JPWO2009096164A1 - Formaldehyde resin-based wood board adhesive composition - Google Patents

Abstract

The adhesive composition includes an aqueous formaldehyde resin solution and a formaldehyde scavenger composed of bisulfite coated with a higher fatty acid that reacts with formaldehyde. The bisulfite is sodium bisulfite.

Description

  The present invention relates to a formaldehyde resin wood-based adhesive composition used for the production of wood boards such as particle boards and fiber boards.

  Conventionally, a formaldehyde resin wood adhesive composition is known as a wood adhesive used for wood materials such as plywood, particle board, and MDF. The formaldehyde resin-based wood adhesive composition is a formaldehyde resin obtained by condensing one or more compounds selected from amino compounds such as urea, melamine and benzoguanamine or phenol compounds such as phenol and resorcinol with formaldehyde It is an aqueous solution. The above-mentioned formaldehyde resin wood adhesive composition is inexpensive and has superior performance in normal adhesive strength compared to vinyl acetate resin emulsion adhesives.

  However, from the wood material using the formaldehyde resin wood adhesive composition, formaldehyde is released and causes health problems such as sick house syndrome and chemical sensitivity, which is a social problem.

  Therefore, on February 27, 2003, Japanese agricultural and forestry standards for plywood stipulated that formaldehyde emission (hereinafter referred to as F emission) is stricter than before, with an average emission of 0.3 mg / L and a maximum value of 0.4 mg. Performance categories below / L were provided. The performance category is represented by a display mark F ☆☆☆☆.

  In order to satisfy the performance category F ☆☆☆☆, as a method for reducing the amount of F emission from the wood material using the formaldehyde resin wood adhesive composition, it was coated with waxes such as paraffin wax. A formaldehyde resin wood-based adhesive composition containing an aldehyde scavenger made of sodium hydrogen sulfite or the like has been proposed (see, for example, Patent Document 1).

However, the formaldehyde resin-based wood adhesive composition containing the aldehyde scavenger has the disadvantage that the amount of formaldehyde emitted from the wood material using the adhesive composition may not be sufficiently reduced. .
JP 2007-38661 A

  An object of the present invention is to provide an adhesive composition for a formaldehyde resin-based wooden board that can eliminate such disadvantages and can sufficiently reduce the amount of formaldehyde emitted from the wooden material using the same.

  To achieve this object, the formaldehyde resin wood board adhesive composition of the present invention comprises an aqueous formaldehyde resin solution and a formaldehyde scavenger comprising a bisulfite salt coated with a higher fatty acid that reacts with formaldehyde. It is characterized by.

  In the adhesive composition for formaldehyde resin wood board according to the present invention, both the bisulfite and the higher fatty acid covering the bisulfite synergistically act as a formaldehyde scavenger, and therefore, simply the sulfite. A better formaldehyde scavenging effect can be obtained than a mixture of a hydrogen salt and the higher fatty acid. Therefore, according to the adhesive composition for formaldehyde resin wood board of the present invention, the amount of F emission from the wood material using the adhesive composition can be sufficiently reduced.

  The adhesive composition for formaldehyde resin wood boards of the present invention can be used particularly advantageously for the production of wood boards such as particle boards and fiber boards.

  Examples of the formaldehyde resin include a resin obtained by condensing formaldehyde with an amino compound.

  In the adhesive composition for formaldehyde resin wood board of the present invention, the bisulfite is coated with the higher fatty acid in the range of 0.5 to 25% by weight with respect to the total amount of the formaldehyde scavenger. It is preferable. If the higher fatty acid is less than 0.5% by weight, the bisulfite may not be sufficiently coated. Further, even if the higher fatty acid exceeds 25% by weight, no further effect can be expected.

  In the adhesive composition for formaldehyde resin wood board of the present invention, the higher fatty acid preferably has a melting point in the range of 40 to 120 ° C. If the melting point of the higher fatty acid is less than 40 ° C., it may melt at room temperature without applying heat. Further, when the melting point of the higher fatty acid exceeds 120 ° C., it may be difficult to coat the bisulfite.

  In the adhesive composition for formaldehyde resin wood board according to the present invention, the higher fatty acid may react with formaldehyde at a temperature in the range of 110 to 200 ° C., for example. Examples of the higher fatty acid include stearic acid, lauric acid, and behenic acid.

  The formaldehyde resin wood board adhesive composition of the present invention preferably contains the formaldehyde scavenger in a range of 2 to 35 parts by weight with respect to 100 parts by weight of the solid content of the formaldehyde resin aqueous solution. If the formaldehyde scavenger is less than 2 parts by weight, a sufficient formaldehyde scavenging effect may not be obtained. On the other hand, if the formaldehyde scavenger exceeds 35 parts by weight, sufficient adhesive strength may not be obtained in the formaldehyde resin-based wood board adhesive composition, which further increases costs.

  Next, the formaldehyde resin-based wood board adhesive composition of the present embodiment will be described in detail.

  An adhesive composition for formaldehyde resin wood board according to the present embodiment includes an aqueous formaldehyde resin solution and a formaldehyde resin wood board adhesive comprising a formaldehyde scavenger made of bisulfite coated with a higher fatty acid that reacts with formaldehyde. It is a composition.

  In the formaldehyde resin-based wood board adhesive composition of the present embodiment, the formaldehyde resin may be a resin in which formaldehyde and an amino compound are condensed. Examples of the amino compound include one or more compounds selected from urea, ethylene urea, melamine, guanidine and the like.

  In the formaldehyde resin-based wood board adhesive composition of the present embodiment, the formaldehyde resin may be one or more compounds selected from phenol compounds, such as phenol and resorcinol, instead of the amino compounds. . Further, instead of the amino compound, a resin using both the amino compound and the phenol compound may be used.

  In the adhesive composition for formaldehyde resin wood board according to the present embodiment, the molar ratio of formaldehyde forming the formaldehyde resin and the amino compound or phenol compound is not particularly limited, and is 0.5 to 2 based on the formaldehyde. .5 range.

  In the present embodiment, the formaldehyde resin may be modified with alcohols such as polyvinyl alcohol.

  In the adhesive composition for formaldehyde resin wood board of the present embodiment, the solid content contained in the aqueous formaldehyde resin solution is not particularly limited, and for example, in the range of 30 to 80% by weight with respect to the total amount of the aqueous solution. can do.

  In the adhesive composition for formaldehyde resin wood board of the present embodiment, examples of the bisulfite include sodium bisulfite.

  In the adhesive composition for formaldehyde resin wood board according to the present embodiment, the higher fatty acid is a solid fatty acid that is solid at room temperature, becomes a low-viscosity liquid when heated, and reacts with formaldehyde. The melting point of the higher fatty acid is not particularly limited, but is preferably 40 to 120 ° C. Moreover, the said higher fatty acid can use what reacts with formaldehyde at the temperature of the range of 110-200 degreeC, for example. Examples of such higher fatty acids include saturated fatty acids such as tridecylic acid, lauric acid, pentadecylic acid, myristic acid, valmitic acid, stearic acid, arachidic acid, behenic acid, lignoceric acid, serotic acid, montanic acid, and melicic acid. However, it is preferably one saturated fatty acid selected from the group consisting of stearic acid, lauric acid and behenic acid. The higher fatty acid may be used by appropriately mixing two or more of the saturated fatty acids.

  In the formaldehyde resin-based wood board adhesive composition of the present embodiment, the amount of the higher fatty acid used is not particularly limited, but is in the range of 0.5 to 25% by weight with respect to the total amount of the formaldehyde scavenger. It is preferable.

  The method for coating the bisulfite with the higher fatty acid is not particularly limited. For example, the bisulfite particles may be mixed with a stirring mixer such as a super mixer, a high speed mixer, a planetary mixer, a ribbon blender, or the like. A method of adding the previously melted higher fatty acid while stirring can be mentioned.

  The adhesive composition for formaldehyde resin wood board of the present embodiment preferably contains the formaldehyde scavenger in the range of 2 to 35 parts by weight with respect to 100 parts by weight of the solid content contained in the aqueous formaldehyde resin solution. More preferably, it is contained in the range of 5 to 30 parts by weight.

  In addition, the formaldehyde resin-based wood board adhesive composition of the present embodiment may contain a filler or a filler as necessary.

  As the extender, those conventionally added to wood board adhesives can be used, and examples of such extenders include wheat flour, starch powder, soybean powder, blood powder and the like. The bulking agent may be used alone or in combination of two or more.

  Examples of the filler include organic fillers such as wood powder, walnut powder, and coconut powder, clay, kaolin clay, calcined clay, acid clay, activated clay, aluminum hydroxide, aluminum oxide, diatomaceous earth, sepiolite, pearlite, and zeolite. And inorganic fillers such as gypsum, calcined gypsum and silica. The said filler may be used independently and may use 2 or more types together.

  The formaldehyde resin-based wood board adhesive composition of the present embodiment may further contain an aqueous latex resin or an emulsion resin as necessary. By blending the aqueous latex resin or emulsion resin with the formaldehyde resin wood board adhesive composition of the present embodiment, the dispersibility of the adhesive composition can be improved and the filling is performed. The mixing stability with the agent and the extender can be improved.

  Examples of the aqueous latex resin or emulsion resin include styrene, styrene derivatives, butadiene, chloroprene, isoprene, vinyl acetate, vinyl propionate, ethylene, acrylonitrile, acrylic acid ester, methacrylic acid ester, vinyl chloride, vinylidene chloride, Examples thereof include a polymer of one type of unsaturated monomer selected from the group consisting of ethyl vinyl ether, acrylamide, isobutene, and the like, and a copolymer of two or more types of unsaturated monomers.

  The polymer or copolymer is a copolymer aqueous latex resin comprising a copolymer of the unsaturated monomer and one or more unsaturated monomers having a hydroxyl group, a carboxyl group or an amide group, or It may be a copolymer emulsion resin. Examples of the unsaturated monomer having a hydroxyl group include allyl alcohol, 2-hydroxylethyl methacrylate, 2-hydroxylethyl acrylate, 2-hydroxypropyl methacrylate, 2-hydroxypropyl acrylate, and monoallyl ethers of polyhydric alcohols. Etc.

  Examples of the unsaturated monomer having a carboxyl group include maleic acid, maleic acid monoester, maleic acid diester, itaconic acid, itaconic acid monoester, fumaric acid, fumaric acid monoester, citraconic acid, citraconic acid monoester, and metacone. Examples thereof include ethylenically unsaturated dicarboxylic acids such as acids and metaconic acid monoesters or esters thereof, crotonic acid, acrylic acid, and monocarboxylic acids of methacrylic acid.

  Examples of the unsaturated monomer having an amide group include N-methylolacrylamide and N-methylolmethacrylamide.

  The adhesive composition for formaldehyde resin wood board of this embodiment can be suitably used as an adhesive for particle board manufacture and an adhesive for fiber board manufacture.

  Next, examples and comparative examples of the present invention are shown.

  In this example, first, 1980 g of sodium bisulfite (trade name: anhydrous sodium bisulfite) manufactured by Daito Chemical Co., Ltd. was charged into a 20 liter supermixer, and 1000 r. p. m. The mixture was heated to 80 ° C. while stirring at a rotation speed of 20 g, and then 20 g of stearic acid (trade name: rubber lunac S-50, melting point 58 to 65 ° C., manufactured by Kao Corporation) previously melted for 1 minute. And dripped. After the entire amount of stearic acid was dropped, the mixture was further stirred at 80 ° C. for 10 minutes, 1000 r. p. m. The surface of the sodium hydrogen sulfite was uniformly coated with stearic acid.

  After coating with stearic acid, 600 r. p. m. Sulfurous acid coated with 1% by weight of stearic acid with respect to the total amount by cooling to room temperature while taking care not to fuse the sodium bisulfite coated with stearic acid to each other A formaldehyde scavenger consisting of sodium hydride was prepared.

  Next, lauan wood chips prepared by adding 3.82 g of formaldehyde scavenger (including 3.78 g of sodium bisulfite) consisting of sodium bisulfite coated with 1% by weight of stearic acid using a 5 mesh full screen sieve. It was mixed uniformly with 441.8 g. The lauan wood chips are dried to a moisture content of 5% or less.

  Next, 100 g of urea / melamine / formaldehyde resin (Oshika Co., Ltd., Oshika Resin TX-202, non-volatile content 64% by weight, viscosity 0.20 Pa · s at 23 ° C.) and urea / formaldehyde resin (manufactured by Oshika Co., Ltd.) , Oshika Resin 283S, nonvolatile content 46% by weight, viscosity 0.32 Pa · s at 23 ° C.) 100 g and ammonium chloride 2.7 g as a curing agent were mixed to prepare an aqueous formaldehyde resin solution.

  Next, 108.3 g of the aqueous formaldehyde resin solution was sprayed uniformly onto 445.6 g of Lauan wood chips uniformly mixed with the formaldehyde scavenger. As a result, the formaldehyde resin wood board adhesive composition of the present example containing the formaldehyde resin aqueous solution and the formaldehyde scavenger was formed on the surface of the Lawan wood chip. The adhesive composition for formaldehyde resin wood board of the present embodiment contains 6.34 parts by weight of the formaldehyde scavenger with respect to 100 parts by weight of the nonvolatile content (solid content) contained in the aqueous formaldehyde resin solution.

  Next, 523.9 g of the lauan wood chip mixed with the formaldehyde resin aqueous solution and the formaldehyde scavenger is weighed and uniformly spread on a 5 mm thick duralumin plate on which a release sheet (polytetrafluoroethylene) is placed. Then, a spacer having a thickness of 5 mm was placed thereon, and the release sheet and the duralumin plate were placed in this order, and then inserted into a hot plate. Next, a particle board having a size of 350 × 350 mm was manufactured with a target thickness of 5 mm under the conditions of 170 ° C., 35 seconds at an initial pressure of 3500 Pa, and 15 seconds at a secondary pressure of 150 Pa (total heat pressure time of 50 seconds). .

  Next, using the particle board as a test plate, bending strength, water absorption thickness swelling rate, and formaldehyde emission were measured. Based on the bending strength test of the particle board specified in JIS (Japanese Industrial Standard) A 5908, the bending strength is prepared from a test piece having a length of 170 mm and a width of 50 mm from the test plate. A load was applied from the surface so that the average deformation speed was 10 mm / min, the maximum load was measured, and the calculation was performed by the following equation (1). The results are shown in Table 1.

Bending strength (N / mm ₂ ) = 3PL / 2bt ₂ (1)
In the formula (1), P is the maximum load (N), L is the span (mm), b is the width (mm) of the test piece, and t is the thickness (mm) of the test piece.

  Next, based on the water absorption thickness swelling rate test specified in JIS A 5908, a test piece having a predetermined dimension was prepared from the test plate. Next, based on a water absorption thickness swelling rate test according to JIS A 5908, the water absorption thickness swelling rate (%) of the test piece was measured. The results are shown in Table 1.

  Next, based on the formaldehyde emission test specified in JIS A 5908, a test piece having a predetermined size was prepared from the test plate. Next, the formaldehyde emission amount (mg / L) of the test piece was measured based on a formaldehyde emission amount test according to JIS A 5908. The results are shown in Table 1.

  In this example, sodium bisulfite (1900 g) and stearic acid (100 g) were used. Except that stearic acid was added dropwise to sodium bisulfite over 2 minutes, this was exactly the same as in Example 1, except that 5% by weight of stearin was used. A formaldehyde scavenger consisting of sodium bisulfite coated with acid was prepared. A particleboard was produced in exactly the same manner as in Example 1 except that 3.98 g of the formaldehyde scavenger (including 3.78 g of sodium bisulfite) was used. The adhesive composition for formaldehyde resin wood board of this example contains 6.61 parts by weight of the formaldehyde scavenger with respect to 100 parts by weight of the nonvolatile content contained in the aqueous formaldehyde resin solution.

  Next, except for using the particle board as a test plate, the bending strength, the water absorption thickness swelling ratio, and the formaldehyde emission amount were measured in the same manner as in Example 1. The results are shown in Table 1.

  In this example, sodium bisulfite (1800 g) and stearic acid (200 g) were used. Except that stearic acid was added dropwise to sodium bisulfite over 3 minutes, the same amount as in Example 1 was obtained. A formaldehyde scavenger consisting of sodium bisulfite coated with acid was prepared. A particle board was produced in exactly the same manner as in Example 1, except that 4.2 g of the formaldehyde scavenger (including 3.78 g of sodium hydrogen sulfite) was used. The adhesive composition for formaldehyde resin wood board of the present Example contains 6.98 parts by weight of the formaldehyde scavenger with respect to 100 parts by weight of the nonvolatile content contained in the aqueous formaldehyde resin solution.

  Next, except for using the particle board as a test plate, the bending strength, the water absorption thickness swelling ratio, and the formaldehyde emission amount were measured in exactly the same manner as in Example 1. The results are shown in Table 1.

  In this example, 1640 g of sodium hydrogen sulfite and 360 g of stearic acid were used, and stearic acid was added dropwise to sodium hydrogen sulfite over 5 minutes. A formaldehyde scavenger consisting of sodium bisulfite coated with acid was prepared. A particle board was produced in exactly the same manner as in Example 1 except that 4.61 g of the formaldehyde scavenger (including 3.78 g of sodium hydrogen sulfite) was used. The adhesive composition for formaldehyde resin wood board of this example contains 7.66 parts by weight of the formaldehyde scavenger with respect to 100 parts by weight of the nonvolatile content contained in the aqueous formaldehyde resin solution.

  Next, except for using the particle board as a test plate, the bending strength, the water absorption thickness swelling ratio, and the formaldehyde emission amount were measured in exactly the same manner as in Example 1. The results are shown in Table 1.

  In this example, a formaldehyde scavenger consisting of sodium bisulfite coated with 10% by weight of stearic acid was prepared in exactly the same manner as in Example 3. A particle board was produced in the same manner as in Example 1 except that 8.4 g of the formaldehyde scavenger (including 7.56 g of sodium hydrogen sulfite) was used. The adhesive composition for formaldehyde resin wood board of the present Example contains 13.95 parts by weight of the formaldehyde scavenger with respect to 100 parts by weight of the nonvolatile content contained in the aqueous formaldehyde resin solution.

Next, except for using the particle board as a test plate, the bending strength, the water absorption thickness swelling ratio, and the formaldehyde emission amount were measured in exactly the same manner as in Example 1. The results are shown in Table 1.
[Comparative Example 1]
In this comparative example, a particle board was produced in exactly the same manner as in Example 1 except that no formaldehyde scavenger was used.

Next, except for using the particle board as a test plate, the bending strength, the water absorption thickness swelling ratio, and the formaldehyde emission amount were measured in exactly the same manner as in Example 1. The results are shown in Table 1.
[Comparative Example 2]
In this comparative example, a particle board was produced in exactly the same manner as in Example 1, except that 3.78 g of sodium bisulfite that was not coated with stearic acid was used.

Next, except for using the particle board as a test plate, the bending strength, the water absorption thickness swelling ratio, and the formaldehyde emission amount were measured in exactly the same manner as in Example 1. The results are shown in Table 1.
[Comparative Example 3]
In this comparative example, the particle board test was carried out in exactly the same way as in Example 1, except that 3.78 g of sodium bisulfite not coated with stearic acid and 0.42 g of 40 mesh whole stearic acid were used. A board was produced. In this comparative example, sodium bisulfite and stearic acid are simply mixed.

Next, except for using the particle board as a test plate, the bending strength, the water absorption thickness swelling ratio, and the formaldehyde emission amount were measured in exactly the same manner as in Example 1. The results are shown in Table 1.
[Comparative Example 4]
In this comparative example, a formaldehyde scavenger was prepared in exactly the same manner as in Example 1, except that 3.78 g of sodium sulfite was used instead of sodium bisulfite and the sodium sulfite was coated with 0.42 g of stearic acid.

  Next, a particle board was produced in the same manner as in Example 1 except that 4.2 g of the formaldehyde scavenger obtained in this comparative example was used.

  Next, except for using the particle board as a test plate, the bending strength, the water absorption thickness swelling ratio, and the formaldehyde emission amount were measured in exactly the same manner as in Example 1. The results are shown in Table 1.

表１から、全量に対して１〜１８重量％のステアリン酸で被覆されている亜硫酸水素ナトリウムからなるホルムアルデヒド捕捉剤を、ホルムアルデヒド樹脂水溶液に含まれる固形分１００重量部に対して、６．３４〜７．６６重量部含む実施例１〜４の木質ボード用接着剤組成物によれば、ホルムアルデヒド捕捉剤を含まない比較例１の木質ボード用接着剤組成物に比較して、ホルムアルデヒド放散量を低減する上で優れた効果を得ることができることが明らかであり、曲げ強さ及び吸水厚さ膨潤率も略同等であることが明らかである。また、実施例３の２倍のホルムアルデヒド捕捉剤を含む実施例５の木質ボード用接着剤組成物によれば、実施例３の木質ボード用接着剤組成物に比較して、さらにホルムアルデヒド放散量を低減できることが明らかである。

From Table 1, the formaldehyde scavenger consisting of sodium bisulfite coated with 1 to 18% by weight of stearic acid with respect to the total amount is from 6.34 to 100 parts by weight of solid content in the aqueous formaldehyde resin solution. According to the adhesive composition for wood boards of Examples 1-4 containing 7.66 parts by weight, the amount of formaldehyde emitted is reduced as compared with the adhesive composition for wood boards of Comparative Example 1 that does not contain a formaldehyde scavenger. It is clear that an excellent effect can be obtained, and it is clear that the bending strength and the water absorption thickness swelling rate are substantially equivalent. Moreover, according to the adhesive composition for wooden boards of Example 5 containing twice the formaldehyde scavenger of Example 3, compared with the adhesive composition for wooden boards of Example 3, the amount of formaldehyde emitted is further increased. Clearly, it can be reduced.

  Further, as a formaldehyde scavenger, Comparative Example 2 containing only a sodium bisulfite that is not coated with stearic acid at all. A comparative example containing a mixture of stearic acid and sodium hydrogen sulfite as a formaldehyde scavenger. According to 3 wood board adhesive composition, compared with the wood board adhesive composition of Comparative Example 1, although the amount of formaldehyde emission can be reduced, Examples 1-5 wood board adhesive It is clear that it does not reach the agent composition.

  In addition, according to the wood board adhesive composition for Comparative Example 4 using sodium sulfite instead of sodium hydrogen sulfite, the amount of formaldehyde diffused was substantially the same as that of the wood board adhesive composition for Comparative Example 1, and formaldehyde emissions were It is clear that the effect of reducing the amount cannot be obtained.

  In this example, except that lauric acid (manufactured by Wako Pure Chemical Industries, Ltd., reagent grade 1, melting point 42-46 ° C.) was used instead of stearic acid, it was exactly the same as Example 3, and the total amount A formaldehyde scavenger consisting of sodium bisulfite coated with 10 wt% lauric acid was prepared. A particle board was produced in exactly the same manner as in Example 1, except that 4.2 g of the formaldehyde scavenger (including 3.78 g of sodium hydrogen sulfite) was used. The adhesive composition for formaldehyde resin wood board of the present Example contains 6.98 parts by weight of the formaldehyde scavenger with respect to 100 parts by weight of the nonvolatile content contained in the aqueous formaldehyde resin solution.

  Next, the bending strength, the water absorption thickness swelling ratio, and the formaldehyde emission amount were measured in exactly the same manner as in Example 1 except that the particle board was used as a test plate. The results are shown in Table 2.

  In this example, behenic acid (manufactured by Wako Pure Chemical Industries, Ltd., reagent grade 1, melting point 80 ° C.) was used in place of stearic acid, and 10 minutes at 100 ° C. and 1000 r. p. m. A formaldehyde scavenger composed of sodium bisulfite coated with 10% by weight of behenic acid was prepared in exactly the same manner as in Example 3 except that stirring was performed at a rotational speed of. A particle board was produced in the same manner as in Example 1 except that 4.2 g of the formaldehyde scavenger (including 3.78 g of total sodium hydrogen sulfite) was used. The adhesive composition for formaldehyde resin wood board of the present Example contains 6.98 parts by weight of the formaldehyde scavenger with respect to 100 parts by weight of the nonvolatile content contained in the aqueous formaldehyde resin solution.

Next, except for using the particle board as a test plate, the bending strength, the water absorption thickness swelling ratio, and the formaldehyde emission amount were measured in exactly the same manner as in Example 1. The results are shown in Table 2.
[Comparative Example 5]
In this comparative example, it was exactly the same as Example 3 except that paraffin wax (manufactured by Nippon Seiki Co., Ltd., trade name: HNP-5, melting point: 62 ° C.) was used instead of stearic acid. A formaldehyde scavenger consisting of sodium bisulfite coated with 10% by weight paraffin wax was prepared. A particle board was produced in the same manner as in Example 1 except that 4.2 g of the formaldehyde scavenger (including 3.78 g of sodium hydrogen sulfite) was used.

  Next, except for using the particle board as a test plate, the bending strength, the water absorption thickness swelling ratio, and the formaldehyde emission amount were measured in exactly the same manner as in Example 1. The results are shown in Table 2.

表２から、ステアリン酸に代えてラウリン酸またはベヘン酸で被覆されている亜硫酸水素ナトリウムからなるホルムアルデヒド捕捉剤を含む実施例６または実施例７の木質ボード用接着剤組成物によれば、ホルムアルデヒド放散量を低減する上で、表２に再掲する実施例３の木質ボード用接着剤組成物と略同等の効果を得ることができることが明らかである。

From Table 2, according to the wood board adhesive composition of Example 6 or Example 7 comprising a formaldehyde scavenger consisting of sodium bisulfite coated with lauric acid or behenic acid instead of stearic acid, formaldehyde emission In reducing the amount, it is apparent that substantially the same effect as the wood board adhesive composition of Example 3 shown in Table 2 can be obtained.

  Moreover, according to the adhesive composition for wood boards of Comparative Example 5 using paraffin wax instead of stearic acid, it is compared with the adhesive composition for wood boards of Comparative Example 1 not using a formaldehyde scavenger (see Table 1). Thus, although it is possible to reduce the amount of formaldehyde emitted, it is clear that it does not reach the adhesive compositions for wood boards of Examples 3, 6 and 7.

  In this example, a formaldehyde scavenger consisting of sodium bisulfite coated with 10% by weight of stearic acid was prepared in exactly the same manner as in Example 3. 6.6 g of the formaldehyde scavenger (including 5.94 g of sodium bisulfite) was uniformly mixed with 347.1 g of cedar wood chips prepared with a 5-mesh sieve. The cedar wood chips are dried to a moisture content of 5% by weight or less.

  Next, a curing agent is mixed with 200 g of urea / melamine / formaldehyde resin (Oshika Co., Ltd., Oshika Resin TB-68, non-volatile content 63.5 wt%, viscosity 2.3 Pa · s at 23 ° C.) An aqueous resin solution was prepared. The curing agent is obtained by dissolving 3 g of ammonium chloride in 12 g of water.

  Next, 83.6 g of the aqueous formaldehyde resin solution was sprayed uniformly onto 353.7 g of cedar wood chips in which the formaldehyde scavenger prepared in this example was uniformly mixed. As a result, the formaldehyde resin-based wood board adhesive composition of this example containing the formaldehyde resin aqueous solution and the formaldehyde scavenger was formed on the surface of the cedar wood chip. The adhesive composition for formaldehyde resin wood board of the present embodiment contains 10.32 parts by weight of the formaldehyde scavenger with respect to 100 parts by weight of the nonvolatile content contained in the aqueous formaldehyde resin solution.

  Next, 391.5 g of the mixed cedar wood chips were sprayed with the formaldehyde resin aqueous solution and the formaldehyde scavenger, and uniformly spread on a 5 mm thick duralumin plate on which a release sheet (polytetrafluoroethylene) was placed. Then, a spacer having a thickness of 4 mm was placed thereon, and the release sheet and the duralumin plate were placed in this order, and then inserted into a hot plate. Next, a particle board having a size of 350 × 350 mm was manufactured with a target thickness of 4 mm under the conditions of 140 ° C., initial pressure 3500 Pa for 35 seconds, and secondary pressure 150 Pa for 13 seconds (total heat pressure time 48 seconds). .

  Next, except for using the particle board as a test plate, the bending strength and formaldehyde emission were measured in exactly the same manner as in Example 1. The results are shown in Table 3.

  In this example, a formaldehyde scavenger comprising sodium bisulfite coated with 10% by weight of stearic acid was prepared in exactly the same manner as in Example 3. A particle board was produced in exactly the same manner as in Example 8, except that 13.2 g of the formaldehyde scavenger (including 11.88 g of sodium bisulfite) was used. The adhesive composition for formaldehyde resin wood board of the present embodiment contains 11.32 parts by weight of the formaldehyde scavenger with respect to 100 parts by weight of the nonvolatile content contained in the aqueous formaldehyde resin solution.

Next, the bending strength and formaldehyde emission were measured in exactly the same manner as in Example 1 except that the particle board was used as a test plate. The results are shown in Table 3.
[Comparative Example 6]
In this comparative example, a particle board was manufactured in exactly the same manner as in Example 8 except that no formaldehyde scavenger was used.

  Next, except for using the particle board as a test plate, the bending strength and formaldehyde emission were measured in exactly the same manner as in Example 1. The results are shown in Table 3.

スギは、それ自体ホルムアルデヒドを放散することが知られている。そこで、表３から、ホルムアルデヒド捕捉剤を全く含まないホルムアルデヒド樹脂水溶液のみからなる比較例６の木質ボード用接着剤組成物によれば、スギ木材チップを接着してパーティクルボードを製造したときに、ホルムアルデヒド放散量が著しく高くなることが明らかである。

Cedar is known to itself emit formaldehyde. Therefore, from Table 3, according to the wood board adhesive composition of Comparative Example 6 consisting only of an aqueous formaldehyde resin solution containing no formaldehyde scavenger, when the particle board was produced by adhering cedar wood chips, It is clear that the amount of emissions is significantly higher.

  On the other hand, according to the adhesive composition for formaldehyde resin wood boards of Examples 8 and 9 including the formaldehyde scavenger consisting of sodium bisulfite coated with 10% by weight of stearic acid based on the total amount, It is clear that even when a cedar wood chip that diffuses formaldehyde itself is adhered to produce a particle board, an excellent effect can be obtained in reducing the amount of formaldehyde emitted. Moreover, according to the adhesive composition for formaldehyde resin wood boards of Examples 8 and 9, it is clear that substantially the same bending strength as that of the wood board adhesive composition of Comparative Example 6 can be obtained.

  In this example, a formaldehyde scavenger comprising sodium bisulfite coated with 10% by weight of stearic acid was prepared in exactly the same manner as in Example 3. Using 4.2 g of the formaldehyde scavenger (including 3.78 g of sodium bisulfite), hot pressing temperature of 115 ° C., total hot pressing time of 60 seconds (45 seconds at initial pressure of 3500 Pa, 15 seconds at secondary pressure of 150 Pa) A particle board was manufactured in exactly the same manner as in Example 1 except that. The adhesive composition for formaldehyde resin wood board of the present Example contains 6.98 parts by weight of the formaldehyde scavenger with respect to 100 parts by weight of the nonvolatile content contained in the aqueous formaldehyde resin solution.

Next, except for using the particle board as a test plate, the bending strength, the water absorption thickness swelling ratio, and the formaldehyde emission amount were measured in the same manner as in Example 1. The results are shown in Table 4.
[Comparative Example 7]
In this comparative example, a formaldehyde scavenger consisting of sodium bisulfite coated with 10% by weight of paraffin wax was prepared in exactly the same manner as in comparative example 5. Using 4.2 g of the formaldehyde scavenger (including 3.78 g of sodium bisulfite), hot pressing temperature of 115 ° C., total hot pressing time of 60 seconds (45 seconds at initial pressure of 3500 Pa, 15 seconds at secondary pressure of 150 Pa) A particle board was manufactured in exactly the same manner as in Example 1 except that.

Next, except for using the particle board as a test plate, the bending strength, the water absorption thickness swelling ratio, and the formaldehyde emission amount were measured in the same manner as in Example 1. The results are shown in Table 4.
[Comparative Example 8]
In this comparative example, no formaldehyde scavenger was used, and the hot press molding temperature was 115 ° C. and the total hot press time was 60 seconds (45 seconds at an initial pressure of 3500 Pa, 15 seconds at a secondary pressure of 150 Pa). A particle board was manufactured in exactly the same manner as in Example 1.

  Next, except for using the particle board as a test plate, the bending strength, the water absorption thickness swelling ratio, and the formaldehyde emission amount were measured in the same manner as in Example 1. The results are shown in Table 4.

  In this example, a formaldehyde scavenger comprising sodium bisulfite coated with 10% by weight of stearic acid was prepared in exactly the same manner as in Example 3. A particle board was produced in exactly the same manner as in Example 1 except that 4.2 g of the formaldehyde scavenger (including 3.78 g of sodium bisulfite) was used and the hot pressing temperature was 140 ° C. The adhesive composition for formaldehyde resin wood board of the present Example contains 6.98 parts by weight of the formaldehyde scavenger with respect to 100 parts by weight of the nonvolatile content contained in the aqueous formaldehyde resin solution.

Next, except for using the particle board as a test plate, the bending strength, the water absorption thickness swelling ratio, and the formaldehyde emission amount were measured in the same manner as in Example 1. The results are shown in Table 4.
[Comparative Example 9]
In this comparative example, a formaldehyde scavenger consisting of sodium bisulfite coated with 10% by weight of paraffin wax was prepared in exactly the same manner as in comparative example 5. A particle board was produced in exactly the same manner as in Example 1 except that 4.2 g of the formaldehyde scavenger (including 3.78 g of sodium bisulfite) was used and the hot pressing temperature was 140 ° C.

Next, except for using the particle board as a test plate, the bending strength, the water absorption thickness swelling ratio, and the formaldehyde emission amount were measured in the same manner as in Example 1. The results are shown in Table 4.
[Comparative Example 10]
In this comparative example, a particle board was produced in exactly the same way as in Example 1 except that no formaldehyde scavenger was used and the hot pressing temperature was 140 ° C.

  Next, except for using the particle board as a test plate, the bending strength, the water absorption thickness swelling ratio, and the formaldehyde emission amount were measured in the same manner as in Example 1. The results are shown in Table 4.

  In this example, a formaldehyde scavenger comprising sodium bisulfite coated with 10% by weight of stearic acid was prepared in exactly the same manner as in Example 3. A particle board was produced exactly as in Example 1, except that 4.2 g of the formaldehyde scavenger (including 3.78 g of sodium hydrogen sulfite) was used and the hot pressing temperature was 200 ° C. The adhesive composition for formaldehyde resin wood board of the present Example contains 6.98 parts by weight of the formaldehyde scavenger with respect to 100 parts by weight of the nonvolatile content contained in the aqueous formaldehyde resin solution.

Next, except for using the particle board as a test plate, the bending strength, the water absorption thickness swelling ratio, and the formaldehyde emission amount were measured in the same manner as in Example 1. The results are shown in Table 4.
[Comparative Example 11]
In this comparative example, a formaldehyde scavenger consisting of sodium bisulfite coated with 10% by weight of paraffin wax was prepared in exactly the same manner as in comparative example 5. A particle board was produced in exactly the same manner as in Example 1 except that 4.2 g of the formaldehyde scavenger (including 3.78 g of sodium bisulfite) was used and the hot pressing temperature was 200 ° C.

Next, except for using the particle board as a test plate, the bending strength, the water absorption thickness swelling ratio, and the formaldehyde emission amount were measured in the same manner as in Example 1. The results are shown in Table 4.
[Comparative Example 12]
In this comparative example, a particle board was produced in the same manner as in Example 1 except that no formaldehyde scavenger was used and the hot pressing temperature was 200 ° C.

  Next, except for using the particle board as a test plate, the bending strength, the water absorption thickness swelling ratio, and the formaldehyde emission amount were measured in the same manner as in Example 1. The results are shown in Table 4.

表４から、全量に対して１０重量％のステアリン酸で被覆されている亜硫酸水素ナトリウムからなるホルムアルデヒド捕捉剤を含む実施例１０〜１２のホルムアルデヒド樹脂系木質ボード用接着剤組成物によれば、熱圧成型温度が１１５℃、１４０℃、２００℃のいずれにおいても、比較例７，９，１１のパラフィンワックスで被覆されている亜硫酸水素ナトリウムからなるホルムアルデヒド捕捉剤を含む木質ボード用接着剤組成物、比較例８，１０，１２のホルムアルデヒド捕捉剤を全く含まない木質ボード用接着剤組成物に対して、ホルムアルデヒド放散量が低く、ホルムアルデヒド放散量を低減する上で、優れた効果を得ることができることが明らかである。

From Table 4, the formaldehyde resin wood board adhesive composition of Examples 10-12 containing a formaldehyde scavenger consisting of sodium bisulfite coated with 10% by weight stearic acid relative to the total amount A wood board adhesive composition comprising a formaldehyde scavenger composed of sodium bisulfite coated with paraffin wax of Comparative Examples 7, 9, and 11 at any of the molding temperatures of 115 ° C., 140 ° C., and 200 ° C., With respect to the wood board adhesive composition containing no formaldehyde scavenger of Comparative Examples 8, 10, and 12, the amount of formaldehyde emission is low, and an excellent effect can be obtained in reducing the amount of formaldehyde emission. it is obvious.

  Therefore, according to the formaldehyde resin-based wood board adhesive composition of Examples 10 to 12 containing a formaldehyde scavenger consisting of sodium bisulfite coated with 10% by weight of stearic acid based on the total amount, It is clear that it is reacting with formaldehyde at a temperature in the range of 115-200 ° C.

  Moreover, according to the adhesive composition for formaldehyde resin-based wooden boards of Examples 10 to 12 containing a formaldehyde scavenger consisting of sodium bisulfite coated with 10% by weight of stearic acid with respect to the total amount, Comparative Example 7 , 9, 11 Adhesive composition for wood board comprising formaldehyde scavenger consisting of sodium bisulfite coated with paraffin wax, Adhesive for wood board containing no formaldehyde scavenger of Comparative Examples 8, 10 and 12 It is clear that a bending strength and a water absorption thickness swelling ratio substantially equal to the composition can be obtained.

Claims (10)

An aqueous formaldehyde resin solution;
An adhesive composition for a formaldehyde resin wood board, comprising a formaldehyde scavenger comprising a bisulfite coated with a higher fatty acid that reacts with formaldehyde.   2. The adhesive composition for formaldehyde resin wood board according to claim 1, wherein the bisulfite is sodium bisulfite.   The formaldehyde resin-based wood board adhesive composition according to claim 1, wherein the formaldehyde resin is a resin in which formaldehyde and an amino compound are condensed.   The formaldehyde resin wood board adhesive according to claim 1, wherein the bisulfite is coated with the higher fatty acid in a range of 0.5 to 25% by weight with respect to the total amount of the formaldehyde scavenger. Agent composition.   The formaldehyde resin wood board adhesive composition according to claim 1, wherein the higher fatty acid has a melting point in the range of 40 to 120 ° C.   2. The formaldehyde resin-based wood board adhesive composition according to claim 1, wherein the higher fatty acid reacts with formaldehyde at a temperature in the range of 110 to 200 ° C.   The higher fatty acid is at least one selected from the group consisting of tridecylic acid, lauric acid, pentadecylic acid, myristic acid, valmitic acid, stearic acid, arachidic acid, behenic acid, lignoceric acid, serotic acid, montanic acid, and melicic acid. The adhesive composition for formaldehyde resin wood board according to claim 1, wherein the composition is a saturated fatty acid.   8. The formaldehyde resin wood board adhesive composition according to claim 7, wherein the higher fatty acid is one kind of saturated fatty acid selected from the group consisting of stearic acid, lauric acid and behenic acid.   2. The formaldehyde resin-based wood board adhesive composition according to claim 1, wherein the formaldehyde scavenger is contained in an amount of 2 to 35 parts by weight with respect to 100 parts by weight of the solid content of the formaldehyde resin aqueous solution.   The formaldehyde resin-based wood board adhesive composition according to claim 1, wherein the formaldehyde scavenger is contained in an amount of 5 to 30 parts by weight with respect to 100 parts by weight of the solid content of the aqueous formaldehyde resin solution.