FLAME RETARDANT POLYOLEFIN COMPOSITION

Abstract

The invention provides a flame retardant polyolefin composition comprising a) an ethylene based plastomer with a density in the range of 0.850 to 0.915 g/cm.sup.3 and an MFR.sub.2 in the range 0.5-30 g/10 min; b) a propylene based plastomer with a density in the range of 0.860 to 0.910 g/cm.sup.3 and an MFR.sub.2 in the range 0.01-30 g/10 min; and c) a flame retardant.

Claims

1. A flame retardant polyolefin composition comprising: a) an ethylene based plastomer with a density in the range of 0.850 to 0.915 g/cm.sup.3 and an MFR.sub.2 in the range 0.5-30 g/10 min; b) a propylene based plastomer with a density in the range of 0.860 to 0.910 g/cm.sup.3 and an MFR.sub.2 in the range 0.01-30 g/10 min; and c) a flame retardant.

2. The flame retardant polyolefin composition according to claim 1, wherein the ethylene based plastomer is a copolymer of ethylene and at least one C3-C10 alpha-olefin.

3. The flame retardant polyolefin composition according to claim 1, wherein the propylene based plastomer is a copolymer of propylene and ethylene or a C4-C10 alpha-olefin.

4. The flame retardant polyolefin composition of claim 1, comprising 20 to 90 wt % of the ethylene based plastomer, relative to a total weight of the composition as a whole.

5. The flame retardant polyolefin composition of claim 1, comprising 5 to 45 wt % of the propylene based plastomer, relative to a total weight of the composition as a whole.

6. The flame retardant polyolefin composition of claim 1, wherein the flame retardant is present in an amount of 1.5 to 30 wt %, or 2.0 to 30 wt %, or 5.0 to 30 wt %, or 10 to 30 wt %, relative to a total weight of the composition as a whole.

7. The flame retardant polyolefin composition of claim 1, further comprising a high melt flow rate propylene based plastomer.

8. The flame retardant polyolefin composition of claim 1, wherein the flame retardant comprises a mixture of an ammonium polyphosphate and a silane functionalised ethylene copolymer.

9. The flame retardant polyolefin composition according to claim 8, wherein the silane functionalised ethylene copolymer is a copolymer of ethylene with a methylacrylate comonomer and a vinyl trimethoxysilane comonomer.

10. A method of applying the flame retardant polyolefin composition of claim 1 on a substrate comprising fabric substrate.

11. A process for coating a substrate with the flame retardant polyolefin composition of claim 1 on, wherein said process comprises applying said composition to a surface of said substrate.

12. A substrate, coated with a flame retardant polyolefin composition of claim 1 on.

13. The substrate as claimed in claim 12, wherein the substrate is a fabric substrate that is a woven or non-woven.

14. An article comprising at least one component formed from the coated substrate as defined in claim 12.

15. The article as claimed in claim 14, wherein the article is selected from the group consisting of office furniture, vehicle interiors, seat cushions, back rest cushions, pillows, upholstered furniture, bed mattresses, wall coverings, shoes ( ), sports bags, inlay of sky boots, sports equipment ( ), carpets, rubber boats, PVC swimming pools, life vests, handbags, purses, table coverings, table mats, stationary ( ), saddlebags, tool bags.

16. The substrate as claimed in claim 13, wherein the fabric substrate is a knitted fabric.

17. The article as claimed in claim 15, wherein the shoes comprise tongue, vamp, heel counter, quarter, or a combination thereof.

18. The article as claimed in claim 15, wherein the sports equipment comprises boxing gloves, boxing balls, or a combination thereof.

19. The article as claimed in claim 15, wherein the stationary comprises books, wood inlay, or any combination thereof.

Description

[0130] The invention will now be described with reference to the following non limiting figures and examples.

[0131] FIG. 1: Calendaring coating roller equipment

Test Methods

Density

[0132] Density of the materials is measured according to ISO 1183-1:2012, with isopropanol-water as gradient liquid. The cooling rate of the plaques when crystallising the samples was 15° C./min. Conditioning time was 16 hours.

Melt Flow Rate (MFR) or Melt Index (MI)

[0133] The melt flow rate (MFR) is determined according to ISO 1133 and is indicated in g/10 min. The MFR is an indication of the melt viscosity of the polymer. The MFR is determined at 190° C. for PE and at 230° C. for PP. The load under which the melt flow rate is determined is usually indicated as a subscript, for instance MFR.sub.2 is measured under 2.16 kg load, MFR.sub.5 is measured under 5 kg load or MFR.sub.21 is measured under 21.6 kg load.

Molecular Weights, Molecular Weight Distribution, Mn, Mw, MWD

[0134] The weight average molecular weight Mw and the molecular weight distribution (MWD=Mw/Mn wherein Mn is the number average molecular weight and Mw is the weight average molecular weight) is measured by a method based on ISO 16014-4:2003.

Comonomer Content

[0135] Comonomer Content (% wt and % mol) was determined by using .sup.13C-NMR. The .sup.13C-NMR spectra were recorded on Bruker 400 MHz spectrometer at 130° C. from samples dissolved in 1,2,4-trichlorobenzene/benzene-d.sub.6 (90/10 w/w). Conversion between % wt and % mol can be carried out by calculation.

Cigarette Test

[0136] An assessment of ignitability was carried out in accordance with the BS EN 1021-1:2006 smouldering cigarette test

Flame Retardancy

[0137] Flame retardant behaviour was assessed using an FTT Dual Cone calorimeter R1771 according to ISO 5660:2015.

Tensile Strength

[0138] Tensile strength was measured according to BS EN ISO 1421:2016

Schildknect Flexing Measured according to Schildknecht Flexing ISO 7854:1997 METHOD B

UV Measurements

[0139] Colourfastness to UV was tested according to ASTM G155-05a. The test was carried out for 200 hours using a Xenon Arc Lamp—Pass if no appreciable colour change.

Experimental

Materials

[0140] Propylene based plastomer (PP plast): a random propylene ethylene metallocene plastomer, density=0.862 g/cm.sup.3, MFR.sub.2 (230° C., 2.16 kg)=20 g/10 min

[0141] Ethylene based plastomer (1) (PE plast 1): an ethylene octene metallocene plastomer, density=0.870 g/cm.sup.3, MFR.sub.2 (190° C./2.16 kg)=6.6 g/10 min

[0142] Ethylene based plastomer (2) (PE plast 2): an ethylene octene metallocene plastomer, density=0.902 g/cm.sup.3, MFR.sub.2 (190° C./2.16 kg)=10 g/10 min

[0143] Ethylene based plastomer (3) (PE plast 3): an ethylene octene metallocene plastomer, density=0.902 g/cm.sup.3, MFR.sub.2 (190° C./2.16 kg)=3 g/10 min

[0144] High MFR PP plastomer (1): a random propylene ethylene metallocene plastomer, density=0.879 g/cm.sup.3, MFR.sub.2 (230° C., 2.16 kg)=7715 g/10 min

[0145] Polypropylene copolymer (PP copo): a propylene ethylene random heterophasic copolymer, density=890 g/cm.sup.3, MFR.sub.2 (230° C., 2.16 kg)=3.8 g/10 min

[0146] Flame retardant 1 (FR1): ammonium polyphosphate (commercially available ADKSTAB FP2500S)

[0147] Flame retardant 2 (FR2): copolymer of ethylene, methyl acrylate and vinyl trimethoxy silane (VTMS), density=0.946 g/cm.sup.3, MFR.sub.2 (190° C./2.16 kg)=3 g/10 min

[0148] Flame retardant 3 (FR3): ammonium polyphosphate (commercially available IC FR5110)

Preparation of Compositions:

[0149] Twenty-two inventive compositions were prepared by gravitmetric feeding of various components to a twin screw extruder.

TABLE-US-00001 TABLE 1 Production Data for Inventive Compositions (expressed in parts by weight) High PE PE PE MFR Anti- PP Plast Plast Plast PP PP Proc. Emulsifier UV static Plast 1 2 3 plast copo FR1 FR2 FR3 Additive (GMS) additive additive Pigment IE1 10 40 — — — 10 16 — — — — — IE2 10 40 — — — 10 16 2.5 — — — — IE3 10 40 — — — 10 22 5 — — — — IE4 10 40 — — — 10 22 2.5 — — — — IE5 10 40 30 — — 10 4 — — — — — IE6 9 36 36 — — 9 3.6 2.5 — — — — IE7 30 43 — — 3 — — 10 12 8 3 2 — 3 IE8 30 43 — — 3 — — 10 12 6 3 2 3 3 IE9 30 43 — — 3 — — 10 12 6 3 2 4 3 IE10 30 43 — — 3 — — 10 12 6 3 2 6 3 IE11 30 43 — — 3 — — 10 12 6 3 2 10  3 IE12 30 43 — 6 1 — — 10 12 8 3 2 — 3 IE13 30 43 — — 1 — — 10 6 8 3 2 3 3 IE14 30 43 — — 1 — — 10 — 8 3 2 3 3 IE15 30 43 — — 1 — — 10 12 8 3 2 3 3 IE16 30 43 — — 1 — — 10 18 8 3 2 3 3 IE17 30 43 — — 1 — — 15 24 8 3 2 3 3 IE18 30 43 — — 1 — — 10 12 8 3 2 3 3 IE19 30 43 — — 1 — — 10 12 — 3 2 — 3 IE20 31 41 — — 1 10.3 — 5.2 6.2 — — 2.1 — 3.1 IE21 28.9 38.9 — — 1 9.7 — 4.9 11.7 — — 2 — 2.9 IE22 26.9 35.9 — — 0.9 9 — 6.7 16.1 — — 1.8 — 2.7

Production of Coated Substrates & Cigarette Test Results:

[0150] Five additional inventive compositions (IE23 to IE27) were prepared in the same manner as for IE1 to IE22 and were coated onto fabric substrates using the following methods. Lab-scale calendaring coating equipment (FIG. 1) was employed, consisting of two heated rollers, onto which the raw material or compounded polymer was placed, in the form of pellets. The rollers mix the polymer until a homogeneous blend is achieved, then the front roller transfers the melted coating onto the backer fabric at a set thickness (total thickness of the backer and coating together), and a surface texture is applied with a water-cooled embossing roller before the fabric is re-wound onto a roll. Dry blends (the separate components—not compounded) do not mix sufficiently to make a homogeneous coating. Therefore, these blends were first compounded using a twin-screw extruder and, where possible, drawn through a water bath to a pelletiser to make compound pellets. These pellets were then applied to the heated rollers for coating. The more flexible blends were too soft to cut into pellets. For these coatings, the compound was extruded straight onto a metal spatula and then transferred to the rollers

[0151] A polyurethane lacquer was further added and the materials subjected to the Cigarette test. The formulations used and the results of the tests are shown in Table 2. Tables 3 to 7 show flame retardancy, flex, tensile strength and UV data for selected compositions.

TABLE-US-00002 TABLE 2 Coated substrate formulations & Cigarette test results (figures represent parts by weight) PE PP High MFR PP Flame Flame UV Cig. Substrate Plastomer 1 Pigment Plastomer plastomer retardant 1 retardant 2 additive Lacquer test IE23 PP jersey 43 3 30 3 12 10 2 PU Pass White IE24 PP jersey 43 3 30 3 12 10 2 PU Pass Orange IE25 PP - FR* 43 3 30 3 2 10 2 PU Pass Blue IE26 PP jersey 43 3 30 3 18 10 2 PU Pass Blue IE27 PP - FR* 43 3 30 3 18 10 2 PU Pass Blue *Polypropylene substrate comprising flame retardant

TABLE-US-00003 TABLE 3 Flame Retardancy results Charac- Observations teristic IE2 IE4 IE6 Comments Initial Surface Surface Surface No inflam- began to began to began to concern mation degrade after degrade after degrade after 5 seconds 4 seconds 4 seconds Scorch Sample 27 cm 19 cm EU length completely Guidance - burnt in max 25 cm 180 seconds Burn rate 60 mm/s >120 mm/s 15 mm/s after 3 min

TABLE-US-00004 TABLE 4 Flame Retardancy results (test carried out on composition only, no fabric) IE24 IE26 burning time s 138 177.5 burning time #1 s 230 305 burning time SD s 130.1 180.3 comment Char formation heat release rate kW/m2 97.56 92.6 heat release rate #1 kW/m2 97.56 92.6 heat release rate SD kW/m2 0 0 ignition time s 138 177.5 Ignition time #1 s 46 50 Ignition time #2 s ignition time SD s 130.1 180.3 Oxygen content % 19 21

TABLE-US-00005 TABLE 5 Tensile Strength data Force Force Force Force at 45% at 100% at 150% Elongation IE8 (open at break elongation elongation elongation at break eye backer) (N) (N) (N) (N) (%) Warp (MD) 1 915.3 540.5 — — 89.3 Warp (MD) 2 915.3 549.4 — — 88.9 Warp (MD) 3 925.1 553.4 — — 90.8 Warp (MD) Mean 920.2 546.4 N/A N/A 89.7 Weft (CD) 1 321.8 111.8 158 191.7 131.6 Weft (CD) 2 336.5 107.2 152.1 186.1 141.6 Weft (CD) 3 351.2 109.9 156 192.1 144.4 Weft (CD) Mean 336.4 109.7 156 189.9 139.2 Force Force Force IE15 Force at 45% at 100% at 150% Elongation (Jersey knit at break elongation elongation elongation at break backer) (N) (N) (N) (N) (%) Warp (MD) 1 937.8 555.2 — — 86.4 Warp (MD) 2 894.7 558.2 — — 841 Warp (MD) 3 922.1 571.9 — — 85 Warp (MD) Mean 918.2 561.8 N/A N/A 84.1 Weft (CD) 1 345.3 138 142.8 165.3 167 Weft (CD) 2 322.7 102.8 136.8 159.2 161.6 Weft (CD) 3 310 105 139.7 162.1 156.4 Weft (CD) Mean 326.1 114.8 139.8 162.2 161.7

TABLE-US-00006 TABLE 6 UV data IE20 IE21 IE22 UV test result Pass Pass Pass

TABLE-US-00007 TABLE 6 Schildknecht Flexing data Assessment of Schildknecht flexing damage at 25,000 cycles Length sample Length sample Length sample Width sample Width sample Width sample IE8 1 2 3 1 2 3 Deterioration in 1-2 1-2 1-2 1-2 1-2 1-2 appearance Type of damage Wrinkling Wrinkling Wrinkling Wrinkling Wrinkling Wrinkling (if any) delamination delamination delamination delamination delamination delamination & flaking & flaking & flaking & flaking & flaking & flaking Depth of Cracking Nil Nil Nil Nil Nil Nil Number of cracks 0 0 0 0 0 0 of the lowest grade Length of the N/A N/A N/A N/A N/A N/A longest crack of the lowest grade (mm)