COMPACTED POLYMER-BASED FILLER MATERIAL FOR PLASTIC ROTOMOULDING

Abstract

The present invention relates to a compacted polymer-based filler material having a top cut particle size d.sub.98 of <500 μm, a process for producing said compacted polymer-based filler material, a rotomoulded product obtained from the compacted polymer-based filler material, a process for producing said rotomoulded product as well as the use of said compacted polymer-based filler material as additive in a rotomoulded product

Claims

1. A compacted polymer-based filler material having a top cut particle size d.sub.98 of ≤500 μm, the material comprising a) from 40 to 98 wt.-%, based on the total weight of the compacted polymer-based filler material, of a surface-treated filler material product comprising an alkaline earth metal carbonate-comprising filler material and a treatment layer on at least a part of the surface of the alkaline earth metal carbonate-comprising filler material, wherein the treatment layer comprises i) at least one mono-substituted succinic anhydride and/or at least one mono-substituted succinic acid and/or reaction products thereof, and/or ii) a phosphoric acid ester blend of one or more phosphoric acid mono-ester and reaction products thereof and/or one or more phosphoric acid di-ester and reaction products thereof, and/or iii) an aliphatic carboxylic acid having a total amount of carbon atoms from C.sub.4 to C.sub.24 and/or reaction products thereof, and/or iv) a polyhydrogensiloxane or an inert silicone oil and/or reaction products thereof, and/or v) an aliphatic aldehyde and/or reaction products thereof, b) from 1.95 to 59.95 wt.-%, based on the total weight of the compacted polymer-based filler material, of a polymer binder, and c) from 0.05 to 5 wt.-%, based on the total weight of the compacted polymer-based filler material, of additive(s) including one or more stabilizers.

2. The compacted polymer-based filler material according to claim 1, wherein the alkaline earth metal carbonate-comprising filler material is a calcium carbonate-comprising filler material.

3. The compacted polymer-based filler material according to claim 1, wherein the alkaline earth metal carbonate-comprising filler material has a weight median particle size d.sub.50 from 0.05 to 30 μm.

4. The compacted polymer-based filler material according to claim 1, wherein the at least one mono-substituted succinic anhydride consists of succinic anhydride mono-substituted with a group selected from a linear, branched, aliphatic and cyclic group having a total amount of carbon atoms from C.sub.2 to C.sub.30 in the substituent.

5. The compacted polymer-based filler material according to claim 1, wherein I) the one or more phosphoric acid mono-ester consists of an o-phosphoric acid molecule mono-esterified with one alcohol molecule selected from unsaturated or saturated, branched or linear, aliphatic or aromatic alcohols having a total amount of carbon atoms from C.sub.6 to C.sub.30 in the alcohol substituent, and/or II) the one or more phosphoric acid di-ester consists of an o-phosphoric acid molecule di-esterified with two alcohol molecules selected from the same or different, unsaturated or saturated, branched or linear, aliphatic or aromatic fatty alcohols having a total amount of carbon atoms from C.sub.6 to C.sub.30 in the alcohol substituent.

6. The compacted polymer-based filler material according to claim 1, wherein the surface-treated filler material product comprises the treatment layer in an amount of at least 0.1 wt.-%, based on the total dry weight of the alkaline earth metal carbonate-comprising filler material.

7. The compacted polymer-based filler material according to claim 1, wherein the polymer binder a) has a rotational viscosity from 100 to 400 000 mPa.Math.s, at 210° C., and/or b) is selected from the group consisting of homopolymers and/or copolymers of polyolefins, polyamides, polystyrenes, poly(meth)acrylates, polyvinylchlorides, polyurethanes, halogen-containing polymers, polyesters, polycarbonates, biodegradable polymers, and mixtures thereof.

8. The compacted polymer-based filler material according to claim 1, wherein the one or more stabilizers is/are a phenolic stabilizer, a phosphite and/or phosphonite stabilizer, sulphur containing stabilizer, sterically hindered amine stabilizers, HALS, UV stabilizer and mixtures thereof.

9. The compacted polymer-based filler material according to claim 1, wherein the compacted polymer-based filler material has a top cut particle size d.sub.98 of ≤150 μm.

10. A process for producing a compacted polymer-based filler material as defined in claim 1, the process comprising the steps of: a) providing a surface-treated filler material product in an amount from 40 to 98 wt.-%, based on the total weight of the compacted polymer-based filler material, the surface-treated filler material product comprising an alkaline earth metal carbonate-comprising filler material and a treatment layer on at least a part of the surface of the alkaline earth metal carbonate-comprising filler material, wherein the treatment layer comprises i) at least one mono-substituted succinic anhydride and/or at least one mono-substituted succinic acid and/or reaction products thereof, and/or ii) a phosphoric acid ester blend of one or more phosphoric acid mono-ester and reaction products thereof and/or one or more phosphoric acid di-ester and reaction products thereof, and/or iii) an aliphatic carboxylic acid having a total amount of carbon atoms from C.sub.4 to C.sub.24 and/or reaction products thereof, and/or iv) a polyhydrogensiloxane or an inert silicone oil and/or reaction products thereof, and/or v) an aliphatic aldehyde and/or reaction products thereof, b) providing a polymer binder in an amount from 1.95 to 59.95 wt.-%, based on the total weight of the compacted polymer-based filler material, c) providing additive(s) including one or more stabilizers in an amount from 0.05 to 5 wt.-%, based on the total weight of the compacted polymer-based filler material, d) simultaneously or subsequently feeding the surface-treated filler material product of step a), the polymer binder of step b) and the additives including one or more stabilizers of step c) into a high speed mixer unit, e) mixing the surface-treated filler material product of step a), the polymer binder of step b) and the additives including one or more stabilizers of step c) in the high speed mixer unit until formation of a compacted material, and f) reducing the temperature of the compacted material obtained from step e) below the melting point or glass transition temperature of the polymer binder.

11. A rotomoulded product obtained from the compacted polymer-based filler material as defined in claim 1.

12. The rotomoulded product according to claim 11 having i) a tensile modulus measured according to ISO 527-2/1B/50 (2012) at a speed of 50 mm/min in the range from 560 to 750 MPa, and/or ii) a Charpy Impact Strength (NIS+23) measured according to ISO 179-1/1e/UN (2010) at +23° C. in the range from 10 to 130 kJ/m.sup.2, and/or iii) a Charpy Impact Strength (NIS-40) measured according to ISO 179-1/1e/UN (2010) at −40° C. in the range from 5 to 80 kJ/m.sup.2.

13. The rotomoulded product according to claim 11, wherein the product is a one- or multi-layer rotomoulded product, and at least one layer is obtained from the compacted polymer-based filler material.

14. A process for producing a rotomoulded product, the process comprising the steps of a) mixing a compacted polymer-based filler material as defined in claim 1 with at least one polymer binder, wherein the polymer binder may be the same or different to the polymer binder in the compacted polymer-based filler material, and b) subjecting the mixture obtained in step a) to one or more rotomoulding process(es), and c) optionally subjecting at least one polymer binder before or after step b) to one or more rotomoulding process(es), wherein the polymer binder may be the same or different to the polymer binder in the compacted polymer-based filler material.

15. The compacted polymer-based filler material as defined in claim 1, suitable for use as an as additive in a rotomoulded product.

16. The compacted polymer-based filler material according to claim 1, wherein the alkaline earth metal carbonate-comprising filler material is a natural ground calcium carbonate.

17. The compacted polymer-based filler material according to claim 1, wherein the alkaline earth metal carbonate-comprising filler material has a weight median particle size d.sub.50 from 0.5 to 8 μm.

18. The compacted polymer-based filler material according to claim 1, wherein the at least one mono-substituted succinic anhydride consists of succinic anhydride mono-substituted with a group selected from a linear, branched, aliphatic and cyclic group having a total amount of carbon atoms from C.sub.4 to C.sub.20 in the substituent.

19. The compacted polymer-based filler material according to claim 1, wherein the polymer binder has a rotational viscosity from 5 000 to 50 000 mPa.Math.s, at 210° C.

20. The compacted polymer-based filler material according to claim 1, wherein the compacted polymer-based filler material has a top cut particle size d.sub.98 of ≤80 μm.

21. The rotomoulded product according to claim 11, wherein the product is a two- or three-layer rotomoulded product, and at least one layer is obtained from the compacted polymer-based filler material.

22. The process of claim 14, wherein step c) is optionally subjecting at least one polymer binder before step b) to one or more rotomoulding process(es), wherein the polymer binder may be the same or different to the polymer binder in the compacted polymer-based filler material.

Description

EXAMPLES

1. Measurement Methods and Materials

[0323] In the following, measurement methods and materials implemented in the examples are described.

[0324] Particle Size of Mineral Particles Method “Sedigraph”

[0325] The weight median particle size d.sub.50 as used herein, as well as the top cut d.sub.98 was determined based on measurements made by using a Sedigraph™ 5120 instrument of Micromeritics Instrument Corporation. The method and the instruments are known to the skilled person and are commonly used to determine grain size of fillers and pigments. The measurement was carried out in an aqueous solution comprising 0.1 wt.-% Na.sub.4P.sub.2O.sub.7. The samples were dispersed using a high speed stirrer and supersonics. For the measurement of dispersed samples, no further dispersing agents were added.

[0326] Particle size of particles method, “Malvern” The weight median particle size d.sub.50 as used herein, as well as the top cut d.sub.98 was determined based on measurements made by using a Malvern Mastersizer 3000 (Malvern Instruments Ltd. Enigma Business Park, Grovewood Road, Malvern, Worcestershire, UK WR14 1XZ) in combination with Malvern Aero S dry dispersion unit and dry cell was used to determine the particle size distribution of the solid inorganic powder material within the fineness range of d.sub.50 of from 500 to 0.1 μm by means of laser diffraction. The methods used are described in the Mastersizer 3000 Basic Guide, Mastersizer 3000 Manual and the Manual for Aero Series Dry dispersion unit available by Malvern Instruments Ltd. Approximately 10 ml of sample was loaded into the Aero S through the corresponding sieve. The results are expressed in V.-% (volume %).

[0327] Specific Surface Area (BET)

[0328] The specific surface area was measured using nitrogen and the BET method according to ISO 9277 (2010).

[0329] Rotational Viscosimetry

[0330] The rotational viscosity was measured by a rheometer from Anton Paar, Austria, model Physica MCR 300 Modular Compact rheometer, with a plate-plate system having a diameter of 25 mm, a gap of 0.2 mm and a shear rate of 5 s.sup.−1.

[0331] Charpy Unnotched Impact Strength (ISO 179-1)

[0332] The charpy unnotched impact strength was determined according to ISO 179/1eUN (2010) at +23° C. (NIS+23) and −40° C. (NIS-40) by using a minimum of 5 test specimens of type 1 for each temperature and a hammer mass of 7.5 J. The test specimens were prepared by thickness being thickness of wall.

[0333] Tensile Properties (ISO 527-2)

[0334] Tensile Modulus, yield stress, yield strain, break strain and break stress were measured according to ISO 527-2/1B/50 (2012) (test speed=50 mm/min; +23° C. and −40° C.) by using a minimum of 5 test specimens of type 1 B. The test specimens were prepared by thickness being thickness of wall. If not otherwise indicated the properties were determined at +23° C. (+23° C.=room temperature).

[0335] MFR

[0336] The melt flow rate MFR is measured according to ISO 1133 (190° C., 2.16 kg load).

[0337] Density

[0338] The density was measured according to ASTM D792.

[0339] Melting Temperature

[0340] The melting temperature (Tm) was measured with a differential scanning calorimetry (DSC).

[0341] Ash Content

[0342] The ash content in wt.-% of a compacted material sample, based on the total weight of the sample, was determined by incineration of a sample in an incineration crucible which was put into an incineration furnace at 400° C. for 40 minutes. The ash content was measured as the total amount of remaining inorganic residues.

2. Examples

[0343] A. Preparation of the Compacted Material

[0344] Materials

[0345] Powder Materials

[0346] CC1: Very fine calcium carbonate powder manufactured from a high purity, white marble, and surface-treated with stearic acid (commercially available from Sigma-Aldrich, Croda, USA). The CC1 has the following characteristics:

TABLE-US-00001 Residue on a 45 μm sieve (ISO 787/7) 0.05% Top cut (d.sub.98)  15 μm Mean particle size (d.sub.50) 2.6 μm Particles <2 μm .sup. 38% Whiteness: Brightness (Ry, C/2°, DIN 53163) .sup. 95% Tappi brightness (R457, ISO 2469) 94.5% Moisture ex works (ISO 787/2)  0.2%

[0347] CC2: Very fine calcium carbonate powder manufactured from a high purity, white marble, and surface-treated with 0.6% stearic acid (commercially available from Omya International AG, CH-4665 Oftringen). The CC2 has the following characteristics:

TABLE-US-00002 PSD (μm) d.sub.50 3 d.sub.98 15

[0348] Polymer Binder and Stabilizer

[0349] Binder A: Ethylene—1-octene-copolymer (Affinity GA 1900), density (ASTM D792)=0.87 g/cm.sup.3, according to the technical data sheet, rotational viscosity=8 500 mPa-s at 190° C., commercially available from The Dow Chemical Company, USA.

[0350] Stabilizer: ALBlend 181 antioxidant is a (1:1) blend of ETHANOX® 310 antioxidant, a primary phenolic antioxidant, and ETHAPHOS® 368 antioxidant, a secondary organophosphite. ALBlend 181 is commercially available from SI Group Inc., USA.

[0351] Hostavin® N 30 P is an oligomeric hindered amine light stabilizer (HALS), designed for light stabilization of plastic materials commercially available from Clariant International Ltd, CH—4133 Pratteln and has the CAS-No [202483-55-4].

[0352] Polyethylene resin (Dowlex 2631.10 UE), MFR=7 g/10 min (190° C., 2.16 kg, ISO 1133), density (ASTM D-792)=0.935 g/cm.sup.3, a melting point Tm (DSC)=124° C. according to the technical data sheet available from The Dow Chemical Company, USA.

[0353] Preparation of the Compacted Material

[0354] A horizontal “Ring-Layer-Mixer/Pelletizer”, namely “AVA Mixer HRM70” with process length of 1100 mm, and diameter of 300 mm was used. The cylinder was fitted with a heating/cooling double wall. Mixing and compacting was obtained by a rotating, cylindrical, pin-fitted screw.

[0355] The powder material CC1 was fed gravimetrically into the feed port at a rate of 500 kg/h. The polymer binder or polymer binder blend was injected in liquid state at a temperature of 230° C. through liquid feeding port at a rate of 65 kg/h. The employed amounts of powder material CC1 and the type and amounts of the polymer binders and stabilizers are indicated in Table A below.

[0356] Mixing and compacting of the powder material and the polymer binder or polymer binder blend was carried out in the “Ring-Layer-Mixer/Pelletizer” at 140-160° C. and a screw speed of 2000-2200 rpm.

[0357] The mixture left the mixer/pelletizer through the outlet port, was transferred by gravity into a second Ring-Layer-Mixer/Pelletizer for compacting and cooling, operated at a temperature of 120-140° C. and a screw speed of 2000-2200 rpm. In this example, both units were of identical size and dimensions. The resulting compacted material CM1 left the unit through the outlet port and was cooled to room temperature with ambient air in a fluid bed.

TABLE-US-00003 TABLE A Compositions and properties of prepared compacted materials CM1 (wt.-% is based on total weight of the compacted material). CM1 CC1 88.5 wt.-% Binder A 11.3 wt.-% Stabilizer  0.2 wt.-% Ash content [wt. -%] 87.8 wt.-% PSD 85-90% <160 micron

TABLE-US-00004 TABLE B Composition of prepared compacted material PCMS (wt.-% is based on total weight of the compacted material). Composition of PCMS Amount (%) CC2 88.3 Affinity 1900 GA 11.1 ALBLEND 181 P 0.3 Hostavin N30 P 0.3

[0358] The compacted material PCMS was produced as outlined above for the compacted material CM1.

[0359] The particle size distributions (PSD) of the compacted materials were determined by the method “Malvern” as indicated above.

TABLE-US-00005 TABLE C Particle size distributions of compacted materials PSD (μm) d.sub.50 d.sub.98 PE (Dowlex 2631.10 UE) 350 ± 15 1000 ± 20 PCMS 520 ± 20 1500 ± 50 PCM1  80 ± 15  250 ± 20 PCMI  65 ± 15  400 ± 20

[0360] PCM1 and PCMI were obtained from PCMS by sieving. The particle size distribution was measured with the method “Malvern”.

[0361] A. Rotomoulding Tests

[0362] Equipment

[0363] A cube test mould with dimensions of 300 mm×330 mm×330 mm together with a ferry Rotospeed rotational moulding machine (LPG burner) was used. The rotation ratio of the drop-arm, which rotates the mould (and has 2 axis), was 8 rpm (major axis):2 rpm (minor axis). A total shot weight of 2.4 kg was used. Rotopaq temperature monitoring used to measure air temperature inside mould as well as air temperature of oven (just outside mould). Oven set temperature: 300° C.

[0364] Mould release was applied to inside surface of mould prior to moulding and allowed to dry for 10 minutes: Freekote700-NC (liquid). Internal air temperature of part when de-moulded: less than 70° C. Cooling was carried out by using forced air convection of ambient air.

[0365] Test 1

[0366] In a first step, 2.4 kg of polyethylene resin were tumble mixed in a plastic bag by hand for 30 seconds. The mixture obtained was then placed inside the mould. The material tumbled on the inside surface of the mould (until it became hot enough to stick to the mould surface).

[0367] The mould was heated to melt the polymer and then cooled to an internal air temperature of 70° C. before demoulding took place. The time in the oven was about 12 minutes.

[0368] Further settings were as follows:

[0369] Cycle time: 47.48 min

[0370] IAT (internal air temperature) at removal from oven: 186° C.

[0371] PIAT (peak internal air temperature): 208.9° C.

[0372] The results are set out in Table 1.

[0373] Test 2

[0374] In a first step, 2.28 kg of polyethylene resin and 0.12 kg of CM1 were tumble mixed in a bag by hand for 30 seconds. The mixture was then placed inside the mould. The material tumbled on the inside surface of the mould (until it became hot enough to stick to the mould surface).

[0375] The mould was heated to melt the polymer and then cooled to an internal air temperature of 70° C. before demoulding took place. The time in the oven was about 11.5 minutes.

[0376] Further settings were as follows:

[0377] Cycle time: 44.27 min

[0378] IAT (internal air temperature) at removal from oven: 186° C.

[0379] PIAT (peak internal air temperature): 207° C.

[0380] The results are set out in Table 2.

[0381] Test 3 to Test 8 were performed as indicated for Tests 1 and 2 above. However, the amounts, ratios of materials used and the results as well are listed in Tables 3 to 8. 2-layered products were obtained by first rotomoulding the outer layer followed by the rotomoulding of the material of the inner layer forming a 2-layered rotomoulded article.

[0382] Table 1 shows the results of Test 1:

TABLE-US-00006 Impact Strength Impact Tensile Yield Yield Impact kJ/m.sup.2 Impact Strength Modulus Stress Strain Break Thickness Width Energy Room Break Energy kJ/m.sup.2 Break MPa MPa % Strain mm mm J Temperature Type J −40° C. Type Trial 1 Side A 1 626.4 18.1 9.8 104.9 4.394 10 4.746 108.0 no break 7.467 169.9 no break 2 642.4 18.1 10.4 86.6 4.322 10 3.906 90.4 no break 6.495 150.3 no break 3 593.2 17.6 10.1 110.0 4.320 10 4.635 107.3 no break 6.485 150.1 no break 4 601.3 17.6 9.6 78.8 4.388 10 4.230 96.4 no break 6.44 146.8 no break 5 623.6 18.0 10.3 88.9 4.308 10 4.623 107.3 no break 7.486 173.8 no break Average 617.4 17.9 10.0 93.8 101.9 158.2 SD 19.9 0.2 0.3 13.1 8.0 12.6

[0383] Table 2 shows the results of Test 2:

TABLE-US-00007 Trial 2 Side A 1 656.8 16.9 9.6 24.6 4.048 10 4.480 110.7 no break 1.325 32.7 break 2 640.3 16.9 9.7 26.6 4.151 10 4.577 110.3 break 1.692 40.8 break 3 660.1 16.7 9.3 30.7 4.190 10 2.125 50.7 no break 2.627 62.7 break 4 628.8 16.3 10.5 34.6 4.051 10 4.177 103.1 no break 2.264 55.9 break 5 633.9 16.7 9.0 25.5 4.170 10 4.292 102.9 no break 2.625 62.9 break Average 644.0 16.7 9.6 28.4 95.5 51.0 SD 13.9 0.3 0.6 4.2 25.3 13.6

TABLE-US-00008 TABLE 3 Monolayer -PE + PCMI .fwdarw. Sheet PE_PCMI - includes Neat PE Monolayer, total: 2.4 kg Material rotomoulded, thickness of the wall of the rotomoulded item 4.0 mm Impact Impact Tensile Yield Yield Break Strength Strength Modulus Stress Strain Strain +23° C. −40° C. MPa MPa % % kJ/m kJ/m.sup.2 PE (%) PCMI (%) 95 5 Trial 1 Side A Average 644.6 15.2 8.5 22.5 101.3 54.9 SD 11.3 0.5 0.7 8.0 18.3 4.4 90 10 Trial 2 Side A Average 563.0 15.1 9.0 16.8 37.7 25.3 SD 47.8 10.4 5.5 10.3 58.7 35.7 70 30 Trial 3 Side A Average 363.7 5.1 5.5 7.7 8.1 4.7 SD 15.2 0.4 0.5 3.2 1.0 1.6

TABLE-US-00009 TABLE 4 Monolayer -PE + PCM1 .fwdarw. Sheet PE_PCM1 Monolayer, total: 2.4 kg Material rotomoulded, thickness of the wall of the rotomoulded item 4.0 mm Impact Impact Tensile Yield Yield Break Strength Strength Modulus Stress Strain Strain +23° C. −40° C. MPa MPa % % kJ/m.sup.2 kJ/m.sup.2 PE (%) PCM1 (%) 100 0 Trial 4 Side A Average 617.4 17.9 10.0 93.8 101.9 158.2 SD 19.9 0.2 0.3 13.1 8.0 12.6 95 5 Trial 5 Side A Average 644.0 16.7 9.6 28.4 95.5 51.0 SD 13.9 0.3 0.6 4.2 25.3 13.6 90 10 Trial 6 Side A Average 532.9 12.7 7.9 14.5 38.4 26.8 SD 26.7 0.4 0.7 0.6 6.5 5.6 70 30 Trial 7 Side A Average 590.8 8.2 5.0 6.5 11.8 8.1 SD 24.8 0.4 0.6 1.3 2.2 1.3

TABLE-US-00010 TABLE 5 Monolayer - PE + PCMS .fwdarw. Sheet PE_PCMS Monolayer, total: 2.4 kg Material rotomoulded, thickness of the wall of the rotomoulded item 4.0 mm Impact Impact Tensile Yield Yield Break Strength Strength Modulus Stress Strain Strain +23° C. −40° C. MPa MPa % % kJ/m.sup.2 kJ/m.sup.2 PE (%) PCMS (%) 95 5 Trial 8 Side A Average 642.9 14.9 9.2 18.9 99.4 64.2 SD 26.8 0.5 0.3 3.3 5.9 40.3 90 10 Trial 9 Side A Average 570.4 13.1 8.2 16.2 47.6 23.4 SD 39.2 0.5 0.1 0.2 23.0 3.0 70 30 Trial 10 Side A Average 473.5 7.8 5.3 7.1 13.9 7.9 SD 13.6 0.3 0.7 1.5 3.7 1.7

TABLE-US-00011 TABLE 6 2-layered PE + PCMI .fwdarw. Sheet 2L_PE_PCMI 2 layers: L1 is the inner layer and L2 is the outer layer, total: 2.4 kg Material rotomoulded, thickness of the wall of the rotomoulded item 4.0 mm Impact Impact Tensile Yield Yield Break Strength Strength Modulus Stress Strain Strain +23° C. −40° C. MPa MPa % % kJ/m.sup.2 kJ/m.sup.2 Layer PE (%) PCMI (%) L1 100 Trial 11 Side A Average 604 17.4 9.2 22.4 84.9 28.1 L2 90 10 SD 9.8 0.9 0.4 3.8 29.0 1.1 L1 100 Trial 12 Side A Average 504.0 13.7 8.6 19.7 48.4 17.5 L2 80 20 SD 3.6 0.4 0.7 1.0 12.0 6.0 L1 100 Trial 13 Side A Average 514.2 15.0 8.8 40.0 30.8 58.4 L2 40 60 SD 18.1 0.6 0.3 12.3 6.5 17.7 L1 90 10 Trial 14 Side A Average 572.3 16.6 9.0 26.3 94.2 30.6 L2 100 SD 24.7 0.6 0.8 6.7 12.5 2.4 L1 80 20 Trial 15 Side A Average 617.7 16.2 8.3 18.1 36.2 13.9 L2 100 SD 26.3 0.8 0.8 3.9 5.9 1.6

TABLE-US-00012 TABLE 7 2-layered PE + PCM1 .fwdarw. Sheet 2L_PE_PCM1 2 layers: L1 is the inner layer and L2 is the outer layer, total: 2.4 kg Material rotomoulded, thickness of the wall of the rotomoulded item 4.0 mm Impact Impact Tensile Yield Yield Break Strength Strength Modulus Stress Strain Strain +23° C. −40° C. MPa MPa % % kJ/m.sup.2 kJ/m.sup.2 Layer PE (%) PCM1 (%) L1 100 Trial 16 Side A Average 483.5 14.3 9.5 26.0 83.6 35.0 L2 90 10 SD 12.0 0.7 0.8 3.9 11.9 8.9 L1 100 Trial 17 Side A Average 459.7 12.8 8.7 22.4 41.2 21.5 L2 80 20 SD 12.0 0.7 0.8 3.9 11.9 8.9 L1 100 Trial 18 Side A Average 296.9 8.8 8.9 29.9 27.3 42.1 L2 40 60 SD 23.9 0.4 0.6 14.5 1.6 11.5 L1 90 10 Trial 19 Side A Average 519.5 15.0 9.2 28.3 105.6 31.4 L2 100 SD 24.6 0.7 0.2 3.3 22.8 2.5 L1 80 20 Trial 20 Side A Average 505.6 13.8 8.4 21.7 44.6 17.2 L2 100 SD 30.3 0.9 0.5 2.1 6.2 3.9

TABLE-US-00013 TABLE 8 2-layered PE + PCMS .fwdarw. Sheet 2L_PE_PCMS 2 layers: L1 is the inner layer and L2 is the outer layer, total: 2.4 kg Material rotomoulded, thickness of the wall of the rotomoulded item 4.0 mm Impact Impact Tensile Yield Yield Break Strength Strength Modulus Stress Strain Strain +23° C. −40° C. MPa MPa % % kJ/m.sup.2 kJ/m.sup.2 Layer PE (%) PCMS (%) L1 100 Trial 21 Side A Average 492.5 14.3 9.2 25.2 83.3 30.3 L2 90 10 SD 30.0 1.0 0.4 3.0 16.5 6.0 L1 100 Trial 22 Side A Average 507.2 13.9 8.5 17.4 51.9 19.5 L2 80 20 SD 22.1 0.9 0.5 5.0 14.6 3.1