Heat-sealable resin composition, heat-seal material, packaging material, lid material, and packaging container

Abstract

A heat-sealable resin composition comprising an ethylene-vinyl ester copolymer (A), an ethylene-unsaturated carboxylic acid ester copolymer (B), and a tackifying resin (C), the content of structural units derived from a vinyl ester in the ethylene-vinyl ester copolymer (A) being 8% by mass or more relative to the total structural units of the copolymer constituting the ethylene-vinyl ester copolymer (A), the tackifying resin (C) comprising an alicyclic hydrocarbon resin (C1) and an aromatic hydrocarbon resin (C2).

Claims

1. A heat-sealing resin composition comprising: Ethylene-vinyl ester copolymer (A) Ethylene-unsaturated carboxylic acid copolymer (B), and Adhesive resin (C) The content of structural units derived from vinyl esters in the ethylene-vinyl ester copolymer (A) is 8% by mass or more, relative to all structural units constituting the copolymer. When the total mass of the resin components contained in the heat-sealing resin composition is set as 100% by mass, the content of the ethylene-vinyl ester copolymer (A) is 25% by mass or more and 70% by mass or less. The unsaturated carboxylic acid in the ethylene-unsaturated carboxylic acid copolymer (B) includes at least one selected from acrylic acid and methacrylic acid. The mass ratio (B / A) of the content of the ethylene-unsaturated carboxylic acid copolymer (B) to the content of the ethylene-vinyl ester copolymer (A) is 0.20 to 1.

0. The adhesive resin (C) comprises an alicyclic hydrocarbon resin (C1) and an aromatic hydrocarbon resin (C2). The mass ratio (C2 / (C1+C2)) of the aromatic hydrocarbon resin (C2) relative to the total content of the alicyclic hydrocarbon resin (C1) and the aromatic hydrocarbon resin (C2) is 0.05 to 0.

4. When the total mass of the resin components contained in the heat-sealing resin composition is set as 100% by mass, the content of the tackifying resin (C) is 15% by mass or more and 30% by mass or less. The total content of the ethylene-vinyl ester copolymer (A), the ethylene-unsaturated carboxylic acid ester copolymer (B), and the tackifying resin (C) is 90% to 100% by mass relative to the total mass of the resin components contained in the heat-sealing resin composition.

2. The heat-sealing resin composition of claim 1, wherein, The softening point of the aromatic hydrocarbon resin (C2) is above 70°C and below 140°C.

3. The heat-sealing resin composition of claim 1, wherein, The mass ratio (B / A) of the content of the ethylene-unsaturated carboxylic acid copolymer (B) to the content of the ethylene-vinyl ester copolymer (A) is more than 0.40 and less than 1.

0.

4. The heat-sealing resin composition of claim 1, wherein, The mass ratio (B / A) of the content of the ethylene-unsaturated carboxylic acid copolymer (B) to the content of the ethylene-vinyl ester copolymer (A) is more than 0.40 and less than 0.

90.

5. The heat-sealing resin composition of claim 1, wherein, When the total mass of the resin components contained in the heat-sealing resin composition is set to 100% by mass, the content of the ethylene-vinyl ester copolymer (A) is 30% by mass or more and 60% by mass or less.

6. The heat-sealing resin composition of claim 1, wherein, When the total mass of the resin components in the heat-sealing resin composition is set as 100% by mass, the content of the ethylene-vinyl ester copolymer (A) is 30% by mass or more and 60% by mass or less. The mass ratio (B / A) of the content of the ethylene-unsaturated carboxylic acid copolymer (B) to the content of the ethylene-vinyl ester copolymer (A) is more than 0.40 and less than 0.

90.

7. The heat-sealing resin composition of claim 1, wherein, When the total mass of the resin components in the heat-sealing resin composition is set as 100% by mass, the content of the ethylene-vinyl ester copolymer (A) is 30% by mass or more and 60% by mass or less. The mass ratio (B / A) of the content of the ethylene-unsaturated carboxylic acid ester copolymer (B) to the content of the ethylene-vinyl ester copolymer (A) is 0.40 to 0.

90. When the total mass of the resin components contained in the heat-sealing resin composition is set to 100% by mass, the content of the tackifying resin (C) is 15% by mass or more and 30% by mass or less.

8. The heat-sealing resin composition of claim 1, wherein, The haze level measured using the following method is less than 6.0%. (method) Use 40mm Three types of 3-layer casting machines, operating at a processing speed of 30 m / min, utilize air knife casting to co-extrude materials with a density of 917 kg / m³. 3 Low-density polyethylene with an MFR of 23 g / 10 min is laminated at a processing temperature of 200°C, and the heat-sealing resin composition is laminated at a processing temperature of 200°C to obtain a packaging material with a low-density polyethylene layer of 22 μm thickness and a heat-sealing resin composition layer of 8 μm thickness. Then, the haze of the obtained packaging material is measured using a haze meter in accordance with JIS K 7136:2000.

9. A heat-sealing material comprising the heat-sealing resin composition according to any one of claims 1 to 8.

10. Packaging material having a substrate layer and a heat-sealing layer disposed on one side of the substrate layer, the heat-sealing layer comprising the heat-sealing material of claim 9.

11. A cover material comprising the packaging material of claim 10.

12. A packaging container comprising a container body having an opening and a cover material of claim 11 for covering the opening of the container body.

13. The packaging container as claimed in claim 12, wherein, At least a portion of the container body comprises amorphous polyethylene terephthalate.

14. The packaging container as claimed in claim 12, wherein, At least a portion of the container body comprises amorphous polyethylene terephthalate coated with organosilicon.

15. The packaging container as claimed in claim 13, wherein, At least a portion of the container body comprises amorphous polyethylene terephthalate coated with organosilicon.

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