Composition for Production of Polyvinylidene Chloride Monolayer Film with Improved Shrinkage and Food Wrapping Package Including Same
Provided is a monolayer film containing a vinylidene chloride-based copolymer composition containing a vinyl chloride comonomer-containing first polyvinylidene chloride copolymer (PVDC-VC); and a methyl acrylate comonomer-containing second polyvinylidene chloride copolymer (PVDC-MA), A crystallinity of the vinylidene chloride-based copolymer composition is 25 to 45%, Also provided is a container including the same, and a method for producing a monolayer film
1 . A monolayer film comprising a vinylidene chloride-based copolymer composition containing:
a vinyl chloride comonomer-containing first polyvinylidene chloride copolymer (PVDC-VC); and
a methyl acrylate comonomer-containing second polyvinylidene chloride copolymer (PVDC-MA),
wherein a crystallinity of the vinylidene chloride-based copolymer composition is to 45%.
2 . The monolayer film of claim 1 , wherein the first polyvinylidene chloride copolymer is contained in an amount of more than 50 wt % and less than 90 wt % with respect to the total weight of the monolayer film, and
the second polyvinylidene chloride copolymer is contained in an amount of more than 10 wt % and less than 50 wt % with respect to the total weight of the monolayer film.
3 . The monolayer film of claim 1 , wherein the first polyvinylidene chloride copolymer contains 10 to 25 wt % of the vinyl chloride comonomer, and
the second polyvinylidene chloride copolymer contains 2 to 8 wt % of the methyl acrylate comonomer.
4 . The monolayer film of claim 1 , wherein a crystallization rate of the vinylidene chloride-based copolymer composition is 7 to 25 minutes.
5 . The monolayer film of claim 1 , wherein a content of crystals melted at 170° C. of the vinylidene chloride-based copolymer composition is 5 to 45% of the total content of crystals.
6 . The monolayer film of claim 1 , further comprising a plasticizer, an additive, or a combination thereof.
7 . The monolayer film of claim 6 , wherein the plasticizer includes epoxidized soybean oil (ESO), dibutyl sebacate (DBS), acetyl tri-n-butyl citrate (ATBC), or a combination thereof.
8 . The monolayer film of claim 6 , wherein the additive includes a polyolefin-based wax, an oxidized polyolefin-based wax, an acrylic wax, an ester-based wax, an amide-based wax, a stearic acid salt, derivatives of the additives, or a combination thereof.
9 . A method for producing a monolayer film, comprising the steps of:
a) melting and extruding a vinylidene chloride-based polymer mixture;
b) heat-stretching the extrudate in at least a biaxial orientation; and
c) heat setting the stretched product.
10 . The method of claim 9 , wherein step b) is performed by simultaneous biaxial stretching in which the extrudate is simultaneously stretched in a longitudinal orientation and a transverse orientation.
11 . The method of claim 9 , wherein step b) is performed at a temperature higher than a glass transition temperature (Tg) of the extrudate and lower than a melting temperature (Tm) of the extrudate.
12 . A container comprising the monolayer film of claim 1 .