JPS5823202B2 - flame retardant plywood - Google Patents

Description

Detailed Description of the Invention The present invention provides an inorganic hydrous compound in a copolymer or mixture of a non-formalin thermosetting resin and a thermoplastic resin on the front and back surfaces of a flame-retardant intermediate plate for manufacturing plywood. Applying a specific flame-retardant adhesive containing the material and gluing the original board together to make plywood,
The present invention relates to a flame-retardant plywood with excellent heat insulation properties, which is coated with a thin layer of foamable fireproofing paint on the surface of the plywood, and which generates very little toxic gas even in the event of a fire.

Conventionally, flame-retardant plywood was produced by injecting known flame-retardant treatment solutions such as ammonium phosphate, ammonium sulfamate, ammonium bromide, and anidine phosphate into the veneer.
Bonded with a plywood adhesive such as formaldehyde resin, melamine-formaldehyde resin, phenol-formaldehyde resin, or a co-condensate thereof.

(2) A foamable flame retardant adhesive containing a foamable flame retardant such as ammonium polyphosphate or carbamate polyphosphate in the above adhesive for plywood is interposed between the intermediate board and the original board.

■It is known that a large amount of foaming fireproof paint is applied to the plywood surface.

However, since the above-mentioned known flame-retardant plywood generates a large amount of formalin gas in the event of a fire, it poses a major problem from the standpoint of protecting precious human life.

In addition, all of them were insufficient in terms of heat insulation properties.

In other words, when veneer is injected with a flame retardant treatment liquid and bonded with ordinary plywood adhesive, it will not have insulation properties when heated in a heating furnace specified in Ministry of Construction Notification I No. 1231. A large through hole is created that reaches the back side of the plywood.

Furthermore, although the amount of CO gas and CO□ gas in the generated exhaust gas is small, the amount of formalin gas generated is large.

Next, ■, in which a foaming flame retardant adhesive containing a foaming flame retardant in a regular plywood adhesive is interposed between the middle board and the original board, is heated in a heating furnace. , a foamed heat insulating layer is temporarily formed on the plywood adhesive layer, but as heating progresses, the original board and the intermediate board separate and the plywood falls apart, and the foamed heat insulating layer is only effective in part i.

Furthermore, since the plywood adhesive layer is completely exposed to flame, a large amount of formalin gas is generated, making it unsuitable for fire prevention treatment.

Next, ■, which is a large amount of foaming fire prevention paint applied to the plywood surface, has a coating amount of 300 g/rr? In the following cases,
It does not pass the flame retardant surface test specified in the Ministry of Construction Notification No. 1231, so a very large amount must be applied.

However, even if a large amount is applied, decorative paper or decorative veneer may be pasted on the surface of the paint, polyester decorative processing, etc.
When a decorative layer such as diallyl phthalate makeup skin i-treatment is applied, the foaming fire prevention paint adheres to the makeup layer at the same time as it is heated from the surface, and the cracks in the foaming fire prevention paint layer become large and a large amount is removed. The effect of the application is not seen at all.

As the heating progresses, carbonization of the plywood progresses from the cracks in the foamable fireproofing paint layer, penetrating the back surface of the plywood.

Also, a large amount of formalin gas is generated.

Flame-retardant decorative plywood is produced by pasting a thin decorative veneer on the surface of flame-retardant plywood that has undergone all of the conventional fire-retardant treatments listed in items ■■ and ■ above. When we conducted a gas hazard test on decorative plywood as stipulated in Ministry of Construction Notification No. 1231, we found that the amount of gas generated by red lauan material, which is a standard material (
COl, 25%, CO24, 17%, 0214.6%)
Compared to
2,01%.

0217.9%), CO gas, and CO□ gas are very small, and although 02 gas is slightly large, it kills mice quickly.

Although the amount of smoke emitted is lower than that of red lauan material, the time it takes to kill mice is faster due to the influence of formalin gas present in the exhaust gas.

In order to solve the above-mentioned drawbacks, the present inventors have conducted extensive research and found that even if a fire occurs, very little toxic gas is generated.
We have succeeded in developing flame-retardant plywood with excellent heat insulation properties.

That is, the present invention provides an inorganic hydrous compound in a copolymer or mixture of a non-formalin thermosetting resin and a thermoplastic resin on the front and back surfaces of an intermediate board for plywood production that has been impregnated with a flame retardant treatment liquid and dried. This flame-retardant plywood is characterized in that it is coated with a flame-retardant adhesive containing .

In the present invention, non-formalin-based thermosetting resins refer to thermosetting resins other than formalin-based thermosetting resins such as urea, melamine, phenol, resorcinol-formaldehyde cocondensation resins, such as epoxy resins, unsaturated polyester resins, etc. , polyester/acrylate resin, triallyl cyanurate resin, etc., and thermoplastic resins include resins such as polyvinyl acetate, polyacrylate, polymethacrylate, polyacrylonyl-IJ, polyvinyl ether, polyvinyl chloride, and polyvinylidene chloride. be.

A mixture or copolymer of this non-formalin thermosetting resin and a thermoplastic resin is used.

Epoxy/vinyl acetate emulsions, epoxy/ethylene vinyl acetate emulsions, crosslinked vinyl acetate emulsions, crosslinked acrylic emulsions, and the like are suitable as copolymers of non-formalin thermosetting resins and thermoplastic resins.

In the present invention, inorganic hydrated compounds include aluminum hydroxide, calcium hydroxide, zinc borate, borax, alumite, or hydration surface, and since these inorganic substances have a large amount of crystal water, When exposed to high temperatures, it has the property of causing a dehydration decomposition reaction at a certain temperature and at the same time absorbing heat.

For example, the decomposition temperature of aluminum hydroxide is 1g at 200℃
The total amount of heat absorbed per hit is 4707! It is.

If a flame-retardant adhesive containing an inorganic hydrous compound such as aluminum hydroxide is interposed between the intermediate plate and the original plate in a non-formalin thermosetting resin, crystallization water of the inorganic hydrous compound will occur when heated. thermally decomposes and causes an endothermic effect, but the adhesive layer is hard and does not form an insulating adhesive layer.

However, surprisingly, as a thermoplastic resin is mixed into a mixture of a non-formalin thermosetting resin and an inorganic hydrous compound, when heated, the thermoplastic resin softens and melts, forming an inorganic hydrous compound. It has been found that the adhesive layer expands when the adhesive layer contains water of crystallization, and an excellent heat-insulating adhesive layer can be obtained.

However, if the thermoplastic resin is used in a very large amount, it will not be heat resistant, and the base plate and the intermediate plate of the plywood will separate, which is undesirable.

In addition, the medium veneer impregnated with a known flame-retardant treatment liquid is covered with a heat-insulating adhesive layer that contains moisture and expands uniformly on both sides, so the medium veneer is not exposed to flames. can be a good insulation layer.

Next, the foamable fireproofing paint used in the present invention may be any foamable fireproofing paint commonly used in the past, and is not particularly limited, but the resin used as a binder may contain a small amount of formalin or be additive-free. is preferred.

This foaming fire prevention paint is applied to provide fire protection for the base veneer and for the decorative layer when the surface is decorated, and the amount of application is 100 to 300 g/lr. It is good to apply a small amount.

A flame retardant surface test and a gas hazard test specified in Ministry of Construction Notification No. 1231 were conducted on test pieces obtained by adhering a decorative veneer to the surface of the flame retardant plywood obtained by the present invention. As the process progresses, the thermoplastic resin interposed in the plywood adhesive layer softens and expands in the non-formalin-based thermosetting resin, and becomes a state containing crystallization water of inorganic hydrous compounds.
This adhesive layer was found to have excellent thermal insulation properties.

It was also found that the flame-retardant veneer, which is not directly exposed to flames, has good heat insulation properties because the base plate and the intermediate plate do not separate or penetrate.

On the other hand, the exhaust gas generated by thermal decomposition has very little amount of toxic gases such as formalin, so it was found that it easily passed the gas toxicity test.

As explained above, the flame-retardant plywood obtained by the present invention is useful as a base plate flame-retardant plywood for decorative processing such as precious wood decorative plywood and polyester decorative plywood, and since inorganic hydrous compounds are generally cheap, manufacturing costs can be reduced. It also has high industrial utility.

Next, the present invention will be explained by giving examples.

Example 1 A medium veneer with a thickness of 4m7n was impregnated with an aqueous solution of a phosphoric acid carbamate flame retardant, and then dried to produce a medium flame retardant treated veneer in which the solid content of the flame retardant was injected at 360 g/771- I got it.

Next, 100 parts by weight of epoxy/ethylene vinyl acetate copolymer resin, 100 parts by weight of aluminum hydroxide, as a copolymer of non-formalin-based thermosetting resin and thermoplastic resin, 100 parts by weight of aluminum hydroxide, Apply 500g/? of flame retardant adhesive consisting of 15 parts by weight of water? 7Z2 coated, thickness 0.8
Plywood was manufactured by stacking the original sheets of m, under heat-pressing conditions normally used for manufacturing plywood.

Next, 100 parts by weight of polyvinyl acetate resin, 120 parts by weight of a flame retardant in a ratio of 1:1:1 of ammonium polyphosphate, pentaerythritol, and melamine, and 150 parts by weight of water were then applied to the surface of this plywood.
A fire-retardant plywood of the present invention was obtained by applying a foamable fire-preventing paint consisting of parts by weight in an amount of 180 g/i and drying.

Example 2 60 parts by weight of a water-soluble epoxy resin as a non-formalin-based thermosetting resin, 40 parts by weight of acrylic vinyl acetate resin as a thermoplastic resin, and calcium hydroxide were added to the front and back surfaces of the medium plate flame-retardant treated veneer described in Example 1. A flame retardant adhesive consisting of 140 parts by weight and 25 parts by weight of water was applied in an amount of 500 g/m2 to a thickness of 0.
．． Plywood was produced by stacking 8 m1n original plates under heat-pressing conditions normally used for producing plywood.

Next, the foamable fireproofing paint described in Example 1 was applied to the surface of this plywood in an amount of 180 g/m 2 and dried to obtain a flame-retardant plywood of the present invention.

Example 3 60 parts by weight of unsaturated polyester resin as a non-formalin-based thermosetting resin, 40 parts by weight of polyacrylate resin as a thermoplastic resin, and 180 parts by weight of alumite were used on the front and back surfaces of the intermediate flame-retardant veneer plate described in Example 1. A flame retardant adhesive consisting of 0.5 parts by weight of methyl ethyl ketone peroxide and 0.5 parts by weight of cobalt naphthenate was applied in an amount of 500 g/7?72, and the original plates with a thickness of 0.8 mm were overlaid. Heating temperature 6
Plywood was manufactured under hot pressure conditions of 0'C1 pressure of 10 kg/m and heat pressure time of 6 minutes.

Next, the foamable fireproofing paint described in Example 1 was applied to the surface of this plywood in an amount of 180 g/yn2 and dried to obtain a flame-retardant plywood of the present invention.

Example 4 100 parts by weight of a cross-linked acrylic/vinyl acetate copolymer resin and borax were added to the front and back surfaces of the flame-retardant intermediate veneer plate described in Example 1 as a copolymer of a non-formalin thermosetting resin and a thermoplastic resin. A flame retardant adhesive consisting of 140 parts by weight and 10 parts by weight of water was applied in an amount of 500 g/? Plywood was produced by stacking 722 pieces of original sheets with a thickness of 0.8 m under heat-pressing conditions for normal plywood production.

Next, the foamable fireproofing paint described in Example 1 was applied to the surface of this plywood at a coating amount of 180 g/d, and dried to obtain a flame-retardant plywood of the present invention.

Example 5 60 parts by weight of a cross-linked polyurethane resin as a non-formalin thermosetting resin, 40 parts by weight of vinyl acetate resin as a thermoplastic resin, and 100 parts by weight of aluminum hydroxide were added to the front and back surfaces of the medium plate flame-retardant treated veneer described in Example 1. 500 g/r/12 of a flame retardant adhesive consisting of 15 parts by weight of water and 15 parts by weight of
．． Plywood was produced by stacking original sheets of 8 mrn together under heat-pressing conditions normally used for producing plywood.

Next, the foaming fireproofing paint described in Example 1 was applied to the surface of this plywood in an amount of 180 g/rr. The flame retardant plywood of the present invention was obtained by coating and drying.

Comparative Example 1 100 parts by weight of urea/formaldehyde resin initial condensate and 18 parts of wheat flour were added to the front and back surfaces of the medium flame-retardant veneer board described in Example 1.
A coating amount of plywood adhesive consisting of 10 parts by weight, 10 parts by weight of water, and 71 parts by weight of ammonium chloride was 360 g/rr? Apply, thickness 0
．． Plywood was manufactured by stacking the original sheets of 8 dragons together under heat-pressing conditions normally used for manufacturing plywood.

Next, the foamable fireproofing paint described in Example 1 was applied to the surface of this plywood in an amount of 180 g/? ? A flame-retardant plywood was obtained by applying 72 and drying.

Comparative Example 2 100 parts by weight of an initial condensate of urea/melamine/formaldehyde resin was applied to the front and back surfaces of the medium flame-retardant veneer plate described in Example 1.
A foaming flame-retardant adhesive consisting of 40 parts by weight of ammonium polyphosphate, 4 parts by weight of wheat flour, and 71 parts by weight of ammonium chloride was applied at a coating amount of 500 g/m2, and the original sheets with a thickness of 0.8 mm were overlaid to form regular plywood. Plywood was manufactured under manufacturing heat and pressure conditions.

Next, the foaming fireproofing paint described in Example 1 was applied to the surface of this plywood in an amount of 180 g/rr. Flame-retardant plywood was obtained by coating and drying.

Comparative Example 3 100 parts by weight of urea/formaldehyde resin initial condensate,
600g of the foamable fireproofing paint described in Example 1 was applied to the surface of a 5.5 mm thick ordinary plywood board bonded with a plywood adhesive consisting of 18 parts by weight of wheat flour, 10 parts by weight of water, and 71 parts by weight of ammonium chloride. /d coating and drying to obtain flame-retardant plywood.

A walnut decorative veneer with a thickness of 0.25 m was attached to the flame-retardant plywood surface described in Examples 1 to 5 and Comparative Examples 1 and 2.3 using an ethylene-vinyl acetate emulsion adhesive to achieve flame retardancy. Manufactured decorative plywood made of precious wood.

Next, a test piece was cut out from this flame-retardant decorative plywood,
A flame retardant surface test and a gas toxicity test were carried out as specified in Ministry of Construction Notification No. 1231 of 1970, and a formaldehyde emission test was carried out as specified in JISA5908.

The results are shown in Table-1. As is clear from the test results in Table 1, the flame-retardant decorative wood plywood based on the flame-retardant plywood of the present invention of Examples 1 to 5 did not emit any formaldehyde and was tested for gas toxicity and flame retardant. It passed the surface test with excellent results.

Claims (1)

[Claims] 1. A flame retardant containing an inorganic hydrous compound in a copolymer or mixture of a non-formalin thermosetting resin and a thermoplastic resin is applied to the front and back surfaces of an intermediate plate for plywood production that has been impregnated with a flame retardant treatment liquid and dried. 1. A flame-retardant plywood, characterized in that a plywood is obtained by applying an adhesive and adhering a base plate to the applied surface, and a foaming fireproofing paint is applied to the surface of the plywood.