Classifications

• • 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
  • D06M15/00—Treating fibres, threads, yarns, fabrics, or fibrous goods made from such materials, with macromolecular compounds; Such treatment combined with mechanical treatment
  • D06M15/19—Treating fibres, threads, yarns, fabrics, or fibrous goods made from such materials, with macromolecular compounds; Such treatment combined with mechanical treatment with synthetic macromolecular compounds
  • D06M15/21—Macromolecular compounds obtained by reactions only involving carbon-to-carbon unsaturated bonds
  • D06M15/244—Macromolecular compounds obtained by reactions only involving carbon-to-carbon unsaturated bonds of halogenated hydrocarbons
  • D06M15/248—Macromolecular compounds obtained by reactions only involving carbon-to-carbon unsaturated bonds of halogenated hydrocarbons containing chlorine
• • 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
  • D06M11/11—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 halogen acids or salts thereof
  • D06M11/13—Ammonium halides or halides of elements of Groups 1 or 11 of the Periodic Table
• • 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
  • D06M11/32—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 oxygen, ozone, ozonides, oxides, hydroxides or percompounds; Salts derived from anions with an amphoteric element-oxygen bond
  • D06M11/36—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 oxygen, ozone, ozonides, oxides, hydroxides or percompounds; Salts derived from anions with an amphoteric element-oxygen bond with oxides, hydroxides or mixed oxides; with salts derived from anions with an amphoteric element-oxygen bond
  • D06M11/47—Oxides or hydroxides of elements of Groups 5 or 15 of the Periodic Table; Vanadates; Niobates; Tantalates; Arsenates; Antimonates; Bismuthates
• • 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
  • D06M23/00—Treatment of fibres, threads, yarns, fabrics or fibrous goods made from such materials, characterised by the process
  • D06M23/08—Processes in which the treating agent is applied in powder or granular form

Definitions

• the present invention relates to a composition for imparting flame retardant properties to cellulosic fabrics and fibres.
• the invention also includes a method of making such a composition and a process for applying the flame retardant composition to a textile.
• compositions including these compounds are generally applied to fabric as a back-coating to produce a barrier effect.
• this type of coating is not ideal because the back-coating is usually opaque and white, the treated fabric is usually objectionably stiff and dry cleaning is not usually possible without destroying the flame retardant properties of the fabric.
• Such a composition is described in FR-A-2099391 where back coating flame retarding coating compositions are described for use in vehicle security inflatable bodies.
• Optional flame retarding materials for use in the composition comprise inorganic halides and antimony trioxide but not in combination.
• the preferred flame retarding materials are phosphates.
• Antimony trioxide is also a well known flame retarding component. It is also known to use antimony trioxide as the only flame-retardant component in a composition for application to textile fabrics.
• a composition for application to textile fabrics One such composition is described in US 3,014,000.
• the composition described comprises antimony trioxide, a composite plasticiser, and a vinyl polymer such as vinyl chloride/vinylidene chloride copolymer.
• the plasticiser which contains at least 15% by weight chlorine is included for a soft feel on the fabric and may be, for example, a chlorinated paraffin, an alkyl ester of an aliphatic or aromatic dicarboxylic acid or phosphoric acid.
• one other undesirable result which often occurs is that the flame retardants tend to discolour or darken the treated cellulosic substrate and/or dyes/pigments. This observation is particularly noticeable on printed metallics such as golds and silvers.
• the discolouring effects by the flame retardant are particularly problematic because they are often dependent upon the type of dyes/pigments used on the various fabrics. For example, the colour difference effect on pigment print may not be the same as the effect on for example vat dyes.
• a water soluble composition useful as a flame retardant for cellulosic material is disclosed in US 4,888,136.
• the composition comprises ammonium bromide and a water-soluble aluminium salt of an organic hydroxy acid.
• the composition is directed in particular to the treatment of paper products although textiles are also mentioned.
• the invention is based on the unexpected finding that a combination of aluminium salt with ammonium bromide produces a synergistic effect.
• a PVC-free flame retardant for finishing mixed polyester/cellulose articles which comprises a chlorine donor and antimony trioxide in a specified ratio.
• halogen donors such as chlorinated paraffins, polyvinyl chloride and bromide
• Ammonium bromide is also described as a suitable flame retardant treatment in GB 1,291,133 for producing disposable fabrics for medical use or for clothing.
• ammonium bromide and other halides have been much more commonly known as flame proofing components for polymeric materials and in particular, for rubber.
• a flame retardant for synthetic resin is obtained by a coating of ammonium chloride or ammonium bromide with antimony trioxide.
• ammonium chloride or bromide with antimony trioxide is used for manufacturing a flame resistant polyolefin.
• the present invention comprises a novel composition which produces particularly effective flame retardancy and which overcomes the problems of the prior art compositions.
• an aqueous composition for imparting flame retardant properties to a cellulosic substrate which comprises an inorganic halide, an oxide of antimony having an average particle size no greater than 2.0 ⁇ m, a binding agent, a plasticiser and a surface modifier.
• the present invention is particularly advantageous because use of an aqueous based composition provides flame retardancy throughout the material and does not act merely as a barrier. Furthermore, the composition of the invention provides a clear finish flame retardancy treatment which does not significantly affect the appearance of the fabric, unlike the known flame retardancy treatment compositions.
• the inorganic halide is preferably an ammonium halide and most preferably is ammonium bromide.
• the halide is generally included in the composition at a concentration of from 50 to 500 g/l and preferably from 100 to 300 g/l.
• the inorganic halide may be used as either a solid or as a suspension or solution.
• the oxide of antimony may be antimony trioxide or tetraoxide but is preferably antimony pentoxide. It may be in a hydrated or non-hydrated form.
• antimony oxide up to a particle size of approximately 2 ⁇ m is still effective and economical, generally, the particle size of the antimony oxide is no greater than 0.5 ⁇ m as it has been found that this prevents pigmentation of the fabric surface and ensures formation of a transparent finish.
• the average particle size is no greater than 0.1 ⁇ m and most preferably, the particle size is from 0.01 to 0.05 ⁇ m because this ensures greater potential antimony interaction.
• Antimony pentoxide is preferred because it can be obtained having the very small particle size preferred for the present invention.
• the antimony oxide may be used as a solid powder but it is preferably used as a colloidal suspension in water. Although colloidal antimony trioxide can also be obtained, for best results, the antimony oxide is most preferably hydrated antimony pentoxide, in the form of an aqueous colloidal suspension. Although antimony pentoxide contains a lower relative amount of antimony then antimony trioxide and therefore could be expected to be less favourable , we have found that it provides especially good flame retardant properties, especially at the preferred low particle sizes.
• the refractive index of the antimony oxide is as close to 1 as possible.
• the antimony oxide is generally included in the composition in an amount of from 25 to 400 g/l and preferably from 25 to 150 g/l.
• the binding agent one or more conventional binding agents which are well known throughout the industry can be used.
• the binding agent can be one or more of a wide variety of polymers and copolymers. However, we have found vinylidene chloride based polymers and admixtures thereof, or for example copolymers of vinyl chloride and ethylene, are eminently suitable. In addition to their primary role in binding other active flame retardant components to the cellulosic material, they also contribute towards the fire retardant effect of the composition by virtue of their halogen content.
• Other binders may be used, for example acrylate based polymers, which may act solely as film-forming agents and bind the active flame retardant components to the cellulose.
• a 10-70% by weight aqueous emulsion of the binder is used for ease of handling, but solid materials may be used if so desired.
• the proportion of binder used in the composition would typically be in the amount of from 200 to 600 g/l and preferably in the range 300 to 500 g/l.
• the plasticiser may be for example as described in US 3014000. It is preferably a halogenated paraffin, and most preferably a chlorinated paraffin. Again, by virtue of their halogen content, these chlorinated paraffins contribute to the flame retardant effect. Particularly suitable chlorinated paraffins contain between 25 and 75% by weight of chlorine, and more preferably between 35 and 50% by weight. Paraffins having a carbon chain length of from C8 to C14 have been found to be particularly suitable.
• the binding agent binds the antimony oxide and inorganic halide to the cellulosic substrate, thereby providing the substrate with flame retardant properties.
• the surface modifier can be any of a number of known compounds and is included in the composition to impart a water resistant elastomeric finish to the substrate.
• elastomeric materials exist, for example, silicones and polyurethanes which can be cross-linked.
• the surface modifier comprises a blend of compounds, for example based on polysiloxane(s) in which the silicon is substituted with two groups which may be the same or different, chosen from alkyl, aralkyl, aryl or hydrogen with the exception that where hydrogen is one substituent, the two groups must be different.
• the blend may be based on polydialkyl siloxane(s).
• the alkyl, aryl or aralkyl groups themselves may or may not be substituted.
• Preferred silicones are the compounds where the alkyl group is either methyl, ethyl, propyl or butyl groups, which may be substituted with one or more groups such as amino, hydroxy, alkoxy or cyano.
• the surface modifier is a reactive amino siloxane in which the amino substituent is positioned on the alkyl group i.e. the silicon is substituted with at least one aminoalkyl group, in which the amino group(s) may be primary and/or secondary amino groups, for example N(2-aminoethyl)-2-ethylamine groups.
• the addition of such a surface modifier significantly improves the resistance to dry-cleaning and water soaking, of the treated cellulose.
• the addition of a surface modifier also ensures that the final treated cellulosic substrate retains a soft handle.
• the total amount of the surface modifier may be from 5 to 250 g/l, but more preferably in the range 5 to 150 g/l.
• compounds in the modifier may be in any ratio. Preferred ratios are dependant on the type and amounts of the other ingredients in the flame retardant composition.
• compositions include afterglow inhibiting agents such as zinc borate, aluminium trihydrate and boric acid esters, handle modifiers such as silicone and non-silicone softeners, perfumes, lubricants, brightening agents, resins, bleaching compounds, thickening additives, anti-bleed agents, anti-leaching compounds, viscosity modifiers, water/oil repellant compounds such as fluorochemical additives and colouring agents etc.
• afterglow inhibiting agents such as zinc borate, aluminium trihydrate and boric acid esters
• handle modifiers such as silicone and non-silicone softeners
• perfumes such as silicone and non-silicone softeners
• lubricants such as silicone and non-silicone softeners
• brightening agents such as zinc borate, aluminium trihydrate and boric acid esters
• perfumes such as silicone and non-silicone softeners
• lubricants such as silicone and non-silicone softeners
• brightening agents such as sodium bicarbonate, sodium bicarbon
• the cellulosic substrates which are to be treated by the composition of the present invention include cotton, viscose and all other cellulosic materials, including fibre blends. Blends including non-cellulosic material are also suitable substrates. For example, polyester-cotton and/or polyester viscose blends comprising from 5 to 95% by weight cellulosic material, preferably at least 20% cellulosic, most preferably at least 50% cellulosic material. Typically blends contain up to 80% cellulosic material.
• the flame retardancy treatment of the invention is particularly directed to treatment of woven or other formed fabrics, but may also be used on suitable non-woven substrates. In particular, it is intended for use on fixed and loose upholstery fabrics and covers.
• the process for the manufacture of the flame retardant composition generally requires high-shear mixing to intimately blend the individual ingredients. It has been found that the order of addition of the ingredients can affect the performance of the flame retardant effect, but is generally governed by ease of handling on the production scale. However, pH control is an important factor during the manufacture.
• the preferred method of manufacture of the composition according to the invention comprises firstly, mixing a suspension of small particle size antimony oxide, preferably antimony pentoxide with water. Secondly, the pH of the mixture is monitored and adjusted to between 7.5 and 9.5, preferably approximately pH 8 to 9, using a base.
• the inorganic halide is then mixed into the composition.
• the pH of the composition is preferably once again monitored and adjusted to the final pH of 6.0 to 9.0, if necessary.
• the base for adjusting the pH the main consideration is whether the particular base chosen will have an adverse effect on the dyes or resins in the cellulosic substrate to be treated. For example, it has been found that sodium hydroxide may produce a yellowing cast on the fabric and is therefore not preferred.
• the most preferred base for adjusting the pH at one or stages is ammonia which may be in the form of ammonia gas, by bubbling through the solution or, preferably, in the form of aqueous solution of ammonia (ammonium hydroxide). Ammonia is preferred because it produces substantially no discolouration on the final fabric.
• the antimony oxide/ammonium halide mixture formed is then mixed with the binding agent and plasticiser and surface modifier in any order of addition.
• the plasticiser and inorganic halide/antimony oxide mixture are mixed vigorously to obtain a substantially homogeneous composition. This is because the halide/antimony oxide mixture is viscous and addition of the plasticiser dilutes the mixture to promote ease of handling of the composition. Because the aqueous antimony oxide/halide mixture is not generally miscible with the plasticiser, an emulsion is formed. Additional dispersants/surfactants may be included to further increase the stability of the emulsion, if desired.
• the binder is then added to the composition, preferably followed by high shear mixing. As the binder is mixed in the composition some reaction occurs with the plasticiser and the viscosity of the composition increases.
• the composition will generally be a white, slightly viscous liquid, having a pH preferably in the range 6.0 to 9.0, and most preferably between 7.0 and 8.0.
• the application of the composition having a pH outside the range of 6.0 to 9.0, to cellulosic substrates will have an adverse effect on the substrate. This is usually exhibited in a reduced tear and tensile strength of the substrate.
• the present invention also includes a process for imparting flame retarding properties to a cellulosic substrate comprising contacting the cellulosic substrate with a composition comprising an inorganic halide, an oxide of antimony having particle size no greater than 2.0 ⁇ m, a binding agent, a plasticiser and a surface modifier.
• the commonly used flame retardant compositions are usually applied to fabrics in a separate process step, often following the printing, dyeing, drying or finishing stages. Obviously, this increases manufacturing costs and in many instances, the final dried fabric will be taken to a separate location for flame retardant treatment.
• the present invention is highly advantageous in that it is compatible with the usual finishing bath additives. Thus a separate treatment stage can be avoided as the flame retardant composition can simply be included in the finishing bath, if so desired.
• the cellulosic material is dried at temperatures normally associated with textile flame retardant treatments, typically between 90°C and 160°C, depending on fabric throughput speed. The drying step can also effect curing of the flame retardant onto the fabric.
• the invention also includes a process for imparting flame retardant properties to a cellulosic substrate by contacting the substrate with a composition comprising an inorganic halide, an oxide of antimony having a particle size of no greater than 2.0 ⁇ m, a binding agent, a plasticiser and a surface modifier in a finishing bath in the printing process for the substrate.
• composition is applied as a separate process step, it must also be followed by a curing stage.
• curing is effected by heating the treated substrate at a temperature of at least 90°C, preferably from 120° to 160°C, most preferably 120°C to 150°C.
• the curing time is from 0.2 to 10 minutes preferably 0.5 to 5 minutes most preferably 0.5 to 3 minutes at the curing temperature. This is a significant advantage over the curing times of most known flame retarding compositions, for which longer curing times, for example up to 20 minutes or even 30 minutes are required.
• the amount of the flame retardant composition required on the finished fabric, in order to give effective flame retardant properties is generally between 5 and 80% by weight of the substrate, preferably from 10 to 30%. These amounts refer to added dry weight of the composition on the substrate. The amount of the composition required depends upon the type of the substrate and the degree of flame retardancy required.
• the method of application of the flame retardant composition is by any of the known techniques in the industry including, pad-mangle, foam impregnation, vacuum impregnation, spray and roller, etc.
• the composition can be used to provide a back coating
• the composition of the invention is advantageous as it is particularly suitable for application by absorption into the substrate and curing to provide a flame retarding composition impregnated throughout the substrate.
• the application process is particularly suited to the pad-mangle method, when the composition is applied to woven cellulosic fabrics.
• the amount of flame retardant on the final treated fabric can be controlled by the method of application as well as the concentration of the composition. Thus, to attain a higher % of flame retardant, a higher wet amount of composition is applied so that on drying a greater % of the flame retardant remains.
• a composition according to the present invention was made up in a stainless steel reactor fitted with a high-shear mixer, temperature control, pH monitor, and cooling facilities.
• Emulsion CE752 this is a 50% emulsion of vinyl chloride/ethylene copolymer in water.
• 64 Kg of Emprimin LR28 (Trade Mark, a sodium lauryl sulphonate anionic surfactant) was added, followed by 32 Kg Silicon VP1445E (Trade Mark): an aqueous emulsion of polydimethylsiloxane.
• a composition was made up in the same manner as in Example 1 with the exception that MYKON 8430 was replaced with DOW Emulsion Q2-7419, an amino-functional polyalkyl siloxane containing surface modifier.
• a composition was made up as in Example 2 and in which 20 kg of zinc borate was also incorporated.
• a sample of printed 52 x 44 (picks per inch, warp by weft) 100% cotton fabric was passed through a finishing bath, containing 650 g/l of the flame retardant composition of example 1.
• the pad-mangle expression was adjusted.
• concentration of the composition and pad-mangle expression determining how much wet composition remains on the substrate), by throughput speed and mangle pressure, were used to load the substrate with a wet amount of composition such that on drying, the required dry weight add-on % flame retardant would remain.
• the fabric was heat treated at 130°C to give a flame retardant finish. No noticeable colour changes to either the fabric or the colouring agents were observed, and the fabric had retained a soft feel, no significant stiffening of the fabric having occurred.
• the treated fabric was subjected to the fire retardant tests as stipulated in the BS 5852 and BS 5651 documents. No flaming was observed in cover or interior which did not cease with 120 secs of the removal of the burner tube. No externally detectable amounts of smoking, heat or glowing was observed 15 min after removal of the burner tube. This effectively resulted in a PASS certificate for BS 5852 Section 4 Ignition Source 1 and Schedule 5 of the Furniture and Furnishings (FIRE) (SAFETY) Regulations 1988.

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• Engineering & Computer Science (AREA)
• Textile Engineering (AREA)
• Chemical & Material Sciences (AREA)
• Chemical Kinetics & Catalysis (AREA)
• Treatments For Attaching Organic Compounds To Fibrous Goods (AREA)
• Chemical Or Physical Treatment Of Fibers (AREA)

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Publications (1)

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Family Applications (1)

Country Status (2)

Cited By (2)

Citations (7)

• 1991
  • 1991-09-12 GB GB919119593A patent/GB9119593D0/en active Pending
• 1992
  • 1992-09-11 EP EP92308312A patent/EP0532357A1/fr not_active Withdrawn

Patent Citations (7)

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