Thermoplastic material containing fragrances and use of fragrances

Abstract

The object of the invention is a thermoplastic material containing SBR rubber mud obtained by shredding car tyres and post-consumer polyolefin, characterised in that it contains SBR rubber mud with a fraction in the range 0.01-1 mm and post-consumer polyolefin with a particle diameter of 4.5-5 mm, with a mass ratio of polyolefin to rubber mud of 9:1 to 7:3, and in that it contains flavouring agents in a mass amount relative to the mixture of rubber pulp and polyolefin such as 1.5- 2.5:100. It is also an object of the invention to use odorants to improve the mechanical properties of thermoplastic materials.

Description

[0001] Thermoplastic material containing fragrances and use of fragrances

[0002] The invention relates to a thermoplastic material. More specifically, the invention relates to a thermoplastic material obtained by extrusion from rubber pulp derived from car tyres and post-consumer polyolefins containing an aroma agent. The object of the invention is used in the manufacture of products in the automotive, construction or furniture industries.

[0003] The dynamic growth of the automotive industry is increasing the amount of rubber waste from used car tyres. From an economic and ecological point of view, the disposal of this waste is a major challenge. At present, the preferred waste management method is material recycling. Tyres are subjected to a milling process and the resulting rubber fines are used in various mixtures, e.g. as a filler in other rubber mixtures. Materials derived from rubber mills and polyolefins are known. The process produces rubber-like materials with limited mechanical properties. The main reason for these problems is the incompatibility of the raw materials. Low levels of compatibility lead to phase separation and poor adhesion. In order to improve it, various chemical processes are used, which are time-consuming and lead to the production of a significant amount of environmentally unfriendly waste. An additional problem associated with rubber-based products is the unpleasant odour emitted from the rubber during processing and subsequent use. To this end, manufacturers use various odour additives, which rarely eliminate the unpleasant odour entirely and at the same time often adversely affect the mechanical properties of the material.

[0004] Application GB1586882A discloses a composite material containing shredded rubber tyres, shredded thermoplastic resin and glass fibre. The composite contains 50 to 80% rubber material. The thermoplastic resin is polyethylene, polystyrene or polypropylene. The glass fibre content does not exceed 10% by weight of the material. The resulting material is porous and has better strength and elasticity properties compared to moulded plastics. The submitted disclosure does not propose a method to neutralise the unpleasant odour of the rubber. The disclosure does not mention specific additives to increase the impact strength of the material.

[0005] Application EP4098683A1 discloses a thermoplastic rubber composition comprising a polyolefin and a thermoplastic elastomer. The polyolefin is a continuous phase and comprises polypropylene with a melt flow rate of less than 5dg / min or polyethylene with a melt flow rate of less than 5dg / min. In contrast, the chemically cross-linked rubber constitutes the elastomeric phase of the composition. The composition can be produced by injection moulding, compression moulding or extrusion. No information is provided in the submitted application regarding the impact strength of the composition. There is also no mention of rubber odour neutralising agents.

[0006] Application CN107936447A discloses a thermoplastic dust-proof elastomer with low dispersion and reduced odour. The composition comprises a resin selected from the group consisting of polypropylene, homopolypropylene and polypropylene copolymer and a thermoplastic elastomer selected from the group consisting of styrene elastomers, ethylene -propylene-diene rubbers, ethyleneoctene copolymer elastomers and thermoplastic vulcanizates. In addition, the composition contains an anti-static agent, a stabiliser, a filler and a fragrance. The thermoplastic elastomer is obtained using a twin-screw extruder with a rotational speed of 200 to 900 rpm. The screw temperature is in the range 140-220° C. The presented application does not describe the effect of the blend components on increasing the impact strength of the elastomers obtained.

[0007] JP2008163098A discloses a polyolefin-based thermoplastic elastomer with an odor neutralizer. The mixture according to the invention contains an olefin resin, a copolymer of ethylene and a-olefin, an organic peroxide and an odour neutraliser. The application does not describe the effect of the fragrance agent on the mechanical properties of the resulting elastomer. Document US6313183 discloses thermoplastic elastomers derived from recycled rubber obtained from post-consumer automotive tyres and other rubber waste. The materials were used to produce car radiator liners and roof liners. They were obtained from rubber dust with a particle size of 0.15-0.8 mm, polyethylene, polypropylene, ethylene- acrylic acid copolymer, SBS copolymer and excipients. The invention does not describe the effect of the excipients on the impact strength of the elastomeric material. Also, no mention is made of an ingredient affecting the odour of the elastomer.

[0008] Application PL103442 discloses a thermoplastic elastomeric composition comprising a mixture of polyolefin resin and vulcanised rubber. The polyolefin resin accounts for 25-45 parts by weight of the composition and the rubber accounts for 55-75 parts by weight. Polyethylene or polypropylene was used as the polyolefin resin. In addition, the composition contains an additional component to counteract the degradation of the rubber in an amount of 0.1-5.0 per cent by weight. The resulting composition has a high tensile strength. The application does not disclose means for neutralising the odour of the rubber and its effect on the impact resistance of the elastomer composition.

[0009] Document PL426348A1 discloses a thermoplastic composition based on waste rubber and post-consumer polyolefin materials. The composition comprises 10-30% by weight of SBR rubber grit with a particle size of 0.1-4 mm, 70-90% by weight of post-consumer high density polyethylene with a particle size of 4-14 mm and 70-90% by weight of post-consumer polypropylene with a particle size of 4-14 mm. The manufacturing method is characterised by the fact that the recycled thermoplastic material and rubber fines are dispensed into the feed hopper of a twin- screw extruder with co-rotating screw direction and a cylinder temperature in the range of 50-220° C. The submitted application does not solve the problem of the unpleasant odour of the rubber compounds. Furthermore, the described solution does not present a way to increase the impact strength of the composition.

[0010] The state of the prior art to date presents polymer compositions containing shredded waste rubber and polyolefins and how to obtain them. The use of fragrances in thermoplastic materials is also described, but without considering their effect on the mechanical properties of the product. Most often, only a mention of the fragrance additive to the elastomer composition as one of many other additives is disclosed, with no indication of the specific fragrance agent (its structure or composition) as well as no proof of its actual effect on eliminating the unpleasant rubber odour. It is therefore important to develop a thermoplastic material with neutralised rubber odour, which has at least no deterioration in mechanical properties and even improved mechanical properties after the addition of the odourant, these mechanical properties being achieved without the addition of other substances such as stabilisers.

[0011] Surprisingly, it was found that the addition of specific agents known as odorants to a similar thermoplastic composition based on waste rubber and postconsumer polyolefin materials to the known PL426348A1 application resulted, on the one hand, in the elimination of the unpleasant rubber odour from the produced odourless thermoplastic material; on the other hand, these agents improved the mechanical properties of the thermoplastic material as expressed by the material's resistance to cracking under dynamic loading as determined by the Charpy method.

[0012] Thus, an objective of the invention is to develop a non-compatible thermoplastic material based on waste rubber and post-consumer polyolefin materials with improved odour properties essentially manifested by the elimination of the unpleasant rubber odour. A further objective of the invention is to develop a non-compatible thermoplastic material based on waste rubber and post-consumer polyolefin materials with an eliminated rubber odour and improved mechanical properties expressed by an increased value of the material's resistance to cracking under dynamic loading determined by the Charpy method.

[0013] The invention solves the technical problem associated with the unpleasant odour of the rubber product, whereby the added odour neutraliser does not impair the physical properties of the thermoplastic material, but furthermore improves these properties. The object of the invention is a thermoplastic material comprising SBR rubber crumb obtained by shredding car tyres and post-consumer polyolefin, characterised in that it contains SBR rubber crumb with a fraction in the range of 0.01-1 mm and post-consumer polyolefin with a particle diameter of 4.5-5 mm, with a mass ratio of the amount of polyolefin to the amount of rubber crumb of 9: 1 to 7:3, and in that it contains an aroma agent with the following composition: or in a quantity by weight relative to the mixture of mastic rubber and polyolefin such as 1.5-2.5: 100.

[0014] Advantageously, the polyolefin is polypropylene or polyethylene. More advantageously the polyolefin is polypropylene. Equally advantageously the polyolefin is polyethylene. Advantageously the polyolefin is high density polyethylene.

[0015] The object of the invention is also the use of fragrances with a composition:

[0016] or for improving the mechanical properties of thermoplastic materials.

[0017] Advantageously, the improvement of the mechanical properties consists in an increase in the Charpy dynamic load fracture toughness value of the material. More preferably, the enhancement of the Charpy dynamic load fracture toughness value of the material consists in increasing the Charpy dynamic load fracture toughness value of the material by 20-35% compared to an unmodified thermoplastic material or in not cracking the sample in this test.

[0018] A problem with rubber-based products is that the problem of unpleasant odour is also transferred to products made from elastomers, such as children's toys. Often, fragrances give a more pleasant odour to such products, but ultimately the rubber smell is still noticeable. Sometimes the odour of the odourant and the smell of the rubber mix badly, still giving an unpleasant sensation of smell. This makes consumers reluctant to choose products made of rubber. The fragrances added to the thermoplastic materials according to the invention caused the rubber odour to be nullified / hidden. At the same time, it was surprisingly found that these fragrances had a positive effect on the properties of the thermoplastic materials.

[0019] The thermoplastic materials prepared in the known way were modified by reactive extrusion with odouring agents. Two commercially available odorants in the form of white powder were used: LUVOMAXX ODOR C DL 70 and LUVOMAXX ODOR R / 3.

[0020] LUVOMAXX ODOR C DL 70 from Lehmann&Voss&Co. is a cherry fragrance on a silica carrier with a BET surface area of more than 300 m2 / g and an oil absorption of no more than 290 ml / lOOg. The active ingredients of LUVOMAXX ODOR C DL 70 are a mixture of plant- terpene oils such as geraniol, citronelol, ionone as well as benzaldehyde and ethyl 2,3-epoxy-3-phenylbutyrate. LUVOMAXX ODOR R / 3, on the other hand, is a reactive odorant with a neutral odor on a silica carrier with a BET surface area of more than 300 m2 / g and an oil absorption of no more than 290 ml / 100g. The active ingredients of LUVOMAXX ODOR R / 3 are organosilanes with an epoxy functional group.

[0021] Analysis of the rheological properties of the thermoplastic materials according to the invention clearly indicated the positive effect of using the aroma agent not only as a deodorant, but also as a reactive compatibiliser or as a kind of plasticiser. Observations of the breakthrough surfaces showed that the fracture mechanics of the samples had changed. The brittle fracture observed for the unmodified material changed to a more ductile character. It can therefore be assumed that the presence of finely dispersed inclusions of the aromatic agent phase leads to an increase in the impact strength values of the materials (Charpy impact strength). This increase was found to be even more than 30 per cent relative to the unmodified material. In some cases, the sample does not fracture at all, which demonstrates the material's resistance to fracture under dynamic loading determined by the Charpy method. The unconventional effect of the aroma agent on the mechanical properties of the modified materials was confirmed.

[0022] Thermoplastic materials according to the invention can be used to manufacture products for the furniture, sports, automotive, construction, etc. industries. Products made from thermoplastic materials according to the invention do not exhibit the unpleasant smell of rubber, which affects their attractiveness. At the same time, they are products that are part of the current of ecological management of waste materials.

[0023] The invention is described below in examples of embodiments.

[0024] EXAMPLES

[0025] Thermoplastic materials for examples 1-6 were obtained by the following method, according to the publication "Metoda wytlaczania dwuslimakowego wspolbieznego (pouzytkowych) mieszanin polimerowych", Krolikowski B., Tworzywa Sztuczne w Przemysle, 2020, no. 3, pp. 11-19. Thermoplastic materials based on waste rubber and post-consumer polyolefins were obtained using a corotating twin-screw extruder showing mixing and shearing properties (d = 112 mm, L / d = 44). Cylinder temperature was 240°C - hopper temperature was 50°C, screw speed was 300 rpm. Initially, the free-flowing fragrance was mixed with polyolefin; the mixture thus prepared was fed from one hopper, while it had rubber from the other hopper. The co-rotating twin-screw extruder consists of a feed hopper, a free degassing zone, a vacuum degassing zone and cylinder heating and cooling zones. The screw zones are divided into the following sections: feed, plasticisation, free degassing, intensive mixing, vacuum degassing, dosing and research and measurement zone. A K2 or K5A screw segment configuration was used, comprising the individual zones: SK - single-scroll segments, SE - double-scroll transport segments, SKN - single-scroll and double-scroll (transition) segments with strictly defined winding pitch and segment length, KBW - kneading segments with a defined angle between cam symmetry axes and number of cam elements, segment length as well as the direction of inclination of the apparent screw line of the cam and screw elements, (left - and right direction). In a co-rotating twin-screw extruder with an interlocking screw coil system, the flowing material forms a figure-eight shape, so its residence time in the machine is longer. The plasticised material is also subjected to an increased shear-mixing function as it passes from one screw to the other.

[0026] The impact strength was determined using a Charpy apparatus in accordance with ISO 179. The test piece, in the form of a barrel, is placed (either flush or edge) on supports and subjected to impact with an impact hammer of constant speed and known impact energy. Standardised Type 1 (ISO 179-1 / leU) fittings of 80 x 10 x 4 mm thermoplastic materials without notches were tested. Ten repetitions in a measurement series were carried out as standard. A Charpy Instron CEAST 9050 impact hammer was used. The pendulum hammer used in the test is a hammer with a maximum energy of 5 J. The energy required to fracture the specimen was measured in the test.

[0027] The SBR rubber dust that was used to implement the invention in the examples below was in the form of a free-flowing powder, black in colour, with a bulk density in the range 380-600 kg / m3and a gradation (fraction determined by sieving through a suitable sieve) of 0.01-1.0 mm. It was obtained on request from the Recykl company in Srem (Poland).

[0028] The post-consumer polypropylene used to carry out the invention in the examples below was in the form of a solid with a melting point of 165° C, in the form of granules with a diameter of 4.5-5 mm, characterised by the following parameters: MFI 190°C / 2.16kg: 4-8g / 10 min, density: 0.89-0.92 g / cm3, relative elongation at break: 73%. It was obtained from the Recyklon company in Koszalin (Poland).

[0029] The post-consumer polyethylene (HDPE) used to implement the invention in the examples below was in the form of pellets with a diameter of 4.5 - 5 mm, characterised by the following parameters: MFI 190°C / 5kg: 1.1 - 1.6 g / 10 min, density: 0.94-0.96 g / cm3, tensile stress: 19-21 N / mm2, relative elongation at break: 400-500%. It was obtained from the Akpol company in Trzydnik Duzy (Poland).

[0030] The odorants LUVOMAXX ODOR C DL 70 and LUVOMAXX ODOR R / 3, which were used to carry out the invention in the examples below, were obtained as commercial materials available from Lehmann&Voss&Co, Hamburg, Germany. Qualitative and quantitative analysis of the odourants was performed using a ThermoQuest GC-MS instrument equipped with a Voyager detector and a DB-5 column (filled with phenylmethylsiloxanes, 30 m x 0.25 mm x 0.5 pm). The analysis parameters were as follows: helium flow 1 ml / min, inlet temperature 150°C, oven temperature isothermally for 2.5 min at 50°C, followed by an increase at a rate of 10°C / min to 300°C. The composition of the resulting liquid products was calculated using the internal normalisation method with response factors.

[0031] It was determined chromatographically that the composition of the LUVOMAXX ODOR C DL 70 that was added to the thermoplastic material was as follows: It was determined chromatographic ally that the composition of the odorant LUVOMAXX ODOR R / 3 that was added to the thermoplastic material was as follows:

[0032] The comparative examples are analogous thermoplastic compositions, but without the addition of a fragrance agent. The comparative thermoplastic materials were obtained in the same way as the thermoplastics according to the invention (Examples 1-6), without the addition of a fragrance agent to the raw material mixture.

[0033] To obtain the thermoplastic materials according to Examples 1, 3, 5 and 6, the following amounts of raw materials were used (the mass ratio of the amount of polyolefin to the amount of rubber pulp is as 9: 1):

[0034] - 8,867 kg polyolefin,

[0035] - 0.985 kg of rubber dust,

[0036] - 0.128 kg of fragrance

[0037] To obtain the thermoplastic materials according to Example 2, 4, the following amounts of raw materials were used (the mass ratio of the amount of polyolefin to the amount of rubber middlings is as 7:3): - 6,896 kg polyolefin,

[0038] - 2,956 kg of rubber dust,

[0039] - 0.148 kg of fragrance.

[0040] Example 1

[0041] The thermoplastic material according to the invention was obtained according to the method described above. The composition of the raw material mixture:

[0042] • SBR rubber dust with a particle size of 0.01-1 mm

[0043] • Post-consumer polypropylene with a particle diameter of 4.5-5 mm

[0044] • LUVOMAXX ODOR C DL 70 cherry fragrance.

[0045] The mass ratio of polypropylene to rubber middlings is like 9: 1.

[0046] The mass ratio of the amount of deodoriser relative to the mixture of gum pulp and polypropylene is as 1.5-2.5: 100.

[0047] The content of the individual components in the mixture is shown in Table 1.

[0048] Table 1 Characteristics of the composition of the samples obtained.

[0049] The thermoplastic materials obtained had an increased impact strength of 24% for 1.48 wt / wt aroma content, 29% for 1.97 wt / wt aroma content and 34% for 2.44 wt / wt aroma content, respectively, higher than the impact strength of the unmodified material (21kJ / mm2). Table 3 below shows a comparison of the impact strength of the samples obtained according to Example 1 and 2. Example 2

[0050] The thermoplastic material according to the invention was obtained according to the method described above. The composition of the raw material mixture:

[0051] • SBR rubber dust with a particle size of 0.01-1 mm

[0052] • Post-consumer polypropylene with a particle diameter of 4.5-5 mm

[0053] • LUVOMAXX ODOR C DL 70 cherry fragrance.

[0054] The mass ratio of polypropylene to rubber middlings is like 7:3.

[0055] The mass ratio of the amount of deodoriser relative to the mixture of gum pulp and polypropylene is as 1.5-2.5: 100.

[0056] The content of the individual components in the mixture is shown in Table 2.

[0057] Table 2 Characteristics of the composition of the samples obtained.

[0058] The thermoplastic materials obtained had an increased impact strength of 22% for 1.48 wt / wt aroma content, 25% for 1.97 wt / wt aroma content and 29% for 2.44 wt / wt aroma content higher than the impact strength of the unmodified material (20kJ / mm2), respectively.

[0059] Table 3. Comparison of impact strength values (Charpy) for materials modified with the aroma agents according to the invention against comparative examples.

[0060]

[0061] Example 3

[0062] The thermoplastic material according to the invention was obtained according to the method described above. The composition of the raw material mixture:

[0063] • SBR rubber dust with a particle size of 0.01-1 mm

[0064] • Post-consumer polypropylene with a particle diameter of 4.5-5 mm

[0065] • LUVOMAXX ODOR R / 3 neutral fragrance.

[0066] The mass ratio of polypropylene to rubber middlings is like 9: 1.

[0067] The mass ratio of the amount of deodoriser relative to the mixture of rubber dust and polypropylene is as 1.5-2.5: 100.

[0068] The content of the individual components in the mixture is shown in Table 4.

[0069] Table 4 Characteristics of the composition of the samples obtained.

[0070] The thermoplastic materials obtained had an increased impact strength of 20 % for 1.48 wt / wt aroma content, 26 % for 1.97 wt / wt aroma content and 29 % for 2.44 wt / wt aroma content higher than the unmodified material, respectively. Example 4

[0071] The thermoplastic materials according to the invention were obtained according to the method described above. The composition of the raw material mixture:

[0072] • SBR rubber dust with a particle size of 0.01-1 mm

[0073] • Post-consumer polypropylene with a particle diameter of 4.5-5 mm

[0074] • LUVOMAXX ODOR R / 3 neutral fragrance.

[0075] The mass ratio of polypropylene to rubber middlings is like 7:3.

[0076] The ratio by mass of the amount of deodoriser to the mixture of the gum and polypropylene is like 1.5-2.5: 100

[0077] The content of the individual components in the mixture is shown in Table 5.

[0078] Table 5 Characteristics of the composition of the samples obtained.

[0079] The thermoplastic materials obtained were characterised by an increased impact strength of 15% for 1.48 wt / wt aroma content, 22% for 1.97 wt / wt aroma content and 25% for 2.44 wt / wt aroma content higher than the unmodified material, respectively. Table 6 shows a comparison of the impact strength of the samples obtained according to Example 3 and Example 4.

[0080] Table 6. Comparison of impact strength values (Charpy) for materials modified with the aroma agents according to the invention against comparative examples.

[0081] Example 5

[0082] The thermoplastic material according to the invention was obtained according to the method described above. The composition of the raw material mixture:

[0083] • SBR rubber dust with a particle size of 0.01-1 mm

[0084] • Post-consumer polyethylene (HDPE) with a particle diameter of 4.5-5 mm

[0085] • LUVOMAXX ODOR C DL 70 cherry fragrance.

[0086] The mass ratio of the amount of polyethylene to the amount of rubber pulp is like 9: 1.

[0087] The mass ratio of the amount of deodoriser relative to the mixture of rubber dust and polypropylene is as 1.5-2.5: 100.

[0088] The content of the individual components in the mixture is shown in Table 7.

[0089] Table 7 Characteristics of the composition of the samples obtained.

[0090]

[0091] The thermoplastic materials obtained had an increased impact strength compared to the unmodified material (26 kJ / m2) - they do not break.

[0092] Example 6

[0093] The thermoplastic material according to the invention was obtained according to the method described above. The composition of the raw material mixture:

[0094] • SBR rubber dust with a particle size of 0.01-1 mm

[0095] • Post-consumer polyethylene (HDPE) with a particle diameter of 4.5-5 mm

[0096] • LUVOMAXX ODOR R / 3 neutral fragrance.

[0097] The mass ratio of the amount of polyethylene to the amount of rubber pulp is like 9: 1.

[0098] The ratio by mass of the amount of deodoriser to the mixture of the rubber compound and the polypropylene is like 1.5-2.5: 100

[0099] The content of the individual components in the mixture is shown in Table 8.

[0100] Table 8 Characteristics of the composition of the samples obtained.

[0101] The thermoplastic materials obtained had an increased impact strength compared to the unmodified material (26 kJ / m2) - they do not break.

[0102] Table 9. Comparison of impact strength values (Charpy) for materials modified with the aroma agents according to the invention against comparative examples.

[0103] As the specimens did not fracture in the Charpy impact test, they were not assigned numerical impact values.

[0104] Example 7.

[0105] Odour test for thermoplastic materials according to the invention

[0106] Table 10 shows the odour intensity in relation to time since production, as determined by surveys of the population (consumer evaluations). Surveys were carried out for all samples disclosed in Examples 1-6. Surveys carried out on a sample of 100 people aged 20-40 years.

[0107] Table 10: Odour emission intensity in relation to time since production.

[0108]

Claims

Claims1. Thermoplastic material containing SBR rubber obtained from the shredding of car tyres and post-consumer polyolefin, characterised in that containing SBR rubber with a particle size of 0.01-1 mm and post-consumer polyolefin with a particle size of 4.5-5 mm, with a mass ratio of polyolefin to rubber mud of 9:1 to 7:3, and in that containing a flavouring agent with the following composition:orin a quantity by weight relative to the mixture of mastic rubber and polyolefin such as 1.5-2.5: 100.

2. Thermoplastic material according to claim 1, characterised in that the polyolefin is polypropylene or polyethylene.

3. Thermoplastic material according to claim 2, characterised in that the polyolefin is polypropylene.

4. Thermoplastic material according to claim 2, characterised in that the polyolefin is polyethylene.

5. Thermoplastic material according to claim 4, characterised in that the polyethylene is high-density polyethylene.

6. Use of fragrances with composition:orfor improving the mechanical properties of thermoplastic materials as defined by any of the claims. 1-5.

7. The use of odorants according to claim 6, characterised in that the improvement of the mechanical properties consists in an increase in the value of the resistance of the material to fracture under dynamic loading determined by the Charpy method.

8. The use of odorants according to claim 7, characterised in that the increase in the Charpy-determined dynamic load fracture toughness value of the material consists in an increase in the Charpy-determined dynamic load fracture toughness value of the material by 20-35% relative to the unmodified thermoplastic material or in the absence of cracking of the sample in this test.

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