CN113227240A

CN113227240A - Heavy type layered pad

Info

Publication number: CN113227240A
Application number: CN202080007488.4A
Authority: CN
Inventors: S·M·阿布巴卡尔; 胡炜; 葛玲; 张以远
Original assignee: ExxonMobil Chemical Patents Inc
Current assignee: ExxonMobil Chemical Patents Inc
Priority date: 2019-02-22
Filing date: 2020-02-06
Publication date: 2021-08-06
Also published as: WO2020171964A8; EP3927769A1; WO2020171964A1

Abstract

A composition suitable for forming a heavy layer of a heavy layered mat and comprising: 5 wt% to 30 wt% of a propylene-based elastomer; 5 wt% -30 wt% of low density polyethylene; 0 wt% to 15 wt% of linear low density polyethylene; 50 wt% -90 wt% of filler; and 0.1 wt% -5 wt% of processing aid. Optionally, the composition may further comprise 0.1 wt% to 20 wt% of a stabilizer and/or an antioxidant. Optionally, the composition may also include 0.1 wt% to 10 wt% of an EVA copolymer, or the composition may be free of EVA copolymers.

Description

Heavy type layered pad

Cross Reference to Related Applications

The present application claims priority from u.s.s.n.62/809,219 filed on 22/2/2019 and EP application 19173686.7 filed on 10/5/2019, which are incorporated herein by reference.

Background

The present disclosure relates to heavy duty layered mats (heavy layered mats) used, for example, as sound insulation in vehicles.

In automotive technology, heavy-duty layer moldings or heavy-duty layered mats are used in particular for sound insulation in the passenger compartment for protection against engine and driving noise. Also, the heavy-duty layered pad is used for sound attenuation of the vibrating vehicle body (vehicle body noise damping).

The heavy duty layered pad includes an acoustically insulative heavy duty layer and a foam layer and/or a pile fabric layer. The heavy-duty layer is made of an ethylene-vinyl acetate (EVA) copolymer and/or an ethylene-propylene-diene monomer (EPDM) rubber, and contains a filler such as calcium carbonate or barium sulfate. The heavy layer has a high weight. In general, it has a density of 2kg/m²-4kg/m²Weight per unit area of, sometimes even 4kg/m²-8kg/m²Weight per unit area of (c).

Typically, the heavy-duty layer is molded into the desired shape prior to application of the foam and/or fleece layer. However, heavy layers made with EPDM rubber can vary in thickness and produce non-uniform thickness during the pre-heating step and cracking or breaking associated with the application of the additional layer(s) during the thermoforming step. It is believed that this thickness variation is caused by insufficient melt strength of the EPDM. The inclusion of the EVA copolymer increases melt strength, but the EVA copolymer can impart a residual vinegar taste to the reformed layer. Newer heavy duty layer formulations have included Linear Low Density Polyethylene (LLDPE) to increase melt strength. However, when a heavy layered mat is prepared with this composition, cracking and breaking of the heavy layer is still observed.

Disclosure of Invention

The present disclosure relates to heavy duty layered mats, for example, for use as sound insulation in vehicles.

An embodiment of the invention is a composition comprising: 5 wt% to 30 wt% of a propylene-based elastomer; 5 wt% -30 wt% of low density polyethylene; 0 wt% to 15 wt% of linear low density polyethylene; 50 wt% -90 wt% of filler; and 0.1 wt% -5 wt% of processing aid. Optionally, the composition may further comprise 0.1 wt% to 20 wt% of a stabilizer and/or an antioxidant. Optionally, the composition further may comprise 0.1 wt% to 10 wt% of an EVA copolymer, or the composition is substantially free of EVA copolymers.

Another embodiment is a heavy duty layered pad comprising: a heavy layer composed of the above composition; and a polyurethane layer on a surface of the heavy duty cushion layer.

Yet another embodiment is a heavy-duty layered pad comprising: a heavy layer consisting of the aforementioned composition; a polyurethane foam layer on a surface of the reforming layer; and a plurality of fibers on the polyurethane foam layer such that the polyurethane foam layer is between the heavy-duty layer and the plurality of fibers.

Another embodiment is a heavy duty layered pad comprising: a heavy layer consisting of the aforementioned composition; a polyurethane foam layer on a surface of the reforming layer; and a multilayer adhesive film on the polyurethane foam layer such that the polyurethane foam layer is between the reforming layer and the multilayer adhesive film, wherein the multilayer adhesive film comprises a polar layer and a non-polar layer.

Another embodiment is a method comprising: thermoforming a polymer sheet having a surface and a back surface with a mold to produce a molded polymer sheet, the polymer sheet comprising: the above composition; and injecting a polyurethane foam into the mold such that the polyurethane foam is on the back surface of the molded polymer sheet.

Drawings

The following drawings are included to illustrate certain aspects of embodiments and should not be considered exclusive embodiments. The disclosed subject matter is capable of considerable modification, alteration, combination, and equivalents in form and function, as will occur to those ordinarily skilled in the pertinent art and having read this disclosure.

Fig. 1 is an overview of the steps of an embodiment method 100 of forming a heavy-duty layer and a heavy-duty layered pad.

FIG. 2 is at 0.01s^-1Extensional viscosity (extensional viscosity) measurements of various samples at strain rate.

FIG. 3 is at 0.1s^-1Extensional viscosity measurements of various samples at strain rate.

FIG. 4 is a graph showing a graph at 1s^-1Extensional viscosity measurements of various samples at strain rate.

FIG. 5 is a graph showing the result at 10s^-1Extensional viscosity measurements of various samples at strain rate.

Fig. 6 is the maximum elongation viscosity (elongation viscocity) of various samples at various strain rates.

FIG. 7 is the tensile strength of various injection molded samples.

FIG. 8 is the flexural modulus of various injection molded samples.

Figure 9 is Izod test measurements of various samples at room temperature and low temperature.

FIG. 10 is at 0.01s^-1Extensional viscosity measurements of various samples at strain rate.

FIG. 11 is at 0.1s^-1Extensional viscosity measurements of various samples at strain rate.

FIG. 12 is a graph showing a graph at 1s^-1Extensional viscosity measurements of various samples at strain rate.

FIG. 13 shows the result at 10s^-1Extensional viscosity measurements of various samples at strain rate.

FIG. 14 is the maximum elongational viscosity at various strain rates for various samples.

Fig. 15 is a picture of cracks in the molded specific gravity type layer.

Fig. 16 is a photograph of a molded inventive heavy-weight layer without cracks.

Detailed Description

The present disclosure relates to heavy duty layered mats, for example, for use as sound insulation in vehicles. More specifically, the present invention includes heavy-duty layer compositions having sufficiently improved melt strength to be processed by conventional methods to produce heavy-duty layered mats. In addition, the heavy-duty layer compositions described herein are preferably substantially free of EVA copolymers and thus have no vinegar odor associated therewith.

The heavy-duty layer composition of the present invention may comprise from 5 wt% to 30 wt% of a propylene-based elastomer; 5 wt% to 30 wt% of a Low Density Polyethylene (LDPE) having a melt index (ASTM D1238-13, 2.16kg, 190 ℃) of 0.5g/10min to 1.5g/10 min; 0 wt% to 15 wt% LLDPE; 50 wt% -90 wt% of filler; and 0.1 wt% -5 wt% of processing aid. Optionally, the composition may further comprise 0.1 wt% to 20 wt% of a stabilizer and/or an antioxidant. Optionally, the composition further may comprise 0.1 wt% to 10 wt% of an EVA copolymer, or the composition is substantially free of EVA copolymers. Without wishing to be bound by theory, it is believed that LDPE instead of part or all of the LLDPE improves the melt strength of the formulation and produces a heavy-duty layer that is more effective for making high quality heavy-duty layered mats.

Definition of

As used herein, "wt%" means wt%, "mol%" means mol%, "vol%" means volume%, all molecular weights, e.g., Mw, Mn, Mz, are in g/mol, unless otherwise specified. In addition, all molecular weights are Mw unless otherwise specified.

The term "polymer" refers to any carbon-containing compound having repeating units derived from one or more different monomers, and includes homopolymers, copolymers, terpolymers, and the like. A "copolymer" is a polymer having two or more monomer units that are different from each other. A "terpolymer" is a polymer having three monomer units that differ from each other. Thus, the definition of copolymer as used herein includes terpolymers and the like.

As used herein, when a polymer is said to comprise a monomer, the monomer is present in the polymer in the polymerized form of the monomer or in the form of a derivative of the monomer. As used herein, "derived units" refers to the polymerized form of the monomer from which the polymer is derived. For example, when a copolymer is said to have an "ethylene" content of 35 wt% to 55 wt%, it is understood that the monomer units in the copolymer are derived from ethylene in the polymerization reaction and the derived units are present at 35 wt% to 55 wt% based on the weight of the copolymer. In addition, the polyethylene comprises ethylene derived units. In addition, the propylene/ethylene/butene terpolymer comprises propylene derived units, ethylene derived units, and butene derived units.

As used herein, "elastomer" or "elastomer composition" refers to any polymer or combination of polymers (e.g., a blend of polymers) as defined in accordance with ASTM D1566-11. Elastomers include mixed blends of polymers, such as melt-mixed and/or reactor blends of polymers. The term may be used interchangeably with the term "rubber(s)".

As used herein, the terms "low density polyethylene" and "LDPE" are meant to have a density of 0.915g/cm³-0.935g/cm³A density of from 0.2g/10min to 10g/10min (ASTM D1238-13, 2.16kg, 190 ℃) and a melt flow ratio (ASTM D1238-13, 21.6kg, 190 ℃ divided by ASTM D1238-13, 2.16kg, 190 ℃) of greater than 40.

As used herein, the terms "linear low density polyethylene" and "LLDPE" are meant to have a density of 0.900g/cm³-0.955g/cm³A density of from 0.1g/10min to 30g/10min (ASTM D1238-13, 2.16kg, 190 ℃) and a melt flow ratio of from 15 to 40 (ASTM D1238-13, 21.6kg, 190 ℃ divided by ASTM D1238-13, 2.16kg, 190 ℃).

As used herein, a composition that is "substantially free of" a material means that the composition does not contain any amount of the material or the amount of the material is so small that the material does not materially affect the basic and novel characteristic(s) of the composition. In particular, for EVA, a composition that is substantially free of EVA may contain no EVA (0 wt%), or it may contain a small amount of EVA that does not cause a vinegar smell or affect the melt strength of the composition.

Propylene-based elastomers

The propylene-based elastomer may be propylene-derived units and derived from ethylene or C₄-C₁₀Copolymers of units of at least one of the alpha-olefins. The propylene-based elastomer may contain at least 60 wt% propylene-derived units, based on the weight of the propylene-based elastomer. The propylene-based elastomer may have limited crystallinity due to adjacent isotactic propylene units and a melting point as described herein. The crystallinity and melting point of propylene-based elastomers are reduced compared to highly isotactic polypropylene due to the introduction of errors in the insertion of propylene. Propylene-based elastomers are generally free of any significant intermolecular heterogeneity in tacticity and comonomer composition, and are also generally free of any significant heterogeneity in intramolecular composition distribution.

The amount of propylene-derived units present in the propylene-based elastomer can be present in an amount of at least 60 wt%, at least 65 wt%, at least 70 wt%, at least 75 wt%, at least 80 wt%, at least 84 wt%, at least 85 wt%, at least 88 wt%, at least 90 wt%, at least 92 wt%, at least 94 wt%, at least 96 wt%, or at least 98 wt% of the propylene-based elastomer. Additionally or alternatively, the amount of propylene-derived units present in the propylene-based elastomer may be present in an amount of up to 98 wt%, up to 96 wt%, up to 94 wt%, up to 92 wt%, up to 90 wt%, up to 88 wt%, up to 85 wt%, up to 84 wt%, or up to 80 wt% of the propylene-based elastomer. Specifically disclosed ranges include combinations of any of the above listed values, such as 60 wt% -98 wt%, 70 wt% -98 wt%, 80 wt% -98 wt%, 85 wt% -98 wt%, 90 wt% -98 wt%, 70 wt% -96 wt%, 75 wt% -96 wt%, 80 wt% -96 wt%, 85 wt% -96 wt%, 90 wt% -96 wt%.

Derived from ethylene or C₄-C₁₀The units, or comonomers, of at least one of the alpha-olefins may be present in an amount of 1 wt% to 35 wt%, or 2 wt% to 35 wt%, or 5 wt% to 35 wt%, or 7 wt% to 32 wt%, or 8 wt% to 25 wt%, or 10 wt% to 25 wt%, orFrom 12 wt% to 20 wt%, or from 8 wt% to 18 wt%, or from 5 wt% to 20 wt%, or from 5 wt% to 15 wt%, or from 2 wt% to 10 wt%, or from 2 wt% to 6.0 wt%, based on the weight of the propylene-based elastomer.

In a preferred embodiment, the comonomer is ethylene, 1-hexene or 1-octene. In some embodiments, the propylene-based elastomer comprises or consists essentially of ethylene-derived units or units derived from propylene and ethylene, i.e., the propylene-based elastomer does not contain any other comonomer in amounts other than those typically present as impurities in the ethylene and/or propylene feed streams used during polymerization, or does not contain any other comonomer in amounts that would significantly affect the 1% secant flexural modulus and/or melt mass flow rate of the propylene-based elastomer, or does not contain any other comonomer intentionally added to the polymerization process. In such embodiments, the propylene-based elastomer may comprise from 2 wt% to 25 wt%, or from 5 wt% to 25 wt%, or from 10 wt% to 25 wt%, or from 6 wt% to 22 wt%, or from 12 wt% to 20 wt%, or from 7 wt% to 20 wt%, or from 5 wt% to 15 wt%, or from 8 wt% to 17 wt%, or from 9 wt% to 16 wt%, or from 2 wt% to 10 wt%, or from 2 wt% to 6.0 wt% ethylene-derived units, based on the weight of the propylene-based elastomer.

The propylene-based elastomer may comprise more than one comonomer. Preferred embodiments of propylene-based elastomers having more than one comonomer include propylene-ethylene-octene, propylene-ethylene-hexene, and propylene-ethylene-butene polymers. In which more than one group derived from ethylene or C is present₄-C₁₀In embodiments where the comonomer of at least one of the alpha-olefins is less than 5 wt% of the propylene-based elastomer, but the total amount of comonomer of the propylene-based elastomer is 5 wt% or greater of the total propylene-based elastomer.

In some embodiments, the propylene-based elastomer may further comprise a diene. The optional diene can be any hydrocarbon structure having at least two unsaturated bonds, wherein at least one unsaturated bond is readily incorporated into the polymer. For example, the optional diene may be selected from linear acyclic olefins such as 1, 4-hexadiene and 1, 6-octadiene; branched acyclic olefins such as 5-methyl-1, 4-hexadiene, 3, 7-dimethyl-1, 6-octadiene and 3, 7-dimethyl-1, 7-octadiene; monocyclic alicyclic olefins such as 1, 4-cyclohexadiene, 1, 5-cyclooctadiene and 1, 7-cyclododecadiene; polycyclic cycloaliphatic fused and bridged cycloalkenes, such as tetrahydroindene, norbornadiene, methyl-tetrahydroindene, dicyclopentadiene, bicyclo (2.2.1) -hepta-2, 5-diene, norbornadiene, alkenylnorbornene, alkylidenenorbornene, such as ethylidene norbornene ("ENB"), cycloalkenyl norbornene and cycloalkylidene norbornene (e.g., 5-methylene-2-norbornene, 5-ethylidene-2-norbornene, 5-propenyl-2-norbornene, 5-isopropylidene-2-norbornene, 5- (4-cyclopentenyl) -2-norbornene, 5-cyclohexylidene-2-norbornene, 5-vinyl-2-norbornene); and cycloalkenyl-substituted alkenes such as vinylcyclohexene, allylcyclohexene, vinylcyclooctene, 4-vinylcyclohexene, allylcyclodecene, vinylcyclododecene and tetracyclo (A-11,12) -5, 8-dodecene. The amount of diene-derived units present in the propylene-based elastomer can be from an upper limit of 15 wt%, 10 wt%, 7 wt%, 5 wt%, 4.5 wt%, 3 wt%, 2.5 wt%, or 1.5 wt% to a lower limit of 0%, 0.1 wt%, 0.2 wt%, 0.3 wt%, 0.5 wt%, or 1 wt%, based on the total weight of the propylene-based elastomer. In some embodiments, the propylene-based elastomer does not contain any diene-derived units.

The propylene-based elastomer may have a pass through of at least 75%, at least 80%, at least 82%, at least 85%, or at least 90%¹³C NMR measured triad tacticity of three propylene units. Preferably, the propylene-based elastomer has a triad tacticity of 50% to 99%, 60% to 99%, 75% to 99%, or 80% to 99%. In some embodiments, the propylene-based elastomer may have a triad tacticity of 60% to 97%.

The propylene-based elastomer can have a DS as described herein of 75J/g or less, 70J/g or less, 50J/g or less, or 45J/g or less, or 35J/g or lessC measured Heat of fusion, (. DELTA.H)_f"). The propylene-based elastomer can have a lower limit Δ H of 0.5J/g, 1J/g, or 5J/g_f. For example,. DELTA.H_fValues can range anywhere from 1.0J/g, 1.5J/g, 3.0J/g, 4.0J/g, 6.0J/g, or 7.0J/g to 30J/g, 35J/g, 40J/g, 50J/g, 60J/g, 70J/g, or 75J/g.

The propylene-based elastomer may have a percent crystallinity of from 2% to 65%, or from 0.5% to 40%, or from 1% to 30%, or from 5% to 35% of the crystallinity of isotactic polypropylene as determined according to the DSC procedure described herein. The maximum order heat energy (i.e., 100% crystallinity) of propylene was estimated to be 189J/g. In some embodiments, the copolymer has a crystallinity of less than 40%, or 0.25% to 25%, or 0.5% to 22% of the isotactic polypropylene. Embodiments of the propylene-based elastomer may have a tacticity index m/r from a lower limit of 4 or 6 to an upper limit of 8 or 10 or 12. In some embodiments, the propylene-based elastomer has an isotacticity index greater than 0%, or in a range having an upper limit of 50% or 25% and a lower limit of 3% or 10%.

The propylene-based elastomer may have a 1% secant flexural modulus of at least 5.0MPa, at least 10MPa, at least 20MPa, at least 30MPa, at least 40MPa, at least 50MPa, at least 60MPa, at least 70MPa, at least 80MPa, at least 90MPa, at least 100MPa, at least 125MPa, at least 150MPa, at least 175MPa, at least 200MPa, at least 225MPa, at least 250MPa, at least 275MPa, at least 300MPa, at least 325MPa, at least 350MPa, at least 375MPa, at least 400MPa, at least 425MPa, at least 450MPa, at least 475MPa, or 500MPa measured according to ASTM D790-17. Additionally or alternatively, the propylene-based elastomer may have a 1% secant flexural modulus measured according to ASTM D790-17 of at most 500MPa, at most 475MPa, at most 450MPa, at most 425MPa, at most 400MPa, at most 375MPa, at most 350MPa, at most 325MPa, at most 300MPa, at most 275MPa, at most 250MPa, at most 225MPa, at most 200MPa, at most 175MPa, at most 150MPa, at most 125MPa, at most 100MPa, at most 90MPa, at most 80MPa, at most 70MPa, at most 60MPa, at most 50MPa, at most 40MPa, at most 30MPa, at most 20MPa, at most 10MPa, or 5.0 MPa. Specifically disclosed ranges include any combination of the above recited values such as 5.0MPa-500MPa, 5.0-250MPa, 5.0MPa-100MPa, 5.0MPa-50MPa, 5MPa-20MPa, 20MPa-500MPa, 20MPa-250MPa, 20MPa-100MPa, 20MPa-50MPa, 40MPa-500MPa, 40MPa-250MPa, 40-100MPa, 40MPa-70MPa, 40MPa-60MPa, 50MPa-500MPa, 50MPa-250MPa, 50MPa-100MPa, 100MPa-500MPa, 100MPa-250MPa, 200MPa-500MPa, 200MPa-450MPa, 200MPa-400MPa, 200MPa-350MPa, 200MPa-300MPa, 300MPa-500MPa, 300MPa-450MPa, 300MPa-400MPa, 300MPa-350MPa, 350MPa-500MPa, 350MPa-450MPa, 350MPa to 400 MPa.

The propylene-based elastomer can have a melt mass flow rate of at least 5g/10min, at least 15g/10min, at least 50g/10min, at least 100g/10min, at least 1,000g/10min, at least 2,500g/10min, at least 5,000g/10min, at least 7,500g/10min, at least 10,000g/10min, at least 12,500g/10min, at least 15,000g/10min, at least 17,500g/10min, at least 20,000g/10min, at least 22,500g/10min, at least 25,000g/10min, at least 27,500g/10min, or 30,000g/10min, measured according to ASTM D1238-13(2.16kg, 230 ℃). Additionally or alternatively, the propylene-based elastomer can have a melt mass flow rate of at most 30,000g/10min, at most 27,500g/10min, at most 25,000g/10min, at most 22,500g/10min, at most 20,000g/10min, at most 17,500g/10min, at most 15,000g/10min, at most 12,500g/10min, at most 10,000g/10min, at most 7,500g/10min, at most 5,000g/10min, at most 2,500g/10min, at most 1,000g/10min, at most 100g/10min, at most 50g/10min, at most 15g/10min, or 5g/10min, measured according to ASTM D1238-13(2.16kg, 230 ℃). Specifically disclosed ranges include any combination of the above recited values such as 5g/10min to 30,000g/10min, 5g/10min to 20,000g/10min, 5g/10min to 10,000g/10min, 5g/10min to 1,000g/10min, 5g/10min to 100g/10min, 5g/10min to 50g/10min, 5g/10min to 15g/10min, 1,000g/10min to 30,000g/10min, 1,000g/10min to 20,000g/10min, 1,000g/10min to 10,000g/10min, 1,000g/10min to 5,000g/10min, 10,000g/10min to 30,000g/10min, 10,000g/10min to 20,000g/10min, 10,000g/10min to 15,000g/10min, 20,000g/10min-30,000g/10min, 20,000g/10min-27,500g/10min, 22,500g/10min-30,000g/10min, 22,500g/10min-27,500,000g/10min, 22,500g/10min-25,000g/10 min.

The propylene-based elastomer can have a melting point temperature (Tm) of 105 ℃ or less, 100 ℃ or less, 90 ℃ or less, 80 ℃ or less, 70 ℃ or less. In some embodiments, the propylene-based elastomer has a Tm of 25 ℃ to 105 ℃, 60 ℃ to 105 ℃, 70 ℃ to 105 ℃, or 90 ℃ to 105 ℃.

Determination of Tm and Δ H for propylene-based elastomers_fThe DSC program of (a) includes the following. The polymer is pressed in a hot press at a temperature of 200 ℃ to 230 ℃ and the resulting polymer sheet is suspended in air to cool under ambient conditions (20 ℃ to 23.5 ℃). A die was used to remove 6-10mg samples of the polymer sheet. These 6-10mg samples were annealed at room temperature (22 ℃) for 80 hours to 100 hours. At the end of this period, the sample was placed in a DSC (Perkin Elmer Pyris One Thermal Analysis System) and cooled to-30 ℃ to-50 ℃ at a rate of 10 ℃/min and held at-50 ℃ for 10 minutes. The sample was heated at 10 ℃/min to reach a final temperature of 200 ℃. The sample was held at 200 ℃ for 5 minutes. Then, a second cooling-heating cycle was performed using the same conditions as described above. The events "first melt" and "second melt" from these two cycles were recorded separately. The exotherm is recorded as the area under the melting peak of the sample, which typically exists between 0 ℃ and 200 ℃. Measured in joules and is the Δ H of the polymer_fIs measured. Melting point temperatures and Δ H referred to herein_fMeans the first melting.

The propylene-based elastomer may have a weight average molecular weight of 0.850 to 0.920g/cm³Or 0.860g/cm³-0.890g/cm³According to ASTM D1505-18.

The propylene-based elastomer may have an elongation at break measured according to ASTM D638-14 of at least 200%, at least 500%, at least 1000%, at least 1500%, at least 2000%, or at least 3000%.

The propylene-based elastomer may have a weight average molecular weight (Mw) of 5,000 g/mole to 5,000,000 g/mole, 10,000 g/mole to 1,000,000 g/mole, 20,000 g/mole to 750,000 g/mole, 30,000 g/mole to 400,000 g/mole.

The propylene-based elastomer can have a number average molecular weight (Mn) of 2,500 g/mole to 250,000 g/mole, 10,000 g/mole to 250,000 g/mole, or 25,000 g/mole to 200,000 g/mole.

The propylene-based elastomer may have a z-average molecular weight (Mz) of from 10,000 g/mole to 7,000,000 g/mole, 80,000 g/mole to 700,000 g/mole, or 100,000 g/mole to 500,000 g/mole.

The propylene-based elastomer may have a molecular weight distribution ("MWD") of from 1.5 to 20, or from 1.5 to 15, preferably from 1.5 to 5, more preferably from 1.8 to 3, most preferably from 1.8 to 2.5.

Molecular weights (weight average molecular weight Mw, number average molecular weight Mn and molecular weight distribution Mw/Mn or MWD) were determined using high temperature Size Exclusion Chromatography (SEC) from Waters corporation or Polymer Lanboratories equipped with a differential refractive index Detector (DRI), an online light scattering detector (LS) and a viscometer. Three Polymer Laboratories PLgel 10mm Mixed-B columns were used. Nominal flow rate of 0.5cm³Min and the nominal injection volume is 300. mu.L. An oven maintained at 145 ℃ was equipped with various transfer lines, columns and differential refractometers (DRI detectors). Polystyrene was used to calibrate the instrument. The solvent used for the SEC experiment was prepared by dissolving 6g of butylated hydroxytoluene as antioxidant in 4L of

Aldrich reagent grade

1, 2, 4-Trichlorobenzene (TCB). The TCB mixture was then filtered through a 0.7 micron glass prefilter followed by a 0.1 micron Teflon filter. The TCB was then degassed with an in-line degasser and then into SEC, and the polymer solution was prepared by: the dried polymer was placed in a glass container, the desired amount of TCB was added, and the mixture was then heated at 160 ℃ while stirring was continued for many hours. All amounts were measured gravimetrically. The density of TCB used to express the polymer concentration in units of mass/volume is 1.463g/ml at room temperature and 1.324g/ml at 135 ℃. The injection concentration ranged from 1.0-2.0mg/mL, with lower concentrations being used for higher molecular weight samples. Before testing each sample, the DRI detector and the injector were purged. The flow rate in the apparatus was then increased to 0.5mL/min and the DRI was allowed to stabilize for 8-9 hours before injecting the first sample. The LS laser was turned on 1 hour to 1.5 hours before the test sample. At each point in the chromatogramConcentration (c) DRI signal (I) from baseline subtracted by the following equation_DRI) And (3) calculating:

c＝K_DRII_DRI/(dn/dc)

wherein K_DRIAre constants determined by calibrating the DRI, (dn/dc) are the same as described below for the LS analysis. The units of the parameters in the entire description of this SEC method satisfy: concentration in g/cm³The molecular weight is expressed in kg/mol and the intrinsic viscosity is expressed in dL/g.

The light scattering detector used was Wyatt Technology High Temperature mini-DAWN. The Polymer molecular weight M at each point of the chromatogram was determined by analyzing the LS output using a Zimm model of static Light Scattering (m.b. huglin, Light Scattering from Polymer Solutions, academy, 1971):

where Δ R (θ) is the excess Rayleigh scattering intensity measured at the scattering angle θ, c is the polymer concentration determined from the DRI analysis, A₂Is the second virial coefficient, P (θ) is the shape factor of the monodisperse random coil (described in the above reference), Ko is the optical constant of the system:

wherein N is_AIs the Avogastron constant, and dn/dc is the refractive index increment of the system. The refractive index n for TCB at 135 ℃ and λ 690nm is 1.500. Furthermore, for the ethylene polymer A₂0.0015 and dn/dc 0.104, and for propylene polymer a₂0.0006 and dn/dc 0.104.

The average molecular weight is generally defined as the lower limit: consider the case where macromolecules are present in the N-containing_iMolecular weight M_iThe discontinuity of the distribution in the discrete fraction i of molecules of (a). Weight average molecular weight M_wDefined as the molecular weight M of each fraction_iMultiplied by its weight ratio w_iSum of products of (a):

because of the weight ratio w_iDefined as molecular weight M_iDivided by the total weight of all molecules present:

number average molecular weight M_nDefined as the molecular weight M of each fraction_iMultiplied by its mole fraction x_iSum of products of (a):

because of the mole fraction x_iIs defined as N_iDivided by the total number of molecules:

in SEC, a high temperature Viscotek Corporation viscometer is used, having four capillaries arranged in a Wheatstone bridge configuration with two pressure sensors. One sensor measures the total pressure drop across the detector and the other sensor, located between the two sides of the bridge, measures the pressure difference. Specific viscosity (. eta.) of solution flowing through viscometer_s) Calculated from their outputs. Intrinsic viscosity [ eta ] at each point in the chromatogram]Calculated by the following equation:

η_s＝c[η]+0.3(c[η])²

where c is determined from the DRI output.

The branching index (g ', also referred to as g' (VIS)) is calculated as follows from the output of the SEC-DRI-LS-VIS method. Average intrinsic viscosity [ eta ] of sample]_avgThe following calculations were made:

where the sum is taken from all chromatogram slices i between the integration limits.

Various propylene-based elastomers having any combination of the above properties are contemplated herein.

The propylene-based elastomer may comprise a copolymer prepared according to the procedures described in WO 02/36651, U.S. patent No. 6,992,158, and/or WO 00/01745, the contents of which are incorporated herein by reference. Preferred methods for preparing propylene-based elastomers can be found in U.S. Pat. Nos. 7,232,871 and 6,881,800, the contents of which are incorporated herein by reference. The present invention is not limited by any particular polymerization process for preparing the propylene-based elastomer, and the polymerization process is not limited by any particular type of reaction vessel.

Suitable propylene-based elastomers may be sold under the trade name VISTA MAXX^TM(available from ExxonMobil Chemical Company) (e.g., VISTA MAX^TM 3000、VISTAMAXX^TM 3588FL、VISTAMAXX^TM 6102、VISTAMAXX^TM 8880)，VERSIFY^TM(available from The Dow Chemical Company), certain grades of TAFMER^TMXM or NOTIO^TM(available from Mitsui Company) and certain grades of SOFTEL^TM(available from BasellPolyolephins). The particular grades of commercially available propylene-based elastomers suitable for use in the present invention can be readily determined using methods generally known in the art.

The heavy-duty layer composition of the present invention may comprise one or more propylene-based elastomers at a total concentration of 5 wt% to 30 wt%, or 7 wt% to 20 wt%, or 10 wt% to 18 wt%, or 12 wt% to 15 wt%, based on the weight of the heavy-duty layer composition.

Low density polyethylene

The LDPE had a density of 0.915g/cm³-0.935g/cm³Or 0.920g/cm³-0.930g/cm³The density of (c).

LDPE has a melt flow index (ASTM D1238-13, 2.16kg, 190 ℃) of 0.2g/10min to 10g/10min, or 0.5g/10min to 7g/10min, or 1g/10min to 5g/10 min.

LDPE has a melt flow ratio (ASTM D1238-13, 21.6kg, 190 ℃ C. divided by ASTM D1238-13, 2.16kg, 190 ℃) of greater than 40, or 40 to 300, or 60 to 250, or 75 to 200.

The LDPE may be a polyethylene homopolymer. Alternatively, the LDPE may be C-containing₃-C₂₀Ethylene copolymers of alpha-olefins. Examples of comonomers include propylene, 1-butene, 3-methyl-1-butene, 3, 3-dimethyl-1-butene, 1-pentene with one or more methyl, ethyl or propyl substituents, 1-hexene with one or more methyl, ethyl or propyl substituents, 1-heptene with one or more methyl, ethyl or propyl substituents, 1-octene with one or more methyl, ethyl or propyl substituents, 1-nonene with one or more methyl, ethyl or propyl substituents, ethyl, methyl or dimethyl substituted 1-decene, 1-dodecene and styrene. Exemplary combinations of ethylene and comonomers include: ethylene 1-butene, ethylene 1-pentene, ethylene 4-methyl-1-pentene, ethylene 1-hexene, ethylene 1-octene, ethylene decene, ethylene dodecene, ethylene 1-butene-1-hexene, ethylene 1-butene-1-pentene, ethylene 1-butene-4-methyl-1-pentene, ethylene 1-butene-1-octene, ethylene 1-hexene-1-pentene, ethylene 1-hexene-4-methyl-1-pentene, ethylene 1-hexene-1-octene, ethylene 1-hexene-decene, ethylene 1-hexene-dodecene, ethylene propylene 1-octene, ethylene 1-octene-1-butene, ethylene 1-octene-1-pentene, ethylene 1-octene-4-methyl-1-pentene, ethylene 1-octene-1-pentene, ethylene 1-butene-1-butene, ethylene 1-butene-1-pentene, ethylene 1-butene-1-butene, ethylene 1-butene-1-butene, ethylene 1-butene-1-butene, ethylene 1-butene, and ethylene, Ethylene 1-octene 1-hexene, ethylene 1-octene decene, ethylene 1-octene dodecene, and combinations thereof. It is to be understood that the above list of comonomers and comonomer combinations is merely exemplary and is not intended to be limiting. Preferably, the comonomer is 1-butene, 1-hexene or 1-octene. Most preferably, the comonomer is 1-hexene.

In the copolymer, the ethylene derived units may comprise 65 wt% to 99.9 wt%, or 70 wt% to 99 wt%, or 85 wt% to 95 wt% of the LDPE and the comonomer may comprise 0.1 wt% to 35 wt%, or 5 wt% to 15 wt% of the LDPE.

LDPE useful in the present invention includes that available under the trade name EXXONMOBIL^TMLDPE is commercially available from ExxonMobil Chemical Company, including, but not limited to, those under the grade designations: LD250, LD259, LD258, LD251, LD252, LD650, LD653, LD200.48, LD201.48, and LD202.48 are commercially available.

The LDPE described herein is not subject to any particular method of preparation and may be formed using any method known in the art. For example, LDPE can be formed by autoclave or tubular reactor processes.

The heavy-duty layer composition of the present invention may comprise one or more LDPE in a total concentration of from 5 wt% to 30 wt%, or from 10 wt% to 20 wt%, or from 5 wt% to 18 wt%, or from 7 wt% to 15 wt%, based on the weight of the heavy-duty layer composition.

Linear low density polyethylene

LLDPE has a density of 0.900g/cm³-0.955g/cm³Or 0.910g/cm³-0.950g/cm³Or 0.920g/cm³-0.945g/cm³The density of (c).

The LLDPE has a melt flow index (ASTM D1238-13, 2.16kg, 190 ℃) of from 0.2g/10min to 30g/10min, or from 0.5g/10min to 25g/10min, or from 1g/10min to 20g/10 min.

The LLDPE has a melt flow ratio (ASTM D1238-13, 21.6kg, 190 ℃ C. divided by ASTM D1238-13, 2.16kg, 190 ℃) of 15 to 40, or 18 to 35, or 20 to 25.

The LLDPE may be a polyethylene homopolymer. Alternatively, the LLDPE may be C-containing₃-C₂₀Ethylene copolymers of alpha-olefins. Examples of comonomers include propylene, 1-butene, 3-methyl-1-butene, 3, 3-dimethyl-1-butene, 1-pentene with one or more methyl, ethyl or propyl substituents, 1-hexene with one or more methyl, ethyl or propyl substituents, 1-heptene with one or more methyl, ethyl or propyl substituents, 1-octene with one or more methyl, ethyl or propyl substituents, 1-nonene with one or more methyl, ethyl or propyl substituents, ethyl, methyl or dimethyl substituentsSubstituted 1-decene, 1-dodecene and styrene. Exemplary combinations of ethylene and comonomers include: ethylene 1-butene, ethylene 1-pentene, ethylene 4-methyl-1-pentene, ethylene 1-hexene, ethylene 1-octene, ethylene decene, ethylene dodecene, ethylene 1-butene-1-hexene, ethylene 1-butene-1-pentene, ethylene 1-butene-4-methyl-1-pentene, ethylene 1-butene-1-octene, ethylene 1-hexene-1-pentene, ethylene 1-hexene-4-methyl-1-pentene, ethylene 1-hexene-1-octene, ethylene 1-hexene-decene, ethylene 1-hexene-dodecene, ethylene propylene 1-octene, ethylene 1-octene-1-butene, ethylene 1-octene-1-pentene, ethylene 1-octene-4-methyl-1-pentene, ethylene 1-octene-1-pentene, ethylene 1-butene-1-butene, ethylene 1-butene-1-pentene, ethylene 1-butene-1-butene, ethylene 1-butene-1-butene, ethylene 1-butene-1-butene, ethylene 1-butene, and ethylene, Ethylene 1-octene 1-hexene, ethylene 1-octene decene, ethylene 1-octene dodecene, and combinations thereof. It is to be understood that the above list of comonomers and comonomer combinations is merely exemplary and is not intended to be limiting. Preferably, the comonomer is 1-butene, 1-hexene or 1-octene. Most preferably, the comonomer is 1-hexene.

In the copolymer, the ethylene-derived units may comprise 65 wt% to 99.9 wt%, or 70 wt% to 99 wt%, or 85 wt% to 95 wt% of the LLDPE, and the comonomer may comprise 0.1 wt% to 35 wt%, or 5 wt% to 15 wt% of the LLDPE.

LLDPE useful in the present invention includes those available under the trade name EXCEED^TMXP (available from ExxonMobil Chemical Company), EXXONMOBIL^TMLLDPE (available from ExxonMobil Chemical Company) and EXXONMOBIL^TMNTX LLDPE (available from ExxonMobil Chemical Company) are those commercially available.

The LLDPE described herein is not subject to any particular method of preparation and can be formed using any method known in the art. For example, LLDPE can be formed by autoclave or tubular reactor processes.

The heavy-duty layer compositions of the present invention may comprise one or more LDDPEs (when present) in a total concentration of 0.1 wt% to 15 wt%, or 1 wt% to 10 wt%, or 1 wt% to 5 wt%, or 0.1 wt% to 2 wt%, based on the weight of the heavy-duty layer composition. The heavy layer composition of the present invention may be absent LLDPE.

Filler material

Examples of fillers may include, but are not limited to, carbon black, fly ash, graphite, cellulose, starch, flour, wood flour, polymeric fibers such as polyester-based, polyamide-based materials, calcium carbonate, aluminum trihydrate, talc, glass fibers, marble dust, cement dust, clay, feldspar, silica or glass, fumed silica, alumina, magnesia, antimony oxide, zinc oxide, barium sulfate, calcium sulfate, aluminum silicate, calcium silicate, titanium dioxide, titanates, clays, nanoclays, organically modified clays or nanoclays, glass microspheres, chalk, and the like, and combinations thereof.

The heavy-duty layer compositions of the present invention may comprise one or more fillers in a total concentration of 50 wt% to 90 wt%, or 60 wt% to 85 wt%, or 65 wt% to 80 wt%, or 75 wt% to 85 wt%, or 70 wt% to 75 wt%, based on the weight of the heavy-duty layer composition.

Processing aid

Examples of processing aids include, but are not limited to, paraffinic oils, naphthenic oils, Polyalphaolefin (PAO) fluids, waxes, fatty acid salts, such as calcium stearate or zinc stearate, alcohols, including glycols, glycol ethers, alcohol ethers, polyesters, and the like, and combinations thereof.

The heavy-duty layer composition of the present invention may comprise one or more processing aids in a total concentration of 0.1 wt% to 5 wt%, or 1 wt% to 4 wt%, or 3 wt% to 5 wt%, or 0.1 wt% to 3 wt%, based on the weight of the heavy-duty layer composition.

Other additives

The heavy layer composition of the present invention may comprise other additives. Examples of other additives include, but are not limited to, flame retardants, antioxidants, flow improvers, colorants, reinforcements, adhesion additives, and the like, and combinations thereof.

The heavy-duty layer composition may further contain an adhesive additive that may promote adhesion of the extruded composition to the primary layer (primary layer) and the tufted carpet fibers (tufted carpet fibers). Useful binders include maleic anhydride functionalized EVA. When employed, the adhesion additive may be present in an amount of up to 10 wt%, or 0.1 wt% to 10 wt%, or 1 wt% to 8 wt%, or 1 wt% to 5 wt%, based on the weight of the heavy-duty layer composition.

The heavy-duty layer composition may contain a thermal stabilizer and/or an antioxidant. Hindered amine stabilizers, such as CHIMASSORB available from Ciba Specialty Chemicals^TMAre exemplary heat and light stabilizers. In addition, sterically hindered phenols may be used as antioxidants. Some suitable hindered phenols include IRGANOX, which is available from Ciba Specialty Chemicals under the trade name IRGANOX^TMThose obtained. When employed, the antioxidants and/or stabilizers can each be present in an amount of up to 20 wt%, or 0.1 wt% to 20 wt%, or 0.5 wt% to 15 wt%, or 1 wt% to 10 wt%, based on the weight of the heavy-duty layer composition.

Manufacture of heavy-duty layers and heavy-duty layered mats

Fig. 1 is an overview of the steps of an embodiment method 100 of forming a heavy-duty layer and a heavy-duty layered pad. First, the heavy layer compositions according to the present disclosure may be compounded by any known method. For example, compounding can be performed by mixing the

components

102a, 102b, 102c, etc. of the heavy-duty layer composition into a continuous mixer 104, such as a brabender mixer, a grinder, or an internal mixer, such as a banbury mixer. Compounding can also be carried out in a continuous process, for example in a twin screw extruder 106. Optionally, a portion of the components of the heavy-duty layer composition may be blended prior to blending with the remaining components.

After the components are heated and blended in the mixer 104 to form the heavy layer melt, the heavy layer melt can be extruded via an extruder 106 into a heavy layer sheet 108 having a thickness of 0.1mm to 5mm, or 0.5mm to 4mm, or 1mm to 3mm, or 3mm to 5 mm. During extrusion, rollers 110 may be used to bring the heavy-duty sheet to a desired thickness. Cutter 112 then cuts the heavy-duty layer sheet 108 into individual heavy-duty layers 114.

The reforming layer 114 may then be molded. First, the heater 116 is used to preheat the reforming layer 114. The pre-heated, reformed layer 114 is then placed into a mold 118, where vacuum 120 and heat are applied to thermoform the reformed layer 114. When in the mold 118, a small amount of space is available between the molded heavy-duty layer 114 and the top of the mold, which provides space for the polyurethane foam 122 to be injected into the mold and forms a polyurethane foam layer 124 on one side of the heavy-duty layer 114. A heavy layered mat 126 with two layers is obtained: a heavy-duty layer 114 and a polyurethane foam layer 124. Optionally, additional steps known to those skilled in the art may be performed to apply a carpet or other fabric to the polyurethane foam layer 124.

The polyurethane foam layer 124 may have a thickness of 0.1mm to 5mm, or 0.5mm to 4mm, or 1mm to 3mm, or 3mm to 5 mm.

An exemplary heavy-duty layered pad comprises a heavy-duty layer comprised of the heavy-duty layer composition described herein; and a polyurethane layer on a surface of the heavy layer.

Another exemplary heavy-duty layered pad includes a heavy-duty layer comprised of the heavy-duty layer composition described herein; a polyurethane layer on a surface of the heavy-duty layer; and a plurality of fibers on the polyurethane foam layer such that the polyurethane foam layer is between the heavy-duty layer and the plurality of fibers.

Yet another exemplary heavy-duty layered pad comprises a heavy-duty layer comprised of the heavy-duty layer composition described herein; a polyurethane foam layer on a surface of the reforming layer; and a multilayer adhesive film on the polyurethane foam layer such that the polyurethane foam layer is between the reforming layer and the multilayer adhesive film, wherein the multilayer adhesive film comprises a polar layer and a non-polar layer.

Advantageously, the heavy-duty layer compositions of the present invention have increased melt strength, which enables the heavy-duty layers to be preheated and thermoformed while maintaining their integrity and thickness. In addition, the heavy-duty layer compositions described herein are preferably substantially free of EVA copolymers and thus have no vinegar odor associated therewith.

Examples embodiments of the invention

A first embodiment of the invention is a composition comprising: 5 wt% to 30 wt% of a propylene-based elastomer; 5 wt% -30 wt% of low density polyethylene; 0 wt% to 15 wt% of linear low density polyethylene; 50 wt% -90 wt% of filler; and 0.1 wt% -5 wt% of processing aid. Optionally, the composition may include one or more of the following elements: element 1: wherein the composition is absent of linear low density polyethyleneAn alkene; element 2: wherein the composition is absent ethylene vinyl acetate copolymer; element 3: wherein the low density polyethylene is a homopolymer of polyethylene; element 4: wherein the low density polyethylene has from 65 wt% to 99.9 wt% ethylene derived units, from 0.1 wt% to 35 wt% derived from C₃-C₁₂Units of at least one of alpha-olefins; element 5: wherein the linear low density polyethylene is a homopolymer of polyethylene; element 6: wherein the linear low density polyethylene has from 65 wt% to 99.9 wt% ethylene derived units, from 0.1 wt% to 35 wt% derived from C₃-C₁₂Units of at least one of alpha-olefins; element 7: wherein the composition further comprises from 0.1 wt% to 20 wt% of a stabilizer and/or antioxidant; and element 8: wherein the composition further comprises from 0.1 wt% to 10 wt% of an ethylene vinyl acetate copolymer. Examples of combinations include, but are not limited to, the

elements

1 and 2 combination not necessarily further combined with one of the elements 3 and 4; the combination of

elements

7 and 8 is not necessarily further combined with one of elements 3 and 4; one of elements 3 and 4 in combination with element 1; one of elements 3 and 4 in combination with element 2; one of elements 3 and 4 in combination with element 7; one of elements 3 and 4 in combination with element 8; one of elements 3 and 4 in combination with one of elements 5 or 6 is not necessarily further combined with element 2; and one of elements 5 or 6 in combination with element 2.

Another embodiment is a heavy duty layered pad comprising: a heavy layer (optionally including one or more of the optional elements described above) comprised of the composition of the first embodiment; and a polyurethane layer on a surface of the heavy duty cushion layer.

Yet another embodiment is a heavy-duty layered pad comprising: a heavy layer (optionally including one or more of the optional elements described above) comprised of the composition of the first embodiment; a polyurethane foam layer on a surface of the reforming layer; and a plurality of fibers on the polyurethane foam layer such that the polyurethane foam layer is between the heavy-duty layer and the plurality of fibers.

Yet another embodiment is a heavy-duty layered pad comprising: a heavy layer (optionally including one or more of the optional elements described above) comprised of the composition of the first embodiment; a polyurethane foam layer on a surface of the reforming layer; and a multilayer adhesive film on the polyurethane foam layer such that the polyurethane foam layer is between the reforming layer and the multilayer adhesive film, wherein the multilayer adhesive film comprises a polar layer and a non-polar layer.

In the three aforementioned embodiments of the heavy-duty layered pad, the heavy-duty layer may optionally have a thickness of 0.1mm to 5mm and/or the polyurethane foam layer may optionally have a thickness of 0.1mm to 5 mm.

Another example embodiment is a method comprising: thermoforming a polymer sheet having a surface and a back surface with a mold to produce a molded polymer sheet, the polymer sheet comprising: the first embodiment composition (optionally including one or more of the optional elements described above); and injecting a polyurethane foam into the mold such that the polyurethane foam is on the back surface of the molded polymer sheet.

Optionally, an embodiment method may include one or more of: the method further comprises the following steps: attaching a plurality of fibers to the polyurethane foam via thermal compression; attaching a multi-layer adhesive film to the polyurethane foam via thermal compression, wherein the multi-layer adhesive film comprises a polar layer and a non-polar layer; the heavy layer may optionally have a thickness of 0.1mm to 5 mm; and/or the polyurethane foam layer may optionally have a thickness of 0.1mm to 5 mm.

Unless otherwise indicated, all numbers expressing quantities of ingredients, properties such as molecular weight, reaction conditions, and so forth used in the specification and claims are to be understood as being modified in all instances by the term "about". Accordingly, unless indicated to the contrary, the numerical parameters set forth in the following specification and attached claims are approximations that may vary depending upon the desired properties sought to be obtained by the embodiments of the present invention. At the very least, and not as an attempt to limit the application of the doctrine of equivalents to the scope of the claims, each numerical parameter should at least be construed in light of the number of reported significant digits and by applying ordinary rounding techniques.

One or more illustrative embodiments incorporating the inventive embodiments disclosed herein are presented herein. In the interest of clarity, not all features of a physical implementation are described or shown in this application. It will be appreciated that in the development of a physical embodiment incorporating embodiments of the present invention, numerous implementation-specific decisions must be made to achieve the developers' specific goals, such as compliance with system-related, business-related, government-related and other constraints, which will vary from one implementation to another. While a developer's efforts might be time consuming, such efforts would still be a routine undertaking for those of ordinary skill in this art, and having the benefit of this disclosure.

Although compositions and methods are described herein in terms of "comprising" various components or steps, the compositions and methods can also "consist essentially of" or "consist of" the various components and steps.

To facilitate a better understanding of embodiments of the present invention, the following examples of preferred or representative embodiments are given. The following examples should not be construed as limiting in any way or limiting the overall scope of the invention.

Examples

Example 1 blends were prepared according to the formulation in table 1.

TABLE 1

The extensional viscosity of each sample was measured. The extensional rheological properties of polymers play an important role in the processing and final properties. All samples were first prepared into sheets by compression molding. The extensional viscosity test was conducted by the STC-EM-RHE-05.00 test method at 200 ℃ on an ARES EFV instrument using a nitrogen atmosphere to avoid oxidative degradation. All samples were tested at a range of strain rates: 0.01s^-1、0.1s^-1、1s^-1、10s^-1. Sample 1 (which is a market benchmark sample) exhibited strain hardening, which indicates good melt strength. Samples 2 and 3 (as comparative samples not containing LDPE) showed no strain hardening,this indicates poor melt strength. Samples 4-7 (which are inventive samples) show strain hardening, which indicates good melt strength.

Example 2 preparation of a blend having Polymer blend Filler (CaCO)₃) Samples in a weight ratio of 40: 60. The polymer blends used are provided in table 2. The properties of each polymer in the blend are provided in table 3. The thermal properties of the samples (i.e., the polymer blends with filler therein) are provided in table 4.

TABLE 2

Available from Dow Chemical

TABLE 3

TABLE 4

Sample (I)	Tc	Tm	Tg	ΔHc
					40:60 wt% sample 8: CaCO₃	110.4	123.4	-30.5	9.5
40:60 wt% sample 9: CaCO₃	96.1	110.1	-30.2	16.3
					40:60 wt% sample 10: CaCO₃	96.7	109.8	-31.1	17.6
40:60 wt% sample 11: CaCO₃	97.9	109.5	-31.4	10.9

The extensional viscosity of each of samples 8-11 was measured as described in example 1. FIGS. 2-5 are provided at 0.01s, respectively^-1、0.1s^-1、1s^-1And 10s^-1Extensional viscosity measurements of (b). FIG. 6 is the maximum elongational viscosity at various strain rates for each sample. Samples 9-11 (each containing LDPE but no LLDPE) gave higher elongational viscosities than sample 8, which contained LLDPE but no LDPE.

The tensile strength of samples 8-11 is provided in FIG. 7. The drawn bars were prepared by injection moulding. The flexural moduli of samples 8-11 are provided in FIG. 8. Flexural modulus sample bars were prepared by injection molding. The tensile strength and stiffness of the samples cannot be elucidated with the presence of LDPE or LLDPE.

Room temperature (20 ℃) and low temperature (-40 ℃) Izod tests were performed on samples 8-11; the results are shown in FIG. 9. For systems involving VISTA MAX^TM6102 and LDPE samples9 and 10, the impact resistance under low temperature conditions is inferior to that at room temperature. In addition, no breaks were observed for all samples, indicating VISTAMAXX based^TM6102 has good impact resistance.

Example 3 samples 12-17 were prepared according to table 5. The extensional viscosities of samples 12-17 were measured as described in example 1, except that the measurements were performed at 190 ℃. FIGS. 10-13 provide samples 12-17 at 0.01s, respectively^-1、0.1s^-1、1s^-1And 10s^-1Extensional viscosity measurements of (b). FIG. 14 shows the maximum elongational viscosity at various strain rates for each of samples 12-17. Samples 14-17, which contained LDPE but no LLDPE, had better elongational viscosities than both EVA-based sample 12 and LLDPE-based sample 13, indicating that adding LDPE at high filler loading formulations correlates with improved melt strength.

TABLE 5

Thermoplastic elastomer

Example 4. use of a composition containing 10 wt% to 15 wt% VISTA MAX^TMA heavy layer composition of 10 wt% to 15 wt% LLDPE, 65 wt% to 75 wt% calcium carbonate and barium sulfate, and 2 wt% to 5 wt% process oil. By using a composition containing 10-15 wt% of VISTA MAX^TMA heavy layer composition of 10 wt% to 15 wt% LDPE, 65 wt% to 75 wt% calcium carbonate and barium sulfate and 2 wt% to 5 wt% processing oil.

These reformed layers were thermoformed into molded reformed layers. Fig. 15 is a picture of cracks in the molded specific gravity type layer. Fig. 16 is a photograph of a molded inventive heavy-weight layer without cracks.

The present invention is, therefore, well adapted to attain the ends and advantages mentioned as well as those that are inherent therein. The particular embodiments disclosed above are illustrative only, as the invention may be modified and practiced in different but equivalent manners apparent to those skilled in the art having the benefit of the teachings herein. Furthermore, no limitations are intended to the details of construction or design herein shown, other than as described in the claims below. It is therefore evident that the particular illustrative embodiments disclosed above may be altered, combined, or modified and all such variations are considered within the scope and spirit of the invention. The invention illustratively disclosed herein suitably may be practiced in the absence of any element which is not specifically disclosed herein and/or any unnecessary element which is disclosed herein. While compositions and methods are described in terms of "comprising," "containing," or "including" various components or steps, the compositions and methods can also "consist essentially of or" consist of the various components and steps. All numbers and ranges disclosed above may vary somewhat. Whenever a numerical range with a lower limit and an upper limit is disclosed, any number and any included range falling within the range is specifically disclosed. In particular, each range of values (of the form "from about a to about b" or, equivalently, "from about a to b" or, equivalently, "from about a-b") disclosed herein is to be understood as listing each number and range encompassed within the broader range of values. In addition, the terms in the claims have their ordinary and customary meaning unless otherwise explicitly and clearly defined by the patentee. Furthermore, the indefinite articles "a" or "an" used in the claims are defined herein to mean one or more of the elements it introduces.

Claims

1. A composition comprising:

5 wt% to 30 wt% of a propylene-based elastomer;

5 wt% -30 wt% of low density polyethylene;

0 wt% to 15 wt% of linear low density polyethylene;

50 wt% -90 wt% of filler; and

0.1 wt% -5 wt% of processing aid.

2. The composition of claim 1, wherein the composition further comprises 0.1 wt% to 20 wt% of a stabilizer and/or antioxidant.

3. The composition of any preceding claim, wherein the composition is free of linear low density polyethylene.

4. The composition of any preceding claim, wherein the composition is free of ethylene vinyl acetate copolymer.

5. The composition of any of claims 1-3, wherein the composition further comprises 0.1 wt% to 10 wt% of an ethylene vinyl acetate copolymer.

6. The composition of any preceding claim, wherein the low density polyethylene is a homopolymer of polyethylene.

7. The composition of any of claims 1-5, wherein the low density polyethylene has 65 wt% to 99.9 wt% ethylene derived units, 0.1 wt% to 35 wt% derived from C₃-C₁₂Units of at least one of alpha-olefins.

8. The composition of any of claims 1-2 or 4-7, wherein the linear low density polyethylene is a homopolymer of polyethylene.

9. The composition of any of claims 1-2 or 4-7, wherein the linear low density polyethylene has from 65 wt% to 99.9 wt% ethylene derived units, from 0.1 wt% to 35 wt% derived from C₃-C₁₂Units of at least one of alpha-olefins.

10. A heavy duty layered pad comprising:

a heavy layer comprised of the composition of any of the preceding claims; and

a polyurethane layer on a surface of the reforming layer.

11. A heavy duty layered pad comprising:

a heavy layer comprised of the composition of any of claims 1-9;

a polyurethane foam layer on a surface of the reforming layer; and

a layer on the polyurethane foam layer such that the polyurethane foam layer is between the heavy-duty layer and the layer.

12. The heavy-duty layered mat of claim 11, wherein said layer comprises a plurality of fibers.

13. The heavy-duty layered mat of claim 11, wherein said layer comprises a multi-layer adhesive film comprising a polar layer and a non-polar layer.

14. The heavy-duty layered pad of one of claims 11-13, wherein the heavy-duty layer has a thickness of 0.1mm to 5 mm.

15. The heavy-duty layered mat of one of claims 11-14, wherein the polyurethane foam layer has a thickness of 0.1mm to 5 mm.

16. The method comprises the following steps:

thermoforming a polymer sheet having a surface and a back surface with a mold to produce a molded polymer sheet, the polymer sheet comprising:

5 wt% to 30 wt% of a propylene-based elastomer;

5 wt% -30 wt% of low density polyethylene;

0 wt% to 15 wt% of linear low density polyethylene;

50 wt% -90 wt% of filler; and

0.1 wt% -5 wt% of processing aid; and

injecting a polyurethane foam into the mold such that the polyurethane foam is on the back surface of the molded polymer sheet.

17. The method of claim 16, further comprising:

attaching a plurality of fibers to the polyurethane foam via thermal compression.

18. The method of claim 16, further comprising:

attaching a multilayer adhesive film including a polar layer and a non-polar layer to the polyurethane foam via thermal compression.

19. The method of one of claims 16-18, wherein the composition is free of linear low density polyethylene.

20. The method of one of claims 16-19, wherein the composition is free of ethylene vinyl acetate copolymer.

21. The method of one of claims 16-19, wherein the composition further comprises 0.1 wt% to 10 wt% of an ethylene vinyl acetate copolymer.

22. The method of one of claims 16 to 20, wherein the composition further comprises 0.1 wt% to 20 wt% of a stabilizer and/or antioxidant.