CH711604B1 - Polyamide-based components with improved fire behavior. - Google Patents

Abstract

Described is a flame-retardant article, in particular for railway applications, containing or consisting of at least one extruded or injection-molded part (A) consisting of a fiber-reinforced, halogen-free flame-retardant polyamide molding compound; wherein the molding has a mineral-containing coating (B) in at least a portion of its exposed surface; and wherein the article at a heat radiation of 50 kW / m 2 and a sample thickness of 3 mm has a MARHE value according to DIN EN 45545-2: 2013 of at most 90 kW / m 2, and wherein the optical smoke density (Ds) after 4 min and the cumulative smoke density VOF4 according to DIN EN 45545-2: 2013 and ISO 5659-2: 50 kW / m 2 preferably do not exceed a value of 300 or 600. Also described are uses and methods of manufacture.

Description

description

TECHNICAL FIELD The present invention relates to components or components which contain these components, from extruded or injection-molded moldings consisting of a fiber-reinforced and flame-retardant polyamide molding compound. Furthermore, the present invention relates to methods for the production of such components or components as well as different uses.

PRIOR ART With the introduction of DIN EN 45545 (railway applications - fire protection in rail vehicles), from March 2016, Europe-wide harmonized rules for the fire protection classification of rail vehicles and uniform requirements for the fire behavior of materials for rail applications apply. According to DIN EN 45545, plastics need an «HL2» (Hazard Level 2) rating in order to be able to be used in most rail vehicles for outside sleeping cars. HL2 in accordance with requirement set R1 (for internal parts) requires that the material • itself goes out in the spread of flame test ISO 5658-2 at> 20 kW / m ² . Comparable flame-retardant polyamides such as those based on PA66, possibly mixed with partially aromatic PA systems, have passed this test with a large safety margin in the past;

• In the “Cone Calorimeter” test ISO 5660-1, an average of 90 kW / m ² may be emitted when irradiated with 50 kW / m ² . This requirement can be met by certain flame retardant polyamides from a thickness of approx. 5 mm;

• In the smoke test ISO 5659-2 with radiation of 50 kW / m ^2, only a little smoke is allowed to develop in the first 4 minutes. Ds (4) and VOF4 denote the optical smoke density after 4 min and the cumulative smoke density from 0 to 4 min. Both values correlate. This requirement can be met by certain flame retardant polyamides from a thickness of approx. 10 mm.

In order to be classified as HL2 according to requirement set R1 according to DIN EN 45545, a material must comply with the following limit values:

requirements set Regarding test methods Parameters and unit Maximum or minimum HL1 HL2 HL3 R1 T02 ISO 5658-2 CFE kWrn “ ² minimum 20 a 20 a 20 a T03.01 ISO 5660-1: 50 kWm ' ² MARHE kWrn ^-2 maximum a 90 60 T10.01 EN ISO 5659-2: 50 kWm ' ² Ds (4) dimensionless maximum 600 300 150 T10.02 EN ISO 5659-2: 50 kWm ' ² of ₄ min maximum 1200 600 300 T11.01 EN ISO 5659-2: 50 kWm ' ² CIT _G dimensionless maximum 1.2 0.9 0.75

An HL2 classification according to requirement sentence R7 (for external parts) means that the material:

undergoes the same three tests as for R1. This time, the smoke test does not depend on the first 4 minutes, but on the maximum smoke density Ds (max.), And the key figure CIT _G for smoke toxicity can be twice as high as for R1.

The limit values for HL2 according to requirement sentence R7 are as follows:

CH 711 604 B1

requirements set Regarding test methods Parameters and unit Maximum or minimum HU HL2 HL3 R7 T02 ISO 5658-2 CFE kWrn “ ² minimum 20 a 20 a 20 a T03.01 ISO 5660-1: 50 kWm ' ² MARHE kWrn ^-2 maximum a 90 60 T10.04 EN ISO 5659-2: 50 kWm ' ² D _s max. dimensionless maximum - 600 300 T11.01 EN ISO 5659-2: 50 kWm ' ² CIT _G dimensionless maximum 1.8 1.5

Both sets of requirements R1 and R7 contain tests of heat release and smoke development when irradiated with 50 kW / m ² . So far, no polyamide has received an HL2 rating according to R1 or R7 for the wall thicknesses common for injection molded parts, because heat and smoke development generally show opposite tendencies.

Basically, the use of flame-retardant fiber-reinforced polyamide for special railway applications, for which other sets of requirements apply, is known. For example, WO 2013/092 302 describes a melam-containing polyamide or polyester molding compound for an HL3 rating in accordance with requirement sentences R22 and R23. The part thickness should be a maximum of 3 mm. An example is a PA46 + PA6 blend with 30% GF and Melam + Exolit OP1230.

Also known is the use of polycarbonate for such railway applications, compare for example WO 2013/130 805, which describes a low-smoking and low-heat-releasing polycarbonate copolymer for an HL2 rating according to R1 at 3 mm. It is also known to use multilayer polymer structures for railway applications. For example, US 2011/0 241 248 describes such a structure based on polyurethane, specifically a laminate of flame-retardant PUR and a second layer of PUR with expanded graphite.

It is also known to apply a so-called insulation layer (intumescent coating) on a plastic component, which foams above a certain temperature and thus causes a delay in combustion, compare, for example, US Pat. No. 20,120,276,391. Such insulation layers consist of a binder and, for example, a phosphorus-containing material that decomposes when exposed to heat.

DISCLOSURE OF THE INVENTION It is, inter alia, the object of the present invention to provide objects based on polyamide which can achieve the best possible rating in the sense of DIN EN 45545 and for as many different applications as possible, even with large ones mechanical load, can be used. The present invention and, inter alia, the solution to the above-mentioned object is a flame-retardant object, in particular for railway applications, containing or consisting of at least one extruded or injection-molded molded part (A) consisting of a fiber-reinforced, halogen-free flame-retardant polyamide molding compound, the molded part being present in at least one Area of its exposed surface has a mineral-containing coating (B). The flame-retardant object according to the invention has a MARHE value in accordance with DIN EN 45545-2 with heat radiation of 50 kW / m ² (with pilot light) and a sample thickness of 3 mm (thickness of molded part A alone, ie measured without the thickness of coating B) : 2013 from a maximum of 90 kW / m ² .

When testing the optical smoke density (Ds) according to DIN EN 45545-2: 2013 and EN ISO 5659-2 with heat radiation of 50 kW / m ² (without pilot light), the three characteristic quantities Ds (4), VOF4 and Ds (max.) Preferably lower than for the uncoated reference, so that the requirements for HL2 (Hazard Level 2) according to R1 or R7 can also be met with a part thickness of 3 mm or more. The latter means that the smoke density preferably does not exceed 600 over the entire test period of 10 minutes.

In the "Cone Calorimeter" test ISO 5660-1 with an irradiation of 50 kW / m ² , a sample may emit a maximum of 90 kW / m ^{2 in} accordance with DIN EN 45545. This requirement can apply to certain flame-retardant polyamides from a thickness 5 mm, but not with a thickness of 3 mm. Plates painted according to the invention surprisingly meet this requirement already at 3 mm.

The requirements for HL2 (requirement sets) for plastics depend on the application. Interesting and particularly demanding are, for example, “high-performance fan wheels”, which according to EN 45545 are considered “non-listed components”. If the exposed surface of the wheels is> 0.2 m ² , the requirement sets R1 apply for indoor and R7 for outdoor applications. The proposed items are able to do both

CH 711 604 B1

To meet requirements and to be used accordingly as such components. Since the wall thickness of the fan wheels varies within the component and from model to model, the fire properties must be checked with sample plates of the lowest and highest thickness. 3-5 mm is often specified as the minimum thickness. Since the test specimens for the smoke test may be a maximum of 25 mm thick, for example 25 mm are set as the maximum thickness. According to EN 45545-2: 2013, § 4.2.e applies to the area in between: "A component that fulfills a requirement in two different thicknesses with the same composition also corresponds by definition to the requirement for all thicknesses in between." [0014] In all investigated polyamide molding compounds, the CIT _G (Conventional Index of Toxicity - see DIN EN 455452: 2013-08) was always well below the HL2 limit of 1.8 for R7 and also well below the limit of 0.9 for R1.

The coating (B) is preferably expressly not foaming (intumescent) or swelling under the action of heat. Furthermore, the coating (B) is preferably free of chemical flame retardants, i.e. Flame retardants in which the radical chain reaction is prevented by the gases generated during their pyrolysis. The coating is preferably free of halogenated flame retardants or flame retardants based on phosphorus compounds or antimony. The coating can contain aluminum trihydroxide (ATH) or magnesium dihydroxide (MDH), which split off water at 200 ° C (ATH) or 300 ° C (MDH), which cools and dilutes the flame zone in the “Spread of Flame” test. The coating arranged on the molded part is known per se. For example, such coatings are known as anti-corrosion coatings. On the other hand, it was unexpected and completely surprising that such coatings with a preferably comparatively high proportion of mineral constituents have an unforeseen advantageous effect on the flame retardancy of the polyamide molded parts coated with them. Without being bound to a theoretical explanation, it can be assumed that the surface coating with regard to binders decomposes under heat and that the mineral components form a protective film on the molded plastic part. On the one hand, this leads to the fact that the heat input to the plastic is reduced, and on the other hand, that the smoke development resulting from the plastic is shielded. The flame formation is also reduced.

With regard to the mineral concentration in the lacquer layer, the amount of mineral constituents of the coating per surface is relevant to a certain extent, for example in units of g / m 2, because the binder probably does not largely have a positive effect on the results in the fire tests at. Rather, the binder is essentially only used to hold the minerals in place when the component is used and to give the component a passable appearance (accordingly, in addition to the layer [B] defined in accordance with the invention, it can also add another, for example, pure Put an optical or mechanical protective layer on it). A quantity of mineral particulate constituents in the coating B of at least 10 g / m ² and typically at most 300 g / m ^{2 is} normally sufficient for the effect according to the invention. However, it should be noted that the fire tests can also be passed with a mineral concentration of more than 300 g / m ² (apart from any crack formation that may occur). However, this is usually no longer economically and technically justifiable because a lot of paint would have to be applied in several applications. An indication that higher mineral concentrations do not necessarily lead to even better fire behavior results from the observation that in the case of a thick coat of paint, the minerals no longer deposit so homogeneously on the surface in the event of a fire, cracks can form, and the fire behavior does not match Improved the higher amount of mineral, but rather deteriorated again.

Fire protection experts have previously assumed that the current requirement sets R1 and R7 for thermoplastics, and thus polyamide, cannot be met. This prejudice is unexpectedly refuted by the present invention. If the layer according to the invention is applied to a thermoplastic based on polyamide, these two sets of requirements can surprisingly be met.

For example, a 2K epoxy filler with mineral components and, inter alia, zinc phosphate can be used as such a coating, which is otherwise used in a completely different context (corrosion protection due to zinc phosphate) as a primer for metal surfaces in rail vehicles.

When using a thick film hardener, dry film thicknesses of up to 200 μm can also be achieved on vertical surfaces in one operation. The known fields of application of such layers known per se are as follows: For the entire area of the metal processing industry on steel, light metal, galvanizing, wood-based materials, certain plastics and mineral substrates, but in each case only as corrosion protection or adhesion promoter or the like, not in connection with flame protection.

According to a first preferred embodiment of the present invention, the object is characterized in that the coating (B) contains the minerals in a binder (B1) in the form of inorganic particulate solids (B2). According to a further preferred embodiment, the area mentioned with the coating on the molded part can be designed such that at least 10 g, or 10-300 g, preferably 50-200 g, particularly preferably 80-180 g, per square meter area of the coating (B) , of inorganic particulate solids (B2).

CH 711 604 B1 [0021] Another preferred embodiment is characterized in that the coating (B) in the area mentioned is designed such that it has a thickness in the range from 10-300 μm, preferably in the range from 20-250 μm, and particularly preferably has a thickness in the range of 50-180 μm.

According to another preferred embodiment, the mineral-containing coating (B) can contain the minerals in a binder (B1) in the form of inorganic particulate solids (B2), in the form of pigments or fillers (including mineral additives) or both, preferably in a proportion in the range of 30-80 percent by weight or 40-65 percent by weight, based on the dried and optionally hardened coating (B).

In the formulation of the coating, in addition to the binder and the mineral constituents, there may also be other constituents, for example additives as are customary in paints, and also pigments based on organic substances or dyes.

According to a further preferred embodiment, the inorganic particulate solids in layer (B) are selected from the following group: talc, talc, calcite, chalk, dolomite and magnesite, mica, silicates, aluminum silicates including calcined aluminum silicates, magnesium aluminum silicates , Silicon dioxide, magnesium aluminum silicate, quartz, christobalite, diatomaceous earth, quartz powder, aerosil, alumina, silica, mica, wollastonite, feldspar, bentonite, wollastonite, kaolin, silicas including pyrogenic silica, magnesium carbonate, metal hydroxides including aluminum hydroxide or magnesium hydroxide, chalk, carbonates ground or precipitated calcium carbonate or magnesium carbonate, ground or precipitated sulfates including calcium sulfate, barium sulfate, barite, gypsum, lime, feldspar, zinc phosphate, barium sulfate, zinc oxide, zinc sulfide, lithopone and metal oxides including aluminum oxide, magnesium oxide, titanium dioxide The modifications are rutile or anatase, iron oxide, iron manganese oxide, spinels including copper iron spinel, copper chromium oxide, zinc iron oxide, cobalt chromium oxide, cobalt aluminum oxide, magnesium aluminum oxide, copper-chromium-manganese mixed oxides, copper-manganese-iron mixed oxides, rutile Pigments including titanium-zinc rutile, nickel-antimony titanate, chromium-antimony titanate, particles of hard or soft magnetic metals or alloys or ceramics, hollow spherical silicate fillers, nitrides including boron nitride, aluminum nitride, carbides including boron carbide, fluorides including calcium fluoride and mixtures from that. These systems can also be treated superficially.

The particulate mineral constituents of the coating (B) are insoluble in the application medium and come in particular from the following chemical classes, examples of which include both products of natural origin and products of synthetic origin:

• Oxides and hydroxides: aluminum oxide, magnesium oxide, aluminum hydroxide, magnesium hydroxide;

• Silicon dioxide silicates: quartz, christobalite, kieselguhr, talc, kaolin, silica, mica, wolastonite, feldspar, pyrogenic silica, precipitated silica, aluminosilicates and calcined aluminosilicates;

• Carbonates: calcium and magnesium carbonates such as calcite, chalk, dolomite and magnesite, precipitated calcium carbonate;

• Sulfates: barium sulfate, calcium sulfate, barite, gypsum, precipitated barium sulfate.

The particulate mineral components of the coating (B) can have a wide variety of particle shapes. The particulate mineral components of the coating (B) on a natural basis usually have particle sizes in the range from about 1 to 300 μm. So commercial products based on natural chalk e.g. ad50 value of usually 1 to 160 μm. Particle sizes below 1 μm are generally only available with fillers produced synthetically, in particular by precipitation processes.

Suitable inorganic color pigments, which also belong to the particulate mineral constituents of the coating (B), are, for example:

White pigments: titanium dioxide (C.I. Pigment White 6), zinc white, colored zinc oxide, zinc sulfide, lithopone;

Black pigments: iron oxide black (C.L Pigment Black 11), iron-manganese black, spinel black (C.L Pigment Black 27); Carbon black (C.I. Pigment Black 7);

Colored pigments: chromium oxide, chromium oxide hydrate green; Chrome green (C.I. Pigment Green 48); Cobalt green (C.I. Pigment Green 50); Ultramarine green; Cobalt blue (C.I. Pigment Blue 28 and 36; C.I. Pigment Blue 72); Ultramarine blue; Manganese blue, ultramarine violet; Cobalt and manganese violet; Iron oxide red (C.I. Pigment Red 101); Cadmium sulfoselenide (C.I. Pigment Red 108); Cerium sulfide (C.L Pigment Red 265); Molybdate red (C.I. Pigment Red 104); ultramarine; Iron oxide brown (Cl Pigment Brown 6 and 7), mixed brown, spinel and corundum phases (Cl Pigment Brown 29, 31.33, 34, 35, 37, 39 and 40), chrome titanium yellow (CL Pigment Brown 24), chrome orange, cerium sulfide (CL Pigment Orange 75); Iron oxide yellow (C.I. Pigment Yellow 42); Nickel titanium yellow (C.I. Pigment Yellow 53; C.I. Pigment Yellow 157, 158, 159, 160, 161, 162, 163, 164 and 189); Chromium titanium yellow; Spinel phases (C.I. Pigment Yellow 119); Cadmium sulfide and cadmium zinc sulfide (C.L Pigment Yellow 37 and 35); Chrome yellow (C.I. Pigment Yellow 34); Bismuth vanadate (C.I. Pigment Yellow 184).

CH 711 604 B1 A further preferred embodiment is characterized in that the inorganic particulate solids of layer (B) have an average particle size (d50) in the range from 0.1-300 μm, preferably in the range from 0.2-160 μm, in particular in the range from 0.3-40 or 0.3-10 μm.

In general, the inorganic particulate solids of the layer (B) can have a selectable particle shape, preferably selected from the following group: spheres, cubes, platelets, fibers or mixtures thereof.

The binder (B1) in the layer (B) may be a binder which may harden and / or crosslink when applied from an aqueous solution, emulsion or dispersion or from an organic solvent.

The organic solvent is preferably selected from the following group: aliphatic, cycloaliphatic and aromatic hydrocarbons, alcohols, glycols, glycol ethers, ketones and esters, or mixtures thereof, including n-hexane, white spirit, cyclohexane, xylene, solvent naphtha, propanol, n-butanol, isobutanol, butyl glycol, butyl diglycol, ethylene glycol, diethyl glycol, butyl acetate, ethyl acetate, 2-butoxyethyl acetate, butanone and acetone or mixtures thereof. In addition or as a substitute for solvents, reactive thinners can also be used. These are substances that act as solvents but crosslink with the binders. The binder is preferably selected from the following group: epoxy resin, including bisphenol A glycidyl ether, polyurethane, acrylic polyurethane, alkyd resin, or mixtures thereof, where the binder can optionally be supplemented by an activator or hardener. A bisphenol A glycidyl ether which is mixed with an aminic hardener is preferably used as the binder. The solvent is then preferably a mixture of xylene and ethylbenzene.

The lacquers used for the production of the coating (B) can contain 10% to 80% by weight of solids. The mineral content (pigments + fillers) in the lacquers used according to the invention is in the range from 30 to 75% by weight. The weight ratio of binder to mineral (pigment + fillers) is in the range from 3: 1 to 1: 3. The mineral content, based on the dry film (dried and hardened lacquer layer), is preferably in the range from 35 to 65% by weight.

A further preferred embodiment of the present invention is characterized in that the object with a heat radiation of 50 kW / m ² and a sample thickness of 3 mm over the entire period of measurement of 10 min according to ISO 5659-2 has a smoke density Ds ( max.) of less than 600, preferably less than 550, more preferably less than 500.

Further preferably, the smoke density (Ds) after 4 minutes is less than 300, preferably less than 250, particularly preferably less than 200.

A further preferred embodiment of the present invention is characterized in that the object has a cumulative smoke density VOF4 of less than 600 with heat radiation of 50 kW / m ² and a sample thickness of 3 mm.

Furthermore, at least 50%, preferably at least 75%, particularly preferably essentially 100% of the free surface of the molded part (A) which is directly exposed to heat radiation in the event of intended use in the event of fire is provided with the coating (B).

The halogen-free flame-retardant polyamide molding compound of the molded part can preferably consist of the following components:

(a) 10-90 weight percent, preferably 20-82 weight percent thermoplastic polyamide, preferably selected as aliphatic, cycloaliphatic and / or aromatic polyamide, (b) 5-30, preferably 8-25 or 10-22, particularly preferably 10-20 weight percent a halogen-free flame retardant, preferably containing 50-100 weight percent, preferably 70-98 weight percent, particularly preferably 75-95 weight percent of a phosphorus-containing flame retardant (b1) and 100 weight percent of the halogen-free flame retardant (b) additionally a flame retardant synergist, which is preferably phosphorus or is nitrogenous, (c) 5-60 percent by weight, preferably 10-55 percent by weight of reinforcing fibers, preferably selected as glass fibers with a round or flat cross-section, basalt fibers, carbon fibers or aramid fibers, (d) 0-10 percent by weight, preferably 0-5 percent by weight of additives and / or aggregates, different from the components (a) - (c), where components (a) - (d) add up to 100% of the polyamide molding compound.

The polyamide of component (a) is preferably selected from the group consisting of: PA 6, 46, 56, 66, 610, 612, 614, 1010, 1012, 1210, 1212, 1112, 6T / 6I, 6T / 6I / 66, 6T / 66, 6T / 10T, 9T, 9MT, 10T, 12T, MACM9-14, PACM9-14, MACMI / 12, MACMI / MACMT, MACMI / MACMT / 12 or mixtures thereof. The labels

CH 711 604 B1 follow ISO 1874-1, MACM stands specifically for bis (4-amino-3-methylcyclohexyl) methane, PACM stands for bis (paminocyclohexyl) methane, I stands for isophthalic acid, T for terephthalic acid, M stands for 2 methyl-1,8-octane diamine.

A mixture of an aliphatic and an amorphous partially aromatic polyamide is preferably selected as the polyamide for component (a). A mixture of an aliphatic polyamide, preferably selected as polyamide 66, and an amorphous, partially aromatic polyamide, preferably selected as polyamide 6I / 6T, is particularly preferably used in a ratio in the range from 5: 1-2: 1.

The halogen-free flame retardant (b1) of component (b) is preferably selected from the group phosphazene, phosphinic acid salt, diphosphinic acid salt or mixtures thereof. In addition, a nitrogen or phosphorus-containing synergist and / or a nitrogen and / or phosphorus-containing flame retardant can be provided, the latter preferably being selected from metal phosphites, in particular mixed alkali / aluminum phosphites, melamine or condensation products of melamine, such as in particular Meiern, Melam, Melon or reaction products of melamine with polyphosphoric acid or reaction products of condensation products of melamine with polyphosphoric acid or mixtures thereof, in particular melamine polyphosphate.

As component (b1), melamine polyphosphate or alkali-aluminum mixed phosphites are particularly preferred. Such flame retardants are known from the prior art. In this regard, reference is made to DE 103463 261 and DE 102 011 120 218, in this regard the disclosure content of this document is expressly included here.

Preferred as component (b) is a metal salt of phosphinic acid and / or diphosphinic acid and / or their polymers, in which the metal ion is from the 2nd or 3rd main or subgroup of the periodic table and the organic radicals are preferably C1 -C10 -Alkyl, linear or branched and / or aryl, alkylene, arylene, alkylarylene or arylalkylene. Aluminum, calcium, barium and zinc are particularly preferred as metal ions.

The reinforcing fibers of component (c) are preferably in the form of cut glass or continuous glass, particularly preferably continuous glass for high mechanical loads, for example for a fan wheel. The fibers can have a round or flat cross section, in the latter case preferably with an aspect ratio in the range of 2-8, preferably in the range of 3-5.

The reinforcing fibers of component (c) are particularly preferably E-glass, S-glass, R-glass, C-glass, ECR-glass, D-glass, AR-glass, Q-glass or hollow glass fibers ,

The additives of component (d) may be the usual additives in connection with such polyamides, for example impact modifiers, adhesion promoters, crystallization accelerators or retarders, flow aids, lubricants, mold release agents, plasticizers, stabilizers, processing aids, flame retardant additives, antistatic agents, pigments, dyes and markers, nanoparticles in platelet form, conductivity additives such as carbon black, graphite powder or carbon nanofibrils, residues from polymerization processes such as catalysts, salts and their derivatives as well as regulators such as mono acids or monoamines. Furthermore, the present invention relates to such an object, which is characterized in that the coating (B) is built up in one or more layers and / or is applied in a plurality of coating steps. The coating is preferably applied in a coating process, knife coating process, casting process, spraying process, a dipping process or a vapor deposition process. In principle, it is possible, for example, to apply the binder first and then the mineral constituents or vice versa, but it is preferably carried out in such a way that the binder and mineral constituents are applied simultaneously in the manner of a pre-formulated lacquer. After application, curing can optionally be carried out in a separate step, for example by elevated temperature, irradiation or the like.

[0046] The proposed object is preferably a component for vehicle and / or building technology, preferably a component for rail vehicles.

The object is preferably an object whose surface, when used as intended, is larger than 0.2 m ² and / or whose total weight is larger than 2 kg.

More specifically, the claimed subject matter is preferably at least one area or preferably as a whole one of the following components, in particular for means of transport, especially rail vehicles: fan wheel, side wall, end wall or end wall, partition wall, room divider, flap, box, Hood, covers, internal doors, interior cladding of doors from end walls and end walls, exterior doors, window frames, sun visors, surfaces in kitchens, overhead luggage racks, vertical luggage racks, luggage stack, luggage containers and luggage compartments, cladding and surfaces of the driver's console, including axial and radial wheels as fan wheels for buildings and rail vehicles, mechanical functional parts in air ducts and cable ducts.

Furthermore, the present invention relates to the use of a mineral-containing coating (B) for flame protection of an object, in particular for railway applications, the object containing or consisting of (A) at least one extruded or injection-molded part consisting of a fiber-reinforced, halogen-free flame-retardant Polyamide molding compound, and wherein the molded part is provided with the mineral-containing coating (B) in at least one region of its exposed surface. With heat radiation of 50 kW / m ² and a sample thickness of 3 mm, the object has a MARHE value according to DIN EN 45545-2: 2013 of at most 90 kW / m ² , and its optical smoke density (Ds) after 4 min according to EN ISO 5659-2 preferably does not exceed a value of 300.

CH 711 604 B1 A preferred embodiment of the use is characterized in that the object has a smoke density with heat radiation of 50 kW / m ² and a sample thickness of 3 mm over the entire period of the measurement of 10 min according to ISO 5659-2 Ds (max.) Of less than 600, preferably less than 550, more preferably less than 500.

A preferred embodiment of the use is characterized in that the object has a cumulative smoke density VOF4 of less than 600 with heat radiation of 50 kW / m ² and a sample thickness of 3 mm.

The mineral-containing coating (B) preferably contains the minerals in a binder (B1) in the form of inorganic particulate solids (B2), preferably in the form of pigments and / or fillers, preferably in a proportion in the range from 35 to 65 percent by weight , based on the dried and possibly hardened coating (B).

In connection with this use, it is preferred if the coating (B) in the area mentioned is designed in such a way that at least 10 g, or 10-300 g, preferably 50-200 g, in particular, per square meter of the coating (B) preferably 80-180 g, of inorganic particulate solids (B2) are present.

Furthermore, in connection with this use, it is preferred if the coating (B) in the region mentioned is designed such that it has a thickness in the range from 10-300 μm, preferably in the range from 20-250 μm, and particularly preferably one Thickness in the range of 50-180 microns.

Furthermore, the present invention relates to the use of an extruded or injection-molded part consisting of a fiber-reinforced, halogen-free, flame-retardant polyamide molding compound as a flame-retardant article, in particular for railway applications, the part having a mineral-containing coating (B) in at least one region of its exposed surface. With heat radiation of 50 kW / m ² and a sample thickness of 3 mm, the object has a MARHE value according to DIN EN 45545-2: 2013 of at most 90 kW / m ² , and its optical smoke density (Ds) after 4 min according to EN ISO 5659-2 preferably does not exceed a value of 300.

A preferred embodiment of the use is characterized in that the object with a heat radiation of 50 kW / m ² and a sample thickness of 3 mm over the entire period of measurement of 10 min according to ISO 5659-2 a smoke density Ds (max. ) of less than 600, preferably 550, more preferably 500. A preferred embodiment of the use is characterized in that the object has a cumulative smoke density VOF4 of less than 600 with heat radiation of 50 kW / m ² and a sample thickness of 3 mm.

Finally, the present invention relates to a process for producing an article as described above, which process is characterized in that the molded part (A) is produced from the fiber-reinforced, halogen-free, flame-retardant polyamide molding composition in an extrusion process or an injection molding process is, and this is then at least partially provided with the mineral-containing coating (B), preferably in one or more coating steps, particularly preferably in the form of a coating process, knife coating process, casting process, spraying process, a dipping process or vapor deposition process, preferably with binders and mineral components at the same time be applied.

Further embodiments are specified in the dependent claims.

Description of preferred embodiments

Examples:

A) Polyamide molding compound (FM).

Polyamide molding compositions consisting of the components were preferred. Table 1 used.

Table 1:

Polyamide molding compound A1 A2 components Composition (% by weight) Composition (% by weight) Polyamide PA66 RV 1.75, melting point 260 ° C 29.9 31.95 Polyamide PA6I / 6T (67/33 mol%) 10.65

RV 1.58.

Glass transition temperature 125 ° C

Cut glass fibers with a diameter of 10 μm 50

CH 711 604 B1

Table 1:

components composition (Wt .-%) composition (Wt .-%) Continuous glass fibers with a diameter of 17 μm 40 Flame retardant Exolit OP1400 20 16 Black masterbatch (10% carbon black in PA66) 1.3 Heat stabilizer Irganox 1098 0.1 0.1

RV: relative viscosity, measured on a solution of 0.5 g polyamide in 100 ml m-cresol at 20 ° C according to ISO 307. Calculation according to RV = t / t ₀ based on Section 11 of the standard.

Production of the polyamide molding compounds:

The polyamide molding composition A1 was on a twin-screw extruder from Werner u. Pfleiderer type ZSK 25 manufactured. All components with the exception of the chopped glass fibers were dosed into the feed zone. The glass fibers were metered into the polymer melt via a side feeder six housing units in front of the nozzle. The housing temperature was set up to 280 ° C as an ascending profile. A throughput of 10 kg was achieved at 150 to 200 rpm. After water bath cooling, granulation and vacuum drying at 110 ° C. for 24 hours, the granulate properties were measured and the test specimens were produced.

The polyamide molding composition A2 was prepared from the components shown in Table 1 on a pultrusion system as 10 mm long fiber-reinforced rod granules (length of the glass fibers corresponds to the length of the granules). All components except the glass fibers were metered into the feed zone of the extruder (type KraussMaffei Berstorff ZE 40 A UTXi) and mixed and melted at temperatures of 300-350 ° C. The preheated continuous fibers were then impregnated with this melt in the nozzle plate, which was heated to 360.degree. The impregnated fiber strands are then formed into a strand with a diameter of approximately 4-5 mm, cooled in air and granulated. Prior to processing, the granules are dried for 24 hours at 110 ° C in a vacuum of 30 mbar.

Processing:

Production of the molded parts for the determination of the mechanical material properties and the fire protection tests:

170 x 20/10 x 4 mm, ISO tension rods type A1, 80 x 10 x 4 mm ISO test rods type B1 and plates 100 x 100 x 3 mm with side sprue made of polyamide molding compound (A) were on an Arburg injection molding machine Allrounder 320210-750 manufactured, the cylinder temperatures from 260 ° C to 300 ° C and a screw peripheral speed of 15 m / min were set. The mold temperature was chosen to be 120 ° C. 75 x 75 x 3 mm plates were cut with a circular saw from 100 x 100 x 3 mm plates.

Table 2 lists the most important mechanical characteristics of the polyamide molding compounds A1 and A2. Both are characterized by high rigidity, strength and heat resistance. The molding compound A2 shows the increased notched impact strength characteristic of long fiber materials:

Table 2:

Polyamide molding compound A1 A2 Tensile modulus of elasticity [GPa], ISO 527 17.0 14.3 Breaking stress [MPa], ISO 527 150 200 Notched impact strength Charpy [kJ / m ² ], ISO 179 / * eA 8th 30 Dimensional stability HDT / A [° C], ISO 75 230 250

Coating the molded parts (A) with epoxy filler (B):

The plates 100 x 100x3 and 75x75x3 mm from the polyamide molding compound (A) were with a spray gun model Selena with a 1.8 mm nozzle at a pressure of 3 bar with 500-700 g / m ² 2K epoxy filler sprayed and coated.

CH 711 604 B1

The mixture used for spraying consisted of 5 parts Etokat Grund white, article number 600.1.1.0100, Walter Mäder AG, Killwangen, Switzerland, in a mixture with 1 part Etokat Aktiv Härter, article number 855.0.0.0049, Walter Mäder AG, Killwangen, Switzerland.

After drying for 48 hours at 25 ° C., the dry layer weight of the 2-component epoxy filler was measured and the dry layer thickness was calculated using the density = 1.8 g / cm ³ .

Optional additional cover layer (C):

Some of the panels with 2-component epoxy filler were sprayed with 100 g / m ² 2-component PUR top coat after drying with a Selena spray gun with a 1.5 mm nozzle at a pressure of 3 bar. Nuvovern WR gray, article number 572.7.3, Walter Mäder AG, Killwangen, Switzerland was used.

After drying for 48 hours at 25 ° C., the dry layer weight of the 2-component PU topcoat was measured and the dry layer thickness was calculated using the density = 1.2 g / cm ³ , cf. Table 2.

The results of the fire protection measurements are summarized in Tab. 3 and Tab. 4.

Table 3: MARHE values according to DIN EN 45545-2: 2013 of uncoated and coated 3 mm thick test specimens; Cone calorimeter test according to ISO 5660-1 with pilot light at an irradiance of 50 kW / m ² :

Requirement HL2 VB1 B1 B2 VB2 B3 B4 B5 Polyamide molding compound A1 A1 A1 A2 A2 A2 A2 Thick mineral filler (B) 75 μm 150 μm 75 μm 150 μm 75 μm Optional coating (C) 50 μm MARHE [kW / m ² ] <90 98.8 81.2 79.5 106.8 79.5 66.4 85.2

Table 4: Key figures of the optical smoke density according to DIN EN 45545-2: 2013 of uncoated and coated 3 mm thick test specimens; Smoke chamber test according to ISO 5659-2 without pilot light at an irradiance of 50 kW / m ² :

Requirement HL2 VB1 B1 VB2 B3 B4 B5B5 Polyamide molding compound A1 A1 A2 A2 A2 A2A2 Thick mineral Filling base (B), μm - 75 - 75 150 75 optional Coating (C), μm - - - - - 50 Requirement set R1: Ds (4) <300 354 248 341 127 294 182 VOF4 <600 732 525 692 198 379 286 Requirement set R7: Ds (max.) <600 429 487 409 409 519 388

measurements:

The measurement of the maximum average rate of heat emission (MARHE) according to DIN EN 45545-1: 2013, chap. 3.39 and DIN EN 45545-2 were carried out with a Cone calorimeter from Fire Testing Technology Ltd. The samples were tested in accordance with EN 45545-2: 2013 chapter 5.1 ref. T03.01 and ISO 5660-1: 2015 with a radiation intensity of 50 kW / m ² and pilot light over a period of 20 min. The device software ConeCalc was used for the acquisition and evaluation of the data.

The measurement of the temporal development of the optical smoke density and the determination of the derived parameters Ds (4), VOF4 and Ds (max.) Was carried out using an NBS Smoke Density Chamber from Fire Testing Technology Ltd. according to DIN EN 45545-1: 2013, chap. 3.12 and Chap. 3.70 and DIN EN 45545-2. The samples were according to EN

CH 711 604 B1

45545-2: 2013 Chapter 5.1 Ref.T10.01, Ref.T10.02 and Ref.T10.04 as well as ISO 5659-2: 2012 with a radiation intensity of 50 kW / m ² without pilot light over a period of 10 min. Smoke measurements according to ISO 5659-2 (December 2012) were also carried out on the samples with a thickness of 3 mm and heat radiation of 50 kW / m ² without pilot light.

Ds denotes the specific optical density according to DIN EN 45545-1 chapter 3.12 and chapter 3.10 of ISO 5659-2, and Ds (4) this value 4 minutes after the heat radiation is switched on.

VOF4 is defined in accordance with DIN EN 45545-1 chapter 3.12 and E.3.2.2 of ISO 5659-2 and denotes the cumulative value of the specific optical density Ds in the first 4 minutes of the test. VOF4 is equal to the area under the Ds (t) curve plotted against time during the test period between t = 0 and t = 4, assuming a trapezoidal area and with a finite element (t) of 1 min.

CIT _G denotes the Conventional Index of Toxicity according to DIN EN 45545-1 Chapter 3.7 and DIN EN 45545-2 Appendix C, determined according to Chapter C.16.2 in DIN EN 45545-2: 2013.

In all investigated polyamide molding compositions, the CIT _G (Conventional Index of Toxicity - see DIN EN 455452: 2013-08) was always significantly below the HL2 limit of 1.8 for R7 and also clearly below the limit of 0.9 for R1.

In contrast to the Ds (max.) Value, the other two smoke density requirements for HL2, i.e. Ds (4) <300 and VOF4 <600 cannot be achieved with different polyamide matrices without the measures according to the invention. Flame-retardant polyamides pyrolyze under the conditions of the smoke test and soot heavily. An open flame can only be observed with thin plates and overall too late. That Molded parts made of reinforced, flame-retardant PA molding compounds do not pass this test with a thickness of 3 mm.

The solution for reaching the HL2 limit values both in the "Cone Calorimeter" test and in the smoke test includes coating with a mineral-pigmented layer, in this case a 2-component epoxy filler, with which the plates are coated thinly , As soon as the binder is burned, the mineral particles (titanium dioxide, barium sulfate, talc, mica, etc.) contained in the filler remain in the form of a “barrier layer”. The plate continues to burn with reduced intensity compared to the uncoated test specimen.

In the smoke test, the coating delays the smoke development by 1 to 4 minutes.

In the case of unpainted 3 mm plates (VB1 and VB2), the smoke density increases to> 300 in the first 4 minutes.

In the case of coated 3 mm plates (B1, B3-B5), the smoke density only passes the 300 mark after 4 minutes. The “barrier layer” made of mineral pigments that remains after the coating has ignited delays the pyrolysis of the flame-retardant polyamide molding compound.

With the assumption based on information for the pure lacquer layer that the lacquered plates in the spread of flame test achieve a CFE value> 20 kW / m ² , the following classification according to Table 5 results:

Table 5:

[0086]

VB1 bl VB2 B3 B4 B5 Rating 3 mm RI: HL1 RI: HL2 RI: HL1 RI: HL2 RI: HL2 RI: HL2 R7: HL1 R7: HL2 R7: HLI R7: HL2 R7: HL2 R7: HL2

The painting with 2K epoxy filler makes it possible to use large parts made of polyamides in the interior of European rail vehicles.

Claims (15)

claims 1. Flame-retardant article, in particular for railway applications, containing, preferably consisting of at least one extruded or injection-molded part (A) consisting of a fiber-reinforced, halogen-free flame-retardant polyamide molding compound; wherein the molded part has a mineral-containing coating (B) in at least a region of its exposed surface; and the object has a MARHE value according to DIN EN 45545-2: 2013 of at most 90 kW / m ² with heat radiation of 50 kW / m ² and a sample thickness of 3 mm. 2. Object according to claim 1, characterized in that the coating (B) contains the minerals in a binder (B1) in the form of inorganic particulate solids (B2), CH 711 604 B1 and in the area mentioned is designed such that at least 10 g, or 10-300 g, preferably 50-200 g, particularly preferably 80-180 g, of inorganic particulate solids (B2 ) are present and / or characterized in that the coating (B) is designed in such a way that it has a thickness in the range of 10-300 μm, preferably in the range of 20-250 μm, and particularly preferably a thickness in the range of 50-180 μm. 3. Object according to claim 2, characterized in that the mineral-containing coating (B) contains the minerals in a binder (B1) in the form of inorganic particulate solids (B2), in the form of pigments and / or fillers, preferably in a proportion in Range of 30-80 percent by weight, based on the dried and possibly hardened coating (B). 4. Object according to claim 2, characterized in that the inorganic particulate solids are selected from the following group: talc, talc, calcite, chalk, dolomite and magnesite, mica, silicates, aluminum silicates including calcined aluminum silicates, magnesium aluminum silicates, silicon dioxide, Magnesium aluminum silicate, quartz, christobalite, diatomaceous earth, quartz powder, aerosil, alumina, silica, mica, wollastonite, feldspar, bentonite, wollastonite, kaolin, silicas including pyrogenic silica, magnesium carbonate, metal hydroxides including aluminum hydroxide or magnesium hydroxide, chalk, carbonates including ground or precipitated calcium carbonate or magnesium carbonate, ground or precipitated sulfates including calcium sulfate, barium sulfate, barite, gypsum, lime, feldspar, zinc phosphate, barium sulfate, zinc oxide, zinc sulfide, lithopone and metal oxides including aluminum oxide, magnesium oxide, titanium dioxide including in the M modifications rutile or anatase, iron oxide, iron manganese oxide, spinels including copper iron spinel, copper chromium oxide, zinc-iron oxide, cobalt-chromium oxide, cobalt-aluminum oxide, magnesium-aluminum oxide, copper-chromium-manganese mixed oxides, copper-manganese-iron mixed oxides, rutile pigments including titanium-zinc rutile, nickel-antimony titanate, chrome-antimony titanate, particles of hard or soft magnetic metals or alloys or ceramics, hollow spherical silicate fillers, nitrides including boron nitride, aluminum nitride, carbides including boron carbide, fluorides including calcium fluoride and mixtures and / or superficial treated forms thereof; and / or that the inorganic particulate solids have an average particle size (D50) in the range from 0.1-300 μm, preferably in the range from 0.2-160 μm, in particular in the range from 0.3-40 or 0.3-10 μm, and / or characterized in that the inorganic particulate solids have a particle shape selected from the following group: spheres, cubes, platelets, fibers. 5. An article according to claim 2, 3 or 4, characterized in that the binder (B1) is a binder which may harden when applied from an aqueous solution, emulsion or dispersion, in particular a binder which cures from an organic solvent, the organic solvent preferably is selected from the following group: aliphatic, cycloaliphatic and aromatic hydrocarbons, alcohols, glycols, glycol ethers, ketones and esters, or mixtures thereof, including n-hexane, white spirit, cyclohexane, xylene, solvent naphtha, propanol, n-butanol, isobutanol, butyl glycol , Butyl diglycol, ethylene glycol, diethyl glycol, butyl acetate, ethyl acetate, 2-butoxyethyl acetate, butanone and acetone or mixtures thereof; and / or characterized in that the binder (B1) is selected from the following group: epoxy resin including A-glycidyl ether, polyurethane, acrylic polyurethane, alkyd resin or mixtures thereof, it being possible for the binder to be supplemented by an activator or hardener. 6. Object according to one of the preceding claims, characterized in that the object with a heat radiation of 50 kW / m ² and a sample thickness of 3 mm over the test period of 10 minutes according to ISO 5659-2: 2012 a maximum optical smoke density Ds (max .) of less than 600, preferably less than 550, particularly preferably less than 500. 7. Object according to one of claims 1 to 5, characterized in that the object after 4 min with heat radiation of 50 kW / m ² and a sample thickness of 3 mm according to DIN EN 45545-2: 2013 and ISO 5659-2: 2012 a smoke density Ds (4) after 4 min of less than 300, preferably less than 250, and / or a cumulative smoke density VOF4 of less than 600 and / or a maximum optical smoke density Ds (max .) of less than 600, preferably less than 550, more preferably less than 500. 8. Object according to one of the preceding claims, characterized in that at least 50%, preferably at least 75%, particularly preferably essentially 100%, of the exposed surface of the molded part (A) with the coating (A) which is directly exposed to heat radiation when used as intended. B) is provided. 9. Object according to one of the preceding claims, characterized in that the halogen-free flame-retardant polyamide molding compound of the molding consists of the following components: (a) 10-90 percent by weight, preferably 20-82 percent by weight, thermoplastic polyamide, preferably selected as aliphatic, cycloaliphatic and / or aromatic polyamide, CH 711 604 B1 (b) 5-30, preferably 8-25 or 10-22, particularly preferably 10-20 percent by weight of a halogen-free flame retardant, preferably containing 50-100 percent by weight, preferably 70-98 percent by weight, particularly preferably 75-95 percent by weight phosphorus-containing flame retardant (b1) and, in addition to 100 weight percent of the halogen-free flame retardant (b), a flame retardant synergist, which preferably contains phosphorus or nitrogen, (c) 5-60 weight percent, preferably 10-55 weight percent reinforcing fibers, selected from the group of glass fibers with round or flat cross-section, basalt fibers, carbon fibers or aramid fibers, (d) 0-10 percent by weight, preferably 0-5 percent by weight of additives and / or additives, different from components (a) - (c), components (a) - (d) add to 100% of the polyamide molding compound. 10. Article according to claim 9, characterized in that the polyamide of component (a) is selected from the group consisting of PA 6, 46, 56, 66, 610, 612, 614, 1010, 1012, 1210, 1212, 1112, 6T / 6I, 6T / 6I / 66, 6T / 66, 6T / 10T, 9T, 9MT, 10T, 12T, MACM9-14, PACM9-14, MACMI / 12, MACMI / MACMT, MACMI / MACMT / 12 or mixtures thereof , preferably a mixture of an aliphatic and an amorphous part of aromatic polyamide is selected, particularly preferably a mixture of polyamide 66 and polyamide 6I / 6T in a ratio in the range of 5: 1-2: 1; and / or wherein preferably the halogen-free flame retardant (b1) of component (b) is selected from the group phosphazene, phosphinic acid salt, diphosphinic acid salt or mixtures thereof; and / or characterized in that the reinforcing fibers (c) are designed as cut glass or continuous glass, the fibers having a round or flat cross section, in the latter case preferably with an aspect ratio in the range of 2-8, preferably in the range of 3-5, have, and / or characterized in that the reinforcing fibers (c) are designed as E-glass, S-glass, M-glass, C-glass, ECR-glass, D-glass, AR-glass, Q-glass or hollow glass fibers , 11. The article as claimed in one of the preceding claims, characterized in that the coating (B) is composed of one or more layers and / or characterized in that the coating (B) is applied in a plurality of coating steps, the coating preferably being carried out in a coating process, knife coating process or casting process , Spraying process, a dipping process or a vapor deposition process, wherein binders and mineral components are preferably applied simultaneously. 12. Object according to one of the preceding claims, characterized in that it is a component for vehicle or building technology, preferably a component for rail vehicles, which is preferably an object whose exposed surface is larger than when used as intended 0.2 m ² and / or its total weight is greater than 2 kg, the object preferably being at least one area or preferably as a whole one of the following components: fan wheel, side wall, end or end wall, partition wall, room divider , Flap, box, hood, cover, interior door, interior paneling of a door from end and end walls, exterior door, window frames, sun visors, surfaces in kitchens, overhead luggage rack, vertical luggage rack, luggage stack, luggage container and luggage compartments, paneling and surfaces of the driver's console including Ax ial and radial wheels as fan wheels for buildings and rail vehicles, mechanical functional parts in air ducts and cable ducts. 13. Use of a mineral-containing coating (B) for flame protection of an object, in particular for railway applications, the object containing, in particular consisting of (A) at least one extruded or injection-molded part consisting of a fiber-reinforced, halogen-free flame-retardant polyamide molding compound; and the shaped part is provided with the mineral-containing coating (B) in at least a region of its exposed surface; and the resulting object has a MARHE value according to DIN EN 45545-2: 2013 of at most 90 kW / m ² with heat radiation of 50 kW / m ² and a sample thickness of 3 mm, and its optical smoke density Ds (4) according to EN ISO 5659-2 preferably after 4 min does not exceed a value of 300, preferably less than 250, and / or its cumulative smoke density VOF4 according to DIN EN 45545-2: 2013 preferably does not exceed a value of 600, and / or its Smoke density Ds (max.) Over the entire period of the measurement of 10 min is less than 600, preferably less than 550, more preferably less than 500, the mineral-containing coating (B) preferably forming the minerals in a binder (B1) of inorganic particulate solids (B2), preferably in the form of pigments and / or fillers, preferably in a proportion in the range of 35-65 percent by weight, based on the dried and optionally hardened coating seal (B), the coating (B) being designed in such a way that at least 10 g, or 10-300 g, preferably 50-200 g, particularly preferably 80-180 g, per square meter area of the coating (B), of inorganic particulate solids (B2) are present CH 711 604 B1 and / or in which the coating (B) is designed in such a way that it has a thickness in the range of 10-300 μm, preferably in the range of 20-250 μm, and particularly preferably a thickness in the range of 50 -180 μm. 14. Use of an extruded or injection-molded part consisting of a fiber-reinforced, halogen-free, flame-retardant polyamide molding compound as a flame-retardant object, in particular for railway applications, the part having a mineral-containing coating (B) in at least one region of its exposed surface; and the object used has a MARHE value according to DIN EN 45545-2: 2013 of at most 90 kW / m ² with heat radiation of 50 kW / m ² and a sample thickness of 3 mm, and its optical smoke density Ds (4) according to EN ISO 5659-2 preferably does not exceed a value of 300, preferably less than 250, after 4 min and / or its cumulative smoke density VOF4 according to DIN EN 45545-2: 2013 preferably does not exceed a value of 600, and / or its maximum Smoke density Ds (max.) Over the entire period of the measurement of 10 min is less than 600, preferably less than 550, more preferably less than 500. 15. A method for producing an article according to any one of the preceding claims 1-12, characterized in that the molded part (A) is produced from the fiber-reinforced, halogen-free, flame-retardant polyamide molding compound in an extrusion process or an injection molding process, and this is then at least in regions with the mineral-containing coating (B) is provided, preferably in one or more coating steps, particularly preferably in the form of a coating process, knife coating process, casting process, spraying process, a dipping process or vapor deposition process, binder and mineral constituents preferably being applied simultaneously.