WO2010146146A1 - Coated foam particles - Google Patents

Abstract

The invention relates to foam particles, preferably composed of a polyolefin polymer or styrene polymer, comprising a combination of a coating containing silicate and a coating based on a polyurethane and/or polyurea.

Description

 Coated foam particles Description

The invention relates to coated foam particles, a process for their preparation and foam moldings produced therefrom and their use.

Particulate foams are usually obtained by sintering foam particles, for example prefoamed expandable polystyrene particles (EPS) or expanded polypropylene particles (EPP) in closed forms by means of steam.

Flame-retardant polystyrene foams are generally equipped with halogen-containing flame retardants, such as hexabromocyclododecane (HBCD). However, the approval as insulation 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.

In WO 2007/012441 A2 foams are described with an inorganic coating. The foams can for example consist of EPS, EPP, PET and PU. From EP 0036616 B1 the foaming of water glass and / or inorganic additives with a rigid polyurethane foam is known. From WO 2007/023089 it is known to provide prefoamed EPS particles with an inorganic coating and to compress them.

WO 00/050500 A1 describes flameproofed 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.

WO 2005/105404 A1 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.

WO 2007/023089 A1 describes a process for the production of foam moldings from prefoamed foam particles which comprise a polymer coating. have direction. The preferred polymer coating used is a mixture of a waterglass solution, waterglass powder and a polymer dispersion. If desired, hydraulic binders based on cement or metal salt hydrates, for example aluminum hydroxide, may be added to the polymer coating. A similar process is described in WO 2008/0437 A1, according to which the coated foam particles can be dried and then processed into a fire and heat-resistant foam moldings.

WO 00/52104 A1 relates to a fire-proofing layer-forming fire protection coating based on foam-forming and carbon-forming substances in the event of fire, which contains melamine polyphosphate as the blowing agent. Information on water resistance is not included.

WO 2008/043700 A1 relates to a process for producing coated foam particles with a water-insoluble polymer film. The non-prepublished patent application PCT / EP 2008/06136 relates to a coating composition for foam particles containing a clay mineral, an alkali metal silicate and a film-forming polymer.

Hydraulic binders such as cement bind in aqueous slurry with carbon dioxide even at room temperature. As a result, embrittlement of the foam plate occur. In addition, keep the foam plates produced according to the cited prior art temperatures of about 800 ⁰ C in case of fire and break down in case of fire.

The known coating compositions are in need of improvement in view of the simultaneous improvement of flame / heat resistance and their water resistance in water exposure or in increased humidity. Many known materials lose their original shape after a short time in the case of direct water exposure. In addition, if a standard fire test is performed, such materials often completely lose their structural integrity. As a rule, this leaves powdery mixtures which no longer meet the technical requirements.

In particular, a major problem is to provide coatings such that they remain in shape consistently under the influence of moisture and / or impact water. In this case, so-called efflorescence occurs on the material or leaching of the coating, resulting in changed material properties. For example, if a certain portion of the coating is washed out, the material loses its structural integrity in the event of fire. The present invention therefore an object of the invention to provide improved coated foam particles and foam moldings produced therefrom, which have both a sufficient flame / heat resistance and a sufficient water resistance with prolonged exposure to water, especially in so-called Durability tests in which a Building material increased humidities (near 100%) and temperatures around 65 ⁰ C is exposed.

The present invention relates to foam particles, in particular of a polyolefin or styrene polymers, characterized in that the foam particles are coated with a combination of a silicate-containing coating and a coating based on a polyurethane and / or polyurea.

foam particles

In a particularly preferred embodiment, the foam particles are selected from expanded polyolefin particles or prefoamed particles of expandable styrene polymers (EPS).

Expanded polyolefins, such as expanded polyethylene (EPE) or expanded polypropylene (EPP) or prefoamed particles of expandable styrene polymers, in particular expandable polystyrene (EPS), can be used as the foam particles. The foam particles generally have a mean particle diameter in the range of 2 to 10 mm. The bulk density of the foam particles is generally 5 to 100 kg / m ³ , preferably 5 to 40 kg / m ³ and in particular 8 to 16 kg / m ³ , determined according to DIN EN ISO 60.

The foamed particles based on styrene polymers can be obtained by prefetching EPS with hot air or steam in a prefoamer to the desired density. By prefoaming once or several times in a pressure or continuous prefoamer, final bulk densities of less than 10 g / l can be obtained.

The foam particles can also be based on polyethylene (PE), polyamide (PA), styrene-acrylonitrile (SAN), amsan (α-methylstyrene-acrylonitrile); Polylactide (PLA), polybutylene terephthalate (PBT), PBAT (polybutylene adipate), melamine resin foam or polyesters.

Silicate-containing coating The silicate-containing coating preferably contains a water-soluble alkali silicate. In a particularly preferred embodiment, the silicate-containing coating is based on a coating composition which contains: a) 20 to 70 parts by weight of a clay mineral b) 20 to 70 parts by weight of an alkali silicate c) 1 to 30 parts by weight of a film-forming polymer and optionally further constituents, in particular d) optionally 1 to 20 parts by weight of a crosslinking agent, in particular based on a phosphate or a melamine compound.

The silicate-containing coating composition is preferably used as an aqueous dispersion, wherein the water content including the water bound, for example, as water of crystallization is preferably in the range of 10 to 40, in particular 15 to 30 wt .-% based on the total aqueous dispersion.

In a particularly preferred embodiment, furthermore, e) contains a hydrophobizing amount of a silicon-containing compound, in particular a silicone, in particular 0.2 to 5 parts by weight. In a particularly preferred embodiment, this is a silicone emulsion with silicone particles of different sizes. As a result, a particularly good penetration in porous materials can be achieved.

A preferred silicate-containing coating composition contains

a) 30 to 50 parts by weight of a clay mineral b) 30 to 50 parts by weight of an alkali silicate c) 5 to 20 parts by weight of a film-forming polymer d) optionally 5 to 10 parts by weight of a phosphate or a melamine e) optionally 0.5 to 3 parts by weight of a silicone f) 5 to 40 parts by weight of an infrared absorbing pigment.

The amounts given above each refer to solids based on solids of the coating composition. The components a) to e) or a) to f) preferably add up to 100% by weight.

Preferably, the weight ratio of clay mineral to alkali silicate in the coating composition is in the range of 1: 2 to 2: 1.

Clay minerals as a), in particular, allophane Al ₂ [SiO _5] & θ3 are ^■ n H ₂ O, kaolinite

Al ₄ [(OH) ₈ | Si ₄ Oio], Halloysite Al ₄ [(OH) ₈ | Si ₄ Oio] ^{■ 2H} ₂ O, montmorillonite (smectite) (Al, Mg, Fe) ₂ [(OH ₂ | Si, Al) ₄ O _10] ^■ Na _0, 3 ₃ (H ₂ O) _4, vermiculite Mg ₂ (Al, Fe, Mg) [(OH ₂ | (Si, Al) ₄ O _10] ^■ Mgo _{, 35} (H ₂ O) ₄ containing minerals or mixtures thereof. Kaolin is particularly preferably used.

The alkali silicate b) used is preferably a water-soluble alkali metal silicate having the composition M ₂ O (SiC) _n with M = sodium or potassium and n = 1 to 4 or mixtures thereof.

In general, the silicate-containing coating composition contains as verfilmendes polymer c) a non-crosslinked polymer comprising one or more glass transition temperatures in the range of -60 ° to + 100 ⁰ C. Preferably, the Glasüber- are transition temperatures of the dried polymer film in the range of -30 ° to + 80 ⁰ C, more preferably in the range of -10 ° to + 60 ⁰ C. The glass transition temperature (by differential scanning calorimetry DSC, in accordance with ISO 1 1357- 2, heating rate 20 K / min) can be determined. The molecular weight of the polymer film, determined by gel permeation chromatography (GPC), is preferably below 400,000 g / mol.

The silicate-containing coating composition preferably comprises as film-forming polymer an emulsion polymer of ethylenically unsaturated 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, ß-unsaturated carboxylic acids such as acrylic acid and methacrylic acid, esters thereof, particularly alkyl esters, such as C ₁₀ alkyl esters of acrylic acid, especially butyl, preferably n-butyl acrylate, and the Ci.io-alkyl esters of methacrylic acid, particularly methyl methacrylate (MMA), or carboxylic acid amides, for example acrylamide and methacrylic acid amide.

The polymers may optionally 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, Acrylamidpropansulfonsäure, methylolacrylamide or the sodium salt of vinylsulfonic acid.

More preferably, the polymer is acrylates verfilmende from one or more of the monomers styrene, butadiene, acrylic acid, methacrylic acid, Ci _-4 alkyl acrylates, Ci _-4 -Alkylmeth-, acrylamide, methacrylamide and methylolacrylic listed builds.

Suitable polymers c) are obtainable, for example, by free-radical emulsion polymerization of ethylenically unsaturated monomers, such as styrene, acrylates or methacrylates, as described in WO 00/50480. The polymers c) are prepared in a manner known per se, for example by emulsion, suspension or dispersion polymerization, preferably in the aqueous phase. The polymer can also be prepared by solution or bulk polymerization, optionally divided and the polymer particles subsequently dispersed in water in the usual way. During the polymerization, the initiators, emulsifiers or suspension aids, regulators or other auxiliaries customary for the particular polymerization process are used with used; it is polymerized continuously or discontinuously at the usual temperatures and pressures for the respective process in conventional reactors.

The crosslinker d) to be used according to the invention is in particular a phosphate or a melamine compound.

In a particularly preferred embodiment, the phosphate is an inorganic phosphate, in particular aluminum phosphate, boron phosphate or ammonium phosphate.

In a further preferred embodiment, the melamine is a melamine phosphate or melamine cyanurate.

In a further particularly preferred embodiment, the crosslinker is a methyl aminopolyphosphate, in particular of the formula

(HMPO3) _n in which mean

M is a melamine radical n is an integer of at least 2, in particular 2 to 10,000.

In a preferred embodiment, crosslinking agent d) comprises melanin polyphosphate together with melamine cyanurate.

Further crosslinkers d) are, for example, amine sulfonate, dicandiamide and tris-hydrazino-triazines.

The silicone e) to be used according to the invention is preferably an aqueous silicone emulsion. In a particularly preferred embodiment, at least one of the following constituents is contained in the silicone emulsion: silicic acid, diethoxycitylsilyltrimethylsil, dimethylsiloxane, hydroxy-limited aminoethylaminopropylsilsesquioxane. To reduce the thermal conductivity, preference is given to using an infrared-absorbing pigment (IR absorber), such as carbon black, coke, aluminum, graphite or titanium dioxide, in amounts of from 5 to 40% by weight, in particular in amounts of from 10 to 30% by weight, based on the solid of the coating used. The particle size of the IR-absorbing pigment is generally in the range of 0.1 to 100 .mu.m, in particular in the range of 0.5 and 10 microns.

Carbon black with an average primary particle size in the range from 10 to 300 nm, in particular in the range from 30 to 200 nm, is preferably used. The BET surface area is preferably in the range of 10 to 120 m ² / g.

The graphite used is preferably graphite having an average particle size in the range from 1 to 50 μm.

Furthermore, the silicate-containing coating composition flame retardants, such as expanded graphite, borates, in particular zinc borates, especially ortho-boron phosphate, or intumescent masses which inflate when exposed to higher temperatures, usually above 80 to 100 ⁰ C, swell, or foam and thereby forming an insulating and heat-resistant foam that protects the underlying heat-insulating foam particles from the effects of fire and heat

When using flame retardants in the polymer coating, it is also possible to achieve adequate fire protection with foam particles which contain no, in particular no halogenated flame retardants, or to make do with smaller amounts of flame retardant, since the flame retardant concentrates in the polymer coating is located on the surface of the foam particles and forms a solid scaffolding net when exposed to heat or fire.

The silicate-containing coating composition may, as additional additives, cleave intumescent compositions containing chemically bound water, or at temperatures above 40 ^° C., such as 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, calcium hydroxide, aluminum hydroxide and borax. Alumni- nium hydroxide is particularly preferred. Suitable metal salt hydrates are all metal salts in whose crystal structure water of crystallization is incorporated. Likewise suitable metal oxide hydrates are all metal oxides which contain water of crystallization incorporated into the crystal structure. The number of crystal water molecules per formula unit may be the maximum possible or below, z. As copper sulfate pentahydrate, trihydrate or monohydrate. In addition to the water of crystallization, the metal salt hydrates or metal oxide hydrates may also contain constitutional water.

Preferred metal salt hydrates are the hydrates of metal halides (especially 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: MW (SCU) ₂ ^.12H ₂ O. As M ¹ , z. For example, potassium, sodium, rubidium, cesium, ammonium, thallium or aluminum ions occur. As M ¹ ", for example, aluminum, gallium, indium, scandium, titanium, vanadium, chromium, manganese, iron, cobalt, rhodium or iridium.

As metal oxide hydrates z. For example, alumina hydrate and preferably zinc oxide hydrate or boron trioxide hydrate.

In addition to the clay minerals, additional minerals, for example cements, aluminum oxides, vermicullite or perlite, can additionally be added to the silicate-containing coating. These may be incorporated into the silicate-containing coating composition in the form of aqueous slurries or dispersions. Cements can also be applied to the foam particles by "powdering". The necessary for the setting of the cement water can then be supplied during sintering with steam.

Polyurethane coating

In addition to the silicate-containing coating, the foam particles according to the invention have a coating based on a polyurethane and / or polyurea. For the purposes of the present invention, polyureas are also referred to below as polyurethanes. For this purpose, prefoamed EPS balls are preferably homogeneously wetted with the silicate-containing coating and subsequently with a polyurethane coating coated, molded and cured. The polyurethane coating can be applied in the form of a dissolved or dispersed polyurethane. In a preferred embodiment, the polyurethane coating is produced by adding at least one isocyanate and at least one isocyanate-reactive compound. It is important to ensure that the pot life of the coating solution is long enough to achieve sufficient compression / shaping. This can be controlled by selecting suitable delayed coating systems, using thermosensitive catalysts under thermal activation or selective activation by using microwave radiation.

In a preferred embodiment, the polyurethane coating of the foam particles is a massive coating that has at least substantially no foam structure. In a further preferred embodiment, the polyurethane coating has a foam structure, for example a soft or hard foam structure.

The polyurethane coating of the invention is obtainable by reactions of at least one polyisocyanate, preferably a diisocyanate A) with at least one isocyanate-reactive component B, preferably a polyol and optionally isocyanate-reactive chain extenders C).

The components A, B, C and optionally D and / or E customarily used in the preparation of the polyurethanes are described below by way of example:

a) As organic isocyanates A it is possible to use generally known aromatic, aliphatic, cycloaliphatic and / or araliphatic isocyanates, preferably diisocyanates, for example 2,2'-, 2,4'- and / or 4,4'-diphenylmethane diisocyanate (MDI), 1, 5-naphthylene diisocyanate (NDI), 2,4- and / or 2,6-toluene diisocyanate (TDI), diphenylmethane diisocyanate, 3,3'-dimethyl-diphenyl-diisocyanate, 1, 2-diphenylethane diisocyanate and / or Phenylene diisocyanate, tri-, tetra-, penta-, hexa-, hepta- and / or octamethylene diisocyanate, 2-methyl-pentamethylene-diisocyanate-1,2,5-ethyl-butylene-diisocyanate-1,4-pentamethylene -diisocyanate-1, 5, butylene-diisocyanate-1,4-l-isocyanato-3,3,5-trimethyl-5-isocyanatomethyl-cyclohexane (isophorone diisocyanate, IPDI), 1-isocyanato-4 - [(4- isocyanatocyclohexyl) methyl] cyclohexane (H12MDI), 2,6-diisocyanatohexanecarboxylic acid ester, 1,4- and / or 1,3-bis (isocyanatomethyl) cyclohexane (HXDI), 1,4-cyclohexane diisocyanate, 1-methyl-2,4 - and / or -2,6-cyclohex an-diisocyanate and / or 4,4-, 2,4'- and 2,2'-dicyclohexylmethane diisocyanate, preferably 2,2'-, 2,4'- and / or 4,4'-diphenylmethane diisocyanate (MDI), 1, 5-naphthylene diisocyanate (NDI), 2,4- and / or 2,6-tolylene diisocyanate (TDI), hexamethylene diisocyanate, 1-isocyanato-4 - [(4-isocyanatocyclohexyl) methyl] cyclohexane, and / or IPDI.

Particularly preferred isocyanates are 2,2'-, 2,4'- and / or 4,4'-

Diphenylmethane diisocyanate (MDI).

b) As isocyanate-reactive compounds (B) it is possible to use the generally known isocyanate-reactive compounds, for example polyesterols, polyetherols and / or polycarbonatediols, which are usually also grouped under the term "polyols", with molecular weights (Mn) between 500 and 8000, preferably 600 to 6000, in particular 800 to less than 3000 g / mol, and preferably an average functionality to isocyanates of 1, 8 to 2.3, preferably 1, 9 to 2.2, in particular 2.

Preference is given to using polyether polyols, for example those based on generally known starter substances and conventional alkylene oxides, for example ethylene oxide, propylene oxide and / or butylene oxide, preferably Polyethe- role based on propylene oxide-1, 2 and ethylene oxide and in particular polyoxytetramethylene glycols. Furthermore, it is possible to use as polyetherols so-called low-unsaturated polyetherols. In the context of this invention, low-unsaturated polyols are understood as meaning, in particular, polyether alcohols having a content of unsaturated compounds of less than 0.02 meq / g, preferably less than 0.01 meq / g. Such polyether alcohols are usually prepared by addition of alkylene oxides, in particular ethylene oxide, propylene oxide and mixtures thereof, to the diols or triols described above in the presence of highly active catalysts.

In another preferred embodiment, polyesterols are used, for example, from dicarboxylic acids having 2 to 12 carbon atoms, preferably 4 to 6 carbon atoms and polyhydric alcohols. Suitable polyester diols can be prepared, for example, from dicarboxylic acids having 2 to 12 carbon atoms, preferably 4 to 6 carbon atoms, and polyhydric alcohols. Suitable dicarboxylic acids are, for example: aliphatic dicarboxylic acids, such as succinic acid, glutaric acid, adipic acid, suberic acid, azelaic acid and sebacic acid and aromatic dicarboxylic acids, such as phthalic acid, isophthalic acid and terephthalic acid. The dicarboxylic acids can be used individually or as mixtures, eg. In the form of an amber, glutaric and adipic acid mixture. For the preparation of the polyester diols it may gege It may also be advantageous to use, instead of the dicarboxylic acids, the corresponding dicarboxylic acid derivatives, such as carbonic diesters having 1 to 4 carbon atoms in the alcohol radical, carboxylic anhydrides or carbonyl chlorides. Examples of polyhydric alcohols are glycols having 2 to 10, preferably 2 to 6 carbon atoms, such as ethylene glycol, diethylene glycol, 1, 4-butanediol, 1, 5

Pentanediol, 1, 6-hexanediol, 1, 10-decanediol, 2,2-dimethyl-1, 3-propanediol, 1, 3-propanediol and dipropylene glycol. Depending on the desired properties, the polyhydric alcohols may be used alone or optionally mixed with each other. Also suitable are esters of carbonic acid with the diols mentioned, in particular those having 4 to 6 carbon atoms, such as 1, 4-

Butanediol or 1,6-hexanediol, condensation products of hydroxycarboxylic acids, for example hydroxycaproic acid and polymerization products of lactones, for example optionally substituted caprolactones. Preferred polyether diols are ethanediol polyadipates, 1,4-butanediol polyadipates, ethanediol-1,4-butanediol polyadipates, 1,6-hexanediol neopentyl glycol polyadipates, 1,6-hexanediol-1,4 butanediol polyadipate and polycaprolactone. The polyester diols have molecular weights of 500 to 5000 g / mol and can be used individually or in the form of mixtures with one another.

Highly reactive catalysts for the preparation of the polyether polyols are, for example, cesium hydroxide and multimetal cyanide catalysts, also referred to as DMC catalysts. A frequently used DMC catalyst is the zinc hexacyanocobaltate. The DMC catalyst can be left in the polyether alcohol after the reaction, usually it is removed, for example by sedimentation or filtration.

Instead of a polyol, it is also possible to use mixtures of different polyols. The thermoplastic polyurethane according to the invention is particularly preferably based on polytetrahydrofuran having a molecular weight (Mn) of between 600 and 2000 g / mol, preferably 800 and 1400 g / mol, particularly preferably 950 and 1050 g / mol as component (b).

As chain extenders C it is possible to use generally known aliphatic, aliphatic, aromatic and / or cycloaliphatic compounds having a molecular weight of from 50 to 499 g / mol, preferably 2-functional compounds, for example alkanediols having from 2 to 10 carbon atoms in the formula Alkylene radical, preferably butanediol-1, 4, hexanediol-1, 6 and / or di-, tri-, tetra-, penta-, hexa-, hepta-, octa-, nona- and / or decaalkylene glycols having 3 to 8 carbon atoms, preferably unbranched alkanediols, in particular propane-1, 3-diol and butane-1, 4-diol. d) Suitable catalysts D, which accelerate in particular the reaction between the NCO groups of the diisocyanates A and B, are the known and customary in the prior art tertiary amines, such as. Triethylamine, dimethylcyclohexylamine, N-methylmorpholine, N, N'-

Dimethylpiperazine, 2- (dimethylaminoethoxy) ethanol, diazabicyclo- (2,2,2) - octane and the like, and in particular organic metal compounds such as titanic acid esters, iron compounds such. As iron (Ml) - acetylacetonate, tin compounds, eg. As tin diacetate, tin dioctoate, tin dilaurate or Zinndialkylsalze aliphatic carboxylic acids such as dibutyltin diacetate, dibutyltin dilaurate or the like. The catalysts are usually used in amounts of 0.00001 to 0.1 parts by weight per 100 parts by weight of polyhydroxyl compound (b).

e) In addition to catalysts D the structural components A to C and conventional aids E can be added. Mention may be made, for example, blowing agents, surface-active substances, flame retardants, nucleating agents, lubricants and mold release agents, dyes and pigments, stabilizers, for. Against hydrolysis, light, heat or discoloration, inorganic and / or organic fillers, reinforcing agents, plasticizers and metal deactivators. As hydrolysis protective agents it is preferred to use oligomeric and / or polymeric aliphatic or aromatic carbodiimides.

The implementation of the isocyanate A with the isocyanate-reactive components is carried out in a preferred embodiment at a ratio between 950 and 1050, more preferably between 970 and 1010, in particular between 980 and 1000. Here, the index is defined by the ratio of the total at the reaction of isocyanate groups used in the component A to the isocyanate-reactive groups, ie in particular the groups B and C. At a ratio of 1000 is an isocyanate group of the component A is an active hydrogen atom. For ratios above 1000, more isocyanate groups exist than OH groups.

In a preferred embodiment, the polyurethane coating is a solid polyurethane coating. It is obtained in a manner known per se.

In a further preferred embodiment, the polyurethane coating is a rigid polyurethane foam. To produce a rigid polyurethane foam, the reaction of the isocyanate and the isocyanate-reactive compound is conducted so that essentially closed-cell foam is produced. Aromatic polyisocyanates with polyols, preferably polyethers and polyester polyols, are usually used in the preparation of such rigid foams in the presence of Propellants, catalysts and auxiliaries and additives reacted. This is controlled by foam stabilizers (for example, polyether-polysiloxane), the foam structure, the open and closed cell size and cell size in a conventional manner.

In a further preferred embodiment, the PU coating is a flexible PU foam. To produce a PU flexible foam, the procedure is in a manner known per se.

PU rigid foam brings mechanical stability and is used in sandwich panels. PU soft foam brings some elasticity in hybrid foam and is used in the Zwischensparparendentämmung.

coating process

In a preferred manner, the foam particles according to the invention are produced by a) providing particles of expanded or expandable foam b) coating them with a silicate-containing coating composition and optionally drying them and c) the silicate-coated foam particles with an isocyanate and an isocyanate-reactive compound or a polyurethane / polyurea formed from it.

Conventional methods, such as spraying, dipping or wetting the foam particles with an aqueous coating composition in conventional mixers, spray devices, dipping devices or drum apparatuses, can be used to coat the foam particles.

In a preferred embodiment, the silicate-containing coating is applied in a preferred step on the foam particles and dried and then coated with the polyurethane coating. In a further preferred embodiment, no drying step takes place between the coating steps. In a further preferred embodiment, the silicate-containing coating and the components of the polyurethane coating are completely mixed and applied uniformly and simultaneously to the foam particles.

Foam Additives For the production of insulating boards with high heat-insulating capacity it is particularly preferred to use pre-expanded, expandable styrene polymers which are athermous. ne solid body, such as carbon black, aluminum, graphite or titanium dioxide, in particular graphite having an average particle size in the range of 1 to 50 microns particle diameter in amounts of 0.1 to 10 wt .-%, in particular 2 to 8 wt .-%, based on EPS , contained and known for example from EP-B 981 574 and EP-B 981 575.

Furthermore, the foam particles may contain from 3 to 60% by weight, preferably from 5 to 20% by weight, based on the prefoamed foam particles, of a filler. Suitable fillers are organic and inorganic powders or fibrous materials, as well as mixtures thereof. As organic fillers z. For example, flour, starch, flax, hemp, ramie, jute, sisal, cotton, cellulose or aramid fibers can be used. As inorganic fillers z. As carbonates, silicates, barite, glass beads, zeolites or metal oxides are used. Preference is given to pulverulent inorganic substances, such as talc, chalk, kaolin (Al ₂ (Si ₂ O ₅ ) (OH) ₄ ), aluminum hydroxide, magnesium hydroxide, aluminum nitride, aluminum silicate, barium sulfate, calcium carbonate, calcium sulfate, silica, quartz powder, Aerosil ^® , alumina or wollastonite or spherical or fibrous inorganic materials such as glass beads, glass fibers or carbon fibers.

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

Particular preference is given to inorganic fillers having a density in the range from 1.0 to 4.0 g / cm ³ , in particular in the range from 1.5 to 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 affect the properties of the expandable thermoplastic polymers and the particle foam moldings obtainable therefrom. The use of adhesion promoters, such as maleic anhydride-modified styrene copolymers, epoxy group-containing polymers, organosilanes or styrene copolymers with isocyanate or acid groups, can significantly improve the binding of the filler to the polymer matrix and thus the mechanical properties of the particle foam moldings.

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

Such filler-containing foam particles can be obtained, for example, by foaming filler-containing, expandable thermoplastic granules. the. At high filler contents required for this expandable granules by extrusion blowing agent-containing thermoplastic melts and subsequent pressurized underwater granulation such. As described in WO 2005/056653.

The polymer foam particles may additionally be equipped with other flame retardants. For example, they may contain from 1 to 6% by weight of an organic bromine compound, such as hexabromodylcododecane (HBCD) and optionally additionally from 0.1 to 0.5% by weight of dicumyl or a peroxide in the interior of the foam particles or the coating. However, preferably no halogen-containing flame retardants are used.

Furthermore, the foam particles coated according to the invention can additionally be coated with amphiphilic or hydrophobic organic compound. The coating with hydrophobing agent is expediently carried out before the application of the aqueous coating composition according to the invention. C ₃₀ - - paraffin waxes, reaction products of N-methylolamine and a fatty acid derivative, reaction products of a Cg - among hydrophobic organic compounds, in particular Ci ₀ are Cn oxo alcohol with ethylene oxide, propylene oxide or butylene oxide or polyfluoroalkyl (meth) acrylates or mixtures to name thereof, which can preferably be used in the form of aqueous emulsions.

Preferred water repellents are paraffin waxes having 10 to 30 carbon atoms in the carbon chain, which preferably have a melting point between 10 and 7O ⁰ C, in particular between 25 and 6O ⁰ C. Such paraffin waxes are contained, 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. Example, a fatty acid amide, amine or alcohol, as z. For example, in US-A 2,927,090 or GB-A 475 170 are described. Its melting point is generally from 50 to 9O ⁰ C. Such resins are for. In the BASF commercial product PERSISTOL HP and in ARCOPHOB EFM from Hoechst.

Finally, polyfluoroalkyl (meth) acrylates are also suitable, for example, perfluorooctyl acrylate. This substance is contained in the BASF commercial product PERSISTOL® O and in OLEOPHOBOL® C from Pfersee. Further suitable 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 by the fact that the coating materials which are customary for the coating of expandable polystyrene, in particular stearates, can be used to a reduced extent or eliminated altogether, without negatively influencing the product quality.

For the production of foam moldings, the foam particles provided with the coating according to the invention can be sintered in a mold. The coated foam particles can be used while still wet or after drying.

The drying of the coating composition applied to the foam particles can take place, for example, in a fluidized bed, paddle dryer or by passing air or nitrogen through a loose bed. In general, a drying time of 5 minutes to 24 hours, preferably 30 to 180 minutes at a temperature in the range of 0 to 80 ⁰ C, preferably in the range of 30 to 60 ⁰ C is sufficient for the formation of the water-insoluble polymer film.

The water content of the coated foam particles after drying is preferably in the range from 1 to 40 wt .-%, more preferably in the range of 2 to 30 wt .-%, most preferably in the range of 5 to 15 wt .-%. It can be determined, for example, by Karl Fischer titration of the coated foam particles. The weight ratio of foam particles / coating mixture after drying is preferably 2: 1 to 1:10, particularly preferably 1: 1 to 1: 5.

Foam moldings

The foam particles coated in accordance with the invention can be sintered in conventional molds with hot air or steam to give foam moldings.

When sintering or gluing the foam particles, the pressure can be generated for example by reducing the volume of the mold by means of a movable punch. As a rule, a pressure in the range from 0.5 to 30 kg / cm ^{2 is} set here. For this purpose, the mixture of coated foam particles is filled into the opened mold. After closing the mold, the foam particles are pressed with the stamp, whereby the air between the foam particles escapes and the gusset volume is reduced. The foam particles are connected by the coating to the foam molding. Preferably, a compression to about 10 to 90%, preferably 60 to 30%, in particular 50 to 30% of the initial volume. In a mold with a cross section of about 1 m ² , a pressure of 1 to 5 bar is usually sufficient for this purpose.

The mold is designed according to the desired geometry of the foam molding. The degree of filling depends u. a. according to the desired thickness of the later molded part. For foam boards, a simple box-shaped form can be used. In particular, in the case of more complicated geometries, it may be necessary to compact the bed of the particles introduced into the mold and in this way to eliminate unwanted voids. The compression can z. B. by shaking the form, tumbling or other suitable measures.

To accelerate setting, hot air or water vapor can be pressed into the mold or the mold heated. For tempering the mold, however, any heat transfer media, such as oil or steam can be used. The hot air or the mold is suitably tempered for this purpose to a temperature in the range of 20 to 120 ⁰ C, preferably 30 to 90 ⁰ C.

Alternatively or additionally, the sintering can be carried out continuously or discontinuously under the action of microwave energy. In this case, microwaves are generally used in the frequency range between 0.85 and 100 GHz, preferably 0.9 to 10 GHz and irradiation times between 0.1 to 15 minutes. It is also possible to produce foam boards with a thickness of more than 5 cm.

When using hot air or steam at temperatures in the range of 80 to 150 ° C or by irradiation of microwave energy usually forms an overpressure of 0.1 to 1, 5 bar, so that the method is carried out without external pressure and without volume reduction of the mold can be. The internal pressure resulting from higher temperatures allows the foam particles to be easily further expanded, whereby they can also weld themselves by softening the foam particles themselves, in addition to bonding via the polymer coating. The gussets disappear between the foam particles. To accelerate setting, the shape can also be heated with a heat transfer medium as described above. When microwaves are irradiated, the inorganic coating constituents are generally heated, which then crosslink or condense more quickly as a result.

For the continuous production of the foam moldings are also double belt systems as they are used for the production of polyurethane foams. For example, the prefoamed and coated foam particles can be continuously applied to the lower of two metal bands, which may optionally have a perforation, and processed with or without compression by the converging metal bands into endless foam boards. In one process embodiment, the volume between the two belts is progressively reduced, compressing the product between the belts and eliminating the gussets between the foam particles. After a curing zone, an endless plate is obtained. In another embodiment, the volume between the bands can be kept constant and pass through a zone with hot air or microwave irradiation, in which the foam particles re-foam. Again, the gussets disappear and an endless plate is obtained. It is also possible to combine the two continuous process operations.

The thickness, length and width of the foam sheets can vary within wide limits and is limited by the size and closing force of the tool. The thickness of the foam sheets is usually 1 to 500 mm, preferably 10 to 300 mm. Further preferred sizes and order ranges are 10 to 200 mm, preferably 20 to 110 mm, particularly preferably 25 to 95 mm.

The density of the foam moldings according to DIN 53420 is generally 10 to 150 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.

The process can also be used crushed foam particles made of recycled foam moldings. To produce the foam moldings of the invention, the comminuted foam recycled to 100% or z. B in proportions of 2 to 90 wt .-%, in particular 5 to 25 wt .-% are used together with virgin material, without significantly affecting the strength and mechanical properties.

The coating may also contain other additives which preferably or only slightly contribute to the combustibility and / or substances which in the non-fired state have a positive influence on the mechanical or thermal properties, for example vermiculites, in addition to the mechanical and hydraulic properties to modify

A preferred process comprises the steps of: i) pre-expanding expandable styrenic polymers into foam particles, ii) applying the silicate-containing coating composition in the form of an aqueous dispersion to the foam particles and simultaneous or subsequent polyurethane coating iii) drying the polymer dispersion on the foam particles to form a water-insoluble polymer film iv) filling the polymeric film-coated foam particles into a mold and sintering.

A particularly preferred method involves the compression of the still water-moist foam particles according to the following process: i) pre-expansion of expandable styrene polymers to foam particles, ii) applying the silicate-containing coating composition in the form of an aqueous dispersion to the foam particles and simultaneous or subsequent polyurethane coating iii) filling with the coating composition coated and still water-moist foam particles in a mold, pressing and curing by the action of temperature and / or microwave.

The process is suitable for the production of simple or complex foam moldings, such as plates, blocks, tubes, rods, profiles, etc. Preferably, plates or blocks, which can be subsequently sawn or cut into sheets, are produced. For example, they can be used in construction for the insulation of exterior walls. They are particularly preferably used as core layer for the production of sandwich elements, for example so-called structural insulation panels (SIP), which are used for the construction of cold stores or warehouses.

The clay minerals can be easily dispersed in aqueous polymer dispersions and applied to the prefoamed foam particles. The ceramization with the alkali silicate is carried out only in case of fire at temperatures of about 500 ⁰ C. The use of clay minerals, such as kaolin in the coating composition does not lead to embrittlement of the foam molding in sintering. The resulting in case of fire porous ceramic framework structure then withstands temperatures of about 1000 ⁰ C stood.

The foam particles provided with the coating according to the invention can be sintered into foam moldings which have a high fire resistance value E30, in particular E60 or F30, in particular F60, and even with prolonged flame exposure of more than 30 or 60 minutes prevent and the structural integrity is maintained by the resulting porous ceramic framework structure.

Such foam moldings can be used as sandwich elements. For better sealing between the joints of such sandwich elements sealing strips between the individual sandwich panels (panels) are usually used, especially in cooling and storage halls. Ideally, the seal should be designed so that the gas-tightness of the joint facing away from the fire still remains even if the panels in case of fire, i. is subjected to dimensional changes when exposed to heat, which can lead to force effects and resulting shifts in different spatial directions in the joints.

Sealing tapes of polyurethanes brittle usually at about 120 ⁰ C. If hot vapors reach the sealing tape brittle this and loses its sealing properties. Therefore, it comes to the breakthrough of the hot gases and the corresponding heating of the temperature sensors on the outside.

Preferably sealing tapes are used which have a certain elasticity even at higher temperatures. That When the joint and the band heats up and "pulls away", the band still seals (airtightness), which prevents the gases from escaping at the front, as evidenced by the fact that there is almost no temperature difference after 30 minutes In this case, it is not necessary to make an asymmetrical structure, since very high temperatures occur within the furnace within a very short time, whereupon the outer sheets of the sandwich elements detach from the core. which immediately allow the gases to escape inside the oven.

The sealing tapes should not only remain elastic when exposed to heat but, within certain limits, also be able to "inflate", ie possess intumescent properties, in order to be able to maintain gas-tightness in the case of dimensional changes in the region of the joint, in particular in the case of gap formation Sealing tapes are inserted between the adjoining core layers of the sandwich elements, which then foam up step by step as the joint widens and both the temperature and the gas propagation are slowed down.This measure can reduce the temperature load which acts on the joint remote from the source of the fire and thus significantly improve the service life of the "outer joint". Also conceivable are foam-like structures or elastic fiber structures which are inserted into the joints during the construction of the panel construction and are pressed together during the final fixing of the panels on the substructure. In the event of fire, especially if the panels are subject to dimensional changes due to the effects of heat, this elastic "inlay" can adapt to the changed dimensions in the area of the joint and thereby seal it more efficiently Suitable for this purpose are, for example, melamine resin foams (Basotect® from BASF SE) , Mineral wool strips or a flame-retardant polyethylene foam strip.

The cores could also be provided with a profile, e.g. As stepped rabbeting or tongue and groove, with integrated or einzusetzender spring, are provided so that the cores interlock and thus also better seal.

Of importance is also the geometry of the joint. Preference is given to "standard joints" with the greatest possible overlap and mechanical rigidity. To seal the joint own from the core material milled groove and springs, for example, after the Inta-Lock concept, with milled into the core material, several centimeters deep groove but with loose, nachzuläglich einzusetzender on the site spring. This can be made of a large number of heat-resistant materials and serves primarily to prevent / reduce gas leakage through the joint in case of fire, even if the core material shrinks slightly due to the effect of heat or the panels deformed in the joint, which without a spring to a Gaping and resulting escape of hot fire lanes in the area of the joint would result.

As materials for the spring are, for example, Regips strips, strips of silicone or intumescent materials such as expanded graphite or silicates, such as Palusol® or the coating composition of the invention, mineral fiber wedges, wedges of melamine resin foams (Basotect ^® ), thin strip of strip, both sides in a thin groove can be inserted.

If necessary, the springs can be fixed mechanically by means of screws, rivets, etc. Furthermore, elastic inlays and sealing tapes are suitable, which are inserted into the metal recess of the joint profile and swell when exposed to heat and seal the joints. The elastic inlays in the surface would be compressed in the construction of the panel wall between the bumps of the core material and in case of fire, if the joint gaped by the heat, shrinks or deformed, within certain limits have a sealing effect or at least significantly reduce the outflow of fumes. Applications include pallets made of foam as a replacement for wooden pallets, cover panels, refrigerated containers, caravans. Due to their excellent fire resistance, they are also suitable for airfreight. Particularly preferred applications are structural applications, for example facades, in particular ventilated facades, flat roofs, trapezoidal flat roofs and fire bars.

Examples: Test methods

The following investigations were carried out to check the quality of the samples.

First, after the proper deposition time, the volume loss in case of fire (Test A) was determined. For this purpose, a cube with 5cm edge length was sintered for 15 minutes at 1030 ⁰ C, or 800 ⁰ C in a muffle furnace. The cubic volume was then determined again and subtracted from the initial value.

Furthermore, the water absorption of the cubes was determined (test B). For this purpose, a cube of 5 cm edge length was completely immersed in 50 ° C warm water and completely wetted with water for 24 hours. Subsequently, the cube was weighed again after drying and thus determined the proportion of leached coating. The water in the container was evaporated and the residue was weighed to give a more accurate reading.

Subsequently, the cube was again completely dried and subjected to a fire test as described in Test A). This resulted in the loss of fire after water exposure (Test C). raw materials

The following substances were used:

Example 1: Standard cubes

In a mixing cup, a mixture of kaolin (100 g), water glass (100 g, 20% water of crystallization), titanium dioxide (20 g), Acronal S790 dispersion (22 g) and water (80 g) was prepared. After complete homogenization, 200 g of the mixture were added to 50 g of EPS spheres (prefoamed, density: 10 g / l) and distributed uniformly. The coated spheres were then placed in a mold and compressed to 50% of the original volume. The plate was heated by contact heat to about 80 ⁰ C for 2 h, then demolded and deposited to constant mass.

Test A: -15% volume loss

Test B:> -25%

Test C: Not measurable because the foam body completely lost its shape

Example 2: Pre-coated beads with PU hard foam system A mixture of kaolin (100 g), water glass (100 g, 20% residual moisture), titanium dioxide (20 g), Acronal S790 dispersion (22 g) and water (80 g) was prepared in a mixing beaker. After complete homogenization, 200 g of the mixture were added to 50 g of EPS spheres (prefoamed, density: 10 g / l), uniformly distributed and dried in a fluidized bed to constant mass. These coated spheres (230 g) were then mixed with 150 g of a Lupranol / MDI mixture, compressed to 50% of the original volume and held for a few minutes. After 5 minutes, the block was completely hardened and could be removed from the mold.

Test A: -23% volume loss Test B: -6% Test C: -25%

Example 3: Serial coating of the individual components

A mixture of kaolin (100 g), water glass (100 g, 20% residual moisture), titanium dioxide (20 g), Acronal S790 dispersion (22 g) and water (80 g) was prepared in a mixing beaker. After complete homogenization, 200 g of the mixture were added to 50 g of EPS spheres (prefoamed, density: 10 g / l) and distributed uniformly. Immediately (230 g) of the coated spheres were mixed with 150 g of a lupranol / MDI mixture, the molding compound was compressed to 50% of the initial volume and held for a few minutes. After a few minutes, the block was completely form / transport stable and could be tested without further intermediate storage. Nevertheless, the material was subjected to constant mass in a drying oven at 70 ⁰ C STORED and then the tests described above.

Test A: -21% volume loss Test B: -5% Test C: -23%

Example 4: Foamable Second Coating, Use of a Flexible Foam System

A mixture of kaolin (100 g), water glass (100 g, 20% residual moisture), titanium dioxide (20 g), Acronal S790 dispersion (22 g) and water (80 g) was prepared in a mixing beaker. After complete homogenization, 200 g of the mixture were added to 50 g of EPS spheres (prefoamed, density: 10 g / l) and distributed uniformly. For this, 100 g of Meyco Flex364 were added and the particles were coated. The entire mixture was compressed by 50% and tied off after about 80 seconds. Increasing the isocyanate content by 20% increases the reaction time to 140 seconds. the. The material was then stored at 70 ^° C. in a drying oven until the constancy of mass remained constant and then subjected to the tests described above.

Test A: -18% volume loss Test B: -5% Test C: -18%

Example 5

The components given in Table 1 below were processed as follows.

All components (silicate, coating, EPS) were mixed homogeneously and placed in teflon-lined aluminum molds. The content of the mold was usually compressed to 50% of the original volume. It was ensured that an annular gap of about 3 mm remains open in order to release any escaping CO ₂ . Unless otherwise noted, the present experiments did not require added heat. When the mold was not pressed, the gussets filled up with the intumescent coating foam (Type B1) and the resulting molded article had a correspondingly low density. However, plates with a compression of 50% usually gave the best performance in the heat test (Test A), see Table 1.

The amount of components was calculated so that one part by weight of EPS was added to the total of coating and ceramics.

The mixtures B1, B2, Sl-II and SI2 used were composed as follows:

B1: Lupranol 2090 (95 parts), deionized water (2 parts), Dabco 8154 (0.2 part), louprages (0.01 part), Silicone Stabilizer DC190 (0.1 part), MDI (37 parts).

B2: Meyco Flex 364 Comp A (100 parts) and Meyco Flex 364 Comp B (100 parts) were mixed homogeneously.

Sl-Il: EPS beads (10 g / L) were sprayed with liquid water glass (25%) and then dried in a stream of air. This process was repeated until the beads have a density of about 38 g / L.

SI-2: kaolin (57 g) and Portil N (56 g) are taken up in lupranol (component of mixture B1) and then mixed with the remaining substances of B1. Table 1: Experiments

Beispiel 6

Example 6

In further tests, so-called "delayed action" catalysts from Air Products were used, which allow a larger processing window, for example Dabco 8154, Dabco BL 17, Dabco TMR 3, Dabco TMR 30. They also achieved advantageous results.

Example 7

In further experiments, Lupragen ^® N700, a heat-active system, was used, which only exerted its effect by an elevated temperature. For this purpose, the experiments were carried out analogously to No. 1 to 5 and later heated. Although the test specimens show a different curing behavior, comparable results in the tests A to C of the above examples.

Claims

claims 1. foam particles, preferably of a polyolefin or styrene polymers, characterized in that the foam particles are coated with a combination of a silicate-containing coating and a coating based on a polyurethane and / or polyurea. 2. Foamed particles according to claim 1, characterized in that the particles are selected from expanded polyolefin particles or prefoamed particles of expandable styrene polymers (EPS). 3. Foam particles according to claim 1, characterized in that the silicate-containing coating is based on a coating composition which comprises a) 20 to 70 parts by weight of a clay mineral b) 20 to 70 parts by weight of an alkali silicate c) 1 contains up to 30 parts by weight of a film-forming polymer and optionally further constituents. 4. foam particles according to claim 3, characterized in that as alkali metal silicate a water-soluble alkali silicate with the composition M ₂ O (SiO ₂ ) _n with M = sodium or potassium and n = 1 to 4 or mixtures thereof is included. 5. Foam particles according to claim 3, characterized in that the filming polymer based on ethylenically unsaturated monomers having a glass transition temperature in the range of -30 to 80 ⁰ C. 6. foam particles according to at least one of the preceding claims, characterized in that the polyurethane / the polyurea based on the implementation of diphenylmethane diisocyanate (MDI) with at least one isocyanate-reactive compound. 7. foam particles according to at least one of the preceding claims, characterized in that the polyurethane / polyurea coating is a solid coating, which has at least substantially no foam structure. 8. foam particles according to at least one of claims 1 to 6, characterized in that the polyurethane / polyurea coating has a soft foam or rigid foam structure. 9. A process for the preparation of coated foam particles according to at least one of the preceding claims, characterized in that one a) particles of expanded or expandable foam b) these coated with a silicate-containing coating composition and optionally dried and c) coated the silicate-coated foam particles with an isocyanate and an isocyanate-reactive compound or a polyurethane / polyurea formed thereof. 10. A process for the production of coated foam particles according to claim 9, characterized in that all broom ichtungsstoffe be applied in one step. 1 1. A process for producing foam bodies, characterized in that coated foam particles are transferred according to at least one of the preceding claims in a form where they are cured in a batch process. 12. A process for producing foam bodies, characterized in that the coated foam particles are cured in a Konti process. 13. Use of foam moldings according to at least one of the preceding claims as a sandwich panel, for facade insulation, for roof applications, fire bars and fire doors.