COMPOSITION FOR MAKING SPUN BOND NONWOVEN FABRIC

Abstract

The invention relates to a composition comprising (A) a propylene-based polymer, (B) a C10-C30 aliphatic carboxylic acid amide and (C) a homopolymer or a copolymer of butene-1, wherein the amount of (B) is 1000 to 5000 ppm based on the total composition and the amount of (C) is 5000 to 50000 ppm based on the total composition.

Claims

1. A composition comprising (A) a propylene-based polymer, (B) a C10-C30 aliphatic carboxylic acid amide and (C) a homopolymer or a copolymer of butene-1, wherein the amount of (B) is 1000 to 5000 ppm based on the total composition and the amount of (C) is 5000 to 50000 ppm based on the total composition.

2. The composition according to claim 1, wherein (B) is an unsaturated C10-C30 aliphatic carboxylic acid amide.

3. The composition according to claim 1, wherein the amount of (B) is 1200 to 3000 ppm.

4. The composition according to claim 1, wherein (C) is a copolymer of butene-1 with a comonomer selected from ethylene, propylene, 4-methyl-1-pentene and octene-1.

5. The composition according to claim 1, wherein (C) has a melt flow rate determined by ISO1133-1:2011 (2.16 kg/190° C.) of 0.1 to 10 dg/min.

6. The composition according to claim 1, wherein the amount of (C) is 8000 to 40000 ppm, with respect to the total composition.

7. The composition according to claim 1, wherein (A) is a propylene homopolymer or a propylene random copolymer consisting of at least 70.0 wt % of propylene-derived units and up to 30.0 wt % of comonomer-derived units based on the total weight of the random copolymer, wherein the comonomer is selected from the group consisting of ethylene and α-olefins having 4-10 carbon atoms.

8. The composition according to claim 1, wherein (A) has a melt flow rate as measured according to ASTM D1238-13 (2.16 kg/230° C.) of 5.0 to 100 dg/min.

9. The composition according to claim 1, wherein the total of (A), (B) and (C) is at least 90.0 wt % of the total composition.

10. The composition according to claim 1, wherein the composition has a melt flow rate as measured according to ASTM D1238-13 (2.16 kg/230° C.) of 5.0 to 100 dg/min.

11. The composition according to claim 1, wherein the composition has a flexural modulus as measured according to ASTM D790 A of at most 2000MPa.

12. The composition according to claim 1, wherein the composition has a Rockwell hardness (L) as measured according to ASTM D785-08 of at most 50.

13. Fibers made of the composition according to claim 1.

14. A spun bond nonwoven fabric made using the fibers according to claim 13.

15. An article comprising the spun bond nonwoven fabric according to claim 14.

16. The article according to claim 15, wherein the article is selected from liners for sanitary articles and liners in protective apparel.

17. The composition according to claim 1, wherein (B) is selected from erucamide and oleamide.

18. The composition according to claim 1, wherein the amount of (B) is 1500 to 2500 ppm, with respect to the total composition.

19. The composition according to claim 1, wherein (C) is a copolymer of butene-1 with ethylene.

20. The composition according to claim 1, wherein the amount of (C) is 10000 to 30000 ppm, with respect to the total composition.

Description

EXAMPLES

[0053] Molded Composition

[0054] A propylene homopolymer having an MFR of 25 dg/min according to ASTM D1238-13 (2.16 kg/230° C.) (PP511A available from Sabic) was blended with components as shown in Tables 1 and 2. The amounts are wt ppm with respect to the total composition. In addition to the additives shown in Table 2, Ex 1-11 contain Irganox 3114 (400 ppm), Irgafos 168 (800 ppm) and Calcium Stearate (350 ppm).

[0055] Each of the samples was melt compounded on a twin-screw compounder KraussMaffei (KM) with 25 mm in diameter at melt temperature 226° C. and screw speed of 100 rpm. S1 to S7 were blended by a Henshel mixer for 15 minutes before extrusion. S8-S11 were blended by a V-blender.

[0056] Samples for measuring the flexural modulus, Izod impact strength and Rockwell hardness were subsequently injection molded by using Battenfield injection molding machine with a general-purpose screw diameter.

[0057] Flexural modulus was measured according to ASTM D790 A.

[0058] Rockwell hardness (L) was measured according to ASTM D785.

[0059] Izod impact strength was measured according to ASTM D256-10e1.

[0060] Melt flow rate as measured according to ASTM D1238-13 (2.16 kg/230° C.).

TABLE-US-00001 TABLE 1 Additive 1 Talc Jetfine ® 3 C A from Imerys Tacl Additive 2 IPC Heterophasic propylene copolymer with a matrix of propylene homopolymer and a dispersed phase of propylene-ethylene copolymer, MFR (ASTM D1230, 230° C., 2.16 kg) of 16 dg/min (SABIC 48MK40) Additive 3 NA-27 Nucleating agent available from ADK as STAB NA-27 Additive 4 HDPE HDPE having MFR (ASTM D1230, 190° C., 2.16 kg) of 20 dg/min (SABIC M200056) Additive 5 HPN20E Nucleating agent available from Milliken as Hyperform ® HPN-20E Additive 6 Erucamide Crodamide ER from CRODA Additive 7 PB-1 Toppyl PB 8220M from LyonDell Basell Additive 8 L-MODU Low molecular weight and low modulus polypropylene S901 available from Idemitsu Kosan as L-MODU S901

TABLE-US-00002 TABLE 2 1 2 3 4 5 6 7 8 9 10 11 Additive 1 500 Additive 2 1000 1000 Additive 3 500 500 Additive 4 500 500 Additive 5 250 Additive 6 1000 1000 2000 2000 2000 2000 Additive 7 1500 10000 25000 Additive 8 100000 Flexural 2083 2157 2028 2276 2358 2124 2410 2158 1996 1236 1112 modulus (MPa) Rockwell 50.67 52.75 52 51.83 53.92 51.58 56.83 53.42 50.75 48.08 41 Hardness (L) (HRL)

[0061] Sample S-11 is a grade having a high softness, containing a relatively large amount of low molecular weight polypropylene.

[0062] It can be understood that the addition of Erucamide and 25000 ppm of PB-1 (S-10) leads to a high softness, which can be seen by the low flexural modulus and the low Rockwell hardness.

[0063] Fibers

[0064] Bulked-continuous filaments were manufactured using a lab scale BCF line “Reiter”. The processing parameters were set to produce a yarn titer counts 1200 denier/80 filaments.

[0065] The melting temperature was set at 235° C., and the take up speed was at about 2000 m/min.

[0066] Tenacity and elongation at break were measured according to ASTM D2256.

TABLE-US-00003 TABLE 3 Tenacity (cN/tex) Elongation at break (%) S-1 14.6 26 S-10 15.3 28 S-11 15.4 25 S-15 15.2 27

[0067] Sample without any of additive 1-8 (S-1) has a slightly lower tenacity and similar elongation at break compared to those of S-9, S-10 and S-11.

[0068] Spunbond Nonwoven Fabrics

[0069] Spunbond nonwoven fabrics were made from S-1 and S-10 on a 1.1 m wide Reicofil 4 line with two beams. The trial was run at a throughput of about 1200 kg/hour/meter using the processing parameters given in the Table 4. The nonwoven was thermally bonded using a new embossed roll pattern.

TABLE-US-00004 TABLE 4 Fabric weight (g/m2) 13 Line speed (m/min) 800 Throughput (kg/h) 2200 Pressure Cabin (Pa) 4500 Suction air fan (rpm) 2400 Process air temperature (° C.) 20 Die pressure (bar) 23 Melt temperature (° C.) 248

[0070] The stiffness, tensile strength and elongation at break were measured.

[0071] The stiffness was measured using a commercial testing equipment known as “Handle-O-Meter” test as specified in operating manual on Handle-O-Meter model number 211-5 from the Thwing-Albert Instrument Co.

[0072] The tensile strength was measured according to Edana standard WSP 110.4.

[0073] The elongation at break was measured according to Edana standard WSP 110.4.

[0074] Results are summarized in Table 5.

TABLE-US-00005 TABLE 5 Tensile Tensile Elongation Elongation Stiffness Stiffness strength strength at break at break (MD) (mN) (CD) (mN) (MD) (N/cm) (CD) (N/cm) (MD) (%) (CD) (%) S-1 36.6 19.2 5.66 3 59.4 75.01 S-10 31 15.5 5.88 2.82 80.9 94.85 MD denotes machine direction and CD denotes cross direction.

[0075] The fabric made from the composition of S-10 exhibits a lower stiffness than that made from S-1, which indicates that the fabric of S-10 is softer than the fabric of S-1.

[0076] The fabric made from the composition of S-10 exhibits a similar tensile strength and a higher elongation at break compared to the fabric of S-1.