WO2025238242A1 - Thermoplastic composition - Google Patents

Abstract

The invention relates to a thermoplastic composition comprising, based on the weight of the composition: A) polycarbonate, B) at least one impact modifier, C) from 0.1 – 10.0 wt.% of a polyolefin, D) from 0.1 – 10.0 wt.% of an olefinic compatibilizer and E) from 0.0 – 2.0 wt.% of further components, wherein the sum of the components A) - E) is 100 wt.%.

Description

THERMOPLASTIC COMPOSITION

The present invention relates to a thermoplastic composition. The invention further relates to articles comprising or consisting such composition such as automotive articles.

Noise reduction is an important issue for the automotive industry. When two materials slide over each other, "squeaking" sound may be heard. Such sounds are not always desirable and accordingly the industry has developed several approaches. One solution is to apply coatings, but this has a disadvantage that it is time-consuming and expensive.

Another approach is to use an additive for anti-squeak performance. For PC/ABS, HMB1903 commercially available from DuPont is a known such additive.

US2023/220196 discloses a polycarbonate blend having reduced disturbing noise. Ex 3 of US2023/220196 relates to a composition consisting of 65.66 wt% of polycarbonate, 24.80 wt% of ABS, 4.00 wt% of HMB1903, 0.10 wt% of heat stabilizer Irganox B900, 0.20 wt% of Irganox 1076, 0.74 wt% of pentaerythritol tetrastearate and 0.50 wt% of Black Pearls 800.

WO2015/098832 discloses a composition suitable for use in automobile parts and having reduced occurrence of squeaking, the composition comprising polycarbonate, a rubber-reinforced aromatic vinyl resin, a polyethylene wax and a compatibilizer.

JP2023084498 discloses a composition suitable for use in automobile parts and having reduced occurrence of squeaking, the composition comprising polycarbonate, ABS, a polyethylene wax and a compatibilizer.

US5266634 discloses a composition comprising polycarbonate, ABS, a polyolefin graft polymer and a terpolymer comprising 50 to 98.5% by weight of an olefin, 0.5 to 10% by weight of an unsaturated dicarboxylic anhydride and 1 to 40% by weight of an alkyl ester of an unsaturated carboxylic acid.

WO2022/036954 discloses a composition comprising a polycarbonate, ABS, LIHMWPE, an antiviral agent and a compatibilizer. EP4006105 discloses a polycarbonate/acrylonitrile butadiene styrene (ABS) composition comprising a compatibilizer and a toughening agent.

It is an objective of the present invention to provide a thermoplastic composition having a good anti-squeak property.

Accordingly, the invention provides a thermoplastic composition comprising, based on the weight of the composition:

A) polycarbonate,

B) at least one impact modifier,

C) from 0.1 - 10.0 wt.% of a polyolefin,

D) from 0.1 - 10.0 wt.% of an olefinic compatibilizer and

E) from 0.0 - 2.0 wt.% of further components, wherein the sum of the components A) - E) is 100 wt.%.

The invention further provides a thermoplastic composition comprising, based on the weight of the composition:

A) polycarbonate,

B) at least one impact modifier,

C) from 0.1 - 10.0 wt.% of a polyolefin,

D) from 0.1 - 10.0 wt.% of an olefinic compatibilizer and

E) from 0.0 - 2.0 wt.% of further components, wherein the sum of the components A) - E) is 100 wt.%, wherein the polyolefin C) is selected from the group consisting of low density polyethylene (LDPE), linear low density polyethylene (LLDPE), high density polyethylene (HDPE) and an elastomeric copolymer of ethylene and an a-olefin having 4 to 10 carbon atoms and combinations thereof, wherein the elastomeric copolymer is a random copolymer.

It was surprisingly found that the thermoplastic composition according to the invention has a good anti-squeak property. It was further surprisingly found that the thermoplastic composition according to the invention has good mechanical properties. This may be due to the combination of the polyolefin and the olefinic compatibilizer allowing a sufficiently homogeneous mixing of the polyolefin in the matrix of A) and B).

A) polycarbonate The thermoplastic composition according to the invention comprises polycarbonate. Preferably, the amount of polycarbonate in the thermoplastic composition is 20 to 80 wt%, for example 25 to 75 wt%, 30 to 70 wt%, 40 to 65 wt% or 45 to 60 wt%, with respect to the total composition.

Polycarbonate and its production methods are per se well-known and is further described in detail e.g. in WO2014130751 , [0037]-[0082], incorporated herein by reference.

The polycarbonate in the polycarbonate composition can be one type of polycarbonate or a mixture of at least two polycarbonates which each may be a homopolymer or a copolymer. It is preferred that the polycarbonate is a polycarbonate homopolymer obtained by reacting a bisphenol, such as bisphenol A, with a carbonate source such as phosgene or a diarylcarbonate such as diphenyl carbonate. Accordingly the polycarbonate of the composition according to the invention may be prepared using the so called interfacial process, wherein BPA reacts with phosgene, or may be prepared by means of the so-called melt or direct transesterification process, wherein BPA reacts with diphenyl carbonate. These two types of polycarbonate are known to the skilled person and may be further referred to herein as interfacial polycarbonate and melt polycarbonate. The skilled person knows that these two types of polycarbonate differ in amount of Fries branching, which only exists in melt polycarbonate and further in the terminal hydroxyl content, which is typically much lower for interfacial polycarbonate.

It is preferred that the polycarbonate is obtained via the interfacial process for the reason that said process, compared to the melt process, typically provides polycarbonate with a low number of hydroxyl chain ends. A low amount of hydroxyl chain ends is advantageous for heat stability and color retention of the polycarbonate. Nonetheless, in some preferred embodiments of the present invention, the polycarbonate is a polycarbonate obtained via the melt process, i.e. melt polycarbonate. In some embodiments the polycarbonate is a mixture of at least one polycarbonate obtained via the interfacial process and at least one polycarbonate obtained with the melt process. In such an embodiment the amount of melt polycarbonate may be from 30 - 70 wt.% and the amount of interfacial polycarbonate from 70 - 30 wt.%, based on the combined weight of the melt polycarbonate and the interfacial polycarbonate. The polycarbonate may comprise or consist of interfacial polycarbonate. It is preferred that the interfacial polycarbonate is prepared by reacting bisphenol A and phosgene. Accordingly it is preferred that the polycarbonate is a bisphenol A polycarbonate or a bisphenol A polycarbonate homopolymer.

Preferably, the polycarbonate, or mixture of polycarbonates, has a melt flow rate according to ISO1133-1 :2011 at 300 °C and 1.2 kg of from 3.0 to 35 g/10min, preferably from 6.0 to 25 g/10min, more preferably from 14 to 21 g/10min.

In some preferred embodiments, the thermoplastic composition comprises a first polycarbonate having a melt flow rate according to ISO1133-1:2011 at 300 °C and 1.2 kg of 3.0 to 15 g/10min and a second polycarbonate having a melt flow rate according to ISO1133-1 :2011 at 300 °C and 1.2 kg of 20 to 35 g/10min.

A specific example of polycarbonate in the thermoplastic composition is a mixture consisting of bisphenol A polycarbonate homopolymer and a polycarbonatepolysiloxane copolymer.

In some embodiments, the polycarbonate comprises post-consumer recycled (PCR) polycarbonate or post-industrial recycled (PIR) polycarbonate.

B) impact modifier

The thermoplastic composition according to the invention comprises an impact modifier. Preferably, the amount of the impact modifier in the thermoplastic composition is 1.0 to 30 wt %, for example 3.0 to 25 wt % or 4.0 to 20 wt %, with respect to the total composition.

These impact modifiers include elastomer-modified graft copolymers comprising (i) an elastomeric (i.e. , rubbery) polymer substrate having a Tg less than or equal to 10° C., more specifically less than or equal to -10° C., or more specifically -40° to -80° C., and (ii) a rigid polymeric superstrate grafted to the elastomeric polymer substrate. As is known, elastomer-modified graft copolymers can be prepared by first providing the elastomeric polymer, then polymerizing the constituent monomer(s) of the rigid phase in the presence of the elastomer to obtain the graft copolymer. The grafts can be attached as graft branches or as shells to an elastomer core. The shell can merely physically encapsulate the core, or the shell can be partially or essentially completely grafted to the core. Preferably, the impact modifier is selected from the group consisting of styrene- butadiene-styrene (SBS), styrene-butadiene (SBR), styrene-ethylene-butadiene- styrene (SEBS), acrylonitrile-butadiene-styrene (ABS), acrylonitrile-ethylene-propylene- diene-styrene (AES), styrene-isoprene-styrene (SIS), methyl methacrylate-butadiene (MB) and methyl methacrylate-butadiene-styrene (MBS) and combinations of at least two of the foregoing copolymers. Preferably, the impact modifier is ABS.

ABS and its preparation methods are well-known and are described e.g. in US5717021.

Three major processes which can be used to prepare ABS include emulsion, bulk/mass and suspension polymerization or combinations thereof.

The emulsion polymerization of ABS is a two step process involving polymerization of butadiene to form a rubber latex, followed by addition and polymerization of acrylonitrile and styrene during which grafting to the rubber and production of the SAN (styreneacrylonitrile) continuous phase takes place. The rubber content of an ABS graft when made in emulsion may range from 10 to 90 weight percent and the SAN will be grafted from 10 to 90 weight percent of the ABS graft composition. The ratio of the styrene to acrylonitrile ranges from 50:50 to 85:15. When made in emulsion, the rubber latex will have a particle size ranging from about 0.15 to about 0.8 microns by weight, preferable 0.3 microns. Compositionally, the rubber phase may be comprised of polybutadiene, styrene-butadiene or butadiene-acrylonitrile copolymers, polyisoprene, EPM (ethylene/propylene rubbers), EPDM rubbers (ethylene/propylene/diene rubbers containing as diene, a nonconjugated diene such as hexadiene-(1 ,5) or norbornadiene in small quantities) and crosslinked alkylacrylate rubbers based on Ci -

Cs alkylacrylates, in particular ethyl, butyl and ethylhexylacrylate. One or more rubber grafted resins from about 10 to 90 and about 90 to 10 weight percent may also be used. The latex emulsion is broken and the ABS is recovered at the end of the polymerization.

In the bulk process, the polymerization is carried out in styrene/acrylonitrile monomer rather than in water. Instead of making the rubber, a pre-produced rubber is dissolved in the monomer solution. The rubber-monomer solution is then fed into the reactors and grafting/polymerization is carried out. When produced via a bulk or bulksuspension process, the soluble rubber will range from 5 to 25 weight percent and the dispersed rubbery phase will have a diameter ranging from about 0.5 microns to about 10 microns. A large weight percent of the free SAN phase is present depending upon the amount of rubber employed.

In place of styrene and acrylonitrile monomers used in the grafted or free rigid resins, monomers such as, a methyl styrene, para-methyl styrene, mono, di or tri halo styrene, alkyl methacrylates, alkyl acrylates, maleic anhydride, methacrylonitrile, maleimide, N- alkyl maleimide, N-aryl maleimide or the alkyl or halo substituted N-aryl maleimides may be replaced for the styrene or acrylonitrile or added to.

Like the bulk process, suspension polymerization uses rubber dissolved in the monomer solution, but after polymerizing SAN to low conversions, the rubber/SAN/monomer mixture is suspended in water and the polymerization is completed.

Preferably, the total amount of A) and B) with respect to the total composition is 90.0 to 98.5 wt%.

The thermoplastic composition according to the invention comprises a polyolefin. The amount of the polyolefin in the thermoplastic composition is 0.1 to 10.0 wt%, preferably 0.5 to 7.5 wt%, more preferably 1.0 to 5.0 wt%, with respect to the total composition.

Examples of the polyolefin include low density polyethylene (LDPE), linear low density polyethylene (LLDPE), high density polyethylene (HDPE), ultrahigh molecular weight polyethylene (UHMwPE) and an elastomeric copolymer of ethylene and an a-olefin having 4 to 10 carbon atoms and combinations thereof.

Preferably, the polyolefin has a density of e.g. 0.850 to 0.970 g/cm³ determined according to ISO1183.

LDPE, LLDPE and HDPE

The production processes of LDPE, LLDPE and HDPE are summarised in Handbook of Polyethylene by Andrew Peacock (2000; Dekker; ISBN 0824795466) at pages 43- 66. The catalysts can be divided in three different subclasses including Ziegler Natta catalysts, Phillips catalysts and single site catalysts. The latter class is a family of different classes of compounds, metallocene catalysts being one of them. As elucidated at pages 53-54 of said Handbook a Ziegler-Natta catalysed polymer is obtained via the interaction of an organometallic compound or hydride of a Group l-lll metal with a derivative of a Group IV-VIII transition metal. An example of a (modified) Ziegler-Natta catalyst is a catalyst based on titanium tetra chloride and the organometallic compound triethylaluminium. A difference between metallocene catalysts and Ziegler Natta catalysts is the distribution of active sites. Ziegler Natta catalysts are heterogeneous and have many active sites. Consequently polymers produced with these different catalysts will be different regarding for example the molecular weight distribution and the comonomer distribution.

LDPE

In some preferred embodiments, the polyolefin in the composition according to the invention comprises or is LDPE. The LDPE may be an ethylene homopolymer or may comprise a comonomer, for example butene or hexene.

Preferably, the LDPE has a density of 0.916 to 0.940 g/cm³, more preferably 0.920 to 0.930 g/cm³, determined according to ISO1183.

Preferably, the LDPE has a Melt flow index of 0.1 to 10.0 g/10 min, more preferably 1 .0 to 5.0 g/10 min, determined according to ASTM D1238 (190°C/2.16kg).

The LDPE may be produced by use of autoclave high pressure technology or by tubular reactor technology.

LLDPE

In some preferred embodiments, the polyolefin in the composition according to the invention comprises or is LLDPE. The LLDPE may be an ethylene homopolymer or may be a polyethylene copolymer comprising ethylene and a C3-C10 alpha-olefin comonomer (ethylene-alpha olefin copolymer). Suitable alpha-olefin co monomers include 1 -butene, 1 -hexene, 4-methyl pentene and 1 -octene. The preferred comonomer is 1 -hexene. Preferably, the alpha- olefin comonomer is present in an amount of about 5 to about 20 percent by weight of the ethylene-alpha olefin copolymer, more preferably an amount of from about 7 to about 15 percent by weight of the ethylene-alpha olefin copolymer.

Preferably, the density of the LLDPE may range between 0.915 g/cm³ and 0.940 g/cm³, preferably 0.930 to 0.940 g/cm³, determined according to ISO1183. Preferably, the melt flow index of the LLDPE ranges from 0.1 to 5.0 g/10min, for example from 0.5 to 4.0 g/10 min, for example from 1.0 to 3.0 g/10 min, determined according to ASTM D1238 (190°C/2.16kg).

The technologies suitable for the LLDPE manufacture include but are not limited to gas-phase fluidized-bed polymerization, polymerization in solution, and slurry polymerization.

According to a preferred embodiment of the present invention the LLDPE has been obtained by gas phase polymerization in the presence of a Ziegler-Natta catalyst. According to another preferred embodiment, the LLDPE may be obtained by gas phase polymerization in the presence of a metallocene catalyst.

HDPE

In some preferred embodiments, the polyolefin in the composition according to the invention comprises or is HDPE. This results in a greatly improved squeaking property.

HDPE may be an ethylene homopolymer or may comprise a comonomer, for example butene or hexene.

Preferably, the HDPE has a density of 0.940 to 0.970 g/cm³, more preferably 0.950 to 0.965 g/cm³, more preferably 0.952 to 0.960 g/cm³, determined according to ISO1183.

Preferably, the HDPE has a Melt flow index of 0.1 to 30.0 g/10 min, for example 0.1 to 5.0 g/10 min or 5.0 to 30.0 g/10 min, measured according to ASTM D1238 (190 °C/5 kg). Preferably, the HDPE has a Melt flow index of 5.0 to 30.0 g/10 min or 10.0 to 25.0 g/10min measured according to ASTM D1238 (190 °C/5 kg). Use of HDPE with such MFI was found to greatly improve the squeaking property.

UHMwPE

In some preferred embodiments, the polyolefin in the composition according to the invention comprises or is UHMwPE. The production processes of UHMwPE is well- known and is described e.g. in EP2791182 and documents cited therein. UHMwPE typically has a molecular mass of between 2 and 8 million.

Elastomeric copolymer In some preferred embodiments, the polyolefin in the composition according to the invention comprises or is an elastomeric copolymer of ethylene and an a-olefin having 4 to 10 carbon atoms. This results in an improved squeaking property and a high impact strength at low temperature.

The polyolefin may be an elastomeric copolymer of ethylene and an a-olefin having 4 to 10 carbon atoms. The a-olefin comonomer in the elastomeric copolymer is preferably an acyclic monoolefin such as 1-butene, 1-pentene, 1-hexene, 1-octene or 4-methylpentene. Most preferably, the elastomeric copolymer is an ethylene- 1-octene copolymer.

Preferably, the elastomeric copolymer is a random copolymer.

Preferably, the elastomeric copolymer has a density of 0.850 to 0.910 g/cm³ according to ASTM D792. Preferably, the density of the elastomeric copolymer is 0.865 to 0.910 g/cm³, for example 0.865 to 0.875 g/cm³, according to ASTM D792. Preferably, the elastomeric copolymer has a melt flow index of 1.0 to 50.0 dg/min, for example 1.0 to 10.0 dg/min or 10.0 to 50.0 dg/min, measured in accordance with ASTM D1238 using a 2.16 kg weight and at a temperature of 190 °C.

The elastomers (elastomeric copolymers) may be prepared using methods known in the art, for example by using a single site catalyst, i.e. , a catalyst the transition metal components of which is an organometallic compound and at least one ligand of which has a cyclopentadienyl anion structure through which such ligand bondingly coordinates to the transition metal cation. This type of catalyst is also known as "metallocene" catalyst. Metallocene catalysts are for example described in U.S. Patent Nos. 5,017,714 and 5,324,820. The elastomer s may also be prepared using traditional types of heterogeneous multi-sited Ziegler-Natta catalysts.

Preferably, the amount of ethylene in the elastomer (elastomeric copolymers) is at least 50 mol%. More preferably, the amount of ethylene in the elastomer is at least 57 mol%, for example at least 60 mol %, at least 65 mol% or at least 70 mol%. Even more preferably, the amount of ethylene in the elastomer is at least 75 mol%. The amount of ethylene in the elastomer may typically be at most 97.5 mol%, for example at most 95 mol% or at most 90 mol%. Preferably, the polyolefin C) is selected from the group consisting of low density polyethylene (LDPE), linear low density polyethylene (LLDPE), high density polyethylene (HDPE) and an elastomeric copolymer of ethylene and an a-olefin having 4 to 10 carbon atoms and combinations thereof.

Preferably, the polyolefin C) is selected from the group consisting of low density polyethylene (LDPE), linear low density polyethylene (LLDPE), high density polyethylene (HDPE) and an elastomeric copolymer of ethylene and an a-olefin having 4 to 10 carbon atoms and combinations thereof, wherein the elastomeric copolymer is a random copolymer.

Preferably, the polyolefin C) is selected from the group consisting of low density polyethylene (LDPE), linear low density polyethylene (LLDPE), high density polyethylene (HDPE) and an elastomeric copolymer of ethylene and an a-olefin having 4 to 10 carbon atoms and combinations thereof, wherein the elastomeric copolymer is a random copolymer and has a density of 0.850 to 0.910 g/cm³, for example 0.865 to 0.875 g/cm³, according to ASTM D792.

D) olefinic compatibiliser

The thermoplastic composition according to the invention comprises an olefinic compatibilizer. The amount of the olefinic compatibilizer in the thermoplastic composition is 0.1 to 10 wt%, preferably 0.3 to 5.0 wt%, more preferably 0.5 to 3.0 wt%, with respect to the total composition.

Preferably, the olefinic compatibilizer is a functionalized polyolefin which is a polyolefin made by copolymerizing olefin and an unsaturated monomer containing epoxy, carboxyl or acid anhydride group or a polyolefin to which an unsaturated monomer containing epoxy, carboxyl or acid anhydride group is grafted. The polyolefin made by copolymerizing olefin and an unsaturated monomer containing epoxy, carboxyl or acid anhydride group consists of units derived from the olefin and units derived from the unsaturated monomer. The polyolefin to which an unsaturated monomer containing epoxy, carboxyl or acid anhydride group is grafted has a main chain consisting of units derived from olefin and side chains of the unsaturated monomer grafted to the main chain. Thus, the functionalized polyolefin is not grafted with styrene (co)polymers or acrylate (co)polymers.

Preferably, olefinic compatibilizer is a functionalized polyolefin which is a polyolefin made by copolymerizing ethylene and an unsaturated monomer containing epoxy, carboxyl or acid anhydride group, a polyethylene to which an unsaturated monomer containing epoxy, carboxyl or acid anhydride group is grafted, a polyolefin made by copolymerizing ethylene and an a-olefin having 4 to 10 carbon atoms and an unsaturated monomer containing epoxy, carboxyl or acid anhydride group, or an elastomeric copolymer of ethylene and an a-olefin having 4 to 10 carbon atoms to which an unsaturated monomer containing epoxy, carboxyl or acid anhydride group is grafted.

Exemplary epoxy-containing unsaturated monomers include glycidyl methacrylate, butylglycidyl malate, butylglycidyl fumarate, propylglycidyl malate, glycidyl acrylate, N- [4-(2,3-epoxypropoxy)-3,5-dimethylbenzyl]-acrylamide, and the like. Among these, beneficial embodiments include glycidyl methacrylate and N-[4-(2,3-epoxypropoxy)-3,5- dimethylbenzyl]acrylamide.

Exemplary carboxyl-containing unsaturated monomers include acrylic acid, methacrylic acid, maleic acid, and the like.

Exemplary unsaturated monomers containing an acid anhydride group are maleic anhydride, itaconic anhydride, citraconic anhydride, and the like. Beneficial embodiments include acrylic acid and maleic anhydride.

Preferably, the unsaturated monomer is selected from glycidyl methacrylate (GMA), methacrylic acid (EMA), maleic anhydride (MAH) and styrene-acrylonitrile (SAN).

Most preferably, the compatibilizer is a copolymer of ethylene and glycidyl methacrylate, a copolymer of ethylene and methacrylic acid, or a maleic anhydride grafted polyethylene.

(E) further components

The thermoplastic composition of the present invention may optionally include further components such as additives which do not interfere with the previously mentioned desirable properties but enhance other favorable properties. Optional additives that may be compounded or blended into the composition of the invention in customary amounts include inert inorganic pigments, dyestuffs, lubricants, UV absorbers, UV stabilizers, anti-oxidants, anti-ozonants, stabilizers, stain- proofing agents, anti-static additives, anti-microbial agents, melt viscosity enhancers, impact modifiers, quenchers, processing aids, and the like. The different additives that can be incorporated in the compositions are commonly used and known to one skilled in the art. Illustrative descriptions of such additives may be found in R. Gachter and H. Muller, Plastics Additives Handbook, 6th edition, 2009.

The further components may comprise a mold release agent, which may also be referred to as a lubricant or a plasticizer. Examples include phthalic acid esters such as dioctyl-4,5-epoxy-hexahydrophthalate; tris-(octoxycarbonylethyl)isocyanurate; tristearin; di- or polyfunctional aromatic phosphates such as resorcinol tetraphenyl diphosphate (RDP), the bis(diphenyl)phosphate of hydroquinone and the bis(diphenyl)phosphate of bisphenol-A; poly-alpha-olefins; epoxidized soybean oil; silicones, including silicone oils; esters, for example, fatty acid esters such as alkyl stearyl esters, e.g., methyl stearate; stearyl stearate, pentaerythritol tetrastearate, and the like; mixtures of methyl stearate and hydrophilic and hydrophobic nonionic surfactants comprising polyethylene glycol polymers, polypropylene glycol polymers, and copolymers thereof, e.g., methyl stearate and polyethylene-polypropylene glycol copolymers in a suitable solvent; waxes such as beeswax, montan wax, paraffin wax or the like.

In some preferred embodiments, the mold release agent is poly-alpha-olefin or pentaerythritol tetrastearate or combination thereof. Preferably, the amount of mould release agent is from 0.1 - 1.0 wt.% with respect to the thermoplastic composition.

The further components may comprise a flame retardant additive. Preferably, the flame retardant additive is selected from the group consisting of potassium perfluorobutane sulfonate, sodium toluene-sulfonate and potassium diphenyl sulfone sulfonate.

The further components may comprise an anti-drip agent, for example polytetrafluoroethylene (PTFE) or polytetrafluoroethylene (PTFE)-encapsulated styrene-acrylonitrile copolymer (TSAN).

In some embodiments, the thermoplastic composition does not comprise or substantially does not comprise an anti-drip agent such as polytetrafluoroethylene (PTFE) or polytetrafluoroethylene (PTFE)-encapsulated styrene-acrylonitrile copolymer (TSAN). If present, the content of anti-drip agent in the thermoplastic composition may e.g. be less than 0.1 wt%, less than 0.05 wt%, less than 0.01 wt%, less than 0.005 wt% with respect to the thermoplastic composition.

The amount of the further components in the thermoplastic composition is 0.0 to 2.0 wt%, for example 0.1 to 1.0 wt%, with respect to the total composition.

Preferably, the thermoplastic composition according to the invention has a melt flow rate according to ISO1133-1 :2011 at 260 °C and 5 kg of from 3.0 to 35 g/10min, preferably from 6.0 to 30 g/10min, more preferably from 14 to 25 g/10min.

The invention further provides a process for making the thermoplastic composition according to the invention comprising melt-mixing components A)-E) e.g. in an extruder.

The invention further provides an article comprising or consisting of the thermoplastic composition according to the invention. Preferably, the article is automotive interior or exterior article, for example selected from the group consisting of door hinge, ventilator, console box & seat, and a screen bezel, a screen frame or a frame for electronic components, for example an infotainment panel or electronics screen framework.

The article may be obtained by molding the composition of the invention, such as by injection molding. The article may also be obtained by extrusion followed by thermoforming.

The invention further provides use of a combination of a polyolefin and an olefinic compatibilizer for improving an anti-squeak property of a thermoplastic composition, wherein the thermoplastic composition comprises, based on the weight of the composition:

A) polycarbonate,

B) at least one impact modifier,

C) from 1.0 - 10.0 wt.% of the polyolefin,

D) from 0.5 - 10.0 wt.% of the olefinic compatibilizer and

E) from 0.0 - 2.0 wt.% of further components, wherein the sum of the components A) - E) is 100 wt.%. It is noted that the invention relates to the subject-matter defined in the independent claims alone or in combination with any possible combinations of features described herein, preferred in particular are those combinations of features that are present in the claims. It will therefore be appreciated that all combinations of features relating to the composition according to the invention; all combinations of features relating to the process according to the invention and all combinations of features relating to the composition according to the invention and features relating to the process according to the invention are described herein.

It is further noted that the term ‘comprising’ does not exclude the presence of other elements. However, it is also to be understood that a description on a product/composition comprising certain components also discloses a product/composition consisting of these components. The product/composition consisting of these components may be advantageous in that it offers a simpler, more economical process for the preparation of the product/composition. Similarly, it is also to be understood that a description on a process comprising certain steps also discloses a process consisting of these steps. The process consisting of these steps may be advantageous in that it offers a simpler, more economical process.

When values are mentioned for a lower limit and an upper limit for a parameter, ranges made by the combinations of the values of the lower limit and the values of the upper limit are also understood to be disclosed.

The invention is now elucidated by way of the following examples, without however being limited thereto.

Compounding and injection moulding

Compositions of Table 5 were prepared and various properties were measured according to test methods of Table 1. All ingredients were dry blended for 3-5 minutes in a super-floater. The resins were pre-dried at 100°C for about 4hrs before extrusion. The blends were added at the throat feeder. Formulations were compounded on a 37mm Toshiba twin-screw. The details of conditions of extrusion and moulding are in Table 2 and Table 3. Table 1. Testing methods and standards

Table 2. Extrusion profile of PC/ABS blends resin Table 3. Molding profile of PC/ABS blends resin

Table 4. Raw materials details

Table 5 summarizes the formulations and test results of PC/ABS compositions. The anti-squeak performance was tested by a Ziegler Stick-Slip testing machine under two loading force (10N and 40N) at testing speed of 1mm/S. The testing result of risk priority number (RPN) value is a measure of the risk for generating noise. Number 1, 2, 3 represents low risk, 4 and 5 means medium risk whereas 6 to 10 indicates high risk. Table 5. Formulations and test results The RPN value of the PC/ABS composition (C1) is high under both low loading condition and high loading condition, hence it shows poor anti-squeak performance. Use of the commercial additives (C2, C3) resulted in reducing the noise generation risk at low loading force (10 N), but showed no effect under high loading force (40N). Moreover, the samples with commercial additives (C2 &C3) showed obvious drop of ductility compared to the PC/ABS composition of C1 at room temperature and low temperature at -30 °C.

The RPN values of the PC/ABS compositions according to the invention (E1, E2, E3) are not more than 3 under both loading conditions, revealing significantly improved anti-squeak performance compared to the PC/ABS composition of C1.

The impact property of the PC/ABS compositions according to the invention (E1 , E2, E3) is comparable to or better than the PC/ABS composition of C1. In particular, E3 shows particularly high impact strength at low temperature. The processing ability (MFR) and thermal stability (HDT) of the PC/ABS compositions according to the invention (E1 , E2, E3) are comparable to the PC/ABS composition of C1.

Claims

1 . A thermoplastic composition comprising, based on the weight of the composition:

A) polycarbonate,

B) at least one impact modifier,

C) from 1.0 - 10.0 wt.% of a polyolefin,

D) from 0.5 - 10.0 wt.% of an olefinic compatibilizer and

E) from 0.0 - 2.0 wt.% of further components, wherein the sum of the components A) - E) is 100 wt.%.

2. The thermoplastic composition according to claim 1 , wherein the polycarbonate is a bisphenol A polycarbonate or a bisphenol A polycarbonate homopolymer.

3. The thermoplastic composition according to any one of the preceding claims, wherein the polycarbonate comprises a first polycarbonate having a melt flow rate according to ISO1133-1 :2011 at 300 °C and 1.2 kg of 3 to 15 g/10min and a second polycarbonate having a melt flow rate according to ISO1133-1 :2011 at 300 °C and

1.2 kg of 20 to 35 g/1 Omin.

4. The thermoplastic composition according to any one of the preceding claims, wherein the polycarbonate comprises post-consumer recycled (PCR) polycarbonate or post-industrial recycled (PIR) polycarbonate.

5. The thermoplastic composition according to any one of the preceding claims, wherein the impact modifier is selected from the group consisting of styrene- butadiene-styrene (SBS), styrene-butadiene (SBR), styrene-ethylene-butadiene- styrene (SEBS), acrylonitrile-butadiene-styrene (ABS), acrylonitrile-ethylene- propylene-diene-styrene (AES), styrene-isoprene-styrene (SIS), methyl methacrylate-butadiene (MB) and methyl methacrylate-butadiene-styrene (MBS) and combinations of at least two of the foregoing copolymers.

6. The thermoplastic composition according to any one of the preceding claims, wherein the polyolefin is selected from the group consisting of low density polyethylene (LDPE), linear low density polyethylene (LLDPE), high density polyethylene (HDPE) and an elastomeric copolymer of ethylene and an a-olefin having 4 to 10 carbon atoms and combinations thereof, wherein the elastomeric copolymer is a random copolymer.

7. The thermoplastic composition according to any one of the preceding claims, wherein the polyolefin is a high density polyethylene (HDPE) or an elastomeric copolymer of ethylene and an a-olefin having 4 to 10 carbon atoms, preferably wherein the elastomeric copolymer is a random copolymer.

8. The thermoplastic composition according to any one of the preceding claims, wherein the polyolefin comprises or is high density polyethylene (HDPE) having a melt flow index of 5.0 to 30.0 g/10 min or 10.0 to 25.0 g/10min measured according to ASTM D 1238 (190 °C/5 kg).

9. The thermoplastic composition according to any one of the preceding claims, wherein the polyolefin comprises or is an elastomeric copolymer of ethylene and an a-olefin having 4 to 10 carbon atoms, wherein the density of the elastomeric copolymer is 0.865 to 0.910 g/cm³, for example 0.865 to 0.875 g/cm³, according to ASTM D792, preferably wherein the elastomeric copolymer is a random copolymer.

10. The thermoplastic composition according to any one of the preceding claims, wherein the olefinic compatibilizer is a polyolefin made by copolymerizing olefin and an unsaturated monomer containing epoxy, carboxyl or acid anhydride group or a polyolefin to which an unsaturated monomer containing epoxy, carboxyl or acid anhydride group is grafted.

11. The thermoplastic composition according to claim 10, wherein the unsaturated monomer is selected from the group consisting of glycidyl methacrylate (GMA), methyl acrylate (MA), maleic anhydride (MAH) and styrene-acrylonitrile (SAN), preferably wherein the compatibilizer is a copolymer of ethylene and glycidyl methacrylate, a copolymer of ethylene and methacrylic acid, or a maleic anhydride grafted polyethylene.

12. The thermoplastic composition according to any one of the preceding claims, wherein the further components comprise a mold release agent, preferably wherein the amount of the mold release agent is 0.1 to 1.0 wt% with respect to the thermoplastic composition.

13. The thermoplastic composition according to any one of the preceding claims, wherein the amount of the polycarbonate is 20 to 80 wt%, the amount of the impact modifier is 1.0 to 30 wt%, the amount of the polyolefin is 1.0 to 5.0 wt%, the amount of the olefinic compatibilizer is 0.5 to 3.0 wt%, with respect to the total composition.

14. An article comprising or consisting of the thermoplastic composition according to any one of the preceding claims.

15. The article according to claim 14, wherein the article is an automotive interior or exterior article, for example selected from the group consisting of door hinge, ventilator, console box & seat, and a screen bezel, a screen frame or a frame for electronic components, for example an infotainment panel or electronics screen framework.

16. Use of a combination of a polyolefin and an olefinic compatibilizer for improving an anti-squeak property of a thermoplastic composition, wherein the thermoplastic composition comprises, based on the weight of the composition:

A) polycarbonate,

B) at least one impact modifier,

C) from 1.0 - 10.0 wt.% of the polyolefin,

D) from 0.5 - 10.0 wt.% of the olefinic compatibilizer and

E) from 0.0 - 2.0 wt.% of further components, wherein the sum of the components A) - E) is 100 wt.%.