Halogen-free plastic floor tile and modified polyester composition for use in producing the same

Abstract

A modified polyester resin composition comprises a combination of a PET polyester, a PCT polyester, a CHDM modified copolyester comprising PCTA, PCTG or PETG, and a modified polymer at least comprising TPU or EPDM, wherein the modified polymer accounts for 3-25 wt % and the rest accounts for 97-75 wt %, based on the total weight of the resin; and the modified polyester resin composition is suited for use in a halogen-free, heavy metal-free, and volatile organic compound-free polyester-based plastic floor tile excellent in higher resistance to wear and tear, better tensile strength, more preferable resistance to both lit cigarette e and solvents, and particularly being friendliness to environment and not hazardous to health.

1 - 16 . (canceled) 
     
     
         17 . A process for producing a halogen-free and heavy metal-free polyester-based plastic floor tile having a total thickness of 0.6-5.0 mm, comprising the steps of:
 (1) uniformly mixing a modified polyester resin composition of claim  1  as a mixture through a mixer device and then introducing the mixture into a Banbury mixer, a kneader, a single-screw extruder or a twin-screw extruder for refinement, and subsequently into a roller machine for well-gelatinization;   (2) processing fully well-gelatinized mixture of step (1) with an extruder or a calendaring machine to produce either a molten surface-layer plastic sheet or a molten middle-layer plastic sheet of 0.08-0.7 mm in thickness, or, alternatively, a molten bottom-layer plastic sheet of 0.3-3.0 mm in thickness, or a molten monolayer floor tile having a total thickness of 0.3-3.0 mm;   (3) after cooling and shaping those molten surface-layer plastic sheet, molten middle-layer plastic sheet, molten bottom-layer plastic sheet or molten monolayer floor tiles, a predetermined size in thickness of a surface-layer plastic sheet, a middle-layer plastic sheet, a bottom-layer plastic sheet or a preform of monolayer floor tiles is produced, respectively; and   (4) stacking one or more layers of the surface-layer plastic sheet and/or the middle-layer plastic sheet of step (3) together with one or more layer of the bottom-layer plastic sheet of step (3) to form a bilayer, trilayer or multilayer laminated preform structure; and   (5) processing the bilayer, trilayer or multilayer laminated preform structure of step (4) or processing the preform of monolayer floor tile of step (3) with a hot press molding machine or a lamination apparatus respectively to form a laminated polyester-based plastic floor tile having a total thickness of 0.6-5.0 mm.