Polyolefin blend and dicing tape backing film

Abstract

The present invention relates to a polypropylene blend comprising a propylene-based elastomer and a propylene copolymer wherein the propylene-based elastomer comprises at least 60 wt% of propylene-derived units and 1 to 35 wt% of at least one comonomer-derived unit selected from ethylene and a C4-C20 alpha-olefin, based on the total weight of the propylene-based elastomer, wherein the propylene-based elastomer has a heat of fusion of less than 80 J / g, and wherein the propylene copolymer is a copolymer of propylene and at least one comonomer selected from ethylene and a C4-C20 alpha-olefin, a weight average molecular weight from greater than 8000 g / mol, or greater than 10000 g / mol, or greater than 12000 g / mol, or greater than 20000 g / mol to less than 1,000,000 g / mol, or less than 800,000 g / mol.

Description

Technical Field

[0001] The disclosure of the present application relates to polypropylene blends comprising a propylene-based elastomer and a propylene copolymer; and a cutting tape backing film obtained therefrom. Background Art

[0002] Dicing tape is a special adhesive tape used in the semiconductor wafer dicing process. This dicing tape can firmly hold the wafer and maintain stability during dicing, thus preventing the wafer from moving or being damaged. Dicing tape plays a key role in the manufacture of integrated circuits and other semiconductor devices because it helps to ensure precise cutting size and shape, such as Figure 6 shown.

[0003] Dicing tapes can be made of materials such as polyvinyl chloride (PVC), polyethylene terephthalate (PET), polyolefin backing materials with adhesives to hold the wafer or substrate in place. In some cases, dicing tapes have a release liner that is removed before mounting the dicing tape on the back side of the wafer, with various adhesive strengths designed for various wafer sizes and materials.

[0004] PVC and PET are commonly used as backing materials for cutting tapes. PVC has excellent performance in terms of coloring properties, processing properties, scratch resistance, weather resistance, etc. Plasticizers are added to PVC for the purpose of imparting flexibility because the PVC film itself has rigidity, which is prone to damage during wafer grinding. However, depending on the plasticizer used, there are problems such as poor compatibility with adhesives, poor stability of adhesive films, and significant exudation of plasticizers. PET also has high stiffness and tends to cause warping problems.

[0005] CN113811565B discloses a substrate film for cutting tape that can take into account both heat resistance and isotropy, the substrate comprising (1) linear low-density polyethylene; and (2) block polypropylene copolymerized with ethylene or homopolypropylene polymerized by polymerizing propylene alone. The storage modulus (E') of the substrate film at 100°C is 20 to 200 MPa, the stress in the MD direction and TD direction (at 100% elongation) is 5 MPa or more and less than 20 MPa, and the thickness is 50 to 300 μm. However, compared with polypropylene resins, polyethylene resins have a lower melting point, so there is still a problem of lack of heat resistance and thermal deformation at high temperatures or in exothermic processes such as wafer cutting and grinding.

[0006] JP4916290B2 provides a substrate film for cutting, characterized in that it has less residual debris during the cutting process with the semiconductor wafer, can reduce waste, and has excellent static static static removal performance. This technical solution mainly uses multiple components such as styrene-butadiene copolymer (SEBS) and polypropylene resin (PP). However, due to the large difference in the chemical structure of styrene-butadiene copolymer (SEBS) and polypropylene resin (PP), it is easy to cause defects in formula compatibility and performance stability.

[0007] JP2008153586A also provides a cutting substrate film for reducing the problem of residual debris during the cutting process of the base film, but there is still room for further optimization in terms of the comprehensive improvement of other key properties of the base film and the uniformity of the lateral and longitudinal properties.

[0008] WO2020218468A1 mainly proposes a solution based on polypropylene and polyolefin elastomers for the softness and optical requirements of the base film. The solution requires the internal turbidity to be less than 20%, the glossiness of at least one surface to be less than 40%, and the tensile elastic modulus in the machine direction to be less than 600MPa. However, there is still room for further optimization for the comprehensive improvement of other key properties of the base film and the uniformity of the transverse and longitudinal properties.

[0009] JP6472972B2 and CN114603961A also reported respectively the production of resin compositions for cutting tape substrates and protective film substrates for cutting integrated circuit packaging substrates. The former uses multiple components such as ethylene α, β-unsaturated carboxylic acid copolymers, multi-component copolymers and polyolefins. The latter uses multiple components such as low-density polyethylene, metallocene linear low-density polyethylene, ethylene-vinyl acetate copolymers and / or polyethylene elastomers, nano zinc oxide, coupling agents, diluents, etc. The formula is complex, and there are significant chemical structure differences and compatibility issues between the components, which easily cause fluctuations and anisotropy in the performance of the base film.

[0010] Therefore, there is still a need in the art for a cutting tape backing film with improved properties, particularly a cutting tape backing film with good compatibility, tensile strength, flexibility, elongation, tear strength and excellent optical properties.

[0011] Technology Development

[0012] Polyolefin substrate films are new types of base films made of polyolefin copolymers, showing good light transmittance, soft texture, waterproof surface and limited small molecule precipitation to ensure cleanliness at the wafer level. At the same time, the soft film is conducive to good adaptation to the wafer process, so that a part of the machine vibration during the cutting process can be absorbed. Compared with PE film, these films have better heat resistance, making it suitable for high temperature conditions of adhesive coating and drying process. The excellent tensile properties and wear resistance of polyolefin substrates also make it a strong alternative to traditional backing materials.

[0013] The technical problems to be solved by the present invention are:

[0014] Therefore, the present invention is completed in view of the above problems, and its purpose is to provide a solution for a substrate film based on a casting process. By adding a propylene-based elastomer to the propylene random copolymer system, such as a propylene-based elastomer provided by the brand Vistamaxx, the compatibility of each component can be greatly improved, and at the same time, the comprehensive performance of the base film in multiple key indicators such as flexibility, tensile properties, and elongation can be improved under the condition of reducing the thickness of the base film. And maintain excellent light transmittance and balance the horizontal and vertical properties. These properties are critical for the application of cutting tapes. Summary of the invention

[0015] In one class of embodiments, the present invention provides a polypropylene blend comprising a propylene-based elastomer and a propylene copolymer, wherein the propylene-based elastomer comprises at least 60 wt% propylene-derived units and 1 to 35 wt% of at least one selected from ethylene and C4-C 20 The propylene-based elastomer comprises units derived from a comonomer of an α-olefin, based on the total weight of the propylene-based elastomer, wherein the heat of fusion of the propylene-based elastomer is less than 80 J / g, wherein the melting point of the propylene-based elastomer is less than or equal to 105°C, and wherein the propylene copolymer is propylene and at least one selected from ethylene and C4-C 20 The copolymer of the comonomer of α-olefin has a weight average molecular weight of greater than 8000 g / mol, or greater than 10000 g / mol, or greater than 12000 g / mol, or greater than 20000 g / mol to less than 1,000,000 g / mol, or less than 800,000 g / mol.

[0016] In another class of embodiments, the present invention provides a slicing tape backing film obtained from the above polypropylene blend.

[0017] The present invention also relates to the following embodiments:

[0018] 1. A polypropylene blend comprising a propylene-based elastomer and a propylene copolymer, wherein the propylene-based elastomer comprises at least 60 wt% propylene-derived units and 1 to 35 wt% of at least one selected from ethylene and C4-C 20 The propylene-based elastomer comprises units derived from a comonomer of an α-olefin, based on the total weight of the propylene-based elastomer, wherein the heat of fusion of the propylene-based elastomer is less than 80 J / g, wherein the melting point of the propylene-based elastomer is less than or equal to 105°C, and wherein the propylene copolymer is propylene and at least one selected from ethylene and C4-C 20 The copolymer of the comonomer of α-olefin has a weight average molecular weight of greater than 8000 g / mol, or greater than 10000 g / mol, or greater than 12000 g / mol, or greater than 20000 g / mol to less than 1,000,000 g / mol, or less than 800,000 g / mol.

[0019] 2. The polypropylene blend according to embodiment 1, wherein the content of propylene-derived units in the propylene-based elastomer is from a lower limit of 60 wt%, 65 wt%, 70 wt%, 75 wt%, 80 wt%, 84 wt%, 85 wt% to an upper limit of 85 wt%, 90 wt%, 92 wt%, 94 wt%, 95 wt%.

[0020] 3. The polypropylene blend according to any one of the above embodiments, wherein at least one of the propylene-based elastomers is selected from ethylene and C4-C 20 The content of comonomer-derived units of alpha-olefins is 5-35 wt%, or 7-30 wt%, or 8-25 wt%, or 8-20 wt%, or 8-18 wt%.

[0021] 4. The polypropylene blend according to any of the above embodiments, wherein the propylene-based elastomer has a crystallinity of 2% to 65% of the crystallinity of isotactic polypropylene.

[0022] 5. The polypropylene blend according to any one of the above embodiments, wherein the propylene-based elastomer has a fractional melt flow rate (MFR) of 2 to 20 g / 10 min.

[0023] 6. The polypropylene blend according to any one of the above embodiments, wherein at least one of the propylene-based elastomers is selected from ethylene and C4-C 20 The α-olefin comonomer is selected from ethylene, 1-hexene or 1-octene, preferably ethylene.

[0024] 7. The polypropylene blend according to any one of the above embodiments, wherein the heat of fusion of the propylene-based elastomer is from a lower limit of 1.0 J / g, 1.5 J / g, 3.0 J / g, 4.0 J / g, 6.0 J / g to an upper limit of 35 J / g, 40 J / g, 50 J / g, 60 J / g, 70 J / g, 75 J / g, 80 J / g.

[0025] 8. The polypropylene blend according to any of the above embodiments, wherein the propylene-based elastomer may further comprise diene-derived units.

[0026] 9. The polypropylene blend according to embodiment 8, wherein the diene is selected from 1,4-hexadiene, 1,6-octadiene, 5-methyl-1,4-hexadiene, 3,7-dimethyl-1,6-octadiene, 1,4-cyclohexadiene, 1,5-cyclooctadiene, 1,7-cyclododecadiene, tetrahydroindene, norbornadiene, methyl-tetrahydroindene, cyclopentadiene, bicyclo-(2.2.1)-hept-2,5-diene, alkenyl norbornene, Ethylidene norbornene, 5-methylene-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, vinylcyclohexene, allylcyclohexene, vinylcyclooctene, 4-vinylcyclohexene, allylcyclodecene, vinylcyclododecene.

[0027] 10. The polypropylene blend according to embodiment 8, wherein the content of the propylene-based elastomeric diene-derived units ranges from a lower limit of 0.1 wt%, 0.2 wt%, 0.3 wt%, 0.5 wt%, 1 wt%, 3 wt%, 5 wt% to an upper limit of 1.5 wt%, 2.5 wt%, 3 wt%, 4.5 wt%, 5 wt%, 7 wt%, 10 wt%, 15 wt%.

[0028] 11. The polypropylene blend according to any one of the above embodiments, wherein the content of the propylene-based elastomer is 6 wt% to 30 wt%, 10 wt% to 30 wt%, 10 wt% to 25 wt%, based on the total weight of the polypropylene blend.

[0029] 12. The polypropylene blend according to any of the above embodiments, wherein the content of the propylene copolymer is 70 wt% to 94 wt%, 70 wt% to 90 wt%, 75 wt% to 90 wt%, based on the total weight of the polypropylene blend.

[0030] 13. The polypropylene blend according to any one of the above embodiments, wherein the polypropylene blend is in the form of a monolayer film or a multilayer film.

[0031] 14. The polypropylene blend according to any of the above embodiments, wherein the propylene copolymer has a 1% secant flexural modulus of 100 to 2300 MPa, preferably 200 to 2100 MPa, more preferably 300 to 2000 MPa and most preferably 400 to 1800 MPa.

[0032] 15. The polypropylene blend according to any of the previous embodiments, wherein the propylene copolymer has a melt flow rate (MFR) from 0.1 dg / min to 2500 dg / min, preferably from 0.3 dg / min to 500 dg / min.

[0033] 16. A slitting tape backing film comprising the polypropylene blend according to any one of the above embodiments.

[0034] 17. Use of the polypropylene blend according to any one of embodiments 1 to 15 in integrated circuits, chips, and semiconductor materials.

[0035] 18. A polypropylene blend comprising a propylene-based elastomer and a propylene copolymer, wherein the propylene-based elastomer has a weight average molecular weight of 100,000 to 300,000 g / mol, a melt flow rate of 2.5 to 10 g / 10 min at 230° C., 2.16 kg according to ASTM 1238, and a density of 0.85 g / cm 3 Up to 0.88g / cm 3 and the content is 6 wt % to 30 wt %, based on the total weight of the polypropylene blend, wherein the propylene copolymer is prepared using a catalyst system comprising an activator and a quinolyl diamino catalyst or a Group 4 bis(phenolate) complex, contains 4 to 16 wt % ethylene and has a content of 70 wt % to 94 wt %, based on the total weight of the polypropylene blend. BRIEF DESCRIPTION OF THE DRAWINGS

[0036] Figure 1 The 1% secant modulus of commercial products and the blends prepared in the technical solution of the present invention are shown.

[0037] Figure 2 The tensile strength of the commercially available product and the blend prepared in the technical solution of the present invention are demonstrated.

[0038] Figure 3 The elongation at break of commercially available products and the blends prepared in the technical solution of the present invention are shown.

[0039] Figure 4 The Elmendorf tear of the blend prepared in the technical solution of the present invention is shown.

[0040] Figure 5 The optical properties of the blend prepared in the technical solution of the present invention are demonstrated.

[0041] Figure 6 is a schematic diagram involving semiconductor cutting. DETAILED DESCRIPTION OF THE INVENTION

[0043] Before disclosing and describing the compounds, components, compositions and / or methods of the present invention, it should be understood that, unless otherwise indicated, the present invention is not limited to specific compounds, components, compositions, reactants, reaction conditions, ligands, metallocene structures, catalyst structures, or the like, as these may vary unless otherwise specified. It should also be understood that the various terms used herein are only for the purpose of describing specific embodiments and are not intended to be limiting.

[0044] In several classes of embodiments of the present invention, the present disclosure relates to polypropylene blends comprising a propylene-based elastomer and a propylene copolymer, wherein the propylene-based elastomer comprises at least 60 wt% propylene-derived units and 1 to 35 wt% of at least one selected from ethylene and C4-C 20 The propylene-based elastomer comprises units derived from a comonomer of an α-olefin, based on the total weight of the propylene-based elastomer, wherein the heat of fusion of the propylene-based elastomer is less than 80 J / g, wherein the melting point of the propylene-based elastomer is less than or equal to 105°C, and wherein the propylene copolymer is propylene and at least one selected from ethylene and C4-C 20 The copolymer of the comonomer of α-olefin has a weight average molecular weight of greater than 8000 g / mol, or greater than 10000 g / mol, or greater than 12000 g / mol, or greater than 20000 g / mol to less than 1,000,000 g / mol, or less than 800,000 g / mol.

[0045] According to the polypropylene blend of the present invention, the content of propylene-derived units in the propylene-based elastomer is from a lower limit of 60wt%, 65wt%, 70wt%, 75wt%, 80wt%, 84wt%, 85wt% to an upper limit of 85wt%, 90wt%, 92wt%, 94wt%, 95wt%.

[0046] According to the polypropylene blend of the present invention, at least one of the propylene-based elastomers is selected from ethylene and C4-C 20 The content of comonomer-derived units of α-olefins is 5-35 wt%, or 7-30 wt%, or 8-25 wt%, or 8-20 wt%, or 8-18 wt%.

[0047] According to the polypropylene blend of the present invention, the crystallinity of the propylene-based elastomer is 2% to 65% of the crystallinity of isotactic polypropylene.

[0048] According to the polypropylene blend of the present invention, the fractional melt flow rate (MFR) of the propylene-based elastomer is 2-20 g / 10 min.

[0049] According to the polypropylene blend of the present invention, at least one of the propylene-based elastomers is selected from ethylene and C4-C 20 The α-olefin comonomer is selected from ethylene, 1-hexene or 1-octene, preferably ethylene.

[0050] According to the polypropylene blend of the present invention, the heat of fusion of the propylene-based elastomer is from a lower limit of 1.0 J / g, 1.5 J / g, 3.0 J / g, 4.0 J / g, 6.0 J / g to an upper limit of 35 J / g, 40 J / g, 50 J / g, 60 J / g, 70 J / g, 75 J / g, 80 J / g.

[0051] According to the polypropylene blend of the present invention, the propylene-based elastomer may further comprise diene-derived units.

[0052] According to the polypropylene blend of the present invention, the diene is selected from 1,4-hexadiene, 1,6-octadiene, 5-methyl-1,4-hexadiene, 3,7-dimethyl-1,6-octadiene, 1,4-cyclohexadiene, 1,5-cyclooctadiene, 1,7-cyclododecadiene, tetrahydroindene, norbornadiene, methyl-tetrahydroindene, cyclopentadiene, bicyclo-(2.2.1)-hept-2,5-diene, alkenyl norbornene, ethylidene cyclohexene, allylcyclohexene, vinylcyclooctene, 4-vinylcyclohexene, allylcyclodecene, and vinylcyclododecene.

[0053] According to the polypropylene blend of the present invention, the content of the propylene-based elastomeric diene-derived units ranges from a lower limit of 0.1 wt%, 0.2 wt%, 0.3 wt%, 0.5 wt%, 1 wt%, 3 wt%, 5 wt% to an upper limit of 1.5 wt%, 2.5 wt%, 3 wt%, 4.5 wt%, 5 wt%, 7 wt%, 10 wt%, 15 wt%.

[0054] According to the polypropylene blend of the present invention, the content of the propylene-based elastomer is 6 wt % to 30 wt %, 10 wt % to 30 wt %, or 10 wt % to 25 wt %, based on the total weight of the polypropylene blend.

[0055] According to the polypropylene blend of the present invention, the content of the propylene copolymer is 70 wt% to 94 wt%, 70 wt% to 90 wt%, or 75 wt% to 90 wt%, based on the total weight of the polypropylene blend.

[0056] According to the polypropylene blend of the present invention, the molecular weight distribution (Mw / Mn) of the propylene copolymer is from 1.5 to 10, preferably from 1.6 to 7, more preferably from 1.7 to 5 and most preferably from 1.8 to 4.

[0057] According to the polypropylene blend of the present invention, the propylene copolymer has a 1% secant flexural modulus of 100 MPa to 2300 MPa, preferably 200 MPa to 2100 MPa, more preferably 300 MPa to 2000 MPa and most preferably 400 MPa to 1800 MPa.

[0058] According to the polypropylene blend of the present invention, the melt flow rate (MFR) of the propylene copolymer is from 0.1 dg / min to 2500 dg / min, preferably from 0.3 dg / min to 500 dg / min.

[0059] Propylene-based elastomers

[0060] The propylene-based elastomer may be a propylene-derived unit with C2 and C 4-10 A copolymer of α-olefin derived units having: (a) C2 and / or C 4-10 The content of α-olefin derived units ranges from about 5 to 30 wt%, preferably from about 5 to 25 wt%, more preferably from about 8 to about 25 wt%, and even more preferably from 8 to 15 wt%; (b) ICD is greater than or equal to 75%, greater than 80%, greater than 85%, and preferably greater than 90%; (c) Tm ranges from about 25°C to about 110°C, preferably from about 25°C to about 85°C, 25°C to about 75°C, about 25°C to about 65°C, about 3 (d) Hf ranges from about 0.5 to about 70 J / g, preferably from about 0.5 to about 50 J / g, or more preferably from about 5 to about 40 J / g; (e) Mw / Mn ranges from about 1.2 to about 4.5; and (f) MFR ranges from about 0.1 to about 40 g / 10 min, preferably from about 1 to about 20 g / 10 min, more preferably from about 2 to about 5 g / 10 min.

[0061] Propylene derived units and one or more C2 and C4-10 The C2 and / or C 4-10 The α-olefin derived units content ranges from about 5 to 30 wt%, preferably from about 5 to 25 wt%, more preferably from about 8 to about 25 wt%, even more preferably from 8 to 15 wt%, based on the weight of the copolymer. The balance of the propylene copolymer may be one or more of the C2 and C 4-10 Thus, the propylene derived units useful in the present invention are combined with one or more C2 and C 4-10 The average propylene content of the copolymer of alpha-olefin derived units is from about 70 to about 95 wt%, more preferably from about 75 to about 95 wt%, more preferably from about 75 to about 92 wt%, most preferably from about 85 to about 92 wt%, based on the weight of the copolymer.

[0062] Propylene derived units with one or more C2 and C 4-10The ICD in the copolymer of α-olefin derived units is greater than 75%, greater than 80%, greater than 85%, preferably greater than 90%. ICD is an indicator of intermolecular uniformity. The intermolecular composition distribution of the copolymer is determined by thermal fractionation in a solvent. Typical solvents are saturated hydrocarbons such as hexane or heptane. The thermal fractionation procedure is as follows. The ICD can be determined by the weight of the polymer separated as one or two adjacent soluble fractions, and the remainder of the polymer in immediately proceeding or consecutive fractions; and wherein the difference in the weight % content of the copolymer monomer in each of these fractions is not greater than 20 wt% (relative), preferably 10 wt% (relative) of the average weight % of the comonomer in the copolymer. The fractions are obtained at a temperature increase of about 8°C between the sections. The ICD of the copolymers was determined by thermal fractionation in hexane as follows: About 30 g of the semi-amorphous polymer was cut into small cubes of about 1 / 8 inch (0.32 cm) on the side and introduced into a thick-walled glass bottle sealed with a screw cap along with 50 mg of Irganox 1076, an antioxidant commercially available from Ciba Specialty Chemicals (Basel, Switzerland). Then, 425 ml of hexane (a major mixture of n- and iso-isomers) was added to the contents of the bottle and the sealed bottle was maintained at about 23° C. for 24 hours. At the end of this period, the solution was decanted and the residue was treated with additional hexane for an additional 24 hours at 23° C. At the end of this period, the two hexane solutions were combined and evaporated to give a polymer residue soluble at 23° C. Sufficient hexane was added to the residue to bring the volume to 425 ml, and the bottle was maintained at about 31° C. in a covered circulating water bath for 24 hours. The soluble polymer was decanted, and additional amounts of hexane were added at about 31° C. for another 24 hours before decanting. In this manner, semi-amorphous polymer fractions soluble at 40° C., 48° C., 55° C., and 62° C. were obtained at increasing temperatures of about 8° C. between stages. The soluble polymer was dried, weighed, and analyzed for composition as wt% ethylene content. In order to produce copolymers having the desired narrow intermolecular composition distribution, it is beneficial if (1) a metallocene catalyst is used, preferably a metallocene catalyst that provides a single statistical mode of addition of only first and second monomer sequences, and (2) the copolymer is thoroughly mixed in a continuous flow stirred tank polymerization reactor that provides only a single polymerization environment for substantially all of the polymer chains in the copolymer.

[0063] Propylene derived units and one or more C2 and C4-C 10The Tm range of the copolymer of α-olefin derived units is from about 25° C. to about 110° C., preferably from about 25° C. to about 85° C., 25° C. to about 75° C., about 25° C. to about 65° C., about 30° C. to about 75° C., more preferably from about 30° C. to about 60° C. Tm is measured using the DSC procedure described above.

[0064] Propylene derived units and one or more C2 and C4-C 10 H of copolymers of α-olefin derived units f The range is about 0.5 to about 70 J / g, preferably about 0.5 to about 50 J / g, or more preferably about 5 to about 40 J / g. Preferably, the propylene derived units and one or more C2 and C4-C 10 The copolymer of α-olefin derived units also has a heat of fusion Hf greater than or equal to about 1 J / g, preferably greater than or equal to about 2.5 J / g, preferably greater than or equal to about 5 J / g. As described above, Hf is determined using a differential scanning calorimeter (DSC) according to the procedure described in ASTM E794-06. The heat of fusion (once melted, Hf, or once crystallized, the heat of crystallization, Hc, is determined using the area under the DSC curve. If the Hf value from the melt is different from the Hf value obtained for the heat of crystallization, the value from the melt (Tm) should be used).

[0065] Propylene derived units and one or more C2 and C4-C 10 The Mw / Mn range for copolymers of alpha-olefin derived units is from about 1.2 to about 4.5. Techniques for determining molecular weight (Mn, number average molecular weight, and Mw, weight average molecular weight) and molecular weight distribution (Mn / Mw) can be found in U.S. Pat. No. 4,540,753, which is incorporated herein by reference, and in Macromolecules 1988, 21, 3360, which is also incorporated herein by reference. Mw and Mn can be determined by size exclusion chromatography (SEC), for example, 3D SEC, also known as GPC-3D. Mn / Mw, also known as the polydispersity index, is the ratio of Mw to Mn.

[0066] Propylene derived units and one or more C2 and C4-C 10 The MFR of the copolymer of α-olefin derived units ranges from about 0.1 to about 40 g / 10 min, preferably from about 1 to about 20 g / 10 min, more preferably from about 2 to about 5 g / 10 min. Also, the MFR is measured by ASTM D-1238 at 230°C and 2.16 kg.

[0067] In a preferred embodiment, the propylene derived units and one or more C2 and C4-C 10The copolymer of alpha-olefin derived units has a g' greater than or equal to about 0.99. g' is determined as previously described. Again, it is well known in the art that as the g' value decreases, long chain branching increases.

[0068] Propylene derived units and one or more C2 and C4-C 10 The copolymers of α-olefin derived units may be characterized by other properties as described below, such as Tc, density, % crystallinity, and the substantial absence of regio-errors corresponding to about 14.6 and about 15.7 ppm. 13 C NMR peak (the intensities of the peaks are approximately the same), mm triad tacticity index, propylene tacticity index m / r, and Mooney viscosity.

[0069] In a particular embodiment, the propylene derived units and one or more C2 and C4-C 10 The copolymer of α-olefin derived units may have any of the following: (i) a Tc of less than or equal to about 200°C, more preferably, less than or equal to 150°C; (ii) a density ranging from about 0.85 to about 0.92 g / cm 3 , more preferably, about 0.87-0.90 g / cm 3 , more preferably about 0.88 to about 0.89 g / cm 3 ; (iii) a % crystallinity ranging from 0.25% to 40%, preferably from about 0.25% to about 25%, more preferably from about 0.5% to about 22%, and most preferably from about 0.5% to about 20%; (iv) an mm triad tacticity index greater than or equal to 75%, greater than or equal to 80%, greater than or equal to 82%, greater than or equal to 85%, or greater than or equal to 90%; (v) there is substantially no region corresponding to about 14.6 and about 15.7 ppm - an error 13 C NMR peaks of approximately equal intensity; (vi) m / r greater than 1; and (vii) a Mooney viscosity less than 100, more preferably less than 75, even more preferably less than 60, and most preferably less than 30.

[0070] Propylene derived units and one or more C2 and C4-C 10 The Tc of the copolymer of alpha-olefin derived units may be less than or equal to about 200° C., more preferably, less than or equal to 150° C. Tc is measured using the DSC method discussed above.

[0071] At room temperature, the propylene-derived units and one or more C2 and C4-C 10 The density of the copolymers of α-olefin derived units may range from about 0.85 to about 0.92 g / cm 3 , more preferably about 0.87-0.90 g / cm3 , more preferably about 0.88 to about 0.89 g / cm 3 , which is measured by ASTM D-1505 test method.

[0072] Propylene derived units and one or more C2 and C4-C 10 The % crystallinity of copolymers of α-olefin derived units can range from 0.25% to 40%, preferably from about 0.25% to about 25%, more preferably from about 0.5% to about 22%, and most preferably from about 0.5% to about 20%, wherein the % crystallinity is determined using the DSC method described above. The heat of transition (Hf once melted, or the heat of crystallization, Hc once crystallized) is determined using the area under the DSC curve, and the crystallinity (also known as % crystallinity) can be calculated using the heat of transition (Hf once melted, or the heat of crystallization, Hc once crystallized, if the Hf value from the melt is different from the Hf value obtained for the heat of crystallization, the value from the melt (Tm) should be used). The % crystallinity (X%) is calculated using the following formula: [area under the curve (in J / g) / H° (in J / g)]*100, where H° is the heat of fusion of the homopolymer of the major monomer component. These values ​​for H° are obtained according to Polymer Handbook, 4th edition, published by John Wiley and Sons, New York 1999, with the exception of a value of 290 J / g used as the equilibrium heat of fusion (H°) for 100% crystalline polyethylene, a value of 140 J / g used as the equilibrium heat of fusion (H°) for 100% crystalline polybutene, and a value of 207 J / g (H°) used as the heat of fusion for 100% crystalline polypropylene.

[0073] Propylene derived units and one or more C2 and C4-C 10 The regions corresponding to about 14.6 and about 15.7 ppm are essentially absent from copolymers of alpha-olefin derived units - erroneous 13 C NMR peaks of approximately equal intensity. Corresponding to the region at about 14.6 and about 15.7 ppm - erroneous 13 The C NMR peaks are believed to be the result of stereoselective 2,1-misinsertion of propylene units into the growing polymer chain. In typical propylene-ethylene copolymers produced by constrained geometry non-metallocene catalysts, these peaks are of approximately equal intensity, and they represent about 0.02 to about 7 mol % propylene inserted into the homopolymer or copolymer chain. Propylene-derived units are stereoselective 2,1-misinsertion of propylene units into the growing polymer chain. 10 Copolymers of alpha-olefin derived units do not have regions corresponding to about 14.6 and about 15.7 ppm - False 13 C NMR peak and was produced using a metallocene catalyst.

[0074] Propylene derived units and one or more C2 and C4-C 10 The copolymer of alpha-olefin derived units also has greater than or equal to 75%, greater than or equal to 80%, greater than or equal to 82%, greater than or equal to 85%, or greater than or equal to 90% of the above 13 The mm triad tacticity index of three propylene units is measured by C NMR technique. 13 C-NMR spectroscopy determines the polymer microstructure discussed herein, including the concentrations of isotactic and syndiotactic diads ([m] and [r]), triads ([mm] and [rr]), and pentads ([mmmm] and [rrrr]). The samples were dissolved in d2-1,1,2,2-tetrachloroethane. The spectra were recorded at 125°C using a 100 MHz NMR spectrometer. The resonance peak of the polymer was mentioned as [mmmm] = 21.8 ppm. The calculations involved in characterizing the polymer by NMR follow the work of FA Bovey in "Polymer Conformation and Configuration," Academic Press, New York 1969 and J. Randall in "Polymer Sequence Determination, 13C-NMR Method," Academic Press, New York, 1977. The percentage of methylene sequences of length 2, %(CH2)2, is calculated as follows: the integral of the methyl carbons between 14-18 ppm (which is equivalent to the concentration of methylene sequences of length 2) divided by the sum of the integral of the methylene sequences of length 1 between 45-49 ppm and the integral of the methyl carbons between 14-18 ppm, multiplied by 100. This is a minimum calculated value for the amount of methylene contained in two or more sequences, since methylene sequences greater than 2 are excluded. The assignments are based on HN Cheong and JA Ewen, Makromol. Chem. 1989, 190, 1931. The mm triad stereoregularity index of a polymer is the relative stereoregularity of a sequence of three adjacent propylene units (a chain consisting of head-to-tail bonds), expressed as a binary combination of m and r sequences. For the copolymers of the present invention, it is usually expressed as the ratio of the number of units of a specified stereoregularity to all propylene triads in the copolymer. The index can be calculated based on the propylene copolymer's 13 The mm triad tacticity index (mm fraction) of the propylene copolymer is determined by CNMR spectroscopy and the following formula:

[0075]

[0076] Wherein PPP(mm), PPP(mr) and PPP(rr) represent the peak areas obtained from the methyl group in the second unit in the following three propylene unit chain (which consists of head-to-tail bonds):

[0077]

[0078] The propylene copolymers were measured as described in U.S. Pat. No. 5,504,172 and U.S. Pat. No. 6,642,316 (column 6, line 38 to column 9, line 18). 13 C NMR spectrum. The spectrum involving the methyl carbon region (19-23 parts per million (ppm)) can be divided into a first region (21.2-21.9 ppm), a second region (20.3-21.0 ppm) and a third region (19.5-20.3 ppm). Each peak in the spectrum is determined with reference to the article in the journal Polymer, Vol. 30 (1989), p. 1350, or the article in the journal Macromolecules, 17, (1984), 1950 (in the case of a conflict between the article in Polymer and the article in Macromolecules, the article in Polymer should be dominant (control)). In the first region, in the three propylene-derived unit chain represented by PPP (mm), the methyl group in the second unit resonates. In the second region, in the three propylene derived unit chains represented by PPP (mr), the methyl group in the second unit resonates, and in the units where its adjacent units are propylene derived units and ethylene derived units, the methyl group (PPE-methyl) in the propylene derived units resonates (at around 20.7 ppm). In the third region, in the three propylene derived unit chains represented by PPP (rr), the methyl group in the second unit resonates, and in the methyl group (EPE-methyl) in the propylene derived units where its adjacent units are ethylene units resonates (at around 19.8 ppm). The calculation of the mm triad stereoregularity index is outlined in the technology shown in U.S. Patent No. 5,504,172. It is possible to obtain the peak area of ​​propylene mistakenly inserted (2,1 and 1,3) from the total peak area of ​​the second and third regions (based on the peak area of ​​3 propylene units-chains (PPP (mr) and PPP (rr)) composed of head-to-tail bonds). Thus, the peak areas of PPP (mm), PPP (mr) and PPP (rr) can be evaluated, and the mm triad tacticity index of propylene units consisting of head-to-tail bonds can be determined. JA Ewen, "Catalytic Polymerization of Olefins", (Ewen method), Eds. T. Keii, K. Soga, Kodanska Elsevier Pub., Tokyo, 1986, p. 271 describes how the tacticity index of the propylene units can be determined based on the tacticity of the polymer.13 Further information on mm triad tacticity can be obtained by measuring C-NMR spectroscopy and as described in detail in paragraphs numbered

[0046] to

[0054] on page 8 of U.S. Patent No. 6,884,850, all of which are incorporated herein by reference.

[0079] Propylene derived units and one or more C2 and C4-C 10 The propylene stereoregularity index of the copolymer of α-olefin derived units, expressed as the ratio of m to r (m / r), may be greater than 1. 13 C NMR technique, the propylene stereoregularity index m / r is determined. The propylene stereoregularity index m / r is calculated as discussed in HN Cheng, Macromolecules, 17, 1950 (1984). The designation "m" or "r" describes the stereochemistry of the paired consecutive propylene groups, where "m" refers to meso and "r" refers to racemic. An m / r ratio of 0 to less than 1.0 generally describes a syndiotactic polymer, an m / r ratio of 1.0 describes an atactic material, and an m / r ratio greater than 1.0 describes an isotactic material. Isotactic materials can theoretically have a near-infinite ratio, and many byproduct atactic polymers have sufficient isotactic content, resulting in a ratio greater than 50. Propylene-derived units are preferably covalently bonded to one or more C2 and C4-C 10 The copolymers of α-olefin derived units may have isotactic stereoregular propylene crystallinity. As used herein, the term "stereoregular" means that the major number, i.e., greater than 80%, of the propylene derived units in the polypropylene (excluding any other monomers, such as ethylene) have the same stereochemical orientation of the 1,2-inserted and pendant methyl groups, either meso or racemic.

[0080] Propylene derived units and one or more C2 and C4-C 10 The copolymer of α-olefin derived units may have a Mooney viscosity ML (1+4) @ 125°C of less than 100, more preferably less than 75, even more preferably less than 60, most preferably less than 30.

[0081] In the embodiments herein, a metallocene catalyst is used to produce propylene derived units and one or more C2 and C4-C 10 In U.S. Pat. No. 6,500,563, the propylene derived units and one or more C2 and C4-C6-olefin derived units used in the present invention are described in detail in the form of "second polymer component (SPC)". 10The invention relates to copolymers of propylene derived units and one or more C2 and C4-C 10 Copolymers of alpha-olefin derived units may include copolymers prepared according to the procedures of WO 02 / 36651; U.S. Patent No. 6,992,158, and / or WO 00 / 01745. A preferred method of producing the copolymers is found in U.S. Patent No. 6,881,800. Preferred copolymers are sold under the trade name Vistamaxx. TM (ExxonMobil, Baytown TX). Suitable examples include: Vistamaxx TM 6202, Vistamaxx TM 3980FL, Vistamaxx TM 3020FL, Vistamaxx TM 6102, and Vistamaxx TM 3000.

[0082] Propylene copolymer

[0083] The propylene copolymers may be semi-crystalline polymers, each of which comprises propylene and 0-5 wt%, preferably 0.1-4 wt%, preferably 0.25-3 wt% of an α-olefin comonomer (based on the weight of the polymer). Preferably, the α-olefin comonomer is C2-C 10 α-olefins, preferably selected from ethylene, butene, pentene, hexene, heptene, octene, nonene and decene, preferably ethylene, butene, hexene and octene, more preferably ethylene. (For the present invention, when the copolymer is described as comprising propylene and one or more C2-C10 olefins or α-olefins, the C2-C10 olefins or α-olefins do not include C3, such as propylene).

[0084] Preferred semi-crystalline polymers have a melting point (Tm - second melt, determined by DSC as described above) of 100-170°C, preferably 110-170°C, preferably 125-170°C.

[0085] Preferred semi-crystalline polymers have a melt flow rate (ASTM 1238-D, 2.16 kg, 230° C.) of 0.1-200 dg / min, preferably 0.25-100 dg / min, preferably 0.5-50 dg / min, preferably 0.5-20 dg / min, preferably 1-20 dg / min.

[0086] Preferred semi-crystalline polymers have an elongation at break of 700% or less, preferably 300-700%, as measured by ASTM D638 (2 in / min / 50 mm / min, 0.125 inch (3.18 mm) thick injection molded specimens).

[0087] Preferred semi-crystalline polymers have a 1° secant flexural modulus of 100,000 psi to 250,000 psi (690-1720 MPa), preferably 150,000 psi to 250,000 psi (1035-1720 MPa), as measured by ASTM D-790A (0.05 in / min / 1.3 mm / min). "High crystalline polypropylenes" such as those having values ​​above 250,000 psi (1720 MPa) may also be used.

[0088] Any propylene polymer having 0-5 wt% comonomer, a melting point of 100-170°C and an MFR of 200 dg / min or less can be used in the practice of the present invention. Suitable examples include polymers produced with Ziegler-Natta catalyst systems, metallocene systems, and the like. The polymers can be prepared by any method, including solution, slurry, gas phase, supercritical or high pressure methods. In a particularly preferred embodiment, the propylene polymers that can be used herein have a molecular weight distribution (Mw / Mn) of 5 or less, preferably 1.5-4, preferably 1.5-3. In another preferred embodiment, preferred propylene polymers that can be used herein include those produced with metallocene catalyst systems. In another embodiment, preferred propylene polymers used herein include those having a composition distribution breadth index (CDBI) of 60% or more, preferably 70% or more, preferably 80% or more, preferably 90% or more. (CDBI is determined as described in WO 93 / 03093 with the modification that any fraction having a weight average molecular weight (Mw) below 25,000 g / mol is disregarded.) Preferred propylene polymers useful in the practice of this invention include those based on ACHIEVE TM Particularly useful grades include ACHIEVE TECHNOLOGY, available from ExxonMobil Chemical Company in Houston, Texas. TM 3854,ACHIEVE TM 1654E1, ACHIEVE TM 3825,ACHIEVE TM1605. Other preferred propylene polymers useful in the practice of the present invention include those propylene homopolymers and random copolymers available from ExxonMobil Chemical Company under the following grade designations: PP1024E4, PP1042, PP1032, PP1044, PP1052, PP1105E1, PP3155 and PP9852E1, PP9272, PP9513, PP9544, PP9562. In some cases, impact copolymers may be used in the practice of the present invention. Several (e.g., PP7032E2) are available from ExxonMobil Chemical Company.

[0089] The propylene copolymers described in the present invention may also be high melting point propylene polymers. For the purposes of the present invention, high melting point propylene polymers (HMPPs) are defined as propylene polymers having a peak melting point greater than 100°C (preferably greater than 110°C, preferably greater than 120°C, preferably greater than 130°C, preferably greater than 140°C, preferably greater than 150°C), preferably having a melt flow rate of 0.1-2000 dg / min (preferably 100 dg / min or less). Preferred HMPPs have a percent crystallinity greater than 35%, preferably greater than 40%, preferably greater than 45%, preferably greater than 50%.

[0090] In a preferred embodiment, the blend of the present invention comprises one or more HMPPs, each HMPP comprising propylene and preferably 0-5 wt% of an α-olefin comonomer (based on the weight of the polymer), preferably 0.1-4 wt%, preferably 0.25-3 wt%. Preferably, the α-olefin comonomer is C2-C 10 α-olefins, preferably selected from ethylene, butene, pentene, hexene, heptene, octene, nonene and decene, preferably ethylene, butene, hexene and octene, preferably ethylene. (For the purposes of the present invention, when a copolymer is said to comprise propylene and one or more C2-C 10 When olefins or α-olefins, the C2-C 10 Olefins or alpha-olefins do not include C3, such as propylene).

[0091] Preferably the HMPP has a melting point (Tm - second melting as measured by DSC as described above) of 105-170°C, preferably 110-170°C, preferably 125-170°C.

[0092] Preferred HMPPs have a melt flow rate (ASTM 1238-D, 2.16 kg, 230° C.) of 0.1-200 dg / min, preferably 0.25-100 dg / min, preferably 0.5-50 dg / min, preferably 0.5-20 dg / min, preferably 1-20 dg / min.

[0093] Preferred HMPPs have an elongation at break (measured by ASTM D 638, 2 in / min / 50 mm / min on 0.125 in (3.18 mm) thick injection molded specimens) of 700% or less, preferably 300-700%.

[0094] Preferred HMPPs have a 1° secant flexural modulus of 100,000 psi to 250,000 (690 to 1720 MPa), preferably 150,000 psi to 250,000 psi (1035 to 1720 MPa), as measured by ASTM D-790A (0.05 in / min / 1.3 mm / min).

[0095] "High crystalline polypropylenes," such as those having values ​​greater than 250,000 psi (1720 MPa), may also be used as HMPP in the present invention.

[0096] Any propylene polymer having 0-5wt% comonomer, a melting point of 100-170, and an MFR of 200dg / min or less can be used in the practice of the present invention as a HMPP. Suitable examples include polymers prepared by Ziegler-Natta catalyst systems, metallocene systems, and the like. The polymer can be prepared by any means, including solution, slurry, gas phase, supercritical or high pressure. In a particularly preferred embodiment, the HMPP useful herein has a molecular weight distribution (Mw / Mn) of 5 or less, preferably 1.5-4, preferably 1.5-3. In another preferred embodiment, the preferred HMPP useful herein include those prepared by metallocene catalyst systems. In another embodiment, the preferred HMPP useful herein include those having a composition distribution breadth index (CDBI) of 60% or more, preferably 70% or more, preferably 80% or more, preferably 90% or more. (CDBI is measured as described in WO 93 / 03093 with the modification that any fraction having a weight average molecular weight (Mw) less than 25,000 g / mol is disregarded.) Preferred HMPPs useful in the practice of this invention include those marketed by ExxonMobil Chemical Company under the trade name ACHIEVE TM Particularly useful grades include ACHIEVE available from ExxonMobil Chemical Company of Houston, Texas. TM 3854、ACHIEVE TM 1654E1, ACHIEVE TM 3825,ACHIEVE TM1605. Other preferred HMPPs useful in the practice of the present invention include those propylene homopolymers, and random copolymers, which are available from ExxonMobil Chemical Company under the following grade designations: PP1024E4, PP1042, PP1032, PP1044, PP1052, PP1105E1, PP3155 and PP9852E1, PP9272, PP9513, PP9544, PP9562.

[0097] The propylene copolymer of the present invention may also be a thermoplastic polymer, which is a propylene copolymer (random or block copolymer) of propylene-derived units and units selected from the following: ethylene and C4-C 20 The α-olefin derived units, in another embodiment, are typically selected from ethylene and C4-C 10 Units derived from α-olefins. Ethylene or C4-C 10 The α-olefin derived units are present in the copolymer in an amount of 0.1 wt% to 50 wt%, in another embodiment, 0.5 to 30 wt%, in yet another embodiment, 1 to 15 wt%, and in yet another embodiment, 0.1 to 5 wt%, wherein desirable copolymers comprise ethylene and C4-C6 hydrocarbons in any combination of any upper wt% limit and any lower wt% limit described herein. 20 The propylene copolymer will have a weight average molecular weight of greater than 8,000 g / mol in one embodiment, greater than 10,000 g / mol in another embodiment, greater than 12,000 g / mol in yet another embodiment, greater than 20,000 g / mol in yet another embodiment, less than 1,000,000 g / mol in yet another embodiment, and less than 800,000 in yet another embodiment, wherein desirable copolymers may include any upper molecular weight limit with any lower molecular weight limit described herein.

[0098] Particularly desirable propylene copolymers useful herein have a molecular weight distribution (Mw / Mn) of 1.5 to 10, in another embodiment 1.6 to 7, in yet another embodiment 1.7 to 5, and in yet another embodiment 1.8 to 4. The propylene copolymers may have a Gardner impact strength (tested on a 0.125 inch (about 0.32 cm) disk at 23°C) of 20 in-lb to 1000 in-lb (about 0.14 to about 6.8 MPa) in one embodiment, 30 in-lb to 500 in-lb (about 0.21 to about 3.45 MPa) in another embodiment, and 40 in-lb to 400 in-lb (about 0.28 to about 2.76 MPa) in yet another embodiment. In yet another embodiment, the 1% secant flexural modulus of the propylene copolymer is from 100 MPa to 2300 MPa, in another embodiment from 200 MPa to 2100 MPa, and in yet another embodiment from 300 MPa to 2000 MPa, wherein the desirable polyolefin may exhibit any combination of any upper flexural modulus limit with any lower flexural modulus limit. The melt flow rate (MFR) of the propylene copolymer is from 0.1 dg / min to 2500 dg / min in one embodiment, and from 0.3 to 500 dg / min in another embodiment.

[0099] In another embodiment, the thermoplastic polymer may be a propylene copolymer comprising propylene and one or more other monomers selected from ethylene and C4-C 20 Linear, branched or cyclic monomers, in some embodiments, are selected from C4-C 12 Linear or branched alpha-olefins, preferably butene, pentene, hexene, heptene, octene, nonene, decene, dodecene, 4-methyl-pentene-1, 3-methylpentene-1, 3,5,5-trimethyl-hexene-1, etc. The monomer may be present in up to 50 wt%, preferably 0-40 wt%, more preferably 0.5-30 wt%, more preferably 2-30 wt%, more preferably 5-20 wt%.

[0100] In a preferred embodiment, any propylene polymer containing 0.01-5 wt% comonomer, preferably a melting point of 100-170°C and an MFR of 200 dg / min or less can be used as a thermoplastic polymer in the practice of the present invention. Suitable examples include polymers prepared by Ziegler-Natta catalyst systems, metallocene systems, etc. The polymer can be prepared by any means, including solution, slurry, gas phase, supercritical or high pressure. In a particularly preferred embodiment, the propylene polymers useful herein have a molecular weight distribution (Mw / Mn) of 5 or less, preferably 1.5-4, preferably 1.5-3. In another preferred embodiment, the preferred propylene polymers useful herein as thermoplastic polymers include those prepared by metallocene catalyst systems. In another embodiment, the preferred propylene polymers useful herein include those having a composition distribution breadth index (CDBI) of 60% or more, preferably 70% or more, preferably 80% or more, preferably 90% or more. (CDBI is measured as described in WO 93 / 03093 with the modification that any fraction having a weight average molecular weight (Mw) of less than 25,000 g / mol is disregarded.) Preferred propylene polymers useful as thermoplastic polymers in the practice of this invention include those sold by ExxonMobil Chemical Company under the trade name ACHIEVE TM Particularly useful grades include ACHIEVE available from ExxonMobil Chemical Company of Houston, Texas. TM 3854、ACHIEVE TM 1654E1, ACHIEVE TM 3825、ACHIEVE TM 1605. Other preferred propylene polymers useful as thermoplastic polymers in the practice of the present invention include those propylene homopolymers and random copolymers available from ExxonMobil Chemical Company under the following grade designations: PP1024E4, PP1042, PP1032, PP1044, PP1052, PP1105E1, PP3155 and PP9852E1, PP9272, PP9513, PP9544, PP9562.

[0101] Blends

[0102] The polypropylene blend of the present invention can be in the form of a single-layer film or a multilayer film, and the thickness is relatively reduced and is generally 50 to 150 μm, preferably 80 to 120 μm, and can be prepared using a simple compounding process. Even in the case of such a reduced thickness, the polypropylene blend of the present invention exhibits excellent properties, in particular the properties shown below:

[0103] (i) a 1% secant modulus of 300 to 600 MPa, preferably 320 to 550 MPa in the machine direction (MD), and a 1% secant modulus of 350 to 600 MPa, preferably 380 to 550 MPa in the transverse direction (TD);

[0104] (ii) a tensile strength of 30 to 40 MPa, preferably 32 to 38 MPa, in the machine direction (MD) and 25 to 35 MPa, preferably 28 to 32 MPa in the transverse direction (TD);

[0105] (iii) an elongation at break of 540% to 640%, preferably 580% to 620%, in the machine direction (MD) and 600% to 640%, preferably 610% to 620% in the transverse direction (TD);

[0106] (iv) an Elmendorf Tear of 1 to 4 g / μm, preferably 1.5 to 3 g / μm in the machine direction (MD), and an Elmendorf Tear of 3 to 11 g / μm, preferably 5 to 10 g / μm in the transverse direction (TD);

[0107] (v) Haze of 84.8% to 85.4%, gloss of 1 to 2.5 (45°, GU).

[0108] The polypropylene blend of the present invention has any one, any two, any three, any four and all five of the above properties (i) to (ii), preferably all five.

[0109] As used herein, "blend" may refer to dry or extruder blends of two or more different polymers, and in-reactor blends, including blends produced in a single reactor zone using multiple or mixed catalyst systems, and blends produced in one or more reactors using one or more catalysts under the same or different conditions (e.g., blends produced in a series of reactors (same or different) where each reactor is operated under different conditions and / or with a different catalyst). The blend may also contain at least one additive ingredient (C) to (M): (C) lubricant; (D) polymer processing aid; (E) antioxidant; (F) metal deactivator; (G) UV-accelerated degradation inhibitor as UV stabilizer; (H) slip agent; (I) hindered amine stabilizer; (J) anti-blocking agent; (K) colorant; (L) anti-fog agent; and (M) antistatic agent; provided that the total amount of the at least one additive is >0 to 5 wt% of the polyolefin composition.

[0110] Additional test methods include the following.

[0111]

[0112] Example

[0113] It should be understood that, although the invention has been described in conjunction with specific embodiments of the invention, the above description is intended to illustrate rather than limit the scope of the invention. Other aspects, advantages and improvements will be apparent to those skilled in the art to which the invention belongs.

[0114] Therefore, the following examples are given to provide a complete disclosure and description to those skilled in the art and are not intended to limit the scope of what the inventors regard as their invention. Unless otherwise specified, the amounts of components used in the present invention are by weight.

[0115] Components used in the examples:

[0116] Propylene-based elastomer: Vistamaxx 3980FL (VM3980FL for short), from ExxonMobil.

[0117] Propylene copolymer: PP9513 from ExxonMobil.

[0118] Example 1

[0119] 90% of PP9513 was blended with 10% of VM3980FL to obtain a blend, and the tensile strength, flexibility, elongation, tear strength, and optical properties of the obtained blend were measured accordingly.

[0120] Example 2

[0121] 80% of PP9513 was blended with 20% of VM3980FL to obtain a blend, and the tensile strength, flexibility, elongation, tear strength, and optical properties of the obtained blend were measured accordingly.

[0122] Example 3

[0123] 75% of PP9513 was blended with 25% of VM3980FL to obtain a blend, and the tensile strength, flexibility, elongation, tear strength, and optical properties of the obtained blend were measured accordingly.

[0124] Results and discussion

[0125] 1. Tensile strength

[0126] For cutting tapes, it is preferred that the backing film has a higher tensile strength so that it is not easily damaged during the cutting process. Figure 1As shown, tensile strength increases specifically in the MD direction by increasing the amount of Vistamaxx 3980FL. An increase of 11%-39% in tensile strength was achieved compared to imported high-end commercial samples, even at higher film thicknesses. Optimal performance was achieved at approximately 20% Vistamaxx 3980FL loading.

[0127] 2. Flexibility

[0128] For cutting tapes, it is preferred that they have higher flexibility to enable conformability to the substrate and good followability during the grinding and cutting process. In order to investigate the flexibility of films based on different Vistamaxx 3980FL in the formulation, the 1% secant modulus of the three formulations was measured. Figure 2 As shown, by increasing the amount of Vistamaxx 3980FL by 10%-25%, the 1% secant modulus decreases in both MD and TD, demonstrating the value of Vistamaxx 3980FL in improving film flexibility. Optimal performance is achieved at approximately 25% Vistamaxx 3980FL loading, achieving lower modulus and higher flexibility than imported high-end commercial samples.

[0129] 3. Elongation

[0130] Polyolefin backing sheets have excellent elongation performance properties (>200%) compared to traditional PVC and PET substrates required by cutting tape applications. Figure 3 As shown, by increasing the amount of Vistamaxx 3980FL, the film elongation % is further enhanced in both MD and TD directions. With the addition of 20% Vistamaxx 3980FL as a modifier, the elongation in both MD and TD directions is greater than 600%, which exceeds the imported high-end commercial samples.

[0131] 4. Tear strength

[0132] For cutting tapes, a backing film with higher tear strength properties can aid the cutting process by absorbing additional energy, reducing vibration and enhancing cutting accuracy. Figure 4 As shown, by increasing the amount of Vistamaxx 3980FL, the film tear strength has been enhanced in both MD and TD directions.

[0133] 5. Optical performance

[0134] The adhesive strength drops significantly after UV irradiation affecting the function of the dicing tape. Therefore, good optical properties and light transmittance are preferred. Figure 5 As shown, all three formulations exhibited low haze and good clarity.

[0135] Unless otherwise specified, the phrase "consisting essentially of" does not exclude the presence of other steps, elements or materials (whether or not specifically mentioned in the specification), provided that these steps, elements or materials do not affect the basic and novel characteristics of the invention, and further, they do not exclude impurities and variations normally associated with the elements and materials used.

[0136] For simplicity, only some numerical ranges are clearly disclosed herein. However, a certain lower limit can be used in combination with any other upper limit to limit the scope that is not clearly recorded. Similarly, a certain lower limit can be used in combination with any other lower limit to limit the scope that is not clearly recorded. Similarly, a certain upper limit can also be used in combination with any upper limit to limit the scope that is not clearly recorded. In addition, even if there is no clear description, each point or individual value between the two end points is also included in the scope. Therefore, each point or individual value itself can be used as a lower limit or upper limit in combination with other points or individual values ​​or other lower or upper limits to limit the scope that is not clearly recorded.

[0137] All prior art documents are incorporated herein by reference, provided that their disclosure does not contradict the description of the present invention. In addition, all documents and references (including test procedures, publications, patents, journal articles, etc.) cited herein are incorporated herein by reference, provided that their disclosure does not contradict the description of the present invention.

[0138] While the invention has been described in terms of numerous embodiments and examples, those skilled in the art, after reading this disclosure, will appreciate that other embodiments can be devised without departing from the scope and spirit of the invention disclosed herein.

Claims

1. A polypropylene blend comprising a propylene-based elastomer and a propylene copolymer, wherein the propylene-based elastomer comprises at least 60 wt% propylene-derived units and 1 to 35 wt% of at least one selected from ethylene and C4-C 20 The propylene-based elastomer comprises units derived from a comonomer of an α-olefin, based on the total weight of the propylene-based elastomer, wherein the heat of fusion of the propylene-based elastomer is less than 80 J / g, wherein the melting point of the propylene-based elastomer is less than or equal to 105°C, and wherein the propylene copolymer is propylene and at least one selected from ethylene and C4-C 20 The copolymer of the comonomer of α-olefin has a weight average molecular weight of greater than 8000 g / mol, or greater than 10000 g / mol, or greater than 12000 g / mol, or greater than 20000 g / mol to less than 1,000,000 g / mol, or less than 800,000 g / mol.

2. The polypropylene blend according to claim 1, wherein the content of propylene-derived units in the propylene-based elastomer is from a lower limit of 60wt%, 65wt%, 70wt%, 75wt%, 80wt%, 84wt%, 85wt% to an upper limit of 85wt%, 90wt%, 92wt%, 94wt%, 95wt%.

3. The polypropylene blend according to any one of the preceding claims, wherein at least one of the propylene-based elastomers is selected from ethylene and C4-C 20 The content of comonomer-derived units of α-olefins is 5-35 wt%, or 7-30 wt%, or 8-25 wt%, or 8-20 wt%, or 8-18 wt%.

4. The polypropylene blend according to any one of the preceding claims, wherein the propylene-based elastomer has a crystallinity of 2% to 65% of the crystallinity of isotactic polypropylene.

5. The polypropylene blend according to any one of the preceding claims, wherein the propylene-based elastomer has a fractional melt flow rate (MFR) of 2 to 20 g / 10 min.

6. The polypropylene blend according to any one of the above claims, wherein the heat of fusion of the propylene-based elastomer is from a lower limit of 1.0 J / g, 1.5 J / g, 3.0 J / g, 4.0 J / g, 6.0 J / g to an upper limit of 35 J / g, 40 J / g, 50 J / g, 60 J / g, 70 J / g, 75 J / g, 80 J / g.

7. The polypropylene blend according to any one of the above claims, wherein the propylene-based elastomer is present in an amount of 6 wt% to 30 wt%, 10 wt% to 30 wt%, 10 wt% to 25 wt%, based on the total weight of the polypropylene blend.

8. The polypropylene blend according to any of the above claims, wherein the propylene copolymer is present in an amount of 70 wt% to 94 wt%, 70 wt% to 90 wt%, 75 wt% to 90 wt%, based on the total weight of the polypropylene blend.

9. The polypropylene blend according to any one of the preceding claims, wherein the polypropylene blend is in the form of a monolayer film or a multilayer film.

10. The polypropylene blend according to any of the preceding claims, wherein the propylene copolymer has a 1% secant flexural modulus of 100 to 2300 MPa, preferably 200 to 2100 MPa, more preferably 300 to 2000 MPa and most preferably 400 to 1800 MPa.

11. The polypropylene blend according to any of the preceding claims, wherein the propylene copolymer has a melt flow rate (MFR) of 0.1 to 2500 dg / min, preferably 0.3 to 500 dg / min.

12. A slitting tape backing film comprising the polypropylene blend according to any one of the preceding claims.

13. Use of the polypropylene blend according to any one of claims 1 to 11 in integrated circuits, chips, and semiconductor materials.

14. A polypropylene blend comprising a propylene-based elastomer and a propylene copolymer, wherein the propylene-based elastomer has a weight average molecular weight of 100,000 to 300,000 g / mol, a melt flow rate of 2.5 to 10 g / 10 min at 230° C., 2.16 kg according to ASTM 1238, and a density of 0.85 g / cm 3 Up to 0.88g / cm 3 and the content is 6 wt % to 30 wt %, based on the total weight of the polypropylene blend, wherein the propylene copolymer is prepared using a catalyst system comprising an activator and a quinolyl diamino catalyst or a Group 4 bis(phenolate) complex, contains 4 to 16 wt % ethylene and has a content of 70 wt % to 94 wt %, based on the total weight of the polypropylene blend.

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