WO2011095552A1

WO2011095552A1 - Flame retardant

Info

Publication number: WO2011095552A1
Application number: PCT/EP2011/051575
Authority: WO
Inventors: Klaus Hahn; Olaf Kriha; Ingo Bellin; Patrick Spies; Sabine Fuchs; Peter Deglmann; Klemens Massonne; Hartmut Denecke; Christoph Fleckenstein; Geert Janssens; Maximilian Hofmann
Original assignee: Basf Se
Priority date: 2010-02-05
Filing date: 2011-02-03
Publication date: 2011-08-11
Also published as: CN102939332B; KR20120116014A; RU2012137686A; EP2531557A1; BR112012019193A2; CN102939332A; JP2013518959A; MX2012008979A

Abstract

The invention relates to phosphine sulfide derivatives of formula (I), S=PR¹R²R³ (I) which are suitable as flame retardants, in particular for polymers, wherein the symbols in formula (I) have the following meanings: R¹, R² are identically or differently C1-C₁₂-alkyl, C₃-C₈-cycloalkyl, which is unsubstituted or substituted by one or more C₁-C4-alkyl groups, C₂-C₁₂-alkenyl, C₂-C₁₂-alkinyl, C₆-C₁₀-aryl, C₆-C₁₀-aryl-C₁-C₄-alkyl; R³ is H, SH, SR⁴, OH, OR⁵ or a group: -(Y¹)_n-[P(= X¹)R⁶ -(Y²)_n]_m-P(= X²)R⁷R⁸; or two groups R¹, R², R³ together with the phosphorus atom to which they are bound form a ring system; X¹, X² are identically or differently O or S; Y¹, Y² are identically or differently O or S; R⁴, R⁵, R⁶, R⁷, R⁸ are independently of each other identically or differently C1-C₁₂-alkyl, C₃-C₈-cycloalkyl, which is unsubstituted or substituted by one or more C₁-C₄-alkyl groups, C₂-C₁₂-alkenyl, C₂-C₁₂-alkinyl, C₆-C₁₀-aryl or C₆-C₁₀-aryl C₁-C₄-alkyl; n is 1 if Y¹ or Y² is O, and 1, 2, 3, 4, 5, 6, 7 or 8 if Y¹ or Y² is S, and m is a whole number between 0 and 100.

Description

Flame retardants

The invention relates to the use of phosphine sulfide derivatives as flame retardants and polymers, in particular foams, which contain these flame retardants.

The equipment of polymers, especially foams, with flame retardants is important for a variety of applications, such as polystyrene foam expandable polystyrene foam (EPS) or expanded polystyrene foam boards (XPS) for building insulation.

Currently, as flame retardants in plastics mainly polyhalogenated hydrocarbons, optionally used in combination with suitable synergists, such as organic peroxides or nitrogen-containing compounds. A typical representative of these classic flame retardants is hexabromocyclododecane (HBCD), which is used, for example, in polystyrene. Due to the bioaccumulation and persistence of some polyhalogenated hydrocarbons, it is a major effort in the plastics industry to substitute halogenated flame retardants.

Flame retardants should, if possible, not only have a high flame retardancy effect in the plastic at low loading for the processing but also sufficient temperature and hydrolysis stability. Furthermore, they should have no bioaccumulation and persistence.

In WO-A 2009/035881 and WO-A 2008/088487 halogen-free flame retardants with sulfur-phosphorus bonds, in particular thiophosphates and thiophosphonates are described.

Nevertheless, there remains a broad scope for improvements of such flame retardants, for example because halogen-free flame retardants generally have to be used in significantly higher quantities in order to achieve the same flame retardancy of halogen-containing flame retardants. Therefore, halogen-free flame retardants which can be used in thermoplastic polymers, such as polystyrene, often also not be used in polymer foams, since they either interfere with the foaming process or affect the mechanical and thermal properties of the polymer foam. In the preparation of expandable polystyrene by suspension polymerization, the high flame retardancy reduce the stability of the suspension. In addition, the effect of the flame retardants used in thermoplastic polymers in polymer foams is often unpredictable due to the different fire behavior and different fire tests.

The object of the invention is therefore to provide compounds which on the one hand are halogen-free and, on the other hand, even in small amounts have good flame retardancy properties in polymers, in particular in polymer foams, such as EPS and XPS.

It has been found that certain phosphine sulfide derivatives, in particular certain derivatives of dithiophosphinic acid, are particularly suitable for use as flame retardants. The invention therefore provides the use of Phosphinsulfiddenvaten of formula (I)

S = PR ¹ R ² R ³ (I) as a flame retardant, in particular for polymers, where the symbols in the formula (I) have the following meanings:

R ^1, R ² are identical or different CrCl ₂ alkyl, C ₃ -C ₈ cycloalkyl which is unsubstituted or substituted by one or more -C ₄ alkyl groups, C ₂ -C ₂ -alkenyl, C ₂ -C ₂ - alkynyl, C ₆ -C ₀ aryl, C ₆ -C ₀ aryl-Ci-C ₄ alkyl; is H, SH, SR ⁴ , OH, OR ³ or a group:

- (Y ¹ ) n - [P (= X ¹ ) R ⁶ - (Y ² ) n] m P (= X ² ) R ⁷ R or two groups R ¹ , R ² , R ³ together with the phosphorus atom that they are bound, a ring system;

X ¹ , X ² are the same or different O or S; Y ¹ , Y ² are the same or different O or S;

R ⁴ , R ⁵ , R ⁶ , R ⁷ , R ⁸ are, identically or differently independently, C ₁ -C ₂ -alkyl, C ₃ -C ₈ -cycloalkyl which is unsubstituted or substituted by one or more C ₁ -C ₄ -alkyl groups, C ₂ - _Ci2 alkenyl, _{_C2-Ci2} alkynyl, C ₆ -C ₀ aryl or C ₆ -C ₀ aryl-Ci-C ₄ alkyl; n is 1 if Y ¹ or Y ^{2 is} O, and 1, 2, 3, 4, 5, 6, 7 or 8 if Y ¹ or Y ^{2 is} S, and m is an integer of 0 to 100 ,

The invention further provides a process for the flame-retardant finishing of foamed and unfoamed polymers, wherein the polymer is added a flame retardant containing one or more compounds of the formula (I).

Likewise provided by the invention is a polymer composition containing a flame retardant which contains one or more compounds of the formula (I). The invention further relates to the use of certain foamed polymer compositions which contain the novel fire retardant as insulation and / or insulating materials.

The compounds of the formula (I) are halogen-free and have a significantly better activity even in small amounts than previously known halogen-free flame retardants in foams, such as dibenz [c, e] [1,2-oxaphosphorine-6-oxide (DOP, see US Pat eg EP-A 1 791 896).

The symbols and indices in the formula (I) preferably have the following meanings:

R ¹ , R ² are preferably identical or different C 1 -C ₈ -alkyl, cyclohexyl, phenyl or benzyl.

R ³ is preferably H, SH, SR ⁴ or a group

It is also preferred that two groups R ¹ , R ^2, R ³ together with the phosphorus atom to which they are attached form a ring system.

X ¹ , X ² are preferred S.

Y ¹ , Y ² are preferably the same or different O or S. R ⁴ , R ⁶ , R ⁷ , R ⁸ are preferably identical or different and independently of one another C 1 -C ₈ -alkyl, cyclohexyl, phenyl or benzyl. n is preferably 1 if Y is ¹ or Y ^{2 is} O, and 1 or 2 if Y ^{2 is} S; m is preferably 0 to 10.

Preference is given to compounds of the formula (I) in which all symbols and indices have the preferred meanings.

The symbols and indices in the formula (I) particularly preferably have the following meanings:

R ¹ , R ² are more preferably phenyl.

R ³ is particularly preferably H, SH, S-benzyl or

a group (Y ¹ ) _n -P (= S) R ⁷ R ⁸ .

Y ¹ is more preferably the same or different O or S.

R ⁷ , R ⁸ are particularly preferably phenyl. n is more preferably 1 if Y ^{1 is} O and 1 or 2 if Y ^{1 is} S. Particular preference is given to compounds of the formula (I) in which all symbols and indices have the particularly preferred meanings.

Preference is also given to compounds of the formula (I) in which R ^{3 is} SH, SR ⁴ , OH, OR ⁵ or a group - (Y ¹ ) _n - [P (XX ¹ ) R ⁶ - (Y ² ) n] mP (= X ² ) R ^{7 is} R ⁸ .

Preference is also given to compounds of the formula (I) in which R ^{3 is} SH, SR ⁴ or a group - (Y ¹ ) _n - [P (XX ¹ ) R ⁶ - (Y ² ) n] mP (XX ² ) R ^{7 is} R ⁸ , with Y ¹ = S.

Preference is also given to compounds of the formula (I) in which R ^{3 is} a group

(Y ¹ ) _n - [P (= X ¹ ) R ⁶ - (Y ² ) n] m P (= X ² ) R ⁷ R ⁸ , more preferably Y ^{1 is} S.

Preference is also given to compounds of the formula (I) in which R ^{3 is} SH.

Also preferred are compounds of the formula (I) in which two radicals R ¹ , R ² ; R ³ together form no ring system. Preference is also given to compounds of the formula (I) in which in each case two of the radicals R ¹ , R ² ; R ³ together with the phosphorus atom to which they are attached form a three- to twelve-membered ring system.

Further preferred are the following groups of compounds of the formula (I):

S = PR ¹ R ² -H (la);

S = PR ¹ R ² -SH b);

S = PR ¹ R ² -SBenzyl (ic);

S = PR ¹ R ² -SP (= S) R ⁷ R ⁸ (Ida);

S = PR ¹ R ² -SSP (= S) R ⁷ R ⁸ (Idb) and

S = PR ¹ R ² -0 -P (= S) R ⁷ R ⁸ (Idc), where the symbols have the meanings given in formula (I).

Preference is also given to compounds of the formula (I) in which R ¹ and R ^{2 are} identical. Preference is also given to compounds of the formula (I) in which R ⁷ and R ^{8 are} identical.

Particular preference is given to compounds of the formula (I) in which R ¹ , R ² , R ⁷ and R ^{8 are} identical. Particularly preferred compounds of the formula (I) are the compounds FSM 1 to FSM 6 listed in the examples.

Preference is given to using 1 compound of the formula (I) as flame retardant. Furthermore, preference is given to using a mixture of two or more, more preferably two to four, in particular two, compounds of the formula (I) as flame retardant.

The compounds of the formula (I) are partially commercially available, for example diphenyldithiophosphinic acid (FSM 1) from ABCR GmbH & Co. KG, Karlsruhe, Germany. They can furthermore be prepared by known methods known to the person skilled in the art, as described, for example, in Houben-Weyl, Methods of Organic Chemistry, 5th ed., Georg Thieme Verlag, Stuttgart 2001. Furthermore, reference is made to the literature cited in the examples section for the synthesis of the compounds FSM 2 to FSM 6. Oligomers and polymers (m = 2 to 100) are obtainable, for example, by reacting halophosphates with dialcohols as described in WO 2008/027536. The compounds of the formula (I) used according to the invention are generally used in an amount in the range from 0.1 to 25 parts by weight. Quantities of 2 to 15 parts by weight, preferably 2.5 to 10 parts by weight, ensure adequate flame retardancy, especially in the case of foams made from expandable polystyrene. The statement of parts by weight in the context of this application - unless otherwise stated - always refers to 100 parts by weight of the compound, in particular of the polymer, which is flame-retardant, without consideration of any additives. The effectiveness of the compounds (I) can be further improved by the addition of suitable flame retardant synergists, such as the thermal radical formers dicumyl peroxide, di-tert-butyl peroxide or biscumyl (2,3-diphenyl-2,3-dimethyl-butane). In this case, in addition to the compound or compounds (I), 0.05 to 5 parts by weight of the flame retardant synergist are usually used.

Also preferred as a synergist is elemental sulfur, preferably in a proportion of 0.05 to 4 parts by weight, particularly preferably 0.1 to 2.5 parts by weight.

The elemental sulfur can also be used in the form of starting compounds which are decomposed under the process conditions to elemental sulfur.

Furthermore, it is possible to use elemental sulfur in encapsulated form. Suitable materials for encapsulating are, for example, melamine resins (analogous to US Pat. No. 4,440,880) and urea-formaldehyde resins (analogous to US Pat. No. 4,698,215). Further materials and references are to be found in WO 99/10429.

In addition, other flame retardants, such as melamine, melamine cyanurates, metal oxides, metal hydroxides, phosphates, phosphonates, phosphinates and expandable graphite or synergists, such as Sb ₂ 0 ₃ , Sn compounds or nitroxyl radicals containing or releasing compounds can be used. Suitable additional halogen-free flame retardants are, for example, commercially available under the names Exolit OP 930, Exolit OP 1312, HCA, HCA-HQ, M-ester Cyagard RF-1241, Cyagard RF-1243, Fyrol PMP, Phoslite IP-A, (aluminum hypophosphite), Melapur 200, Melapur MC APP (ammonium polyphosphate) and Budit 833 available. If it is possible to dispense with complete halogen freedom, halogen-reduced materials can be obtained by using the compounds (I) according to the invention and adding minor amounts of halogen-containing, in particular brominated flame retardants, such as hexabromocyclododecane (HBCD) or brominated styrene homo- or styrene copolymers / oligomers (cf. Example styrene-butadiene copolymers, as described in WO-A 2007/058736), preferably in amounts ranging from 0.05 to 1, in particular 0.1 to 0.5 parts by weight, are prepared. A preferred embodiment is therefore also a use according to the invention wherein the compound (s) of the formula (I) is used in admixture with one or more further flame-retardant compounds and / or one or more synergists. In a preferred embodiment, the flame retardant of the invention is halogen-free.

The composition of polymer, flame retardant and other additives is particularly preferably halogen-free.

The flame retardants according to the invention, that is, compounds of the formula (I) alone or in admixture with one another and / or in admixture with synergists and / or in admixture with other flame-retardant substances, are used according to the invention for the production of flame-retardant materials, preferably unfoamed or foamed polymers, in particular thermoplastic polymers used. For this purpose, the flame retardant is preferably physically mixed with the corresponding polymer in the melt and then finished as a polymer mixture with phosphorus contents between 0.05 parts by weight and 5 parts by weight and then in a second process step together with the same or with another Polymer further processed. Alternatively, in the case of styrene polymers, the addition of the compounds (I) according to the invention before, during and / or after the preparation by suspension polymerization is preferred.

The invention also provides a, preferably thermoplastic, polymer composition comprising a flame retardant according to the invention containing one or more compounds of the formula (I).

For example, foamed or unfoamed styrenic polymers, including ABS, ASA, SAN, AMSAN, polyesters, polyimides, polysulfones, polyolefins, such as polyethylene and polypropylene, polyacrylates, can be used as the thermoplastic polymer. Polyetheretherketone, polyurethanes, polycarbonates, polyphenylene oxides, unsaturated polyester resins, phenolic resins, polyamides, polyethersulfones, polyether ketones and polyether sulfides, each used individually or in admixture as polymer blends.

Foamed or unfoamed styrene homopolymers and copolymers are each individually or in mixture as polymer blends.

Preference is given to flameproofed polymer foams, in particular based on styrene polymers, preferably EPS and XPS.

The flameproofed polymer foams preferably have a density in the range from 5 to 200 kg / m ³ , particularly preferably in the range from 10 to 50 kg / m ³ , and are preferably more than 80%, particularly preferably 90 to 100% closed-cell.

The flame-retardant, expandable styrene polymers (EPS) and styrene polymer extrusion foams (XPS) according to the invention can be made into expandable granules by adding the blowing agent and the inventive flame retardant before, during and / or after the suspension polymerization or by mixing a blowing agent into the polymer melt and subsequent extrusion and granulation under pressure (EPS) or by extrusion and relaxation using appropriately shaped nozzles to foam plates (XPS) or foam strands are processed.

According to the invention, the term "styrene polymer" comprises polymers based on styrene, α-methylstyrene or mixtures of styrene and α-methylstyrene, analogously for the styrene fraction in SAN, AMSAN, ABS, ASA, MBS and MABS (see below) are based on at least 50% by weight of styrene and / or alpha-methylstyrene monomers.

In a preferred embodiment, the polymer is an expandable polystyrene (EPS). In another preferred embodiment, the foam is a styrenic polymer extrusion foam (XPS).

Expandable styrenic polymers preferably have a molecular weight M _w in the range from 120,000 to 400,000 g / mol, particularly preferably in the range from 180,000 to 300,000 g / mol, measured by gel permeation chromatography according to DIN 55672-1 with refractiometric detection (Rl) versus polystyrene standards, on. Due to the reduction in molecular weight by shear and / or temperature, the molecular weight of the expandable polystyrene is usually about 10,000 g / mol below the molecular weight of the polystyrene used.

Preference is given as styrene polymers to glassy polystyrene (GPPS), toughened polystyrene (HIPS), anionically polymerized polystyrene or toughened polystyrene (A-IPS), styrene-alpha-methylstyrene copolymers, acrylonitrile-butadiene-styrene polymers (ABS), styrene-acrylonitrile Copolymers (SAN), acrylonitrile-alpha-methylstyrene copolymers (AMSAN), acrylonitrile-styrene-acrylic esters (ASA), methyl acrylate-butadiene-styrene (MBS), methyl methacrylate-acrylonitrile-butadiene-styrene (MABS) polymers or mixtures thereof or with polyphenylene ether (PPE) used.

The styrene polymers mentioned can be used to improve the intrinsic mechanical properties or the thermal stability, if appropriate by using compatibilizers with thermoplastic polymers, such as polyamides (PA), polyolefins, such as polypropylene (PP) or polyethylene (PE), polyacrylates, such as polymethyl methacrylate (PMMA), Polycarbonate (PC), polyesters, such as polyethylene terephthalate (PET) or polybutylene terephthalate (PBT), polyethersulfones (PES), polyether ketones or polyether sulfides (PES) or mixtures thereof, generally in proportions of not more than 30 parts by weight, preferably in the range from 1 to 10 parts by weight, based on the polymer melt, are mixed. Furthermore, mixtures in the abovementioned quantitative ranges are also possible with, for example, hydrophobically modified or functionalized polymers or oligomers, rubbers, such as polyacrylates or polydienes, for example styrene-butadiene block copolymers or biodegradable aliphatic or aliphatic / aromatic copolyesters.

Suitable compatibilizers are, for example, maleic anhydride-modified styrene copolymers, polymers or organosilanes containing epoxide groups.

The styrene polymer melt may also be mixed with polymer recyclates of the above-mentioned thermoplastic polymers, in particular styrene polymers and expandable styrene polymers (EPS), in amounts which do not substantially impair their properties, generally in quantities of not more than 50 parts by weight, in particular in amounts of 1 to 20 parts by weight.

The propellant-containing styrene polymer melt usually contains one or more propellants in a homogeneous distribution in a proportion of 2 to 10 parts by weight, preferably 3 to 7 parts by weight, based on 100 parts by weight of Styrene polymer melt. Suitable blowing agents are the physical blowing agents commonly used in EPS, such as aliphatic hydrocarbons having 2 to 7 carbon atoms, alcohols, ketones, ethers or halogenated hydrocarbons. Preference is given to using isobutane, n-butane, isopentane, n-pentane. For XPS it is preferred to use C0 ₂ or mixtures thereof with alcohols and / or C ₂ -C ₄ -carbonyl compounds, in particular ketones.

To improve the foamability, finely distributed internal water droplets can be introduced into the styrene polymer matrix. This can be done, for example, by the addition of water into the molten styrene polymer matrix. The addition of the water can be done locally before, with or after the propellant dosage. A homogeneous distribution of the water can be achieved by means of dynamic or static mixers. In general, 0 to 2, preferably 0.05 to 1, 5 parts by weight of water are sufficient.

Expandable styrene polymers (EPS) with at least 90% of the internal water in the form of inner water droplets with a diameter in the range of 0.5 to 15 μηη form during foaming foams with sufficient cell count and homogeneous foam structure.

The added amount of blowing agent and water is chosen such that the expandable styrene polymers (EPS) have an expansion capacity a, defined as bulk density before foaming / bulk density after being applied, at most 125, preferably 25 to 100.

The expandable styrene polymer pellets (EPS) according to the invention generally have a bulk density of at most 700 g / l, preferably in the range from 590 to 660 g / l. When using fillers, depending on the type and amount of the filler, bulk densities in the range of 590 to 1200 g / l may occur.

Furthermore, additives, nucleating agents, fillers, plasticizers, soluble and insoluble inorganic and / or organic dyes and pigments, for example IR absorbers, such as carbon black, graphite or aluminum powder, may be jointly or spatially separated from the styrene polymer melt, for example via mixers or side extruders. are given. In general, the dyes and pigments are added in amounts ranging from 0.01 to 30, preferably in the range of 1 to 5 parts by weight. For homogeneous and microdispersed distribution of the pigments in the styrene polymer, it may be expedient in particular for polar pigments to use a dispersing aid, for example organosilanes, polymers containing epoxy groups or maleic anhydride-grafted styrene polymers. Preferred plasticizers are mineral oils, Phthalates, which can be used in amounts of 0.05 to 10 parts by weight. Analogously, these substances can also be added before, during and / or after the suspension polymerization to inventive EPS. To prepare the expandable styrene polymers according to the invention by the granulation method, the blowing agent can be mixed into the polymer melt. One possible method comprises the stages a) melt production, b) mixing c) cooling d) conveying and e) granulation. Each of these stages can be carried out by the apparatuses or apparatus combinations known in plastics processing. For mixing, static or dynamic mixers are suitable, for example extruders. The polymer melt can be taken directly from a polymerization reactor or produced directly in the mixing extruder or a separate melt extruder by melting polymer granules. The cooling of the melt can take place in the mixing units or in separate coolers. For example, pressurized underwater granulation, granulation with rotating knives and cooling by spray misting of tempering liquids or sputtering granulation may be considered for the granulation. Apparatus arrangements suitable for carrying out the method are, for example:

Polymerization reactor - static mixer / cooler - granulator

Polymerization Reactor - Extruder - Granulator

Extruder - static mixer - granulator

Extruder - Granulator Furthermore, the arrangement can have side extruders for introducing additives, for example solids or thermally sensitive additives.

The propellant-containing styrene polymer melt is generally conveyed through the nozzle plate at a temperature in the range from 140 to 300.degree. C., preferably in the range from 160 to 240.degree. Cooling down to the range of the glass transition temperature is not necessary.

The nozzle plate is heated at least to the temperature of the blowing agent-containing polystyrene melt. Preferably, the temperature of the nozzle plate is in the range of 20 to 100 ° C above the temperature of the blowing agent-containing polystyrene melt. This prevents polymer deposits in the nozzles and ensures trouble-free granulation.

In order to obtain marketable granule sizes, the diameter (D) of the nozzle bores at the nozzle exit should be in the range of 0.2 to 1.5 mm, preferably in the range of 0.3 to 1, 2 mm, more preferably in the range of 0.3 to 0.8 mm. Thus, even after strand expansion granulate sizes under 2 mm, in particular in the range 0.4 to 1, 4 mm set specifically. Particularly preferred is a process for the preparation of halogen-free flame-retardant, expandable styrene polymers (EPS), comprising the steps a) mixing an organic blowing agent and 1-25 parts by weight of the flame retardant according to the invention in the polymer melt by means of static or dynamic mixer at a temperature of at least

150 ° C,

b) cooling the propellant-containing styrene polymer melt to a temperature of at least 120 ° C.

c) discharge through a nozzle plate with holes whose diameter at the nozzle outlet is no more than 1, 5 mm and

d) granulating the blowing agent-containing melt directly behind the nozzle plate under water at a pressure in the range of 1 to 20 bar.

It is also preferable to prepare the expandable styrene polymers (EPS) according to the invention by suspension polymerization in aqueous suspension in the presence of the flame retardant according to the invention and of an organic blowing agent.

In the suspension polymerization is preferably used as the monomer styrene alone. However, up to 20% of its weight may be replaced by other ethylenically unsaturated monomers such as alkylstyrenes, divinylbenzene, acrylonitrile, 1,1-diphenyl ether or alpha-methylstyrene.

In the suspension polymerization, the customary auxiliaries, for example peroxide initiators, suspension stabilizers, blowing agents, chain transfer agents, expanding aids, nucleating agents and plasticizers may be added. The flame retardant of the invention is added in the polymerization in amounts of 0.5 to 25 wt .-%, preferably from 5 to 15 wt .-%. Propellants are added in amounts of 2 to 10 wt .-%, based on monomer. It can be added before, during or after the polymerization of the suspension. Suitable propellants are, for example, aliphatic hydrocarbons having 4 to 6 carbon atoms. It is advantageous to use as suspension stabilizers inorganic Pickering dispersants, e.g. Magnesium pyrophosphate or calcium phosphate use.

In the suspension polymerization, pear-shaped, substantially round particles having an average diameter in the range of 0.2 to 2 mm are formed. To improve processability, the final expandable styrenic polymer granules may be coated by glycerol esters, antistatic agents or anticaking agents.

The EPS granules may be mixed with glycerol monostearate GMS (typically 0.25 parts by weight), glycerol tristearate (typically 0.25 parts by weight) finely divided silica Aerosil R972 (typically 0.12 parts by weight) and Zn stearate (typically 0.15 parts by weight), and antistatic coating.

The expandable styrene polymer granules according to the invention can be prefoamed in a first step by means of hot air or steam to foam particles having a density in the range of 5 to 200 kg / m ³ , in particular 10 to 50 kg / m ³ and welded in a second step in a closed mold to particle moldings become.

The expandable polystyrene particles can be made into polystyrene foams having densities of from 8 to 200 kg / m ^3, preferably from 10 to 50 kg / m ³ . For this purpose, the expandable particles are prefoamed. This is usually done by heating the particles with water vapor in so-called pre-expanders. The pre-expanded particles are then welded into shaped bodies. For this purpose, the prefoamed particles are brought into forms that do not close in a gas-tight manner and subjected to steam. After cooling, the moldings can be removed. In another preferred embodiment, the foam is an extruded polystyrene (XPS), available from:

(a) heating a polymer component P to form a polymer melt,

(b) introducing a blowing agent component T into the polymer melt to form a foamable melt,

(c) extruding the foamable melt into a lower pressure region with foaming to form an extrusion foam and

(D) adding the flame retardant according to the invention and optionally further auxiliaries and additives in at least one of the steps a) and / or b).

Foams according to the invention based on styrene polymers, in particular EPS and XPS, are suitable, for example, for use as insulating and / or insulating materials, in particular in the construction industry. Preferred is a use as halogen-free insulating and / or insulating material, especially in the construction industry. Foams according to the invention, in particular based on styrene polymers, such as EPS and XPS, preferably exhibit a quenching time (fire test B2 according to DIN 4102 at a foam density of 15 g / l and a deposition time of 72 h) of <15 seconds, particularly preferably <10 seconds, and thus meet the conditions for passing the said fire test, as long as the flame height does not exceed the measurement mark specified in the standard.

The invention is explained in more detail by the following examples, without thereby restricting them.

Examples

Flame retardants used (FSM) 1 to 6 phosphine sulfides

Diphenyldithiophosphinic acid FSM1

Diphenylphosphine sulphide FSM2

Benzylphosphinodithioate FSM3

Di- and oligo-phosphine chalcogenides

Diphenyl thiophosphine thio anhydride FSM4

Bis (diphenylphosphinothioyl) disulfide FSM5

The organic phosphorus compounds used in the examples were synthesized according to the following instructions: FSM1 is commercially available (ABCR).

FSM2: Parsons, Andrew F .; Sharpe, David J .; Taylor, Philip; Synlett; 2005; 19;

2981 -2983.

FSM3: K. Goda; R. Okazaki; K. Akiba; N. Inamoto; Chem. Soc. Japan; 1978;

51; 1 ; 260-264.

FSM4: T.R. Hopkins; P. W. Bird; J. Amer. Chem. Soc. 1956; 78; 4447-4450.

FSM5: M.G. Zimin; N. G. Zabirov; V. Smirnov; Zhoournal Obschei Khimii; 1980; 50;

1 ; 24-30.

FSM6: Maier, Ludwig; Helvetica Chimica Acta; 1964; 157; 1448-1459. Expandable styrene polymers (extrusion process)

7 parts by weight of n-pentane were mixed into a polystyrene melt of PS 148G BASF SE with a viscosity number VZ of 83 ml / g. After cooling the propellant-containing melt from originally 280 ° C to a temperature of 190 ° C, a polystyrene melt containing the flame retardants listed in the table was mixed via a Steitenstromextruder in the main stream.

The stated amounts in parts by weight relate to the total amount of polystyrene which corresponds to 100 parts by weight.

The mixture of polystyrene melt, blowing agent and flame retardant was conveyed at 60 kg / h through a nozzle plate with 32 holes (diameter of the nozzle 0.75 mm). With the help of pressurized underwater granulation, compact granules with a narrow size distribution were produced.

The granules were prefoamed by the action of flowing steam and, after being stored for 12 hours by further treatment with steam, sealed in a closed mold to form foam blocks of a density of 15 kg / m ³ . The determination of the fire behavior of the foam panels was carried out after 72 hours of storage at a foam density of 15 kg / m ³ according to DIN 4102.

Hexabromocyclododecane (referred to below as HBCD) was used as comparison experiment.

The results are summarized in Table 1:

Table 1: Fire behavior of EPS sheets according to the invention

Extruded polystyrene foam boards

100 parts by weight of polystyrene 158K BASF SE with a viscosity number of 98 ml / g, 0.1 parts of talc as nucleating agent for controlling the cell size and the parts indicated in the table of flame retardants and optionally Flammschutzmittelsynergisten (for example, 2,3-diphenyl -2,4-dimethylbutane) were continuously fed to an extruder having an inner screw diameter of 120 mm. A blowing agent mixture consisting of 3.25 parts by weight of ethanol and 3.5 parts by weight of CO ₂ was simultaneously pressed in continuously through an inlet opening in the extruder.

The gel, kneaded uniformly in the extruder at 180 ° C., was passed through a settling zone and after a residence time of 15 minutes with a discharge temp. temperature of 105 ° C passed through a mold channel connected to the extruder, wherein a foamed sheet web with a cross section 650mm 50 mm and a density of 35g / l was formed. The product was cut into plates. The fire behavior of the samples with a thickness of 10 mm after a deposit time of 30 days according to DIN 4102 was tested.

The results of the examples are summarized in Table 2. Table 2: Fire behavior of XPS plates according to the invention

The examples show that with the inventive flame retardants EPS and XPS foams can be produced which show the same or better fire behavior than with these agents without the use of halogenated flame retardants.

Claims

claims

Use of phosphine sulfide derivatives of the formula (I)

S = PR ¹ R ² R ³ (I) as a flame retardant, where the symbols in the formula (I) have the following meanings:

R ¹ , R ² are identical or different C ₁ -C ² -alkyl, C ₃ -C ₈ -cycloalkyl, the

unsubstituted or substituted by one or more -C ₄ alkyl groups, C ₂ -Ci2 alkenyl, C ₂ -C ₂ alkynyl, C ₆ -C ₀ aryl, C ₆ -C ₀ aryl-Ci- C ₄ alkyl ;

R ³ is H, SH, SR ⁴ , OH, OR ⁵ or a group:

X ¹ ) R ⁶ - (Y ² ) n] _m -P (= X ² ) R ⁷ R ⁸ ; or two groups R ¹ , R ² , R ³ together with the phosphorus atom to which they are attached form a ring system;

X ¹ , X ² are the same or different O or S;

Y ¹ , Y ² are the same or different O or S;

R ⁴ , R ⁵ , R ⁶ , R ⁷ , R ⁸ are the same or different independently

CrCi2-alkyl, C ₃ -C ₈ cycloalkyl which is unsubstituted or substituted by one or more -C ₄ alkyl groups, C ₂ -Ci2 alkenyl, C ₂ -C ₂ alkynyl, C ₆ -C ₀ aryl, or C ₆ -C ₀ - aryl-CrC ₄ alkyl; n is 1 if Y ¹ or Y ² O, and 1, 2, 3, 4, 5, 6, 7 or 8 if Y ¹ or

Y ^{2 is} S, and m is an integer from 0 to 100.

Use according to claim 1, wherein the symbols and indices in the formula (I) have the following meanings:

R ¹ , R ² are identical or different CrC ₈ alkyl, cyclohexyl, phenyl or

benzyl; R ³ is H, SH, SR ⁴ or a group

or two groups R ¹ , R ² , R ³ together with the phosphorus atom to which they are attached form a ring system;

X ¹ , X ² are S;

Y, Y are the same or different O or S;

R ⁴ , R ⁶ , R ⁷ , R ⁸ are identical or different and independently of one another C 1 -C ₈ -alkyl, cyclohexyl, phenyl or benzyl; n is 1 if Y ¹ or Y ^{2 is} O, and 1 or 2 if Y ^{2 is} S, and m is an integer of 0 to 10.

Use according to claim 1 or 2, wherein the symbols and indices in the formula (I) have the following meanings:

R ¹ , R ² are phenyl;

R ³ is H, SH, S-benzyl or a group (Y ¹ ) _n -P (= S) R ⁷ R ⁸ ;

Y ¹ is the same or different O or S;

R ⁷ , R ⁸ are phenyl; is 1 if Y ^{1 is} O and 1 or 2 if Y ^{1 is} S.

4. Use according to any one of claims 1 to 3, wherein the compound (s) of the formula (I) are selected from the group:

S = PR ¹ R ² -H (la);

S = PR ¹ R ² -SH b);

S = PR ¹ R ² -SBenzyl (ic);

S = PR ¹ R ² -SP (= S) R ⁷ R ⁸ (Ida);

S = PR ¹ R ² -SSP (= S) R ⁷ R ⁸ (Idb) and

S = PR ¹ R ² -0 -P (= S) R ⁷ R ⁸ (Idc), wherein the symbols have the meanings given in formula (I) according to one of claims 1 to 3. 5. Use according to any one of claims 1 to 4, wherein the compound of formula (I) is selected from Diphenyldithiophosphinsäure, Diphenylphosphinsulfid, Benzylphosphinodithioat, Diphenylthiophosphinsäurethioanhydrid, bis (diphenylphosphinothioyl) disulfide and Diphenylthiophosphinsäureanhydrid. 6. Use according to claim 1 or 2, wherein the radical R ³ in the formula (I) SH, SR ⁴ , OH, OR ⁵ or a group - (Y ¹ ) _n - [P (= X ¹ ) R ⁶ - ( Y ² ) n] mP (= X ² ) R ^{7 is} R ⁸

7. Use according to claim 6, wherein R ^{3 is} SH, SR ⁴ or a group - (Y ¹ ) n- [P (= X ¹ ) R ⁶ - (Y ² ) n] mP (= X ² ) R ⁷ R ⁸ with Y ¹ = S.

8. Use according to claim 7, wherein R ^{3 is} SH or a group - (Y ¹ ) n- [P (= X ¹ ) R ⁶ - (Y ² ) n] mP (= X ² ) R ⁷ R ⁸ with Y ¹ = S is.

9. Use according to any one of claims 1 to 8, wherein 1 compound of the formula (I) is used.

10. Use according to any one of claims 1 to 8, wherein at least two compounds of formula (I) are used. 1 1. Use according to any one of claims 1 to 10, wherein the compound (s) of the formula (I) is used in admixture with one or more further flame retardants and / or one or more synergists.

12. Process for the flame retardant finishing of foamed or

unfoamed polymers, wherein the polymer is added a flame retardant according to any one of claims 1 to 1 1.

13. A polymer composition containing one or more polymers and a

Flame retardant according to one of claims 1 to 11.

A polymer composition according to claim 13, containing 0.1 to 25 parts by weight (based on 100 parts by weight of polymer) of the flame retardant.

15. Polymer composition according to claim 13 or 14, characterized in that it is halogen-free.

16. A polymer composition according to any one of claims 13 to 15, containing a styrenic polymer. 17. Polymer composition according to one of claims 13 to 16, characterized in that the polymer is a polymer foam.

18. A polymer composition according to claim 16 in the form of an expandable styrene polymer (EPS).

19. A process for producing an expandable styrene polymer (EPS) according to claim 18, comprising the steps:

a) incorporation of an organic blowing agent and one or more compounds of the formula (I) according to one of claims 1 to 11 and, if appropriate, further auxiliaries and additives in a styrene polymer melt by means of static and / or dynamic mixer at a temperature of at least 150 ° C.,

b) cooling the propellant-containing styrene polymer melt to a temperature of at least 120 ° C,

c) discharge through a nozzle plate with holes whose diameter at

Nozzle outlet is at most 1, 5 mm and

d) granulating the blowing agent-containing melt directly behind the nozzle plate under water at a pressure in the range of 1 to 20 bar. 20. A process for producing an expandable styrene polymer according to claim 18, comprising the steps: a) polymerization of one or more styrene monomers in suspension, b) addition of one or more compounds of the formula (I) according to one of claims 1 to 11 and optionally further auxiliary and additives before, during and / or after the polymerization,

c) adding an organic blowing agent before, during and / or after the polymerization and

d) separating the expandable styrene polymer particles containing one or more compounds of formula (I) from the suspension.

21. Polymer composition according to claim 16 or 17 in the form of a

Styrene polymer extrusion foam (XPS).

22. A process for preparing a styrene extrusion foam (XPS) according to claim 21 comprising the steps of: a) heating a polymer component P which comprises at least one styrene polymer to form a polymer melt,

b) introducing a blowing agent component T into the polymer melt to form a foamable melt,

c) extrusion of the foamable melt into a region of lower pressure with foaming to form an extrusion foam and

d) adding at least one compound of the formula (I) according to one of the

Claims 1 to 1 1 as a flame retardant and optionally further auxiliary and additives in at least one of steps a) and b).

Use of a polymer composition according to claim 21 and / or a polymer composition according to claim 18 in expanded form as an insulating and / or insulating material.