DE102012217668A1 - Expandable polymer granule obtained from polymer component, physical blowing agent component, and flame retardant system useful in foam molded part, foam block or composite molded part in e.g. furniture construction - Google Patents

Abstract

Expandable polymer granule obtained from (a) polymer component comprising (a1) styrene copolymer component made of at least one styrene-acrylonitrile copolymer or a mixture of at least one styrene-acrylonitrile copolymer and at least one styrene-maleic acid anhydride copolymer and/or at least one styrene-acrylonitrile-maleic acid anhydride copolymers and (a2) at least one thermoplastic polymer, (b) a physical blowing agent component comprising at least one 2-7C hydrocarbon, and (c) a flame retardant system comprising at least one brominated trialkyl phosphate (I), is claimed. Expandable polymer granule obtained from (a) 100 pts. wt. polymer component comprising (a1) 90-100 wt.% styrene copolymer component based on the polymer component, made of at least one styrene-acrylonitrile copolymer or a mixture of at least one styrene-acrylonitrile copolymer and at least one styrene-maleic acid anhydride copolymer and/or at least one styrene-acrylonitrile-maleic acid anhydride copolymers and (a2) 0-10 wt.% at least one thermoplastic polymer comprising aromatic polyethers, polyolefins, polyacrylates, polycarbonates, polyesters, polyamides, polysulfones, polyethersulfone, polyether ketones or polystyrene, based on the polymer component (b) 2-8 pts. wt. physical blowing agent component based the on polymer component, comprising 80-100 wt.% at least one 2-7C hydrocarbon based on the physical blowing agent component, and (c) a flame retardant system comprising 1-10 pts. wt. at least one brominated trialkyl phosphate of formula ((O)P(OR) 3) (I) as a flame retardant based on the polymer component, is claimed. R : optionally branched 1-6C alkyl, where at least one H is substituted with Br. Independent claims are also included for: (1) producing the expandable polymer granule, comprising (a) providing the polymer component, (b) heating the polymer component to form a polymer melt, (c) introducing 2-8 wt.% physical blowing agent component based on the polymer component into the polymer melt to form a foamable melt, (d) homogenizing the mixture, (e) adding the flame retardant system and optionally further additives to the polymeric component in at least one of the steps (a)-(d), (f) extruding the blowing agent containing polymer melt through a die plate, and (g) granulating the blowing agent containing melt in a liquid-filled chamber under a pressure of 1-20 bar; (2) producing a foam molded part, comprising producing the expandable polymer granules by the above mentioned method, prefoaming the granules to foam particles and welding the foam particles into a closed mold; (3) the foam molded part or a foam block obtained from expandable polymer particles; and (4) a composite molded part comprising a core material and at least one cover layer, where the core material is the foam molded part or the foam block.

Description

The invention relates to a flame-retardant expandable polymer granules based on styrene-acrylonitrile copolymers (SAN), a process for its production, foam moldings which are obtainable from the polymer granules according to the invention and their use, in particular for lightweight construction applications in furniture construction.

Styrene-acrylonitrile (SAN) copolymers are common styrenic copolymers for applications requiring increased solvent and temperature resistance compared to pure polystyrene. By equipping a granulate with an organic blowing agent, SAN-based foams with a wide variety of additives can be produced by the melt impregnation process developed a few years ago. Due to the stated advantages in terms of solvent and temperature resistance, these SAN-based foams make it possible to develop new fields of application, for example for the production of sandwich elements which can be used, inter alia, in the furniture industry and in wind power plants.

Materials and applications of this kind are eg in the WO 2005/056652 . WO 2009/000872 and WO 2009/112392 described.

The new fields of application, however, make high demands on the fire protection properties of such materials, especially in terms of applications in furniture construction.

The object was therefore to develop a SAN-based, expandable polymer granules which has good fire protection properties and in which neither processing nor mechanical properties of the molded parts formed are adversely affected by the flame retardant.

The object is achieved by the use of a bromine-containing phosphoric acid ester as a flame retardant.

The invention therefore provides an expandable polymer granules obtainable from
P) 100 parts by weight of a polymer component consisting of
PS) 90-100% by weight (based on P) of a styrene copolymer component consisting of
PS1) one or more styrene-acrylonitrile copolymers (SAN)
or
PS2) of a mixture of one or more styrene-acrylonitrile copolymers (SAN) and one or more styrene-maleic anhydride copolymers (SMA)
and or
PS3) one or more styrene-acrylonitrile-maleic anhydride copolymers (SANMA)
and
PT) 0 to 10 wt .-% (based on P) of one or more thermoplastic polymers selected from the group consisting of aromatic polyethers; polyolefins; polyacrylates; Polycarbonates (PC); polyesters; polyamides; Polyethersulfones (PES); polysulfones; Polyether ketones (PEK) and polystyrene;
T) 2 to 8 parts by weight (based on P) of a physical blowing agent component (T) containing 80 to 100% by weight (based on T) of one or more hydrocarbons having 2 to 7 carbon atoms;
F) a flame retardant system comprising 1 to 10 parts by weight, preferably 4 to 9 parts by weight, particularly preferably 5 to 8 parts by weight, based on P, of one or more brominated trialkyl phosphates as flame retardant (F1), (O) P (OR) ₃ (I) in which
R is the same or different, preferably the same, a straight-chain or branched alkyl group having 1 to 6 carbon atoms, where one, two or three hydrogen atoms are substituted by bromine, preferably 3-bromo-2,2'-bis (bromomethyl) -propyl, 3,4-dibromo-2- (bromomethyl) -butyl or 2,3-dibromopropyl, more preferably 3-bromo-2,2'-bis (bromomethyl) -propyl.

• a) Bereitstellen der erfindungsgemäßen Polymerkomponente (P)
• (b) Erhitzen der Polymerkomponente (P) zur Ausbildung einer Polymerschmelze,
• (c) Einbringen von 2 bis 8 Gew.-% (bezogen auf P) einer physikalischen Treibmittelkomponente (T), enthaltend 80–100 Gew.-% (bezogen auf (T)) an einem oder mehreren Kohlenwasserstoffen mit 2 bis 7 Kohlenstoffatomen, in die Polymerschmelze zur Ausbildung einer schäumbaren Schmelze,
• (d) Homogenisieren der Mischung,
• (e) Zugabe des erfindungsgemäßen Flammschutzsystems F) und gegebenenfalls Zugabe von weiteren Additiven zu der Polymerkomponente P in mindestens einem der Schritte a), b), c) und/oder d),
• (f) Extrusion der treibmittelhaltigen Polymerschmelze durch eine Düsenplatte,
• (g) Granulieren der treibmitteilhaltigen Schmelze in einer flüssigkeitsgefüllten Kammer unter einem Druck von 1 bis 20 bar zu einem Granulat.

The invention further provides a process for the preparation of the polymer granules according to the invention, comprising the steps

• a) providing the polymer component (P) according to the invention
• (b) heating the polymer component (P) to form a polymer melt,
• (c) introducing from 2 to 8% by weight (based on P) of a physical blowing agent component (T) containing 80-100% by weight (based on (T)) of one or more hydrocarbons having 2 to 7 carbon atoms, in the polymer melt to form a foamable melt,
• (d) homogenizing the mixture,
• (e) addition of the flame retardant system F) according to the invention and optionally addition of further additives to the polymer component P in at least one of the steps a), b), c) and / or d),
• (f) extrusion of the blowing agent-containing polymer melt through a nozzle plate,
• (G) granulating the Treibmitteilhaltigen melt in a liquid-filled chamber under a pressure of 1 to 20 bar to granules.

• a)–g) die Herstellung des erfindungsgemäßen Granulats,
• h) Vorschäumen des erfindungsgemäßen Granulats, vorzugsweise mit Heißluft oder Wasserdampf, zu Schaumpartikeln und
• i) Verschweißen der Schaumpartikel in einer geschlossenen Form.

The invention further provides a process for producing a foam molding, comprising

• a) -g) the preparation of the granulate according to the invention,
• h) pre-foaming the granules according to the invention, preferably with hot air or water vapor, to foam particles and
• i) welding the foam particles in a closed mold.

The invention also provides a foam molding obtainable according to the invention, in particular a foam block and a composite molding comprising at least one core layer and a cover layer, wherein the core layer is a foam molding according to the invention.

The invention further relates to the use of granules according to the invention, foam moldings and composite moldings in furniture construction, exhibition construction, the construction industry, in particular for thermal insulation, the automotive industry, in boat and shipbuilding and / or in wind turbines.

The expandable polymer particles (granules) obtainable according to the invention have excellent fire protection and mechanical properties.

The styrene copolymer component (PS) used according to the invention preferably consists of one or more, preferably 1 or 2, more preferably 1 polymer which consists of copolymerized styrene and copolymerized acrylonitrile (SAN), (PS1).

The SAN generally contains from 18 to 40% by weight, preferably from 20 to 35% by weight and in particular from 25 to 35% by weight of copolymerized acrylonitrile and generally from 60 to 82% by weight, preferably from 65 to 80% by weight. % and particularly preferably 65 to 75 wt .-% of copolymerized styrene (in each case based on SAN).

SAN used according to the invention generally has a melt volume rate MVR (220 ° C./10 kg) ISO 113 in the range of 5 to 100 cm ^3/10 min.

Suitable types of SAN are, for example, polymers of Styrolution GmbH such as Luran 3380, Luran 33100, Luran 2580 and Luran VLN.

In a preferred embodiment of the invention, a SAN is used in admixture with an SMA.

Preferably used SMA preferably consists of 10 to 45 wt .-%, preferably 15 to 30 wt .-% of copolymerized maleic anhydride and 55 to 90 wt .-%, preferably 70 to 85 wt .-% of copolymerized styrene. SMA is commercially available, for example under the Xiran brands from Polyscope.

In a further preferred embodiment of the inventor, one or more, preferably one, SANMA are used as component PS.

Preference is given to SANMA which contains 1.0 to 10% by weight, preferably 1.5 to 10% by weight, more preferably 2.0 to 5% by weight (based on PS3), copolymerized maleic anhydride units and 18 to 35 Wt .-%, preferably 15 to 30 wt .-%, particularly preferably 18 to 28 wt .-%, of copolymerized acrylonitrile contain and a proportion of copolymerized styrene of 65 to 81 wt .-%, preferably 68.5 to 80.5 , Particularly preferably 70 to 80 wt .-% (all wt .-% - data based on PS3) have.

The abovementioned styrene polymers (PS) can be used to improve the mechanical properties or the thermal stability, if appropriate by using compatibilizers with thermoplastic polymers (PT) such as polyamides (PA), polyolefins such as polypropylene (PP) or polyethylene (PE), polyacrylates such as polymethyl methacrylate (PMMA). , Polycarbonates (PC), polyesters such as polyethylene terephthalate (PET) or polybutylene terephthalate (PBT), polysulfones, polyethersulfones (PES), polyether ketones or mixtures thereof in proportions of not more than 10% by weight, preferably, if present, in the range of 1 be mixed to 5 wt .-%, based on the polymer melt. Also possible as component (PT) are styrene polymers other than component (PS), such as polystyrene. Furthermore, mixtures in the stated quantitative ranges are also possible with, for example, hydrophobically modified or functionalized polymers or oligomers, rubbers such as polyacrylates or polydienes, for example styrene-butadiene block copolymers or biodegradable aliphatic or aliphatic / aromatic copolyesters.

Suitable compatibilizers are, for example, maleic anhydride-modified styrene copolymers, polymers or organosilanes containing epoxide groups. usually in amounts of at most 50 wt .-%, in particular in amounts of 1 to 20 wt .-%, based on the total amount of polymers.

The blowing agent component (T) used according to the invention comprises one or more blowing agents in a proportion of 2 to 8, preferably 3 to 4,% by weight, based on (P). Suitable blowing agents are aliphatic hydrocarbons having 2 to 7, preferably having 3 to 7 carbon atoms and mixtures of 2 or more such hydrocarbons and / or 2 or more isomers of such hydrocarbons. Preference is given to butane and pentane isomers, such as isobutane, n-butane, isopentane, n-pentane and mixtures thereof, in particular pentane isomers, such as iso-pentane and n-pentane, and mixtures of such isomers. Suitable as Cotreibmittel, preferably in a proportion of 0 to 3 wt .-%, preferably from 0.25 to 2.5 wt .-%, in particular 0.5 to 2.0 wt .-% (based on (P)) , (C ₁ -C ₄ ) -carbonyl compounds, such as ketones and esters, C ₁ -C ₄ -alcohols and C ₁ -C ₄ -ether. Preferred co-propellants are ketones, particularly preferably acetone. In order to achieve a preliminary nucleation of the granules during granulation, it is possible, for example, to use CO ₂ or N ₂ , preferably N ₂ , as co-blowing agent, in a proportion of 0 to 2% by weight, preferably 0.1 to 1% by weight, particularly preferably 0 , 1 to 0.5 wt .-% (based on (P)) hinyugeben.

Due to fire safety regulations in the construction industry and other industries, one or more flame retardants are added. Sufficient flame retardancy (B2 test after DIN 4102 Part 1 ) is achieved by a brominated flame retardant with a thermogravimetric (TGA) determined weight loss of at most 2 wt .-% at 250 ° C, preferably 1 wt .-% at 260 ° C, particularly preferably 1 wt .-% at 280 ° C. According to the invention, therefore, the polymer granulate additionally contains 1 to 10 parts by weight, preferably 2 to 8 parts by weight, particularly preferably 3 to 7 parts by weight, based on 100 parts by weight P, of a brominated trialkyl phosphate of the formula (I) as flame retardant, (O) P (OR) ₃ (I) in which
R is the same or different, preferably the same, a straight-chain or branched alkyl group having 1 to 6 carbon atoms, where one, two or three hydrogen atoms are substituted by bromine, preferably 3,4-dibromo-2- (bromomethyl) butyl or 2,3 Dibromopropyl, more preferably 3-bromo-2,2'-bis (bromomethyl) -propyl.

Preferred are tris (tribromoneopentyl) phosphate (R = 3-bromo-2,2'-bis (bromomethyl) -propyl) (TPP) and tris (2,3-dibromopropyl) phosphate (R = 2,3-dibromopropyl), especially preferred is TPP (II):

TTP is commercially available, for example, under the designation FR370 from ICL, Tel Aviv, Israel.

As a flame retardant synergist (F2), the polymer granules preferably additionally contain 0.01 to 3 parts by weight, preferably 0.1 to 1.5 parts by weight, based on 100 parts by weight P, of a synergist from the group consisting of dicumyl, N-hydroxysuccinimide, distearylhydroxylamine, N, N-Dibenzylhydroxylamine, 4-hydroxy-TEMPO, (+) - O, O'-diacetyl-L-tartaric anhydride from mixtures thereof. The synergist (F2) preferably consists of dicumyl.

The flame retardant synergists (F2) are commercial products. Dicumyl is available, for example, under the name Perkadox 30 from Akzo Nobel, The Netherlands.

In addition to polymer (P) flame retardant (F) and blowing agent component (T), one or more additives are preferably added to the polymer granules according to the invention. Suitable additives are known to the person skilled in the art.

In a preferred embodiment, at least one nucleating agent is added to the polymer component (P). As nucleating agents, e.g. finely divided inorganic solids such as talc, silica, mica, clay, zeolites, calcium carbonate and / or polyethylene waxes are used in amounts of generally 0.1 to 10 wt .-%, preferably 0.1 to 3 wt .-%, particularly preferably 0.1 to 1.5 wt .-%, based on (P), are used. The average particle diameter of the nucleating agent is generally in the range of 0.01 to 100 .mu.m, preferably 1 to 60 microns. A particularly preferred nucleating agent is talc, for example talc from Luzenac Pharma. The nucleating agent may be added by methods known to those skilled in the art.

If desired, other additives, such as fillers (for example, mineral fillers, such as glass fibers), plasticizers, flame retardants, IR absorbers, such as carbon black, cokes, graphenes and / or graphite, aluminum powder and titanium dioxide, soluble and insoluble dyes, pigments, UV stabilizers and / or thermal stabilizers are added.

Particularly preferred for thermal insulation is the addition of graphite, carbon black, cokes, graphenes, aluminum powder or an IR dye (e.g., indoaniline dyes, oxonol dyes or anthraquinone dyes). Especially preferred are graphite and carbon black.

Very particular preference is given to adding graphite in amounts of generally from 0.05 to 25% by weight, particularly preferably in amounts of from 2 to 8% by weight, based on (P). Suitable particle sizes for the graphite used are in the range from 1 to 50 μm, preferably in the range from 2 to 10 μm.

Suitable additional flame retardants are, for example, tetrabromobisphenol A, brominated polystyrene oligomers, tetrabromobisphenol A diallyl ether and hexabromocyclododecane (HBCD), in particular the industrial products which essentially contain the α-, β- and γ-isomer and an addition of synergists such as dicumyl. Preference is given to brominated aromatics, such as tetrabromobisphenol A, and brominated styrene oligomers. Suitable halogen-free flame retardants are, for example, red phosphorus and phosphorus compounds, such as expandable graphite, red phosphorus, triphenyl phosphate and 9,10-dihydro-9-oxa-10-phosphaphenanthrene-10-oxide. The polymer granules according to the invention preferably contain no further flame retardants in addition to the flame retardant system according to the invention.

The total amount of additives is generally 0 to 30 wt .-%, preferably 0 to 20 wt .-%, based on the total weight of the expandable polymer granules.

In general, the dyes and pigments are added in amounts ranging from 0.01 to 30, preferably in the range of 1 to 5 wt .-% (based on P). For the homogeneous and microdispersed distribution of the pigments in the polymer melt, it may be expedient in particular for polar pigments to use a dispersing aid, e.g. Organosilane, epoxy group-containing polymers or maleic anhydride-grafted styrenic polymers to use. Preferred plasticizers are fatty acid esters, fatty acid amides and phthalates, which can be used in amounts of from 0.05 to 10% by weight, based on the polymer component P.

• – Polymerisationsreaktor – statischer Mischer/Kühler – Zahnradpumpe – Granulator
• – Polymerisationsreaktor – Schmelzeextruder – Zahnradpumpe – Granulator
• – Extruder – statischer Mischer – Granulator
• – Extruder – Zahnradpumpe – Granulator
• – Extruder – Zahnradpumpe – statischer Mischer – Granulator
• – Extruder – statischer Mischer – Zahnradpumpe – Granulator
• – Extruder – Granulator.
• – Extruder – statischer Mischer – Zahnradpumpe – Granulator
• – Extruder – Zahnradpumpe – statischer Mischer / Wärmetauscher – Zahnradpumpe – Granulator
• – Extruder – statischer Mischer – Zahnradpumpe – statischer Mischer / Wärmetauscher – Zahnradpumpe – Granulator.

To produce the expandable particle foam according to the invention, the blowing agent, preferably at elevated pressures, preferably at 40 to 280 bar, is mixed directly into the polymer melt. Each of steps a) to g) of the process according to the invention can be carried out by the apparatuses or apparatus combinations known in plastics processing. The polymer melt can be taken directly from a polymerization reactor or produced directly in the mixing extruder or a separate melt extruder by melting polymer granules. Static mixers or dynamic mixers, for example extruders, are suitable for mixing in the blowing agents. To set the desired melt temperature, cooling of the melt can optionally be carried out. For this purpose, the mixing units used, separate coolers or heat exchangers are suitable. The granulation is carried out by pressurized granulation in a liquid, especially water-filled chamber. Thus, an expansion of the blowing agent-containing melt at the nozzle exit is at least partially suppressed. To build up pressure for the nozzles of the granulation, the mixing unit (extruder) can be used per se or an additional, pressure-building melt aggregate. Favor a gear pump is used. Apparatus arrangements suitable for carrying out the method are, for example, but not limited to:

• - Polymerization reactor - Static mixer / cooler - Gear pump - Granulator
• - Polymerization Reactor - Melt Extruder - Gear Pump - Granulator
• - extruder - static mixer - granulator
• - Extruder - gear pump - granulator
• - Extruder - gear pump - static mixer - granulator
• - extruder - static mixer - gear pump - granulator
• - Extruder - Granulator.
• - extruder - static mixer - gear pump - granulator
• - Extruder - gear pump - static mixer / heat exchanger - gear pump - granulator
• - extruder - static mixer - gear pump - static mixer / heat exchanger - gear pump - granulator.

• – Extruder – Zahnradpumpe – Granulator
• – Extruder – Zahnradpumpe – statischer Mischer – Granulator.

The arrangements are preferred:

• - Extruder - gear pump - granulator
• - Extruder - gear pump - static mixer - granulator.

Further advantageous is the melt impregnation during the extrusion step by adding the blowing agent in the extruder, whereby residence time and thermal stress of the material can be significantly reduced in the production of the granules.

Furthermore, the assembly may include one or more side extruders or side feeds for incorporation of further polymers and additives, e.g. of solids or thermally sensitive additives. In addition, liquid additives can be injected at any point of the process, preferably in the field of static and dynamic mixing units.

The blowing agent-containing polymer melt is usually at a temperature in the range of 150 to 300 ° C, preferably 180 to 260 ° C, more preferably in the range of 190 to 230 ° C promoted through the nozzle plate.

The nozzle plate is preferably heated to at least 10 ° C above the temperature of the blowing agent-containing polymer melt in order to prevent polymer deposits in the nozzles and to ensure trouble-free granulation. Preferably, the temperature of the nozzle plate is in the range of 10 to 200 ° C, more preferably 10 to 120 ° C above the temperature of the blowing agent-containing polymer melt

The extrusion through the nozzle plate takes place in a chamber which is filled with a liquid, preferably water. The temperature of the liquid is preferably in the range of 20 to 95 ° C, particularly preferably 40 to 80 ° C.

• a) Her- oder Bereitstellen einer Schmelze der erfindungsgemäßen Polymerkomponente (P) aus PS) und gegebenenfalls (PT),
• b) Erhitzen der Polymerkomponente (P) zur Ausbildung einer Polymerschmelze,
• c) Einmischen von der erfindungsgemäßen Treibmittelkomponente in die Polymerschmelze mittels statischer oder dynamischer Mischer bei einer Temperatur von mindestens 150°C,
• d) thermisches Homogenisieren und gegebenenfalls Kühlen der treibmittelhaltigen Polymerschmelze auf eine Temperatur von mindestens 120°C,
• e) gegebenenfalls Zugabe von Additiven zu der Polymerkomponente P oder in mindestens einem der Schritte a), b), c) und/oder d),
• f) Austrag durch eine Düsenplatte mit Bohrungen, deren Durchmesser am Düsenaustritt 0.1 bis 1.0 mm beträgt,
• g) Granulieren der treibmittelhaltigen Schmelze.

Preferred is a process for producing a granulate according to the invention, comprising the steps

• a) preparing or providing a melt of the polymer component (P) according to the invention from PS) and optionally (PT),
• b) heating the polymer component (P) to form a polymer melt,
• c) mixing the blowing agent component according to the invention into the polymer melt by means of static or dynamic mixers at a temperature of at least 150 ° C.,
• d) thermal homogenization and optionally cooling of the blowing agent-containing polymer melt to a temperature of at least 120 ° C.,
• e) optionally adding additives to the polymer component P or in at least one of the steps a), b), c) and / or d),
• f) discharge through a nozzle plate with holes whose diameter at the nozzle exit is 0.1 to 1.0 mm,
• g) granulating the blowing agent-containing melt.

In a further preferred embodiment of the method according to the invention, the expandable polymer particles are coated in one step h) with one or more coating components, wherein these coating components may optionally be adsorbed to a porous solid.

Suitable coating components are, for example, glycerol esters, zinc stearate, esters of citric acid and silica.

In addition to silica, the mono-, di- and triglycerides which are obtainable from glycerol and stearic acid, glycerol and 12-hydroxystearic acid and glycerol and ricinoleic acid are preferred. Particularly preferred are mixtures of glycerol mono- and tristearate.

worin die Symbole und Indizes folgende Bedeutungen haben:
R¹ist C₁-C₁₀-Alkyl oder C₃-C₈-Cycloalkyl; vorzugsweise C₁-C₁₀-Alkyl;
m ist 0, 1, 2 oder 3;
n ist 1, 2, 3 oder 4 und
R ist C₁-C₃₀-Alkyl.Also preferred as coating agents are alkyl esters of cyclohexanecarboxylic acids of the formula (I),

wherein the symbols and indices have the following meanings:
R ¹ is C ₁ -C ₁₀ alkyl or C ₃ -C ₈ cycloalkyl; preferably C ₁ -C ₁₀ -alkyl;
m is 0, 1, 2 or 3;
n is 1, 2, 3 or 4 and
R is C ₁ -C ₃₀ -alkyl.

The symbols and indices in the formula (I) particularly preferably have the following meanings:
m is 0;
n is 2 and
R is C ₈ -C ₁₀ alkyl.

In particular, 1,2-cyclohexanedicarboxylate as, for example, under the name Hexamoll ^® DINCH by BASF SE (Ludwigshafen, Germany) is sold. Production and use as plasticizers are for example in WO99 / 32427 and the DE 20021356 described.

wobei
R² (C₁₀-C₂₁)-Alkyl, bevorzugt (C₁₃-C₁₇)-Alkyl, ist.Also preferred as coating agents are phenyl esters of (C ₁₀ -C ₂₁ ) -alkyl sulfonic acids of the formula (II) (component b))

in which
R ^{2 is} (C ₁₀ -C ₂₁ ) alkyl, preferably (C ₁₃ -C ₁₇ ) alkyl.

Preferred plasticizers b) are mixtures of (C ₁₀ -C ₂₁ ) -alkanesulfonic acid phenyl esters. Particularly preferred is a mixture which consists of 75 to 85% of a mixture of secondary alkanesulfonyl and additionally contains 15 to 25% of secondary alkanedisulfonate and 2 to 3% non-sulfonated alkanes, the alkyl radicals are predominantly unbranched and the chain lengths in the range of 10 21 are mainly from 13 to 17 carbon atoms.

Such mixtures are, for example, under the mesamoll ^® trademarks of Lanxess AG sold (Leverkusen, Germany).

Also preferred as a coating agent is glycerol tribenzoate (GTB), in particular in a mixture with glycerol monostearate and a precipitated silica, wherein the ratio of the three components is preferably 50-74% by weight to 25-49% by weight to 1-20% by weight ( based on the sum of the components).

A coating agent used according to the invention is preferably applied to the expandable polymer granules in an amount of from 0.01 to 1% by weight, preferably 0.1-0.8% by weight, particularly preferably 0.2-0.5% by weight ,

In addition, further substances such as antistatics, hydrophobizing agents, flame retardants, finely divided silica and inorganic fillers may be applied as the coating. The proportion of these agents depends on the type and effect and is for inorganic fillers usually 0 to 1 wt .-%, based on coated polymer granules.

Suitable antistatic agents are, for example, compounds such as emulsifier K30 (mixture of secondary sodium alkanesulfonates) or surfactant 743.

The coating in step h) can be carried out directly after the preparation of the particle without prior drying, after working up and drying, on compact particles or on prefoamed particles. The coating preferably takes place after work-up and drying of compact particles or prefoamed particles.

The application of coating components can be carried out in any order successively or simultaneously, preferably in succession.

The coating components may be dissolved and / or dispersed (e.g., suspended or emulsified). Depending on the type and amount of components, this can be done by simply stirring. In the case of poorly miscible (poorly dispersible) components, elevated temperatures and / or pressures, as well as, where appropriate, special mixing devices may be required in order to achieve a uniform mixing. If necessary, it is possible to use auxiliaries which facilitate mixing, for example customary wetting agents. In addition, the resulting coating composition may be obtained by adding suitable additives, e.g. common protective colloids or anti-settling agents, stabilize against segregation.

The coating components are applied, for example by spraying or by tumbling in conventional mixers on the polymer particles to be coated. It is also possible to immerse or wet the particles to be coated in a suitable solution, dispersion, emulsion or suspension. The coating is preferably applied as a powder mixture.

For this purpose, conventional mixers, sprayers or drum apparatuses are used.

The expandable polymer particles according to the invention or produced according to the invention can be processed into foams according to the invention with densities in the range from 10 to 150 kg / m ³ , preferably 15 to 100 kg / m ³ , particularly preferably 40 to 90 kg / m ³ . For this purpose, the expandable polymer particles are prefoamed. This is generally done by heating with steam and / or hot air in so-called pre-expanders. The pre-expanded particles are then welded to form bodies. For this purpose, the prefoamed particles are brought into closed, but not gas-tight closing forms and usually subjected to steam. After cooling, the foam moldings according to the invention can be removed.

The foams and foam moldings according to the invention are preferably used as insulation material for technical applications and the construction sector or as a foam element for lightweight construction and composite applications, for example in furniture construction, exhibition construction, the construction industry, the automotive industry, in boat and shipbuilding and / or in wind turbines.

In addition to these and the uses mentioned above, a use for composite moldings, in particular in furniture construction preferred. For this purpose, at least one further layer is applied to foam moldings according to the invention, which are in the form of a foam sheet, by known methods known to the person skilled in the art.

In addition to a first layer of the described foam plate such composite moldings thus contain at least one further layer. The first layer is preferably connected to at least two surfaces with one or more further layers. Further preferably, the first layer is on at least two surfaces (in the case of a rectangular cross-section top and bottom), also preferably all surfaces are connected to one or more further layers.

In one embodiment of the invention, the structure of the composite molding consists of one or more core layers, one or more cover layers and a surface layer.

In a further embodiment of the invention, the structure of the composite molding consists of a core layer and a surface layer.

For planking as a surface and optionally covering layer are, for example, aminoplast resin films, in particular melamine films, PVC (polyvinyl chloride), glass fiber reinforced plastic (GRP), for example a composite of polyester resin, epoxy resin, or polyamide and glass fibers, prepregs, films, laminates, for example HPL (high pressure laminates) and CPL (continuous pressure laminates), veneers, and metal, especially aluminum or lead coatings. Also suitable are fabrics and nonwovens, in particular of natural and / or synthetic fibers.

Furthermore come for a planking of composite moldings according to the invention (s) all materials into consideration, which are made of wood strips, wood fibers, wood chips, wood, wood veneers, glued woods, veneers or a combination of the corresponding manufacturing process. Also preferred is a planking of the moldings (s) according to the invention with OSB, chipboard, HDF (high-density fiberboard) or MDF (medium-density fiberboard), in particular thin chipboard, HDF and MDF with a thickness of 2 to 10 mm.

As adhesives, conventional materials, for example dispersion adhesives e.g. White glue, epoxy resins, formaldehyde condensation resins such as phenolic resins, urea-formaldehyde resins, melamine-formaldehyde resins, melamine-urea-formaldehyde resins, resorcinol and phenolic resorcinol resins, isocyanate adhesives, polyurethane adhesives and hot melt adhesives.

The invention is explained in more detail by the examples without wishing to be limited thereby. Xiran ^® SZ26080: SMA with a maleic anhydride content of 26 wt% and a MFR (240 ° C, 10 kg) of 58 g / 10 min from Polyscope Luran ^® 3380: SAN with an acrylonitrile content of 33% by weight and a viscosity number of 80 ml / g (commercial product of BASF SE) Luran ^® 2580: SAN with an acrylonitrile content of 25 wt% and a viscosity number of 80 ml / g (commercial product of BASF SE) Luran ^® VLN: SAN with an acrylonitrile content of about 25 wt% and a viscosity number of 62 ml / g (commercial product of BASF SE) PS 158K Q4 Polystyrene with an MVR (200 ° C., 5 kg) of 3 ml / 10 min and a Vicat softening temperature (VST / A / 50) of 106 ° C. (commercial product of Styrolution GmbH) Pentane S: Mixture of 80 wt% n-pentane and 20 wt% iso-pentane from Haltermann FR 370: Tris (tribromoneopentyl) phosphate: commercial product of ICL with TGA% WT.Loss of 1% @ 282 ° C dicumyl: Perkadox 30, Akzo Nobel GMS: glycerol; Dimodan HR 75 / B from Danisco GTS: glyceryl; Tegin BL 150 V from Evonik Goldschmidt silica: Precipitated silica; Tixosil 38 from Rhodia HBCD: Hexabromocyclododecane (FR-1206); Commercial product of the company ICL with TGA% WT.Loss of 2% @ 243 ° C Printex ^® FP: Carbon black, product of (Degussa AG) Bayferrox ^® : synthetic α-Fe ₂ O ₃ (Lanxess AG) Thermoplast yellow 104: Solvent Yellow 93, methine dye

N-hydroxysuccinimide, N-hydroxysuccinimide, distearylhydroxylamine (Irgastab FS042), N, N-dibenzylhydroxylamine, 4-hydroxy-TEMPO: commercial products from Sigma Aldrich

1. Preparation of foam samples for rapid fire test procedures

10 g of the polymer or of the polymer mixture were mixed with the amount of the flame retardant and any synergists mentioned in Tab. 1, dissolved in 30 ml of dichloromethane and stored for slow evaporation of the solvent at room temperature for 24 h. Subsequently, the still remaining dichloromethane-containing samples were stored at about 110 ° C for about 1 h which - caused by the Resttreibmittel - formed a foam body. The samples thus obtained were then set on fire with a Bunsen burner and assessed the flame retardancy achieved qualitatively. Table 1 Produced foam specimens and qualitative assessment of flame retardancy (++ = very good, + = good, ○ = moderate, - = bad, - = very bad). Polymer 1 Polymer 2 (Tris (tribromoneopentyl) phosphate) synergist Qualitative assessment flame retardant effect Luran 3380: 10g n / A 0.75 g n / A ++ Luran 3380: 10g n / A 0.5 g n / A ++ Luran 3380: 10g n / A 0.75 g Dicumyl: 1 phr ++ Luran 3380: 10g n / A 0.75 g Dicumyl: 0.6 phr ++ Luran 3380: 10g n / A 0.75 g Dicumyl: 0.4 phr ++ Luran 3380: 10g n / A 0.5 g Dicumyl: 1 phr ++ Luran 3380: 10g n / A 0.5 g Dicumyl: 0.6 phr ++ Luran 3380: 10g n / A 0.5 g Dicumyl: 0.4 phr ++ Luran 3380: 10g n / A 0.4 g Dicumyl: 1 phr + Luran 3380: 10g n / A 0.4 g Dicumyl: 0.6 phr + Luran 3380: 10g n / A 0.4 g Dicumyl: 0.4 phr + Luran 3380: 10g n / A 0.75 g N-hydroxysuccinimide: 1 phr ++ Luran 3380: 10g n / A 0.5 g N-hydroxysuccinimide: 1 phr ++ Luran 3380: 10g n / A 0.4 g N-hydroxysuccinimide: 1 phr + Luran 3380: 10g n / A 0.75 g N-hydroxysuccinimide: 0.6 phr ++ Luran 3380: 10g n / A 0.5 g N-hydroxysuccinimide: 0.6 phr ++ Luran 3380: 10g n / A 0.4 g N-hydroxysuccinimide: 0.6 phr + Luran 3380: 4 g Xiran SZ26080 6 g 0.4 g + Luran 3380: 4 g Xiran SZ26080 6 g 0.3 g + Luran 3380: 4 g Xiran SZ26080 6 g 0.4 g Dicumyl: 0.3 phr ++ Luran 3380: 4 g Xiran SZ26080 6 g 0.3 g Dicumyl: 0.3 phr ++

2. Production of expandable granules and moldings

In a twin-screw extruder ZE40, 90% by weight of Luran 3380 were melted at about 230-260 ° C. with about 6.5% of the additive mixture given in table 3. Subsequently, the polymer melt was loaded with about 3.5% pentane S (based on the polymer matrix), homogenized in two static mixers and cooled to about 220-230 ° C. A second twin-screw extruder ZDSK30 was used to add 10% by weight of Luran 3380 with the amount of flameproofing components indicated in Tab. 2, melted at 200-240 ° C. and fed to the main amount via a gear pump. After homogenization via two further static mixers, the melt was cooled to 200 ° C-220 ° C and extruded through a heated perforated plate (4 holes with 0.65 mm bore and 300-320 ° C perforated plate temperature). The polymer strand was cut off by means of underwater granulation (8-10 bar underwater pressure, 70-80 ° C. water temperature), so that a propellant-loaded minigranulate having a narrow particle size distribution d '(~ 1.0 mm) was obtained.

The produced expandable granules were precoated with 200 ppm of antistatic agent 743 (BASF SE). Subsequently, in a Lödige mixer, the main coating was applied to the expandable granules. The main coating (GTS / GMS / silicic acid = 6/3/1) was mixed before application to the granules to form a uniform powder.

The granules coated in this way were prefoamed in a prefoamer (PREEX 1000 from Hirsch) at a water vapor pressure of about 1.1 bar and with a molding machine (EHV-C from Erlenbach) to give plates having a density of about 80 g / l welded at a vapor pressure of 2.1 bar. From these samples, the required burn bodies for the B2 test (10 mm = thin, 60 mm = thick) were subsequently cut out. In each case 5 specimens were examined per thickness and the mean value was formed. Table 2 below gives an overview of the described experiments. Tab. 2 Produced SAN-based expandable granules with flameproofing equipment and B2 results according to DIN 4102 part 1: 1998-05 (* = completely burned; ** = T _g determined according to ISO 11357) VBsp: comparative example). example (Tris (tribromo-neopentyl) -phosphate) [% by weight] Dicumyl [% by weight] B2 test passed? Fire height [mm] Burning time [s] Tg [° C] ** VBsp1 0 0 NO 108 bsp1 7 0 YES Thin: 104 Thick: 60 Thin: 13 Thick: 16 105 BSP2 7 0.6 YES Thin: 122 Thick: 80 Thin: 12 Thick: 17 104 EX3 7 0.4 YES Thin: 106 Thick: 76 Thin: 9 Thick: 16 104 Tab. 3 Additive mixture used Luran 3380 [wt.%] Talcum [wt.%] Carbon black Printex FP [weight%] Bay-ferrox 110M [weight%] Thermoplastic yellow [weight%] 72.32 8.00 0.88 10.00 8.8

All settings were also examined with regard to their mechanical properties (compressive strength, bending strength, bending work). The results can be found in Table 4. Tab. 4 Mechanical data of the granules (VBsp: Comparative Example). example Bending strength [kPa] Compressive strength [kPa] Bending work [Nm] VBsp1 925 73 ^ 4.47 bsp1 852 727 4.15 BSP2 775 701 4.05 EX3 613 562 4.18

QUOTES INCLUDE IN THE DESCRIPTION

This list of the documents listed by the applicant has been generated automatically and is included solely for the better information of the reader. The list is not part of the German patent or utility model application. The DPMA assumes no liability for any errors or omissions.

Cited patent literature

• WO 2005/056652 [0003]
• WO 2009/000872 [0003]
• WO 2009/112392 [0003]
• WO 99/32427 [0050]
• DE 20021356 [0050]

Cited non-patent literature

• ISO 113 [0015]
• DIN 4102 Part 1 [0024]

Claims (12)

Expandable polymer granules obtainable from P) 100 parts by weight of a polymer component consisting of PS) 90-100% by weight (based on P) of a styrene copolymer component consisting of PS1) one or more styrene-acrylonitrile copolymers (SAN) or PS2) Mixture of one or more styrene-acrylonitrile copolymers (SAN) and one or more styrene-maleic anhydride copolymers (SMA) and / or PS3) one or more styrene-acrylonitrile-maleic anhydride copolymers (SANMA) and PT) 0 to 10% by weight (based on P) of one or more thermoplastic polymers selected from the group consisting of aromatic polyethers; polyolefins; polyacrylates; Polycarbonates (PC); polyesters; polyamides; polysulfones; Polyethersulfones (PES); Polyether ketones (PEK) and polystyrene; T) 2 to 8 parts by weight (based on P) of a physical blowing agent component (T) containing 80 to 100% by weight (based on T) of one or more hydrocarbons having 2 to 7 carbon atoms, F) a flame retardant system containing 1 to 10 parts by weight, based on P, of one or more brominated trialkyl phosphates as flame retardants (F1), (O) P (OR) ₃ (I) where R is, identically or differently, a straight-chain or branched alkyl group having 1 to 6 carbon atoms, where one, two or three hydrogen atoms are substituted by bromine. Expandable polymer granules according to claim 1, characterized in that the flame retardant (F1) is tris (tribromoneopentyl) phosphate. Expandable Polymergranluat according to claim 1 or 2, containing as further component F2) 0.01 to 3 parts by weight based on P, of dicumyl or one or more compounds from the group of hydroxylamines and anhydrides or mixtures thereof as Flammschutzsynergisten. Expandable polymer granules according to claim 3, characterized in that the flame retardant synergist (F2) is dicumyl. Expandable polymer granules according to any one of claims 1 to 4, wherein the styrene copolymer component consists of one or more styrene-acrylonitrile copolymers (SAN). An expandable polymer granule according to any one of claims 1 to 4, wherein the styrene copolymer component consists of a mixture of SAN and SMA. An expandable polymer granule according to any one of claims 1 to 4, wherein the styrene copolymer component consists of one or more styrene-acrylonitrile-maleic anhydride terpolymers. A process for producing an expandable polymer granule according to any one of claims 1 to 7, comprising the steps a) providing the polymer component (P), (b) heating the polymer component (P) to form a polymer melt, (c) introducing from 2 to 8% by weight (based on P) of a physical blowing agent component (T) containing 80-100% by weight (based on (T)) of one or more hydrocarbons having 2 to 7 carbon atoms, in the polymer melt to form a foamable melt, (d) homogenizing the mixture, (e) addition of the flame retardant system F) according to the invention and optionally addition of further additives to the polymer component P in at least one of the steps a), b), c) and / or d), (f) extrusion of the blowing agent-containing polymer melt through a nozzle plate, (G) granulating the Treibmitteilhaltigen melt in a liquid-filled chamber under a pressure of 1 to 20 bar to granules. A process for producing a foam molding comprising a) -g) the preparation of an expandable polymer granulate according to any one of claims 1 to 7, h) pre-foaming the granules according to the invention into foam particles and i) welding the foam particles in a closed mold. Foam molding or foam block, obtainable from expandable polymer particles according to one of claims 1 to 7. Composite molding comprising a core material and at least one cover layer, wherein the core material is a foam molding or foam block according to claim 10. Use of a foam molding or foam block according to claim 10 or a composite molding according to claim 11 in furniture, in the construction industry, in exhibition construction, in the automotive industry, in boat and shipbuilding, in wind turbines and / or for thermal insulation.