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US 6,395,791 B1Granted
Grafted thermoplastic compositions and fabricated articles therefrom
AssigneeThe Dow Chemical Company
InventorsBharat I. Chaudhary, Thoi H. Ho, Thomas Oswald, Jennifer DellaMea
Life of this patent
Estimating the term…
Abstract
This invention describes grafted blend compositions, processes for their preparation and fabricated articles, especially foams therefrom. The blends exhibit enhanced melt strength, melt elongation greater than or equal to about 20 mm/s, increased upper service temperature, increased modulus, and increased hardness. The grafted blend compositions have little or no high shear viscosity increase over a corresponding polymer of the same chemical composition absent the coupling agent.
Claims11
A process for making a polymer foam;
- which comprises;
- i) converting a grafted blend composition into a polymer melt, said composition comprising
- A) one or more homopolymers or interpolymers with peak crystalline melting temperature (Tm) and/or or glass transition temperature (Tg by DSC) of 90° C. or more;
- B) one or more homopolymers or interpolymers with peak crystalline melting temperature (Tm) and/or glass transition temperature (Tg by DSC) of 80° C. or less;
- and
- C) at least one coupling agent;
- and wherein
- 1) the upper service temperature of said grafted blend is greater than about 80° C.;
- 2) the gel content of said grafted blend is 50 percent or less (as determined by insolubility of the gels in boiling xylene when tested according to ASTM D-2765A-84);
- 3) said grafted blend composition exhibits at least one of the following improvements relative to the same blend in the absence of Component C;
- (a) the melt strength is increased by 5% or more;
- and/or
- (b) the upper service temperature is increased by 0.5° C. or more.
- (ii) introducing, at an elevated pressure, at least one blowing agent into the polymer melt to form a foamable gel, the blowing agent being present in a total amount of from 0.05 to 5.0 gram-moles per kilogram of polymers contained in the polymer melt;
- (iii) cooling the foamable gel to an optimum temperature;
- and
- (iv) extruding the foamable gel from step iii through a die to a region of lower pressure to form a foam.
14 more elements
A process for making a foam in the form of thermoplastic foam beads, which process comprises sequential steps (i)-(v);
- i) converting a grafted blend composition into a polymer melt, said composition comprising
- A) one or more homopolymers or interpolymers with peak crystalline melting temperature (Tm) and/or or glass transition temperature (Tg by DSC) of 90° C. or more;
- B) one or more homopolymers or interpolymers with peak crystalline melting temperature (Tm) and/or glass transition temperature (Tg by DSC) of 80° C. or less;
- and
- C) at least one coupling agent;
- and wherein
- 1) the upper service temperature of said grafted blend is greater than about 80° C.;
- 2) the gel content of said grafted bland is 50 percent or less (as determined by insolubility of the gels in boiling xylene when tested according to ASTM D-2765A-84);
- 3) said grafted blend composition exhibits at least one of the following improvements relative to the same blend in the absence of Component C;
- (a) the melt strength is increased by 5% or more;
- and/or
- (b) the upper service temperature is increased by 0.5° C. or more;
- (ii) cooling and granulating the polymer melt to form discrete resin particles;
- (iii) creating a suspension by dispersing the resin particles in a liquid medium in which they are substantially insoluble;
- (iv) introducing at an elevated temperature and pressure, at least one blowing agent (and optionally a cross-linking agent) into the suspension to form resin particles having a blowing agent incorporated therein;
- and
- (v) rapidly discharging product formed in step iv into an atmosphere that promotes converting the product into foam beads.
14 more elements
A process for making a polymer foam;
- which comprises;
- i) converting a grafted blend composition into a polymer melt, said composition comprising
- A) a blend of;
- 1) one or more linear or substantially linear ethylene homopolymers or interpolymers and one or more branched ethylene homopolymers or interpolymers;
- 2) one or more linear or substantially linear ethylene homopolymers or interpolymers and one or more substantially random interpolymers;
- or
- 3) one or more linear or substantially linear ethylene homopolymers or interpolymers, one or more branched ethylene homopolymers or interpolymers and one or more substantially random interpolymers;
- and
- (B) one or more coupling agents;
- and wherein said grafted blend composition has
- a) a melt strength, greater than about 8 cN;
- b) a melt elongation of 20 mm/s or greater;
- c) a flexural modulus of 80,000 psi or greater;
- and
- d) a gel content which is 50 percent or less, as determined by insolubility of the gels in boiling xylene when tested according to ASTM D-2765A-84;
- (ii) introducing, at an elevated pressure, at least one blowing agent into the polymer melt to form a foamable gel, the blowing agent being present in a total amount of from 0.05 to 5.0 gram-moles per kilogram of polymers contained in the polymer melt;
- (iii) cooling the foamable gel to an optimum temperature;
- and
- (iv) extruding the foamable gel from step iii through a die to a region of lower pressure to form a foam.
16 more elements
A process for making a foam in the form of thermoplastic foam beads, which process comprises sequential steps (i)-(v):
- i) converting a grafted blend composition into a polymer melt, said composition comprising
- A) a blend of;
- 1) one or more linear or substantially linear ethylene homopolymers or interpolymers and one or more branched ethylene homopolymers or interpolymers;
- 2) one or more linear or substantially linear ethylene homopolymers or interpolymers and one or more substantially random interpolymers;
- or
- 3) one or more linear or substantially linear ethylene homopolymers or interpolymers, one or more branched ethylene homopolymers or interpolymers and one or more substantially random interpolymers;
- and
- (B) one or more coupling agents;
- and wherein said grafted blend composition has
- a) a melt strength, greater than about 8 cN;
- b) a melt elongation of 20 mm/s or greater;
- c) a flexural modulus of 80,000 psi or greater;
- and
- d) a gel content which is 50 percent or less, as determined by insolubility of the gels in boiling xylene when tested according to ASTM D-2765A-84;
- (ii) cooling and granulating the polymer melt to form discrete resin particles;
- (iii) creating a suspension by dispersing the resin particles in a liquid medium in which they are substantially insoluble;
- (iv) introducing, at an elevated temperature and pressure, at least one blowing agent (and optionally a cross-linking agent) into the suspension to form resin particles having a blowing agent incorporated therein;
- and
- (v) rapidly discharging product formed in step iv into an atmosphere that promotes converting the product into foam beads.
16 more elements
A process for making a polymer foam;
- which comprises;
- i) converting a grafted blend composition into a polymer melt, said composition having a melt index I2, of about 0.05 to about 10 g/10 min and comprising;
- A) from 55 to 90 wt percent (based on the combined weights of component A and B) of a linear or substantially linear ethylene homopolymer or interpolymer, having a density of greater than 0.9450 g/cm3;
- B) from 10 to 45 wt percent (based on the combined weights of component A and B) of a branched ethylene homopolymer or interpolymer having a melt strength of greater than 5 cN;
- and
- C) from 0.005 wt percent to about 0.2 wt % (based on the combined weights of A and B) of a coupling agent;
- and
- wherein the melt strength of said grafted blend is greater than 5 cN;
- ii) introducing, at an elevated pressure, at least one blowing agent into the polymer melt to form a foamable gel, the blowing agent being present in a total amount of from 0.05 to 5.0 gram-moles per kilogram of polymers contained in the polymer melt;
- iii) cooling the foamable gel to an optimum temperature;
- and
- iv) extruding the foamable gel from step iii through a die to a region of lower pressure to form a foam.
9 more elements
A process for making aq foam in the form of thermoplastic foam beads, which process comprises sequential steps (i)-(v):
- i) converting a grafted blend composition into a polymer melt, said composition having a melt index, I2, of about 0.05 to about 10 g/10 min and comprising;
- A) from 55 to 90 wt percent (based on the combined weights of component A and B) of a linear or substantially linear ethylene homopolymer or interpolymer, leaving a density of greater than 0.9450 g/cm3;
- B) from 10 to 45 wt percent (based on the combined weights of component A and B) of a branched ethylene homopolymer or interpolymer having a melt strength of greater than 5 cN;
- and
- C) from 0.005 wt percent to about 0.2 wt % (based on the combined weights of A and B) of a coupling agent;
- and
- wherein the melt strength of said grafted blend is greater than 5 cN;
- ii) cooling and granulating the polymer melt to form discrete resin particles;
- iii) creating a suspension by dispersing the resin particles in a liquid medium in which they are substantially insoluble;
- iv) introducing, at an elevated temperature and pressure, at least one blowing agent (and optionally a cross-linking agent) into the suspension to form resin particles having a blowing agent incorporated therein;
- and
- v) rapidly discharging product formed in step iv into an atmosphere that promotes converting the product into foam beads.
9 more elements
A process for making a polymer foam;
- which comprises;
- i) converting a grafted blend composition into a polymer melt, said composition comprising;
- A) one or more olefinic polymers other than polypropylene;
- B) one or more propylene homopolymers or interpolymers;
- and
- C) at least one coupling agent;
- and wherein said grafted blend has
- 1) a gel content which is 50 percent or less, as determined by insolubility of the gels in boiling xylene when tested according to ASTM D-2765A-84;
- 2) a melt elongation greater than or equal to about 20 mm/s,
- 3) a melt strength greater than about 5 cN;
- and
- 4) a flexural modulus of 50,000 psi or greater;
- ii) introducing, at an elevated pressure, at least one blowing agent into the polymer melt to form a foamable gel, the blowing agent being present in a total amount of from 0.05 to 5.0 gram-moles per kilogram of polymers contained in the polymer melt;
- iii) cooling the foamable gel to an optimum temperature;
- and
- iv) extruding the foamable gel from step iii through a die to a region of lower pressure to form a foam.
13 more elements
A process for making a foam in the form of thermoplastic foam beads, which process comprises sequential steps (i)-(v);
- i) converting a grafted blend composition into a polymer melt, said composition comprising;
- A) one or more olefinic polymers other than polypropylene;
- B) one or more propylene homopolymers or interpolymers;
- and
- C) at least one coupling agent;
- and wherein said grafted blend has
- 1) a gel content which is 50 percent or less, as determined by insolubility of the gels in boiling xylene when tested according to ASTM D-2765A-84;
- 2) a melt elongation greater than or equal to about 20 mm/s,
- 3) a melt strength greater than about 5 cN;
- and
- 4) a flexural modulus of 50,000 psi or greater,
- ii) cooling and granulating the polymer melt to form discrete resin particles;
- iii) creating a suspension by dispersing the resin particles in a liquid medium in which they are substantially insoluble;
- iv) introducing, at an elevated temperature and pressure, at least one blowing agent (and optionally a cross-linking agent) into the suspension to form resin particles having a blowing agent incorporated therein;
- and
- v) rapidly discharging product formed in step iv into an atmosphere that promotes converting the product into foam beads.
13 more elements
Dependencies are inferred from the claim text.