Scratch-resistant coating agent based on arcylates

Abstract

The invention relates to a coating composition, a method of coating molded articles with the coating composition, and the molded articles so coated, particularly molded articles comprised of thermoplastic or thermoelastic plastics. The coating, in the form of a cured thin layer, is particularly optically clear, scratch-resistant, and weather-resistant. It is produced on the plastic substrate material by polymerization of a layer of flowable coating comprised of the coating material, which layer contains polyfunctional (meth)acrylic monomers, and said layer further contains, as a "leveling" agent, fluoroalkyl (meth)acrylates of formula I ##STR1## where R 1 represents H or CH 3 , and R 2 represents a fluorine-containing alkyl group with 2-20 C atoms.

What is claimed as new and is desired to be secured by Letters Patent of the United States is: 
     
       1. A scratch-resistant, weather-resistant, polymerized coating having desirable optical properties, prepared by the process comprising: (a) applying to a substrate a polymerizable flowable coating composition, said composition comprising as components (i) one or more multi-functional (meth)acrylate monomers, said multi-functional monomers containing two or more polymerizable carbon-carbon double bonds;   (ii) one or more singly unsaturated comonomers;   (iii) from 5-40 wt. percent, based on the total weight of all polymerizable monomers in said composition, of a fluorinated-alkyl-group-containing leveling agent having the formula ##STR4## wherein R 1  represents H or CH 3  ; and R 2  represents C a  H b  F c , wherein     a is an integer of from 2-20,   b is an integer of from 0-4,   and c=2a+1-b; and (iv) optionally, customary additives; and     (b) curing said coating composition by polymerization.   
     
     
       2. The coating of claim 1, wherein said component (i) comprises a multifunctional (meth)acrylate monomer or oligomer having three or more polymerizable double bonds in an amount such that the weight percent of said (meth) acrylate monomer or oligomer having three or more double bonds comprises 30 wt. % or more of all polymerizable monomers; and from 5-20 wt. % of said fluorinated-alkyl-group-containing (meth)acrylate monomer I based on the total of all polymerizable monomers. 
     
     
       3. The coating of claim 1, wherein component (i) contains a difunctional monomer, and wherein at least 70 wt % of said component (i) comprises acrylates. 
     
     
       4. The coating of claim 2, wherein component (i) contains a difunctional monomer, and wherein at least 70 wt % of said component (i) comprises acrylates. 
     
     
       5. The coating of claim 1, wherein said component (iv) comprises a UV-protective agent. 
     
     
       6. The coating of claim 2, wherein said component (iv) comprises a UV-protective agent. 
     
     
       7. The coating of claim 3, wherein said component (iv) comprises a UV-protective agent. 
     
     
       8. The coating of claim 4, wherein said component (iv) comprises a UV-protective agent. 
     
     
       9. The coating of claim 5, wherein said UV protective agent contains a polymerizable double bond. 
     
     
       10. The coating of claim 6, wherein said UV protective agent contains a polymerizable double bond. 
     
     
       11. The coating of claim 7, wherein said UV protective agent contains a polymerizable double bond. 
     
     
       12. The coating of claim 8, wherein said UV protective agent contains a polymerizable double bond. 
     
     
       13. A non-aqueous, solvent free, polymerizable coating composition suitable for the preparation of scratch-resistant, weather-resistant coatings having desirable optical properties, comprising: (i) one or more multi-functional (meth)acrylate monomers, said multi-functional monomers containing two or more polymerizable carbon-carbon double bonds;   (ii) one or more singly unsaturated comonomers;   (iii) from 5-40 wt. percent, based on the total weight of all polymerizable monomers in said composition, of a fluorinated-alkyl-group-containing leveling agent having the formula ##STR5## wherein R 1  represents H or CH 3  ;and R 2  represents C a  H b  F c , wherein   a is an integer of from 2-20,   b is an integer of from 0-4,   and c=2a+1-b; and   (iv) optionally, customary additives.   
     
     
       14. The polymerizable coating composition of claim 13, wherein said component (i) comprises a multifunctional (meth)acrylate monomer or oligomer having three or more polymerizable double bonds in an amount such that the weight percent of said (meth)acrylate monomer or oligomer having three or more double bonds comprises 30 wt. % or more of all polymerizable monomers; and from 5-20 wt. % of said fluorinated-alkyl-group-containing (meth)acrylate monomer I based on the total of all polymerizable monomers. 
     
     
       15. The polymerizable coating composition of claim 13, wherein component (i) contains a difunctional monomer, and wherein at least 70 wt % of said component (i) comprises acrylates. 
     
     
       16. The polymerizble coating composition of claim 1, wherein said component (iv) comprises a UV-protective agent. 
     
     
       17. The polymerizable coating composition of claim 1, wherein said component (iv) comprises a UV-protective agent. 
     
     
       18. The coating of claim 1, wherein said composition comprises less than 30 wt. % of said singly unsaturated comonomers. 
     
     
       19. The coating of claim 1, wherein methacrylic monomers are ≧30 wt. % of (meth)acrylic monomers in said composition. 
     
     
       20. The polymerizable coating composition of claim 13, wherein said composition comprises less than 30 wt. % of said singly unsaturated comonomers. 
     
     
       21. The polymerizable coating composition of claim 13, wherein methacrylic monomers are ≧30 wt. % of (meth)acrylic monomers in said composition.