Resin composition
Provided is a resin composition capable of forming a coated product that exhibits low adhesion to a metal roll during production and is superior in oxygen barrier property and capable of forming a film or sheet superior in oxygen barrier property, impact strength under low humidity and color tone. The resin composition of the present invention contains 50 to 98 parts by mass of a modified starch (A), 2 to 50 parts by mass of a polyvinyl alcohol (B), 0.1 to 10 parts by mass of a polyoxyalkylene (C), and optionally 0 to 5 parts of a polyol plasticizer (D), wherein the total content of the (A), (B), (C) and (D) is 100 parts by mass.
1 . A resin composition comprising:
50 to 98 parts by mass of a modified starch (A);
2 to 50 parts by mass of a polyvinyl alcohol (B);
0.5 to 10 parts by mass of a polyoxyalkylene (C); and optionally
0 to 5 parts by mass of a polyol plasticizer (D),
wherein the total content of the (A), (B), (C) and (D) is 100 parts by mass, and
wherein the polyoxyalkylene has an average molecular weight of 50,000 or more and 3,000,000 or less.
2 . The resin composition according to claim 1 , wherein the total content of the modified starch (A), the polyvinyl alcohol (B), the polyoxyalkylene (C) and the polyol plasticizer (D) is 80% by mass or more with respect to the mass of the resin composition.
3 . The resin composition according to claim 1 , wherein the modified starch (A) has an average amylose content of 50% by mass or more.
4 . The resin composition according to claim 1 , wherein the modified starch (A) is at least one selected from the group consisting of an etherified starch, an esterified starch, a cationized starch, and a crosslinked starch.
5 . The resin composition according to claim 1 , wherein the modified starch (A) is at least one selected from the group consisting of an etherified starch having a hydroxyalkyl group having 2 to 6 carbon atoms and an esterified starch having a structural unit derived from a dicarboxylic anhydride.
6 . The resin composition according to a claim 1 , wherein a 4% aqueous solution of the polyvinyl alcohol (B) has a viscosity of 1 to 50 mPa·s at 20° C. measured in accordance with JIS Z 8803.
7 . A hydrous composition comprising the resin composition according to claim 1 , wherein the hydrous composition has a water content of 1 to 50% by mass.
8 . A coated product in which a paper or a film is coated with the hydrous composition according to claim 7 .
9 . A multilayer structure comprising the coated product according to claim 8 and one or more layers (X).
10 . A packaging material comprising the coated product according to claim 8 .
11 . A method for producing the coated product according to claim 8 , comprising a step of coating a paper or a film conveyed by a winding device with the hydrous composition by using an extruder, wherein during the step, a draw ratio is 5 to 20 where the draw ratio is represented by Formula (1):
Draw Ratio=(Winding speed of the winding device (m/s))/(Flow rate at an die outlet of the extruder (m/s)) (1).
12 . A film or sheet comprising the resin composition according to claim 1 .
13 . A laminate comprising the film or sheet according to claim 12 and one or more layers (X).
14 . A packaging tray or cup comprising the film or sheet according to claim 12 .
15 . A method for producing the packaging tray or cup according to claim 14 , comprising a step of obtaining a film or sheet by shaping the resin composition by using an extruder, a step of obtaining a laminate by laminating the resulting film or sheet and one or more layers (X) together by lamination, and a step of thermoforming the resulting laminate into a packaging tray or cup.
16 . The resin composition according to claim 1 , wherein the resin composition comprises 4 parts by mass or less of the polyol plasticizer (D).
17 . The resin composition according to claim 1 , wherein the resin composition comprises 3 parts by mass or less of the polyol plasticizer (D).
18 . The resin composition according to claim 1 , wherein the modified starch (A) comprises two or more modified starches and has an average amylose content of 50% by mass or more.
19 . The resin composition according to claim 1 , wherein the modified starch (A) comprises two or more modified starches, and wherein at least one of the modified starches comprises an etherified starch having a hydroxyalkyl group having 2 to 6 carbon atoms.
20 . The resin composition according to claim 1 , wherein the resin composition excludes a fatty acid having 12 to 22 carbon atoms or salt thereof.