(CO)POLYMER CONTAINING MODIFIED DIENE, METHOD FOR PREPARING THE SAME, AND ITS USE AS A FLAME RETARDANT

Abstract

The present invention relates to the field of modified diene-containing (co)polymers, in particular a modified styrene-butadiene copolymer, which can be used as flame retardants for expandable polystyrene polymer compositions; in particular, the invention relates to a modified diene-containing (co)polymer, a method for preparing it, and its use as a flame retardant for expandable polystyrene; the modified diene-containing (co)polymer claimed in the invention is characterized by high thermostability, namely a 5% weight loss temperature of at least 180°C, a molecular weight of at least 1500 g / mol, and a halogen content of at least 35% by weight; the tertiary and / or allyl halide content is on the scale of 0 to less than 1.5%, and it does not affect the polymerization process and the formation of polystyrene granules, and it allows obtaining polystyrene granules with a yellowness index of 2 to 6 units, comparable to the yellowness index of polystyrene granules containing HBCD (from 0 to 3 units).

Description

OF THE SAME, AND ITS USE AS A FLAME RETARDER CAMTOJDEJA^ The present invention relates to the field of modified diene-containing (co)polymers, in particular to a modified styrene-butadiene copolymer that can be used as a flame retardant for polymer compositions comprising expandable polystyrene. Specifically, the invention relates to a modified diene-containing (co)polymer, a method for preparing the same, and its use as a flame retardant for polystyrene, including expandable polystyrene. BACKGROUND OF THE INVENTION Flame retardants are widely used in articles made from various polymers and polymer compositions, for example, in articles comprising expandable polystyrene to provide flame-retardant properties [Stockholm Convention on Persistent Organic Pollutants, UNEP / POPS / POPRC.6 / 10, October 15, 2010]. Several low-molecular-weight brominated compounds, such as hexabromocyclododecane (HBCD), are commonly used in these polymer compositions as flame retardants. However, the results of many studies have shown HBCD's capacity for bioaccumulation, high toxicity, and stability under environmental conditions [Stockholm Convention on Persistent Organic Pollutants, UNEP / POPS / POPRC.6 / 10, October 15, 2010, Article 4]. This has led to restrictions on the use of HBCD as a flame retardant in order to reduce environmental risks. For some polymer compositions, for example, those comprising expandable polystyrene [Stockholm Convention on Persistent Organic Pollutants, UNEP / POPS / POPRC.6 / 10, October 15, 2010, Article 74], processing temperatures are often very high, which can cause the flame retardant to decompose during the polymer composition's processing. In this case, there is a loss of flame-retardant properties in the polymer composition and the formation of decomposition products such as HBr. Therefore, it is important that the flame retardant be thermally stable at the processing temperatures of the polymeric materials and that it also meet non-toxicity requirements and be environmentally friendly. The prior art represented by documents WO2008021418 (DI), WO2008021417 (D2), WO2016123263 (D3), RU2414479 (D4) and RU2530021 (D5), describes alternative flame retardants that are more environmentally friendly compared to HBCD, and are obtained on the basis of diene-containing (co)polymers, in particular, styrene-butadiene copolymers. Thus, in particular, application WO2008021418 (DI) proposes a process for preparing a brominated styrene-butadiene copolymer having a 5% weight loss temperature of at least 200°C. The known process for preparing a brominated styrene-butadiene copolymer comprises (a) contacting a solution of a starting copolymer in a solvent with elemental bromine in an amount of 0.5 to 1.5 equivalents per equivalent of aliphatic carbon-carbon double bonds in the starting copolymer, wherein such contact is in the presence of at least 0.5 moles of an aliphatic alcohol per mole of bromine; and (b) maintaining the reaction solution under reaction conditions for a period sufficient to brominate more than 50 percent of the aliphatic double bonds contained in the starting copolymer. The known DI procedure is characterized by using elemental bromine as a brominating agent, which results in the formation of tertiary bromides in the flame retardant molecule, which in turn results in a decrease in the thermal stability of the flame retardants of the (co)polymers obtained. Document RU2414479 (D4) indicates that, following the use of elemental bromine as the brominating agent to prepare a brominated styrene-butadiene copolymer, the reduced thermal stability of the flame retardant is provided by the formation of tertiary bromides via free-radical mechanisms. When placed in solution, this brominated copolymer releases bromine, hydrogen bromide (HBr), or both. Furthermore, free-radical bromination, in addition to the bromination of unsaturated carbon-carbon double bonds, can result in the bromination of benzyl groups in the aromatic vinyl portions, which also influences the thermal stability of the resulting flame retardant. The prior art represented by documents WO2008021417 (D2), WO2016123263 (D3), RU2414479 (D4), and RU2530021 (D5) also describes the preparation of thermoset brominated butadiene copolymers by carrying out a selective bromination reaction to ensure the absence of tertiary bromides in the flame retardant molecule. Preferably, tribromides such as tetraalkylammonium tribromide or pyridinium tribromide are used as the brominating agent, which minimizes or excludes the formation of tertiary bromine-containing portions. According to the cited sources, the bromination preferably proceeds via an ionic mechanism, specifically a cationic one, rather than a free-radical mechanism.Ionic bromination is preferable to free radical bromination, as the latter results in the formation of products containing tertiary bromine, which in turn represents the main factor that contributes to the very poor thermostability of the flame retardant obtained. Specifically, patent RU2414479 (D4) describes a thermoset brominated styrene-butadiene copolymer that can be used as a flame retardant in expanded and non-expanded polymeric materials. The known brominated styrene-butadiene copolymer is characterized by a 5% weight loss temperature of at least 200°C, determined according to the thermogravimetric analysis (TGA) method. Furthermore, patent RU2414479 (D4) proposes a polymer blend comprising the indicated thermoset brominated styrene-butadiene copolymer, and also proposes a molded article comprising the indicated polymer blend. The known flame retardant D4 has low thermal stability which becomes evident under high processing temperatures of expandable polystyrene, and also the limited compatibility of highly brominated styrene-butadiene copolymers with polystyrene, which can make it difficult to obtain a homogeneous structure of the expanded polystyrene with a high thickness of the articles manufactured from it. Patent application WO2016123263 (D3) describes examples of polymeric flame retardants for expandable polystyrene comprising hydroxybrominated styrene-butadiene copolymers. The flame retardant described in application WO2016123263 (D3) is obtained by brominating 50 to 98% of butadiene repeating units in the starting styrene-butadiene copolymer with a quaternary ammonium tribromide to obtain a partially brominated copolymer, followed by reacting the partially brominated copolymer with the N-halomide compound, for example, an N-dorosuccinimide or N-bromosuccinimide, in the presence of water and a water-miscible solvent to halohydrate a portion of the butadiene repeating units to produce a hydroxybrominated styrene-butadiene copolymer. The resulting hydroxybrominated styrene-butadiene copolymer comprises 2 to 50 wt% of butadiene units that are hydroxybrominated, and 50 to 98 wt% of butadiene units that are brominated, and has a 5% weight loss temperature of at least 250°C. The flame retardant known from document WO2016123263 (03) has low thermal stability which becomes evident under high processing temperatures of expandable polystyrene, and also the absence of functional groups capable of absorbing the HBr released under high temperatures. / co / nn / Lznz / E / YiAi In addition to this, the procedure for preparing a proposed flame retardant according to the known invention is characterized by a large amount of time spent in the step of preparing a hydroxybrominated styrene-butadiene copolymer, and in the step of isolating it from a reaction mass, and also the need for the use of expensive reagents, in particular, N-halomide. Furthermore, patent RU2530021 (D5) selected by the authors as the prototype of the present invention describes the use of a brominated and epoxidized styrene-butadiene copolymer as a flame retardant for expandable polystyrene. In accordance with D5, the flame retardant is obtained by a method comprising the epoxidation step and the bromination step to obtain a brominated and epoxidized styrene-butadiene copolymer. The flame retardant obtained according to the known invention is characterized by a molecular weight of at least 1500 g / mol, a bromine content of at least 35% by weight, and a 5% weight loss temperature of at least 180°C. However, although the flame retardant comprises epoxy groups capable of absorbing the HBr released under high processing temperatures from polymer compositions comprising expandable polystyrene, the low compatibility of the flame retardant with polystyrene is observed. Notwithstanding the fact that the prior art describes an effective method for producing brominated flame retardants with the use, in particular, of quaternary ammonium tribromides, which allow the formation of tertiary bromides in the flame retardant molecule to be avoided (see D5), the authors of the present invention have surprisingly established that the method described in the known prior art results in the formation of bromine atoms in an allyl position for double bonds of diene portions (allyl bromides), and these allyl and tertiary bromides, as is known, also have a negative influence on the thermal stability of the flame retardants obtained, which is confirmed by the examples shown in the present invention. Thus, flame retardants comprising diene-containing (co)polymers and methods for preparing them known from the prior art are not sufficiently effective, and also require large economic and time costs. In view of this, the strategic route is the development of a flame retardant comprising a diene-containing (co)polymer that will be thermoset, including, due to the reduced content, preferably the total absence of tertiary halides and / or allyl, will meet the requirements of environmental friendliness, and will not adversely affect a process of polymerization and granulation of polystyrene, where it will provide excellent flame retardant properties for polystyrene, including expandable polystyrene. BRIEF DESCRIPTION OF THE INVENTION It is an objective of the present invention to develop a modified diene-containing (co)polymer that can be used as a flame retardant, and also a method for producing it, and the use thereof as a flame retardant for expandable polystyrene. The technical result of the present invention is the preparation of a modified diene-containing (co)polymer characterized by high thermal stability, namely a 5% weight loss temperature of at least 180°C, a molecular weight of at least 1500 g / mol, and a halogen content of at least 35% by weight, by means of a tertiary halide and / or alloy content on the scale of 0 to less than 1.5% by weight, which does not adversely affect a process of polymerization and formation of polystyrene granules, and which also allows obtaining polystyrene granules having a yellowness index of 2 to 6 units, comparable to the yellowness index of polystyrene granules containing HBCD (from 0 to 3 units) as defined below. The indicated technical result is achieved due to a modified diene-containing (co)polymer comprising epoxy groups, hydroxyl groups and also halogen atoms, and which is substantially free of tertiary and / or allyl halides, which can be obtained by reacting a starting diene-containing (co)polymer and a halogenating agent in the presence of water in an allowable amount of 0 to less than 0.5% by weight, followed by reaction with a modification system comprising halogen and water, in the presence of an aliphatic alcohol. The authors of the present invention have surprisingly discovered that the modified diene-containing (co)polymer comprising epoxy groups, hydroxyl groups and also halogen atoms, comprising tertiary and / or allyl halides on the scale of 0 to less than 1.5% by weight, more preferably 0 to less than 1.0% by weight, even more preferably 0 to less than 0.5% by weight, is thermoset, does not adversely affect a process of polymerization and formation of polystyrene granules, and allows obtaining polystyrene granules having a yellowness index of 2 to 6 units, preferably less than 6 units, more preferably less than 5 units, and most preferably less than 3 units, comparable to the yellowness index of polystyrene granules containing HBCD (0 to 3 units). Furthermore, the inventors of the present invention have discovered that the indicated modified diene-containing (co)polymer can be obtained by a method comprising a halogenation step using a halogenating agent in the substantial absence of water in a reaction system, in particular, the permissible water content in the system being from 0 to less than 0.5 wt%, followed by a modification step using a halogen-water mixture as the modification system in the presence of an aliphatic alcohol. Hypothetically, the presence of a significant amount of water in the system during the halogenation step results in the formation of alcohol halides, which in turn results in a decrease in the thermal stability of the resulting modified diene-containing (co)polymer. Furthermore, the claimed method allows incorporation into the starting (co)polymer structure of hydroxyl groups and halogen atoms, followed by the partial dehydrohalogenation reaction procedure to form epoxy groups in the (co)polymer structure. The modified diene-containing (co)polymer obtained in accordance with the present invention, comprising epoxy and hydroxyl groups, and also halogen atoms, and characterized by the presence of tertiary and / or allyl halides on the scale of 0 to less than 1.5% by weight, can be used as a flame retardant in different polymer compositions, for example, polymer compositions comprising polystyrene, including expandable polystyrene. BRIEF DESCRIPTION OF THE DRAWINGS To illustrate the technical solutions that reveal the essence of the present invention, Figures 1 to 4 are presented. Figure 1 is a flow diagram showing the sequence of steps for producing a (co)polymer containing a modified diene according to the present invention. Figure 2 shows the 1H NMR spectrum of a modified diene-containing (co)polymer comprising epoxy groups, hydroxyl groups and halogen atoms, and which is free of tertiary and allyl bromides, obtained in accordance with the present invention. Figure 3 shows the XH NMR spectrum of a styrene-butadiene copolymer containing epoxy groups, hydroxyl groups and halogen atoms, and also containing an allyl bromide. Figure 4 shows the :H NMR spectrum of the obtained styrene-butadiene copolymer containing epoxy groups, hydroxyl groups and halogen atoms, and also containing a tertiary bromide. / co / nn / Lznz / E / YiAi DETAILED DESCRIPTION OF THE INVENTION The present invention relates to a modified diene-containing (co)polymer representing a thermoset modified diene-containing (co)polymer characterized by a weight-average molecular weight of at least 1500 g / mol, preferably 2000 to 280000 g / mol, more preferably 10000 to 150000 g / mol, and most preferably 60000 to 100000 g / mol, and also by a majority of non-conjugated carbon-carbon double bonds, wherein at least two double bonds (but fewer than all of the non-conjugated carbon-carbon double bonds) are modified, and the modified diene-containing (co)polymer comprises at least 35 wt%, preferably at least 60 wt%, and more preferably at least 75 wt% of a halogen, at least one epoxidized non-conjugated carbon-carbon double bond, and at least one double bond of non-conjugated hydroxyhalogenated carbon-carbon bond. At the same time, the distinctive peculiarity of the modified diene-containing (co)polymer obtained in accordance with the present invention is the low content of tertiary and / or allyl halides on the scale of 0 to less than 1.5% by weight, more preferably 0 to 1.0% by weight, more preferably 0 to less than 0.5% by weight, even more preferably in total absence of tertiary and / or allyl halides in the molecule of the modified diene-containing (co)polymer obtained, i.e., the highly preferable content of tertiary and / or allyl halides is 0% by weight. The term thermal stability in the present invention means a 5% weight loss temperature of the modified diene-containing (co)polymer, as defined by the thermogravimetric analysis (TGA) method described below. The thermoset modified diene-containing (co)polymer obtained according to the invention comprises at least one epoxy group, wherein the amount of epoxy groups in the obtained modified diene-containing (co)polymer is from 0.01 to 5% by weight, preferably from 0.05 to 3% by weight, more preferably from 1 to 2% by weight. The thermoset modified diene-containing (co)polymer obtained comprises at least one hydroxyl group, wherein the amount of hydroxyl groups in the modified diene-containing (co)polymer obtained is from 0.05 to 5% by weight, preferably from 0.1 to 3% by weight, more preferably from 0.15 to 1% by weight. According to the present invention, the 5% weight loss temperature of the modified diene-containing (co)polymer is at least 180°C, preferably at least 220°C, more preferably at least 240°C. / co / nn / Lznz / E / Yi In one embodiment of the present invention, the modified diene-containing (co)polymer represents, but is not limited to, a modified diene-containing (co)polymer of the / co / nn / Lznz / E / YiAi where Ri-R··· are the same or different, and can represent hydrogen or a hydrocarbon group having 1 to 6 carbon atoms, in particular, an alkyl group; Hal is halogen; n is a number of polymer chain units that is l <n<400, de preferencia 100<n<350, más preferiblemente 140<n<250; y k, m, I, p, o y q pueden ser iguales o diferentes, y constituyen l<k<37, 0<m<19, 2<(l+p)<3660, 0<o<8, 0<q<8, de preferencia 6<k<12, 3<m<6, 610<(l+p)<1220, 0<o<5, 0<q<5, más preferiblemente 7<k<10, 4<m<5, 730<(l+p)<980, o=0, q=0. According to the present invention, the modified diene-containing (co)polymer, wherein the tertiary and / or alkyl halides are present in the range of 0 to less than 1.5 wt%, more preferably 0 to less than 1.0 wt%, and most preferably 0 to less than 0.5 wt%, is obtained by carrying out a halogenation step using a halogenating agent in the substantial absence of water in the system. Within the scope of this application, the substantial absence of water means that the permissible amount of water in the system ranges from 0 to less than 0.5 wt%, more preferably from 0 to less than 0.3 wt%, and even more preferably from 0 to less than 0.1 wt%, followed by the modification step using, as the modification system, a mixture of halogen and water in the presence of an aliphatic alcohol. The halogen atom indicated in the structure of the modified diene-containing (co)polymer according to the present invention is selected from the group consisting of chlorine, bromine, or iodine. Most preferably, the modified diene-containing (co)polymer comprises bromine atoms as the halogen. The present invention is, in another respect, a method for producing a modified diene-containing (co)polymer, comprising the following steps: a) a dissolution step comprising (optionally) preliminary milling of a starting diene-containing (co)polymer followed by dissolution in an organic solvent; b) a partial halogenation step, using a halogenating agent and optionally an aliphatic alcohol to a degree of halogenation of at least 60%, preferably at least 90%, and most preferably at least 95%; c) a washing and separation step, comprising adding water to the reaction mass obtained in step b) and separating an aqueous layer and an organic layer; d) a modification step, comprising adding components of a modification system and optionally an aliphatic alcohol to the organic layer obtained in step c) comprising a (co)polymer containing a partially halogenated diene; e) a neutralization and separation step, comprising adding an aqueous solution of a neutralizing agent to the reaction mass obtained in step d) and separating an aqueous layer and an organic layer; f) an isolation step, comprising precipitating or degassing a (co)polymer containing a modified diene; and g) a filtration step and a subsequent drying step of the isolated modified diene-containing (co)polymer, wherein in the partial halogenation step b) the allowable water content in the system is 0 to less than 0.5% by weight, more preferably 0 to less than 0.3% by weight, even more preferably 0 to less than 0.1% by weight, and in the modification step d) a mixture of halogen and water is used at a halogen:water ratio of 1:0.01 to 1:1, preferably 1:0.5 to 1:0.7, more preferably 1:0.25 to 1:0.7 per total number of double bonds in the starting (co)polymer used as the modification system. Dissolution step a) In step a) of the claimed method, a preliminary milling of a starting diene-containing (co)polymer is optionally carried out, followed by dissolving the same in an organic solvent while stirring. The starting diene-containing (co)polymer according to the present invention is a polymer or copolymer of a conjugated diene. The preferred conjugated dienes are conjugated dienes having 4 to 12 carbon atoms, for example, selected from the group consisting of 1,3-butadiene, 2-methyl-1,3-butadiene (isoprene), 2-ethyl-1,3-butadiene, 2,3-di(C5-Cl alkyl)-1,3-butadienes, such as 2,3-dimethyl-1,3-butadiene, 2,3-diethyl-1,3-butadiene, 2-methyl-3-ethyl-1,3-butadiene, 2-methyl-3-isopropyl-1,3-butadiene, phenyl-1,3-butadiene, 1,3-pentadiene, 2,4-hexadiene, 2-methylpentadiene, 4-methylpentadiene, or mixtures thereof. Preferably, 1,3-butadiene or isoprene are used. / co / nn / Lznz / E / YiAi Suitable comonomers in the starting diene-containing (co)polymer according to the present invention are vinylaromatic compounds selected from the group consisting of styrene, α-methylstyrene, ortho-, meta-, and para-methylstyrene, 3-vinyltoluene, ethylvinylbenzene, 4-cyclohexylstyrene, para-tert-butylstyrene, methoxystyrenes, vinylmesitylene, divinylbenzene, 1-vinylnaphthalene, 2,4,6-trimethylstyrene, or a mixture thereof. Preferably, styrene or α-methylstyrene are used. Suitable polymers and copolymers of the conjugated diene comprise at least 30% by weight, preferably at least 50% by weight, more preferably 70% by weight of polymerized units of the conjugated diene. Preferably, butadiene, styrene-butadiene and styrene-butadiene-isoprene (co)polymers, and most preferably the styrene-butadiene copolymer, i.e., the double and triple block copolymers of butadiene and styrene, are used as the starting diene-containing (co)polymer. Examples of commercially available diene-containing (co)polymers are, but are not limited to, butadiene polymers with the trade names BR-1243 Nd Grade B (LP), BR-1243 Nd Grade B and BR-1243 ND HV; styrene-butadiene block copolymers with the trade names DST R 30-00, SBS L 30-01A, SBS R 30-00A, DST L 30-01 and DST L 30-01 (SR); styrene-butadiene copolymers obtained by the solution polymerization method, with the trade names DSSK-2560-M27 (Grade AA), DSSK-2560-M27 BB (Grade A) and DSSK-4040-M27 (Grade A) from the manufacture of PJC SIBUR-Holding. The suitable starting diene-containing (co)polymers according to the present invention have an average molecular weight of at least 700 g / mol, preferably from 1000 to 400000 g / mol, more preferably from 2000 to 300000 g / mol, more preferably from 5000 to 200000 g / mol, more preferably from 20000 to 120000 g / mol, most preferably from 20000 to 50000 g / mol, and are characterized by a polydispersity index of 0.8 to 3, more preferably from 1 to 1.8, most preferably from 1.1 to 1.5, and by an amount of 1,2-units that is at least 10 to 100% by weight, preferably at least 50 to 99% by weight, most preferably from 60 to 80% by weight. polybutadiene of the (co)polymer. The starting diene-containing (co)polymer is optionally ground by any known prior art method, e.g., using crushers (blade, hammer or rotor), mills (fluid or worm), etc., but is not limited to them. After dissolving the starting diene-containing (co)polymer in step a), stirring is carried out by any known prior art method, for example, using a device equipped with a mixer, static mixer, at a temperature of 10 to 50°C, preferably 15 to 40°C, more preferably 20 to 30°C. / co / nn / Lznz / E / YiAi Suitable solvents include, but are not limited to, organic solvents, preferably with a purity of 99% or higher, such as ethers (e.g., tetrahydrofuran), halogenated saturated aliphatic hydrocarbons (e.g., carbon tetrachloride, chloroform, dibromomethane, dichloromethane, 1,2-dichloroethane), aliphatic hydrocarbons (e.g., cyclohexane), aromatic hydrocarbons (e.g., toluene), and halogenated aromatic hydrocarbons (e.g., bromobenzene, chlorobenzene, and dichlorobenzene). Preferred organic solvents are those that are liquid under the modification conditions of the starting diene-containing (co)polymer and that do not react with the modification system or the starting (co)polymer. Tetrahydrofuran, chloroform, dichloromethane, dichloroethane, cyclohexane, or toluene are preferably used as the solvent. Tetrahydrofuran, chloroform, or dichloromethane are preferred. A mass ratio of the organic solvent to the starting diene-containing (co)polymer is 5:1 to 30:1, preferably 8:1 to 20:1, more preferably 10:1 to 15:1. The dissolution procedure time is at most 60 minutes, in particular, at most 50 minutes, preferably at most 40 minutes, at most 30 minutes, at most 25 minutes, at most 20 minutes, at most 15 minutes, at most 13 minutes, at most 11 minutes, at most 9 minutes, at most 7 minutes, at most 5 minutes. The mass obtained as a result of the dissolution step a) described above is a solution of the starting diene-containing (co)polymer in the organic solvent. Partial halogenation step b) In the partial halogenation step b), a halogenating agent and optionally an aliphatic alcohol are added to a solution of the (co)polymer containing the starting diene obtained in step a). A degree of halogenation of the partially halogenated diene-containing (co)polymer obtained in step b) is at least 60%, preferably at least 90%, more preferably at least 95%. The partial halogenation step b) is carried out substantially in the absence of water in a system, where the substantial absence of water is understood to mean that the allowable water content is from 0 to less than 0.5% by weight, more preferably from 0 to less than 0.3% by weight, even more preferably from 0 to less than 0.1% by weight. Chlorine, bromine, and iodine are used as the halogen in a halogenating agent in step b). Preferably, elemental bromine (Bq) as such, and also in the form of a solution in the organic solvent with a bromine content of not more than 70% by weight, more preferably not more than 60% by weight, even more preferably not more than 50% by weight, is used as the halogenating agent. In addition, suitable halogenating agents are, but are not limited to, quaternary ammonium bromides, for example, phenyltriethylammonium bromide, benzyltrimethylammonium bromide, tetramethylammonium bromide, tetraethylammonium bromide, tetrapropylammonium bromide, tetra-n-butylammonium bromide, and quaternary phosphonium bromides, for example, tetramethylphosphonium bromide, tetraethylphosphonium bromide, tetrapropylphosphonium bromide, tetra-n-butylphosphonium tribromide, or mixtures thereof. Preferably, a mixture of elemental bromine (Br₂) and quaternary ammonium bromides or quaternary phosphonium bromides is used as the halogenating agent. At the same time, the use of quaternary ammonium bromide or quaternary phosphonium bromide prevents substantial substitution of hydrogen with bromine at tertiary and / or allyl carbon atoms, which in turn affects the thermostability of the resulting modified diene-containing (co)polymer. As an aliphatic alcohol, alcohols with 1 to 6 carbon atoms are used, such as methanol, ethanol, propanol, isopropanol, butanol, isobutanol, pentanol, and hexanol, but are not limited to them. Preferably, propanol, butanol, isobutanol, and pentanol are used as aliphatic alcohols; and more preferably, butanol, isobutanol, and pentanol are used. A molar ratio of a starting diene-containing (co)polymer:a halogenating agent:an aliphatic alcohol in step b) is 1:1.5:3 to 1:5:3, more preferably 1:2:3 to 1:4:3, most preferably 1:2.5:3 to 1:3:3. Furthermore, in the case of using the mixture of elemental bromine and quaternary ammonium bromide or quaternary phosphonium bromide as the halogenating agent, a molar ratio of elemental bromine to bromine atoms in the quaternary ammonium bromide or quaternary phosphonium bromide is 1:1 to 1:4, more preferably 1:2 to 1:3, most preferably 1:1 to 1:1.5. The addition of the halogenating agent and an aliphatic alcohol, if used, to the solution of the starting diene-containing (co)polymer obtained in step a) can be carried out in any order. Preferably, the aliphatic alcohol is added first to the solution of the starting diene-containing (co)polymer, followed by the addition of the halogenating agent. Simultaneously, when using a combination of a quaternary ammonium bromide or quaternary phosphonium bromide and elemental bromine as the halogenating agent, the entire mass of the quaternary ammonium bromide or quaternary phosphonium bromide, in the form of a solution thereof in an organic solvent, is immediately added to the reaction mass. / co / nn / Lznz / E / YiAi Preferably, the addition of elemental bromine in the partial halogenation step b) is carried out in the form of its solution in the organic solvent by dosing the solution to the reaction mass at a rate between 0.80 and 50 ml / min, preferably between 1 and 10 ml / min, and more preferably between 1.5 and 5 ml / min. A very high dosing rate results in local overheating of the reaction mass, an increase in its viscosity, which in turn may result in the preparation of the (co)polymer containing a modified diene with a low halogen atom content (less than 35 wt%). Adding the entire volume of elemental bramyl (Brz) solution to the starting diene-containing (co)polymer solution obtained in step a) may also result in its entanglement, local overheating of the reaction mass, and an increase in the viscosity of the reaction mass, which may also result in the preparation of the diene-containing (co)polymer modified with a low halogen atom content (less than 35% by weight). The halogenating agent may be dissolved in the organic solvent or a mixture thereof, preferably having a purity of 99% or higher, and representing ether, for example, tetrahydrofuran; halogenated saturated aliphatic hydrocarbons, for example, chloroform, dibromomethane, dichloromethane, 1,2-dichloroethane; cycloaliphatic hydrocarbons, for example, cyclohexane; aromatic hydrocarbons, for example, toluene; or halogenated aromatic hydrocarbons, for example, bromobenzene, chlorobenzene, and dichlorobenzene. Preferably, the halogenating agent is added in the form of a solution thereof in the same solvent that was used in step a) to dissolve the starting diene-containing (co)polymer. The partial halogenation step (b) is carried out in any known batch or continuous equipment of the prior art. Suitable equipment includes, but is not limited to, a continuous stirred-tank reactor, a batch stirred-tank reactor, or an autoclave with a mixer, all of which are designed to work with highly corrosive media. Preferably, the partial halogenation step of the starting diene-containing (co)polymer solution obtained in step a) is carried out without exposure to light, for example, by carrying out the modification procedure in dark glass containers, wrapping the reactor with thin metal foil, or carrying out the procedure in metallic reactors to reduce the likelihood of non-selective photocatalytic halogenation reactions. The partial halogenation step b) is carried out at a temperature of 0 to 50°C, preferably 20 to 45°C, more preferably 30 to 40°C, and under atmospheric pressure. The stirring speed of the reaction mass after the addition of the halogenating agent is 50 to 600 rpm, preferably 100 to 500 rpm, more preferably 200 to 300 rpm. / co / nn / Lznz / E / YiAi The partial halogenation step (b) may be carried out for any time sufficient to achieve the required degree of halogenation of the starting diene-containing (co)polymer, as described above. Preferably, the time for the partial halogenation step (b) is at least 15 minutes, at least 20 minutes, at least 25 minutes, at least 30 minutes, at least 45 minutes, at least 60 minutes, or at least 120 minutes. Washing and separation step c) Step c) includes washing the reaction mass obtained in step b) containing the partially halogenated diene-containing (co)polymer, adding water, followed by the separation of an aqueous layer and an organic layer containing the partially halogenated diene-containing (co)polymer. In the context of the present invention, water is, but is not limited to, distilled, deionized, demineralized, osmotic or double-distilled water. The water washing is carried out using an excess of water of at least once, preferably at least twice, more preferably at least three times relative to the volume of the reaction mass, as a result of which the reaction mass is separated into two layers: the organic layer containing the (co)polymer containing partially halogenated diene and the aqueous layer. In this case, the permissible residual content of the halogenating agent in the organic layer after washing with water in step c) is 0 to 0.5% by weight, preferably 0 to 0.1% by weight, more preferably 0 to 0.01% by weight. Preferably, the washing procedure is carried out at a temperature of 15 to 50°C, preferably 20 to 40°C, more preferably 25 to 30°C, and under atmospheric pressure. The separation of the organic layer and the aqueous layer is carried out using any equipment known from the prior art, for example, using a separating funnel, separator, or sedimentation tank. Modification step d) In modification step d) the components of a modification system are added to the organic layer obtained in step c) which contains a (co)polymer containing a partially halogenated diene. According to the present invention, the halogen and water are used together as the modification system in the presence of an aliphatic alcohol at a halogen:water mass ratio of 1:0.01 to 1:1, preferably 1:0.5 to 1:0.7, most preferably from / co / nn / Lznz / E / YiAi 1:0.25 to 1:0.7, based on the total number of double bonds in the starting diene-containing (co)polymer. Chlorine, bromine, or iodine is used as the halogen. Elemental bromine (Br2) is preferably used as the halogen, and also in the form of a solution in an organic solvent with a bromine content of not more than 70% by weight, more preferably not more than 60% by weight, and most preferably not more than 50% by weight. In the context of the present invention, water is, but is not limited to, distilled, deionized, demineralized, osmotic or double-distilled water. Alcohols having 1 to 6 carbon atoms, such as methanol, ethanol, propanol, isopropanol, butane, isobutanol, pentanol, or hexanol, are used as the aliphatic alcohol, but are not limited to them, in the formulation of the modification system in step d). Preferably, propanol, butane, isobutanol, or pentanol are used as the aliphatic alcohol; more preferably, butanol, isobutanol, and pentanol are used. A ratio of (co)polymer containing partially halogenated diene:modification system:aliphatic alcohol in step d) is from 1:1.5:3 to 1:5:3, more preferably from 1:2:3 to 1:4:3, very preferably from 1:2.5:3 to 1:3:3. The order of addition of the modification system components and the aliphatic alcohol to the partially halogenated diene-containing (co)polymer solution can be any order. Preferably, the aliphatic alcohol is added first to the partially halogenated diene-containing (co)polymer solution, followed by the addition of water, or vice versa. Preferably, the addition of halogen to the (co)polymer solution containing a partially halogenated diene is carried out by dosing the solution into the organic solvent in the reaction mass. The halogen may be dissolved in an organic solvent or a mixture of organic solvents, preferably having a purity of 99% or more, and representing an ether, for example tetrahydrofuran; a halogenated saturated aliphatic hydrocarbon, for example chloroform, dibromomethane, dichloromethane, 1,2-dichloroethane; a cycloaliphatic hydrocarbon, for example cyclohexane; an aromatic hydrocarbon, for example toluene; or a halogenated aromatic hydrocarbon, for example bromobenzene, chlorobenzene, and dichlorobenzene. Preferably, the halogen is dosed in the form of a solution thereof in the same solvent that was used in step a) to dissolve the starting diene-containing (co)polymer. In one embodiment of the invention, the halogen is introduced into the reaction mass in the form of a solution in an organic solvent, as described above, after pre-mixing said solution with water. The dosing rate of the halogen solution or a mixture of the halogen solution and water is 0.80 to 50 ml / min, preferably 1 to 10 ml / min, more preferably 1.5 to 5 ml / min. A very high dosing rate results in local overheating of the reaction mass and an increase in its viscosity, which in turn may result in the preparation of the (co)polymer containing a modified diene with a low halogen atom content (less than 35 wt%). Adding the entire volume of the halogen solution to the starting diene-containing (co)polymer solution at once can result in cross-linking of the diene, local overheating of the reaction mass, and increased viscosity of the reaction mass, which can also result in the preparation of the diene-containing (co)polymer modified with a low halogen atom content (less than 35% by weight). Modification step (d) is carried out in any known batch or continuous prior art equipment. Suitable equipment includes, but is not limited to, a continuous stirred-tank reactor, a batch stirred-tank reactor, or an autoclave with a mixer, all of which are designed to work with highly corrosive media. Preferably, the modification step d) of the (co)polymer containing partially halogenated diene is carried out without exposure to light, e.g., by carrying out the modification procedure in dark glass containers, wrapping the reactor with thin metal foil, or carrying out the procedure in metallic reactors to reduce the likelihood of non-selective photocatalytic halogenation reactions. The modification step d) is carried out at a temperature of 0 to 50°C, preferably 20 to 45°C, more preferably 30 to 40°C, and under atmospheric pressure. The stirring speed of the reaction mass after the addition of the modification system is 50 to 600 rpm, preferably 100 to 500 rpm, more preferably 200 to 300 rpm. The modification step (d) may be carried out for any time sufficient to achieve the required degree of modification of the partially halogenated diene-containing (co)polymer, as described above. Preferably, the modification step (d) should be carried out for at least 15 minutes, at least 20 minutes, at least 25 minutes, at least 30 minutes, at least 45 minutes, at least 60 minutes, or at least 120 minutes. The mass obtained after modification step d) contains the target product, i.e., the modified diene-containing (co)polymer. Neutralization and separation step e) Step e) involves neutralizing the reaction mass obtained in step d) containing the modified diene-containing (co)polymer by adding a solution of a neutralizing agent, followed by washing the neutralized reaction mass with water, and separating an aqueous layer and an organic layer containing the modified diene-containing (co)polymer. As the neutralizing agent in step (e), known aqueous basic solutions of the prior art are used, for example, aqueous solutions of sodium hydroxide, sodium thiosulfate, sodium bisulfite, or sodium carbonate, but are not limited to them. Preferably, aqueous sodium hydroxide solution is used. A molar ratio of an amount of neutralizing agent to an amount of halogen added in step d) is usually 1:1 to 3:1, preferably 1:1 to 2:1, more preferably 1:1. Preferably, the neutralization procedure is carried out at a temperature of 15 to 50°C, preferably 20 to 40°C, more preferably 25 to 30°C, and under atmospheric pressure. Washing with water is carried out using an excess of water of at least once, preferably at least twice, more preferably at least three times relative to the volume of the reaction mass undergoing neutralization, resulting in the separation of the reaction mass into two layers - an organic layer containing a modified diene-containing (co)polymer, and an aqueous layer. The separation of the organic layer and the aqueous layer is carried out using any equipment known from the prior art, for example, using a separating funnel, separator, or sedimentation tank. Isolation step f) In the embodiment of the present invention involving the precipitation of the modified diene-containing (co)polymer resulting from isolation step f), an alcohol precipitant is added to an organic layer containing the modified diene-containing (co)polymer at a mass ratio of alcohol precipitant to modified (co)polymer on the scale of 15:1 to 1:1, preferably 10:1 to 3:1, more preferably 5:1 to 4:1. Suitable alcohol precipitants used in step f) are, but are not limited to, aliphatic alcohols having 1 to 4 carbon atoms. Examples of these alcohols are, but are not limited to, methanol, ethanol, propanol, isopropanol, butanol, and isobutanol. Preferably, methanol and ethanol are used as the alcohol precipitant. In another embodiment of the present invention, which involves degassing the modified diene-containing (co)polymer resulting from isolation step f), water is added to the organic layer obtained in step e), followed by distillation of a water-solvent mixture at high temperature and under reduced pressure to isolate the target modified diene-containing (co)polymer, and remove water and / or vapors thereof and the solvent and / or vapors thereof. In the context of the present invention, water is, but is not limited to, distilled, deionized, demineralized, osmotic or double-distilled water. In this case, the volume ratio of the water added to the organic layer in the isolation step f) is 5:1 to 0.1:1, preferably 3:1 to 1:1, more preferably 2:1. According to the present invention, the temperature of the water when added to the system in step f) is not more than 30°C, preferably not more than 25°C, more preferably not more than 20°C. When water with a temperature above 30°C is used, boiling and subsequent abrupt evaporation of the solvent occur, which frequently results in an undesirable change in the physical and mechanical characteristics of the resulting modified diene-containing (co)polymer. The degassing in step f) is carried out in any suitable equipment known from the prior art, in particular, in apparatus that provides good mixing, heat exchange, and maintenance of reduced pressure. Examples of such apparatus include, but are not limited to, continuous or intermittent apparatus equipped with a jacket and a mixer. The temperature of the degassing step is 20 to 150°C, preferably 50 to 100°C, very preferably 80 to 95°C. The pressure in the degassing step is maintained at a level of less than 800 mbarias, preferably less than 300 mbarias, more preferably less than 100 mbarias. Preferably, the duration of the degassing step in step f) is at least 30 minutes, more preferably at least 60 minutes, very preferably at least 120 minutes. After carrying out isolation step f), the filtration and drying step of the target modified diene-containing (co)polymer is performed. Filtration and drying step a) In the filtration and drying step g), in order to purify the modified diene-containing (co)polymer from the solvent residues and the alcohol precipitant, filtration is carried out in any apparatus known from the prior art, e.g., in filters equipped with porous filter partitions, Nutsch filters and similar devices. The filtration of the modified diene-containing (co)polymer is carried out at a temperature of 20 to 40°C inclusive. In order to remove water and / or water vapors, a solvent and / or solvent vapors from the resulting modified diene-containing (co)polymer residue, said (co)polymer / co / nn / Lznz / E / YiAi is dried. The drying procedure of the modified diene-containing (co)polymer can be carried out using physical methods commonly employed for separating and purifying organic substances (solvent distillation under reduced pressure, drying in a vacuum drying oven), as well as using drying agents that remove moisture through adsorption, hydrate formation, or a chemical reaction with water and solvents. Preferably, drying is carried out at a temperature of 50 to 105°C and a pressure of 1 to 20 kPa. The invention is clarified in Figure 1, which shows a flow diagram for preparing a modified diene-containing (co)polymer, wherein 101 is a dissolving unit of a starting diene-containing (co)polymer, 102 is a partial halogenation unit of the dissolved starting diene-containing (co)polymer, 103 is a washing and separation unit, 104 is a modification unit of a partially halogenated diene-containing (co)polymer, 105 is a neutralization and separation unit, 106 is an isolation unit, 107 is a filtration unit, and 108 is a drying unit. According to the presented method, the starting diene-containing (co)polymer (1), if necessary, is ground into the dissolution unit 101, where it is mixed with an organic solvent (2) to obtain a solution of the starting diene-containing (co)polymer. This solution of (co)polymer (3) is then passed to the partial halogenation unit 102, where a halogenating agent (4) and, optionally, an aliphatic alcohol (5) are also supplied. Following this, the partially halogenated diene-containing (co)polymer (6) obtained in unit 102 is directed to the washing and separation unit 103, where water (7) is fed. The organic layer (9) containing the partially halogenated diene-containing (co)polymer and an aqueous layer (8) are then separated.The organic layer (9) containing the partially halogenated diene-containing (co)polymer is then fed to the modification unit 104, which is also fed with a modification system (10) and an aliphatic alcohol (11). Following this, the modified diene-containing (co)polymer (12) obtained in unit 104 is sent to the neutralization and separation unit 105, which is supplied with a neutralizing agent (15) followed by a water supply (14) to wash the neutralized reaction mass. The organic layer (16) containing the modified diene-containing (co)polymer is then separated from the aqueous layer (15). The organic layer (16) containing the modified diene-containing (co)polymer is then sent to the isolation unit 106 to isolate the modified diene-containing (co)polymer.The sequentially isolated modified diene-containing (co)polymer (17, 18) is then fed to filtration unit 107 and drying unit 108 to obtain the final product, namely the modified diene-containing (co)polymer (19). The method for preparing the modified diene-containing (co)polymer / co / nn / Lznz / E / YiAi may also comprise an organic solvent regeneration unit with subsequent recirculation of the starting diene-containing (co)polymer into the dissolution unit 101 (not shown in Figure 1). The flowchart presented in Figure 1 is an example of the embodiment of the present invention, and does not limit it. A further aspect of the present invention is the use of the modified diene-containing (co)polymer obtained according to the present invention as a flame retardant in various polymers and polymer compositions, for example, based on expandable polystyrene, to impart flame-retardant properties. In this case, the flame retardants are compatible with the polymer or polymer composition. According to the present invention, the modified diene-containing (co)polymer is introduced into the expandable polystyrene in the preparation step thereof according to a method comprising the production of polystyrene by polymerizing styrene in the presence of a polymerization initiator, a polymerization stabilizer and other technological additives, followed by the expansion of the prepared polystyrene (see, for example, US patent 5086078). At the same time, the amount of the modified diene-containing (co)polymer used as the flame retardant should not be less than 0.5 parts by weight, preferably not less than 0.7 parts by weight, more preferably not less than 1 part by weight; otherwise, the efficiency in improving the flame-retardant characteristics of the resulting expandable polystyrene is reduced. Furthermore, an additional aspect of the present invention is the expandable polystyrene that includes traditional additives that ensure the achievement of the necessary complex of technological, physical-mechanical and operational characteristics, such as antistatic agents, stabilizers, colorants, lubricants, fillers and adhesion-reducing agents. According to the present invention, expandable polystyrenes are used for the production of a wide range of articles, such as heat and sound insulation in buildings, in particular, heat and sound insulation boards, fixed formwork, automotive components and floating articles, as well as raw materials for polystyrene foam blocks required in the construction of roads and bridges, and the packaging of household appliances.These expandable polystyrenes contain, as a flame retardant, the modified diene-containing (co)polymer according to the present invention, since said modified diene-containing (co)polymer is characterized by having high thermostability, in particular, a 5% weight loss temperature of at least 180°C, measured by thermogravimetric analysis, and does not affect the polymerization process and granule formation of the polystyrene, as confirmed by the granulometry of the prepared polystyrene. Furthermore, the flame retardant obtained according to the present invention imparts flame-retardant properties to the expandable polystyrene without affecting its other characteristics and properties. The modified diene-containing (co)polymer obtained according to the present invention also allows for the production of polystyrene granules with a yellowness index of 2 to 6 units, preferably less than 6 units, more preferably less than 5 units, and most preferably less than 3 units, comparable to the yellowness index of polystyrene granules containing HBCD (0 to 3 units). The method for determining the yellowness index of the polystyrene granules is presented later. Furthermore, the flame retardant obtained in accordance with the present invention imparts flame retardant properties to the expandable polystyrene, which makes it possible to classify the expandable polystyrene, containing the proposed flame retardant in accordance with the present invention, as moderately flammable materials with flammability class B2 (in accordance with clause 7 of article 13 of Technical Rules on Flame Safety Requirements (Federal Act No. 123 dated July 22, 2008, amended July 29, 2017). The invention is described more specifically in the examples below. These examples are given only to illustrate the present invention and do not limit it. Modalities of the invention Research methods for a modified diene-containing (co)polymer Thermoravimetric analysis (TGA) To determine the thermal stability of the resulting modified diene-containing (co)polymer, a 5% weight loss temperature was measured by studying the thermal behavior of (co)polymer samples using the simultaneous thermal analysis (STA) method (the combined methods of differential scanning calorimetry (DSC) and thermogravimetry (TG)) in accordance with ISO 11358 using the STA 449 Jupiter NETZSCH apparatus. Experimental conditions: the inert atmosphere (argon) on the temperature scale of 30°C to 600°C, and a heating rate of -10°C / min. / co / nn / Lznz / E / YiAi Nuclear magnetic resonance (NMR) method The microstructure of a polymer chain from modified diene-containing (co)polymer samples was determined by hydrogen nuclei NMR spectroscopy using a Bruker Avance III instrument (400 MHz). A 30 mg sample was dissolved in 0.6 mL of deuterated chloroform to prepare the solution for the study. The number of scans performed on the hydrogen nuclei was 32. Gel permeation chromatography (GPC) The molecular mass characteristics of the starting diene-containing (co)polymer and modified diene-containing (co)polymer samples were determined by the low-temperature GPC method in accordance with ISO 16014-3 on an Agilent 1200 liquid chromatography system with a refractometric detector. Conditions for analysis: the eluent is tetrahydrofuran; the dissolution and measurement temperature is 40°C; the eluent flow rate is 1.0 mL / min; and the column is PLgel Mixed-C (2 to 3 pieces). The calculation was carried out according to relative calibration using polystyrene standards (EasiVial PS-H 4 mL, Agilent Technologies) with the Mark-Houwink constants K = 0.000374, a = -0.699 for a (co)polymer. Gas chromatography and mass spectrometry (GC-MS) The identification of the components of an impurity that gives color to polystyrene was carried out by the gas chromatography-mass spectrometry (GC-MS) method using the Agilent 7890 / 5975 GC-MS apparatus: Analysis conditions: DB-5 capillary column (30 m x 0.25 mm x 0.25 pm); evaporator temperature is 290°C; column thermostat initial temperature is 50°C (1 minute isotherm); heating rate is 5°C / min; column thermostat final temperature is 310°C (20 minute isotherm); carrier gas is helium; carrier gas flow rate is 1 ml / min; split ratio is 200:1; and injection volume is 0.2 μL. Polystyrene granulometry The particle size distribution of the polystyrene powder was determined using a HAVER EML digital plus test sieve shaker. A series of sieves with cell diameters of 2.0, 1.6, 1.0, 0.70, 0.40, and 0.20 mm were used for sieving. The sieving time was 15 minutes. The mass of the powder on the sieves was determined using the gravimetric method. / co / nn / Lznz / E / YiAi Determination of the yellowness index of polystyrene granules The determination of the yellowness index of polystyrene granules containing a flame retardant was carried out by spectroscopy in the visible spectral region on an SP62 X-Rite spectrophotometer in accordance with ASTM D 6290-13. Conditions for conducting the tests: A test tube for samples was filled to the brim with granules from the samples. The filled tube was placed in the center of the sensor port for measurement. The sample tube was covered with an opaque, non-light-protective device or cover. Light source: D65 (daylight), viewing angle of -10°, taking into account reflected light (spin). To determine the yellowness index, the required readings were obtained from the three-color diagram X, Y, Z. The number of parallel measurements was 3. The yellowness index value was obtained in accordance with ASTM E 3013-10. Compression of polystyrene samples The samples were pressed in a Collin hydraulic press with a force of 300 kN. The sample was previously kept in a drying oven at a temperature of 50°C. The compression of the samples was carried out for 18 minutes, with gradual heating to 190°C over 5 minutes at a pressure of 50 bar; the sample was then held at 50 bar at 190°C for 3 minutes. Subsequently, the sample was cooled to 40°C under a pressure of 50 bar for 10 minutes. Flame resistance test The determination of the flame resistance of expandable polystyrene samples containing a flame retardant was carried out in accordance with TT 2214-01953505711-2010. Sample preparation: 40 mm was cut from a molded article and this portion was discarded. Then, 5 samples were cut with dimensions of (190 ± 1) x (90 ± 0.5) x (20.0 ± 0.5) mm, ensuring that no processing film, cracks, chips, or cavities would form during block formation. The bottom edge of the sample should be cut uniformly with sharp edges and form right angles with the side edges. The method is based on determining the height of the flame of the combustion sample, for 20 seconds after the removal of the flame source. Test preparation: The device was prepared and configured for operation. Ventilation was turned off in a chamber. Air velocity was measured using a thermal anemometer in the exhaust pipe of the test chamber. The required value is 0.5 to 0.8 m / s. Before testing, the samples were conditioned for at least 14 days at a temperature of (23 ± 5)°C, and the relative humidity of the air (50 ± 20)% at a constant mass. Next, a mark was placed on the sample 150 mm from the bottom edge on both the front and back sides. The samples were then hung vertically in the combustion chamber in a mount with the measurement mark facing upwards, and the bottom edge aligned with the mark on the tripod support. The mount with the sample was then moved vertically so that the flame-stabilizing nozzle made contact along the bottom edge of the sample. The burner was then lit and the flame was adjusted using a mold held from the side, so that the height of the flame with a yellow glow was (20 ± l)mm. Before each exposure of the flame to the sample, the height of the flame was checked. Two layers of filter paper were placed in a wire box under the sample at the bottom of the test chamber. Test performance: The combustion chamber was sealed. Laterally, at the center of the free end (edge) of the sample, the burner was positioned with the flame at a 45° angle, and a stopwatch was started. The sample was exposed to the flame for 15 seconds, after which the burner was removed, and the combustion of the sample was observed. Simultaneously, the time was measured from the start of flame exposure until the top of the flame reached the measured mark of 150 mm, provided the flame did not extinguish itself. The tests were stopped after 20 seconds (from the start of flame processing of the sample), and the maximum flame height and dripping (falling of combustion fragments) were estimated. The test is considered complete if, for each of the 5 samples tested, the top of the flame of the combustion sample does not pass beyond the measuring mark before the twentieth second expires, and when the combustion drops (falling out of the combustion fragments) fall onto the filter paper for no more than 2 seconds, not resulting in combustion of the filter paper. / co / nn / Lznz / E / YiAi HEMEtOl temtraLfcg££ÍanosjLdfi^^ In a dark glass flask with a volume of 500 ml, a solution of a starting styrene-butadiene copolymer in dichloromethane (5 g of the copolymer per 50 g of dichloromethane) is added. Then, 15 g of butane and a solution of tetraethylammonium bromide in dichloromethane (12.96 g of tetraethylammonium bromide per 143 g of dichloromethane) are added to the flask. Next, a solution of bromine in dichloromethane (9.56 g of bromine per 9.56 g of dichloromethane) is dosed into the flask, and the solution is stirred for 30 minutes at 35°C. The reaction mixture is then washed with a three-fold excess of distilled water. After that, the aqueous layer is drained, and an organic layer containing a partially brominated styrene-butadiene copolymer is loaded into a 500 ml dark glass flask equipped with a stirrer, and stirring is started. Then, a modification system (0.3 g of bromine and 8.3 g of water) is added to the flask, and the contents are stirred for 30 minutes at 35°C. When the reaction is complete, a sodium hydroxide solution is added to the flask, and neutralization is carried out for 60 minutes. The reaction mass is then washed with three times the volume of water, followed by precipitation of the resulting modified styrene-butadiene copolymer with isopropyl alcohol. The resulting modified styrene-butadiene copolymer is then dried by distilling the solvent at 30–95°C and 3 kPa, followed by further drying in a vacuum drying oven at 70°C and 0.5 kPa. Table 1 presents the characteristics of the modified styrene-butadiene copolymer that is free of tertiary bromides and allyl and obtained in accordance with Example 1. The Ή NMR spectrum of the resulting modified styrene-butadiene copolymer is shown in Figure 2. X-ray NMR spectrum (CDCb, δ, ppm): 7.2-6.3 (styrene); 4.6-3.7 (brominated butadienes); 3.6 (hydroxyl groups); 3.9-3.7 (hydroxyl groups); 3.0-2.7 (epoxy groups). / co / nn / Lznz / E / YiAi EMEI 2 Preparation of a modified styrene-betadiene polymer containing chlorophyll bromides In the example, the preparation of the modified styrene-butadiene copolymer is carried out by combining partial halogenation with the modification step. In a 500 ml dark glass flask, a solution of the starting styrene-butadiene copolymer in dichloromethane (5 g of copolymer per 50 g of dichloromethane) is added. Then, 15 g of butanol, 2.5 g of water, and a solution of tetraethylammonium bromide in dichloromethane (12.96 g of tetraethylammonium bromide per 143 g of dichloromethane) are added to the flask. A solution of bromine in dichloromethane (9.56 g of bromine per 9.56 g of dichloromethane) is added to the flask, and the solution is stirred for 30 minutes at 35°C. When the reaction is complete, a solution of sodium hydroxide is added to the flask, and neutralization is carried out for 60 minutes.The reaction mass is then washed with a three-times excess volume of distilled water, followed by precipitation of the resulting modified styrene-butadiene copolymer, which is free of tertiary bromides and comprises allyl bromides, in isopropyl alcohol, and the solvent is distilled at a temperature of 30-95°C and a pressure of 3 kPa, followed by further drying in a vacuum drying oven at 70°C and under 0.5 kPa. The characteristics of the product obtained in accordance with example 2 are presented in table 1. The 'H NMR spectrum of the resulting modified styrene-butadiene copolymer is shown in Figure 3. X-ray NMR spectrum (CDCb, δ, ppm): 5.5-6.4 (styrene); 5.2-4.8 (allyl bromide); 4.6 (1,4-butadiene); 4.4 (1,2-butadiene); 3.6-2.8 (brominated butadienes); 2.8-3.0 (hydroxyl groups); 2.4-2.1 (epoxy groups). ElEMELOl Preparation of a modified styrene-butadiene cosalymer containing tertiary bromates (comparative) In the example, the modified styrene-butadiene copolymer is obtained without the preliminary partial halogenation. In a dark glass flask with a volume of 250 ml, a solution of the starting styrene-butadiene copolymer in dichloromethane (10 g of rubber per 150 g of dichloromethane) is added. Then, 30 g of butanol and 7.6 g of water are added to the flask, followed by a solution of 17.74 g of bromine in 20 ml of dichloromethane. The modification reaction is carried out for 30–40 minutes. When the reaction is complete, a sodium hydroxide solution is added to the flask, and neutralization is carried out for 60 minutes. The reaction mass containing the modified styrene-butadiene copolymer is then washed with a three-fold excess of distilled water. The resulting modified styrene-butadiene copolymer is then filtered, followed by precipitation of the same with isopropanol, after which it is dried by distilling the solvent at a temperature of 30-95°C and a pressure of 3 kPa, followed by further drying in a vacuum drying oven at 70°C and under 0.5 kPa. The characteristics of the product obtained in accordance with example 3 are presented in table 1. The Ή NMR spectrum of the resulting modified styrene-butadiene copolymer is shown in Figure 4. Η NMR spectrum (CDCh, δ, ppm): 5.4-6.4 (styrene); 4.6-4.8 (1,4-butadiene); 4.4 (1,2-butadiene); 2.8-3.6 (brominated butadienes); 2.8 (hydroxyl groups); 2.6 (tertiary bromides); 1.9-2.3 (epoxy groups). EXAMPLE 4 .te^aradón de de aíslo (comparative) The preparation of a modified styrene-butadiene copolymer is carried out in accordance with the procedure described in Example 1, and except for step c), the additional washing and separation step is not performed. Table 1 presents the characteristics of the modified styrenebutadiene (co)polymer comprising allyl bromides and obtained in accordance with Example 4. / co / nn / Lznz / E / YiAi TABLE J. Unit content, % by weight | Nitrogen bromide 9.78 - 7.51 Tertiary bromide IXJ LO Epoxybutadiene 0.05 0.78 0.04 Hydroxybutadiene 0.13 90.0 0.53 0.11 Bromobutadiene 76.92 56.76 76.32 61.42 1,4-butadiene 0EE 1,2-butadiene 2.19 6.05 5.53 Styrene 20.20 27.02 20.85 24.88 Decomposition temperature (5% weight loss), °C 241 230 220 231 Weight average molecular weight 103, g / mol 100 08 120 100 Example No. Example 1 Example 2 Example 3 Example 4 / co / nn / Lznz / E / YiAi HEMELOS Preparation of expandable polystyrene: 0.43 parts of water and 0.43 parts of a polymerization stabilizer (a mixture of sodium pyrophosphate and magnesium sulfate) are mixed in a flask at a temperature of 25°C. A mixture of 100 parts of styrene, 0.46 parts of a mixture of polymerization initiators (benzoyl peroxide and tert-butyl perbenzoate), 0.62 parts of a flame retardant, prepared in accordance with Examples 1 and 3, and 0.21 parts of a flame retardant synergist, namely dicumyl peroxide, are added to this mixture after stirring. The mixture is stirred for 2 hours at a temperature up to 85°C, and then heated to 115°C for 4.5 hours. 70 minutes after the temperature in the flask reaches 80°C, a 10% aqueous solution of polyvinylpyrrolidone is added to the reaction mixture. After another 100-120 minutes, a solution of 0.10 parts of a chain transfer agent is added to the reaction mass.7 parts of an expanding agent, namely n-heptane, to expand the polystyrene. After reaching 115°C, the flask is kept at a constant temperature for 3 hours, after which the mixture is cooled to a temperature of 25°C for 3 hours. The expanded polystyrene granules containing the flame retardant according to Example 3 have a yellowish tint (Table 2). The inventors of the present invention presumably associate this with the fact that during the high-temperature expansion step of the polystyrene at 115°C, bromine radicals begin to be released from unstable positions of the flame retardant molecule, in particular, from the allyl and / or tertiary positions. At the same time, presumably, the bromine radicals catalyze chain-radical oxidation of the aromatic rings in the system in the presence of peroxides, resulting in the formation of small amounts of parabenzoquinone (approximately 0.89 wt%), the formation of which is detected by gas chromatography-mass spectrometry (GC-MS).At the same time, the starting styrene did not contain hydroquinone (a tert-butylpyrocatechin stabilizer). Para-benzoquinone is colored bright yellow, so at a low concentration it imparts the yellowish color to the final product. Table 2 presents the results of the comparison of the yellowness index (average yellowness index) for expanded polystyrene granules, containing flame retardants in accordance with Examples 1 and 3, and HBCD. / co / nn / Lznz / E / YiAi »DRD2 Comparison of the yellowness index of expanded polystyrene granules that Ώ0Ώ3Ρ£®Μ§ιη^^ / co / nn / Lznz / E / YiAi Flame retardant average yellowness index HBCD 1.42-2.1 Example 1 3 Example 3 7.36 The particle size distribution of the polystyrene obtained before the expansion step was also determined. The results of the particle size distribution determination are presented in Table 3. TABLE 3 GraiwlomettiaJeL&gliestta Example 5 Flame retarder (according to the example) Sieve No. Example 1 Example 2 Example 3 Example 4 2.00 2.48 11.22 0.08 9.81 1.60 25.22 22.16 1.85 20.13 1.00 65.59 41.58 62.27 44.51 0.70 5.31 17.15 25.59 17.43 0.40 1.21 7.27 8.51 5.35 Smallest size eli 0.19 0.62 2.70 2.77 Sum of target fractions (1.60+1.00+0.70) 96.12 80.89 89.71 82.07 It is obvious to those skilled in the art from the data presented in Table 1 that the brominated hydroxy-epoxy styrene-butadiene copolymer obtained in Example 1, which is free of tertiary and allyl bromides, has better thermostability than the brominated hydroxy-epoxy styrene-butadiene copolymers comprising tertiary or allyl bromides in their structure (Examples 2 to 4). Without wishing to be limited to any particular theory, the inventors of the present invention believe that the presence of a significant amount of water in the reaction system during the halogenation step results in the formation of allyl halides, which, in turn, result in a decrease in the thermostability of the resulting modified (co)polymer.The presence of two types of functional groups, in addition to halogen atoms, in the modified diene-containing (co)polymer allows for the resolution of several problems. Specifically, the epoxy groups act as HBr absorbers, which, as mentioned earlier, can be released during the processing of polymers and polymer compositions containing a flame retardant at high temperatures. In turn, the hydroxyl groups impart a polar and hydrophilic character to the (co)polymer. As a result, after the introduction of a flame retardant into the styrene suspension polymerization process, a stable suspension is formed. The styrene polymerization process proceeds without deviation due to the complex influence of three types of functional groups: an epoxy group, a hydroxyl group, and halogen atoms, all present in the modified diene-containing (co)polymer. This results in improved distribution of the flame retardant within the suspension during styrene suspension polymerization, enabling the production of polystyrene particle sizes that meet consumer requirements. Furthermore, the flame retardant obtained according to the present invention is characterized by the preferential absence of tertiary and / or allyl halides in its structure, which also results in increased thermostability of the resulting flame retardant. This, in turn, is characterized by the absence of halogen radicals, which at high temperatures, including those in the polystyrene expansion process, can be released from all unstable positions, particularly the tertiary and / or allyl positions, and enter into radical reactions. This can result in the appearance of chromaticity in the expanded polystyrene compared to expanded polystyrene containing HBCD. This is confirmed by comparing the chromaticity of polystyrene granules containing HBCD and polystyrene granules containing the flame retardant according to the present invention. It is clear from the data presented in Table 2 that the introduction of the brominated hydroxy-epoxy styrene-butadiene copolymer obtained in Example 1, which is free of tertiary bromides and allyl, has a significantly smaller effect on the chromaticity of the resulting polystyrene granules. The hydroxy-epoxy-brominated styrene-butadiene copolymers obtained in accordance with Examples 1 to 4, when incorporated into polystyrene, do not affect the granulometry, a stable suspension is formed, and granules of the required size are obtained, which fully satisfy TT 2214-019-53505711-2010 (Table 3).

Claims

1. A modified diene-containing (co)polymer, wherein a 5% weight loss temperature is at least 180°C, having an average molecular weight of at least 1500 g / mol and a halogen content of at least 35% by weight, characterized in that its structure comprises in addition to halogen atoms at least one epoxy group, at least one hydroxyl group, and 0 to less than 1.5% by weight of tertiary and / or alloy halides.

2. The (co)polymer containing modified diene according to claim 1, further characterized in that the stated (co)polymer has a 5% weight loss temperature of at least 220°C, preferably at least 240°C.

3. The (co)polymer containing modified diene according to claim 1, further characterized in that the (co)polymer has a weight average molecular weight of 2000 to 280000 g / mol, preferably 10000 to 150000 g / mol, more preferably 60000 to 100000 g / mol.

4. The (co)polymer containing modified diene according to claim 1, further characterized in that the halogen atom content is at least 60% by weight, preferably at least 75% by weight.

5. The (co)polymer containing modified diene according to claim 1, further characterized in that the content of epoxy groups is from 0.01 to 5% by weight, preferably from 0.05 to 3% by weight, more preferably from 1 to 2% by weight.

6. The (co)polymer containing modified diene according to claim 1, further characterized in that the content of hydroxyl groups is from 0.05 to 5% by weight, preferably from 0.1 to 3% by weight, preferably from 0.15 to 1% by weight.

7. The (co)polymer containing modified diene according to claim 1, further characterized in that the content of tertiary halides and / or allyl is from 0 to less than 1% by weight, preferably from 0 to less than 0.5% by weight.

8. The (co)polymer containing modified diene according to any of claims 1 to 7, further characterized in that it is a modified butadiene polymer, styrene-butadiene copolymer, or styrene-butadiene-isoprene copolymer, preferably a modified styrene-butadiene copolymer.

9. The (co)polymer containing modified diene according to any of claims 1 to 8, further characterized in that the halogen in the structure of the (co)polymer containing modified diene is iodine, bromine, or iodine, preferably bromine. / co / nn / Lznz / E / Yii 10. The (co)polymer containing modified diene according to any of claims 1 to 9, further characterized in that it has the general formula (1): / co / nn / Lznz / E / YiAi wherein R1-R4 are the same or different, and may represent hydrogen or a hydrocarbon group having from 1 to 6 carbon atoms, in particular, an alkyl group; Hal is halogen; n is a number of polymer chain units which is l <n<400, de preferencia 100<n<350, más preferiblemente 140<n<250; y k, m, I, p, o y q pueden ser iguales o diferentes, y constituyen l<k<37, 0<m<19, 2<(l+p)<3660, 0<o<8, 0<q<8, de preferencia 6<k<12, 3<m<6, 610<(l+p)<1220, 0<o<5, 0<q<5, más preferiblemente 7<k<10, 4<m<5, 730<(l+p)<980, o=0, q=0.

11. A method for producing a modified diene-containing (co)polymer, comprising the following steps: a) a dissolution step, comprising dissolving a starting diene-containing (co)polymer in an organic solvent; b) a partial halogenation step, comprising using a halogenating agent and optionally an aliphatic alcohol to partially halogenate the diene-containing (co)polymer to a degree of halogenation of at least 60%; c) a washing and separation step, comprising adding water to a reaction mass obtained in step b) followed by the separation of an aqueous layer and an organic layer; d) a modification step, comprising adding the components of a modification system and optionally an aliphatic alcohol to the organic layer obtained in step c) comprising a partially halogenated diene-containing (co)polymer;e) a neutralization and separation step, comprising adding an aqueous solution of a neutralizing agent to the reaction mass obtained in step d) followed by the separation of an aqueous layer and an organic layer; f) an isolation step, comprising precipitating or degassing a modified diene-containing (co)polymer; and g) a filtration and subsequent drying step, comprising filtering and drying the isolated modified diene-containing (co)polymer, characterized in that in the partial halogenation step b) the permissible water content in the system is from 0 to less than 0.5% by weight, and in the modification step d) the modification system is a mixture of halogen and water at a halogen:water ratio of 1:0.01 to 1:1, due to the total number of double bonds in the starting diene-containing (co)polymer. 12.- The method according to claim 11, further characterized in that in the partial halogenation step b) the permissible water content in the system is from 0 to less than 0.3% by weight, preferably from 0 to less than 0.1% by weight.

13. The method according to claim 11, further characterized in that a starting diene-containing (co)polymer is represented by polymers and copolymers of a conjugated diene. 14.- The method according to claim 13, further characterized in that the conjugated diene is a conjugated diene selected from the group consisting of 1,3-butadiene, 2-methyl-1,3-butadiene (isoprene), 2-ethyl-1,3-butadiene, 2,3-di(Cl-C5 alkyl)-1,3-butadienes, such as 2,3-dimethyl-1,3-butadiene, 2,3-diethyl-1,3-butadiene, 2-methyl-3-ethyl-1,3-butadiene, 2-methyl-3-isopropyl-1,3-butadiene, phenyl-1,3-butadiene, 1,3-pentadiene, 2,4-hexadiene, 2-methyl-pentadiene, 4-methyl-pentadiene, or mixtures thereof, preferably 1,3-butadiene or isoprene.

15. The method according to claim 13, further characterized in that vinylaromatic compounds selected from the group consisting of styrene, amethystyrene, ortho-, meta- and para-methylstyrene, 3-vinyltoluene, ethylvinylbenzene, 4-acidohexylstyrene, para-tert-butylstyrene, methoxystyrenes, vinylmesitylene, divinylbenzene, 1-vinylnaphthalene and 2,4,6-trimethylstyrene, or a mixture thereof, preferably styrene or α-methylstyrene, are used as a comonomer in the starting diene-containing (co)polymer. 16.- The method according to claim 11, further characterized in that the starting diene-containing (co)polymer is a butadiene polymer, styrene-butadiene copolymer or styrene-butadiene-isoprene copolymer, preferably a styrene-butadiene copolymer.

17. The method according to claim 11, further characterized in that the starting diene-containing (co)polymer has a weight average molecular weight of at least 700 g / mol, preferably 1000 to 400000 g / mol, more preferably 2000 to 300000 g / mol, more preferably 5000 to 200000 g / mol, more preferably 20000 to 120000 g / mol, and most preferably 20000 to 50000 g / mol. 18.- The method according to claim 11, further characterized in that the starting diene-containing (co)polymer has a polldispersity index of 0.8 to 3, preferably 1 to 1.8, more preferably 1.1 to 1.

5.

19. The method according to claim 11, further characterized in that the 1,2-unit content in the starting diene-containing (co)polymer is at least 10 to 100% by weight, preferably at least 50 to 99% by weight, more preferably 60 to 80% by weight of a polybutadiene (co)polymer portion. / co / nn / Lznz / E / YiAi 20.- The method according to claim 11, further characterized in that organic solvents representing ethers such as tetrahydrofuran, halogenated saturated aliphatic hydrocarbons such as carbon tetrahydrogen, chloroform, dibromomethane, dichloromethane, 1,2-dichloroethane, dehydroaliphatic hydrocarbons such as cyclohexane, aromatic hydrocarbons such as toluene, halogenated aromatic hydrocarbons such as bromobenzene, chlorobenzene and dichlorobenzene, are used as a solvent in the dissolution step a). 21.- The method according to claim 20, further characterized in that tetrahydrofuran, chloroform, dichloromethane, dichloroethane, cyclohexane or toluene, preferably tetrahydrofuran, chloroform, dichloromethane, are used as a solvent in the dissolution step a).

22. The method according to claim 11, further characterized in that a weight ratio of an organic solvent to a starting diene-containing (co)polymer in the dissolution step a) is from 5:1 to 30:1, preferably from 8:1 to 20:1, more preferably from 10:1 to 15:

1. 23.- The method according to claim 11, further characterized in that a degree of halogenation in the partial halogenation step b) is at least 90%, preferably at least 95%.

24. The method according to claim 11, further characterized in that in the partial halogenation step b) chlorine, bromine or iodine is preferably used as a halogen in a halogenating agent.

25. The method according to claim 11, further characterized in that a halogenating agent is bromine as such, in a solution comprising no more than 70% by weight of bromine, preferably no more than 60% by weight, more preferably no more than 50% by weight, of quaternary ammonium bromides or quaternary phosphonium bromides, or mixtures thereof.

26. The method according to claim 25, further characterized in that elemental bromine and quaternary ammonium bromides such as phenyltriethylammonium bromide, benzyltrimethylammonium bromide, tetramethylammonium bromide, tetraethylammonium bromide, tetrapropylammonium bromide, tetra-n-butylammonium bromide, or mixtures thereof, are used as a quaternary ammonium bromide or quaternary phosphonium bromides such as tetramethylphosphonium bromide, tetraethylphosphonium bromide, tetrapropylphosphonium bromide, tetra-n-butylphosphonium bromide, or mixtures thereof, are used as a quaternary phosphonium bromide and are preferably used simultaneously as a halogenating agent. 27.- The method according to claim 11, further characterized in that a molar ratio of a starting diene-containing (co)polymer: halogenation agent: aliphatic alcohol is from 1:1.5:3 to 1:5:3, preferably from 1:2:3 to 1:4:3, more preferably from 1:2.5:3 to 1:3:

3. 28.- The method according to claim 11, further characterized in that a molar ratio of elemental bromine: bromine atoms in the quaternary ammonium bromide or quaternary phosphonium bromide is from 1:1 to 1:4, preferably from 1:2 to 1:3, and more preferably from 1:1 to 1:1.

5.

29. The method according to claim 11, further characterized in that methane, ethanol, propanol, isopropanol, butanol, isobutanol, pentanol or hexanol are used as an aliphatic alcohol in step b) of brown halogenation.

30. The method according to claim 11, further characterized in that the partial halogenation step b) is carried out at a temperature of 0 to 50°C, preferably 20 to 45°C, more preferably 30 to 40°C.

31. The method according to claim 11, further characterized in that in the partial halogenation step b) a stirring speed of the reaction mass after the addition of the halogenating agent is 50 to 600 rpm, preferably 100 to 500 rpm, more preferably 200 to 300 rpm. 32.- The method according to claim 11, further characterized in that the conduction time of the partial halogenation step b) is at least 15 minutes, at least 20 minutes, at least 25 minutes, at least 30 minutes, at least 45 minutes, at least 60 minutes, at least 120 minutes. 33.- The method according to claim 11, further characterized in that in the washing and separation step c) the permissible residual content of the halogenating agent in the organic layer after washing with water is 0 to 0.5% by weight, preferably 0 to 0.1% by weight, more preferably 0 to 0.01% by weight. 34.- The method according to claim 11, further characterized in that a halogen:water ratio in a modification system in step d) is from 1:0.5 to 1:0.7, preferably from 1:0.25 to 1:0.

7.

35. The method according to claim 11, further characterized in that chlorine, bromine or iodine, preferably bromine, is used as a halogen in the modification system in step d).

36. The method according to claim 11, further characterized in that the bromine in the modification system of step d) is used in the form of bromine as such, or in the form of a solution comprising no more than 70% by weight of bromine, preferably no more than 60% by weight, more preferably no more than 50% by weight. / co / nn / Lznz / E / YiAi 37.- The method according to claim 11, further characterized in that the water in the modification system in step d) is distilled, deionized, demineralized, osmotic or double-distilled water.

38. The method according to claim 11, further characterized in that methanol, ethanol, propanol, isopropanol, butanol, isobutanol, pentanol or hexanol, preferably propanol, butanol, isobutanol, pentanol, more preferably butanol, isobutanol, pentanol are used as an aliphatic alcohol in modification step d). 39.- The method according to claim 11, further characterized in that in the modification step d) a ratio of starting diene-containing (co)polymer: modification system: aliphatic alcohol is from 1:1.5:3 to 1:5:3, preferably from 1:2:3 to 1:4:3, and more preferably from 1:2.5:3 to 1:3:

3.

40. The method according to claim 11, further characterized in that the modification in step d) is carried out at a temperature of 0 to 50°C, preferably 20 to 45°C, more preferably 30 to 40°C. 41.- The method according to claim 11, further characterized in that the driving time of the modification step d) is at least 15 minutes, at least 20 minutes, at least 25 minutes, at least 30 minutes, at least 45 minutes, at least 60 minutes, at least 120 minutes.

42. The method according to claim 11, further characterized in that aqueous solutions of sodium hydroxide, sodium thiosulfate, sodium bisulfite or sodium carbonate are used as a neutralizing agent in neutralization step e). 43.- The method according to claim 11, further characterized in that a molar ratio of an amount of the neutralizing agent to an amount of halogen added in the modification step d) is from 1:1 to 3:1, preferably from 1:1 to 2:1, more preferably from 1:

1.

44. The method according to claim 11, further characterized in that the neutralization procedure in step e) is carried out at a temperature of 15 to 50°C, preferably 20 to 40°C, more preferably 25 to 30°C, 45.- The method according to claim 11, further characterized in that after precipitation in isolation step f), methanol, ethanol, propanol, iso-propanol, butanol or iso-butanol are used as an alcohol precipitant.

46. ​​The method according to claim 11, further characterized in that the weight ratio of alcohol precipitant to modified diene-containing (co)polymer is 15:1 to 1:1, preferably 10:1 to 3:1, more preferably 5:1 to 4:

1. / co / nn / Lznz / E / YiAi 47.- The method according to claim 11, further characterized in that after degassing in the isolation step f), the water is distilled, deionized, demineralized, osmotic or double-distilled water.

48. The method according to claim 47, further characterized in that the water temperature while being added to the system is not more than 30°C, preferably not more than 25°C, more preferably not more than 20°C.

49. The method according to claim 11, further characterized in that after degassing in the isolation step f), a volume ratio of the added water: the organic layer is from 5:1 to 0.1:1, preferably from 3:1 to 1:1, more preferably from 2:

1.

50. The method according to claim 11, further characterized in that the degassing in the insulation step f) is carried out at a temperature of 20 to 150°C, preferably at a temperature of 50 to 100°C, more preferably at a temperature of 80 to 95°C. 51.- The method according to claim 11, further characterized in that the degassing in the isolation step f) is carried out under a pressure of less than 800 mbaries, preferably under a pressure of less than 300 mbaries, more preferably under a pressure of less than 100 mbaries.

52. The method according to claim 11, further characterized in that the degassing lead time in the insulation step f) is at least 30 minutes, preferably at least 60 minutes, more preferably at least 120 minutes.

53. The method according to claim 11, further characterized in that the filtration of the modified diene-containing (co)polymer in step g) is carried out in filters provided with porous filter partitions or in nutsch filters.

54. The method according to claim 11, further characterized in that the filtration of the modified diene-containing (co)polymer in step g) is carried out at a temperature of 20 to 40°C. 55.- The method according to claim 11, further characterized in that the drying of the (co)polymer containing modified diene in step g) is carried out at a temperature of 50 to 105°C.

56. The method according to claim 11, further characterized in that the drying of the (co)polymer containing the modified diene in step g) is carried out under a pressure of 1 to 20 kPa. / co / nn / Lznz / E / YiAi 57.- The method according to claim 11, further characterized in that the starting diene-containing (co)polymer is pre-milled. 5 8,- The use of a modified diene-containing (co)polymer as claimed in any of claims 1 to 10 as a flame retardant. 59.- The use as claimed in claim 58, wherein the (co)polymer containing modified diene is used as the Ñama retarder in an expandable polystyrene. 60.- An expandable polystyrene, characterized in that it comprises a (co)polymer containing diene modified according to any of claims 1 to 10 as a flame retardant.

61. The expandable polystyrene according to claim 60, further characterized in that the content of the (co)polymer containing modified diene is not less than 0.5 parts by weight, preferably not less than 0.7 parts by weight, more preferably not less than 1 part by weight. 62.- A polymer composition based on an expandable polystyrene, characterized in that it comprises a (co)polymer containing diene modified according to any of claims 1 to 10 as a flame retardant and additives providing a complex of technological, physical-mechanical and operational characteristics.

63. The polymer composition according to claim 62, further characterized in that antistatic agents, stabilizers, colorants, lubricants, fillers and adhesion-reducing agents are used as additives.