Method for preparing nucleated polypropylene masterbatch based on bis-2-hydroxyethylene terephthalate

Abstract

To provide bis-hydroxyethylene terephthalate based nucleated polypropylene masterbatch which can be added to any grade of polypropylene, does not cause inhalation hazards while handling, is easy to handle, and has improved dispersion in base polypropylene, and a process for preparation thereof.SOLUTION: The masterbatch comprises, by weight, 0.1 to 60 wt.% of a bis-2-hydroxyethylene terephthalate (BHETA) based nucleating agent, and 40 to 99.9 wt.% of polypropylene. The present invention also discloses a process for preparation of a polypropylene masterbatch by mixing polypropylene with a nucleating agent.SELECTED DRAWING: Figure 2

Description

[Technical field]

[0001] The present invention discloses a method for preparing a nucleated polypropylene masterbatch. More specifically, the present invention discloses a method for preparing a polypropylene masterbatch by melt mixing polypropylene with bis-2-hydroxyethylene terephthalate (BHETA) as a nucleating agent. [Background technology]

[0002] Nucleating agents are a set of additives added during the manufacturing of polymers to enhance the mechanical properties and clarity of the finished polymer, and also provide faster crystallization rates. Nucleating agents are now in higher demand than ever before as they help induce crystallization and enhance production rates. A sufficient amount of nucleating agents can maintain spherulites of a certain size. The market for nucleating agents is highly dependent on the plastics and polymer manufacturing industry. Nucleating agents are widely adopted to increase strength, reduce cycle time by increasing the rate of crystallization, and improve clarification of plastics and other polymers. Nucleating agents are expected to grow along with the plastics and polymer manufacturing industry. The growth of the packaging industry is considered as a key factor in developing the global nucleating agents market for plastics and polymers.

[0003] In a research paper titled 'Organic Compound as Both Plasticizer and Nucleating Agent' (Nils Leone, Manta Roy, Sarah Saidi, Gijs de Kort, Daniel Hermida-Merino, Carolus H.R.M. Wilsens; ACS Omega, 2019, 4(6), 10376-10387, DOI:10.1021 / acsomega.9b00848), Nils et al. disclose the combined plasticizing and nucleating effects of BHET, making it a versatile additive to control the processing and performance of poly-l-lactide (PLA).

[0004] US 2003 / 0236332 discloses a method for nucleating a thermoplastic formulation comprising the steps of: a) providing a thermoplastic formulation in a molten state; b) introducing, either simultaneously or separately, at least one compound that is substantially soluble in step "a" of said formulation selected from the group consisting of at least one bicyclic compound, at least one monocyclic aliphatic compound, and at least one organic salt; and c) cooling the synthesis mixture in step "b" to form a nucleated thermoplastic, said nucleated thermoplastic exhibiting a peak crystallization temperature that exceeds the peak crystallization temperature of the same thermoplastic without any nucleating agent therein.

[0005] WO2010104628 discloses a masterbatch composition for use in a film, the masterbatch comprising at least 10-97 wt.% of a polyolefin and 90-3 wt.% of an additive composition comprising (i) a hydrocarbon resin having a molecular weight lower than the molecular weight of the polyolefin, and (ii) a nucleating agent for increasing the crystallization temperature of the polyolefin compared to a mixture of the polyolefin and the additive composition without the nucleating agent present.

[0006] Therefore, there is a need to provide a polypropylene nucleating masterbatch composition that uses bis-2-hydroxyethylene terephthalate (BHETA) as a nucleating agent that can be added to any grade of polypropylene to obtain the required concentration. Summary of the Invention [Problem to be solved by the invention]

[0007] It is the primary object of the present invention to prepare a masterbatch of polypropylene (PP).

[0008] A further object of the present invention is to prepare a masterbatch of polypropylene (PP) using a nucleating agent.

[0009] Another object of the present invention is to prepare a masterbatch of polypropylene (PP) using bis-2-hydroxyethylene terephthalate (BHETA) as a nucleating agent. [Means for solving the problem]

[0010] In an aspect of the invention, the present invention comprises: a) polypropylene having a melt flow index in the range of 1.5 to 40 g / 10 min; b) a nucleating agent; c) optionally a dispersant which is a non-ionic surfactant. 、 The nucleating agent is bis-2-hydroxyethylene terephthalate (BHETA) and is present in an amount ranging from 0.1 to 60% by weight, the BHETA being prepared from the depolymerization of waste polyethylene terephthalate (PET). A nucleated polypropylene masterbatch composition is disclosed.

[0011] In a feature of the invention, the polypropylene is a homopolymer and is present in an amount ranging from 40 to 99.9% by weight.

[0013] In a feature of the invention, the dispersant is selected from the group consisting of Tween 20, Span 60, Span 80, and any combination thereof, and is present in an amount ranging from 0.01 to 10% by weight.

[0014] In an aspect of the invention, the present invention comprises: i. combining polypropylene with a nucleating agent and optionally adding a dispersing agent to form a reaction mixture; ii. feeding the reaction mixture obtained in step i) into an extruder through a hopper; iii. maintaining the temperature from the feed zone to the die zone of the extruder; iv. cooling the extrudate coming out of the extruder using a water bath and then granulating it; v. drying the granules obtained in step iv) to obtain a polypropylene masterbatch. 、 The nucleating agent is bis-2-hydroxyethylene terephthalate (BHETA) and is present in an amount ranging from 0.1 to 60% by weight. A method for preparing a nucleated polypropylene masterbatch composition is disclosed.

[0015] In a feature of the invention, the polypropylene is a homopolymer and is present in an amount ranging from 40 to 99.9% by weight.

[0017] In a feature of the present invention, the extruder is a twin screw extruder. 、 in a batch mixer, microcompounder, single screw extruder, or other processing equipment be .

[0018] In a feature of the invention, the temperature in step iii) is maintained in the range of 150-300°C.

[0019] In a feature of the present invention, the temperature of the water bath in step iv) is maintained at 25°C to 30°C.

[0020] In a feature of the present invention, the drying in step v) is carried out in a thermostatic bath at a temperature of 90-110° C. for about 2-3 hours.

[0021] In a feature of the invention, the polypropylene masterbatch is further diluted to various concentrations using the extruder, which may be a batch mixer, microcompounder, single screw extruder, or other processing equipment.

[0022] In a feature of the present invention, the concentration of the nucleating agent is diluted in polypropylene in the range of 250 to 20,000 ppm; Crystallization temperature ranges from 115℃ to 122℃ A nucleated polypropylene is prepared.

[0023] In a feature of the invention, the polypropylene is a polypropylene homopolymer and / or a polypropylene copolymer with any other alkene or acrylate or halogenated hydrocarbon. [Brief description of the drawings]

[0024] [Figure 1] 1 shows optical microscope images obtained for iPPs of Examples 2, 5, 8, 10, 11, and 12. [Diagram 2] 1 illustrates a process for preparing a polypropylene masterbatch by mixing polypropylene with a nucleating agent. DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS

[0025] In an aspect of the invention, the present invention comprises: d) polypropylene having a melt flow index in the range of 1.5 to 40 g / 10 min; e) a nucleating agent; and f) optionally a dispersing agent which is a non-ionic surfactant.

[0026] In an embodiment of the invention, the polypropylene is a homopolymer and is present in an amount ranging from 40 to 99.9 wt %.

[0027] In an embodiment of the invention, the nucleating agent is bis-2-hydroxyethylene terephthalate (BHETA) and is present in an amount ranging from 0.1 to 60% by weight, the BHETA being prepared from the depolymerization of waste polyethylene terephthalate (PET).

[0028] In an embodiment of the present invention, the dispersant is selected from the group consisting of Tween 20, Span 60, Span 80, and any combination thereof, and is present in an amount ranging from 0.01 to 10% by weight.

[0029] In an aspect of the invention, the present invention comprises: vi. combining polypropylene with a nucleating agent and optionally adding a dispersing agent to form a reaction mixture; vii. feeding the reaction mixture obtained in step i) into an extruder through a hopper; viii. maintaining the temperature from the feed zone to the die zone of the extruder; ix. cooling the extrudate coming out of the extruder using a water bath and then granulating it; x. drying the granules obtained in step iv) to obtain a polypropylene masterbatch.

[0030] In an embodiment of the invention, the polypropylene is a homopolymer and is present in an amount ranging from 40 to 99.9 wt %.

[0031] In an embodiment of the invention, the nucleating agent is bis-2-hydroxyethylene terephthalate (BHETA) and is present in an amount ranging from 0.1 to 60% by weight.

[0032] In an embodiment of the invention, the extruder is a twin screw extruder and the masterbatch is prepared in a batch mixer, microcompounder, single screw extruder, or other processing equipment.

[0033] In an embodiment of the present invention, the temperature in step iii) is maintained in the range of 150-300°C.

[0034] In an embodiment of the present invention, the temperature of the water bath in step iv) is maintained at 25°C to 30°C.

[0035] In an embodiment of the present invention, the drying in step v) is carried out in a thermostatic bath at a temperature of 90-110° C. for about 2-3 hours.

[0036] In an embodiment of the invention, the polypropylene masterbatch is further diluted to various concentrations using an extruder, the dilution being carried out in a batch mixer, microcompounder, single screw extruder, or other processing equipment.

[0037] In an embodiment of the present invention, the concentration of the nucleating agent is diluted in polypropylene to a range of 250 to 20,000 ppm to prepare nucleated polypropylene.

[0038] In an embodiment of the invention, the polypropylene is a polypropylene homopolymer and / or a polypropylene copolymer with any other alkene or acrylate or halogenated hydrocarbon.

[0039] In a feature of the present invention, depolymerization of waste polyethylene terephthalate (PET) to prepare bis-2-hydroxyethylene terephthalate was carried out as per the methodology of More et al. (More, AP, Kute, RA, Mhaske, ST. 2014. Chemical conversion of PET waste using ethanolamine to bis (2-hydroxyethyl) terephthalamide (BHETA) through aminolysis and a novel plasticizer for PVC. Iranian Polymer Journal, 23(1), pp. 59-67).

[0040] The nucleating agent is added into polypropylene (PP) to prepare a masterbatch. The advantages of the masterbatch are as follows: The prepared masterbatch can be added to any grade of polypropylene. No inhalation of powder during handling Easy to handle Better dispersibility in PP during dilution to required concentration

[0041] The materials used are: MFI 12.5g / 10min and 0.9g / cm 3 Polypropylene homopolymer (iPP) with a concentration of 0.1%. Ethanolamine and zinc acetate were purchased from Sigma-Aldrich. Waste PET bottles collected from the market were delabeled and capped, washed with soap solution, and dried thoroughly. The bottles were cut into flakes using a cutting mill, and the resulting flakes were used for depolymerization. All chemicals were used as obtained without further adjustment or purification.

[0042] The polymer processing is as follows. The masterbatch preparation methodology is as follows. Extrusion of iPP and prepared blends was carried out in a co-rotating twin screw extruder (Bhorani Engineering Corporation Ltd., Mumbai, India) with 30 mm screw diameter, L / D of 48 / 1 and 8 heating zones. PP was first premixed with the nucleating agent in a high speed mixer for 5-20 minutes and then fed into the extruder through a hopper. The temperature profile in the extruder was maintained at 160-230°C from the feed zone to the die zone. The feeder screw and extruder screw speeds were set at 10 rpm and 225 rpm, respectively. The extrudate was cooled by passing through a water bath (maintained at 25°C with continuous water circulation) and subsequently pelletized. The resulting pellets were dried in a thermostatic oven at 105°C for about 2-3 hours before injection molding. The above mentioned masterbatches can also be prepared using a batch mixer, microcompounder, single screw extruder, or other processing equipment.

[0043] Nucleating agent masterbatches can be prepared with nucleating agent concentrations ranging from 0.1 wt% to 60 wt%, while to prepare nucleated polypropylene, the prepared masterbatches can be diluted to concentrations of 250 to 20,000 ppm. In the present disclosure, the concentration of nucleating agent in the masterbatches was maintained at 10 wt%.

[0044] Masterbatch dilution and sample preparation are as follows: Masterbatch dilutions to prepare 500, 1000, and 2000 ppm nucleated polypropylene were done in three ways using the following: ·Twin-screw extrusion ·Single-screw extrusion Batch mixing method

[0045] The twin screw extrusion process is as follows: Dilution of the masterbatch to prepare 500-2000 ppm nucleated polypropylene was carried out using process conditions similar to those described in the extrusion process under the masterbatch preparation methodology.

[0046] The single screw extrusion process was as follows: iPP and the prepared master batches were extruded in a single screw extruder (Dr. Collins, Germany) with a screw diameter of 20 mm, L / D of 30 / 1, and four heating zones. PP was first premixed with the nucleating agent master batch in a high-speed mixer for 5-20 min and then fed into the single screw extruder through a hopper. The temperature profile in the extruder was maintained at 160-230 °C from the feed zone to the die zone. The speed of the extruder screw was set at 60 rpm. The extrudate was cooled by passing through a water bath (maintained at 25 °C with continuous water circulation) and subsequently pelletized. The resulting pellets were dried in a thermostatic oven at 105 °C for about 2-3 h before injection molding.

[0047] The injection molding process was as follows: Injection molding (Arburg Allrounder 410C, Germany) was performed by maintaining a temperature profile of 190-230°C from the hopper to the injection nozzle. The injection pressure, packing pressure, and cooling time were kept constant at 240 bar, 1000 bar, and 20 s, respectively, during the molding process.

[0048] The batch compounding method is as follows: Batch compounding was performed using a Banbury batch mixing chamber (HAAKE® PolyLab® OS Systems, Inc.). After adding the nucleating masterbatch / polypropylene premix, batch mixing was continued for 15 minutes at 230°C and 60 rpm. The resulting mix was oven dried at 105°C for approximately 2-3 hours prior to compression molding.

[0049] Compression molding was as follows: the extruded pellets were first melted by light contact (0 psi) with a hot platen for 5 min before compression molding at 230° C. for 15 min, then cooled to room temperature under pressure.

[0050] Testing and characterization are as follows: Melt flow index (MFI) was determined as per ASTM D1238. Tensile properties [tensile strength (TS) and elongation at yield (E@Y)] and flexural properties [flexural modulus (FM)] were measured according to ASTM D638 and D790, respectively. Shore D hardness (SD) was determined according to ASTM D2240. Differential scanning calorimetry (DSC) testing was performed as per ASTM D3418. The percent crystallinity was determined using DSC as per the method provided by Brzozowska-Stanuch et al. (Brzozowska-Stanuch, A., Rabiej, S., Fabia, J., and Nowak, J., 2014, Changes in thermal properties of isotactic polypropylene with different additives during aging process, Polymery, 59(4), pp. 302-307). The heat deflection temperature (HDT) and Vicat softening temperature (VSP) of the prepared compositions were determined as per ASTM D648 (Method A) and D1525 (Method A), respectively.

[0051] The spherulite morphology of the prepared polypropylene compositions was observed on thin films of approximately 0.1 mm thickness using a Leica DMLP (Linkam Scientific Instruments, UK) polarizing microscope with automated hot stage thermal control. The samples were sandwiched between two microscope cover glasses and melted at 230° C. for 5 minutes to erase the thermal history, then cooled to room temperature at a rate of 10° C. / min. Working Example

[0052] In Examples 1-3 and Comparative Examples 1-3, the BHETA nucleating masterbatch and subsequent dilution in polypropylene were carried out using a twin screw extrusion process, and the samples were prepared using an injection molding method.

[0053] Example 1 is as follows: Example 1 was prepared by adding 5.0 g (0.50 phr) of BHETA-MB (MB: master batch, the concentration of BHETA was maintained at 10 wt%) to 1000 g of iPP, and the concentration of the nucleating agent in the prepared nucleated polypropylene was 500 ppm.

[0054] Comparative Example 1 is as follows: Comparative Example 1 was prepared by directly adding 0.50 g (500 ppm) of BHETA into 1000 g of iPP.

[0055] Example 2 is as follows: Example 2 was prepared by adding 10.0 g (1.00 phr) of BHETA-MB to 1000 g of iPP, and the concentration of the nucleating agent in the prepared nucleated polypropylene was 1000 ppm.

[0056] Comparative Example 2 is as follows: Comparative Example 2 was prepared by adding 1.00 g (1000 ppm) of BHETA directly into 1000 g of iPP.

[0057] Example 3 is as follows: Example 3 was prepared by adding 20.0 g (2.00 phr) of BHETA-MB to 1000 g of iPP, so that the concentration of the nucleating agent in the prepared nucleated polypropylene was 2000 ppm.

[0058] Comparative Example 3 is as follows: Comparative Example 3 was prepared by adding 2.00 g (2000 ppm) of BHETA directly into 1000 g of iPP.

[0059] Table 1 details the compositions prepared in Examples 1 to 3 and Comparative Examples 1 to 3. The properties obtained for the examples prepared are listed in Tables 2 to 4.

[0060] Table 1: Preparation compositions: Examples 1-3 and Comparative Examples 1-3 [Table 1] Nucleating agent concentration (NA concentration): The final concentration of nucleating agent in polypropylene with the addition of BHETA-MB * Direct addition of 500 / 1000 / 2000ppm nucleating agent (BHETA) into iPP

[0061] Table 2: Mechanical properties obtained for Examples 1 to 3 and Comparative Examples 1 to 3 [Table 2]

[0062] Table 3: DSC analysis data obtained for Examples 1 to 3 and Comparative Examples 1 to 3 [Table 3]

[0063] Table 4: Thermal properties obtained for Examples 1-3 and Comparative Examples 1-3 [Table 4]

[0064] Example 4 is as follows: Example 4 was prepared by adding 5.0 g (0.50 phr) of BHETA-MB to 1000 g of iPP, resulting in a nucleating agent concentration of 500 ppm in the prepared nucleated polypropylene. The material was processed using single screw extrusion and samples were prepared using injection molding method.

[0065] Example 5 is as follows: Example 5 was prepared by adding 10.0 g (1.0 phr) of BHETA-MB to 1000 g of iPP, so that the concentration of the nucleating agent in the prepared nucleated polypropylene was 1000 ppm. The material was processed using single screw extrusion and the samples were prepared using injection molding method.

[0066] Example 6 is as follows: Example 6 was prepared by adding 20.0 g (2.0 phr) of BHETA-MB to 1000 g of iPP, resulting in a nucleating agent concentration of 2000 ppm in the prepared nucleated polypropylene. The material was processed using single screw extrusion and samples were prepared using injection molding method.

[0067] Example 7 is as follows: Example 7 was prepared by adding 5.0 g (0.50 phr) of BHETA-MB to 1000 g of iPP, resulting in a nucleating agent concentration of 500 ppm in the prepared nucleated polypropylene. The material was processed using a batch compounding method, and samples were prepared using a compression molding method.

[0068] Example 8 is as follows: Example 8 was prepared by adding 10.0 g (1.0 phr) of BHETA-MB to 1000 g of iPP, resulting in a nucleating agent concentration of 1000 ppm in the prepared nucleated polypropylene. The material was processed using a batch compounding method, and samples were prepared using a compression molding method.

[0069] Example 9 is as follows: Example 9 was prepared by adding 20.0 g (2.0 phr) of BHETA-MB to 1000 g of iPP, resulting in a nucleating agent concentration of 2000 ppm in the prepared nucleated polypropylene. The material was processed using a batch compounding method, and samples were prepared using a compression molding method.

[0070] Table 5 details the compositions prepared in Examples 4 to 9. The DSC results obtained for the examples prepared are set forth in Table 6.

[0071] Table 5: Preparation Compositions: Examples 4-9 [Table 5] Nucleating agent concentration (NA concentration): The final concentration of nucleating agent in polypropylene with the addition of BHETA-MB

[0072] Table 6: DSC characteristics obtained for Examples 4 to 9 [Table 6]

[0073] Table 7 details the compositions prepared in Examples 10 to 12. The properties obtained for the examples prepared are listed in Table 8.

[0074] Example 10 is as follows: Example 10 is Example 2 mixed with 500 ppm Tween 20 dispersant (a non-ionic surfactant).

[0075] Example 11 is as follows: Example 11 is Example 2 mixed with 500 ppm Span 60 dispersant (a non-ionic surfactant).

[0076] Example 12 is as follows: Example 12 is Example 2 mixed with 500 ppm Span 80 dispersant (a non-ionic surfactant).

[0077] Table 7: Preparation Compositions: Examples 10-12 [Table 7] Nucleating agent concentration (NA concentration): The final concentration of nucleating agent in polypropylene with the addition of BHETA-MB

[0078] Table 8: DSC characteristics obtained for Examples 10 to 12 [Table 8]

Claims

1. a) polypropylene having a melt flow index in the range of 1.5 to 40 g / 10 min; b) a nucleating agent; c) optionally a dispersant which is a non-ionic surfactant; 1. A nucleated polypropylene masterbatch composition, characterized in that the nucleating agent is bis-2-hydroxyethylene terephthalate (BHETA) and is present in an amount ranging from 0.1 to 60 wt %, the BHETA being prepared from the depolymerization of waste polyethylene terephthalate (PET).

2. The nucleated polypropylene masterbatch composition of claim 1, wherein the polypropylene is a homopolymer and is present in an amount ranging from 40 to 99.9 weight percent.

3. 2. The nucleated polypropylene masterbatch composition of claim 1, wherein the dispersant is selected from the group consisting of Tween 20, Span 60, Span 80, and any combination thereof, and is present in an amount ranging from 0.01 to 10 wt.%.

4. i. combining polypropylene with a nucleating agent, and optionally adding a dispersing agent, to form a reaction mixture; ii. feeding the reaction mixture obtained in step i) through a hopper into an extruder; iii. maintaining the temperature from the feed zone to the die zone of the extruder; iv. cooling the extrudate coming out of the extruder using a water bath and then granulating it; v. drying the granules obtained in step iv) to obtain a polypropylene masterbatch; A method for preparing a nucleated polypropylene masterbatch composition, characterized in that the nucleating agent is bis-2-hydroxyethylene terephthalate (BHETA) and is present in an amount ranging from 0.1 to 60 wt %.

5. 5. The process for preparing a nucleated polypropylene masterbatch composition according to claim 4, wherein the polypropylene is a homopolymer and is present in an amount ranging from 40 to 99.9 wt.%.

6. 5. The method for preparing a nucleated polypropylene masterbatch composition according to claim 4, wherein the extruder is a twin screw extruder, a batch mixer, a microcompounder, a single screw extruder, or other processing equipment.

7. A method for preparing a nucleated polypropylene masterbatch composition as described in claim 4, characterized in that the temperature in step iii) is maintained in the range of 150 to 300°C.

8. A method for preparing a nucleated polypropylene masterbatch composition as described in claim 4, characterized in that the temperature of the water tank in step iv) is maintained at 25°C to 30°C.

9. A method for preparing a nucleated polypropylene masterbatch composition as described in claim 4, characterized in that the drying in step v) is carried out in a constant temperature bath at a temperature of 90 to 110°C for about 2 to 3 hours.

10. 5. The method of claim 4, wherein the polypropylene masterbatch is further diluted to various concentrations using the extruder, the dilution being carried out in a batch mixer, a microcompounder, a single screw extruder, or other processing equipment.

11. The method for preparing a nucleated polypropylene masterbatch composition according to claim 4, characterized in that the concentration of the nucleating agent is diluted in the range of 250 to 20,000 ppm in polypropylene to prepare a nucleated polypropylene exhibiting a crystallization temperature in the range of 115°C to 122°C.

12. 5. The method for preparing a nucleated polypropylene masterbatch composition according to claim 4, characterized in that the polypropylene is a polypropylene homopolymer and / or a polypropylene copolymer with any other alkene or acrylate or halogenated hydrocarbon.

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