Non-Dust Blend

Abstract

The present invention relates to non-dusting blends containing tris(2-t-butylphenyl) phosphite.

Description

[Technical Field]

[0001] The present invention relates to non-dust blends (NDBs) containing phosphite antioxidants. More specifically, the present invention relates to non-dust blends containing tris(2-t-butylphenyl) phosphite. The non-dust blends of the present invention are used to stabilize polymers. [Background technology]

[0002] Phosphite antioxidants are used as processing stabilizers in polymers in several applications where the phosphites and related decomposition products can be extracted and lead to human exposure, for example, in food packaging and drinking water pipes.

[0003] In recent years, regulatory agencies have focused on degradation products, often referred to as non-intentionally added substances (NIAS). Because phosphites are hydrolytically unstable (even hydrolysis-resistant phosphites), they undergo some degree of hydrolysis, forming their respective alkylated phenolic components as degradation products. These components are also oxidized to phosphates during antioxidant protection. Concerns have been raised about the alkylated phenolic components in particular, and several of these substances are currently included on the EU's list of substances of very high concern or are under scrutiny through the EU's Community Rolling Action Plan (CoRAP). All of the substances under review that have raised concerns about them share one commonality: they are all substituted at the para position of the phenolic ring.

[0004] In vitro assays published in 1997 by Sumpter et al (EJ Routledge, JP Sumpter, J. Biol. Chem. 1997, 272, 3280-3288) clearly demonstrated that para-substituted alkylphenols exhibited estrogenic (endocrine disrupting) effects in the assay, whereas the corresponding ortho- and meta-substituted species did not. The most common phosphite antioxidants on the market today are derived from phenols with at least one substituent at the para position of the phenol ring, opening the door to future regulatory action on the resulting degradation products.

[0005] Suitable replacements for para-substituted alkaryl phosphites, preferably replacements with improved performance, would be desirable. Tris(2-t-butylphenyl)phosphite (TOTBP) (CAS 31502-36-0) has been identified by the present inventors as such an improved replacement.

[0006] TOTBP has a higher phosphorus content (6.5%) per gram of material than tris(2,4-t-butylphenyl) phosphite (4.8%), a commercially available para-substituted alkaryl phosphite sold by SI Group under the trade name ALKANOX™ 240. As a result, it can, in principle, be used at lower loadings (up to about 25% lower) than commercially available materials with comparable antioxidant efficacy. Alternatively, when used at comparable loadings, TOTBP may provide superior polymer protection.

[0007] 2-t-Butylphenol (2TBP, the precursor to TOTBP) does not have the same endocrine disrupting concerns as para-substituted butylphenols and is considered a safer material to use. Summary of the Invention

[0008] TOTBP is disclosed in the art in the following terms:

[0009] European Patent No. 0026893 (counterpart: German Patent No. 2490548) discloses a method for preparing crystalline TOTBP by treating 2-t-butylphenol with phosphorus trichloride (PCl3), followed by degassing and distillation to remove excess phenol, and finally crystallization and recrystallization from liquid alcohol to obtain colorless crystals (melting point 72°C).

[0010] British Patent No. 2227490 discloses the preparation of a number of phosphite additives, including TOTBP, by treatment with 2-t-butylphenol (PCl3) in the presence of aluminum trichloride with vigorous stirring at 72-74°C for 6 hours, followed by distillation to remove excess PCl3 and purification to give a transparent yellow product that reportedly solidifies at room temperature to give a glass-like solid product.

[0011] EP 0211663 discloses stabilized polyolefin resin compositions containing a phenolic compound and a phosphite compound, which may be TOTBP. Many other phosphites are disclosed, and the use of TOTBP is not exemplified.

[0012] EP 281189 and U.S. Pat. No. 4,957,956 relate to solid stabilizer compositions for synthetic polymers, their preparation methods, and their use in stabilizing synthetic polymers. Many phosphites are listed, including TOTBP and A240. EP 278579 constitutes a similar disclosure.

[0013] EP 1151034 and U.S. Patent Application Publication No. 2005 / 0113494, as well as EP 1885787 and U.S. Patent No. 7135511, disclose the use of polyolefins in combination with aryl alkyl phosphites and additional additives such as triaryl phosphites and hindered phenols. TOTBP is often cited as a suitable triaryl phosphite.

[0014] EP 2459575, U.S. Patent Application Publication No. 2003 / 0158306, and U.S. Patent No. 7,135,511 disclose liquid phosphite compositions in combination with ethanolamine-based amines of various structures. The phosphite component includes at least two phosphites, one of which may be TOTBP.

[0015] US Pat. No. 4,187,212 and US Pat. No. 4,290,941 refer to TOTBP among many other phosphites in combination with hindered phenols in polyethylene (PP) or polypropylene (PE).

[0016] U.S. Patent No. 4,348,308 discloses the use of stabilizer compositions containing phosphites in PVC. While the embodiments mentioned include TOTBP, many of the compounds disclosed are 2-tert-butylphenyl compounds with a para(4-)tert-butyl group.

[0017] U.S. Pat. No. 4,360,617 discloses TOTBP suitable for combination with phenolic components to stabilize various polymers other than PE and PP, but the disclosure emphasizes phosphites with 4-position substituents.

[0018] U.S. Patent No. 4,829,112 discloses the use of a hindered phenol derived from the reaction of a dihydric alcohol with PP-BASE and a phosphite. TOTBP is specifically claimed as the preferred phosphite.

[0019] US Patent No. 5,487,856 discloses the use of TOTBP in forming spinnable polyamide blends by melt mixing a fiber-forming polyamide in addition to an end-group-enhancing amine / alcohol and water or mixtures thereof.

[0020] No. 8,048,946 discloses a composition comprising a mixture of a phosphite and an alkanolamine that is liquid at room temperature. TOTBP is listed in the group of optional phosphites.

[0021] US Pat. No. 8,258,214 discloses a PE film stabilized with a mixture of two phosphites, either one of which can be TOTBP.

[0022] U.S. Patent No. 4,282,141 discloses the use of a PVC additive composition containing a diketone metal salt together with an organic phosphite. TOTBP is included in the general description of what the phosphite can be. The general formula is included in the claims, but not specifically TOTBP.

[0023] British Patent No. 2227490 discloses stabilizers for polymeric substrates having a general formula including TOTBP.

[0024] No. 6,051,671 relates to a stabilization package containing fillers, heat stabilizers, light stabilizers, pigments, colorants, and nucleating agents. The secondary antioxidants are generally organic phosphites, including triaryl phosphites, of which TOTBP is an example.

[0025] EP 254348 discloses a process for producing heat-stabilized α-olefin polymers or copolymers, which comprises carrying out the polymerization in the presence of an antioxidant selected from organic phosphites, diphosphites, phosphonites, and diphosphonites, including aryl phosphites having the general formula, including TOTBP, as specifically recited in the claims.

[0026] British Patent No. 2156360 discloses a transparent, radiation-stable polypropylene resin composition comprising a) a polypropylene resin, b) a sorbitol derivative, c) a specific phosphite compound, and d) a polyamine compound, wherein the phosphite compound c) can be TOTBP.

[0027] U.S. Pat. No. 7,468,410 discloses a method for stabilizing polyolefins comprising incorporating or applying to the polyolefin an effective stabilizing amount of a mixture of at least two different tris-(mono-alkyl)phenyl phosphite esters of the formula including TOTBP.

[0028] U.S. Pat. No. 3,644,536 describes a method for producing 1,3,5-tris(α-hydroxyisopropyl)benzene, which comprises using a catalytic amount of nickel tetracarbonyl and a compound having the structure (R n The method includes heating in an inert organic solvent, methylbutynol, at a temperature of 40°C to 120°C in the presence of an ortho-substituted aryl phosphite, ArO)P, where Ar is an aryl radical selected from the group consisting of phenyl and naphthyl, R is an alkyl, cycloalkyl, or phenyl having 1 to 6 carbon atoms, n is an integer from 0 to 6, and the second ortho position of the aryl radical is not substituted with oxygen.

[0029] U.S. Pat. No. 6,444,836 describes a method for producing an organic phosphite having a purity of at least 95.5% by weight, which comprises reacting a hydroxyl-containing compound with a phosphorus compound and desorbing the residual hydroxyl-containing compound in the reaction product in a desorption column using an inert gas as the desorbent.

[0030] Although TOTBP has been widely disclosed in the art as a polymer stabilizer, it will be found consistently associated with many other diverse phosphites, often including para-substituted alkaryl phosphites. It has never been recognized in the art as being more or less suitable for antioxidant purposes than any of the many commonly disclosed organic phosphites. Its melting point is relatively low (72°C), making it difficult to handle. It is prepared, like other organic phosphites, by combining an alkylated phenol starting material with phosphorus trichloride, specifically by adding phosphorus trichloride to the alkylated phenol starting material. Reactions that typically result in some undesirable dealkylation, etc., have therefore not been widely studied for various reasons.

[0031] Another consideration is the form in which the phosphite antioxidant is provided.

[0032] Antioxidant additives, including phosphite antioxidants, are often provided in powder form. However, there are some disadvantages associated with the use of antioxidant additives in powder form, particularly the formation of dust. Dust particles can pose serious environmental health and safety issues, such as the risk of inhaling dust particles, which can be harmful to health, and the risk of explosion due to fine dust particles in the air.

[0033] Low dust content blends are known in the art.

[0034] EP 0719824 describes low-dust granules of plastic additives containing at least 10% by weight of calcium stearate, wherein the moisture content of the calcium stearate is less than 2%, the particle size distribution according to ISO 3435 is 1 mm to 10 mm, the loose bulk density is more than 400 g / L, and the flowability according to DIN 53492 is less than 15 s (tR25).

[0035] WO 01 / 70869 describes a composition consisting essentially of dry granules of an unmelted additive system comprising at least one sterically hindered phenol, said dry granules having cohesive properties and balanced hardness.

[0036] U.S. Patent Application Publication No. 2015 / 122151 describes a method for producing dust-free 100% additive blend pellets using melt extrusion, the method including blending two or more additives to form an additive blend, feeding the additive blend into an extruder feed hopper of an extruder having controlled temperature zones, controlling the temperature zones of the extruder so that at least one additive is melted, extruding the homogenous mixture of additives from the extruder at high throughput and passing through a die to form partially or fully molten strands, and following cooling, cutting the homogenous strands of the additive blend into substantially dust-free solid pellets.

[0037] U.S. Patent Application Publication No. 2002 / 117651 describes a compacted particulate polymer additive composition in dry granular form formed from the following components: (a) at least one particulate organic phosphite, organic phosphonite, and / or organic phosphonate, and (b) one or more particulate polymer additives other than one of the components in (a), wherein the particles of the composition are held together in compacted, dry granular form by contacting only or substantially only with dry surfaces of particles in situ desolvated from particles of one or more at least partially solvated components of (a), and optionally with dry surfaces of particles in situ desolvated from particles of one or more at least partially solvated components of (b).

[0038] French Patent No. 2647800 describes tris(2,4-di-tert-butylphenyl)phosphite, which is characterized in that it is coated with 2% to 20% by weight of a polyolefin wax or a paraffin hydrocarbon wax.

[0039] However, none of these documents describe the use of TOTBP in blends.

[0040] Thus, the present invention relates to the selection of TOTBP as a particularly suitable and improved alternative to para-substituted alkaryl phosphites and the provision of TOTBP in non-dust blends. The inventors of the present invention have also discovered a synergistic effect between TOTBP and certain other additives (such as other antioxidants) in non-dust blends. DETAILED DESCRIPTION OF THE INVENTION

[0041] According to one aspect of the present invention, there is provided a non-dusting blend comprising tris(2-t-butylphenyl) phosphite.

[0042] In this context, the term "non-dusty blend" means substantially dust-free granules.

[0043] For the avoidance of doubt, the term "granules" includes pellets, chips, flakes, tablets, lozenges, pieces, particles and the like.

[0044] "Dust" in this context means material that passes through a sieve with 0.5 mm openings.

[0045] By "substantially dust-free" is meant that there is little or no dust in the granules. For example, the amount of dust can be less than 15%, less than 10%, less than 5%, less than 1%, less than 0.5%, or less than 0.1% by weight of the granules.

[0046] Preferably, the amount of dust in the non-dust blend is less than about 1%, less than about 0.5%, or less than about 0.1% by weight of the non-dust blend.

[0047] The low level of dust in the non-dusting blends is advantageous for a number of reasons, including reducing the risk of inhalation of dust particles by personnel and reducing the risk of explosion due to fine dust particles in the air. Additionally, it reduces physical loss of additives in the form of dust, reducing agglomeration and clogging of machinery.

[0048] The non-dusting blend may be free of tris(2,4-di-t-butylphenyl) phosphite.

[0049] The non-dusting blend may be free of aryl phosphites having a t-butyl group para to the phosphite group.

[0050] The non-dust blend may be free of aryl phosphites having an alkyl group para to the phosphite group.

[0051] In this context, "absent of" means present, if at all, only at a de minimis level.

[0052] By "de minimis" it is meant below the level at which the absent compound would be considered to contribute significantly to the phosphorus loading of the non-dust blend.

[0053] By "below a level that would be considered a significant contribution to the phosphorus loading" is meant a contribution of less than 20% by weight, less than 10% by weight, less than 5% by weight, less than 2% by weight, less than 1% by weight, or about 0% by weight or 0% of the total phosphorus present in the non-dust blend.

[0054] The absence of any aryl phosphites having an alkyl group in the para position relative to the phosphite group can be advantageous for the non-dusting blends of the present invention because such phosphites, upon hydrolysis, form the respective alkylated phenols as degradation products. Concerns have been raised regarding many of these alkylated phenols substituted at the para position of the phenol ring, and some are currently included on the EU list of substances of very high concern.

[0055] Not only do we seek to avoid the presence of aryl phosphites having an alkyl group para to the phosphite group, but it can also be advantageous for the non-dust blend to be free of de-alkylated, and in particular de-butylated, aryl phosphites, due to the risk of producing undesirable phenol as a by-product during use of the non-dust blend.

[0056] As a result, the non-dusting blend may be completely free of di(2-t-butylphenyl) monophenyl phosphite.

[0057] Di(2-t-butylphenyl)monophenylphosphite can be generated by debutylation in the preparation of TOTBP, resulting in the production of undesirable phenol (as well as the t-butyl chloride by-product). Phenol subsequently reacts with PCl3 and 2TBP to produce di(2-t-butylphenyl)monophenylphosphite as a reaction by-product.

[0058] In conventional methods for forming TOTBP, phosphorus trihalide is added to 2-t-butylphenol in what is considered a "standard addition." However, surprisingly, the present inventors have discovered that by adding 2-t-butylphenol to phosphorus trihalide in a "reverse addition," the amount of debutylation is dramatically reduced and a high purity TOTBP product is obtained. The addition of 2-t-butylphenol to phosphorus trihalide has not previously been considered, likely due to safety concerns and the complexity of such an addition.

[0059] Thus, the non-dusting blend may comprise tris(2-t-butylphenyl) phosphite which may be obtained or is obtained by adding 2-t-butylphenol to a phosphorus trihalide.

[0060] The phosphorus trihalide can be phosphorus trichloride (PCl3).

[0061] The 2-t-butylphenol may be added to the phosphorus trihalide by subsurface addition. Subsurface addition is used as a means to ensure that the 2-t-butylphenol is uniformly distributed within the phosphorus trihalide as the addition proceeds. This method of addition advantageously prevents the undesired debutylation of 2-t-butylphenol to phenol, thereby preventing the loss of t-butyl chloride to the atmosphere.

[0062] The addition of 2-t-butylphenol to the phosphorus trihalide can be carried out stepwise or continuously, such that 2-t-butylphenol is gradually added to the bulk of the phosphorus trihalide.

[0063] The reaction temperature during the addition of 2-t-butylphenol to the phosphorus trihalide can be maintained at 150°C or less, 125°C or less, 100°C or less, or 75°C or less for at least a portion of the time required to add 2-t-butylphenol to the phosphorus trihalide.

[0064] The term "at least a portion of the time required" can mean at least 10%, at least 25%, or at least 50% of the time required for the 2-t-butylphenol to be added to the phosphorus trihalide.

[0065] The reaction temperature during the addition of 2-t-butylphenol to the phosphorus trihalide can be maintained at 150° C. or less, 125° C. or less, 100° C. or less, or 75° C. or less during part or all, preferably all, of the initial stage of the addition of 2-t-butylphenol to the phosphorus trihalide. The term "initial stage" can refer to the first 10%, the first 25%, or the first 50% of the time required for the 2-t-butylphenol to be added to the phosphorus trihalide.

[0066] The addition of 2-t-butylphenol to the phosphorus trihalide may be carried out in the presence of a catalyst.

[0067] The addition of 2-t-butylphenol to the phosphorus trihalide can be carried out in the presence of a catalyst having the formula NRRR, where R is hydrogen (H) or an optionally substituted hydrocarbyl group, and R and R, which may be the same or different, are both optionally substituted hydrocarbyl groups having a carbon chain length of >1, >2, >3, >4, >5, >6, >7, or 8. The hydrocarbyl groups (each, either, or all) can be alkyl groups. The catalyst can be N,N-dioctylamine.

[0068] Additionally or alternatively, the addition of 2-t-butylphenol to the phosphorus trihalide may be carried out in a catalyst having a cation and an anion, the cation being of the formula N + The reaction may be carried out in the presence of a catalyst having R1R2R3R4, where R1-R4, which may be the same or different, are both optionally substituted hydrocarbyl groups having >1, >2, >3, or >4 carbon atoms. The hydrocarbyl groups (each, either, or all) may be alkyl groups. The catalyst may be tetrabutylammonium chloride.

[0069] The present inventors have surprisingly found that the addition of 2-t-butylphenol to phosphorus trihalide in the presence of a catalyst provides a high yield and purity of the TOTBP product.

[0070] After adding 2-t-butylphenol to phosphorus trihalide, the tris(2-t-butylphenyl) phosphite product can be obtained from single crystallization.

[0071] Crystallization may be carried out using alcohol and / or ketone solvents.

[0072] The alcohol solvent may be isopropanol.

[0073] The ketone solvent may be methyl ethyl ketone.

[0074] Advantageously, the present inventors have discovered that a high purity TOTBP product, which may be free of di(2-t-butylphenyl) monophenyl phosphite, can be obtained from a single crystallization, and unlike many of the prior art processes, no recrystallization is required.

[0075] The tris(2-t-butylphenyl)phosphite can be substantially pure.

[0076] By "substantially pure" it is meant that the tris(2-t-butylphenyl)phosphite has a purity of at least about 98%, at least about 98.5%, at least about 99%, or at least 99.5%.

[0077] Substantially pure tris(2-t-butylphenyl) phosphite can be produced by a single chemical reaction followed by a single crystallization.

[0078] Here, the single chemical reaction involves adding 2-t-butylphenol to phosphorus trihalide in the manner previously described.

[0079] As outlined above, the present inventors have surprisingly found that a highly pure TOTBP product can be obtained with just a single crystallization. Prior art processes, such as those in German Patent No. 2,490,548, have tended to require crystallization followed by recrystallization. Even with multiple crystallization steps, prior art TOTBP products have not achieved the purity or yield realized by the present invention.

[0080] The non-dusting blend may additionally include one or more of the following: i. Phenolic antioxidants; ii. sulfur-containing antioxidants; iii. Amine antioxidants; iv.UV stabilizers; v. Metal carboxylates; vi. Clarifying and / or nucleating agents; vii. secondary inorganic antioxidants or reducing agents; and / or viii. Inorganic acid scavengers.

[0081] Overall, the non-dust blends of the present invention significantly improve the heat aging properties of various polymers, especially with respect to color stability, even during prolonged or repeated heat exposure. Additionally, the non-dust blends of the present invention have been found to improve the retention of melt flow properties and viscosity of various polymers, even during prolonged or repeated heat exposure. These effects are most pronounced when the non-dust blends further comprise one or more of the components i-viii listed above.

[0082] The presence of one or more of components i-viii may produce a synergistic effect with respect to the color stability of various polymers. More specifically, such combinations in the non-dust blends may significantly reduce color development.

[0083] Preferably, the non-dusting blend comprises a phenolic antioxidant and one or more of components ii-viii.

[0084] As a specific example, the non-dusting blend may include TOTBP, a phenolic antioxidant, and an inorganic acid scavenger.

[0085] As a further example, the non-dusting blend may include TOTBP, a phenolic antioxidant, and a metal carboxylate.

[0086] When present, the phenolic antioxidant may comprise one or more of a fully hindered phenolic antioxidant, a partially hindered phenolic antioxidant, a weakly hindered phenolic antioxidant, and / or a non-hindered phenolic antioxidant.

[0087] In this context, "fully hindered" preferably means that the phenolic antioxidant contains substituent hydrocarbyl groups in both positions ortho to the phenolic -OH group, and each of these substituents is branched at the C1 and / or C2 positions relative to the aromatic ring, preferably at the C1 position.

[0088] The fully hindered phenolic antioxidants, when present, are selected from the group consisting of tetrakismethylene(3,5-di-t-butyl-4-hydroxyhydrocinnamate)methane (ANOX™ 20-CAS 6683-19-8), 2,2'thiodiethylenebis[3(3,5-di-t-butyl-4-hydroxyphenyl)propionate] (ANOX™ 70-CAS 41484-35-9), octadecyl 3-(3',5'-di-t-butyl-4'-hydroxyphenyl)propionate (ANOX™ PP18-CAS 2082-79-3), 1,3,5-tris(3,5-di-t-butyl-4-hydroxybenzyl)isocyanurate (ANOX™ IC14-CAS 27676-62-6), 1,3,5-trimethyl-2,4, 6-tris(3,5-di-t-butyl-4-hydroxybenzyl)benzene (ANOX™ 330 - CAS 1709-70-2), N,N'-hexamethylenebis[3-(3,5-di-t-butyl-4-hydroxyphenyl)propionamide] (LOWINOX™ HD98 - CAS 23128-74-7), 1,2-bis(3,5-di-t-butyl-4-hydroxyhydrocinnamoyl)hydrazine (LOWINOX™ MD24 - CAS 32687-78-8), 2,2'-ethylidenebis[4,6-di-t-butylphenol] (ANOX™ 29 - CAS 35958-30-6), butylated hydroxytoluene (BHT - CAS 128-37-0), and / or compatible mixtures of two or more thereof.

[0089] In this context, "partially hindered" preferably means that the phenolic antioxidant comprises at least one substituted hydrocarbyl group ortho to the phenolic -OH group, and only one or each of these substituents is branched at the C1 and / or C2 position relative to the aromatic ring, preferably at the C1 position.

[0090] The partially hindered phenolic antioxidant, when present, is 1,3,5-tris(4-tert-butyl-3-hydroxy-2,6-dimethylbenzyl)-1,3,5-triazine-2,4,6-(1H,3H, 5H)-trione (LOWINOX™ 1790 - CAS 40601-76-1), triethylene glycol-bis-[3-(3-t-butyl-4-hydroxy-5-methylphenyl)propionate] (LOWINOX™ GP45 - CAS 36443-68-2), butylated reaction products of p-cresol and dicyclopentadiene (LOWINOX™ CPL - CAS 68610-51-5), 2,2'-methylenebis(6-t-butyl-4-methylphenol) (LOWINOX™ 22M46 - CAS 119-47-1), ethylene bis[3,3-bis[3-(1,1-dimethylethyl)-4-hydroxyphenyl]butanoate] (CAS 32509-66-3), and / or compatible mixtures of two or more thereof.

[0091] In this context, "low hindered" preferably means that the phenolic antioxidant contains at least one substituted hydrocarbyl group ortho to the phenolic -OH group, and none of these substituents is branched at the C1 or C2 position relative to the aromatic ring, preferably at the C1 position.

[0092] In this context, "unhindered" preferably means that the phenolic antioxidant does not contain a substituted hydrocarbyl group ortho to the phenolic --OH group.

[0093] It is preferred that the non-dusting blend include a phenolic antioxidant, as the combination of phenolic antioxidant and TOTBP provides good stability for a range of polymers.

[0094] Particularly preferred phenolic antioxidants are tetrakismethylene(3,5-di-t-butyl-4-hydroxyhydrocinnamate)methane (ANOX™ 20 - CAS 6683-19-8) and / or octadecyl 3-(3',5'-di-t-butyl-4'-hydroxyphenyl)propionate (ANOX™ PP18 - CAS 2082-79-3).

[0095] Liquid phenolic antioxidants may be tolerated in small amounts (eg, less than 5% by weight, or less than 2% by weight of the total weight of the non-dust blend) as long as they do not affect the formation of the non-dust blend. Such liquid phenolic antioxidants, when present, may include C13-C15 linear and branched alkyl esters of 3-(3',5'-di-t-butyl-4'-hydroxyphenyl)propionic acid (ANOX™ 1315 - CAS 171090-93-0), C9-C11 linear and branched alkyl esters of 3-(3',5'-di-t-butyl-4'-hydroxyphenyl)propionic acid (NAUGARD PS48™ - CAS 125643-61-0), tocopherol and tocopherol derivatives, and tocotrienol and tocotrienol derivatives (vitamin E, e.g., DL α-tocopherol - CAS 10191-41-0), and / or compatible mixtures of two or more thereof.

[0096] When present, the phenolic antioxidant may be present in the non-dust blend in an amount of from about 1% to about 80% by weight, from about 10% to about 70% by weight, from about 20% to about 60% by weight, or from about 30% to about 50% by weight, based on the total weight of the non-dust blend.

[0097] The non-dust blend may further comprise an additional organic phosphite antioxidant, which, when present, may include any organic phosphite antioxidant other than TOTBP, such as distearyl pentaerythritol diphosphite (WESTON™ 618-CAS 3806-34-6), 3,9-bis(2,6-di-tert-butyl-4-methylphenoxy)-2,4,8,10-tetraoxa-3,9-diphosphaspiro[5.5]undecane (CAS 80693-00-1), bis(2,4-dicumylphenyl)pentaerythritol diphosphite (CAS 154862-43-8), and / or compatible mixtures of two or more thereof.

[0098] Liquid organic phosphite antioxidants may be tolerated in small amounts (e.g., less than 5% by weight, or less than 2% by weight of the total weight of the non-dust blend) as long as they do not affect the formation of the non-dust blend. Such liquid organic phosphite antioxidants, when present, may be tris(dipropylene glycol) phosphite:C 18 H 39 O9P (WESTON™ 430-CAS 36788-39-3), poly(dipropylene glycol) phenyl phosphite (WESTON™ DHOP-CAS 80584-86-7), diphenyl isodecyl phosphite:C 22 H 31 It may include O3P (WESTON™ DPDP-CAS 26544-23-0), phenyl diisodecyl phosphite (WESTON™ PDDP-CAS 25550-98-5), heptakis(dipropylene glycol) triphosphite (WESTON™ PTP-CAS 13474-96-9), and / or compatible mixtures of two or more thereof.

[0099] Preferably, the following organic phosphite antioxidants are excluded from possible additional organic phosphite antioxidants in the non-dust blend: a. tris(2,4-di-t-butylphenyl) phosphite and / or b. Any aryl phosphite having a t-butyl group para to the phosphite group.

[0100] The organophosphite antioxidant (comprising or consisting of TOTBP) may be present in the non-dust blend in an amount of from about 10% to about 100% by weight, from about 20% to about 80% by weight, or from about 30% to about 60% by weight, based on the total weight of the non-dust blend.

[0101] The sulfur-containing antioxidant, when present, has the formula —CH—(S) x It may have sulfur groups of -CH2-, where x=1 or 2, and optionally, none of the -CH2- groups are directly attached to an aromatic.

[0102] Such stabilizing components may have greater stabilizing effectiveness compared to stabilized antioxidant compositions that include sulfur-containing antioxidants in which one or both of the —CH— groups are directly bonded to an aromatic group, or one or both of the sulfur atoms are directly bonded to an aromatic group, such as 2,4-bis-(n-octylthio)-6-(4-hydroxy-3,5-di-tert-butylanilino)-1,3,5-triazine (CAS 991-84-4).

[0103] The sulfur-containing antioxidant, when present, has the formula R—CH—(S) x It may have the formula -CH2-R, where x=1 or 2, and each R group, which may be the same or different, is independently an aliphatic group or contains an aliphatic group, and when more than one such aliphatic group is present in either or each R group, the aliphatic groups may be the same or different.

[0104] Each or any of the aliphatic groups may be straight or branched chain and may be substituted with one or more functional groups.

[0105] The sulfur-containing antioxidant may contain one or more thioether groups and one or more ester groups.

[0106] The sulfur-containing antioxidant, when present, may include dilauryl-3,3'-thiodipropionate (NAUGARD™ DLTDP-CAS 123-28-4), distearyl-3,3'-thiodipropionate (NAUGARD™ DSTDP-CAS 693-36-7), pentaerythritol tetrakis(β-laurylthiopropionate) (NAUGARD™ 412S-CAS 29598-76-3), 2,2'-thiodiethylenebis[3(3,5-di-t-butyl-4-hydroxyphenyl)propionate] (ANOX™ 70-CAS 41484-35-9), dimyristyl thiodipropionate (CAS 16545-54-3), distearyl disulfide (CAS 2500-88-1), and / or compatible mixtures of two or more thereof.

[0107] Additionally or alternatively, the sulfur-containing antioxidant may include one or more diphenyl thioethers, such as 4,4'-thiobis(2-tert-butyl-5-methylphenol) (LOWINOX™ TBM-6-CAS96-69-5) and / or 2,2'-thiobis(6-t-butyl-4-methylphenol) (LOWINOX™ TBP-6-CAS90-66-4).

[0108] Liquid sulfur-containing antioxidants may be tolerated in small amounts (eg, less than 5% by weight, or less than 2% by weight of the total weight of the non-dust blend) as long as they do not affect the formation of the non-dust blend.

[0109] Such liquid sulfur-containing antioxidants, when present, may include ditridecylthiodipropionate (NAUGARD™ DTDTDP (Liquid) - CAS 10595-72-9).

[0110] When present, the sulfur-containing antioxidant may be present in the non-dust blend in an amount of from about 1% to about 50% by weight, from about 1% to about 40% by weight, from about 1% to about 30% by weight, from about 1% to about 20% by weight, or from about 5% to about 15% by weight, based on the total weight of the non-dust blend.

[0111] The amine antioxidant, when present, may be, for example, acetone diphenylamine (AMINOX™ - CAS 68412-48-6), reaction product of diphenylamine and acetone (BLE™ - CAS 112-39-4), N,N'-diphenyl-p-phenylenediamine (FLEXAMINE™ - CAS 74-31-7), benzamine, bis[4-(2-phenyl-2-propyl)phenyl]amine (NAUGARD™ 445 - CAS 10081-67-1), poly(1,2-dihydro-2,2,4-trimethylquinoline) (NAUGARD™ Q - CAS 26780-96-1), diphenylamine (DI ... diphenylamine (DIAMINOX™ - CAS 68412-48-6), reaction product of diphenylamine and acetone (BLE™ - CAS 112-39-4), diphenylamine (DIAMINOX™ - CAS 68412-48-6), diphenylamine (DIAMINOX™ - CAS 68412-48-6), reaction product of diphenylamine and acetone (BLE™ - CAS 112-39-4), diphenylamine (DIAMINOX™ N,N',N''-tris[4-[(1,4-dimethylpentyl)amino]phenyl]-1,3,5-triazine-2,4,6-triamine (DURAZONE™ 37 - CAS 121246-28-4), N-isopropyl-N'-phenyl-1,4-phenylenediamine (FLEXZONE™ 3C - CAS 101-72-4), and / or compatible mixtures of two or more thereof.

[0112] Liquid amine antioxidants may be tolerated in small amounts (e.g., less than 5% by weight, or less than 2% by weight of the total weight of the non-dust blend) so long as they do not affect the formation of the non-dust blend. If present, such liquid amine antioxidants may include the reaction product of N-phenyl- with 2,4,4-trimethylpentene (NAUGARD™ PS30 - CAS 68411-46-1), N,N-bis-(1,4-dimethylpentyl)-p-phenylenediamine (FLEXZONE™ 4L - CAS 3081-14-9), diphenylamine (CAS 122-39-4), (1,3-dimethylbutyl)-N'-phenyl-p-phenylenediamine (CAS 793-24-8), and / or compatible mixtures of two or more thereof.

[0113] When present, the amine antioxidant may be present in the non-dust blend in an amount of about 1% to about 50% by weight, about 1% to about 40% by weight, about 1% to about 30% by weight, about 1% to about 20% by weight, or about 5% to about 15% by weight, based on the total weight of the non-dust blend.

[0114] When present, the UV stabilizers may include hindered amine light stabilizers (HALS) and / or UV absorbers.

[0115] The UV stabilizers, when present, include butanedioic acid, 1,4-dimethyl ester, polymer with 4-hydroxy-2,2,6,6-tetramethyl-1-piperidineethanol (LOWILITE™ 62-CAS 65447-77-0), bis(2,2,6,6-tetramethyl-4-piperidyl) sebacate (LOWILITE™ 77-CAS 52829-07-9), poly[[6-[(1,1,3,3-tetramethylbutyl)amino]-1,3,5-triazine-2,4-diyl][2,2,6,6-tetramethyl-4 1,5,8,12-tetrakis[4,6-bis(N-butyl-N-1,2,2,6,6-pentamethyl-4-piperidylamino)-1,3,5-triazin-2-yl]-1,5,8,12-tetraazadodecane (LOWILITE™ 19-CAS 106990-43-6), and / or compatible mixtures of two or more thereof.

[0116] Liquid UV stabilizers may be tolerated in small amounts (e.g., less than 5% by weight, or less than 2% by weight of the total weight of the non-dust blend) as long as they do not affect the formation of the non-dust blend. If present, such liquid UV stabilizers may include bis(1,2,2,6,6-pentamethyl-4-piperidyl) sebacate (LOWILITE™ 92-CAS 41556-26-7).

[0117] When present, the UV stabilizer may be present in the non-dust blend in an amount of from about 1% to about 80% by weight, from about 10% to about 70% by weight, from about 20% to about 60% by weight, or from about 30% to about 50% by weight, based on the total weight of the non-dust blend.

[0118] When present, the metal carboxylate may comprise one or more of a metal stearate and / or a metal lactate. Preferably, the metal carboxylate comprises a metal stearate.

[0119] When present, the metallic stearates may include calcium stearate, zinc stearate, aluminum stearate, magnesium stearate, lithium stearate, sodium stearate, cadmium stearate, barium stearate, and / or mixtures of two or more thereof.

[0120] When present, the metal lactate may include sodium lactate, magnesium lactate, calcium lactate, zinc lactate, and / or mixtures of two or more thereof.

[0121] When present, the metal carboxylate may be present in the non-dust blend in an amount of from about 1% to about 50% by weight, from about 1% to about 40% by weight, from about 1% to about 30% by weight, or from about 5% to about 25% by weight, based on the total weight of the non-dust blend.

[0122] The clarifying and / or nucleating agent, if present, may comprise a metal benzoate and / or a sorbitol derivative. The metal benzoate, if present, may comprise sodium benzoate, magnesium benzoate, calcium benzoate, zinc benzoate, and / or a mixture of two or more thereof.

[0123] The clarifying and / or nucleating agent, when present, may include bis(3,4-dimethylbenzylidene)sorbitol (CAS 135861-56-2), bis(4-propylbenzylidene)sorbitol (CAS 882073-43-0), 2,4,8,10-tetra(tert-butyl)-6-hydroxy-12H-dibenzo[d,g][1,3,2]dioxaphosphocin 6-oxide, sodium salt (CAS 85209-91-2), and / or compatible mixtures of two or more thereof.

[0124] When present, the clarifying agent and / or nucleating agent may be present in the non-dust blend in an amount of from about 1% to about 50% by weight, from about 1% to about 40% by weight, from about 1% to about 30% by weight, or from about 5% to about 25% by weight, based on the total weight of the non-dust blend.

[0125] When present, the secondary inorganic antioxidant may comprise one or more of metal hypophosphites, metal thiosulfates, metal bisulfites, metal metabisulfites, and / or metal hydrosulfites.

[0126] The metal of the hypophosphite, thiosulfate, bisulfite, metabisulfite, and / or hydrosulfite may be an alkali metal and / or alkaline earth metal. The alkali metal may be selected from lithium (Li), sodium (Na), and potassium (K). The alkaline earth metal may be selected from calcium (Ca) and magnesium (Mg).

[0127] The metal hypophosphite may be selected from compounds having the formula: MPO2H2. The metal thiosulfate may be selected from compounds having the formula: M2S2O3. The metal bisulfite may be selected from compounds having the formula: MHSO3. The metal metabisulfite may be selected from compounds having the formula: M2S2O5. The metal hydrosulfite may be selected from compounds having the formula: M2S2O4. In each case, M is an alkali metal cation. The alkali metal cation may be selected from lithium (Li), sodium (Na), and potassium (K).

[0128] The metal hypophosphite may be in an anhydrous form, i.e., anhydrous metal hypophosphite. Alternatively, the metal hypophosphite may be in a hydrated form, i.e., a hydrated metal hypophosphite, for example, monohydrate metal hypophosphite. Similar to hypophosphites, thiosulfates, bisulfites, metabisulfites, and hydrosulfites may also be suitable for use in the present invention. All of these may be provided as metal salts, such as alkali metal salts. Similar to metal hypophosphites, these may be provided in an anhydrous form or as hydrates. Examples include thiosulfate pentahydrate and hydrosulfite dihydrate, and other suitable materials will be apparent to those skilled in the art.

[0129] When present, the secondary inorganic antioxidant may include sodium hypophosphite.

[0130] When present, the secondary inorganic antioxidant may be present in the non-dust blend in an amount of from about 1% to about 50% by weight, from about 1% to about 40% by weight, from about 1% to about 30% by weight, from about 1% to about 20% by weight, or from about 5% to about 15% by weight, based on the total weight of the non-dust blend.

[0131] When present, the inorganic acid scavenger may comprise one or more of a metal oxide, a metal hydroxide, a metal carbonate, a metal carboxylate, a metal salt, and / or a hydrotalcite-like compound, such as hydrotalcite.

[0132] When present, the inorganic acid scavenger may be present in the non-dust blend in an amount of from about 1% to about 50% by weight, from about 1% to about 40% by weight, from about 1% to about 30% by weight, from about 1% to about 20% by weight, or from about 5% to about 15% by weight, based on the total weight of the non-dust blend.

[0133] Additional antioxidants, such as hydroxylamine or its precursors, lactone radical scavengers, acrylate radical scavengers, and / or chelating agents may be included in the non-dusting blend.

[0134] According to another aspect of the present invention, there is provided a method for forming the above-described non-dusting blend, comprising the steps of: a. extruding or otherwise processing tris(2-t-butylphenyl) phosphite, optionally as part of a blend with one or more other additives, to provide a substrate; b. cooling the substrate; and c. Optionally, the method includes the step of fragmenting the cooled substrate.

[0135] If TOTBP is provided as part of a blend with one or more other additives, there may be an additional step before step a, which includes mixing the TOTBP with the one or more other additives to form a uniform blend. The mixing step can be carried out using any suitable equipment known in the art, such as, for example, a horizontal plow shear, a horizontal ribbon blender, a vertical cone blender, a high shear mixer, etc.

[0136] For the avoidance of doubt, when reference is made in the following paragraphs to TOTBP, this also covers blends of TOTBP with one or more other additives, unless otherwise specified.

[0137] The substrate may be, for example, an extrudate or a processable substrate formed by compression and / or partial or complete melting and / or kneading of TOTBP.

[0138] Extrusion or other processing of TOTBP can be carried out using an extruder, kneader, and / or other melting and mixing equipment. The extruder can be a screw extruder, such as a twin-screw extruder.

[0139] The extruder can include any number of heating zones, for example, from 1 to 10 heating zones.

[0140] The temperature of any or all of the heating zones may be from about 30° C. to about 250° C., for example, from about 40° C. to about 200° C. The temperature of the heating zones is determined by the screw profile, including, for example, the type, number, and position of elements, such as conveying and kneading elements. The temperature of the heating zones is also determined by the type of TOTBP / TOTBP blend being extruded.

[0141] The extruder may also include a die through which the TOTBP is extruded to form the substrate, or alternatively, the extruder may be operated with an open die.

[0142] The method may further include passing the substrate through a die face cutter to form granules of the substrate. This method step may occur between steps a and b.

[0143] The present inventors have surprisingly found that during the extrusion of TOTBP (or blends containing TOTBP), it is important to control the temperature profile of the heating zone before the die and the temperature profile of the die itself to produce a processable substrate, i.e., a high viscosity, non-sticky paste.

[0144] It has been found that in some cases, the melt temperature at the die should not deviate by more than ±5°C from the melt temperature of TOTBP (meaning, in this case, TOTBP itself, not a blend containing TOTBP). For example, this has been found to be the case when TOTBP is blended with the fully hindered phenolic antioxidant ANOX™ 20. This is surprising considering that a comparable formulation containing the phosphite antioxidant ALKANOX™ 240 and the fully hindered phenolic antioxidant ANOX™ 20 has a much wider operating window, where the melt temperature at the die can deviate by at least ±20°C and still produce a processable substrate. Therefore, the methods of the prior art cannot be used to extrude TOTBP (or blends containing TOTBP). The present invention overcomes the problem of how to extrude TOTBP (or blends containing TOTBP) to produce a processable substrate. This is achieved by controlling the temperature profile and screw speed.

[0145] In other instances where TOTBP is blended with a phenolic antioxidant that has a lower melting temperature than TOTBP, it may be preferred that the melting temperature at the die not deviate more than ±5°C from the melting temperature of the phenolic antioxidant.

[0146] Therefore, the melt temperature at the die may not deviate by more than ±5°C from the melt temperature of the TOTBP itself or the melt temperature of the phenolic antioxidant, if present, whichever is lower.

[0147] The rotation speed of the extruder screw can be any suitable speed for forming an extrudate, for example, from about 50 rpm to about 200 rpm, or from about 80 rpm to about 150 rpm.

[0148] Step b involves cooling the substrate from step a. This can be done by passing the substrate through one or more cooling drums, cooling belts, fluid vibration coolers, and / or other cooling devices. By the end of step b, the substrate has cooled to a plastic or solid state.

[0149] Step c, if present, comprises fragmenting the cooled substrate.

[0150] Fragmentation can be carried out using any suitable device. Fragmentation may be carried out using a single component or a combination of crushing devices.

[0151] Techniques by which fragmentation can be performed include: 1. Impact fragmentation, which can be impacted by an abrasive tool or other particles. Examples of suitable equipment include air conveyors or drum mills. 2. Shear fragmentation, where the force between two or more solid surfaces moving in opposite directions produces a shearing effect. There may be at least one fixed surface and at least one moving surface. Examples of suitable devices include hammer mills or centrifugal mills. 3. Cutting and fragmentation, involving forces between two or more surfaces. There may be at least one fixed cutting edge and at least one movable cutting edge. Examples of suitable devices include knife mills, shredders, or cutting mills. 4. Pressure fragmentation, where a force is applied between two solid surfaces. The solid surfaces may be the surface of a grinding tool or the surface of an adjacent particle. The pressure is applied by a grinding tool, which may be, for example, a jaw crusher.

[0152] As a non-limiting example, fragmentation may be performed using first and second counter-rotating rollers, optionally with one or both rollers having a profiled surface. The counter-rotation of the rollers forces the substrate between the two rollers and through the fragmentation pinch point.

[0153] The method may further comprise the step of removing dust by sieving. Sieves suitable for this purpose are well known in the art.

[0154] After sieving, the amount of dust in the non-dust blend may be less than about 1%, less than about 0.5%, or less than about 0.1% by weight of the non-dust blend.

[0155] Alternatively, the non-dusting blend may be prepared by a method of cold extrusion and compression.

[0156] Cold extrusion may be carried out using, for example, a KAHL™ mill or a California Pellet Mill (CPM™). Compaction may be carried out using, for example, a FITZPATRICK™ roller compactor.

[0157] The non-dusting blend formed from cold extrusion and compaction may be sieved to remove dust. Sieves suitable for this purpose are well known in the art.

[0158] After sieving, the amount of dust in the non-dust blend may be less than about 1%, less than about 0.5%, or less than about 0.1% by weight of the non-dust blend.

[0159] According to another aspect of the present invention, there is provided the use of the non-dusting blend as described above for stabilizing a polymer.

[0160] According to another aspect of the present invention, there is provided a stabilized polymer composition comprising a polymer and the non-dusting blend described above.

[0161] It should be understood that when the non-dust blend of the present invention is combined with a polymer to form a stabilized polymer composition, it does not necessarily have to retain its granular form. Rather, the components of the non-dust blend can be uniformly dispersed throughout the polymer.

[0162] The non-dusting blend may be present in an amount of about 0.01% to about 5% by weight, about 0.01% to about 2% by weight, or about 0.1% to about 1.5% by weight, based on the total weight of the stabilized polymer composition.

[0163] The polymer may include a polyolefin.

[0164] The polyolefin may include homopolymers of ethylene, propylene, butylene, or higher alkenes.

[0165] The ethylene homopolymer may include low density polyethylene (LDPE), linear low density polyethylene (LLDPE), and / or high density polyethylene (HDPE).

[0166] Ethylene homopolymers can be produced by high-pressure radical polymerization processes or by homogeneous or heterogeneous low-pressure processes. Such processes can be catalyzed by Ziegler-Natta catalysts, metallocene catalysts, single-site catalysts, chromium-based catalysts, and / or suitable combinations thereof. Ethylene homopolymers can be post-reactor modified and / or crosslinked.

[0167] The propylene homopolymer can be isotactic, syndiotactic, or atactic.

[0168] Propylene homopolymers can be produced by homogeneous or heterogeneous processes. Such processes can be catalyzed by Ziegler-Natta catalysts, metallocene catalysts, single-site catalysts, and / or suitable combinations thereof. Propylene homopolymers may be visbroken and / or post-reactor modified.

[0169] Additionally or alternatively, the polyolefin may comprise a copolymer of ethylene, propylene, butylene, isobutylene, hexene, octene, acrylic acid, vinyl acetate, ethyl acrylate, and / or carbon monoxide. The copolymer may be a random copolymer or a block copolymer. For example, the polyolefin may comprise an ethylene / propylene block copolymer, an ethylene / propylene random copolymer, an ethylene / propylene / butylene random terpolymer, or an ethylene / propylene / butylene block terpolymer.

[0170] The ethylene copolymer may include ultra-high molecular weight polyethylene (UHMWPE), HDPE, medium density polyethylene (MDPE), LLDPE, very low density polyethylene (VLDPE), very low density polyethylene (ULDPE), ethylene vinyl acetate (EVA), ethylene ethyl acrylate copolymer (EEA), ethylene acrylic acid copolymer (EAA), ethylene butyl acrylate copolymer (EBA), ethylene vinyl alcohol (EVOH), olefin block copolymer (OBC), ethylene carbon monoxide copolymer (E / CO), and / or ethylene containing plastomers and / or ionomers.

[0171] Ethylene copolymers can be produced by high-pressure radical polymerization processes or by homogeneous or heterogeneous low-pressure processes. Such processes can be catalyzed by Ziegler-Natta catalysts, metallocene catalysts, single-site catalysts, and / or suitable combinations thereof. Ethylene homopolymers can be post-reactor modified and / or crosslinked.

[0172] Propylene copolymers can be produced by homogeneous or heterogeneous processes. Such processes can be catalyzed by Ziegler-Natta catalysts, metallocene catalysts, single-site catalysts, and / or suitable combinations thereof. Propylene copolymers can also be visbroken and / or post-reactor modified.

[0173] Additionally or alternatively, the polymer may comprise an ethylene-propylene-diene monomer (EPDM) copolymer, for example, formed with ethylene, propylene, and diene comonomers such as ethylidene norbornene (ENB), dicyclopentadiene (DCPD), and vinyl norbornene (VNB), and / or suitable combinations thereof. The EPDM copolymer may be post-reactor modified and / or crosslinked.

[0174] Additionally or alternatively, the polymer may include homopolymers and / or copolymers of styrene, butadiene, isobutylene, isoprene, chloroprene, acrylonitrile, and / or copolymers thereof with ethylene, propylene, and / or butylene. For example, the polymer may include styrene butadiene rubber (SBR), butadiene rubber (BR), high styrene rubber (HSR), nitrile rubber (NBR), styrene butadiene styrene (SBS), styrene-isoprene-styrene (SIS), chloroprene rubber (CR), styrene-ethylene / butylene-styrene (SEBS), styrene-ethylene / propylene (SEP), high impact polystyrene (HIPS), acrylonitrile-butadiene-styrene (ABS), styrene-acrylonitrile (SAN), and / or suitable combinations thereof.

[0175] Polymers such as polyurethanes, polyamides, polyesters, polycarbonates, acrylics, polyvinyl chloride (PVC), and polymers of lactic acid may also be contemplated by the present invention.

[0176] The polymer may be in virgin form, industrial recycled form, post-consumer recycled form, and / or any suitable combination thereof.

[0177] The polymers may be based on monomers synthesized from petrochemicals or other fossil feedstocks. Additionally or alternatively, the polymers may be based on monomers synthesized from renewable industrial feedstocks, such as those derived from plants or animals, or chemically recycled monomers.

[0178] According to another aspect of the present invention, there are provided articles made from the aforementioned stabilized polymeric compositions.

[0179] Compounds designated by the trade names AMINOX™, ANOX™, BLE™, DURAZONE™, FLEXAMINE™, FLEXZONE™, LOWILITE™, LOWINOX™, NAUGARD™, NOVAZONE™, OCTAMINE™, and WESTON™ are available from SI Group USA (USAA) LLC, 4 Mountain View Terrace #200, Danbury, CT 06810, USA.

[0180] For the avoidance of doubt, all features relating to the non-dust blend also relate to the method of forming the non-dust blend, the use of the non-dust blend, and the stabilising polymer composition, where appropriate, and vice versa.

[0181] The present invention will now be more particularly described with reference to the following non-limiting examples. [Example]

[0182] Preparation of non-dusting blends containing TOTBP Example 1 Powder blends were prepared having the ingredients specified in Table 1. [Table 1]

[0183] 10 kg of the powder blend was charged to a BRABENDER™ FW40 Plus feeder. The powder blend was introduced into Zone 1 of a STEER™ MEGA 30 twin-screw extruder at a rate of 11 kg / hr. The powder blend was processed through the twin-screw extruder set at a screw speed of 130 rpm and the temperature conditions outlined in Table 2. [Table 2]

[0184] The extrudate was passed through a die with four 3 mm diameter holes arranged in a row. The extruded strand was cooled on a stainless steel belt, and the cooled strand was fragmented by pneumatic conveying. The resulting material was passed through two sieve towers (5 mm and 0.5 mm openings) to produce non-dust blend granules with pellets ranging from 5 mm to 0.5 mm.

[0185] Example 2 Powder blends were prepared having the ingredients specified in Table 3. [Table 3]

[0186] 10 kg of the powder blend was charged to a BRABENDER™ FW40 Plus feeder. The powder blend was introduced into Zone 1 of a STEER™ MEGA 30 twin-screw extruder at a rate of 11 kg / hr. The powder blend was processed through the twin-screw extruder set at a screw speed of 90 rpm and the temperature conditions outlined in Table 4. [Table 4]

[0187] The extrudate was passed through a die with four 3 mm diameter holes arranged in a row. The extruded strand was cooled on a stainless steel belt, and the cooled strand was fragmented by pneumatic conveying. The resulting material was passed through two sieve towers (5 mm and 0.5 mm openings) to produce non-dust blend granules with pellets ranging from 5 mm to 0.5 mm.

[0188] Example 3 Powder blends were prepared having the ingredients specified in Table 5. [Table 5]

[0189] 10 kg of the powder blend was charged to a BRABENDER™ FW40 Plus feeder. The powder blend was introduced into Zone 1 of a STEER™ MEGA 30 twin-screw extruder at a rate of 11 kg / hr. The powder blend was processed through the twin-screw extruder set at a screw speed of 110 rpm and the temperature conditions outlined in Table 6. [Table 6]

[0190] The extrudate was passed through a die with four 3 mm diameter holes arranged in a row. The extruded strand was cooled on a stainless steel belt, and the cooled strand was fragmented by pneumatic conveying. The resulting material was passed through two sieve towers (5 mm and 0.5 mm openings) to produce non-dust blend granules with pellets ranging from 5 mm to 0.5 mm.

[0191] Example 4 Example 4 is a prophetic example.

[0192] A powder blend is prepared having the ingredients specified in Table 7. [Table 7]

[0193] 10 kg of the powder blend is charged to a BRABENDER™ FW20 feeder. The powder mixture is introduced at a rate of 1-2 kg / hr into a California Pellet Mill (CPM™) CL3 laboratory mill equipped with a die (hole diameter = 3.2 mm, wall thickness = 25.4 mm, effective path length = 25.4 mm) with the cutting blade positioned 5 mm from the die. The mill is operated at pressure and roller speed sufficient to affect pelletization while maintaining the temperature of the discharged pellets below the melting point of TOTBP.

[0194] The resulting material is cooled and passed through two sieve towers (5 mm and 0.5 mm openings) to form non-dust blend granules with pellets in the range of 5 mm to 0.5 mm. The present invention includes the following aspects. <1> Non-dusting blend containing tris(2-t-butylphenyl) phosphite. <2> The amount of dust in the non-dust blend is less than about 1% by weight of the non-dust blend. <1> The non-dusting blend described in <3> The tris(2-t-butylphenyl)phosphite can be obtained or is obtained by adding 2-t-butylphenol to phosphorus trihalide; <1> or <2> The non-dusting blend described in <4> the 2-t-butylphenol is added to the phosphorus trihalide by subsurface addition; <3> The non-dusting blend described in <5> the addition of the 2-t-butylphenol to the phosphorus trihalide is carried out in the presence of a catalyst; <3> or <4> The non-dusting blend described in <6> The catalyst has the formula NR 1 R 2 R 3 and R 1 are hydrogen (H) or optionally substituted hydrocarbyl groups, and R may be the same or different. 2 and R 3 are both optionally substituted hydrocarbyl groups with a carbon chain length of more than 1 (>1), and / or The catalyst has a cation and an anion, the cation being of the formula N + R 1 R 2 R 3 R 4 R may be the same or different 1 ~R 4 are both optionally substituted hydrocarbyl groups containing more than one carbon atom (>1); <5> The non-dusting blend described in <7> the tris(2-t-butylphenyl)phosphite has a purity of at least about 98%, at least about 98.5%, at least about 99%, or at least 99.5%; <1> ~ <6> 10. The non-dusting blend according to any one of claims 1 to 9. <8> The non-dusting blend additionally comprises one or more of the following: <1> ~ <7> 1. The non-dusting blend of claim 1, i. Phenolic antioxidants; ii. sulfur-containing antioxidants; iii. Amine antioxidants; iv. UV stabilizers, wherein said UV stabilizers optionally include hindered amine light stabilizers (HALS) and / or UV absorbers; v. Metal carboxylates; vi. Clarifying and / or nucleating agents; vii. secondary inorganic antioxidants or reducing agents; and / or viii. Inorganic acid scavengers. <9> a phenolic antioxidant and one or more of components ii to viii, <8> The non-dusting blend described in <10> the phenolic antioxidant comprises a fully hindered phenolic antioxidant; <8> or <9> The non-dusting blend described in <11> The fully hindered phenolic antioxidant is tetrakismethylene(3,5-di-t-butyl-4-hydroxyhydrocinnamate)methane, 2,2'-thiodiethylenebis[3 (3,5-di-t-butyl-4-hydroxyphenyl)propionate], octadecyl 3-(3',5'-di-t-butyl-4'-hydroxyphenyl)propionate, 1,3,5-tris(3,5-di-t-butyl-4-hydroxybenzyl)isocyanurate, 1,3,5-trimethyl-2,4,6-tris(3,5-di-t-butyl-4-hydroxybenzyl)benzene, N,N'-hexamethylenebis[3-(3,5-di-t-butyl-4-hydroxyphenyl)propionamide], 1,2-bis(3,5-di-t-butyl-4-hydroxyhydrocinnamoyl)hydrazine, 2,2'-ethylidenebis[4,6-di-t-butylphenol], butylated hydroxytoluene, and / or compatible mixtures of two or more thereof, <10> The non-dusting blend described in <12> the metal carboxylate comprises one or more of a metal stearate and / or a metal lactate; the clarifying and / or nucleating agent comprises a metal benzoate and / or a sorbitol derivative; the secondary inorganic antioxidant comprises one or more of metal hypophosphites, metal thiosulfates, metal bisulfites, metal metabisulfites, and / or metal hydrosulfites; and / or the inorganic acid scavenger comprises one or more of a metal oxide, a metal hydroxide, a metal carbonate, a metal carboxylate, a metal salt, and / or a hydrotalcite-like compound; <8> ~ <11> 10. The non-dusting blend according to any one of claims 1 to 9. <13> <1> ~ <12> 1. A method of forming the non-dusting blend of claim 1, comprising: a. extruding or otherwise processing tris(2-t-butylphenyl) phosphite, optionally as part of a blend with one or more other additives, to provide a substrate; b. cooling the substrate; and c. optionally, fragmenting the cooled substrate. <14> Step a. is carried out using an extruder, optionally a screw extruder; <13> The method described below. <15> The extruder includes a plurality of heating zones, and optionally, the temperature of any or all of the heating zones is from about 30°C to about 250°C. <14> The method described below. <16> The extruder includes a die maintained at a temperature that deviates no more than ±5°C from the melting temperature of tris(2-t-butylphenyl)phosphite. <14> or <15> The method described below. <17> Further comprising the step of removing dust by sieving. <13> ~ <16> 10. The method according to any one of the preceding claims. <18> including cold extrusion and compression, <1> ~ <12> 10. A method of forming the non-dusting blend of any one of claims 1 to 9. <19> To stabilize the polymer, <1> ~ <12> 10. Use of the non-dusting blend according to any one of claims 1 to 9. <20> Polymers and <1> ~ <12> A stabilized polymer composition comprising the non-dusting blend of any one of claims 1 to 4. <21> The non-dusting blend is present in an amount of about 0.01% to about 5% by weight, based on the total weight of the stabilized polymer composition. <20> The stabilized polymer composition according to claim 1. <22> <21> 10. An article made from the stabilized polymer composition of claim 1.

Claims

1. Non-dusting granules containing tris(2-t-butylphenyl) phosphite.

2. 2. The non-dust granules according to claim 1, wherein the amount of dust in the non-dust granules is less than 1% by weight of the non-dust granules.

3. 3. The non-dusting granules according to claim 1 or claim 2, wherein the tris(2-t-butylphenyl) phosphite has a purity of at least 98%.

4. A granular non-dust blend comprising tris(2-t-butylphenyl)phosphite in an amount of 10% to 80% by weight based on the total weight of the non-dust blend, and one or more of the following: i. a phenolic antioxidant in an amount of 1% to 80% by weight, based on the total weight of the non-dust blend; ii. a sulfur-containing antioxidant in an amount of 1% to 50% by weight, based on the total weight of the non-dust blend; iii. an amine antioxidant in an amount of 1% to 50% by weight, based on the total weight of the non-dust blend; iv. a UV stabilizer in an amount of 1% to 50% by weight, based on the total weight of the non-dust blend; v. a metal carboxylate in an amount of 1% to 50% by weight, based on the total weight of the non-dust blend; vi. a clarifying and / or nucleating agent in an amount of 1% to 50% by weight, based on the total weight of the non-dusting blend; vii. a secondary inorganic antioxidant or reducing agent in an amount of 1% to 50% by weight, based on the total weight of the non-dust blend; and / or viii. An inorganic acid scavenger in an amount of 1% to 50% by weight based on the total weight of said non-dust blend.

5. 5. The non-dusting blend of claim 4, comprising a phenolic antioxidant and one or more of components ii-viii.

6. 6. The non-dusting blend of claim 4 or claim 5, wherein the phenolic antioxidant comprises a fully hindered phenolic antioxidant.

7. The fully hindered phenolic antioxidant may be tetrakismethylene(3,5-di-t-butyl-4-hydroxyhydrocinnamate)methane, 2,2'-thiodiethylenebis[3 7. The non-dusting blend of claim 6, comprising an alkyl acrylate or octadecyl 3-(3',5'-di-t-butyl-4'-hydroxyphenyl)propionate, 1,3,5-tris(3,5-di-t-butyl-4-hydroxybenzyl)isocyanurate, 1,3,5-trimethyl-2,4,6-tris(3,5-di-t-butyl-4-hydroxybenzyl)benzene, N,N'-hexamethylenebis[3-(3,5-di-t-butyl-4-hydroxyphenyl)propionamide], 1,2-bis(3,5-di-t-butyl-4-hydroxyhydrocinnamoyl)hydrazine, 2,2'-ethylidenebis[4,6-di-t-butylphenol], butylated hydroxytoluene, and / or compatible mixtures of two or more thereof.

8. the metal carboxylate comprises one or more of a metal stearate and / or a metal lactate; the clarifying and / or nucleating agent comprises a metal benzoate and / or a sorbitol derivative; the secondary inorganic antioxidant comprises one or more of metal hypophosphites, metal thiosulfates, metal bisulfites, metal metabisulfites, and / or metal hydrosulfites; and / or the inorganic acid scavenger comprises one or more of a metal oxide, a metal hydroxide, a metal carbonate, a metal carboxylate, a metal salt, and / or a hydrotalcite-like compound; The non-dusting blend according to any one of claims 4 to 7.

9. A method for forming the non-dusting granules according to any one of claims 1 to 3, comprising the steps of: a. extruding or otherwise processing tris(2-t-butylphenyl) phosphite to provide a substrate; and b. Cooling the substrate; A method comprising:

10. A method for forming the non-dusting blend of any one of claims 4 to 8, comprising: a. extruding or otherwise processing tris(2-t-butylphenyl) phosphite as part of a blend with one or more other additives to provide a substrate; and b. Cooling the substrate; A method comprising:

11. The method of claim 9 or claim 10, further comprising, after step b. of cooling the substrate, step c. of fragmenting the cooled substrate.

12. The method of any one of claims 9 to 11, wherein step a. is carried out using an extruder.

13. The method of claim 12, wherein the extruder is a screw extruder.

14. 14. The method of claim 12 or claim 13, wherein the extruder comprises multiple heating zones.

15. The method of claim 14, wherein the temperature of any or all of the heating zones is between 30°C and 250°C.

16. The method of any one of claims 12 to 15, wherein the extruder comprises a die maintained at a temperature that deviates no more than ±5°C from the melting temperature of tris(2-t-butylphenyl)phosphite.

17. The method according to any one of claims 9 to 16, further comprising the step of removing dust by sieving.

18. A method for forming the non-dusting granules of any one of claims 1 to 3 or the granular non-dusting blend of any one of claims 4 to 8, comprising cold extrusion and compaction.

19. The method of claim 9, comprising adding 2-t-butylphenol to phosphorus trihalide to obtain tris(2-t-butylphenyl)phosphite.

20. The method of claim 19, wherein the 2-t-butylphenol is added to the phosphorus trihalide by subsurface addition.

21. The method of claim 19 or claim 20, wherein the addition of 2-t-butylphenol to the phosphorus trihalide is carried out in the presence of a catalyst.

22. The catalyst has the formula NR 1 R 2 R 3 , where R 1 is hydrogen (H) or an optionally substituted hydrocarbyl group, and R 2 and R 3 , which may be the same or different, are both optionally substituted hydrocarbyl groups having a carbon chain length greater than 1; and / or 22. The method of claim 21, wherein the catalyst has a cation and an anion, the cation having the formula N + R 1 R 2 R 3 R 4 , where R 1 -R 4 , which may be the same or different, are optionally substituted hydrocarbyl groups having more than one carbon atom.

23. Use of the non-dusting granules according to any one of claims 1 to 3 or the non-dusting blend according to any one of claims 4 to 8 for stabilizing a polymer.

24. A stabilized polymer composition comprising a polymer and the non-dusting granules according to any one of claims 1 to 3 or the non-dusting blend according to any one of claims 4 to 8.

25. The stabilized polymer composition of claim 24, wherein the non-dust granules or the non-dust blend are present in an amount of 0.01% to 5% by weight relative to the total weight of the stabilized polymer composition.

26. 26. An article made from the stabilized polymer composition of claim 25.

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