Flame-retardant composition containing high melting strength polypropylene

Abstract

The present invention relates to a propylene polymer (PP), a nitrogen-containing flame retardant (FR), and a flame retardant strength determined according to ISO 16790:2005 of at least 20 cN. 30 and a sag-preventing agent (A) that is a high melt strength polypropylene (HMS-PP) having a melt strength of at least 20 cN. 30 The present invention relates to the use of a high melt strength polypropylene (HMS-PP) having melt strength as an anti-sag agent, and to an article comprising the flame retardant polypropylene composition (C).

Description

Technical Field

[0001] The present invention relates to a flame-retardant polypropylene composition (C) comprising a propylene polymer (PP), a nitrogen-containing flame retardant (FR), and a droop inhibitor (A) which is a high-melt-strength polypropylene (HMS-PP) having a melt strength of at least 20 cN as determined according to ISO 16790:2005. Further, the present invention relates to the use of a high-melt-strength polypropylene (HMS-PP) having a melt strength of at least 20 cN as determined according to ISO 16790:2005 as a droop inhibitor, and to an article comprising the flame-retardant polypropylene composition (C). 30 The present invention relates to a flame-retardant polypropylene composition (C) comprising a propylene polymer (PP), a nitrogen-containing flame retardant (FR), and a droop inhibitor (A) which is a high-melt-strength polypropylene (HMS-PP) having a melt strength of at least 20 cN as determined according to ISO 16790:2005. Further, the present invention relates to the use of a high-melt-strength polypropylene (HMS-PP) having a melt strength of at least 20 cN as determined according to ISO 16790:2005 as a droop inhibitor, and to an article comprising the flame-retardant polypropylene composition (C). 30 The present invention relates to the use of a high-melt-strength polypropylene (HMS-PP) having a melt strength of at least 20 cN as determined according to ISO 16790:2005 as a droop inhibitor, and to an article comprising the flame-retardant polypropylene composition (C).

Background Art

[0002] In electrical applications, certain flame-retardant requirements are demanded. Most commonly, a UL94 V0 rating with a specimen thickness of 1.6 mm or less must be achieved. Further, since it is environmentally friendly, a halogen-free type is preferred.

[0003] As part of the next UL94 rating of the combustion behavior controlled by a flame-retardant additive, the dripping behavior needs to be controlled. For this purpose, polytetrafluoroethylene (PTFE) is typically used in a total amount of 0.2 to 0.3% by weight, mainly for unfilled or low-filled polypropylene grades. According to regulations, a flame-retardant material combined with PTFE is still considered to be halogen-free, but in fact, a small amount of halogen still remains in the formulation. In addition, REACH restrictions aimed at restricting the production, market shipment and use of all perfluoroalkyl compounds and polyfluoroalkyl compounds (PFAS) in the EU have been proposed. Therefore, fluoropolymers are being considered for the possibility of restriction.

Summary of the Invention

Problems to be Solved by the Invention

[0004] Therefore, it is interesting to replace the PTFE in the flame-retardant polypropylene formulation and still meet the above-mentioned flame-retardant requirements. In other words, the object of the present invention is to provide a halogen-free flame-retardant polypropylene composition.

Means for Solving the Problems

[0005] Accordingly, the present invention provides a flame-retardant polypropylene composition (C) comprising, based on the total weight of the flame-retardant polypropylene composition (C), i) 23.0 to 80.0% by mass of a propylene polymer (PP), ii) 10.0 to 40.0% by weight of a nitrogen-containing flame retardant (FR), iii) 10.0 to 37.0% by weight of a sag prevention agent (A) which is a high melt strength polypropylene (HMS-PP) having an F 30 melt strength of at least 20 cN as determined according to ISO 16790:2005, iv) 0.0 to 15.0% by weight of carbon black (CB) and does not contain glass fibers, and is directed to a flame-retardant polypropylene composition (C).

[0006] According to one embodiment of the present invention, the propylene polymer (PP) is a) a matrix (M) which is a polymer of propylene, b) an elastomer (E) which is a copolymer containing units derived from propylene and ethylene and / or C4-C8 α-olefins and is a heterophasic propylene copolymer (HECO).

[0007] The present invention provides a flame-retardant polypropylene composition (C) comprising i) a propylene polymer (PP) which is a heterophasic propylene copolymer (HECO), a) a matrix (M) which is a polymer of propylene, and b) An elastomer (E) which is a copolymer containing units derived from propylene and ethylene and / or C4-C8 α-olefins A propylene polymer (PP) containing ii) A nitrogen-containing flame retardant (FR); iii) A dripping inhibitor (A) which is a high melt strength polypropylene (HMS-PP) having an ISO 16790:2005 determined F melt strength of at least 20 cN 30 ; and iv) Optionally, carbon black (CB) The flame-retardant polypropylene composition (C) is also directed to.

[0008] The flame-retardant polypropylene composition (C) is based on the total weight of the flame-retardant polypropylene composition (C): i) 20.0 to 65.0% by weight of propylene polymer (PP); ii) 10.0 to 40.0% by weight of nitrogen-containing flame retardant (FR); iii) 10.0 to 40.0% by weight of dripping inhibitor (A); iv) 0.0 to 15.0% by weight of carbon black (CB) and preferably contains.

[0009] According to one embodiment of the present invention, the flame-retardant polypropylene composition (C) does not contain halogen.

[0010] According to another embodiment of the present invention, the total amount of the propylene polymer (PP), the nitrogen-containing flame retardant (FR), the dripping inhibitor (A) and optionally the carbon black (CB) constitutes at least 90% by weight of the flame-retardant polypropylene composition (C), preferably 100% by weight in total.

[0011] According to a further embodiment of the present invention, the nitrogen-containing flame retardant (FR) contains a first nitrogen-containing phosphate (FR1) and a second nitrogen-containing phosphate (FR2).

[0012] According to yet another embodiment of the present invention, the weight ratio of the first nitrogen-containing phosphate (FR1) to the second nitrogen-containing phosphate (FR2) is in the range of 60:40 to 40:60.

[0013] It is particularly preferred that the first nitrogen-containing phosphate (FR1) is melamine polyphosphate and the second nitrogen-containing phosphate (FR2) is piperazine pyrophosphate.

[0014] According to one embodiment of the present invention, the heterophasic propylene copolymer (HECO) i) has a comonomer content in the range of 4.0 to 17.0 mol%, preferably in the range of 6.0 to 10.0 mol%, and / or ii) has a cold xylene soluble part (XCS) in the range of 7.0 to 25.0 wt%, preferably in the range of 11.0 to 22.0 wt%, based on the total weight of the heterophasic propylene copolymer (HECO). has.

[0015] According to another embodiment of the present invention, the xylene soluble part (XCS) of the heterophasic propylene copolymer (HECO) i) has a comonomer content in the range of 25.0 to 65.0 mol%, preferably in the range of 40.0 to 45.0 mol%, and / or ii) has an intrinsic viscosity (IV) measured according to ISO1628 / 1 (135 °C in decalin) of less than 3.5 dl / g, preferably in the range of 2.4 to 3.4 dl / g. has.

[0016] According to a further embodiment of the present invention, the high melt strength polypropylene (HMS-PP) has a melt flow rate MFR2 (230 °C, 2.16 kg) determined according to ISO1133 in the range of 0.5 to 15.0 g / 10 min.

[0017] It is particularly preferred that the flame-retardant polypropylene composition (C) has a melt flow rate MFR2 (230 °C, 2.16 kg) determined according to ISO1133 in the range of 1.0 to 30.0 g / 10 min.

[0018] Furthermore, as an anti - sagging agent (A) for a composition containing a propylene polymer (PP) and a nitrogen - containing flame retardant (FR), an F determined according to ISO16790:2005 of at least 20 cN 30 Use of a high - melt - strength polypropylene (HMS - PP) having a melt strength, wherein a) the composition does not contain glass fibers and / or b) the propylene polymer (PP) is a heterophasic propylene copolymer (HECO) comprising a matrix (M) which is a polymer of propylene and an elastomer (E) which is a copolymer containing units derived from propylene and ethylene and / or C4 - C8 α - olefins is directed to use.

[0019] The present invention is also directed to an article comprising the above - mentioned flame - retardant polypropylene composition (C).

[0020] Hereinafter, the present invention will be described in more detail.

Embodiments for Carrying out the Invention

[0021] Flame - retardant polypropylene composition (C) The flame - retardant polypropylene composition (C) according to the present invention comprises a propylene polymer (PP), a nitrogen - containing flame retardant (FR), and an anti - sagging agent (A) which is a high - melt - strength polypropylene (HMS - PP) having an F determined according to ISO16790:2005 of at least 20 cN 30 and a melt strength.

[0022] According to a preferred embodiment of the present invention, the flame - retardant polypropylene composition (C) does not contain a fluoropolymer. In particular, it is preferred that the flame - retardant polypropylene composition (C) does not contain a fluoropolymer in an amount exceeding 0.5% by weight, more preferably exceeding 0.1% by weight, even more preferably exceeding 0.01% by weight, for example exceeding 0.001% by weight. It is particularly preferred that no fluoropolymer is used in the production of the flame - retardant polypropylene composition (C). As used herein, the term "fluoropolymer" refers to a polymeric compound containing fluorine atoms. Examples of fluoropolymers are poly(tetrafluoroethylene) (PTFE), tetrafluoroethylene-hexafluoropropylene copolymer (FEP), and polychlorotrifluoroethylene (PCTFE).

[0023] According to another preferred embodiment of the present invention, the flame-retardant polypropylene composition (C) does not contain halogen atoms. As used herein, the term "halogen" refers to the elements of Group 17 of the periodic table. Therefore, it is preferred not to use compounds containing halogen atoms in the production of the flame-retardant polypropylene composition (C).

[0024] According to one embodiment of the present invention, the flame-retardant polypropylene composition (C) does not contain glass fibers. In particular, the flame-retardant polypropylene composition (C) preferably does not contain glass fibers in an amount exceeding 0.5% by weight, more preferably exceeding 0.1% by weight, even more preferably exceeding 0.01% by weight, for example exceeding 0.001% by weight. It is particularly preferred not to use glass fibers in the production of the flame-retardant polypropylene composition (C).

[0025] According to the embodiment in which the flame-retardant polypropylene composition (C) does not contain glass fibers, the flame-retardant polypropylene composition (C) is based on the total weight of the flame-retardant polypropylene composition (C), i)) 23.0 to 80.0% by weight, more preferably 28.0 to 65.0% by weight, even more preferably 30.0 to 55.0% by weight, for example 35.0 to 50.0% by weight of a propylene polymer (PP), and ii) 10.0 to 40.0% by weight, more preferably 12.0 to 35.0% by weight, even more preferably 18.0 to 33.0% by weight, for example 22.0 to 30.0% by weight of a nitrogen-containing flame retardant (FR), and iii) 10.0 to 37.0% by weight, more preferably 12.0 to 36.0% by weight, even more preferably 15.0 to 32.0% by weight, for example 19.0 to 31.0% by weight of an anti-dripping agent (A) and contains.

[0026] The total amount of the propylene polymer (PP), the nitrogen-containing flame retardant (FR), and the anti-dripping agent (A) preferably constitutes at least 90% by weight of the flame-retardant polypropylene composition (C), more preferably 100% by weight in total.

[0027] According to one embodiment of the present invention, the flame-retardant polypropylene composition (C) further contains carbon black (CB). The flame-retardant polypropylene composition (C) according to this embodiment preferably contains, based on the total weight of the flame-retardant polypropylene composition (C), i) 23.0 to 65.0% by weight, more preferably 28.0 to 60.0% by weight, even more preferably 30.0 to 55.0% by weight, for example 35.0 to 50.0% by weight of the propylene polymer (PP), and ii) 10.0 to 40.0% by weight, more preferably 12.0 to 35.0% by weight, even more preferably 18.0 to 33.0% by weight, for example 22.0 to 30.0% by weight of the nitrogen-containing flame retardant (FR), and iii) 10.0 to 37.0% by weight, more preferably 12.0 to 36.0% by weight, even more preferably 15.0 to 32.0% by weight, for example 19.0 to 31.0% by weight of the anti-dripping agent (A), and iv) 0.01 to 15.0% by weight, more preferably 1.0 to 12.0% by weight, even more preferably 2.0 to 11.0% by weight, for example 3.0 to 10.0% by weight of the carbon black (CB) and contains.

[0028] In the embodiment where the flame-retardant polypropylene composition (C) contains carbon black (CB), the total amount of the propylene polymer (PP), the nitrogen-containing flame retardant (FR), the anti-dripping agent (A), and the carbon black (CB) preferably constitutes at least 90% by weight of the flame-retardant polypropylene composition (C), more preferably 100% by weight in total.

[0029] The flame-retardant polypropylene composition (C) according to the present invention may further contain additives (AD), such as acid scavengers, antioxidants, colorants, light stabilizers, slip agents, anti-scratch agents, dispersants, processing aids, lubricants, pigments, and the like.

[0030] Therefore, the flame-retardant polypropylene composition (C) is based on the total weight of the flame-retardant polypropylene composition (C), i) 23.0 to 64.99% by weight, more preferably 28.0 to 60.0% by weight, even more preferably 30.0 to 55.0% by weight, for example 35.0 to 50.0% by weight of a propylene polymer (PP), and ii) 10.0 to 40.0% by weight, more preferably 12.0 to 35.0% by weight, even more preferably 18.0 to 33.0% by weight, for example 22.0 to 30.0% by weight of a nitrogen-containing flame retardant (FR), and iii) 10.0 to 37.0% by weight, more preferably 12.0 to 36.0% by weight, even more preferably 15.0 to 32.0% by weight, for example 19.0 to 31.0% by weight of a dripping inhibitor (A), and iv) 0.01 to 15.0% by weight, more preferably 1.0 to 12.0% by weight, even more preferably 2.0 to 11.0% by weight, for example 3.0 to 10.0% by weight of carbon black (CB), and v) 0.01 to 5.0% by weight, more preferably 0.1 to 3.5% by weight, even more preferably 0.2 to 2.0% by weight, for example 0.3 to 1.0% by weight of additives (AD) and preferably contains, more preferably consists of these. The additives (AD) are described in more detail below.

[0031] In an embodiment where the flame-retardant polypropylene composition (C) contains additives (AD), the total amount of the propylene polymer (PP), nitrogen-containing flame retardant (FR), dripping inhibitor (A), optionally carbon black (CB) and additives (AD) preferably constitutes at least 90% by weight of the flame-retardant polypropylene composition (C), more preferably 100% by weight in total.

[0032] According to another embodiment of the present invention, the propylene polymer (PP) is a heterophasic propylene copolymer (HECO) containing a matrix (M) which is a polymer of propylene and an elastomer (E) which is a copolymer containing units derived from propylene and ethylene and / or C4-C8 α-olefins.

[0033] In an embodiment where the propylene polymer (PP) is a heterophasic propylene copolymer (HECO), the flame-retardant polypropylene composition (C) is based on the total weight of the flame-retardant polypropylene composition (C), i) 20.0 to 80.0% by weight, more preferably 28.0 to 65.0% by weight, even more preferably 30.0 to 55.0% by weight, for example 35.0 to 50.0% by weight of the propylene polymer (PP) which is a heterophasic propylene copolymer (HECO), and ii) 10.0 to 40.0% by weight, more preferably 12.0 to 35.0% by weight, even more preferably 18.0 to 33.0% by weight, for example 22.0 to 30.0% by weight of a nitrogen-containing flame retardant (FR), and iii) 10.0 to 40.0% by weight, more preferably 12.0 to 36.0% by weight, even more preferably 15.0 to 32.0% by weight, for example 19.0 to 31.0% by weight of a dripping inhibitor (A) and comprises.

[0034] It is preferable that the total amount of the propylene polymer (PP) which is a heterophasic propylene copolymer (HECO), the nitrogen-containing flame retardant (FR) and the dripping inhibitor (A) constitutes at least 90% by weight of the flame-retardant polypropylene composition (C), and more preferably the total is 100% by weight.

[0035] According to one embodiment of the present invention, the flame-retardant polypropylene composition (C) further contains carbon black (CB). The flame-retardant polypropylene composition (C) according to this embodiment preferably is based on the total weight of the flame-retardant polypropylene composition (C), i) 20.0 to 65.0 wt%, more preferably 28.0 to 60.0 wt%, even more preferably 30.0 to 55.0 wt%, for example 35.0 to 50.0 wt% of a propylene polymer (PP) which is a heterophasic propylene copolymer (HECO), ii) 10.0 to 40.0 wt%, more preferably 12.0 to 35.0 wt%, even more preferably 18.0 to 33.0 wt%, for example 22.0 to 30.0 wt% of a nitrogen-containing flame retardant (FR), iii) 10.0 to 40.0 wt%, more preferably 12.0 to 36.0 wt%, even more preferably 15.0 to 32.0 wt%, for example 19.0 to 31.0 wt% of an anti-dripping agent (A), iv) 0.01 to 15.0 wt%, more preferably 1.0 to 12.0 wt%, even more preferably 2.0 to 11.0 wt%, for example 3.0 to 10.0 wt% of carbon black (CB) and comprises.

[0036] In an embodiment where the flame-retardant polypropylene composition (C) contains carbon black (CB), the total amount of the propylene polymer (PP) which is a heterophasic propylene copolymer (HECO), the nitrogen-containing flame retardant (FR), the anti-dripping agent (A) and the carbon black (CB) preferably constitutes at least 90 wt% of the flame-retardant polypropylene composition (C), more preferably 100 wt% in total.

[0037] The flame-retardant polypropylene composition (C) according to the above embodiment of the present invention may further contain an additive (AD), for example, an acid scavenger, an antioxidant, a colorant, a light stabilizer, a slip agent, an anti-scratch agent, a dispersant, a processing aid, a lubricant, a pigment, etc.

[0038] Therefore, the flame-retardant polypropylene composition (C) is based on the total weight of the flame-retardant polypropylene composition (C), i) 20.0 to 64.99 wt%, more preferably 28.0 to 60.0 wt%, even more preferably 30.0 to 55.0 wt%, for example 35.0 to 50.0 wt% of a propylene polymer (PP) which is a heterophasic propylene copolymer (HECO), ii) 10.0 to 40.0% by weight, more preferably 12.0 to 35.0% by weight, even more preferably 18.0 to 33.0% by weight, for example 22.0 to 30.0% by weight of a nitrogen-containing flame retardant (FR), and iii) 10.0 to 40.0% by weight, more preferably 12.0 to 36.0% by weight, even more preferably 15.0 to 32.0% by weight, for example 19.0 to 31.0% by weight of an anti-dripping agent (A), and iv) 0.01 to 15.0% by weight, more preferably 1.0 to 12.0% by weight, even more preferably 2.0 to 11.0% by weight, for example 3.0 to 10.0% by weight of carbon black (CB), and v) 0.01 to 5.0% by weight, more preferably 0.1 to 3.5% by weight, even more preferably 0.2 to 2.0% by weight, for example 0.3 to 1.0% by weight of an additive (AD) and preferably contains these, more preferably consists of these. The additive (AD) will be described in more detail below.

[0039] In an embodiment where the flame-retardant polypropylene composition (C) contains an additive (AD), the total amount of the propylene polymer (PP) which is a heterophasic propylene copolymer (HECO), the nitrogen-containing flame retardant (FR), the anti-dripping agent (A), optionally carbon black (CB) and the additive (AD) preferably constitutes at least 90% by weight of the flame-retardant polypropylene composition (C), more preferably totaling 100% by weight.

[0040] The flame-retardant polypropylene composition (C) according to the present invention preferably has a melt flow rate MFR2 (230 °C, 2.16 kg) determined according to ISO 1133 in the range of 1.0 to 30.0 g / 10 min, more preferably in the range of 3.0 to 20.0 g / 10 min, even more preferably in the range of 4.0 to 15.0 g / 10 min, for example in the range of 5.0 to 10.0 g / 10 min.

[0041] Regarding the mechanical properties, the flame-retardant polypropylene composition (C) preferably has a tensile modulus determined at 23 °C according to ISO 527-1A in the range of 1000 to 5000 MPa, more preferably in the range of 1100 to 3000 MPa, even more preferably in the range of 1500 to 2500 MPa, for example, in the range of 1700 to 2200 MPa.

[0042] In addition to or instead of the previous paragraph, the flame-retardant polypropylene composition (C) has a notched Charpy impact strength of at least 2.0 kJ / m 2 , more preferably in the range of 2.0 to 30.0 kJ / m 2 , even more preferably in the range of 2.2 to 20.0 kJ / m 2 , for example, in the range of 2.5 to 10.0 kJ / m 2 , determined at 23 °C according to ISO 179 1eA, which is preferable.

[0043] Furthermore, the flame-retardant polypropylene composition (C) according to the present invention preferably satisfies the requirements of UL94V-0 of the Standard for Safety of Flammability of Plastic Materials at a thickness of 1.6 mm or less, more preferably 1.2 mm or less, even more preferably 1.0 mm or less, for example, 0.9 mm or less.

[0044] The flame-retardant polypropylene composition (C) is preferably obtained by blending, preferably melt-blending (melt-mixing), a propylene polymer (PP), a nitrogen-containing flame retardant (FR), a dripping inhibitor (A), and optionally carbon black (CB) and an additive (AD).

[0045] Hereinafter, the propylene polymer (PP), the nitrogen-containing flame retardant (FR), and the dripping inhibitor (A) will be described in more detail.

[0046] Propylene polymer (PP) The flame-retardant polypropylene composition (C) according to the present invention contains a propylene polymer (PP). The propylene polymer (PP) may be a mixture of two or more propylene polymer (PP) components.

[0047] The propylene polymer (PP) has a melt flow rate MFR2 (230 ° C, 2.16 kg) determined according to ISO 1133 in the range of 5.0 to 300 g / 10 min, more preferably in the range of 8.0 to 100 g / 10 min, even more preferably in the range of 10.0 to 75.0 g / 10 min, for example in the range of 15.0 to 50.0 g / 10 min.

[0048] The propylene polymer (PP) can be a homopolymer or copolymer of propylene. Furthermore, the propylene polymer (PP) can contain one or more different propylene polymer (PP) components.

[0049] When the propylene polymer (PP) is a copolymer of propylene, the comonomer is preferably selected from ethylene and / or C4-C8 α-olefins. It is particularly preferred that the comonomer is ethylene. For a propylene polymer (PP) containing a plurality of, for example, two different propylene polymer components that are copolymers of propylene, it is preferred that all propylene polymer components contain the same comonomer, for example ethylene.

[0050] The propylene polymer (PP) is preferably a copolymer of propylene and ethylene and / or at least another C4-C8 α-olefin.

[0051] The propylene polymer (PP) preferably has a comonomer content, for example an ethylene content, in the range of 2.0 to 25.0 mol%, more preferably in the range of 4.0 to 20.0 mol%, even more preferably in the range of 6.0 to 15.0 mol%, for example in the range of 6.2 to 12.0 mol%.

[0052] In a preferred embodiment of the present invention, the propylene polymer (PP) is i) a matrix (M) that is a polymer of propylene, and ii) an elastomer (E) that is a copolymer containing units derived from propylene and ethylene and / or C4-C8 α-olefins It is a heterophasic propylene copolymer (HECO) containing

[0053] Generally in the present invention, the expression "heterophasic" indicates that the elastomer is (finely) dispersed in the matrix. In other words, the elastomer forms an inclusion in the matrix. Accordingly, the matrix contains (finely) dispersed inclusions that are not part of the matrix, and these inclusions contain the elastomer. The term "inclusion" according to the present invention preferably means that the matrix and this inclusion form different phases within the heterophasic polypropylene, and this inclusion is visible by a high-resolution microscopy method such as, for example, electron microscopy or scanning force microscopy.

[0054] It is understood that the propylene polymer (PP) which is a heterophasic propylene copolymer (HECO) preferably has a rather low total comonomer content, preferably an ethylene content. Accordingly, the comonomer content of the heterophasic propylene copolymer (HECO) is preferably in the range of 4.0 to 17.0 mol%, more preferably in the range of 5.0 to 14.0 mol%, still more preferably in the range of 6.0 to 10.0 mol%.

[0055] The heterophasic propylene copolymer (HECO) is generally characterized by a cold xylene soluble (XCS) fraction and a cold xylene insoluble (XCI) fraction. For the purposes of the present application, the cold xylene soluble (XCS) fraction of the heterophasic propylene copolymer (HECO) is essentially the same as the elastomer of the heterophasic propylene copolymer (HECO).

[0056] Therefore, when referring to the intrinsic viscosity and ethylene content of the elastomer of the heterophasic propylene copolymer (HECO), the intrinsic viscosity and ethylene content of the cold xylene soluble (XCS) fraction of this heterophasic propylene copolymer (HECO) are intended.

[0057] Therefore, the matrix (M) content in the propylene polymer (PP) which is a heterophasic propylene copolymer (HECO), that is, the cold xylene insoluble (XCI) content, is preferably in the range of 75.0 to 93.0% by weight, more preferably in the range of 77.0 to 91.0% by weight, for example in the range of 78.0 to 89.0% by weight.

[0058] On the other hand, the elastomer (E) in the propylene polymer (PP) which is a heterophasic propylene copolymer (HECO), that is, the content of the cold xylene soluble (XCS) part, is preferably in the range of 7.0 to 25.0% by weight, more preferably in the range of 9.0 to 23.0% by weight, for example in the range of 11.0 to 22.0% by weight.

[0059] The first component of the propylene polymer (PP) as the heterophasic propylene copolymer (HECO) is the matrix (M).

[0060] The polypropylene suitable for use as the matrix (M) may include any type of isotactic or mainly isotactic polypropylene homopolymer or random copolymer known in the art. Therefore, the polypropylene may be a propylene homopolymer, or an isotactic random copolymer of propylene and ethylene and / or C4-C8 α-olefins, such as 1-butene, 1-hexene or 1-octene, and the total comonomer content is in the range of 0.05 to 10% by weight.

[0061] Furthermore, and preferably, the polypropylene matrix (M) has a medium melt flow rate. Thus, in the present invention, the polypropylene matrix (M), i.e., the cold xylene insoluble (XCI) fraction of the propylene polymer (PP), has a melt flow rate MFR2 (230 °C, 2.16 kg) determined according to ISO 1133 in the range of 15.0 to 120 g / 10 min, more preferably in the range of 20.0 to 100 g / 10 min, even more preferably in the range of 30.0 to 80.0 g / 10 min, for example in the range of 35.0 to 50.0 g / 10 min.

[0062] Furthermore, the polypropylene matrix (M) can be multimodal (multiphasic) or bimodal (biphasic) from the viewpoint of molecular weight.

[0063] The expressions "multimodal" or "bimodal" used throughout the present invention relate to the modality (aspect) of the polymer, i.e., · the form of the molecular weight distribution curve of the polymer, which is a graph of the molecular weight fraction as a function of molecular weight, and / or · the form of the comonomer content distribution curve of the polymer, which is a graph of the comonomer content as a function of the molecular weight of the polymer fraction and are used in relation to.

[0064] However, it is preferred that the polypropylene matrix (M) is neither multimodal nor bimodal.

[0065] The second component of the propylene polymer (PP) as the heterophasic propylene copolymer (HECO) is the elastomer (E).

[0066] The elastomer (E) contains units derivable from (i) propylene and (ii) ethylene and / or at least another C4-C8 α-olefin, more preferably units derivable from (i) propylene and (ii) ethylene and at least another α-olefin selected from the group consisting of 1-butene, 1-pentene, 1-hexene, 1-heptene and 1-octene, and preferably consists of these. The elastomer copolymer (E) may further contain units derived from a conjugated diene such as butadiene or a non-conjugated diene, however, this elastomer copolymer preferably consists only of units derivable from (i) propylene and (ii) ethylene and / or C4-C8 α-olefins. Suitable non-conjugated dienes for use include linear and branched acyclic dienes such as 1,4-hexadiene, 1,5-hexadiene, 1,6-octadiene, 5-methyl-1,4-hexadiene, 3,7-dimethyl-1,6-octadiene, 3,7-dimethyl-1,7-octadiene, and mixed isomers of dihydromyrcene and dihydroocimene, and monocyclic alicyclic dienes such as 1,4-cyclohexadiene, 1,5-cyclooctadiene, 1,5-cyclododecadiene, 4-vinylcyclohexene, 1-allyl-4-isopropylidene cyclohexane, 3-allylcyclopentene, 4-cyclohexene and 1-isopropenyl-4-(4-butenyl) cyclohexane. Also suitable are polycyclic alicyclic fused-ring dienes and bridged-ring dienes containing tetrahydroindene, methyltetrahydroindene, dicyclopentadiene, bicyclo(2,2,1)hepta-2,5-diene, 2-methylbicycloheptadiene, and alkenylnorbornene, alkylidenenorbornene, cycloalkenylnorbornene and cycloalkylidenenorbornene, such as 5-methylene-2-norbornene, 5-isopropylidene norbornene, 5-(4-cyclopentenyl)-2-norbornene, and 5-cyclohexylidene-2-norbornene. Preferred non-conjugated dienes are 5-ethylidene-2-norbornene, 1,4-hexadiene and dicyclopentadiene.

[0067] Accordingly, the elastomer (E) contains units derivable at least from propylene and ethylene, and may contain other units derivable from further α-olefins defined in the previous paragraph. However, it is particularly preferred that the elastomer (E) contains only units derivable from propylene and ethylene, and optionally a conjugated diene such as butadiene, or a non-conjugated diene such as 1,4-hexadiene defined in the previous paragraph. Accordingly, ethylene-propylene non-conjugated diene monomer polymers (EPDM) and / or ethylene-propylene rubbers (EPR) as the elastomer (E) are particularly preferred, with the latter being most preferred.

[0068] Similar to the matrix (M), the elastomer (E) may be unimodal (monomodal) or multimodal, for example bimodal. For the definitions of unimodal and multimodal, for example bimodal, refer to the above definitions.

[0069] In the present invention, the content of units derivable from propylene in the elastomer (E) is equal to the content of detectable propylene in the cold xylene-soluble part (XCS) fraction. Accordingly, the detectable propylene in the cold xylene-soluble part (XCS) fraction is in the range of 20.0 to 80.0 mol%, more preferably 35.0 to 70.0 mol%. The comonomers present in the cold xylene-soluble part (XCS) fraction are those defined above for the elastomer (E). Accordingly, in certain embodiments, the elastomer (E), i.e., the cold xylene-soluble part (XCS) fraction, contains 25.0 to 65.0 mol%, more preferably 30.0 to 60.0 mol%, even more preferably 35.0 to 50.0 mol%, for example 40.0 to 45.0 mol% of units derivable from at least one of the comonomers defined above for the elastomer (E). Preferably, the elastomer (E) is an ethylene-propylene non-conjugated diene monomer polymer (EPDM) or an ethylene-propylene rubber (EPR) having the propylene and / or ethylene content specified in this paragraph, with the latter being particularly preferred. In one preferred embodiment, the comonomer of the elastomer (E) is only ethylene.

[0070] A further preferred requirement of the present invention is that the intrinsic viscosity (IV) of the cold xylene soluble (XCS) fraction of the propylene polymer (PP) which is a heterophasic propylene copolymer (HECO) is quite low. Thus, it is understood that the intrinsic viscosity of the cold xylene soluble (XCS) fraction of the propylene polymer (PP) which is a heterophasic propylene copolymer (HECO) is less than 3.5 dl / g, more preferably 3.4 dl / g or less. Even more preferably, the intrinsic viscosity of the cold xylene soluble (XCS) fraction of the propylene polymer (PP) which is a heterophasic propylene copolymer (HECO) is in the range of 1.8 to less than 3.5 dl / g, more preferably in the range of 1.9 to 3.4 dl / g, for example 2.0 to 3.4 dl / g. The intrinsic viscosity is measured at 135 °C in decalin according to ISO 1628.

[0071] When the propylene polymer (PP) is a heterophasic propylene copolymer (HECO) as defined above, preferably, the propylene content of the propylene polymer (PP) is more preferably 85.0 to 96.0 wt%, more preferably 88.0 to 94.0 wt% based on the total weight of the propylene polymer (PP), and even more preferably based on the combined amount of the matrix (M) and the elastomeric copolymer (E).

[0072] The propylene polymer (PP) which is a heterophasic propylene copolymer (HECO) can be produced by blending a matrix (M) and an elastomer (E). However, the heterophasic propylene copolymer (HECO) is preferably produced in a continuous process using a plurality of reactors in a series configuration and operating under different reaction conditions. As a result, each fraction prepared in a particular reactor may have its own molecular weight distribution and / or comonomer content distribution.

[0073] The propylene polymer (PP) that is a heterophasic propylene copolymer (HECO) according to the present invention is preferably produced by a sequential polymerization process known in the art, i.e., a multi-step process, in which a (semi)crystalline propylene polymer (M) is produced in at least one slurry reactor, preferably in a slurry reactor, and optionally in a subsequent gas-phase reactor, and subsequently an elastomer (E) is produced in at least one, i.e., one or two, gas-phase reactors.

[0074] Accordingly, the propylene polymer (PP) that is a heterophasic propylene copolymer (HECO) is (a) polymerizing propylene and optionally at least one ethylene and / or C4-C8 α-olefin in a first reactor (R1) to obtain a first polypropylene fraction of the matrix (M), preferably this first polypropylene fraction is a propylene homopolymer; (b) optionally transferring the first polypropylene fraction to a second reactor (R2); (c) optionally polymerizing propylene and optionally at least one ethylene and / or C4-C8 α-olefin in the second reactor (R2) and in the presence of the first polypropylene fraction, thereby obtaining a second polypropylene fraction, preferably this second polypropylene fraction is a second propylene homopolymer, and the first polypropylene fraction and optionally the second polypropylene fraction form the matrix (M), i.e., the matrix of the heterophasic propylene copolymer (HECO); (d) transferring the matrix (M) of step (c) to a third reactor (R3); (e) polymerizing propylene and ethylene in the third reactor (R3) and in the presence of the matrix (M) obtained in step (a) or (c) to obtain an elastomer (E) dispersed in the matrix (M), and this matrix (M) and elastomer (E) form the propylene polymer (PP) that is a heterophasic propylene copolymer (HECO). It is preferably produced by a sequential polymerization process.

[0075] The propylene polymer (PP), which is a heterophasic propylene copolymer (HECO), (a) a Ziegler-Natta catalyst comprising a compound of a transition metal of Groups 4 to 6 of the IUPAC (TC), a Group 2 metal compound (MC), and an internal donor (ID), (b) optionally, a cocatalyst (Co), and (c) optionally an external donor (ED) is preferably prepared in the presence of.

[0076] This Ziegler-Natta catalyst may be any stereospecific Ziegler-Natta catalyst for propylene polymerization, and such a catalyst can preferably catalyze the polymerization and copolymerization of propylene and optional comonomers at a pressure of 500 to 10000 kPa, particularly 2500 to 8000 kPa, and a temperature of 40 to 110 °C, particularly 60 to 110 °C.

[0077] Preferably, the above Ziegler-Natta catalyst includes a high-yield Ziegler-Natta type catalyst containing an internal donor component, which can be used at a high polymerization temperature of 80 °C or higher. Such a high-yield Ziegler-Natta catalyst can include a succinic acid ester, a diether, a citraconic acid ester, a phthalic acid ester, etc., or a mixture thereof as the internal donor (ID). Preferably, the internal donor (ID) does not contain a phthalic acid ester compound.

[0078] According to one preferred embodiment of the present invention, the propylene polymer (PP) consists of a heterophasic propylene copolymer (HECO).

[0079] In another embodiment, the propylene polymer (PP) includes a heterophasic propylene copolymer (HECO) and one or more additional homopolymers or copolymers of propylene such as a further heterophasic propylene copolymer. When the propylene polymer (PP) includes a further copolymer of propylene such as a further heterophasic propylene copolymer, the heterophasic propylene copolymer (HECO) and the further copolymer of propylene preferably contain the same comonomer, preferably ethylene.

[0080] Flame retardant composition (FR) The polypropylene composition (C) according to the present invention contains a nitrogen-containing flame retardant (FR).

[0081] According to a preferred embodiment of the present invention, the nitrogen-containing flame retardant (FR) does not contain halogen. That is, it is preferred that the nitrogen-containing flame retardant (FR) does not contain an organic compound or an inorganic compound containing a halogen atom. As used herein, the term "halogen" refers to the elements of Group 17 of the periodic table.

[0082] The nitrogen-containing flame retardant (FR) preferably contains at least one nitrogen-containing phosphate (phosphoric acid ester), preferably at least one organic nitrogen-containing phosphate. Preferably, this organic nitrogen-containing phosphate is a phosphate of a heterocyclic C3-C6-, more preferably C3-C4-alkyl or aryl compound containing at least one N atom.

[0083] According to a preferred embodiment of the present invention, the nitrogen-containing flame retardant (FR) includes a first nitrogen-containing phosphate (FR1) and a second nitrogen-containing phosphate (FR2) different from the first nitrogen-containing phosphate (FR1).

[0084] Preferably, the first nitrogen-containing phosphate (FR1) and the second nitrogen-containing phosphate (FR2) are organic nitrogen-containing phosphates. It is particularly preferred that the first nitrogen-containing phosphate (FR1) and the second nitrogen-containing phosphate (FR2) are phosphates of a heterocyclic C3-C6, more preferably C3-C4-alkyl or aryl compound containing at least one N atom.

[0085] It is preferred that the first nitrogen-containing phosphate (FR1) is an organic nitrogen-containing polyphosphate. More preferably, the first nitrogen-containing phosphate (FR1) is a polyphosphate of a heterocyclic C3-C6-, more preferably C3-C4-aryl compound containing at least one N atom. It is particularly preferred that the first nitrogen-containing phosphate (FR1) is melamine polyphosphate (melamine polyphosphate).

[0086] It is preferred that the second nitrogen-containing phosphate (FR2) is an organic nitrogen-containing diphosphate. More preferably, the second nitrogen-containing phosphate (FR2) is a diphosphate of a heterocyclic C3-C6-, more preferably C3-C4-alkyl compound containing at least one N atom, for example two N atoms. It is particularly preferred that the second nitrogen-containing phosphate (FR2) is piperazine pyrophosphate (piperazine pyrophosphate).

[0087] According to a preferred embodiment of the present invention, the weight ratio of the first nitrogen-containing phosphate (FR1) to the second nitrogen-containing phosphate (FR2) is in the range of 60:40 to 40:60.

[0088] A suitable nitrogen-containing flame retardant (FR) is preferably commercially available. A highly suitable example of a commercially available nitrogen-containing flame retardant (FR) is a flame retardant product sold under the trade name Phlamoon-1090A manufactured and supplied by SULI (Suli, Jiangsu Suli Fine Chemical Co., Ltd.).

[0089] The amount of the nitrogen-containing flame retardant (FR) means, in this specification, the amount of the nitrogen-containing flame retardant (FR) supplied by the manufacturer with respect to the total weight of the polypropylene composition (C). Accordingly, the nitrogen-containing flame retardant (FR) may contain in small amounts additional components such as additives, flame-retardant synergists and / or carrier media. Accordingly, it should be understood that such additional components are included in the amount of the nitrogen-containing flame retardant (FR).

[0090] Antidripping agent (A) The polypropylene composition (C) of the present invention further comprises an antidripping agent (A).

[0091] As used herein, the term "antidripping agent" refers to an additive that prevents or reduces the effect of dripping of a polymeric material under UL94 test conditions. During the UL94 test, it is necessary to observe whether the sample drips and, if there is dripping, whether the drips are flaming (burning). The classification of the polymeric product in the UL94 vertical burning test depends on the burning time and the dripping phenomenon. The burning time after removal of the ignition source determines whether the polymer is V0, V1 or unclassified (failed). The dripping phenomenon differentiates between the V2 and V1 classifications. If a flaming material drips and ignites the cotton placed under the test piece, the polymeric product is classified as V2. Clearly, the dripping phenomenon is important for the UL94 vertical test (see Y. Wang et al., Journal of Fire Sciences 2012, 30(6), 477 - 501).

[0092] According to a preferred embodiment of the present invention, the antidripping agent (A) does not contain halogen. That is, it is preferred that the antidripping agent (A) does not contain any organic or inorganic compound containing a halogen atom. As used herein, the term "halogen" refers to the elements of Group 17 of the periodic table.

[0093] The antidripping agent (A) according to the present invention has an F determined in accordance with ISO 16790:2005 of at least 20 cN 30It is a high melt strength polypropylene (HMS-PP) having a melt strength.

[0094] High melt strength polypropylene is branched and thus different from linear polypropylene in that the polypropylene backbone extends to the side chains, while linear polypropylene, i.e., non-branched polypropylene, does not extend to the side chains. The side chains have a significant impact on the rheology of polypropylene. Therefore, linear polypropylene and high melt strength polypropylene can be clearly distinguished by their flow behavior under stress.

[0095] Branching can be achieved by using a specific catalyst, i.e., a specific single-site catalyst, or by chemical modification. Regarding the preparation of branched polypropylene obtained by using a specific catalyst, reference is made to European Patent Application Publication No. 1892264. Regarding branched polypropylene obtained by chemical modification, reference is made to European Patent Application Publication No. 0879830A1. In such cases, the branched polypropylene is also called high melt strength polypropylene.

[0096] The branching index g' defines the degree of branching and correlates with the amount of branching of the polymer. Preferably, high melt strength polypropylene (HMS-PP) has a branching index g' determined by GPC of 0.95 or less, more preferably 0.90 or less, even more preferably 0.85 or less, for example 0.80 or less.

[0097] High melt strength polypropylene (HMS-PP) as the main component of the polypropylene composition has an F of at least 20 cN 30 melt strength and a v of more than 200 mm / s 30 melt extensibility, and preferably has an F of 20 - 50 cN 30 melt strength and a v of more than 200 to 300 mm / s 30 melt extensibility. F 30 melt strength and v 30 The melt strength and melt extensibility are measured according to ISO16790:2005.

[0098] In addition, high melt strength polypropylene (HMS-PP) can be further defined by a strain hardening factor (SHF). Therefore, high melt strength polypropylene (HMS-PP) has a strain hardening coefficient (SHF) measured at a strain rate of 3.0 s -1 and a Hencky strain of 2.5, preferably in the range of at least 1.7, more preferably at least 1.9, even more preferably in the range of 1.9 to 7.0, and even more preferably in the range of 1.9 to 6.5.

[0099] Furthermore, high melt strength polypropylene (HMS-PP) preferably has a melt flow rate MFR2 (230 °C, 2.16 kg) measured according to ISO 1133 in the range of 0.5 to 15.0 g / 10 min, even more preferably in the range of 1.0 to 10.0 g / 10 min, for example in the range of 1.8 to 3.0 g / 10 min.

[0100] Preferably, high melt strength polypropylene (HMS-PP) has a melting point of at least 130 °C, more preferably at least 135 °C, and most preferably at least 140 °C. The crystallization temperature is preferably at least 120 °C.

[0101] Furthermore, high melt strength polypropylene (HMS-PP) can be a high melt strength random propylene copolymer (R-HMS-PP) or a high melt strength propylene homopolymer (H-HMS-PP), with the latter being preferred.

[0102] For the purposes of the present invention, the expression "propylene homopolymer" refers substantially, i.e., to polypropylene consisting of at least 97 mol%, preferably at least 98 mol%, more preferably at least 99 mol%, and most preferably at least 99.8 mol% of propylene units. In a preferred embodiment, only propylene units are detectable in the propylene homopolymer.

[0103] When the high melt strength polypropylene (HMS-PP) is a high melt strength random propylene copolymer (R-HMS-PP), it is a monomer copolymerizable with propylene, such as ethylene and / or C4~C 12 α-olefins, especially ethylene and / or C4~C 10 α-olefins, and includes comonomers such as 1-butene and / or 1-hexene. Preferably, the high melt strength random propylene copolymer (R-HMS-PP) includes, and particularly consists of, monomers copolymerizable with propylene from the group consisting of ethylene, 1-butene, and 1-hexene. More specifically, the high melt strength random propylene copolymer (R-HMS-PP) includes units derivable from ethylene and / or 1-butene in addition to propylene. In a preferred embodiment, the high melt strength random propylene copolymer (R-HMS-PP) includes only units derivable from ethylene and propylene. The comonomer content in the high melt strength random propylene copolymer (R-HMS-PP) is preferably in the range of more than 0.2 to 10.0 mol%, even more preferably in the range of more than 0.5 to 7.0 mol%.

[0104] In this regard, it should be mentioned that the high melt strength polypropylene (HMS-PP), which is either a high melt strength propylene homopolymer (H-HMS-PP) or a high melt strength random propylene copolymer (R-HMS-PP), may contain additional unsaturated monomers different from the comonomers defined for the high melt strength random propylene copolymer (R-HMS-PP). In other words, the high melt strength propylene homopolymer (H-HMS-PP) or the high melt strength random propylene copolymer (R-HMS-PP) may be a bifunctional unsaturated monomer and / or a polyfunctional unsaturated low molecular weight polymer as defined in detail below, such as propylene, ethylene, and other C4~C 12It may contain unsaturated monomers different from α-olefins. Therefore, the definitions of homopolymers and copolymers from the perspective of high melt strength polypropylene (HMS-PP) actually relate to the unmodified polypropylene used to obtain melt strength polypropylene (HMS-PP) by chemical modifications defined in detail below.

[0105] As described above, high melt strength polypropylene (HMS-PP) is a modified polypropylene. Therefore, high melt strength polypropylene (HMS-PP) can be further defined by the method by which it is obtained. High melt strength polypropylene (HMS-PP) is preferably the result of treating unmodified polypropylene with a thermal decomposable radical former and / or ionizing radiation. However, in such cases, there is a high risk that the unmodified polypropylene will deteriorate, and deterioration is harmful. Therefore, modification is preferably achieved by the use of difunctional unsaturated monomers (multiple types possible) and / or polyfunctional unsaturated low molecular weight polymers (multiple types possible) as chemical bonding cross-linking units. Suitable methods for obtaining high melt strength polypropylene (HMS-PP) are disclosed, for example, in European Patent Application Publication No. 0787750, European Patent Application Publication No. 0879830A1, and European Patent Application Publication No. 0890612A2. All documents are hereby incorporated by reference into this specification. Thereby, the amount of peroxide is preferably in the range of 0.05 to 3.00% by weight based on the unmodified polypropylene (PP).

[0106] Therefore, in one preferred embodiment, high melt strength polypropylene (HMS-PP) is (a) when high melt strength polypropylene (HMS-PP) is a high melt strength propylene homopolymer (H-HMS-PP), (i) propylene, and (ii) difunctional unsaturated monomers (multiple types possible) and / or polyfunctional unsaturated low molecular weight polymers (multiple types possible) derived units from or (b) When the high melting strength polypropylene (HMS-PP) is a high melting strength random propylene copolymer (R-HMS-PP), (i) Propylene, (ii) Ethylene and / or C4-C 10 α-olefins, such as 1-butene and / or 1-hexene, preferably ethylene, and (iii) Bifunctional unsaturated monomer(s) and / or polyfunctional unsaturated low molecular weight polymer(s) units derived from are included.

[0107] As used above, "bifunctional unsaturated or polyfunctional unsaturated" preferably means the presence of two or more non-aromatic double bonds, such as in divinylbenzene or cyclopentadiene or polybutadiene. Preferably only such bifunctional or polyfunctional unsaturated compounds that can be polymerized with the aid of free radicals are used. Since each of the double bonds is used for covalent bonding to the polymer chain of the unmodified polypropylene, the unsaturated sites in the bifunctional or polyfunctional unsaturated compounds are actually in a chemically bonded state that is not "unsaturated".

[0108] The reaction of the bifunctional unsaturated monomer, synthesized from one and / or more unsaturated monomers, and / or preferably the polyfunctional unsaturated low molecular weight polymer having a number average molecular weight (M n ) of 10,000 g / mol or less with the unmodified polypropylene may be carried out in the presence of a thermal free radical forming agent, such as a decomposable free radical forming agent, such as a thermal decomposable peroxide and / or ionizing radiation or microwave radiation.

[0109] The bifunctional unsaturated monomer is divinyl compounds such as divinylaniline, m-divinylbenzene, p-divinylbenzene, divinylpentane and divinylpropane, allyl compounds such as allyl acrylate, allyl methacrylate, allyl methyl maleate and allyl vinyl ether, Dienes such as 1,3-butadiene, chloroprene, cyclohexadiene, cyclopentadiene, 2,3-dimethylbutadiene, heptadiene, hexadiene, isoprene and 1,4-pentadiene, aromatic and / or aliphatic bis(maleimide) bis(citraconimide) and mixtures of these unsaturated monomers may also be used.

[0110] Particularly preferred difunctional unsaturated monomers are 1,3-butadiene, isoprene, dimethylbutadiene and divinylbenzene.

[0111] The polyfunctional unsaturated low molecular weight polymer preferably having a number average molecular weight (M n ) of 10,000 g / mol or less may be synthesized from one or more unsaturated monomers.

[0112] Examples of such low molecular weight polymers are · polybutadiene, especially polybutadiene in which different microstructures in the polymer chain, i.e., 1,4-cis, 1,4-trans and 1,2-(vinyl), are mainly in the 1,2-(vinyl) configuration, · copolymers of butadiene and styrene having 1,2-(vinyl) in the polymer chain are.

[0113] Preferred low molecular weight polymers are polybutadiene, especially polybutadiene having more than 50.0% by weight of butadiene in the 1,2-(vinyl) configuration.

[0114] High melt strength polypropylene (HMS-PP) may contain a plurality of difunctional unsaturated monomers and / or polyfunctional unsaturated low molecular weight polymers. Even more preferably, the amount of the difunctional unsaturated monomers and polyfunctional unsaturated low molecular weight polymers in the high melt strength polypropylene (HMS-PP) is, in total, 0.01 to 10.0% by weight based on the above high melt strength polypropylene (HMS-PP).

[0115] As described above, the bifunctional unsaturated monomer and / or the polyfunctional unsaturated low molecular weight polymer are preferably used in the presence of a thermal decomposable free radical forming agent.

[0116] Peroxides are preferred thermal decomposable free radical forming agents. More preferably, the thermal decomposable free radical forming agent is selected from the group consisting of acyl peroxides, alkyl peroxides, hydroperoxides, peresters (peroxy esters) and peroxyesters (peroxy carbonates).

[0117] The following listed peroxides are particularly preferred.

[0118] Acyl peroxides: benzoyl peroxide, 4-chlorobenzoyl peroxide, 3-methoxybenzoyl peroxide and / or methylbenzoyl peroxide.

[0119] Alkyl peroxides: allyl t-butyl peroxide, 2,2-bis(t-butylperoxybutane), 1,1-bis(t-butylperoxy)-3,3,5-trimethylcyclohexane, n-butyl-4,4-bis(t-butylperoxy)valerate, diisopropylaminomethyl-t-amyl peroxide, dimethylaminomethyl-t-amyl peroxide, diethylaminomethyl-t-butyl peroxide, dimethylaminomethyl-t-butyl peroxide, 1,1-di-(t-amylperoxy)cyclohexane, t-amyl peroxide, t-butylcumyl peroxide, t-butyl peroxide and / or 1-hydroxybutyl n-butyl peroxide.

[0120] Peresters and peroxicarbonates: butyl peracetate, cumyl peracetate, cumyl perpropionate, cyclohexyl peracetate, di-t-butyl peradipate, di-t-butyl perazelate, di-t-butyl perglutarate, di-t-butyl perphthalate, di-t-butyl persebacate, 4-nitrocumyl perpropionate, 1-phenylethyl perbenzoate, phenylethyl nitroxyl perbenzoate, t-butyl bicyclo-(2,2,1)heptane percarboxylate, t-butyl 4-carbomethoxy perbutyrate, t-butyl cyclobutane percarboxylate, t-butyl cyclohexyl percarboxylate, t-butyl cyclopentyl percarboxylate, t-butyl cyclopropane percarboxylate, t-butyl dimethyl percinnamate, t-butyl 2-(2,2-diphenylvinyl) perbenzoate, t-butyl 4-methoxy perbenzoate, t-butyl perbenzoate, t-butyl carboxycyclohexane, t-butyl pernaphthoate, isopropyl t-butyl percarbonate, t-butyl per-toluate, t-butyl 1-phenylcyclopropyl percarboxylate, t-butyl 2-propyl-2-perpentenoate, t-butyl 1-methylcyclopropyl percarboxylate, t-butyl 4-nitrophenyl peracetate, t-butyl nitrophenyl percarbamate, t-butyl N-succinimidopercarboxylate, t-butyl percrotonate, t-butyl permaleate, t-butyl permethacrylate, t-butyl peroctanoate, isopropyl t-butyl percarbonate, t-butyl perisobutyrate, t-butyl peracrylate and / or t-butyl perpropionate.

[0121] Mixtures of the free radical forming agents listed above are also contemplated.

[0122] Preferably, the unmodified polypropylene is a propylene homopolymer.

[0123] After preparation, the high melt strength polypropylene (HMS-PP) may be subjected to a modification (modification) process, and the polymer may be further modified. Such modification processes include, for example, grafting in which one or more functional comonomers are grafted onto the polypropylene chain, and visbreaking in which the molecular weight of polypropylene is reduced by combining the molten polymer in an extruder with a free radical generator such as a peroxide. Such processes are well known to those skilled in the art, and references thereto can be found in the literature.

[0124] Additive (AD) In addition to the propylene copolymer (PP), the nitrogen-containing flame retardant (FR), and the anti-dripping agent (A), the polypropylene composition (C) of the present invention may contain an additive (AD). Typical additives are acid scavengers, antioxidants, colorants, light stabilizers, slip agents, anti-scratch agents, dispersants, processing aids, lubricants, pigments, and the like.

[0125] The content of the additive in the polypropylene composition (C) of the present invention usually does not exceed 5.0% by weight, preferably ranges from 0.01 to 5.0% by weight, more preferably from 0.1 to 3.5% by weight, and even more preferably from 0.2 to 2.0% by weight, for example, from 0.3 to 1.0% by weight.

[0126] Such additives are commercially available and are described, for example, in "Plastic Additives Handbook" by Hans Zweifel, 6th Edition, 2009 (pages 1141-1190).

[0127] Furthermore, the term "additive (AD)" according to the present invention also includes carrier materials, particularly polymer carrier materials.

[0128] Polymer carrier material Preferably, the flame-retardant polypropylene composition (C) of the present invention does not contain any additional polymer(s) (multiple types are possible) different from the propylene polymer (PP) and the high-melt-strength polypropylene (HMS-PP) in an amount exceeding 5.0% by weight, preferably exceeding 3.0% by weight, more preferably exceeding 2.0% by weight, based on the weight of the flame-retardant polypropylene composition (C). Any polymer serving as a carrier material for the additive (AD) is accounted for in the amount of each additive, rather than in the amount of the polymer compound as shown in the present invention.

[0129] The polymer carrier material for the additive (AD) is a carrier polymer for ensuring a uniform distribution in the flame-retardant polypropylene composition (C) of the present invention. This polymer carrier material is not limited to a specific polymer. The polymer carrier material may be an ethylene homopolymer, an ethylene copolymer obtained from α-olefin comonomers such as ethylene and C3-C8 α-olefin comonomers, a propylene homopolymer, and / or a propylene copolymer obtained from propylene and α-olefin comonomers such as ethylene and / or C4-C8 α-olefin comonomers. It is preferable that the polymer carrier material does not contain monomer units derivable from styrene or its derivatives.

[0130] Use The present invention further provides an anti-dripping agent (A) for a composition containing a propylene polymer (PP) and a nitrogen-containing flame retardant (FR), the F determined according to ISO 16790:2005 of at least 20 cN 30 Use of a high-melt-strength polypropylene (HMS-PP) having a melt strength, wherein the above composition does not contain glass fibers and / or the above propylene polymer (PP) is a heterophasic propylene copolymer (HECO) containing a matrix (M) that is a polymer of propylene and an elastomer (E) that is a copolymer containing units derived from propylene and ethylene and / or C4-C8 α-olefins, and is directed to use.

[0131] For propylene polymer (PP), heterophasic propylene copolymer (HECO), high melt strength polypropylene (HMS-PP) and nitrogen-containing flame retardant (FR), refer to the definitions provided above.

[0132] Article The present invention also relates to an article comprising the flame-retardant polypropylene composition (C) defined above. In particular, the present invention relates to an article comprising at least 60% by weight, more preferably at least 80% by weight, even more preferably at least 90% by weight, for example at least 95% by weight or at least 99% by weight of the flame-retardant polypropylene composition (C) defined above. In a particularly preferred embodiment, the present invention relates to an article consisting of the flame-retardant polypropylene composition (C) defined above.

[0133] Preferably, the article is an automotive article, an automotive part, and a container or part of a power electronics component of a home appliance part in the field of electronic parts such as an electrical cable insulator and a housing of an electrical device.

[0134] The present invention will now be described in more detail by the following examples.

Examples

[0135] A. Measurement method The following definitions and determination methods of terms apply to the above general description of the present invention and the following examples unless otherwise defined.

[0136] MFR2 (230 ° C) is measured in accordance with ISO1133 (230 ° C, 2.16 kg load).

[0137] Quantification of microstructure by NMR spectroscopy Quantitative nuclear magnetic resonance (NMR) spectroscopy was used to quantify the comonomer content and comonomer sequence distribution of the polymer. Quantitative 13 C{ 1 H} NMR spectrum is 1 H and 13For C, it was recorded in solution state using a Bruker Advance III 400 NMR spectrometer operating at 400.15 MHz and 100.62 MHz, respectively. All spectra were recorded using nitrogen gas for all pressures with a 10 mm extended temperature probe head optimized for 13 13C. Approximately 200 mg of the material was dissolved in 3 ml of 1,2-tetrachloroethane-d2 (TCE-d2) together with chromium(III) acetylacetonate (Cr(acac)3) giving a 65 mM solution of the relaxant in the solvent (Singh, G., Kothari, A., Gupta, V., Polymer Testing 28 5 (2009), 475). To ensure a homogeneous solution, after the initial sample preparation in a heat block, the NMR tube was further heated in a rotary oven for at least 1 hour. After insertion into the magnet, the tube was rotated at 10 Hz. This setting was chosen mainly for the high resolution and quantitative nature necessary for the accurate quantification of the ethylene content. Standard single pulse excitation without NOE was employed using an optimized tip angle, a recycle delay of 1 s and a bilinear WALTZ16 decoupling scheme (Zhou, Z., Kuemmerle, R., Qiu, X., Redwine, D., Cong, R., Taha, A., Baugh, D., Winniford, B., J. Mag. Reson. 187 (2007) 225; Busico, V., Carbonniere, P., Cipullo, R., Pellecchia, R., Severn, J., Talarico, G., Macromol. Rapid Commun. 2007, 28, 1128). A total of 6144 (6k) transient signals were acquired per spectrum. Quantitative 13 13C{ 1The 1H NMR spectra were processed, integrated, and the relevant quantitative characteristics were determined from the integration values using an in-house computer program. All chemical shifts were indirectly referenced to the central methylene group of the ethylene block (EEE) at 30.00 ppm using the chemical shift of the solvent. This approach enabled comparable referencing even in the absence of this structural unit. Characteristic signals corresponding to the incorporation of ethylene were observed (Cheng, H. N., Macromolecules 17 (1984), 1950). For polypropylene homopolymers, all chemical shifts were referenced to the methyl isotactic pentad (mmmm) at 21.85 ppm as an internal standard. Characteristic signals corresponding to positional defects (Resconi, L., Cavallo, L., Fait, A., Piemontesi, F., Chem. Rev. 2000, 100, 1253; Wang, W-J., Zhu, S., Macromolecules 33 (2000), 1157; Cheng, H. N., Macromolecules 17 (1984), 1950) or comonomers were observed. The tacticity distribution was quantified by integrating the methyl region from 23.6 to 19.7 ppm, correcting for any sites not related to the stereosequence of interest (Busico, V., Cipullo, R., Prog. Polym. Sci. 26 (2001) 443; Busico, V., Cipullo, R., Monaco, G., Vacatello, M., Segre, A. L., Macromolecules 30 (1997) 6251). Specifically, the effects of positional defects and comonomers on the quantification of the tacticity distribution were corrected by subtracting the integration values of representative positional defects and comonomers from specific integration regions of the stereosequence. Isotacticity was determined at the pentad level and reported as the percentage of isotactic pentad (mmmm) sequences relative to all pentad sequences. [mmmm]% = 100 × (mmmm / sum of all pentads) The presence of the 2,1 erythro positional defect was indicated by the presence of two methyl sites at 17.7 and 17.2 ppm and confirmed by other characteristic sites. Characteristic signals corresponding to other types of positional defects were not observed (Resconi, L., Cavallo, L., Fait, A., Piemontesi, F., Chem. Rev. 2000, 100, 1253). The amount of the 2,1 erythro positional defect was quantified using the average integral values of the two characteristic methyl sites at 17.7 and 17.2 ppm. P 21e =(I e6 +I e8 ) / 2 The amount of 1,2 primary inserted propene was quantified based on the methyl region. At that time, corrections were made for the sites contained in this region but not related to primary insertion and the primary insertion sites excluded from this region. P 12 =I CH3 +P 12e The total amount of propene was quantified as the sum of the primary inserted propene and all other existing positional defects. P 全 =P 12 +P 21e The mole percent of the 2,1 erythro positional defect was quantified relative to the total propene. [21e] mol% = 100×(P 21e / P 全 ) For the copolymer, characteristic signals corresponding to the incorporation of ethylene were observed (Cheng, H. N., Macromolecules 17(1984), 1950). When positional defects were also observed (Resconi, L., Cavallo, L., Fait, A., Piemontesi, F., Chem. Rev. 2000, 100, 1253; Wang, W-J., Zhu, S., Macromolecules 33(2000), 1157; Cheng, H. N., Macromolecules 17(1984), 1950), correction for the effect of such defects on the comonomer content was necessary. The comonomer fraction was 13 quantified by integrating multiple signals over the entire spectral region of the C{ 1 H} spectrum using the method of Wang et al. (Wang, W-J., Zhu, S., Macromolecules 33 (2000) 1157). This method was chosen because of its robustness and the ability to account for the presence of positional defects if necessary. The integration region was slightly adjusted to enhance its applicability over the entire range of the comonomer content faced. For systems where only isolated ethylene in the PPEPP sequence is observed, the method of Wang et al. was modified to reduce the effect of non-zero integration at sites known to be absent. This approach reduces the overestimation of the ethylene content for such systems, which is achieved by reducing the number of sites used to determine the absolute ethylene content to E = 0.5(Sββ + Sβγ + Sβδ + 0.5(Sαβ + Sαγ)) The use of this set of sites results in the corresponding integral equation being written in the same notation as used in the paper by Wang et al. (Wang, W-J., Zhu, S., Macromolecules 33 (2000), 1157) as E = 0.5(I + I H + 0.5(I G + I C + I D )) The equation used for the absolute propylene content was not modified. The equation used for the absolute propylene content was not modified. The comonomer incorporation in mole percent was calculated from the mole fraction. E [mol%] = 100 × fE The comonomer incorporation in weight percent was calculated from the mole fraction. E [wt%] = 100 × (fE × 28.06) / ((fE × 28.06) + ((1 - fE) × 42.08)) The comonomer sequence distribution at the triad level was determined using the analysis method of Kakugo et al. (Kakugo, M., Naito, Y., Mizunuma, K., Miyatake, T. Macromolecules 15 (1982) 1150). This method was chosen because of the integration region that was slightly adjusted to enhance its robustness and applicability to a wider range of comonomer contents.

[0138] The intrinsic viscosity (IV) of propylene homopolymers and copolymers was measured according to DIN ISO 1628 / 1, October 1999 (at 135 °C in decalin).

[0139] Cold xylene soluble part (XCS, wt%): The content of the cold xylene soluble part (XCS) was determined at 25 °C according to ISO 16152; First Edition; 2005-07-01.

[0140] The notched Charpy impact strength was determined according to ISO 179-1 / 1eA at 23 °C and -30 °C using injection molded test specimens (80 × 10 × 4 mm) prepared according to EN ISO 1873-2.

[0141] Tensile properties were determined for injection molded dumbbell test specimens with a thickness of 4 mm prepared according to EN ISO 1873-2. The tensile modulus was determined according to ISO 527-1A at a strain rate of 1 mm / min and at 23 °C, 80 °C and 120 °C, and the yield stress was determined at a strain rate of 50 mm / min and at 23 °C, 80 °C and 120 °C.

[0142] Branching index g’ The relative amount of branching is determined using the g’ index of the branched polymer sample. The long chain branching (LCB) index is g’ = [η] br / [η] linIt is defined as follows. It is well-known that the branching content decreases as the g’ value increases. [η] is the intrinsic viscosity of a polymer sample with a certain molecular weight at 160 °C in TCB, and is measured by an on-line viscosity and concentration detector. The intrinsic viscosity was measured using the Solomon-Gatesman equation as described in the handbook of Cirrus Multi-Offline SEC-Software version 3.2. The required concentration of each elution slice is determined by an RI detector. [η] lin is the intrinsic viscosity of a linear sample, and [η] br is the viscosity of a branched sample with the same molecular weight and chemical composition. The number-average g’ n and weight-average g’ w are defined as follows. [Number] In the above formula, a i is dW / dlogM of fraction i, and A i is the cumulative dW / dlogM of the polymer up to fraction i. The [η] of the linear standard (linear isotactic PP) with respect to the molecular weight was measured with an on-line viscosity detector. The K and α values (K = 30.68×10 lin and α = 0.681) were obtained from the linear standard in the molecular weight range of logM = 4.5 to 6.1. The [η] per slice molecular weight for g’ calculation -3 is calculated by the following relationship [η] lin = K×M lin,i = K×M i α . [η] br,i was measured for each specific sample by an on-line viscosity and concentration detector.

[0143] gpcBR index The gpcBR index is calculated using the following formula. [Number] In the above formula, using Cirrus Multi-Offline SEC-Software version 3.2 and below approaches, Mw(LS15) is calculated from the light scattering elution area at an angle of 15°, and [η](bulk) is calculated from the corresponding viscosity detector elution area.

Number

[0144] F 30 and melt strength and v 30 and melt drawability The tests described in this specification comply with ISO16790:2005. The strain hardening behavior is determined by the method described in the paper "Rheotens-Mastercurves and Drawability of Polymer Melts (Rheotens Mastercurves and Drawability of Polymer Melts)", M.H. Wagner, Polymer Engineering and Science, Vol. 36, pp. 925-935. The strain hardening behavior of the polymer is analyzed by a Rheotens device (product of Goettfert, Siemensstr. 2, 74711 Buchen, Germany). In this device, the strand of the melt is stretched by pulling it down at a specified acceleration. The Rheotens experiment simulates industrial spinning and extrusion processes. In principle, the melt is compressed or extruded through a round die and the resulting strand is drawn off. The stress applied to the extrudate is recorded as a function of the melt properties and the measurement parameters (notably the ratio of output to draw-off speed, practically a measure of the elongation rate). For the results shown below, the material was extruded using an experimental extruder HAAKE Polylab system and a gear pump equipped with a cylindrical die (L / D = 6.0 / 2.0 mm). F 30 Melt strength and v 30 To measure the melt extensibility, the pressure at the extruder outlet (= gear pump inlet) is set to 30 bar by bypassing a part of the extruded polymer. The gear pump was pre-adjusted so that the extrusion speed of the strand was 5 mm / s and the melt temperature was set to 200 °C. The spinline length between the die and the Rheotens wheel was 80 mm. At the start of the experiment, the take-up speed of the Rheotens wheel was adjusted to the speed of the extruded polymer strand (zero tensile force). Then, the experiment was started by slowly increasing the take-up speed of the Rheotens wheel until the polymer filament broke. The acceleration of the wheel was made small enough so that the tensile force was measured in a quasi-steady state. The acceleration of the drawn-down melt strand was 120 mm / s 2 This Rheotens was operated in combination with a PC program "EXTENS". This is a real-time data acquisition program that displays and saves the measured data of the tensile force and the draw-down speed. The end point of the Rheotens curve (force vs. pulley rotation speed) at which the polymer strand breaks is taken as the F 30 Melt strength and v 30 value of the melt strength and v

[0145] The UL94 vertical burning test was conducted in accordance with UL94:2016. The sample was injection molded into a piece with a length of 125 ± 5 mm, a width of 13.0 ± 0.5 mm, and a thickness of 0.025 to 13 mm. Under pretreatment condition I, the sample must be conditioned for 48 hours at a constant room temperature of 23 ± 2 °C and a humidity of 50 ± 10%. Under pretreatment condition II, the sample must be conditioned for 168 hours at 70 ± 1 °C in an air circulation oven before the test and then cooled in a desiccator at room temperature for at least 4 hours. The test must be carried out within 30 minutes after removing the sample from conditioning. The sample is vertically suspended in the test chamber and subjected to a first ignition for 10 seconds, followed by a second ignition for another 10 seconds. Record the burning time after each ignition, and also pay attention to whether there is afterglow, whether there is a dripping of burning liquid that ignites the cotton at the bottom of the chamber, and whether there is a flame or red-hot light up to the holding clamp. The classification is V-0, V-1, V-2, or no classification, and the classification depends on the thickness of the object under test.

[0146] Dripping test This method is intended to determine how different formulations drip when they burn. A metal grid with a size of 8 mesh and a diameter of 150 mm is used. Each polymer composition test plate is pressed to a thickness of 3.0 mm and cut to an area of 65×65 mm. Before the test, the sample is conditioned at 23 °C with a relative humidity of 50% for at least 16 hours. The test is then carried out in a fume cupboard. The temperature inside the fume cupboard shall be (23 ± 10) °C. The calibration of the flowmeter is carried out when the gas cylinder is replaced. The recorder is calibrated and the flow rate on the flowmeter is set to butane: 650 ± 30 ml / min (23 °C, 100 kPa). The plate is placed in the center of the net. The burner is lit with a stable flame of about 130 mm with a blue inner flame of about 50 mm. The burner is placed at an angle of 45 degrees inclined towards the center of the sample so that the tip of the inner blue flame hits the center of the surface of the object under test. The burner is maintained in this position throughout the test run. The test time varies greatly depending on the flammability of the material. When the combustion of the sample stops, the burner is removed. At least 3 tests are carried out per sample. The drippings are collected in the bottom water bath. The water is dried and the drippings are weighed. The weight of the remaining dry droplets is divided by the original mass (m / m) and calculated as the weight percentage of the original mass. This test is a comparable test and can be divided into comparable materials.

[0147] 2. Examples Polypropylene polymer (PP) Catalyst preparation The catalyst for the preparation of PP was prepared as follows. 3.4 L of 2-ethylhexanol and 810 mL of propylene glycol butyl monoether (molar ratio 4 / 1) were added to a 20 L reactor. Next, 7.8 L of a 20.0% toluene solution of BEM (butylethylmagnesium) provided by Crompton GmbH was slowly added to the above-mentioned well-stirred alcohol mixture. During the addition, the temperature was maintained at 10.0 °C. After the addition, the temperature of the reaction mixture was raised to 60.0 °C, and mixing was continued at this temperature for 30 minutes. Finally, after cooling to room temperature, the obtained Mg-alkoxide was transferred to a storage container. 21.2 g of the Mg alkoxide prepared above was mixed with 4.0 mL of bis(2-ethylhexyl) citraconate for 5 minutes. After mixing, the obtained Mg complex was immediately used for the preparation of the catalyst component. 19.5 mL of titanium tetrachloride was placed in a 300 mL reactor equipped with a mechanical stirrer at 25.0 °C. The mixing speed was adjusted to 170 rpm. 26.0 g of the Mg complex prepared above was added within 30 minutes while maintaining the temperature at 25.0 °C. 3.0 mL of Viscoplex 1-254 and 1.0 mL of a toluene solution containing 2 mg of Necadd 447 were added. Then, 24.0 mL of heptane was added to form an emulsion. Mixing was continued at 25.0 °C for 30 minutes. Then, the temperature of the reactor was raised to 90.0 °C within 30 minutes. The reaction mixture was stirred at 90.0 °C for an additional 30 minutes. Then, stirring was stopped, and the reaction mixture was allowed to settle at 90.0 °C for 15 minutes.

[0148] This solid material was washed 5 times. The washing was carried out at 80.0 °C with stirring at 170 rpm for 30 minutes. After stopping the stirring, the reaction mixture was allowed to stand for 20 - 30 minutes and then suctioned with a siphon. Washing 1: The washing was carried out with a mixture of 100 mL of toluene and 1 mL of donor. Washing 2: The washing was carried out with a mixture of 30 mL of TiCl4 and 1 mL of donor. Washing 3: The washing was carried out with 100 mL of toluene. Washing 4: The washing was carried out with 60 mL of heptane. Washing 5: The washing was carried out with 60 mL of heptane under stirring for 10 minutes.

[0149] Subsequently, the stirring was stopped, the reaction mixture was allowed to stand for 10 minutes, the temperature was lowered to 70 °C, then suction was performed with a siphon, and subsequently N2 injection (sparging) was carried out for 20 minutes to obtain an air-sensitive powder.

[0150] VCH modification of the catalyst 35 mL of paraffin oil (Paraffinum Liquidum PL68) was added to a 125 mL stainless steel reactor, and then 0.82 g of triethylaluminum (TEAL) and 0.33 g of dicyclopentyldimethoxysilane (donor D) were added at room temperature under inert conditions. After 10 minutes, 5.0 g of the catalyst prepared with 1a (Ti content 1.4 wt%) was added, and after another 20 minutes, 5.0 g of vinylcyclohexane (VCH) was added. The temperature was raised to 60 °C over 30 minutes and maintained at this level for 20 hours. Finally, the temperature was lowered to 20 °C, and the concentration of unreacted VCH in the oil / catalyst mixture was analyzed and found to be 120 ppm by weight.

[0151] The process for preparing a propylene polymer (PP), which is a heterogeneous propylene copolymer, is summarized in Table 1.

[0152]

Table 1

[0153] Preparation of polypropylene composition (C) The propylene polymer PP was melt-blended in a co-rotating twin-screw extruder with a flame retardant composition (FR) and a dripping inhibitor (A) in the amounts shown in Table 2 below.

[0154]

Table 2

[0155] FR is the commercially available flame retardant composition Phlamoon-1090A of SULI, which contains 55 - 60 wt% of melamine polyphosphate and 40 - 55 wt% of piperazine pyrophosphate. HMS-PP is a commercially available long-chain branched polypropylene WB140 HMS from Borealis having a melt flow rate MFR2 (230 °C, 2.16 kg) of 2.1 g / 10 min, an F of 36 cN 30 melt strength and a v of 230 mm / sec 30 melt drawability. PTFE is commercially available PTFE DYNEON TF 2025 Z PTFE (3M). CB is commercially available carbon black masterbatch CBMB-LD-09-A02 (40% carbon black in PE).

[0156] As can be seen from Table 2, the composition of the present invention containing HMS-PP instead of PTFE as a dripping inhibitor is evaluated as V0, and the occurrence of the dripping phenomenon is at a low level.

Claims

1. A flame-retardant polypropylene composition (C), based on the total weight of the flame-retardant polypropylene composition (C), i) 23.0 to 80.0% by weight of a propylene polymer (PP), The propylene polymer (PP) is, a) a matrix (M) that is a polymer of propylene, b) an elastomer (E) that is a copolymer containing units derived from propylene and ethylene and / or C ４ ~C ８ α-olefins and is a heterophasic propylene copolymer (HECO) containing, ii) 10.0 to 40.0% by weight of a nitrogen-containing flame retardant (FR), iii) 10.0 to 37.0% by weight of F determined according to ISO 16790:2005 with a melt strength of 20 cN to 50 cN ３０ an anti - sagging agent (A) which is a high - melt - strength polypropylene (HMS - PP) having a melt strength iv) 0.0 to 15.0% by weight of carbon black (CB) and does not contain glass fibers, The flame-retardant polypropylene composition (C) does not contain halogen, The total amount of the propylene polymer (PP), the nitrogen-containing flame retardant (FR), the anti-dripping agent (A) and optionally the carbon black (CB) is 100% by weight of the flame-retardant polypropylene composition (C). Flame-retardant polypropylene composition (C).

2. A flame-retardant polypropylene composition (C), i) a propylene polymer (PP) which is a heterophasic propylene copolymer (HECO), a) a matrix (M) that is a polymer of propylene, and b) An elastomer (E) which is a copolymer containing units derived from propylene and ethylene and / or C ４ -C ８ α-olefins a propylene polymer (PP) containing, ii) a nitrogen-containing flame retardant (FR), iii) F determined according to ISO 16790:2005 of 20 cN to 50 cN ３０ An anti - sagging agent (A) which is a high - melting - strength polypropylene (HMS - PP) having a melt strength, and iv) optionally, carbon black (CB) and, The flame-retardant polypropylene composition (C) does not contain halogen, The total amount of the propylene polymer (PP), the nitrogen-containing flame retardant (FR), the anti-dripping agent (A) and optionally the carbon black (CB) is 100% by weight of the flame-retardant polypropylene composition (C). Flame-retardant polypropylene composition (C).

3. Based on the total weight of the flame-retardant polypropylene composition (C), i) 20.0 to 65.0% by weight of the propylene polymer (PP), ii) 10.0 to 40.0% by weight of the nitrogen-containing flame retardant (FR), iii) 10.0 to 40.0% by weight of the anti-dripping agent (A), iv) 0.0 to 15.0% by weight of carbon black (CB) The flame-retardant polypropylene composition (C) according to claim 2, comprising.

4. The nitrogen-containing flame retardant (FR) comprises a first nitrogen-containing phosphate (FR1) and a second nitrogen-containing phosphate (FR2). The flame-retardant polypropylene composition (C) according to any one of claims 1 to 3.

5. The flame-retardant polypropylene composition (C) according to claim 4, wherein the weight ratio of the first nitrogen-containing phosphate (FR1) to the second nitrogen-containing phosphate (FR2) is in the range of 60:40 to 40:

60.

6. The flame-retardant polypropylene composition (C) according to claim 4, wherein the first nitrogen-containing phosphate (FR1) is melamine polyphosphate and the second nitrogen-containing phosphate (FR2) is piperazine pyrophosphate.

7. The heterophasic propylene copolymer (HECO) is i) having a comonomer content in the range of 4.0 to 17.0 mol%, and / or ii) having a cold xylene soluble part (XCS) in the range of 7.0 to 25.0% by weight based on the total weight of the heterophasic propylene copolymer (HECO) The flame-retardant polypropylene composition (C) according to claim 2 or claim 3.

8. The cold xylene soluble part (XCS) of the heterophasic propylene copolymer (HECO) is i) having a comonomer content in the range of 25.0 to 65.0 mol%, and / or ii) having an intrinsic viscosity (IV) of less than 3.5 dl / g measured according to ISO 1628 / 1 (at 135 °C in decalin) The flame-retardant polypropylene composition (C) according to claim 7.

9. The high melting strength polypropylene (HMS-PP) has a melt flow rate MFR determined in accordance with ISO 1133 in the range of 0.5 to 15.0 g / 10 min ２ The flame-retardant polypropylene composition (C) according to any one of claims 1 to 3, having ２ (230 °C, 2.16 kg).

10. 1.0 to 30.0 g / 10 min of melt flow rate MFR determined according to ISO 1133 ２ The flame-retardant polypropylene composition (C) according to any one of claims 1 to 3 having ２ (230 °C, 2.16 kg).

11. For use as a sag prevention agent (A) for a halogen-free composition comprising a propylene polymer (PP), a nitrogen-containing flame retardant (FR) and optionally carbon black (CB), F determined according to ISO 16790:2005 of 20 cN to 50 cN ３０ Use of a high melt strength polypropylene (HMS-PP) having a melt strength, a) The composition does not contain glass fibers, and / or b) The propylene polymer (PP) is a heterophasic propylene copolymer (HECO) comprising a matrix (M) that is a polymer of propylene and an elastomer (E) that is a copolymer containing units derived from propylene and ethylene and / or C ４ to C ８ α-olefins, The total amount of the propylene polymer (PP), the nitrogen-containing flame retardant (FR), the anti-dripping agent (A) and optionally the carbon black (CB) is 100% by weight of the composition, for use.

12. An article comprising the flame-retardant polypropylene composition (C) according to any one of claims 1 to 3.

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