Flame-retardant poly(arylene ether) composition and its use as a covering for coated wire

An extruded article, comprising:

• the product of extrusion molding a composition comprising
• 20 to 44 weight percent of a poly(arylene ether);
• 29 to 57 weight percent of total polyolefin;
• wherein total polyolefin consists of polyolefins and the polyolefin content of block copolymers comprising a poly(alkenyl aromatic) block and a polyolefin block;
• and
• 10 to 25 weight percent of a flame retardant composition consisting of
• 1 to 10 weight percent of a metal dialkyl phosphinate;
• 1 to 17 weight percent of a nitrogen-containing flame retardant selected from the group consisting of melamine phosphate, melamine pyrophosphate, melamine polyphosphates, and mixtures thereof;
• 1 to 10 weight percent of a triaryl phosphate that is a liquid at one atmosphere and at least one temperature in the range 25 to 50° C.;
• and
• optionally, 0.05 to 2.5 weight percent of zinc borate;
• wherein all weight percents are based on the total weight of the thermoplastic composition;
• wherein the poly(arylene ether) and total polyolefin are present in a weight ratio of 0.53:1 to 1.2:1;
• and
• wherein a test sample coated wire exhibits
• a tensile stress at break of at least 10 megapascals, measured at 23° C. according to UL 1581, Section 470,
• a tensile elongation at break of at least 100 percent, measured at 23° C. according to UL 1581, Section 470, and
• a passing flame test rating according to UL 1581, Section 1080,
• wherein the test sample coated wire consists of an AWG 24 conductor having a nominal cross sectional area of 0.205 millimeter2, and a tubular covering comprising the thermoplastic composition and having a nominal outer diameter of 2 millimeters.

A coated wire, comprising:

• a conductor, and
• a covering disposed on the conductor;
• wherein the covering comprises a composition comprising
• 20 to 44 weight percent of a poly(arylene ether);
• 29 to 57 weight percent of total polyolefin;
• wherein total polyolefin consists of polyolefins and the polyolefin content of block copolymers comprising a poly(alkenyl aromatic) block and a polyolefin block;
• and
• 10 to 25 weight percent of a flame retardant composition consisting of
• 1 to 10 weight percent of a metal dialkyl phosphinate;
• 1 to 17 weight percent of a nitrogen-containing flame retardant selected from the group consisting of melamine phosphate, melamine pyrophosphate, melamine polyphosphates, and mixtures thereof;
• 1 to 10 weight percent of a triaryl phosphate that is a liquid at one atmosphere and at least one temperature in the range 25 to 50° C.;
• and
• optionally, 0.05 to 2.5 weight percent of zinc borate;
• wherein all weight percents are based on the total weight of the thermoplastic composition;
• wherein the poly(arylene ether) and total polyolefin are present in a weight ratio of 0.53:1 to 1.2:1;
• and
• wherein a test sample coated wire exhibits
• a tensile stress at break of at least 10 megapascals, measured at 23° C. according to UL1581, Section 470,
• a tensile elongation at break of at least 100 percent, measured at 23° C. according to UL1581, Section 470, and
• a passing flame test rating according to UL 1581, Section 1080,
• wherein the test sample coated wire consists of an AWG 24 conductor having a nominal cross sectional area of 0.205 millimeter2, and a tubular covering comprising the thermoplastic composition and having a nominal outer diameter of 2 millimeters.

A thermoplastic composition, comprising:

• 20 to 44 weight percent of a poly(arylene ether);
• 29 to 57 weight percent of total polyolefin;
• wherein total polyolefin consists of polyolefins and the polyolefin content of block copolymers comprising a poly(alkenyl aromatic) block and a polyolefin block;
• and
• 10 to 25 weight percent of a flame retardant composition consisting of
• 1 to 10 weight percent of a metal dialkyl phosphinate;
• 1 to 17 weight percent of a nitrogen-containing flame retardant selected from the group consisting of melamine phosphate, melamine pyrophosphate, melamine polyphosphates, and mixtures thereof;
• 1 to 10 weight percent of a triaryl phosphate that is a liquid at one atmosphere and at least one temperature in the range 25 to 50° C.;
• and
• optionally, 0.05 to 2.5 weight percent of zinc borate
• wherein all weight percents are based on the total weight of the thermoplastic composition;
• wherein the poly(arylene ether) and total polyolefin are present in a weight ratio of 0.53:1 to 1.2:1;
• and
• wherein the thermoplastic composition exhibits
• a UL 94 Vertical Burning Flame Test rating of V-0 or V-1 at a sample thickness less than or equal to 6.4 millimeters,
• a tensile stress at break of at least 5 megapascals, measured at 23° C. according to ASTM D638, and
• a flexural modulus of 10 to 1,000 megapascals, measured at 23° C. according to ASTM D790.