EP3499119A1 - Device for dissipating heat from a heat source and use of this device - Google Patents

Abstract

The subject of the present invention is a device for dissipating heat from a heat source. This device comprises a heat pipe, a heat input element and a heat extraction element, also called heat sink, wherein the heat sink substantially of a thermally conductive thermoplastic composition having a thermal conductivity in plane of 1 to 50 W / (m * K), preferably 2 to 30 W / ( m * K) is preferably 4 to 20 W / (m * K), and the quotient from outside diameter to wall thickness of the heat pipe is from 10: 1 to 4: 1. The subject matter of the present invention is also a luminaire which comprises the device according to the invention.

Description

The subject of the present invention is a device for dissipating heat from a heat source. This device comprises a heat pipe, a heat input element, and a heat decoupling element, also called a heat sink, the heat sink essentially consisting of a thermally conductive thermoplastic composition with a heat conductivity in plane of 1 to 50 W / (m * K), preferably 2 to 30 W / (m * K) is preferably 4 to 20 W / (m * K), and the quotient of outside diameter to wall thickness of the heat pipe from 10: 1 to 4: 1. The subject matter of the present invention is also a luminaire which comprises the device according to the invention.

All transformations from one energy form to another will result in energy losses. This loss of energy is usually noticeable by the emission of heat. The result of this is that mechanical, electrical and electronic devices and other devices, devices and instruments, collectively referred to as apparatuses, heat up during operation. This heating, in turn, may result in damage to the apparatus or parts of these apparatus or parts of the environment of these apparatus, which is of course undesirable.

In order to avoid or at least reduce such damage, devices have been provided early in the history of the art for dissipating excess heat from a heat source. In the simplest case, this can be done by cooling by running water or an air flow, water or air so serve as a heat transfer medium. In particular, in the latter case, the cooling is often supported by a so-called heat sink, which has a good thermal conductivity and is usually designed so that it has a large surface area over which the heat can be dissipated.

Obviously, the more cramped the spatial conditions in the apparatus, the more difficult is the removal of heat from an apparatus or from the heat source of an apparatus. This is especially true when the spatial conditions in the immediate vicinity of the heat source are very cramped and / or there is a heat-sensitive material in the vicinity of the heat source. On the other hand, this difficulty is increasingly coming to the fore with the increasing downsizing of apparatuses on the one hand and the increasing use of plastics on the other hand, in particular with the increasing use of thermoplastics.

One approach to overcome this difficulty is the use of a heat pipe, also called heat pipe. These are known in principle to the person skilled in the art.

A heat pipe is a heat exchanger that allows a high heat flux density using the heat of vaporization of a working fluid, d. H. On small cross-sectional area large amounts of heat can be transported. Although heatpipes can be used only in a limited temperature range, for example in the range of 0 to 250 ° C for copper heatpipes with water as the working medium, but in this they have a thermal resistance, which is significantly smaller than that of metals. The behavior of the heat pipes therefore comes very close to the isothermal state change. There is an almost constant temperature over the length of the heat pipe. For the same transmission capacity much lighter construction methods than conventional heat exchangers are possible under the same conditions of use. Heatpipes contain a hermetically encapsulated volume in the form of a tube, each with a heat source facing the end and a heat sink facing the end. The tube is filled with a working medium, for example water or ammonia, which fills the volume to a small extent in liquid, for the most part in the vapor state. When heat enters the working medium begins to evaporate and that at the heat source end facing. As a result, the pressure in the vapor space is increased locally above the liquid level, which leads to a low pressure gradient within the heat pipe. The resulting vapor therefore flows to a location of lower temperature, ie the end facing the heat sink, where it condenses. At this point, the temperature increases due to the released heat of condensation. The previously absorbed latent heat is released to the environment. The now liquid working medium returns by capillary forces back to the point at which the heat is introduced. (Source: Wikipedia).

Since heatpipes can be designed to be very thin, with these properties they are well suited for dissipating the heat of a heat source in space-constrained conditions. So revealed US20040252502A1 an LED reflector, where the waste heat of the LEDs is dissipated by a heat pipe. The reflector contains a thermally conductive plastic and serves at the same time as a heat input element, wherein the heat pipe is encapsulated with the thermally conductive plastic, so as to ensure improved heat transfer from the reflector to the heat pipe. Use finds in the US20040252502A1 disclosed device, for example, in vehicle headlights, vehicle rear lights, flashing lights or other lighting devices that have LEDs.

However, it has been found that the overmolding of heatpipes with plastic is difficult, since the heatpipes often collapse, burst or otherwise at least be damaged in the pressures occurring during encapsulation, which impedes effective heat dissipation, for example by pinching the heatpipe in places , whereby at this point the internal structure of the heat pipe is damaged. Since such damage is usually within the overmolded area of the heat pipe, they are not easily visible because of the encapsulation. This can result in such a damaged overmolded heatpipe being processed further and the damage only noticeable during a later quality control or even only in the event of a failure of a heatpipe-comprising overall device. At this time, however, the repair of the damage is complex and expensive. This problem has been noted in both the copper pipe jacket very commonly used heatpipes and, for example, in heatpipes with stainless steel sheath.

It has also been found that the use of thermally conductive plastic as a component of a heat coupling element is not very effective, since due to the thermal conductivity of metals such as copper (240 to 401 W / (m * K), depending on the purity) or aluminum ( 75 to 236 W / (m * K), depending on the purity) significantly lower thermal conductivity in plane of thermally conductive plastics (1 to 50 W / (m * K)) an effective transfer of the heat emitted by the heat source to the heat pipe is not guaranteed can be. In this case, it is also unhelpful to increase the area of the heat-conducting plastic element containing a thermally conductive plastic. As a result, although the heat given off by the heat source is better absorbed, this does not necessarily mean that this heat is also quantitatively supplied to the heat pipe. On the contrary, an increased area of the heat coupling element causes more heat to be released to the environment of the heat source, thus this heat does not reach the heat transfer surface of the end of the heat pipe facing the heat source and therefore can not be effectively dissipated via the heat pipe. This, in turn, can lead to problems, for example, in a vehicle headlight in which there is a heat source, for example by LEDs as the light source, which locally emits a high-temperature waste heat which must be dissipated. For example, electrical components or heat-sensitive materials of the headlight in the vicinity of an LED or the LED itself may be damaged. Of course, such problems also arise with other light sources, for example halogen lamps.

In addition revealed US20040252502A1 not how the heat dissipated by the heat source can be used.

The object of the present invention is therefore to provide a device which overcomes the disadvantages of the prior art.

In particular object of the present invention is therefore to provide a device comprising a heat pipe for dissipating heat from a heat source available that dissipates heat from this heat source reliably and effectively.

The heat pipe should be suitable to be encapsulated with a plastic, without collapse, aufzuplatzen, or even to be damaged so far that an effective heat dissipation is hindered. Thus, the ability of the heat pipe for heat dissipation after encapsulation should be at least 80%, preferably at least 90%, particularly preferably at least 95%, in particular at least 98% of the heat dissipation capability of the non-encapsulated heat pipe, ie the heat pipe before encapsulation.

Also, the device should have a heat input element that ensures an effective transfer of the heat emitted by the heat source to the heat pipe.

Also, the device should have a heat input element containing a thermally conductive plastic.

Preferably, the device should also be capable of utilizing the heat derived from the heat source at another point in a beneficial manner.

This object is achieved by a device having a heat pipe, a heat input element, and a heat coupling element, wherein the Wärmekkoppelement consists of at least 50 wt .-% of a thermally conductive thermoplastic composition, and wherein the heat pipe, in particular the heat decoupling element facing the end of the heat pipe , is overmolded with the thermally conductive thermoplastic composition of the heat extraction element, and wherein the quotient of outside diameter to wall thickness of the heat pipe from 10: 1 to 4: 1.

Preferably, the heat decoupling element to at least 65 wt .-%, preferably at least 80 wt .-%, more preferably at least 95 wt .-% of a thermally conductive thermoplastic composition.

In addition, a functional element may be attached to the heat sink, for example a fastening element or a housing. This functional element may also be a thermoplastic composition and be sprayed. The thermoplastic composition of the functional element does not need a thermally conductive thermoplastic composition However, it can be in the sense of the present invention. Also, this functional element is not considered within the meaning of the present invention as part of the heat sink.

This thermally conductive thermoplastic composition preferably has a thermal conductivity in plane of from 1 to 50 W / (m * K), preferably 2 to 30 W / (m * K), preferably 4 to 20 W / (m * K). When in the context of the present invention of thermal conductivity in plane is mentioned, it is meant according to ASTM E 1461-01 at 23 ° C certain thermal conductivity. The quotient of the outside diameter to the wall thickness of the heat pipe is preferably from 10: 1 to 4: 1, more preferably from 8: 1 to 4: 1, particularly preferably from 7: 1 to 5: 1.

Preferred working medium of the heat pipe is water, possibly water with additives.

In the range of the specified quotients, on the one hand, the heat pipe is prevented from collapsing, bursting or otherwise damaged during encapsulation with the thermally conductive thermoplastic composition of the heat decoupling element, and, on the other hand, the ability to dissipate heat effectively is not reduced. Thus, the ability of the heat pipe for heat dissipation after encapsulation is at least 80%, preferably at least 90%, particularly preferably at least 95%, in particular at least 98% of the ability to heat dissipate the heat pipe before encapsulation.

In a preferred embodiment of the invention, the heat dissipation system is formed as part of a lamp, preferably a headlight, particularly preferably a vehicle headlight or vehicle tail light, hereinafter referred to collectively as vehicle headlights.

In this case, the heat decoupling element is preferably designed as part of the housing of a vehicle headlight, in particular of a vehicle front headlamp or vehicle tail light. When using LEDs in these headlamps, there is the problem that the windows of these headlights are hardly heated by the waste heat of the LEDs. Although LEDs generate locally in operation a waste heat with high temperature, which must be effectively dissipated, as already described above, but the total amount of heat emitted by an LED heat energy compared to, for example, halogen lamps with the same light output for a much lower, on the other hand The resulting heat almost exclusively on the back and not given off in the form of heat radiation in the direction of the lens. If it happens now that in cold weather, the windows fog or freeze, so is conventional Vehicle headlamps do not sufficiently dissipate the heat from the LEDs to free the headlamp windows from fogging or frost. This may mean that the amount of light emitted by such headlamps is no longer sufficient for safe road access.

According to the invention, the heat decoupling element may be formed as a heat sink, which is inside or outside, preferably inside, more preferably inside down, on the vehicle headlamp and this heated, in particular by convection, but also by heat conduction and heat radiation.

The heat sink is preferably designed as a body with a structured surface for enlarging the same. For example, it can be designed as a substantially flat body, for example as a disk, or as a body with planar projections, such as cooling ribs; other shapes that have an enlarged surface but are also possible according to the invention.

According to the invention, the heat sink can also be designed as a cuboid, cylinder, sphere, cone or any other shape that serves the purpose of the heat sink.

In this way it can be ensured that, even in a vehicle headlamp equipped with LEDs, in particular only vehicle headlights equipped with LEDs, the vehicle headlamp disc is freed of fogging or frost after a short time in cold weather when the light is switched on.

If we are talking here about LED (light emitting diode, in the majority of LEDs), this means a light-emitting semiconductor component whose electrical properties correspond to a diode, as well as laser diodes, ie semiconductor components which generate laser radiation.

• Ein Wärmeableitungssystem für eine Wärmequelle, wobei das Wärmeableitungssystem eine Heatpipe, ein Wärmeeinkoppelelement, ein Wärmeauskoppelelement (Kühlkörper) aufweist, wobei das Wärmeauskoppelelement zu mindestens 65 Gew.-%, besonders bevorzugt zu mindestens 80 Gew.-%, ganz besonders bevorzugt zu mindestens 95 Gew.-% aus einer wärmeleitfähigen thermoplastischen Zusammensetzung mit einer Wärmeleitfähigkeit in plane von 1 bis 50 W/(m*K), bevorzugt 2 bis 30 W/(m*K) bevorzugt 4 bis 20 W/(m*K) besteht, und der Quotient vonAußendurchmesser zu Wandstärke der Heatpipe von 10:1 bis 4:1 beträgt.

The subject of the present invention is thus:

• A heat dissipation system for a heat source, wherein the heat dissipation system has a heat pipe, a heat input element, a heat coupling element (heat sink), wherein the heat coupling element to at least 65 wt .-%, more preferably at least 80 wt .-%, most preferably at least 95 wt .-% of a thermally conductive thermoplastic composition having a thermal conductivity in plane of 1 to 50 W / (m * K), preferably 2 to 30 W / (m * K) preferably 4 to 20 W / (m * K), and the ratio of outside diameter to wall thickness of the heat pipe is from 10: 1 to 4: 1.

The quotient of the outside diameter to the wall thickness of the heat pipe is preferably from 8: 1 to 4: 1, particularly preferably from 7: 1 to 5: 1.

Preferably, the heat pipe of the heat dissipation system is encapsulated with the thermally conductive thermoplastic composition of the heat extraction element.

In this case, the ability of the heat pipe to dissipate heat after encapsulation is preferably at least 80%, preferably at least 90%, particularly preferably at least 95%, in particular at least 98%, of the heat dissipation capability of the non-encapsulated heat pipe.

The thermally conductive thermoplastic composition is preferably a composition containing a polycarbonate.

The heat source is preferably a light source, preferably an LED.

The heat dissipation system is preferably a component of a luminaire, particularly preferably a headlamp, very particularly preferably a vehicle headlamp, in particular particularly preferably a vehicle headlight or rear vehicle headlamp.

It is preferably a part of the housing of a vehicle headlight.

Alternatively, preferably, the heat extraction element is designed as a heat sink, which is located on the inside of the vehicle headlamp and this heats.

• Eine Leuchte, umfassend das erfindungsgemäße Wärmeableitungssystem.

The subject of the present invention is also:

• A luminaire comprising the heat dissipation system according to the invention.

This lamp is preferably a headlight, particularly preferably a vehicle headlight.

1. A) 20,0 bis 80,49 Gew.-% Polycarbonat,
2. B) 15,0 bis 60,0 Gew.-% expandierten Graphit, wobei der D(0,5) des Graphits, bestimmt durch Siebanalyse gemäß DIN 51938, < 1,2 mm ist,
3. C) 4,5 bis 10 Gew.-% mindestens einer Phosphorverbindung der allgemeinen Formel (V)
   
   worin
   • R¹, R², R³ und R⁴ unabhängig voneinander C₁- bis C₈-Alkyl, jeweils gegebenenfalls halogeniert und jeweils verzweigt oder unverzweigt, und/oder C₅- bis C₆-Cycloalkyl, C₆- bis C₂₀-Aryl oder C₇- bis C₁₂-Aralkyl, jeweils gegebenenfalls durch verzweigtes oder unverzweigtes Alkyl, vorzugsweise C₁- bis C₄-Alkyl, und/oder Halogen, vorzugsweise Chlor und/oder Brom, substituiert,
   • n unabhängig voneinander 0 oder 1,
   • q einen ganzzahligen Wert von 0 bis 30,
   • X einen ein- oder mehrkernigen aromatischen Rest mit 6 bis 30 C-Atomen oder einen linearen oder verzweigten aliphatischen Rest mit 2 bis 30 C-Atomen, der jeweils substituiert oder unsubstituiert, verbrückt oder unverbrückt sein kann, bedeuten;
4. D) 0,01 bis 5,0 Gew.-% mindestens eines Ethylen/Alkyl(meth)acrylat-Copolymers, welches bevorzugt einen Schmelzflussindex von mindestens 2,5 g/10 min, ermittelt nach ASTM D1238 (bei 190°C und 2,16 kg), aufweist,
5. E) gegebenenfalls mindestens ein weiteres Polymeradditiv, ausgewählt aus der Gruppe der Thermostabilisatoren, von Komponente C verschiedene Flammschutzmittel, Antistatika, Farbmittel, Pigmente, Entformungsmittel, UV-Absorber, IR-Absorber und/oder der Füllstoffe, ausgewählt aus der Gruppe Kreide, Quarzpulver, Titandioxid, Silikate, Alumosilikate, Aluminiumoxid, Silica, Magnesiumhydroxid und/oder Aluminiumhydroxid,
   wobei die Komponenten A bis E sich zu 100 Gew.-% ergänzen.

The thermally conductive thermoplastic composition may be, for example, those in the WO 2015/135958 A1 be selected described. These compositions contain:

1. A) 20.0 to 80.49% by weight of polycarbonate,
2. B) 15.0 to 60.0% by weight of expanded graphite, the D (0.5) of the graphite, determined by sieve analysis according to DIN 51938, being <1.2 mm,
3. C) 4.5 to 10% by weight of at least one phosphorus compound of the general formula (V)
   
   wherein
   • R ¹ , R ² , R ³ and R ⁴ independently of one another C ₁ - to C ₈ -alkyl, in each case optionally halogenated and in each case branched or unbranched, and / or C ₅ - to C ₆ -cycloalkyl, C ₆ - to C ₂₀ - Aryl or C ₇ - to C ₁₂ -aralkyl, each optionally substituted by branched or unbranched alkyl, preferably C ₁ - to C ₄ -alkyl, and / or halogen, preferably chlorine and / or bromine,
   • n independently of one another 0 or 1,
   • q an integer value from 0 to 30,
   • X is a mononuclear or polynuclear aromatic radical having 6 to 30 carbon atoms or a linear or branched aliphatic radical having 2 to 30 carbon atoms, which may in each case be substituted or unsubstituted, bridged or unbridged;
4. D) 0.01 to 5.0 wt .-% of at least one ethylene / alkyl (meth) acrylate copolymer, which preferably has a melt flow index of at least 2.5 g / 10 min, determined according to ASTM D1238 (at 190 ° C and 2 , 16 kg),
5. E) optionally at least one further polymer additive selected from the group of heat stabilizers, flame retardants other than component C, antistatics, colorants, pigments, mold release agents, UV absorbers, IR absorbers and / or fillers selected from the group consisting of chalk, quartz powder, Titanium dioxide, silicates, aluminosilicates, alumina, silica, magnesium hydroxide and / or aluminum hydroxide,
   wherein the components A to E add up to 100 wt .-%.

The thermoplastic compositions of the invention have a minimum thermal conductivity (in plane) of preferably ≥ 9 W / (m * K), a heat resistance of ≥ 100 ° C and a melt volume flow rate at 330 ° C and 2.16 kg load of ≥ 10 cm ^3/10 min. Particularly preferred thermoplastic compositions of the invention have a heat resistance of ≥ 110 °.

Inventive thermoplastic compositions are also characterized by a length shrinkage of ≤ 0.14% and an E-modulus of ≤ 6500 N / mm ² , whereby the thermoplastic compositions have sufficient resistance to externally applied elastic deformation without too rigid behavior to show.

Component A

As component A polycarbonates are used.

By "polycarbonate" according to the invention are meant both homopolycarbonates as well as copolycarbonates and polyestercarbonates.

The thermoplastic polycarbonates including the thermoplastic aromatic polyester carbonates have average molecular weights M _w (determined by measuring the relative viscosity at 25 ° C in CH ₂ Cl ₂ and a concentration of 0.5 g per 100 ml CH ₂ Cl ₂ ) of 20,000 g / mol to 32,000 g / mol, preferably from 23,000 g / mol to 31,000 g / mol, in particular from 24,000 g / mol to 31,000 g / mol.

A portion, up to 80 mole%, preferably from 20 mole% to 50 mole%, of the carbonate groups in the polycarbonates used in this invention may be replaced by aromatic dicarboxylic acid ester groups. Such polycarbonates, which contain both acid residues of carbonic acid and acid residues of aromatic dicarboxylic acids incorporated into the molecular chain, are referred to as aromatic polyester carbonates. They are subsumed in the context of the present invention under the generic term of the thermoplastic, aromatic polycarbonates.

The preparation of the polycarbonates is carried out in a known manner from diphenols, carbonic acid derivatives, optionally chain terminators and optionally branching agents, wherein for the production of polyester carbonates, a part of the carbonic acid derivatives is replaced by aromatic dicarboxylic acids or derivatives of dicarboxylic acids, depending on the extent to be replaced in the aromatic polycarbonates Carbonate structural units by aromatic dicarboxylic ester structural units.

Z

ein aromatischer Rest mit 6 bis 30 C-Atomen ist, der einen oder mehrere aromatische Kerne enthalten kann, substituiert sein kann und aliphatische oder cycloaliphatische Reste bzw. Alkylaryle oder Heteroatome als Brückenglieder enthalten kann.

Dihydroxyaryl compounds suitable for the preparation of polycarbonates are those of the formula (2)

HO-Z-OH (2),

in which

Z

is an aromatic radical having 6 to 30 carbon atoms, which may contain one or more aromatic nuclei, may be substituted and may contain aliphatic or cycloaliphatic radicals or alkylaryl or heteroatoms as bridge members.

in der

R⁶ und R⁷

unabhängig voneinander für H, C₁- bis C₁₈-Alkyl-, C₁- bis C₁₈-Alkoxy, Halogen wie Cl oder Br oder für jeweils gegebenenfalls substituiertes Aryl- oder Aralkyl, bevorzugt für H oder C₁- bis C₁₂-Alkyl, besonders bevorzugt für H oder C₁- bis C₈-Alkyl und ganz besonders bevorzugt für H oder Methyl stehen, und

X

für eine Einfachbindung, -SO₂-, -CO-, -O-, -S-, C₁- bis C₆-Alkylen, C₂- bis C₅-Alkyliden oder C₅- bis C₆-Cycloalkyliden, welches mit C₁- bis C₆-Alkyl, vorzugsweise Methyl oder Ethyl, substituiert sein kann, ferner für C₆- bis C₁₂-Arylen, welches gegebenenfalls mit weiteren Heteroatome enthaltenden aromatischen Ringen kondensiert sein kann, steht.

Z in formula (2) preferably represents a radical of the formula (3)

in the

R ⁶ and R ⁷

independently of one another are H, C ₁ - to C ₁₈ -alkyl, C ₁ - to C ₁₈ -alkoxy, halogen, such as Cl or Br, or in each case optionally substituted aryl or aralkyl, preferably for H or C ₁ - to C ₁₂ - Alkyl, particularly preferably H or C ₁ - to C ₈ -alkyl and very particularly preferably H or methyl, and

X

for a single bond, -SO ₂ -, -CO-, -O-, -S-, C ₁ - to C ₆ -alkylene, C ₂ - to C ₅ -alkylidene or C ₅ - to C ₆ -cycloalkylidene, which with C ₁ - to C ₆ -alkyl, preferably methyl or ethyl, may be substituted, furthermore C ₆ - to C ₁₂ -arylene, which may optionally be condensed with further heteroatom-containing aromatic rings is.

wobei

R⁸ und R⁹

für jedes X¹ individuell wählbar, unabhängig voneinander Wasserstoff oder C₁-bis C₆-Alkyl, vorzugsweise Wasserstoff, Methyl oder Ethyl, bedeuten und

X¹

Kohlenstoff und

n

eine ganze Zahl von 4 bis 7, bevorzugt 4 oder 5 bedeuten,

mit der Maßgabe, dass an mindestens einem Atom X¹, R⁸ und R⁹ gleichzeitig Alkyl sind.X is preferably a single bond, C ₁ - to C ₅ -alkylene, C ₂ - to C ₅ -alkylidene, C ₅ - to C ₆ -cycloalkylidene, -O-, -SO-, -CO-, -S-, -SO ₂ -
or a radical of the formula (3a) or (3b)

in which

R ⁸ and R ⁹

individually selectable for each X ¹ , independently of one another denote hydrogen or C _{1 to} C ₆ alkyl, preferably hydrogen, methyl or ethyl, and

X ¹

Carbon and

n

an integer from 4 to 7, preferably 4 or 5,

with the proviso that on at least one atom X ¹ , R ⁸ and R ^{9 are} simultaneously alkyl.

Examples of dihydroxyaryl compounds (diphenols) are: dihydroxybenzenes, dihydroxydiphenyls, bis (hydroxyphenyl) alkanes, bis (hydroxyphenyl) -cycloalkanes, bis (hydroxyphenyl) -aryls, bis (hydroxyphenyl) ethers, bis (hydroxyphenyl) - ketones, bis (hydroxyphenyl) sulfides, bis (hydroxyphenyl) sulfones, bis (hydroxyphenyl) sulfoxides, 1,1'-bis (hydroxyphenyl) diisopropylbenzenes and their nuclear alkylated and ring-halogenated compounds.

Diphenols suitable for the preparation of the polycarbonates to be used according to the invention are, for example, hydroquinone, resorcinol, dihydroxydiphenyl, bis (hydroxyphenyl) alkanes, bis (hydroxyphenyl) cycloalkanes, bis (hydroxyphenyl) sulfides, bis (hydroxyphenyl) ethers, bis - (hydroxyphenyl) ketones, bis (hydroxyphenyl) sulfones, bis (hydroxyphenyl) sulfoxides, α, α'-bis (hydroxyphenyl) diisopropylbenzenes and their alkylated, nuclear-alkylated and ring-halogenated compounds.

Preferred diphenols are 4,4'-dihydroxydiphenyl, 2,2-bis (4-hydroxyphenyl) -1-phenyl-propane, 1,1-bis (4-hydroxyphenyl) -phenylethane, 2,2-bis (4 -hydroxyphenyl) propane, 2,4-bis (4-hydroxyphenyl) -2-methylbutane, 1,3-bis [2- (4-hydroxyphenyl) -2-propyl] benzene (bisphenol M), 2,2- Bis (3-methyl-4-hydroxyphenyl) -propane, bis (3,5-dimethyl-4-hydroxyphenyl) -methane, 2,2-bis (3,5-dimethyl-4-hydroxyphenyl) -propane, Bis- (3,5-dimethyl-4-hydroxyphenyl) sulfone, 2,4-bis (3,5-dimethyl-4-hydroxyphenyl) -2-methylbutane, 1,3-bis- [2- (3, 5-dimethyl-4-hydroxyphenyl) -2-propyl] -benzene and 1,1-bis (4-hydroxyphenyl) -3,3,5-trimethylcyclohexane (bisphenol TMC).

Particularly preferred diphenols are 4,4'-dihydroxydiphenyl, 1,1-bis (4-hydroxyphenyl) -phenyl-ethane, 2,2-bis (4-hydroxyphenyl) -propane, 2,2-bis (3,5 -dimethyl-4-hydroxyphenyl) -propane, 1,1-bis (4-hydroxyphenyl) cyclohexane and 1,1-bis (4-hydroxyphenyl) -3,3,5-trimethylcyclohexane (bisphenol TMC).

These and other suitable diphenols are, for example, in US Pat. No. 2,999,835 . 3 148 172 A . 2 991 273 A . 3 271 367 A . 4 982 014 A and 2,999,846 A , in the German publications 1 570 703 A . 2 063 050 A . 2 036 052 A . 2 211 956 A and 3 832 396 A , the French patent 1 561 518 A1 , in the Monograph "H. Schnell, Chemistry and Physics of Polycarbonates, Interscience Publishers, New York 1964, p. 28ff . S.102ff .", and in " DG Legrand, JT Bendler, Handbook of Polycarbonates Science and Technology, Marcel Dekker New York 2000, p. 72ff . "described.

In the case of homopolycarbonates, only one diphenol is used; in the case of copolycarbonates, two or more diphenols are used. The diphenols used, as well as all other chemicals and auxiliaries added to the synthesis, may be contaminated with the impurities derived from their own synthesis, handling and storage. However, it is desirable to work with as pure as possible raw materials.

The monofunctional chain terminators required to control the molecular weight, such as phenols or alkylphenols, in particular phenol, p-tert. Butylphenol, iso-octylphenol, cumylphenol, their chlorocarbonic acid esters or acid chlorides of monocarboxylic acids or mixtures of these chain terminators are either added to the bisphenolate or the bisphenolates of the reaction or added at any time during the synthesis, as long as phosgene or Chlorkohlensäureendgruppen in the reaction mixture are present, or in the case of acid chlorides and chloroformate as a chain terminator, as long as enough phenolic end groups of the forming polymer are available. Preferably, however, the chain terminator (s) are added after phosgenation at one point or at a time when phosgene is no longer present but the catalyst has not yet been metered or are added in front of the catalyst, together with the catalyst or in parallel.

In the same way, any branching or debranching compounds to be used are added to the synthesis, but usually before the chain terminators. Usually trisphenols, quarterphenols or acid chlorides of tri- or tetracarboxylic acids are used, or mixtures of polyphenols or acid chlorides.

Some of the branching compounds having three or more than three phenolic hydroxyl groups include, for example, phloroglucinol, 4,6-dimethyl-2,4,6-tri- (4-hydroxyphenyl) -hepten-2, 4,6-dimethyl-2, 4,6-tri- (4-hydroxyphenyl) -heptane, 1,3,5-tris- (4-hydroxyphenyl) -benzene, 1,1,1-tri- (4-hydroxyphenyl) -ethane, tris (4 -hydroxyphenyl) -phenylmethane, 2,2-bis [4,4-bis (4-hydroxyphenyl) -cyclohexyl] -propane, 2,4-bis (4-hydroxyphenyl-isopropyl) -phenol, tetra- (4 hydroxyphenyl) methane.

Some of the other trifunctional compounds are 2,4-dihydroxybenzoic acid, trimesic acid, cyanuric chloride and 3,3-bis (3-methyl-4-hydroxyphenyl) -2-oxo-2,3-dihydroindole.

Preferred branching agents are 3,3-bis (3-methyl-4-hydroxyphenyl) -2-oxo-2,3-dihydroindole and 1,1,1-tri (4-hydroxyphenyl) -ethane.

The amount of optionally used branching agent is 0.05 mol% to 2 mol%, based in turn on moles of diphenols used in each case.

The branching agents may either be initially charged with the diphenols and the chain terminators in the aqueous alkaline phase or may be added dissolved in an organic solvent prior to phosgenation.

All these measures for the preparation of the polycarbonates are familiar to the expert.

For the preparation of the polyester carbonates suitable aromatic dicarboxylic acids are, for example, orthophthalic acid, terephthalic acid, isophthalic acid, tert-butylisophthalic acid, 3,3'-diphenyldicarboxylic acid, 4,4'-diphenyldicarboxylic acid, 4,4-Benzophenondicarbonsäure, 3,4'-Benzophenondicarbonsäure, 4.4 'Diphenyl ether dicarboxylic acid, 4,4'-diphenylsulfonedicarboxylic acid, 2,2-bis- (4-carboxyphenyl) -propane, trimethyl-3-phenylindane-4,5'-dicarboxylic acid.

Of the aromatic dicarboxylic acids, terephthalic acid and / or isophthalic acid are particularly preferably used.

Derivatives of the dicarboxylic acids are the dicarboxylic acid dihalides and the dicarboxylic acid dialkyl esters, in particular the dicarboxylic acid dichlorides and the dimethyl dicarboxylates.

Substitution of the carbonate groups by the aromatic dicarboxylic ester groups is essentially stoichiometric and also quantitative, so that the molar ratio of the reactants is also found in the finished polyester carbonate. The incorporation of the aromatic dicarboxylic acid ester groups can be carried out both statistically and in blocks.

Preferred methods of preparation of the polycarbonates to be used according to the invention, including the polyestercarbonates, are the known interfacial process and the known melt transesterification process (cf. WO 2004/063249 A1 . WO 2001/05866 A1 . WO 2000/105867 . US 5,340,905 A . US 5,097,002 A . US Pat. No. 5,717,057 A ).

In the first case serve as acid derivatives preferably phosgene and optionally dicarboxylic acid dichlorides, in the latter case preferably diphenyl carbonate and optionally dicarboxylic. Catalysts, solvents, work-up, reaction conditions, etc., for the production of polycarbonate or production of polyester carbonate are adequately described and known in both cases.

The polycarbonates, polyester carbonates and polyesters can be worked up in a known manner and processed to form any shaped articles, for example by extrusion or injection molding.

Component B

As component B expanded graphite is used.

In the expanded graphites, the individual basal planes of the graphite are separated by a special treatment, resulting in an increase in volume of the graphite, preferably by a factor of 200 to 400 results. The production of expanded graphites is among others in the writings US 1,137,373 A . US 1,191,383 A such as US 3,404,061 A described.

Graphites are used in the form of fibers, rods, spheres, hollow spheres, platelets, in powder form, both in aggregated and in agglomerated form, preferably in platelet form, in the compositions.

The platelet-shaped structure is understood in the present invention to mean a particle which has a flat geometry. Thus, the height of the particles is usually significantly lower compared to the width or length of the particles. Such flat particles may in turn be agglomerated or aggregated into entities.

The height of the platelet-shaped primary particles is less than 500 nm, preferably less than 200 nm and particularly preferably less than 100 nm. Due to the small sizes of these primary particles, the shape of the particles may be bent, curved, wavy or otherwise deformed.

The length dimensions of the particles can be determined by standard methods, for example electron microscopy.

Graphite is in the inventive thermoplastic compositions in amounts of from 15.0 to 60.0 wt .-%, preferably 20.0 to 45.0 wt .-%, particularly preferably 20.0 to 35.0 wt .-%, all particularly preferably 30.0 to 35 wt .-% used to obtain a good thermal conductivity of the thermoplastic compositions while ensuring a high processing width.

According to the invention, preference is given to using a graphite having a relatively high specific surface, determined as the BET surface area by means of nitrogen adsorption according to ASTM D3037. Preference is given to using graphites having a BET surface area of ≥ 5 m ² / g, particularly preferably ≥ 10 m ² / g and very particularly preferably ≥ 18 m ² / g, in the thermoplastic compositions.

The D (0.5) of the graphite, determined by sieve analysis according to DIN 51938, is <1.2 mm.

Preferably, the graphites have a particle size distribution which is characterized by the D (0,9) of at least 1 mm, preferably of at least 1.2 mm, more preferably of at least 1.4 mm and even more preferably of at least 1.5 mm ,

Also preferably, the graphites have a particle size distribution characterized by the D (0.5) of at least 400 microns, preferably at least 600 microns, more preferably at least 750 microns and even more preferably at least 850 microns.

The graphites preferably have a particle size distribution which is characterized by the D (0,1) of at least 100 μm, preferably of at least 150 μm, more preferably of at least 200 μm and even more preferably of at least 250 μm.

The key figures D (0,1), D (0,5) and D (0,9) are determined by sieve analysis in accordance with DIN 51938.

The graphites used have a density, determined with xylene, in the range from 2.0 g / cm ³ to 2.4 g / cm ³ , preferably from 2.1 g / cm ³ to 2.3 g / cm ^3, and more preferably from 2.2 g / cm ³ to 2.27 g / cm ³ .

The carbon content of the graphites used according to the invention, determined in accordance with DIN 51903 at 800 ° C. for 20 hours, is preferably ≥ 90%, more preferably ≥ 95% and even more preferably ≥ 98%.

The residual moisture content of the graphites used according to the invention, determined according to DIN 38414 at 110 ° C. for 8 hours, is preferably ≦ 5%, more preferably ≦ 3% and even more preferably ≦ 2%.

The thermal conductivity of the graphites used according to the invention before processing is parallel to the basal planes between 250 and 400 W / (m * K) and perpendicular to the basal planes between 6 to 8 W (m * K).

The electrical resistance of the graphites used according to the invention before processing is parallel to the basal planes about 0.001 Ω * cm and is perpendicular to the basal planes less than 0.1 Ω * cm.

The bulk density of the graphites, determined according to DIN 51705, is usually between 50 g / l and 250 g / l, preferably between 65 g / l and 220 g / l and more preferably between 100 g / l and 200 g / l.

Preference is given to using graphites in the thermoplastic compositions which have a sulfur content of less than 200 ppm.

Preference is also given to using graphites in the thermoplastic compositions which have a leachable chlorine ion content of less than 100 ppm.

Also preferably, graphites are used in the thermoplastic compositions, which have a content of nitrates and nitrites less than 50 ppm.

Particularly preferred are graphites which satisfy all these limits, i. for the sulfur, the chloride ion, the nitrate and the nitrite content.

Commercially available graphites include Ecophit® GFG 5, Ecophit® GFG 50, Ecophit® GFG 200, Ecophit® GFG 350, Ecophit® GFG 500, Ecophit® GFG 900, Ecophit® GFG 1200 from SGL Carbon GmbH, TIMREX® BNB90 , TIMREX® KS5-44, TIMREX® KS6, TIMREX® KS150, TIMREX® SFG44, TIMREX® SFG150, TIMREX® C-THERM ™ 001 and TIMREX® C-THERM ™ 011 from TIMCAL Ltd., SC 20 O, SC 4000 O / SM and SC 8000 O / SM from Graphit Kropfmühl AG, Mechano-Cond 1, Mechano-Lube 2 and Mechano-Lube 4G from HC Carbon GmbH, Nord-Min 251 and Nord-Min 560T from Nordmann Rassmann GmbH and ASBURY A99, Asbury 230U and Asbury 3806 from Asbury Carbons.

Component C

Components C in the sense of the invention are selected from the group of mono- and phosphoric and phosphoric esters, wherein mixtures of a plurality of components, selected from one or more of these groups, can also be used as component C.

worin

• R¹, R², R³ und R⁴ unabhängig voneinander C₁- bis C₈-Alkyl, jeweils gegebenenfalls halogeniert und jeweils verzweigt oder unverzweigt, und/oder C₅- bis C₆-Cycloalkyl, C₆- bis C₂₀-Aryl oder C₇- bis C₁₂-Aralkyl, jeweils gegebenenfalls durch verzweigtes oder unverzweigtes Alkyl, und/oder Halogen, vorzugsweise Chlor und/oder Brom, substituiert,
• n unabhängig voneinander 0 oder 1,
• q einen ganzzahligen Wert von 0 bis 30 und
• X einen ein- oder mehrkernigen aromatischen Rest mit 6 bis 30 C-Atomen, oder einen linearen oder verzweigten aliphatischen Rest mit 2 bis 30 C-Atomen, der jeweils substituiert oder unsubstituiert, verbrückt oder unverbrückt sein kann, bedeuten.

Mono- and oligomeric phosphoric or phosphonic acid esters used according to the invention are phosphorus compounds of the general formula (V)

wherein

• R ¹ , R ² , R ³ and R ⁴ independently of one another C ₁ - to C ₈ -alkyl, in each case optionally halogenated and in each case branched or unbranched, and / or C ₅ - to C ₆ -cycloalkyl, C ₆ - to C ₂₀ - Aryl or C ₇ - to C ₁₂ -aralkyl, each optionally substituted by branched or unbranched alkyl, and / or halogen, preferably chlorine and / or bromine,
• n independently of one another 0 or 1,
• q is an integer value from 0 to 30 and
• X is a mononuclear or polynuclear aromatic radical having 6 to 30 carbon atoms, or a linear or branched aliphatic radical having 2 to 30 carbon atoms, which in each case may be substituted or unsubstituted, bridged or unbridged.

Preferably, R ¹ , R ² , R ³ and R ⁴ independently of one another are branched or unbranched C ₁ - to C ₄ -alkyl, phenyl, naphthyl or phenyl substituted by C ₁ - to C ₄ -alkyl. In the case of aromatic groups R ¹ , R ² , R ³ and / or R ⁴ , these in turn may be substituted by halogen and / or alkyl groups, preferably chlorine, bromine and / or C ₁ - to C ₄ -alkyl, branched or unbranched , Particularly preferred aryl radicals are cresyl, phenyl, xylenyl, propylphenyl or butylphenyl and the corresponding brominated and chlorinated derivatives thereof.

X in the formula (V) is preferably derived from diphenols. n in the formula (V) is preferably equal to 1.

worin

• R¹, R², R³ und R⁴ jeweils unabhängig voneinander lineares oder verzweigtes C₁- bis C₈-Alkyl und/oder gegebenenfalls durch lineares oder verzweigtes Alkylsubstituiertes C₅- bis C₆-Cycloalkyl, C₆- bis C₁₀-Aryl oder C₇- bis C₁₂-Aralkyl,
• n unabhängig voneinander 0 oder 1,
• q unabhängig voneinander 0, 1, 2, 3 oder 4,
• N eine Zahl zwischen 1 und 30,
• R₅ und R₆ unabhängig voneinander lineares oder verzweigtes C₁- bis C₄-Alkyl, vorzugsweise Methyl, und
• Y lineares oder verzweigtes C₁- bis C₇-Alkyliden, lineares oder verzweigtes C₁- bis C₇-Alkylen, C₅- bis C₁₂-Cycloalkylen, C₅- bis C₁₂-Cycloalkyliden, -O-, -S-, - SO-, SO₂ oder -CO- bedeuten,

enthalten ist.q is preferably 0 to 20, particularly preferably 0 to 10, in the case of mixtures for average values of 0.8 to 5.0, preferably 1.0 to 3.0, more preferably 1.05 to 2.00 and particularly preferably from 1.08 to 1.60.
As the phosphorus compound of the general formula V, a compound of the formula I is preferred:

wherein

• R ¹ , R ² , R ³ and R ^{4 are} each independently of the other linear or branched C ₁ - to C ₈ -alkyl and / or optionally linear or branched alkyl-substituted C ₅ - to C ₆ -cycloalkyl, C ₆ - to C ₁₀ - Aryl or C ₇ - to C ₁₂ -aralkyl,
• n independently of one another 0 or 1,
• q independently 0, 1, 2, 3 or 4,
• N is a number between 1 and 30,
• R ₅ and R ₆ independently of one another linear or branched C ₁ - to C ₄ -alkyl, preferably methyl, and
• Y linear or branched C ₁ - to C ₇ -alkylidene, linear or branched C ₁ - to C ₇ -alkylene, C ₅ - to C ₁₂ -cycloalkylene, C ₅ - to C ₁₂ -cycloalkylidene, -O-, -S- , -SO-, SO ₂ or -CO- mean

is included.

oder deren chlorierte und/oder bromierte Derivate. Bevorzugt leitet sich X (mit den angrenzenden Sauerstoffatomen) von Hydrochinon, Bisphenol A oder Diphenylphenol ab. Ebenfalls bevorzugt leitet sich X von Resorcin ab. Besonders bevorzugt leitet sich X von Bisphenol A ab.X in formula V is particularly preferred for

or their chlorinated and / or brominated derivatives. Preferably, X (with the adjacent oxygen atoms) is derived from hydroquinone, bisphenol A or diphenylphenol. Also preferably, X is derived from resorcinol. X is particularly preferably derived from bisphenol A.

Phosphorus compounds of the formula (V) are, in particular, tributyl phosphate, triphenyl phosphate, tricresyl phosphate, diphenyl cresyl phosphate, diphenyl octyl phosphate, diphenyl 2-ethyl cresyl phosphate, tri (isopropylphenyl) phosphate, resorcinol bridged oligophosphate and bisphenol A bridged oligophosphate. The use of oligomeric phosphoric acid esters of the formula (V) derived from bisphenol A is particularly preferred.

Highly preferred as component C is bisphenol A-based oligophosphate according to formula (Va).

Also particularly preferred are oligophosphates analogous to the formula (Va), in which q is between 1.0 and 1.2.

The phosphorus compounds according to component C are known (cf., for example EP 0 363 608 A1 . EP 0 640 655 A2 ) or can be prepared by known methods in an analogous manner (eg Ullmanns Enzyklopadie der technischen Chemie, Vol. 18, p. 301 ff., 1979 ; Houben-Weyl, Methods of Organic Chemistry, Vol. 12/1, p. 43 ; Beilstein Vol. 6, p. 177 ).

Preference is given to using mixtures having the same structure and different chain length, the stated q value being the mean q value. The mean q value is determined by determining the composition of the phosphorus compound mixture (molecular weight distribution) by means of high pressure liquid chromatography (HPLC) at 40 ° C. in a mixture of acetonitrile and water (50:50) and from this the mean values for q are calculated ,

The compositions according to the invention contain 4.5 to 10% by weight, preferably 6.0 to 10.0% by weight, particularly preferably 6.0 to 9.0% by weight of component C.

Alternatively, particularly preferred compositions according to the invention contain from 5.0 to 7.0% by weight of component C.

Component D

wobei

• R₁ Methyl oder Wasserstoff,
• R₂ Wasserstoff oder ein C₁- bis C₁₂-Alkylrest, bevorzugt Methyl, Ethyl, Propyl, Isopropyl, Butyl, sec-Butyl, tert-Butyl, Isobutyl, Hexyl, Isoamyl oder tert-Amyl,
• x und y je ein eigenständiger Polymerisationsgrad (ganze Zahl) und
• n eine ganze Zahl ≥ 1 ist.

Component D in the context of the present invention is an ethylene / alkyl (meth) acrylate copolymer of the formula (VI)

in which

• R _{1 is} methyl or hydrogen,
• R _{2 is} hydrogen or a C ₁ - to C ₁₂ -alkyl radical, preferably methyl, ethyl, propyl, isopropyl, butyl, sec-butyl, tert-butyl, isobutyl, hexyl, isoamyl or tert-amyl,
• x and y each have an independent degree of polymerization (integer) and
• n is an integer ≥ 1.

The ratios of the degrees of polymerization x and y are preferably in the range of x: y = 1: 300 to 90:10.

The ethylene / alkyl (meth) acrylate copolymer may be a random, block or multiblock copolymer or mixtures of these structures. In a preferred embodiment, branched and unbranched ethylene / alkyl (meth) acrylate copolymers, particularly preferably linear ethylene / alkyl (meth) acrylate copolymers, are used.

The melt flow index (MFR) of the ethylene / alkyl (meth) acrylate copolymer (measured at 190 ° C at 2.16 kg load, ASTM D1238) is preferably in the range of 2.5-40.0 g / (10 min), more preferably in the range from 3.0-10.0 g / (10 min), most preferably in the range of 3.0-8.0 g / (10 min).

It is preferred to use Elvaloy® 1820 AC (DuPont) in compositions according to the invention. This is an ethylene / methyl acrylate copolymer with a methyl acrylate content of 20% and a melt flow index of 8 g / (10 min), determined at 190 ° C and 2.16 kg according to ASTM D1238.

The compositions according to the invention contain from 0.01 to 5% by weight, preferably from 2 to 4.5% by weight, very particularly preferably from 3 to 4% by weight of component D.

Component E

The polycarbonate compositions can also be added to the conventional thermoplastics customary additives such as flame retardants, fillers, heat stabilizers, antistatic agents, colorants and pigments, mold release agents, UV absorbers and IR absorber in the usual amounts.

Preferably, the compositions according to the invention contain no further flame retardants in addition to component C. Preferably, the compositions according to the invention are also free of fluorine-containing anti-dripping agents, such as PTFE (polytetrafluoroethylene).

The amount of further additives is preferably up to 5 wt .-%, particularly preferably 0.01 to 3 wt .-%, based on the total composition.

Suitable additives are described, for example, in " Additives for Plastics Handbook, John Murphy, Elsevier, Oxford 1999 ", in the " Plastics Additives Handbook, Hans Zweifel, Hanser, Munich 2001 ".

Suitable antioxidants or thermal stabilizers are, for example alkylated monophenols, alkylthiomethylphenols, hydroquinones and alkylated hydroquinones, tocopherols, hydroxylated thiodiphenyl ethers, alkylidenebisphenols, O, N and S benzyl compounds, hydroxybenzylated malonates, hydroxybenzyl aromatic compounds, triazine compounds, acylaminophenols, esters of β- (3,5-di-tert-butyl) butyl-4-hydroxyphenyl) propionic acid, esters of β- (5-tert-butyl-4-hydroxy-3-methylphenyl) propionic acid, esters of β- (3,5-dicyclohexyl-4-hydroxyphenyl) propionic acid, esters of 3, 5-di-tert-butyl-4-hydroxyphenylacetic acid, amides of β- (3,5-di-tert-butyl-4-hydroxyphenyl) propionic acid, suitable thiosynergists, secondary antioxidants, phosphites and phosphonites, benzofuranones and indolinones.

Preference is given to organic phosphites such as triphenylphosphine, tritoluylphosphine or (2,4,6-tri-t-butylphenyl) - (2-butyl-2-ethyl-propane-1,3-diyl) -phosphite, phosphonates and phosphanes, usually those in which the organic radicals consist entirely or partially of optionally substituted aromatic radicals.

Very particularly suitable additives are IRGANOX® 1076 (octadecyl-3,5-di (tert-butyl) 4-hydroxyhydrocinnamate, CAS No. 2082-79-3 ) as well as triphenylphosphine (TPP).

Suitable mold release agents are, for example, the esters or partial esters of monohydric to hexahydric alcohols, in particular of glycerol, pentaerythritol or Guerbet alcohols.

Monohydric alcohols include stearyl alcohol, palmityl alcohol and Guerbet alcohols. A dihydric alcohol is, for example, glycol; a trihydric alcohol is, for example, glycerol; tetrahydric alcohols are, for example, pentaerythritol and mesoerythritol; pentahydric alcohols are, for example, arabitol, ribitol and xylitol; Hexahydric alcohols include mannitol, glucitol (sorbitol) and dulcitol.

The esters are preferably the monoesters, diesters, triesters, tetraesters, pentaesters and hexaesters or mixtures thereof, in particular random mixtures, of saturated, aliphatic C ₁₀ - to C ₃₆ -monocarboxylic acids and optionally hydroxymonocarboxylic acids, preferably with saturated, aliphatic C ₁₄ - ₃₂ -monocarboxylic acids and optionally hydroxymonocarboxylic acids.

The commercially available fatty acid esters, in particular of pentaerythritol and of glycerol, may contain <60% of different partial esters as a result of the preparation.

Saturated, aliphatic monocarboxylic acids having 10 to 36 carbon atoms are, for example, capric, lauric, myristic, palmitic, stearic, hydroxystearic, arachidic, behenic, lignoceric, cerotic and montan acids.

Suitable IR absorbers are, for example, in EP 1 559 743 A1 . EP 1 865 027 A1 . DE 10022037 A1 . DE 10006208 A1 as well as in the Italian patent applications RM2010A000225 . RM2010A000227 such as RM2010A000228 disclosed. Among the IR absorbers mentioned in the cited literature, boride- and tungstate-based composites, in particular cesium tungstate or zinc-doped cesium tungstate, and absorbers based on ITO and ATO and combinations thereof are preferred.

Suitable UV absorbers from the class of the benzotriazoles are, for example, Tinuvin® 171 (2- [2-hydroxy-3-dodecyl-5-methylbenzyl) phenyl] -2H-benzotriazole ( CAS-No. 125304-04-3 )), Tinuvin® 234 (2- [2-hydroxy-3,5-di (1,1-dimethylbenzyl) phenyl] -2H-benzotriazole ( CAS-No. 70321-86-7 )), Tinuvin® 328 (2-2 [hydroxy-3,5-di-tert-amyl-phenyl] -2H-benztriazole ( CAS-No. 25973-55-1 )).

Suitable UV absorbers from the oxalanilide class are, for example, Sanduvor® 3206 (N- (2-ethoxyphenyl) -ethanediamide ( CAS-No. 82493-14-9 )) of Clariant or N- (2-ethoxyphenyl) -N '- (4-dodecylphenyl) oxamide ( CAS-No. 79102-63-9 ).

Suitable UV absorbers from the class of hydroxybenzophenones are, for example, Chimasorb® 81 (2-benzoyl-5-octyloxyphenol ( CAS-No. 1843-05-6 )) from BASF SE, 2,4-dihydroxybenzophenone ( CAS-No. 131-56-6 ), 2-hydroxy-4- (n-octyloxy) benzophenone ( CAS-No. 1843-05-6 ), 2-hydroxy-4-dodecyloxybenzophenone ( CAS-No. 2985-59-3 ).

Suitable UV absorbers from the class of the triazines are, for example, 2- [2-hydroxy-4- [3- (2-ethylhexyl-1-oxy) -2-hydroxypropyloxy] phenyl] -4,6-bis (2,4-) dimethylphenyl) -1,3,5-triazine ( CAS-No. 137658-79-8 ) also known as Tinuvin® 405 (BASF SE) and 2,4-diphenyl-6- [2-hydroxy-4- (hexyloxy) phenyl] -1,3,5-triazine ( CAS-No. 147315-50-2 ), available as Tinuvin® 1577 (BASF SE).

The compound 2- [2-hydroxy-4- [(octyloxycarbonyl) ethylidenoxy] phenyl] -4,6-di (4-phenyl) phenyl-1,3,5-triazine has the CAS-No. 204848-45-3 and is available from BASF SE under the name Tinuvin® 479.

The compound 2- [2-hydroxy-4 - [(2-ethylhexyl) oxylphenyl] -4,6-di (4-phenyl) phenyl-1,3,3,5-triazine has the CAS-No. 204583-39-1 and is available from BASF SE under the names CGX-UVA006 and Tinuvin® 1600, respectively.

UV absorbers are generally used in an amount of 0.01 to 5 wt .-%, preferably 0.01 to 2 wt .-%, particularly preferably 0.01 to 0.05 wt .-%, based on the total composition ,

The polycarbonate composition may be added to organic and inorganic fillers in conventional amounts. In principle, all finely ground organic and inorganic materials are suitable for this purpose. These may e.g. have particulate, flaky or fibrous character. By way of example, chalk, quartz powder, titanium dioxide, silicates / aluminosilicates, e.g. Talc, wollastonite, mica / clay minerals, montmorillonite, especially in an ion-exchange modified organophilic form, kaolin, zeolites, vermiculite and alumina, silica, magnesium hydroxide and aluminum hydroxide. It is also possible to use mixtures of different inorganic materials.

Preferred inorganic fillers are finely divided (nanoscale) inorganic compounds of one or more metals of the 1st to 5th main group and 1st to 8th subgroup of the Periodic Table, preferably from the 2nd to 5th main group, more preferably on the 3rd to 5th Main group, or on the 4th to 8th subgroup, with the elements oxygen, sulfur, boron, phosphorus, carbon, nitrogen, hydrogen and / or silicon.

Examples of preferred compounds are oxides, hydroxides, hydrous / basic oxides, sulfates, sulfites, sulfides, carbonates, carbides, nitrates, nitrites, nitrides, borates, silicates, phosphates and hydrides.

As colorants or pigments, for example, organic or inorganic pigments or organic dyes or the like can be used.

Coloring agents or pigments for the purposes of the present invention are sulfur-containing pigments such as cadmium red or cadmium yellow, iron cyanide-based pigments such as Berlin Blue, oxide pigments such as titanium dioxide, zinc oxide, red iron oxide, black iron oxide, chromium oxide, titanium yellow, zinc-iron-based brown , Titanium-cobalt-based green, cobalt blue, copper-chromium-based black and copper-iron-based black, or chromium-based pigments such as chrome yellow, phthalocyanine-derived dyes such as copper phthalocyanine blue or copper phthalocyanine green, condensed polycyclic Dyes and pigments such as azo-based (eg nickel-azo yellow), sulfur indigo dyes, perinone-based, perylene-based, quinacridone-derived, dioxazine-based, isoindolinone-based and quinophthalone-derived derivatives, anthraquinone based, heterocyclic systems.

Concrete examples of commercial products are z. MACROLEX® Blue RR, MACROLEX® Violet 3R, MACROLEX® Violet B (Lanxess AG, Germany), Sumiplast® Violet RR, Sumiplast® Violet B, Sumiplast® Blue OR, (Sumitomo Chemical Co., Ltd.), Diaresin® Violet D, Diaresin® Blue G, Diaresin® Blue N (Mitsubishi Chemical Corporation), Heliogen® Blue or Heliogen® Green (BASF AG, Germany).

Of these, cyanine derivatives, quinoline derivatives, anthraquinone derivatives, phthalocyanine derivatives are preferred.

1. A) 20,0 bis 77,0 Gew.-% Polycarbonat,
2. B) 15,0 bis 60,0 Gew.-% expandierten Graphit, wobei der D(0,5) des Graphits, bestimmt durch Siebanalyse gemäß DIN 51938, < 1,2 mm ist,
3. C) 5,0 bis 7,0 Gew.-% mindestens einer Phosphorverbindung der Formel
   
   wobei q zwischen 1,0 und 1,2, bevorzugt bei 1,1, liegt,
4. D) 3,0 bis 4,0 Gew.-% mindestens eines Ethylen/Alkyl(meth)acrylat-Copolymers,
5. E) gegebenenfalls mindestens ein weiteres Polymeradditiv, ausgewählt aus der Gruppe der Thermostabilisatoren, von Komponente C verschiedene Flammschutzmittel, Antistatika, Farbmittel, Pigmente, Entformungsmittel, UV-Absorber, IR-Absorber und/oder der Füllstoffe, ausgewählt aus der Gruppe Kreide, Quarzpulver, Titandioxid, Silikate, Alumosilikate, Aluminiumoxid, Silica, Magnesiumhydroxid und/oder Aluminiumhydroxid,

wobei die Komponenten A) bis E) sich zu 100 Gew.-% ergänzen.A preferred composition according to the invention contains

1. A) 20.0 to 77.0% by weight polycarbonate,
2. B) 15.0 to 60.0% by weight of expanded graphite, the D (0.5) of the graphite, determined by sieve analysis according to DIN 51938, being <1.2 mm,
3. C) 5.0 to 7.0 wt .-% of at least one phosphorus compound of the formula
   
   where q is between 1.0 and 1.2, preferably 1.1,
4. D) 3.0 to 4.0% by weight of at least one ethylene / alkyl (meth) acrylate copolymer,
5. E) optionally at least one further polymer additive selected from the group of heat stabilizers, flame retardants other than component C, antistatics, colorants, pigments, mold release agents, UV absorbers, IR absorbers and / or fillers selected from the group consisting of chalk, quartz powder, Titanium dioxide, silicates, aluminosilicates, alumina, silica, magnesium hydroxide and / or aluminum hydroxide,

wherein the components A) to E) add up to 100 wt .-%.

1. A) 52,0 bis 72,0 Gew.-%, bevorzugt 52,0 bis 71,0 Gew.-% Polycarbonat,
2. B) 20,0 bis 35,0 Gew.-% expandierten Graphit, wobei der D(0,5) des Graphits, bestimmt durch Siebanalyse gemäß DIN 51938, < 1,2 mm ist,
3. C) 5,0 bis 10,0, bevorzugt 5,0 bis 7,0 Gew.-% mindestens einer Phosphorverbindung der Formel
   
4. D) 2,0 bis 4,0 Gew.-%, bevorzugt 3,0 bis 4,0 Gew.-% mindestens eines Ethylen/Alkyl(meth)acrylat-Copolymers,
5. E) gegebenenfalls mindestens ein weiteres Polymeradditiv, ausgewählt aus der Gruppe der Thermostabilisatoren, von Komponente (C) verschiedene Flammschutzmittel, Antistatika, Farbmittel, Pigmente, Entformungsmittel, UV-Absorber, IR-Absorber und/oder der Füllstoffe, ausgewählt aus der Gruppe Kreide, Quarzpulver, Titandioxid, Silikate, Alumosilikate, Aluminiumoxid, Silica, Magnesiumhydroxid und/oder Aluminiumhydroxid,

wobei die Komponenten A) bis E) sich zu 100 Gew.-% ergänzen.According to a particularly preferred embodiment, the composition according to the invention contains

1. A) 52.0 to 72.0% by weight, preferably 52.0 to 71.0% by weight polycarbonate,
2. B) 20.0 to 35.0% by weight of expanded graphite, the D (0.5) of the graphite, determined by sieve analysis according to DIN 51938, being <1.2 mm,
3. C) 5.0 to 10.0, preferably 5.0 to 7.0 wt .-% of at least one phosphorus compound of the formula
   
4. D) 2.0 to 4.0% by weight, preferably 3.0 to 4.0% by weight of at least one ethylene / alkyl (meth) acrylate copolymer,
5. E) if appropriate at least one further polymer additive selected from the group of thermostabilizers, flame retardants other than component (C), antistatics, colorants, pigments, mold release agents, UV absorbers, IR absorbers and / or fillers selected from the group consisting of chalk, Quartz powder, titanium dioxide, silicates, aluminosilicates, alumina, silica, magnesium hydroxide and / or aluminum hydroxide,

wherein the components A) to E) add up to 100 wt .-%.

Particularly preferred in this embodiment, the melt flow index of component D is at least 2.5 g / 10 min, determined according to ASTM D1238 (at 190 ° C and 2.16 kg).

1. A) 52,0 bis 60,0 Gew.-% Polycarbonat,
2. B) 30,0 bis 35,0 Gew.-% expandierten Graphit, wobei der D(0,5) des Graphits, bestimmt durch Siebanalyse gemäß DIN 51938, < 1,2 mm ist,
3. C) 5,0 bis 10,0 Gew.-%, bevorzugt 5,0 bis 7,0 Gew.-% mindestens einer Phosphorverbindung der Formel
   
   wobei q zwischen 1,0 und 1,2, bevorzugt bei 1,1, liegt,
4. D) 3,0 bis 4,0 Gew.-% mindestens eines Ethylen/Alkyl(meth)acrylat-Copolymers,
5. E) gegebenenfalls mindestens ein weiteres Polymeradditiv, ausgewählt aus der Gruppe der Thermostabilisatoren, von Komponente (C) verschiedene Flammschutzmittel, Antistatika, Farbmittel, Pigmente, Entformungsmittel, UV-Absorber, IR-Absorber und/oder der Füllstoffe, ausgewählt aus der Gruppe Kreide, Quarzpulver, Titandioxid, Silikate, Alumosilikate, Aluminiumoxid, Silica, Magnesiumhydroxid und/oder Aluminiumhydroxid,

wobei die Komponenten A) bis E) sich zu 100 Gew.-% ergänzen und wobei die Zusammensetzung frei von Fluor-haltigem Antitropfmittel ist.Another particularly preferred composition according to the invention contains

1. A) 52.0 to 60.0% by weight polycarbonate,
2. B) 30.0 to 35.0 wt .-% expanded graphite, wherein the D (0.5) of the graphite, determined by sieve analysis according to DIN 51938, <1.2 mm,
3. C) 5.0 to 10.0 wt .-%, preferably 5.0 to 7.0 wt .-% of at least one phosphorus compound of the formula
   
   where q is between 1.0 and 1.2, preferably 1.1,
4. D) 3.0 to 4.0% by weight of at least one ethylene / alkyl (meth) acrylate copolymer,
5. E) if appropriate at least one further polymer additive selected from the group of thermostabilizers, flame retardants other than component (C), antistatics, colorants, pigments, mold release agents, UV absorbers, IR absorbers and / or fillers selected from the group consisting of chalk, Quartz powder, titanium dioxide, silicates, aluminosilicates, alumina, silica, magnesium hydroxide and / or aluminum hydroxide,

wherein the components A) to E) add up to 100 wt .-% and wherein the composition is free of fluorine-containing anti-drip agent.

The preparation of the polymer compositions according to the invention containing the abovementioned components is carried out by customary incorporation methods by combining, mixing and homogenizing the individual constituents, wherein in particular the homogenization preferably takes place in the melt under the action of shearing forces. Optionally, the merging and mixing takes place before the melt homogenization using powder premixes.

It is also possible to use premixes of granules or granules and powders with the additives according to the invention.

It is also possible to use premixes which have been prepared from solutions of the mixture components in suitable solvents, if appropriate homogenizing in solution and subsequently removing the solvent.

In particular, in this case the components and aforementioned additives of the compositions according to the invention can be introduced by known methods or as a masterbatch.

The use of masterbatches is particularly preferred for introducing the additives, in particular masterbatches based on the respective polymer matrix being used.

In this connection, the composition can be combined, mixed, homogenized and then extruded in conventional equipment such as screw extruders (for example twin-screw extruder, ZSK), kneaders, Brabender or Banbury mills. After extrusion, the extrudate can be cooled and comminuted. It is also possible to premix individual components and then to add the remaining starting materials individually and / or likewise mixed.

Other thermally conductive thermoplastic compositions also useful in the present invention are disclosed, for example, in U.S. Pat WO2012 / 174574A2 , the WO2017 / 005735A1 , the WO2017 / 005738A1 and the WO2017005736A1 , where in the WO2017 / 005735A1 disclosed thermally conductive thermoplastic compositions of the invention are particularly suitable. In particular, those in the WO2017 / 005735A1 disclosed diglycerol esters as flow improvers in connection with the thermally conductive thermoplastic compositions of the invention particularly suitable.

The diglycerol esters used as flow improvers are esters of carboxylic acids with diglycerol. In this case, esters based on various carboxylic acids are suitable. Also, different isomers of diglycerol can form base for the esters. In addition to monoesters and multiple esters of diglycerol can be used. Instead of pure compounds and mixtures can be used.

Isomers of diglycerol, which form the basis for the diglycerol esters used according to the invention, are the following:

For the diglycerol esters used according to the invention, it is possible to use those isomers of these formulas which have been singly or multiply esterified. Mixtures which can be used as flow aids consist of the diglycerol educts and ester end products derived therefrom, for example with the molecular weights 348 g / mol (monolauryl ester) or 530 g / mol (dilauryl ester).

The diglycerol esters according to the invention contained in the composition are preferably derived from saturated or unsaturated monocarboxylic acids having a chain length of 6 to 30 carbon atoms. Suitable monocarboxylic acids are, for example, caprylic acid (C ₇ H ₁₅ COOH, octanoic acid), capric acid (C ₉ H ₁₉ COOH, decanoic acid), lauric acid (C ₁₁ H ₂₃ COOH, dodecanoic acid), myristic acid (C ₁₃ H ₂₇ COOH, tetradecanoic acid), palmitic acid ( C ₁₅ H ₃₁ COOH, hexadecanoic acid), margaric acid (C ₁₆ H ₃₃ COOH, heptadecanoic acid), stearic acid (C ₁₇ H ₃₅ COOH, octadecanoic acid), arachidic acid (C ₁₉ H ₃₉ COOH, eicosanoic acid), behenic acid (C ₂₁ H ₄₃ COOH, Docosanoic acid), lignoceric acid (C ₂₃ H ₄₇ COOH, tetracosanoic acid), palmitoleic acid (C ₁₅ H ₂₉ COOH, (9Z) -hexadeca-9-enoic acid), petroselinic acid (C ₁₇ H ₃₃ COOH, (6Z) octadeca-6-enoic acid ), Elaidic acid (C ₁₇ H ₃₃ COOH, (9E) octadeca-9-enoic acid), linoleic acid (C ₁₇ H ₃₁ COOH, (9Z, 12Z) octadeca-9,12-dienoic acid), alpha- or gamma-linolenic acid (C ₁₇ H ₂₉ COOH, (9Z, 12Z, 15Z) -Octadeca-9,12,15-trienoic acid, and (6Z, 9Z, 12Z) -Octadeca-6,9,12-trienoic acid) (acid, arachidonic acid C ₁₉ H ₃₁ COOH, (5Z, 8Z, 11Z, 14Z) -eicosa-5,8,11,14-tetraenoic acid), Timnodons acid (C ₁₉ H ₂₉ COOH, (5Z, 8Z, 11Z, 14Z, 17Z) -eicosa-5,8,11,14,17-pentaenoic acid) and cervonic acid (C ₂₁ H ₃₁ COOH, (4Z, 7Z, 10Z, 13Z, 16Z, 19Z) -Docosa-4,7,10,13,16,19-hexaenoic). Particularly preferred are lauric acid, palmitic acid and / or stearic acid.

mit R = COC_nH2_n+1 und/oder R = COR',
wobei n eine ganze Zahl ist und R' ein verzweigter Alkylrest oder ein verzweigter oder unverzweigter Alkenylrest ist und C_nH_2n+1 ein aliphatischer, gesättigter linearer Alkylrest ist,
enthalten.As diglycerol ester, at least one ester of the formula (I) is particularly preferably

with R = COC _n H2 _{n + 1} and / or R = COR ',
wherein n is an integer and R 'is a branched alkyl radical or a branched or unbranched alkenyl radical and C _n H _{2n + 1 is} an aliphatic, saturated linear alkyl radical,
contain.

N is preferably an integer of 6-24, so that C _n H _{2n + 1 is,} for example, n-hexyl, n-heptyl, n-octyl, n-nonyl, n-decyl, n-dodecyl, n-tridecyl, n Tetradecyl, n-hexadecyl or n-octadecyl. More preferably n = 8 to 18, more preferably 10 to 16, most preferably 12 (diglycerol monolaurate isomer having the molecular weight 348 g / mol, which is particularly preferred as the main product in a mixture). According to the invention, the abovementioned ester groups are preferably also present in the other isomers of diglycerol.

It may therefore also be a mixture of different diglycerol esters.

wobei M_lipophil die Molmasse des lipophilen Anteils des Diglycerolesters ist und M die Molmasse des Diglycerolesters.Preferred diglycerol esters have an HLB value of at least 6, particularly preferably 6 to 12, the HLB value being understood as meaning the so-called "hydrophilic-lipophilic balance", which is calculated according to the Griffin method as follows: $$\mathrm{HLB}=\mathrm{20}\times \left(\mathrm{1}-{\mathrm{M}}_{\mathrm{lipophilic}}/\mathrm{M}\right).$$

where M is _lipophilic the molecular weight of the lipophilic portion of the diglycerol ester and M is the molecular weight of the diglycerol ester.

Table 1 shows by way of example with reference to various heat pipes made of different materials and with different outer diameters and wall thicknesses, that the quotient of outer diameter to wall thickness of the heat pipe is critical so that the heat pipe withstands the loads occurring during encapsulation, without the invention being limited to these examples. In each case, an injection pressure of about 1000 bar was applied during injection molding with a holding pressure of 600 bar. <b> Table 1 </ b> material outer diameter Wall thickness Injured injection process without damage? copper 4 mm 0.2 mm No copper 6 mm 1 mm Yes copper 8 mm 1 mm Yes stainless steel 1.5 mm 0.25 mm Yes stainless steel 3 mm 0.25 mm No stainless steel 3 mm 0.5 mm Yes copper 4 mm 0.5 mm Yes copper 4 mm 0.75 mm Yes copper 4 mm 1 mm Yes copper 5 mm 0.5 mm Yes

A preferred embodiment of the invention is illustrated by the following figure, without thereby limiting the invention to this embodiment.

1

Wärmequelle,

2

Wärmeeinkoppelelement,

3

Heatpipe,

4

Kühlkörper.

Fig. 1 shows the inventive heat dissipation system for a heat source; are:

1

Heat source

2

Wärmeeinkoppelelement,

3

heat pipe,

4

Heatsink.

Claims (11)

A heat dissipation system for a heat source, wherein the heat dissipation system has a heat pipe, a heat input element, a heat decoupling element (heat sink), wherein the heat decoupling element to at least 50 wt .-%, preferably to 65 wt .-%, particularly preferably at least 80 wt .-% , very particularly preferably at least 95 wt .-% of a thermally conductive thermoplastic composition having a thermal conductivity in plane of 1 to 50 W / (m * K), preferably 2 to 30 W / (m * K) preferably 4 to 20 W / (m * K), and the quotient of outside diameter to wall thickness of the heat pipe is from 10: 1 to 4: 1. Heat dissipation system according to claim 1, wherein the quotient of outside diameter to wall thickness of the heat pipe from 8: 1 to 4: 1, more preferably 7: 1 to 5: 1. A heat dissipation system according to claim 1 or 2, wherein the heat pipe is overmolded with the thermally conductive thermoplastic composition of the thermal decoupling element. Heat dissipation system according to one of claims 1 to 3, wherein the ability of the heat pipe for heat dissipation after encapsulation is at least 80%, preferably at least 90%, more preferably at least 95%, in particular at least 98% of the heat dissipation capability of the non-encapsulated heat pipe. A heat dissipation system according to any one of claims 1 to 4, wherein the thermally conductive thermoplastic composition is a composition containing a polycarbonate. Heat dissipation system according to one of claims 1 to 5, wherein it is the heat source is a bulb, preferably an LED. Heat dissipation system according to one of claims 1 to 6, wherein the heat dissipation system is a component of a lamp, preferably a headlamp, particularly preferably a vehicle headlamp, very particularly preferably a vehicle headlamp or vehicle tail light. A heat dissipation system according to any one of claims 1 to 7, wherein the heat dissipation system is a part of the housing of a vehicle headlamp. Heat dissipation system according to one of claims 1 to 7, wherein the heat decoupling element formed as a heat sink, which is inside or outside, preferably inside, particularly preferably inside down, on the vehicle headlamp disk. Luminaire comprising the heat dissipation system according to one of claims 1 to 9. Luminaire according to claim 10, wherein this is designed as a headlamp, preferably as a vehicle headlamp.

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