Polyolefin composition, method of making nonwoven fabric, and nonwoven fabric

Abstract

The present disclosure relates to a polyolefin composition, a method of preparing a nonwoven fabric using the polyolefin composition, and a nonwoven fabric comprising the polyolefin composition or a nonwoven fabric obtained by the method. The polyolefin composition disclosed by the invention has excellent mechanical properties, narrower molecular weight distribution and good spinnability, and particularly drips less in a spinning process, and a fabric prepared from the polyolefin composition has few surface defects and excellent fabric performance. According to the method for preparing the non-woven fabric, the low temperature and the low pressure of the drafting air pressure box are adopted, so that few drips exist in the spinning process, and fabric defects are reduced.

Description

Technical Field

[0001] The present disclosure relates to a polyolefin composition, a method for preparing a nonwoven fabric using the polyolefin composition, and a nonwoven fabric comprising the polyolefin composition or obtained by the method. Background Art

[0002] In the nonwovens industry, there is a lot of bi-component recycled diaper trim that is either discarded or sold to third-party processors for recycling at unfavorable prices.

[0003] According to statistics, in the nonwoven spunbond industry, about 15% of recycled auxiliary materials are produced during the production process. However, only up to 10% of the recycled auxiliary materials are sent back to the extruder to reduce waste. However, for recycled bi-component material auxiliary materials, nonwoven processors have to sell these auxiliary materials to third-party processors at unfavorable prices for scrap materials when they try to recycle these auxiliary materials into the production line in order to achieve a closed-loop circular economy.

[0004] Therefore, it is necessary to develop a feasible solution to achieve a closed loop of the circular economy, and the resulting materials have good properties and are suitable for the spinning industry. Summary of the invention

[0005] One aspect of the present disclosure relates to a polyolefin composition, wherein the components forming the polyolefin composition include:

[0006] (i) a first polypropylene;

[0007] (ii) a compound masterbatch, the compound masterbatch comprising, based on the total weight of the compound masterbatch:

[0008] 4-35% by weight of propylene-based elastomer,

[0009] A two-component material of 65-96 wt.% polypropylene and polyethylene, and

[0010] 0-5% by weight of antioxidants,

[0011] and

[0012] The amount of the bicomponent material of polypropylene and polyethylene is 2-8.4 wt%, such as 5-8.4 wt%, based on the total weight of the polyolefin composition.

[0013] In one aspect, the present disclosure relates to a method for preparing a nonwoven fabric using the polyolefin composition of the present disclosure, wherein the method is carried out using an apparatus including an extruder, a die, a spinneret, a drafting air pressure box, a mesh belt, a calender roller and a winder, wherein the temperature of the extruder area adjacent to the die and the die is 190-215°C, for example, 195-205°C, and the pressure of the drafting air pressure box is 2450-2600Pa, for example, 2500-2580Pa.

[0014] In one aspect, the present disclosure relates to a nonwoven fabric comprising the polyolefin composition of the present disclosure or a nonwoven fabric obtained by the process of the present disclosure.

[0015] The polyolefin composition disclosed in the present invention has excellent mechanical properties, narrow molecular weight distribution, good spinnability, especially less dripping during the spinning process, and the fabric obtained therefrom has fewer surface defects and excellent fabric properties. The method for preparing the nonwoven fabric disclosed in the present invention adopts a lower temperature and a lower pressure of the drafting air pressure box, so that the spinning process has less dripping and reduces fabric defects. BRIEF DESCRIPTION OF THE DRAWINGS

[0016] Figure 1 (a), (b) and (c) show the atomic force microscopy images of compound masterbatches 1, 2 and 3, respectively. DETAILED DESCRIPTION

[0017] Polyolefin composition

[0018] One aspect of the present disclosure relates to a polyolefin composition, wherein the components forming the polyolefin composition include:

[0019] (i) a first polypropylene;

[0020] (ii) a compound masterbatch, the compound masterbatch comprising, based on the total weight of the compound masterbatch:

[0021] 4-35% by weight of propylene-based elastomer,

[0022] A two-component material of 65-96 wt.% polypropylene and polyethylene, and

[0023] 0-5% by weight of antioxidants,

[0024] and

[0025] The amount of the bicomponent material of polypropylene and polyethylene is 2-8.4 wt%, such as 5-8.4 wt%, based on the total weight of the polyolefin composition.

[0026] Among the components forming the polyolefin composition, the amount of the compound masterbatch may be 3-30 wt % (e.g., 5 wt %, 6 wt %, 8 wt %, 10 wt %, 12 wt %, 15 wt %, 20 wt % or 25 wt %), such as 5-20 wt %, based on the total weight of the polyolefin composition.

[0027] In one embodiment, the compound masterbatch has a molecular weight distribution (Mw / Mn) of 3 to 3.45 (e.g., 3.1, 3.2, 3.3, or 3.4), or has a molecular weight distribution of 3.1 to 3.3.

[0028] In one embodiment, the compound masterbatch has a melt flow rate of 20-45 g / 10 min (e.g., 25 g / 10 min, 30 g / 10 min, 35 g / 10 min, 38 g / 10 min, 40 g / 10 min, 42 g / 10 min, or 44 g / 10 min), such as 25-45 g / 10 min or 25-40 g / 10 min, as measured in accordance with ASTM D1238 at 230° C., 2.16 kg load.

[0029] According to the present disclosure, the compound masterbatch comprises 4-35 wt% (e.g., 6 wt%, 8 wt%, 10 wt%, 15 wt%, 20 wt%, 25 wt%, 30 or 32 wt%) of propylene-based elastomer, such as 6-35 wt%, such as 10-32 wt%, 20-32 wt%, or 25-30 wt% of propylene-based elastomer, based on the total weight of the compound masterbatch. According to the present disclosure, when the amount of propylene-based elastomer in the compound masterbatch is high, such as 25 wt% or more, such as 30 wt%, the spinnability of the polyolefin composition can be improved and the surface defects of the resulting fabric can be significantly reduced.

[0030] The propylene-based elastomer comprises units derived from propylene and units derived from one or more C2 or C4-C 12 In the propylene-based elastomer, the amount of units derived from propylene can be at least 60 wt%, or at least 75 wt%, or at least 80 wt%. In one embodiment, the propylene-based elastomer comprises at least 60 wt%, or at least 75 wt%, or at least 80 wt% of units derived from propylene and 3-25 wt% (e.g., 5 wt%, 8 wt%, 10 wt%, 12 wt%, 15 wt%, 18 wt%, or 20 wt%) of units derived from one or more C2 or C4-C6 hydrocarbons. 12 The α-olefin may be selected from 1-butene, 1-pentene, 1-hexene, 4-methyl-1-pentene or 1-octene.

[0031] The compound is derived from one or more C2 or C4-C 12 The units of α-olefins may consist essentially of units derived from ethylene, for example units derived from one or more C2 or C4-C 12 At least 95 wt % or at least 98 wt % of the units of the α-olefins are units derived from ethylene. In one embodiment, the units derived from one or more C2 or C4-C 12 The units of α-olefins are composed of units derived from ethylene.

[0032] In one embodiment, the propylene-based elastomer has a melt flow rate of 12-30 g / 10 min (e.g., 14 g / 10 min, 15 g / 10 min, 18 g / 10 min, 20 g / 10 min, 22 g / 10 min, 25 g / 10 min, or 28 g / 10 min), such as 15-25 g / 10 min, as measured under a load of 2.16 kg and 230° C. in accordance with ASTM D1238.

[0033] In one embodiment, the propylene-based elastomer has a g / cm 3 (e.g. 0.88 g / cm 3 or 0.90g / cm 3 ) density.

[0034] In one embodiment, the propylene-based elastomer is a semi-crystalline propylene-ethylene copolymer prepared by a metallocene catalyst. For example, the propylene-based elastomer has a crystallinity of 1% to 40% (e.g., 2%, 5%, 10%, 15%, 20%, 25%, 30% or 35%), or has a crystallinity of 2% to 30%.

[0035] According to the present disclosure, the compound masterbatch contains 65-96 wt% (e.g., 66 wt%, 67 wt%, 68 wt%, 69 wt%, 70 wt%, 75 wt%, 80 wt%, 85 wt%, 90 wt%, 92 wt% or 94 wt%) of the two-component material of polypropylene and polyethylene, such as 69-92 wt%, or 67-78 wt%, 68-78 wt% or 69-78 wt%, or 80-92 wt% of the two-component material of polypropylene and polyethylene, based on the total weight of the compound masterbatch.

[0036] In the two-component material of polypropylene and polyethylene, the weight ratio of polypropylene to polyethylene can be 10:1-1:5 (such as 9:1, 8:1, 7:1, 6:1, 5:1, 4:1, 3:1, 2:1, 1:1, 1:2, 1:3 or 1:4), such as 8:1-1:1 or 5:1-2:1.

[0037] The weight average molecular weight (Mw) of the two-component material of polypropylene and polyethylene can be 70,000-200,000 g / mol (such as 80,000 g / mol, 90,000 g / mol, 100,000 g / mol, 120,000 g / mol, 150,000 g / mol or 180,000 g / mol), for example, 80,000-150,000 g / mol. The number average molecular weight (Mn) of the two-component material of polypropylene and polyethylene can be 25,000-80,000 g / mol (such as 28,000 / mol, 30,000 g / mol, 35,000 g / mol, 40,000 g / mol, 50,000 g / mol, 60,000 g / mol or 70,000 g / mol), for example, 30,000-60,000 g / mol. The molecular weight distribution (Mw / Mn) of the two-component material of polypropylene and polyethylene can be 2.2-4 (such as 2.5, 2.8, 3, 3.2, 3.5 or 3.8), for example, 2.5-3.5.

[0038] According to the present disclosure, the bicomponent material of polypropylene and polyethylene can be a recycled material (e.g., a material recycled from sanitary products) or a scrap material, such as a scrap material in industrial production. The bicomponent material can first be subjected to a densification process, such as forming a popcorn-like material through a densification process, and then used to prepare a compound masterbatch.

[0039] According to the present disclosure, the amount of the two-component material of polypropylene and polyethylene is 2-8.4 wt% (e.g., 2.5 wt%, 3 wt%, 4 wt%, 5 wt%, 6 wt%, 7 wt%, 8 wt% or 8.2 wt%), such as 5-8.4 wt%, based on the total weight of the polyolefin composition.

[0040] According to the present disclosure, the compound masterbatch contains 0-5 wt % (e.g., 0.01 wt %, 0.02 wt %, 0.05 wt %, 0.08 wt %, 0.1 wt %, 0.2 wt %, 0.5 wt %, 0.8 wt %, 1 wt %, 2 wt %, 3 wt % or 4 wt %) of antioxidant, for example, 0.05-5 wt %, such as 0.1-2 wt % or 0.1-1 wt % or 0.1-0.8 wt % of antioxidant, based on the total weight of the compound masterbatch. Antioxidants include, for example, hindered phenols, hindered amines, phosphates and phosphites.

[0041] According to the present disclosure, the components forming the polyolefin composition may further include an additional propylene-based elastomer (iii), i.e., a propylene-based elastomer other than the propylene-based elastomer in the compound masterbatch. The amount of the additional propylene-based elastomer (iii) may be 1-15 wt % (e.g., 2 wt %, 3 wt %, 5 wt %, 8 wt %, 10 wt %, 12 wt % or 14 wt %), such as 5-10 wt % additional propylene-based elastomer (iii), based on the gross weight of the polyolefin composition. According to the present disclosure, the additional propylene-based elastomer (iii) (e.g., when its amount is 5 wt % or more) contributes to improving the spinnability of the polyolefin composition and reducing the surface defects of the resulting fabric. The specific details of the additional propylene-based elastomer (iii) are as described above for the propylene-based elastomer in the masterbatch.

[0042] According to the present disclosure, the amount of the first polypropylene can be 60-95 wt% (e.g., 65 wt%, 68 wt%, 70 wt%, 72 wt%, 75 wt%, 80 wt%, 85 wt%, 90 wt%, 92 wt% or 94 wt%), such as 70-92 wt% or 70-85 wt% or 72-85 wt%, based on the total weight of the polyolefin composition.

[0043] The first polypropylene has a melt flow rate of 1-500 g / 10 min (e.g., 2 g / 10 min, 5 g / 10 min, 10 g / 10 min, 15 g / 10 min, 20 g / 10 min, 30 g / 10 min, 40 g / 10 min, 50 g / 10 min, 80 g / 10 min, 100 g / 10 min, 150 g / 10 min, 200 g / 10 min, 250 g / 10 min, 300 g / 10 min, 350 g / 10 min, 400 g / 10 min or 450 g / 10 min), such as 5-200 g / 10 min or 10-100 g / 10 min or 15-50 g / 10 min, and the melt flow rate is measured according to ASTM D1238 at 2.16 kg load and 230°C.

[0044] The polypropylene may be predominantly crystalline, such as having a melting point of 110-170°C (eg, 110°C, 115°C, 130°C, 140°C, 150°C, or 160°C), or a melting point of 115-160°C or 130-150°C.

[0045] As used herein, the term "crystalline" is characterized by those polymers having a high degree of intermolecular and intramolecular order. The polypropylene has a heat of fusion of at least 60 J / g, or at least 70 J / g, or at least 80 J / g, as determined by DSC analysis. The heat of fusion depends on the composition of the polypropylene.

[0046] The weight average molecular weight (Mw) of the polypropylene may be 40,000-1,000,000 g / mole, or 50,000-500,000 g / mole, or 80,000-400,000 g / mole. The number average molecular weight (Mn) may be 20,000-70,000 g / mole, or 30,000-60,000 g / mole, or 40,000-55,000 g / mole. The molecular weight distribution (Mw / Mn) may be 1.5-5.5, or 2-5, or 2.5-4.5.

[0047] There is no particular restriction on the method for preparing the polypropylene of the present disclosure. For example, the polymer can be a propylene homopolymer obtained by homopolymerization of propylene in a single-stage or multistage reactor. The polymerization method includes high pressure, slurry, gas, bulk or solution phase or a combination thereof, using a traditional Ziegler-Natta catalyst or a single-site metallocene catalyst system or a combination thereof, including a bimetallic supported catalyst system. The polymerization can be carried out by a continuous or intermittent method and can include the use of a chain transfer agent, a scavenger or other additives that are considered to be applicable. However, it is most preferred to use a Ziegler-Natta catalyst to form a polypropylene homopolymer.

[0048] According to the present disclosure, the first polypropylene is a propylene homopolymer.

[0049] In one embodiment, the components forming the polyolefin composition further include 0.1-5 wt % (e.g., 0.2 wt %, 0.4 wt %, 0.5 wt %, 0.8 wt %, 1 wt %, 1.5 wt %, 2 wt %, 2.5 wt %, 3 wt %, 3.5 wt %, 4 wt % or 4.5 wt %), such as 0.2-2 wt % of a slip masterbatch, based on the total weight of the polyolefin composition. In one embodiment, the slip masterbatch is an erucamide-based slip masterbatch.

[0050] In one embodiment, the components forming the polyolefin composition include:

[0051] (i) 60 to 95 wt. % of a first polypropylene, based on the total weight of the polyolefin composition;

[0052] (ii) 3 to 30 wt% of a compound masterbatch based on the total weight of the polyolefin composition, the compound masterbatch comprising, based on the total weight of the compound masterbatch:

[0053] 4-35% by weight of propylene-based elastomer,

[0054] A two-component material of 65-96 wt.% polypropylene and polyethylene, and

[0055] 0-5% by weight of antioxidants,

[0056] and

[0057] (iii) 0-15 wt% of an additional propylene-based elastomer based on the total weight of the polyolefin composition; (iv) 0-5 wt% of a slip masterbatch based on the total weight of the polyolefin composition;

[0058] The amount of the bicomponent material of polypropylene and polyethylene is 2-8.4 wt%, such as 5-8.4 wt%, based on the total weight of the polyolefin composition.

[0059] In one embodiment, the components forming the polyolefin composition include:

[0060] (i) 70 to 92 wt% of a first polypropylene, based on the total weight of the polyolefin composition;

[0061] (ii) 5 to 20 wt% of a compound masterbatch based on the total weight of the polyolefin composition, the compound masterbatch comprising, based on the total weight of the compound masterbatch:

[0062] 10-32% by weight of a propylene-based elastomer,

[0063] A two-component material of 65-90 wt.% polypropylene and polyethylene, and

[0064] 0-5% by weight of antioxidants,

[0065] and

[0066] (iii) 1-15 wt% of an additional propylene-based elastomer based on the total weight of the polyolefin composition; (iv) 0.1-5 wt% of a slip masterbatch based on the total weight of the polyolefin composition;

[0067] The amount of the bicomponent material of polypropylene and polyethylene is 2-8.4 wt%, such as 5-8.4 wt%, based on the total weight of the polyolefin composition.

[0068] In one embodiment, the components forming the polyolefin composition include:

[0069] (i) 70 to 92 wt% of a first polypropylene, based on the total weight of the polyolefin composition;

[0070] (ii) 5 to 20 wt% of a compound masterbatch based on the total weight of the polyolefin composition, the compound masterbatch comprising, based on the total weight of the compound masterbatch:

[0071] 20-32% by weight of propylene-based elastomer,

[0072] A two-component material of 65-80 wt.% polypropylene and polyethylene, and

[0073] 0.05-2% by weight of an antioxidant, and

[0074] (iii) 5-15 wt% of an additional propylene-based elastomer based on the total weight of the polyolefin composition; (iv) 0.1-5 wt% of a slip masterbatch based on the total weight of the polyolefin composition;

[0075] The amount of the bicomponent material of polypropylene and polyethylene is 2-8.4 wt%, such as 5-8.4 wt%, based on the total weight of the polyolefin composition.

[0076] In one aspect, the present disclosure relates to a polyolefin composition, wherein the components forming the polyolefin composition comprise:

[0077] (i) 70 to 85 wt% of a first polypropylene, based on the total weight of the polyolefin composition;

[0078] (ii) 5 to 20 wt% of a compound masterbatch based on the total weight of the polyolefin composition, the compound masterbatch comprising, based on the total weight of the compound masterbatch:

[0079] 20-32% by weight of propylene-based elastomer,

[0080] 67-78 wt % of a two-component material of polypropylene and polyethylene, wherein the weight ratio of polypropylene to polyethylene in the two-component material of polypropylene and polyethylene is 5:1-2:1, and

[0081] 0.1-2 wt% antioxidant;

[0082] The melt flow rate of the compound masterbatch is 20-45 g / 10 min, such as 25-40 g / 10 min, and the melt flow rate is measured according to ASTM D1238 at a load of 2.16 kg and 230° C.;

[0083] The compound masterbatch has a molecular weight distribution of 3-3.45;

[0084] (iii) 5 to 10 wt. % of an additional propylene-based elastomer, based on the total weight of the polyolefin composition;

[0085] (iv) 0.2-2 wt% of a slip masterbatch based on the total weight of the polyolefin composition;

[0086] wherein the amount of the bicomponent material of polypropylene and polyethylene is 5-8.4 wt% based on the total weight of the polyolefin composition; and

[0087] The propylene-based elastomer has a melt flow rate of 15-25 g / 10 min, and the melt flow rate is measured at 230° C. under a load of 2.16 kg according to ASTM D1238.

[0088] Method for preparing nonwoven fabric and nonwoven fabric

[0089] One aspect of the present disclosure relates to a method for preparing a nonwoven fabric using the polyolefin composition of the present disclosure, wherein the method is carried out using an apparatus including an extruder, a die, a spinneret, a drafting plenum, a mesh belt, a calender roll and a winder, wherein the temperature of the extruder zone adjacent to the die and the die is 190-215°C (such as 192°C, 195°C, 198°C, 200°C, 202°C, 205°C, 208°C, 210°C and 212°C), for example, 195-205°C, and the pressure of the drafting plenum is 2450-2600Pa (such as 2480Pa, 2500Pa, 2520Pa, 2550Pa or 2580Pa), for example, 2500-2580Pa.

[0090] In the process of the present disclosure, continuous filaments are formed from the polyolefin composition and formed into a web, which is then thermally bonded by (heated) calender rolls to form a nonwoven fabric.

[0091] The temperature in other zones of the extruder may be 10-40°C higher than the die temperature, for example 20-35°C.

[0092] The temperature of the calender rolls is typically 120-160°C, such as 130-150°C.

[0093] Those skilled in the art can understand that in the method of the present disclosure, the polyolefin composition passes through an extruder, a die, a spinneret, a drafting air pressure box, a mesh belt, a calender roller and a winder in sequence.

[0094] One aspect of the present disclosure relates to a nonwoven fabric comprising the polyolefin composition of the present disclosure or a nonwoven fabric obtained by the process of the present disclosure.

[0095] The nonwoven fabric of the present disclosure may have 1, 2, 3 or 4 of the following properties:

[0096] The maximum longitudinal tensile strength of the nonwoven fabric of the present disclosure may be 20-30N (e.g., 21N, 22N, 23N, 24N, 25N, 26N or 28N), for example, 20-25N;

[0097] The elongation corresponding to the maximum longitudinal strength of the nonwoven fabric of the present invention may be 50-70% (e.g., 51%, 52%, 55%, 58%, 60%, 62%, 65% or 68%), for example, 52-68%;

[0098] The maximum tensile strength in the transverse direction of the nonwoven fabric of the present disclosure may be 10-20N (e.g., 11N, 12N, 13N, 14N, 15N, 16N or 18N), for example, 10-15N;

[0099] The nonwoven fabric of the present invention may have a transverse maximum strength corresponding to an elongation of 40-70% (e.g., 41%, 42%, 45%, 48%, 50%, 55%, 60%, 65% or 68%), for example, 42-65% or 48-65%.

[0100] The tensile test, i.e. the test of the maximum tensile strength and the elongation corresponding to the maximum strength, can be carried out as follows: according to Edana test method WSP 110.4 (05) "Standard test method for breaking force and elongation of nonwoven materials (strip method)", option B.

[0101] Those skilled in the art can more easily understand the present invention according to the following embodiments:

[0102] 1. A polyolefin composition, wherein the components forming the polyolefin composition comprise:

[0103] (i) a first polypropylene;

[0104] (ii) a compound masterbatch, the compound masterbatch comprising, based on the total weight of the compound masterbatch:

[0105] 4-35% by weight of propylene-based elastomer,

[0106] A two-component material of 65-96 wt.% polypropylene and polyethylene, and

[0107] 0-5% by weight of antioxidants,

[0108] and

[0109] The amount of the bicomponent material of polypropylene and polyethylene is 2-8.4 wt%, such as 5-8.4 wt%, based on the total weight of the polyolefin composition.

[0110] 2. The polyolefin composition according to embodiment 1, wherein the amount of the compound masterbatch is 3-30 wt %, such as 5-20 wt %, based on the total weight of the polyolefin composition, and / or the melt flow rate of the compound masterbatch is 20-45 g / 10 min, such as 25-40 g / 10 min, and the melt flow rate is measured according to ASTM D1238 at 2.16 kg load and 230°C.

[0111] 3. The polyolefin composition according to embodiment 1 or 2, wherein in the compound masterbatch, the amount of the two-component material of polypropylene and polyethylene is 69-92 wt% or 67-78 wt%, based on the total weight of the compound masterbatch.

[0112] 4. The polyolefin composition according to any one of embodiments 1 to 3, wherein in the compound masterbatch, the amount of propylene-based elastomer is 6-35 wt%, such as 10-32 wt% or 20-32 wt%, based on the total weight of the compound masterbatch.

[0113] 5. The polyolefin composition according to any one of embodiments 1 to 4, wherein in the compound masterbatch, the amount of antioxidant is 0.05-5 wt%, such as 0.1-2 wt%, based on the total weight of the compound masterbatch.

[0114] 6. The polyolefin composition according to any one of embodiments 1 to 5, wherein the components forming the polyolefin composition further comprise 1-15 wt%, such as 5-10 wt%, of an additional propylene-based elastomer (iii), based on the total weight of the polyolefin composition.

[0115] 7. The polyolefin composition according to any one of embodiments 1 to 6, wherein the propylene-based elastomer comprises units derived from propylene and units derived from one or more C2 or C4-C 12 The units of α-olefins, such as propylene-based elastomers, contain at least 60 wt. % or at least 75 wt. % units derived from propylene and 3-25 wt. % units derived from one or more C2 or C4-C 12 The α-olefin units and / or the propylene-based elastomer have an MFR of 12-30 g / 10 min, such as 15-25 g / 10 min, as measured at 230° C. under a load of 2.16 kg according to ASTM D1238.

[0116] 8. The polyolefin composition according to embodiment 7, wherein in the propylene-based elastomer, the propylene-based elastomer is derived from one or more C2 or C4-C 12 The α-olefin units are substantially composed of ethylene.

[0117] 9. The polyolefin composition according to any one of embodiments 1 to 8, wherein the weight ratio of polypropylene to polyethylene in the bicomponent material of polypropylene and polyethylene is 10:1 to 1:5, such as 8:1 to 1:1 or 5:1 to 2:1.

[0118] 10. The polyolefin composition according to any of embodiments 1 to 9, wherein the amount of the first polypropylene is 60-95 wt%, such as 70-92 wt% or 70-85 wt%, based on the total weight of the polyolefin composition, and / or the first polypropylene has a melt flow rate of 1-500 g / 10 min, such as 5-200 g / 10 min or 10-100 g / 10 min, the melt flow rate being determined according to ASTM D1238 at 230° C. under a load of 2.16 kg.

[0119] 11. The polyolefin composition according to any one of embodiments 1 to 10, wherein the components forming the polyolefin composition further comprise 0.1-5 wt%, such as 0.2-2 wt%, of a slip masterbatch (iv), based on the total weight of the polyolefin composition.

[0120] 12. The polyolefin composition according to any one of embodiments 1 to 11, wherein the weight average molecular weight of the bicomponent material of polypropylene and polyethylene is 70,000 to 200,000 g / mol or 80,000 to 150,000 g / mol.

[0121] 13. A polyolefin composition, wherein the components forming the polyolefin composition comprise:

[0122] (i) 70 to 85 wt% of a first polypropylene, based on the total weight of the polyolefin composition;

[0123] (ii) 5 to 20 wt% of a compound masterbatch based on the total weight of the polyolefin composition, the compound masterbatch comprising, based on the total weight of the compound masterbatch:

[0124] 20-32% by weight of propylene-based elastomer,

[0125] 67-78 wt % of a two-component material of polypropylene and polyethylene, wherein the weight ratio of polypropylene to polyethylene in the two-component material of polypropylene and polyethylene is 5:1-2:1, and

[0126] 0.1-2 wt% antioxidant;

[0127] The melt flow rate of the compound masterbatch is 20-45 g / 10 min, such as 25-40 g / 10 min, and the melt flow rate is measured according to ASTM D1238 at a load of 2.16 kg and 230° C.;

[0128] The compound masterbatch has a molecular weight distribution of 3-3.45;

[0129] (iii) 5 to 10 wt. % of an additional propylene-based elastomer, based on the total weight of the polyolefin composition;

[0130] (iv) 0.2-2 wt% of a slip masterbatch based on the total weight of the polyolefin composition;

[0131] wherein the amount of the bicomponent material of polypropylene and polyethylene is 5-8.4 wt% based on the total weight of the polyolefin composition; and

[0132] The propylene-based elastomer has a melt flow rate of 15-25 g / 10 min, and the melt flow rate is measured at 230° C. under a load of 2.16 kg according to ASTM D1238.

[0133] 14. A method for preparing a nonwoven fabric using a polyolefin composition according to any one of embodiments 1 to 13, wherein the method is carried out using an apparatus comprising an extruder, a die, a spinneret, a drafting air pressure box, a mesh belt, a calender roller and a winder, wherein the temperature of the extruder zone adjacent to the die and the die is 190-215° C., for example 195-205° C., and the pressure of the drafting air pressure box is 2450-2600 Pa, for example 2500-2580 Pa.

[0134] 15. A nonwoven fabric comprising the polyolefin composition according to any one of embodiments 1 to 14 or a nonwoven fabric obtained by the process according to embodiment 14.

[0135] Example

[0136] The following examples are provided to illustrate but not to limit the present invention. Unless otherwise specified, the amount of each substance in the examples is based on weight.

[0137] raw material

[0138] PP3155E5:ExxonMobil TM PP3155E5 propylene homopolymer, having an MFR of 36 g / 10 min (ASTM D1238, 2.16 kg, 230° C.), available from ExxonMobil;

[0139] Vistamaxx TM 7020BF: Propylene-based elastomer, a semi-crystalline propylene-ethylene copolymer prepared by metallocene catalyst, with an ethylene content of 15 wt%, 20 g / 10 min MFR (ASTM D1238, 2.16 kg, 230 ° C), 0.863 g / cm 3 The density can be purchased from ExxonMobil (hereinafter referred to as 7020BF);

[0140] Two-component PP / PE (70 / 30): scrap of a two-component material of polypropylene and polyethylene, having a propylene / ethylene weight ratio of 70 / 30, a weight average molecular weight (Mw) of 109,834 g / mol, a number average molecular weight of 37,489 g / mol, and a molecular weight distribution (Mw / Mn) of 2.93, from Fitesa Simpsonville;

[0141] Antioxidants: 168, phosphite antioxidant, purchased from BASF;

[0142] Slip masterbatch: erucamide-based slip masterbatch.

[0143] method

[0144] Atomic Force Microscopy (AFM): Each sample was cryo-microtomed prior to scanning to create a smooth surface at -125 °C and purged under N2 in a desiccator prior to AFM imaging. Imaging was performed on an Icon AFM according to EM-120. Scan sizes included 85 μm and 45 μm over the bulk area in two regions. A TESPA tip was used for scanning, and the data channels monitored were height and phase;

[0145] Melt flow rate (MFR): measured according to ASTM D1238 at 2.16 kg load and 230°C;

[0146] Molecular weight distribution: measured by GPC;

[0147] Differential Scanning Calorimetry (DSC): Based on ASTM D-3418;

[0148] Average fiber size (average fiber width): measured using a Carl Zeiss Axio Scope A1 microscope, where the fiber size was measured 10 times at 10 random positions of the fabric sample and the average value was taken. The results are shown in Table 5;

[0149] Tensile test: According to Edana test method WSP 110.4 (05) "Standard test method for breaking force and elongation of nonwoven materials (strip method)", option B: Edana ERT20.2-89: "50 mm strip tensile specimen", where for each fabric sample, five nonwoven fabric strips with a width of 50 mm and a length of about 250 mm are prepared in the machine direction (MD) and the cross direction (CD). The samples are conditioned in a constant temperature laboratory at 23°C ± 2°C and 50% ± 10% relative humidity for at least 40 hours. The nonwoven fabric strips are tested on a Zwick material testing machine Z010TN at a test speed of 100 mm / min, and the results are average values.

[0150] Example 1: Preparation of compound masterbatch

[0151] The two-component PP / PE material is crushed and then densified for subsequent preparation of the compound masterbatch. Specifically, the two-component PP / PE material is cut into small pieces by a high-speed rotor in a long cylindrical device and compacted into a popcorn shape, during which the material does not melt or undergo any heat treatment, but some heat is generated due to shearing, so that the surface of the material reaches a temperature of 60-70°C. After densification, the cooled popcorn-like material is collected from the device for subsequent preparation of the compound masterbatch.

[0152] The compound masterbatch is prepared by a twin screw extruder with an L / D of 44:1, a co-rotating twin screw extruder, and a maximum output of 500 kg / h. The temperature profile of the twin screw extruder is: the temperature of zone 1 to zone 10 is 190-205°C. The densified two-component PP / PE material is fed into the main feeder, and the antioxidant and 7020BF are mixed and fed through the side feeder. Compound masterbatches 1, 2 and 3 are prepared from the components and their amounts shown in Table 1. The MFR, molecular weight distribution and differential scanning calorimetry (DSC) results of the compound masterbatches are also shown in Table 1.

[0153] Table 1

[0154]

[0155] As can be seen from Table 1, compared with compound masterbatch 1, the molecular weight distribution of compound masterbatch 3 with the addition of 7020BF is reduced by 7%, which is conducive to better processing performance during the nonwoven fiber spinning process.

[0156] The atomic force microscopy images of compound masterbatches 1, 2 and 3 are shown in Figure 1. Figure 1 As shown in (a), (b) and (c), compound masterbatch 1 shows larger polymer domains. Compound masterbatches 2 and 3 show finely dispersed regular-sized polymer domains, so 7020BF can improve the phase dispersion of bicomponent PP / PE materials. The improvement in phase dispersion helps to improve the spinning stability of nonwoven fibers and the overall mechanical properties of nonwoven fabrics.

[0157] Example 2: Preparation of nonwoven fabric samples 1-7 and spinning process therein

[0158] Nonwoven fabric samples 1-7 are prepared using the compound masterbatch prepared in Example 1 and other components shown in Table 2. The components shown in Table 2 are processed on a single-head spunbond line from Hongda Co., Ltd., which includes an extruder, a die, a spinneret, a drafting air pressure box, a mesh belt, a calender roll and a winder in sequence, wherein a spunbond process is used to form continuous filaments and a web, which is then thermally bonded by a heated calender roll to produce a spunbond fabric with a basis weight of 15 grams per square meter. Table 3 below shows the processing parameters of the experiment. Table 4 shows a comparison of the processing parameters of the conventional method with the processing parameters of the present disclosure, and the other processing parameters of the conventional method are the same as those of the present disclosure. The average fiber width and tensile properties of fabric samples 1-7 are shown in Table 5.

[0159] Similar to the preparation of fabric samples 2-4, 9% of compound masterbatch 1 was used instead of compound masterbatch 2 to prepare spunbond fabrics. However, the yarns were often interrupted during the spinning process, and the resulting fabric samples had serious defects, so the fabric samples could not be successfully prepared using the spunbond process.

[0160] Table 2: Components and weight percentages for preparing fabric samples 1-7

[0161] PP3155E5 Compound Masterbatch 2 Compound Masterbatch 3 7020BF Slip Masterbatch Fabric sample 1 99％ - - - 1％ Fabric Sample 2 90％ 9％ - - 1％ Fabric Sample 3 85％ 9％ - 5％ 1％ Fabric Sample 4 80％ 9％ - 10％ 1％ Fabric Sample 5 87％ - 12％ - 1％ Fabric Sample 6 82％ - 12％ 5％ 1％ Fabric Sample 7 77％ - 12％ 10％ 1％

[0162] As shown in Table 2, for the fabric samples added with 9% of Compound Master Batch 2 or 12% of Compound Master Batch 3, the amounts of the two-component PP / PE in the fabric samples were 8.08 wt% and 8.38 wt%, respectively.

[0163] Applicants also attempted to prepare fabric samples containing more than 8.4% bicomponent PP / PE, however severe dripping occurred during the spinning process.

[0164] During the spinning process, it was observed that the addition of 5% 7020BF in the preparation of fabric samples 3 and 6 resulted in improved spinnability and less dripping compared to the preparation of fabric samples 2 and 5, respectively, the spinnability of fabric sample 4 with the addition of 10% 7020BF was similar to that of fabric sample 3, and the spinnability of fabric sample 7 with the addition of 10% 7020BF was similar to that of fabric sample 6. In the spinning process of preparing fabric samples 5, 6 and 7, significantly improved spinnability was observed due to the use of compound masterbatch 3 compared to the preparation of fabric samples 2, 3 and 4, respectively, and the surfaces of the resulting fabric samples were almost free of defects.

[0165] Table 3: Processing parameters for preparing fabric samples

[0166] Processing parameters Processing condition setting Total flow rate (kg / h) 150 Extruder temperature: Zone 1 (℃) 200 Extruder temperature: Zone 2 (℃) 215 Extruder temperature: Zone 3 (℃) 230 Extruder temperature: Zone 4 (℃) 230 Extruder temperature: Zone 5 (℃) 200 Die head temperature (℃) 200 Drafting air pressure (Pa) 2570 Embossing calender roller temperature (℃) 145 Smooth calendering roller temperature (℃) 143

[0167] Table 4: Comparison of processing parameters of conventional methods and processing parameters of the present disclosure

[0168] Conventional methods Processing parameters of the present disclosure Extruder temperature: Zone 5 (℃) 230℃ Reduce by 30℃ Die head temperature (℃) 230℃ Reduce by 30℃ Drafting air pressure (Pa) 2800Pa Reduced by 8%

[0169] When spinning was performed using the processing parameters of the conventional method shown in Table 4 (other parameters of the conventional method were the same as those of the present disclosure), severe filament breakage was observed during the spinning process, and the resulting fabric samples had many defects. Compared with the conventional method, in the method of the present disclosure, a lower melt temperature and die head temperature and a proper reduction in drafting air pressure were used to obtain a fabric with significantly fewer defects, and less dripping during the spinning process.

[0170] Table 5:

[0171]

[0172]

[0173] As can be seen from Table 5, compared with the fabric sample 1 without any propylene-based elastomer 7020BF, the fabric samples 2-6 containing different amounts of propylene-based elastomer 7020BF provide better stretch properties in both the longitudinal and transverse directions.

[0174] Propylene-based elastomer 7020BF helps to achieve the closed loop of the circular economy of two-component PP / PE materials. Propylene-based elastomer 7020BF improves the quality and performance of compound masterbatch. In the spunbond spinning process, propylene-based elastomer 7020BF helps to improve spinning stability and fabric performance.

[0175] Although the present invention is disclosed as above with preferred embodiments, the present invention is not limited thereto. Any changes and modifications made by any person skilled in the art without departing from the spirit and scope of the present invention should be included in the protection scope of the present invention, so the protection scope of the present invention should be based on the scope defined by the claims.

Claims

1. A polyolefin composition, wherein the components forming the polyolefin composition comprise: (i) a first polypropylene; (ii) a compound masterbatch, the compound masterbatch comprising, based on the total weight of the compound masterbatch: 4-35% by weight of propylene-based elastomer, A two-component material of 65-96 wt.% polypropylene and polyethylene, and 0-5% by weight of antioxidants, and The amount of the bicomponent material of polypropylene and polyethylene is 2-8.4 wt%, such as 5-8.4 wt%, based on the total weight of the polyolefin composition.

2. The polyolefin composition according to claim 1, wherein the amount of the compound masterbatch is 3-30 wt%, such as 5-20 wt%, based on the total weight of the polyolefin composition, and / or the melt flow rate of the compound masterbatch is 20-45 g / 10 min, such as 25-40 g / 10 min, the melt flow rate being measured according to ASTM D1238 at 2.16 kg load and 230°C.

3. The polyolefin composition according to claim 1 or 2, wherein in the compound masterbatch, the amount of the two-component material of polypropylene and polyethylene is 69-92 wt% or 67-78 wt%, based on the total weight of the compound masterbatch.

4. The polyolefin composition according to any one of claims 1 to 3, wherein in the compound masterbatch, the amount of propylene-based elastomer is 6-35 wt%, such as 10-32 wt% or 20-32 wt%, based on the total weight of the compound masterbatch.

5. The polyolefin composition according to any one of claims 1 to 4, wherein in the compound masterbatch, the amount of antioxidant is 0.05-5 wt%, such as 0.1-2 wt%, based on the total weight of the compound masterbatch.

6. The polyolefin composition according to any one of claims 1 to 5, wherein the components forming the polyolefin composition further comprise 1 to 15 wt%, such as 5 to 10 wt%, of an additional propylene-based elastomer (iii), based on the total weight of the polyolefin composition.

7. The polyolefin composition according to any one of claims 1 to 6, wherein the propylene-based elastomer comprises units derived from propylene and units derived from one or more C2 or C4-C 12 The units of α-olefins, such as propylene-based elastomers, contain at least 60 wt. % or at least 75 wt. % units derived from propylene and 3-25 wt. % units derived from one or more C2 or C4-C 12 The α-olefin units and / or the propylene-based elastomer have an MFR of 12-30 g / 10 min, such as 15-25 g / 10 min, as measured at 230° C. under a load of 2.16 kg according to ASTM D1238.

8. The polyolefin composition according to claim 7, wherein in the propylene-based elastomer, the propylene-based elastomer is derived from one or more C2 or C4-C 12 The α-olefin units are substantially composed of ethylene.

9. The polyolefin composition according to any one of claims 1 to 8, wherein the weight ratio of polypropylene to polyethylene in the bicomponent material of polypropylene and polyethylene is 10:1 to 1:5, such as 8:1 to 1:1 or 5:1 to 2:

1.

10. The polyolefin composition according to any of claims 1 to 9, wherein the amount of the first polypropylene is 60-95 wt%, such as 70-92 wt% or 70-85 wt%, based on the total weight of the polyolefin composition, and / or the first polypropylene has a melt flow rate of 1-500 g / 10 min, such as 5-200 g / 10 min or 10-100 g / 10 min, the melt flow rate being determined according to ASTM D1238 at 230°C, 2.16 kg load.

11. The polyolefin composition according to any one of claims 1 to 10, wherein the components forming the polyolefin composition further comprise 0.1 to 5 wt%, such as 0.2 to 2 wt%, of a slip masterbatch (iv), based on the total weight of the polyolefin composition.

12. The polyolefin composition according to any one of claims 1 to 11, wherein the weight average molecular weight of the bicomponent material of polypropylene and polyethylene is 70,000 to 200,000 g / mol or 80,000 to 150,000 g / mol.

13. A polyolefin composition, wherein the components forming the polyolefin composition comprise: (i) 70 to 85 wt% of a first polypropylene, based on the total weight of the polyolefin composition; (ii) 5 to 20 wt% of a compound masterbatch based on the total weight of the polyolefin composition, the compound masterbatch comprising, based on the total weight of the compound masterbatch: 20-32% by weight of propylene-based elastomer, 67-78 wt % of a two-component material of polypropylene and polyethylene, wherein the weight ratio of polypropylene to polyethylene in the two-component material of polypropylene and polyethylene is 5:1-2:1, and 0.1-2 wt% antioxidant; The melt flow rate of the compound masterbatch is 20-45 g / 10 min, such as 25-40 g / 10 min, and the melt flow rate is measured according to ASTM D1238 at a load of 2.16 kg and 230° C.; The compound masterbatch has a molecular weight distribution of 3-3.45; (iii) 5 to 10 wt. % of an additional propylene-based elastomer, based on the total weight of the polyolefin composition; (iv) 0.2-2 wt% of a slip masterbatch based on the total weight of the polyolefin composition; wherein the amount of the bicomponent material of polypropylene and polyethylene is 5-8.4 wt% based on the total weight of the polyolefin composition; and The propylene-based elastomer has a melt flow rate of 15-25 g / 10 min, and the melt flow rate is measured at 230° C. under a load of 2.16 kg according to ASTM D1238.

14. use according to the method for preparing nonwoven fabric of any polyolefin composition among the claim 1-13, wherein utilize the equipment that comprises forcing machine, die head, spinneret, drafting air pressure box, mesh belt, calendering roller and winder to carry out described method, wherein the extruder zone next to die head and the temperature of die head are 190-215 ℃, for example 195-205 ℃, and the pressure of the drafting air pressure box is 2450-2600Pa, for example 2500-2580Pa.

15. Nonwoven fabric comprising a polyolefin composition according to any one of claims 1 to 14 or a nonwoven fabric obtainable by a process according to claim 14.

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