11.8 0.05 2 0.29 17.0 0.48 11.1 0.05 3 0.30 19.1 0.49 11.6 0.07 Example
8 One 0.30 18.1 0.49 10.0 0.15 2 0.40 18.7 0.59 10.4 0.16 3 0.39 18.3 0.40 9.7 0.10 Comparative Example 1 One 0.25 16.7 0.44 14.4 0.03 2 0.28 20.0 0.50 13.7 0.01 3 0.19 15.8 0.53 12.7 0.11 Comparative Example 2 One 0.32 17.1 0.61 12.1 0.10 2 0.40 18.0 0.58 12.9 0.11 3 0.33 19.2 0.73 13.3 0.03 Comparative Example 3 One 0.28 17.9 0.38 14.0 0.01 2 0.29 17.6 0.39 13.1 0.02 3 0.26 17.9 0.43 11.9 0.06 Comparative Example 4 One 0.50 16.8 0.66 13.0 0.12 2 0.38 16.1 0.53 12.3 0.07 3 0.32 19.6 0.37 13.4 0.08 Comparative Example 5 One 0.30 17.1 0.40 11.1 0.12 2 0.31 16.9 0.41 11.6 0.09 3 0.26 18.2 0.36 10.9 0.09 Comparative Example 6 One 0.22 16.9 0.45 11.9 0.06 2 0.28 17.4 0.34 11.0 0.07 3 0.31 15.5 0.53 8.0 0.08 * Peeling strength: Internal Bond, flexural strength: Modulus of rupture
* Formaldehyde emission amount: Desiccator method
* Thickness expansion rate: Thickness swelling
* V313 (EN321): 3 cycles (20℃ 72hr, -12℃ 24hr, 70℃ 72hr)

KS F 3104 Particle Board
Quality standards
(180 type, U type, E0 type),
EN321-V313 Peel strength* (MPa)
> 0.3

Heat pressure time: 140 seconds Peel strength* (MPa)
> 0.3
Heat pressure time: 160 seconds Peel strength* (MPa)
> 0.3
Heat pressure time: 180 seconds Example 1 One 0.29 0.30 0.32 2 0.29 0.31 0.28 3 0.32 0.31 0.33 Example 2 One 0.29 0.30 0.31 2 0.33 0.33 0.34 3 0.32 0.31 0.34 Example 3 One 0.35 0.38 0.40 2 0.32 0.32 0.34 3 0.31 0.39 0.43 Example 4 One 0.38 0.40 0.42 2 0.42 0.43 0.45 3 0.30 0.34 0.39 Example 5 One 0.37 0.45 0.46 2 0.32 0.44 0.50 3 0.37 0.42 0.45 Example 6 One 0.31 0.45 0.49 2 0.45 0.55 0.60 3 0.39 0.43 0.47 Example 7 One 0.31 0.30 0.31 2 0.29 0.31 0.32 3 0.30 0.29 0.28 Example 8 One 0.32 0.31 0.32 2 0.30 0.34 0.30 3 0.29 0.28 0.29 Comparative Example 1 One 0.21 0.20 0.25 2 0.24 0.25 0.28 3 0.17 0.16 0.19 Comparative Example 2 One 0.26 0.28 0.28 2 0.25 0.30 0.29 3 0.22 0.24 0.28 Comparative Example 3 One 0.24 0.29 0.28 2 0.18 0.26 0.27 3 0.27 0.31 0.30 Comparative Example 4 One 0.24 0.33 0.30 2 0.21 0.26 0.27 3 0.18 0.25 0.25 Comparative Example 5 One 0.20 0.26 0.29 2 0.15 0.23 0.24 3 0.17 0.22 0.26 Comparative Example 6 One 0.13 0.19 0.25 2 0.22 0.25 0.24 3 0.16 0.27 0.25

Table 2 shows a comparison of the characteristics (physical properties) of the particle board manufactured by the manufacturing method of the present invention and the particle board manufactured in the laboratory by the conventional manufacturing method.

As shown in Table 2, as a result of using the urea formaldehyde resin, curing accelerator, and formaldehyde trapping agent of the present invention, and using the trapping agent input process of the present invention, the peel strength, flexural strength, formaldehyde emission amount, and thickness expansion rate are all quality standards. ) Passed.

Examples 7 and 8 in which the curing accelerator of the present invention used Chemical Formula 2 having four amorphous functional groups among glyoxal-based compounds were compared to Examples 1 and 6 using Chemical Formula 4 having four crystalline functional groups. Overall physical properties declined, but quality standards were met.

In the case of Comparative Example 1 in which the curing accelerator, which is a reactivity enhancing additive in the urea-formaldehyde resin of the present invention, was not added, only the amount of formaldehyde emission was within the quality standard, and in the case of Comparative Example 2, the peel strength and the flexural strength met the quality standard. However, the thickness expansion rate and the release amount of formaldehyde did not meet the quality standards.

In Comparative Example 3, which was mixed with a resin without using the trapping agent input process of the present invention, only the amount of formaldehyde emission met the quality standard, and in the case of Comparative Example 4, only the peel strength met the quality standard.

In Comparative Examples 5 and 6, when melamine was added to a conventional low molar ratio urea-formaldehyde resin, and a conventional formaldehyde trapping agent was used, only the formaldehyde emission amount and the thickness expansion rate met the quality criteria.

In addition, as a result of the V313 test, which is a water resistance test, in the case of peel strength, it was confirmed that all examples of the present invention exhibited superior physical properties (Superb properties) in the range of 0.07 to 0.19 MPa on average, and from 0.03 to 0.10 MPa on average of all comparative examples.

Table 3 shows the characteristics (physical properties) of the particle board according to the manufacturing method of the present invention and the particle board manufactured in the laboratory by the conventional manufacturing method as a comparison of the peel strength by heat pressure time.

As shown in Table 3, urea-formaldehyde resin modified with the curing accelerator of the present invention and a formaldehyde trapping agent were used, and as a result of using the trapping agent input process of the present invention, the heat pressure time was shortened from 180 seconds to 160 seconds and 140 seconds. Although it was within the strength quality standard, in all comparative examples, the peel strength did not satisfy the quality standard.

Claims (11)

Cutting the wood material with a crusher to produce wood chips;
Drying the wood chips;
Dividing the dried wood chips by size and weight and classifying them into a surface layer chip and a middle layer chip;
Forming a mixture by independently mixing an adhesive composition, a formaldehyde scavenger composition, and a curing accelerator with the surface chip and the intermediate chip;
Forming a mat by laminating a surface chip mixture layer, an intermediate chip mixture layer, and a surface chip mixture layer in this order;
Including the step of producing a particle board by hot pressure processing the laminated mat,
The adhesive composition has a molar ratio of formaldehyde and (NH ₂ ) ₂ of 1.3 to 2.5: 1,
The formaldehyde scavenger composition comprises urea, polyphenol type compounds, ammonium salt and carboxylic acid compounds. Manufacturing method. The method according to claim 1,
The adhesive composition is a method of manufacturing an eco-friendly particle board comprising a urea derived monomer and a formaldehyde derived monomer. delete The method according to claim 1,
The curing accelerator is converted into heterocyclic glycoluril type compounds by reacting glyoxal type compounds with urea, and then hydroxy alkyl urea compounds, carboxylic acid compounds. A method of manufacturing an eco-friendly particle board containing a prepolymer obtained by reacting a compound (Carboxylic acid type compounds). delete The method of claim 4,
The glyoxal-based compounds include glyoxal, sodium glyoxylate, glycoluril, tetramethylol glycoluril, and glyoxal-based compounds of Formulas 1 to 4 below (Glyoxal). type compounds), a method of manufacturing an eco-friendly particle board containing at least one selected from the group consisting of.
[Formula 1]

[Formula 2]

[Formula 3]

[Formula 4]

The method according to claim 1,
The weight ratio of the adhesive composition and the curing accelerator is 1: 0.02 to 0.06 in the manufacturing method of the eco-friendly particle board. The method of claim 4,
The prepolymer is a method of manufacturing an eco-friendly particle board that is a compound of Formula 5.
[Formula 5]

(Wherein, R is an alkyl group having 1 to 5 carbon atoms, and n is an integer of 1 to 10.)
The method according to claim 1,
Preparation of the adhesive composition,
A first raw material input step of preparing a mixture by adding urea derived monomer, formaldehyde derived monomer, and a curing accelerator;
A first acidity control step (pH control) of adding a catalyst to the mixture through the raw material input step;
A first condensation polymerization step of heating and reacting a mixture that has undergone the first acidity control step;
A second raw material input step of injecting urea into a polymer (Condensate) that has undergone the first condensation polymerization step;
A second condensation polymerization step of reacting the polymer through the second raw material input step; And
A method of manufacturing an eco-friendly particle board comprising a cooling step of cooling the polymer produced through the secondary condensation polymerization step. The method of claim 9,
In the step of preparing the mixture, a method of manufacturing an eco-friendly particle board to which a curing accelerator is added to the reactor. It is prepared by the manufacturing method of any one of claims 1 to 2, 4, 6 to 10,
Eco-friendly particle board comprising a condensation polymer of urea and formaldehyde and the curing accelerator.

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