EP4298146A1

EP4298146A1 - Reactive flame-proof composition

Info

Publication number: EP4298146A1
Application number: EP22710344.7A
Authority: EP
Inventors: Andreas Moser; Gernot Peer; Christian Buchinger
Original assignee: Sunpor Kunststoff GmbH
Current assignee: Sunpor Kunststoff GmbH
Priority date: 2021-02-26
Filing date: 2022-02-24
Publication date: 2024-01-03
Also published as: WO2022180156A1; US20240101905A1; DE102021104714A1; CN116670230A

Abstract

The present invention relates to a reactive flame-proof composition for vinyl polymers, consisting at least of a first monomer and a second monomer that can be polymerised using the first monomer, wherein the first monomer has at least one aliphatic double bond and can be polymerised using the second monomer to form a reactive flame-proof polymer having an aliphatic double bond. The invention also relates to: a reactive flame-proof polymer produced by polymerisation of the reactive flame-proof composition; a use of the flame-proof composition and the flame-proof polymer; a flame-resistant vinyl polymer comprising the reactive flame-proof polymer; and methods for the production thereof. The subjects according to the invention can in particular advantageously reduce dripping of vinyl polymers during fires and can thus improve the flame-proof nature of such polymers.

Description

Reactive flame retardant composition

The present invention relates to a reactive flame retardant composition for vinyl polymers, a reactive flame retardant polymer, a use of the flame retardant composition and the flame retardant polymer, methods for producing flame retardant vinyl polymers, and flame retardant vinyl polymers.

Vinyl polymers are polymers made from vinyl monomers, which are mostly obtained by free-radical polymerization of the vinyl groups. Vinyl polymers find applications in numerous industrial sectors. Of particular relevance is the vinyl polymer polystyrene, which is used in particular as an insulating material.

Polystyrene is a thermoplastic polymer made from styrene monomers, which is usually available as granules with a density of approx. 1050 kg/m ³ . Polystyrene granulate is often further processed in a known manner for various applications. Depending on the type of processing, a distinction is made between expanded polystyrene (EPS) and extruded polystyrene (XPS).

XPS is produced in a known manner with an extruder by melting the raw granules and pressing the melt, in particular with a blowing agent, through a nozzle. The homogeneous material foams up and can be removed from the process as a continuous part. EPS is obtained in a known manner by expanding raw granules loaded with a blowing agent (for example with pentane) at temperatures above 90.degree. The granules are usually pre-expanded in a first step. In a second step, the pre-expanded granules are further expanded in a hollow mold. The expanded granulate particles fuse to form a cohesive molded body and form a particle of foam.

XPS and EPS moldings are often used for thermal insulation or impact sound insulation or as precisely fitting transport packaging for sensitive objects. Furthermore, moldings made of EPS are used for special applications, for example for helmets. In addition, such moldings can be used as a positive model in metal casting processes.

Of importance for vinyl polymers is their fire behavior. For example, the regulations governing the use of polystyrene particle foams as insulating material for buildings require flame retardant equipment in most cases. Particle foams, especially those made from expanded polystyrene, pose a particular challenge, as they can easily soften and drip off in the event of a fire, which can accelerate the spread of the fire.

It is known that flame retardants which reduce the flammability of the polymers can be added to vinyl polymers. However, known flame retardants hardly affect the dripping behavior of the polymer in fires or often accelerate it, so that an important factor in the fire behavior of vinyl polymers has hitherto remained largely unconsidered. The flame retardancy of vinyl polymers therefore still offers potential for improvement. In particular, there is potential for improvement in influencing the fire behavior itself and the dripping behavior in the event of a fire.

It is therefore the object of the present invention to provide improved flame retardancy for vinyl polymers, in particular by reducing the dripping behavior in the event of fire.

This object is achieved by the reactive flame retardant composition according to claim 1, the reactive flame retardant polymer according to claim 7, the use according to claim 8, the processes for producing flame-retardant vinyl polymers according to claims 9 and 10, and by flame-retardant vinyl polymers according to claim 11.

Preferred embodiments of the invention are specified in the subclaims, in the description or in the example, with further features described or shown in the subclaims or in the description or in the example being able to constitute an object of the invention, individually or in any combination, if from the context does not clearly indicate the opposite.

The invention proposes a reactive flame retardant composition for vinyl polymers.

The reactive flame retardant composition consists of at least a first monomer and a second monomer polymerizable with the first monomer, the first monomer having at least one aliphatic double bond and being polymerizable with the second monomer to form a reactive flame retardant polymer having an aliphatic double bond. A vinyl polymer is understood to mean a polymer made from monomers which have a vinyl group, ie an ethene radical.

An aliphatic double bond is understood as meaning a carbon-carbon double bond of an aliphatic hydrocarbon. For the purposes of the present invention, an aromatic hydrocarbon can also have an aliphatic double bond if the carbon-carbon double bond is not part of the aromatic system.

In the context of the present invention, an aliphatic double bond is also understood to mean a carbon-carbon double bond of a cycloaliphatic hydrocarbon, it being possible for the aliphatic double bond to also be provided within the ring structure of the cycloaliphatic hydrocarbon.

The term polymerizable is to be understood as meaning that the first and the second monomer each have reactive groups which can react with one another to form a bond between the first and second monomer, it being possible overall for a step-growth reaction to take place with the formation of an optionally branched polymer chain or A polymer network of interconnected first and second monomers.

For the purposes of the present invention, the term reactive means that the flame retardant composition or the flame retardant polymer improves the flame retardancy and/or the dripping behavior of a polymer in the event of a fire by chemical reaction.

The reactive flame retardant composition described above can advantageously result in vinyl polymers having such a reactive flame retardant composition having improved fire retardant properties. Furthermore, can be achieved by the above-described reactive flame retardant composition that vinyl polymers having such a reactive flame retardant composition harden in a fire and flow less accordingly. As a result, it can advantageously be achieved that the vinyl polymer drips less in the event of a fire, as a result of which the spread of fire can be greatly reduced.

Without being bound by theory, it is assumed that the reactive flame retardant composition, which is present in a vinyl polymer at least partially as a reactive flame retardant polymer, can react in a fire with nascent vinyl radicals, which arise from a reaction of the vinyl polymer and vinyl polymers, vinyl oligomers or vinyl monomers of the vinyl polymer. This binds the vinyl radicals to form a duromer, which greatly increases the viscosity of the melt produced during firing. The dripping of the melt during the fire can thus be greatly reduced and improved fire protection can result.

In a preferred embodiment it can be provided that the vinyl polymer is a particle foam.

For the purposes of the present invention, a particle foam is to be understood as meaning a polymer which can be expanded or has been expanded from granules to form a foam body.

In a preferred embodiment it can be provided that the vinyl polymer is polyethylene, polypropylene, polystyrene, polyvinyl chloride, polyvinyl acetate or polyacrylonitrile, as well as a copolymer and/or a mixture thereof.

It can preferably be provided that the vinyl polymer is a polystyrene, particularly preferably expandable polystyrene (EPS). For the purposes of the present invention, polystyrene is also understood to mean copolymers of polystyrene, such as, for example, styrene-butadiene graft copolymers, styrene-butadiene block copolymers, styrene-acrylonitrile copolymers, acrylonitrile-butadiene-styrene copolymers and mixtures thereof.

For example, it can be provided that the polystyrene is selected from the group consisting of crystal-clear polystyrene (GPPS), high-impact polystyrene (HIPS), anionically polymerized polystyrene or high-impact polystyrene (A-IPS), styrene-alpha-methylstyrene copolymer, acrylonitrile-butadiene-styrene polymer (ABS), styrene-acrylonitrile polymer (SAN), acrylonitrile-styrene-acrylic ester polymer (ASA), methacrylate-butadiene-styrene polymer (MBS), methyl methacrylate-acrylonitrile-butadiene-styrene polymer (MABS) or mixtures thereof, and optionally blended with polyphenylene ether (PPE) or polyphenylene sulfide (PPS).

To improve the mechanical properties or the temperature resistance, the polystyrene mentioned may contain 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),

Polyether sulfones (PES), polyether ketones or polyether sulfides (PES) or mixtures thereof, usually in proportions totaling up to less than or equal to 30% by weight, preferably in the range from greater than or equal to 1 to less than or equal to 10% by weight, based on the polystyrene. Surprisingly, it could be shown that the reactive

Flame retardant composition particularly well suited for the flame retardant of polystyrene, since this drips particularly strongly in fires and the reactive Flame retardant composition achieved effect on the dripping behavior of polystyrene is particularly pronounced.

It can preferably be provided that the first monomer is a monomer of the general formula (I):

[Formula (I)] where *-X-* is substituted or unsubstituted alkyl, substituted or unsubstituted heteroalkyl, substituted or unsubstituted aryl, or substituted or unsubstituted heteroaryl, where X has at least one aliphatic double bond, where A ¹ and A ² are each separately or together connected are a polymerizable group; and wherein the second monomer is a monomer of general formula (II):

[Formula (II)] where *-Y-* is substituted or unsubstituted alkyl, substituted or unsubstituted heteroalkyl, substituted or unsubstituted aryl, or substituted or unsubstituted heteroaryl, where B ¹ and B ² are each a group polymerizable with A ¹ and A ² .

By A ¹ and A ² each separately or linked together being a polymerizable group is meant that A ¹ and A ² are each a polymerized group or A ¹ and A ² are linked together to form a group which can be split into two Groups can be split, which in turn are each polymerizable. For example A ¹ and A ² can together form a carboxylic acid anhydride which can react with cleavage with two monomers.

Advantageously, the reactive flame retardant composition described above can be achieved in that the reactive flame retardant composition can be converted particularly easily in a vinyl polymer to form a corresponding reactive flame retardant polymer. In particular, this can advantageously result in the aliphatic double bond of the reactive flame retardant polymer corresponding to the aliphatic double bond of the first monomer. As a result, the chemical properties of the aliphatic double bond of the reactive flame retardant polymer can advantageously be adjusted in a particularly simple manner.

It can preferably be provided that A ¹ and A ² are each a carboxylic acid, an alcohol or an amine, or A ¹ and A ² together form a carboxylic acid anhydride.

Surprisingly, it was able to be shown that such first monomers can be introduced particularly well into vinyl polymers and can be polymerized therein with the second monomers to form the reactive flame retardant polymer. It can preferably be provided that the *-X-* is selected from the general formula (Ia), (Ib), (Ic) or (Id):

[Formula (Ia)] [Formula (Ib)]

[Formula (Ic)] [Formula (Id)] wherein R ¹ and R ² are independently selected from a single bond, a substituted or unsubstituted C1-C30 alkyl, a substituted or unsubstituted C1-C30 heteroalkyl, a substituted or unsubstituted C6-C24 aryl, and a substituted or unsubstituted C6-C24 heteroaryl , and where R ¹ and R ² optionally form a cycle,

R ³ is selected from a substituted or unsubstituted C1-C30 alkyl, a substituted or unsubstituted C1-C30 heteroalkyl, a substituted or unsubstituted C6-C24 aryl, and a substituted or unsubstituted C6-C24 heteroaryl, and R ⁴ is selected from H, halogen, a substituted or unsubstituted C1-C30 alkyl, a substituted or unsubstituted C1-C30 heteroalkyl, a substituted or unsubstituted C6-C24 aryl, and a substituted or unsubstituted C6-C24 heteroaryl.

It can thereby be achieved that the aliphatic double bond of a corresponding reactive flame retardant polymer has a particularly positive influence on the drip properties of the vinyl polymer in the event of a fire. It can preferably be provided that B ¹ and B ² are each an epoxide, an alcohol, an amine, a carboxylic acid or an isocyanate. It was surprisingly possible to show that such second monomers can be incorporated particularly well into vinyl polymers and polymerized therein with the first monomers to form the reactive flame retardant polymer.

It can preferably be provided that A ¹ and A ² are a carboxylic acid and B ¹ and B ² are each an epoxide, an alcohol or an amine; that A ¹ and A ² together form a carboxylic acid anhydride and B ¹ and B ² are each an epoxide, an alcohol, or an amine; that A ¹ and A ² are an alcohol and B ¹ and B ² are each a carboxylic acid; or that A ¹ and A ² are an amine and B ¹ and B ² are each an epoxide or a carboxylic acid.

The aforementioned combinations of first and second monomers can advantageously be achieved in that the reactive flame retardant composition can also be polymerized in a vinyl polymer to form the reactive flame retardant polymer using particularly simple means and under mild conditions.

It can preferably be provided that A ¹ and A ² together form a carboxylic acid anhydride and B ¹ and B ² are each an epoxide.

The result of this is that the reactive flame retardant composition can be mixed particularly well with the vinyl polymer and can be polymerized particularly easily to give the reactive flame retardant polymer. Furthermore, it can be achieved that the mechanical properties of the vinyl polymer are changed as little as possible. In addition, the above-described flame retardant composition can achieve a particularly good increase in the viscosity of the melt of the vinyl polymer in the event of a fire, resulting in particularly improved flame retardant properties.

In a preferred embodiment it can be provided that B ¹ and B ² are an epoxide and *-Y-* is a novolak. For the purposes of the present invention, novolaks are low molecular weight phenolic resins which have been obtained from phenols or phenol derivatives, such as cresols, and formaldehyde, and have a formaldehyde/phenol (derivative) ratio of less than 1:1.

In other words, it can preferably be provided that the second monomer is an epoxidized novolak, ie for example an epoxy phenol novolak (EPN). It can thereby be achieved that the reactive flame retardant composition is particularly thermally stable.

In an alternative preferred embodiment, it can be provided that B ¹ and B ² are an epoxide, and *-Y-* has the general formula (Ha): [Formula Ha] wherein Z is selected from a substituted or unsubstituted C1-C30 alkyl, a substituted or unsubstituted C1-C30 heteroalkyl, a substituted or unsubstituted C6-C24 aryl, and a substituted or unsubstituted C6-C24 heteroaryl, where n is an integer greater than or equal to is equal to 0 to less than or equal to 60.

As a result, the viscosity of the reactive flame retardant composition can be adjusted. In particular, small n can result in a low viscosity and thus possibly a high reactivity of the second monomer be reached. Large n, on the other hand, can result in the second monomer being a solid and the polymerization to form the reactive flame retardant polymer first having to be activated. This allows better control of the polymerization to be achieved. Provision can preferably be made for the *-Z-* to have the general formula (IIb): [Formula (IIb)] where R ⁵ , R ⁶ , R ⁷ and R ⁸ are independently H, a substituted or unsubstituted Cl-C30 alkyl radical or Br, where preferably R ⁵ , R ⁶ , R ⁷ and R ⁸ are H or R ⁵ , R ⁶ , R ⁷ and R ⁸ are Br, where *-L-* is selected from formulas (IIc) and (IId) below

[Formula (IIc)] [Formula (IId)] where R ⁹ and R ¹⁰ are independently H, methyl, ethyl, phenyl, or together are cyclohexyl or fluorenyl.

What can advantageously be achieved thereby is that the flame retardant properties of the reactive flame retardant composition and of the reactive flame retardant polymer obtained from the reactive flame retardant composition can be adjusted.

It can preferably be provided that *-B' and *-B ² have the general formula (Ile): [Formula (Ile)]

As a result, it can advantageously be achieved that the second monomer can be polymerized particularly easily with the first monomer.

It can preferably be provided that the second monomer is an epoxy resin, for example a brominated epoxy resin, the second monomer being a brominated epoxy resin with the following formula in one embodiment

As a result, it can advantageously be achieved that the second monomer is particularly easy to polymerize with the first monomer and, in addition to increasing the viscosity of the melt of the vinyl polymer provided with the corresponding reactive flame retardant polymer, additional flame retardancy can also be achieved through the formation of bromine-containing gases during combustion .

Provision can preferably be made for the first monomer to be selected from substituted or unsubstituted tetrahydrophthalic anhydride and maleic anhydride, the first monomer being, for example, tetrahydrophthalic anhydride having the following formula

It was able to be shown that such first monomers are particularly suitable for increasing the viscosity of the melt of a corresponding vinyl polymer particularly strongly in the event of a fire. Without being bound to a theory, it is assumed that the aliphatic double bond of such monomers allows the aliphatic double bond to remain particularly reactive for vinyl radicals in the corresponding reactive flame retardant polymer as well. In an alternative preferred embodiment it can be provided that the first monomer is a diene, preferably selected from butadiene, isoprene and mixtures thereof, and the second monomer has a vinyl group, the second monomer preferably being selected from styrene, ethylene, propylene and mixtures of them. Surprisingly, it could be shown that a reactive flame retardant polymer can also be obtained by the first and second monomers described above, which can increase the viscosity of the melt in the event of a fire in a vinyl polymer containing the reactive flame retardant polymer and can thus positively influence the drip and fire properties.

Provision can preferably be made for the reactive flame retardant composition to have a polymerization catalyst which is suitable for catalyzing the polymerization between the first monomer and the second monomer. This can ensure that the polymerization of the reactive

Flame retardant composition for reactive flame retardant polymer can also be mixed well in a vinyl polymer.

It can preferably be provided that the reactive flame retardant composition has the polymerization catalyst in an amount of greater than or equal to 0.1% by weight to less than or equal to 20% by weight, based on the reactive flame retardant composition, preferably greater than or equal to 1% by weight. -% to less than or equal to 5% by weight, particularly preferably 2% by weight.

This can ensure that the polymerization of the reactive

Flame retardant composition can be well controlled and at the same time the resulting flame retardant polymer is not too contaminated by remaining catalyst.

It can preferably be provided that A ¹ and A ² together form a carboxylic acid anhydride, B ¹ and B ² are each an epoxide and the polymerization catalyst is an N-based catalyst, preferably an imidazole, particularly preferably isopropylimidazole.

Surprisingly, it could be shown that such catalysts are particularly suitable for the polymerization of such monomers, especially when the reactive flame retardant composition has already been introduced into a vinyl polymer and is to be polymerized to form the reactive flame retardant polymer.

It can preferably be provided that the molar ratio of the reactive groups of the first monomer to the second monomer is greater than or equal to 1:5 to less than or equal to 5:1, preferably greater than or equal to 1:2 to less than or equal to 2:1, more preferably greater than or equal to 1:1.1 to less than or equal to 1.1:1, most preferably 1:1. What can thereby be achieved is that the degree of polymerization of the reactive flame-retardant polymer obtained from the reactive flame-retardant composition can be adjusted.

A reactive flame retardant polymer is also proposed with the invention. The reactive flame retardant polymer is produced by polymerizing the reactive flame retardant composition described above, the reactive flame retardant polymer having an aliphatic double bond.

Without being bound to a theory, it is assumed that the reactive flame retardant polymer introduced into a vinyl polymer can react in the event of a fire with vinyl radicals that are produced. This binds the vinyl radicals to form a duromer, which greatly increases the viscosity of the melt produced during firing. The dripping of the melt during the fire can thus be greatly reduced and improved fire protection can result.

In a preferred embodiment it can be provided that the reactive flame retardant polymer is an epoxy resin crosslinked with tetrahydrophthalic anhydride, for example a brominated epoxy resin crosslinked with tetrahydrophthalic anhydride.

As a result, the dripping behavior of the vinyl polymer in the event of a fire can be improved particularly well and the flameproofing polymer can be introduced into the vinyl polymer particularly easily.

In an alternative preferred embodiment it can be provided that the reactive flame retardant polymer is a styrene-butadiene-styrene (SBS) block copolymer, a styrene-isoprene-styrene (SIS) block copolymer, a rubber-modified polystyrene (high-impact polystyrene; HIPS ) or an ethylene-propylene-diene rubber. As a result, it can advantageously be achieved that the mechanical properties of the vinyl polymer are impaired particularly little by the reactive flame retardant polymer.

Thus, the above reactive flame retardant composition for vinyl polymers and the above reactive flame retardant polymer each serve to improve flame retardancy for vinyl polymers. The invention thus also proposes the use of a reactive flame retardant composition as described above as flame retardant for vinyl polymers and products made from them, and the use of a reactive flame retardant polymer as described above as flame retardant for vinyl polymers and products made from them.

The invention also proposes a method for producing a flame retardant vinyl polymer.

In one embodiment of the method, a vinyl polymer is mixed with the reactive flame retardant composition described above with the input of energy, the reactive flame retardant composition polymerizing at least partially to form the reactive flame retardant polymer having an aliphatic double bond.

The reactive flame retardant polymer is thus only obtained in the vinyl polymer from the reactive flame retardant composition.

This can advantageously be achieved that the reactive flame retardant polymer in particular in comparison to commercially available unsaturated polymers homogeneously distributed in the vinyl polymer. Furthermore, it can advantageously be achieved that reactive flame retardant polymers with mechanical properties that differ significantly from those of the vinyl polymer can also be introduced homogeneously into the vinyl polymer. For example, reactive flame retardant polymers with significantly higher hardness or higher melting point can be well incorporated into the vinyl polymer because the blending is realized with the reactive flame retardant composition, which may have different mechanical properties than the reactive flame retardant polymer.

In an alternative embodiment of the method, a vinyl polymer is mixed with the reactive flame retardant polymer described above.

The reactive flame retardant polymer is thus incorporated directly into the vinyl polymer.

As a result, it can advantageously be achieved that the mixing can take place in a particularly simple manner. In particular, in the production by this method, when mixing, it is not necessary to ensure that an energy input is realized, by which the polymerization of the reactive flame retardant composition is driven.

It can preferably be provided that the vinyl polymer with reactive flame retardant composition or reactive flame retardant polymer in an amount based on the vinyl polymer of greater than or equal to 1 wt .-% to less than or equal to 20 wt .-%, preferably greater than or equal to 3 wt .-% to less than or equal to 7% by weight, particularly preferably 5% by weight.

It could be shown that with this amount of reactive flame retardant composition or reactive flame retardant polymer, there is a significant improvement in the fire properties of the vinyl polymer can be achieved without adversely affecting the mechanical properties of the vinyl polymer too much.

Provision can preferably be made for the vinyl polymer and the reactive flame retardant composition or the reactive flame retardant polymer to be mixed with an extruder, in particular with a twin-screw extruder, with a polymer melt that is produced in the process preferably being conveyed through a nozzle plate and being granulated with a pressurized underwater granulator. As a result, it can advantageously be achieved that the reactive flame retardant composition can be polymerized in a simple manner and/or the reactive flame retardant polymer can be distributed homogeneously in the vinyl polymer. The proposed extruder makes it possible to control the process in a particularly simple manner. Furthermore, it can optionally be achieved that a homogeneous granulate is obtained. For example, the method described above can be used to obtain polystyrene granules if the vinyl polymer is polystyrene, in particular expandable polystyrene granules if a blowing agent is added to the vinyl polymer or polystyrene. Provision can preferably be made for a blowing agent to be metered into the vinyl polymer and the reactive flame retardant composition or the reactive flame retardant polymer in the extruder. The blowing agent is particularly preferably metered in in an amount of greater than or equal to 2% by weight to less than or equal to 10% by weight, based on the sum of the masses of the vinyl polymer, the reactive flame retardant composition or the reactive flame retardant polymer and the blowing agent. The blowing agent can preferably be an aliphatic hydrocarbon having 2 to 7 carbon atoms, an alcohol, a ketone, an ether or a halogenated hydrocarbon. The propellant can particularly preferably be isobutane, n-butane, isopentane or n-pentane. The blowing agent can very particularly preferably be n-pentane.

Furthermore, additives, nucleating agents, fillers, plasticizers, soluble and insoluble inorganic and/or organic dyes and pigments, e.g. IR absorbers such as carbon black, graphite or aluminum powder, can be added to the vinyl polymer in the extruder together or separately, e.g. via mixers or side extruders. be admitted. In general, the dyes and pigments are added in amounts ranging from 0.01 to 30% by weight, based on the vinyl polymer, preferably in the range from 1 to 10% by weight. For the homogeneous and microdisperse distribution of the pigments in the vinyl polymer, it can be advantageous, particularly in the case of polar pigments, to use a dispersing agent, e.g. 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% by weight, based on the vinyl polymer.

The invention also proposes a flame retardant vinyl polymer. The flame-retardant vinyl polymer was produced according to the process described above, with the vinyl polymer having the reactive flame retardant polymer described above and optionally having an additional flame retardant.

The flame-retardant vinyl polymer described above can advantageously have better dripping behavior in the event of a fire than known flame-retardant vinyl polymers. An additional flame retardant can further improve the flame retardant properties of the flame-retardant vinyl polymer in a known manner. For example, the additional flame retardant can be brominated styrene-butadiene copolymer. A flame-retardant polystyrene granulate is also proposed with the invention. The flame-retardant polystyrene granulate was produced as described above, with the vinyl polymer being polystyrene, and has the reactive flame-retardant polymer described above and optionally an additional flame-retardant.

The above-described flame-retardant polystyrene granules can advantageously have improved dripping behavior in the event of a fire compared to known flame-retardant polystyrene granules.

Provision can particularly preferably be made for the flame-retardant polystyrene granules to be flame-retardant, expandable polystyrene granules, with a blowing agent having been metered into the vinyl polymer or polystyrene and the reactive flame-retardant composition or the reactive flame-retardant polymer in the extruder.

The invention also proposes a molded body made of expanded, flame-retardant polystyrene granules, the molded body having been produced with the flame-retardant polystyrene granules described above, in particular with the flame-retardant, expandable polystyrene granules.

The invention is explained further below using an example.

Example 1:

A styrene polymer (SETNPOREPS-SE: 6% by weight of pentane, chain length Mw=200,000 g/mol, dispersity Mw/Mn=2.5) was admixed with a reactive flame retardant composition consisting of 4% by weight of brominated compound in the intake area of a twin-screw extruder Epoxy resin (ICL IP F2200HM) as second monomer, 1% by weight Tetrahydrophthalic anhydride (THPA) as the first polymer and 0.1% by weight of isopropylimidazole as the polymerization catalyst, based on the total amount of the EPS granules obtained. The mixture was melted in the extruder at 170.degree. The polymer melt obtained in this way was conveyed through a nozzle plate at a throughput of 15 kg/h and granulated using a pressurized underwater granulator to give compact EPS granules.

When used, the EPS granules obtained in this way had improved flame retardancy and drainage properties compared to EPS granules produced without a reactive flame retardant composition.

Reference example 1:

Analogously to Example 1, additives were added in the intake area of a twin-screw extruder which, in contrast to the subject invention, cannot be polymerized to form a reactive flame-retardant polymer having an aliphatic double bond and do not form a flame-retardant composition for the purposes of the present invention. In order to generate this property, 1% by weight of phthalic anhydride (PA) was used as the first polymer instead of THPA, which, in contrast to tetrahydrophthalic anhydride (THPA), contains no aliphatic double bond. The second monomer used was again 4% by weight of F2200HM and the polymerization catalyst was also 0.1% by weight of isopropylimidazole, based on the total amount of the EPS granules obtained.

Simulation of a fire on a house facade

In order to simulate the actual conditions of an EPS insulation layer behind a facade in the event of a fire, the EPS granules produced from example 1, reference example 1 and a commercially available EPS granulate (Sunpor LP750) were used at 2 melted directly on a hot plate at different temperatures. The temperatures selected were 240° C. and 280° C., and 2 g of the EPS granules were melted for 5 minutes (measured after a homogeneous melt was obtained). The samples treated in this way were subsequently examined further. Without being bound to a theory, it can be assumed that the polystyrene radicals formed at these temperatures react with the aliphatic double bonds of the composition according to the invention and counteract the runoff of the decomposing thermoplastic with an increase in viscosity, which cannot be achieved by compositions not according to the invention. Rheometry experiments in oscillation mode

The melts of the EPS granules from example 1, the commercial product and reference example 1, which were (partially) decomposed according to the test described above, were measured by means of oscillatory rheometry in order to determine viscosity differences and network properties of the same. A TA Instruments HR 20 rheometer was used for this, which was used with a 25 mm plate-plate system with a 1 mm gap spacing at 180°C. The deflection during the measurement was 1% and the shear rate range from 0.01 Hz to 100 Hz was measured. Table 1 shows the dynamic viscosity (h) at 1 Hz and the frequency intercept (Fs) of the storage modulus and loss modulus.

Table 1: Oscillatory rheometry results

^* Frequency intersection point already outside the measuring range Table 1 shows a clear influence of the subject according to the invention both on the dynamic viscosity and on the frequency intersection point. While the viscosity of example 1 is already -40% higher at a melting temperature of 240° C., the difference at a melting temperature of 280° C. is particularly evident compared to the reference example without a polymerizable double bond. Here the increase in Example 1 is already 240%, while an increase in viscosity of 24% can also be determined for the commercial product.

The frequency intercept of the storage modulus and loss modulus is a measure of the molecular mobility at a given temperature. While a completely continuous network, e.g. with duromers, means that the storage modulus is above the loss modulus even at the lowest frequencies and all temperatures, with thermoplastics the temperature, the molecular weight and any gel fractions are very important. Thus, the crossover point is a good measure of the effectiveness of the subject invention.

Table 1 shows that example 1 has a significantly lower frequency crossing point than the commercial product and the reference example at both 240 °C and 280 °C melting temperature. This clearly shows that the molecular mobility is significantly restricted and a reaction has taken place in the simulated fire.

The flame retardant compositions according to the invention accordingly show improved run-off properties in the event of fire for vinyl polymers, in particular also compared to compositions which differ from the compositions according to the invention only in that the first monomer has no aliphatic double bond.

Claims

patent claims

1. Reactive flame retardant composition for vinyl polymers, consisting of at least a first monomer and a second monomer polymerizable with the first monomer, characterized in that the first monomer has at least one aliphatic double bond and can be polymerized with the second monomer to form a reactive flame retardant polymer having an aliphatic double bond .

2. Reactive flame retardant composition according to claim 1, characterized in that the first monomer is a monomer of general formula (I):

3. Reactive flame retardant composition according to claim 2, characterized in that *-X-* is selected from the general formula (Ia), (Ib), (Ic) or (Id):

[Formula (Ia)] [Formula (Ib)] wherein R ¹ and R ² are independently selected from a single bond, a substituted or unsubstituted C1-C30 alkyl, a substituted or unsubstituted C1-C30 heteroalkyl, a substituted or unsubstituted C6-C24 aryl, and a substituted or unsubstituted C6-C24 heteroaryl , and where R ¹ and R ² optionally form a cycle,

4. Reactive flame retardant composition according to one of claims 2 or 3, characterized in that B ¹ and B ² are an epoxide, and *-Y-* has the general formula (Ha):

[Formula Ha] wherein Z is selected from a substituted or unsubstituted C1-C30 alkyl, a substituted or unsubstituted C1-C30 heteroalkyl, a substituted or unsubstituted C6-C24 aryl, and a substituted or unsubstituted C6-C24 heteroaryl, where n is an integer greater than or equal to is equal to 0 to less than or equal to 60.

5. Reactive flame retardant composition according to claim 4, characterized in that the *-Z-* has the general formula (IIb):

[Formula (IIb)] where R ⁵ , R ⁶ , R ⁷ and R ⁸ are independently H, a substituted or unsubstituted C1-C30 alkyl radical or Br, where preferably R ⁵ , R ⁶ , R ⁷ and R ⁸ are H or R ⁵ , R ⁶ , R ⁷ and R ⁸ are Br, where *-L-* is selected from the following formulas (IIc) and (IId) [formula (IIc)] [formula (IId)] where R ⁹ and R ¹⁰ are independently H, methyl, ethyl, phenyl, or together are cyclohexyl or fluorenyl.

6. A reactive flame retardant composition as claimed in any one of the preceding claims characterized in that the first monomer is selected from substituted or unsubstituted tetrahydrophthalic anhydride and maleic anhydride, preferably wherein the first monomer is tetrahydrophthalic anhydride having the formula

7. Reactive flame retardant polymer produced by polymerization of the reactive flame retardant composition according to any one of the preceding claims, characterized in that the reactive flame retardant polymer has an aliphatic double bond.

8. Use of a reactive flame retardant composition according to any one of claims 1 to 6 and / or a reactive flame retardant polymer according to claim 7, as a flame retardant for a vinyl polymer and/or as a flame retardant for a product made from the vinyl polymer.

9. A method for preparing a flame-retardant vinyl polymer, characterized in that a vinyl polymer with the reactive

Flame retardant composition according to one of claims 1 to 6 is mixed with energy input, wherein the reactive flame retardant composition at least partially polymerizes to form the reactive flame retardant polymer having an aliphatic double bond.

10. A method for producing a flame-retardant vinyl polymer, characterized in that a vinyl polymer is blended with the reactive flame-retardant polymer according to claim 7.

11. A flame retardant vinyl polymer, characterized in that it has been produced by the method according to any one of claims 9 or 10, wherein the vinyl polymer comprises the reactive flame retardant polymer according to claim 7 and optionally comprises an additional flame retardant.