Thermoplastics for Slurry Transport Pipes

Abstract

The present invention relates to a thermoplastic material, wherein the thermoplastic material comprises an ethylene-based polymer material, wherein the ethylene-based polymer material has a Vicat softening temperature of ≥50°C measured according to ISO 306 (2013), method A50, and a weight loss of ≤0.50% by weight measured on a compression molded sheet according to ISO 15527 (2010), Annex B, using a silica sand / water slurry with a mass ratio of 3:2, a test duration of 7 hours. The present invention also relates to a slurry transport pipe comprising the thermoplastic material as its inner layer or consisting of the thermoplastic material.

Description

[0001] The present invention relates to a thermoplastic material which can be used to manufacture a transport pipe suitable for slurry transport. The present invention also relates to a transport pipe for slurry comprising the thermoplastic material.

[0002] For pipes to be suitable for slurry transport, they must meet certain specifications to ensure their long-lasting and reliable operation. Pipes are often used to transport slurries over long distances and can be used in both remote and densely populated areas; in each case, it will be understood that the quality and reliability of such pipes is critical to avoid leaks, spills or other disruptions to the transport process.

[0003] The transport pipes which are the subject of the present invention are generally used for transporting very large quantities of slurries. One field of application in which the pipes can be used is the mining industry, where for example slurries of excavated material are transported by pipes from the excavation area to an area where the excavated material is further processed into a form which allows the excavated product to be suitable for use.

[0004] Examples of processes in which such slurries are transported through pipes are coal and lignite processing, iron ore processing, oil and tar sands processing, but also food processing such as the transport of grain and rice.

[0005] Such slurries usually contain a certain proportion of quite abrasive materials, which may be organic or inorganic materials. Furthermore, the slurry is transported through the interior of the tube at particularly high speeds. As a result, the inner surface of the tube is subjected to severe abrasive forces. Therefore, the tube used for this purpose needs to be designed to withstand such forces during its expected service life.

[0006] At present, the pipes used for such purposes are usually made of steel or ceramic. Such pipes are expensive to produce, they are heavy, and the operations of installation and replacement are complicated. In some cases, pipes of high-density polyethylene (HDPE) are used. However, the life of such pipes is quite short and they need to be replaced regularly, which adversely affects the continuity of the transportation process, not to mention the economy.

[0007] It will therefore be appreciated that there is a need for a material from which pipes for slurry transport may be manufactured which are particularly lightweight whilst still being of such quality as to withstand abrasive forces and operation at high temperatures and have a desired lifespan.

[0008] This object is now achieved according to the invention by a thermoplastic material, wherein the thermoplastic material comprises an ethylene-based polymer material, wherein the ethylene-based polymer material has a Vicat softening temperature of ≥ 50°C, determined according to ISO 306 (2013), method A50, and a weight loss of ≤ 0.50 wt.-%, determined according to ISO 15527 (2010), annex B, using a silica sand / water slurry in a mass ratio of 3:2 and a test duration of 7 hours, on a compression molded sheet.

[0009] Such materials meet the requirements set for slurry transport pipes and in particular allow the required wear resistance and high operating temperatures to be achieved at low weight and high durability.

[0010] In a specific embodiment, the ethylene-based polymer material has a hardness of ≥0.875 and ≤0.900 g / cm2 as determined according to ISO 1183-1 (2019). 3 Even more particularly, the ethylene-based polymer may have a density of ≥0.880 and ≤0.890 g / cm 3 density.

[0011] In certain embodiments, the ethylene-based polymer material may be, for example, an ethylene-1-octene copolymer having:

[0012] ≥0.880 and ≤0.890 g / cm2 as determined according to ISO 1183-1(2019) 3 density.

[0013] 20.0 and ≤40.0 wt. %, preferably ≥20.0 and ≤30.0 wt. %, of structural moieties derived from 1-octene, relative to the total weight of the ethylene-1-octene copolymer; and / or

[0014] Molecular weight distribution M ≥1.5 and ≤2.5 w / M n , where the weight average molecular weight M w and number average molecular weight M n It is measured according to ASTM D6474 (2012).

[0015] Specific embodiments of the present invention also include thermoplastic materials comprising an ethylene-based polymer material comprising a proportion (A) of a first ethylene-based polymer (P1) and a proportion (B) of a second ethylene-based polymer (P2); wherein:

[0016] The first ethylene-based polymer P1 has a molecular weight of <0.880 g / cm2 as measured according to ISO 1183-1(2019). 3 , preferably >0.850 and <0.880 g / cm 3 density; and

[0017] The second ethylene-based polymer P2 has a molecular weight of >0.890 g / cm2 as measured according to ISO 1183-1(2019). 3 , preferably >0.890 and <0.930 g / cm 3 density.

[0018] The ethylene-based polymer has >10.0 wt% and <90.0 wt% of P1 relative to the sum of the weights of P1 and P2.

[0019] The thermoplastic material may for example comprise ≥ 90.0 wt. %, preferably ≥ 95.0 wt. %, more preferably ≥ 98.0 wt. % of ethylene-based material relative to the total weight of the thermoplastic material. In another preferred embodiment, the thermoplastic material consists of an ethylene-based polymer material.

[0020] For example, both P1 and P2 can be ethylene-1-octene copolymers. P1 may, for example, include ≥30.0 ​​and ≤45.0 wt %, preferably ≥30.0 ​​and ≤40.0 wt %, more preferably ≥35.0 and ≤40.0 wt % of the structure derived from 1-octene relative to the total weight of P1. P2 may, for example, include ≥0.5 and ≤10.0 wt %, preferably ≥5.0 and ≤10.0 wt % of the structure derived from 1-octene relative to the total weight of P2. For example, P1 may include ≥30.0 ​​and ≤45.0 wt % of the structure derived from 1-octene, and P2 may, for example, include ≥0.5 and ≤10.0 wt % of the structure derived from 1-octene. Preferably, P1 may include ≥35.0 and ≤40.0 wt % of the structure derived from 1-octene, and P2 may include ≥5.0 and ≤10.0 wt % of the structure derived from 1-octene.

[0021] P1 may, for example, have a melt mass flow rate (MFR2) of ≥0.10 and ≤2.00 g / 10 min, preferably ≥0.10 and ≤0.80 g / 10 min, measured according to ISO 1133-1 (2011) at 190° C. and a load of 2.16 kg. P2 may, for example, have an MFR2 of ≥0.50 g / 10 min, preferably ≥0.85 and ≤2.00 g / 10 min. Preferably, P1 has a melt mass flow rate (MFR2) of ≥0.10 and ≤2.00 g / 10 min, preferably ≥0.10 and ≤0.80 g / 10 min, measured according to ISO 1133-1 (2011) at 190° C. and a load of 2.16 kg, and P2 has an MFR2 of ≥0.50 g / 10 min, preferably ≥0.85 and ≤2.00 g / 10 min. For example, P1 may have an MFR2 that is at least 0.20 g / 10 min lower than that of P2, preferably at least 0.40 g / 10 min.

[0022] In a specific embodiment of the present invention, P1 has a molecular weight distribution M of ≥2.0 and ≤2.5. w / M n , and / or P2 has a molecular weight distribution M of ≥2.0 and ≤2.5 w / Mn .

[0023] Other specific embodiments of the present invention are directed to thermoplastic materials, wherein the thermoplastic material comprises an ethylene-based polymer material, wherein the ethylene-based polymer material has a Vicat softening temperature of ≥50°C as determined according to ISO 306 (2013), method A50, and a weight loss of ≤0.50 wt% as determined on a compression molded sheet according to ISO 15527 (2010), Annex B, using a silica sand / water slurry with a mass ratio of 3:2 and a test duration of 7 hours, wherein the ethylene-based material is an ethylene-1-octene copolymer having:

[0024] ≥0.880 and ≤0.890 g / cm2 as determined according to ISO 1183-1(2019) 3 density;

[0025] a proportion of ≥20.0 and ≤30.0 weight percent of the structural moiety derived from 1-octene relative to the total weight of the ethylene-1-octene copolymer; and / or

[0026] Molecular weight distribution M ≥1.5 and ≤2.5 w / M n , where the weight average molecular weight M w and number average molecular weight M n It is measured according to ASTM D6474 (2012).

[0027] In yet other specific embodiments of the present invention, the thermoplastic material consists of an ethylene-based polymer material, wherein the ethylene-based polymer material has a Vicat softening temperature of ≥50°C measured according to ISO 306 (2013), method A50, and a weight loss of ≤0.50 wt.% measured on a compression molded sheet according to ISO 15527 (2010), Annex B, using a silica sand / water slurry with a mass ratio of 3:2 and a test duration of 7 hours, wherein the ethylene-based material is an ethylene-1-octene copolymer having:

[0028] ≥0.880 and ≤0.890 g / cm2 as determined according to ISO 1183-1(2019) 3 density;

[0029] A proportion of ≥20.0 and ≤30.0 wt. % of the structural moiety derived from 1-octene, relative to the total weight of the ethylene-1-octene copolymer; and / or

[0030] Molecular weight distribution M ≥1.5 and ≤2.5 w / M n , where the weight average molecular weight M w and number average molecular weight M nIt is measured according to ASTM D6474 (2012).

[0031] Another embodiment of the present invention is also directed to a thermoplastic material, wherein the thermoplastic material comprises or consists of an ethylene-based polymer material, wherein the ethylene-based polymer material has a Vicat softening temperature of ≥50°C measured according to ISO 306 (2013), method A50, and a weight loss of ≤0.50 wt.% measured on a compression molded sheet according to ISO 15527 (2010), Annex B, using a silica sand / water slurry with a mass ratio of 3:2 and a test duration of 7 hours, wherein the ethylene-based polymer material comprises a first ethylene-based polymer (P1) in a certain proportion (A) and a second ethylene-based polymer (P2) in a certain proportion (B); wherein:

[0032] The first ethylene-based polymer P1 has a molecular weight of <0.880, preferably <0.870 g / cm2, measured according to ISO 1183-1 (2019). 3 , preferably >0.850 and <0.880 g / cm 3 , more preferably >0.850 and <0.870 g / cm 3 density; and

[0033] The second ethylene-based polymer P2 has a molecular weight of >0.890, preferably >0.900 g / cm2, measured according to ISO 1183-1 (2019). 3 , preferably >0.890 and <0.930 g / cm 3 , more preferably >0.900 and <0.930 g / cm 3 density;

[0034] The ethylene-based polymer contains >10.0 wt% and <90.0 wt% of P1 relative to the sum of the weights of P1 and P2.

[0035] In certain embodiments thereof, the present invention also relates to a tube comprising or consisting of a thermoplastic material.Such a tube may have an inner layer of a thermoplastic material.

[0036] In a specific embodiment, the present invention relates to a pipe comprising a thermoplastic material, wherein the thermoplastic material consists of an ethylene-based polymer material, wherein the ethylene-based polymer material has a Vicat softening temperature of ≥50°C measured according to ISO 306 (2013), method A50, and a weight loss of ≤0.50 wt. % measured on a compression molded sheet according to ISO 15527 (2010), Annex B, using a silica sand / water slurry with a mass ratio of 3:2 and a test duration of 7 hours, wherein the ethylene-based material is an ethylene-1-octene copolymer having

[0037] ≥0.880 and ≤0.890 g / cm2 as determined according to ISO 1183-1(2019) 3 density.

[0038] A proportion of ≥20.0 and ≤30.0 wt. % of the structural moiety derived from 1-octene, relative to the total weight of the ethylene-1-octene copolymer; and / or

[0039] Molecular weight distribution M ≥1.5 and ≤2.5 w / M n , where the weight average molecular weight M w and number average molecular weight M n It is measured according to ASTM D6474 (2012).

[0040] In another embodiment, the present invention is directed to a pipe comprising a thermoplastic material, wherein the thermoplastic material consists of an ethylene-based polymer material, wherein the ethylene-based polymer material has a Vicat softening temperature of ≥50°C measured according to ISO 306 (2013), method A50, and a weight loss of ≤0.50 wt.% measured on a compression molded sheet according to ISO 15527 (2010), Annex B, using a silica sand / water slurry with a mass ratio of 3:2 and a test duration of 7 hours, wherein the ethylene-based polymer material comprises a first ethylene-based polymer (P1) in a certain proportion (A) and a second ethylene-based polymer (P2) in a certain proportion (B); wherein:

[0041] The first ethylene-based polymer P1 has a molecular weight of <0.870 g / cm2 as measured according to ISO 1183-1(2019). 3 , preferably >0.850 and <0.870 g / cm 3 density; and

[0042] The second ethylene-based polymer P2 has a molecular weight of >0.900 g / cm2 as measured according to ISO 1183-1(2019). 3 , preferably >0.900 and <0.930 g / cm 3 density.

[0043] Wherein, the ethylene-based polymer contains >10.0 wt% and <90.0 wt% of P1 relative to the sum of the weights of P1 and P2.

[0044] For example, the tube of the present invention may comprise an inner layer comprising or consisting of a thermoplastic material. The inner layer may, for example, have a thickness of >0.05 and <10.0 cm, preferably >0.1 and <2.0 cm. The tube may, for example, consist of a single layer of material. The tube may, for example, have an inner diameter of >0.02 and <2.00 m, preferably >0.05 and <1.00 m.

[0045] The present invention further relates to a method for producing a thermoplastic material, wherein the method comprises polymerizing reactants in two or at least two reactors arranged in series, wherein a first ethylene-based polymer P1 is produced by polymerizing a first reactant mixture in a first reactor, and then a second ethylene-based polymer P2 is produced by polymerizing a second reactant mixture in a second reactor, wherein the second reactant mixture comprises the first ethylene-based polymer P1.

[0046] Alternatively, the present invention relates to a method for producing a thermoplastic material, wherein the method comprises combining by blending under melt conditions or in solid phase an amount of a first ethylene-based polymer P1 and an amount of a second ethylene-based polymer P2.

[0047] The invention will now be illustrated by the following non-limiting examples.

[0048] Materials used

[0049]

[0050]

[0051] MFR2 is the melt mass flow rate measured at 190° C. under a load of 2.16 kg according to ISO 1133 (2011); similarly, MFR5 is the melt mass flow rate measured at 190° C. under a load of 5.0 kg. Density is measured according to ISO 1183-1 (2012).

[0052] Using the above materials, a polymer formulation was prepared by melt mixing the materials in a ZSK26Mc twin screw melt extruder, which was connected to an underwater pelletizing system to form solidified pellets of the polymer formulation. The conditions of the extruder are as follows:

[0053]

[0054] Through this melt mixing, an exemplary formulation was produced according to the material composition listed in the following table:

[0055]

[0056] For each formulation, material properties were determined as shown in the following table:

[0057] Example MFR2 density Vika hardness weightlessness Tensile modulus 1 0.81 0.896 64.2 91.6 0.521 47.4 2 0.74 0.893 58.4 90.0 0.445 41.7 3 0.70 0.892 53.6 88.7 0.331 33.1 4 0.70 0.888 49.2 86.7 0.275 22.8 5 0.68 0.885 45.5 84.3 0.250 23.9 6 0.63 0.879 41.7 79.9 0.192 15.9 7 0.53 0.872 39.0 70.3 0.110 5.8 8 0.56 0.878 42.0 75.2 0.090 8.8 9 0.57 0.883 47.0 80.1 0.140 13.3 10 0.59 0.888 51.0 84.8 0.260 27.1 11 0.37 0.875 37.7 71.2 0.090 10.3 12 0.28 0.882 40.4 79.7 0.160 15.9 13 0.20 0.889 46.2 87.2 0.190 35.0 14 0.15 0.897 55.1 92.8 0.400 91.0 15 0.73 0.884 58.4 87.7 0.358 30.3 16 1.00 0.894 72.9 91.3 0.617 44.6 17 1.05 0.902 80.9 93.8 0.844 73.4 18 1.00 0.870 37.5 70.7 0.155 5.4 19 0.96 0.881 49.8 83.5 0.310 15.7 20 0.98 0.887 59.6 87.9 0.421 25.5 21 0.94 0.898 83.6 93.5 0.769 64.5 22 1.16 0.912 98.7 95.7 1.549 126.9 23 0.14* 0.954 131.2 96.6 2.715 1187.4

[0058] *For Example 23, MFR5 was determined.

[0059] in:

[0060] MFR2 and MFR5 are determined as described above and are expressed in g / 10min; density is determined as described above and is expressed in g / cm 3 express;

[0061] Vicat is the Vicat softening temperature measured according to ISO 306 (2013) at a heating rate of 50 °C / h and under a load of 10 N;

[0062] Hardness is Shore A hardness (dimensionless) measured according to ISO 868;

[0063] Weight loss is determined according to ISO 15527 (2010), Annex B, using a silica sand / water slurry with a mass ratio of 3:2 and a test duration of 7 hours, on compression molded sheets and is expressed in weight %;

[0064] The tensile modulus is determined according to ISO 527 and is expressed in MPa.

Claims

1. A thermoplastic material, wherein the thermoplastic material comprises an ethylene-based polymer material, wherein the ethylene-based polymer material has a Vicat softening temperature of ≥50°C measured according to ISO 306 2013, method A50, and a weight loss of ≤0.50 wt% measured on a compression molded sheet according to ISO 15527 2010, Annex B, using a silica sand / water slurry having a mass ratio of 3:2, a test duration of 7 h; wherein the thermoplastic material comprises an ethylene-based polymer material, the ethylene-based polymer material comprising a first ethylene-based polymer P1 in a certain proportion A and a second ethylene-based polymer P2 in a certain proportion B; wherein: The first ethylene-based polymer P1 has a molecular weight of >0.850 and <0.880 g / cm2, measured according to ISO 1183-1 2019. 3 density, melt mass flow rate MFR2 of ≥0.10 and ≤2.00 g / 10 min measured at 190°C and a load of 2.16 kg according to ISO 1133-1 2011, molecular weight distribution M of ≥2.0 and ≤2.5 w / M n , and ≥30.0 ​​and ≤45.0 wt. % of moieties derived from 1-octene; and The second ethylene-based polymer P2 has a molecular weight of >0.890 and <0.930 g / cm2, measured according to ISO 1183-1 2019. 3 Density, MFR2 ≥ 0.50 and ≤ 2.00 g / 10 min, measured at 190°C and a load of 2.16 kg according to ISO 1133-1 2011, molecular weight distribution M ≥ 2.0 and ≤ 2.5 w / M n , and ≥0.5 and ≤10.0 wt. % of a moiety derived from 1-octene; wherein the ethylene-based polymer comprises >10.0 wt% and <90.0 wt% of P1 relative to the sum of the weights of P1 and P2; and Wherein both P1 and P2 are ethylene-1-octene copolymers.

2. The thermoplastic material of claim 1, wherein the thermoplastic material comprises ≥ 90.0 wt% of the ethylene-based polymer material.

3. The thermoplastic material of claim 1, wherein the thermoplastic material consists of the ethylene-based polymer material.

4. The thermoplastic material according to any one of claims 1 to 3, wherein the ethylene-based polymer material has a molecular weight of ≥0.875 and ≤0.900 g / cm2 as determined according to ISO 1183-1 2019. 3 density.

5. Thermoplastic material according to any one of claims 1 to 3, wherein P1 comprises ≥ 35.0 and ≤ 45.0 wt.-% of moieties derived from 1-octene, and / or wherein P2 comprises ≥ 5.0 and ≤ 10.0 wt.-% of moieties derived from 1-octene.

6. Thermoplastic material according to any one of claims 1 to 3, wherein P1 has an MFR2 which is at least 0.20 g / 10 min lower than the MFR2 of P2.

7. The thermoplastic material according to claim 6, wherein: P1 has an MFR2 of ≥0.10 and ≤0.80 g / 10min; and P2 has an MFR2 of ≥ 0.85 and ≤ 2.00 g / 10min; and / or P1 has an MFR2 which is at least 0.40 g / 10 min lower than the MFR2 of P2.

8. A pipe comprising an inner layer comprising or consisting of a thermoplastic material according to any one of claims 1 to 7.

9. The tube of claim 8, wherein the tube consists of a single layer of material.

10. The tube according to any one of claims 8-9, wherein the tube has an inner diameter of ≥ 0.10 and ≤ 1.00 m.

11. The tube according to any one of claims 8-9, wherein the inner layer has a thickness of ≥ 0.1 and ≤ 10.0 cm.

12. A method for producing a thermoplastic material according to any one of claims 1 to 7, wherein the method comprises polymerizing reactants in two or at least two reactors arranged in series, wherein the first ethylene-based polymer P1 is produced by polymerizing a first reactant mixture in a first reactor, and then the second ethylene-based polymer P2 is produced by polymerizing a second reactant mixture in a second reactor, wherein the second reactant mixture comprises the first ethylene-based polymer P1.

13. The method for producing a thermoplastic material according to any one of claims 1 to 7, wherein the method comprises combining a certain amount of the first ethylene-based polymer P1 and a certain amount of the second ethylene-based polymer P2 by blending under melt conditions or in a solid phase.

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