Two Component Polyoxymethylene Based Systems

Abstract

A two component polyoxymethylene based system is disclosed. The two component system is comprised of a first polymer layer and a second polymer layer. The first polymer layer is comprised of a polyoxymethylene polymer composition comprising a polyoxymethylene polymer and optionally a tribological modifier. The second polymer layer is comprised of a second polymer composition comprising a liquid crystalline polymer, a polyarylene sulfide polymer, or a combination thereof and at least one tribological modifier. The compositions provide polymer articles, such as conveyor components, with improved tribological properties.

1 . A polymer article comprising:
 a first polymer layer comprising a polyoxymethylene polymer composition comprising
 a polyoxymethylene polymer, and 
 optionally, at least one tribological modifier; 
   a second polymer layer connected to the first polymer layer, the second polymer layer comprising a second polymer composition, the second polymer composition comprising
 a liquid crystalline polymer, a polyarylene sulfide polymer, or a combination thereof, and 
 at least one tribological modifier. 
   
     
     
         2 . The polymer article of  claim 1 , wherein the tribological modifier in the second polymer composition comprises a polytetrafluoroethylene. 
     
     
         3 . The polymer article of  claim 2 , wherein the polytetrafluoroethylene is present in an amount of from about 1 wt. % to about 40 wt. %. 
     
     
         4 . The polymer article of  claim 1 , wherein the second polymer composition further comprises glass fibers. 
     
     
         5 . The polymer article of  claim 1 , wherein the polyoxymethylene polymer composition comprises a tribological modifier selected from the group consisting of boron nitride, ultra-high molecular weight silicone, or a combination thereof 
     
     
         6 . The polymer article of  claim 1 , wherein the polyoxymethylene polymer composition comprises a tribological modifier selected from the group consisting of calcium carbonate, ultrahigh-molecular weight polyethylene, stearyl stearate, silicone oil, polyethylene wax, amide wax, or a combination thereof. 
     
     
         7 . The polymer article of  claim 1 , wherein the liquid crystalline polymer contains aromatic ester repeating units. 
     
     
         8 . The polymer article of  claim 7 , wherein the aromatic ester repeating units comprise aromatic dicarboxylic acid repeating units, aromatic hydroxycarboxylic acid repeating units, or a combination thereof. 
     
     
         9 . The polymer article of  claim 1 , wherein the liquid crystalline polymer repeating units comprise units formed from a hydroxycarboxylic acid, a dicarboxylic acid, and an aromatic diol. 
     
     
         10 . The polymer article of  claim 1 , wherein the polyarylene sulfide polymer is a polyphenylene sulfide polymer. 
     
     
         11 . The polymer article of  claim 1 , wherein the first polymer layer and the second polymer layer are connected by an interlocking mechanism. 
     
     
         12 . The polymer article of  claim 1 , wherein the first polymer layer and the second polymer layer are connected by overmolding. 
     
     
         13 . The polymer article of  claim 1 , wherein the first polymer layer and the second polymer layer are connected by a fastener. 
     
     
         14 . The polymer article of  claim 1 , wherein the first polymer layer is in contact with the second polymer layer. 
     
     
         15 . The polymer article of  claim 1 , wherein the second polymer layer covers at least 85% of the surface area of one surface of the first polymer layer. 
     
     
         16 . The polymer article of  claim 1 , wherein the second polymer layer has a thickness of from about 0.01 mm to about 5 mm. 
     
     
         17 . The polymer article of  claim 1 , wherein the polymer article exhibits a dynamic coefficient of friction against a polyethylene terephthalate surface of from about 0.01 to about 0.18 as determined in accordance with VDA 230-206. 
     
     
         18 . The polymer article of  claim 1 , wherein the polymer article exhibits a dynamic coefficient of friction against a polyacetal surface, a steel surface, a polyethylene surface, or a polypropylene surface of from about 0.01 to about 0.18 as determined in accordance with VDA 230-206. 
     
     
         19 . The polymer article of  claim 1 , wherein the polymer article is a conveyor component. 
     
     
         20 . The polymer article of  claim 1 , wherein an external lubricant is not present on a surface of the polymer article.