DE102008038916A1 - Expandable styrene polymers, useful for producing foam molded parts such as sheets, blocks, pipes, rods and profiles, preferably plates or blocks, comprises coating comprising a halogen-free flame retardants, and an organic binder - Google Patents

Abstract

Expandable styrene polymers comprises 2-50 wt.% of coating comprising (A) 10-99.9 wt.% of a halogen-free flame retardants, and (B) 0.1-90 wt.% of an organic binder. An independent claim is included for a process for preparation of the styrene polymer, comprising providing expandable styrene polymer in a mixing device, providing the organic binder under homogenous agitation, and providing the halogen-free flame retardant to form the coating.

Description

The This invention relates to expandable styrenic polymers which are from 2 to 50 Wt .-%, based on the expandable styrene polymer, of a coating have, process for their preparation and use for the production of particle foams.

Flame-retardant polystyrene foams are generally provided with halogen-containing flame retardants, such as hexabromocyclododecane (HBCD) ( WO 2006/082233 , However, the approval as an insulating material in the construction sector is limited to certain applications. One of the reasons for this is the melting and dripping of the polymer matrix in case of fire. In addition, the halogen-containing flame retardants can not be used without restriction in terms of their toxicological properties.

The WO 00/050500 describes flame-retardant foams of prefoamed polystyrene particles, which are mixed together with an aqueous sodium silicate solution and a latex of a high molecular weight vinyl acetate copolymer, poured into a mold and dried in air while shaking. This results in only a loose bed of polystyrene particles that are glued together at a few points and therefore have only insufficient mechanical strength.

The WO 2005/105404 describes an energy-saving process for the production of foam moldings in which the prefoamed foam particles are coated with a resin solution which has a lower softening temperature than the expandable polymer. The coated foam particles are then sealed in a mold using external pressure or by post-expansion of the foam particles with hot steam.

The WO 2005/07331 describes expanded polystyrene foam particles having a functional coating which is applied by means of a solvent which attacks the polystyrene foam particles only manoeuvrable. For flame retardance coating, the surface can be coated, for example, with a methanolic polyvinyl acetate solution containing aluminum hydroxide particles. In order to prevent sticking during the removal of the solvent, the particles must be sprayed with a separating liquid, for example ethylene glycol.

Become in the usual molding machine coated foam particles used, so when using steam water-soluble constituents are dissolved out. In the aforementioned documents, the coating is in each case on applied the prefoamed foam particles.

by virtue of stability problems during suspension polymerization or the thermal lability can a number of interesting additives in the preparation in the suspension or Extrusion process not incorporated directly into the EPS granules become.

Expandable styrenic polymers such as expandable polystyrene (EPS) are usually provided with small amounts of from 0.1 to 1% by weight of a coating. The coating composition consists essentially of processing aids such as glycerol tristearate (GTS), glycerol monostearate (GMS), antistatic agents, zinc stearate or silicas ( DE-C 195 41 725 ). These are applied in powder form to the EPS raw pearl without any binding. Higher amounts of coating agent can not be realized as high abrasion during transport and processing causes problems.

Especially for halogen-free Hamm-protected expandable styrene polymers are generally high for adequate fire safety Amounts of flame retardant additives needed.

The GB 855152 describes a coating composition of discrete expandable polymer particles, a binder, and a solvent that can be applied to a surface and dried and cured into an adhesive, decorative film. The binders used are preferably phenol-formaldehyde resins. During heating, the expandable polymer particles foam on the coated substrate and form a texture in the coating film.

task The invention was expandable styrene polymers with halogen-free To provide flame retardant coating in the usual Apparatuses for foam particles prefoamed and closed Moldings can be sintered. Furthermore, should a method for applying the necessary amounts the expandable styol polymers are provided.

• A) 10 bis 99,9 Gew.-%, bevorzugt 80 bis 99 Gew.-%, bezogen auf die Beschichtungszusammensetzung, eines halogenfreien Flammschutzmittels, und
• B) 0,1 bis 90 Gew.-%, bevorzugt 1 bis 20 Gew.-%, bezogen auf die Beschichtungszusammensetzung, eines organischen Bindemittels,

enthält.Accordingly, expandable styrenic polymers having from 2 to 50% by weight, based on the expandable styrenic polymer, of a coating have been found, wherein the coating

• A) 10 to 99.9 wt .-%, preferably 80 to 99 wt .-%, based on the coating composition, of a halogen-free flame retardant, and
• B) 0.1 to 90% by weight, preferably 1 to 20% by weight, based on the coating composition, of an organic binder,

contains.

Prefers the expandable styropolymers 5 to 20 wt .-%, based on the expandable styrene polymer, a coating on.

The Weight ratio of halogen-free flame retardant A) to organic binder is preferably in the range from 1: 5 to 1:50, more preferably in the range of 1:10 to 1:20.

As expandable styrene polymers in particular expandable polystyrene (EPS) are used. The EPS particles generally have a mean particle diameter in the range of 0.1 to 3 mm. They usually contain 1 to 10, in particular 3 to 8 wt .-%, based on the expandable styrene polymer, of a volatile blowing agent, in particular a C ₃ -C ₈ hydrocarbon such as butane, pentane, hexane or cyclohexane.

Because of their high thermal insulation capability, it is particularly preferable to use expandable styrene polymers containing athermanous solids, such as carbon black, aluminum or graphite, in particular graphite having an average particle size in the range from 1 to 50 μm particle diameter in amounts of from 0.1 to 10% by weight, in particular 2 to 8 wt .-%, based on EPS, and for example from EP-B 981 574 and EP-B 981 575 are known.

Of Furthermore, the inventive expandable styrene polymers 3 to 60 wt .-%, preferably 5 to 20 wt .-%, based on the expandable styrene polymer, of a filler contain. Fillers are organic and inorganic Powders or fibrous materials, as well as mixtures thereof into consideration. When organic fillers may, for. Wood flour, starch, Flax, hemp, ramie, jute, sisal, cotton, cellulose or Aramid fibers are used. As inorganic fillers can z. As carbonates, silicates, barite, glass beads, Zeolites or metal oxides are used. Preference is given to powdery inorganic substances such as talc, chalk, kaolin (Al2 (Si2O5) (OH) 4), Aluminum hydroxide, magnesium hydroxide, aluminum nitride, aluminum silicate, Barium sulfate, calcium carbonate, calcium sulfate, silicic acid, Quartz flour, aerosil, alumina or wollastonite or spherical or fibrous, inorganic substances, such as glass beads, glass fibers or carbon fibers.

The average particle diameter or fibrous fillers the length should be in the range of cell size or less. Preference is given to an average particle diameter in the range of 1 to 100 μm, preferably in the range of 2 up to 50 μm.

Particularly preferred are inorganic fillers having a density in the range of 1.0-4.0 g / cm ³ , in particular in the range of 1.5-3.5 g / cm ³ . The whiteness / brightness (DIN / ISO) is preferably 50-100%, in particular 60-98%.

The Type and amount of fillers can change the properties the expandable styrene polymer and the obtainable therefrom Influence particle foam moldings. By use of adhesion promoters, such as maleic anhydride-modified Styrene copolymers, epoxy group-containing polymers, organosilanes or styrene copolymers with isocyanate or acid groups, the connection of the Filler to the polymer matrix and thus the mechanical Properties of the particle foam moldings are significantly improved.

In In general, inorganic fillers reduce flammability. In particular, by addition of inorganic powders, such as aluminum hydroxide, Magnesium hydroxide or borax, the fire behavior can be further improved become.

Such filler-containing expandable styrene polymers, for example, by extrusion blowing agent-containing styrene polymer melts and subsequent pressurized underwater granulation such. In WO 2005/056653 described, can be obtained.

The expandable styrene polymers may additionally be equipped with other flame retardants. You can for example, 1 to 6 wt .-% of an organic bromine compound, such as Hexabromcylcododecan (HBCD) and optionally in addition 0.1 to 0.5 wt .-% dicumyl or a peroxide inside the expandable Styrene polymers or the coating included. To be favoured However, no halogen-containing flame retardants used.

When halogen-free flame retardant A) contains the coating prefers expandable graphite, bristle, in particular zinc bristle, Melamine compounds or phosphorus compounds or intumescent Masses which, when exposed to higher temperatures, usually over 80 to 100 ° C, bloat, swell or lather while doing an insulating and form heat-resistant foam, the underlying Protects materials from the effects of fire and heat.

There the flame retardant A) is in the coating is It also possible to provide adequate fire protection when using of expandable styrene polymers that do not contain halogenated flame retardants contained, or with smaller amounts of flame retardants get along, since the flame retardant in the polymer coating concentrated on the surface of the expandable styrenic polymers and, if exposed to heat or fire, a solid scaffolding net forms.

Especially preferably contains the coating as a flame retardant A) intumescent masses containing chemically bound water or split off water at temperatures above 40 ° C, such as alkali metal silicates, metal hydroxides, metal salt hydrates and Metal oxide hydrates.

suitable Metal hydroxides are in particular those of groups 2 (alkaline earth metals) and 13 (boron group) of the periodic table. Preference is given to magnesium hydroxide, Aluminum hydroxide and borax. Particularly preferred is aluminum hydroxide.

When Metal salt hydrates are all metal salts in their crystal structure Crystal water is installed. Analog are suitable as metal oxide hydrates all metal oxides, the water of crystallization incorporated into the crystal structure contain. The number of crystal water molecules can be per formula unit the maximum possible or below lie, z. As copper sulfate pentahydrate, trihydrate or monohydrate. In addition to the water of crystallization, the metal salt hydrates or metal oxide hydrates also contain constitutional water.

preferred Metal salt hydrates are the hydrates of metal halides (in particular Chlorides), sulfates, carbonates, phosphates, nitrates or borates. Suitable examples are magnesium sulfate decahydrate, Sodium sulfate decahydrate, copper sulfate pentahydrate, nickel sulfate heptahydrate, Cobalt (II) chloride hexahydrate, chromium (III) chloride hexahydrate, sodium carbonate decahydrate, Magnesium chloride hexahydrate, and the tin borate hydrates. Magnesium sulfate decahydrate and tin borate hydrates are particularly preferred.

Also suitable as metal salt hydrates are double salts or alums, for example those of the general formula: M (I) M (III) (SO ₄ ) ₂ .12H ₂ O. As potassium, sodium, rubidium, cesium, ammonium, thallium or aluminum ions occur. As M (III) act z. As aluminum, gallium, indium, scandium, titanium, vanadium, chromium, manganese, iron, cobalt, rhodium or iridium.

When Metal oxide hydrates are suitable for. For example, alumina hydrate and preferred Zinc oxide hydrate or boric trioxide hydrate.

When halogen-free flame retardant contains the coating the expandable styrene polymer preferably a phosphorus compound, Aluminum hydroxide, borate, expandable graphite or alkali metal silicate.

As organic binder B), the coating preferably contains a polymer which has one or more glass transition temperatures in the range from -60 ° to + 100 ° C. The glass transition temperatures of the dried polymer film are preferably in the range from -30 ° to + 80 ° C., more preferably in the range from -10 ° to + 60 ° C. The glass transition temperature can after ISO 11357-2 determined by differential scanning calorimetry (DSC) at a heating rate of 20 K / min. The molecular weight of the polymer, determined by gel permeation chromatography (GPC), is generally below 400,000 g / mol, preferably in the range from 100,000 to 350,000 g / mol.

Conventional methods such as spraying, dipping or wetting the expandable styrene polymers with a polymer solution or an aqueous polymer dispersion in conventional mixers, spray devices, dipping devices or drum apparatuses can be used to coat the expandable styrene polymers be set.

When organic binders are, for example, polymers Base of monomers such as vinylaromatic monomers, such as α-methylstyrene, p-methylstyrene, ethylstyrene, tert-butylstyrene, vinylstyrene, vinyltoluene, 1,2-diphenylethylene, 1,1-diphenylethylene, alkenes such as ethylene or Propylene, dienes, such as 1,3-butadiene, 1,3-pentadiene, 1,3-hexadiene, 2,3-dimethylbutadiene, isoprene, piperylene or isoprene, α, β-unsaturated Carboxylic acids, such as acrylic acid and methacrylic acid, their esters, in particular alkyl esters, such as C1-10-alkyl esters of Acrylic acid, in particular the butyl esters, preferably n-butyl acrylate, and the C1-10 alkyl esters of methacrylic acid, in particular Methyl methacrylate (MMA), or carboxylic acid amides, for example Acrylic acid amide and methacrylic acid amide.

The Optionally, polymers may contain from 1 to 5% by weight of comonomers, such as (meth) acrylonitrile, (meth) acrylamide, ureido (meth) acrylate, 2-hydroxyethyl (meth) acrylate, 3-hydroxypropyl (meth) acrylate, acrylamidopropanesulfonic acid, Methylolacrylamide or the sodium salt of vinylsulfonic acid contain.

Prefers For example, the polymers of the coating composition are one or several of the monomers styrene, butadiene, acrylic acid, methacrylic acid, C1-4-alkyl acrylates, C1-4-alkyl methacrylates, acrylic acid amide, Methacrylamide and methylolacrylamide built up.

Particularly suitable binders for the coating are acrylate resins which are applied according to the invention as aqueous polymer dispersions to the expandable styrene polymers, if appropriate additionally with hydraulic binders based on cement, lime cement or gypsum. Suitable polymer dispersions are, for example, by free-radical emulsion polymerization of ethylenically unsaturated monomers, such as styrene, acrylates or methacrylates, as in WO 00/50480 described, available.

Especially Preference is given to pure acrylates or styrene-acrylates, which from the Monomeric styrene, n-butyl acrylate, methyl methacrylate (MMA), methacrylic acid, Acrylamide or methylolacrylamide.

When Organic binder contains the coating of the expandable Styol polymers preferably polyvinylpyrrolidone, monocarboxylic acids or polyacrylates.

The Preparation of a suitable polymer dispersion takes place in itself known manner, for example by emulsion, suspension or dispersion polymerization, preferably in the aqueous phase. You can also use the polymer by solution or bulk polymerization, if necessary split and the polymer particles then in water in the usual way. In the polymerization are the usual for the respective polymerization Initiators, emulsifiers or suspension aids, regulators or other excipients used with; and polymerized continuously or discontinuous in the usual for the respective process Temperatures and pressures in common reactors.

• a') 20 bis 95, bevorzugt 40 bis 90 Gew.-Teilen einer Aluminiumhydroxidsuspension mit einem Aluminiumhydroxidgehalt von 10 bis 90, bevorzugt 20 bis 70 Gew.-%,
• b') 5 bis 40, bevorzugt 10 bis 30 Gew.-Teile einer Polymerdispersion mit einem Feststoffgehalt von 10 bis 60, bevorzugt 20 bis 50 Gew.-%,

erhalten werden.A preferred coating composition can be prepared by mixing
40 to 80, preferably 50 to 70 parts by weight of a waterglass solution having a water content of 40 to 90, preferably 50 to 70 wt .-%,
20 to 60, preferably 30 to 50 parts by weight of a waterglass powder having a water content of 0 to 30, preferably 1 to 25 wt .-%, and
5 to 40, preferably 10 to 30 parts by weight of a polymer dispersion having a solids content of 10 to 60, preferably 20 to 50 wt .-%, or by mixing

• a ') 20 to 95, preferably 40 to 90 parts by weight of an aluminum hydroxide suspension having an aluminum hydroxide content of 10 to 90, preferably 20 to 70 wt .-%,
• b ') 5 to 40, preferably 10 to 30 parts by weight of a polymer dispersion having a solids content of 10 to 60, preferably 20 to 50 wt .-%,

to be obtained.

additionally to the flame retardant A) and the binder B), the coating also other, different from A) and B) additives, such as inorganic Fillers, such as pigments or halogenated flame retardants contain. The proportion of additives depends on its type and the desired effect from and amounts to inorganic fillers usually 15 to 99 wt .-%, preferably from 20 to 98% by weight, based on the coating composition

Prefers is used to reduce the thermal conductivity IR absorbers, such as carbon black, coke, aluminum or graphite in quantities from 0.1 to 10% by weight, in particular in amounts of from 2 to 8% by weight, based on the solid of the coating used.

Prefers becomes soot with a mean primary particle size in the range of 10 to 300 nm, in particular in the range of 30 to 200 nm used. The BET surface area is preferably in the Range from 10 to 120 m2 / g.

When Graphite is preferably graphite having a mean particle size used in the range of 1 to 50 microns.

Of others can the invention expandable styrenic polymers with amphiphilic or hydrophobic organic Compound be coated. The coating with water repellent takes place expediently before applying the aqueous polymer dispersion according to the invention. Among the hydrophobic organic compounds are in particular C10-C30 paraffin waxes, reaction products of N-methylolamine and a fatty acid derivatives, reaction products of a C9-C11 oxo-alcohol with ethylene oxide, propylene oxide or butylene oxide or polyfluoroalkyl (meth) acrylates or mixtures thereof, preferably in the form of aqueous Emulsions can be used.

preferred Water repellents are paraffin waxes having 10 to 30 carbon atoms in the carbon chain, which preferably has a melting point between 10 and 70 ° C, in particular between 25 and 60 ° C, exhibit. Such paraffin waxes are, for example, in the BASF commercial products RAMASIT KGT, PERSISTOL E and PERSISTOL HP as well as in AVERSIN HY-N from Henkel and CEROL ZN from Sandoz.

Another class of suitable hydrophobizing agents are resinous reaction products of an N-methylolamine with a fatty acid derivative, e.g. As a fatty acid amide, amine or alcohol, as described for. In US-A 2,927,090 or GB-A 475 170 are described. Their melting point is generally 50 to 90 ° C. Such resins are for. In the BASF commercial product PERSISTOL HP and in ARCOPHOB EFM from Hoechst.

After all Polyfluoroalkyl (meth) acrylates are also suitable, for example Polyperfluorooctyl. This substance is in the BASF commercial product PERSISTOL O and OLEOPHOBOL C from Pfersee included.

When other coating agents are antistatic agents, such as emulsifier K30 (Mixture of secondary sodium alkanesulfonates) or glycerol stearates, such as glycerol monostearate GMS or glycerol tristearate. However, the method according to the invention is distinguished characterized in that the for the coating of expandable Polystyrene customary coating compositions, in particular stearates can be used to a reduced extent or completely eliminated, without negatively affecting product quality.

• a) Vorlegen von expandierbaren Styrolpolymeren in einer Mischvorrichtung,
• b) Aufbringen von 0,1 bis 90 Gew.-%, bezogen auf die Beschichtungszusammensetzung, eines organischen Bindemittels B) auf die expandierbaren Styrolpolymeren unter gleichmäßiger Umwälzung,
• c) Aufbringen von 10 bis 99,9 Gew.-% bezogen auf die Beschichtungszusammensetzung, eines halogenfreien Flammschutzmittels A),

wobei die Beschichtung aus organischem Bindemittel und halogenfreiem Flammschutzmittel 2 bis 50 Gew.-%, bezogen auf das expandierbare Styrolpolymer, ausmacht.The expandable styrenic polymers of the present invention can be prepared by a process comprising the following steps:

• a) presentation of expandable styrene polymers in a mixing device,
• b) applying from 0.1 to 90% by weight, based on the coating composition, of an organic binder B) to the expandable styrene polymers with uniform circulation,
• c) applying from 10 to 99.9% by weight, based on the coating composition, of a halogen-free flame retardant A),

wherein the coating of organic binder and halogen-free flame retardant 2 to 50 wt .-%, based on the expandable styrene polymer, makes up.

The Application of the organic binder (stage b) and the halogen-free Flame retardant (step c) is preferably carried out alternately in two or more subsets.

The Drying of an applied to the expandable styrene polymers Polymer dispersion can, for example, in a fluidized bed, paddle dryer or by passing air or nitrogen through a loose one Pouring done. In general, for education the water-insoluble polymer film has a drying time from 5 minutes to 24 hours, preferably 30 to 180 minutes a temperature in the range of 0 to 80 ° C, preferably in Range of 30 to 60 ° C is sufficient.

Of the Water content of the coated expandable styrene polymers is after drying, preferably in the range from 1 to 40% by weight, especially preferably in the range of 2 to 30 wt .-%, most preferably in the range of 5 to 15 wt .-%. He can for example by Karl Fischer titration the coated expandable styrene polymers are determined.

By Prefoaming the expandable invention Strol polymers with hot air or steam in a prefoamer can foam particles with the desired Density can be obtained. By prefoaming once or several times in a pressure or continuous prefoamer in this case final bulk densities below 10 g / l are obtained.

The expandable styrene polymers coated according to the invention can be sintered in conventional molds with hot air or steam to give foam moldings. Depending on the amount of flame retardant A) in the coating, the foam body in the building material class B1 or A2 according to DIN 4102 or Euroclasses A2, B and C according to the European fire classification DIN EN 13501-1 get ranked.

At the Sintering or gluing the foam particles, the pressure for example, by reducing the volume of the mold by means of a movable punch are generated. In general, this is one Pressure set in the range of 0.5 to 30 kg / cm2. The mixture from coated foam particles is this in the open Filled shape. After closing the mold pressed the foam particles with the stamp, with the air escapes between the foam particles and reduces the gusset volume becomes. The foam particles are through the polymer coating connected to the foam molding.

The Mold tool will be according to the desired geometry designed the foam body. The degree of filling is directed u. a. according to the desired thickness of the later Molding. For foam boards can be a simple box-shaped Form to be used. Especially with more complicated geometries It may be necessary to fill the bulk of the mold compacted filled particles and in this way eliminate unwanted voids. The compacting can z. B. by shaking the form, wobbling or other appropriate measures are taken.

to Acceleration of setting can be hot air or water vapor pressed into the mold or heated the mold. to Temperature control of the mold, however, any heat transfer media, as oil or steam are used. The hot air or the shape is expediently for this purpose to a temperature in the range of 20 to 120 ° C, preferably Tempered at 30 to 90 ° C.

alternative or in addition, the sintering may be continuous or discontinuously under irradiation of microwave energy. As a rule, microwaves in the frequency range between 0.85 and 100 GHz, preferably 0.9 to 10 GHz and irradiation times between Used for 0.1 to 15 minutes. This can also be foam boards with a thickness of more than 5 cm.

at Use of hot air or steam with temperatures in the range of 80 to 150 ° C or by irradiation of Microwave energy usually forms an overpressure from 0.1 to 1.5 bar, allowing the procedure even without external Pressure and without volume reduction of the mold can be. By the microwaves or higher temperatures resulting internal pressure leaves the foam particles easily expand, in addition to bonding over the polymer coating also by softening the foam particles can weld yourself. It will disappear the gussets between the foam particles. For acceleration the setting can also here the form as described above with a Heat transfer medium additionally heated become.

to continuous production of the foam moldings Also suitable are double belt systems such as those used to produce polyurethane foams be used. For example, the pre-foamed and coated foam particles continuously on the lower of two metal bands, which optionally has a perforation may be applied, and with or without Compression by the converging metal bands too endless foam boards are processed. At a high Compression pressure are preferably metal link chains used.

Also suitable is a double-band system with a lower band and a synchronously with the lower band moving upper band has, as for example in WO 02/26457 for the production of inorganic foams is described. The subband of the double belt system consists of a variety of Segments that define in cross section the lower and the two lateral areas of the foam profile. The upper belt dips in a portion of the double belt system sealing in the segments of the lower belt, so that this portion of the double belt plant forms a closed, well-sealed room. The segments of the upper and lower band are preferably made of stainless steel.

In In a procedural execution, the volume between the Both bands are increasingly decreasing, reducing the product between the bands is compressed and the gusset between the foam particles disappear. After a curing zone an endless plate is obtained. In another embodiment The volume between the bands can be kept constant and a zone with hot air or microwave irradiation go through in the foam particles nachschäumen. Again, the gussets disappear and an endless plate is obtained. It is also possible to use the two continuous Verfahrensauführungen to combine.

in the Case of a double belt system with metal bands is the Microwave prefers laterally in the gap between the upper and irradiated lower metal band. In another embodiment can the metal strip section after compression end, the Further transport and shape retention of the endless foam board is also circulating through a downstream system coated natural or synthetic fiber ribbons which are both over the side gap as well flat through the natural or artificial fiber ribbons can be irradiated with a microwave

The Thickness, length and width of foam boards can be in Wide limits vary and is determined by the size and closing force of the tool limited. The thickness of the Foam sheets are usually 1 to 500 mm, preferably 10 to 300 mm.

The density of the foam moldings according to DIN 53420 is usually 10 to 120 kg / m ³ , preferably 20 to 90 kg / m ³ . With the method it is possible to obtain foam moldings with uniform density over the entire cross section. The density of the edge layers corresponds approximately to the density of the inner regions of the foam molding.

at The process can also crushed foam particles be used from recycled foam moldings. For the production of foam moldings can the shredded foam recyclates to 100% or z. B in units from 2 to 90% by weight, in particular from 5 to 25% by weight, together with virgin material be used without significant impairment of Strength and mechanical properties.

The Method is suitable for the production of simple or complex Foam moldings, such as plates, blocks, tubes, rods, Profiles, etc. Preferred are plates or blocks, which then sawn or cut into slabs can be made. You can, for example in construction for the insulation of exterior walls be used. They are particularly preferred as the core layer for the production of sandwich element, for example so-called structural insulation panels (SIP) used which the construction of cold stores or warehouses be used.

The Expandable styrene polymer according to the invention can prefoamed according to the conventional EPS processing method and processed into moldings or blocks. The Welding of prefoamed EPS granules This is due to the presence of the organic binder facilitated in the coating. The particle foams produced therefrom show a high thermal stability, favorable Fire protection and good heat insulation.

Further Applications include pallets of foam as Replacement for wooden pallets, cover viewing panels, refrigerated containers, Caravans. Due to the excellent fire resistance These are also suitable for air freight.

Examples:

• Additive A1: Struktol POLYDIS 3710 (reactive phosphorus compound)
• Additive A2: aluminum hydroxide
• Additive A3: soda waterglass powder (Portil N)
• Binder BM 1: Luvitec K30 ^® (30% polyvinylpyrrolidone solution in ethanol)
• Binder BM 2: Tefacid (unsaturated linear monocarboxylic acid)
• Binder BM 3: Acronal ^® S790 (acrylic dispersion, solids content: about 50%)

Example 1-7

expandable Polystyrene granules were packed in a paddle mixer with 5 l void volume (Somakon) submitted. The mixer was until the end of the coating operated under a nitrogen atmosphere. The mixer speed was chosen so that a uniform Circulation of the beads was guaranteed. Then it became a portion of the binder (50%) is added slowly while the mixer is running. After a corresponding post-mixing time, at which the binder was evenly distributed on the beads was a part of the additive slowly rotating within 3-5 with the mixer rotating Minutes added. After a short mixing time was another Part of the additive and the remainder of the binder added. The drying took place in the mixer at a temperature of the gas space of 60 ° C.

Table 1 shows the additives and binders used (binder solution or dispersion used). The weight concentration data relate to the EPS particles used. Table 1 example additive Additive amount [wt%] binder Binder [% by weight] 1 A1 14.3 BM 1 2 × 0.5 2 A1 8.0 BM 1 0.3 3 A1 6.35 BM 2 1.5 4 A2 17 BM 1 2.5 5 A3 16.6 BM 3 2.5 6 A3 14.1 BM 3 1.1 7 A4 16.6 BM 3 2.0

QUOTES INCLUDE IN THE DESCRIPTION

This list The documents listed by the applicant have been automated generated and is solely for better information recorded by the reader. The list is not part of the German Patent or utility model application. The DPMA takes over no liability for any errors or omissions.

Cited patent literature

• WO 2006/082233 [0002]
• WO 00/050500 [0003]
• WO 2005/105404 [0004]
• WO 2005/07331 [0005]
• - DE 19541725 C [0008]
• GB 855152 [0010]
• - EP 981574 B [0016]
• EP 981575 B [0016]
• WO 2005/056653 [0022]
• WO 00/50480 [0038]
• US 2927090 [0049]
• - GB 475170 [0049]
• WO 02/26457 [0064]

Cited non-patent literature

• - ISO 11357-2 [0033]
• - DIN 4102 [0057]
• - DIN EN 13501-1 [0057]
• - DIN 53420 [0068]

Claims (7)

Expandable styrenic polymers, which have 2 to 50 wt .-%, based on the expandable styrene polymer, a coating, characterized in that the coating A) 10 to 99.9 wt .-%, based on the coating composition, of a halogen-free flame retardant, and B) 0.1 to 90 wt .-%, based on the coating composition, of an organic binder. Expandable polystyrenes according to claim 1, characterized characterized in that the coating is off A) 80 to 99% by weight, based on the coating composition, a halogen-free Flame retardant, and B) 1 to 20 wt .-%, based on the Coating composition, an organic binder consists. Expandable styrene polymers according to claim 1 or 2, characterized in that the coating as halogen-free Flame retardant A) a phosphorus compound, aluminum hydroxide, Contains borate, expandable graphite or alkali metal silicate. Expandable styrenic polymers according to any one of claims 1 to 3, characterized in that the coating as organic Binder B) polyvinylpyrrolidone, monocarboxylic acids or Contains polyacrylates. Expandable styrenic polymers according to any one of claims 1 to 4, characterized in that the weight ratio halogen-free flame retardant A) to organic binder in Range from 1: 5 to 1:50. Process for the preparation of expandable styol polymers, comprising the steps a) presentation of expandable styrene polymers in a mixing device, b) applying from 0.1 to 90% by weight, based on the coating composition, an organic binder B) to the expandable styrene polymers under uniform Circulation, c) application of 10 to 99.9 wt .-% based to the coating composition, a halogen-free flame retardant A) wherein the coating of organic binder and halogen-free flame retardant 2 to 50 wt .-%, based on the expandable styrenic polymer. Method according to Claim 6, characterized that the application of the organic binder (stage b) and the halogen-free flame retardant (stage c) alternately in two or more subsets takes place.