LIVING HINGE OF AN ALPHA-NUCLEATED PROPYLENE COPOLYMER

Abstract

Living hinge consisting of a polypropylene composition comprising as main component a propylene copolymer having comonomer content in the range of 2.0 to 6.5 mol-% and an alpha-nucleating agent.

Claims

1. A living hinge consisting of a polypropylene composition comprising: (a) at least 95.0 wt. %, based on the total weight of the polypropylene composition, of a propylene copolymer, said propylene copolymer has a comonomer selected from the group consisting of 1-butene, 1-hexene and 1-octene, and (b) 0.01 to 1.0 wt. %, based on the total weight of the polypropylene composition, of an alpha-nucleating agent, wherein further the polypropylene composition has: (i) a comonomer content, measured by .sup.13C-NMR, in the range of 2.0 to 6.5 mol %, the comonomer is selected from the group consisting of 1-butene, 1-hexene and 1-octene, (ii) 2,1 erythro regio-defects, measured by .sup.13C NMR, in the range of >0.35 to 0.85 mol %, and (iii) a melt flow rate MFR.sub.2 (230 C.; 2.16 kg), measured according to ISO 1133, in the range of 15 to 100 g/10 min.

2. The living hinge according to claim 1, wherein the polypropylene composition has a molecular weight distribution (MWD) determined by Gel Permeation Chromatography (GPC) in the range of 2.2 to 3.5.

3. The living hinge according to claim 1, wherein the polypropylene composition is monophasic and optionally has a xylene cold soluble (XCS) fraction, determined at 25 C. according to ISO 16152, in the range of 0.1 to 1.0 wt. %.

4. The living hinge according to claim 1, wherein the polypropylene composition: (a) has a highest melting peak temperature Tp,m measured by DSC (scan rate of 10 C./min; second heating step) in the range of 140 to 152 C., and (b) complies with the equation 1: $\begin{array}{cc}24C.<\mathrm{Tp},m-\mathrm{Tp},c<32C.& \left(1\right)\end{array}$ wherein T.sub.p,m is the highest melting peak temperature T.sub.p,m [ C.] measured by DSC (scan rate of 10 C./min; second heating step) of the polypropylene composition and T.sub.p,c is the highest crystallization peak temperature T.sub.p,c [ C.] measured by DSC (scan rate of 10 C./min, cooling step) of the polypropylene composition.

5. The living hinge according to claim 1, wherein the propylene copolymer has: (a) a comonomer content, measured by .sup.13C-NMR, in the range of 2.0 to 6.5 mol %, and (b) 2,1 erythro regio-defects in the range of >0.35 to 0.85 mol %, measured by .sup.13C NMR.

6. The living hinge according to claim 1, wherein the propylene copolymer comprises: (a) a first propylene copolymer fraction (F1) having a comonomer content, measured by .sup.13C-NMR, in the range of 2.0 to 6.5 mol %, and (b) a second propylene copolymer fraction (F2), wherein the comonomer for the first propylene copolymer fraction (F1) and the second propylene copolymer (F2) is the same, but the amount of comonomer in the first propylene copolymer (F1) and second propylene copolymer (F2) is different; the weight ratio between the first propylene copolymer fraction (F1) and the second propylene copolymer fraction (F2) [(F1)/(F2)] is in the range of 60/40 to 40/60, and the total amount of the first propylene copolymer fraction (F1) and the second propylene copolymer fraction (F2) together, based on the propylene copolymer, is at least 98 wt. %.

7. The living hinge according to claim 6, wherein the propylene copolymer complies with the equation 2: $\frac{C\left(\mathrm{PPC}\right)}{\left(C\left(F1\right).Math.\left(F1\right)/\left(\mathrm{PPC}\right).Math.\right)}>2.5$ wherein C(PPC) is the comonomer content [mol %], measured by .sup.13C NMR, of the propylene copolymer; C(F1) is the comonomer content [mol %], measured by .sup.13C NMR, of the first propylene copolymer fraction (F1); (F1)/(PPC) is the amount of the first propylene copolymer fraction (F1) in the propylene copolymer divided by the amount of the propylene copolymer, and optionally the comonomer content between the first propylene copolymer fraction (F1) and the second propylene copolymer fraction (F2) differs in the range of 1.0 to 2.5 mol %.

8. The living hinge according to claim 1, wherein the polypropylene composition comprises further one or more propylene homopolymer(s), wherein the total amount of the one or more propylene homopolymer(s), based on the total amount of the polypropylene composition, is in the range of 0.5 to 3.0 wt. %.

9. The living hinge according to claim 1, wherein the alpha-nucleating agent is selected from the group consisting of polymeric nucleating agent, sorbitol-based nucleating agent, nonitol-based nucleating agent and/or benzene-trisamide-based nucleating agent.

10. The living hinge according to claim 1, wherein the living hinge is obtained by injection molding the polypropylene composition and said living hinge has a thickness in the range of 0.05 to 0.50 mm.

11. An injection molded article comprising two rigid pieces which are connected by one or more living hinge(s), wherein, the injection molded article consists of the polypropylene composition as defined in claim 1, and the injection molded article is made as a single piece, wherein further the one or more living hinge(s) has/have a wall thickness in the range of 0.05 to 0.50 mm.

12. The injection molded article according to claim 11, being a thin wall injection molded article, wherein the thin wall injection molded article has a wall thickness in the range of 0.05 to 2.00 mm.

13. The injection molded article according to claim 11, wherein the two rigid pieces are compartments which are connected by one or more living hinge(s), wherein the two compartments have a wall thickness in the range of 0.06 to 2.00 mm and the one or more living hinge(s) have/has a wall thickness in the range of 0.05 to 0.50 mm.

14. The injection molded article according to claim 11, being a hinge cap, wherein one rigid piece is the cap and the other rigid piece is the mount.

15. (canceled)

16. The living hinge according to claim 8, wherein the further one or more propylene homopolymer(s) have a melt flow rate MFR.sub.2 (230 C.; 2.16 kg), measured according to ISO 1133, in the range of 1.0 to 25.0 g/10 min.

17. A living hinge according to claim 16, wherein the further one or more propylene homopolymer(s) have a highest melting peak temperature T.sub.p,m measured by DSC (scan rate of 10 C./min; second heating step) in the range of 162 to 169 C.

Description

PREFERRED EMBODIMENTS

[0135] In the following some especially preferred embodiments of the invention are listed.

[0136] A living hinge, preferably an injection molded living hinge, or [0137] an Injection molded article, preferably a thin wall injection molded article, wherein the thin wall injection molded article has a wall thickness up to 2.00 mm, comprising two rigid pieces which are connected by at least one living hinge, wherein [0138] the injection molded article is made as a single piece, [0139] wherein further the living hinge and the injection molded article consists of a polypropylene composition [0140] said polypropylene composition comprises [0141] (a) at least 95.0 wt.-%, more preferably at least 97.0 wt.-%, based on the total weight of the composition, of a propylene copolymer, said propylene copolymer has a comonomer selected from the group consisting of 1-butene, 1-hexene and 1-octene, preferably said propylene copolymer is a propylene 1-butene copolymer, [0142] (b) 0.01 to 1.0 wt.-%, more preferably 0.05 to 0.5 wt.-%, based on the total weight of the composition, of an alpha-nucleating agent, preferably the alpha-nucleating agent is selected from the group consisting of polymeric nucleating agent, sorbitol-based nucleating agent, nonitol-based nucleating agent and/or benzene-trisamide-based nucleating agent, [0143] wherein further the composition has [0144] (i) a comonomer content, measured by .sup.13C-NMR, in the range of 2.0 to 6.5 mol-%, preferably in the range of 3.0 to 5.5 mol-%, the comonomer is selected from the group consisting of 1-butene, 1-hexene and 1-octene, preferably the comonomer is 1-butene, [0145] (ii) 2, 1 erythro regio-defects, measured by .sup.13C NMR, in the range of >0.35 to 0.85 mol-%, preferably in the range of 0.4 to 0.75 mol-%, and [0146] (iii) a melt flow rate MFR.sub.2 (230 C.; 2.16 kg), measured according to ISO 1133, in the range of 15 to 100 g/10 min, preferably in the range of 16 to 90 g/10 min, more preferably in the range of 17 to 80 g/10 min.

[0147] Still more preferably the invention is directed to a living hinge, preferably an injection molded living hinge, or [0148] an Injection molded article, preferably a thin wall injection molded article, wherein the thin wall injection molded article has a wall thickness up to 2.00 mm, comprising two rigid pieces which are connected by at least one living hinge, wherein [0149] the injection molded article is made as a single piece, [0150] wherein further the living hinge and the injection molded article consists of a polypropylene composition [0151] said polypropylene composition comprises [0152] (a) at least 95.0 wt.-%, more preferably at least 97.0 wt.-%, based on the total weight of the composition, of a propylene copolymer, said propylene copolymer has a comonomer selected from the group consisting of 1-butene, 1-hexene and 1-octene, preferably said propylene copolymer is a propylene 1-butene copolymer, [0153] (b) 0.01 to 1.0 wt.-%, more preferably 0.05 to 0.5 wt.-%, based on the total weight of the composition, of an alpha-nucleating agent, preferably the alpha-nucleating agent is selected from the group consisting of polymeric nucleating agent, sorbitol-based nucleating agent, nonitol-based nucleating agent and/or benzene-trisamide-based nucleating agent, [0154] wherein further the propylene copolymer has [0155] (i) a comonomer content, measured by .sup.13C-NMR, in the range of 2.0 to 6.5 mol-%, preferably in the range of 3.0 to 5.5 mol-%, the comonomer is selected from the group consisting of 1-butene, 1-hexene and 1-octene, preferably the comonomer is 1-butene, and [0156] (ii) 2, 1 erythro regio-defects in the range of >0.35 to 0.85 mol-%, preferably in the range of 0.4 to 0.75 mol-%. measured by .sup.13C NMR, wherein still further the composition has [0157] (iii) a comonomer content, measured by .sup.13C-NMR, is in the range of 2.0 to 6.5 mol-%, preferably in the range of 3.0 to 5.5 mol-%, the comonomer is selected from the group consisting of 1-butene, 1-hexene and 1-octene, preferably the comonomer is 1-butene, [0158] (iv) 2,1 erythro regio-defects in the range of >0.35 to 0.85 mol-%, preferably in the range of 0.4 to 0.75 mol-%. measured by .sup.13C NMR, and [0159] (v) a melt flow rate MFR.sub.2 (230 C.; 2.16 kg), measured according to ISO 1133, in the range of 15 to 100 g/10 min, preferably in the range of 16 to 90 g/10 min, more preferably in the range of 17 to 80 g/10 min.

[0160] Still yet more preferably the invention is directed to a living hinge, preferably an injection molded living hinge, or [0161] an Injection molded article, preferably a thin wall injection molded article, wherein the thin wall injection molded article has a wall thickness up to 2.00 mm, comprising two rigid pieces which are connected by at least one living hinge, wherein [0162] the injection molded article is made as a single piece, [0163] wherein further the living hinge and the injection molded article consists of a polypropylene composition [0164] said polypropylene composition consists of, [0165] (a) at least 95.0 wt.-%, more preferably at least 97.0 wt.-%, based on the total weight of the composition, of a propylene copolymer, said propylene copolymer has a comonomer selected from the group consisting of 1-butene, 1-hexene and 1-octene, preferably said propylene copolymer is a propylene 1-butene copolymer, [0166] (b) 0.01 to 1.0 wt.-%, more preferably 0.05 to 0.5 wt.-%, based on the total weight of the composition, of an alpha-nucleating agent, preferably the alpha-nucleating agent is selected from the group consisting of polymeric nucleating agent, sorbitol-based nucleating agent, nonitol-based nucleating agent and/or benzene-trisamide-based nucleating agent, [0167] (c) 0.05 to 1.0 wt.-%, based on the total weight of the composition, of additives being not an alpha-nucleating agent, and [0168] (d) optionally 0.5 to 4.0 wt.-%, based on the total weight of the composition, of one or more propylene homopolymer(s), preferably wherein said one or more propylene homopolymer(s) has/have a melt flow rate MFR.sub.2 (230 C.; 2.16 kg), measured according to ISO 1133, in the range of 1.0 to 25.0 g/10 min, more preferably wherein said one or more propylene homopolymer(s) has/have a melt flow rate MFR.sub.2 (230 C.; 2.16 kg), measured according to ISO 1133, in the range of 1.0 to 25.0 g/10 min and a highest melting peak temperature T.sub.p,m measured by DSC (scan rate of 10 C./min; second heating step) in the range of 162 to 169 C., still more preferably wherein said one or more propylene homopolymer(s) has/have a melt flow rate MFR.sub.2 (230 C.; 2.16 kg), measured according to ISO 1133, in the range of 1.0 to 25.0 g/10 min, a highest melting peak temperature T.sub.p,m measured by DSC (scan rate of 10 C./min; second heating step) in the range of 162 to 169 C. and no detectable 2, 1 erythro regio-defects measured by .sup.13C NMR, [0169] wherein further the composition has [0170] (i) a comonomer content, measured by .sup.13C-NMR, in the range of 2.0 to 6.5 mol-%, preferably in the range of 3.0 to 5.5 mol-%, the comonomer is selected from the group consisting of 1-butene, 1-hexene and 1-octene, preferably the comonomer is 1-butene, [0171] (ii) 2, 1 erythro regio-defects, measured by .sup.13C NMR, in the range of >0.35 to 0.85 mol-%, preferably in the range of 0.4 to 0.75 mol-%, and [0172] (iii) a melt flow rate MFR.sub.2 (230 C.; 2.16 kg), measured according to ISO 1133, in the range of 15 to 100 g/10 min, preferably in the range of 16 to 90 g/10 min, more preferably in the range of 17 to 80 g/10 min.

[0173] In another preferred embodiment the invention is directed to a living hinge, preferably an injection molded living hinge, or [0174] an Injection molded article, preferably a thin wall injection molded article, wherein the thin wall injection molded article has a wall thickness up to 2.00 mm, comprising two rigid pieces which are connected by at least one living hinge, wherein the injection molded article is made as a single piece, [0175] wherein further the living hinge and the injection molded article consists of a polypropylene composition [0176] said polypropylene composition consists of, [0177] (a) at least 95.0 wt.-%, more preferably at least 97.0 wt.-%, based on the total weight of the composition, of a propylene copolymer, said propylene copolymer has a comonomer selected from the group consisting of 1-butene, 1-hexene and 1-octene, preferably said propylene copolymer is a propylene 1-butene copolymer, [0178] (b) 0.01 to 1.0 wt.-%, more preferably 0.05 to 0.5 wt.-%, based on the total weight of the composition, of an alpha-nucleating agent, [0179] (c) 0.05 to 1.0 wt.-%, based on the total weight of the composition, of additives being not an alpha-nucleating agent, and [0180] (d) optionally 0.5 to 4.0 wt.-%, based on the total weight of the composition, of one or more propylene homopolymer(s), preferably wherein said one or more propylene homopolymer(s) has/have a melt flow rate MFR.sub.2 (230 C.; 2.16 kg), measured according to ISO 1133, in the range of 1.0 to 25.0 g/10 min, more preferably wherein said one or more propylene homopolymer(s) has/have a melt flow rate MFR.sub.2 (230 C.; 2.16 kg), measured according to ISO 1133, in the range of 1.0 to 25.0 g/10 min and a highest melting peak temperature T.sub.p,m measured by DSC (scan rate of 10 C./min; second heating step) in the range of 162 to 169 C., still more preferably wherein said one or more propylene homopolymer(s) has/have a melt flow rate MFR.sub.2 (230 C.; 2.16 kg), measured according to ISO 1133, in the range of 1.0 to 25.0 g/10 min, a highest melting peak temperature T.sub.p,m measured by DSC (scan rate of 10 C./min; second heating step) in the range of 162 to 169 C. and no detectable 2, 1 erythro regio-defects measured by .sup.13C NMR, [0181] wherein further the propylene copolymer has [0182] (i) a comonomer content, measured by .sup.13C-NMR, in the range of 2.0 to 6.5 mol-%, preferably in the range of 3.0 to 5.5 mol-%, the comonomer is selected from the group consisting of 1-butene, 1-hexene and 1-octene, preferably the comonomer is 1-butene, and [0183] (ii) 2, 1 erythro regio-defects in the range of >0.35 to 0.85 mol-%, preferably in the range of 0.4 to 0.75 mol-%. measured by .sup.13C NMR, wherein still further the composition has [0184] (iii) a comonomer content, measured by .sup.13C-NMR, is in the range of 2.0 to 6.5 mol-%, preferably in the range of 3.0 to 5.5 mol-%, the comonomer is selected from the group consisting of 1-butene, 1-hexene and 1-octene, preferably the comonomer is 1-butene, [0185] (iv) 2, 1 erythro regio-defects in the range of >0.35 to 0.85 mol-%, preferably in the range of 0.4 to 0.75 mol-%. measured by .sup.13C NMR, and [0186] (v) a melt flow rate MFR.sub.2 (230 C.; 2.16 kg), measured according to ISO 1133, in the range of 15 to 100 g/10 min, preferably in the range of 16 to 90 g/10 min, more preferably in the range of 17 to 80 g/10 min.

[0187] In still another preferred embodiment the invention the invention is directed to a living hinge, preferably an injection molded living hinge, or [0188] an Injection molded article, preferably a thin wall injection molded article, wherein the thin wall injection molded article has a wall thickness up to 2.00 mm, comprising two rigid pieces which are connected by at least one living hinge, wherein the injection molded article is made as a single piece, [0189] wherein further the living hinge and the injection molded article consists of a polypropylene composition [0190] said polypropylene composition consists of, [0191] (a) at least 95.0 wt.-%, more preferably at least 97.0 wt.-%, based on the total weight of the composition, of a propylene copolymer, said propylene copolymer has a comonomer selected from the group consisting of 1-butene, 1-hexene and 1-octene, preferably said propylene copolymer is a propylene 1-butene copolymer, [0192] (b) 0.01 to 1.0 wt.-%, more preferably 0.05 to 0.5 wt.-%, based on the total weight of the composition, of an alpha-nucleating agent, preferably the alpha-nucleating agent is selected from the group consisting of polymeric nucleating agent, sorbitol-based nucleating agent, nonitol-based nucleating agent and/or benzene-trisamide-based nucleating agent, [0193] (c) 0.05 to 1.0 wt.-%, based on the total weight of the composition, of additives being not an alpha-nucleating agent, and [0194] (d) optionally 0.5 to 4.0 wt.-%, based on the total weight of the composition, of one or more propylene homopolymer(s), preferably wherein said one or more propylene homopolymer(s) has/have a melt flow rate MFR.sub.2 (230 C.; 2.16 kg), measured according to ISO 1133, in the range of 1.0 to 25.0 g/10 min, more preferably wherein said one or more propylene homopolymer(s) has/have a melt flow rate MFR.sub.2 (230 C.; 2.16 kg), measured according to ISO 1133, in the range of 1.0 to 25.0 g/10 min and a highest melting peak temperature T.sub.p,m measured by DSC (scan rate of 10 C./min; second heating step) in the range of 162 to 169 C., still more preferably wherein said one or more propylene homopolymer(s) has/have a melt flow rate MFR.sub.2 (230 C.; 2.16 kg), measured according to ISO 1133, in the range of 1.0 to 25.0 g/10 min, a highest melting peak temperature T.sub.p,m measured by DSC (scan rate of 10 C./min; second heating step) in the range of 162 to 169 C. and no detectable 2, 1 erythro regio-defects measured by .sup.13C NMR, [0195] wherein further the composition has [0196] (i) a comonomer content, measured by .sup.13C-NMR, in the range of 2.0 to 6.5 mol-%, preferably in the range of 3.0 to 5.5 mol-%, the comonomer is selected from the group consisting of 1-butene, 1-hexene and 1-octene, preferably the comonomer is 1-butene, [0197] (ii) 2, 1 erythro regio-defects, measured by .sup.13C NMR, in the range of >0.35 to 0.85 mol-%, preferably in the range of 0.4 to 0.75 mol-%, and [0198] (iii) a melt flow rate MFR.sub.2 (230 C.; 2.16 kg), measured according to ISO 1133, in the range of 15 to 100 g/10 min, preferably in the range of 16 to 90 g/10 min, more preferably in the range of 17 to 80 g/10 min. [0199] (iv) the highest melting peak temperature T.sub.p,m measured by DSC (scan rate of 10 C./min; second heating step) in the range of 140 to 152 C., and wherein still further the composition [0200] (v) complies with the equation 1, preferably equation 1a,

[00004]$\begin{array}{cc}24C.<\mathrm{Tp},m-\mathrm{Tp},c<32C.& \left(1\right)\end{array}$$\begin{array}{cc}25C.<\mathrm{Tp},m-\mathrm{Tp},c<30C.& \left(1a\right)\end{array}$ [0201] wherein [0202] T.sub.p,m is the highest melting peak temperature T.sub.p,m [ C.] measured by DSC (scan rate of 10 C./min; second heating step) and [0203] T.sub.p,c is the highest crystallization peak temperature T.sub.p,c [ C.] measured by DSC (scan rate of 10 C./min; cooling step).

[0204] In still yet another preferred embodiment the invention the invention is directed to a living hinge, preferably an injection molded living hinge, or [0205] an Injection molded article, preferably a thin wall injection molded article, wherein the thin wall injection molded article has a wall thickness up to 2.00 mm, comprising two rigid pieces which are connected by at least one living hinge, wherein the injection molded article is made as a single piece, [0206] wherein further the living hinge and the injection molded article consists of a polypropylene composition [0207] said polypropylene composition consists of, [0208] (a) at least 95.0 wt.-%, more preferably at least 97.0 wt.-%, based on the total weight of the composition, of a propylene copolymer, said propylene copolymer has a comonomer selected from the group consisting of 1-butene, 1-hexene and 1-octene, preferably said propylene copolymer is a propylene 1-butene copolymer, [0209] (b) 0.01 to 1.0 wt.-%, more preferably 0.05 to 0.5 wt.-%, based on the total weight of the composition, of an alpha-nucleating agent, preferably the alpha-nucleating agent is selected from the group consisting of polymeric nucleating agent, sorbitol-based nucleating agent, nonitol-based nucleating agent and/or benzene-trisamide-based nucleating agent, [0210] (c) 0.05 to 1.0 wt.-%, based on the total weight of the composition, of additives being not an alpha-nucleating agent, and [0211] (d) optionally 0.5 to 4.0 wt.-%, based on the total weight of the composition, of one or more propylene homopolymer(s), preferably wherein said one or more propylene homopolymer(s) has/have a melt flow rate MFR.sub.2 (230 C.; 2.16 kg), measured according to ISO 1133, in the range of 1.0 to 25.0 g/10 min, more preferably wherein said one or more propylene homopolymer(s) has/have a melt flow rate MFR.sub.2 (230 C.; 2.16 kg), measured according to ISO 1133, in the range of 1.0 to 25.0 g/10 min and a highest melting peak temperature T.sub.p,m measured by DSC (scan rate of 10 C./min; second heating step) in the range of 162 to 169 C., still more preferably wherein said one or more propylene homopolymer(s) has/have a melt flow rate MFR.sub.2 (230 C.; 2.16 kg), measured according to ISO 1133, in the range of 1.0 to 25.0 g/10 min, a highest melting peak temperature T.sub.p,m measured by DSC (scan rate of 10 C./min; second heating step) in the range of 162 to 169 C. and no detectable 2,1 erythro regio-defects measured by .sup.13C NMR, [0212] wherein further the propylene copolymer has [0213] (i) a comonomer content, measured by .sup.13C-NMR, in the range of 2.0 to 6.5 mol-%, preferably in the range of 3.0 to 5.5 mol-%, the comonomer is selected from the group consisting of 1-butene, 1-hexene and 1-octene, preferably the comonomer is 1-butene, and [0214] (ii) 2, 1 erythro regio-defects in the range of >0.35 to 0.85 mol-%, preferably in the range of 0.4 to 0.75 mol-%. measured by .sup.13C NMR, [0215] wherein still further the composition has [0216] (iii) a comonomer content, measured by .sup.13C-NMR, in the range of 2.0 to 6.5 mol-%, preferably in the range of 3.0 to 5.5 mol-%, [0217] (iv) 2, 1 erythro regio-defects, measured by .sup.13C NMR, in the range of >0.35 to 0.85 mol-%, preferably in the range of 0.4 to 0.75 mol-%, and [0218] (v) a melt flow rate MFR.sub.2 (230 C.; 2.16 kg), measured according to ISO 1133, in the range of 15 to 100 g/10 min, preferably in the range of 16 to 90 g/10 min, more preferably in the range of 17 to 80 g/10 min. [0219] (vi) the highest melting peak temperature T.sub.p,m measured by DSC (scan rate of 10 C./min; second heating step) in the range of 140 to 152 C., and [0220] wherein still further the composition [0221] (vii) complies with the equation 1, preferably equation 1a,

[00005]$\begin{array}{cc}24C.<\mathrm{Tp},m-\mathrm{Tp},c<32C.& \left(1\right)\end{array}$$\begin{array}{cc}25C.<\mathrm{Tp},m-\mathrm{Tp},c<30C.& \left(1a\right)\end{array}$ [0222] wherein [0223] T.sub.p,m is the highest melting peak temperature T.sub.p,m [ C.] measured by DSC (scan rate of 10 C./min; second heating step) and [0224] T.sub.p,c is the highest crystallization peak temperature T.sub.p,c [C] measured by DSC (scan rate of 10 C./min; cooling step).

[0225] The invention is also directed to a living hinge, preferably an injection molded living hinge, or an Injection molded article, preferably a thin wall injection molded article, wherein the thin wall injection molded article has a wall thickness up to 2.00 mm, comprising two rigid pieces which are connected by at least one living hinge, wherein [0226] the injection molded article is made as a single piece, [0227] wherein further the living hinge and the injection molded article consists of a polypropylene composition [0228] said polypropylene composition consists of, [0229] (a) at least 95.0 wt.-%, more preferably at least 97.0 wt.-%, based on the total weight of the composition, of a propylene copolymer, said propylene copolymer has a comonomer selected from the group consisting of 1-butene, 1-hexene and 1-octene, preferably said propylene copolymer is a propylene 1-butene copolymer, [0230] (b) 0.01 to 1.0 wt.-%, more preferably 0.05 to 0.5 wt.-%, based on the total weight of the composition, of an alpha-nucleating agent, preferably the alpha-nucleating agent is selected from the group consisting of polymeric nucleating agent, sorbitol-based nucleating agent, nonitol-based nucleating agent and/or benzene-trisamide-based nucleating agent, [0231] (c) 0.05 to 1.0 wt.-%, based on the total weight of the composition, of additives being not an alpha-nucleating agent, and [0232] (d) optionally 0.5 to 4.0 wt.-%, based on the total weight of the composition, of one or more propylene homopolymer(s), preferably wherein said one or more propylene homopolymer(s) has/have a melt flow rate MFR.sub.2 (230 C.; 2.16 kg), measured according to ISO 1133, in the range of 1.0 to 25.0 g/10 min, more preferably wherein said one or more propylene homopolymer(s) has/have a melt flow rate MFR.sub.2 (230 C.; 2.16 kg), measured according to ISO 1133, in the range of 1.0 to 25.0 g/10 min and a highest melting peak temperature T.sub.p,m measured by DSC (scan rate of 10 C./min; second heating step) in the range of 162 to 169 C., still more preferably wherein said one or more propylene homopolymer(s) has/have a melt flow rate MFR.sub.2 (230 C.; 2.16 kg), measured according to ISO 1133, in the range of 1.0 to 25.0 g/10 min, a highest melting peak temperature T.sub.p,m measured by DSC (scan rate of 10 C./min; second heating step) in the range of 162 to 169 C. and no detectable 2,1 erythro regio-defects measured by .sup.13C NMR, [0233] wherein further the propylene copolymer has [0234] (i) a comonomer content, measured by .sup.13C-NMR, in the range of 2.0 to 6.5 mol-%, preferably in the range of 3.0 to 5.5 mol-%, and [0235] (ii) 2,1 erythro regio-defects in the range of >0.35 to 0.85 mol-%, preferably in the range of 0.4 to 0.75 mol-%. measured by .sup.13C NMR, wherein still further the composition has [0236] (iii) a comonomer content, measured by .sup.13C-NMR, in the range of 2.0 to 6.5 mol-%, preferably in the range of 3.0 to 5.5 mol-%, the comonomer is selected from the group consisting of 1-butene, 1-hexene and 1-octene, preferably the comonomer is 1-butene, [0237] (iv) 2,1 erythro regio-defects, measured by .sup.13C NMR, in the range of >0.35 to 0.85 mol-%, preferably in the range of 0.4 to 0.75 mol-%, and [0238] (v) a melt flow rate MFR.sub.2 (230 C.; 2.16 kg), measured according to ISO 1133, in the range of 15 to 100 g/10 min, preferably in the range of 16 to 90 g/10 min, more preferably in the range of 17 to 80 g/10 min, [0239] (vi) a xylene cold soluble (XCS) fraction, determined at 25 C. according to ISO 16152, in the range of 0.1 to 1.0 wt.-%, preferably in the range of 0.2 to 0.6 wt.-%, [0240] (vii) a molecular weight distribution (MWD) determined by Gel Permeation Chromatography (GPC) in the range of 2.0 to 5.0, more preferably in the range of 2.1 to 4.5, still more preferably in the range of 2.2 to 3.5, [0241] (viii) the highest melting peak temperature T.sub.p,m measured by DSC (scan rate of 10 C./min; second heating step) in the range of 140 to 152 C., and [0242] wherein still further the composition [0243] (ix) complies with the equation 1, preferably equation 1a,

[00006]$\begin{array}{cc}24C.<\mathrm{Tp},m-\mathrm{Tp},c<32C.& \left(1\right)\end{array}$$\begin{array}{cc}25C.<\mathrm{Tp},m-\mathrm{Tp},c<30C.& \left(1a\right)\end{array}$ [0244] wherein [0245] T.sub.p,m is the highest melting peak temperature T.sub.p,m [ C.] measured by DSC (scan rate of 10 C./min; second heating step) and [0246] T.sub.p,c is the highest crystallization peak temperature T.sub.p,c [ C.] measured by DSC (scan rate of 10 C./min; cooling step).

[0247] In the following the invention is described by way of examples.

A. Measuring Methods

[0248] The following definitions of terms and determination methods apply for the above general description of the invention including the claims as well as to the below examples unless otherwise defined.

Quantification of Microstructure by NMR Spectroscopy

[0249] Quantitative nuclear-magnetic resonance (NMR) spectroscopy was used to quantify the comonomer content of the polymers. Quantitative .sup.13C {.sup.1H} NMR spectra recorded in the molten-state using a Bruker Avance III 500 NMR spectrometer operating at 500.13 and 125.76 MHz for .sup.1H and .sup.13C respectively. All spectra were recorded using a .sup.13C optimised 7 mm magic-angle spinning (MAS) probe head at 180 C. using nitrogen gas for all pneumatics. Approximately 200 mg of material was packed into a 7 mm outer diameter zirconia MAS rotor and spun at 4 kHz. This setup was chosen primarily for the high sensitivity needed for rapid identification and accurate quantification. Standard single-pulse excitation was employed utilising the NOE at short recycle delays and the RS-HEPT decoupling scheme. A total of 1024 (1k) transients were acquired per spectra using a 3 s recycle delay.

[0250] Quantitative .sup.13C {.sup.1H} NMR spectra were processed, integrated and relevant quantitative properties determined from the integrals. All chemical shifts are internally referenced to the methyl isotactic pentad (mmmm) at 21.85 ppm.

Basic Comonomer Content Method Spectral Analysis Method:

[0251] Characteristic signals corresponding to the incorporation of 1-butene were observed and the comonomer content quantified in the following way.

[0252] The amount of 1-butene incorporated in PPBPP isolated sequences was quantified using the integral of the .sub.B2 sites at 43.6 ppm accounting for the number of reporting sites per comonomer:

[00007]$B=I_{}/2$

[0253] The amount of 1-butene incorporated in PPBBPP double consecutively sequences was quantified using the integral of the .sub.B2B2 site at 40.5 ppm accounting for the number of reporting sites per comonomer:

[00008]$\mathrm{BB}=2*I_{}$

[0254] When double consecutive incorporation was observed the amount of 1-butene incorporated in PPBPP isolated sequences needed to be compensated due to the overlap of the signals .sub.B2 and .sub.B2B2 at 43.9 ppm:

[00009]$B=\left(I_{}-2*I_{}\right)/2$

[0255] The total 1-butene content was calculated based on the sum of isolated and consecutively incorporated 1-butene:

[00010]$B_{\mathrm{total}}=B+\mathrm{BB}$

[0256] The amount of propene was quantified based on the main S methylene sites at 46.7 ppm and compensating for the relative amount of B2 and B2B2 methylene unit of propene not accounted for (note B and BB count number of butene monomers per sequence not the number of sequences):

[00011]$P_{\mathrm{total}}=I_S+B+\mathrm{BB}/2$

[0257] The total mole fraction of 1-butene in the polymer was then calculated as:

[00012]$f_B=B_{\mathrm{total}}/\left(B_{\mathrm{total}}+P_{\mathrm{total}}\right)$

[0258] The full integral equation for the mole fraction of 1-butene in the polymer was:

[00013]$f_B=\left(\left(\left(I_{}-2*I_{}\right)/2\right)+\left(2*I_{}\right)\right)/\left(I_S+\left(\left(I_{}-2*I_{}\right)/2\right)+\left(\left(2*I_{}\right)/2\right)\right)+\left(\left(I_{}-2*I_{}\right)/2\right)+\left(2*I\right))$

[0259] This simplifies to:

[00014]$f_B=\left(I_{}/2+I_{}\right)/\left(I_S+I_{}+I_{}\right)$

[0260] The total incorporation of 1-butene in mole percent was calculated from the mole fraction in the usual manner:

[00015]$B\left[\mathrm{mol}-\%\right]=100*f_B$

[0261] The total incorporation of 1-butene in weight percent was calculated from the mole fraction in the standard manner:

[00016]$B\left[\mathrm{wt}.-1\%\right]=100*\left(f_B*56.11\right)/\left(\left(f_B*56.11\right)+\left(\left(1-f_B\right)*42.08\right)\right)$

[0262] Details of these procedures can be found in Katja Klimke, Matthew Parkinson, Christian Piel, Walter Kaminsky Hans Wolfgang Spiess, Manfred Wilhelm, Macromol. Chem. Phys. 2006, 207, 382; Matthew Parkinson, Katja Klimke, Hans Wolfgang Spiess, Manfred Wilhelm, Macromol. Chem. Phys. 2007, 208, 2128; Patrice Castignolles, Robert Graf, Matthew Parkinson, Manfred Wilhelm, Marianne Gaborieau: Polymer 2009, 50, 2373; M. Pollard, K. Klimke, R. Graf, H. W. Spiess, M. Wilhelm, O. Sperber, C. Piel, W. Kaminsky, Macromolecules 2004, 37, 813; Xenia Filip, Carmen Tripon, Claudiu Filip, J. Magn. Reson. 2005, 176, 239; John M. Griffin, Carmen Tripon, Ago Samoson, Claudiu Filip, Steven P. Brown, Mag. Res. in Chem. 2007, 45 (S1), S198; J. Randall Rev. Macromol. Chem. Phys. 1989, C29, 201.

Melt Flow Rate

[0263] The melt flow rate (MFR) is determined according to ISO 1133 and is indicated in g/10 min. The MFR is an indication of the flowability, and hence the processability, of the polymer. The higher the melt flow rate, the lower the viscosity of the polymer. The MFR.sub.2 of the polypropylene is determined at a temperature of 230 C. and a load of 2.16 kg.

Calculation of Melt Flow Rate MFR.SUB.2 .(230 C.) of the Second Polypropylene (PP2):

[00017]$\mathrm{MFR}\left(\mathrm{PP}2\right)={10}^{\left[\frac{\log \left(\mathrm{MFR}\left(\mathrm{PP}\right)\right)-w\left(\mathrm{PP}1\right)\log \left(\mathrm{MFR}\left(\mathrm{PP}1\right)\right)}{w\left(\mathrm{PP}\right)}\right]}$ [0264] wherein [0265] w(PP1) is the weight fraction [in wt.-%] of the first polypropylene (PP1), [0266] w(PP2) is the weight fraction [in wt.-%] of the second polypropylene (PP2), [0267] MFR(PP1) is the melt flow rate MFR.sub.2 (230 C.) [in g/10 min] the first polypropylene (PP1), [0268] MFR(PP) is the melt flow rate MFR.sub.2 (230 C.) [in g/10 min] of the reactor powder of the polypropylene (PP), [0269] MFR(PP2) is the calculated melt flow rate MFR.sub.2 (230 C.) [in g/10 min] of the second polypropylene (PP2).

Molecular Weight

[0270] Molecular weight averages (Mz, Mw and Mn) and Molecular weight distribution (MWD), i.e. Mw/Mn, were determined by Gel Permeation Chromatography (GPC) according to ISO 16014-4:2003 and ASTM D 6474-99 using the following formulas:

[00018]$M_n=\frac{{.Math.}_{i=1}^N{A}_i}{.Math.\left(A_i/M_i\right)}$$M_w=\frac{{.Math.}_{i=1}^N\left(A_i{M}_i\right)}{.Math.A_i}$$M_z=\frac{{.Math.}_{i=1}^N\left(A_i{M}_i^2\right)}{.Math.\left(A_i/M_i\right)}$ [0271] where Ai and Mi are the chromatographic peak slice area and polyolefin molecular weight (MW). [0272] A PolymerChar GPC instrument, equipped with infrared (IR) detector was used with 3 Olexis and 1 Olexis Guard columns from Polymer Laboratories and 1,2,4-trichlorobenzene (TCB, stabilized with 250 mg/l 2,6-Di-tert-butyl-4-methyl-phenol) as solvent at 160 C. and at a constant flow rate of 1 ml/min. 200 L of sample solution were injected per analysis. The column set was calibrated using universal calibration (according to ISO 16014-2:2003) with at least 15 narrow MWD polystyrene (PS) standards in the range of 0.5 kg/mol to 11500 kg/mol. Mark Houwink constants used for PS, PE and PP are as described per ASTM D 6474-99. All samples were prepared by dissolving 5.0 to 9.0 mg of polymer in 8 ml (at 160 C.) of stabilized TCB (same as mobile phase) for 2.5 hours for PP or 3 hours for PE at 160 C. under continuous gentle shaking in the autosampler of the GPC instrument.

The Xylene Soluble Fraction at Room Temperature (XCS, Wt.-%):

[0273] The amount of the polymer soluble in xylene was determined at 25 C. according to ISO 16152; 5th edition; 2005 Jul. 1.

[0274] DSC analysis, melting peak temperature (T.sub.p,m) and heat of fusion (H.sub.f), crystallization peak temperature (T.sub.p,c) and heat of crystallization (H.sub.c): measured with a TA Instrument Q200 differential scanning calorimetry (DSC) on 5 to 7 mg samples. DSC is run according to ISO 11357/part 3/method C2 in a heat/cool/heat cycle with a scan rate of 10 C./min in the temperature range of 30 to +225 C. Highest crystallization peak temperature (T.sub.p,c) and heat of crystallization (H.sub.c) are determined from the cooling step, while highest melting peak temperature (T.sub.p,m) and heat of fusion (H.sub.f) are determined from the second heating step.

Flexural Modulus

[0275] The Flexural Modulus was determined according to ISO 178 method A (3-point bending test) on 80104 mm specimens. Following the standard, a test speed of 2 mm/min and a span length of 16 times the thickness was used. The testing temperature was 232 C. Injection moulding was carried out according to ISO 19069-2 using a melt temperature of 200 C. for all materials irrespective of material melt flow rate.

Haze

[0276] Haze was determined according to ASTM D1003-00 on 60601 mm.sup.3 plaques injection molded in line with EN ISO 1873-2 using a melt temperature of 230 C.

Charpy Notched Impact Strength (NIS)

[0277] The Charpy notched impact strength (NIS) was measured according to ISO 179 1 eA at +23 C., using injection moulded bar test specimens of 80104 mm prepared in accordance with EN ISO 1873-2.

B. Preparation of Polypropylene Composition

[0278] Catalyst for the inventive examples

Catalyst Complex

[0279] The following metallocene complex has been used as described in WO 2019/179959:

##STR00002##

Preparation of MAO-Silica Support

[0280] A steel reactor equipped with a mechanical stirrer and a filter net was flushed with nitrogen and the reactor temperature was set to 20 C. Next silica grade DM-L-303 from AGC Si-Tech Co, pre-calcined at 600 C. (5.0 kg) was added from a feeding drum followed by careful pressuring and depressurising with nitrogen using manual valves. Then toluene (22 kg) was added. The mixture was stirred for 15 min. Next 30 wt. % solution of MAO in toluene (9.0 kg) from Lanxess was added via feed line on the top of the reactor within 70 min. The reaction mixture was then heated up to 90 C. and stirred at 90 C. for additional two hours. The slurry was allowed to settle and the mother liquor was filtered off. The catalyst was washed twice with toluene (22 kg) at 90 C., following by settling and filtration. The reactor was cooled off to 60 C. and the solid was washed with heptane (22.2 kg). Finally MAO treated SiO.sub.2 was dried at 60 C. under nitrogen flow for 2 hours and then for 5 hours under vacuum (0.5 barg) with stirring. MAO treated support was collected as a free-flowing white powder found to contain 12.2% Al by weight.

Single Site Catalyst System 1 (SSCS1) Preparation

[0281] 30 wt. % MAO in toluene (0.7 kg) was added into a steel nitrogen blanked reactor via a burette at 20 C. Toluene (5.4 kg) was then added under stirring. The metallocene complex as described above (93 g) was added from a metal cylinder followed by flushing with 1 kg toluene. The mixture was stirred for 60 minutes at 20 C. Trityl tetrakis(pentafluorophenyl)borate (91 g) was then added from a metal cylinder followed by a flush with 1 kg of toluene. The mixture was stirred for 1 h at room temperature. The resulting solution was added to a stirred cake of MAO-silica support prepared as described above over 1 hour. The cake was allowed to stay for 12 hours, followed by drying under N.sub.2 flow at 60 C. for 2 h and additionally for 5 h under vacuum (0.5 barg) under stirring.

[0282] Dried catalyst was sampled in the form of pink free flowing powder containing 13.9% Al and 0.11% Zr.

TABLE-US-00001 TABLE 1 Polymerization conditions Polymer Poly 1 Catalyst SSCS1 Prepoly reactor Temp. [ C.] 20 Press. [kPa] 4756 Residence time [h] 0.33 Loop reactor Temp. [ C.] 68 Press. [kPa] 4923 Feed H2/C3 ratio [mol/kmol] 0.13 Feed C4/C3 ratio [mol/kmol] 44.0 Polymer Split* [wt.-%] 47 MFR.sub.2* [g/10 min] 24 Total C4* [wt.-%] 4.4 Total C4* [mol-%] 3.3 XCS* [wt.-%] 0.3 GPR (F2) Temp. [ C.] 80 Press. [kPa] 2500 H2/C3 ratio [mol/kmol] 1.6 C4/C3 ratio [mol/kmol] 38.0 Polymer Split [wt.-%] 53 C4** [wt.-%] 6.7 C4** [mol-%] 5.11 MFR.sub.2*** [g/10 min] 19 Pellet MFR.sub.2 [g/10 min] 21 Total C4 [wt.-%] 5.6 Total C4 [mol-%] 4.3 2,1 erythro [mol-%] 0.61 XCS [wt.-%] 0.4 *MFR.sub.2, Total C4, XCS and Polymer Split are measured in the loop reactor, i.e. is the combination of Prepoly Reactor and Loop reactor and considered as the first propylene copolymer fraction (F1) **C4 is calculated from the Total C4 measured in the loop reactor and Total C4 measured from the pellet ***MFR.sub.2 is calculated from the MFR.sub.2 measured in the loop reactor and the MFR.sub.2 of the pellet using the formula given above defining the measurement of MFR.sub.2

TABLE-US-00002 TABLE 2 Polypropylene composition IE1 CE1 CE2 CE3 Poly1 [wt.-%] 97.66 Poly2 [wt.-%] 2.00 100 Poly3 [wt.-%] 100 Poly4 [wt.-%] 100 AO1 [wt.-%] 0.05 AO2 [wt.-%] 0.05 CS [wt.-%] 0.04 AN1 [wt.-%] 0.2 C4 [mol-%] 4.3 0 0 0 C2 [mol-%] 0 0 0 5.8 XCS [wt.-%] 0.4 1.5 2.0 6.5 2,1 erythro [mol-%] 0.60 0.0 0.0 0.0 MWD [] 2.6 5.8 4.0 5.6 MFR.sub.2 [g/10 min] 21 20 19 30 T.sub.p, c [ C.] 118.0 129 111 122 T.sub.p, m [ C.] 145.5 165 161 150 FM [MPa] 1359 2000 1220 1050 Haze [%] 9.0 57 35 20 FM/haze [MPa/%] 151 35 35 53 Charpy NIS (23 C.) [kJ/m.sup.2] 3.7 2.5 2.2 5.5 FM is the flexural modulus; Poly2 is the commercial alpha-nucleated polypropylene homopolymer HF955MO of BorealisAG; Poly3 is the commercial polypropylene homopolymer HF420FB of Borealis AG Poly4 is the commercial alpha-nucleated propylene-ethylene copolymer BorePure RG466MO of Borealis AG; AO1 is the sterically hindered phenol pentaerythrityl-tetrakis(3-(3,5-di-tert. butyl-4-hydroxyphenyl)-propionate Irganox 1010 of BASF AO2 is the phosphorous based antioxidant tris (2,4-di-t-butylphenyl) phosphite Irgafos 168 of BASF CS is calcium stearate AN1 is the commercial alpha-nucleating agent Millad 3988 of Milliken containing bis-(3,4-dimethylbenzylidene)-sorbitol (DMDBS);

C. Preparation of Lunch Boxes

[0283] Lunch boxes of an outer dimension of 160.9130.069.1 mm.sup.3 having rounded corners and edges as shown in FIG. 1 were produced by injection molding. Said lunch boxes consist of a lower half of 35.3 mm height and an upper part of 33.8 mm height, connected with a first living hinge in position A and equipped with a closure including a second living hinge in position A according to FIG. 1. The wall thickness of said lunch box is 1.54 mm, and the first and second living hinges have a thickness of 0.30 mm. The mould is equipped with a single point gate and yields the boxes in an open position, allowing testing of the first living hinge connecting the halves in an un-deformed state. An Engel ES 1350/350 HL injection moulding machine was used for production, setting a melt temperature of 260 C., a mould temperature of 25 C. and a filling velocity of 119 cm.sup.3/s. This gave a filling time of approximately 1 s, followed by a holding time of 5 s with a holding pressure of 493 bar, and a cooling time before ejection of 12 s. The lunch boxes were stored in open position at 23 C. for at least 96 h prior to testing.

Top Load Test

[0284] For this test, five of the lunch boxes per material were closed and the closure snapped in. Compression test according to DIN 55526-1991 was performed on each box with attest speed of 10 mm/min up to a deformation of 20 mm. The maximum compression force and the deformation at maximum were recorded and the average of the five results calculated.

Hinge Strength Test

[0285] For this test, specimens for an adapted tensile test were cut from the first living hinge side of five lunch boxes per material. The specimens were first cut to a width of 11 mm with a band saw parallel to the A-A cross section plane in the central part of the hinge, leaving a 10 mm long plane part of full wall thickness on both sides for clamping. To avoid edge disturbance, the specimens were then trimmed by cutting and milling to a width of 10 mm. The resulting specimens were subjected to a normal tensile test according to ISO 527-1 on a Zwick Z100-725333 machine, using a strain rate of 1 mm/min and testing up to the breakage of the specimen. The stress and extension resp. strain at break were recorded and the average of the five results calculated.

TABLE-US-00003 TABLE 3 Lunch box properties Top load test Hinge strength test Fmax Smax StrB ExtB Fmax*StrB [N] [mm] [MPa] [%] [N*MPa] IE1 4052 17.8 24.8 98.6 100653 CE1 5445 18.0 14.8 49.1 80799 CE2 3960 18.2 17.5 60.7 69423 CE3 3053 14.7 24.7 130.9 75409

[0286] Experience shows that the stress and strain at break in a tensile test of a living hinge are proportional to the long-term stability of said hinge, i.e. the number of time which the hinge can be flexed without damage or break. The data of Table 3 consequently show the improved property balance between top load and hinge stability for the inventive example over all of the comparative examples. This good performance is combined with low haze and very low xylene solubles content, as can be seen from the data in Table 2.