Toughened polyester compositions

Abstract

Toughened polyester compositions containing specified amounts of certain reinforcing fillers, a polymeric toughening agent, and sepiolite-type clay, in which the sepiolite is added before or during polymerization to form the polyester, are especially useful for parts which have appearance surfaces and/or are painted. Such compositions are useful for items such as appliance parts, automotive body panels, power tool housing, and electronics housings. Processes for coating such compositions are also described.

1 . A composition, comprising: 
 (a) at least about 40 weight percent, based on the total of all ingredients in the composition, of at least one polyester with a melting point of about 100° C. or higher;    (b) about 0.1 to about 20 weight percent of sepiolite-type clay, based on the weight of polyester plus sepiolite-type clay.    (c) about 0 to about 35 weight percent, based on the total of all ingredients in the composition, of a reinforcing agent, exclusive of the sepiolite-type clay, with an average aspect ratio of about 2.0 or more, and whose average longest dimension is 20 μm or less; and    (d) about 1 to about 30 weight percent, based on the total of all ingredients in the composition, of a polymeric toughening agent which contains functional groups reactive with said polyester; and    provided that a mixture of said polyester and said sepiolite-type clay is prepared by a process comprising mixing a sepiolite-type clay with at least one polyester precursor selected from the group consisting of 
 (i) at least one diacid or diester and at least one diol;  
 (ii) at least one polymerizable polyester monomer;  
 (iii) at least one linear polyester oligomer, and  
 (iv) at least one macrocyclic polyester oligomer,  
   and subsequently polymerizing said at least one polyester precursor in the presence or absence of solvent;    
   
   
       2 . The composition as recited in  claim 1  wherein said polyester has a melting point of about 200° C. or more.  
   
   
       3 . The composition as recited in  claim 1  wherein said polyester consists essentially of repeat units derived from one or more of terephthalic acid, isophthalic acid and 2,6-naphthalene dicarboxylic acid, and one or more of HO(CH 2 ) n OH, 1,4-cyclohexanedimethanol, HO(CH 2 CH 2 O) m CH 2 CH 2 OH, and HO(CH 2 CH 2 CH 2 CH 2 O) n CH 2 CH 2 CH 2 CH 2 OH (III), wherein n is an integer of 2 to 10, m on average is 1 to 4, and z is an average of about 7 to about 40.  
   
   
       4 . The composition as recited in  claim 1  wherein said polyester is poly(ethylene terephthalate), poly(1,3-propylene terephthalate), poly(1,4-butylene terephthalate), poly(ethylene 2,6-naphthoate), or poly(1,4-cylohexyldimethylene terephthalate).  
   
   
       5 . The composition as recited in  claim 1  wherein said reinforcing agent has an average aspect ratio of about 3.0 or more, and an average maximum dimension of about 10 μm or less.  
   
   
       6 . The composition as recited in  claim 1  wherein said reinforcing agent is wollastonite, mica, talc, potassium titanate whiskers, boron nitride whiskers or aluminum borate whiskers.  
   
   
       7 . The composition as recited in  claim 1  wherein said reinforcing agent is about 5 to about 20 weight percent of said composition.  
   
   
       8 . The composition as recited in  claim 1  wherein said polymeric toughening agent contains epoxy or carboxylic anhydride functional groups.  
   
   
       9 . The composition as recited in  claim 1  wherein said polymeric toughening agent comprises repeat units derived from an epoxy containing (meth)acrylate and ethylene.  
   
   
       10 . The composition as recited in  claim 1  wherein said polymeric toughener contains about 1.0 to about 15 weight percent of one or more monomers containing functional groups.  
   
   
       11 . The composition as recited in  claim 1  wherein said composition contains about 5 to about 25 weight percent of said polymeric toughener.  
   
   
       12 . The composition as recited in  claim 1  wherein said polyester is poly(ethylene terephthalate); said reinforcing agent has an aspect ratio of about 3.0 or more, an average maximum dimension of 10 μm or less, and is about 5 to about 20 weight percent of said composition; said polymeric toughening agent contains epoxy functional groups, contains about 7 to about 13 weight percent of one or more epoxy group containing monomers, and is about 10 to about 20 weight percent of said composition.  
   
   
       13 . The composition as recited in  claim 12  wherein said reinforcing agent is wollastonite, talc or potassium titanate whiskers.  
   
   
       14 . An article of manufacture comprising the composition of  claim 1 .  
   
   
       15 . The article of  claim 14  wherein said article is an appearance part.  
   
   
       16 . The appearance part as recited in  claim 15  which is an automotive body panel, an interior automotive panel, an appliance part, a power tool housing, electronic cabinet or housing, an exterior or interior panel for a vehicle, a decorative interior panel for a building, a piece of furniture, or a telephone or other telephone equipment.  
   
   
       17 . The appearance part as recited in  claim 16  which is pigmented.  
   
   
       18 . An automobile, truck, snowmobile, construction vehicle, or farm equipment vehicle, comprising the composition of  claim 1 .  
   
   
       19 . The automobile, truck, snowmobile, construction vehicle, or farm equipment vehicle as recited in  claim 18 , wherein said composition is coated.  
   
   
       20 . A process for making a composition, said composition comprising: 
 (a) at least about 40 weight percent, based on the total of all ingredients in the composition, of at least one polyester with a melting point of about 100° C. or higher;    (b) about 0.1 to about 20 weight percent of sepiolite-type clay, based on the weight of polyester plus sepiolite-type clay.    (c) about 0 to about 35 weight percent, based on the total of all ingredients in the composition, of a reinforcing agent, exclusive of the sepiolite-type clay, with an average aspect ratio of about 2.0 or more, and whose average longest dimension is 20 μm or less; and    (d) about 1 to about 30 weight percent, based on the total of all ingredients in the composition, of a polymeric toughening agent which contains functional groups reactive with said polyester.    wherein said composition additionally comprises at least one or more active ingredients and optionally one or more inactive ingredients, said process comprising the steps: 
 A). in a first mixing step, mixing materials comprising said polyester containing said exfoliated sepiolite-type clay, said polymeric toughening agent, and optionally said polyester, to form an intermediate composition; and then  
 B). in one or more subsequent mixing steps, mixing materials comprising said intermediate composition, and said one or more active ingredients;  
   and provided that each of said one or more inactive ingredients is initially mixed in said first mixing step, or one or more of said subsequent mixing steps.    and further provided hat a mixture of said polyester and said sepiolite-type clay is prepared by a process comprising mixing a sepiolite-type clay with at least one polyester precursor selected from the group consisting of 
 (i) at least one diacid or diester and at least one diol;  
 (ii) at least one polymerizable polyester monomer;  
 (iii) at least one linear polyester oligomer, and  
 (iv) at least one macrocyclic polyester oligomer,  
   and subsequently polymerizing said at least one polyester precursor in the presence or absence of solvent.    
   
   
       21 . The process as recited in  claim 20  wherein said polyester consists essentially of repeat units derived from one or more of terephthalic acid, isophthalic acid and 2,6-naphthalene dicarboxylic acid, and one or more of HO(CH 2 ) n OH (I), 1,4-cyclohexanedimethanol, HO(CH 2 CH 2 O) m CH 2 CH 2 OH, and HO(CH 2 CH 2 CH 2 CH 2 O) n CH 2 CH 2 CH 2 CH 2 OH, wherein n is an integer of 2 to 10, m on average is 1 to 4, and z is an average of about 7 to about 40.  
   
   
       22 . The process as recited in  claim 20  wherein said polyester is poly(ethylene terephthalate), poly(1,3-propylene terephthalate), poly(1,4-butylene terephthalate), poly(ethylene 2,6-naphthoate), or poly(1,4-cylohexyldimethylene terephthalate).  
   
   
       23 . The process as recited in  claim 20  wherein said reinforcing agent is wollastonite, talc or potassium titanate whiskers, and is about 5 to about 20 weight percent of said composition.  
   
   
       24 . The process as recited in  claim 20  wherein said polymeric toughening agent contains epoxy functional groups.  
   
   
       25 . The process as recited in  claim 20  wherein said polyester is poly(ethylene terephthalate); said reinforcing agent has an aspect ratio of about 3.0 or more, an average maximum dimension of 10 μm or less, and is about 5 to about 20 weight percent of said composition; said polymeric toughening agent contains epoxy functional groups, contains about 7 to about 13 weight percent of one or more epoxy group containing monomers, and is about 10 to about 20 weight percent of said composition.  
   
   
       26 . A process for coating substrates assembled from metal parts and at least one plastic part, with visible plastic surfaces, comprising the successive steps of: 
 (1) electrodeposition coating the substrates, removing non-deposited electrodeposition coating agent from the substrate and thermally cross-linking the deposited electrodeposition coating and thereby forming an electrodeposition coating primer on the metal surfaces; and    (2) application and curing of at least one additional coating at least on all the visible metal and plastic surfaces;    provided that at least some of the plastic parts make up the visible plastic surfaces of the substrate, and at least some of the plastic parts have a composition which comprises:    (a) at least about 40 weight percent, based on the total of all ingredients in the composition, of at least one polyester with a melting point of about 100° C. or higher;    (b) about 0.1 to about 20 weight percent of sepiolite-type clay, based on the weight of polyester plus sepiolite-type clay.    (c) about 0 to about 35 weight percent, based on the total of all ingredients in the composition, of a reinforcing agent, exclusive of the sepiolite-type clay, with an average aspect ratio of about 2.0 or more, and whose average longest dimension is 20 μm or less; and    (d) about 1 to about 30 weight percent, based on the total of all ingredients in the composition, of a polymeric toughening agent which contains functional groups reactive with said polyester.    wherein said composition additionally comprises at least one or more active ingredients and optionally one or more inactive ingredients.    and provided that a mixture of said polyester and said sepiolite-type clay is prepared by a process comprising mixing a sepiolite-type clay with at least one polyester precursor selected from the group consisting of 
 (i) at least one diacid or diester and at least one diol;  
 (ii) at least one polymerizable polyester monomer;  
 (iii) at least one linear polyester oligomer, and  
 (iv) at least one macrocyclic polyester oligomer,  
   and subsequently polymerizing said at least one polyester precursor in the presence or absence of solvent.    
   
   
       27 . The process as recited in  claim 26  wherein said polyester consists essentially of repeat units derived from one or more of terephthalic acid, isophthalic acid and 2,6-naphthalene dicarboxylic acid, and one or more of HO(CH 2 ) n OH (I), 1,4-cyclohexanedimethanol, HO(CH 2 CH 2 O) m CH 2 CH 2 OH, and HO(CH 2 CH 2 CH 2 CH 2 O) n CH 2 CH 2 CH 2 CH 2 OH, wherein n is an integer of 2 to 10, m on average is 1 to 4, and z is an average of about 7 to about 40.  
   
   
       28 . The process as recited in  claim 26  wherein said polyester is poly(ethylene terephthalate), poly(1,3-propylene terephthalate), poly(1,4-butylene terephthalate), poly(ethylene 2,6-naphthoate), or poly(1,4-cylohexyldimethylene terephthalate).  
   
   
       29 . The process as recited in  claim 26  wherein said polyester is poly(ethylene terephthalate); said reinforcing agent has an aspect ratio of about 3.0 or more, an average maximum dimension of 10 μm or less, and is about 5 to about 20 weight percent of said composition; said polymeric toughening agent contains epoxy functional groups, contains about 7 to about 13 weight percent of one or more epoxy group containing monomers, and is about 10 to about 20 weight percent of said composition.  
   
   
       30 . The process of  claim 26 , wherein the substrates are car bodies.  
   
   
       31 . The process of  claim 30 , wherein the plastic parts are selected from the group consisting of fenders, hoods, doors, lift-up tailgates, trunk lids, tank caps, bumpers, protective moldings, side panels, body sills, mirror housings, handles, spoilers and hub caps.  
   
   
       32 . Coated substrates which are coated according to the process of  claim 26 .  
   
   
       33 . A vehicle manufactured according to a method which comprises the process of  claim 26 .  
   
   
       34 . The vehicle of  claim 33  wherein said vehicle is an automobile, truck, snowmobile, construction vehicle, or farm equipment vehicle.