HK1171240A

HK1171240A - Tpo compositions, articles, and methods of making the same

Info

Publication number: HK1171240A
Application number: HK12111894.0A
Authority: HK
Inventors: Anteneh Worku; Kim Walton; Henry Heck
Original assignee: 陶氏环球技术有限责任公司
Priority date: 2009-07-02
Filing date: 2010-07-01
Publication date: 2013-03-22

Description

TPO compositions, articles, and methods for making said compositions

Cross Reference to Related Applications

This application claims benefit of U.S. provisional application 61/222,677 filed on 7/2/2009, which is incorporated herein by reference in its entirety.

Technical Field

The present invention relates to a thermoplastic olefin (TPO) composition having excellent flame retardant properties.

Background

Thermoplastic olefin compositions are used in a variety of applications, including automotive and footwear applications. One emerging area is the use of these compositions in electrical applications, such as injection molded containers for electrical components and equipment. These applications require compositions having good flame retardant properties, as indicated by the UL94 rating of "V-0", which means that test bars formed from the compositions self-extinguish in a vertical position after repeated exposure to flame.

International publication WO2008/07998 discloses compositions containing platy fillers. These compositions contain a propylene homopolymer, an ethylene/alpha-olefin interpolymer, a platy filler, and a source of nitrogen and phosphorus.

European patent application EP1081183a2 discloses compositions containing a filler, for example a glass filler, and a flame retardant effective additive (at least one polyphosphate, a sulfur-containing compound, a catalyst and a nitrogen-containing compound such as melamine). Polymers include those selected from the group consisting of: polyamides, polybutylene terephthalate, polyethylene terephthalate, polypropylene, polyethylene, polystyrenes, polyurethanes and polyacrylics, polycarbonates, polyarylates, polysulfones, polyether ketones, polyether ether ketones, polyphenylene oxides, polyphenylene sulfides, epoxy resins, and thermosets, and blends thereof. Additional fillers include mineral fibers, carbon fibers, aramid fibers, gypsum, silica lime, and lignin-containing fibers.

Us publication 2007/0299171 discloses compositions comprising formulations based on phosphinates and melamine derivatives. The compositions are useful for making articles for electrical or electronic connection.

U.S. publication 2002/0155348 discloses a battery housing formed from a composition containing a blend of a homopolymer, a copolymer, and ammonium polyphosphate. Other components include polyols, intumescent char-forming agents and melamine, which are used as blowing agents. Alternatively, the battery housing contains a polymer composition that contains a halogen-containing flame retardant component and a polypropylene component.

Other compositions are described in EP1719800a 1.

There remains a need for thermoplastic polyolefin compositions having excellent flame retardant properties. In addition, there is a need for such compositions having high filler loading to meet tensile properties such as flexural modulus. Furthermore, there is a need for highly filled compositions containing fillers that do not interfere with the flame retardant properties of the flame retardant. The present invention meets these needs.

Disclosure of Invention

The present invention provides a composition comprising:

A) a propylene-based polymer having a flexural modulus greater than 1500MPa and an HDT greater than 100 ℃;

B) an ethylene/α -olefin interpolymer having a Tg of less than-30 ℃, a tan δ, measured at 0.1 radians/sec at 190 ℃, of less than 3, and an HDT of greater than or equal to the peak melting temperature of the ethylene/α -olefin interpolymer, measured by differential scanning calorimetry; and

C) a fibrous filler; and

D) a nitrogen source and/or a phosphorous source, wherein at least one source is derived from at least one organic compound or salt thereof; and

wherein the propylene-based polymer: the ethylene/alpha-olefin interpolymer (A: B) weight ratio is from 9: 1 to 6: 4.

The present invention also provides a polyolefin composition comprising:

B) an ethylene/α -olefin interpolymer having a Tg less than-30 ℃ and a tan delta less than 3 measured at 0.1 radians/sec at 190 ℃; and

C) a fibrous filler; and

wherein the propylene-based polymer to ethylene/alpha-olefin interpolymer (A: B) weight ratio is from 9: 1 to 6: 4.

Detailed Description

As noted above, in a first aspect, the present invention provides a polyolefin composition comprising:

C) fibrous filler, and

D) a nitrogen source and/or a phosphorus source, wherein at least one source is derived from (is a compound or a derivative of) at least one organic compound or a salt thereof, and

In a second aspect, the present invention also provides a polyolefin composition comprising:

B) an ethylene/α -olefin interpolymer having a Tg of less than-30 ℃ and a tan delta of less than 3 measured at 0.1rad/sec at 190 ℃, and

C) fibrous filler, and

D) a nitrogen source and/or a phosphorus source, wherein at least one source is derived from at least one organic compound or a salt thereof, and

The embodiments described herein are applicable to the above first aspect and the above second aspect of the present invention.

In a preferred embodiment, the filler is a calcium-based filler. In another embodiment, the fibrous filler is silica fume.

In one embodiment, the filler is present in an amount greater than, or equal to, 10 weight percent, preferably greater than, or equal to, 15 weight percent, and more preferably greater than, or equal to, 20 weight percent, based on the weight of the composition.

In one embodiment, the total weight of components A, B, C and D is greater than or equal to 95 weight percent, preferably greater than or equal to 98 weight percent, and more preferably greater than or equal to 99 weight percent, based on the weight of the composition.

In one embodiment, the composition has a Heat Deflection Temperature (HDT) greater than about 100 ℃ and a flexural modulus greater than about 1930 MPa.

In one embodiment, the composition has a UL-94 rating of V-0.

In one embodiment, the composition comprises a sufficient amount of filler such that the composition has a flexural modulus efficiency factor of 3 or greater and an HDT efficiency factor of 1.5 or greater.

The reinforcing efficiency of the filler to the composition was evaluated by the following method: the effect of "20 wt%" addition of filler on flexural modulus and HDT of blends of propylene-based polymers and ethylene/a-olefin interpolymers was measured. The flexural modulus of the blends with and without filler was measured. The flexural modulus efficiency factor can then be calculated in units of percent increase in modulus/percent loading of filler. This factor is relatively linear over a filler loading range of about 10-40 wt%. The associated HDT efficiency factor may be similarly calculated for each packing stage by: the propylene-based polymer and ethylene/α -olefin interpolymer were compounded with "20 wt%" reinforcing filler and not compounded with filler, and each HDT was measured.

In one embodiment, the fibrous filler is present in an amount greater than 15 weight percent, preferably greater than or equal to 18 weight percent, and more preferably greater than or equal to 20 weight percent, based on the weight of the composition.

The compositions of the present invention may comprise a combination of two or more embodiments as described herein.

In one embodiment, the nitrogen source is derived from melamine, isocyanuric acid, an isocyanate (isocyanate), or a triazine.

In one embodiment, the nitrogen source is derived from at least one organic compound selected from the group consisting of: melamine, melamine cyanurate (melamine cyanurate), melamine borate (melamine borate), melamine phosphate (melamine phosphate), melamine polyphosphate (melamine pyrophosphate), melamine pyrophosphate (melamine pyrophosphate), ethylenediamine isocyanurate (ethylene) or tris (hydroxyethyl) isocyanurate (tris).

In one embodiment, the phosphorus source is derived from at least one compound selected from the group consisting of: a phosphate compound (phosphate compound), a phosphinate compound (phosphinate compound), a phosphonate compound (phosphonate compound), a polyphosphate compound (polyphosphate compound), or a phosphine oxide (phosphine oxide).

In one embodiment, the nitrogen and/or phosphorus source is derived from an amine salt of phosphoric acid, an amine salt of polyphosphoric acid, an ammonium salt of phosphoric acid, or an ammonium salt of polyphosphoric acid.

In one embodiment, the phosphorus source is derived from at least one compound selected from the group consisting of: ammonium polyphosphate, bisphenol a diphenyl phosphate, melamine polyphosphate or melamine pyrophosphate.

In one embodiment, the nitrogen source and the phosphorous source are derived from the same compound.

In one embodiment, the nitrogen source and the phosphorous source are derived from at least one compound selected from the group consisting of: ammonium polyphosphate, melamine phosphate, melamine polyphosphate, ethylenediamine phosphate (ethylenediamine pyrophosphate), or melamine pyrophosphate.

In one embodiment, the nitrogen source and phosphorus source are present as pre-formulated additives (e.g., a masterbatch formulation).

In a preferred embodiment, the propylene-based polymer is a propylene homopolymer.

In one embodiment, the propylene-based polymer is a propylene homopolymer having a flexural modulus greater than 1930 MPa.

In one embodiment, the propylene homopolymer has an isotactic index greater than 98%, as measured by 13C NMR, and is related to xylene solubility (ASTM D5492).

In one embodiment, the propylene homopolymer has a flexural modulus greater than or equal to 2070MPa and an HDT greater than 110 ℃. In another embodiment, the propylene homopolymer has a flexural modulus of greater than 2210MPa, and an HDT of greater than 120 ℃.

In one embodiment, the ethylene/α -olefin interpolymer has a tan δ of less than 2 measured at 190 ℃ at 0.1 rad/sec.

In one embodiment, the ethylene/α -olefin interpolymer has a tan δ, measured at 0.1rad/sec at 190 ℃, of less than 3, preferably less than 2.5, more preferably less than 2.2.

In one embodiment, the α -olefin of the ethylene/α -olefin interpolymer is a C3-C20 α -olefin. In another embodiment, the α -olefin of the ethylene/α -olefin interpolymer is selected from the group consisting of: propylene, 1-butene, 1-hexene and 1-octene.

In one embodiment, the ethylene/α -olefin interpolymer has a glass transition temperature (Tg) of less than-40 ℃, preferably less than-50 ℃.

In one embodiment, the difference between the HDT and the melting point (Tm) of the ethylene/a-olefin interpolymer is at least 4. In one embodiment, the difference between the HDT and the melting point (Tm) of the ethylene/a-olefin interpolymer is at least 8.

In one embodiment, the ethylene/α -olefin interpolymer has a tan δ, measured at 190 ℃ and 0.10 rad/sec, of 3 or less, and preferably 2 or less. In one embodiment, the ethylene/α -olefin interpolymer has a tan δ, measured at 190 ℃ and 0.10 rad/sec, of 2.5 or less, preferably 1.8 or less.

In one embodiment, the composition has a "UL-94 rating" of V-0.

In one embodiment, the composition has a flexural modulus greater than or equal to 290kpsi (2000MPa), preferably greater than or equal to 300kpsi (2069MPa), more preferably greater than or equal to 320kpsi (2207MPa), and even more preferably greater than or equal to 350kpsi (2414 MPa).

The present invention also provides an article comprising at least one component formed from the composition of the present invention.

The present invention also provides a molded article comprising at least one component formed from the composition of the present invention, and wherein the article is selected from the group consisting of electronic parts, electronic housings (electronic enclosures), computer parts, building or construction materials, household appliances, containers, furniture, footwear components, and toys. In another embodiment, the article is in an electronic component or an electronic enclosure. In another embodiment, the article is a building or construction material.

The articles can be prepared by injection molding, extrusion-followed by thermoforming, low pressure molding, compression molding, and by other methods known in the art.

The present invention also provides molded articles comprising at least one part formed from the composition of the present invention. In another embodiment, the article is formed by injection molding.

Articles of the invention (including molded articles) may comprise a combination of two or more embodiments described herein.

The invention also provides a method of forming the composition of the invention comprising polymerizing a propylene-based polymer and an ethylene/a-olefin interpolymer in separate reactors and then mixing the propylene-based polymer and the ethylene/a-olefin interpolymer with a fibrous filler, a nitrogen source, and/or a phosphorus source.

In one embodiment, the present invention also provides a method of making the composition of the present invention using co-rotating intermeshing twin screw extruders.

The present invention provides a process for preparing the composition of the present invention comprising mixing the components of the composition in a twin screw extruder. In another embodiment, the nitrogen and/or phosphorus source is added to the extruder using a first side arm extruder (side arm extruder). In one embodiment, the filler is added to the extruder using a second side arm extruder.

The present methods may comprise a combination of two or more embodiments described herein.

Fibrous filler

In one embodiment, the fibrous filler is a calcium-based filler. Calcium-based fillers include calcium, and calcium, typically in the form of calcium oxide.

In one embodiment, the fibrous filler is silica fume.

Silica fume fibrous fillers are available from r.t. vanderbilt Company, inc.

The silicon lime is calcium inosilicate mineral (CaSiO)₃) It may contain small amounts of iron, magnesium and manganese in place of calcium.

In one embodiment, the fibrous filler is a mineral fiber.

Related minerals include garnet, tremolite, diopside, tremolite, celadon, plagioclase, pyroxene, and calcite.

In one embodiment, the fibrous filler comprises at least one mineral selected from the group consisting of: garnet, tremolite, diopside, tremolite, echeverite, plagioclase, pyroxene, calcite, calcium inosilicate, and mixtures thereof.

In one embodiment, the fibrous filler comprises at least one mineral selected from the group consisting of: tremolite, diopside, tremolite, celadon, plagioclase, pyroxene, calcite, calcium inosilicate, and mixtures thereof.

In one embodiment, the fibrous filler comprises at least one mineral selected from the group consisting of: plagioclase, pyroxene, calcite, calcium inosilicate, and mixtures thereof.

In one embodiment, the fibrous filler comprises at least one mineral selected from the group consisting of: calcite, calcium inosilicate, and mixtures thereof.

In one embodiment, the fibrous filler comprises calcium inosilicate, magnesium inosilicate, or mixtures thereof.

In one embodiment, the aspect ratio (length/diameter) of the fibrous filler is from 3: 1 to 20: 1, preferably from 5: 1 to 20: 1.

In one embodiment, the fibrous filler is a silica fume powder. In another embodiment, the ratio of length to diameter of the lime silica powder is from 3: 1 to 5: 1.

In one embodiment, the fibrous filler is acicular silica-lime powder. In another embodiment, the acicular silica lime powder has an aspect ratio of from 15: 1 to 20: 1.

The fibrous filler may be surface treated with a silane, silicone or titanate, and preferably, treated with a solution of a silane, silicone or titanate. Useful silanes include, but are not limited to, vinyldimethoxysilane, vinyltrimethoxysilane, vinyldiethoxysilane, vinyltriethoxysilane, alkylsilanes, and aminosilanes.

In one embodiment, the fibrous filler is treated with a silane. In another embodiment, the fibrous filler is silane treated silica lime.

In one embodiment, the fibrous filler is treated with a silane selected from the group consisting of: vinyldimethoxysilane, vinyltrimethoxysilane, vinyldiethoxysilane, vinyltriethoxysilane, alkylsilanes and aminosilanes. In another embodiment, the fibrous filler is silane treated silica lime.

In one embodiment, the fibrous filler is treated with a silane selected from the group consisting of: alkyl silanes and amino silanes. In another embodiment, the fibrous filler is silane treated silica lime.

The fibrous filler may comprise a combination of two or more embodiments described herein.

Flame retardant additives

Table 1 gives a list of halogen-free additives that may be used in the compositions of the present invention. Most flame retardants are organic based and therefore can be used for partitioning into the polymeric phase of the composition. Other flame retardants are described in EP1719800a1, which is incorporated herein by reference.

In general, suitable phosphorus-containing compounds include phosphates, phosphinates, phosphonates, and phosphine oxides.

Table 1 below classifies the swelling additives by functional group type. When an additive contains a mixed functional group, it is listed under each category and under the combined category. Thus, for example, melamine polyphosphate is listed under phosphorus, nitrogen and mixed "phosphorus plus nitrogen".

In one embodiment of the composition of the invention, component D is derived from a nitrogen source.

In one embodiment, component D is derived from a phosphorous source.

In one embodiment, component D is derived from a nitrogen source and a phosphorous source.

Table 1: flame retardant additives

1: available from Clariant

2: available from Ciba Specialty Chemicals

3: available from Suspresta

Propylene-based polymers

Propylene-based polymers include propylene homopolymers and propylene-based interpolymers. Some examples of propylene-based Polymers include INSPIRE Performance Polymers (e.g., INSPIRE D221, INSPIRE 114, and INSPIRE 216), and other Performance polypropylenes available from The Dow Chemical Company, and PROFAX PD702 and PROFAX SB912 Polymers (both available from LyondellBasell).

In one embodiment, the propylene-based polymer has a melt flow rate MFR greater than, or equal to, 0.1g/10min, preferably greater than, or equal to, 0.2g/10min, and more preferably greater than, or equal to, 0.5g/10 min. In one embodiment, the propylene-based polymer is a propylene homopolymer. In another embodiment, the propylene-based polymer is a propylene-based interpolymer.

In one embodiment, the propylene-based polymer has a melt flow rate MFR less than, or equal to, 5g/10min, preferably less than, or equal to, 4g/10min, more preferably less than, or equal to, 3g/10 min. In one embodiment, the propylene-based polymer is a propylene homopolymer. In another embodiment, the propylene-based polymer is a propylene-based interpolymer.

In one embodiment, the propylene-based polymer has a melt flow rate MFR less than, or equal to, 12g/10min, preferably less than, or equal to, 10g/10min, more preferably less than, or equal to, 8g/10 min. In one embodiment, the propylene-based polymer is a propylene homopolymer. In another embodiment, the propylene-based polymer is a propylene-based interpolymer.

In one embodiment, the propylene-based polymer has a Melt Flow Rate (MFR) (230 ℃/2.16kg weight) of from 0.1 to 5, preferably from 0.2 to 4g/10min, more preferably from 0.5 to 3g/10 min. All individual values and subranges from 0.1 to 5g/10min are included herein and disclosed herein. In one embodiment, the propylene-based polymer is a propylene homopolymer. In another embodiment, the propylene-based polymer is a propylene-based interpolymer.

In one embodiment, the propylene-based polymer has a melting point greater than 145 ℃. In another embodiment, the propylene-based polymer has a melting point Tm of 130 ℃ to 180 ℃, preferably 140 ℃ to 170 ℃. In one embodiment, the propylene-based polymer is a propylene homopolymer. In another embodiment, the propylene-based polymer is a propylene-based interpolymer.

In one embodiment, the propylene-based polymer has a crystallization temperature Tc greater than or equal to 110 ℃, preferably greater than or equal to 120 ℃, and more preferably greater than or equal to 130 ℃, and most preferably greater than or equal to 140 ℃. In one embodiment, the propylene-based polymer is a propylene homopolymer. In another embodiment, the propylene-based polymer is a propylene-based interpolymer.

Polymerization processes for making high melting polymers include slurry processes, which operate at about 50-90 c and 0.5-1.5MPa (5-15atm), as well as gas phase and liquid monomer processes, in which amorphous polymer must be removed with extra care. Propylene-based polymers can also be prepared by using any of a variety of single-site metallocene and constrained geometry catalysts and their associated methods. The polymerization can be carried out in stirred tank reactors, gas phase reactors, single continuous stirred tank reactors, single slurry loop reactors, and other suitable reactors.

In one embodiment, the propylene-based polymer has a molecular weight distribution (Mw/Mn) of from 2 to 6, more preferably from 2 to 5 and most preferably from 3 to 5. All individual values and subranges from 2 to 6 are included herein and disclosed herein. In another embodiment, the molecular weight distribution is less than or equal to 6, and more preferably less than or equal to 5.5, and more preferably less than or equal to 5. In one embodiment, the propylene-based polymer is a propylene homopolymer. In another embodiment, the propylene-based polymer is a propylene-based interpolymer.

In one embodiment, the propylene-based polymer has a density greater than, or equal to, 0.88g/cc, preferably greater than, or equal to, 0.89 g/cc. In one embodiment, the propylene-based polymer is a propylene homopolymer. In another embodiment, the propylene-based polymer is a propylene-based interpolymer.

In one embodiment, the propylene-based polymer has a density less than, or equal to, 0.92g/cc, preferably less than, or equal to, 0.91 g/cc. In one embodiment, the propylene-based polymer is a propylene homopolymer. In another embodiment, the propylene-based polymer is a propylene-based interpolymer.

In one embodiment, the propylene-based polymer has a density of from 0.88 to 0.92g/cc, and preferably from 0.89 to 0.91 g/cc. All individual values and subranges from 0.88 to 0.92g/cc are included herein and disclosed herein. In one embodiment, the propylene-based polymer is a propylene homopolymer. In another embodiment, the propylene-based polymer is a propylene-based interpolymer.

Preferred grades of highly crystalline isotactic homopolymer have a flexural modulus of greater than or equal to about 2070MPa (300kpsi) and an HDT of greater than about 110 ℃. The most preferred grades of highly crystalline isotactic homopolymer polypropylene have flexural moduli greater than about 2210MPa (320kpsi) and HDT greater than about 120 ℃.

In one embodiment, the propylene homopolymer has an HDT greater than about 90 ℃, preferably greater than about 100 ℃, more preferably greater than about 110 ℃, even more preferably greater than about 120 ℃, and most preferably greater than about 130 ℃.

In another embodiment, the propylene homopolymer has a flexural modulus of greater than about 1720MPa (250kpsi), preferably greater than about 1930MPa (280kpsi), more preferably greater than about 2000MPa (290kpsi), and most preferably greater than about 2210MPa (320 kpsi).

The propylene-based polymer may comprise a combination of two or more embodiments described herein.

The propylene homopolymer may comprise a combination of two or more embodiments as described herein.

The propylene-based interpolymer may comprise a combination of two or more embodiments described herein.

Ethylene/alpha-olefin interpolymers

The compositions of the present invention comprise at least one ethylene/α -olefin interpolymer, which optionally may contain a diene. As used herein, "interpolymer" refers to a polymer having polymerized therein at least two monomers. It includes, for example, copolymers, terpolymers and tetrapolymers. In particular, it includes polymers prepared by polymerizing ethylene with at least one comonomer, which is generally an alpha olefin (α -olefin) having from 3 to 20 carbon atoms (C3-C20), preferably from 3 to 8 carbon atoms (C3-C8). In one embodiment, the alpha-olefin is a C4-C8 alpha-olefin.

Interpolymers include ethylene/butene (EB) copolymers, ethylene/hexene-1 (EH) copolymers, ethylene/octene (EO) copolymers, ethylene/alpha-olefin/diene modified (EAODM) interpolymers such as ethylene/propylene/diene modified (EPDM) interpolymers, and ethylene/propylene/octene terpolymers. Preferred copolymers include EP (ethylene/propylene) copolymers, EB (ethylene/butene) copolymers, EH (ethylene/hexene) copolymers and EO (ethylene/octene) copolymers. Suitable diene monomers include conjugated and non-conjugated dienes, and preferably non-conjugated dienes. Preferred non-conjugated dienes include ENB, 1, 4-hexadiene, 7-methyl-1, 6-octadiene, and a more preferred diene is ENB. Suitable conjugated dienes include 1, 3-pentadiene, 1, 3-butadiene, 2-methyl-1, 3-butadiene, 4-methyl-1, 3-pentadiene or 1, 3-cyclopentadiene.

In one embodiment, the ethylene/a-olefin interpolymer is an ethylene/a-olefin copolymer. In another embodiment, the alpha-olefin is a C3 to C20 alpha-olefin, preferably a C4 to C8 alpha-olefin. In another embodiment, the copolymer is selected from EB, EH or EO copolymers.

By modifying highly crystalline isotactic homopolymer polypropylene with an EAO elastomeric impact modifier (or ethylene/alpha-olefin interpolymer), excellent low temperature impact resistance is contributed. To provide the impact resistance required at-30 ℃, the glass transition temperature (Tg) of the EAO elastomeric impact modifier is preferably less than-30 ℃, more preferably less than-40 ℃, and most preferably less than-50 ℃.

In addition, two other characteristics of elastomeric impact modifiers affect the properties of the composition. First, because the EAO elastomeric impact modifier will be well above the melting point before the highly crystalline isotactic propylene homopolymer begins to melt, it is desirable to select a grade with an HDT significantly above the melting point. In one embodiment, preferred grades of EAO elastomeric impact modifiers have a positive δ, more preferred grades have a δ of 4 or greater, even more preferred grades have a δ of 6 or greater, and most preferred grades have a δ of 8 or greater. Suitable polymeric ethylene/α -olefin interpolymers include ENGAGE 8100 and ENGAGE 8842 polyolefin elastomers and ENR 7380 developmental polyolefin elastomers, both from the Dow Chemical Company.

Second, the tan δ of the elastomer (ethylene/α -olefin interpolymer) measured at 190 ℃ at 0.1 radians/second (rad/sec) is related to the gloss of the final injection molded part. the lower the tan δ, the lower the gloss of the molded part.

Preferred grades of EAO elastomeric impact modifiers have Tg and δ properties as described above and a tan δ of about 3 or less, preferably 2.5 or less, more preferably 2 or less, and even more preferably about 1.8 or less, and most preferably about 1.6 or less, measured at 190 ℃ and 0.1 rad/sec.

In one embodiment, the ethylene/α -olefin interpolymer has a molecular weight distribution (Mw/Mn) from 1 to 5, more preferably from 1.5 to 4, and most preferably from 2 to 3. All individual values and subranges from 1 to 5 are included herein and disclosed herein.

In one embodiment, the ethylene/α -olefin interpolymer has a density greater than, or equal to, 0.80g/cc, preferably greater than, or equal to, 0.82g/cc, and more preferably greater than, or equal to, 0.83 g/cc.

In one embodiment, the ethylene/α -olefin interpolymer has a density less than, or equal to, 0.90g/cc, preferably less than, or equal to, 0.88g/cc, and more preferably less than, or equal to, 0.87 g/cc.

In one embodiment, the ethylene/α -olefin interpolymer has a density from 0.80 to 0.90g/cc, preferably from 0.82 to 0.88g/cc, and more preferably from 0.83 to 0.87 g/cc. All individual values and subranges from 0.80 to 0.90g/cc are included herein and disclosed herein. In another embodiment, the ethylene/α -olefin interpolymer has a density less than, or equal to, 0.875g/cc, preferably less than, or equal to, 0.86g/cc, and more preferably less than, or equal to, 0.85 g/cc.

In one embodiment, the ethylene/α -olefin interpolymer has a melt index, I2, greater than, or equal to, 0.05g/10min, preferably greater than, or equal to, 0.1g/10min, and more preferably greater than, or equal to, 0.2g/10 min.

In one embodiment, the ethylene/α -olefin interpolymer has a melt index, I2, of less than, or equal to, 10g/10min, preferably less than, or equal to, 5g/10min, and more preferably less than, or equal to, 2g/10 min.

In one embodiment, the ethylene/α -olefin interpolymer has a melt index, I2(190 ℃/2.16kg), of from 0.05 to 10g/10min, preferably from 0.1 to 5g/10min, and more preferably from 0.2 to 2g/10min, or from 0.5 to 1g/10 min. All individual values and subranges from 0.05 to 10g/10min are included herein and disclosed herein. In another embodiment, the melt index I2 of the elastomer component is 1g/10min or less, preferably 0.5g/10min or less, and more preferably 0.3g/10min or less.

In one embodiment, the ethylene/α -olefin interpolymer has a mooney viscosity (ML 1+4 at 125 ℃) of from 10 to 100, preferably from 20 to 70, more preferably from 30 to 60(ASTM D1646).

In one embodiment, the ethylene/α -olefin interpolymer has a Tg less than-30 ℃, preferably less than-40 ℃, and more preferably less than-50 ℃.

In one embodiment, the ethylene/a-olefin interpolymer is a homogeneously branched linear ethylene/a-olefin interpolymer or a homogeneously branched substantially linear ethylene/a-olefin interpolymer.

In one embodiment, the ethylene/a-olefin interpolymer is a homogeneously branched linear ethylene/a-olefin interpolymer.

In one embodiment, the ethylene/a-olefin interpolymer is a homogeneously branched, substantially linear ethylene/a-olefin interpolymer.

The terms "homogeneous" and "homogeneously branched" are used in reference to an ethylene/α -olefin polymer (or interpolymer) wherein one or more comonomers are randomly distributed in a given polymer molecule and all polymer molecules have the same or substantially the same ratio of one or more comonomers to ethylene. Homogeneously branched ethylene interpolymers include linear ethylene interpolymers and substantially linear ethylene interpolymers.

Homogeneously branched linear ethylene interpolymers include ethylene interpolymers such as: such ethylene interpolymers lack a measurable amount of long chain branching, but do have short chain branches derived from the comonomer polymerized into the interpolymer, and they are uniformly distributed, whether within the same polymer chain or between different polymer chains. Commercial examples of homogeneously branched linear ethylene/α -olefin interpolymers include TAFMER polymers supplied by Mitsui Chemical Company and EXACT polymers supplied by ExxonMobil Chemical Company.

Commercial examples of homogeneously branched substantially linear ethylene/α -olefin interpolymers include ENGAGE polyolefin elastomers (The Dow Chemical Company) and AFFINITY polyolefin plastomers (The Dow Chemical Company). In addition, substantially linear ethylene interpolymers are homogeneously branched ethylene polymers having long chain branching. The long chain branches have about the same comonomer distribution as the polymer backbone, and may have about the same length as the length of the polymer backbone. The term "substantially linear" generally means that the polymer is substituted with an average of 0.01 long chain branches per 1000 total carbons (including backbone and branched carbons) to 3 long chain branches per 1000 total carbons. The length of the long chain branches is greater than the length resulting from incorporation of one comonomer unit into the polymer backbone.

Substantially linear ethylene interpolymers form a unique class of homogeneously branched ethylene polymers. Essentially, they differ from the well-known class of conventional homogeneously branched linear ethylene interpolymers described by Elston in U.S. patent No. 3,645,992, and they are not in the same class as conventional heterogeneously branched "Ziegler-Natta catalyst polymerized" linear ethylene polymers (e.g., Ultra Low Density Polyethylene (ULDPE), Linear Low Density Polyethylene (LLDPE), or High Density Polyethylene (HDPE), prepared, for example, using the techniques disclosed by Anderson et al in U.S. patent No. 4,076,698); they also do not belong to the same class as high pressure free radical initiated highly branched polyethylenes such as Low Density Polyethylene (LDPE), ethylene-acrylic acid (EAA) copolymers and ethylene/vinyl acetate (EVA) copolymers.

In one embodiment, the ethylene/α -olefin interpolymer has a PRR (process rheology ratio, described below) greater than, or equal to, 4, preferably greater than, or equal to, 8, more preferably greater than, or equal to, 12, and even more preferably greater than, or equal to, 18. In one embodiment, the ethylene/α -olefin interpolymer has a PRR from 8 to 70, preferably from 12 to 50, and more preferably from 18 to 30.

Interpolymer viscosities are conveniently measured in poise (dyne-sec/square centimeter (d-sec/cm) using a dynamic mechanical spectrometer (e.g., RMS-800 or ARES, from Rheometrics) under a dynamic scan from 0.1 to 100rad/sec using a shear rate in the range of 0.1 to 100rad/sec and at 190 ℃ under a nitrogen atmosphere²) ) meter. The viscosities at 0.1rad/sec and 100rad/sec, respectively, can be expressed as V_0.1And V₁₀₀The ratio of the two is called RR and denoted as V_0.1/V₁₀₀。

The PRR value is calculated by the following formula:

PRR ═ RR + [3.82 ] -interpolymer Mooney viscosity (ML at 125 ℃)₁₊₄)]X 0.3. The PRR assay is described in us patent 6,680,361, the entire contents of which are incorporated herein by reference. Ethylene/α -olefin interpolymers suitable for the present invention may be prepared by the process described in U.S. patent 6,680,361 (see also WO 00/26268). Examples of suitable interpolymers include ENGAGE 7487, ENGAGE 7387, and ENGAGE 6386 (all available from The Dow Chemical Company).

The ethylene/a-olefin interpolymer may comprise a combination of two or more embodiments as described herein.

Composition comprising a metal oxide and a metal oxide

The compositions of the present invention preferably contain from 60 to 90 weight percent, preferably from 65 to 85 weight percent, and more preferably from 70 to 75 weight percent of the propylene-based polymer, based on the total weight of the propylene-based polymer and the ethylene/α -olefin interpolymer. The compositions of the present invention preferably contain from 10 to 40 weight percent, preferably from 15to 37 weight percent, and more preferably from 20 to 35 weight percent of the ethylene/a-olefin interpolymer, based on the total weight of the propylene-based polymer and the ethylene/a-olefin interpolymer.

In one embodiment, the composition contains from 5to 35 wt% of fibrous filler, preferably from 10 to 30 wt%, and more preferably from 15to 25 wt%, based on the total weight of the composition.

In one embodiment, the composition contains from 15to 25 weight percent fibrous filler, preferably from 18 to 20 weight percent, and more preferably from 20 to 25 weight percent, based on the total weight of the composition.

In one embodiment, the composition contains from 5to 35 weight percent of the nitrogen-containing compound, preferably from 10 to 30 weight percent, and more preferably from 15to 25 weight percent, based on the total weight of the composition.

In one embodiment, the composition contains 5to 35 wt% of the phosphorus-containing compound, preferably 10 to 35 wt%, and more preferably 15to 25 wt%, based on the total weight of the composition.

In one embodiment, the crystallization temperature Tc of the composition is greater than or equal to 110 ℃, preferably greater than or equal to 120 ℃, and more preferably greater than or equal to 130 ℃, and most preferably greater than or equal to 140 ℃.

In one embodiment, the composition has an HDT of greater than or equal to 110 ℃, preferably greater than or equal to 120 ℃, and more preferably greater than or equal to 130 ℃, and most preferably greater than or equal to 140 ℃ as measured by ASTM D648.

In one embodiment, the composition is free of other propylene-based polymers other than the propylene-based polymer component.

In one embodiment, the composition contains greater than or equal to 50 weight percent, preferably greater than or equal to 60 weight percent, and more preferably greater than or equal to 70 weight percent of the propylene-based polymer, based on the total weight of the composition.

In one embodiment, the composition contains less than or equal to 40 weight percent, preferably less than or equal to 35 weight percent, and more preferably less than or equal to 30 weight percent of the ethylene/a-olefin interpolymer, based on the total weight of the composition.

In one embodiment, the composition is free of copolymers containing only ethylene and propylene monomer units.

In one embodiment, the composition is free of styrenic block copolymers.

In one embodiment, the composition contains only one ethylene/a-olefin interpolymer.

In one embodiment, the composition contains only one propylene-based polymer.

In one embodiment, the composition is free of EPDM polymer.

In one embodiment, the composition is free of EPR polymer.

In one embodiment, the composition is free of block copolymers.

In one embodiment, the composition is free of silicone polymers.

In one embodiment, the composition is free of polydimethylsiloxane.

In one embodiment, the composition is free of grafted ethylene-based polymers (e.g., maleic anhydride grafted ethylene-based polymers) or grafted propylene-based polymers (e.g., maleic anhydride grafted propylene-based polymers).

In one embodiment, the composition is free of grafted ethylene-based polymers (e.g., maleic anhydride grafted ethylene-based polymers), and free of grafted propylene-based polymers (e.g., maleic anhydride grafted propylene-based polymers).

The composition may further comprise at least one additive. These additives include, but are not limited to, process oils; an antioxidant; a surface tension modifier; an ultraviolet stabilizer; crosslinking agents such as peroxides; antimicrobial agents such as organometallic compounds, isothiazolones, organosulfur compounds and thiols; antioxidants such as phenolic compounds, secondary amines, phosphites and thioesters; antistatic agents such as quaternary ammonium compounds, amines and ethoxylated, propoxylated or glycerol compounds.

Definition of

The term "composition" as used herein includes mixtures of materials that make up the composition, as well as reaction products and decomposition products formed from the materials of the composition.

The term "polymer" as used herein refers to a polymeric compound prepared by polymerizing monomers, whether of the same type or of different types. Thus, the generic term polymer includes the term homopolymer (used to refer to polymers prepared from only one type of monomer) and the term interpolymer as defined below.

The term "interpolymer," as used herein, refers to a polymer prepared by the polymerization of at least two different types of monomers. The generic term interpolymer thus includes copolymers (used to refer to polymers prepared from two different types of monomers) and polymers prepared from more than two different types of monomers.

The term "ethylene-based polymer," as used herein, refers to a polymer comprising polymerized ethylene in a majority amount, based on the weight of the polymer.

The term "ethylene/a-olefin interpolymer," as used herein, refers to a polymer comprising a majority amount of polymerized ethylene (based on the weight of the interpolymer) and an a-olefin.

The term "ethylene/alpha-olefin copolymer," as used herein, refers to a polymer comprising a majority amount of polymerized ethylene (based on the weight of the copolymer) and an alpha-olefin as the only two monomer types.

The term "propylene-based polymer," as used herein, refers to a polymer comprising polymerized propylene in a majority amount, based on the weight of the polymer.

The term "propylene-based interpolymer," as used herein, refers to a polymer comprising a majority amount of polymerized propylene, based on the weight of the interpolymer, and at least one comonomer.

The term "blend" or "polymer blend" as used herein means a blend of two or more polymers. Such blends may be miscible (not phase separated at the molecular level) or immiscible. Such blends may be phase separated or non-phase separated. Such blends may or may not contain one or more domain structures, as determined by transmission electron microscopy, light scattering, x-ray scattering, and other methods known in the art.

The term "nitrogen source" as used herein refers to a compound (organic or inorganic) containing one or more nitrogen atoms, and is preferably an organic compound.

The term "phosphorus source" as used herein refers to a compound (organic or inorganic) containing one or more phosphorus atoms, and is preferably an organic compound.

The terms "comprising", "containing", "having" and derivatives thereof do not exclude the presence of any other component, step or operation, whether or not the same is explicitly disclosed. For the avoidance of any doubt, all compositions claimed through use of the term "comprising" may contain any other additive, adjuvant or compound, whether polymeric or otherwise, unless specified to the contrary. In contrast, the term "consisting essentially of excludes any other components, steps or operations from any subsequently listed range, except for those that are not necessary for operability. The term "consisting of" excludes any component, step, or operation not explicitly depicted or recited.

Measuring

The term "MI" denotes the melt index I2 or I in g/10min₂Ethylene-based polymers (majority weight percent polymerized ethylene based on the weight of the polymer) were measured using ASTM D-1238-04, condition 190 ℃/2.16 kg.

The term "MFR" refers to the melt flow rate, as measured using ASTM D-1238-04, condition 230 ℃/2.16kg for propylene-based polymers (majority weight percent polymerized propylene, based on the weight of the polymer).

Density is measured according to ASTM D-792-00. The measured density is "fast density", meaning that the density is determined after one hour of molding. The samples were compression molded at 190 ℃ for six minutes at low pressure (about 5000-.

Flexural (Flex) modulus (1% secant) was measured according to ASTM D-790 on "5 inch x 1/2 inch x 1/8 inch" test specimens (see Experimental section for injection molding conditions).

Heat distortion (deflection) temperature (HDT)

The test was performed on an injection molded (see experimental section) ASTM flex bar (ASTM D-790) to achieve the desired test span (neck of tensile specimen is too short). The rod dimensions were "5 inches x 1/2 inches x 1/8 inches". The tests were run according to ASTM D-648 (06). The test has two load options, data is reported at a lower load of 66psi (0.455 MPa).

tanδ

The test was a melt test, performed on discs cut from "1/8 inch thick (1 inch diameter)" test specimens from injection molded (see experimental section) ASTM D-790 tensile dog bone specimen. The sample is placed between two parallel plates of a dynamic mechanical spectrometer such as RMS-800 or ARES (from Rheometrics).

The tan delta (melt tan delta) test temperature was measured at 190 ℃. Polymer viscosity is measured in poise (dynes-sec/square centimeter (cm) using a dynamic mechanical spectrometer such as RMS-800 or ARES (from Rheometrics) under a nitrogen atmosphere at shear rates in the range of 0.1rad/sec to 100rad/sec and at 190 ℃. (Dadyne-sec/cm)²) And (6) counting. Reference is made to tan delta values at 0.1rad/sec and at 190 ℃.

Gel permeation chromatography

The average molecular weight and molecular weight distribution of the ethylene-based Polymer were determined using a gel permeation chromatography system consisting of a Polymer Laboratories, Model 200 series high temperature chromatograph. For ethylene-based polymers, the column and carousel compartments (carousel components) were operated at 140 ℃. The columns were three Polymer Laboratories 10-micron Mixed-B columns. The solvent is 1, 2, 4-trichlorobenzene. Samples were prepared at a concentration of 0.1 grams of polymer in 50 milliliters of solvent. The solvent was used as the mobile phase and, to prepare the samples, contained 200ppm of Butylated Hydroxytoluene (BHT). An ethylene-based polymer was prepared by gently shaking at 160 ℃ for 2 hours, and a propylene-based polymer was dissolved for 2.5 hours. The injection volume was 100 microliters, and the flow rate was 1.0 milliliters/minute. Calibration of the GPC column set was performed with narrow molecular weight distribution polystyrene standards of molecular weight 580-400,000 available from Polymer Laboratories (UK). The polystyrene standard peak molecular weight was converted to polyethylene molecular weight (as described in Williams and Ward, j.polym.sci., polym.let., 6, 621 (1968)) using the following equation:

m polyethylene ═ A × (M polystyrene)^B，

Where M is the molecular weight, A has a value of 0.4315 and B equals 1.0.

Polyethylene equivalent molecular weight calculations were performed using VISCOTEK TriSEC software version 3.0. The molecular weight of propylene-based polymers can be determined according to ASTM D6474.9714-1 using Mark-Houwink ratios, where a-0.702 and log K-3.9 for polystyrene and 0.725 and log K-3.721 for polypropylene. For the propylene-based samples, the column and carousel compartments were operated at 160 ℃.

Differential scanning calorimetry

Differential Scanning Calorimetry (DSC) can be used to measure crystallinity in ethylene-based (PE) samples (and compositions) and polypropylene-based (PP) samples (and compositions). The sample was pressed into a film at a temperature of 190 ℃. About 5-8 mg of the film sample was weighed and placed in a DSC pan. The lid was crimped to the pan to ensure a hermetic atmosphere. Place sample pan in DSCIn the compartment, and then heated at a rate of about 10 deg.C/min to a temperature of about 180 deg.C and 200 deg.C for PE (230 deg.C for PP). The sample was held at this temperature for 3 minutes. The sample is then cooled at a rate of 10 ℃/min, for PE to-90 ℃ (for PP, -90 ℃) and held at this temperature for 3-5 minutes. The sample was then heated at a rate of 10 ℃/min until completely melted (second heat; about 180 ℃ for PE and 230 ℃ for PP). Unless otherwise specified, the melting point (T) of each polymer sample was determined from the second heating curve obtained from DSC as described above_m) And glass transition temperature (Tg). Measuring the crystallization temperature (T) from the first cooling curve_c)。

UL 94-test

The test uses an "1/2 inch by 5 inch by 1/16 inch" specimen that is held in a vertical position at one end (via a clamp). The bunsen burner flame was applied to the free end of the specimen for two 10 second intervals separated by the time it took to extinguish after the first ignition. Groups of 5 specimens were tested. Three vertical ratings V2, V1, and V0 (best ratings) indicate that the material tested in a vertical position and self-extinguished within a specified time (as specified by ASTM D3801) after the ignition source was removed. The vertical rating also indicates whether the test sample drips a flaming particle that ignites a cotton indicator located below the sample.

The following examples illustrate the invention, but do not limit it, whether explicitly or implicitly. All parts and percentages are by weight unless otherwise indicated.

Experiment of

I. Different reinforcing fillers

The following reinforcing fillers were evaluated for flame retardant properties as shown in table 2.

TABLE 2

Reinforcing filler	Physical shape	Composition of	Specific gravity of
				CIMPACT 550C	Sheet-like shape	Talc	2.8
POLYFIL DL	Sheet-like shape	Kaolin clay	2.6
				POLYFIL DLX	Sheet-like shape	Kaolin clay	2.6
NYGLOS MSTPO	Fiber	Treated silica lime	2.9
				ASPECT 4000	Fiber	Silicon lime	2.9
ASPECT 4992	Fiber	Treated silica lime	2.9

Batch mixing of samples

Haake blending

The formulations shown in tables 3 and 4 were prepared in a heated laboratory mixer RHEOMIX 3000(414 cubic centimeter bowl capacity) with CAM type blades. To slightly increase the batch size, the filling degree was increased from 60% to 70% of the total mixer capacity. The mixer was connected to an RS5000 torque rheometer drive controlled by System 5 (PC based, control/data acquisition software designed to operate RS5000 drive). The quality of the mix was observed by continuous visual monitoring and temperature adjustments were made as needed.

For each formulation, the following conditions were used:

temperature: 170-190 ℃,

the filling factor is 60-70% by volume,

the air is cooled in a region 2 of the bowl,

RPM: an addition fraction of 10, then mixed to 55, an

Mixing time: 1500 seconds to 3000 seconds.

One or more polymer components of each formulation were added to a heated mixer at 10RPM (to minimize particle ejection during the addition step), and then the mixing speed was increased to 55RPM to obtain good melt plasticization of the polymer. The additives were then added at the measured levels. Mixing was continued until the sample appeared well mixed. The mixed formulation was removed and cooled.

Pelletized and UL-94 compression molded sheet

Each of the mixed formulations was granulated in a COLORTRONIC M103 granulator to form granulated samples.

Each granulated sample was pressed into a "4 inch x 0.0625 inch" slab using a CARVER hydraulic press set at 180 ℃ and 25000 psi. The panels for the UL-94 test were molded using TEFLON coated stainless steel die sleeves with outer dimensions "4 inches by 6 inches by 1/16 inches". The sample-containing mold sleeve was sandwiched between two PTFE (polytetrafluoroethylene) -covered aluminum sheets in the following layered structure: 1) a die sleeve holder, 2) MYLAR sheet, 3) stainless steel lapping plate, 4) MYLAR sheet, 5) PTFE-covered aluminum sheet, 6) a die sleeve containing the sample, 7) PTFE-covered aluminum sheet, 8) MYLAR sheet, 9) stainless steel lapping plate, and 10) MYLAR sheet. This layered structure was placed in a heated platen and a pressure of 25000psi was applied for 5-6 minutes. The molded samples were then transferred to a cold-pressed plate (set point 15 ℃) with a cooling time of at least 3 minutes. The samples were removed from the die case and the flash was trimmed using laboratory scissors. 5 sample bars (size 1/2 "x 5" x 1/16 ") for UL94 testing were cut from injection molded plaques (size 1/2" x 5 "x 1/16") using a vented hand punch press (model D.G.D., equipped with NAEF, manufactured by Switzerland, ASTM die-size 1/2 "x 5").

Injection molded samples for UL-94 testing

Pellets (from the compound prepared on a batch mixer) were injection molded on an ARBURG ALL-ROUNDER, 80 ton injection molding machine or made on a ZSK-25 extruder (described below). This molding machine was fitted with a "4 inch by 6 inch" sheet mold having a thickness of 1/16 inches. Samples for UL94 were die cut from these sheets.

Of major concern in injection molding is the minimization of thermal decomposition of the polymer during injection molding and the avoidance of "tiger stripes" in these sheets as much as possible. Since a "high isotactic index" homopolymer polypropylene grade was used, the peak melting temperature was 165-169 ℃. To avoid thermal decomposition and still melt the polypropylene, the barrel temperature was set between 170 ℃ and 190 ℃. For thin specimens, by increasing the mold temperature, drag at the mold wall is minimized. The mold temperature was initially set at 60 c but later set as high as 75 c to avoid higher melting temperatures and/or tiger stripes. The injection rate was checked between 10 and 20 cubic centimeters per second (cc/s) to find the optimum velocity for each material.

These samples were molded at a 15bar (1bar equals 14.5psi) back pressure setting. This is the polymer pressure or unit pressure, as opposed to the hydraulic pressure. The polymer pressure is equal to the hydraulic pressure times the intensification ratio (the ratio of the surface area of the "hydraulic ram" to the "screw surface area"). Thus, the 15bar setting is 10 times lower than the expected matching "100 psi hydraulic". It should be noted that higher back pressures are known to improve melt homogenization.

The molding compound was distributed in a flat barrel at 190 ℃. Samples of siliceous lime were molded acceptably under these conditions, although slight tiger stripes were observed when filling "1/16 inch thick" 6 inch long "boards. Under these conditions, there is evidence that the three-component additive system results in film formation on the mold. The barrel temperature was reduced and the back pressure was increased (to achieve better mixing without higher barrel temperatures) until the elimination of "film build up" on the die and tiger stripes on "1/16 inch" thick sheet material were observed.

Filler loading 10 wt% -20 wt%

This study evaluated the performance differences between two grades of kaolin clay, platy talc and three grades of silica fume at a "10 weight percent" loading (based on the total weight of the formulation). Representative grades were also evaluated at "15 wt%" filler loading. Formulation and Flame Retardant (FR) properties are shown in table 3.

Table 3: formulations (10 and 15 wt% filler) and FR Properties-all Haake blending and compression Molding

Molded samples	6-1	6-2	6-3	6-4	6-5	6-6	6-7	6-8	6-9
										D18(1)	45	45	45	45	45	43	43	43	43
EO87(2)	19	19	19	19	19	18	18	18	18
										POLYFIL DLX	10
POLYFIL DL		10						15
										CIMPACT 550C			10						15
NYGLOS MSTPO				10
										ASPECT 4000					10
ASPECT 4992						10	15
										Phosphorus/nitrogen flame retardants A	25	25	25	25	25	25	24	24	24
UL-94t1 (seconds)	13	6	6	6	7	7	8	＞130	23
										t2 (seconds)	＞180	28	15	20	12	24	＞87	BC(3)	BC(3)
Rating	NR(3)	V-0	V-0	V-0	V-0	V-0	V-2	NR(4)	NR(4)

(1) D18 is a polypropylene homopolymer (flexural modulus 2070MPa, HDT 120 ℃, density 0.90 g/cc).

(2) EO87 is a homogeneously branched, substantially linear ethylene/butene copolymer (Tg-57 ℃, Tm 37 ℃, tan δ 2.1(190 ℃, 0.1rad/sec), HDT (failure), density 0.86g/cc, mooney viscosity (ML 1+4 at 125 ℃) 44).

(3) BC ═ burned to the clamp (sample failed).

(4) NR ═ not rated (sample failed).

With a "10 wt%" filler loading, all samples, except sample 6-1(POLYFIL DLX), achieved a UL V-0 rating, as shown in Table 2 above. At "15 wt%" filler loading, only samples 6-7(ASPECT 4992 and D18 matrix) exhibited evidence of improved swelling behavior when tested. To reduce sag and dripping in some samples, a higher viscosity (lower MFR) propylene-based polymer was used-see table 4 (UL-94 performance for higher viscosity polypropylene with "15 wt%" and "20 wt%" filler loading).

Table 4: formulations (15 wt% and 20 wt% filler) and FR Properties-all Haake blending and injection Molding

Molded sample numbering	12-1	12-2	12-3	12-5	12-6
						D18(MFR 8)	42.84	42.84	44.96
D02*(MFR 2)			42.84		44.96

EO 87	18.36	18.36	18.36	11.24	11.24
						ASPECT 4992	15		15	20	20
ASPECT 4000		15
						Phosphorus/nitrogen flame retardants A	23.8	23.8	23.8	23.8	23.8
UL-94t1 (seconds)	9	8	5	10	10
						t2 (seconds)	19	＞150	20	＞140	27
Rating	V-0	BC**	V-0	NR＊＊＊	V-0

D02 is a polypropylene homopolymer (flexural modulus 2070MPa, HDT 130 ℃, density 0.90 g/cc).

BC: burn to clamp (sample not passed).

NR: not rated (sample failed).

On the second ignition of the sample, a faster self-extinguishing time was observed in sample 12-1. This allowed a "15 wt%" filler loading and a "70: 30 PP: samples at the elastomer "level (12-1 and 12-3) achieved a" UL-94V-0 "rating. Sample 12-2 (70: 30 PP: elastomer based on D18) was burned into the jig as the sagging sample destroyed any char layer formed and exposed the original polymer to the flame. The use of a "20 wt%" filler loading in sample 12-5 did not result in a V-0 rating. In the second ignition, the higher melt flow (MFR 8) of the PP gives a longer extinguishing time. The use of a polypropylene homopolymer with a lower MFR (MFR 2) enables the use of a "20 wt%" filler loading and results in a V-0 rating (see samples 12-6).

Overall, higher filler levels lead to more challenges for intumescent FR additives. With increasing filler levels, other factors such as melt flow rate and FR additive levels of the propylene-based polymer become more important to passing the UL-94 test. As shown in table 4, samples based on either D18(8MFR) and D02(2MFR) were able to achieve a "UL-94V-0" rating at a "15 wt%" filler loading. This rating was achieved based on the D02 sample alone, at "20 wt%".

Extruded samples

Twin screw compounding was carried out on a ZSK 25 MEGACOMPOUNDER, fully intermeshing twin screw extruder (available from Coperion). This extruder outputs "82N-m/shaft" at 1200 rpm. The extruder had a cooled feed head and eleven separate controlled heating zones. The extruder was equipped with three K-Tron gravimetric feeders with single screw augers for controlled feeding of polymer pellets. The fourth K-Tron gravimetric feeder was equipped with a twin screw auger for controlled feeding of the powder ingredients and was positioned in a feed side arm extruder. The side arm extruder entered the main extruder at a point midway between the feed port and the die. The extruder is equipped with a four-hole die head.

Two pass mixing

The FR additive and reinforcing filler were fed into the extruder using a "two pass" compounding process. Reinforcing filler is added to a sidearm extruder on the first pass to form a TPO pre-formulation, and pellets of the TPO pre-formulation are collected. The FR additive is then added to the pre-formulation in a second pass to achieve the final extruded formulation.

TPO pre-formulations were prepared under standard conditions, supplied at 50lb/hr and utilized a flat temperature profile of 200 ℃. Inserts associated with a "talc stack" and vacuum devolatilization vents were inspected before and after each run. The melt was extruded through a four-hole die and cooled in a water bath, and then the strands were cut to make pellets. Residual heat in the pellets makes drying unnecessary.

A primary concern with the second channel is to avoid degradation of the expansion mechanism due to thermal decomposition or exposure to moisture. Temperature management requires attention not only to temperature settings but also to the heat generated by shear heating in a twin screw extruder.

Two methods are used to control the temperature on the second channel. The barrel temperature setting was ramped to start high to melt the propylene-based polymer and then decreased in a subsequent zone so that the polymer was near 170 ℃, in which case the FR additive was added with a side arm extruder. The extruder RPM was set at 200 with a target of 30lb/hr output to reduce specific energy and hence shear heating. This helps to minimize the difference between the temperature set point and the actual measured melt temperature.

Single-channel mixing

The FR additive was supplied into the throat of the extruder and the reinforcing filler was supplied to the extruder using a side arm. This formulation was used as a control. For the second test, the powder additive and silica fume fibers were pre-blended and added with a side arm inlet. Processing the silica fume with the unmelted pellets results in excessive breakage of the fibers and potential wear on the extruder (mohs hardness of silica fume 4.5).

Subsequently, the single pass blend was replicated by blending the silica lime and FR additive in a HENSCHEL mixer. The pre-blend is then added to a side arm extruder used to feed the twin screw extruder. This leads to problems due to the low bulk density of the pre-blend. To ensure that the material does not back up in the throat, the RPM of the twin screw extruder was increased to 600 and the throughput was reduced by 20% to 40 lb/hr. Both factors increase the specific energy and therefore the melting temperature of the polymer.

When the fibers were processed through the extruder only once, less fiber breakage was observed, which resulted in less reduction of the reinforcing effect of the fibers. For the system containing "20 wt%" ASPECT 4992 (sample 70-2 of Table 5), this resulted in a higher flexural modulus. This also resulted in an approximately "20% higher flexural modulus" compared to the "20 wt% filler" sample (sample 66-6) made via the two-step compounding process. This improved flexural modulus was slightly higher than that achieved with the "25 wt%" filler loading (sample 66-8). These results are shown in table 5 below.

Table 5: extruder-single and dual channel-all extrusion and injection molding

One of the 5 bars tested burned for more than 30 seconds

Additional formulations

The following additional formulations were examined using the UL-94 flammability test, as shown in Table 6. Each sample formulation was prepared by Haake blending as described above. Each of the blended formulations was granulated and then compression molded into plaques for UL-94 test specimens as described above. Both samples were burned to a clamp (no pass). The presence of MAH-grafted ethylene-based polymer and silicone polymer did not improve the swelling behavior of these samples.

Table 6: additional formulations

	Sample 1	Sample 2
				Number of parts	Number of parts
D18	42.84	42.84
			EO 87	18.36	18.36
ASPECT 4000	15	15
			MAH-G-PE*	0	2
Siloxane polymer masterbatch	1.5	1.5
			Phosphorus/nitrogen flame retardants A	23.3	23.8
IRGANOX B225	0.2	0.2

Maleic anhydride grafted ethylene-based polymer, 0.8 wt% MAH, I2 ═ 1.25g/10min (190 ℃, 2.16 kg).

DOW CORNING MB50-002 (Silicone Polymer dispersed in Low Density polyethylene)

Although the present invention has been described in some detail in the foregoing detailed description of the embodiments, such detail is presented primarily for purposes of illustration. Numerous changes and modifications may be made by those skilled in the art without departing from the spirit and scope of the invention as defined in the following claims.

Claims

1. A polyolefin composition comprising:

C) a fibrous filler; and

2. The composition of claim 1, wherein the filler is a calcium-based filler.

3. The composition of any of the preceding claims, wherein the total weight of components A, B, C and D is greater than or equal to 95 weight percent, based on the total weight of the composition.

4. The composition of any of the foregoing claims, wherein the composition has a Heat Deflection Temperature (HDT) of greater than about 100 ℃ and a flexural modulus of greater than about 1930 MPa.

5. The composition of any of the preceding claims, wherein the fibrous filler is present in an amount greater than 15 weight percent, based on the weight of the composition.

6. The composition of any one of the preceding claims, wherein the nitrogen source is derived from at least one organic compound selected from the group consisting of: melamine, melamine cyanurate, melamine borate, melamine phosphate, melamine polyphosphate, melamine pyrophosphate, ethylenediamine, and tris (hydroxyethyl) isocyanurate.

7. The composition of any of claims 1-5, wherein the phosphorus source is derived from at least one compound selected from the group consisting of: a phosphate compound, a phosphinate compound, a phosphonate compound, a polyphosphate compound, and a phosphine oxide.

8. The composition of any of the preceding claims, wherein the propylene-based polymer is a propylene homopolymer having a flexural modulus greater than 1930 MPa.

9. A polyolefin composition comprising:

A) propylene-based polymerization with flexural modulus greater than 1500MPa and HDT greater than 100 ℃

C) a fibrous filler; and

10. The composition of claim 9, wherein the filler is a calcium-based filler.

11. The composition of any one of claim 9 or claim 10, wherein the composition has a Heat Deflection Temperature (HDT) greater than about 100 ℃ and a flexural modulus greater than about 1930 MPa.

12. The composition of any of claims 9-11, wherein the fibrous filler is present in an amount greater than 15 weight percent, based on the weight of the composition.

13. The composition of any one of claims 9 to 12, wherein the nitrogen source is derived from at least one organic compound selected from the group consisting of: melamine, melamine cyanurate, melamine borate, melamine phosphate, melamine polyphosphate, melamine pyrophosphate, ethylenediamine, and tris (hydroxyethyl) isocyanurate.

14. The composition of any of claims 9-12, wherein the phosphorus source is derived from at least one compound selected from the group consisting of: a phosphate compound, a phosphinate compound, a phosphonate compound, a polyphosphate compound, and a phosphine oxide.

15. An article comprising at least one component formed from the composition of any of the preceding claims.