JP7260110B2 - Incombustible decorative board and its manufacturing method - Google Patents

Description

TECHNICAL FIELD The present invention relates to a noncombustible decorative board and a method for manufacturing the same.

According to Article 2, Item 9 of the Building Standards Law, it is possible to meet the requirements for each performance category of fireproof materials in exothermic tests (heating a 10 cm x 10 cm specimen at 50 kW/ ^m2 ) in accordance with ISO 5600-1. In the required exothermic test, for 5 minutes after the start of heating, (1) the total calorific value is 8 MJ / ^m2 or less, (2) there are no cracks or holes penetrating to the back surface, (3) heat generation rate not exceed 200 kW/ ^m2 continuously for 10 seconds or longer, "flame retardant" if it satisfies these three requirements, "semi-nonflammable" if it satisfies these three requirements for 10 minutes, and if it satisfies these three requirements for 20 minutes is evaluated as "non-combustible". In general, it is considered preferable that a decorative board used as a housing building material or the like has noncombustible performance equal to or higher than "semi-incombustible."

Patent Document 1 below describes that an MDF having semi-incombustible or better performance can be obtained by forming a coating film made of an inorganic coating agent on one or both sides of an MDF containing a flame retardant agent. (paragraphs 0043 to 0046).

As a method for imparting flame retardancy to wood materials such as MDF, Patent Document 2 below describes adding a wood material to an aqueous solution (hereinafter referred to as "flame retardant solution") in which a water-soluble flame retardant agent is dissolved in water. A method of impregnating by immersing and repeatedly depressurizing and pressurizing several times is known.

Further, in Patent Document 3 below, a noncombustible sheet layer is laminated via an adhesive layer containing aluminum hydroxide on one surface of a flame-retardant substrate mainly composed of a volcanic vitreous double layer plate. A sex veneer has been proposed.

Japanese Patent Application Laid-Open No. 2006-1267 JP-A-2-270547 JP-A-2000-037710

However, the MDF for which performance equal to or better than semi-noncombustible is obtained in Patent Document 1 has a thickness of at least 12 mm (Table 2 in paragraph 0043), and similarly for thinner MDF, performance equal to or better than semi-noncombustible is obtained. It is unknown whether or not Rather, in order to give a board made of a wooden base material such as MDF a semi-incombustible or higher performance, it is necessary to suppress the shrinkage of the wooden base material and prevent burning out, and the thickness has a great influence on this. Therefore, with the technique described in Patent Document 1, it is considered difficult to give thin MDF a property equal to or higher than semi-incombustibility. If a decorative material using thick MDF as described in Patent Document 1 is used as an interior material, a step will occur with respect to building materials such as frames and baseboards, so it will be necessary to use a separate parting material. , construction labor and cost increase. In addition, as a face material for fittings with a flush structure, a material having a thickness of about 3 mm is usually used. Handling becomes difficult and workability is deteriorated.

Regarding the technology described in Patent Document 2, as is well known in the art, wood fiber boards such as MDF have hard layers with high density on the front and back sides, so the wood fiber board can be treated by a conventional method. Even if an attempt is made to impregnate the flame retardant solution, the front and back hard layers are hardly impregnated. When a wood fiber board is impregnated with a flame-retardant solution, the flame-retardant solution penetrates from the low-density part (the middle layer located between the hard layers on the front and back) exposed to the wood end, gradually moving toward the center in the longitudinal direction of the board. Therefore, several days of impregnation are required for the flame retardant solution to spread evenly over the entire wood fiber board (from the edge to the center in the longitudinal direction), resulting in extremely low production efficiency. becomes. In addition, the flame retardant performance improves in proportion to the content of the flame retardant agent. Damage such as deformation or cracking may occur. Furthermore, water-soluble flame retardant agents cause efflorescence due to chemical precipitation on the board surface due to changes in the environment around the wooden base material, especially changes in temperature and humidity, and this affects the decorative material provided on the surface. Therefore, the designability is deteriorated.

In addition, in Patent Document 3, use of a flame-retardant substrate mainly composed of a volcanic vitreous double-layered plate is an essential requirement for improving flame-retardant performance, but such an inorganic plate has machinability. It is difficult to process it into a desired shape because of its poor quality. Moreover, since the sharpness of the blade used for cutting tends to deteriorate, it must be replaced frequently, resulting in an increase in cost.

That is, with these prior arts, it is difficult to provide a decorative board using a relatively thin wood fiber board having a thickness of, for example, about 3 mm as a base material, with performance equal to or better than semi-incombustibility. As a result of extensive research and testing on imparting noncombustibility to wood fiber boards by methods other than impregnation, the inventors of the present invention have found that flame retardants are mixed into wood fibers together with an adhesive during the molding stage of wood fiber boards. By mixing a flame retardant agent into the adhesive used to attach the decorative material, and by adopting a method for improving the non-combustibility of the decorative material, a decorative material with performance equal to or greater than semi-noncombustible can be obtained. The present inventors have found that the present invention has been completed.

Accordingly, the problem to be solved by the present invention is to provide a decorative board using a relatively thin wood fiber board having a thickness of, for example, about 2.7 mm as a base material, with performance equal to or better than semi-incombustibility.

In order to solve this problem, the invention according to claim 1 of the present application provides that 10 to 40 parts by weight of a water-insoluble phosphorus and nitrogen-based flame retardant agent made of powder is added to the weight of wood fiber boards in an absolutely dry state. On one or both sides of the base material made of wood fiberboard attached to the surface , via an adhesive layer containing 10 to 40 parts by weight of a halogen/antimony oxide mixed flame retardant agent per 100 parts by weight of the adhesive. A noncombustible decorative board characterized by having a decorative material on the back side and a multilayer decorative material laminated with a metal foil on one of the laminated positions on the back side of the laminated decorative board.

The invention according to claim 2 of the present application is the noncombustible decorative board according to claim 1 , wherein the multilayer decorative material has a laminated structure of decorative material/resin layer/metal foil/resin layer/paper from the surface side. characterized by

The invention according to claim 3 of the present application is a wood fiber board molding for molding a wood fiber board containing 10 to 40 parts by weight of a water-insoluble phosphorus-nitrogen flame retardant agent with respect to the weight of the bone-dry wood fiber board. an adhesive application step of applying an adhesive containing 10 to 40 parts by weight of a halogen/antimony oxide mixed flame retardant agent to 100 parts by weight of the adhesive on the surface of the molded wood fiber board; a step of laminating and adhering a multilayer decorative material having a decorative material on the front surface and a metal foil laminated to one of the lamination positions on the back side of the adhesive applied surface of the fiberboard. The wood fiber board molding step includes a first step of spraying a part of the total amount of adhesive necessary for molding onto the wood fibers while stirring the wood fibers to attach the adhesive to the wood fibers; While stirring the mixture obtained in the step, 10 to 40 parts by weight of a powdery water-insoluble phosphorus/nitrogen flame retardant agent is mixed with the weight of the bone-dried wood fiber board to obtain a water-insoluble phosphorus/nitrogen flame retardant agent. A second step of adhering a nitrogen-based flame retardant agent to wood fibers via an adhesive; and a third step of obtaining a mixture consisting of an adhesive and a water-insoluble phosphorus-nitrogen flame retardant agent; and a fourth step of thermocompression molding the mixture obtained in the third step. , a method for manufacturing a noncombustible decorative board.

The invention according to claim 4 of the present application is the method for manufacturing a noncombustible decorative board according to claim 3 , wherein the adhesive is sprayed in an amount of 10 to 90% by weight of the necessary total amount in the first step, and the necessary amount is sprayed in the third step. 90 to 10% by weight of the adhesive is sprayed.

The invention according to claim 5 of the present application is the method for manufacturing a noncombustible decorative board according to claim 3 or 4 , wherein in the first step, 3% or more of the adhesive is sprayed with respect to the absolute dry weight of the wood fiber, It is characterized by spraying 3% or more of the adhesive with respect to the absolute dry weight of the wood fiber in the process.

According to the first aspect of the invention, the wood fiber board used as the base material and the adhesive used for adhering the multi-layered decorative material to one or both sides thereof each contain a flame retardant agent, and the multi-layered decorative material Since the metal foil is laminated on the material, even if a relatively thin wood fiber board is used as the base material, the decorative board can have performance equal to or higher than semi-incombustibility. When this incombustible decorative board is exposed to flame, the metal foil in the multilayer decorative material reflects heat, and the flame retardant agent contained in the adhesive and the wood fiber board suppresses the generation of combustible gas during heating. Therefore, burning of the incombustible decorative board can be prevented.

In addition, the wood fiber board contains 10 parts by weight or more of a water-insoluble phosphorus-nitrogen-based flame retardant based on the weight of the wood fiber board in an absolutely dry state, and the adhesive layer contains a halogen・By containing 10 parts by weight or more of antimony oxide-mixed flame retardant agent, it is possible to reliably provide semi-incombustible or better performance. Also, if the content of the water-insoluble phosphorus/nitrogen-based flame retardant agent relative to the weight of the bone-dry wood fiber board exceeds 40 parts by weight, the moldability of the wood fiber board deteriorates, so the upper limit is 40. Parts by weight (preferably 35 parts by weight). On the other hand, if the content of the mixed halogen/antimony oxide flame retardant agent in the adhesive layer exceeds 40 parts by weight, the flame retardant agent clumps together, deteriorating the surface property and causing poor adhesion of the multilayer decorative material. Therefore, the upper limit is set to 40 parts by weight (preferably 30 parts by weight).

According to the invention of claim 2 , the metal foil, which is difficult to adhere directly to the surface of the base material, is interposed between a resin layer such as polyethylene and paper to ensure good adhesion. can do. Further, by interposing a resin layer such as polyethylene between the surface side of the metal foil and the decorative material, the adhesiveness can be improved.

According to the third aspect of the invention , the wood fiber board used as the base material in the wood fiber board molding step contains a predetermined amount of a water-insoluble phosphorus-nitrogen flame retardant agent, and in the adhesive application step, one side or both sides of the wood fiber board A multi-layered decorative material in which a predetermined amount of a halogen/antimony oxide mixed flame retardant agent is contained in the adhesive used for attaching the multi-layered decorative material, and a metal foil is laminated in the process of attaching the multi-layered decorative material. Therefore, even when a relatively thin wood fiber board is used as a base material, it is possible to manufacture a decorative board having performance equal to or higher than semi-incombustible. When this incombustible decorative board is exposed to flame, the metal foil in the multilayer decorative material reflects heat, and the flame retardant agent contained in the adhesive and the wood fiber board suppresses the generation of combustible gas during heating. Therefore, burning of the incombustible decorative board can be prevented.

In the wood fiber board molding step, 10 to 40 parts by weight of a water-insoluble phosphorus/nitrogen flame retardant agent is added to the weight of the bone-dried wood fiber board. If the content of the water-insoluble phosphorus/nitrogen-based flame retardant is less than 10 parts by weight, it is not possible to achieve semi-incombustible or better performance.

In the adhesive application step, an adhesive containing 10 to 40 parts by weight of a halogen/antimony oxide mixed flame retardant agent is applied to 100 parts by weight of the adhesive. If the content of the halogen/antimony oxide mixed flame retardant agent is less than 10 parts by weight, it is not possible to achieve a performance equal to or higher than semi-incombustibility, and if it exceeds 40 parts by weight, the surface becomes lumpy and the surface property is deteriorated, resulting in a multi-layered structure. The decorative material causes poor adhesion.

According to the third aspect of the invention , in the wood fiber board molding step, the wood fiber board is molded containing 10 to 40 parts by weight of the water-insoluble phosphorus/nitrogen flame retardant agent relative to the absolute dry weight of the wood fiber board. In this case, the total amount of adhesive necessary for molding into the wood fiber board is sprayed in two steps (first and third steps), during which the water-insoluble phosphorus/nitrogen flame retardant agent is mixed. (Second process) method is adopted.

To explain this point in detail, generally, wood fiber boards are obtained by steaming and fibrillating wood, and the amount necessary for molding into wood fibers (in the case of MDF, generally 3 to 50 %, see Patent Document 2) is sprayed to form a mixture, and the mixture is molded into a mat shape and then hot-pressed. If a chemical is to be mixed in, it is thought that a mixture obtained by mixing an adhesive and a flame-retardant agent with wood fibers should be thermocompressed. However, it has been found that if the required amount of adhesive is mixed all at once, problems such as failure to evenly adhere the flame retardant chemical and molding defects will occur (details will be described later).

Based on this knowledge, in the invention according to claim 3 , the entire amount of adhesive required for molding into a wood fiber board is not charged at once, but is charged in two stages, which will be described later. As is clear from the test results, it is possible to effectively produce a wood fiber board with enhanced flame retardancy due to the uniform adhesion of the flame retardant agent over the entire surface of the wood fiber board without causing molding defects, deformation, or breakage. can be produced effectively.

According to the invention of claim 4 , 10 to 90% by weight of the total amount of the adhesive required for molding into the wood fiber board is sprayed onto the wood fibers in the first step, so that the adhesive is spread evenly over the wood fibers. , and the water-insoluble phosphorus/nitrogen flame retardant agent is added by performing the second step of mixing the entire amount of the water-insoluble phosphorus/nitrogen flame retardant agent with the adhesive-attached wood fiber obtained by this. It can be uniformly attached to the wood fibers through the adhesive, and in the third step, by spraying 90 to 10% by weight of the adhesive as the remainder of the total amount of adhesive necessary for molding into the wood fiber board. , a mixture in which the wood fiber, the adhesive, and the water-insoluble phosphorus/nitrogen-based flame retardant agent are uniformly mixed can be obtained. A wood fiber board in which the nitrogen-based flame retardant agent is evenly and uniformly distributed can be produced. Therefore, even a long wood fiber board can be made into a wood fiber board having substantially uniform flame retardancy in the longitudinal direction.

Further, according to the invention of claim 5 , in the first step, 3% or more of the adhesive is sprayed relative to the absolute dry weight of the wood fiber, and in the third step, 3% or more of the absolute dry weight of the wood fiber is sprayed. By spraying the adhesive described above, the above effects can be achieved more reliably.

1 is a schematic cross-sectional view of a noncombustible decorative board according to one embodiment of the present invention; FIG. FIG. 3 is a schematic cross-sectional view of a multilayer decorative material used for this noncombustible decorative board. be. It is explanatory drawing which shows the manufacturing process of the base material (MDF) used for this incombustible decorative board. FIG. 4 is a microphotograph (magnification: 150) showing the state of adhesion of the adhesive to the wood fibers after the third step of FIG. 3; 5 is a micrograph (magnification: 300 times) showing the same portion as in FIG. 4, further enlarged.

FIG. 1 is a cross-sectional view schematically showing a noncombustible decorative board 1 according to one embodiment of the present invention. 4 are laminated and adhered, and the total thickness is 3 mm.

The base material 2 is a water-insoluble (powder) phosphorus/nitrogen-based flame retardant based on the absolute dry weight of a wood fiber board (in this embodiment, MDF with a thickness of 2.7 mm and a density of 0.80 to 0.95). It contains 10 to 40 parts by weight of a flame retardant. As the water-insoluble phosphorus/nitrogen-based flame retardant agent, a phosphorus/nitrogen-based compound such as ammonium polyphosphate is used. If the content of the water-insoluble phosphorus/nitrogen-based flame retardant is less than 10 parts by weight, it is not possible to achieve semi-incombustible or better performance. From this point of view, the content of the water-insoluble phosphorus/nitrogen-based flame retardant is preferably 10 to 40 parts by weight, more preferably 15 to 35 parts by weight, relative to the absolute dry weight of the wood fiber board. An inorganic compound such as aluminum hydroxide may be mixed with this predetermined weight part of the phosphorus/nitrogen flame retardant agent.

The adhesive layer 3 is made of a vinyl acetate, ethylene vinyl acetate, water-based vinyl urethane, or PUR (polyurethane reactive) adhesive that is generally used for adhering the multilayer decorative material 4 to the base material 2. 10 to 40 parts by weight of a halogen/antimony oxide mixed flame retardant agent is contained in 100 parts by weight of an adhesive such as a melt. Halogen-antimony oxide mixed flame retardants consist of a mixture of a halogen compound such as decabromodiphenylethane and an antimony oxide such as antimony pentoxide. The mixed halogen/antimony oxide flame retardant agent contained in the adhesive layer 3 can be either water-soluble or water-insoluble, and an appropriate one is selected according to the adhesive to be used. If the content of the halogen/antimony oxide mixed flame retardant agent is less than 10 parts by weight, it is not possible to achieve a performance equal to or higher than semi-incombustibility, and if it exceeds 40 parts by weight, the surface becomes lumpy and the surface property is deteriorated, resulting in a multi-layered structure. The decorative material 4 causes poor adhesion. From this point of view, the content of the halogen/antimony oxide mixed flame retardant agent with respect to 100 parts by weight of the adhesive is preferably 10 to 40 parts by weight, more preferably 10 to 30 parts by weight.

In this embodiment, as shown in FIG. 2, the multi-layer decorative material 4 has a five-layer laminated structure of decorative paper 4a/polyethylene 4b/aluminum foil 4c/polyethylene 4d/paper 4e from the surface side. It is material 4. The decorative paper 4a is positioned on the outermost surface of the incombustible decorative board 1 and provides a desired decoration. Instead of paper, a decorative veneer such as veneer or a resin sheet such as an olefin sheet may be used.

When the noncombustible decorative board 1 is exposed to flame, the aluminum foil 4c reflects the heat, and the water-insoluble phosphorus/nitrogen flame retardant agent and the adhesive layer 3 contained in the base material (MDF) 2 Combustion of the noncombustible decorative panel 1 can be prevented by suppressing the contained halogen/antimony oxide mixed flame retardant agent from being heated and generating combustible gas. The thickness of aluminum foil 4c is, for example, 0.02 mm.

As described above, the aluminum foil 4c is used together with the water-insoluble phosphorus/nitrogen flame retardant agent contained in the base material (MDF) 2 and the halogen/antimony oxide mixed flame retardant agent contained in the adhesive layer 3. 1, but since it is difficult to directly bond the aluminum foil 4c to the surface of the MDF 2, polyethylene 4d and paper 4e are interposed between them to bond improving sexuality. The paper 4e may be general paper, kraft paper, titanium paper, resin-impregnated paper, or the like. The same effect can be achieved by using a metal foil such as iron or copper instead of the aluminum foil.

Similarly, polyethylene 4b is interposed between the surface side of the aluminum foil 4c and the decorative paper 4a to improve adhesiveness. Instead of the polyethylene 4b, 4d, a resin such as an aqueous vinyl urethane resin, an ethylene vinyl acetate resin, an acrylic resin, or PUR (polyurethane reactive hot melt) may be used.

Since this noncombustible decorative board 1 has a total thickness of 3 mm, it is thin as a decorative board having noncombustible performance, and when used as an interior material, it does not cause a step with respect to fixtures such as frames and baseboards, and is a parting material. etc. can be omitted, so that the workability can be improved and the cost can be reduced. Moreover, when used as a face material for fittings having a flush structure, the weight of the fittings can be reduced, thereby improving workability.

This incombustible decorative board 1 can be manufactured as follows. In this manufacturing method, first, a part of the total amount of adhesive necessary for molding the wood fiber board, preferably 10 to 90% by weight of the required amount, is sprayed onto the wood fibers to adhere the adhesive to the wood fibers. and a predetermined amount of water-insoluble flame retardant agent (phosphorus/nitrogen flame retardant agent) required to impart flame retardancy to the mixture obtained in the first step, and the flame retardant agent is applied via an adhesive. and the mixture obtained in the second step is sprayed with the remainder of the required amount, preferably 90 to 10% by weight of the required amount of the adhesive to combine the wood fiber, the adhesive and the flame retardant. A third step of obtaining a mixture consisting of a chemical agent and a fourth step of hot-pressing the mixture obtained in the third step are sequentially performed to obtain a wood fiber board uniformly impregnated with a water-insoluble flame retardant agent. manufacture.

More specifically, referring to FIG. 3, wood fibers 10 are prepared (a), put into a blender 11 and stirred (b), and an adhesive 13a is primarily sprayed from a sprayer 12 (c). ), and then a powdery water-insoluble flame retardant chemical 15 is mixed from the chemical charging device 14 (d). Since the adhesive 13a is already attached to the wood fibers 10 at this point, the wood fibers 10a in FIG. 3(a), (b)) are shown by thicker lines.

Next, the adhesive 13b is secondarily sprayed from the spray 16 (which may be the same as the spray 12) onto the wood fibers 10b to which the primary sprayed adhesive 13a and the water-insoluble flame retardant agent 15 are adhered (e). , primary spray adhesive 13a, water-insoluble flame retardant agent 15 and secondary spray adhesive 13b are adhered to the mixture (f). Arrows in FIGS. 3(b) to 3(d) indicate that the wood fibers 10 and 10a are being agitated. The resulting mixture (FIG. 3(f)) is hot-pressed between the upper and lower heating plates 17, 18 (g) to obtain a wood fiber board 19 (MDF 2 in FIG. 1) containing 10 to 40 parts by weight of a flame retardant agent. (h).

Among the steps shown in FIGS. 3(a) to (h), FIG. 3(c) corresponds to the first step, FIG. 3(d) corresponds to the second step, and FIG. This corresponds to the third step, and FIG. 3G corresponds to the fourth step.

As the wood fibers 10, wood fibers obtained by steaming and defibrating coniferous or broad-leaved wood can be used, such as wood fibers derived from construction waste materials and pallet waste materials, and vegetable fibers such as pulp, hemp, and flax. can be The adhesives 13a and 13b to be sprayed in FIGS. 3(c) and 3(e) include urea resin adhesive, melamine resin adhesive, urea melamine co-condensation resin adhesive, phenol resin adhesive, or MDI (diphenylmethane diisocyanate), TDI (tolylene diisocyanate), MDI prepolymer, TDI prepolymer, and other isocyanate resin adhesives can be used.

As the flame retardant agent 15 to be mixed in FIG. . When a water-soluble flame-retardant agent 15 is used, when the manufactured flame-retardant agent-containing wood fiber board 19 absorbs moisture, the flame-retardant agent 15 is transferred to the surface of the flame-retardant agent-containing wood fiber board 19 by the moisture. As the flame retardant agent 15, a water-insoluble one is used because the flame retardant agent 15 is dissolved, and not only does the appearance deteriorate and the surface smoothness is lowered, but also the flame retardancy is lowered.

The flame retardant agent-containing wood fiber board 19 (MDF2) obtained in FIG. , an adhesive containing a predetermined amount of flame retardant agent (halogen/antimony oxide mixed flame retardant agent) is applied, and then five layers of the multilayer decorative material 4 are laminated on the adhesive-applied surface of the MDF 2 and cold-pressed. Thus, the incombustible decorative board 1 of FIG. 1 is obtained. These steps (moisture content adjustment, sanding, adhesive application, multilayer decorative material attachment) are performed by using an adhesive containing a predetermined amount of flame retardant in the adhesive application process, and Except for using the multilayer decorative material 4 (FIG. 2) containing the aluminum foil 4c in the adhering step, it can be carried out according to a conventional method. In the step of attaching the multilayer decorative material, instead of obtaining five layers of the multilayer decorative material 4 in advance and then bonding the multilayer decorative material 4, the multilayer decorative material 4 is constructed. Each laminated material (decorative paper 4a, polyethylene 4b, aluminum foil 4c, polyethylene 4d, paper 4e) may be laminated and adhered one by one or multiple layers in sequence. Alternatively, the laminated decorative material 4 may be adhered by hot pressure instead of cold pressure.

EXAMPLES Examples of the present invention will be described below along with comparative examples in some test examples. First, the case where the substrate 2 and the adhesive layer 3 each contain a flame retardant (Example 1) and the case where one of them does not contain a flame retardant (Comparative Examples 1 and 2). A test was conducted to evaluate the difference in noncombustible performance. That is, Example 1 is a noncombustible decorative board 1 (Fig. 1) having a total thickness of 3 mm manufactured by the above-described manufacturing method, and the base material 2 has a water-insoluble phosphorus and nitrogen-based flame retardant agent relative to its absolute dry weight. 30 parts by weight of MDF with a thickness of 2.7 mm, and the adhesive layer 3 contains 30 parts by weight of a water-insoluble halogen-antimony oxide mixed flame retardant agent per 100 parts by weight of a vinyl acetate adhesive. It is a thing. Comparative Example 1 is the same as Example 1 except that the adhesive layer 3 does not contain a flame retardant agent, and Comparative Example 2 is the same as Example 1 except that the substrate 2 does not contain a flame retardant agent. is. These Example 1 and Comparative Examples 1 and 2 were subjected to a test based on ISO 5600-1 "pyrogenicity test (corn calorimeter test)" and evaluated according to the following three items. Table 1 shows the results. In Table 1, the "number of seconds" to the right of the "maximum heat release rate" indicates the time during which the heat release rate exceeded 200 kW/ ^m2 .
・Presence or absence of cracks and holes in the specimen after the test ・Total calorific value (MJ/m ² ) after 5 minutes, 10 minutes, and 20 minutes
・The heat release rate must not exceed 200 kW/ ^m2 continuously for 10 seconds or longer.

As shown in Table 1, in Example 1, there were no cracks or holes, the total heat release after 20 minutes was 3.57 MJ/m ² , and the heat release rate did not exceed 200 kW/m ² for 10 seconds or more. Therefore, it was evaluated as having non-combustible performance. On the other hand, in Comparative Example 1, the total calorific value after 20 minutes was 3.91 MJ/m ² , and the heat generation rate did not exceed 200 kW/m ² continuously for 10 seconds or more, but cracks and holes were observed. Therefore, it was evaluated as not having noncombustibility. Comparative Example 2 was inferior in all of the above three evaluation items, and was evaluated as having no nonflammability. From the above test results, it was confirmed that both the base material 2 and the adhesive layer 3 must contain a flame retardant agent as in Example 1 in order to obtain a noncombustible decorative board having noncombustible properties. rice field.

Next, a test was conducted to confirm suitable manufacturing conditions for imparting flame retardancy to the wood fiber board (MDF) serving as the base material 2 of the noncombustible decorative board 1 . In this test, 926 g of wood fiber in absolute dry weight (using wood fibers obtained from waste hardwood of multiple tree species) was added to 274 g (relative to the absolute dry weight of wood fiber) as the amount required to form a wood fiber board. and 303 g (about 33% relative to the oven dry weight of the wood fiber) of water-insoluble A mixture obtained by mixing a flame retardant agent (phosphorous and nitrogen-based flame retardant agent) is hot-pressed under the conditions of a temperature of 180°C, a surface pressure of 46 kg/cm ² , and a heat-pressing time of 8 minutes to produce a wood fiber board. bottom.

In Examples 2 to 4, in the first step, while stirring the wood fibers, a part of the adhesive amount (90%, 50%, 10% of the total amount) necessary for molding into a wood fiber board was added. After the second step of spraying and mixing the flame retardant agent, in the third step, while stirring the wood fibers after mixing the adhesive and the flame retardant agent, the remaining amount of the adhesive (10% of the total amount) , 50%, 90%) to obtain a mixture, in Comparative Example 3 the entire required amount of adhesive was sprayed in the first step (no third step), and in Comparative Example 4 no adhesive was required. The entire amount was sprayed in the third step (no first step). The first to third steps were carried out in the same blender 11.

The mixtures of Examples and Comparative Examples thus obtained were subjected to thermocompression molding under the conditions described above, and the presence or absence of molding defects was evaluated. Table 2 shows the mixing conditions of wood fibers, adhesives and flame retardants in Examples 2 to 4 and Comparative Examples 3 and 4 in this test and the presence or absence of defective molding by visual observation.

As shown in Table 2, molding defects did not occur in Examples 2 to 4 in which the required amount of adhesive was sprayed in two steps, the first step and the third step, but the total amount of adhesive required In Comparative Examples 3 and 4 in which the was sprayed at once, the molding was defective. The reason for this can be considered as follows.

The purpose of spraying the adhesive in the first step is to evenly and evenly adhere the adhesive over the entire wood fiber. ) can be evenly attached to the wood fibers through the adhesive.

On the other hand, in Comparative Example 4 in which the first step was not performed, even if the flame retardant agent was added in the second step, the powdery flame retardant agent was sufficiently attached to the wood fibers to which the adhesive was not attached. It simply becomes a state of being dispersed without wearing it. For this reason, even if the required amount of the adhesive was sprayed in the third step, the flame retardant agent floated up, resulting in defective molding (so-called puncture) during hot pressing. Further, when the bottom of the blender 11 was observed after performing the second step of mixing the flame retardant agent, the flame retardant agent did not fall to the bottom in any of Examples 2 to 4, whereas Comparative Example 4 , it was confirmed that a large amount of the flame retardant had fallen to the bottom of the blender 11 . This means that even if molding were possible, a sufficient amount of the flame retardant agent could not be mixed into the wood fiber board, and the effect of improving the flame retardant performance would be insufficient. .

The spraying of the adhesive in the third step is for applying the adhesive to the surface of the flame retardant agent attached to the wood fibers through the first and second steps, and for the shortage of the adhesive sprayed in the first step. This is done to supplement the amount and provide the adhesive necessary for molding into a wood fiber board. According to Examples 2 to 4, through the first step and the second step, a state in which the flame retardant agent was evenly attached to the wood fibers through the adhesive was obtained. By spraying a sufficient amount of the adhesive, a mixture in which both the flame retardant agent and the adhesive are evenly mixed with the wood fibers can be obtained, resulting in good moldability. 4 and 5 are microphotographs showing the state after the third step of Example 3, and it can be seen that the adhesive (which looks like particles) is evenly and evenly attached to the entire wood fibers.

On the other hand, in Comparative Example 3 in which the entire amount of adhesive required for molding was sprayed in the first step, an excessive amount of adhesive with respect to the amount of flame retardant agent adhered to the wood fibers. When the flame retardant agent is added in the second step, the flame retardant agent adheres to the adhesive in places and hardens, and a state in which the flame retardant agent adheres evenly and uniformly to the wood fibers cannot be obtained. In addition, since the adhesive is not applied to the surface of the flame retardant agent attached to the wood fibers, the flame retardant agent cannot be entangled and adhered between the wood fibers, resulting in poor molding when hot pressed. (Cracks, peeling, etc.) occur, and even if molding is possible, it is not possible to produce a wood fiber board having uniform flame retardancy particularly in the longitudinal direction.

Next, a test was conducted to confirm the suitable range of the amount of adhesive to be sprayed in the first step and the amount of adhesive to be sprayed in the third step. In this test, the amount of adhesive sprayed in the first step was fixed at 27 g (about 3% relative to the absolute dry weight of wood fibers), while the amount of adhesive sprayed in the third step was changed to 27 g, 57 g, 84 g, and 108 g (about 3%, about 6%, about 9%, and about 12%, respectively, relative to the absolute dry weight of the wood fiber) was changed in four ways, but the test was performed under the same conditions as the above test. The presence or absence of was visually observed. These conditions and results are shown in Table 2.

As described above, the purpose of spraying the adhesive in the first step is to evenly and evenly adhere the adhesive over the entire wood fiber. By spraying the agent, the adhesive is evenly attached to the wood fibers, so that the entire amount of the flame retardant agent mixed in the second step can be attached to the wood fibers through the adhesive. A wood fiber board having uniform flame retardancy can be produced without causing molding defects. When the bottom of the blender was observed after the second step of mixing the flame retardant agent, almost no flame retardant agent fell to the bottom in any of Examples 5 to 8. This indicates that the entire amount of the flame retardant agent mixed in the second step adhered to the wood fibers via the adhesive sprayed in the first step. In this test, the spray amount of the adhesive in the first step was fixed at 3%, but it was demonstrated that molding defects did not occur in Examples 5 to 8, which was set to 3%. It is clear that the same effect can be exhibited even if the spray amount is set to .

Considering the results of Comparative Example 4 (Table 2) in which the first step was omitted (that is, the amount of adhesive sprayed in the first step was 0), the amount of adhesive sprayed in the first step was 3%. If it is less than that, the adhesive cannot be evenly attached to the wood fibers, and part of the flame retardant agent mixed in the second step cannot adhere to the wood fibers and is stirred up by stirring or blended. Since it falls to the bottom of 11, molding defects such as puncture are likely to occur, and even if it can be molded, it becomes difficult to manufacture a wood fiber board having uniform flame retardancy as a whole.

As mentioned above, one purpose of spraying the adhesive in the third step is to apply the adhesive to the surface of the flame retardant agent attached to the wood fiber through the first and second steps. From the point of view, the results in Table 3 demonstrate that the spray amount is preferably 3% or more with respect to the absolute dry weight of the wood fiber.

Considering the results of Comparative Example 3 (Table 1), in which the third step was omitted (that is, the amount of adhesive sprayed in the third step was 0), the amount of adhesive sprayed in the third step was 3%. If it is less than that, even if the flame retardant agent can be attached evenly and uniformly to the wood fibers through the first and second steps, the adhesive will be attached to the surface of all the flame retardant agents in the third step. Since the flame retardant agent cannot be entangled and attached between the wood fibers, it causes molding defects such as cracks and peeling.

Another purpose of the amount of adhesive sprayed in the third step is to make up for the shortage of the adhesive sprayed in the first step and provide the adhesive necessary for molding into the wood fiber board. 3% or more, and the total amount including the spray amount of the adhesive in the first step is set to be the above required amount for molding, but this total amount is 6% relative to the absolute dry weight of the wood fiber It is preferable to make it to 35%. Within this range, a wood fiber board having flame retardancy can be produced without causing poor molding. If the total amount of adhesive is less than 6%, it becomes difficult for the adhesive to spread all over the wood fibers, resulting in portions where the wood fibers are not adhered to each other, which may cause molding defects. If the total amount of the adhesive exceeds 35%, the amount of moisture contained in the adhesive becomes excessive, and it takes a long time for the adhesive to harden during hot pressing, resulting in a decrease in manufacturing efficiency. In addition, moisture contained in the adhesive becomes high temperature and high pressure at the time of hot pressing, and it expands as water vapor in the compressed wood fibers, which easily causes molding defects such as cracks and peeling.

From the test results and considerations described above, the spray amount of the adhesive in the first step is 3 to 32% of the absolute dry weight of the wood fiber, and the spray amount of the adhesive in the third step is the absolute dry weight of the wood fiber. A preferred range is considered to be 3 to 32% by dry weight.

Although the present invention has been described in detail based on the embodiments above, the present invention is not limited thereto, and various modifications and changes can be made within the scope of the invention interpreted based on the description of the claims. It is possible. In FIG. 3, the first step (c), the second step (d) and the third step (e) are performed in the same blender 11, but different blenders may be used, and the wood fibers 10 or These steps may be performed while the wood fibers 10a and 10b to which the adhesive and the like are attached are blown by a duct or the like.

1 Noncombustible decorative board 2 Base material (wood fiber board)
3 Adhesive layer 4 Multilayer decorative material 4a Decorative paper (decorative material)
4b polyethylene (resin layer)
4c aluminum foil (metal foil)
4d polyethylene (resin layer)
4e Paper 10 Wood fiber 10a Wood fiber 10b with adhesive (partial) Adhesive (part) and flame retardant agent attached wood fiber 10c Adhesive (whole amount) and flame retardant agent attached wood fiber 11 Blender 12 Spray 13a Adhesive 13b Part of the total amount necessary for molding Remaining adhesive 14 Chemical injection device 15 Water-insoluble flame retardant chemical 16 Spray 17 Upper heating plate 18 Lower heating plate 19 Contains flame retardant agent wood fiber board

Claims (5)

10 to 40 parts by weight of a water-insoluble phosphorous/nitrogen flame retardant powder made of powder per 100 parts by weight of bone-dried wood fibers is adhered to the wood fibers on one or both sides of a substrate made of a wood fiber board. , with a decorative material on the surface and at any lamination position on the back side, through an adhesive layer containing 10 to 40 parts by weight of a halogen/antimony oxide mixed flame retardant agent per 100 parts by weight of the adhesive. A noncombustible decorative board, characterized in that a multi-layered decorative material laminated with metal foil is adhered thereto. 2. The noncombustible decorative board according to claim 1, wherein said multilayer decorative material has a laminated structure of decorative material/resin layer/metal foil/resin layer/paper from the surface side. a wood fiber board forming step of forming a wood fiber board containing 10 to 40 parts by weight of a water-insoluble phosphorus-nitrogen-based flame retardant agent with respect to 100 parts by weight of absolutely dry wood fibers;
an adhesive application step of applying an adhesive containing 10 to 40 parts by weight of a halogen/antimony oxide mixed flame retardant agent to 100 parts by weight of the adhesive on the surface of the molded wood fiber board;
A step of laminating and adhering a multi-layer decorative material having a decorative material on the front surface and a metal foil laminated on one of the lamination positions on the back side of the wood fiber board onto the adhesive-applied surface of the wood fiber board; has
The wood fiber board forming step includes:
a first step of spraying a part of the total amount of adhesive necessary for molding onto the wood fibers while stirring the wood fibers to attach the adhesive to the wood fibers;
While stirring the mixture obtained in the first step, 10 to 40 parts by weight of a water-insoluble phosphorus-nitrogen-based flame retardant agent is mixed with 100 parts by weight of bone-dried wood fiber to obtain powdery water. a second step of adhering an insoluble phosphorus/nitrogen-based flame retardant agent to wood fibers via an adhesive;
The mixture obtained in the second step is stirred while the rest of the necessary adhesive is sprayed onto the mixture to obtain a mixture consisting of wood fibers, an adhesive and a water-insoluble phosphorus/nitrogen flame retardant. process and
and a fourth step of hot-pressing the mixture obtained in the third step. 4. The method according to claim 3, wherein 10 to 90% by weight of the required total amount of adhesive is sprayed in the first step, and 90 to 10% by weight of the required amount of adhesive is sprayed in the third step. A method for producing a noncombustible decorative board. In the first step , 3 parts by weight or more of the adhesive is sprayed to 100 parts by weight of the absolute dry wood fibers, and in the third step , 3 parts by weight or more of the adhesive is sprayed to 100 parts by weight of the absolute dry wood fibers. 5. The method for producing a noncombustible decorative board according to claim 3 or 4, characterized in that the spraying of

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