Classifications

• • C—CHEMISTRY; METALLURGY
  • C09—DYES; PAINTS; POLISHES; NATURAL RESINS; ADHESIVES; COMPOSITIONS NOT OTHERWISE PROVIDED FOR; APPLICATIONS OF MATERIALS NOT OTHERWISE PROVIDED FOR
  • C09K—MATERIALS FOR MISCELLANEOUS APPLICATIONS, NOT PROVIDED FOR ELSEWHERE
  • C09K21/00—Fireproofing materials
  • C09K21/02—Inorganic materials
• • 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
• • C—CHEMISTRY; METALLURGY
  • C08—ORGANIC MACROMOLECULAR COMPOUNDS; THEIR PREPARATION OR CHEMICAL WORKING-UP; COMPOSITIONS BASED THEREON
  • C08H—DERIVATIVES OF NATURAL MACROMOLECULAR COMPOUNDS
  • C08H8/00—Macromolecular compounds derived from lignocellulosic materials
• • C—CHEMISTRY; METALLURGY
  • C08—ORGANIC MACROMOLECULAR COMPOUNDS; THEIR PREPARATION OR CHEMICAL WORKING-UP; COMPOSITIONS BASED THEREON
  • C08K—Use of inorganic or non-macromolecular organic substances as compounding ingredients
  • C08K3/00—Use of inorganic substances as compounding ingredients
  • C08K3/01—Use of inorganic substances as compounding ingredients characterized by their specific function
  • C08K3/016—Flame-proofing or flame-retarding additives
• • D—TEXTILES; PAPER
  • D06—TREATMENT OF TEXTILES OR THE LIKE; LAUNDERING; FLEXIBLE MATERIALS NOT OTHERWISE PROVIDED FOR
  • D06M—TREATMENT, NOT PROVIDED FOR ELSEWHERE IN CLASS D06, OF FIBRES, THREADS, YARNS, FABRICS, FEATHERS OR FIBROUS GOODS MADE FROM SUCH MATERIALS
  • D06M11/00—Treating fibres, threads, yarns, fabrics or fibrous goods made from such materials, with inorganic substances or complexes thereof; Such treatment combined with mechanical treatment, e.g. mercerising
  • D06M11/07—Treating fibres, threads, yarns, fabrics or fibrous goods made from such materials, with inorganic substances or complexes thereof; Such treatment combined with mechanical treatment, e.g. mercerising with halogens; with halogen acids or salts thereof; with oxides or oxyacids of halogens or salts thereof
  • D06M11/09—Treating fibres, threads, yarns, fabrics or fibrous goods made from such materials, with inorganic substances or complexes thereof; Such treatment combined with mechanical treatment, e.g. mercerising with halogens; with halogen acids or salts thereof; with oxides or oxyacids of halogens or salts thereof with free halogens or interhalogen compounds
• • D—TEXTILES; PAPER
  • D21—PAPER-MAKING; PRODUCTION OF CELLULOSE
  • D21H—PULP COMPOSITIONS; PREPARATION THEREOF NOT COVERED BY SUBCLASSES D21C OR D21D; IMPREGNATING OR COATING OF PAPER; TREATMENT OF FINISHED PAPER NOT COVERED BY CLASS B31 OR SUBCLASS D21G; PAPER NOT OTHERWISE PROVIDED FOR
  • D21H17/00—Non-fibrous material added to the pulp, characterised by its constitution; Paper-impregnating material characterised by its constitution
  • D21H17/03—Non-macromolecular organic compounds
  • D21H17/05—Non-macromolecular organic compounds containing elements other than carbon and hydrogen only
  • D21H17/11—Halides
• • D—TEXTILES; PAPER
  • D21—PAPER-MAKING; PRODUCTION OF CELLULOSE
  • D21H—PULP COMPOSITIONS; PREPARATION THEREOF NOT COVERED BY SUBCLASSES D21C OR D21D; IMPREGNATING OR COATING OF PAPER; TREATMENT OF FINISHED PAPER NOT COVERED BY CLASS B31 OR SUBCLASS D21G; PAPER NOT OTHERWISE PROVIDED FOR
  • D21H21/00—Non-fibrous material added to the pulp, characterised by its function, form or properties; Paper-impregnating or coating material, characterised by its function, form or properties
  • D21H21/14—Non-fibrous material added to the pulp, characterised by its function, form or properties; Paper-impregnating or coating material, characterised by its function, form or properties characterised by function or properties in or on the paper
  • D21H21/34—Ignifugeants
• • D—TEXTILES; PAPER
  • D21—PAPER-MAKING; PRODUCTION OF CELLULOSE
  • D21H—PULP COMPOSITIONS; PREPARATION THEREOF NOT COVERED BY SUBCLASSES D21C OR D21D; IMPREGNATING OR COATING OF PAPER; TREATMENT OF FINISHED PAPER NOT COVERED BY CLASS B31 OR SUBCLASS D21G; PAPER NOT OTHERWISE PROVIDED FOR
  • D21H5/00—Special paper or cardboard not otherwise provided for
  • D21H5/0002—Flame-resistant papers; (complex) compositions rendering paper fire-resistant
• • 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
  • B27K3/16—Inorganic impregnating agents
  • B27K3/163—Compounds of boron
• • 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
  • B27K3/20—Compounds of alkali metals or ammonium
• • 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
• • C—CHEMISTRY; METALLURGY
  • C08—ORGANIC MACROMOLECULAR COMPOUNDS; THEIR PREPARATION OR CHEMICAL WORKING-UP; COMPOSITIONS BASED THEREON
  • C08L—COMPOSITIONS OF MACROMOLECULAR COMPOUNDS
  • C08L2201/00—Properties
  • C08L2201/02—Flame or fire retardant/resistant
• • Y—GENERAL TAGGING OF NEW TECHNOLOGICAL DEVELOPMENTS; GENERAL TAGGING OF CROSS-SECTIONAL TECHNOLOGIES SPANNING OVER SEVERAL SECTIONS OF THE IPC; TECHNICAL SUBJECTS COVERED BY FORMER USPC CROSS-REFERENCE ART COLLECTIONS [XRACs] AND DIGESTS
  • Y10—TECHNICAL SUBJECTS COVERED BY FORMER USPC
  • Y10S—TECHNICAL SUBJECTS COVERED BY FORMER USPC CROSS-REFERENCE ART COLLECTIONS [XRACs] AND DIGESTS
  • Y10S428/00—Stock material or miscellaneous articles
  • Y10S428/92—Fire or heat protection feature
  • Y10S428/921—Fire or flameproofing
• • Y—GENERAL TAGGING OF NEW TECHNOLOGICAL DEVELOPMENTS; GENERAL TAGGING OF CROSS-SECTIONAL TECHNOLOGIES SPANNING OVER SEVERAL SECTIONS OF THE IPC; TECHNICAL SUBJECTS COVERED BY FORMER USPC CROSS-REFERENCE ART COLLECTIONS [XRACs] AND DIGESTS
  • Y10—TECHNICAL SUBJECTS COVERED BY FORMER USPC
  • Y10S—TECHNICAL SUBJECTS COVERED BY FORMER USPC CROSS-REFERENCE ART COLLECTIONS [XRACs] AND DIGESTS
  • Y10S57/00—Textiles: spinning, twisting, and twining
  • Y10S57/904—Flame retardant

Definitions

• This invention relates to the flameproofing of cellulosic compositions containing lignin and in particular to the production of lignocellulosic articles having some degree of resistance to burning.
• lignocellulosic articles will be understood to mean lignincontaining cellulosic bodies or structures such as wooden beams, veneers or rods; paper sheets, rolls of newsprint; strawboard or chip board; yarns, webs, woven or knitted fabrics, ropes or belts made of lignocellulosic fibers such as, for example, jute, kenaf, sisal, hemp or the like; and such bodies or structures are distinguished from uniformed masses such as paper pulp.
• Previous methods of rendering lignocellulosic articles flame-resistant have generally involved either the surfacecoating or the impregnation of the articles with inorganic salts or organic compounds having a flame retarding effect.
• Coating or impregnating materials which have been used for this purpose include Water-soluble silicates, phosphates and borates, tin, iron, antimony and chromium oxides, and chlorinated or brominated organic compounds. that the flame retardant composition remains as a material extraneous to the lignocellulosic article and does not bond chemically thereto.
• the enhanced flame-resistance which is imparted to the article is gradually lost when the article is exposed to weathering or is soaked in water for any substantial length of time.
• relatively large amounts of the flame-retardant composition are necessary which adversely alfect the material thus treated.
• Wood is composed of three major ingredients, namely cellulose, hemicellulose and lignin.
• the first two are long chain carbohydrates whilst the lignin is a compound containing condensed phenyl-propane units.
• the lignin and hemicellulose form the so-called middle lamella which occurs between the fibrous cellsof wood and many other plant tissues; the lignin also occurs in the lignocellulosic fibers such as those of jute, hemp and sisal.
• the middle lamella surrounds the fibrous cells, which themselves are composed mostly of cellulose, and cements the fibers together thereby serving to maintain the structureof the fiber bundle.
• This invention consists in lignocellulosic articles in which the lignin component is halogenated.
• the halogenation may be elfected at any desired stage of the manufacture of the lignocellulosic articles.
• a fiber pulp may be so halogenated, or a semimanufactured product such as groundwood which is used in the manufacture of newsprint, or a finished article may be subjected to the halogenation, e.g., a wood veneer, building timber or the like.
• the combustion resistance of the lignocellulose can be enhanced.
• This has the advantage that it is the inflammable material itself whose properties are modified, that is, the combustion resistance conferred in this way is not dependent upon the presence of an extraneous material which can be leached out.
• the lignin surrounds the fibrous cells, the present invention makes provision for a protective coating around each fiber.
• the combustion resistance imparted by the present invention is relatively stable and permanent, as the halogen is bound chemically to the lignin and constitutes an integral part of the lignocellulosic structure.
• halogen used for the treatment of the lignocellulosic material depends on many factors, e.g., the halogen used, the nature of the material to be flameproofed, the degree of flame-resistance which is required. For a given degree of halogenation, the time required to effect the halogenation will in general be less where the lignocellulose to be treated is finely comminuted. This applies for example in the case of groundwood or wood pulp, and in other cases where a large specific.
• surface is available for example in the case of yarn and rope, as contrasted with chips for the fabrication of chip board, or with wooden veneers or structural wood.
• groundwood treated with 4 to 8% by weight of bromine will produce a paper which does not burn when ignited with a match.
• bromine will confer a smaller degree of non-inflammability whilst nevertheless representing a considerable improvement as compared with paper produced from untreated groundwood.
• the general properties of the materials treated in this Way are not substantially changed, especially if care is taken to avoid degradation of the cellulose by the acid formed as a by-product of the halogenation process, which can be done, for example, by neutralization of the reaction mixture or by the use of butters, as will be described below.
• the halogenation can be carried out in various ways.
• the lignocellulosic material to be treated may be brought into contact with gaseous halogen in a closed vessel at room temperature or any other temperature below the inflammation point of the material.
• the residence time may be from a few seconds to several hours, depending on the nature of the materials being treated, the degree of halogenation required and the conditions of halogenation such as the pressure of the halogen gas, temperature and illumination.
• the material to be treated may be immersed in an aqueous halogen solution for a time ranging from several seconds to several hours.
• the aqueous solution may contain the predetermined amount of halogen required for the production of the desired degree of halogenation, and the process is terminated when the halogen content of the solution has been exhausted.
• the liquor containing the solution of the hydrogen halide formed during the halo- Smaller additions of genation is then decanted or filtered off, and the halogenated lignocellulosic material can be neutralized with a dilute solution of ammonia or another alkalifying agent such as sodium carbonate or milk of lime whereby the desired pH of the halogenated material is obtained.
• the aqueous halogen solution may also contain buffers, e.g., mixtures of borax and boric acid, or of alkali metal or ammonium phosphates of the desired pH, in order to prevent the acid formed in the course of the halogenation from attacking the cellulose.
• buffers e.g., mixtures of borax and boric acid, or of alkali metal or ammonium phosphates of the desired pH, in order to prevent the acid formed in the course of the halogenation from attacking the cellulose.
• These butters are absorbed by the material to be treated in amounts which may range from, for example, 0.01 to 16%. In addition to their bufl'ering action they may also enhance the fiameprooiing of the material.
• alkaline flameproofing agents such as sodium silicate can also be incorporated into the aqueous solution.
• buffers and alkaline flameproofing agents can also be used where the halogenation is etlected by means of gaseous halogen.
• the lignocellulosic material may be impregnated, before or after the halogenation, with the buffer or alkaline fireproofing material which latter can be employed either as a solution or as a fine powder.
• bromine is the halogenating agent it may be used in the form of an aqueous alkali metal hypobromite solution, which has the advantage of immediately neutralizing the acid forming in the course of the bromination.
• the halogen may gradually be introduced into an aqueous bath in which the lignocellulosic material is immersed or suspended.
• the bromine may be used in the form of an aqueous solution of a mixture of equivalent amounts of bromide and bromate, e.g., those of an alkali metal or an alkaline-earth metal, which solution is gradually acidulated whereby elementary bromine is liberated at the desired rate.
• the spent halogenating aqueous liquor separated from the halogenated lignocellulosic material contains hydrobromic acid or bromides formed in the course of the halogenation
• elementary bromine may be recovered by the introduction into the liquor of an equivalent amount of chlorine in gaseous form or as an aqueous solution, and the aqueous bromine-chloride solution thereby formed, which may in addition contain elementary chlorine, can be used as a brominating solution for the treatment of lignocellulosic material.
• halogen e.g., bromine
• organic solvent such as, for example, chloroform or carbon tetrachloride.
• lignocellulosic articles according to the invention acquire resistance not only to combustion but also to biological deterioration, such as the action of fungi.
• halogen-containing compounds can serve for the protection of lignocellulosic materials against biological deterioration; for example, pentachlorophenol has been used for this purpose on wood.
• chlorinated compounds are, however, extraneous additions to the lignocellulosic material to be protected, and they are not stable on leaching, storage and weathering.
• the halogen enters into the composition of the lignocellulosic material.
• Example 1 80.4 grams of air-dry beech veneer sheets of 1 mm. thickness were placed in a closed desiccator-like vessel of 6v liters capacity. The air was evacuated from the vessel, then 12.9 grams of gaseous bromine were introduced from an ampoule into the evacuated vessel. After 30 minutes the bromination was completed and the vessel was flushed with air. The veneer sheets were rinsed in cold water until neutral, and dried in air. The veneers were then analyzed by the Carius method for bromine and were found to contain 8% by Weight of bromine.
• Example 2 24 grams of Okume wood veneers of 1.5 mm. thickness were brominated with 2.35 grams of gaseous bromine for 15 minutes similarly as in Example 1. After the bromination the sample contained 4.1% of bromine. The sample was rinsed in water and immersed for 3 minutes in 300 rnls. of a solution containing per liter 18 grams of borax and 1 gram of boric acid, and airdried.
• Specimens of the brominated Okume veneers were then tested in the Inclined-Panel Infiammability tester in the manner described in Example 1. The specimens were classified as non-inflammable. Not-brominated specimens of the same Okume veneer burnt out completely when tested under the same conditions.
• Example 3 520 grams of commercial spruce groundwood were suspended in 4.0 liters of water at room temperature. A solution of 40 grams of bromine in 4.0 liters of water was added to the suspension with vigorous stirring in the course of 3 minutes, then the stirring was continued for another 2 minutes. Thereafter the mixture was filtered and the amount of hydrobromic acid, determined in the filtrate by potentiometric titration with 0.1 N sodium hydroxide, corresponded to 20 grams of bromine, i.e., half of the bromine originally added to the suspension was recovered as hydrobromic acid. The other half had reacted with the lignin of the ground-wood structure.
• the filtered mass was returned to the vessel and neutralized with a dilute ammonia solution so as to adjust the pH of the suspension to 7 as measured with a Beckmann model pH meter.
• the pulp was then filtered again.
• the lignocellulosic material contained 4% of bromine calculated on the oven-dry weight of the groundwood, as determined by Carius determination.
• a part of the pulp was made into standard sheets of a basic weight of 250 g./m. in the Standard T.A.P.P.I. Sheetmaking Apparatus.
• the sheets were tested by the Inclined-Panel Test as described in Example 1. The sheets did not inflame and were classified as non-inflammable.
• Several sheets were stored for 210 days at 21 C. and 70% relative humidity. After that time the sheets were analyzed for bromine by the Carius determination and were found to contain 4%.
• the stored sheets were tested by the Inclined-Panel Test and were non-inflammable.
• Example 4 1800 grams of wet insulation-board-grade pulp, containing 500 g. of oven-dry material consisting to 80% of Eucalyptus rostram wood and to 20% of Okume wood, was suspended in 8.0 liters of Water at room temperature. 27.0 grams of bromine dissolved in 3 liters of water were added to the suspension under vigorous stirring in the course of seconds, then the stirring continued for another 110 seconds. Then the supernatant liquid was decanted and the residual pulp was neutralized with ammonium carbonate and filtered. The pulp contained 2.7% of bromine, calculated on the oven-dry Weight as determined by the Carius method.
• the pulp was made up by a suitable board making apparatus into insulation boards of 32 by 32 cm. and a thickness of 5 mm.
• the specific gravity of the insulation boards was 0.4 g./cm.
• the insulation boards made from the brominated pulp, and those made in the same manner from the not-brominated pulp, were tested by the Fire Testing Apparatus and method according to the French Standard Method, based on the Decree of the Minister of Interior, No. 57-1161 of 17.10.1957 and published in the Journal Ofliciel de la Rpublique Frangaise of January 16, 1958, pp. 611-618.
• the insulation boards made from the brominated material were classified as non-inflammable since the Index of Infiammability (i), the Index of Flame Spreading (S) and the Index of the Maximum Height of Flame (h) were 0.0. and the Index of Combustibility (C) was 0.8, i.e., smaller than 1.0. According to the French Standard these results show that the sample is not-inflammable.
• the process of forming fire resistant lignocellulose articles comprising: applying a nondestructive liquid reaction medium to a material naturally containing lignin and cellulose, said liquid reaction medium comprising a solution of a metal bromide and wherein bromine is liberated from said bromide to provide essentially elementary bromine in an amount insuflicient to destroy the lignin; brominating said lignin component in situ up to a bromine content of 2.7 to 8% by Weight of the ligno- I 6 the bromine contained in the reaction solution while the other half of the bromine in solution is converted into bromide to form said reaction medium, comprising the said step of introducing elementary chlorine into the previously utilized reaction medium to reconvert said bromide ion into elementary bromine.
• a process in accordance with claim 1 further comprising gradually adding bromine to the reaction medium during the bromination.
• liquid reaction medium also comprises dissolved bufier flameproofing agents.
• buffer flameproofing agents are selected from the group consisting of alkali metal phosphates, ammonium phosphates, sodium silicate, and mixtures of boraX and boric acid.
• Fire resistant material in accordance with claim 1 wherein the materialis in the form of particle boards.

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• Chemical & Material Sciences (AREA)
• Engineering & Computer Science (AREA)
• Organic Chemistry (AREA)
• Materials Engineering (AREA)
• Life Sciences & Earth Sciences (AREA)
• Health & Medical Sciences (AREA)
• Inorganic Chemistry (AREA)
• Chemical Kinetics & Catalysis (AREA)
• Medicinal Chemistry (AREA)
• Polymers & Plastics (AREA)
• Biochemistry (AREA)
• Textile Engineering (AREA)
• Wood Science & Technology (AREA)
• Forests & Forestry (AREA)
• Chemical And Physical Treatments For Wood And The Like (AREA)
• Fireproofing Substances (AREA)

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Cited By (6)

Citations (8)

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• 1960
  • 1960-05-25 GB GB18522/60A patent/GB940575A/en not_active Expired
• 1961
  • 1961-05-16 US US110331A patent/US3150919A/en not_active Expired - Lifetime
  • 1961-05-17 DE DED36113A patent/DE1299849B/de active Pending
  • 1961-05-24 FR FR862726A patent/FR1313746A/fr not_active Expired
  • 1961-05-25 SE SE547761A patent/SE220169C1/sv unknown
• 1964
  • 1964-12-28 OA OA51082A patent/OA00978A/fr unknown

Patent Citations (8)

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