WO2014014648A2

WO2014014648A2 - Textiles with brominated polymer flame retardant

Info

Publication number: WO2014014648A2
Application number: PCT/US2013/048998
Authority: WO
Inventors: William G. Stobby; Michal E. Matteucci; Manesh N. SEKHARAN; Ted A. Morgan; Maureen B. Nunn; Timothy J. Young
Original assignee: Rohm And Haas Company; Dow Global Technologies Llc
Priority date: 2012-07-18
Filing date: 2013-07-02
Publication date: 2014-01-23
Also published as: WO2014014648A3

Abstract

A textile comprises fiber and a brominated flame retardant that is a copolymer having copolymerized therein a butadiene moiety and a vinyl aromatic monomer moiety, the copolymer having, prior to bromination, a vinyl aromatic monomer content of from 5 to 90 percent by weight based upon copolymer weight, a 1,2-butadiene isomer content of greater than zero percent by weight based upon butadiene moiety weight, and a weight average molecular weight of at least 1000, the brominated copolymer having an unbrominated, non-aromatic double bond content of less than or equal to 50 percent based upon non-aromatic double bond content of the copolymer prior to bromination as determined by proton nuclear magnetic resonance spectroscopy, a five percent weight loss temperature, as determined by thermogravimetric analysis of at least 170 degrees Celsius.

Description

TEXTILES WITH BROMINATED POLYMER FLAME RETARDANT

BACKGROUND OF THE INVENTION

Field of the Invention

The present invention relates to textiles that comprise a brominated polymer flame retardant and a method for imparting a brominated polymer flame retardant onto a textile.

Introduction

Textiles, including woven and non- woven materials, have an assortment of uses including clothing, carpeting, upholstery, window treatments, bedding and even filtration. Many of these applications benefit from, if not require that the textiles achieve some level of flame retardant properties. Many common textiles tend to be undesirably flammable unless treated with some type of flame retardant material.

Brominated flame retardants are one type of flame retardant historically used to increase flame retardant properties of textiles. Brominated flame retardants act as flame retardants by introducing bromine radicals that interfere with combustion of gas phase components. Therefore, brominated flame retardants need to produce bromine radicals at a temperature corresponding to the gas phase combustion temperature of the materials they are protecting. If the brominated flame retardant is too stable, the textile will burn before bromine radicals are produced to inhibit combustion. If the brominated flame retardant is too unstable, bromine radicals will be produced before the textile is hot enough to burn causing the flame retardant to be consumed before it is needed to protect the textile.

Brominated flame retardants for use in textiles include hexabromocyclododecane (HBCD), small molecule brominated aromatic compounds such as decabromodiphenyl ether and tetrabromobisphenol A, and brominated aromatic polymers such as brominated polystyrene, brominated polyacrylates and polymers derived from tetrabromobisphenol A epoxy resins.

Small molecule brominated flame retardants (both aliphatic and aromatic) tend to be more fugitive than large molecule brominated flame retardants such a brominated polymers. Fugitive flame retardants can have a tendency to migrate from a textile to which they are applied. Fugitive flame retardants are undesirable because over time their migration from a textile can leave the textile with reduced flame retardant properties. Migration into the environment is a particular concern and problem with small molecule brominated flame retardants, which tend to fall under regulatory scrutiny as persistent and bioaccumulative.

Small molecule brominated flame retardants can also have a sufficiently high vapor pressure that they evaporate off from a textile at a temperature lower than the thermal degradation temperature of the textile they are supposed to protect. Therefore, the flame retardant is no longer present, or at least greatly diminished in concentration, at temperatures where they are needed to inhibit combustion of the textile.

Brominated aromatic compounds have bromide bound to aromatic rings and tend to be exceptionally stable to production of bromine radicals. For many textiles, a highly stabile flame retardant appears to be desirable in order to survive high processing

temperatures during textile manufacturing and/or to maintain a desired color of a textile resulting from thermal degradation of the flame retardant. However, a highly stable flame retardant can be less effective at inhibiting combustion of the textile since the textile may burn at a temperature sufficiently low that only a minor amount of the bromine is released from the aromatic brominated flame retardant. As a result, either high loadings of the aromatic brominated flame retardant are required to achieve desirable bromine release during combustion or synergists such as antimony trioxide must be included with the flame retardant to render the bromine radicals more labile. Antimony is a heavy metal that is an undesirable component to include if exclusion is possible.

It would advance the art of flame retardant textiles to obtain a textile that contains polymer brominated molecules that are not aromatic so that the problems associated with brominated aromatic flame retardants and small molecule flame retardants can be avoided.

BRIEF SUMMARY OF THE INVENTION

The present invention advances the art of flame retardant textiles by providing a textile and a method for preparing a textile comprising a brominated flame retardant with aliphatic bromine. The present invention provides an alternative to commonly known textiles containing brominated flame retardants. The alternative resolves problems associated with currently used brominated flame retardants including migration of small molecule brominated flame retardants from the textile and decomposition of brominated polystyrene and brominated polyacrylates into small molecule flame retardants capable of being vaporized before generating bromine radicals. Surprisingly, the alternative utilizes a brominated aliphatic polymer (that is, a polymer where bromide is bound to aliphatic rather than aromatic moieties). This is surprising because brominated aliphatic compounds have a lower stability (produce bromine radicals at a lower temperature) than brominated aromatic compounds commonly associated with textiles and yet the brominated aliphatic polymer used in the present invention is effective at imparting flame retardant properties to textiles

In a first aspect, the present invention is a textile comprising fibers and a brominated polymer flame retardant wherein the brominated polymer flame retardant is characterized as being a copolymer that has copolymerized therein a butadiene moiety and a vinyl aromatic monomer moiety, the copolymer having, prior to bromination, a vinyl aromatic monomer content of from 5 to 90 percent by weight based upon copolymer weight, a 1,2-butadiene isomer content of greater than zero percent by weight based upon butadiene moiety weight, and a weight average molecular weight of at least 1000, the brominated copolymer having an unbrominated, non-aromatic double bond content of less than or equal to 50 percent based upon non-aromatic double bond content of the copolymer prior to bromination as determined by proton nuclear magnetic resonance spectroscopy, a five percent weight loss temperature, as determined by thermogravimetric analysis of at least 170 degrees Celsius.

In a second aspect, the present invention is a method for preparing the textile of Claim 1, the method comprising the following steps: (a) providing a dispersion of the brominated polymer flame retardant and binder in an aqueous continuous phase; (b) distributing the dispersion around the fibers of the textile; and (c) removing at least a portion of the continuous aqueous phase leaving brominated polymer flame retardant disposed on the fibers.

Textiles of the present invention are useful in application such as clothing, carpet backing, upholstery and window treatments. The method of the present invention is useful for preparing the textiles of the present invention.

DETAILED DESCRIPTION OF THE INVENTION

Test methods refer to the most recent test method as of the priority date of this document when a date is not indicated with the test method number. References to test methods contain both a reference to the testing society and the test method number. The following test method abbreviations and identifiers apply herein: ASTM refers to American Society for Testing and Materials; EN refers to European Norm; DIN refers to Deutsches Institut fur Normung; ISO refers to International Organization for Standards and NFPA refers to National Fire Protection Association.

"Multiple" means two or more. "And/or" means "and, or as an alternative". All ranges include endpoints unless otherwise indicated.

"Unsubstituted" and "non- substituted" are interchangeable herein and refer to a molecule that lacks substitution, or the particular substitution referred to in the context of the term's usage.

"Brominated aromatic" refers to a compound having bromine ("aromatic bromine") bound to an aromatic moiety.

"Brominated aliphatic" refers to a compound having bromine ("aliphatic bromine") bound to an aliphatic moiety.

"Textile" refers broadly to woven and non-woven materials comprising a network of multiple fibers. Textiles can be made directly from fibers or a web of fibers or from yarn comprising a compilation of fibers. Textiles include clothes and fabrics. The fibers can be selected from any one or combination of more than one material characterized as: animal (for example, wool, and silk), plant (for example, cotton, flax, and jute), mineral (for example, asbestos, glass fiber) and synthetic (for example, nylon, polyamide, polyester, and acrylic). Desirably, the textile of the present invention is "non-mineral" meaning it contains less than 10 weight-percent, preferably 5 weight-percent or less, and more preferably one weight-percent or less and can be free of mineral fibers relative to total weight of the textile.

The textile, in many applications, is desirably drapable. Drapable means it is capable of folding over an object and hanging loosely under its own weight. Drapable textiles are desirable for use in, for example, clothing, upholstery, window drapes, and curtains. For other applications, such as for use in some filtration and support medium applications, the textile is desirably non-drapabable.

In some desirable embodiments of the present invention, the textile consists of fibers selected from animal and plant fibers. Such textiles are "natural" textiles since they are made of fibers from naturally occurring materials. Natural textiles tend to have different burning characteristics than many synthetic materials. Synthetic materials can melt away from a flame rather than char or burn. In contrast, natural materials tend to burn or char rather than melt. That can make them more challenging to render flame retardant than synthetic polymeric fibers. The textile of the present invention comprises a brominated polymer flame retardant ("brominated polymer") disposed on the fibers of the textile. The brominated polymer has copolymerized therein a butadiene moiety and a vinyl aromatic monomer moiety. "Alkenyl aromatic" and "vinyl aromatic", whether used to describe "monomer" or "polymer", have the same meaning and the generic use of either term includes both substituted and unsubstituted (non- substituted) species. Suitable alkenyl aromatic species include non- aromatic substituted (for example, poly(alpha-methylstyrene)), ring- substituted (for example, halogenated styrenes such as 2- or 4-bromostyrene), alkoxylated styrenes such as 2- or 4-methoxystyrene, nitrated styrenes (for example, 2-nitrostyrene or 4-nitrostyrene), and alkylated styrenes such as 2- or 4-methylstyrene or 2,4-dimethylstyrene, and unsubstituted species (for example, polystyrene homopolymer), as well as copolymers (for example, styrene/acrylonitrile copolymers, styrene/methylmethacrylate copolymers, and

styrene/acrylic acid copolymers) or interpolymers (for example, ethylene/styrene

interpolymers, or ethylene/propylene/styrene interpolymers).

The brominated polymer has, prior to bromination, a vinyl aromatic monomer content of from 5 to 90 percent by weight based upon polymer weight and a 1,2-butadiene isomer content of greater than zero percent by weight based upon butadiene moiety weight. Furthermore, prior to bromination, the polymer has a weight- averaged molecular weight (Mw) of at least 1000. Determine Mw using gel permeation chromatography relative to a polystyrene standard using an Agilent 1100 series liquid chromatograph equipped with two Polymer Laboratories PLgel 5 micrometer Mixed-C columns connected in series and an Agilent G1362A refractive index detector (or equivalent device), with tetrahydrofuran (THF) flowing at a rate of 1 milliliter per minute (ml/min) and heated to a temperature of 35°C as the eluent.

Desirably, the brominated polymer contains at least 10 wt , preferably 20 wt or more, still more preferably 30 wt or more, yet more preferably 40 wt or more, even more preferably 50 wt or more and most preferably 60 wt or more or even 70 wt or more bromine based on total brominated polymer weight. Determine the amount bromine in the brominated polymer by x-ray fluorescence spectroscopy using an Oxford Lab XI 005 X-ray fluorescence analyzer, or equivalent thereto.

The brominated polymer is further characterized by having an unbrominated non- aromatic double bond content ("residual double bond content") of less than or equal to 50 percent (%), preferably 25 % or less and more preferably 15% or less based on non-aromatic double bond content of the polymer prior to bromination as determined by proton nuclear magnetic resonance spectroscopy. That is, over 50%, preferably 75% or more and more preferably 85% or more of the non-aromatic double bonds in the pre -brominated polymer are brominated in the brominated polymer. As such, the brominated polymer comprises aliphatic bromine (bromine bound to non-aromatic structure). In fact, it is desirable that more than 50 weight-percent (wt ), preferably more than 75wt and more preferably 90wt or more of the bromine in the brominated polymer is aliphatic based on total weight of bromine. 95 wt or more and even 98 wt or more of the bromine in the brominated polymer can be aliphatic bromine. Determine the percent of aliphatic or aromatic bromine by carbon- 13 nuclear magnetic resonance (NMR) spectroscopy by comparing the integrated area of signals due to aliphatic carbon atoms bonded to bromine (chemical shift less than 100 ppm relative to

tetramethylsilane (TMS), and aromatic carbon atoms bonded to bromine (chemical shift greater than 100 ppm relative to TMS)

The brominated polymer may contain chlorine or be free of chlorine. When chlorine is present it can be present at a concentration of up to 25 wt relative to total weight of the brominated polymer. Determine the amount chlorine in the brominated polymer by x-ray fluorescence spectroscopy using an Oxford Lab XI 005 X-ray fluorescence analyzer, or equivalent thereto.

Regarding thermal stability, the brominated polymer has a five percent weight loss temperature, as determined by dynamic thermogravimetric analysis of at least 170 degrees Celsius (°C), preferably 200 °C or higher, still more preferably 220°C or higher, even more preferably 240°C or higher. Typically, the brominated polymer has a five percent weight loss temperature of 300°C or lower, and more typically 280°C or lower. Determine five percent weight loss temperature using the following dynamic thermogravimetric analysis: 10 milligrams of the polymer is analyzed using a TA Instruments model Hi-Res TGA 2950 or equivalent device, with a 60 millimeters per minute (ml/min) flow of gaseous nitrogen and a heating rate of 10°C/minute over a range of from 25°C to 600°C. The mass lost by the sample is monitored during the heating step and the temperature at which the sample has lost 5% of its initial weight is designated the five percent weight loss temperature (5% WLT).

A desirable brominated polymer is a brominated styrene-butadiene block copolymer. A particularly desirable brominated polymer is a brominated styrene-butadiene-styrene block copolymer. European patent 1957544B1 describes brominated polymers that are particularly well suited for use as brominated polymer in the present invention. The amount of brominated polymer in the textile is desirably 2 wt or more, preferably 5 wt or more, still more preferably 10 wt or more and yet more preferably 20 wt or more and can be 30 wt or more, 40 wt or more, 50 wt or more and even 60 wt or more relative to the weight of the textile with the brominated polymer present. At the same time, the amount of brominated polymer is generally 80 wt or less and can be 70 wt or less relative to the weight of the textile with the brominated polymer present.

The brominated polymer desirably exists within the textile as solid particles on the fibers of the textile (as opposed to, for example, being dispersed within the fibers such as an additive in a polymeric fiber). The brominated polymer particles preferably have a particle size of 50 nanometers or greater, preferably 0.1 micrometer or greater, more preferably 0.5 micrometers or greater, still more preferably one micrometer or greater, yet more preferably ten micrometer or greater and even more preferably 25 micrometer or greater. At the same time, it is desirably that the brominated polymer particles have a particle size that is smaller than 800 micrometer, preferably 600 micrometers or less and more preferably 400 micrometers or less, still more preferably 200 micrometers or less, 100 micrometers or less, or even 50 micrometers or less. These particle sizes render the brominated polymer effective at rendering flame retardant properties.

Determine particle size by one of two methods, depending on the size range of the particles. If more 90 wt or more of the particles are retained on a 100 micrometer sieve then determine particle size as a weight-mean particle size using a sieve analysis.

Otherwise, determine particle size as a volume-average particle size using a laser diffraction method.

Determine weight- mean particle size by the following sieve analysis: (1) prepare two stacks of sieves, first cleaning and recording a tare weight for each sieve. The first stack contains sieves with the following mesh values, in order: 8, 10, 18, 25, 35, 40, 50 and a bottom pan. The second stack contains sieves with the following mesh values, in order: 60, 80, 100, 120, 200, 270, 400, 500 and a bottom pan; (2) record the mass (preferably 10-100 grams) of a quantity of brominated polymer particles, place the quantity on the top sieve (8 mesh) of the first stack, cover the top sieve, place the stack on a Retsch Model AS200 Sieve Shaker, turn the power of the Sieve Shaker to 60% for 20 minutes; (3) remove the stack of sieves from the sieve shaker and weigh each sieve. Subtract the tare weight to determine the mass of material retained on each sieve; (4) place any material that is in the bottom pan onto the top sieve (60 mesh) of the second stack and shake for 20 minutes as described in step (2); (5) determine the mass of material retained on each sieve as described in step (3); (6) determine the weight-mean particle size for the brominated polymer. The weight-mean particle size is the sieve mesh size above and below which 50 wt of the brominated polymer is retained. When the weight-mean particle is between two sieve sizes used in the test method, determine the weight-mean particle size by linear extrapolation between the mesh sizes of those two sieve sizes.

Determine volume-average particle size by laser diffraction method using a

Beckman Coulter LSI 3 320 laser diffraction particle size analyzer with a "Tornado" dry powder disperser.

Particle sizes for the brominated polymer particles can be determined after they have been disposed onto a textile by means of scanning electron microscopy in combination with electron dispersive spectroscopy (SEM-EDS). Particle sizes can be determined by scanning electron microscopy while detection of whether the particle contains bromine can be accomplished by electron dispersive spectroscopy.

The textile of the present invention desirably comprises a binder. The binder is useful for adhering the brominated polymer to the textile. The binder is desirably a chlorinated material such as poly( vinyl chloride). Chlorinated materials offer further flame retardant properties to the textile. The binder is typically applied concomitantly with the brominated polymer particles. For example, the brominated polymer particles can be dispersed in an aqueous latex of binder particles and then the latex can be disposed onto a textile. As the latex dries the binder particles can adhere to both the textile and the brominated polymer particles. The binder desirably is a poly(vinyl chloride) based latex binders (for example, VYCAR™ 460x16 acrylic latex, VYCAR is a trademark of Lubrizol). Another desirable binder is a polyvinylidene dichloride (PVDC) based latex (for example, SERFENE™ 2022 PVDC copolymer emulsion, SERFENE is a trademark of Rohm and Haas Chemicals LLC).

The textile of the present invention further desirably contains a plasticizer to provide flexibility to the flame retardant coating imparted on the textile. The plasticizer is desirably a phosphate ester that is compatible with the binder and that is capable of offering some flame retardant properties to the textile. An example of a desirable phosphate ester plasticizer is a 2-ethylhexyl diphenyl phosphate such as that sold under the tradename SANTICIZER™ 141 (SANTICIZER is a trademark of Ferro Corporation).

Conceivably, the brominated polymer can reside on the textile fibers without aid of a binder (that is, the textile can be free of a binder attaching the brominated polymer to a textile fiber). For example, a dispersion of brominated polymer can be disposed on to a textile (by, for example, filtering through the textile) and the continuous fluid of the dispersion removed to leave the brominated polymer disposed on the textile.

It is also conceivable to prepare a textile out of material that already contains the brominated polymer. For example, synthetic fibers containing the brominated polymer can be used to prepare a textile of the present invention. Fiber (synthetic or natural) can also contain the brominated polymer disposed on them prior to forming the textile by disposing the brominated polymer onto the fibers in fiber form via known coating methods (for example, dip coating into a dispersion of brominated polymer, spray coating, printing and/or froth coating). Alternatively, the textile is prepared from fibers free of the brominated polymer and the brominated polymer is applied to the textile after it is made.

Prepare the textile of the present invention according to the following steps: (a) provide a dispersion of the brominated polymer flame retardant in an aqueous continuous phase; (b) apply the dispersion around the fibers of the textile; and (c) removing at least a portion of the continuous aqueous phase leaving brominated polymer flame retardant disposed on the fibers.

Use a dispersion of brominated polymer to apply the brominated polymer within a textile. There are numerous ways to provide a dispersion of the brominated polymer within an aqueous continuous phase and the following methods are merely illustrative of some methods that are suitable.

The brominated polymer can be dispersed as particles directly into an aqueous phase.

For example, a dispersant can be added to an aqueous phase along with a wetting agent and the brominated polymer can be added to the aqueous mixture while mixing to form a dispersion.

Alternatively, the brominated polymer can first be dissolved in a solvent and then dispersed in an aqueous phase. For example, the brominated polymer can be dissolved in an inert solvent such as methylene chloride to form a solution that is subsequently dispersed into an aqueous phase comprising a surfactant such as sodium lauryl sulfate using a high shear Oakes-type rotor stator mixer. It is desirable for the inert solvent to have a relatively high vapor pressure so that it can flashed out from the dispersion before or after disposition of the dispersion onto a textile (for example, by application of a vacuum or heat or both heat and a vacuum).

The dispersion of brominated polymer desirably comprises 5 wt or more, preferably 10 wt or more and still more preferably 25 wt or more and at the same time typically comprises 80 wt or less, preferably 70 wt or less and can contain 60 wt or less brominated polymer based on total weight of dispersion.

Distribute the dispersion of brominated polymer into a textile by any means. For example, dispersion can be applied to the surface of a textile using an applicator blade or a textile can be submerged in the dispersion. The dispersion, once coated on the surface of a textile can further be pressed into the fibrous network of the textile using a blade, nip roller, or other pressing means.

Remove the aqueous phase typically by heating the textile after disposing the dispersion on the textile. Heating is desirable because it can serve multiple purposes, depending on the nature of the dispersion. In addition to removing water, heating can at the same time induce polymerization of a monomeric solvent to encapsulate the brominated polymer and/or melt a polymer encapsulating the brominated polymer so as to bind the brominated polymer to the textile fibers. It is desirable to remove the water from the dispersion and leave the brominated polymer as solid particles dispersed on the surface of the fibers of the textile.

It is possible, and desirable, for the brominated polymer to remain in a solid state throughout the process of providing a dispersion, disposing the dispersion on a textile and then removing water from the dispersion.

The dispersion can comprise components other than the brominated polymer and an aqueous phase. Suitable additional components include surfactants, flame retardant synergists (such as antimony trioxide, dicumyl, polycumyl and discumyl peroxide), plasticizers, antioxidants, and acid scavengers (such as epoxy compounds).

A desirable textile of the present invention further comprises a phosphorous- containing compound, a chlorine-containing compound, or both a phosphorous-containing compound and a chlorine-containing compound to assist with imparting flame retardant properties to the textile. The concentration of phosphorous in the textile is typically at least 0.15 wt , preferably 0.25 wt or more, and still more preferably at least 0.40 wt and typically 0.75 wt or less relative to total textile weight.

When chlorine is present, it can come from a number of possible sources. In some instances, the brominated polymer can contain chlorine. Additionally, or alternatively, chlorine-containing compounds other than the brominated polymer can be present in the textile. When chlorine is present, the amount of chlorine is typically 0.5 wt or more and can be 1.0 wt or more, 10 wt or more and even 20 wt or more while at the same time it is generally 30 wt or less relative to total textile weight.

Determine the concentration of phosphorous and chlorine by using an Oxford

Lab XI 005 X-ray Fluorescence analyzer. A sample of textile sample is submitted to x-ray radiation from a radioactive cadmium source. The x-ray radiation stimulates bromine, chlorine or phosphorous contained in the sample and results in x-ray emissions specific to each atomic species. Measuring the intensity of the x-rays emissions allows one to individually quantify each species contained in the sample

The following examples provide illustrations of embodiments of the present invention.

Examples

Preparation of Brominated Polymer Flame Retardant

Prepare three brominated polymer flame retardants PB-1 and PB-2 by brominating a poly(styrene-butadiene-styrene) triblock copolymer (rubber) according to the method set forth in Example 7 of WO2008/021417A2. Characteristics of the resulting brominated polymers are in Table 1. Determine total weight-percent bromine by x-ray fluorescence as described above.

Prepare PB-1 using a low 1,2 mole-percent poly(styrene-butadiene- styrene) triblock rubber (Rubber 1) from Scientific Polymer Products, the rubber characterized by proton NMR and gel permeation chromatography (as described above) to have the following properties: weight average molecular weight (Mw) of 128,000 grams per mole,

polydispersity of 1.13, styrene content of 31 wt and a 1,2 vinyl content of 8 mole-percent based on total moles of butadiene present. Isolate PB-1 after bromination using an inverse isopropyl alcohol (IPA) method similar to that used to isolate product in example SBC-12 in European patent 1957544B1, except place two liters of brominated rubber solution into the 10-liter precipitation vessel and add six liters of IPA using an FMI pump to the brominated rubber solution while stirring at about 400 revolutions per minute (RPM) over a period of 30 minutes. Collect the resulting white solid by vacuum filtration on a coarse glass frit, rinse with fresh IPA, suction dry on the glass frit for 30 minutes. Transfer the fine white particle to a glass try and dry in a vacuum oven at 55°C for three days. At this temperature, PB-1 becomes fused together and needs to be ground up. Grind PB-1 with a mortar sufficiently so that it fits through a 250 micron sieve.

Prepare PB-2 using a rubber (Rubber 2) prepared according to the process of European patent 1957544B1, example SBC-12 (1,2-vinyl content of 83 mole-percent) except the moles of n-butyl-lithium initiator and styrene were reduced to prepare a final rubber having a Mw of 143,000 grams per mole, polydispersity of 1.1, total styrene content of 34 wt and a 1,2 vinyl content of 84 mole-percent as measured by proton NMR spectroscopy. Isolate PB-2 in like manner as described for PB-1, however grinding with a mortar is unnecessary as the polymer dries in the form of a fine powder. Determine particle size by the laser diffraction method.

Table 1. Brominated Polymer Characteristics

Back- Coating Formulation

Formulate the flame retardant into a back-coating formulation for disposing the flame retardant onto a textile. Prepare the back-coating formulation by first forming an initial dispersion and then neutralizing the initial dispersion with ammonia. The actual compositions for the formulations are in Table 2. For preparing the initial dispersion from PB-1, PB-2 and hexabromocyclododecane (HBCD, used as a reference) flame retardants start by adding approximately 80 grams of water to a plastic container and begin vigorous stirring with a paddle stirrer. Add one gram of sodium dioctyl sulfosuccinate (70-71 wt solids in water, for example AEROSOL OT- 70PG surfactant, AEROSOL is a trademark of Cytec Technology Corp.) and then 200 grams of the flame retardant while continuing vigorous stirring. Add a silicone based antifoaming agent (FOAM BLAST™ 10 defoamer, FOAM BLAST is a trademark of Emerald Foam Control, LLC) to the amount shown in Table 2 in order to form a uniform dispersion. Add water as needed until achieving a flowable dispersion having a viscosity of approximately 1000 centipoise (water amounts for these Examples are listed in Table 2). Continue mixing for 2-3 minutes before neutralizing the resulting initial dispersion. While continuing to mix, add a plasticizer (SANTICIZER 141 Plasticizer) and binder (VYCAR 460x46 PVC acrylic latex) at the amounts noted in Table 2 and then continue to mix for another 2-3 minutes.

Neutralize the initial dispersion to form a back-coating formulation by titrating the initial dispersion with a 25wt ammonia solution to achieve a pH of 8.0-8.5. Measure the initial viscosity and then add a polyacrylate thickener (for example ACRYSOL™ ASE95NP alkali soluble, acrylic thickener, ACRYSOL is a trademark of Rohm and Haas Company) while mixing until achieving a viscosity in a range of 2000-6000 centiPoise. Measure viscosity using a Brookfield (DV-E) viscometer. The result is a back-coating formulation.

Table 2 provides the compositions and characteristics for a reference formulation comprising HBCD (for use in Comparative Example A) and formulations for PB-1 and PB- 2 for use in Examples 1-3 respectively.

Table 2

Coating Cotton Textile

Apply the back-coating to a cotton utility fabric having a weight of 8.5 ounces per square yard. Apply the coating to the fabric using an 20.32 centimeter (8-inch) wide

Gardner knife with the height adjusted so as to apply the loading of back-coating specified in Table 3. Dry the fabric after coating in a Pro tor Schwartz forced air oven set at 71°C for 30 minutes. Cut resulting treated fabric into two 30.48 x 10.16 centimeter (12 x 4 inch) samples for fire testing. Store the samples at 22°C and 50% relative humidity for 24 hours prior to testing.

Use one of the sample pieces to determine the wt% of the coating using the following calculation:

Wt% Coating = 100 x ((Ave wt CS)-(Ave Wt Fabric))/(Ave wt CS) where "Ave wt CS" is the average weight of the two coated samples and "ave wt Fabric" is the average weight of the pre-coated fabric.

Use the second sample piece to characterize the burn performance according to NFPA 701 where a "passing" rating corresponds to both a "time to extinguishment" value of less than 40 seconds and a "char length" that is less than 15.24 centimeters (6 inches). Characterization is done after hanging the sample vertically and applying an ignition burner for 12 seconds. Timer for the "time to extinguishment" begins when the burner is removed. Table 3 presents the results for Comp Ex A and Exs land 2:

Table 3

These results reveal that a textile comprising a brominated polymer flame retardant instead of HBCD can pass the NFPA 701 burn test and even at lower bromine concentration levels than the HBCD sample.

Claims

WHAT IS CLAIMED IS:

1. A textile comprising fibers and a brominated polymer flame retardant wherein the brominated polymer flame retardant is characterized as being a copolymer that has copolymerized therein a butadiene moiety and a vinyl aromatic monomer moiety, the copolymer having, prior to bromination, a vinyl aromatic monomer content of from 5 to 90 percent by weight based upon copolymer weight, a 1,2-butadiene isomer content of greater than zero percent by weight based upon butadiene moiety weight, and a weight average molecular weight of at least 1000, the brominated copolymer having an unbrominated, non- aromatic double bond content of less than or equal to 50 percent based upon non-aromatic double bond content of the copolymer prior to bromination as determined by proton nuclear magnetic resonance spectroscopy, a five percent weight loss temperature, as determined by thermogravimetric analysis of at least 170 degrees Celsius.

2. The textile of Claim 1, wherein the brominated polymer flame retardant is further characterized as having a 50 percent weight loss at 210 degrees Celsius within 10 to 60 minutes as determined by dynamic thermogravimetric analysis.

3. The textile of Claim 1 or Claim 2, wherein the brominated polymer flame retardant is further characterized by comprising at least 10 weight-percent bromine relative to total brominated polymer flame retardant weight.

4. The textile of any of Claims 1-3, further characterized by the brominated polymer flame retardant providing a concentration of bromine that is at least two weight- percent of the total textile weight.

5. The textile of any of Claims 1-4, further characterized by the brominated polymer flame retardant being disposed on the fibers of the textiles.

6. The textile of any one of Claims 1-5, further characterized by the brominated polymer flame retardant being in a solid particulate form where the particulates have particle size of 0.1 micrometers or greater and at the same time 50 micrometers or smaller.

7. The textile of any one of Claims 1-6, further characterized by the textile further comprising a binder adhering the brominated polymer flame retardant to the textile.

8. The textile of claim 7, wherein the binder is a chlorinated material.

9. The textile of Claim 8, wherein the binder is a poly(vinyl chloride).

10. A method for preparing the textile of Claim 1, the method comprising the following steps: (a) providing a dispersion of the brominated polymer flame retardant and binder in an aqueous continuous phase; (b) distributing the dispersion around the fibers of the textile; and (c) removing at least a portion of the continuous aqueous phase leaving brominated polymer flame retardant disposed on the fibers.

11. The method of Claim 7, further characterized by maintaining the brominated polymer flame retardant in a solid state throughout steps (a)-(c).

12. The method of any one of Claims 9-10, wherein the dispersion (a) further comprises a binder.

13. The method of Claim 12, wherein the binder is a chlorinated binder.

14. The method of Claim 13, wherein the binder is poly( vinyl chloride).