# US 10,501,615 B2 · Bimodal polypropylene and process for the preparation thereof > Agents: this data is available as JSON from the patentgrep API and MCP server — see https://patentgrep.com/llms.txt - Number: US 10,501,615 B2 - Document ID: US10501615B2 - Status: Granted - Kind: B2 - Application number: 15/542,846 - Filed: 2016-01-22 - Published: 2018-11-29 - Granted: 2019-12-10 - Earliest claimed: 2015-01-23 - Assignees: Total Research & Technology Feluy - Applicants: Total Research & Technology Feluy - Inventors: Alain Standaert; Kristien Roegiers; Aurélien Vantomme - Web page: https://patentgrep.com/patent/US10501615B2 ## CPC - C08L 23/12: Polypropene - C08K 5/0083: {Nucleating agents promoting the crystallisation of the polymer matrix} - C08L 23/142: {at least partially crystalline copolymers of propene with other olefins} - C08L 2201/10: Transparent films; Clear coatings; Transparent materials - C08L 2205/025: containing two or more polymers of the same hierarchy C08L, and differing only in parameters such as density, comonomer content, molecular weight, structure - C08L 2308/00: Chemical blending or stepwise polymerisation process with the same catalyst - C08L 2314/06: Metallocene or single site catalysts - C08L: COMPOSITIONS OF MACROMOLECULAR COMPOUNDS (compositions based on polymerisable monomers C08F, C08G; artificial filaments or fibres D01F; textile treating compositions D06) - C08K: Use of inorganic or non-macromolecular organic substances as compounding ingredients (paints, inks, varnishes, dyes, polishes, adhesives C09) ## Abstract The present invention relates to a polypropylene composition comprising: a first polypropylene homopolymer or random copolymer (PPR1) having a comonomer content lower than the comonomer content of the second polypropylene, a second polypropylene (PPR2) which is a random copolymer of propylene and of the comonomer; said comonomer being an alpha-olefin different from propylene, the melting temperature of the polypropylene composition (Tm(PPR)) being defined as Tm(PPR)>165−6.9*[total comonomer content]−8.4*[comonomer content of the first polypropylene], the difference between the melting temperature and the crystallization temperature of the polypropylene composition ranges from 27 and 33, and a xylene soluble fraction (XS) at 23° C. of not more than 1.5 wt. %. The present invention also relates to a process for the preparation of said polypropylene composition. The present invention further relates to the use of said polypropylene composition for producing films or moulded articles. ## Claims ### Claim 1 A polypropylene composition (PPR) comprising: (A) a first polypropylene homopolymer or random copolymer (PPR1) having a comonomer content from 0 to lower than the comonomer content of the second polypropylene, (B) a second polypropylene (PPR2) which is a random copolymer of propylene and of the comonomer; wherein: the polypropylene composition has a total comonomer content ranging from 0.25 to 4.5 wt % based on the total weight of the polypropylene composition, the comonomer is selected from the group consisting of ethylene, butene-1, pentene-1, hexene-1 and 4-methyl-1-pentene, the melting temperature, measured by DSC based on ISO 3146, of the polypropylene composition (Tm(PPR)) is defined as Tm(PPR)>165−6.9×[total comonomer content]−8.4×[comonomer content of the first polypropylene], the difference between the melting temperature and the crystallization temperature, both measured by DSC, of the polypropylene composition ranges from 27 to 33, a xylene soluble fraction (XS) of not more than 1.5 wt %, and wherein the polypropylene composition has a melt flow index ranging from 20 to 200 g/10 min, the values of melt flow index being measured according to ISO 1133 at (230° C., under a 2.16 kg load), and a regiodefects content ranging from 0.1% to 5%. ### Claim 2 (depends on 1) A polypropylene composition according to claim 1 wherein the comonomer is ethylene. ### Claim 3 (depends on 1) A polypropylene composition according to claim 1 wherein the melt flow index of the first polypropylene is greater than the melt flow index of the second polypropylene; the values of melt flow index being measured according to ISO 1133 (230° C., 2.16 kg load). ### Claim 4 (depends on 1) A polypropylene composition according to claim 1 wherein the melt flow index of the first polypropylene has a melt flow index ranging from 1 to 200 g/10 min and the second polypropylene has a melt flow index ranging from 1 to 200 g/10 min. ### Claim 5 (depends on 1) A polypropylene composition according to claim 1 having a flexural modulus greater than 1000 MPa, the flexural modulus being measured at 23° C. according to ISO 178. ### Claim 6 (depends on 1) A polypropylene composition according to claim 1 having notched Izod impact strength between 3.0 and 4.0 kJ/m2. ### Claim 7 A process for the preparation of the polypropylene composition comprising the steps of: (i) providing a first polypropylene having a comonomer content from 0 to lower than the comonomer content of the second polypropylene, (ii) providing a second polypropylene which is a random copolymer of propylene and of the comonomer, (iii) recovering the polypropylene composition having a total comonomer content ranging from 0.25 and 4.5 wt % based on the total weight of the polypropylene composition, wherein steps (i) and (ii) are carried out by polymerizing propylene and, if any, the comonomer in presence of a metallocene-based polymerization catalyst, wherein the polypropylene composition comprises: (A) a first polypropylene homopolymer or random copolymer (PPR1) having a comonomer content from 0 to lower than the comonomer content of the second polypropylene, (B) a second polypropylene (PPR2) which is a random copolymer of propylene and of the comonomer; wherein: the polypropylene composition has a total comonomer content ranging from 0.25 to 4.5 wt % based on the total weight of the polypropylene composition, the comonomer is selected from the group consisting of ethylene, butene-1, pentene-1, hexene-1 and 4-methyl-1-pentene, the melting temperature, measured by DSC based on ISO 3146, of the polypropylene composition (Tm(PPR)) is defined as Tm(PPR)>165−6.9×[total comonomer content]−8.4×[comonomer content of the first polypropylene], the difference between the melting temperature and the crystallization temperature, both measured by DSC, of the polypropylene composition ranges from 27 to 33, a xylene soluble fraction (XS) of not more than 1.5 wt. %, and wherein the polypropylene composition has a melt flow index ranging from 20 to 200 g/10 min, the values of melt flow index being measured according to ISO 1133 at (230° C., under a 2.16 kg load), and a regiodefects content ranging from 0.1% to 5%. ### Claim 8 (depends on 7) A process according to claim 7 wherein the comonomer content of the first polypropylene is lower than 3.5 wt % based on the total weight of the first polypropylene. ### Claim 9 (depends on 8) A process according to claim 8, wherein the comonomer content of the second polypropylene is greater than 1.5 wt % and is at most 8.0 wt %, preferably ranges from 1.5 to 6.0 wt % based on the total weight of the second polypropylene. ### Claim 10 (depends on 8) A process according to claim 8 wherein step (iii) is carried out by blending the first polypropylene and the second polypropylene or by mixing the first polypropylene to the second polypropylene simultaneously to the preparation thereof. ### Claim 11 (depends on 1) An article comprising a polypropylene composition according to claim 1. ### Claim 12 (depends on 1) A method comprising using the polypropylene composition according to claim 1 for the production of films or moulded articles.