Polyolefin composition, method for preparing nonwoven fabric, and nonwoven fabric

Abstract

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. The polyolefin composition disclosed herein has excellent mechanical properties, a narrow molecular weight distribution, and good spinnability, particularly low dripping during the spinning process. The resulting fabric has few surface defects and excellent fabric properties. The disclosed method for preparing the nonwoven fabric utilizes lower temperatures and lower drafting air pressure box pressure, resulting in less dripping during the spinning process and fewer fabric defects.

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 a nonwoven fabric 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, approximately 15% of recycled trimmings are generated during the nonwoven spunbond industry's production process. However, only a maximum of 10% of this recycled trimmings are returned to the extruder to reduce waste. However, when nonwoven processors attempt to achieve a closed-loop circular economy and return these trimmings to the production line, they are forced to sell these trimmings to third-party processors at unfavorable scrap prices.

[0004] Therefore, it is necessary to develop a feasible solution to achieve a closed loop of 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 comprise:

[0006] (i) a first polypropylene;

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

[0008] 4-35% by weight of a 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 calendering roll, 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 2450-2600 Pa, for example, 2500-2580 Pa.

[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 herein has excellent mechanical properties, a narrow molecular weight distribution, and good spinnability, particularly low dripping during the spinning process. The resulting fabric has few surface defects and excellent fabric properties. The disclosed method for preparing a nonwoven fabric utilizes lower temperatures and lower drafting air box pressure, resulting in less dripping during the spinning process and fewer 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 comprise:

[0019] (i) a first polypropylene;

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

[0021] 4-35% by weight of a 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] Of 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 under a 2.16 kg load at 230°C.

[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, for example, 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 higher, for example, 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-C 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 to 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 to 25 g / 10 min, as measured in accordance with ASTM D1238 under a 2.16 kg load and at 230°C.

[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 polypropylene and polyethylene bicomponent material can be 70,000-200,000 g / mol (e.g., 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 polypropylene and polyethylene bicomponent material can be 25,000-80,000 g / mol (e.g., 28,000 g / 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 polypropylene and polyethylene bicomponent material can be 2.2-4 (e.g., 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 polypropylene and polyethylene bicomponent material can be recycled material (e.g., recycled material from sanitary products) or scrap, such as scrap from 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 bicomponent 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 comprises 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 an 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 an 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 component forming the polyolefin composition can 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) can 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 usage is 5 wt % or more) helps to improve the spinnability of the polyolefin composition and reduces 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, the melt flow rate being measured according to ASTM D1238 under a 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 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 process comprises high pressure, slurry, gas, bulk or solution phase or a combination thereof, using traditional Ziegler-Natta catalysts or single-site metallocene catalyst systems or a combination thereof, including bimetallic supported catalyst systems. Polymerization can be carried out by continuous or batch methods and can include the use of chain transfer agents, scavengers or other additives that are considered to be applicable. However, most preferably, Ziegler-Natta catalysts are used to form polypropylene homopolymers.

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

[0049] In one embodiment, the components forming the polyolefin composition further comprise 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 comprise:

[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. % based on the total weight of the polyolefin composition of a compound masterbatch, the compound masterbatch comprising, based on the total weight of the compound masterbatch:

[0053] 4-35% by weight of a 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 comprise:

[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. % based on the total weight of the polyolefin composition of a compound masterbatch, 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 to 15 wt% of an additional propylene-based elastomer, based on the total weight of the polyolefin composition; (iv) 0.1 to 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 comprise:

[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. % based on the total weight of the polyolefin composition of a compound masterbatch, the compound masterbatch comprising, based on the total weight of the compound masterbatch:

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

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

[0081] 0.1-2% by weight of an 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 a temperature of 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 under a load of 2.16 kg and at 230° C. 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 2450-2600 Pa (such as 2480 Pa, 2500 Pa, 2520 Pa, 2550 Pa, or 2580 Pa), for example, 2500-2580 Pa.

[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) calendering 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 calendering rolls is typically 120-160°C, such as 130-150°C.

[0093] Those skilled in the art will appreciate that, in the method disclosed herein, the polyolefin composition passes through an extruder, a die, a spinneret, a drafting air pressure box, a mesh belt, a calendering 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 fabrics of the present disclosure may have one, two, three, or four of the following properties:

[0096] The maximum tensile strength in the longitudinal direction 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 strength in the longitudinal direction 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 comprising, based on the total weight of the compound masterbatch:

[0105] 4-35% by weight of a 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 compound masterbatch has a melt flow rate of 20-45 g / 10 min, such as 25-40 g / 10 min, as measured according to ASTM D1238 under a load of 2.16 kg and at 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 to 5 wt%, such as 0.1 to 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 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.

[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% of units derived from propylene and 3-25 wt% of 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 according to ASTM D1238 at 230° C. under a load of 2.16 kg.

[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 essentially 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 to 95 wt%, such as 70 to 92 wt% or 70 to 85 wt%, based on the total weight of the polyolefin composition, and / or the first polypropylene has a melt flow rate of 1 to 500 g / 10 min, such as 5 to 200 g / 10 min or 10 to 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 to 5 wt%, such as 0.2 to 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 a propylene-based elastomer,

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

[0126] 0.1-2% by weight of an 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 a temperature of 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 under a load of 2.16 kg and at 230° C. 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 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., e.g., 195-205° C., and the pressure of the drafting plenum is 2450-2600 Pa, e.g., 2500-2580 Pa.

[0134] 15. Nonwoven fabric comprising the polyolefin composition according to any of embodiments 1 to 14 or 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 stated, the amounts of the various substances in the examples are 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% by weight, 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] Bicomponent PP / PE (70 / 30): scrap of a bicomponent material of polypropylene and polyethylene with 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 at -125°C prior to scanning to create a smooth surface and purged in a desiccator under N2 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 230°C under a load of 2.16 kg;

[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. The fiber size was measured 10 times at 10 random locations on the fabric sample and the average value was taken. The results are shown in Table 5.

[0149] Tensile testing: 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 Specimens" was used. For each fabric sample, five nonwoven fabric strips, 50 mm wide and approximately 250 mm long, were prepared in both the machine direction (MD) and the cross direction (CD). The samples were 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 were tested on a Zwick materials testing machine Z010TN at a test speed of 100 mm / min. The results are average values.

[0150] Example 1: Preparation of compound masterbatch

[0151] The two-component PP / PE material is pulverized 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-like shape. During this process, the material does not melt or undergo any heat treatment. However, some heat is generated due to shearing, causing the material surface temperature to reach 60-70°C. After densification, the cooled popcorn-like material is collected from the device and used for subsequent preparation of the compound masterbatch.

[0152] The compound masterbatches were prepared using a co-rotating twin-screw extruder with an L / D ratio of 44:1 and a maximum output of 500 kg / h. The temperature profile of the twin-screw extruder was 190-205°C in zones 1 to 10. The densified two-component PP / PE material was fed into the main feeder, while the antioxidant and 7020BF were mixed and fed via a side feeder. Compound masterbatches 1, 2, and 3 were prepared using the components and 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 shown in Table 1, compared with the compound masterbatch 1, the molecular weight distribution of the 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 microscope images of compound master batches 1, 2 and 3 are shown in Figure 2. Figure 1 As shown in (a), (b), and (c), masterbatch 1 exhibits larger polymer domains. Masterbatches 2 and 3 exhibit finely dispersed, regularly sized polymer domains. Therefore, 7020BF can improve the phase dispersion of bicomponent PP / PE materials. This improved phase dispersion contributes to improved spinning stability of nonwoven fibers and overall mechanical properties of nonwoven fabrics.

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

[0158] Nonwoven fabric samples 1-7 were prepared using the compound masterbatch prepared in Example 1 and the other components shown in Table 2. The components shown in Table 2 were processed on a single-head spunbond line from Hongda Co., Ltd., which sequentially includes an extruder, a die, a spinneret, a drafting air pressure box, a mesh belt, a calender roll, and a winder, wherein a spunbond process is utilized to form continuous filaments and form a web, which is then thermally bonded by a heated calender roll to produce a spunbond fabric having a basis weight of 15 g / m2. Table 3 below shows the processing parameters for 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, making it impossible to successfully prepare fabric samples using the spunbond process.

[0160] Table 2: Components and weight percentages used to prepare fabric samples 1-7

[0161] PP3155E5 Compound Masterbatch 2 Compound Masterbatch 3 7020BF Slippery 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 Masterbatch 2 or 12% of Compound Masterbatch 3, the amounts of bicomponent 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. Compared to the preparation of fabric samples 2, 3 and 4, respectively, in the spinning process of fabric samples 5, 6 and 7, significantly improved spinnability was observed due to the use of compound masterbatch 3, 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 (°C) 200 Extruder temperature: Zone 2 (°C) 215 Extruder temperature: Zone 3 (°C) 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 method 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 numerous defects. Compared to the conventional method, the method of the present disclosure employed lower melt and die temperatures and appropriately reduced draft pressure, resulting in fabrics 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 which does not contain 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 close the circular economy loop for bicomponent PP / PE materials. Propylene-based elastomer 7020BF improves the quality and performance of compound masterbatches. In spunbond spinning processes, propylene-based elastomer 7020BF helps improve spinning stability and fabric properties.

[0175] Although the present invention is disclosed above with reference to preferred embodiments, the present invention is not limited thereto. Any changes and modifications made by those skilled in the art without departing from the spirit and scope of the present invention should be included in the scope of protection of the present invention. Therefore, the scope of protection 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) 70 to 95 weight percent of a first polypropylene, based on the total weight of the polyolefin composition; (ii) 5 to 30 wt% of a compound masterbatch, based on the total weight of the polyolefin composition, wherein the compound masterbatch has a melt flow rate of 20 to 45 g / 10 min, as measured in accordance with ASTM D1238 under a 2.16 kg load and at 230° C., and the compound masterbatch comprises, based on the total weight of the compound masterbatch: 4-35% by weight of a propylene-based elastomer, a two-component material of 65-96 wt% polypropylene and polyethylene, and 0.05-5% by weight of an antioxidant, and The amount of the bicomponent material of polypropylene and polyethylene is 3-8.4 wt % based on the total weight of the polyolefin composition.

2. The polyolefin composition according to claim 1, wherein the amount of the bicomponent material of polypropylene and polyethylene is 5 to 8.4 wt. %, based on the total weight of the polyolefin composition.

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

4. 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%, based on the total weight of the compound masterbatch.

5. The polyolefin composition according to claim 4, wherein in the compound masterbatch, the amount of the two-component material of polypropylene and polyethylene is 67-78 wt%, based on the total weight of the compound masterbatch.

6. The polyolefin composition according to claim 1 or 2, wherein in the compound masterbatch, the amount of the propylene-based elastomer is 6 to 35 wt%, based on the total weight of the compound masterbatch.

7. The polyolefin composition according to claim 6, wherein in the compound masterbatch, the amount of propylene-based elastomer is 10-32 wt%, based on the total weight of the compound masterbatch.

8. The polyolefin composition according to claim 6, wherein in the compound masterbatch, the amount of the propylene-based elastomer is 20-32 wt%, based on the total weight of the compound masterbatch.

9. The polyolefin composition according to claim 1 or 2, wherein in the compound masterbatch, the amount of antioxidant is 0.1 to 2 wt%, based on the total weight of the compound masterbatch.

10. The polyolefin composition according to claim 1 or 2, wherein the components forming the polyolefin composition further comprise 1 to 15 wt% of an additional propylene-based elastomer (iii), based on the total weight of the polyolefin composition.

11. The polyolefin composition according to claim 10, wherein the components forming the polyolefin composition further comprise 5 to 10 wt% of an additional propylene-based elastomer (iii), based on the total weight of the polyolefin composition.

12. The polyolefin composition according to claim 1 or 2, wherein the propylene-based elastomer comprises units derived from propylene and 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 to 30 g / 10 min, as measured under a load of 2.16 kg at 230° C. in accordance with ASTM D1238.

13. The polyolefin composition according to claim 12, wherein the propylene-based elastomer comprises at least 60 wt% of units derived from propylene and 3-25 wt% of units derived from one or more C2 or C4-C 12 α-olefin units.

14. The polyolefin composition according to claim 12, wherein the propylene-based elastomer comprises at least 75 wt. % of units derived from propylene and 3-25 wt. % of units derived from one or more C2 or C4-C 12 α-olefin units.

15. The polyolefin composition according to claim 12, wherein the propylene-based elastomer has an MFR of 15 to 25 g / 10 min, as measured at 230°C under a load of 2.16 kg according to ASTM D1238.

16. The polyolefin composition according to claim 12, 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 essentially composed of ethylene.

17. The polyolefin composition according to claim 1 or 2, wherein the weight ratio of polypropylene to polyethylene in the bicomponent material of polypropylene and polyethylene is from 10:1 to 1:

5.

18. The polyolefin composition according to claim 17, wherein the weight ratio of polypropylene to polyethylene in the bicomponent material of polypropylene and polyethylene is from 8:1 to 1:

1.

19. The polyolefin composition according to claim 17, wherein the weight ratio of polypropylene to polyethylene in the bicomponent material of polypropylene and polyethylene is from 5:1 to 2:

1.

20. The polyolefin composition according to claim 1 or 2, wherein the amount of the first polypropylene is 70-92 wt%, based on the total weight of the polyolefin composition, and / or the first polypropylene has a melt flow rate (MFR) of 1-500 g / 10 min, as measured according to ASTM D1238 at 230° C. and 2.16 kg load.

21. The polyolefin composition according to claim 20, wherein the amount of the first polypropylene is 70-85 wt%, based on the total weight of the polyolefin composition.

22. The polyolefin composition according to claim 20, wherein the first polypropylene has a melt flow rate of 5 to 200 g / 10 min, the melt flow rate being determined according to ASTM D1238 at 230°C under a load of 2.16 kg.

23. The polyolefin composition according to claim 20, wherein the first polypropylene has a melt flow rate of 10 to 100 g / 10 min, the melt flow rate being determined according to ASTM D1238 at 230°C under a load of 2.16 kg.

24. The polyolefin composition according to claim 1 or 2, wherein the components forming the polyolefin composition further comprise 0.1 to 5 wt% of a slip masterbatch (iv), based on the total weight of the polyolefin composition.

25. The polyolefin composition according to claim 24, wherein the components forming the polyolefin composition further comprise 0.2 to 2 wt% of a slip masterbatch (iv), based on the total weight of the polyolefin composition.

26. The polyolefin composition according to claim 1 or 2, wherein the weight average molecular weight of the bicomponent material of polypropylene and polyethylene is 70,000 to 200,000 g / mol.

27. The polyolefin composition according to claim 26, wherein the bicomponent material of polypropylene and polyethylene has a weight average molecular weight of 80,000 to 150,000 g / mol.

28. 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 a propylene-based elastomer, 67-78 wt% of a bicomponent material of polypropylene and polyethylene, wherein the weight ratio of polypropylene to polyethylene in the bicomponent material of polypropylene and polyethylene is 5:1-2:1, and 0.1-2% by weight of an antioxidant; The melt flow rate of the compound masterbatch is 20-45 g / 10 min, and the melt flow rate is measured according to ASTM D1238 at a load of 2.16 kg and a temperature of 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 to 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 under a load of 2.16 kg and at 230° C. according to ASTM D1238.

29. The polyolefin composition according to claim 28, wherein the compound masterbatch has a melt flow rate of 25 to 45 g / 10 min, as measured according to ASTM D1238 at 230°C under a load of 2.16 kg.

30. use according to the method for nonwoven fabric of any one polyolefin composition among the claim 1-29, wherein utilize the equipment that comprises forcing machine, die head, spinneret, drafting plenum, mesh belt, calendering roller and winder to carry out described method, wherein the temperature of the extruder zone of next-door neighboring die head and die head is 190-215 ℃, and the pressure of drafting plenum is 2450-2600Pa.

31. The process according to claim 30, wherein the temperature of the extruder zone immediately adjacent to the die and the die is from 195 to 205°C.

32. The method according to claim 30, wherein the pressure of the drafting air pressure box is 2500-2580 Pa.

33. Nonwoven fabric comprising a polyolefin composition according to any one of claims 1 to 29 or obtainable by a process according to any one of claims 30 to 32.

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