MXPA97009027A - Polyolefine compositions used to make leaves in relief with improved grain retention - Google Patents

Abstract

Embossed sheets having improved grain retention can be made of a polyolefin composition containing a propylene polymer material, and a partially crosslinked thermoplastic olefin elastomer composition. Large parts such as car doors and dashboards can be formed from these sheets.

Description

"POLYOLEFINE COMPOSITIONS USED TO DEVELOP LEAVES IN RELIEF WITH IMPROVED GRAIN RETENTION" This invention relates to a polyolefin composition comprising (A) a propylene polymer material and (B) a partially crosslinked thermoplastic olefin elastomer composition. With advances in polyolefin technology, the use of polypropylene materials, particularly thermoplastic olefin materials (TPOs), in automotive applications has increased dramatically, replacing non-olefin materials such as the acrylonitrile / butadiene / styrene terpolymer , polyvinyl chloride and polycarbonate. The thermoplastic olefins are uncrosslinked mixtures of olefin polymers and polyolefin elastomers. The new reactor product TPOs is finding use in areas such as interior fittings (eg, dashboards and door panels) due to its soft touch, thermoformability and resistance to ultraviolet light and heat. The process of producing these parts involves the following steps: (a) extruding or calendering the TPO sheet, (b) subjecting the calendered extruded sheet to relief (on or off the line) to produce a textured or "grain" surface ", (c) laminating and / or ligating the extruded or calendered sheet to a foam or cloth for softness, (d) coating or painting the sheet of scratch resistance and ultraviolet light deterioration, and (e) forming the final piece or Another sheet item, thermoforming or injection molding at low pressure. U.S. Patent No. 5,338,801 discloses a polyolefin composition comprising (A) from 70 percent to 90 percent of a propylene polymer material and (B) from 30 percent to 10 percent of an olefin polymer material that is selected from the group consisting of (1) a partially crosslinked thermoplastic olefin elastomer composition consisting of a thermoplastic elastomer and a resin rubber composition, (2) a non-crosslinked ethylene-propylene-conjugated diene terpolymer rubber. and (3) mixtures of (B) (1) and (B) (2). The composition provides low luster after processing with retention of physical and mechanical properties. A major inconvenience of the TPOs has been their inability to retain the grain in relief after the sheet is thermoformed into a large piece such as an instrument panel. The low melting strength and the thinning mechanical stress that are typical of TPOs result in the loss of the textured surface and the walls that are too thin when the TPOs are formed into pieces or other articles. The polyolefin composition of this invention comprises, by weight, (A) from 40 percent to 70 percent of a propylene polymer material consisting essentially of: (1) from 10 percent to 50 percent of a homopolymer of propylene having an isotactic index of about 80 percent to about 99 percent, or a copolymer selected from the group consisting of (a) propylene and ethylene, (b) propylene, ethylene, and an alpha-olefin CH2 = CHR , wherein R is a straight or branched alkyl group of 2 to 8 carbon atoms, and (c) propylene and an alpha-olefin as defined above in (1) (b), containing the copolymer of percent to 99 percent propylene and having an isotactic index greater than 80 percent approximately 98 percent. (2) from 3 percent to 20 percent of a fraction of an essentially linear, crystalline copolymer having crystallinity from about 20 percent to about 60 percent by differential scanning calorimetry (DSC), wherein the The copolymer is selected from the group consisting of (a) ethylene and propylene containing more than 50 percent ethylene; (b) ethylene, propylene, and an alpha-olefin as defined above in (1) (b), which contains from 1 to 10 percent of the alpha-olefin and more than 50 percent to 98 percent both ethylene and alpha-olefin; and (c) ethylene and an alpha-olefin as defined in (1) (b) containing more than 50 percent and up to 98 percent of the alpha-olefin, whose copolymer is insoluble in xylene at room temperature, and (3) from 40 percent to 80 percent of a copolymer fraction that is selected from the group consisting of a copolymer of (a) ethylene and propylene, wherein the copolymer contains from 20 percent to less than 40 percent ethylene; (b) ethylene, propylene, and an alpha-olefin as defined in (1) (b), wherein the alpha-olefin is present in an amount of 1 percent to 10 percent, and the amount of ethylene and alpha - olefin present is from 20 percent to less than 40 percent; and (c) ethylene and an alpha-olefin as defined in (1) (b), containing from 20 percent to less than 40 percent alpha-olefin, and optionally containing from 0.5 percent to 10 percent of a diene, the fraction of copolymer (3) being soluble in xylene at room temperature, and having an intrinsic viscosity of 1.7 to 3.0 deciliters per gram, wherein the total amount of fractions (2) and (3), based on The total olefin polymer composition is from about 65 percent to 80 percent, the weight ratio of fractions (2) / (3) is from 0.1 to about 0.3, and the total ethylene or alpha- olefin of 4 to 8 carbon atoms or combination thereof in the fractions (2) + (3) is less than 50 percent, and (B) from 60 percent to 30 percent of a composition of the thermoplastic olefin elastomer partially crosslinked consisting essentially of: (1) from 20 to 80 parts by weight of a thermoplastic elastomer which consists essentially of: (a) from 20 percent to 70 percent of a propylene homopolymer having an isotactic index greater than 90, or a crystalline propylene copolymer with ethylene and / or an alpha-olefin of 4 at 8 carbon atoms having a propylene content greater than 85 percent, and an isotactic index greater than 85 percent; (b) from 30 percent to 75 percent of an amorphous ethylene-propylene or ethylene-butene copolymer fraction, optionally containing from 1 percent to 10 percent of a diene, which is soluble in xylene at room temperature and containing from 30 percent to 70 percent ethylene; and (c) from 3 percent to 30 percent of an ethylene-propylene or semicrystalline ethylene-butene copolymer that is insoluble in xylene at room temperature containing more than 90 percent ethylene; and, (2) from 80 to 20 parts by weight of an ethylene / propylene / diene terpolymer rubber containing from 1 percent to 10 percent of a diene and 30 percent to 70 percent of ethylene. The addition of the partially crosslinked DE TPO elastomer composition of the propylene polymer material results in sheet materials exhibiting significant improvement in grain retention and reduction in shear thinning. Large parts such as automobile doors and instrument panels can be formed from these sheets. All parts and percentages used in this specification are by weight unless otherwise specified. The ambient temperature is approximately 25 ° C. The component (A) used in the composition of the present invention is a propylene polymer material consisting essentially of: (1) from 10 percent to 50 percent of a propylene homopolymer, preferably 10 percent at 40 percent, and especially preferably 20 percent to 35 percent, having an isotactic index of about 80 to about 99 percent, and preferably 85 percent to 99 percent, or a copolymer which is selected from the group consisting of (a) propylene and ethylene, (b) propylene, ethylene and an alpha-olefin CH2 = CHR, wherein R is a straight or branched alkyl group of 2 to 8 carbon atoms, and (c) propylene and an alpha-olefin as defined above in (1) (b), wherein the copolymer contains from 85 percent to 99 percent, and preferably from 90 percent to 99 percent propylene, and has an isotactic index greater than 80 percent to 98 percent preferably greater than 85 percent to about 98 percent. (2) from 3 percent to 20 percent of a fraction of an essentially linear semi-crystalline copolymer, preferably from 7 percent to 15 percent, having a crystallinity of from about 20 percent to about 60 percent, in differential scanning calorimetry (DSC), wherein the copolymer is selected from the group consisting of (a) ethylene and propylene containing more than 50 percent ethylene; (b) ethylene, propylene and an alpha-olefin as defined above in (1) (b) containing from 1 percent to 10 percent alpha-olefin and more than 50 percent through 98 percent of preference of 80 percent to 95 percent, both ethylene and alpha-olefin; and (c) ethylene and an alpha-olefin defined in (1) (b), which contains more than 50 percent to 98 percent, preferably 80 percent to 95 percent of - li ¬ the alpha-olefin, whose copolymer is insoluble in xylene at room temperature, and (3) from 40 percent to 80 percent of a copolymer fraction, preferably from 50 percent to 70 percent, which is selected from the group consisting of of a copolymer of (a) ethylene and propylene, wherein the copolymer contains from 20 percent to less than 40 percent, preferably from 20 percent to 38 percent, and particularly preferably from 25 percent to 38 percent ethylene, (b) ethylene, propylene and an alpha-olefin as defined in (1) (b), wherein the alpha-olefin is present in an amount of 1 percent to 10 percent, preferably 1 percent to 5 percent, and the amount of ethylene and alpha-olefin present is 20 percent to less than 40 percent, and (c) ethylene and an alpha-olefin as defined in (1) (b), which contains from 20 percent to less than 40 percent, preferably from percent to 38 percent, and especially preferably 25 percent to 38 percent of the alpha-olefin, and optionally containing 0.5 percent to 10 percent, preferably 1 percent to 5 percent of a diene, the fraction of the copolymer (3) being soluble in xylene at room temperature, and having an intrinsic viscosity of preferably 1.7 to 3.0, deciliters per gram, wherein the total amount of the ethylene units or the alpha units -olefin in the composition of the olefin or ethylene polymer and alpha-olefin units when both are present in the olefin polymer composition is from 15 percent to 35 percent, the total amount of the fractions (2) and ( 3), based on the composition of the total olefin polymer is preferably from about 65 percent to 80 percent, the weight ratio of the fractions (2) / (3) is preferably from 0.1 to about 0.3, and the total content of ethyl of the alpha-olefin of 4 to 8 carbon atoms with the combination thereof in the fractions (2) + (3) is less than 50 percent and preferably 20 percent to 45 percent. The propylene polymer material of component (A) has at least one melting peak that is determined by DSC, exhibits temperatures greater than 120 ° C, and at least one peak, relative to the glass transition temperature. present at temperatures from -10 ° C to -35 ° C. In addition, these materials have a flexural modulus of less than 150 MPa, generally 20 to 100 MPa; a resistance to the tension to the yield of 10 to 20 MPa; elongation at break of more than 400 percent; a tension adjustment of 75 percent deformation from 20 percent to 50 percent; a Shore D hardness of 20 to 35; a turbidity value of less than 40 percent, preferably less than 35 percent, and they do not break (there is no failure due to brittle impact) when the Izod impact test is carried out -50 ° C. Component (A) is present in an amount of 60 percent to 40 percent, preferably 50 percent to 40 percent of the total composition. Component (A) can be prepared by a polymerization process comprising at least two stages, wherein in the first stage, propylene, or propylene and ethylene, or alpha-olefin, or propylene, ethylene and alpha- olefin are polymerized to form component (A) (1), and in the following steps, mixtures of ethylene and propylene or alpha-olefin, or of propylene, ethylene and alpha-olefin and optionally a diene, are polymerized to form the components (2) and (3). The polymerization can be carried out in the liquid phase, the gas phase, or the liquid-gas phase using separate reactors, all of which can be carried out either intermittently or continuously. For example, it is possible to carry out the polymerization of component (A) (1) using liquid propylene, as a diluent, and the polymerization of components (2) and (3) in the gas phase, without intermediate steps except in what it refers to the partial degassing of propylene. The preparation of the propylene polymer material is described in greater detail in U.S. Patent No. 5,212,246, the process of which is incorporated herein by reference. The component (B) of the present invention is a composition of a partially crosslinked thermoplastic olefin elastomer consisting essentially of: (1) from 20 to 80 parts by weight of a composition of the thermoplastic elastomer consisting essentially of: (a) 20 percent to 70 percent preferably 20 to 50 percent of a propylene homo-polymer having an isotactic index greater than 90, preferably greater than 98 percent, or a copolymer of crystalline propylene with an ethylene and / or an alpha-olefin of 4 to 8 carbon atoms having a propylene content greater than 85 percent, and an isotactic index greater than 85 percent, (b) from 30 percent to 75 percent, preferably from 30 percent to 50 percent, of an amorphous ethylene-propylene or ethylene-butene copolymer fraction, optionally containing from 1 percent to 10 percent, preferably from 1 percent to 5 percent of a diene, which is soluble and n xylene at ambient temperature and containing 20 percent to 70 percent ethylene; and (c) from 3 percent to 30 percent, preferably from 5 percent to 20 percent, of a semi-crystalline ethylene-propylene or ethylene-butene copolymer that is insoluble in xylene at room temperature and that contains more than 75 percent. ethylene percent, preferably more than 85 percent, and (2) 80 parts to 20 parts by weight of an ethylene / propylene / diene terpolymer rubber containing 1 percent to 10 percent diene and 30 percent. percent to 70 percent ethylene. In the compositions of the present invention, component (B) is present in an amount of 60 percent to 30 percent, preferably 55 percent to 30 percent, and especially preferably 50 percent to 30 percent. hundred. Alpha-olefins of 4 to 10 carbon atoms useful in the preparation of components (A) and (B) of the polyolefin composition of this invention include buten-1, penten-1; hexen-1; 4-methylpenten-1, and octen-1. The diene, when present, is typically a butadiene; 1,4-hexadiene; 1, 5-hexadiene, or ethylidenenorbornene. Component (B) is prepared by adding a peroxide cure system comprising an organic peroxide and at least one crosslinking aid that is selected from poly (1,2-butadiene) and furan derivatives, to a mixture of the components (B) (1) (a), (b), and (c) and (B) (2) and subjecting the mixture to curing conditions while the mixture is chewed to effect the desired dynamic partial cure. Preferably, components (B) (l), (a), (b) and (c) are formed in a reactor or series of reactors in at least two stages, first polymerizing propylene to form component (a) and then polymerizing ethylene and propylene or ethylene and butene, in the presence of the component ( a), and the catalyst used in the first stage, to form the components (b) and (c). The polymerization can be carried out in the liquid or gas phase or in a liquid-gas phase. In the alternative, components (a), (b) and (c) can be prepared separately and then mixed by melt kneading or melt mixing. The term "partially cured" means that the degree of cure, in terms of the gel content, is at least 80 percent and not more than 94 percent in cyclohexane. Preferably, the gel content is from 85 percent to 92 percent. The percentage of gel content is determined by soaking a test specimen of 38.10 millimeters by 19.05 millimeters by 2.03 millimeters in approximately 100 milliliters of cyclohexane at a temperature of about 23 ° C for 48 hours, stirring the sample and drying to a constant weight (approximately 72 hours) in a vacuum oven at 80 ° C. The percentage of gel is calculated as: % of gel = Initial weight of rubber -. Weight of rubber extracted x 100% Initial weight of rubber in the sample The preparation of the partially cured thermoplastic elastomer is described in greater detail in U.S. Patent No. 5,196,462, the process of which is incorporated herein by reference.

The melt blending or combination of the components (A), (B) of the present invention, can be carried out on an open roll, in an internal mixer (Banbury or Haake mixers), and single screw extrusion apparatus or twin screws. The polyolefin composition of the present invention may contain other conventional additives, for example, antioxidants, stabilizers, extender oils, such as paraffinic or naphthenic oils, fillers or fillers such as CaC 3, talc and zinc oxide or flame retardant agents. The evaluation of grain retention is highly subjective, since there are no standardized tests to measure this property per se. The aesthetic appearance of the part or final piece is currently the industry standard for determining the acceptability of the specimen. In order to assess the relative grain retention of the olefin polymer materials, the appearance of the specimens of the thermoformed sample prepared from raised sheets when viewed with the naked eye was compared to the compression fit value of the present standards. of the industry that is, polyvinyl chloride (PVC) and mixtures of PVC and acrylonitrile / butadiene / styrene (ABS). Both mixtures of PVC and PVC / ABS have good grain retention. The compression fit measures the percentage to which the polymer remains compressed after compression under normal conditions, ie, 22 hours at 100 ° C according to Method 395 B of the American Society for the Testing of Materials. For example, a compression adjustment of 100 percent is transferred to a sample that when compressed remains 100 percent compressed and does not recover to its original dimensions. Conversely, a sample with 0 percent compression adjustment bounces back to 100 percent of its initial dimensions. The lower the compression adjustment value, the better the material retains its original configuration. The PVC had a compression setting value of 80 and the PVC / ABS mixture had a value of 78. From a measurement of the compression adjustment value of the different materials, it was concluded that an equal compression setting value at or less than 85 percent would result in a material with acceptable grain retention in automotive parts.

Example 1 This experiment demonstrates the effect on the value of compression adjustment and grain retention when the different amounts of the propylene polymer material, and a partially reticulated thermoplastic elastomer composition were mixed together. Each sample was combined and granulated in a single screw extrusion apparatus of 6.35 centimeters (30: 1 L / D) using a tubular body temperature of 232 ° C to 260 ° C, with resulting melting temperatures of 232 ° C. 260 ° C. The screw was equipped with a mixing section to ensure proper melt mixing. The granules of the polymer of the mixing step were subsequently formed into 1.01 millimeter flat sheets using a 3.81 centimeter (30: 1 L / D) single screw extrusion apparatus equipped with a 24.13 centimeter sheet die. The tubular body temperatures varied from 232 ° C to 274 ° C with melting temperatures resulting from 260 ° C to 279 ° C. Each sheet was embossed with an 18 x 16 square mesh screen using a heated Carver press. The platens of the upper and lower press were heated to 121 ° C. The sieve pattern was embedded in the sheet using a force of 10 tons for 10 seconds. The relief sheet was formed into beakers of 7.62 centimeters in diameter by 5.08 centimeters in depth using thermoforming aided by plug. Both the stopper and the mold were heated to 38 ° C. The thermoforming processing conditions were brought to the optimum for each sheet formulation so that a better case comparison could be made between each formulation. Grain retention was determined by examining the embossed parts with the naked eye after thermoforming. The thermoformed pieces of each formulation were compared side by side and classified from best to worst, using the pattern retention in relief and the absence of wall thinning as the main criteria. Component (A) was a composition consisting of: (1) 100 parts by weight of a propylene polymer material comprising (a) 33 percent of a random copolymer of propylene-ethylene having an ethylene content of 3.3 percent and an isotactic index, defined as the xylene insoluble fraction of 94, (b) 8.3 percent of a fraction of the semi-crystalline ethylene-propylene copolymer containing ~ 83 percent ethylene, and (c) 58.7 percent of the amorphous ethylene-propylene copolymer fraction containing ~ 22 percent ethylene. (2) 0.2 part by weight of the Tinuvin 123 stabilizer that can be obtained commercially from Ciba-Geigy by 100 parts of the propylene polymer material (pph). (3) 0.2 pph of (2- (2-hydroxy-3,5-di-ter-amiphenyl) -2H-benzotriazole), (4) 0.2 pph of Chi assorb 119 a light stabilizer, commercially obtainable from Ciba-Geigy , and (5) 0.2 pph of Irganox B-225 an antioxidant of (2, 2-bis [[3- [3,5-bis (1,1-dimethylethyl) -4-hiroxy-benzenepropanoate and tris (2,4-di-tert-butylphenyl) phosphite as a 50/50 mixture] ) that can be obtained commercially from Ciba-Geigy. Component B was a composition comprising: (1) 42.6 percent of a thermoplastic elastomer consisting of (i) 35 percent of a propylene homopolymer having an isotactic index, defined as the insoluble fraction of xylene, of 97.5, (ii) 6.9 percent of a semi-crystalline ethylene-propylene copolymer that is insoluble in xylene at room temperature (iii) 58.1 percent of an amorphous ethylene-propylene copolymer rubber that is soluble in xylene at room temperature. (2) 18.65 percent of an ethylene / propylene / ethylideneorbornene terpolymer rubber containing 69 percent ethylene and 4 percent ethylideneorbornene, which has a Mooney viscosity of 60 ML (1 + 4) at 125 ° C, which it can be obtained commercially from Enichem. (3) 6.4 percent CaC03, (4) 1.86 percent ZnO, (5) 0.32 percent tetrakis (methylene (3, 5-di-tert-buty1-4-hydroxyhydrocinnamate) methane, (6) 0.16 percent cent of 4,4 '-thio-bis- (6-tert-butyl-m-cresol). (7) 21.31 percent paraffin oil, (8) 1.49 percent 2, 5-dimethyl-2, 5 -t-butyl-peroxyhexane, which was added as 50 percent of the active peroxide in the clay, (9) 0.8 percent of Struktol TR 016, a mixture of salts and esters of fatty acid, which can be obtained commercially from Struktol Company, (10) 5.34 percent polybutadiene added as 65 percent active polybutadiene on silica, and (11) 1.07 percent zinc salt of mercaptobenzothiazole.

TABLE 1 Component Component Retention Value of A (%) (B) (%) Grade Adjustment Qualitative Compression 90 10 90 Poor 80 20 87 Regular-Good 70 30 85 Good 60 40 84 Good 50 50 75 Good 40 60 73 Good 70 65 Regular- Poor The data shows that when too much propylene polymer material is present (Component (A)) (> 70 percent), the grain retention was poor.

When too much of the partially crosslinked thermoplastic olefin elastomer (Component (B)) (> 60 percent) was present, there was also inadequate grain retention. Other particularities, advantages and embodiments of the invention disclosed herein will be readily apparent to those skilled in the art after reading the aforementioned expositions. In this regard, even though the specific embodiments of the invention have been described in considerable detail, any variation and modification of these embodiments may be made without departing from the spirit and scope of the invention as described and claimed.

Claims (8)

CLAIMS:

1. A polyolefin composition comprising, by weight, (A) from 40 percent to 70 percent of a propylene polymer material consisting essentially of: (1) from 10 percent to 50 percent of a homopolymer of propylene having an isotactic Index of about 80 percent to about 99 percent, or a copolymer selected from the group consisting of (a) propylene and ethylene (b) propylene, ethylene and an alpha-olefin CH2 = CHR, in where R is a straight or branched chain alkyl group of 2 to 8 carbon atoms, and (c) propylene and an alpha-olefin as defined above (1) (b), the copolymer contains 85 100 to 99 percent propylene and has an isotactic index greater than 80 percent to about 98 percent, (2) 3 percent to 20 percent of a fraction of the essentially linear semi-crystalline copolymer that has a crystallinity from about 20 percent to about 60 p percent by differential scanning calorimetry (DSC), wherein the copolymer is selected from the group consisting of (a) ethylene and propylene containing more than 50 percent ethylene; (b) ethylene, propylene, an alpha-olefin as defined above (1) (b), containing from 1 percent to 10 percent of an alpha-olefin and more than 50 by ethylene up to 98 percent a hundred as much ethylene as alpha-olefin; and (c) 'ethylene and an alpha-olefin as defined in (1) (b) containing more than 50 percent and up to 98 percent alpha-olefin, whose copolymer is insoluble in xylene at room temperature, and (3) from 40 percent to 80 percent of a fraction of the copolymer selected from the group consisting of a copolymer of (a) ethylene and propylene, wherein the copolymer contains from 20 percent to less than 40 percent of ethylene; (b) ethylene, propylene, and an alpha-olefin as defined in (1) (b), wherein the alpha-olefin is present in an amount of 1 percent to 10 percent, and the amount of ethylene and alpha - olefin present is from 20 percent to less than 40 percent; and (c) ethylene and an alpha-olefin as defined in (1) (b), containing from 20 percent to less than 40 percent alpha-olefin, and optionally containing from 0.5 percent to 10 percent of a diene, the fraction of the copolymer (3) being soluble in xylene at room temperature, and having an intrinsic viscosity of 1.7 to 3.0 deciliters per gram, wherein the total amount of the fractions (2) and (3), based on the total composition of the olefin polymer is from about 65 percent to 80 percent, the weight ratio of fractions (2) / (3) is from 0.1 to about 0.3, and the total content of ethylene or alpha -olefin of 4 to 8 carbon atoms or combination thereof in the fractions (2) + (3) being less than 50 percent, and (B) from 60 percent to 30 percent of an elastomer composition of partially crosslinked thermoplastic olefin consisting essentially of: (1) from 20 parts to 80 parts by weight of the thermoplastic elastomer consisting essentially of: (a) from 20 percent to 70 percent of a propylene homopolymer having an isotactic index greater than 90, or a crystalline propylene copolymer with ethylene and / or an alpha-olefin of 4 to 8 carbon atoms having a propylene content greater than 85 percent, and an isotactic index greater than 85 percent; (b) from 30 percent to 75 percent of an amorphous ethylene-propylene or ethylene-butene copolymer fraction, optionally containing from 1 percent to 10 percent of a diene, which is soluble in xylene at room temperature and containing from 30 percent to 70 percent ethylene; and (c) from 3 percent to 30 percent of a semicrystalline ethylene-propylene or ethylene-butene copolymer that is insoluble in xylene at room temperature containing more than 90 percent ethylene; and, (2) from 80 parts to 20 parts by weight of an ethylene / propylene / diene terpolymer rubber containing from 1 percent to 10 percent of a diene and 30 percent to 70 percent of ethylene.

2. The composition of claim 1, wherein the amount of component (B) is from 50 percent to 30 percent.

3. The composition of claim 1, wherein component (A) (1) is a propylene / ethylene copolymer, (A) (2) is an ethylene / propylene copolymer, and (A) (3) is a ethylene / propylene copolymer. The composition of claim 1, wherein component (B) (1) (a) is a propylene homopolymer, (B) (1) (b) is an ethylene / propylene copolymer, and (B) ( 1) (c) is an ethylene / propylene copolymer. 5. A relief sheet comprising the composition of claim 1. 6. A relief sheet comprising the composition of claim 2. 7. A relief sheet comprising the composition of claim 3. 8. A sheet in Embodiment comprising the composition of claim 4.