Polyester-based shock-resistant compositions and process for their preparation

Claim 2

Shock-resistant polymeric compositions comprising: a) from 55 to 98% by weight of one or more saturated polyesters; b) from 1 to 35% by weight of butadiene and/or acrylic rubber; and c) from 1 to 10% by weight of an elastomeric copolyester.

Claim 3

Polymeric compositions according to claim 1, wherein the butadiene rubber or the acrylic rubber is in the form of particles having a size comprised within the range of from 0.1 to 2 microns.

Claim 4

Polymeric compositions according to claim 1 or 2, wherein the saturated polyester has an intrinsic viscosity of at least 0.4 dl/g and is obtained from an aromatic or cycloaliphatic bicarboxylic acid, with a diol having the formula: HO - R - OH (I) wherein R is a linear or branched alkylene radical, containing from 2 to 20 C atoms, or an arylene or cycloalkylene radical containing from 6 to 20 C atoms.

Claim 5

Polymeric compositions according to claim 3, wherein the saturated polyester contains an amount lower than 15% by mol, in respect to the aromatic or cycloaliphatic bicarboxy­lic acid, of an aliphatic bicarboxylic acid contaninig from 4 to 20 C atoms.

Claim 6

Polymeric compositions according to any of preceding claims from 1 to 4, wherein the butadiene rubber or the acrylic rubber has a glass transition temperature (T g ) lower than 0°C, and a crosslinking degree comprised within the range of from 0 to 99% by weight, preferably of from 50 to 99% by weight.

Claim 7

Polymeric compositions according to claim 5, wherein the butadiene rubber is obtained either by direct polymerization, or by polymerization and subsequent grafting reaction, of butadiene and/or isoprene with an ethylenically unsaturated monomer selected from styrene, acrylonitrile, methacrylonitrile, acrylic and methacrylic esters, acrylic and methacrylic acid, maleic acid and anhydride, maleic and fumaric esters, alkylstyrenes, in any combinations with one another and the acrylic rubber is obtained either by direct polymerization, or by polymerization and subsequent grafting reaction, of acrylic or methacrylic alkyl-esters containing from 1 to 10 C atoms in their alkyl chain, possibly in combination with other ethylenically unsaturated monomers, and with from 0.1 to 5% by weight, of bi- or polyfunctional monomers, respectively.

Claim 8

Polymeric compositions according to any of preceding claims from 1 to 6, wherein the elastomeric copolyester is a block-copolyester having a melting point lower than 190°C, and is obtained by polycondensation or transesterification of an aromatic bicarboxylic acid with a diol havin a formu­la (I), and with a polyetherglycol having formula: HO - (R₁- O) m - H (II) wherein R₁ is a linear or branched alkylene radical, containing from 2 to 20 C atoms, and m is an integer higher than 2, and such that the molecular weight of the polyetherglycol is comprised within the range of from 300 to 10,000, preferably of from 600 to 4,000.

Claim 9

Polymeric compositions according to claim 7, wherein the block-copolyester has a content of rigid segments comprised within the range of from 10 to 75% by weight, preferably of from 30 to 50% by weight, and a ratio of the number of C atoms to the number of oxygen atoms in the flexi­ble segments is equal to or higher than 2.

Claim 10

Polymeric compositions according to any of preceding claims from 1 to 8, characterized in that they can contain a further thermoplastic material, e.g. polycarbonate or thermo­plastic polyurethane, in an amount lower than 25%, preferably of from 1 to 10% by weight, relatively to total composition.

Claim 11

Polymeric compositions according to any of preceding claims from 1 to 9, characterized in that they contain various additives, such as: stabilizers, antioxidants, pigments, dyes, flame-proofing agents, lubricants, organic and inorganic rein­forcing agents, and nucleating agents.