Thermoplastic vulcanisate blend

Abstract

The invention relates to a new polymer blend comprising: 20 to 70 wt % of a mixture (A) of two or more polyalkylene phthalates; 2 to 60 wt % of a cross-linked acrylate rubber; 0.5 to 20 wt % of an ionomer; and 1 to 30 wt % of a terpolymer of ethylene, butylacrylate (BA) and glycidylmethacrylate (GMA); wherein the weight percentages are based on the sum of the above ingredients. The polymer blend of the invention is particularly suitable for blow-moulding, to make parts for high-temperature, high-oil-exposure uses.

1 . A polymer blend comprising: 20 to 70 wt % of a mixture (A) of two or more polyalkylene phthalates; 
 2 to 60 wt % of a cross-linked acrylate rubber;    0.5 to 20 wt % of an ionomer; and    1 to 30 wt % of a terpolymer of ethylene, butylacrylate (BA) and glycidylmethacrylate (GMA);    wherein the weight percentages are based on the sum of the above ingredients.    
   
   
       2 . A polymer blend comprising: 20 to 80 wt % of a mixture (A) of two or more polyalkylene phthalates; 
 2 to 60 wt % of a cross-linked acrylate rubber;    0 to 20 wt % of an ionomer; and    0 to 30 wt % of a terpolymer of ethylene, butylacrylate (BA) and glycidylmethacrylate (GMA);    wherein the weight percentages are based on the sum of the above ingredients.    
   
   
       3 . The polymer blend of  claim 1 , wherein the mixture (A) is a mixture of two components (A1) and (A2), wherein: 
 (A1) is a block copolyester elastomer; and    (A2) is a poly(butylene terephthalate) (PBT).    
   
   
       4 . The polymer blend of  claim 1 , wherein the block copolyester elastomer (A1) is preferably a copolyether-ester selected from block copolymers of poly(butylene terephthalate) and poly(tetramethylene glycol), block copolymers of polybutylene terephthalate and ethylene-oxide-capped poly(propylene glycol), and mixtures of such block copolymers.  
   
   
       5 . The polymer blend of any one of  claim 1 , wherein the block copolyester elastomer (A1) is present at or about 5 to at or about 60 wt % with respect to the overall polymer blend.  
   
   
       6 . The polymer blend of  claim 3 , wherein the block copolyester elastomer (A1) is present at or about 12 to at or about 55 wt % with respect to the overall polymer blend.  
   
   
       7 . The polymer blend of  claim 3 , wherein the poly(butylene terephthalate) (A2) has a number average molecular weight of between about 7500 and about 150,000.  
   
   
       8 . The polymer blend of  claim 3 , wherein the poly(butylene terephthalate) (A2) is present at or about 2 to at or about 60 wt % with respect to the overall polymer blend.  
   
   
       9 . The polymer blend of  claim 3 , wherein the poly(butylene terephthalate) (A2) is present at or about 2 to at or about 50 wt % with respect to the overall polymer blend.  
   
   
       10 . The polymer blend of  claim 1 , wherein the rubber is selected from poly(meth)acrylate and a mixed polymer of ethylene and methyl acrylate.  
   
   
       11 . The polymer blend of  claim 10 , wherein the rubber is dynamically cross-linked with a free radical initiator and an organic diene co-agent.  
   
   
       12 . The polymer blend of  claim 11 , wherein the free radical initiator is selected from 2,5 dimethyl-2,5-di-(t-butylperoxy)hexyne-3; 2,5-dimethyl-2,5-di-(t-butylperoxy)hexane; and t-butyl peroxybenzoate.  
   
   
       13 . The polymer blend of  claim 11 , wherein the free radical initiator is present at or about 0.5-5 wt %, based on the rubber.  
   
   
       14 . The polymer blend of  claim 11 , wherein the free radical initiator is present at or about 0.75-2.5 wt %, based on the rubber.  
   
   
       15 . The polymer blend of any one of  claim 11 , wherein the organic diene co-agent is selected from diethylene glycol diacrylate, diethylene glycol dimethacrylate, N,N′-m-phenylene dimaleimide, and triallylisocyanurate.  
   
   
       16 . The polymer blend of any one of  claim 11 , wherein the organic diene co-agent is present at or about 0.5-6 wt %, based on the rubber.  
   
   
       17 . The polymer blend of any one of  claim 11 , wherein the organic diene co-agent is present at or about 1.5-4 wt %, based on the rubber.  
   
   
       18 . The polymer blend of any one of  claim 1 , wherein the rubber comprises copolymers of ethylene and methyl acrylate together with at least one other monomer with a reactive chemical group which can be cross-linked.  
   
   
       19 . The polymer blend of  claim 18 , wherein the reactive chemical group which can be cross-linked is a carboxylate group, and wherein cross-linking is carried out with a diamine cross-linking agent.  
   
   
       20 . The polymer blend of  claim 1 , wherein the ionomer is a random copolymer poly(ethylene-co-methacrylic acid), neutralised with 10-100% metal ion selected from Na +  and Zn ++ .  
   
   
       21 . The polymer blend of  claim 1 , wherein the ionomer comprises at least 60% by weight of ethylene, 5-15% by weight of acrylic acid or methacrylic acid, and 0-35% by weight of a moiety selected from at least one of methyl acrylate, iso-butyl acrylate and n-butyl acrylate, and the acid groups are neutralized from 30-70% with sodium as counterion.  
   
   
       22 . The polymer blend of  claim 1 , wherein the ionomer is present at or about 0.5 to at or about 12 wt % with respect to the overall polymer blend.  
   
   
       23 . The polymer blend of  claim 1 , wherein the terpolymer is selected from terpolymers of ethylene, butylacrylate (BA) and glycidylmethacrylate (GMA), wherein the three components are present in at or about the following weight percentages: ethylene 50-98 wt %, BA 1-40 wt %, and GMA 1-15 wt %.  
   
   
       24 . The polymer blend of  claim 1 , wherein the terpolymer is present at or about 1 to at or about 25 wt % with respect to the overall polymer blend.  
   
   
       25 . An extruded, moulded or shaped article comprising the polymer blend of  claim 1 .  
   
   
       26 . The article of  claim 25 , which is blow moulded.  
   
   
       27 . The article of  claim 25 , which is an automotive duct, an automotive hose, an automotive seal, or an automotive body plug.  
   
   
       28 . A process for making a polymer blend comprising compounding in a melt extruder at a temperature sufficient to melt and mix all components: 
 a TPV component (X) comprising (X1) from 15 to 60 weight percent of a polyalkylene terephthalate polyester polymer or copolymer continuous phase and (X2) from 40 to 85 weight percent of a rubber disperse phase wherein said rubber is poly(meth)acrylate or a mixed polymer of ethylene and methyl acrylate dynamically cross-linked with an organic peroxide free radical initiator and an organic diene co-agent; and    a thermoplastic polyester component (Y) comprising (Y1) at or about 5-25% by weight of a copolyether-ester block copolymer elastomer, (Y2) at or about 40-65% by weight of poly(butylene terephthalate), (Y3) at or about 5-20% by weight of an ionomer, and (Y4) at or about 5-30% by weight of a terpolymer of ethylene, butylacrylate and glycidylmethacrylate; provided that: the total of (Y1)-(Y4) is 100%; and the total content of (Y1) and (Y2) does not exceed 70%.    
   
   
       29 . A batch process for making a polymer blend comprising the following steps: 
 (1) mixing the following ingredients in a batch melt blender:    20 to 70 wt % of a mixture (A) of two or more polyalkylene phthalates;    2 to 60 wt % of a rubber comprising poly(meth)acrylate or a mixed polymer of ethylene and methyl acrylate that is capable of being dynamically cross-linked;    0.5 to 20 wt % of an ionomer;    1 to 30 wt % of a terpolymer of ethylene, butylacrylate and glycidylmethacrylate;    at a temperature sufficient to melt all the components, to make a homogeneous melt; and    (2) adding an organic diene co-agent and a free-radical initiator and continuing the mixing until the cross-linking of the rubber is essentially completed.    
   
   
       30 . A continuous process for making a polymer blend comprising the following steps: 
 (1) mixing the following ingredients in a continuous melt blender:    20 to 70 wt % of a mixture (A) of two or more polyalkylene phthalates;    2 to 60 wt % of a rubber comprising poly(meth)acrylate or a mixed polymer of ethylene and methyl acrylate that is capable of being dynamically cross-linked;    0.5 to 20 wt % of an Ionomer;    1 to 30 wt % of a terpolymer of ethylene, butylacrylate and glycidylmethacrylate;    an organic diene co-agent and a free-radical initiator; and    (2) heating at a temperature sufficient to melt all the components, to make a homogeneous melt and continuing the mixing until the cross-linking of the rubber is essentially completed.    
   
   
       31 . A process for making a shaped article comprising extruding, blow-moulding or injection-moulding a polymer blend according to any one of  claims 1  to  24 .  
   
   
       32 . The process of  claim 31 , comprising the step of blow-moulding a polymer blend according to any one of  claims 1  to  24 .  
   
   
       33 . A process for making a polymer blend comprising compounding in a melt extruder at a temperature sufficient to melt and mix all components: 
 25-95% of a TPV component (X) comprising (X1) from 15 to 60 weight percent of a polyalkylene terephthalate polyester polymer or copolymer continuous phase and (X2) from 40 to 85 weight percent of a rubber disperse phase wherein said rubber is poly(meth)acrylate or a mixed polymer of ethylene and methyl acrylate dynamically cross-linked with an organic peroxide free radical initiator and an organic diene co-agent; and    75 to 5% of a polyakylene phthalate polyester different from (X1).