Process for preparing long-chain branched polypropylene compositions

Abstract

A process for preparing a long-chain branched polypropylene composition is provided. The process includes the steps of: i) providing a long-chain branched polypropylene; ii) providing a polyfunctional unsaturated compound; iii) optionally providing a radical initiator; iv) combining the long-chain branched polypropylene, the polyfunctional unsaturated compound, and the optional radical initiator to provide a mixture; and v) melt extruding the mixture to obtain a long-chain branched polypropylene composition. A long-chain branched polypropylene composition is provided that can be obtained by melt extruding a mixture comprising (a) long-chain branched polypropylene, (b) a polyfunctional unsaturated compound, and (c) optionally, a radical initiator. Use of the polyfunctional unsaturated compound to reduce melt strength loss during melt extrusion of the long-chain branched polypropylene, preferably recycled long-chain branched polypropylene, is also provided.

Description

[Technical Field]

[0001] This application relates to a process for preparing a long-chain branched polypropylene composition, and to the long-chain branched polypropylene composition itself. This application further relates to a process for reducing the melt strength loss of long-chain branched polypropylene during melt extrusion. [Background technology]

[0002] Long-chain branched polypropylenes are a group of polypropylenes that have relatively high melt strength and are used in many applications where high melt strength polypropylene is required, such as foaming applications.

[0003] For example, WO 2012 / 049690 A1 describes a process for preparing high melt strength propylene polymers. Furthermore, WO 2011086581 A1 describes a process for modifying propylene polymers via melt grafting of polyfunctional monomers (PFMs).

[0004] Like other polymer materials, long-chain branched polypropylene typically degrades during melt extrusion processing. A common problem is that long-chain branched polypropylene that has already been subjected to two or more melt extrusion processes loses its melt strength to a significant extent. This means that the degraded long-chain branched polypropylene can no longer serve its intended purpose when the material is recycled. Therefore, the degradation and loss of melt strength limit the reusability of long-chain branched polypropylene, as the reused polypropylene material may no longer have sufficient melt strength to provide its full functionality.

[0005] Therefore, there is a continuing need in the art to provide a process that can minimize degradation and / or loss of melt strength of long chain branched polypropylene during processing. [Prior art documents] [Patent documents]

[0006] [Patent Document 1] International Publication No. 2012 / 049690A1 Brochure [Patent Document 2] International Publication No. 2011086581A1 Brochure Summary of the Invention [Problem to be solved by the invention]

[0007] One object of the present application is to provide a process for preparing a long-chain branched polypropylene composition. Another object of the present application is to provide a long-chain branched polypropylene composition. [Means for solving the problem]

[0008] One aspect of the present invention provides a method for preparing a long-chain branched polypropylene composition, the method comprising: i) providing a long chain branched polypropylene; ii) providing a polyfunctional unsaturated compound; iii) optionally providing a radical initiator; iv) combining the long chain branched polypropylene, the multifunctional unsaturated compound, and optionally the radical initiator to provide a mixture; v) melt-extruding the mixture to obtain a long-chain branched polypropylene composition; Includes:

[0009] One finding of the present inventors is that combining long-chain branched polypropylene, such as reused or recycled long-chain branched polypropylene, with a polyfunctional unsaturated compound can reduce the loss of melt strength during melt extrusion. It has further been found that the addition of a polyfunctional unsaturated compound, and optionally a radical initiator, can reduce the gel content, as determined, for example, by the hot xylene-insoluble fraction. This finding was unexpected because the addition of a polyfunctional unsaturated compound during the extrusion process typically results in crosslinking of the polymer, which in turn increases the gel content. An increase in gel content is undesirable because the gel is usually no longer dispersible and therefore leads to material defects in many applications, such as the preparation of films and fibers, and in some cases, even during molding.

[0010] Another aspect of the present invention provides a long-chain branched polypropylene composition, the polypropylene composition comprising: (a) long-chain branched polypropylene; (b) a polyfunctional unsaturated compound; and (c) optionally a radical initiator; The composition can be obtained by melt-extruding a mixture comprising:

[0011] Another aspect of the present invention provides the use of a polyfunctional unsaturated compound to reduce the loss of melt strength of long-chain branched polypropylene, preferably recycled long-chain branched polypropylene, during melt extrusion. The present invention also provides a method for reducing the loss of melt strength of long-chain branched polypropylene during melt extrusion, the method comprising the steps of: i) combining long-chain branched polypropylene with a polyfunctional unsaturated compound, and optionally a radical initiator, to provide a mixture; and ii) melt extruding the mixture.

[0012] Further embodiments of the invention are defined in the dependent claims.

[0013] According to one embodiment of the present invention, the long-chain branched polypropylene is a recycled long-chain branched polypropylene.

[0014] According to one embodiment of the present invention, the long-chain branched polypropylene is a long-chain branched propylene homopolymer.

[0015] According to one embodiment of the present invention, the long-chain branched polypropylene has the following properties: i) a melt flow rate MFR2 (ISO1133, 2.16 kg load, 230°C) in the range of 0.5 to 10 g / 10 min, preferably in the range of 1.5 to 7.5 g / 10 min, more preferably in the range of 2.5 to 6.0 g / 10 min; ii) a melt strength F in the range of 5.0 to 50.0 cN, preferably 10.0 to 50.0 cN, more preferably 15.0 to 35.0 cN, and even more preferably 20.0 to 30.0 cN; 30 (ISO16790:2005), iii) a melt drawability v in the range of 200 to 300 mm / s, preferably 220 to 290 mm / s, more preferably 240 to 280 mm / s; 30 (ISO16790:2005) The present invention has one or more, preferably all, of the following:

[0016] According to one embodiment of the present invention, the polyfunctional unsaturated compound is a polyfunctional (meth)acrylate compound, preferably a polyfunctional acrylate monomer.

[0017] According to one embodiment of the present invention, the mixture provided in step iv) comprises a radical initiator, preferably a peroxide radical initiator, more preferably an organic peroxide radical initiator.

[0018] According to one embodiment of the present invention, step iii) is not performed and the mixture provided in step iv) does not contain a radical initiator.

[0019] According to one embodiment of the present invention, the mixture provided in step iv) comprises: (a) 95.0 to 99.95% by weight, preferably 97.5 to 99.95% by weight, more preferably 99.0 to 99.90% by weight of the long-chain branched polypropylene; (b) 0.05 to 5.0 wt %, preferably 0.05 to 2.5 wt %, and even more preferably 0.10 to 1.0 wt % of the polyfunctional unsaturated compound; (c) optionally, 0.0001 to 0.20 wt %, preferably 0.004 to 0.15 wt %, more preferably 0.004 to 0.10 wt % of a radical initiator; wherein all amounts by weight are based on the total weight of the mixture provided in step iv), and optionally the amounts by weight of components (a)-(c) add up to 100 wt.%.

[0020] According to one embodiment of the invention, the mixture provided in step iv) comprises the components provided in steps i) to iii) in the following relative amounts: (a) the long-chain branched polypropylene in the range of 95.0 to 99.95 parts by weight (pbw), preferably 97.5 to 99.95 parts by weight (pbw), more preferably 99.0 to 99.90 parts by weight (pbw), for example, 99.25 to 99.90 parts by weight (pbw); (b) 0.05 to 5.0 parts by weight (pbw), preferably 0.05 to 2.5 parts by weight (pbw), even more preferably 0.10 to 1.0 parts by weight (pbw), for example 0.10 to 0.75 parts by weight (pbw), of the polyfunctional unsaturated compound; and (c) optionally, a radical initiator in the range of 0.0001 to 0.20 parts by weight (pbw), preferably 0.004 to 0.15 parts by weight (pbw), more preferably 0.004 to 0.10 parts by weight (pbw), for example 0.005 to 0.10 parts by weight (pbw).

[0021] According to one embodiment of the present invention, the long-chain branched polypropylene composition obtained in step v) has a melt strength F of a comparative long-chain branched polypropylene composition obtained by a comparative process that does not use the above-mentioned polyfunctional unsaturated compound in a comparative test. 30Increased, preferably at least 3.0% increased melt strength F compared to (ISO16790:2005) 30 (ISO16790:2005).

[0022] According to one embodiment of the present invention, the long-chain branched polypropylene composition obtained in step v) has, in a comparative test, a hot-xylene insoluble fraction (XHI) that is reduced by at least 50%, preferably at least 60%, more preferably at least 80%, and even more preferably at least 90% compared to the hot-xylene insoluble fraction (XHI) of a comparative long-chain branched polypropylene composition obtained by a comparative process that does not use the polyfunctional unsaturated compound.

[0023] According to one embodiment of the present invention, the long-chain branched polypropylene composition has the following properties: i) a melt flow rate MFR2 (ISO1133, 2.16 kg load, 230°C) in the range of 3.0 to 30 g / 10 min, preferably in the range of 5.0 to 25.0 g / 10 min, more preferably in the range of 8.0 to 20.0 g / 10 min; ii) A melt strength F in the range of 3.0 to 25.0 cN, preferably in the range of 4.0 to 15.0 cN, and more preferably in the range of 4.0 to 7.5 cN 30 (ISO16790:2005), iii) Melt drawability v in the range of 200 to 290 mm / s, preferably in the range of 220 to 290 mm / s, more preferably in the range of 240 to 280 mm / s 30 (ISO16790:2005) The present invention has one or more, preferably all, of the following:

[0024] According to one embodiment of the present invention, the long-chain branched polypropylene composition has a hot xylene insoluble fraction (XHI) of less than 0.10 wt%, preferably less than 0.05 wt%, more preferably 0.02 wt% or less, based on the total weight of the long-chain branched polypropylene composition.

[0025] According to one embodiment of the present invention, the long-chain branched polypropylene composition comprises at least 95.0 wt.%, preferably at least 97.5 wt.%, more preferably at least 98.0 wt.%, of long-chain branched polypropylene, based on the total weight of the long-chain branched polypropylene composition.

[0026] Where the term "comprising" is used in the present specification and claims, it does not exclude other unspecified elements, whether functionally significant or immaterial. For the purposes of the present invention, the terms "essentially consisting of" and "consisting of" are considered to be specific embodiments of the term "comprising of." Hereinafter, when a group is defined as including at least a certain number of features or embodiments, this should be understood to also disclose groups that optionally consist essentially of or consist of only these features or embodiments. Whenever the terms "including" or "having" are used, these terms are meant to be equivalent to "comprising" as defined above.

[0027] In the following, the invention will be explained in more detail. DETAILED DESCRIPTION OF THE INVENTION

[0028] Process for preparing long-chain branched polypropylene compositions One aspect of the present invention provides a process for preparing a long-chain branched polypropylene composition, the process comprising: i) providing a long chain branched polypropylene; ii) providing a polyfunctional unsaturated compound; iii) optionally providing a radical initiator; iv) combining the long chain branched polypropylene, the multifunctional unsaturated compound, and optionally the radical initiator to provide a mixture; v) melt-extruding the mixture to obtain a long-chain branched polypropylene composition; Includes:

[0029] The process is preferably carried out for the purpose of reducing the loss of melt strength of the long-chain branched polypropylene during melt extrusion, i.e., melt mixing and / or melt compounding in an extruder, and is therefore preferably a process for preparing a long-chain branched polypropylene composition having reduced loss of melt strength.

[0030] "Reduced melt strength loss" and "reduced melt strength loss" can be determined by comparing a long-chain branched polypropylene composition obtained by the process of the present invention with a long-chain branched polypropylene composition obtained in a comparative test by a comparative process that does not use a polyfunctional unsaturated compound.

[0031] Process i) Step i) of the process provides long chain branched polypropylene. Long chain polypropylenes are known to those skilled in the art.

[0032] Long-chain branched polypropylene differs from linear polypropylene in that the polypropylene backbone contains long side chains, while unbranched polypropylene, i.e., linear polypropylene, does not. The long side chains branching from the polymer backbone significantly affect the rheology of polypropylene. Therefore, linear polypropylene and long-chain branched polypropylene can be clearly distinguished, for example, by their flow behavior under stress (e.g., the ratio of polymer melt viscosities measured under different loads). Additionally or alternatively, long-chain branching can be determined by analyzing the content of long-chain branches by NMR and / or by measuring the long-chain branching index g', for example, by using SEC / VISC-LS (size exclusion chromatography / viscometry-light scattering) as known in the art. The branching index g' is a parameter of the degree of branching. The branching index g' correlates with the amount of branching in a polymer. A low g' value is an indicator of a highly branched polymer. That is, the smaller the g' value, the more branched the polypropylene. For example, a g' value of at least 0.96, such as at least 0.97 or at least 0.98, typically indicates an absence of long chain branching, while a g' value of 0.9 or less (e.g., 0.6-0.9), such as 0.8 or less, typically indicates that the polymer contains long chain branching.

[0033] The long-chain branched polypropylene provided in step i) of the process preferably has a branching index g' of 0.9 or less, for example in the range of 0.6 to 0.9. The long-chain branching index g' can be determined, for example, by using SEC / VISC-LS (size exclusion chromatography / viscometry-light scattering) as known in the art. Further details regarding the branching index g' and how to determine it are described, for example, in the "Measuring methods" section of EP 3280748 B1, which is incorporated herein by reference.

[0034] Due to its particular melt strength properties, long chain branched polypropylene is also referred to in the art as high melt strength polypropylene.

[0035] Long-chain branching can usually be achieved by using specific catalysts, i.e., specific single-site catalysts, or by chemical modification. For the preparation of long-chain branched polypropylene obtained by using specific catalysts, see EP 1 892 264. For long-chain branched polypropylene obtained by chemical modification, see, for example, EP 0 787 750, EP 0 879 830 A1, and EP 0 890 612 A2.

[0036] Long-chain branched polypropylenes typically have a relatively low melt flow rate combined with high melt strength and high melt extensibility.

[0037] The long-chain branched polypropylene provided in step i) may generally be any type of long-chain branched polypropylene, preferably any type of long-chain branched polypropylene that undergoes degradation during melt extrusion. Thus, this long-chain branched polypropylene may be new long-chain branched polypropylene (also referred to in the art as "virgin grade") or recycled long-chain branched polypropylene.

[0038] The long-chain branched polypropylene provided in step i) is preferably a recycled long-chain branched polypropylene. "Recycled long-chain branched polypropylene" is preferably understood as a long-chain branched polypropylene that has already been subjected to at least one melt extrusion process, for example one or two melt extrusion processes. Thus, the long-chain branched polypropylene may be a degraded long-chain branched polypropylene.

[0039] This recycled long-chain branched polypropylene can be collected from different sources, such as from waste streams or from production by-products that do not meet given specifications ("off-spec product", e.g., edges in sheet production). The recycled long-chain branched polypropylene provided in step i) of the process may be provided as a single component or in another relatively pure form containing 5.0 wt. % or less of other components, based on the total weight of the material comprising the recycled long-chain branched polypropylene. However, the recycled long-chain branched polypropylene provided in step i) of the process can also be provided in the form of a blend with other components, such as polymer blend partners.

[0040] The recycled long chain branched polypropylene provided in step i) has a melt strength F 30 It may also be recycled long-chain branched polypropylene that has lost at least 10% (e.g., 10-95%), for example at least 20%, of its original melt strength as determined by ISO 16790:2005. The "original melt strength" is the melt strength of new long-chain branched polypropylene (also referred to in the art as "virgin grade"), i.e., that which has not yet been subjected to a melt extrusion process.

[0041] When the long chain branched polypropylene provided in step i) is a recycled long chain branched polypropylene, process step i) preferably comprises i-1) melt-extruding a long-chain branched polypropylene or a composition containing long-chain branched polypropylene; i-2) collecting the melt-extruded long-chain branched polypropylene or the melt-extruded composition comprising long-chain branched polypropylene, optionally in the form of a waste or by-product, to provide recycled long-chain branched polypropylene or a composition comprising recycled long-chain branched polypropylene; Includes.

[0042] Thus, the long chain branched polypropylene provided in step i) is preferably i-1) melt-extruding a long-chain branched polypropylene or a composition containing long-chain branched polypropylene; i-2) collecting the melt-extruded long-chain branched polypropylene or the melt-extruded composition comprising long-chain branched polypropylene, optionally in the form of a waste or by-product, to provide recycled long-chain branched polypropylene or a composition comprising recycled long-chain branched polypropylene; The recycled long chain branched polypropylene is obtained or obtainable by a process comprising:

[0043] The long-chain branched polypropylene provided in step i), more preferably the recycled long-chain branched polypropylene, preferably has certain properties.

[0044] According to one embodiment of the present invention, the long-chain branched polypropylene provided in step i), preferably the recycled long-chain branched polypropylene, has a melt flow rate MFR2 (ISO 1133, 2.16 kg load, 230°C) in the range of 0.5 to 10 g / min, preferably 1.5 to 7.5 g / 10 min, more preferably 2.5 to 6.0 g / 10 min, for example, 3.0 to 5.0 g / 10 min. For example, the melt flow rate MFR2 (ISO 1133, 2.16 kg load, 230°C) may be about 3.9 g / 10 min.

[0045] According to one embodiment of the present invention, the long-chain branched polypropylene provided in step i), preferably the recycled long-chain branched polypropylene, has a melt strength F in the range of 5.0 to 50.0 cN (e.g., 5.0 to 30.0 cN), preferably 10.0 to 50.0 cN, more preferably 15.0 to 35.0 cN, even more preferably 20.0 to 30.0 cN, for example, 25.0 to 28.0 cN. 30 (ISO16790:2005). For example, melt strength F 30 (ISO16790:2005) may be approximately 26 cN.

[0046] According to one embodiment of the present invention, the long-chain branched polypropylene provided in step i), preferably the recycled long-chain branched polypropylene, has a melt extensibility v in the range of 200 to 300 mm / s, preferably 220 to 290 mm / s, more preferably 240 to 280 mm / s, for example 250 to 270 mm / s. 30 (ISO16790:2005). For example, melt extensibility v 30 (ISO16790:2005) may be approximately 268 mm / s.

[0047] The long-chain branched polypropylene provided in step i), preferably the recycled long-chain branched polypropylene, is preferably characterized by a combination of properties. Thus, according to one preferred embodiment of the present invention, the long-chain branched polypropylene provided in step i), preferably the recycled long-chain branched polypropylene, has the following properties i) and ii), more preferably all of the following properties i) to iii). i) a melt flow rate MFR2 (ISO1133, 2.16 kg load, 230°C) in the range of 0.5 to 10 g / 10 min, preferably in the range of 1.5 to 7.5 g / 10 min, more preferably in the range of 2.5 to 6.0 g / 10 min, for example in the range of 3.0 to 5.0 g / 10 min; ii) A melt strength F in the range of 5.0 to 50.0 cN (for example, 5.0 to 30.0 cN), preferably 10.0 to 50.0 cN, more preferably 15.0 to 35.0 cN, even more preferably 20.0 to 30.0 cN, for example, 25.0 to 28.0 cN 30 (ISO16790:2005), iii) a melt drawability v in the range of 200 to 300 mm / s, preferably 220 to 290 mm / s, more preferably 240 to 280 mm / s, for example, 250 to 270 mm / s; 30 (ISO16790:2005).

[0048] The long-chain branched polypropylene provided in step i) is not particularly limited with respect to the linear polypropylene forming its longest chain or backbone, and may be a long-chain branched propylene copolymer or a long-chain branched propylene homopolymer.

[0049] The long-chain branched polypropylene provided in step i), preferably the long-chain branched polypropylene to be reused, is preferably a long-chain branched propylene homopolymer.

[0050] In the case where the long-chain branched polypropylene is a long-chain branched polypropylene obtained (initially) by chemical modification of a linear polypropylene, the definitions propylene homopolymer and propylene copolymer should be understood to refer to the linear polypropylene used to obtain the long-chain branched polypropylene by chemical modification with difunctional unsaturated monomer(s) and / or polyfunctional unsaturated low molecular weight polymer(s), e.g. in reactive extrusion.

[0051] As mentioned above, the long-chain branched polypropylene provided in step i) is preferably recycled long-chain branched polypropylene. The recycled long-chain branched polypropylene is preferably obtained from virgin long-chain branched polypropylene, i.e., long-chain branched polypropylene that has not been previously melt extruded ("virgin grade" material), hereinafter referred to as "virgin long-chain branched PP".

[0052] Virgin long-chain branched PP has the following properties: i) a melt flow rate MFR2 (ISO1133, 2.16 kg load, 230°C) in the range of 0.5 to 5.0 g / 10 min, preferably in the range of 1.0 to 4.0 g / 10 min, more preferably in the range of 1.5 to 3.0 g / 10 min; ii) A melt strength F of more than 25.0 cN, preferably in the range of more than 25.0 to 50.0 cN, more preferably in the range of 30.0 to 40.0 cN 30 (ISO16790:2005), and iii) a melt drawability v in the range of 200 to 300 mm / s, preferably 220 to 290 mm / s, more preferably 220 to 270 mm / s; 30 (ISO16790:2005) It may have one or more, preferably all, of:

[0053] The virgin long-chain branched PP may have a melting point in the range of 140 to 175° C., preferably in the range of 145 to 170° C., and most preferably in the range of 150 to 167° C. The crystallization temperature may be in the range of 110 to 140° C., preferably in the range of 115 to 135° C., and most preferably in the range of 120 to 132° C.

[0054] In one preferred embodiment, the long chain branched polypropylene provided in step i) is i-1) melt extruding virgin long-chain branched polypropylene or a composition comprising virgin long-chain branched polypropylene, wherein the virgin long-chain branched polypropylene is preferably as defined above; i-2) collecting the melt-extruded long-chain branched polypropylene or the melt-extruded composition comprising long-chain branched polypropylene obtained in step i-2), optionally in the form of a waste or by-product, to provide recycled long-chain branched polypropylene or a composition comprising recycled long-chain branched polypropylene; The recycled long chain branched polypropylene is obtained or obtainable by a process comprising:

[0055] Virgin long-chain branched PP can be obtained by treating linear polypropylene with a radical former, preferably in the presence of difunctionally unsaturated monomer(s) and / or polyfunctionally unsaturated low molecular weight polymer(s).

[0056] The polyfunctionally unsaturated low molecular weight polymer preferably has a number average molecular weight (Mn) of 10,000 g / mol or less. The difunctionally unsaturated monomer may be selected from divinyl compounds, allyl compounds, dienes, etc. Suitable methods for obtaining virgin long-chain branched PP are disclosed, for example, in EP 0 787 750 A, EP 0 879 830 A1 and EP 0 890 612 A2.

[0057] A suitable virgin long-chain branched PP is WB140HMS™ commercially available from Borealis AG. Accordingly, a suitable recycled long-chain branched polypropylene provided in step i) is long-chain branched polypropylene WB140HMS™ that is recycled after a melt extrusion process, for example a single melt extrusion process, and is optionally provided in the form and / or as part of a waste or by-product.

[0058] Process ii) In step ii) of the process, a polyfunctional unsaturated compound is provided. The polyfunctional unsaturated compound may generally be any compound capable of reacting with the long-chain branched polypropylene during melt extrusion, optionally under radical reaction conditions. Preferably, the polyfunctional unsaturated compound is a liquid or solid, more preferably a liquid, such as a low volatility liquid.

[0059] The polyfunctional unsaturated compound is preferably a compound having two or more (e.g., two to four) non-aromatic carbon-carbon (C-C) double bonds. The two or more non-aromatic C-C double bonds are preferably terminal C-C double bonds. Those skilled in the art can identify terminal double bonds in chemical structures. A terminal C-C double bond is a C-C double bond in which one of the two C atoms has two hydrogen substituents.

[0060] The polyfunctional unsaturated compound may be a monomer, oligomer, or polymer, and is preferably a monomer. Monomers are typically small organic compounds that can undergo a polymerization reaction.

[0061] Preferably, the polyfunctional unsaturated compound is a polyfunctional unsaturated monomer having a molecular weight of less than 500 g / mol, more preferably 400 g / mol or less (for example in the range of 100 to 400 g / mol).

[0062] The polyfunctional unsaturated compound is preferably a branched-chain compound.

[0063] According to one embodiment, the polyfunctional unsaturated compound has two or more, preferably two to four (e.g., three) terminal C-C double bonds and a molecular weight of less than 500 g / mol, preferably 400 g / mol or less (e.g., in the range of 100 to 400 g / mol).

[0064] The polyfunctional unsaturated compound is preferably a polyfunctional unsaturated (meth)acrylate compound, more preferably a polyfunctional unsaturated acrylate compound, and even more preferably a polyfunctional unsaturated acrylate monomer.

[0065] The polyfunctional unsaturated (meth)acrylate compound is preferably an ester of a diol, triol, or tetraol with (meth)acrylic acid, more preferably an ester with acrylic acid. Thus, the polyfunctional unsaturated (meth)acrylate compound may be, but is not limited to, a di(meth)acrylate, a tri(meth)acrylate, or a tetra(meth)acrylate, preferably a diacrylate, a triacrylate, or a tetraacrylate.

[0066] According to one embodiment, the polyfunctional unsaturated compound is a polyfunctional unsaturated (meth)acrylate compound, preferably a polyfunctional unsaturated acrylate compound, containing two or more, preferably two to four (e.g., three) acrylate esters.

[0067] According to one preferred embodiment, the polyfunctional unsaturated compound is a polyfunctional unsaturated (meth)acrylate compound, preferably a polyfunctional unsaturated acrylate compound, which contains two or more, preferably two to four (e.g., three) acrylate esters and has a molecular weight of less than 500 g / mol, preferably 400 g / mol or less (e.g., in the range of 100 to 400 g / mol).

[0068] For example, the polyfunctional unsaturated compound may be a triacrylate. According to one preferred embodiment, the polyfunctional unsaturated compound is a polyfunctional unsaturated (meth)acrylate compound, preferably a polyfunctional unsaturated acrylate compound, containing three acrylate esters and having a molecular weight of less than 500 g / mol, preferably 400 g / mol or less (e.g., in the range of 100 to 400 g / mol).

[0069] A suitable polyfunctional unsaturated compound is trimethylolpropane triacrylate, also known in the art as TMPTA.

[0070] Process iii) In optional step iii) of the process, a radical initiator is provided. Radical initiators are known to those skilled in the art. The radical initiator may be, for example, a peroxide, an azo compound, a nitroxide, a trialkylborane, or the like. The radical initiator provided in step iii) is preferably an effective radical initiator when used in an amount ranging from 1 to 2000 ppm.

[0071] The radical initiator may be any radical initiator suitable for initiating the radical reaction between a polyfunctional unsaturated compound, preferably a polyfunctional unsaturated (meth)acrylate compound, and polypropylene, preferably long-chain branched polypropylene.

[0072] The radical initiator is preferably a peroxide radical initiator, more preferably an organic peroxide radical initiator. The organic peroxide radical initiator can be, but is not limited to, a peroxycarbonate compound, a peroxyether compound, a peroxyester compound, or a peroxyacid compound. In one embodiment, the radical initiator is:

[0073] A preferred radical initiator is tert-butyl peroxyisopropyl carbonate.

[0074] Process iv) In step iv) of the process, the long-chain branched polypropylene provided in step i), the polyfunctional unsaturated compound provided in step ii), and the optional radical initiator optionally provided in step iii) are combined to provide a mixture.

[0075] Combining the above ingredients can be done by any means known in the art.

[0076] The components provided in steps i) to iii) can be mixed or blended outside the extruder by conventional means. Thus, the components provided in steps i) to iii) can be pre-mixed or pre-blended in step iv) and before step v), i.e., the components are pre-mixed in step iv) before being fed to the extruder. It is also possible to provide the components provided in steps ii) and iii) together in the form of a masterbatch.

[0077] Alternatively, the components provided in steps i)-iii) can be combined in an extruder, for example, in the feed screw of the extruder. In such cases, the components are not premixed or preblended before being fed to the extruder, but are added to the extruder as a single component. It is also possible to premix or preblend selected components and then combine the premix or preblend with other components in the extruder to provide the mixture.

[0078] Generally, the mixture provided in step iv) is not necessarily limited to the components provided in steps i)-iii), and additional components may be added to or present with the components provided in steps i)-iii).

[0079] Thus, the mixture provided in step iv) may contain additional components other than those provided in steps i) to iii), which may be, but are not limited to, one or more additional polymer components and / or one or more additives.

[0080] The one or more additional polymeric components may be polymeric components that are melt mixable and / or melt compoundable with the long chain branched polypropylene provided in step i).

[0081] The one or more additives may be selected by those skilled in the art as needed. For example, the one or more additives may include a foaming agent. The foaming agent is known to those skilled in the art and may be selected from chemical foaming agents and physical foaming agents known in the art. The physical foaming agent may be injected into the mixture in step v).

[0082] According to one embodiment, the mixture provided in step iv) comprises a polymer material other than the long-chain branched polypropylene provided in step i) in an amount of 10.0 wt % or less (e.g., 0.0 to 10.0 wt %) based on the total weight of the mixture provided in step iv).

[0083] The components provided in steps i) to iii) are preferably present in particular relative and / or total amounts in the mixture provided in step iv).

[0084] The long-chain branched polypropylene, polyfunctional unsaturated compound and optional radical initiator may be combined in a mixture in specific relative amounts.

[0085] According to one preferred embodiment, the long-chain branched polypropylene provided in step i) is combined with the polyfunctional unsaturated compound provided in step ii) in a weight ratio [long-chain branched polypropylene:polyfunctional unsaturated compound] in the range of 90.0:10.0 to 99.95:0.05, preferably 95.0:5.0 to 99.95:0.05, more preferably 97.5:2.5 to 99.95:0.05, and even more preferably 99.0:1.0 to 99.90:0.10.

[0086] According to one preferred embodiment, the mixture provided in step iv) comprises the components provided in steps i) to iii) in the following relative amounts: (a) the long-chain branched polypropylene in the range of 95.0 to 99.95 parts by weight (pbw), preferably 97.5 to 99.95 parts by weight (pbw), more preferably 99.0 to 99.90 parts by weight (pbw), for example, 99.25 to 99.90 parts by weight (pbw); (b) 0.05 to 5.0 parts by weight (pbw), preferably 0.05 to 2.5 parts by weight (pbw), even more preferably 0.10 to 1.0 parts by weight (pbw), for example 0.10 to 0.75 parts by weight (pbw), of the polyfunctional unsaturated compound; and (c) optionally, a radical initiator in the range of 0.0001 to 0.20 parts by weight (pbw), preferably 0.004 to 0.15 parts by weight (pbw), more preferably 0.004 to 0.10 parts by weight (pbw), for example 0.005 to 0.10 parts by weight (pbw).

[0087] The long-chain branched polypropylene, polyfunctional unsaturated compound and optional radical initiator may be combined in a specific total amount based on the total weight of the mixture provided in step iv).

[0088] According to one preferred embodiment of the present invention, the mixture provided in step iv) comprises: (a) 95.0 to 99.95% by weight, preferably 97.5 to 99.95% by weight, more preferably 99.0 to 99.90% by weight, for example, 99.25 to 99.90% by weight of the long-chain branched polypropylene; (b) 0.05 to 5.0% by weight, preferably 0.05 to 2.5% by weight, even more preferably 0.10 to 1.0% by weight, for example, 0.10 to 0.75% by weight of the polyfunctional unsaturated compound; (c) optionally, in the range of 0.0001 to 0.20 wt %, preferably 0.004 to 0.15 wt %, more preferably 0.004 to 0.10 wt %, for example 0.005 to 0.10 wt %, of a radical initiator; and all amounts by weight are based on the total weight of the mixture provided in step iv).

[0089] The radical initiator may be absent from the mixture provided in step iv), i.e., step iii) may not be carried out. In this case, the mixture provided in step iv) may contain: (a) 95.0 to 99.95% by weight, preferably 97.5 to 99.95% by weight, more preferably 99.0 to 99.90% by weight, for example, 99.25 to 99.90% by weight of the long-chain branched polypropylene; (b) 0.05 to 5.0% by weight, preferably 0.05 to 2.5% by weight, even more preferably 0.10 to 1.0% by weight, for example, 0.10 to 0.75% by weight of the polyfunctional unsaturated compound; and all amounts by weight are based on the total weight of the mixture provided in step iv).

[0090] In another embodiment, the radical initiator is present in the mixture provided in step iv), i.e., step iii) is carried out, in which case the mixture provided in step iv) comprises: (a) 95.0 to 99.95% by weight, preferably 97.5 to 99.95% by weight, more preferably 99.0 to 99.90% by weight, for example, 99.25 to 99.90% by weight of the long-chain branched polypropylene; (b) 0.05 to 5.0% by weight, preferably 0.05 to 2.5% by weight, even more preferably 0.10 to 1.0% by weight, for example, 0.10 to 0.75% by weight of the polyfunctional unsaturated compound; (c) a radical initiator in the range of 0.0001 to 0.20% by weight, preferably 0.004 to 0.15% by weight, more preferably 0.004 to 0.10% by weight, for example, 0.005 to 0.10% by weight; and all amounts by weight are based on the total weight of the mixture provided in step iv).

[0091] In one embodiment, the mixture provided in step iv) comprises: (a) 95.0 to 99.9499% by weight, preferably 97.5 to 99.946% by weight, more preferably 99.0 to 99.896% by weight, for example, 99.25 to 99.895% by weight of the long-chain branched polypropylene; (b) 0.05 to 5.0% by weight, preferably 0.05 to 2.5% by weight, even more preferably 0.10 to 1.0% by weight, for example, 0.10 to 0.75% by weight of the polyfunctional unsaturated compound; (c) a radical initiator in the range of 0.0001 to 0.20% by weight, preferably 0.004 to 0.15% by weight, more preferably 0.004 to 0.10% by weight, for example, 0.005 to 0.10% by weight; and all amounts by weight are based on the total weight of the mixture provided in step iv).

[0092] No additional components other than those provided in steps i) to iii) may be present in the mixture provided in step iv). Thus, according to one embodiment, the mixture provided in step iv) comprises: (a) 95.0 to 99.95% by weight, preferably 97.5 to 99.95% by weight, more preferably 99.0 to 99.90% by weight, for example, 99.25 to 99.90% by weight of the long-chain branched polypropylene; (b) 0.05 to 5.0% by weight, preferably 0.05 to 2.5% by weight, even more preferably 0.10 to 1.0% by weight, for example, 0.10 to 0.75% by weight of the polyfunctional unsaturated compound; (c) optionally, in the range of 0.0001 to 0.20 wt %, preferably 0.004 to 0.15 wt %, more preferably 0.004 to 0.10 wt %, for example 0.005 to 0.10 wt %, of a radical initiator; consisting essentially of, and preferably consisting of, all amounts by weight based on the total weight of the mixture provided in step iv), with the amounts by weight of components (a)-(c) adding up to 100% by weight, which should be understood in that when the optional radical initiator is not present, the amounts by weight of components (a) and (b) add up to 100% by weight, and when the radical initiator is present, the amounts by weight of components (a)-(c) add up to 100% by weight.

[0093] According to one embodiment, the mixture provided in step iv) comprises: (a) 95.0 to 99.95% by weight, preferably 97.5 to 99.95% by weight, more preferably 99.0 to 99.90% by weight, for example, 99.25 to 99.90% by weight of the long-chain branched polypropylene; (b) 0.05 to 5.0% by weight, preferably 0.05 to 2.5% by weight, even more preferably 0.10 to 1.0% by weight, for example, 0.10 to 0.75% by weight of the polyfunctional unsaturated compound; (c) optionally, in the range of 0.0001 to 0.20 wt %, preferably 0.004 to 0.15 wt %, more preferably 0.004 to 0.10 wt %, for example 0.005 to 0.10 wt %, of a radical initiator; and preferably consists essentially of, and all amounts by weight are based on the total weight of the mixture provided in step iv).

[0094] In one embodiment, the mixture provided in step iv) comprises: (a) 95.0 to 99.95% by weight, preferably 97.5 to 99.95% by weight, more preferably 99.0 to 99.90% by weight, for example, 99.25 to 99.90% by weight of the long-chain branched polypropylene; (b) 0.05 to 5.0% by weight, preferably 0.05 to 2.5% by weight, even more preferably 0.10 to 1.0% by weight, for example, 0.10 to 0.75% by weight of the polyfunctional unsaturated compound; all amounts by weight based on the total weight of the mixture provided in step iv), and the amounts by weight of components (a) and (b) add up to 100% by weight.

[0095] In another embodiment, the mixture provided in step iv) comprises: (a) 95.0 to 99.95% by weight, preferably 97.5 to 99.95% by weight, more preferably 99.0 to 99.90% by weight, for example, 99.25 to 99.90% by weight of the long-chain branched polypropylene; (b) 0.05 to 5.0% by weight, preferably 0.05 to 2.5% by weight, even more preferably 0.10 to 1.0% by weight, for example, 0.10 to 0.75% by weight of the polyfunctional unsaturated compound; (c) a radical initiator in the range of 0.0001 to 0.20% by weight, preferably 0.004 to 0.15% by weight, more preferably 0.004 to 0.10% by weight, for example, 0.005 to 0.10% by weight; all amounts by weight are based on the total weight of the mixture provided in step iv) and the amounts by weight of components (a)-(c) add up to 100 wt.%.

[0096] In one embodiment, the mixture provided in step iv) comprises: (a) 95.0 to 99.9499% by weight, preferably 97.5 to 99.946% by weight, more preferably 99.0 to 99.896% by weight, for example, 99.25 to 99.895% by weight of the long-chain branched polypropylene; (b) 0.05 to 5.0% by weight, preferably 0.05 to 2.5% by weight, even more preferably 0.10 to 1.0% by weight, for example, 0.10 to 0.75% by weight of the polyfunctional unsaturated compound; (c) a radical initiator in the range of 0.0001 to 0.20% by weight, preferably 0.004 to 0.15% by weight, more preferably 0.004 to 0.10% by weight, for example, 0.005 to 0.10% by weight; all amounts by weight being based on the total weight of the mixture provided in step iv).

[0097] Process v) In step v) of the process, the mixture provided in step iv) is melt extruded, which means that the mixture provided in step iv) is subjected to a melt extrusion process. Melt extrusion processes are well known in the art.

[0098] The melt extrusion according to step v) typically comprises melt mixing and / or melt compounding the mixture provided in step iv) in an extruder, and extruding the melt mixed and / or melt compounded mixture through a die to provide the long-chain branched polypropylene composition. The extruder can be, but is not limited to, a twin-screw extruder, a single-screw extruder, or a tandem extrusion line known in the art.

[0099] Step v) provides a long-chain branched polypropylene composition. The long-chain branched polypropylene composition obtained in step v) typically has specific properties.

[0100] The long-chain branched polypropylene composition may have a melt flow rate MFR2 (ISO1133, 2.16 kg load, 230°C) in the range of 3.0 to 30 g / 10 min, preferably in the range of 5.0 to 25.0 g / 10 min, more preferably in the range of 8.0 to 20.0 g / 10 min, for example, in the range of 10.0 to 20.0 g / 10 min.

[0101] The long-chain branched polypropylene composition has a melt strength F in the range of 3.0 to 25.0 cN, preferably in the range of 4.0 to 15.0 cN, more preferably in the range of 4.0 to 7.5 cN, for example in the range of 5.0 to 6.5 cN. 30 (ISO16790:2005).

[0102] The long-chain branched polypropylene composition has a melt extensibility v in the range of 200 to 290 mm / s, preferably in the range of 220 to 290 mm / s, more preferably in the range of 240 to 280 mm / s, for example in the range of 240 to 275 mm / s. 30 (ISO16790:2005).

[0103] The long-chain branched polypropylene composition may have a hot xylene insoluble fraction (XHI) of less than 0.10 wt %, preferably less than 0.05 wt %, more preferably 0.02 wt % or less, for example, in the range of 0.0 to 0.02 wt %, based on the total weight of the long-chain branched polypropylene composition.

[0104] The long-chain branched polypropylene composition provided in step v) may have a specific combination of properties. Preferably, the long-chain branched polypropylene composition has the following properties: i) a melt flow rate MFR2 (ISO1133, 2.16 kg load, 230°C) in the range of 3.0 to 30 g / 10 min, preferably in the range of 5.0 to 25.0 g / 10 min, more preferably in the range of 8.0 to 20.0 g / 10 min, for example, in the range of 10.0 to 20.0 g / 10 min; ii) A melt strength F in the range of 3.0 to 25.0 cN, preferably in the range of 4.0 to 15.0 cN, more preferably in the range of 4.0 to 7.5 cN, for example in the range of 5.0 to 6.5 cN 30 (ISO16790:2005), iii) a melt drawability v in the range of 200 to 290 mm / s, preferably in the range of 220 to 290 mm / s, more preferably in the range of 240 to 280 mm / s, for example in the range of 240 to 275 mm / s 30 (ISO16790:2005) It has two or more, more preferably all, of the above.

[0105] According to one embodiment, the long-chain branched polypropylene composition has the following characteristics: i) a melt flow rate MFR2 (ISO1133, 2.16 kg load, 230°C) in the range of 3.0 to 30 g / 10 min, preferably in the range of 5.0 to 25.0 g / 10 min, more preferably in the range of 8.0 to 20.0 g / 10 min, for example, in the range of 10.0 to 20.0 g / 10 min; ii) A melt strength F in the range of 3.0 to 25.0 cN, preferably in the range of 4.0 to 15.0 cN, more preferably in the range of 4.0 to 7.5 cN, for example in the range of 5.0 to 6.5 cN 30 (ISO16790:2005), iii) a melt drawability v in the range of 200 to 290 mm / s, preferably in the range of 220 to 290 mm / s, more preferably in the range of 240 to 280 mm / s, for example in the range of 240 to 275 mm / s 30 (ISO16790:2005), and iv) a hot xylene insoluble fraction (XHI) of less than 0.10% by weight, preferably less than 0.05% by weight, more preferably 0.02% by weight or less, for example, in the range of 0.0 to 0.02% by weight, based on the total weight of the long-chain branched polypropylene composition It has.

[0106] The processes described herein may achieve one or more particular advantages, and preferably may at least partially prevent, in comparative tests, a particular loss in melt strength of the melt-extruded components, as compared to the properties of a comparative long-chain branched polypropylene composition obtained by a comparative process that does not use a polyfunctional unsaturated compound.

[0107] The long-chain branched polypropylene composition obtained in step v) preferably has a melt strength F of a comparative long-chain branched polypropylene composition obtained by a comparative process without using a polyfunctional unsaturated compound in a comparative test. 30 (ISO16790:2005) increased, more preferably at least 3.0% (e.g., in the range of 3.0 to 20% or 5.0 to 20%) melt strength F 30 (ISO16790:2005).

[0108] The long-chain branched polypropylene composition obtained in step v) preferably has, in a comparative test, a hot xylene insoluble fraction (XHI) that is reduced by at least 50%, more preferably at least 60%, even more preferably at least 80%, and even more preferably at least 90% compared to the hot xylene insoluble fraction (XHI) of a comparative long-chain branched polypropylene composition obtained by a comparative process that does not use a polyfunctional unsaturated compound.

[0109] The long-chain branched polypropylene composition obtained in step v) is preferably i) an increased melt strength F, more preferably at least 3.0% (e.g., in the range of 3.0 to 20% or 5.0 to 20%); 30 (ISO16790:2005), and ii) In a comparative test, the melt strength F of a comparative long-chain branched polypropylene composition obtained by a comparative process without using a polyfunctional unsaturated compound 30 (ISO 16790:2005) and a hot xylene insoluble fraction (XHI) reduced by at least 50%, more preferably at least 60%, even more preferably at least 80%, and even more preferably at least 90% compared to the hot xylene insoluble fraction (XHI) It has.

[0110] Those skilled in the art will understand how to conduct comparative tests suitable for comparing the properties of a test compound with the properties of a long-chain branched polypropylene composition according to one embodiment of the present invention, and will know how to adjust the process parameters and ingredients of the comparative composition for the comparative tests.

[0111] The comparative test may require that the long-chain branched polypropylene composition and the comparative long-chain branched polypropylene composition are obtained by (i) using approximately the same process parameters (e.g., selected from heating zones in the extruder, pressure in the extruder, screw rotation speed, die pressure, etc.), and (ii) using the same ingredients as the mixture extruded in step v), except that the mixture extruded in step v) does not contain the polyfunctional unsaturated compound, and (iii) using the same equipment (e.g., extruder). The amount of the polyfunctional unsaturated compound in the mixture extruded in step v) is preferably replaced with the same amount of the long-chain branched polypropylene of step i) in the comparative test.

[0112] Furthermore, the processes described herein may achieve one or more particular advantages, preferably at least partially prevent, in comparative tests, a particular loss in melt strength of the melt-extruded component, compared to the properties of the long-chain branched polypropylene provided in step i) as a single component melt-extruded under otherwise identical conditions.

[0113] The long-chain branched polypropylene composition obtained in step v) preferably has a melt strength F of a comparative long-chain branched polypropylene composition obtained by melt extruding the long-chain branched polypropylene provided in step i) as a single component under otherwise identical conditions in a comparative test. 30 (ISO16790:2005) increased, more preferably at least 3.0% (e.g., in the range of 3.0 to 20% or 5.0 to 20%) melt strength F 30 (ISO16790:2005).

[0114] Those skilled in the art will understand how to select conditions for comparative testing suitable for comparing the properties of the test compound with the properties of the long-chain branched polypropylene composition according to one embodiment of the present invention.

[0115] In this context, the phrase "otherwise the same conditions except for ..." can be understood to mean that the inventive long-chain branched polypropylene composition and the comparative long-chain branched polypropylene composition must be obtained using approximately the same process parameters (e.g., selected from heating zones in an extruder, pressure in an extruder, screw rotation speed, die pressure, etc.) and the same equipment (e.g., extruders, etc.).

[0116] The long-chain branched polypropylene composition obtained in step v) is preferably In comparative tests, the hot xylene insoluble fraction (XHI) is reduced by at least 50%, more preferably at least 60%, even more preferably at least 80%, and even more preferably at least 90% compared to the hot xylene insoluble fraction (XHI) of a comparative long-chain branched polypropylene composition obtained by melt extruding the long-chain branched polypropylene provided in step i) as a single component under otherwise identical conditions. It has.

[0117] More preferably, the long-chain branched polypropylene composition obtained in step v) has, in a comparative test, a melt strength F of a comparative long-chain branched polypropylene composition obtained by melt extruding the long-chain branched polypropylene provided in step i) as a single component under otherwise identical conditions, except that it is a single component. 30 (ISO16790:2005) and hot xylene insoluble fraction (XHI), i) increased melt strength F, more preferably at least 3.0% increased 30 (ISO16790:2005), and ii) a reduction in the hot xylene insoluble fraction (XHI) of at least 50%, more preferably at least 60%, even more preferably at least 80%, and even more preferably at least 90% It has.

[0118] The long-chain branched polypropylene composition obtained in step v) preferably contains long-chain branched polypropylene in an amount of at least 95.0 wt % (e.g., 95.0 to 100 wt %), preferably at least 97.5 wt %, more preferably at least 98.0 wt %, based on the total weight of the long-chain branched polypropylene composition. Thus, the process described herein may be a process for preparing long-chain branched polypropylene.

[0119] The long-chain branched polypropylene composition may comprise long-chain branched polypropylene in an amount of at least 99.0 wt%, based on the total weight of the long-chain branched polypropylene composition. The long-chain branched polypropylene composition may consist essentially of, or consist of, long-chain branched polypropylene.

[0120] Long-chain branched polypropylene composition In one aspect of the present invention, there is provided a long-chain branched polypropylene composition, the long-chain branched polypropylene composition comprising: (a) long-chain branched polypropylene; (b) a polyfunctional unsaturated compound; and (c) optionally a radical initiator; The composition can be obtained by melt-extruding a mixture comprising:

[0121] According to one preferred embodiment, the long-chain branched polypropylene composition can be obtained by the process described herein. The long-chain branched polypropylene (a) is preferably defined as the long-chain branched polypropylene provided in step i) of the process described herein. The polyfunctional unsaturated compound (b) is preferably defined as the polyfunctional unsaturated compound provided in step ii) of the process described herein.

[0122] The long-chain branched polypropylene composition is preferably a reaction product of the above-mentioned long-chain branched polypropylene, a polyfunctional unsaturated compound, and an optional radical initiator. When a polyfunctional unsaturated (meth)acrylate compound is used as component (b), the long-chain branched polypropylene composition preferably comprises a subgroup detectable by infrared (IR) spectroscopy, such as a carbonyl group.

[0123] Typically, the long chain branched polypropylene composition has specific properties.

[0124] The long-chain branched polypropylene composition may have a melt flow rate MFR2 (ISO1133, 2.16 kg load, 230°C) in the range of 3.0 to 30 g / 10 min, preferably in the range of 5.0 to 25.0 g / 10 min, more preferably in the range of 8.0 to 20.0 g / 10 min, for example, in the range of 10.0 to 20.0 g / 10 min.

[0125] The long-chain branched polypropylene composition has a melt strength F in the range of 3.0 to 25.0 cN, preferably in the range of 4.0 to 15.0 cN, more preferably in the range of 4.0 to 7.5 cN, for example in the range of 5.0 to 6.5 cN. 30 (ISO16790:2005).

[0126] The long-chain branched polypropylene composition has a melt extensibility v in the range of 200 to 290 mm / s, preferably in the range of 220 to 290 mm / s, more preferably in the range of 240 to 280 mm / s, for example in the range of 240 to 275 mm / s. 30 (ISO16790:2005).

[0127] The long-chain branched polypropylene composition may have a hot xylene insoluble fraction (XHI) of less than 0.10 wt%, preferably less than 0.05 wt%, and more preferably less than 0.02 wt%, based on the total weight of the long-chain branched polypropylene composition.

[0128] The long-chain branched polypropylene composition provided in step v) may have a specific combination of properties. Preferably, the long-chain branched polypropylene composition has the following properties: i) a melt flow rate MFR2 (ISO1133, 2.16 kg load, 230°C) in the range of 3.0 to 30 g / min, preferably in the range of 5.0 to 25.0 g / 10 min, more preferably in the range of 8.0 to 20.0 g / 10 min, for example, in the range of 10.0 to 20.0 g / 10 min; ii) A melt strength F in the range of 3.0 to 25.0 cN, preferably in the range of 4.0 to 15.0 cN, more preferably in the range of 4.0 to 7.5 cN, for example in the range of 5.0 to 6.5 cN 30 (ISO16790:2005), iii) a melt drawability v in the range of 200 to 290 mm / s, preferably in the range of 220 to 290 mm / s, more preferably in the range of 240 to 280 mm / s, for example in the range of 240 to 275 mm / s 30 (ISO16790:2005) It has two or more, more preferably all, of the above.

[0129] According to one embodiment, the long-chain branched polypropylene composition has the following characteristics: i) a melt flow rate MFR2 (ISO1133, 2.16 kg load, 230°C) in the range of 3.0 to 30 g / min, preferably in the range of 5.0 to 25.0 g / 10 min, more preferably in the range of 8.0 to 20.0 g / 10 min, for example, in the range of 10.0 to 20.0 g / 10 min; ii) A melt strength F in the range of 3.0 to 25.0 cN, preferably in the range of 4.0 to 15.0 cN, more preferably in the range of 4.0 to 7.5 cN, for example in the range of 5.0 to 6.5 cN 30 (ISO16790:2005), iii) a melt drawability v in the range of 200 to 290 mm / s, preferably in the range of 220 to 290 mm / s, more preferably in the range of 240 to 280 mm / s, for example in the range of 240 to 275 mm / s 30 (ISO16790:2005), and iv) a hot xylene insoluble fraction (XHI) of less than 0.10% by weight, preferably less than 0.05% by weight, more preferably 0.02% by weight or less, for example, in the range of 0.0 to 0.02% by weight, based on the total weight of the long-chain branched polypropylene composition It has.

[0130] The long-chain branched polypropylene composition preferably contains the long-chain branched polypropylene in an amount of at least 95.0 wt % (e.g., 95.0 to 100 wt %), preferably at least 97.5 wt %, more preferably at least 98.0 wt %, based on the total weight of the long-chain branched polypropylene composition.

[0131] The long-chain branched polypropylene composition may comprise long-chain branched polypropylene in an amount of at least 99.0 wt%, based on the total weight of the long-chain branched polypropylene composition. The long-chain branched polypropylene composition may consist essentially of, or consist of, long-chain branched polypropylene.

[0132] use In another aspect, the present invention provides the use of a polyfunctional unsaturated compound to reduce the loss of melt strength of long-chain branched polypropylene, preferably recycled long-chain branched polypropylene, during melt extrusion.

[0133] The polyfunctional unsaturated compound and the long-chain branched polypropylene are preferably defined as described herein in relation to the long-chain branched polypropylene provided in step i) and the polyfunctional unsaturated compound provided in step ii).

[0134] "Reducing the loss of melt strength of long-chain branched polypropylene" preferably refers to a long-chain branched polypropylene composition obtained by melt extruding a mixture containing a polyfunctional unsaturated compound in combination with long-chain branched polypropylene, and in a comparative test, the melt strength F of a comparative long-chain branched polypropylene composition obtained by melt extruding the same mixture containing long-chain branched polypropylene but not containing a polyfunctional unsaturated compound.30 (ISO16790:2005) increased, preferably at least 3.0% (e.g., in the range of 3.0 to 20% or 5.0 to 20%) melt strength F 30 (ISO16790:2005).

[0135] Those skilled in the art will understand how to conduct comparative tests suitable for comparing the properties of a test compound with the properties of a long-chain branched polypropylene composition according to one embodiment of the use of the present invention, and will know how to adjust the process parameters and ingredients of the comparative composition for the comparative tests.

[0136] The comparative test may require that the long-chain branched polypropylene composition and the comparative long-chain branched polypropylene composition are obtained by (i) using approximately the same process parameters (e.g., selected from heating zones in the extruder, pressure in the extruder, screw rotation speed, die pressure, etc.), and (ii) using the same ingredients as the mixture, except that the mixture does not contain the polyfunctional unsaturated compound, and (iii) using the same equipment (e.g., extruder). The amount of the polyfunctional unsaturated compound is preferably replaced with the same amount of long-chain branched polypropylene in the comparative test.

[0137] Additionally, the use of the polyfunctional unsaturated compound can include use to reduce the hot xylene insoluble fraction (XHI) of long-chain branched polypropylene, preferably recycled long-chain branched polypropylene.

[0138] "Reducing the hot xylene insoluble fraction (XHI) of long-chain branched polypropylene" should preferably be understood to mean that a long-chain branched polypropylene composition obtained by melt extruding a mixture comprising a polyfunctionally unsaturated compound in combination with a long-chain branched polypropylene has, in a comparative test, a hot xylene insoluble fraction (XHI) that is reduced by at least 50%, more preferably at least 60%, even more preferably at least 80%, and even more preferably at least 90% compared to the hot xylene insoluble fraction (XHI) of a comparative long-chain branched polypropylene composition obtained by melt extruding the same mixture comprising long-chain branched polypropylene but which does not contain the polyfunctionally unsaturated compound.

[0139] The polyfunctional unsaturated compound is preferably used in a mixture as defined herein in relation to the mixture provided in step iv). Accordingly, the polyfunctional unsaturated compound can be used in combination with a radical initiator, which is preferably defined as described herein for the radical initiator optionally provided in step iii).

[0140] The use of the polyfunctional unsaturated compound preferably includes providing a long chain branched polypropylene composition as defined herein.

[0141] The present invention also provides a process for reducing the loss of melt strength of long-chain branched polypropylene during melt extrusion, which process uses a multifunctional unsaturated compound.

[0142] Preferably, the process comprises: combining the long-chain branched polypropylene with a polyfunctional unsaturated compound, and optionally a radical initiator, to provide a mixture; melt-extruding the mixture; Includes.

[0143] Additionally, the process may be a process for reducing the hot xylene insoluble fraction (XHI) of long chain branched polypropylene.

[0144] This process preferably provides a long-chain branched polypropylene composition as defined herein above in section "Step v)" and section "Long-chain branched polypropylene composition".

[0145] With regard to the effects "to reduce loss of melt strength" and "to reduce the hot xylene insoluble fraction (XHI)", please refer to the explanations and definitions provided herein above.

[0146] The long-chain branched polypropylene, polyfunctional unsaturated compound, optional radical initiator, and melt-extruded mixture are preferably defined as described herein above for steps i) to iv) of the process. Accordingly, the long-chain branched polypropylene used in conjunction with the use or process for reducing melt strength loss of long-chain branched polypropylene during melt extrusion is preferably defined as defined herein above in section "Step i"). The polyfunctional unsaturated compound used in conjunction with the use or process for reducing melt strength loss of long-chain branched polypropylene during melt extrusion is preferably defined as defined herein above in section "Step ii". The optional radical initiator used in conjunction with the use or process for reducing melt strength loss of long-chain branched polypropylene during melt extrusion is preferably defined as defined herein above in section "Step iii". The melt-extruded mixture in conjunction with the use or process for reducing melt strength loss of long-chain branched polypropylene during melt extrusion is preferably as described herein above in section "Step iv".

[0147] Below, the present invention is illustrated by specific examples, which should not be construed as limiting the invention in any way. [Example]

[0148] method Melt Flow Rate (MFR): The melt flow rate MFR was determined according to ISO 1133 under a load of 2.16 kg and at a temperature of 230°C.

[0149] Melt Strength F 30 and melt extensibility v 30 : The tests described herein are in accordance with ISO 16790:2005. Tests were carried out at a pressure of 30 bar.

[0150] The strain hardening behavior is determined by the method described in the article "Rheotens - Mastercurves and Drawability of Polymer Melts," M. H. Wagner, Polymer Engineering and Science, Vol. 36, pp. 925-935, the contents of which are incorporated by reference. The strain hardening behavior of polymers is analyzed in a Rheotens apparatus (product of Goettfert, Siemensstr. 2, 74711 Buchen, Germany), in which a strand of melt is drawn by pulling down at a defined acceleration.

[0151] Rheotens experiments simulate industrial spinning and extrusion processes. In principle, a melt is squeezed or extruded through a circular die, and the resulting strand is drawn. The stress on the extrudate is recorded as a function of melt properties and measured parameters, particularly the ratio of the power output to the drawing rate, which in practice is a measure of elongation. For the results presented below, materials were extruded using a HAAKE Polylab system laboratory extruder and a gear pump equipped with a cylindrical die (L / D = 6.0 / 2.0 mm). The gear pump was pre-adjusted to achieve a strand extrusion rate of 5 mm / s, and the melt temperature was set to 200 °C. The spin line length between the die and the Rheotens wheel was 80 mm. At the start of the experiment, the winding speed of the Rheotens wheel was adjusted to the speed of the extruded polymer strand (zero tensile force). The experiment was then initiated by slowly increasing the winding speed of the Rheotens wheel until the polymer filament broke. The wheel acceleration was kept small enough so that the tensile force was measured in a quasi-steady state. The acceleration of the pulled-down melt strand is 120 mm / s 2 The Rheotens was operated in conjunction with the PC program "EXTENS", a real-time data acquisition program that displays and stores the measured data of the pull force and drawdown rate. The end points of the Rheotens curve (force vs. pulley rotation rate) were measured as F 30 The melt strength and stretchability were measured.

[0152] Hot xylene insoluble fraction (XHI): Approximately 2 g of polymer (m p ) is weighed and placed in a weighed metal mesh (m p+m The polymer in the mesh is extracted with boiling xylene in a Soxhlet apparatus for 5 hours. The eluent is then replaced with fresh xylene and boiling is continued for another hour. The mesh is then dried and reweighed (m XHI+m ). formula m XHI+m -m m =m XHI The mass (m XHI) to the weight of the polymer (m p ) to obtain the xylene insoluble fraction m XHI / m p get.

[0153] material Long-chain branched polypropylene: The long-chain branched polypropylene was recycled long-chain branched polypropylene (BPP) obtained by single-pass melt extrusion of commercial product Daploy WB140HMS manufactured by Borealis in a ZSK18 twin-screw extruder (melt temperature of 200°C and output rate of 7 kg / h). This recycled long-chain branched polypropylene (recycled BPP) had a melt flow rate MFR2 of 3.9 g / 10 min (ISO 1133, 2.16 kg load, 230°C), a melt strength F of 26 cN, and a melt flow rate of 1.0 g / 10 min. 30 (ISO16790:2005), and melt elongation v of 268 mm / s 30 (ISO16790:2005).

[0154] Polyfunctional unsaturated compounds: The polyfunctional unsaturated compound (PUC) was trimethylolpropane triacrylate (TMPTA, CAS number 15625-89-5) supplied by Sigma-Aldrich.

[0155] Radical initiator: The radical initiator (INI) was an organic peroxide radical initiator, namely tert-butylperoxyisopropyl carbonate supplied by Akzo Nobel as Trigonox® BPIC-C75.

[0156] Linear polypropylene (reference material): To collect reference data on the properties of linear polypropylene before (be) and after (ae) extrusion, three different linear polypropylenes (LPP) were subjected to a melt extrusion process using a twin-screw extruder. The reference data are shown in Table 1 below.

[0157] [Table 1] LPP-1: Propylene homopolymer available as BE50 from Borealis AG LPP-2: Propylene homopolymer available as HC600TF from Borealis AG LPP-3: Propylene homopolymer available as HE125MO from Borealis AG

[0158] Example Examples IE1-IE5 and CE1 were prepared by melt extruding long-chain branched polypropylene (BPP), with or without a polyfunctional unsaturated compound (PUC), optionally in combination with a radical initiator (INI), in a ZSK18 twin-screw extruder at a melt temperature of 200° C. and a production rate of 7 kg / h. Table 2 shows the formulations and properties of these examples.

[0159] [Table 2]

[0160] As can be seen from Example CE1, after the second extrusion, the melt strength F 30 The viscosity further decreases from 26 cN to 5 cN for the recycled BPP, and the melt flow rate MFR2 further increases from 3.9 g / 10 min to 11 g / 10 min for the recycled BPP. The gel content, as indicated by the hot xylene insolubles (XHI), is 0.13 wt%.

[0161] When long-chain branched polypropylene is extruded in the presence of the polyfunctional unsaturated compounds of Examples IE1 to IE5, the melt strength F 30 The melt flow rate (MFR) does not decrease as much as in Example CE1. Thus, Examples IE1-IE5 show a reduced loss of melt strength compared to Example CE1. Furthermore, in Examples IE1-IE5, the gel content is reduced to near or 0 wt%. The use of a radical initiator in Examples IE4 and IE5 increases the melt flow rate (MFR).

[0162] Furthermore, examples IE1 to IE5 have a melt drawability v of 261 mm / s or more.30 , MFR of 11g / 10min or more, and melt strength F of 5.2cN or more 30 This combination of rheological properties clearly demonstrates that long-chain branched polypropylene compositions are obtained in all of Examples IE1 to IE5. Indeed, a comparison with the linear polypropylene reference materials listed in Table 1 shows a significant difference in rheological properties. All LPP reference materials exhibit melt drawability of less than 200 mm / s, and melt strength F decreases with increasing MFR. 30 For example, l-PP3 exhibits a MFR of about 13 g / 10 min (be) and a melt strength F of less than 2 cN. 30 These rheological properties are characteristic of linear polypropylene.

Claims

1. 1. A method for preparing a long-chain branched polypropylene composition, comprising: i) providing a long chain branched polypropylene; ii) providing a polyfunctional unsaturated compound; iii) optionally providing a radical initiator; iv) combining said long chain branched polypropylene, said multifunctional unsaturated compound, and optionally said radical initiator to provide a mixture; v) melt-extruding the mixture to obtain a long-chain branched polypropylene composition; A method comprising:

2. 10. The method of claim 1, wherein the long-chain branched polypropylene is recycled long-chain branched polypropylene.

3. 3. The method according to claim 1 or claim 2, wherein the long-chain branched polypropylene is a long-chain branched propylene homopolymer.

4. The long-chain branched polypropylene has the following characteristics: i) A melt flow rate (MFR) in the range of 0.5 to 10 g / 10 min, preferably in the range of 1.5 to 7.5 g / 10 min, more preferably in the range of 2.5 to 6.0 g / 10 min ２ (ISO1133, 2.16 kg load, 230 ° C), ii) a melt strength F in the range of 5.0 to 50.0 cN, preferably in the range of 10.0 to 50.0 cN, more preferably in the range of 15.0 to 35.0 cN, and even more preferably in the range of 20.0 to 30.0 cN ３０ (ISO16790:2005), iii) a melt drawability v in the range of 200 to 300 mm / s, preferably 220 to 290 mm / s, more preferably 240 to 280 mm / s ３０ (ISO16790:2005) 4. The method according to any one of claims 1 to 3, comprising one or more, preferably all, of:

5. 5. The method according to any one of claims 1 to 4, wherein the polyfunctional unsaturated compound is a polyfunctional (meth)acrylate compound, preferably a polyfunctional acrylate monomer.

6. 6. The method according to any one of claims 1 to 5, wherein the mixture provided in step iv) comprises a radical initiator, preferably a peroxide radical initiator, more preferably an organic peroxide radical initiator.

7. 6. The method of any one of claims 1 to 5, wherein step iii) is not performed and the mixture provided in step iv) does not contain a radical initiator.

8. The mixture provided in step iv) comprises (a) 95.0 to 99.95% by weight, preferably 97.5 to 99.95% by weight, more preferably 99.0 to 99.90% by weight of the long-chain branched polypropylene; (b) 0.05 to 5.0 wt %, preferably 0.05 to 2.5 wt %, more preferably 0.10 to 1.0 wt % of said polyfunctional unsaturated compound; (c) optionally, 0.0001 to 0.20 wt. %, preferably 0.004 to 0.15 wt. %, more preferably 0.004 to 0.10 wt. % of a radical initiator; wherein all amounts by weight are based on the total weight of the mixture provided in step iv), and optionally the amounts by weight of components (a) to (c) add up to 100 wt.%.

9. 9. The method of any one of claims 1 to 8, wherein the mixture provided in step iv) comprises the components provided in steps i) to iii) in the following relative amounts: (a) 95.0 to 99.95 parts by weight (pbw), preferably 97.5 to 99.95 parts by weight (pbw), more preferably 99.0 to 99.90 parts by weight (pbw), for example 99.25 to 99.90 parts by weight (pbw) of said long-chain branched polypropylene; (b) 0.05 to 5.0 parts by weight (pbw), preferably 0.05 to 2.5 parts by weight (pbw), even more preferably 0.10 to 1.0 parts by weight (pbw), for example 0.10 to 0.75 parts by weight (pbw), of said polyfunctional unsaturated compound; and (c) optionally, a radical initiator in the range of 0.0001 to 0.20 parts by weight (pbw), preferably 0.004 to 0.15 parts by weight (pbw), more preferably 0.004 to 0.10 parts by weight (pbw), for example 0.005 to 0.10 parts by weight (pbw).

10. In a comparative test, the long-chain branched polypropylene composition obtained in step v) was found to have a melt strength F ３０ (ISO 16790:2005) ３０ (ISO 16790:2005) and / or The long-chain branched polypropylene composition obtained in step v) has, in a comparative test, a hot xylene insoluble fraction (XHI) that is reduced by at least 50%, preferably at least 60%, more preferably at least 80%, and even more preferably at least 90% compared to the hot xylene insoluble fraction (XHI) of a comparative long-chain branched polypropylene composition obtained by a comparative method that does not use the polyfunctional unsaturated compound.

10. The method of any one of claims 1 to 9.

11. The long-chain branched polypropylene composition obtained in step v) has the following properties: i) A melt flow rate (MFR) in the range of 3.0 to 30 g / 10 min, preferably in the range of 5.0 to 25.0 g / 10 min, more preferably in the range of 8.0 to 20.0 g / 10 min ２ (ISO1133, 2.16 kg load, 230 ° C), ii) a melt strength F in the range of 3.0 to 25.0 cN, preferably in the range of 4.0 to 15.0 cN, more preferably in the range of 4.0 to 7.5 cN ３０ (ISO16790:2005), iii) a melt drawability v in the range of 200 to 290 mm / s, preferably in the range of 220 to 290 mm / s, more preferably in the range of 240 to 280 mm / s ３０ (ISO16790:2005) 11. The method according to any one of claims 1 to 10, comprising one or more, preferably all, of:

12. A long-chain branched polypropylene composition comprising: (a) a long-chain branched polypropylene, preferably a long-chain branched polypropylene according to any one of claims 2 to 4; (b) a polyfunctional unsaturated compound, preferably a polyfunctional unsaturated compound according to claim 5; (c) optionally a radical initiator, preferably a radical initiator according to claim 6; A long-chain branched polypropylene composition obtained by melt extruding a mixture comprising:

13. The long-chain branched polypropylene composition has the following characteristics: i) A melt flow rate (MFR) in the range of 3.0 to 30 g / 10 min, preferably in the range of 5.0 to 25.0 g / 10 min, more preferably in the range of 8.0 to 20.0 g / 10 min ２ (ISO1133, 2.16 kg load, 230 ° C), ii) a melt strength F in the range of 3.0 to 25.0 cN, preferably in the range of 4.0 to 15.0 cN, more preferably in the range of 4.0 to 7.5 cN ３０ (ISO16790:2005), iii) a melt drawability v in the range of 200 to 290 mm / s, preferably in the range of 220 to 290 mm / s, more preferably in the range of 240 to 280 mm / s ３０ (ISO16790:2005) 13. The long chain branched polypropylene composition according to claim 12, comprising one or more, preferably all, of:

14. 14. The long-chain branched polypropylene composition according to claim 12 or claim 13, having a hot xylene insoluble fraction (XHI) of less than 0.10 wt%, preferably less than 0.05 wt%, more preferably 0.02 wt% or less, based on the total weight of the long-chain branched polypropylene composition.

15. 15. The long-chain branched polypropylene composition according to any one of claims 12 to 14, comprising at least 95.0 wt%, preferably at least 97.5 wt%, more preferably at least 98.0 wt%, of long-chain branched polypropylene, based on the total weight of the long-chain branched polypropylene composition.

16. Use of a polyfunctional unsaturated compound to reduce the loss of melt strength of long-chain branched polypropylene, preferably recycled long-chain branched polypropylene, during melt extrusion.

17. 1. A method for reducing melt strength loss of long chain branched polypropylene during melt extrusion, comprising: combining a long chain branched polypropylene with a multifunctional unsaturated compound, and optionally a radical initiator, to provide a mixture; melt-extruding the mixture; wherein the long-chain branched polypropylene is preferably a long-chain branched polypropylene as defined in any one of claims 2 to 4, the polyfunctional unsaturated compound is preferably a polyfunctional unsaturated compound as defined in claim 5, and the mixture is preferably a mixture as defined in any one of claims 6 to 9.

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