Process for preparing sterically hindered nitroxyl ethers

Abstract

A process for the preparation of compounds of the class of sterically hindered alkoxyamines is described, which comprises the step of alkylating a sterically hindered nitroxyl compound to the corresponding sterically hindered alkoxyamine by reacting the sterically hindered nitroxyl compound with a peroxide selected from diacyl peroxides of formula (A), peresters of formula (A) and oxalic acid peresters of formula (D); R-CO-OOZR(A), RZ"-X-CO-CO-OOZ"-R (D) wherein each R independently represents a primary or secondary alkyl or cycloalkyl group, preferably containing 1 to 15 carbon atoms, X is oxygen -O-, or a peroxy group -OO-, Z represents CO, or an alkylene bonded to a quaternary carbon atom, which is an alkylene of formula (C)R'-C-R'(C), wherein each R' is selected from alkyls of 1 to 15 carbon atoms, and Z" represents said alkylene bonded to a quaternary carbon atom of formula (C). The process described affords the corresponding O-alkylated derivatives of sterically hindered nitroxyls, typically compounds of the class known as NO-alkyl HALS, with extremely high selectivity and conversion, and without the need for catalysts, especially metal catalysts.

Description

[Technical field]

[0001] The present invention relates to a novel process for the alkylation of certain N-oxyl secondary amines and the preparation of the corresponding N-alkoxyamines in high purity. More specifically, the novel chemical process relates to the preparation of such sterically hindered N-alkoxyamines by selective O-alkylation of nitroxyls by reaction with certain primary or secondary alkyl groups. The process may further include a pre-oxidation step to obtain said sterically hindered nitroxyls from the corresponding secondary (NH) amines.

[0002] Further described are some novel compounds that can be obtained using this process. The reaction products of this process can be used in various fields of chemistry and polymer technology. An important type of reaction products belongs to sterically hindered amines, which are commonly used in polymer technology, for example as flame retardants, polymerization regulators or stabilizers against degradation by light, oxygen and / or heat for organic substances, such as organic polymer compositions. [Background technology]

[0003] Many publications describe the stabilization of organic materials using certain sterically hindered amine compounds as stabilizers, which are also known as hindered amine light stabilizers (HALS). A useful group of sterically hindered amines are compounds whose nitrogen atoms are bonded to two tertiary carbon atoms that are part of two hydrocarbon residues or one heterocyclic ring, such as a piperidine ring. For use as stabilizers, such compounds can contain unsubstituted nitrogen (NH-HALS) or substituted nitrogen (e.g., N-alkyl HALS). An important group due to certain properties, such as the reduced basicity of these compounds, is the HALS compounds in which the hindered nitrogen atom has an additional organic substituent bonded on the oxygen atom (typically NO-alkyl HALS, see, for example, US Pat. No. 5,399,623 and US Pat. No. 5,499,623). Such NO-alkyl HALS compounds are also called hindered amine ethers. Additional applications of sterically hindered amines, particularly NO-alkyl HALS, include flame retardants, rheology modifiers, and free radical polymerization initiators for controlled polymerizations (see Nitroxyl radicals and nitroxyl ethers beyond stabilization: radical generators for efficient polymer modification).

[0004] Most commercial applications of hindered N-alkoxyamines require a pronounced thermal stability of the product. As is well known in the scientific literature, the carbon-oxygen bonds of hindered N-alkoxyamines have low bond energy, while properties such as thermal stability or dissociation are governed by such bond strength. As also described in the above-mentioned literature, the thermal decomposition of certain N-alkoxyamines (especially NO-alkyl HALS) for use as flame retardants or in rheology modifier applications is designed to occur at a desired temperature. Typically, at extrusion processing temperatures, this is to initiate a free radical reaction between the N-alkoxyamine and the molten polymer. This leads to polymer chain scission or crosslinking, thereby modifying both the rheology of the molten polymer and the mechanical properties of the final plastic article thus obtained. For such applications, the R group of the N-alkoxyamine in the flame retardant and rheology modifier is selected with an R substituent with lower thermal stability compared to the light stabilizer. In contrast, for light stabilization applications, N-alkoxy derivatives are typically designed to have the highest thermal stability possible while avoiding any changes in the rheological or mechanical properties of the plastic article.

[0005] For the above reasons, in order to produce products based on hindered N-alkoxyamines with well-defined thermal stability, it is highly desirable to use a versatile process that is applicable to a wide range of hindered N-alkoxyamines with a series of different R substituents and allows high yields and high selectivities for the desired N-alkoxyamines. In fact, many known processes for the production of N-alkoxyamines have low selectivity for the desired products and result in the production of undesirable by-products whose thermal stability or activation temperature is outside the desired temperature range. This is even more important in the case of molecules with multiple hindered amine moieties, such as precursors of oligomeric HALS stabilizers, flame retardants, or rheology modifiers, where such by-products cannot be separated by purification and may become part of the final reaction product, negatively affecting the thermal stability and color of the reaction product. The preparation of sterically hindered nitroxyl compounds is described, for example, in (US Pat. No. 5,333,393). A recent evaluation of oligomeric compounds and methods for the conversion of red nitroxyl to high molecular weight NO-alkyl HALS is described in (Non-Patent Document 2) (https: / / doi.org / 10.1021 / op500301r).

[0006] Furthermore, it is also desirable to use manufacturing processes that have high productivity, low cost and comply with the principles of green chemistry, in particular without the use of heavy metals.

[0007] Many of the secondary amine or hindered amine precursors are commercially available or can be prepared by applying known methods. These secondary hindered amines characterized by NH moieties are conveniently converted to the corresponding nitroxyls by methods described in the literature. Useful precursors can be found, inter alia, in the above-mentioned references cited herein (see, for example, (Patent Document 4), p. 12, line 22 to p. 13, line 5).

[0008] Problems encountered in known methods for the conversion of suitable precursors, such as HALS with NH- or N-oxyl functional groups, into the corresponding sterically hindered amine alkyl ethers are often unsatisfactory conversion rates or percentages of unreacted precursor functional groups in the reaction product, which can, for example, lead to insufficient thermal stability or to undesired side reactions.For example, the N-methoxyhindered amines obtained after pyrolysis of a chlorobenzene solution of nitroxyl groups and di-tert-butyl peroxide (Example 1 of (US Pat. No. 5,399,433)) require a chromatographic purification step to isolate the desired reaction product from by-products and unreacted starting materials. [Prior art documents] [Patent documents]

[0009] [Patent Document 1] U.S. Pat. No. 5,204,473 [Patent Document 2] U.S. Patent No. 5,096,950 [Patent Document 3] U.S. Pat. No. 4,665,185 [Patent Document 4] International Publication No. 2008-003605 [Non-patent literature]

[0010] [Non-Patent Document 1] Rudolf Pfaendner,CRChimie,9(2006)1338~1344 [Non-Patent Document 2] E.Cote et al,Org.Process Res.Dev.,2014,18,12,1843~1849 Summary of the Invention [Problem to be solved by the invention]

[0011] Conversion of the N-oxyl precursors to the corresponding sterically hindered amine alkyl ethers can be further improved in terms of efficiency and environmental friendliness. [Means for solving the problem]

[0012] The present invention relates to a novel process for the alkylation of sterically hindered nitroxyl groups and for the preparation of the corresponding sterically hindered nitroxyl ethers. More specifically, the novel chemical process relates to the preparation of sterically hindered nitroxyl ethers by highly selective O-alkylation reactions via the generation and coupling of carbon-centered radicals starting from suitable precursors from the group of free radical initiators or photoinitiators under specific reaction conditions. Short reaction times, high selectivity and high yields of the desired nitroxyl ethers are crucial features of the novel process, especially for the preparation of compounds containing multiple hindered amine ether functional groups, such as polymeric compounds, due to the high conversion of N-oxyl groups in oligomeric or polymeric HALS. The products of the process are commercially very important as stabilizers, flame retardants, rheology modifiers or initiators for controlled polymerization.

[0013] It has thus been found that nitroxyl compounds, such as the sterically hindered nitroxyls described in the above-mentioned documents as precursors for the preparation of radical scavenging additives, such as, inter alia, NO-alkyl HALS, can be alkylated on their oxygen atom by reaction with peroxides to give the corresponding sterically hindered alkoxyamines.

[0014] The peroxide is selected from the diacyl peroxides of formula (A), the peresters of formula (A), and the oxalic acid peresters of formula (D): R-CO-OOZR (A) RZ”-X-CO-CO-OOZ”-R (D) wherein each R independently represents a primary or secondary alkyl or cycloalkyl group, the primary or secondary alkyl or cycloalkyl group preferably containing 1 to 15 carbon atoms; X is an oxygen atom -O- or a peroxy group -OO-; Z represents CO or an alkylene bonded to a quaternary carbon atom, which is represented by the following formula (C): R'-C-R' (C) wherein each R' is selected from alkyl of 1 to 15 carbon atoms. is an alkylene of the formula: Z″ represents said alkylene bonded to a quaternary carbon atom of formula (C).

[0015] When Z is CO, the sterically hindered nitroxyl compound is not 4-hydroxy-1-oxyl-2,2,6,6-tetramethyl-piperidine.

[0016] Peroxides for use in the present process often have the formula (B): R-CO-OO-CO-R (B) wherein each R independently represents a primary or secondary alkyl or cycloalkyl group, the primary or secondary alkyl or cycloalkyl group preferably containing 1 to 15 carbon atoms. It is a diacyl peroxide of the formula:

[0017] To summarize the invention, nitroxyl compounds, such as sterically hindered nitroxyls, which have been described in the literature as precursors for the preparation of radical scavenging additives, such as NO-alkyl HALS, among others, are represented by the formula (A): R-CO-OOZR (A) or preferably a peroxide of formula (B): R-CO-OO-CO-R (B) It has been found that the amines can be alkylated on the oxygen atom by reaction with diacyl peroxides to give the corresponding sterically hindered alkoxyamines, where Z is CO or an alkylene bonded to a quaternary carbon atom, i.e., the following formula (C): [ka] wherein each R' is selected from alkyl of 1 to 15 carbon atoms. and Each R independently represents a primary or secondary alkyl or cycloalkyl group, which preferably contains 1 to 15 carbon atoms.

[0018] The peroxide may be selected from oxalic acid peresters of formula (D): RZ”-X-CO-CO-OOZ”-R (D) wherein each R independently represents a primary or secondary alkyl or cycloalkyl group, the primary or secondary alkyl or cycloalkyl group preferably containing 1 to 15 carbon atoms; X is oxygen -O- or, preferably, a peroxy group -OO-; Z″ is represented by the following formula (C): R'-C-R' (C) wherein each R' is selected from alkyl of 1 to 15 carbon atoms. represents an alkylene bonded to a quaternary carbon atom of

[0019] Such oxalic acid based peroxides may offer the advantage of milder reaction conditions, such as lower reaction temperatures, as described below.

[0020] Surprisingly, it has been discovered that this reaction affords the corresponding O-alkylated derivatives, preferably NO-alkyl HALS, with extremely high selectivity and conversion, without the need for the use of a catalyst, particularly a metal catalyst or an iodide catalyst.

[0021] High selectivity and conversion are especially important for oligomeric or polymeric reaction products to improve the quality of the reaction products. Such N-alkoxy compounds with high thermal stability are also suitable as stabilizers for polymers at higher extrusion temperatures, such as polypropylene fibers and nonwovens, because they survive the processing steps without changing the properties of the polymer and provide undiminished stabilization performance.

[0022] Thanks to its high conversion, the process is also suitable for improving the product quality of NO-alkyl HALS products, some of which are commercial products, which may be marred by unreacted nitroxyl content and / or undesirable coloration of the products.

[0023] The present invention further relates to one or more compounds of formula (IIIa): [ka] The present invention also relates to a process as described above for converting sterically hindered nitroxyl compounds, characterized in that they contain a group The educts are already partially converted and have one or more of the following formula (Ia): [ka] [The asterisk (*) in each formula indicates the point of attachment of those groups to the rest of the molecule, while R represents an alkyl group as defined above]. The compound contains the group:

[0024] Such a process for improving the quality of the reaction product and the alkylation rate is therefore particularly useful where the oligomeric or polymeric compound contains at least 6, e.g., 6 to 100, moieties of formula (Ia), but also contains some unreacted nitroxyl moieties, e.g., of formula (IIIa). Exemplary reaction products of these groups are further illustrated below.

[0025] In yet another discovery of the present invention, nitroxyl compounds, such as sterically hindered nitroxyl compounds, can be converted to the corresponding alkoxyamines in the absence of metal catalysts (also called heavy metals), or even any catalytic material, according to the processes described herein.

[0026] Within the scope of the present invention, the term "primary alkyl" or "secondary alkyl or cycloalkyl" group refers to any alkyl or cycloalkyl group forming a carbon-centered radical, which is either bonded to another carbon and two hydrogen atoms or to three hydrogen atoms, thus forming a primary carbon group or, as a specific form thereof, a methyl group, or the radical center is bonded to two carbon atoms and one hydrogen atom, thus forming a secondary carbon group. The term "radical" or "radical" refers to a monovalent group (i.e., a primary alkyl group or a secondary alkyl or cycloalkyl group) when it is part of a molecule, such as the aforementioned derived educts and the reaction products of the process (i.e., diacyl peroxides and alkoxyamines). The primary or secondary carbon of the R group above is not part of a conjugated system (e.g., benzyl or allyl or cyano). It is preferably not adjacent to an electron-withdrawing group, otherwise thermal stability would be reduced.

[0027] In a preferred process of the invention, R is independently selected from the following: methyl, ethyl, 1-propyl, 2-propyl, 1-butyl, 2-butyl, 1-pentyl, 2-pentyl, 3-pentyl, 1-hexyl, 2-hexyl, 3-hexyl, 1-heptyl, 2-heptyl, 3-heptyl, 4-heptyl, 1-octyl, 2-octyl, 3-octyl, 4-octyl, nonyl, decyl, undecyl, dodecyl, cyclopentyl, cyclohexyl, cycloheptyl, cyclooctyl, cyclononyl, cyclodecyl, cycloundecyl, cyclododecyl. In particular, both residues R represent the same group.

[0028] The term "sterically hindered amine" refers to a secondary or tertiary amine in which the nitrogen atom is bonded to two carbon atoms, each of which is a quaternary carbon.

[0029] The term "metal catalyst" typically includes transition metals such as copper, iron, palladium, etc. In general, it refers to any compound that contains a metal element other than an alkali or alkaline earth element.

[0030] The terms "alkylate" or "alkylation" refer to a reaction that proceeds in the process of the present invention involving the formation of a chemical bond between an alkyl group, e.g., R, and the oxygen of a nitroxyl group.

[0031] In a typical process of the present invention, the resulting sterically hindered alkoxyamine is a compound of formula (I): (R 2 ) 2 N-OR (I) wherein R is as defined in claim 1 or 2 or 3; Each R 2 are hydrocarbons, preferably bonded together to form a divalent hydrocarbon group, and both R 2 contains a total of 2 to 500 carbon atoms, and optionally further contains one or more moieties (groups) selected from the group consisting of a tertiary nitrogen moiety, a secondary nitrogen moiety; an ester moiety, COO; and chloro.

[0032] R is preferably C 1 ~C 12 Alkyl or C 5 ~C 8 cycloalkyl, and each R 2 are hydrocarbons, preferably linked together to form a divalent hydrocarbon residue, and both R 2contain a total of 2 to 500 carbon atoms and optionally contain one or more tertiary nitrogen moieties, one or more ester moieties COO, and / or one or more divalent >N-OR moieties.

[0033] The sterically hindered nitroxyl educts typically belong to the group of 1-oxyl-2,2,6,6-tetramethyl-piperidines containing one or more groups of formula (IIIa), and the corresponding sterically hindered alkoxyamine compounds belong to the group of 1-alkoxy-2,2,6,6-tetramethyl-piperidines containing one or more groups of formula (Ia), where the asterisk (*) indicates the position of the bond connecting the groups to the rest of the molecule, and R is as defined above. [ka]

[0034] The sterically hindered alkoxyamine compounds obtainable in this process often correspond to the formula (Ib) (HA) p Y (Ib) [In the formula, HA is a hindered amine ether group (HE) of formula (Ia) as defined above; p is a number ranging from 1 to 6; and Y is hydrogen, oxo, or Y is a group of formula (IX): T 3 -(N[T 4 ]-A 2 ) q -N[T 1 T 2 ] (IX) (wherein q is in the range of 0 to 3). or Y is an anchor group having a valence of 2 to 6, as further defined below; When p is 1, Y is a compound of the formula -DC-A 1 is an anchor group; When p is 2, Y is the formula DC-A 2 - Is it an anchor group for DC; Or, Y is the above divalent anchor group of formula (IX), where q is zero and T 3 represents an open bond, and T 1 is R 1 is defined for T 2 is the formula (X): [ka] or Or, q is 1 and T 1 and T 3 Each of R 1 is defined for T 2 and T 4 each of which is the above divalent aminotriazinyl of formula (X); When p is 3, Y is a trivalent anchor group of formula (IX) where q is zero and T 3 represents an open bond, and T 1 is R 1 is defined for T 2 is represented by formula (XI): [ka] or a trivalent diaminotriazinyl of the formula Or, q is 1 and T 1 is R 1 is defined for T 2 is a divalent aminotriazinyl of formula (X) and T 3 and T 4 independently represent an open bond or a divalent aminotriazinyl of formula (X); When p is 4, Y is a tetravalent anchor group of formula (IX) where q is 3 and T 2 and residue T 4 represent a divalent diaminotriazinyl of formula (XI), while T 1 and T 3 and the remaining residues T 4 is R 1is defined for; When p is 5, Y is a pentavalent anchor group of formula (IX) where q is 1 and T 1 is a trivalent diaminotriazinyl of formula (XI) and T 3 is a divalent aminotriazinyl of formula (X) and T 2 and T 4 independently represent an open bond or a divalent aminotriazinyl of formula (X); When p is 6, Y is a hexavalent anchor group of formula (IX): where q is 1 and T 1 and T 3 each of which is a trivalent diaminotriazinyl of formula (XI) and T 2 and T 4 represents independently an open bond or a divalent aminotriazinyl of formula (X); Or q is 2 and T 2 and each T 4 represents a trivalent diaminotriazinyl of formula (XI), while each T 1 and T 3 is R 1 is defined for; Or q is 3 and T 2 and two residues T 4 represents a trivalent diaminotriazinyl of formula (XI), while T 1 and T 3 , as well as the remaining residues T 4 Each of R 1 is defined for; Or q is 3 and T 2 and T 3 and residue T 4 one of which represents a trivalent diaminotriazinyl of formula (XI), while T 1 and the remaining residue T 4 Each of R 1 is defined for; A 1 is C 1 ~C 12 Alkyl, or C interrupted by O or COO2 ~C 12 Alkyl or the alkyl group is C 1 ~C 12 alkyl, and are preferably identical; di(dialkylamino)triazinyl; A 2 is C 2 ~C 12 is alkylene; DC is a divalent linking group, typically a direct bond, an ester group -COO-, an ether group -O-, or a group of the formula -NR 1 - an amino group; R 1 is H or lower alkyl, in particular H or C 1 ~C 6 is alkyl; and X is Cl or N(R 1 ) 2 [is].

[0035] The number of open bonds in the anchor group Y is equal to p.

[0036] Each of the groups of formula (X) and (XI) contains two different classes of open bonds, one of which is a bond at the triazine core, NR 1 When present in an anchor group of formula (IX), one open bond from the triazine core is always attached to a nitrogen atom in formula (IX). Thus, NR 1 The open bond at is attached to a group of formula (Ia) or (IIIa).

[0037] An example of a preferred reaction product obtainable by this process is a compound of formula (Ib), where Y is an anchor group of formula (IX), q is in the range of 0 to 3; T 1 , T 2 , T 3 , and T (if present) 4 Each of R 1 or an open bond or formula (XII): [ka] is a diaminotriazinyl of When p is 4 or 6, Y is further represented by formula (XIII): [ka] [Wherein, R′ and R′ 1 Each of R 1 or is an open bond] containing a tetravalent or hexavalent group of where the number of open bonds in the anchor group Y is equal to p.

[0038] One example is A. 2 is tetra-, penta-, or hexamethylene, each R' is an open bond, and each R' is C 2 ~C 6 Compounds containing an anchor group of formula (XIII) that is alkyl, particularly butyl, and thus the anchor group has six open bonds, one on each aliphatic nitrogen atom. The term "aliphatic" is to be understood herein as not belonging to a ring structure that contains a double bond. Thus, all six open bonds are attached to the hindered amine group of formula (Ia).

[0039] Thus, the sterically hindered nitroxyl educt typically conforms to the following formula (Ic): (HOx) p Y(Ic) [In the formula, HOx is a hindered amine oxyl group of formula (IIIa) as defined above; p and Y are defined above for formula (Ib).

[0040] The reaction is typically carried out for a period of from 5 minutes to 100 hours. The reaction is typically carried out in the absence of a heavy metal catalyst.

[0041] The present invention further relates to a process for the conversion of sterically hindered secondary amines (i.e. NH amines as derivatives) to the corresponding alkoxylated amines (i.e. NO-alkylamines, preferably NO-alkyl HALS), which process comprises the steps of: i) contacting a secondary hindered amine with a suitable oxidizing agent to obtain a nitroxide (NO·); and ii) reacting the reaction product obtained in step (i) with a peroxide of formula (A) or preferably (B) according to the methods described above.

[0042] Each of the above steps, i.e., step (i) of oxidizing a secondary amine to an oxyl, and step (ii) of the present invention of converting said nitroxyl to its corresponding alkoxyamine, are typically carried out in liquid phase, at a temperature in the range of 0-140° C., e.g., 0-120° C., especially in the presence of an inert solvent.

[0043] Methods for carrying out this step (i) and the oxidizing agents used for this step are generally known in the art (see, for example, the documents cited above). The oxidizing agent is typically a peroxide such as hydrogen peroxide, a hydrogen peroxide-releasing compound, or a peracid (e.g., peracetic acid).

[0044] Particularly preferred temperatures for this step (ii) are in the range of from 15 to 100°C, especially from 30 to 100°C, most preferably when the peroxide used in the process is a diacyl peroxide (formula A) or an oxalic acid perester (formula D).

[0045] The process comprising steps (i) and (ii) is preferably carried out in the presence of a solvent, which is selected from: non-polar solvents, such as C5-C12 hydrocarbons, for example alkanes, cycloalkanes, aromatic hydrocarbons or arylalkanes, optionally dried; and polar solvents, such as alcohols, ethers, esters, in particular those containing methyl and / or tert-alkyl moieties, for example tert-butanol, methyl-tert-butyl ether, methyl acetate, tert-butyl acetate. Of particular industrial importance are mixtures of such non-polar and polar solvents. Of particular industrial interest are processes in which the reaction is carried out under protective gas, excluding oxygen, for example under nitrogen.

[0046] Of particular industrial importance is a process for the alkylation of sterically hindered nitroxyl compounds to the corresponding sterically hindered alkoxyamines, which comprises reacting said sterically hindered nitroxyl compounds with peroxides of formula (A) or, in particular, formula (B) as defined above, in which the sterically hindered nitroxyl compounds correspond to the following formula: [ka] and the sterically hindered alkoxyamine corresponds to the following formula (V): [ka] [In each formula, n is in the range of 1 to 10, and R is as defined in claim 1 or 2, preferably C1-C5 alkyl, in particular 1-propyl. Matches.

[0047] Equally important is the process: in a first step (i), [ka] wherein n is as defined above for formula (V). is converted to said sterically hindered nitroxyl compound, said process comprising the steps of: i) contacting the sterically hindered secondary amine derivative with a suitable oxidizing agent to obtain the nitroxide (NO·) compound; and thereafter ii) reacting the reaction product obtained in step (i) with a peroxide of formula (A) or preferably (B) to obtain a compound of formula (V) as above.

[0048] Due to the high conversion achieved in the present process, the conversion of large molecules containing multiple, e.g., six or more, nitroxyl groups leads to NO-alkyl reaction products that are substantially different from reaction products obtained using conventional alkylation. Thus, the present invention further relates to at least six, e.g., 6-100, particularly 8-100, NO-alkylated compounds of formula (Ia): [ka] The present invention also relates to oligomeric or polymeric reaction products comprising compounds containing groups of the formula (I) where an asterisk (*) indicates the location of the bond connecting those groups to other portions of the molecule. The novel reaction product preferably has formula (IV) or (V): [ka] [In the formula, A 2 and R 1 is as defined above, and R is a group represented by the following formula (V): [ka] (In the formula, n is in the range of 1 to 10, R is as defined in claim 1 or 3, preferably C1-C5 alkyl, in particular 1-propyl. [defined as and wherein the sterically hindered oligomeric or polymeric alkoxyamine compound corresponds to one of Said oligomeric or polymeric reaction products are characterized in that they are obtainable by the process according to the present disclosure.

[0049] As mentioned above, the conversion of oligomeric or polymeric HALS to NO-alkyl typically results in a reaction product containing a certain amount of unreacted nitroxyl, and there may be additional groups remaining unreacted due to side reactions.As a result of the high conversion rate of nitroxyl to alkoxyamine in the product by this process, the present invention results in a novel reaction product containing one or more compounds represented by formula (V) above, which is characterized in that: the reaction product contains more than 87%, preferably 90-99.9%, more preferably more than 95%, typically 96%-99.9% of the derivative nitroxyl converted to alkoxyamine group N-OR (particularly R is 1-propyl) as shown in formula (V). The reaction product thus comprises a mixture of compounds, including compounds similar to the compound of formula (V), but where one or more of the groups N-OR have been replaced by nitroxyl, typically also by other derivatives of the tetramethylpiperidine group, such as NH, hydroxylamine or lower alkylamines, which correspond to unreacted raw materials or groups, or to the products of side reactions. Thus, the present invention allows a significant reduction in the nitroxyl remaining in the final reaction product, for example to 0.1-4% of the nitroxyl originally present in the derivative.

[0050] Preferred secondary amine derivatives for this step (i) include the following compounds: Derivative 1 of the formula: [ka]

[0051] Derivative 2 of the formula: [ka] [wherein n ranges from 1 to 10 (available from BASF as Chimassorb 2020 (RTM)];

[0052] Derivative 3 of the formula: [ka] [wherein n is in the range of 1 to 10, particularly 4 to 5 (available from BASF as Chimassorb 944 (RTM))];

[0053] Derivative 4 of the formula: [ka] [Available from Solvay as Cyasorb UV-3346 (RTM; CAS-No.: 90751-07-8)];

[0054] Derivative 5 of the formula: [ka] [described as a derivative of Example 11 in US Pat. No. 5,130,429 (Chimassorb 119 (RTM), associated with BASF); a similar structure in the form of an N-cyclohexyloxy derivative (three R groups instead of four in the tetraamine) is available as Flamestab NOR 116 (RTM) from BASF];

[0055] Derivative 6 of the formula: [ka] [Available as Cyasorb 3853 (RTM; CAS-No.: 24860-22-8)];

[0056] Derivative 7 of the formula: [ka] [Available as Uvinul 4050 (RTM; CAS-No.: 123172-53-8)];

[0057] Derivative 8 of the formula: [ka] [Available as Uvinul 5050 (RTM; CAS-No.: 199237-39-3)];

[0058] Derivative 9 of the formula: [ka] [In the formula, R represents a group of the following formula: [ka] (wherein the wavy line represents the bond to the molecule shown above) (Uvasorb HA 88(RTM); CAS-No.: 136504-96-6), available from 3V Sigma];

[0059] Derivative 10 of the formula: [ka] [This is available from Clariant as Nylostab S-EED (RTM; CAS-No.: 42774-15-2)];

[0060] Derivative 11 of the formula: [ka]

[0061] Derivative 12 of the formula: [ka]

[0062] Derivative 13 of the formula: [ka]

[0063] Derivative 14 of the formula: [ka]

[0064] Derivative 15 of the formula: [ka] (Secondary amine analogues of Examples 1-3 of WO2012-052377);

[0065] Derivative 16 of the formula: [ka]

[0066] Derivative 17 of the formula: [ka] (Bis(2,2,6,6-tetramethylpiperidin-4-yl)sebacate; available from BASF as Tinuvin 770 (RTM).

[0067] Derivatives 12, 13, and especially 16 are useful as intermediates for oligomeric HALS and the corresponding oligomeric NO-alkyl HALS.

[0068] Nitroxyl compounds suitable as intermediates in the process of the present invention include compounds of the formula: [ka] [wherein n ranges from 1 to 10]; as well as any of the above secondary amine derivatives for step (i) in the form of an oxidized form available as the reaction product of step (i).

[0069] Preferred reaction products of the present process include the following compounds: a) bis(1-octyloxy-2,2,6,6-tetramethylpiperidin-4-yl) sebacate (i.e., Tinuvin 123 (RTM), CAS-No. 129757-67); b) The product of CAS No. 191680-81-6 of the following formula: [ka] [wherein N4-amine is a trivalent amine of the formula XHN-CH 2 CH 2 CH 2 -NX-CH 2 CH 2 CH 2 -NX-CH 2 CH 2 CH 2 -NHX (Xa) (wherein one symbol X represents hydrogen and three symbols X represent single bonds (Flamestab NOR 116[RTM]); c) [ka] [In the formula, n is in the range of 1 to 10].

[0070] Also preferred as reaction products of the present process are monomeric hindered amine ethers, such as those of the formula: [ka] wherein R is as defined above and Z is hydrogen, OH or OR or OCOR or N(R 1 ) R or oxo (i.e., O=); Some preferred oligomeric compounds obtainable according to the process of the present invention have the formula (XV): [ka] [In the formula, R, R 1 is as defined above, R is preferably n-propyl or n-octyl or n-undecyl, and / or R1 is preferably n-butyl]; and correspond to NO-alkyl HALS compounds (a) and (b) above.

[0071] The sterically hindered alkoxyamine compounds obtainable in this process, such as compounds of formula (I), in particular compounds containing a group of formula (Ia), such as the above compounds of formula (XV) or compounds a) to d), are effective stabilizers for organic substances, such as organic polymers, against the harmful effects of light, oxygen, and / or heat. Organic polymers that can be stabilized in this way are, for example, those listed in GB-A-2334717, from page 30, line 10 down to page 35, line 9 down. Typical compositions of the present invention are then similar to those described in the same document, from page 35, line 8 down to page 36, but with the HALS compounds listed in GB-A-2334717 replaced by the sterically hindered alkoxyamines of the present invention or one of the reaction products of the following examples. The corresponding compositions may be thermoplastic polymer compositions or coating compositions similar to those described in GB-A-2334717, from page 48 to page 54, line 19, containing one or more organic polymers. The composition typically further comprises a co-additive such as those disclosed in GB-A2334717, pages 37-47.

[0072] As mentioned above, the mixture of compounds obtainable by the present invention and containing a functional group of formula (Ia) can be advantageously used as a stabilizer for organic substances, such as organic polymer compositions, against degradation by light, oxygen, and / or heat. The reaction products of the present process can furthermore exhibit improved thermal stability compared to the corresponding compositions or compounds prepared according to the prior art processes, as well as exhibit improved antioxidant performance, especially in polymer processing conditions, preventing degradation or oxidation of the polymer during high temperature processing (e.g. extrusion, casting, etc.). EXAMPLES

[0073] The invention is further illustrated in the following examples. In the examples, as in the rest of the description and claims, all parts and percentages are by weight unless otherwise specified. Room temperature refers to a temperature in the range of 20-30° C. Overnight refers to a period of at least 12 hours and up to 16 hours. Whenever stated, lower alkyl is C 1 ~C 8 Alkyl, especially C 1 ~C 6 Alkyl, e.g., methyl, ethyl, propyl, butyl, pentyl, hexyl. All peroxides (derivatives of formula A in this process, e.g., dibutanoyl peroxide) are obtained analogously to RF D Rury and Z, L. Kaplan, Journal of the American Chemical Society, 94:11, May 31, 1972. The alkylation rate (NO-alkyl content) is determined from proton NMR as shown in Table 1, unless otherwise stated. In the given formula (chemical formula), Bu, as well as C 4 H 9 Each represents 1-butyl. The index n used in the formula represents the number of repeats, typically at least 3, for example 3 to 1000 repeats, unless otherwise specified.

[0074] Abbreviation: HPLC: High performance liquid chromatography T: Temperature (in °C unless otherwise stated) RTM: Registered trademark 1H NMR: Proton nuclear magnetic resonance MTBE: Methyl tert-butyl ether TMP: Tetramethylpiperidine

[0075] Example 1 (prior art) : Oxidation of derivative 2 (Chimassorb® 2020; from Org. Process Res. Dev., 2014, 18, 1843-1849) Na in deionized water (13 g) 2 CO3 10H 2 O (1.08 g, 3.77 mmol) and Na 2 WO 4 2H 2 A solution of 0.93 g, 2.82 mmol) is added to a solution of derivative 2 (a commercial product from BASF) (324 g, approximately 108 mmol) in toluene (486 g) at ambient temperature. Then, 50% H 2 O 2 (308 g, 4.52 mol) is added via pump to the reaction mixture over 8 hours while maintaining the temperature at 60° C. Then Na 2 CO 3 (97 g) of 25% aqueous solution is poured in over 0.5 h and stirring is continued for 1 h at 60° C. Phase separation is carried out at 70° C., the aqueous phase is removed and the organic phase is washed with 23% NaCl (75 g). The aqueous phase is separated to give a reddish organic phase (709 g). The organic solvent is removed in vacuum to give the pure reaction product as a red powder (see Table 2).

[0076] Example 2 Conversion of the intermediate obtained in Example 1 (derivative 1) into an alkoxyamine ether a) 4.32 g of the intermediate of Example 1 are dissolved in 30 mL of chlorobenzene. 2.66 g of dibutanoyl peroxide are added in small portions while the reactants are heated to 90° C. The temperature is kept between 90-100° C. for 75 minutes. Cool, add 2 mL of water, continue stirring for 30 minutes, then remove all volatile components in vacuum at temperatures up to 90° C. The alkoxyamine content is measured by 1H NMR. b) A mixture of 2.9 g of the intermediate of Example 1 in toluene (80 mL) is gradually heated to 80° C. under stirring. Starting at 40° C., 2.4 g of dibutanoyl peroxide are added in 5 portions over 60 minutes. Stirring is continued for 120 minutes to give a yellow-orange solution. On cooling, 5 mL of water is added, stirring is continued for 30 minutes, and then all volatile components are removed under vacuum. The alkoxyamine content is determined to be 95% by 1H NMR. c) A mixture of 0.65 g of the intermediate of Example 1 in toluene (5 mL) is slowly heated to 90° C. under stirring. Starting at 40° C., 1.3 g of dilauroyl peroxide is added portionwise over 60 minutes. Stirring is continued for 120 minutes to give a yellow solution. Upon cooling, all volatile components are removed in vacuo. The alkoxyamine content is determined to be 95% by 1H NMR.

[0077] Example 3 : Color improvement of commercial Tinuvin® NOR® 371 (available from BASF) 5.0 g of Tinuvin® NOR® 371 is dissolved in 20 mL of toluene. The mixture is heated to 85° C. under vigorous stirring. Dibutanoyl peroxide (2.1 g) is added to the reaction mixture in small portions over 6 hours. Stirring is then continued for another 8 hours. Upon cooling, all volatiles are removed in vacuo to give a pale yellow foam. The removal of the original color is evident from UV / VIS measurements, as seen in Table 2.

[0078] Example 4 : Improvement of the alkoxyamine content of the commercially available Tinuvin® NOR® 371 0.5 g of Tinuvin® NOR® 371 is dissolved in 5 mL of toluene. At ambient temperature, dibutanoyl peroxide (0.25 g) is added to the reaction mixture. The mixture is heated to 50° C. until the red color disappears. Then, 2 mL of water is added dropwise and stirring is continued for 0.5 h. Upon cooling, all volatiles are removed in vacuo to obtain the optimized reaction product. The alkoxyamine content is determined to be 99% by 1H NMR.

[0079] Example 5 Improved color and alkoxyamine content of commercially available Tinuvin® NOR® 356 (available from BASF) 0.5 g of commercially available Tinuvin® NOR® 356 (derivative) is dissolved in 5 mL of toluene. At ambient temperature, dibutanoyl peroxide (0.25 g) is added to the reaction mixture. The mixture is heated to 50° C. until the red color disappears. Then, 2 mL of water is added dropwise and stirring is continued for 0.5 h. Upon cooling, all volatiles are removed in vacuo to obtain a pale yellow foam. 96% conversion is achieved from the total amount of reactive nitrogen moieties convertible to alkoxyamines as determined by 1H-NMR. As also seen in Table 2, visual comparison shows that the reddish color of the derivative has almost disappeared in the reaction product.

[0080] Example 6 General procedure for preparing tert-butyl peroxyesters (not part of the present invention) Under nitrogen, a 100 mL three-neck flask equipped with magnetic stirring, a condenser, a thermometer, and an addition funnel, cooled in an ice-water bath, is charged with 25 mL of MTBE, 4.1 mL (22 mmol) of 5.5 M tert-butyl hydroperoxide in decane, and 2.5 mL (30.0 mmol) of pyridine. The mixture is stirred and cooled to 0° C. Over a period of 10-15 minutes, a solution of the desired acid chloride is slowly added (e.g., acetyl chloride, oxalyl chloride; 22 mmol for monofunctional acid chloride; 11.0 mmol for oxalyl dichloride; each dissolved in 5 mL of MTBE). Immediately after the addition begins, pyridinium chloride forms as a solid. After the addition, the reaction mass is stirred for 60 minutes at 2° C. Then 10 mL of water is added and the reaction mass is stirred for an additional 10 minutes at 3-4° C. The aqueous layer is then separated and the organic layer is washed three times with 35 mL of 5% aqueous HCl, then twice with 75 mL portions of water. The reaction product solution is diluted with 5% by weight anhydrous MgSO 4 After drying on a lid and separating the desiccant by filtration, the mixture is stored in a refrigerator at 4°C.

[0081] Example 7 (Invention) Conversion of the reaction product of Example 1 with the reaction product of Example 6 a) 3.0 mL of tert-butyl peroxyacetate (50% by weight solution in an aliphatic hydrocarbon) is diluted with 3.0 mL of xylene. 2.8 g of the solution of the reaction product of Example 1 in xylene is added over 45 min at 132-138° C. After an additional 2 h of stirring, a pale yellow solution is obtained. All volatiles are removed in vacuo at 90° C. to give 2.47 g of an off-white foam. The alkoxyamine content is determined to be 84% by 1H NMR. b) A solution of di-t-butyl peroxyoxalate in toluene is heated to 60-70°C. A solution of the reaction product of Example 1 in toluene is added over a period of 30 minutes. After 2 hours of additional stirring, a pale yellow solution is obtained. All volatiles are removed in vacuo to give an off-white foam. The presence of the alkoxyamine is determined by proton NMR (signal at 3.74 ppm).

[0082] Example 8 (not part of the present invention) a) Preparation of derivative compound 1 of the formula [ka] In a 1 L stainless steel autoclave equipped with mechanical stirring, the following is added: 110 g of N,N,N',N'-tetrabutyl-6-chloro-1,3,5-triazine-2,4-diamine (prepared as described in Katritzky, Alan R.; Oniciu, Daniela C.; Ghiviriga, Ion; Barcock, Richard A., Journal of the Chemical Society, Perkin Transactions 2: Physical Organic Chemistry (1972-1999), 1995, #4, p. 785) dissolved in 300 mL of xylene, 64 g of 2,2,6,6-tetramethyl-4-n-butylaminopiperidine (nBut-TAD, commercially available from Evonik or other suppliers), followed by 43 mL of 30% aqueous NaOH. The autoclave is then closed, placed under vigorous stirring, heated to 180° C., and allowed to react for 12 hours.

[0083] The reaction mixture is allowed to cool to 50° C., the aqueous phase is discarded, and the organic phase is washed several times with deionized water under vigorous stirring until the aqueous phase is pH neutral.

[0084] The organic phase is then transferred to a rotavap and all solvent is removed under vacuum to give an off-white solid which is dried in a vacuum oven overnight.

[0085] The final reaction product (derivative 1, MW 567, white powder) is weighed, the yield calculated, and characterized by NMR.

[0086] Example 9 Preparation and selective alkylation of compound 2 of the formula: [ka] In a 350 mL round-bottom flask equipped with a mechanical stirrer, reflux condenser, thermometer, and dropping funnel, the following are introduced at room temperature: 100 mL toluene, 100 mL tert-butanol, 25 g of compound 1, and 9 g NaHCO dissolved in 120 mL of deionized water. 3 The reaction mixture is heated to 50°C.

[0087] From the dropping funnel, 19.5 g of 35% peracetic acid are added dropwise, while maintaining the temperature below 60° C. The reaction mixture is then cooled to 20° C. and transferred to a separating funnel, discarding the aqueous phase. The organic phase is then washed several times with water until a neutral pH is reached.

[0088] At this point, approximately 0.5 mL of dibutanoyl peroxide of the formula: (prepared according to RF Drury and Z. L. Kaplan, Journal of the American Chemical Society, 94:11, May 31, 1972) [ka] (MW 174) is added to the reaction mixture, heated to 80° C. and left to react overnight. At the end of the reaction, the mixture is washed with an aqueous solution of sodium sulfite and then concentrated in a rotary evaporator to remove the solvent and any volatile products. [ka] The final reaction product is characterized by HPLC and 1H-NMR. 1 H-NMR (CDCl 3 ), δ(ppm)0.83-1.08(m,30H),1.26-1.40(m,10H),1.44-1.64(m,14H),1.73(qt,2H),3.20-3.35(m,10H),3.43(m,1H),3.71(t,2H). HPLC (Waters Alliance 2690 / 2695 HPLC System and Waters 2996 PDA Director, column Hypersil GOLD™ C4×5 cm; method: isocratic 95 / 5 CH 3 CN / H 2 0, temperature 70° C., 1.0 mL / min, UV detector 240 nm) shows 2% peak remaining for starting material and 95% peak for desired reaction product.

[0089] Example 10 :Reaction of dilauroyl peroxide with compound 2 The procedure described in Example 2 is repeated, except that di-butanoyl peroxide is replaced by di-1-dodecanoic peroxide. The reaction product, 2-(1-undecaneoxy-2,2,6,6-tetramethylpiperidin-4-yl)-butylamino-4,6-bis(dibutylamino)-1,3,5-triazine, is characterized by HPLC and 1H-NMR.

[0090] The excellent quality of the reaction products of this process is evident from the following tables: Table 1 summarizes the data obtained by 1H-NMR on the alkylation rate of the nitroxyl intermediate, while Table 2 shows the data showing the color of some reaction products by UV / Vis measurement of the absorption at 470 nm (the absorption maximum of the nitroxide group in solution).

[0091] [Table 1]

[0092] [Table 2]

[0093] Treatment according to the present process results in a reaction product with less color, along with a significantly improved alkylation rate.

Claims

1. A process for alkylating a sterically hindered nitroxyl compound to the corresponding sterically hindered alkoxyamine, comprising the step of reacting said sterically hindered nitroxyl compound with a peroxide selected from a diacyl peroxide of formula (A), a perester of formula (A), and an oxalic acid perester of formula (D): R-CO-O-O-Z-R (A) R-Z"-X-CO-CO-O-O-Z"-R (D) wherein each R independently represents a primary or secondary alkyl or cycloalkyl group, said primary or secondary alkyl or cycloalkyl group preferably containing 1 to 15 carbon atoms; X is oxygen —O— or a peroxy group —O—O—; Z represents CO or an alkylene bonded to a quaternary carbon atom, said alkylene having the formula (C): R'-C-R' (C) where each R' is selected from alkyl of 1 to 15 carbon atoms. is an alkylene of the formula: Z″ represents said alkylene bonded to a quaternary carbon atom of formula (C); with the proviso that when Z is CO, said sterically hindered nitroxyl compound is not 4-hydroxy-1-oxyl-2,2,6,6-tetramethylpiperidine.

2. 2. A method for alkylating a sterically hindered nitroxyl compound to the corresponding sterically hindered alkoxyamine according to claim 1, comprising reacting the sterically hindered nitroxyl compound with a peroxide of formula (A): R-CO-O-O-Z-R (A) wherein each R independently represents a primary or secondary alkyl or cycloalkyl group, said primary or secondary alkyl or cycloalkyl group preferably containing 1 to 15 carbon atoms; and Z represents CO or an alkylene bonded to a quaternary carbon atom, the alkylene being represented by the following formula (C): R'-C-R' (C) where each R' is selected from alkyl of 1 to 15 carbon atoms. is an alkylene of the formula: with the proviso that when Z is CO, said sterically hindered nitroxyl compound is not 4-hydroxy-1-oxyl-2,2,6,6-tetramethyl-piperidine.

3. 3. The method according to claim 1 or 2, wherein the peroxide is a peroxide of formula (A) and is a diacyl peroxide and Z represents CO, or a perester and Z represents an alkylene bonded on a quaternary carbon atom of formula (C), or a method according to claim 1, wherein the peroxide is an oxalic acid perester of formula (D), The sterically hindered nitroxyl compound has the following formula (IIIa): 【Chemistry 1】 (wherein the asterisk (*) indicates the position of the bond connecting those groups to the rest of the molecule). and The corresponding sterically hindered alkoxyamine compounds have one or more of the following formula (Ia): 【Chemistry 2】 where the asterisk indicates the position of the bond connecting those groups to the rest of the molecule, and where R is as defined in claim 1 or 2. which belongs to the group of 1-alkoxy-2,2,6,6-tetramethyl-piperidines containing the group

4. 4. The method of claim 3, wherein the sterically hindered alkoxyamine compound conforms to the following formula (Ib): (HA) ｐ Y (Ib) [In the formula, HA is a hindered amine ether group (HE) of formula (Ia) above; p is a number ranging from 1 to 6; and Y is represented by the following formula (IX): () ３ !(!) ４ __ ２ ) ｑ ___ １ () ２ * ()) (wherein q ranges from 0 to 3). or Y is an anchor group as further defined below; When p is 1, Y has the formula -NR １ -A １ is an anchor group of When p is 2, Y is a group of the formula DC-A ２ - DC anchor group; Or, Y is the divalent anchor group of formula (IX), where q is zero, and T ３ represents an open bond, T １ is R １ and T ２ is represented by the following formula (X): 【Chemistry 3】 or Or, q is 1 and T １ and T ３ Each of the above is R １ and T ２ and T ４ each of which is said divalent aminotriazinyl of formula (X); When p is 3, Y is a trivalent anchor group of formula (IX) where q is zero and T ３ represents an open bond, T １ is R １ and T ２ is represented by formula (XI): 【Chemistry 4】 or a trivalent diaminotriazinyl of the formula Or, q is 1 and T １ is R １ is defined for T ２ is a divalent aminotriazinyl of the formula (X), and T ３ and T ４ represents independently an open bond or a divalent aminotriazinyl of formula (X); When p is 4, Y is a tetravalent anchor group of formula (IX) above, where q is 3, and T ２ and residue T ４ Two of the groups represent a divalent diaminotriazinyl of formula (XI) above, while T １ and T ３ and the remaining residues T ４ is R １ is defined for When p is 5, Y is a pentavalent anchor group of formula (IX) above, where q is 1, and T １ is a trivalent diaminotriazinyl of formula (XI), T ３ is a divalent aminotriazinyl of the formula (X), and T ２ and T ４ represents independently an open bond or a divalent aminotriazinyl of formula (X); When p is 6, Y is a hexavalent anchor group of formula (IX) above, where q is 1 and T １ and T ３ each of which is a trivalent diaminotriazinyl of formula (XI) above, and T ２ and T ４ independently represents an open bond or a divalent aminotriazinyl of formula (X) above; Or q is 2 and T ２ and each T ４ represents a trivalent diaminotriazinyl of formula (XI) above, while each T １ and T ３ is R １ is defined for Or q is 3, T ２ and two residues T ４ represents a trivalent diaminotriazinyl of formula (XI) above, while T １ and T ３ , and the remaining residues T ４ Each of the above is R １ is defined for Or q is 3, T ２ and T ３ and residue T ４ one of the groups represents a trivalent diaminotriazinyl of formula (XI) above, while T １ and the remaining residue T ４ Each of the above is R １ is defined for A １ is C １ ~C １２ Alkyl, or C interrupted by O or COO ２ ~C １２ is alkyl; A ２ is C ２ ~C １２ is alkylene; DC is a divalent linking group, typically a direct bond, an ester group -COO-, an ether group -O-, or a group of the formula -NR １ -amino group; R １ is H or lower alkyl, especially C １ ~C ６ is alkyl; and X is Cl or N(R １ ) ２ is]; or, The process according to claim 1, wherein said sterically hindered nitroxyl compound is an oligomeric or polymeric compound comprising 6 or more, in particular 7 or more, more in particular 7 to 100, groups of said formula (Ia) and / or (IIIa), wherein at least one group of said formula (IIIa) is present.

5. 5. The process according to any one of claims 1 to 4, wherein R in formula (A) or (D) is independently selected from methyl, ethyl, 1-propyl, 2-propyl, 1-butyl, 2-butyl, 1-pentyl, 2-pentyl, 3-pentyl, 1-hexyl, 2-hexyl, 3-hexyl, 1-heptyl, 2-heptyl, 3-heptyl, 4-heptyl, 1-octyl, 2-octyl, 3-octyl, 4-octyl, nonyl, decyl, undecyl, dodecyl, cyclopentyl, cyclohexyl, cycloheptyl, cyclooctyl, cyclononyl, cyclodecyl, cycloundecyl, cyclododecyl, in particular where both radicals R represent the same group.

6. A process according to any one of claims 1 to 5, wherein the reaction is carried out at a temperature in the range of from 0 to 140°C, for example from 0 to 120°C, and in particular in the presence of an inert solvent.

7. 7. The process according to any one of claims 1 to 6, wherein the peroxide is a diacyl peroxide of formula (A) or an oxalic acid perester of formula (D) and the reaction is carried out at a temperature in the range from 15 to 100°C, in particular from 30 to 100°C, or the peroxide is a perester of formula (A) and the reaction is carried out at a temperature in the range from 30 to 140°C, in particular from 50 to 140°C.

8. 8. The method according to claim 1, wherein the reaction is carried out for a period of time between 5 minutes and 100 hours, and / or the reaction is carried out in the absence of a heavy metal catalyst, and / or the reaction is carried out under a protective gas free of oxygen, e.g. under nitrogen.

9. 9. The process according to any one of claims 1 to 8, wherein the reaction is carried out in the presence of a solvent, which may optionally be dried, selected from non-polar solvents, such as C5 to C12 hydrocarbons, such as alkanes, cycloalkanes, aromatic hydrocarbons or arylalkanes; and polar solvents, such as alcohols, ethers, esters, especially those containing methyl and / or tert-alkyl moieties, such as tert-butanol, methyl-tert-butyl ether, methyl acetate, tert-butyl acetate; and mixtures of non-polar and polar solvents.

10. The process according to any one of claims 3 to 9, wherein the sterically hindered alkoxyamine obtained in the process is a compound of formula (I): (R ２ ) ２ N-OR (I) wherein R is as defined in claim 1 or 2; Each R ２ are hydrocarbons, preferably linked together to form a divalent hydrocarbon group, and both R ２ contains a total of 2 to 500 carbon atoms, and optionally further comprises one or more moieties selected from the group consisting of a tertiary nitrogen moiety, a secondary nitrogen moiety; an ester moiety COO; chloro; Preferably, R is C １ ~C １２ Alkyl or C ５ ~C ８ is an alkyl selected from cycloalkyl; Each R ２ are hydrocarbons and are preferably bonded together to form a divalent hydrocarbon group, and both R ２ contain a total of 2 to 500 carbon atoms, and optionally contain one or more tertiary nitrogen moieties, one or more ester moieties COO, and / or one or more divalent moieties >N-OR; And most preferably, the sterically hindered nitroxyl compounds belong to the group of 1-oxyl-2,2,6,6-tetramethylpiperidines containing one or more groups of formula (IIIa), and the corresponding sterically hindered alkoxyamine compounds belong to the group of 1-alkoxy-2,2,6,6-tetramethyl-piperidines containing one or more groups of formula (Ia); 【Chemistry 5】 (wherein the asterisk (*) indicates the position of the bond where those groups are attached to the rest of the molecule). R is C １ ~C １２ Alkyl or C ５ ~C ８ cycloalkyl.

11. A process according to any one of claims 1 to 10 for preparing a sterically hindered alkoxyamine compound, comprising the steps of: The sterically hindered alkoxylamine compound is represented by the following formula (XIV) or (XV): 【Chemistry 6】 [In the formula, R, R １ is as defined in claims 1 to 10, Z is hydrogen, OR, COR, or N(R １ ) R or oxo. matches; or bis(1-octyloxy-2,2,6,6-tetramethylpiperidin-4-yl) sebacate; Or at least 6, for example 6 to 100, of the following formula (Ia): 【Chemistry 7】 where the asterisk (*) indicates the position of the bond where the group is attached to the rest of the molecule, for example, oligomeric or polymeric compounds of the formula: 【Chemistry 8】 [In the formula, N4-amine is represented by the following formula: XHN-CH ２ CH ２ CH ２ -NX-CH ２ CH ２ CH ２ -NX-CH ２ CH ２ CH ２ -NHX where one symbol X represents hydrogen and three symbols X represent bonds. Product of CAS No.: 191680-81-6; Preferably, the compound represented by the following formula (IV) or (V): 【Chemistry 9】 [In the formula, A ２ is C ２ ~C １２ is alkylene; R １ is H or lower alkyl, especially C １ ~C ６ is alkyl; and R is represented by the following formula (V): 【Chemistry 10】 (wherein n ranges from 1 to 10; R is as defined in claim 1 or 3, preferably C1-C5 alkyl, in particular 1-propyl. is defined as The compound is an oligomeric or polymeric sterically hindered alkoxyamine compound corresponding to one of the following:

12. The sterically hindered nitroxyl compound has the formula (IV) or (V): 【Chemistry 11】 [In the formula, A ２ is C ２ ~C １２ is alkylene; R １ is H or lower alkyl, especially C １ ~C ６ is alkyl; and R is as defined in claim 1 or 3, preferably C1-C5 alkyl, in particular 1-propyl; 【Chemistry 12】 wherein n ranges from 1 to 10 and R is as defined above. or an oligomeric or polymeric sterically hindered alkoxyamine compound represented by one of the following formulas: Or the following formula: 【Chemistry 13】 [In the formula, N4-amine is represented by the following formula: XHN-CH ２ CH ２ CH ２ -NX-CH ２ CH ２ CH ２ -NX-CH ２ CH ２ CH ２ -NHX wherein one symbol X represents hydrogen and three symbols X represent bonds. It is a reaction product represented by CAS No.: 191680-81-6, in which one or more of the residues O-R or O-cycloalkyl are substituted by nitroxyl, The method according to any one of claims 1 to 11.

13. The method according to any one of claims 1 to 12, In the first step (i), a sterically hindered secondary amine derivative, typically containing one or more groups 2,2,6,6-tetramethyl-piperidin-4-yl, is converted into a sterically hindered nitroxyl compound, by the following steps: (i) contacting the sterically hindered secondary amine derivative (i.e., secondary hindered amine derivative) with a suitable oxidizing agent to obtain a nitroxide (NO.) compound; and then (ii) reacting the reaction product obtained in step (i) with a peroxide according to any one of claims 1 to 13; Including, Preferably, the secondary amine derivative here is an oligomeric or polymeric compound comprising at least 6, in particular from 6 to 100, radicals 2,2,6,6-tetramethyl-piperidin-4-yl, For example, a compound selected from the following: Derivative 2 of the formula: 【Chemistry 14】 [wherein n ranges from 1 to 10]; Derivative 3 of the formula: 【Chemistry 15】 wherein n ranges from 1 to 10, particularly 4 to 5; Derivative 4 of the formula: 【Chemistry 16】 (CAS-No.: 90751-07-8); Derivative 5 of the formula: 【Chemistry 17】 Derivative 8 of the formula: 【Chemistry 18】 (CAS-No.: 199237-39-3); Derivative 9 of the formula: 【Chemistry 19】 wherein R is a group of the formula 【Chemistry 20】 ] (CAS-No.: 136504-96-6); Derivative 15 of the formula: 【Chemistry 21】 。

14. 14. The method of any one of claims 2 to 11 and 13, wherein the peroxide is a peroxide of formula (A) or (B) and the sterically hindered alkoxyamine reaction product conforms to formula (V).

15. At least 6, for example 6 to 100, of formula (Ia): 【Chemical 22】 (wherein the asterisk (*) indicates the location of the bond connecting those groups to the rest of the molecule). Compounds containing the group Preferably, the compound represented by formula (IV) or (V): 【Chemistry 23】 [In the formula, A ２ and R １ is as defined in claims 1 to 14, and R is as defined in the following formula (V): 【Chemistry 24】 [Wherein, n ranges from 1 to 10; R is as defined in claim 1 or 3, preferably C １ ~C ５ alkyl, in particular 1-propyl.

1. An oligomeric or polymeric reaction product comprising an oligomeric or polymeric sterically hindered alkoxyamine compound corresponding to one of 15. A reaction product, characterised in that the oligomeric or polymeric reaction product is obtainable by the process according to any one of claims 1 to 13 or, if the reaction product is of formula (V), alternatively by the process of claim 14.

16. 16. A reaction product according to claim 15, preferably according to the formula (V), which is 87%, typically 90-99.9%, in particular 96-99.9%, of N-OR, where R is C １ ~C ５ The reaction product is characterized in that it contains the N--O moiety in alkylated form as alkyl, particularly 1-propyl.

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