JPH10286807A - Manufacture of woody board - Google Patents

Abstract

PROBLEM TO BE SOLVED: To hold the amount of bleeding of formaldehyde below a specific value and prevent the adverse effect of an antimildew agent upon a human body from occurring and also prevent the harmful substances such as the chlorine of an organic antimildew agent and a chemical combustion product of a halogen compound from being generated by adding an inorganic antimildew agent to a formalin adhesive. SOLUTION: A silver a tifungus agent such as zeolite-silver, ceramic-silver, zirconium phosphate-silver or calcium phosphate-silver, or an inorganic antifungus agent of copper or zinc series as inorganic antifungus agent is added to a formalin additive as an amino resin aqueous adhesive such as urea resin, urea-melamine cocondensation resin, melamine resin or urea-phenol cocondensation resin, and these components are uniformly dispersed and this dispersion is used. Consequently the amount of bleeding of formaldehyde is considerably lessened to the level of 1.5 mg/l, or less, so that the adverse effect of formaldehyde upon the human body is diminished. Further the wooden board is made more effectively resistant to mildews by the action of an inorganic antimildew agent.

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention
(Abbreviated PB), fiber board (abbreviated FB),
Furthermore, the present invention relates to a method for producing a wooden board such as plywood, and to a method for producing a wooden board which emits a small amount of formaldehyde.

[0002]

2. Description of the Related Art In recent years, the problem of environmental pollution has been greatly addressed by formaldehyde generated from building materials using wooden boards, and the development of wooden boards that emit less formaldehyde is strongly desired. . The living environment improves when the emission of formaldehyde decreases,
Deterioration of mold prevention performance is a new problem. PB and wood containing fibreboard (MDF), etc. JIS standards for formaldehyde emission of JIS E ₂ (hereinafter formaldehyde emission amount 5.0 mg / l) and plywood JAS standards for formaldehyde emission of formaldehyde are defined in JAS F ₂ release The amount of 5.0 mg / l or less (all methods of measuring the concentration in water using a desiccator) could be expected to have antifungal performance. However, wood board - de formaldehyde emissions 1.5 mg / l or less (JIS E _1), although especially the influence of the human body in the living environment by JIS E ₀ and the JAS F ₁ formaldehyde is reduced, with formaldehyde No antifungal performance could be expected.

A method of adding a fungicide to the adhesive for producing wood board has been considered, but the toxicity of organic fungicides generally used at present is often stronger than that of formaldehyde. Organic fungicides are decomposed during the process of hot-pressing wooden boards at a high temperature and their effectiveness is reduced.
In addition, when a wooden board such as MDF or PB is manufactured, if the precure layer on those surfaces is polished with a sander, there is a risk that sander dust mixed with a fungicide is absorbed by the human body. Further, chlorine and other halogen compounds contained in the organic antifungal agent have a problem that there is a risk of generating dioxin or a harmful substance having a structure similar to dioxin during combustion.

[0004]

A wood board obtained by applying a formalin-based adhesive to wood chips, wood chips or wood fibers to form a mat and hot-press molding to a predetermined thickness;
For example, PB, FB, OSB (Oriented str)
plywood, LVL (single-ply laminate), LVB (single-ply laminate) obtained by laminating a plurality of veneers with a formalin-based adhesive and hot-press bonding A) a method for producing a woody board comprising the steps of: adding an inorganic fungicide to the formalin-based adhesive; and providing a woody board having a formaldehyde emission of 1.5 mg / l or less. I do. An inorganic fungicide is used as an inorganic fungicide in addition to a formalin adhesive. Inorganic fungicides include silver-based fungicides such as zeolite-silver, ceramic-silver, zirconium phosphate-silver or calcium phosphate-silver. In addition, copper-based and zinc-based agents, as well as silver, may be used as a carrier such as zeolite if necessary. Furthermore, even if the above silver-based, copper-based, and zinc-based agents are combined and added to the adhesive as an inorganic germicide and used, an antifungal effect of one or more types can be expected. Since such an inorganic fungicide is added to a formalin-based adhesive and dispersed uniformly, the fungicide effect is high, and it is not necessary to treat the wood board with a fungicide. Can be omitted. In addition, the formaldehyde emission is 1.5 mg / l
Since the following wooden boards are manufactured, the influence on the human body can be significantly reduced.

[0005] When a wood board is produced by adding a hardening accelerator such as ammonium chloride to a formalin-based adhesive, the hardening of the adhesive can be expected to be further enhanced, and the time required for hot pressing can be reduced. Suitable examples of the curing accelerator include salts of strong acids and weak alkalis such as ammonium nitrate and ammonium sulfate, and esters of fatty acids and lower alcohols such as acetic acid and ethyl alcohol and formic acid and methyl alcohol. Aqueous adhesives of amino resins such as urea resin, urea melamine co-condensation resin, melamine resin or urea phenol co-condensation resin are suitable as formalin-based adhesives.

[0006]

According to the first aspect of the present invention, the formaldehyde emission is small, the influence of the human body is minimal, and in addition to the action of the inorganic fungicide added to the formalin-based adhesive, the antifungal property of the wood board is improved. Go up.

[0007]

EXAMPLES Examples of the present invention will be described in detail along with comparative examples.

Example 1 To 100 parts by weight of an odorless urea resin adhesive having a resin content of 60%, 0.5 part by weight of Zeomic AC (produced by Sinanen Zeomic Co., Ltd.) was added and stirred well. The adhesive was added to a PB surface layer chip having a water content of 5% in a resin solid content of 12%. In addition, this adhesive is made of PB having a water content of 5%.
8% of resin solid content was added to the inner layer chip. 165 ° C,
Heat press at 25 kg / cm ² for 4.5 minutes and set specific gravity 0.72
Of 12mm path - Tikurubo - made a de (JIS E _1).

Example 2 To 100 parts by weight of an odorless urea resin adhesive having a resin content of 60%, 0.6 parts by weight of NOVALON AG300 (manufactured by Toa Gosei Co., Ltd.) was added and stirred well. This adhesive is applied to a PB surface layer chip having a moisture content of 5% in a resin solid content of 1%.
2% was added. Odorless urea resin adhesive with resin content of 60% 10
0.6 parts by weight of Novalon AG300 in 0 parts by weight, 20%
5 parts by weight of an aqueous solution of ammonium chloride was added, and the mixture was stirred well. This adhesive was added to a PB inner layer chip having a water content of 5% in a resin solid content of 8%. Heat-pressed at 165 ° C and 25 kg / cm ² for 4 minutes.
(JIS E ₁ ).

Example 3 To 100 parts by weight of an odorless urea resin adhesive having a resin content of 60%, 0.6 parts by weight of Novalon AG300 (manufactured by Toa Gosei Co., Ltd.) and 2 parts by weight of a 20% aqueous ammonium chloride solution were added. Stirred. The adhesive was applied to fibers above the fiber saturation point. The adhesive was added at a resin solid content of 15% based on the fiber-dry weight. The fiber to which the blended adhesive has been added is passed through a flash dryer to have a water content of 15%, formed, inserted into a hot press, and heated to a temperature of 200 ° C.
Heat pressure at 25kg / cm ² for 3 minutes, set thickness 7m
m, MDF (JIS E ₁ ) having a set specific gravity of 0.75 was prepared.

Comparative Example 1 A 20% ammonium chloride aqueous solution was added to 100 parts by weight of an odorless urea resin adhesive having a resin content of 60%.
5 parts by weight of 20 parts by weight of hexamethylenetetramine water was added thereto, and the mixture was stirred well. The adhesive was added to a PB surface layer chip having a water content of 5% in a resin solid content of 12%. Resin 60
5 parts by weight of a 20% ammonium chloride aqueous solution was added to 100 parts by weight of the odorless urea resin adhesive of 100% by weight and stirred well. This adhesive is applied to a PB inner layer chip having a water content of 5% to a resin solid content of 8%.
Was added. Heat-press at 165 ° C. and 25 kg / cm ² for 4 minutes to set a specific gravity of 0.72 for a 12 mm particle board (JI
Made a S E _1).

Comparative Example 2 To 100 parts by weight of an odorless urea resin adhesive having a resin content of 60%, 2 parts by weight of a 20% aqueous solution of hexamethylenetetramine and 2 parts by weight of a 20% aqueous solution of ammonium chloride were added and stirred well. The adhesive was applied to fibers above the fiber saturation point. The adhesive was added at a resin solid content of 15% based on the fiber-dry weight. The fiber to which the blended adhesive was added was passed through a flash dryer to a water content of 15%, then formed, inserted into a hot press, and placed at a temperature of 200 ° C. and a pressure of 2 ° C.
Heat-press at 5 kg / cm ² for 3 minutes and set the specific gravity to 0.75.
mmMDF (JIS E ₁ ) was made.

Each of the test pieces of Examples 1 to 3 and Comparative Examples 1 and 2 was subjected to a fungicide test according to JIS Z 2911 mold resistance test method, and the results are shown in Table 1 below.

[0014]

[Table 1]

[Discussion] As is apparent from the results shown in Table 1, the test pieces of the wooden boards prepared by adding and dispersing the inorganic fungicide to the adhesive in Examples 1 to 3 are as follows. All were negative for the degree of mold development, ie, no mold erosion was observed. On the other hand, in the test pieces of the wooden board made without adding and mixing the inorganic mold agent to the adhesive in Comparative Examples 1 and 2, the degree of mold occurrence was positive or extremely positive.
That is, mold erosion was observed.

[0016]

According to the first aspect of the present invention, the amount of formaldehyde released from the manufactured wooden board is considerably reduced to 1.5 mg / l or less, so that the effect on the human body is significantly reduced. The antifungal property, which has been a pending issue, can also be greatly expected.

Claims (1)

[Claims] 1. A particle board or fiber obtained by applying a formalin-based adhesive to wood chips or wood fibers to form a forming mat and hot-press molding to a predetermined thickness.
A method for producing a wood board such as a plywood board obtained by laminating wood boards such as a board or a plurality of veneers with a formalin-based adhesive therebetween and hot-press bonding. A formaldehyde release amount of 1.5 mg, characterized by adding an inorganic fungicide to a formalin-based adhesive for a board.
/ L or less wood board production method.