Dispenser device including polyester composition

Abstract

A dispenser device intended to be attached to a container to form a dispenser for a fluid product, characterized in that it consists essentially of a polyester composition consisting essentially of a mixture of components A and B, which are defined as follows: A: Copolyetherester elastomer (COPE) consisting essentially of polyester hard segments and aliphatic polyether soft segments, with a Shore D hardness of less than 50. B: Polyethylene terephthalate (PET) or copolyester, or a blend of both

Description

[Technical Field]

[0001] The present invention relates to polyester compositions, such as those based on polyethylene terephthalate (PET), to be used as a replacement for polyolefins (polyethylene (PE) or polypropylene (PP)) for the manufacture of dispenser devices for the packaging industry intended to be attached to bottles, tubes, jars, etc., for the packaging industry.

[0002] Advantageous fields of use include the food, cleaning, personal care, pharmaceutical and cosmetic fields. [Background technology]

[0003] In a circular economy for plastic packaging, there is a need to design mono-material packaging systems, i.e. packaging systems in which the various components are made of compatible polymeric materials or materials from the same chemical family, in order to optimize recycling.

[0004] The majority of closures and dispenser devices currently on the market that are intended for use with PET containers such as bottles, tubes and pots are either multi-material components or single-material components based on polyolefins such as polyethylene or polypropylene.

[0005] To the best of our knowledge, to date, no polyester-based single-material dispenser device for PET containers has been described in any literature.

[0006] [About PET] Polyethylene terephthalate (PET) is a semi-crystalline thermoplastic polyester obtained by polycondensation of two monomers, terephthalic acid and ethylene glycol, as shown in the chemical structure below.

[0007] Its main properties are impermeability to gases and liquids, chemical resistance, rigidity and transparency.

[0008] [ka]

[0009] PET is widely used in various sectors, including packaging (water and carbonated drink bottles, fruit trays, cosmetic bottles, etc.), automotive (car door handles, interior parts, air vents), and electronics (sockets, lamp holders, fuse boxes).

[0010] In addition to the above properties, PET is currently the most recycled plastic, making it a good candidate for the circular economy.

[0011] [Comparison with other polymers] Below (Table 1) compares the properties of PET with those of other polymers such as polypropylene, polyethylene, and ABS.

[0012] [Table 1]

[0013] Compared to polyolefins (PP or PE), PET has the following advantages:

[0014] Gas barrier properties Excellent chemical and heat resistance In addition to the advantages mentioned above, there are other advantages, but there are also disadvantages as summarized below (Table 2).

[0015] [Table 2] [Prior art documents] [Patent documents]

[0016] [Patent Document 1] European Patent Application Publication No. 1054038 Summary of the Invention [Problem to be solved by the invention]

[0017] Despite the beneficial properties and clear benefits to the circular economy, it is clear that pure PET cannot be used to replace polyolefins, as shown in (Table 1).

[0018] The object of the present invention is to provide a novel thermoplastic composition, primarily for, but not limited to, injection molding, which has lower hardness, lower tensile modulus, higher impact strength, and lower melt viscosity compared to pure PET, bringing these properties closer to those of PP, while maintaining the recyclability of PET obtained through the normal PET recycling stream.

[0019] Another object of the present invention is to provide a range of polyester material formulations from which materials can be selected having properties adaptable to the needs of design and manufacture of components intended for use in dispenser devices for the packaging industry, in particular containers distributed in the packaging industry, and which can be made based on PET or copolyesters. [Means for solving the problem]

[0020] To achieve the above object, the present invention provides a dispenser device intended to be attached to a container to form a dispenser for a fluid product, characterized in that it consists essentially of a polyester composition consisting essentially of a mixture of components A and B, as defined below: A: Copolyetherester elastomer (COPE) consisting essentially of polyester hard segments and aliphatic polyether soft segments, with a Shore D hardness of less than 50. B: Polyethylene terephthalate (PET) or copolyester, or a blend of both The present invention thus defines a dispenser device, such as a stopper, applicator or more generally an integrated dispenser device, intended to be attached to or associated with a polyester container to form a dispenser for a fluent product, the dispenser device consisting essentially of a polyester composition consisting essentially of A and B as defined above.

[0021] A fluid product is defined herein as any substance that can flow, and therefore includes liquid products as well as powdered or granular solids.

[0022] The present invention also relates to a dispenser device intended to be attached to a container to form a dispenser for a fluid product, characterized in that it does not contain polyolefins and is composed of several elements, at least one of which is essentially composed of a polyester composition consisting essentially of a mixture of components A and B as defined below, and all other elements are composed of components A or B. A: Copolyetherester elastomer (COPE) consisting essentially of polyester hard segments and aliphatic polyether soft segments, with a Shore D hardness of less than 50. B: Polyethylene terephthalate (PET) or copolyester, or a blend of both Thus, a multi-component dispenser device, such as a pump or valve, intended to be attached to or associated with a polyester container to form a dispenser for a fluid product is defined, which dispenser device is polyolefin-free and in which at least one component essentially consists of a polyester composition as defined above, consisting essentially of components A and B, and all other components are made from components A or B. The polyester composition does not exclude the presence of functional additives, and in any case remains essentially composed of A and B.

[0023] Advantageously, said copolyester is obtained by polymerizing at least one acid chosen from terephthalic acid, 2,5-furandicarboxylic acid or isophthalic acid with an alcohol chosen from ethylene glycol, cyclohexanedimethanol, trimethylene glycol and isosorbide, or by recycling a polymer made from these monomers.

[0024] The copolyester can also be a glycol modified polyethylene terephthalate (PETG).

[0025] The copolyester may also be selected from glycol-modified polycyclohexylene dimethylene terephthalate (PCTG), acid-modified polycyclohexylene dimethylene terephthalate (PCTA), polyethylene-co-isosorbide terephthalate (PEIT), and polyethylene furanoate (PEF).

[0026] Blends of several copolyesters such as PETG, PCTG, PCTA, PEIT, PEF, etc. may be envisaged.

[0027] It is also possible to envisage the use of raw materials corresponding to the above characteristics that have been "recycled" by mechanical or chemical treatment.

[0028] According to another aspect of the invention, component A is present in a weight ratio of 0.5% to 40%, advantageously 1% to 30%, preferably 5% to 15%, and component B is present in a weight ratio of 60% to 99.5%, advantageously 70% to 99%, preferably 85% to 95%.

[0029] According to another embodiment, the hard segments of the polyester of component A are composed of butylene terephthalate units.

[0030] Butylene terephthalate may be substituted for ethylene terephthalate without departing from the scope of the invention.

[0031] The addition of elastomers (COPE) to polyester matrices (PET or similar) results in compositions that have lower tensile modulus, lower hardness, improved impact strength, and superior melt viscosity compared to pure polyester matrices (e.g., PET) or polypropylene, making them more suitable for processing, including but not limited to injection molding, and for designing dispenser systems intended for use with polyester containers, sometimes obtained through recycling.

[0032] The present invention further defines a dispenser for a fluid product comprising a one-piece or multi-component dispenser device as defined above.

[0033] Advantageously, the dispenser for a fluid product comprises a container made from component B, to which said dispenser device is attached for dispensing the fluid product contained in said container.

[0034] The container can be made of polyester or polyolefin, or it can be made of glass, metal, ceramic, or the like. [Brief explanation of the drawings]

[0035] [Figure 1] 1 is a graph showing curves of shear thinning behavior measured by a capillary rheometer at 275° C. for Examples 1, 4, and 9, and at 205° C. for Example 2. DETAILED DESCRIPTION OF THE INVENTION

[0036] The present invention relates to polyester compositions that can be used in molding processes suitable for plastics, such as injection molding.

[0037] The polyester blends may or may not be premixed in compounding or extrusion equipment before use in injection molding, injection blow molding, extrusion molding, extrusion blow molding, calender molding, or thermoforming, or any other means suitable for polymer conversion and processing.

[0038] It is preferred that the high temperature treatment of the polyester material be preceded by adequate drying at a rate of less than 0.05% by weight.

[0039] The predominant polyester matrix will be polyethylene terephthalate (PET) or a copolyester obtained by polymerizing terephthalic acid, 2,5-furandicarboxylic acid, or isophthalic acid with ethylene glycol, cyclohexanedimethanol, trimethylene glycol, or isosorbide. Such copolyesters include materials known to those skilled in the art by acronyms such as PETG, PCTG, PCTA, PEIT, and PEF.

[0040] Such polyesters can be used to make containers, bottles, tubes and jars, typically for the mass distribution and packaging industries.

[0041] This polyester matrix may be obtained by recycling, and its chemical composition always meets the above criteria.

[0042] An elastomer from any of the following series is mixed with the main polyester matrix in an amount of 0.5 to 40% by weight, advantageously 1 to 30% by weight, preferably 5 to 15% by weight.

[0043] This elastomer preferably has a Shore D hardness of less than 50 and belongs to the family of polyester ether elastomers (COPE), which are thermoplastic copolymer elastomers formed from two microstructural phases whose components are linked by ester chemical bonds.

[0044] Hard Phase (Ester-Based Hard Segments): A crystalline polymer that ensures the material's cohesion and strength.

[0045] The hard phase of COPE is often PBT (polybutylene terephthalate), but can also be the hard segment of PET (polyethylene terephthalate).

[0046] Flexible Phase (Ether-Based Soft Segment): A rubbery polymer that gives the material elastomeric properties, typically a polyether glycol such as polytetramethylene ether glycol (PTMEG), but including but not limited to polyethylene glycol.

[0047] It should be noted that COPE can be replaced by one of three chemical families depending on the type of application and the properties required:

[0048] (1) Thermoplastic polyurethane (TPU) elastomer TPUs have a microstructure similar to COPEs: they are materials formed from two microstructural phases, with urethane bonds between the components.

[0049] Hard phase (polyurethane-based hard segment): A crystalline polymer that ensures the material's cohesion and strength.

[0050] The hard phase of a TPU is typically composed of, but not limited to, methylene diisocyanate (MDI) or toluene diisocyanate (TDI) in combination with a chain-extending diol molecule, typically butanediol (BDO).

[0051] Flexible phase (ether-based or polyester-based soft segments): A rubbery polymer that gives the material elastomeric properties, which may be, but is not limited to, a polyether glycol such as PTMEG (polytetramethylene ether glycol), or a macrodiol based on an aliphatic polyester such as polycaprolactone or polybutylene succinate (PBS).

[0052] (2) Polyetheramide elastomer (COPA) COPA is a thermoplastic copolymer elastomer formed from two microstructural phases, with amide bonds between the components.

[0053] Hard phase (polyamide-based hard segments): A crystalline polymer that ensures the material's cohesion and strength.

[0054] The hard phase of COPA is generally polyamide 12, obtained by, but not limited to, polycondensation of aminolauric acid or ring-opening polymerization of laurolactam.

[0055] Flexible Phase (Ether-Based Soft Segment): A rubbery polymer that gives the material elastomeric properties may be, but is not limited to, a polyether glycol such as PTMEG (polytetramethylene ether glycol). (3) Glycols (also known as aliphatic polyethers) Polyethylene glycol (PEG) or polytetrahydrofuran (PTMEG) is a flexible molecule with the following chemical structure: Example of the chemical structure of a glycol (in this case, polyethylene glycol)

[0056] [ka]

[0057] In order to minimize migration into the product contained in the dispenser, it is desirable to use products in the mixture with an average molar mass of at least 4000 g / mol. 〔example〕 Testing Procedures [Implementation method] The raw material blend was first mixed in the form of granules in the appropriate proportions, and then dried at 120°C for 6 hours before carrying out the high-temperature conversion process.

[0058] The dried granule mixture was either injection molded into dumbbell-shaped specimens for mechanical testing or compounded in an extruder and converted into granules for rheological testing. [Density measurement] Density measurements were performed using a balance equipped with a metal wire density measurement kit according to the instructions of Method A of the ISO 1183 standard. [Mechanical Testing] The tensile properties of the various examples shown below were measured according to ISO 527 standard using an A1 dumbbell at a pulling rate of 50 mm / min.

[0059] Impact strength values ​​were obtained according to the ISO 179 standard. Hardness values ​​were obtained according to the ISO 868 procedure. [Rheology test] Using a capillary rheometer, curves of melt viscosity as a function of shear rate were obtained, measured at a temperature of 275° C. All granular samples were dried at 120° C. for 6 hours before measurement. ·result [Example 1] In Example 1, a control sample composed of 100% PET obtained from the polymerization of terephthalic acid and ethylene glycol, with an IV viscosity of 0.8 dL / g and considered "bottle grade" in the packaging industry, was dried at 120°C for 6 hours before being injection molded into an A1 dumbbell shape for mechanical testing. Dried granules of this raw material were also compounded in an extruder to obtain processed granules. This example is included here solely for comparison with the following examples.

[0060] See Table 3 and Figure 1 for the mechanical properties and shear thinning behavior curves in the melt state. [Example 2] In Example 2, a control sample consisting of 100% polypropylene copolymer having a melt flow index considered "injection grade" suitable for injection molding into bottle caps and closures by the packaging industry was injection molded into A1 dumbbell-shaped samples for mechanical testing. Granules of this material were also compounded in an extruder to obtain a modified granule. This example is included herein solely for comparison with the following examples.

[0061] See Table 3 and Figure 1 for the mechanical properties and shear thinning behavior curves in the melt state.

[0062] The mechanical properties and melt viscosity are significantly different from Example 1, illustrating the gap between the two materials that this invention seeks to overcome. [Example 3] to [Example 6] In these examples, granules of PET (considered "bottle grade" by those skilled in the art) with an IV viscosity of 0.8 dL / g were mixed with granules of COPE (an example of such a product is Celanese's Riteflex 425) with a Shore D hardness of 25 (referred to as COPE1 in Table 3 below) in weight ratios ranging from 1 to 30% as shown in Table 3.

[0063] The mixture was then dried at 120°C for 6 hours, after which A1 dumbbell-shaped specimens for mechanical testing were made by injection molding. The dried granule mixture was also compounded in an extruder to obtain processed granules.

[0064] The mechanical properties are shown in Table 3. By increasing the amount of COPE in the sample, the mechanical properties of the material can be tuned, with Example 6 approaching the properties of Example 2 while still achieving better impact resistance than Examples 1 and 2.

[0065] Furthermore, compared to Examples 1 and 2, Example 3 exhibits a significant improvement in impact resistance without significant changes in other mechanical properties.

[0066] Examples 4 and 5 show that even when the COPE loading is less than 15%, the flexural modulus and hardness are significantly reduced.

[0067] Thus, Examples 3 to 5 demonstrate that the composition of the polyester blend can be selected according to the needs of the application. [Example 7] In Example 7, a 5% by weight blend of PET granules (considered "bottle grade" by those skilled in the art) with an IV viscosity of 0.8 dL / g and COPE granules with a Shore D hardness of 40 (an example of such a product is Riteflex 640A from Celanese) (referred to as COPE2 in Table 3 below) was prepared as shown in Table 3.

[0068] The mixture was then dried at 120°C for 6 hours, after which A1 dumbbell-shaped specimens for mechanical testing were made by injection molding. See Table 3 and Figure 1 for the mechanical properties and shear thinning behavior curves in the molten state.

[0069] This Example 7 has similar properties to Example 4, while maintaining impact resistance comparable to Examples 1 and 2, and is useful in applications requiring lower impact strength.

[0070] Example 7 has similar flexural properties to Example 4, but lower impact resistance than Examples 1 and 2. These properties may be of interest for applications in polyester devices with anti-intrusion capabilities.

[0071] Example 7 has a lower melt viscosity than Example 1, which makes it easier to process by injection molding, especially for thin-walled parts. [Example 8] In Example 8, a 5% by weight blend of PET granules (considered "bottle grade" by those skilled in the art) with an IV viscosity of 0.8 dL / g and flakes of a polytetrahydrofuran product (PTMEG; an example of this product is Carbowax PEG 8000 from Dow Chemical Company) with a molecular weight of 8000 g / mol was prepared as shown in Table 3.

[0072] The mixture was then dried at 120°C for 6 hours, after which A1 dumbbell shaped specimens were made by injection molding for mechanical testing. The mechanical properties are shown in Table 3 below.

[0073] In this example, the changes in properties shown in the previous example are not observed, demonstrating the need for a two-phase elastomer to achieve the desired results.

[0074] However, when 5% PTMEG was added to the PET matrix, a tensile strain-softening behavior was observed that was not observed in Examples 1 to 7, making it possible to use the material in functional parts that operate at higher strain rates, such as living hinges and film-type hinges. [Example 9] In Example 9, a 5% by weight blend of PET granules having an IV viscosity of 0.8 dL / g (considered "bottle grade" by those skilled in the art) and TPU polyurethane elastomer granules having a Shore A hardness of 71 (an example of such a product is Elastollan 1170 A 10 FC from BASF) was prepared as shown in Table 3.

[0075] The mixture was then dried at 120°C for 6 hours, after which A1 dumbbell-shaped specimens for mechanical testing were made by injection molding.

[0076] In Examples 8 and 9, PTMEG and TPU are used instead of COPE (1 or 2).

[0077] It should be noted that protection may be sought for polyester compositions obtained from mixtures of PET (or similar) with PTMEG or TPU.

[0078] Compositions that blend PET (or similar) with multiple components from COPE, PTMEG, and TPU are also envisioned. The dry granules were then mixed in an extruder to obtain processed granules. See Table 3 and Figure 1 for the mechanical properties and shear thinning behavior curves in the molten state.

[0079] Example 9 exhibits low flexural modulus and low impact resistance comparable to Examples 4 and 7. The melt viscosity is also significantly reduced, making it very suitable for injection molding.

[0080] Table 3

Claims

1. A dispenser device intended to be attached to a container to form a dispenser for a fluid product, comprising: consisting essentially of a polyester composition consisting essentially of a mixture of components A and B, defined as follows:

10. A dispenser device comprising: A: Copolyetherester elastomer (COPE) essentially consisting of polyester hard segments and aliphatic polyether soft segments, with a Shore D hardness of less than 50 B: Polyethylene terephthalate (PET) or copolyester, or a mixture of both

2. A dispenser device intended to be attached to a container to form a dispenser for a fluid product, comprising: The polyester composition does not contain polyolefins and is composed of multiple components, at least one of which is essentially composed of a polyester composition consisting essentially of a mixture of components A and B defined below, and all other components are composed of either component A or B.

10. A dispenser device comprising: A: Copolyetherester elastomer (COPE) essentially consisting of polyester hard segments and aliphatic polyether soft segments, with a Shore D hardness of less than 50 B: Polyethylene terephthalate (PET) or copolyester, or a mixture of both

3. The copolyester is obtained by polymerizing at least one acid selected from terephthalic acid, 2,5-furandicarboxylic acid, or isophthalic acid with an alcohol selected from ethylene glycol, cyclohexanedimethanol, trimethylene glycol, and isosorbide, or by recycling a polymer composed of these monomers.

3. A dispenser device according to claim 1 or 2.

4. The copolyester is glycol-modified polyethylene terephthalate (PETG). Dispenser device according to any one of claims 1 to 3.

5. The copolyester is selected from glycol-modified polycyclohexylene dimethylene terephthalate (PCTG), acid-modified polycyclohexylene dimethylene terephthalate (PCTA), polyethylene-co-isosorbide terephthalate (PEIT), and polyethylene furanoate (PEF). A dispenser device according to any one of claims 1 to 4.

6. Component A is present in a weight ratio of 0.5% to 40%, advantageously 1% to 30%, preferably 5% to 15%, and component B is present in a weight ratio of 60% to 99.5%, advantageously 70% to 99%, preferably 85% to 95%. Dispenser device according to any one of claims 1 to 5.

7. The hard segments of the polyester of component A are composed of butylene terephthalate units. Dispenser device according to any one of claims 1 to 6.

8. A dispenser for a fluid product comprising a dispenser device according to any one of claims 1 to 7.

9. a container made from component B, the dispenser device being attached to the container and dispensing the fluid product in the container; 9. The fluid product dispenser of claim 8.

10. The container is made of polyester, and the dispenser device is attached to the container to dispense the fluid product in the container.

10. The fluid product dispenser of claim 9.

11. The container is made of polyolefin, and the dispenser device is attached to the container to dispense the fluid product in the container.

10. The fluid product dispenser of claim 9.

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