US 2026/0078246 A1 · THERMOPLASTIC ELASTOMER COMPOSITION AND MOLDED ARTICLE OF THE SAME

Abstract

Provided is, for example, a thermoplastic elastomer composition having excellent heat aging resistance when exposed to a high-temperature environment for a long period of time, also excellent hardness and mechanical properties as well as excellent extrusion processability. A thermoplastic elastomer composition (I) including a cross-linked product of an ethylene/α-olefin/nonconjugated polyene copolymer (A) having a weight-average molecular weight of 350,000 or more, with a phenolic resin-based cross-linking agent (E), and including 360 to 460 parts by mass of a crystalline polyolefin (B), 2 to 6 parts by mass of a fatty acid-based lubricant (D), and 80 parts by mass or more of a softener (C1), relative to 100 parts by mass of the copolymer (A), in which the thermoplastic elastomer composition (I) has a ½ crystallization time at 120° C. of 200 seconds or less, and a polyolefin component included in the thermoplastic elastomer composition (I) has a maximum spherulite size in a range of 8 μm or less.

Claims13

Dependent claims

A thermoplastic elastomer composition (I) comprising a cross-linked product of an ethylene/α-olefin/nonconjugated polyene copolymer (A), wherein the α-olefin has 3 or more carbon atoms, satisfying the following requirements (a1) to (a4), with a phenolic resin-based cross-linking agent I, and comprising

360 to 460 parts by mass of a crystalline polyolefin (B) having a melt flow rate of 8.0 g/10 min or less as measured under conditions of 230° C. and a load of 2.16 kg;
2 to 6 parts by mass of a fatty acid-based lubricant (D), and
80 parts by mass or more of a softener (C1), based on 100 parts by mass of the copolymer (A);
wherein the thermoplastic elastomer composition (I) has a ½ crystallization time at 120° C. of 200 seconds or less, and
a polyolefin component comprised in the thermoplastic elastomer composition (I) has a maximum spherulite size in a range of 8 μm or less:
(a1) a weight-average molecular weight is 350,000 or more;
(a2) an intrinsic viscosity [η] is 4.0 dL/g or more;
(a3) an ethylene content is 57.0% by mass or more;
and
(a4) a content of the nonconjugated polyene is 4.0% by mass or more.

7 more elements

A method for producing a thermoplastic elastomer composition (I), comprising a step (β) of mixing a mixture (α) comprising an ethylene/α-olefin/nonconjugated polyene copolymer (A), wherein the α-olefin has 3 or more carbon atoms, satisfying the following requirements (a1) to (a4) and a softener (C1);

360 to 460 parts by mass of a crystalline polyolefin (B) having a melt flow rate of 8.0 g/10 minutes or less measured under conditions of 230° C. and a load of 2.16 kg;
2 to 9 parts by mass of a phenolic resin-based cross-linking agent €;
2 to 6 parts by mass of a fatty acid-based lubricant (D), based on 100 parts by mass of the copolymer (A);
and
optionally the softener (C1);
wherein a total amount of the softener (C1) comprised in the mixture (α) and the softener (C1) optionally mixed in the step (β) is 80 parts by mass or more, and
a mass fraction of the softener (C1) comprised in the mixture (α) relative to the total amount of the softener (C1) comprised in the mixture (α) and the softener (C1) optionally mixed in the step (β) is 60 to 100% by mass:
(a1) a weight-average molecular weight is 350,000 or more;
(a2) an intrinsic viscosity [η] is 4.0 dL/g or more;
(a3) an ethylene content is 57.0% by mass or more;
and
(a4) a content of the nonconjugated polyene is 4.0% by mass or more.

9 more elements

Dependencies are inferred from the claim text.

Thermoplastic elastomer composition and molded article of the same

Life of this patent

Thermoplastic elastomer composition and molded article of the same

Life of this patent

Abstract

Claims13