Classifications

• • C—CHEMISTRY; METALLURGY
  • C04—CEMENTS; CONCRETE; ARTIFICIAL STONE; CERAMICS; REFRACTORIES
  • C04B—LIME, MAGNESIA; SLAG; CEMENTS; COMPOSITIONS THEREOF, e.g. MORTARS, CONCRETE OR LIKE BUILDING MATERIALS; ARTIFICIAL STONE; CERAMICS; REFRACTORIES; TREATMENT OF NATURAL STONE
  • C04B16/00—Use of organic materials as fillers, e.g. pigments, for mortars, concrete or artificial stone; Treatment of organic materials specially adapted to enhance their filling properties in mortars, concrete or artificial stone
  • C04B16/04—Macromolecular compounds
  • C04B16/08—Macromolecular compounds porous, e.g. expanded polystyrene beads or microballoons
• • C—CHEMISTRY; METALLURGY
  • C04—CEMENTS; CONCRETE; ARTIFICIAL STONE; CERAMICS; REFRACTORIES
  • C04B—LIME, MAGNESIA; SLAG; CEMENTS; COMPOSITIONS THEREOF, e.g. MORTARS, CONCRETE OR LIKE BUILDING MATERIALS; ARTIFICIAL STONE; CERAMICS; REFRACTORIES; TREATMENT OF NATURAL STONE
  • C04B18/00—Use of agglomerated or waste materials or refuse as fillers for mortars, concrete or artificial stone; Treatment of agglomerated or waste materials or refuse, specially adapted to enhance their filling properties in mortars, concrete or artificial stone
  • C04B18/02—Agglomerated materials, e.g. artificial aggregates
  • C04B18/027—Lightweight materials
• • C—CHEMISTRY; METALLURGY
  • C08—ORGANIC MACROMOLECULAR COMPOUNDS; THEIR PREPARATION OR CHEMICAL WORKING-UP; COMPOSITIONS BASED THEREON
  • C08J—WORKING-UP; GENERAL PROCESSES OF COMPOUNDING; AFTER-TREATMENT NOT COVERED BY SUBCLASSES C08B, C08C, C08F, C08G or C08H
  • C08J9/00—Working-up of macromolecular substances to porous or cellular articles or materials; After-treatment thereof
  • C08J9/0014—Use of organic additives
  • C08J9/0023—Use of organic additives containing oxygen
• • C—CHEMISTRY; METALLURGY
  • C08—ORGANIC MACROMOLECULAR COMPOUNDS; THEIR PREPARATION OR CHEMICAL WORKING-UP; COMPOSITIONS BASED THEREON
  • C08J—WORKING-UP; GENERAL PROCESSES OF COMPOUNDING; AFTER-TREATMENT NOT COVERED BY SUBCLASSES C08B, C08C, C08F, C08G or C08H
  • C08J9/00—Working-up of macromolecular substances to porous or cellular articles or materials; After-treatment thereof
  • C08J9/0066—Use of inorganic compounding ingredients
• • C—CHEMISTRY; METALLURGY
  • C08—ORGANIC MACROMOLECULAR COMPOUNDS; THEIR PREPARATION OR CHEMICAL WORKING-UP; COMPOSITIONS BASED THEREON
  • C08J—WORKING-UP; GENERAL PROCESSES OF COMPOUNDING; AFTER-TREATMENT NOT COVERED BY SUBCLASSES C08B, C08C, C08F, C08G or C08H
  • C08J9/00—Working-up of macromolecular substances to porous or cellular articles or materials; After-treatment thereof
  • C08J9/04—Working-up of macromolecular substances to porous or cellular articles or materials; After-treatment thereof using blowing gases generated by a previously added blowing agent
  • C08J9/12—Working-up of macromolecular substances to porous or cellular articles or materials; After-treatment thereof using blowing gases generated by a previously added blowing agent by a physical blowing agent
  • C08J9/14—Working-up of macromolecular substances to porous or cellular articles or materials; After-treatment thereof using blowing gases generated by a previously added blowing agent by a physical blowing agent organic
  • C08J9/141—Hydrocarbons
• • C—CHEMISTRY; METALLURGY
  • C08—ORGANIC MACROMOLECULAR COMPOUNDS; THEIR PREPARATION OR CHEMICAL WORKING-UP; COMPOSITIONS BASED THEREON
  • C08J—WORKING-UP; GENERAL PROCESSES OF COMPOUNDING; AFTER-TREATMENT NOT COVERED BY SUBCLASSES C08B, C08C, C08F, C08G or C08H
  • C08J9/00—Working-up of macromolecular substances to porous or cellular articles or materials; After-treatment thereof
  • C08J9/16—Making expandable particles
• • C—CHEMISTRY; METALLURGY
  • C04—CEMENTS; CONCRETE; ARTIFICIAL STONE; CERAMICS; REFRACTORIES
  • C04B—LIME, MAGNESIA; SLAG; CEMENTS; COMPOSITIONS THEREOF, e.g. MORTARS, CONCRETE OR LIKE BUILDING MATERIALS; ARTIFICIAL STONE; CERAMICS; REFRACTORIES; TREATMENT OF NATURAL STONE
  • C04B2111/00—Mortars, concrete or artificial stone or mixtures to prepare them, characterised by specific function, property or use
  • C04B2111/20—Resistance against chemical, physical or biological attack
  • C04B2111/28—Fire resistance, i.e. materials resistant to accidental fires or high temperatures
• • C—CHEMISTRY; METALLURGY
  • C08—ORGANIC MACROMOLECULAR COMPOUNDS; THEIR PREPARATION OR CHEMICAL WORKING-UP; COMPOSITIONS BASED THEREON
  • C08J—WORKING-UP; GENERAL PROCESSES OF COMPOUNDING; AFTER-TREATMENT NOT COVERED BY SUBCLASSES C08B, C08C, C08F, C08G or C08H
  • C08J2325/00—Characterised by the use of homopolymers or copolymers of compounds having one or more unsaturated aliphatic radicals, each having only one carbon-to-carbon double bond, and at least one being terminated by an aromatic carbocyclic ring; Derivatives of such polymers
  • C08J2325/02—Homopolymers or copolymers of hydrocarbons
  • C08J2325/04—Homopolymers or copolymers of styrene
• • Y—GENERAL TAGGING OF NEW TECHNOLOGICAL DEVELOPMENTS; GENERAL TAGGING OF CROSS-SECTIONAL TECHNOLOGIES SPANNING OVER SEVERAL SECTIONS OF THE IPC; TECHNICAL SUBJECTS COVERED BY FORMER USPC CROSS-REFERENCE ART COLLECTIONS [XRACs] AND DIGESTS
  • Y10—TECHNICAL SUBJECTS COVERED BY FORMER USPC
  • Y10S—TECHNICAL SUBJECTS COVERED BY FORMER USPC CROSS-REFERENCE ART COLLECTIONS [XRACs] AND DIGESTS
  • Y10S521/00—Synthetic resins or natural rubbers -- part of the class 520 series
  • Y10S521/907—Nonurethane flameproofed cellular product

Definitions

• the invention relates to particulate expandable styrene polymers in particle form containing graphite particles, their preparation and foams produced therefrom.
• Polystyrene particle foams have been known for a long time and have been retained in many areas. Such foams are produced by foaming polystyrene particles impregnated with blowing agents and the subsequent welding of the foam particles thus produced to shaped bodies. An important area of application is thermal insulation in construction.
• the foams be self-extinguishing. It is known that this can be done by adding flame retardants, e.g. of bromine compounds can be achieved; However, whether a foam passes a certain fire test depends on various factors, such as the composition and density of the foam, the type and amount of flame retardant, and the type and amount of other additives.
• flame retardants e.g. of bromine compounds
• the foam panels made of polystyrene particle foam used for thermal insulation mostly have densities of at least 30 g / 1, since the thermal conductivity of the polystyrene particle foam is at a minimum at these densities.
• foam boards with lower densities especially ⁇ . 15 g / 1, to be used for heat insulation.
• the production of such foams is technically not a problem.
• Sc aumstoffplatten with lower density however, have a drastically deteriorated thermal insulation, so that they do not meet the requirements of thermal conductivity class 035 (DIN 18 164, Part 1).
• EP-A 372 343 describes polystyrene foams which contain 1 to 25% by weight of carbon black.
• the carbon black has a particle size of 10 to 100 nm and a surface of 10 to 1500 m-Vg.
• the polystyrene foams described there are predominantly produced by the extrusion process and preferably have a density of 32-40 g / 1, as is typical for these foams, on.
• the addition of flame retardants is mentioned;
• the polystyrene particle foams described in the examples with a content of 1.7% by weight of hexabromocyclododecane fail the fire test B2 according to DIN 4102).
• EP-A 620 246 describes moldings made of polystyrene particle foam which contain a particulate, athermanous material, in particular carbon black, but also graphite.
• the density of the molded body is less than 20 g / 1.
• the particles are preferably incorporated into the shaped bodies by surface coating the pre-expanded polystyrene beads or by embedding them in the not yet expanded polystyrene granules.
• this distribution of the particles on the surface leads to a severe deterioration in the welding of the pre-foamed beads and consequently to less good foams, and abrasion from the surface of the molded body can also occur.
• the particles are in any case not homogeneously distributed inside the polystyrene particles; the addition of flame retardants is not described.
• GB-A 1 588 314 describes a similar process, according to which antistatic polystyrene foams are produced by coating unfoamed or pre-foamed particles with a graphite suspension.
• the object of the invention was to provide expandable styrene polymers containing graphite particles which can be processed into polystyrene particle foams both with low density and with low thermal conductivity and which have good processing properties, good physical properties and in particular very good fire protection properties.
• particulate, expandable styrene polymers which contain graphite particles in a homogeneous distribution and can be processed into foams with a density of ⁇ 35 g / 1, which are preferably self-extinguishing and pass fire test B2 (according to DIN 4102).
• the invention furthermore relates to processes for producing the expandable styrene polymers and the polystyrene particle foams produced from them.
• Expandable styrene polymers are understood to mean styrene polymers containing blowing agents.
• the expandable styrene polymers according to the invention contain, as polymer matrix, in particular homopolystyrene or styrene copolymers with up to 20% by weight, based on the weight of the polymers, of ethylenically unsaturated comonomers, in particular alkylstyrenes, divinylbenzene, acrylonitrile or ⁇ -methylstyrene.
• Blends made of polystyrene and other polymers, in particular with rubber and polyphenylene ether, are also possible.
• the styrene polymers can contain the customary and known auxiliaries and additives, for example flame retardants, nucleating agents, UV stabilizers, chain transfer agents, blowing agents, plasticizers, pigments and antioxidants.
• auxiliaries and additives for example flame retardants, nucleating agents, UV stabilizers, chain transfer agents, blowing agents, plasticizers, pigments and antioxidants.
• the expandable particles are coated with the customary and known coating agents, for example metal stearates, glycerol esters and finely divided silicates.
• coating agents for example metal stearates, glycerol esters and finely divided silicates.
• the particle size is preferably in the range of 0.2-2 mm.
• the graphite used preferably has an average particle size of 1 to 50 ⁇ m, in particular 2.5 to 12 ⁇ m, a bulk density of 100 to 500 g / 1 and a specific surface area of 5 to 20 ⁇ m / g.
• Natural graphite or ground synthetic graphite can be used.
• the graphite particles are preferably contained in the styrene polymer in amounts of 0.05 to 25% by weight, in particular 2 to 8% by weight. Surprisingly, it has been shown that graphite particles are effective even in amounts of less than 0.5% by weight.
• the expandable styrene polymers are added with flame retardants, in particular those based on organic bromine compounds.
• the bromine compound (without synergist) should be added in an amount of more than 3% by weight, based on the weight of the expandable styrene polymers. Bl and B2 are missed with the usual amount of flame retardants.
• the organic bromine compounds should have a bromine content of> 70% by weight.
• this amount of flame retardants does not impair the mechanical properties of the polystyrene particle foams containing carbon black.
• Aliphatic, cycloaliphatic and aromatic bromine compounds such as hexabromocyclododecane, pentabromomochlorocyclohexane, pentabromophenyl allyl ether, are particularly suitable.
• the effect of the bromine-containing flame retardants is considerably improved by adding C-C or O-O-labile organic compounds.
• suitable flame retardant synergists are dicumyl and dicumyl peroxide.
• a preferred combination consists of 0.6 to 5% by weight of organic bromine compound and 0.1 to 1.0% by weight of the C-C or O-O-unstable organic compound.
• the expandable styrene polymers according to the invention can be prepared by various processes.
• the graphite particles are mixed with a melt of the styrene polymer, preferably in an extruder.
• the blowing agent is metered into the melt.
• the graphite particles can also be incorporated into a melt of blowing agent-containing styrene polymer, expediently using screened fractions of a bead spectrum of blowing agent-containing polystyrene beads formed in a suspension polymerization.
• the polystyrene melt containing the blowing agent and graphite particles is pressed out and comminuted into granules containing blowing agent.
• graphite has cooled quickly after pressing under pressure to avoid foaming. It is therefore expedient to carry out underwater pelletizing under pressure.
• blowing agent to the styrene polymers containing graphite particles in a separate process step.
• the granules are then preferably impregnated with the blowing agent in aqueous suspension.
• the fine-particle graphite particles can be added directly to the polystyrene melt.
• the graphite particles can also be added to the melt in the form of a concentrate in polystyrene.
• polystyrene granules and graphite Enter the particles together in an extruder, melt the polystyrene and mix it with the graphite.
• the graphite particles in the course of the suspension polymerization. They can be added to the monomeric styrene before the suspension or can be added to the reaction mixture in the course, preferably during the first half, of the polymerization cycle.
• the blowing agent is preferably added in the course of the polymerization, but it can also be incorporated into the styrene polymer afterwards. It has been shown that it is favorable for the stability of the suspension if a solution of polystyrene (or a corresponding styrene copolymer) in styrene (or the mixture of styrene with comonomers) is present at the start of the suspension polymerization.
• a 0.5 to 30, in particular 5 to 20% by weight solution of polystyrene in styrene is preferably used. It is possible to dissolve fresh polystyrene in monomers, but expediently so-called fractions are used, which are sieved out as beads which are too large or too small when the expandable polystyrene is produced, and in practice such fractions which cannot be used have such fractions Diameters greater than 2.0 mm or less than 0.2 mm. Recycled polystyrene and recycled foam polystyrene can also be used. Another possibility is to prepolymerize styrene in bulk up to a conversion of 0.5 to 70% and to suspend and prepolymerize the prepolymer together with the graphite particles in the water phase.
• the blowing agent is in the usual amounts of about
• Aliphatic hydrocarbons having 3 to 10, preferably 4 to 6, carbon atoms are usually used as blowing agents.
• the expandable, carbon black-containing styrene polymers according to the invention can be processed into polystyrene foams with densities of 5-35 g / 1, preferably 8 to 25 g / 1 and in particular 10-15 g / 1.
• the expandable particles are pre-foamed. This is usually done by heating the particles with water vapor in so-called previewers. The pre-foamed particles are then welded to form bodies. For this purpose, the pre-foamed "" particles are brought into non-gas-tight molds and water vapor is applied. After cooling, the molded parts can be removed.
• Another surprising effect of the addition of graphite particles is that the cooling time when demolding welded foam blocks can be reduced. For example, an addition of 0.5 to 5% by weight of graphite leads to a reduction in the cooling time of 10 to 90%.
• the foams produced from the expandable styrene polymers according to the invention are notable for excellent thermal insulation. This effect is particularly evident at low densities.
• the thermal conductivity could be reduced from 44 mW / m-K to below 35 mW / mK.
• Another object of the invention are polystyrene particle foams with a density of ⁇ 35 g / 1, which contain 0.05 to 25% by weight of graphite particles in a homogeneous distribution, the thermal conductivity of which is reduced to such an extent that they meet the requirements of thermal conductivity class 035 (according to DIN 18 164, Part 1, Table 4), which are preferably self-extinguishing and meet fire test B2 (according to DIN 4102).
• Material savings can be achieved through the possibility of significantly reducing the density of the styrene polymers while maintaining the same thermal conductivity. Since, in comparison with conventional expandable styrene polymers, the same thermal insulation can be achieved with significantly lower rubble densities, thinner foam sheets can be used with the expandable polystyrene particles produced according to the invention, which enables space to be saved.
• the expandable styrene polymers according to the invention can be processed into foams of low density without any problems. There is no loss of blowing agent or disturbances in the cell structure of the foams, although the person skilled in the art had to assume that the graphite acts as a nucleating agent and would lead to an undesirable fine cell structure of the foam and poor welding. In addition, despite the addition of graphite particles, self-extinguishing foams can be produced that pass fire test B2 and in most cases also B1. Due to the integration of the graphite particles in the polymer matrix there is no abrasion of the graphite and "" therefore no contamination when working with such components.
• the foams according to the invention can be used for the thermal insulation of buildings and parts of buildings, for the thermal insulation of machines and household appliances and as packaging materials.
• EPS fractions are dissolved in 16.6 kg styrene and 16.6 g powdered graphite (Graphitwerk Kropfmuhl KG, UF2 96/97), i.e. 0.1% graphite, based on the total amount of styrene and EPS, homogeneously suspended with the addition of 83.0 dicumyl peroxide and 4.15 g dibenzoyl peroxide, and 112.033 g hexabromocyclododecane (HBCD).
• the organic phase is introduced into 19.3 l of completely demineralized water in a 50 l Ruhr kettle.
• the aqueous phase contains 46.127 g of sodium pyrophosphate and 86.348 g of magnesium sulfate (Epsom salt).
• the suspension is heated to 80 ° C. within 140 minutes.
• 2.32 g of emulsifier K 30/40 (Bayer AG) are added.
• 1330 g of pentane are metered in and polymerized at 126 ° C.
• Example 1 was repeated without adding graphite.
• the coefficient of thermal conductivity at a density of 10 g / 1 was 44 mW / mK.
• Example 3
• HBCD hexabromocyclododecane
• the mixture was then stirred at 90 ° C. for a further 2 hours and 7 parts of a mixture of 80% n-pentane and 20% iso-pentane were added. 5 The mixture was then stirred at 110 ° C. for 2 hours and finally at 140 ° C. for 2 hours.
• the expandable polystyrene beads obtained were washed with deionized water and sieved to 0.7-1.0 mm and then dried with warm air.
• the beads were pre-foamed by the action of flowing water vapor and after storage for one day by further treatment with steam in a closed mold they were welded into foam blocks with a density of 15 g / l.
• the measurement of the coefficient of thermal conductivity was carried out at 10 n C according to DIN 52612. The result was a value of 34 mW / mK.
• the pearls can be used
• Example 4 was repeated with 4% graphite.
• Example 4 was repeated with t 2% graphite
• Example 4 was repeated with 1% graphite.
• Example 4 was repeated with 0.5% graphite.
• Example 4 was repeated with 0.2% graphite.
• Example 4 was carried out without the addition of graphite.
• Example 4 was repeated, 127 g of hexabromocyclododecane and 85 g of dicumyl being added as the flame retardant system.
• the polymerization was carried out at 125 ° C. There was one Thermal conductivity of 34 mW / mK. Fire protection class B 2 was achieved.
• Polystyrene with an average molecular weight (M w ) of 220,000 (PS 148 H BASF) and a content of 2.1% HBCD and 0.42% dicumyl was added as a 20% batch in polystyrene with the addition of the amounts of graphite given in Table 1 plasticized in a heated twin-screw extruder at 180 C and pressed through a die plate of 1 mm in diameter. The strands were solidified in a water bath and then granulated to a particle size of 2x2x2 mm using rotating knives.
• Example 15 foaming to a density of 10.3 g / 1, in Example 16 (with a shorter evaporation time) to a density of 15 g / 1.
• the thermal conductivities were 34 and 32 mW / m-K. The B2 test was passed in each case.
• the coefficient of thermal conductivity was 34 and 44 mW / m-K. The B2 test was not passed in each case.
• Polystyrene PS 158 K (BASF AG) was metered together with 2% graphite, 1.4% HBCD and 0.7% dicumyl in a twin-screw extruder (ZSK 53). In addition, 5% pentane was added to the melt in the extruder.
• the melt emerging from the extruder die was granulated using an underwater pelletizer from Gala (USA). The granulation was carried out under 5 bar pressure. This pressure was achieved by means of a throttle (hose with a length of 50 m) which was installed between the granulation and dryer. Pearl-shaped black granules with an average diameter of about 1.5 mm were obtained. Moldings produced by foaming and sintering the foam particles had a thermal conductivity of 35 mW / m-K at a density of 13 g / 1.
• Pre-expanded EPS beads were mixed with 2.0% graphite in a mixing unit. An incomplete coating and uneven distribution of the graphite on the surface of the pearls were found. A strong abrasion of the graphite from the pearl surface was observed during further processing. The use of binders (glycerin stearate, white oil) did not improve the quality of the coating results. The welding of the molded parts was unsatisfactory.

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• 1997
  • 1997-05-14 WO PCT/EP1997/002458 patent/WO1998051735A1/de not_active Ceased
  • 1997-05-14 JP JP54871798A patent/JP4324250B2/ja not_active Expired - Lifetime
  • 1997-05-14 AT AT97923073T patent/ATE196158T1/de active
  • 1997-05-14 US US09/423,613 patent/US6340713B1/en not_active Expired - Lifetime
  • 1997-05-14 DE DE59702327T patent/DE59702327D1/de not_active Expired - Lifetime
  • 1997-05-14 EP EP97923073A patent/EP0981574B1/de not_active Expired - Lifetime
  • 1997-05-14 AU AU28979/97A patent/AU2897997A/en not_active Abandoned
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