Propylene polymer pipes for pipelines

Abstract

Single- or multilayer propylene polymer pipes and pipe components for pipelines with improved resistance to rapid crack propagation made from a propylene homopolymer with a melt index of 0.05 to 10 g/10 min at 230° C./2.16 kg or propylene block copolymer from 90.0 to 99.9 wt % of propylene and 0.1 to 10.0 wt % of a α-olefins with 2 or 4 to 18 carbon atoms with a melt index of 0.05 to 8 g/10 min at 230° C./2.16 kg or mixtures thereof, wherein the propylene homopolymers or propylene block copolymers are β-nucleated propylene polymers, and the propylene polymer pipes for pipelines made from the β-nucleated propylene homopolymers have a rapid crack propagation characterized by a critical temperature of −5 to +40° C. and a critical pressure ≧3 bar below the critical temperature and the propylene polymer pipes made from β-nucleated propylene block copolymers have a rapid crack propagation characterized by a critical temperature of −25 to 0° C. and a critical pressure ≧3 bar below the critical temperature. The propylene polymer pipes with improved resistance to rapid crack propagation are suitable for the transportation of fluids and pressurized fluids such as natural gas, water and the like.

1 . Propylene polymer single- or multilayer pipes and pipe components for pipelines with improved resistance to rapid crack propagation comprising a propylene homopolymer with a melt index of 0.05 to 8 g/10 min at 230° C./2.16 kg or propylene block copolymers from 90.0 to 99.9 wt % of propylene and 0.1 to 10.0 wt % of α-olefins with 2 or 4 to 18 carbon atoms with a melt index of 0.05 to 8 g/10 min at 230° C./2.16 kg or mixtures thereof, wherein the propylene homopolymers or propylene block copolymers are β-nucleated propylene polymers, where the β-nucleated propylene homopolymers or the homopolymer block of the β-nucleated propylene block copolymers have an IRτ≧0.97 and the propylene polymer pipes for pipelines made from the β-nucleated propylene homopolymers have a rapid crack propagation characterized by a critical temperature of −5 to +40° C. and a critical pressure ≧3 bar below the critical temperature and the propylene polymer pipes made from β-nucleated propylene block copolymers have a rapid crack propagation characterized by a critical temperature of −25 to 0° C. and a critical pressure ≧3 bar below the critical temperature.  
     
     
         2 . Propylene polymer pipes and pipe components according to  claim 1 , wherein the β-nucleated propylene polymers of the propylene polymer pipes are β-nucleated propylene homopolymers having an IRτ≧0.98, a tensile modulus ≧1500 MPa at +23° C. and a Charpy impact strength, of ≧3 kJ/m 2  at −20° C. using notched test specimens or the β-nucleated propylene block copolymers having an IRτ of the propylene homopolymer block of ≧0.98, a tensile modulus ≧1100 MPa at 23° C. and a Charpy impact strength at −20° C. of ≧6 kJ/m 2  using notched test specimens.  
     
     
         3 . Propylene polymer pipes according to  claim 2 , wherein the β-nucleated propylene polymers with an IRτ≧0.98 being propylene polymers obtained by polymerization with a Ziegler-Natta catalyst system comprising titanium-containing solid components, an organoalumina, magnesium or titanium compound as cocatalyst and an external donor according to the formula  
       R x R′ y Si(MeO) 4-x-y ,  
       wherein R and R′ are identical or different and are branched or cyclic aliphatic or aromatic hydrocarbon residues, and y and x independently from each other are 0 or 1, provided that x+y are 1 or 2.  
     
     
         4 . Propylene polymer pipes according to  claim 3 , wherein the external donor is dicyclopentyidimethoxysilane.  
     
     
         5 . Propylene polymer pipes of one of  claims 1  to  4 , wherein the β-nucleated propylene polymer contains 0.01 to 2.0 wt %, in each case based on the propylene polymers used, of 
 dicarboxylic acid derivative type diamide compounds from C 5 -C 8 -cycloalkyl monoamines or C 6 -C 12 -aromatic monoamines and C 5 -C 8 -aliphatic, C 5 -C 8 -cycloaliphatic or C 6 -C 12 -aromatic dicarboxylic acids, preferably N,N′-di-C 5 -C 8 -cycloalkyl-2,6-naphthalene dicarboxamide compounds, N,N′-di-C 5 -C 8 -cycloalkyl-4,4-biphenyldicarboxamide compounds, N,N′-di-C 5 -C 8 -cycloalkylterephthalamide compounds, N,N′-di-C 5 -C 8 -cycloalkyl-1,4-cyclohexanedicarbox-amide compounds and/or N,N′-di-C 6 -C 12 -aryl-C 5 -C 8 -diamide compounds; and/or  
 diamine derivative type diamide compounds from C 5 -C 8 -cycloalkyl monocarboxylic acids or C 6 -C 12 -aromatic monocarboxylic acids and C 5 -C 8 -cycloaliphatic or C 6 -C 12 -aromatic diamines, preferably N,N′-C 6 -C 12 -arylene-bis-benzamide compounds, N,N′-C 5 -C 8 -cycloalkyl-bis-benzamide compounds, N,N′-p-C 6 -C 12 -arylene-bis-C 5 -C 8 -cycloalkylcarboxamide compounds and/or N,N′-C 5 -C 8 -cycloalkyl-bis-cyclohexanecarboxamide compounds; and/or  
 amino acid derivative type diamide compounds from amidation reaction of C 5 -C 8 -alkyl-, C 5 -C 8 -cycloalkyl- or C 6 -C 12 -arylamino acids, C 5 -C 8 -alkyl-, C 5 -C 8 -cycloalkyl- or C 6 -C 12 -aromatic monocarboxylic acid chlorides and C 5 -C 8 -alkyl-, C 5 -C 8 -cycloalkyl- or C 6 -C 12 -aromatic mono-amines, preferably N-phenyl-5-(N-benzoylamino) pentaneamide and/or N-cyclohexyl-4-N-cyclohexylcarbonylamino) benzamide, as β-nucleating agent.  
 
     
     
         6 . Propylene polymer pipes of one of  claims 1  to  4 , wherein the β-nucleated propylene polymer contains 0.0001 to 2.0 wt %, based on the polypropylene used, quinacridone type compounds, preferably quinacridone, dimethylquinacridone and/or dimethoxyquinacridone; quinacridonequinone type compounds, preferably quinacridonequinone, a mixed crystal of 5,12-dihydro(2,3b)acridine-7,14-dione with quino(2,3b)acridine-6,7,13,14-(5H, 12H)-tetrone and/or dimethoxyquinacridonequinone; and/or dihydroquinacridone type compounds, preferably dihydroquinacridone, dimethoxydihydroquinacridone and/or dibenzodihydroquinacridone, as β-nucleating agent.  
     
     
         7 . Propylene polymer pipes of one of  claims 1  to  4 , wherein the β-nucleated propylene polymer contains 0.01 to 2.0 wt %, based on the polypropylene used, dicarboxylic acid salts of metals from group IIa of periodic system, preferably pimelic acid calcium salt and/or suberic acid calcium salt; and/or mixtures of dicarboxylic acids and salt of metals from group IIa of periodic system, as β-nucleating agent.  
     
     
         8 . Propylene polymer pipes of one of  claims 1  to  4 , wherein the β-nucleated propylene polymer contains 0.01 to 2.0 wt %, based on the polypropylene used, salts of metals from group II of periodic system and imido acids of the formula  
       
         
           
           
               
               
           
         
       
       wherein x=1 to 4; R═H, —COOH, C 1 -C 12 -alkyl, C 5 -C 8 -cycloalkyl or C 6 -C 12- aryl, and Y═C 1 -C 12 -alkyl, C 5 -C 8 -cycloalkyl or C 6 -C 12 -aryl - substituted bivalent C 6 -C 12 -aromatic residues, preferably calcium salts of phthaloylglycine, hexahydrophthaloylglycine, N-phthaloylalanine and/or N-4-methylphthaloylglycine, as β-nucleating agent.  
     
     
         9 . A process for producing single- or multilayer propylene polymer pipes and pipe components for pipelines with improved resistance to rapid crack propagation from a propylene homopolymer with a melt index of 0.05 to 8 g/10 min at 230° C./2.16 kg or propylene block copolymers from 90.0 to 99.9 wt % of propylene and 0.1 to 10.0 wt % of α-olefins with 2 or 4 to 18 carbon atoms with a melt index of 0.05 to 8 g/10 min at 230° C./2.16 kg or mixtures thereof, wherein the propylene homopolymers or propylene block copolymers are β-nucleated propylene polymers, and the propylene polymer pipes for pipelines made from the β-nucleated propylene homopolymers have rapid crack propagation properties characterized by a critical temperature of −5 to +40° C. and a critical pressure ≧3 bar below the critical temperature and the propylene polymer pipes made from β-nucleated propylene block copolymers have a rapid crack propagation characterized by a critical temperature of −25 to 0° C. and a critical pressure ≧3 bar below the critical temperature.  
     
     
         10 . Use of propylene polymer pipes for pipelines of one of  claims 1  to  8  for the conveyance of fluids and pressurized fluids such as natural gas and water and the like.