RU2826070C1 - Granule production method in press-granulator, granule and application thereof - Google Patents

Abstract

FIELD: chemistry.

SUBSTANCE: group of inventions relates to a method of producing a granule in a press granulator, as well as to a granule for producing a stabilized polymer, to the use of the granule as a polymer stabilizer for dust-free handling of its components in production of stabilized polymer, to method of producing stabilized polymer and mixture for compaction. Method of producing a granule is carried out in a press granulator, which includes a roll and a matrix with a nozzle, wherein the method involves the following stages: (A) pressing the mixture for compaction with the help of a roller through a nozzle to obtain a thread and (B) grinding this thread to obtain a granule. Mixture for compaction contains (i) from 87 to 97 wt.% of polymer stabilizer, which is tris (2,4-di-tert-butylphenyl)phosphite, and (ii) from 3 to 13 wt.% of process additive, which is a copolymer of propylene and ethylene and which has an enthalpy of fusion below 100 J/g at 101.32 kPa, and wt.% are converted to the weight of the mixture for compaction.

EFFECT: homogeneous distribution of polymer stabilizers in polyolefin during its processing at high temperature with formation of stable granules.

21 cl, 8 dwg, 2 tbl, 8 ex

Description

The present invention relates to a method for producing a granule, such that includes the steps of pressing a compaction mixture that contains a polymer stabilizer that is tris(2,4-di-tert-butylphenyl)phosphite and a processing aid, through a nozzle of a pellet press to obtain a filament and grinding these filaments to obtain a granule. Another embodiment is a granule that contains a polymer stabilizer and a processing aid. Another embodiment is the use of this granule for dust-free handling of its components in the production of a stabilized polymer. Another embodiment is a method for producing a stabilized polymer, which includes a step of incorporating this granule into a polymer that is a polyolefin, polystyrene or a mixture thereof, to obtain a stabilized polymer. Another embodiment is a compaction mixture.

An organic polymer that is used as a structural material for manufacturing or as a part of an article is subject to degradation by oxidation, heat or light. There is short-term degradation that occurs during polymer processing, such as when the polymer obtained from polymer synthesis is mechanically converted into a desired final article or into an intermediate article. The intermediate article is often the product of a process that serves to incorporate specifically desired additives into the polymer obtained from polymer synthesis. Short-term degradation is often characterized by relatively short exposure to a relatively high process temperature, such as from above 80 °C to 330 °C, which in many cases occurs in combination with mechanical stress.

It has long been known that a polymer stabilizer is included in an organic polymer for stabilization against degradation by oxidation, heat or light. The introduction of a polymer stabilizer is usually carried out for a thermoplastic polymer during the processing of this polymer, when the heated polymer has a reduced viscosity or is in a state close to a liquid, and thus a homogeneous distribution of the polymer stabilizer in this polymer is maintained. The polymer stabilizer is very often solid at room temperature and is formed in the form of a powder as a result of its synthesis. When actually introducing a polymer stabilizer in the form of a powder, application problems arise. When handling the powder, there is a tendency for dust to be easily formed. Dust is of critical importance from the standpoint of occupational hygiene for workers in a manufacturing plant, from the standpoint of plant safety, such as dust explosion, and from the standpoint of plant cleanliness, such as dust contamination of plant equipment. In addition, the introduction of powder into the polymer is usually not carried out in a batch manner. Instead, continuous dosing of powder to a polymer that is processed continuously, such as in an extruder, in an amount that is typically less than 0.5% by weight of the polymer in question, is subject to variations in the amount actually injected at a given time. Consequently, a significant total amount of polymer subsequently contains statistically the same amount of polymer stabilizer, but this is not necessarily true for individual units of production from that total amount of polymer.

There are several known approaches to obtaining a suitable dust-free dosage form of a polymer stabilizer. One approach is to provide a suitable dust-free dosage form without adding an additional ingredient, i.e., an ingredient that is not required as a polymer stabilizer. For example, a polymer stabilizer in powder form is subjected to agglomeration by pressing by compaction with rollers to obtain flakes. Another approach is to form lozenges from the polymer stabilizer in powder form by melting said stabilizer and allowing individual droplets of the melt to solidify on a cooled surface. Another approach is to form granules from the polymer stabilizer in powder form by heating and kneading said stabilizer in an extruder at a temperature above the softening point of this polymer stabilizer, extruding the heated mass through a nozzle to form a warm thread and cutting this warm thread into granules. Another direction is to provide a suitable dust-free dosage form by adding a further ingredient, i.e. an ingredient that is not required as a polymer stabilizer. This further ingredient, sometimes called a compaction additive, binder or processing aid, in the case of a polymer further ingredient also a polymer masterbatch or carrier polymer, typically acts as a kind of hot melt adhesive for the polymer stabilizer powder or its particles. Whether the polymer stabilizer itself melts, at least to a large extent, depends on the temperature used and the chemical nature of the further ingredient in relation to the polymer stabilizer, in particular on whether there is a type of mutual solubility. The addition of a further ingredient to the dosage form of the polymer stabilizer has advantages. In particular, the dosage form of the polymer stabilizer can be produced dust-free initially, simply by sifting or screening the dust at the end of its production. However, the abrasion resistance of the initially dust-free dosage form is a property that becomes relevant in view of the transportation of this dosage form and the associated dust formation.

Tris(2,4-di-tert-butylphenyl)phosphite (CAS-No. 31570-04-4) is a polymer stabilizer that acts as a stabilizer for short-term processing. It has a melting range of 180-183°C and is found, for example, in Irgafos 168 (TM, commercially available from BASF SE).

Japanese patent JP H06-254845 relates to a stabilizer having dust-preventing properties and dispersibility obtained by a method in which, after mixing a powder of a heat stabilizer and a powder of an organic compounding agent having a lower melting point or softening point than that of the heat stabilizer at a predetermined ratio, the mixture is fed onto a ring-shaped mesh plate and extruded into a granular form from the mesh plate by means of a rotating roller.

US Patent US 5846656 relates to a stabilizing system for stabilizing polymeric materials with respect to the effects of ultraviolet light and thermal-oxidative degradation, in which the stabilizing system is in the form of granules. The granule is formed from a substantially dry homogeneous mixture of at least one stabilizer and an agent that will prevent melting of the stabilizer. The stabilizer compound constitutes from about 50% to about 98% by weight of the mixture. The stabilizers are antioxidants such as phosphites and sterically hindered phenols or UV light stabilizers based on sterically hindered amines or a combination thereof. The melting preventing agent may be a compound derived from a fatty acid or fatty alcohol, or a fatty acid or fatty alcohol, or a combination of fatty acids or fatty alcohols that constitutes from about 3% to 10% of the homogeneous mixture. The fatty acids, fatty alcohols and compounds derived therefrom preferably have a low melting point in the range of 50 to 100°C and preferably in the range of 50 to about 80°C. The melting preventing agent may alternatively be a lubricating agent having a small particle size that is about 2 to 50% by weight of the homogeneous mixture.

US Patent US 6,596,198 relates to a granular stabilizer additive system and a method for producing the same with a good yield of granules, preferably at least about 90% by weight. The stabilizer additive system comprises at least a stabilizer and a processing aid, preferably a mold release agent. The processing aid has a lower melting point than the stabilizer. The stabilizer comprises less than 50% by weight of the combined total weight of the stabilizer and mold release agent.

International application WO 2008-033410 relates to highly concentrated granular concentrates of additives or polymer stabilizing agents or mixtures thereof and compositions thereof, which can be used in various polymerization processes to improve stability. The granular concentrates of additives contain at least 10% by weight of a carrier polymer and are obtained in the examples by heating mixtures of additives together with a carrier polymer in an extruder above the melting temperature of the carrier polymer, but below the melting temperature of the main additive, followed by cutting the warm strands into granules. Example 4 leads to granules with a content of 48% by weight of tris (2,4-di-tert-butylphenyl) phosphite with a total content of polymer stabilizer of 70% by weight, and a content of polyethylene as a carrier polymer of 30% by weight.

There is still a need for other solid dosage forms of the polymer stabilizer, which is tris(2,4-di-tert-butylphenyl)phosphite, originally presented as a starting material in the form of powders. In the first aspect, the production of the dosage form, respectively the units of the dosage form, should ideally take place without heating the polymer stabilizers or at least minimize it. Firstly, this saves the process energy that would be needed to heat the polymer stabilizer either by direct heating or indirect heating, i.e., the mechanical stress is converted into thermal energy, which leads to a clear increase in the temperature of the polymer stabilizer being processed. Secondly, it also avoids unnecessary exposure of the polymer stabilizer to elevated temperatures. In addition to the fact that unnecessary exposure should generally be avoided, the individual polymer stabilizer can also undergo a phase transition, for example, an initially crystalline material changes into a viscous state. Furthermore, the production of the dosage form must occur without the formation of a defective product, i.e., the polymer stabilizer starting material used must be recycled into the dosage form in a high percentage in one cycle. In other words, the amount of waste generated must be low, even if this waste is in a form that it can be reused directly again as starting material. An example of waste removal is the sieving of the desired dosage form to obtain an initially dust-free dosage form. In a second aspect, the dosage form of the polymer stabilizer must remain stable during storage and transportation after its production. In particular, an initially dust-free dosage form can again form dust or fines due to the friction of the dosage form units against each other when subjected to vibration, for example during pouring into a bag, during transportation of a filled bag or during feeding operations of the dosage form units for introduction into the polymer to be stabilized. Accordingly, a certain level of abrasion resistance of the dosage form is desirable. In the third aspect, the dosage form units should ideally not be too diverse in shape and weight, since this allows a more accurate feeding of the dosage form units when incorporated into the polymer to be stabilized. A consequence of a more accurate feeding, especially when continuously fed into the polymer to be stabilized, is that the concentration of the polymer stabilizer fluctuates less in the stabilized polymer. In other words, the local concentration of the polymer stabilizer in a certain part of the stabilized polymer shows a smaller deviation from the average concentration of the polymer stabilizer in the entire stabilized polymer. If the feeding of the dosage form units occurs when incorporated into the polymer to be stabilized, at a stage when the polymer itself is still present in the form of solid units, for example granules, then it is advantageous for the dosage form units to be relatively similar in shape and weight to the solid units of the polymer. This does not contribute to the fact that the mixture of dosage form units and solid units of the polymer to be stabilized is separated during transportation as a mixture. An example of such transportation is the pneumatic transportation of a mixture of a polymer to be stabilized and a polymer stabilizer from a warehouse to the equipment for inclusion in the polymer, for example, an extruder. In the fourth aspect, the dosage form of the polymer stabilizer should have a low content of an auxiliary ingredient. This auxiliary ingredient may be present only during the manufacture of the dosage form, for example, by adding a solvent, which is then removed. The auxiliary ingredient may be present continuously, that is, the composition of the dosage form contains an auxiliary ingredient that will be included in the polymer to be stabilized. In the fifth aspect, the stabilization of the polymer is maintained due to the ideally uniform distribution of individual molecules of the polymer stabilizer in the polymer to be stabilized. Or, in the case where the polymer stabilizer does not dissolve as an individual molecule in the polymer to be stabilized, aggregates of individual molecules of the insoluble polymer stabilizer or even larger particles of aggregates of individual molecules of the polymer stabilizer are homogeneously distributed in the polymer to be stabilized. The potential influence of the dosage form on the distribution of the polymer stabilizer becomes apparent when one considers that initially all the molecules of the polymer stabilizer are concentrated in the dosage form, while later all the molecules of the polymer stabilizer are perfectly homogeneously distributed in the polymer to be stabilized. Non-uniform distribution of the polymer stabilizer in the polymer to be stabilized may also manifest itself in other ways than a decrease in the resistance to fracture of the stabilized polymer compared to a polymer stabilized as a result of a more perfect initial distribution, as in the case of mixing polymer powders and polymer stabilizers. For example, a non-uniformly distributed polymer stabilizer in a stabilized polymer may impair the surface properties in the case of producing a thin polymer film from this stabilized polymer, or may lead to clogging of filters or nozzles in the case of spinning extrusion of the stabilized polymer. The nature of the polymer to be stabilized interacts with a suitable polymer stabilizer. For example, polyamide, during its transition to the molten state, is converted into a type of solvent comparable to dimethyl sulfoxide, whereas polyolefin, during its transition to the molten state, is usually converted only into a type of solvent such as n-hexane or decalin. Consequently, there is less scope for adjusting the distribution of polymer stabilizers in polyolefin during its high-temperature processing than in polyamide.

In this work, a method for producing granules in a pellet press was discovered, which includes a roller and a die with a nozzle, and this method includes the following stages:

(A) pressing the mixture to be compacted using a roller through a nozzle to form a thread and

(B) grinding the said thread to obtain a granule,

wherein the sealing mixture contains

(i) from 87 to 97% by weight of a polymer stabilizer, which is tris(2,4-di-tert-butylphenyl)phosphite (CAS No. 31570-04-4),

(ii) from 3 to 13% by weight of a processing aid which is a copolymer of propylene and ethylene and which has a melting enthalpy below 100 J/g at 101.32 kPa,

and % of mass, recalculated to the mass of the mixture for compaction.

The mass percentages of components (i) and (ii) in the compaction mixture are recalculated to the mass of the given compaction mixture. Accordingly, the mass percentages of all components contained in the compaction mixture, which includes components (i) and (ii), add up to 100% by mass. In other words, the sum of all components is 100% by mass. The sum of components (i) and (ii) is less than or equal to 100% by mass.

A polymer stabilizer serves to stabilize a polymer susceptible to oxidative, thermal or light-induced degradation against degradation by oxidation, heat or light. Tris(2,4-di-tert-butylphenyl)phosphite (CAS-No. 31570-04-4) is shown below

and is contained, for example, in the commercial polymer stabilizer Irgafos 168 (TM BASF). It acts primarily as a short-term stabilizer. A short-term stabilizer is used against short-term degradation, which is often characterized by a relatively short-term exposure of the polymer to a relatively high process temperature, for example from above 80°C to 330°C, which in many cases occurs in combination with mechanical stress.

Preferably, the polymer stabilizer is in the form of a powder. The bulk density of this powder is determined in accordance with DIN EN ISO 17892-3. Preferably, the polymer stabilizer is in the form of a powder and has a bulk density of above 300 g/l and below 900 g/l, as defined by DIN EN ISO 17892-3, very preferably above 350 g/l and below 600 g/l, in particular above 380 g/l and below 550 g/l and, very particularly, above 400 g/l and below 500 g/l.

The processing aid has a melting enthalpy of less than 100 J/g at 101.32 kPa, a peak melting point and a melting range. The melting enthalpy is determined by differential scanning calorimetry (DSC) according to EN ISO 11357-3, preferably at atmospheric pressure, for example 101.32 kPa. The melting point and melting range are also determined by differential scanning calorimetry according to EN ISO 11357-3, preferably at atmospheric pressure, for example 101.32 kPa. Preferably, the tests according to EN ISO 11357-3 at atmospheric pressure are carried out with three successive heating cycles, wherein (a) from 0°C to 200°C at 10°C/min and 30 ml/min _N2 , (b) from 200°C to 0°C at 10°C/min and 30 ml/min _N2 , (c) from 0°C to 200°C at 10°C/min and 30 ml/min _N2 .

Preferably, the enthalpy of fusion of the processing aid is above 10 J/g and below 100 J/g at 101.32 kPa, very preferably above 15 J/g and below 85 J/g, in particular above 17 J/g and below 70 J/g, very particularly above 18 J/g and below 55 J/g, especially above 19 J/g and below 40 J/g, very particularly above 20 J/g and below 30 J/g and most particularly above 21 J/g and below 25 J/g.

Preferably, the peak melting temperature of the processing aid is above 50°C and below 85°C, very preferably above 55°C and below 83°C, in particular above 60°C and below 81°C, very particularly above 65°C and below 80°C, especially above 70°C and below 79°C, very particularly above 73°C and below 78°C and most particularly above 75°C and below 77°C.

Preferably, the melting range of the processing additive is between 20°C and 100°C, very preferably between 21°C and 99°C, in particular between 22°C and 98°C, very particularly between 23°C and 97°C and in particular between 24°C and 96°C.

A preferred method of producing granules is one in which the process additive has a peak melting point above 50°C and below 85°C.

The processing additive, which is a copolymer of propylene and ethylene, has a weight average molecular weight (Mw), a number average molecular weight (Mn) and a polydispersity index (PD), which is the ratio between Mw and Mn. Preferably, the weight average molecular weight, the number average molecular weight and the polydispersity index are determined by gel permeation chromatography (GPC), very preferably by high temperature gel permeation chromatography (HT-GPC) in accordance with ISO 16014-4. In gel permeation chromatography, the detector is preferably a refractive index detector (RI detector). The solvent is preferably trichlorobenzene. The column temperature is preferably 150°C. The calibration standard preferably contains polystyrene.

Preferably, the weight average molecular weight of the processing aid, which is a copolymer of propylene and ethylene, is greater than 10,000 Da (Dalton) and less than 40,000 Da, very preferably greater than 12,000 Da and less than 35,000 Da, in particular greater than 14,000 Da and less than 30,000 Da, very particularly greater than 15,000 Da and less than 25,000 Da, especially greater than 16,000 Da and less than 20,000 Da, and very particularly greater than 17,000 Da and less than 18,000 Da.

Preferably, the number average molecular weight of the processing aid, which is a copolymer of propylene and ethylene, is greater than 2000 Da and less than 10000 Da, very preferably greater than 3000 Da and less than 9000 Da, in particular greater than 4000 Da and less than 8000 Da, very particularly greater than 5000 Da and less than 7500 Da, and in particular greater than 6000 Da and less than 7000 Da.

Preferably, the polydispersity index of the processing additive, which is a copolymer of propylene and ethylene, is greater than 1.3 and less than 7, very preferably greater than 1.5 and less than 5, in particular greater than 1.7 and less than 4, very particularly greater than 1.9 and less than 3.5, especially greater than 2.1 and less than 3, and very particularly greater than 2.3 and less than 2.7.

Preferably, the weight-average molecular weight of the processing aid which is a copolymer of propylene and ethylene is above 10,000 Da and below 40,000 Da, and the number-average molecular weight is above 2,000 Da and below 10,000 Da, very preferably, the weight-average molecular weight is above 12,000 Da and below 35,000 Da, and the number-average molecular weight is above 3,000 Da and below 9,000 Da, in particular, the weight-average molecular weight is above 14,000 Da and below 30,000 Da, and the number-average molecular weight is above 4,000 Da and below 8,000 Da, very specifically, the weight-average molecular weight is above 15,000 Da and below 25,000 Da, and the number-average molecular weight is above 5,000 Da and below 7,500 Da, in particular, the average molecular weight is above 16,000 Da and below 20,000 Da, and the average number molecular weight is above 6,000 Da and below 7,000 Da.

Preferably, the polydispersity index of the processing aid which is a copolymer of propylene and ethylene is above 1.3 and below 7, and the weight average molecular weight is above 10,000 Da (Dalton) and below 40,000 Da, very preferably, the polydispersity index is above 1.5 and below 5, and the weight average molecular weight is above 12,000 Da and below 35,000 Da, in particular, the polydispersity index is above 1.7 and below 4, and the weight average molecular weight is above 14,000 Da and below 30,000 Da, very specifically, the polydispersity index is above 1.9 and below 3.5, and the average molecular weight is above 15,000 Da and below 25,000 Da, in particular, the polydispersity index is above 2.1 and below 3, and the average molecular weight is above 16000 Da and below 20000 Da, and very specifically, the polydispersity index is above 2.3 and below 2.7, and the average molecular weight is above 17000 Da and below 18000 Da.

It is understood that the polydispersity index is mathematically correlated with the weight-average molecular weight and the number-average molecular weight. Therefore, the range given below for the polydispersity index means that only those specific polydispersity indices are meant that can be achieved by selecting an appropriate specific average molecular weight from the given range for the average molecular weight and by selecting an appropriate specific number-average molecular weight from the given range for the number-average molecular weight. Preferably, the polydispersity index of the processing aid which is a copolymer of propylene and ethylene is higher than 1.3 and lower than 7, the weight-average molecular weight is higher than 10,000 Da (Dalton) and lower than 40,000 Da, and the number-average molecular weight is higher than 2,000 Da and lower than 10,000 Da. Very preferably, the polydispersity index is above 1.5 and below 5, the weight-average molecular weight is above 12,000 Da and below 35,000 Da, and the number-average molecular weight is above 3,000 Da and below 9,000 Da. In particular, the polydispersity index is above 1.7 and below 4, the weight-average molecular weight is above 14,000 Da and below 30,000 Da, and the number-average molecular weight is above 4,000 Da and below 8,000 Da. Very specifically, the polydispersity index is above 1.9 and below 3.5, the average molecular weight is above 15,000 Da and below 25,000 Da, and the number-average molecular weight is above 5,000 Da and below 7,500 Da. In particular, the polydispersity index is above 2.1 and below 3, the average molecular weight is above 16,000 Da and below 20,000 Da, and the number average molecular weight is above 6,000 Da and below 7,000 Da.

A method for producing granules in which the technological additive has an average molecular weight of above 10,000 Da and below 40,000 Da is preferred.

Preferably, the processing aid is in the form of a powder. The bulk density of the powder is determined in accordance with DIN EN ISO 17892-3. Preferably, the processing aid is in the form of a powder and has a bulk density of greater than 200 g/l and less than 800 g/l, as determined in accordance with DIN EN ISO 17892-3, very preferably greater than 250 g/l and less than 600 g/l, in particular greater than 280 g/l and less than 400 g/l, and very particularly greater than 300 g/l and less than 400 g/l.

Preferably, the processing aid is a propylene-ethylene copolymer which is a wax. Preferably, the processing aid is a wax of a propylene-ethylene copolymer which is synthesized with a metallocene catalyst of propylene and ethylene. Preferably, the processing aid is a propylene-ethylene copolymer which is long polymer chains branched by short chains (-CH ₃ ), very preferably branched essentially only by short chains and, in particular, branched only by short chains. Preferably, the processing aid is a wax of a propylene-ethylene copolymer which has a density at 23°C according to ISO 1183 of higher than 0.85 g/cm ³ and lower than 0.90 g/cm ³ , very preferably 0.87 g/cm ³ . Preferably, the processing aid is a wax of propylene-ethylene copolymer which has a dropping point according to ASTM D 3954 of above 80°C and below 100°C, very preferably above 85°C and below 95°C and, in particular, a dropping point in the range between 87°C and 93°C. Preferably, the processing aid is a propylene-ethylene copolymer wax which has a viscosity at 170°C according to DIN 53019 of above 50 mPa⋅s and below 750 mPa⋅s, very preferably above 100 mPa⋅s and below 500 mPa⋅s, in particular above 120 mPa⋅s and below 350 mPa⋅s and, very particularly, the viscosity is in the range between 150 mPa⋅s and 250 mPa⋅s. Preferably, the processing aid is a propylene-ethylene copolymer wax, which is Licocene PP 1302.

A preferred method of producing a granule is one in which the processing additive is a copolymer of propylene and ethylene, which is a wax.

A preferred method of producing a granule is one in which the compaction mixture comprises

(i) from 88 to 97% by weight of a polymer stabilizer and

(ii) from 3 to 12% by weight of technological additive.

A preferred method of producing a granule is one in which the compaction mixture comprises

(i) from 90 to 97% by weight of a polymer stabilizer and

(ii) from 3 to 10% by weight of a technological additive.

A preferred method of producing a granule is one in which the compaction mixture comprises

(i) from 91 to 97% by weight of a polymer stabilizer and

(ii) from 3 to 9% by weight of a technological additive.

A preferred method of producing a granule is one in which the compaction mixture comprises

(i) from 89 to 96% by weight of a polymer stabilizer and

(ii) from 4 to 11% by weight of technological additive.

A preferred method of producing a granule is one in which the compaction mixture comprises

(i) from 90 to 96% by weight of a polymer stabilizer and

(ii) from 4 to 10% by weight of a technological additive.

A preferred method of producing a granule is one in which the compaction mixture comprises

(i) from 91 to 96% by weight of a polymer stabilizer and

(ii) from 4 to 9% by weight of technological additive.

A preferred method of producing a granule is one in which the compaction mixture comprises

(i) from 87 to 94% by weight of a polymer stabilizer and

(ii) from 6 to 13% by weight of technological additive.

A preferred method of producing a granule is one in which the compaction mixture comprises

(i) from 88 to 94% by weight of a polymer stabilizer and

(ii) from 6 to 12% by weight of technological additive.

A preferred method of producing a granule is one in which the compaction mixture comprises

(i) from 87 to 93% by weight of a polymer stabilizer and

(ii) from 7 to 13% by weight of technological additive.

A preferred method of producing a granule is one in which the compaction mixture comprises

(i) from 88 to 93% by weight of a polymer stabilizer and

(ii) from 7 to 12% by weight of technological additive.

If the sealing mixture contains an additional ingredient that differs from the polymer and the processing aid, this additional ingredient is present only in a relatively small amount, i.e. up to 10% by weight (= 0 to 10% by weight). The additional ingredient also comprises a mixture of additional ingredients. Accordingly, the mixture of additional ingredients is present only in a relatively small amount, i.e. up to 10% by weight (= 0 to 10% by weight). The additional ingredient is, for example, another polymer stabilizer, another processing aid or a filler. The other polymer stabilizer is, for example, a phenolic antioxidant, a UV absorber, a hindered amine light stabilizer, a metal deactivator, a phosphite that differs from this polymer stabilizer, a phosphonite, a hydroxylamine or an amine N-oxide, a thiosynergist, an acid scavenger or a peroxide scavenger. Another processing aid is, for example, oleamide, erucamide, behenamide or glyceryl monostearate. The filler is, for example, silicon dioxide, talc or wollastonite. Preferably, the additional ingredient has a maximum light absorption at a wavelength below 380 nm, very preferably below 350 nm, in particular below 300 nm, very particularly below 280 nm, especially below 260 nm, and very particularly does not have a maximum light absorption above 250 nm.

The additional ingredient is preferably in solid form at 23°C and 101.32 kPa. Preferably, this additional ingredient is in powder form. The bulk density of this powder is determined in accordance with DIN EN ISO 17892-3. Very preferably, the additional ingredient is in powder form and has a bulk density of greater than 200 g/l and less than 950 g/l.

Preferably, the additional ingredient is present in the compacting mixture in an amount of up to 9% by weight (= 0 to 9% by weight), very preferably in an amount of up to 8% by weight (= 0 to 8% by weight), in particular in an amount of up to 7% by weight (= 0 to 7% by weight), very particularly in an amount of up to 6% by weight (= 0 to 6% by weight), especially in an amount of up to 5% by weight (= 0 to 5% by weight), very particularly in an amount of up to 3% by weight (= 0 to 3% by weight), most particularly in an amount of up to 1% by weight (0 to 1% by weight) and, in the most particular case, the compacting mixture does not contain the additional ingredient.

A preferred method is for producing granules in a pellet press, which includes a roller and a die with a nozzle, and this method includes the following stages:

(A) pressing the mixture to be compacted using a roller through a nozzle to form a thread and

(B) grinding the said thread to obtain a granule, wherein the compaction mixture comprises

(i) from 87 to 97% by weight of a polymer stabilizer, which is tris(2,4-di-tert-butylphenyl)phosphite (CAS No. 31570-04-4),

(ii) from 3 to 13% by weight of a processing aid which is a copolymer of propylene and ethylene and which has a melting enthalpy below 100 J/g at 101.32 kPa, and

(iii) up to 10% by weight of an additional ingredient that is different from component (i) and component (ii),

and the sum of components (i), (ii) and (iii) is less than or equal to 100% by weight.

A preferred method is for producing granules in a pellet press, which includes a roller and a die with a nozzle, and this method includes the following stages:

(A) pressing the mixture to be compacted using a roller through a nozzle to form a thread and

(B) grinding the said thread to obtain a granule,

and the mixture for compaction consists of

(i) from 87 to 97% by weight of a polymer stabilizer, which is tris(2,4-di-tert-butylphenyl)phosphite (CAS No. 31570-04-4),

(ii) from 3 to 13% by weight of a processing aid which is a copolymer of propylene and ethylene and which has a melting enthalpy below 100 J/g at 101.32 kPa, and

(iii) from 0 to 10% by weight of an additional ingredient that is different from component (i) and component (ii),

and the sum of components (i), (ii) and (iii) is 100% by weight.

A preferred method of producing a granule is one in which the compaction mixture comprises

(iii) from 0 to 3% by weight of an additional ingredient.

A preferred method of producing a granule is one in which the compaction mixture consists of

(i) from 88 to 97% by weight of a polymer stabilizer,

(ii) from 3 to 12% by weight of a technological additive and

(iii) from 0 to 9% by weight of an additional ingredient,

and the sum of components (i), (ii) and (iii) is 100% by weight.

A preferred method of producing a granule is one in which the compaction mixture consists of

(i) from 90 to 97% by weight of a polymer stabilizer,

(ii) from 3 to 10% by weight of a technological additive, and

(iii) from 0 to 7% by weight of an additional ingredient,

and the sum of components (i), (ii) and (iii) is 100% by weight.

A preferred method of producing a granule is one in which the compaction mixture consists of

(i) from 91 to 97% by weight of a polymer stabilizer,

(ii) from 3 to 9% by weight of a technological additive, and

(iii) from 0 to 6% by weight of an additional ingredient,

and the sum of components (i), (ii) and (iii) is 100% by weight.

A preferred method of producing a granule is one in which the compaction mixture consists of

(i) from 89 to 96% by weight of a polymer stabilizer,

(ii) from 4 to 11% by weight of a technological additive and

(iii) from 0 to 7% by weight of an additional ingredient,

and the sum of components (i), (ii) and (iii) is 100% by weight.

A preferred method of producing a granule is one in which the compaction mixture consists of

(i) from 90 to 96% by weight of a polymer stabilizer,

(ii) from 4 to 10% by weight of a technological additive and

(iii) from 0 to 6% by weight of an additional ingredient,

and the sum of components (i), (ii) and (iii) is 100% by weight.

A preferred method of producing a granule is one in which the compaction mixture consists of

(i) from 91 to 96% by weight of a polymer stabilizer,

(ii) from 4 to 9% by weight of a technological additive and

(iii) from 0 to 5% by weight of an additional ingredient,

and the sum of components (i), (ii) and (iii) is 100% by weight.

A preferred method of producing a granule is one in which the compaction mixture consists of

(i) from 87 to 94% by weight of polymer stabilizer,

(ii) from 6 to 13% by weight of a technological additive and

(iii) from 0 to 7% by weight of an additional ingredient,

and the sum of components (i), (ii) and (iii) is 100% by weight.

A preferred method of producing a granule is one in which the compaction mixture consists of

(i) from 88 to 94% by weight of polymer stabilizer,

(ii) from 6 to 12% by weight of a technological additive and

(iii) from 0 to 6% by weight of an additional ingredient,

and the sum of components (i), (ii) and (iii) is 100% by weight.

A preferred method of producing a granule is one in which the compaction mixture consists of

(i) from 87 to 93% by weight of a polymer stabilizer,

(ii) from 7 to 13% by weight of a technological additive, and

(iii) from 0 to 6% by weight of an additional ingredient,

and the sum of components (i), (ii) and (iii) is 100% by weight.

A preferred method of producing a granule is one in which the compaction mixture consists of

(i) from 88 to 93% by weight of polymer stabilizer,

(ii) from 7 to 12% by weight of the technological additive and

(iii) from 0 to 5% by weight of an additional ingredient,

and the sum of components (i), (ii) and (iii) is 100% by weight.

The compaction mixture is preferably in solid form at 23°C and 101.32 kPa. Very preferably, the compaction mixture is in powder form. Preferably, the compaction mixture in powder form is obtained by physically mixing a polymer stabilizer in powder form and a processing aid in powder form and, optionally, an additional ingredient in powder form. The physical mixing does not involve completely melting the polymer stabilizer or the processing aid and does not involve dissolving the polymer stabilizer or the processing aid in a solvent and then evaporating part or all of the solvent. The solid particles of the powders of components (i), (ii) and, optionally, (iii) are homogeneously distributed in the compaction mixture. The physical mixing can be carried out in a batch mode or continuously.

The compaction mixture is a raw material in the method for producing granules in a pellet press. The compaction mixture is usually continuously dosed into a section of the pellet press comprising a die with a nozzle and a roller by gravity. If the temperature of the compaction mixture is too high when it is dosed into the section of the pellet press comprising a die with a nozzle and a roller, a pasty mass is formed in the roller area, which may lead to a malfunction of the production method. The temperature of the compaction mixture during dosing is preferably below 40 ° C, very preferably, the dosing occurs at room temperature. The roller pre-compacts and degasses the feed material and presses this feed material through the nozzle. A cylindrical thread is formed. In more detail, the compaction mixture as a feed material is further compacted in the feed zone of the nozzle, which may have a conical shape, and begins to heat up and agglomerate in the elongated channel of the nozzle, usually cylindrical, due to friction against the surface of the nozzle. The corresponding nozzle surface is the surface of the channel, which usually has a cylindrical shape, of the nozzle along the smallest diameter of the channel. The smallest diameter of the nozzle is defined in this document as the nozzle diameter. The pressing length is defined here as the distance at which the smallest diameter of the cylindrical channel is applied. The cylindrical channel of the nozzle can be expanded after the pressing length, but the expanded part of the cylindrical channel does not contribute to the creation of friction by the feed material. The nozzle diameter and the pressing length are parameters that influence the degree of agglomeration. The grinding of the thread to obtain granules occurs, for example, with a cutting knife as a grinding device, at an adjustable distance from the outside of the die. The cutting knife cuts or, respectively, breaks the thread into granules of different lengths, usually 1 to 3 times longer than the nozzle diameter. The granules are then cooled and can be sieved, for example, through a sieve with a mesh size of 1.6 mm, which can be carried out, for example, in a vibrating sieve. The screened fine fraction, consisting mainly of the compaction mixture in partially compacted form, can be directly reused as starting material or reused after grinding. A more detailed description is given in the experimental part in section E). It should be noted that two or more stages (A) can take place before stage (B), i.e. two or more pressings take place before the grinding of the formed thread. The parameter for this is the distance between the end of the pressing length and the grinding device, for example a cutting knife.

Before stage (A), the compaction mixture is fed into a section of the pellet press that includes a die with a nozzle and a roller. The compaction mixture is preferably fed into the pellet press in powder form. This occurs preferably under the action of gravity.

A preferred method is for producing a granule, which method comprises the step of

(pre-A) feeding the compaction mixture into the pellet press, wherein the compaction mixture is in the form of powder,

and this stage (pre-A) is carried out before stage (A).

The formed thread has a surface temperature that is elevated after exiting the nozzle compared to the ambient temperature due to the friction that occurs. The surface temperature of the thread is determined, for example, by measuring its infrared radiation. Preferably, the surface temperature of the thread is above 50°C and below 110°C, very preferably above 55°C and below 105°C, in particular above 60°C and below 103°C, very particularly above 62°C and below 101°C.

A preferred method of producing granules is one in which the thread has a surface temperature above 50°C and below 110°C.

The pellet press is preferably a ring die pellet press or a flat die pellet press. In the toothed type pellet press, two toothed wheels act as a roller and form an equivalent of a nozzle and a die by cylindrical toothing between the toothed wheels, which causes the mixture to be compressed and compacted for compaction.

A preferred method for producing granule is one in which the pellet press is a ring die pellet press, wherein the die has a geometric shape of a ring with an inner side and an outer side, and the nozzle is a passage from the inner side to the outer side, or the pellet press is a flat die pellet press, wherein the die has a geometric shape of a flat plate with an upper side and a lower side, and the nozzle is a passage from the upper side to the lower side.

A preferred method of producing granules is one in which a ring die pellet mill has a rotating ring and a roller with a fixed axis of rotation, while a flat die pellet mill has a fixed axis of rotation and a roller with a rotating axis of rotation.

The main factor for the amount of mechanical energy supplied is the ratio of the pressing length of the nozzle to the diameter of the nozzle. For example, the surface temperature is affected by the selected pressing length of the nozzle and the diameter of the nozzle. Preferably, the ratio of the pressing length to the diameter of the nozzle is from 2 to 8, very preferably from 3 to 7, in particular from 4 to 6 and very specifically 5.

A preferred method for producing granule is one in which the nozzle has a nozzle diameter and a pressing length, and the ratio of the pressing length to the nozzle diameter is from 2 to 8.

The roller, preferably two or more rollers, very preferably two or three rollers, are usually driven by friction between the roller, the compaction mixture and the die. A smooth surface of the roller may cause the roller to slip. An excessive degree of slippage, which could lead to a malfunction of the production method, is reduced by a ribbed surface of the roller.

The preferred method of producing granules is one in which the surface of the roller is corrugated.

In a ring die pellet mill, another factor influencing the amount of mechanical energy supplied is the rotation speed of the ring die, and therefore its rotation frequency.

A preferred method for producing granules is one in which the pellet press is a ring die pellet press.

The number of dies on the pellet press depends on their design and technical considerations. Preferably, the pellet press comprises one die. The number of rolls on the pellet press depends on their design and technical considerations. A greater number of rolls allows, in the case of a die with two or more nozzles, which are arranged on a given die opposite each other, that stages (A) and (B) can occur on the pellet press more frequently over a certain period of time. The pellet press preferably comprises two or more rolls, very preferably two, three or four rolls, in particular two or three rolls and, in particular, two rolls. The number of nozzles on the die depends on their design and technical considerations. A greater number of nozzles on the die allows that stage (A) occurs on individual nozzles in parallel or with a time shift, which leads to the formation of two or more strands in parallel mode. Time-shifted in this case means that step (A) takes place in another nozzle before step (A) is repeated again on the initially first nozzle. Step (B) then takes place in principle in parallel, i.e. the grinding of two or more strands takes place in principle in parallel. In this way, two or more granules are produced in principle in parallel. Consequently, the productivity in terms of the number of granules per period of time increases significantly. The die of the pellet press preferably comprises two or more nozzles, very preferably from 48 to 20,000, in particular from 96 to 16,000, particularly in particular from 360 to 14,000, in particular from 720 to 12,000, particularly in particular from 1,440 to 11,000 and most in particular from 3,600 to 10,000.

A preferred method of producing pellets is one in which the pellet press comprises two rollers.

A preferred method of producing granules is one in which the pellet press comprises a ring with two or more nozzles.

A preferred method of producing granules is one in which the pellet press comprises one ring.

A preferred method for producing granules is one in which the pellet press comprises two or more rollers and the die comprises two or more nozzles.

A preferred method for producing granules is one in which the pellet press comprises one die, two or more rollers, and the die comprises two or more nozzles.

A preferred method for producing a pellet is one in which the pellet press comprises one die, two or more rollers, and the die comprises two or more nozzles, and step (A) occurs in the first of the two or more nozzles and at the same time or with a time shift in the second of the two or more nozzles, but before step (A) is again carried out in the first of the two or more nozzles.

The granule obtained by the pressing method contains

(i) from 87 to 97% by weight of a polymer stabilizer, which is tris(2,4-di-tert-butylphenyl)phosphite (CAS No. 31570-04-4),

(ii) from 3 to 13% by weight of a processing additive which is a copolymer of propylene and ethylene having an enthalpy of melting below 100 J/g at 101.32 kPa,

and % by weight are recalculated to the weight of the given granule.

The mass percentages of components (i) and (ii) in a granule are recalculated to the mass of the granule. Accordingly, the mass percentages of all components contained in the granule, which includes components (i) and (ii), add up to 100% by mass. In other words, the sum of all components is 100% by mass. The sum of components (i) and (ii) is less than or equal to 100% by mass.

Preferably, the granule contains

(i) from 87 to 97% by weight of a polymer stabilizer, which is tris(2,4-di-tert-butylphenyl)phosphite (CAS No. 31570-04-4),

(ii) from 3 to 13% by weight of a processing additive which is a copolymer of propylene and ethylene having a melting enthalpy below 100 J/g at 101.32 kPa, and

(iii) up to 10% by weight of an additional ingredient that is different from component (i) and component (ii),

and the sum of components (i), (ii) and (iii) is less than or equal to 100% by weight.

Preferably, the granule consists of

(i) from 87 to 97% by weight of a polymer stabilizer, which is tris(2,4-di-tert-butylphenyl)phosphite (CAS No. 31570-04-4),

(ii) from 3 to 13% by weight of a processing additive which is a copolymer of propylene and ethylene having a melting enthalpy below 100 J/g at 101.32 kPa, and

(iii) from 0 to 10% by weight of an additional ingredient that is different from component (i) and component (ii),

and the sum of components (i), (ii) and (iii) is 100% by weight.

The granule preferably has the shape of a round rod. The ideal shape of the round rod is a cylinder, but the two regions of the base of the cylinder in the case of this granule are not always flat and parallel to each other, in particular, they are not flat and parallel to each other. This is due to the grinding of the thread in step (B), which includes more breaking elements than in the case of hot cutting with a knife of a thread that is uniformly heated to a temperature above 110 ° C. The round rod has a circumference diameter. Preferably, the round rod has a circumference diameter that is from 2 mm to 4 mm, very preferably 3 mm. The length of the granule in this case is understood as the greatest distance in the direction of formation of the thread in the nozzle, i.e., the axis of the granule, which is determined by the presence of an average of the same distance to the points of the granule surface, with the exception of those points on the granule surface that are formed as a result of grinding the thread. In the case of a round rod, the axis of the granule is the axis of rotation of the round rod. The granule preferably has a length that is 1 to 3 times the diameter of the circle. While one granule itself has a specific length value, a plurality of granules may have an average granule length. This is caused by the stage (B), which occurs by cutting with elements of destruction. In addition to the distance to the grinding device in stage (B), the design of the nozzle and its nozzle channel plays a role. One option is that the pressing length of the nozzle is followed by a section with a diameter that is larger than the diameter of the nozzle. Therefore, the nozzle has a channel with a section of the pressing length and an expanded section that follows the section of the pressing length. The expanded section makes it possible that the desired thickness of the matrix is greater than the pressing length of the nozzle. A certain thickness of the matrix may be desired for reasons of mechanical strength of a given matrix, for example, to avoid matrix breakage.

A possible step (C) is to screen the granules from step (B), for example using a 1.6 mm sieve. This removes the fine fractions that are formed as a result of the granule manufacturing process, for example in step (B).

Possible stage (D) is the cooling of the pellets. For example, the cooling results in a pellet temperature that is similar to the temperature surrounding the pellet press. The temperature surrounding the pellet press is preferably room temperature, very preferably 23°C. This cooling may partially or completely occur already during possible stage (C). The cooling may be maintained by an air flow.

The above-described definitions and preferences for the method of producing a granule in a pellet press, for the compaction mixture and for the granule are described for the method of producing a granule in a pellet press. These definitions and preferences also apply to other embodiments of the invention.

Another embodiment of the invention is a compaction mixture that comprises

(i) from 87 to 97% by weight of a polymer stabilizer in the physical form of a powder, which is tris(2,4-di-tert-butylphenyl)phosphite (CAS No. 31570-04-4), and

(ii) from 3 to 13% by weight of a processing additive in the physical form of a powder, which is a copolymer of propylene and ethylene having an enthalpy of melting below 100 J/g at 101.32 kPa,

and the mass % are recalculated to the mass of the mixture for compaction.

The mass percentages of components (i) and (ii) in the compaction mixture are recalculated to the mass of the compaction mixture. Accordingly, the mass percentages of all components contained in the compaction mixture, which includes components (i) and (ii), add up to 100% by mass. In other words, the sum of all components is 100% by mass. The sum of components (i) and (ii) is less than or equal to 100% by mass.

Preferably, the sealing mixture comprises

(i) from 87 to 97% by weight of a polymer stabilizer in the physical form of a powder, which is tris(2,4-di-tert-butylphenyl)phosphite (CAS No. 31570-04-4),

(ii) from 3 to 13% by weight of a processing aid in the physical form of a powder, which is a copolymer of propylene and ethylene having an enthalpy of fusion below 100 J/g at 101.32 kPa, and

(iii) up to 10% by weight of an additional ingredient that is different from component (i) and component (ii),

and the sum of components (i), (ii) and (iii) is less than or equal to 100% by weight.

Preferably, the sealing mixture consists of

(i) from 87 to 97% by weight of a polymer stabilizer in the physical form of a powder, which is tris(2,4-di-tert-butylphenyl)phosphite (CAS No. 31570-04-4),

(ii) from 3 to 13% by weight of a processing aid in the physical form of a powder, which is a copolymer of propylene and ethylene having an enthalpy of fusion below 100 J/g at 101.32 kPa, and

(iii) from 0 to 10% by weight of an additional ingredient that is different from component (i) and component (ii),

and the sum of components (i), (ii) and (iii) is 100% by weight.

The sealing mixture is preferably in powder form.

Another embodiment of the invention is a granule that contains

(i) from 87 to 97% by weight of a polymer stabilizer, which is tris(2,4-di-tert-butylphenyl)phosphite (CAS No. 31570-04-4), and

(ii) from 3 to 13% by weight of a processing additive which is a copolymer of propylene and ethylene having an enthalpy of melting below 100 J/g at 101.32 kPa,

and the mass % are recalculated to the mass of the given granule.

The mass percentages of components (i) and (ii) in a granule are recalculated to the mass of the granule. Accordingly, the mass percentages of all components contained in the granule, which includes components (i) and (ii), add up to 100% by mass. In other words, the sum of all components is 100% by mass. The sum of components (i) and (ii) is less than or equal to 100% by mass.

Preferably, the granule contains

(i) from 87 to 97% by weight of a polymer stabilizer, which is tris(2,4-di-tert-butylphenyl)phosphite (CAS No. 31570-04-4),

(ii) from 3 to 13% by weight of a processing additive which is a copolymer of propylene and ethylene having a melting enthalpy below 100 J/g at 101.32 kPa, and

(iii) up to 10% by weight of an additional ingredient that is different from component (i) and component (ii),

and the sum of components (i), (ii) and (iii) is less than or equal to 100% by weight.

Preferably, the granule consists of

(i) from 87 to 97% by weight of a polymer stabilizer, which is tris(2,4-di-tert-butylphenyl)phosphite (CAS No. 31570-04-4),

(ii) from 3 to 13% by weight of a processing additive which is a copolymer of propylene and ethylene having a melting enthalpy below 100 J/g at 101.32 kPa, and

(iii) from 0 to 10% by weight of an additional ingredient that is different from component (i) and component (ii),

and the sum of components (i), (ii) and (iii) is 100% by weight.

A granule which has the shape of a round rod is preferred, and this round rod has a circumference diameter which is from 2 to 4 mm.

The preferred granule length is 1 to 3 times the diameter of the circle.

Another embodiment of the invention is a method for producing a stabilized polymer, which comprises the steps of:

(AP) dosing granules into polymer to obtain a mixture of granules and polymer,

(BP) subjecting a mixture of granules and polymer to a temperature in the range of 120 to 340°C with mechanical mixing to obtain a stabilized polymer, wherein the polymer is a polyolefin, polystyrene or a mixture thereof,

the granule contains

(i) from 87 to 97% by weight of a polymer stabilizer, which is tris(2,4-di-tert-butylphenyl)phosphite (CAS No. 31570-04-4),

(ii) from 3 to 13% by weight of a processing additive which is a copolymer of propylene and ethylene having an enthalpy of melting below 100 J/g at 101.32 kPa,

and the mass % are recalculated to the mass of the given granule.

The mass percentages of components (i) and (ii) in a granule are recalculated to the mass of the granule. Accordingly, the mass percentages of all components contained in the granule, which includes components (i) and (ii), add up to 100% by mass. In other words, the sum of all components is 100% by mass. The sum of components (i) and (ii) is less than or equal to 100% by mass.

Preferably, in the method for producing a stabilized polymer, the granule comprises

(i) from 87 to 97% by weight of a polymer stabilizer, which is tris(2,4-di-tert-butylphenyl)phosphite (CAS No. 31570-04-4),

(ii) from 3 to 13% by weight of a processing additive which is a copolymer of propylene and ethylene having a melting enthalpy below 100 J/g at 101.32 kPa, and

(iii) up to 10% by weight of an additional ingredient that is different from component (i) and component (ii),

and the sum of components (i), (ii) and (iii) is less than or equal to 100% by weight.

Preferably, in the method for producing a stabilized polymer, the granule consists of

(i) from 87 to 97% by weight of a polymer stabilizer, which is tris(2,4-di-tert-butylphenyl)phosphite (CAS No. 31570-04-4),

(ii) from 3 to 13% by weight of a processing additive which is a copolymer of propylene and ethylene having a melting enthalpy below 100 J/g at 101.32 kPa, and

(iii) from 0 to 10% by weight of an additional ingredient that is different from component (i) and component (ii),

and the sum of components (i), (ii) and (iii) is 100% by weight.

In the (AP) stage, the granule size is preferably well selected, since too large granules are more difficult to dose, mix and disperse in the polymer.

In step (BP), the components of the granules are homogeneously distributed and/or dissolved in the polymer to be stabilized, with mechanical stirring. This is facilitated by the thermal effect on the mixture of granules and polymers, which leads to a decrease in the viscosity of the polymer on the one hand and to melting of the components of the granules on the other hand, if the corresponding melting range of the component is reached. Preferably, the temperature in step (BP) is in the range from 135°C to 330°C, very preferably from 150°C to 310°C, in particular from 180°C to 300°C, very particularly from 190°C to 290°C, especially from 200°C to 280°C and especially particularly from 210°C to 260°C.

Polyolefin is, for example:

1. Homopolymer of monoolefins and diolefins, for example, polypropylene, polyisobutylene, polybut-1-ene, poly-4-methylpent-1-ene,

polyvinylcyclohexane, polyisoprene or polybutadiene, as well as cycloolefin polymers, for example from cyclopentene or norbornene, polyethylene, for example high-density polyethylene (HDPE), medium-density polyethylene (MDPE), low-density polyethylene (LDPE), linear low-density polyethylene (LLDPE) or mixtures thereof, for example mixtures of polypropylene with polyisobutylene, polypropylene with polyethylene (for example PP/HDPE, PP/LDPE) or mixtures of different types of polyethylene (for example LDPE/HDPE).

2. A copolymer of monoolefins or diolefins with each other or with other vinyl monomers, for example ethylene/propylene copolymers, propylene/but-1-ene copolymers, propylene/isobutylene copolymers, ethylene/but-1-ene copolymers, ethylene/hexene copolymers, ethylene/methylpentene copolymers, ethylene/heptene copolymers, ethylene/octene copolymers, ethylene/vinylcyclohexane copolymers, ethylene/cycloolefin copolymers, for example ethylene/norbornene, such as COC, ethylene/1-olefin copolymers in which the 1-olefin is formed in-situ, propylene/butadiene copolymers, isobutylene/isoprene copolymers, ethylene/vinylcyclohexene copolymers, ethylene/alkyl acrylate copolymers, ethylene/alkyl methacrylate copolymers, ethylene/vinyl acetate copolymers or ethylene/acrylic acid copolymers and their salts (ionomers), as well as terpolymers of ethylene with propylene and a diene such as hexadiene, dicyclopentadiene or ethylidene norbornene, and mixtures of such copolymers with one another or mixtures with other polyolefins, for example polypropylene/ethylene-propylene copolymers, LDPE/ethylene-vinyl acetate (EVA) copolymers or LDPE/ethylene-acrylic acid (EAA) copolymers.

Polyolefins from monoolefins, preferably polyethylene and polypropylene, can be obtained by various methods, in particular the following:

a) radical polymerization (usually at high pressure and elevated temperature)

b) catalytic polymerization using a catalyst which typically contains one or more metals from Groups 4, 5, 6 (e.g. chromium) or 7 of the Periodic Table. These metals typically have one or more ligands, typically oxides, halides, alcoholates, esters, ethers, amines, alkyls, alkenyls and/or aryls which may be pi- or sigma-coordinated. These metal complexes may be in free form or fixed on supports, typically activated magnesium chloride, titanium (III) chloride, aluminum oxide or silica. These catalysts may be soluble or insoluble in the polymerization medium. The catalysts may be used in the polymerization by themselves or additional activators may be used, typically metal alkyls, metal hydrides, metal alkyl halides, metal alkyl oxides or metal alkyloxanes, said metals being elements of Groups 1, 2 and/or 3 of the Periodic Table. The activators may conveniently be modified with additional ester, ether, amine or silyl ether groups. These catalyst systems are commonly referred to as Phillips, Standard Oil Indiana, Ziegler (-Natta), TNZ (DuPont), metallocene or single site catalysts (SSC).

Polystyrene is, for example:

1. Homopolymer of styrene.

2. A copolymer of styrene and a comonomer which is, for example, ethylene, propylene, dienes, nitriles, acids, maleic anhydrides, maleimides, vinyl acetate, acrylic derivatives and mixtures thereof, for example styrene/butadiene, styrene/acrylonitrile, styrene/ethylene, styrene/alkyl methacrylate, styrene/butadiene/alkyl acrylate, styrene/butadiene/alkyl methacrylate, styrene/maleic anhydride, styrene/acrylonitrile/methyl acrylate, block copolymers of styrene with a comonomer, for example styrene/butadiene/styrene, styrene/isoprene/styrene, styrene/ethylene/butylene/styrene or styrene/ethylene/propylene/styrene.

3. Graft copolymers of styrene, for example styrene on polybutadiene, styrene on polybutadiene-styrene or polybutadiene-acrylonitrile copolymers, styrene and acrylonitrile on polybutadiene, styrene, acrylonitrile and methyl methacrylate on polybutadiene, styrene and maleic anhydride on polybutadiene, styrene, acrylonitrile and maleimide on polybutadiene, styrene and maleimide on polybutadiene, styrene and alkyl acrylates or methacrylates other than methyl acrylate on polybutadiene, styrene and acrylonitrile on ethylene/propylene/diene terpolymers, styrene and acrylonitrile on polyalkyl acrylates or polyalkyl methacrylates, styrene and acrylonitrile on acrylate/butadiene copolymers.

In the polyolefin copolymer, at least two different monomers are copolymerized. Preferred is a polyolefin copolymer in which the weight content of the polymerized olefin monomer exceeds 50% based on the weight of all polymerized monomers. In the polystyrene copolymer, at least two different monomers are copolymerized or one monomer is grafted onto at least another monomer that has been polymerized. Preferred is a polystyrene copolymer in which the weight content of the polymerized or grafted styrene exceeds 50% based on the weight of all polymerized or grafted monomers.

Preferably, the polymer, which is a polyolefin, polystyrene or a mixture thereof, is thermoplastic, that is, it can be given a new shape at an elevated temperature, for example at a temperature in the range from 120 °C to 340 °C, in particular from 135 °C to 330 °C.

The polymer, which is a polyolefin, polystyrene or a mixture of both, is subject to oxidative, thermal or light-induced degradation.

The amount of granules to be dosed to the polymer, which is a polyolefin, polystyrene or a mixture thereof, varies depending on the specific polymer and the desired degree of protection against oxidative, thermal or light-induced degradation. Preferably, the amount of granules in weight percent is from 0.01 to 5% by weight based on the weight of the polymer, very preferably from 0.02 to 3% by weight, in particular from 0.04 to 2% by weight, very particularly from 0.05 to 1% by weight, in particular from 0.08 to 0.8% by weight and, particularly particularly, from 0.1 to 0.4% by weight.

A preferred method for producing a stabilized polymer is one in which the (BP) step is carried out in an extruder or co-mixer.

At the (AP) stage, the granules can be dosed to the polymer, which already has a polymer temperature in the range of 120 to 340°C. For example, the granules are dosed to the polymer, which is already heated in an extruder or a co-mixer. For example, the granules are introduced by means of a feed device, which is, for example, an extruder, into the already warm and viscous polymer to be stabilized. Accordingly, the mixture of granules and polymer immediately has a polymer temperature in the range of 120 to 340°C and the granule begins to disintegrate.

A preferred method is for producing a stabilized polymer, wherein the polymer to which the granules are added at step (AP) has a polymer temperature in the range of 120 to 340°C.

In step (AP), granules can be dosed to a polymer that has a polymer temperature below 40°C. In the case where the polymer is in the form of granules, a mixture of granules and polymer is formed, which contains components (a) granules and (b) polymer granules. The polymer granules have, for example, a geometrical cylindrical shape and are obtained, for example, by hot cutting of an extruded warm polymer thread with subsequent cooling in a quenching water bath. The mixture of granules and polymer obtained in step (AP), where the polymer is in the form of granules, can be prepared and stored independently of step (BP) or prepared immediately before step (BP).

A preferred method for producing a stabilized polymer is one in which the polymer to which the granules are added is in the form of granules at step (AP) and has a polymer temperature below 40°C.

The definitions and preferences described for the method of producing a stabilized polymer or its use also apply to other embodiments of the invention.

Another embodiment of the invention is the use of a granule for dust-free handling of its components in the production of a stabilized polymer, wherein the polymer is a polyolefin, polystyrene or a mixture thereof, and wherein the granule contains

(i) from 87 to 97% by weight of a polymer stabilizer in the physical form of a powder, which is tris(2,4-di-tert-butylphenyl)phosphite (CAS No. 31570-04-4), and

(ii) from 3 to 13% by weight of a processing additive in the physical form of a powder, which is a copolymer of propylene and ethylene having an enthalpy of melting below 100 J/g at 101.32 kPa,

and % of mass, recalculated to the mass of a given granule.

The mass percentages of components (i) and (ii) in a granule are recalculated to the mass of the granule. Accordingly, the mass percentages of all components contained in the granule, which includes components (i) and (ii), add up to 100% by mass. In other words, the sum of all components is 100% by mass. The sum of components (i) and (ii) is less than or equal to 100% by mass.

Preferably, when using the granule for dust-free handling of its components in the production of a stabilized polymer, the granules contain

(i) from 87 to 97% by weight of a polymer stabilizer in the physical form of a powder, which is tris(2,4-di-tert-butylphenyl)phosphite (CAS No. 31570-04-4),

(ii) from 3 to 13% by weight of a processing aid in the physical form of a powder, which is a copolymer of propylene and ethylene having an enthalpy of fusion below 100 J/g at 101.32 kPa, and

(iii) up to 10% by weight of an additional ingredient that is different from component (i) and component (ii),

and the sum of components (i), (ii) and (iii) is less than or equal to 100% by weight.

Preferably, when using the granule for dust-free handling of its components in the production of a stabilized polymer, the granule consists of

(i) from 87 to 97% by weight of a polymer stabilizer in the physical form of a powder, which is tris(2,4-di-tert-butylphenyl)phosphite (CAS No. 31570-04-4),

(ii) from 3 to 13% by weight of a processing aid in the physical form of a powder, which is a copolymer of propylene and ethylene having an enthalpy of fusion below 100 J/g at 101.32 kPa, and

(iii) from 0 to 10% by weight of an additional ingredient that is different from component (i) and component (ii),

and the sum of components (i), (ii) and (iii) is 100% by weight.

Fig. 1 shows granules obtained from Example E-1-1 placed on graph paper.

Fig. 2 shows granules obtained from Example E-1-2 placed on graph paper.

Fig. 3 shows granules obtained from Example E-1-3 placed on graph paper.

Fig. 4 shows granules obtained from Example E-1-4 placed on graph paper.

Fig. 5 shows granules obtained from Example E-1-5 placed on graph paper.

Fig. 6 shows granules obtained from Example E-1-6 placed on graph paper.

Fig. 7 shows granules obtained from Example E-1-7 placed on graph paper.

Fig. 8 shows granules obtained from Example E-1-8 placed on graph paper.

The following examples further illustrate the invention without limiting it. Percentages are weight percent unless otherwise stated.

A) Characterization methods

The average particle size is determined, unless otherwise stated, using a Camsizer P4 from Retsch Technology GmbH by means of digital image analysis. The measuring principle is dynamic image analysis in accordance with ISO 13322-2.

Bulk density is measured in accordance with DIN EN ISO 17892-3.

The melt flow index of the polymer is measured according to the ISO 1133 standard using a Goettfert MI-Robo device with specially set parameters.

Differential scanning calorimetry (DSC) measurements are carried out according to EN ISO 11357-3 at atmospheric pressure. The heating cycles are: (a) 0°C to 200°C at 10°C/min and 30 ml/min N ₂ , (b) 200°C to 0°C at 10°C/min and 30 ml/min N ₂ , (c) 0°C to 200°C at 10°C/min and 30 ml/min N ₂ . The melting range, peak melting temperature and enthalpy of fusion are determined in heating cycle (c).

High-temperature gel permeation chromatography (HT-GPC) measurements are carried out according to ISO 16014-4. An Agilent PL-GPC 220 with a refractometric detector is used as an apparatus. One Agilent PFgel Olexis Guard 50×7.5 mm column (catalog number PL1110-1400) is used as a precolumn. Three Agilent PLgel Olexis 13 μm 300×7.5 mm columns (catalog number PL1110-6400) are used as columns. The column temperature is 150°C. Calibration standards are polystyrene and High EasiVial GPC/SEC calibration standards from Agilent (catalog number PL2010-0201 and catalog number PL2010-0202). Trichlorobenzene is used as the eluent with a flow rate of 1 ml/min, a sample concentration of 3 mg/ml and an injection volume of 200 μl. The determined number average molecular weight Mn and the determined weight average molecular weight Mw are used to calculate the polydispersity index (PD) as the ratio between Mw and Mn.

The sieve analysis is carried out using a Camsizer P4 from Retsch Technology GmbH by means of digital image analysis. The measuring principle is dynamic image analysis according to ISO 13322-2 with the values D10, D50 and D90.

The Norner attrition test is a test using a vibrating sieve shaker and glass beads to mechanically impact the test form. An initial sieve analysis is carried out for 1 minute, followed by further sieving using glass beads on sieve tiers to mechanically impact the material and measure the change in sieve fractions after 5, 10 and 20 minutes. The sieves selected are arranged from bottom to top: 200 µm, 500 µm, 1 mm, 1.6 mm, 2.5 mm and 4 mm. The glass beads used (Sigmund Lindner GmbH, type P) have dimensions of 16 mm ±0.02 mm, a mass of 5.36 g/glass bead and are made of soda-lime glass with a fine-grained matt surface.

The test procedure is as follows:

1. Load 50 g of sample into a sieve shaker without glass beads and sift at 1 mm amplitude for 1 minute. Measure the mass on each sieve plate and sieve tier.

2. Add 8 glass beads to a 500 µm sieve, 9 glass beads to a 1.0 mm sieve, 10 to a 1.6 mm sieve and 11 to a 2.5 mm sieve. Continue sieving for 5 minutes, then measure the mass on each sieve plate and sieve tier.

3. Continue sifting for another 5 minutes, repeat the weighing procedure.

4. Continue sifting for another 10 minutes, repeat the weighing procedure.

The sieve shaker used is the Retsch Sieve Shaker AS 200 control system from Retsch GmbH.

The total fine fraction content is the sum of all the material collected from the bottom plate and the 200 µm sieve. Accordingly, fragments of the sample that are formed under the action of friction stress and fall through the 500 µm sieve (<500 µm) are considered fine fractions. The proportion of particle size in % by weight <500 µm after 20 minutes is the key result (Norner value) for determining the abrasion resistance and impact resistance of the tested mold. The range of results can vary from 0% for extremely resistant to 100% for extremely unstable.

The average mass of pellets is measured by taking a certain number of pellets (about 45 pellets), weighing that certain number of pellets to get the total mass, and dividing the total mass by that certain number of pellets.

The average length of the granules is calculated by multiplying the average mass of the granules by the accepted density of 0.95 g/ ^cm3 and dividing by the area of the circle with a granule diameter of 3 mm.

B) Source material

SM-PS-1: lrqafos168

Irgafos 168 (TM, commercially available from BASF SE, melting point in the range of 180-183°C), which contains tris(2,4-di-tert-butylphenyl)phosphite (CAS-No. 31570-04-4), as shown below,

in the form of powder, that is, a loose bulk material with a bulk density of 467 g/l and an average particle size of 400 µm.

SM-PA-1: Licocene PP 1302

Licocene PP 1302 (TM, commercially available from Clariant, commercial technical form used: fine grain) is a wax based on a copolymer of propylene and ethylene (CAS-No. 9010-79-1), which is synthesized with a metallocene catalyst of propylene and ethylene. Branching of long polymer chains occurs by means of short chains (-CH ₃ ). Some physicochemical properties are measured and presented in Table B-1.

The technical data sheet indicates the density at 23°C according to ISO 1183, which is 0.87 g/ ^cm3 .

The technical data sheet indicates the dropping point according to ASTM D 3954, which is 87-93°C.

The technical data sheet indicates viscosity at 170°C according to DIN 53019, which is 150-250 mPa⋅s.

For the sieve analysis of the material in its technical fine-grained form, measurements were taken and are listed in Table B-2. The bulk density was measured to be 338 g/l. The material is used for compaction in its technical fine-grained form.

SM-PA-2: Petrolite EP-700

Petrolite EP-700 (TM, commercially available from Baker Hughes) is a wax based on a copolymer of propylene and ethylene (CAS-No. 9010-79-1). Controlled branching of the long polymer chains occurs at the expense of short chains from propylene (-CH ₃ ). Some physicochemical properties are measured and presented in Table B-1.

The technical data sheet states the dropping point according to ASTM D-127, which is 96°C.

The technical data sheet indicates viscosity at 99°C as 12 pes (120 mPa⋅s).

Petrolite EP-700 is ground in a Pallmann PF 300 disc mill. For the sieve analysis of the obtained ground material, measurements were taken and are listed in Table B-2. The bulk density of the ground material was measured to be 473 g/l. This ground material is used for compaction.

SM-PA-3: Luwax AL-3

Luwax AL-3 (TM, commercially available from BASF as powder) is a polyethylene wax (CAS-No. 9002-88-4) which is synthesized by high pressure polymerization. Branching of long polymer chains occurs due to long chains (-[CH ₂ -CH ₂ -] _n -H). Some physicochemical properties are measured and presented in Table B-1.

The technical data sheet indicates the density at 23°C according to DIN 53479 and ASTM D-792 standards, which is 0.91-0.925 g/ ^cm3 .

The technical data sheet indicates the dropping point (Ubbelohde) according to DIN 51801 and ASTM D-3954 standards, which is 101-112°C.

The technical data sheet indicates the melting point (DSC) according to DIN 51007 and ASTM D-3418 standards, which is 102-108°C.

The technical data sheet indicates the melt viscosity at 120°C according to DIN 51562 and ASTM D-2162 standards, which is 135-240 ^mm2 /s.

For the sieve analysis of the material in the technical form of powder, measurements were taken and are listed in Table B-2. The bulk density was measured to be 495 g/l. The material is used for compaction in its technical form.

SM-PA-4: Dow PG 7008

Dow PG 7008 (TM, commercially available from Dow Chemicals) is a low-density polyethylene (CAS-No. 9002-88-4). Some physicochemical properties are measured and presented in Table B-1.

The technical data sheet indicates the density at 23°C according to ASTM D-792, which is 0.918 g/ ^cm3 .

The technical data sheet indicates a melting point (DSC) of 106°C.

The technical data sheet indicates the Vicat softening temperature according to ISO 306/A, which is 89.0°C.

The technical data sheet states the melt index (190°C/2.16 kg) according to ISO 1133, which is 7.7 g/10 min.

Dow PG 7008 is ground in a Pallmann PF 300 disc mill. For the sieve analysis of the resulting ground material, measurements were taken and are listed in Table B-2. The bulk density of the ground material was measured to be 285 g/l. This ground material is used for compaction.

SM-PA-5: Borflow HL 708 FB

Borflow HL 708 FB (TM, commercially available from Borealis) is a polypropylene (CAS-No. 9003-07-0). Some physicochemical properties have been measured and are presented in Table B-1.

The technical data sheet indicates a melting point (DSC) of 158°C.

The technical data sheet states the melt index (130°C/2.16 kg) according to ISO 1133, which is 800 g/10 min.

Borflow HL 708 FB is ground in a Pallmann disc mill PF 300. For the sieve analysis of the obtained ground material, measurements were taken and are listed in Table B-2. The bulk density of the ground material was measured to be 365 g/l. This ground material is used for compaction.

B) Preparation of mixtures for compaction

The sealing mixtures consisting of the polymer stabilizer and the processing aid are prepared by mixing the starting materials as shown in Table C-1 in a 100 L capacity MTI mixer for 5 minutes at room temperature.

D) Flakes by roller compaction

For example, D-1-1, the starting material SM-PS-1 (100%) is subjected to agglomeration by pressing by means of a roller compaction process to obtain flakes for comparison. SM-PS-1 in the form of powder in a feed hopper is forced into the compaction zone by a feed screw. The compaction zone is formed by the remaining gap between two rollers with slightly ribbed surfaces that rotate towards each other. The rollers are cooled with cold water in order to maintain a temperature close to room temperature. A suitable laboratory roller compactor is, for example, the model WP 50N/75 (roller diameter: 150 mm, roll length: 75 mm, maximum pressing power: 12.8 t, maximum linear load: 1.71 t/cm) from Alexanderwerk GmbH in Germany. The compacted raw material, which comes out of the compaction zone in the form of plates, is granulated by a sieve granulator with a sieve of 1.6 mm; for example, the model GLA-ORV-0215 from Frewitt Ltd in Switzerland is suitable, to create free-flowing flakes (= D-1-1 flakes). For D-1-1 flakes, the Norner abrasion test is carried out, and the result is shown in Table E-1.

E) Granules by compaction with a ring die pellet press

For the compaction tests of the materials as specified in Table E-1, a ring die pellet mill, namely the Muench Pelletizer RMP 250, is used. The Muench ring die pellet mill is shown, for example, in the article "Produktgestaltung liber mechanisches Agglomerieren von Pulvern", W. Raehse, Chemie Ingeneur Technik, 2015, 87, No. 7, 881-902 in Figure 18 on page 898. The Muench Pelletizer RMP 250 has a rotating ring die which is equipped with nozzles, for example nozzles with a nozzle diameter of 3 mm and a pressing length of 15 mm or 18 mm. The inner diameter of the ring die is 250 mm and its thickness is about 4 cm. A row with two or three nozzles is suitable for this thickness. The nozzles are expanded at an angle of 60° to the inside of the ring die. The nozzle diameter is defined in this case as the smallest diameter of the cylindrical bore of the nozzle, and the pressing length is the distance over which this smallest diameter is applied. The cylindrical bore of the nozzle may expand after the pressing length, but the expanded portion of the cylindrical bore does not contribute to the friction of the material to be compacted. In this case, the nozzle bores are not expanded. The specific nozzle diameter and pressing length used are shown in Table E-1. The material to be compacted is metered at room temperature by a volumetric single screw feeder, which is located above the pellet pressing section of the ring die pellet press, gravimetrically, into the pellet pressing section, which contains the die with its nozzles and two rollers. The rollers, each 96 mm in diameter and 30 mm thick, have a ribbed surface. In the granule pressing section, these two rollers push the material into the nozzles of a rotating ring die, where this material is compacted and heated by shear force to a temperature at which the technological additive begins to soften, and in the process of agglomeration, the compacted material is granulated into cylindrical granules. To start the process, the rotation of the ring die is set at a peripheral speed of about 4 m / s on the inner surface of the ring die, that is, at a distance of 12.5 cm from the axis of rotation of this ring die. The material for compaction is fed to the pressing section in the form of powder. An initial starting phase of about 15 minutes is necessary until stable operation of the process is achieved. At the same time that initially the powder of the material for compaction flows through the nozzles, this changes in the direction of the formation of a thread on some of the materials for compaction, and the ring die, rollers and nozzles reach a stable temperature. A temperature that would be too high for the compaction material would result in the formation of a pasty mass that blocks further feeding of the compaction material. At the outlet of the nozzle, the thread is cut/broken by two knives with an adjustable distance to the ring die into granules with a length of approximately 1 to 3 times the diameter of these granules, i.e. approximately 3 mm to 9 mm. Ideally, the length fluctuation should be minimal, but certain deviations cannot be avoided due to the cutting/breaking. Table E-1 indicates whether granules are produced and thus also whether a thread is formed. Once the process has stabilized, the temperature of the material leaving the nozzles in the die is measured by a non-contact IR temperature sensor by measuring the emitted IR radiation and is indicated in Table E-1 as the thread surface temperature. Statistically, the emitted IR radiation of the outer surface of the ring is also taken into account. However, in a stable process, the ring die is heated to a temperature close to the surface temperature of the thread. The ring die itself is not heated (except for example E-1-4) or cooled, but is heated by the friction of the compaction material. The resulting granules are sieved through a 1.6 mm sieve (a laboratory vibrating sieve with a diameter of 200 mm) to separate fine fractions from the resulting granules. The amount of fine fractions removed by sieving in relation to the total amount of compaction material is shown in Table E-1. The removed fine fractions can be directly reused as a material to be compacted. The granules were cooled to room temperature. If granules are obtained, after sieving, the granules are subjected to a Norner abrasion test, and the results are presented in Table E-1. Other characteristics of the resulting granules are presented in Table E-2. Images of the granules obtained in Examples E-1-1 to E-1-8 are shown in Figs. 1 to 8.

From the results of table E-1:

Example D-1-1 shows that SM-PS-1 (Irgafos 168) can be cold pressed into flakes, but the flakes perform poorly in the Norner abrasion test;

Example E-1-4 shows that SM-PS-1 (Irgafos 168) without processing aid requires special preheating for pelletizing in a ring die pellet press / this leads to the conclusion that SM-PS-1 itself has too high a melting point and requires a processing aid as a binder to ensure the formation of stable pellets;

Example E-1-2 compared to Example E-1-3 shows that the longer matrix length as a result of greater friction leads to a higher process temperature, which, however, does not lead to a better abrasion test result in the Norner test;

Example E-1-3 compared to Example E-1-4 shows that SM-PA-1 (Licocene 1302) results in granules with a significantly better result in the Norner attrition test than without the processing aid;

Example E-1-2 compared with Example E-1-5 shows that SM-PA-1 (Licocene 1302) produces granules with a significantly better Norner attrition test result than SM-PA-2 (Petrolite EP-700), despite the fact that both processing aids are propylene-ethylene copolymer waxes;

Examples E-1-5 and E-1-8 show that the amount of fines that are formed in the process itself and removed by the 1.6 mm sieve is not a reliable indicator of a positive result in the Norner attrition test.

From the results of table E-2:

Example E-1-4 shows that SM-PS-1 without processing additive produces granules with only a low average mass;

Example E-1-7 shows that high average weight is not a reliable indicator of a positive Norner abrasion test result;

The resulting granules look quite similar in the pictures, except for the granules obtained in example E-1-4, and this is not a reliable indicator of a positive result in the Norner abrasion test.

Claims (39)

1. A method for producing granules in a pellet press, which includes a roller and a die with a nozzle, wherein this method includes the stages: (A) pressing the mixture to be compacted using a roller through a nozzle to form a thread and (B) grinding the said thread to obtain a granule, wherein the compaction mixture comprises (i) from 87 to 97% by weight of a polymer stabilizer, which is tris(2,4-di-tert-butylphenyl)phosphite, and (ii) from 3 to 13% by weight of a processing aid which is a copolymer of propylene and ethylene and which has a melting enthalpy below 100 J/g at 101.32 kPa, and the mass % are recalculated to the mass of the mixture for compaction. 2. The method according to claim 1, wherein the enthalpy of fusion is determined using differential scanning calorimetry in accordance with standard EN ISO 11357-3. 3. The method according to item 1, wherein the technological additive has an average molecular weight of greater than 10,000 Da and less than 40,000 Da. 4. The method according to claim 1, wherein the technological additive has a peak melting temperature above 50°C and below 85°C. 5. The method according to claim 4, wherein the peak melting temperature is determined using differential scanning calorimetry in accordance with standard EN ISO 11357-3. 6. The method according to claim 1, wherein the technological additive is a copolymer of propylene and ethylene, which is a wax. 7. The method according to claim 1, wherein the compaction mixture comprises (i) from 89 to 96% by weight of a polymer stabilizer, (ii) from 4 to 11% by weight of technological additive. 8. The method according to claim 1, wherein the thread has a surface temperature above 50°C and below 110°C. 9. The method according to claim 1, wherein this method includes the step (pre-A) feeding the compaction mixture into the pellet press, wherein the compaction mixture is in the form of powder, and this stage (pre-A) is carried out before stage (A). 10. The method according to claim 1, wherein the pellet press is a ring die pellet press, wherein the die has the geometric shape of a ring with an inner side and an outer side, and the nozzle is a passage from the inner side to the outer side, or the pellet press is a flat die pellet press, wherein the die has the geometric shape of a flat plate with an upper side and a lower side, and the nozzle is a passage from the upper side to the lower side. 11. The method according to claim 10, wherein in a pellet press with a ring die the ring rotates and the roller has an axis of rotation that is stationary, and in a pellet press with a flat die the die is stationary and the roller has an axis of rotation that rotates. 12. The method according to claim 1, wherein the nozzle has a nozzle diameter and a pressing length, and the ratio of the pressing length to the nozzle diameter is from 2 to 8. 13. The method according to item 1, wherein the surface of the roll is corrugated. 14. The method according to claim 1, wherein the pellet press is a pellet press with a ring die. 15. The method according to any one of claims 1 to 14, wherein the pellet press comprises two or more rollers and the die comprises two or more nozzles. 16. A granule for the production of a stabilized polymer, which contains (i) from 87 to 97% by weight of a polymer stabilizer, which is tris(2,4-di-tert-butylphenyl)phosphite, and (ii) from 3 to 13% by weight of a processing additive, which is a copolymer of propylene and ethylene having an enthalpy of melting below 100 J/g at 101.32 kPa, and the mass % are recalculated to the mass of the given granule. 17. A granule according to claim 16, which has the shape of a round rod, and this round rod has a circumference diameter that is from 2 to 4 mm. 18. A granule according to item 17, which has a length 1-3 times greater than the diameter of the circle. 19. Use of a granule as defined in one of paragraphs 16 to 18 as a polymer stabilizer for dust-free handling of its components in the production of a stabilized polymer, wherein the polymer is a polyolefin, polystyrene or a mixture thereof. 20. A method for producing a stabilized polymer, which comprises the steps of: (AP) dosing granules as defined in one of paragraphs 16-18 into a polymer to obtain a mixture of granules and polymer, (BP) exposure of a mixture of granules and polymer to temperatures in the range of 120 to 340°C with mechanical mixing to obtain a stabilized polymer, wherein the polymer is a polyolefin, polystyrene or a mixture thereof. 21. A sealing mixture which contains (i) from 87 to 97% by weight of a polymer stabilizer in the physical form of a powder, which is tris(2,4-di-tert-butylphenyl)phosphite, and (ii) from 3 to 13% by weight of a processing additive in the physical form of a powder, which is a copolymer of propylene and ethylene having an enthalpy of melting below 100 J/g at 101.32 kPa, and the mass % are recalculated to the mass of the mixture for compaction.