EP0838316A1 - Method of rendering wooden material flame-retardant and process for producing flame-retarded plywood therewith - Google Patents

Method of rendering wooden material flame-retardant and process for producing flame-retarded plywood therewith Download PDF

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Publication number
EP0838316A1
EP0838316A1 EP96912291A EP96912291A EP0838316A1 EP 0838316 A1 EP0838316 A1 EP 0838316A1 EP 96912291 A EP96912291 A EP 96912291A EP 96912291 A EP96912291 A EP 96912291A EP 0838316 A1 EP0838316 A1 EP 0838316A1
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EP
European Patent Office
Prior art keywords
flame
retarding
materials
wooden
solution
Prior art date
Legal status (The legal status is an assumption and is not a legal conclusion. Google has not performed a legal analysis and makes no representation as to the accuracy of the status listed.)
Withdrawn
Application number
EP96912291A
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German (de)
English (en)
French (fr)
Inventor
Mithuo Kimura
Current Assignee (The listed assignees may be inaccurate. Google has not performed a legal analysis and makes no representation or warranty as to the accuracy of the list.)
Touhoku Sensyoku Corp
Original Assignee
Touhoku Sensyoku Corp
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Filing date
Publication date
Application filed by Touhoku Sensyoku Corp filed Critical Touhoku Sensyoku Corp
Publication of EP0838316A1 publication Critical patent/EP0838316A1/en
Withdrawn legal-status Critical Current

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    • B—PERFORMING OPERATIONS; TRANSPORTING
    • B27—WORKING OR PRESERVING WOOD OR SIMILAR MATERIAL; NAILING OR STAPLING MACHINES IN GENERAL
    • B27K—PROCESSES, APPARATUS OR SELECTION OF SUBSTANCES FOR IMPREGNATING, STAINING, DYEING, BLEACHING OF WOOD OR SIMILAR MATERIALS, OR TREATING OF WOOD OR SIMILAR MATERIALS WITH PERMEANT LIQUIDS, NOT OTHERWISE PROVIDED FOR; CHEMICAL OR PHYSICAL TREATMENT OF CORK, CANE, REED, STRAW OR SIMILAR MATERIALS
    • B27K3/00—Impregnating wood, e.g. impregnation pretreatment, for example puncturing; Wood impregnation aids not directly involved in the impregnation process
    • B27K3/52—Impregnating agents containing mixtures of inorganic and organic compounds
    • B—PERFORMING OPERATIONS; TRANSPORTING
    • B27—WORKING OR PRESERVING WOOD OR SIMILAR MATERIAL; NAILING OR STAPLING MACHINES IN GENERAL
    • B27K—PROCESSES, APPARATUS OR SELECTION OF SUBSTANCES FOR IMPREGNATING, STAINING, DYEING, BLEACHING OF WOOD OR SIMILAR MATERIALS, OR TREATING OF WOOD OR SIMILAR MATERIALS WITH PERMEANT LIQUIDS, NOT OTHERWISE PROVIDED FOR; CHEMICAL OR PHYSICAL TREATMENT OF CORK, CANE, REED, STRAW OR SIMILAR MATERIALS
    • B27K3/00—Impregnating wood, e.g. impregnation pretreatment, for example puncturing; Wood impregnation aids not directly involved in the impregnation process
    • B27K3/16—Inorganic impregnating agents
    • B27K3/32—Mixtures of different inorganic impregnating agents
    • B—PERFORMING OPERATIONS; TRANSPORTING
    • B27—WORKING OR PRESERVING WOOD OR SIMILAR MATERIAL; NAILING OR STAPLING MACHINES IN GENERAL
    • B27K—PROCESSES, APPARATUS OR SELECTION OF SUBSTANCES FOR IMPREGNATING, STAINING, DYEING, BLEACHING OF WOOD OR SIMILAR MATERIALS, OR TREATING OF WOOD OR SIMILAR MATERIALS WITH PERMEANT LIQUIDS, NOT OTHERWISE PROVIDED FOR; CHEMICAL OR PHYSICAL TREATMENT OF CORK, CANE, REED, STRAW OR SIMILAR MATERIALS
    • B27K5/00—Treating of wood not provided for in groups B27K1/00, B27K3/00
    • B27K5/001—Heating
    • B—PERFORMING OPERATIONS; TRANSPORTING
    • B27—WORKING OR PRESERVING WOOD OR SIMILAR MATERIAL; NAILING OR STAPLING MACHINES IN GENERAL
    • B27K—PROCESSES, APPARATUS OR SELECTION OF SUBSTANCES FOR IMPREGNATING, STAINING, DYEING, BLEACHING OF WOOD OR SIMILAR MATERIALS, OR TREATING OF WOOD OR SIMILAR MATERIALS WITH PERMEANT LIQUIDS, NOT OTHERWISE PROVIDED FOR; CHEMICAL OR PHYSICAL TREATMENT OF CORK, CANE, REED, STRAW OR SIMILAR MATERIALS
    • B27K2240/00—Purpose of the treatment
    • B27K2240/30—Fireproofing
    • B—PERFORMING OPERATIONS; TRANSPORTING
    • B27—WORKING OR PRESERVING WOOD OR SIMILAR MATERIAL; NAILING OR STAPLING MACHINES IN GENERAL
    • B27K—PROCESSES, APPARATUS OR SELECTION OF SUBSTANCES FOR IMPREGNATING, STAINING, DYEING, BLEACHING OF WOOD OR SIMILAR MATERIALS, OR TREATING OF WOOD OR SIMILAR MATERIALS WITH PERMEANT LIQUIDS, NOT OTHERWISE PROVIDED FOR; CHEMICAL OR PHYSICAL TREATMENT OF CORK, CANE, REED, STRAW OR SIMILAR MATERIALS
    • B27K3/00—Impregnating wood, e.g. impregnation pretreatment, for example puncturing; Wood impregnation aids not directly involved in the impregnation process
    • B27K3/02—Processes; Apparatus
    • B27K3/0228—Spraying apparatus, e.g. tunnels

Definitions

  • This invention relates to a method for flame-retarding treating of wooden materials which enables to attain the flame-retarding performance which fulfills the flame-retarding examination according to the JIS (Japanese Industrial Standard), fire prevention regulations, or the like, prescribed by public organizations.
  • the invention intends to provide a new method for flame-retarding treating of wooden materials, which is easier and more economical than conventional methods, and also to provide a method for producing a flame-retarded plywood by using the new method.
  • building related laws or regulations require several performances such as flame-retarding or noncombustible performances more than ever to new building materials, especially to those used in public spaces and portions or spaces such as kitchens where fire is used. It is believed that such laws or regulations will be more strengthened in the future, but never be loosened.
  • This invention relates to the method for flame-retarding treating of wooden materials.
  • the method includes the following steps. At first, flame-retarding materials are mixed with an aqueous solution such that the mixed solution includes the flame-retarding material of about 30 to 50%.
  • the flame-retarding materials include ammonium phosphate, ammonium bromide, boric acid, borax, ammonium chloride, magnesium oxide, calcium phosphate and lanthanum chloride of about 30, 10, 10, 20, 20, 6, 2 and 2%, respectively.
  • the aqueous solution includes only ether, or ether and alcohol of about 10%.
  • the mixed solution is heated and stirred for a predetermined time.
  • the heating is stopped, and the mixed solution is sprayed directly onto the surface of the wooden materials set under the normal temperature and pressure while the temperature of the mixed solution is kept over 60°C. Then, spraying the mixed solution is stopped after the predetermined time when the weight of the wooden materials increases by at least about 20 to 30% of its original weight measured under the dry condition of about 10% hydrous rate. Finally, the wooden materials are dried under proper condition.
  • This invention also relates to a method for producing flame-resistant plywood which relates to the above-mentioned method.
  • a flame-retarding material is mixed with an aqueous solution such that the mixed solution includes the flame-retarding material of about 30 to 50%.
  • the flame-retarding material includes ammonium phosphate, ammonium bromide, boric acid, borax, ammonium chloride, magnesium oxide, calcium phosphate and lanthanum chloride of about 30, 10, 10, 20, 20, 6, 2 and 2%, respectively.
  • the aqueous solution includes only ether, or ether and alcohol of about 10%.
  • the mixed solution is heated and stirred for a predetermined time. After that, heating is stopped, and the mixed solution is sprayed directly onto the surface of the wooden materials set under the normal temperature and pressure while the temperature of the mixed solution is kept over 60°C.
  • FIGS. 1-3 are graphs showing a change of exhaust temperatures and smoke amounts of samples No.1, 2 and 3 with the passage of time, respectively. These graphs are appended to a certificate of flame-retarding test (September 17, 1992, CHOUTEI No. 1518, certified by the chief director of the foundation, Akita prefecture industrial material laboratory) which complies with the Japanese rule, flame-retarding test 3rd grade.
  • FIGS.4-6 are graphs showing a change of exhaust temperatures and smoke amounts of samples No. A, B and C with the passage time, respectively. These graphs are appended to a certificate of flame-retarding test (October 30, 1992, YOYO (SHI) No.5, certified by the Superintendent of the Tokyo Fire Board) which complies with the Japanese rule of fire prevention, ⁇ 63, 2nd clause.
  • a flame-retarding material is mixed with an aqueous solution including about 10 % of ether, or ether and alcohol. Then, the aqueous solution including the flame-retarding material is heated and stirred for a predetermined time so as to prepare a mixed solution which includes flame-retarding materials falling within the range of about 30 to 50%.
  • the flame-retarding material includes a combination of ammonium phosphate, ammonium bromide, boric acid, borax, ammonium chloride, magnesium oxide, calcium phosphate and lanthanum chloride of, for example, about 30, 10, 10, 20, 20, 6, 2 and 2%, respectively.
  • the mixed solution is sprayed directly onto a wooden material under the normal temperature and pressure for a predetermined time.
  • the wooden material for example, is a 2 to 3 mm-thick sawed wooden plate for flame-retarding plywood. This step may continue until the weight of the wooden material increases by at least about 20 to 30% of its original weight. The original weight is measured under dry condition at which the hydrous rate is about 10%. Then the wooden material is dried.
  • the flame-retarding material includes at least ammonium phosphate, ammonium bromide, boric acid, borax, ammonium chloride, magnesium oxide, calcium phosphate and lanthanum chloride, and their concentrations in the mixed solution are usually about 30, 10, 10, 20, 20, 6, 2, 2%, respectively. Their concentrations may be variable within a reasonable range. In a particular case such that, for example, a wooden material is easy to decay, the concentration of the ammonium bromide may be increased up to 20 to 30%.
  • Magnesium oxide, calcium phosphate and lanthanum chloride are prepared as their solutions.
  • a solvent is selected from ether and/or alcohol which meets following requirements. First, it accelerates to dissolve the flame-retarding material into water. Secondly, it makes to open pits of the cells of the wooden materials, wherein the pits are usually formed in patches of sap and have valves which control transfer of water, and the pits are usually closed after the wooden materials are cut. Thirdly, it is harmless to the human body and cheap. Fourthly, it increases its dissolving ability as the temperature rises, and its velocity of evaporation is almost the same as that of water, thus even if the temperature of the mixed solution rises, the solvent will not evaporate earlier than water so as not to change the concentration.
  • diethyleneglycol monoethylether (KARUBITORU:C 6 H 14 O 3 ) among ether is preferably selected, and propyleneglycol (propanediol:C 3 H 8 O 2 ) or triethyleneglycol(C 6 H 14 O 4 ) among alcohol is preferably selected, each having relatively low molecular weight and the characteristic which increases the dissolving ability as the temperature rises.
  • the combination of ether and alcohol as a solvent firstly may be changed depending on the type of the wooden materials to be fire-retarding treated, for example, whether it is relatively lower grade and allows to change color as lauan, whether it is higher grade and does not allow to change color, or whether it is higher grade and has fine structure which is difficult to permeate.
  • the virulence of ether should also be considered.
  • Ether having low molecular weight is economical but virulent.
  • a mixed solvent including alcohol of up to about 30% is selected.
  • the above-mentioned solvent of 10% to water is mixed with the prescribed volume of flame-retarding material (ammonium phosphate, ammonium bromide, boric acid, borax, ammonium chloride, magnesium oxide, calcium phosphate and lanthanum chloride).
  • flame-retarding material ammonium phosphate, ammonium bromide, boric acid, borax, ammonium chloride, magnesium oxide, calcium phosphate and lanthanum chloride.
  • the mixed solution is prepared which includes a preferable amount of the flame-retarding material falling within the range of about 30 to 50%. And heating and stirring the mixed solution is stopped, thereby dropping of the temperature. Soon after stopping heating and stirring, the mixed solution is sprayed, in a manner like a shower, onto the whole surface of the wooden material while keeping the temperature over 60°C.
  • the flame-retarding material dissolved in the mixed solution permeates and gets fixed in the wooden material. This spraying step is kept until the weight of the material increases by about 20-30% of its original weight. The original weight is measured under dry condition at which the hydrous rate is about 10%. Though the spraying time varies depending on not only the quality and thickness of the wooden materials but also the type of the solvent, it usually continues about 20-24 hours. Then, the wooden material is dried by a conventional method. Thus, the flame-retarding treating is completed.
  • the permeating step is conducted such that the wooden material is hung in a sealed vessel and the pressurized mixed solution is evenly sprayed onto the whole surface of the wooden material in a manner like a shower through a nozzle set in the vessel while keeping the temperature of the mixed solution over 60°C.
  • This spraying step should be continuously kept until the weight of the wooden material increases by about 20 to 30% of its original weight which is measured under dry condition when the hydrous rate is about 10%.
  • the step can be conducted economically in the following circulating system.
  • the mixed solution is gathered in a reservoir with steam pipes installed in the lower part of a sealed vessel and is sprayed through the nozzle while controlling the solution temperature by passing steam through the steam pipes depending on the solution temperature detected by a sensor.
  • the wooden material is taken out from the sealed vessel and transferred to a drying room so as to be dried by a conventional method.
  • the drying method is carried out in an atmosphere in which an appropriate amount of dry air is mixed in steam of about 125°C.
  • a flame-retarding material in a drying condition of 10% hydrous rate is obtained.
  • resorcinol resin is most preferably used, which is an addition condensation type phenolic resin and has excellent properties such as being waterproof, chemical-resistant, aging-resistant and heat-resistant over 150 to 180°C, and formaldehyde (methanol) as a hardening agent is added to the resorcinol resin.
  • hexamethylenetetramine (UROTOROPIN), which is crystallized by adding ammonia water, is added to the hardening agent so as to prevent from generating formalin gas.
  • zirconium oxide (ZrO 2 ), zirconium carbide (ZrC) and tantalum carbide (TaC) are also added so as to improve the property of being heat-resistant. The ratio thereof is 3 : 1 : 1, respectively. They are mixed at 5% in total weight.
  • Predetermined pieces of thus obtained flame-retarding single wooden plates for example 5 or 7 pieces of single wooden plates comprising a plywood, are prepared and are piled by way of the above-mentioned heat-resisting adhesive layer under pressure for a predetermined time by a conventional plywood manufacturing process to manufacture a flame-retarding plywood such as 5-ply flame-retarding plywood or 7-ply flame-retarding plywood.
  • the method for flame-retarding treating of wooden material according to the present invention only includes the steps of adding predetermined solvent (permeator) and flame-retarding material to water, heating and stirring the solution to obtain a homogeneous solution, and controlling the temperature of the solution over 60°C.
  • the method for flame-retarding treating of wooden material can be simple and economical because pressure increasing or pressure reducing operation as required in conventional methods is not required in the present invention and the treating can be performed under a normal condition.
  • the cost of the equipment is one third or one fourth of that of the conventional equipment.
  • a conventional pressure-increasing or pressure-reducing equipment costs about several ten million yen to several hundred million yen
  • an equipment according to this invention costs about ten million yen. More concretely, in an equipment which can produce three hundred pieces of 12 mm thick flame-retarding plywood per day, the cost can be reduced to about one fifth to one tenth, and thus the consumer price thereof will be three thousand yen to four thousand yen. Therefore, the conventional plywood price of ten thousand yen to twenty thousand yen can be reduced to one third to one fourth thereof, thus this invention is very prominent for fire-retarding treating of wooden material.
  • the reason why the flame-retarding treating can be done by such a simple equipment may be as follows.
  • the wooden materials are composed of a number of cells each partitioned by cell walls each having pits.
  • the pits are closed after the wooden materials are cut and will further be firmly closed when heated or dried to prevent sap from moving from one cell to another. Therefore, after wooden materials are cut, the frame-retarding solution is not absorbed in the wooden materials because the pits are closed.
  • the mixed solution which is peculiar to this invention, especially a predetermined amount of the solvent (permeator) included in the mixed solution, opens the pits so as to promote the permeation of the flame-retarding materials into the cells of wooden materials.
  • the thus obtained flame-retarding wooden materials can be increased in weight by about 20 to 30% of its original weight.
  • Table 1 the results of performance tests are reported in a certification of flame-retarding test (conducted on September 17, 1992, CHOTEI No.1518, certified by the chief director of the foundation, Akita prefecture industrial material laboratory) which complies with the JIS (Japanese Industrial Standard) A1321 flame-retarding test 3rd grade.
  • Graphs.1-3 show the relationship between exhaust temperatures and smoke amounts of samples Nos. 1, 2 and 3, respectively. As understood from the graphs, flame-retarding performances which exceed the regulated level are attained.
  • Graphs 4-6 show the relationship between exhaust temperatures and smoke amounts of samples No. A, B and C, respectively. As understood from the graphs, flame-retarding performances of the flame-retarding wooden materials obtained by the method of the present invention can be surely obtained, which exceed the predetermined flame-retarding performance required by public organization.
  • the flame-retarding performances may be obtained by the following reasons.
  • the flame-retarding materials which are fixed in the wooden materials, are decomposed by heating and incombustible materials such as ammonia gas, carbon dioxide, steam, or the like, are generated. These gases cover the surface of the wooden materials and prevent oxygen from being supplied into the wooden materials. These gases also take dissolution heat away from the wooden materials, thereby preventing the temperature of the wooden materials from rising.
  • the flame-retarding materials contribute to flame-retarding of the wooden materials changed by heating.
  • the flame-retarding materials such as lanthanum chloride, borax, or ammonium chloride, or the like, produces material whose melting point is very high by heat reaction between themselves as follows. 2NH 4 Cl 4 +B 2 O 3 ⁇ 2NB+2HCl+3H 2 O
  • the melting point of NB is 3000 °C.
  • a high melting point material is produced as follows, 7Zr+3B 4 C+B 2 O 3 ⁇ 7ZrB 2 +3CO
  • the melting point of ZrB 2 is 3000°C.
  • Mg 3 N 2 a high melting point material, Mg 3 N 2 , is produced as follows. 3Mg(OH) 2 +2NH 4 Cl ⁇ Mg 3 N 2 +6H 2 O+2HCl
  • zirconium oxide is produced by heating zirconium sulfate, Zr(SO 4 ) 2 over 380°C, and magnesium oxide is produced by heating over 350°C.
  • the melting points of these materials are 2700°C and 2852°C, respectively.
  • the method for flame-retarding treating of wooden materials according to the present invention does not require compulsory permeation operation such as pressure increasing or decreasing operation as required in the conventional methods, and enables flame-retarding materials to easily permeate into the cells of the wooden materials or their vicinities and fix therein by using the peculiar mixed solution under the normal temperature and pressure (normal condition).
  • flame-retarding treating can be done by a very simple equipment.
  • the permeation can be done very smoothly with high efficiency.
  • this method enables to remarkably reduce the costs compared to the conventional methods.
  • the flame-retarding performances by the flame-retarding treating or by the manufacturing method for flame-retarding plywood using the same treating is very reliable. Therefore, they can meet the public requirements and can be widely used in buildings and structures. Also they will contribute to spread fire-prevention facilities and be helpful to protect people's lives and fortunes.

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  • Life Sciences & Earth Sciences (AREA)
  • Chemical & Material Sciences (AREA)
  • Inorganic Chemistry (AREA)
  • Engineering & Computer Science (AREA)
  • Wood Science & Technology (AREA)
  • Forests & Forestry (AREA)
  • Chemical And Physical Treatments For Wood And The Like (AREA)
EP96912291A 1995-04-27 1996-04-30 Method of rendering wooden material flame-retardant and process for producing flame-retarded plywood therewith Withdrawn EP0838316A1 (en)

Applications Claiming Priority (3)

Application Number Priority Date Filing Date Title
JP128942/95 1995-04-27
JP12894295A JPH08300311A (ja) 1995-04-27 1995-04-27 木質材の難燃化処理方法、およびそれを使用した難燃合板の製造方法
PCT/JP1996/001189 WO1996033848A1 (fr) 1995-04-27 1996-04-30 Procede pour ignifuger un materiau a base de bois et procede pour produire un contreplaque ignifuge

Publications (1)

Publication Number Publication Date
EP0838316A1 true EP0838316A1 (en) 1998-04-29

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Application Number Title Priority Date Filing Date
EP96912291A Withdrawn EP0838316A1 (en) 1995-04-27 1996-04-30 Method of rendering wooden material flame-retardant and process for producing flame-retarded plywood therewith

Country Status (6)

Country Link
EP (1) EP0838316A1 (ja)
JP (1) JPH08300311A (ja)
AU (1) AU5515596A (ja)
BR (1) BR9608320A (ja)
CA (1) CA2219317A1 (ja)
WO (1) WO1996033848A1 (ja)

Cited By (2)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
EP1930138A1 (de) * 2006-12-10 2008-06-11 Moralt Tischlerplatten GmbH & Co. KG Leichtbauplatte sowie Herstellungsverfahren
WO2019120421A1 (en) * 2017-12-20 2019-06-27 Burnblock Holding Aps Fire retardant impregnation of wooden plates

Family Cites Families (5)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
JPS5135078B2 (ja) * 1972-09-14 1976-09-30
IT1075018B (it) * 1976-07-21 1985-04-22 Gandini Giuseppe Composizione chimica antincendio
JPS6220584A (ja) * 1985-07-19 1987-01-29 ヒイスス・ムリヨ・コントレラス 耐火組成物および耐火性付与方法
JPS62231074A (ja) * 1986-03-28 1987-10-09 村田　友昭 耐火性繊維性製品の製法
JPH04173102A (ja) * 1990-11-05 1992-06-19 Sueo Ishikawa 難燃性木材加工品およびその製造方法

Non-Patent Citations (1)

* Cited by examiner, † Cited by third party
Title
See references of WO9633848A1 *

Cited By (2)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
EP1930138A1 (de) * 2006-12-10 2008-06-11 Moralt Tischlerplatten GmbH & Co. KG Leichtbauplatte sowie Herstellungsverfahren
WO2019120421A1 (en) * 2017-12-20 2019-06-27 Burnblock Holding Aps Fire retardant impregnation of wooden plates

Also Published As

Publication number Publication date
BR9608320A (pt) 1999-11-30
CA2219317A1 (en) 1996-10-31
AU5515596A (en) 1996-11-18
JPH08300311A (ja) 1996-11-19
WO1996033848A1 (fr) 1996-10-31

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