Green preparation method of granular plastic additive

Abstract

The invention relates to a method for producing a particulate plastic additive, comprising the following steps: a) providing at least one additive solution comprising a plastic additive and a solvent, b) optionally mixing the additive solutions, c) subjecting the additive solution to thin-film evaporation to produce a concentrated additive, and d) subjecting the concentrated additive to a heat treatment. D) stirring the concentrated additive under vacuum to produce a hot melt, e) mixing a molten carrier polymer with the concentrated additive during extrusion, and f) cooling and shaping the hot melt comprising the plastic additive and the carrier polymer to produce the particulate plastic additive. The invention also relates to a particulate plastic additive obtainable by this method.

Description

[0001] The present invention relates to a method for preparing a granular plastic additive, the method comprising the following steps

[0002] a) providing at least one additive solution, the at least one additive solution comprising a plastic additive and a solvent,

[0003] b) optionally mixing these additive solutions,

[0004] c) subjecting the additive solution to thin film evaporation to produce a concentrated additive,

[0005] d) stirring the additive concentrate under vacuum to produce a hot melt,

[0006] e) mixing a molten carrier polymer with the additive concentrate during extrusion, and

[0007] f) cooling and shaping the hot melt comprising the plastic additive and the carrier polymer to produce the granulated plastic additive.

[0008] The invention also relates to a granulated plastic additive obtainable by this process.

[0009] Organic polymers often require the addition of plastic additives in order to facilitate processing and to retain their properties in use for as long as possible. In addition to light and heat, factors that have a damaging effect on organic polymers include residues of catalysts used during preparation. Generally speaking, additives and additive mixtures can be in the form of powders, granules or solutions.

[0010] The aim was to find a process for preparing granular plastic additives which are homogeneously formed, have an adjustable particle size, good flowability, considerable abrasion resistance, low dust levels, good storage stability and which can be easily metered into the organic polymer to be stabilized. Another advantage of the process for preparing granular plastic additives is that the procedure for obtaining the final sales product is significantly simplified and a large part of the handling of the powder is eliminated. Finally, there are sustainability advantages, drying by precipitation from water is avoided and the energy requirement is reduced net.

[0011] These objects are achieved by a method for preparing a granulated plastic additive, which comprises the following steps

[0012] a) providing at least one additive solution, the at least one additive solution comprising a plastic additive and a solvent,

[0013] b) optionally mixing these additive solutions,

[0014] c) subjecting the additive solution to thin film evaporation to produce a concentrated additive,

[0015] d) stirring the additive concentrate under vacuum to produce a hot melt,

[0016] e) mixing a molten carrier polymer with the additive concentrate during extrusion, and

[0017] f) cooling and shaping the hot melt comprising the plastic additive and the carrier polymer to produce the granulated plastic additive.

[0018] These objects are also achieved by a granular plastics additive obtainable by the process.

[0019] Step a)

[0020] Step a) is to provide at least one additive solution, the at least one additive solution comprising a plastic additive and a solvent.

[0021] The additive solution comprises a plastic additive and a solvent. The additive solution may comprise at least one (e.g. one, two or three) plastic additives. Preferably, the additive solution comprises one plastic additive and a solvent. The additive solution may be provided at room temperature or at an elevated temperature (e.g. up to a few degrees below the boiling point of the solution, e.g. 10°C to 100°C). The additive solution is preferably provided at at least 50°C, and in particular at least 70°C.

[0022] At least one additive solution is provided, such as one, two or three additive solutions. In a preferred form, one additive solution is provided and step b) of mixing the additive solutions is not applicable. In another preferred form, at least two additive solutions are provided and step b) of mixing the additive solutions is applicable. In the case of providing at least two additive solutions, each additive solution may contain a different plastic additive. In the case of providing at least two additive solutions, each additive solution may contain the same solvent or different solvents.

[0023] The solvent can be any solvent or a mixture of different solvents. Often, the solvent is a solvent used in the previous synthesis of plastic additives. Preferably, the solvent comprises toluene, xylene, ethylbenzene, trimethylbenzene, isopropylbenzene, diisopropylbenzene, water-insoluble organic ketones (such as methyl ethyl ketone or methyl isobutyl ketone) or a mixture thereof. In particular, the solvent comprises xylene, ethylbenzene and toluene, and especially xylene. The solvent typically comprises at least 60, 80 or 90wt% of toluene, xylene, ethylbenzene, trimethylbenzene, isopropylbenzene, diisopropylbenzene, water-insoluble organic ketones or a mixture thereof. The solvent typically comprises preferably at least 60, 80 or 90wt% of xylene.

[0024] The additive solution comprises at least 15, 25, 35, 40 or 45 wt% solvent. Preferably, the additive solution comprises at least 25 wt%, and in particular at least 50 wt% solvent.

[0025] Suitable plastic additives are any plastic additives, such as antioxidants, UV absorbers, light stabilizers, metal deactivators, phosphites, phosphonates, hydroxylamine and amine N-oxides, nitrones, thiosynergists, peroxide scavengers, acid scavengers, alkaline co-stabilizers, nucleating agents, benzofuranones and indolinones, and flame retardants.

[0026] Suitable antioxidants are:

[0027] 1. Antioxidants

[0028] 1.1. Alkylated monophenols, for example 2,6-di-tert-butyl-4-methylphenol, 2-tert-butyl-4,6-dimethylphenol, 2,6-di-tert-butyl-4-ethylphenol, 2,6-di-tert-butyl-4-n-butylphenol, 2,6-di-tert-butyl-4-isobutylphenol, 2,6-dicyclopentyl-4-methylphenol, 2-(α-methylcyclohexyl)-4,6-dimethylphenol, 2,6-dioctadecyl-4-methylphenol, 2,4,6-tricyclohexylphenol, 2,6- Di-tert-butyl-4-methoxymethylphenol, nonylphenol with a linear or branched side chain, such as 2,6-dinonyl-4-methylphenol, 2,4-dimethyl-6-(1'-methylundecane-1'-yl)phenol, 2,4-dimethyl-6-(1'-methylheptadecan-1'-yl)phenol, 2,4-dimethyl-6-(1'-methyltridecane-1'-yl)phenol, 2,4-dimethyl-6-(1'-methyl-1'-tetradecyl-methyl)phenol, and mixtures thereof.

[0029] 1.2. Alkylthiomethylphenols, for example 2,4-dioctylthiomethyl-6-tert-butylphenol, 2,4-dioctylthiomethyl-6-methylphenol, 2,4-dioctylthiomethyl-6-ethylphenol, 2,6-di-dodecylthiomethyl-4-nonylphenol.

[0030] 1.3. Hydroquinones and alkylated hydroquinones, for example 2,6-di-tert-butyl-4-methoxyphenol, 2,5-di-tert-butylhydroquinone, 2,5-di-tert-amylhydroquinone, 2,6-diphenyl-4-octadecyloxyphenol, 2,6-di-tert-butylhydroquinone, 2,5-di-tert-butyl-4-hydroxyanisole, 3,5-di-tert-butyl-4-hydroxyanisole, 3,5-di-tert-butyl-4-hydroxyphenyl stearate, bis(3,5-di-tert-butyl-4-hydroxyphenyl) adipate.

[0031] 1.4. Tocopherols, such as α-tocopherol, β-tocopherol, γ-tocopherol, δ-tocopherol and mixtures thereof (vitamin E), vitamin E acetate. Particularly preferred is the addition of 2,5,7,8-tetramethyl-2-[4,8,12-trimethyltridecyl]-chroman-6-ol], a commercially available vitamin E (e.g. Irganox E 201 TM ).

[0032] 1.5. Hydroxylated thiodiphenyl ethers, for example 2,2'-thiobis(6-tert-butyl-4-methylphenol), 2,2'-thiobis(4-octylphenol), 4,4'-thiobis(6-tert-butyl-3-methylphenol), 4,4'-thiobis(6-tert-butyl-2-methylphenol), 4,4'-thiobis(3,6-di-sec-pentylphenol), 4,4'-bis(2,6-dimethyl-4-hydroxyphenyl) disulfide.

[0033] 1.6. Alkylene bisphenols, for example 2,2'-methylenebis(6-tert-butyl-4-methylphenol), 2,2'-methylenebis(6-tert-butyl-4-ethylphenol), 2,2'-methylenebis[4-methyl-6-(α-methylcyclohexyl)phenol], 2,2'-methylenebis(4-methyl-6-cyclohexylphenol), 2,2'-methylenebis(6-nonyl-4-methylphenol), 2,2'-methylenebis(4,6-di-tert-butyl ...4-methyl-6-cyclohexylphenol), 2,2'-methylenebis(4 Ethyl bis(4,6-di-tert-butylphenol), 2,2'-ethylene bis(6-tert-butyl-4-isobutylphenol), 2,2'-methylene bis[6-(α-methylbenzyl)-4-nonylphenol], 2,2'-methylene bis[6-(α,α-dimethylbenzyl)-4-nonylphenol], 4,4'-methylene bis(2,6-di-tert-butylphenol), 4,4'-methylene bis(6-tert-butyl-2-methylphenol), 1,1-bis(5-tert-butyl-4-hydroxy-2 -methylphenyl)butane, 2,6-bis(3-tert-butyl-5-methyl-2-hydroxybenzyl)-4-methylphenol, 1,1,3-tri(5-tert-butyl-4-hydroxy-2-methylphenyl)butane, 1,1-bis(5-tert-butyl-4-hydroxy-2-methylphenyl)-3-n-dodecylmercaptobutane, ethylene glycol bis[3,3-bis(3'-tert-butyl-4'-hydroxyphenyl)butyrate], bis(3-tert-butyl-4-hydroxy-5-methyl-phenyl)dicyclopentadiene, Bis[2-(3'-tert-butyl-2'-hydroxy-5'-methylbenzyl)-6-tert-butyl-4-methylphenyl]terephthalate, 1,1-bis-(3,5-dimethyl-2-hydroxyphenyl)butane, 2,2-bis(3,5-di-tert-butyl-4-hydroxyphenyl)propane, 2,2-bis-(5-tert-butyl-4-hydroxy-2-methylphenyl)-4-n-dodecylmercaptobutane, 1,1,5,5-tetrakis(5-tert-butyl-4-hydroxy-2-methylphenyl)pentane.

[0034] 1.7. O-, N- and S-benzyl compounds, for example 3,5,3',5'-tetra-tert-butyl-4,4'-dihydroxydibenzyl ether, octadecyl 4-hydroxy-3,5-dimethylbenzylmercaptoacetate, tridecyl 4-hydroxy-3,5-di-tert-butylbenzylmercaptoacetate, tris(3,5-di-tert-butyl-4-hydroxybenzyl)amine, bis(4-tert-butyl-3-hydroxy-2,6-dimethylbenzyl)dithioterephthalate, bis(3,5-di-tert-butyl-4-hydroxybenzyl) sulfide, isooctyl 3,5-di-tert-butyl-4-hydroxybenzylmercaptoacetate.

[0035] 1.8. Hydroxybenzylated malonates, for example dioctadecyl 2,2-bis(3,5-di-tert-butyl-2-hydroxybenzyl)malonate, dioctadecyl 2-(3-tert-butyl-4-hydroxy-5-methylbenzyl)malonate, didodecylmercaptoethyl 2,2-bis(3,5-di-tert-butyl-4-hydroxybenzyl)malonate, bis[4-(1,1,3,3-tetramethylbutyl)phenyl]2,2-bis(3,5-di-tert-butyl-4-hydroxybenzyl)malonate.

[0036] 1.9. Aromatic hydroxybenzyl compounds, for example 1,3,5-tris(3,5-di-tert-butyl-4-hydroxybenzyl)-2,4,6-trimethylbenzene, 1,4-bis(3,5-di-tert-butyl-4-hydroxybenzyl)-2,3,5,6-tetramethylbenzene, 2,4,6-tris(3,5-di-tert-butyl-4-hydroxybenzyl)phenol.

[0037] 1.10. Triazine compounds, for example 2,4-bis(octylmercapto)-6-(3,5-di-tert-butyl-4-hydroxyanilino)-1,3,5-triazine, 2-octylmercapto-4,6-bis(3,5-di-tert-butyl-4-hydroxyanilino)-1,3,5-triazine, 2-octylmercapto-4,6-bis(3,5-di-tert-butyl-4-hydroxyphenoxy)-1,3,5-triazine, 2,4,6-tris(3,5-di-tert-butyl-4-hydroxyphenoxy)-1,2,3-triazine, 1,3,5-Tris(3,5-di-tert-butyl-4-hydroxybenzyl) isocyanurate, 1,3,5-tris(4-tert-butyl-3-hydroxy-2,6-dimethylbenzyl) isocyanurate, 2,4,6-tris(3,5-di-tert-butyl-4-hydroxyphenylethyl)-1,3,5-triazine, 1,3,5-tris(3,5-di-tert-butyl-4-hydroxyphenylpropionyl)-hexahydro-1,3,5-triazine, 1,3,5-tris(3,5-dicyclohexyl-4-hydroxybenzyl) isocyanurate.

[0038] 1.11. Benzylphosphonates, for example dimethyl 2,5-di-tert-butyl-4-hydroxybenzylphosphonate, diethyl 3,5-di-tert-butyl-4-hydroxybenzylphosphonate, dioctadecyl 3,5-di-tert-butyl-4-hydroxybenzylphosphonate, dioctadecyl 5-tert-butyl-4-hydroxy-3-methylbenzylphosphonate, the calcium salt of the monoethyl ester of 3,5-di-tert-butyl-4-hydroxybenzylphosphonic acid, (3,5-di-tert-butyl-4-hydroxyphenyl)methylphosphonic acid.

[0039] 1.12. Acylaminophenols, for example 4-hydroxylauroylanilide, 4-hydroxystearoylanilide, octyl N-(3,5-di-tert-butyl-4-hydroxyphenyl)carbamate.

[0040] 1.13. Esters of β-(3,5-di-tert-butyl-4-hydroxyphenyl)propionic acid with mono- or polyhydric alcohols, for example esters with methanol, ethanol, n-octanol, isooctyl alcohol, mixtures of linear and branched C7-C9-alkanols, octadecyl alcohol, linear and branched C 13 -C 15 -alkanol mixtures, 1,6-hexanediol, 1,9-nonanediol, ethylene glycol, 1,2-propylene glycol, neopentyl glycol, thiodiethylene glycol, diethylene glycol, triethylene glycol, tetraethylene glycol, pentaerythritol, tris(hydroxyethyl)isocyanurate, N,N'-bis-(hydroxyethyl)oxamide, 3-thiaundecanol, 3-thiapentadecanol, trimethylhexanediol, trimethylolpropane, 4-hydroxymethyl-1-phospha-2,6,7-trioxabicyclo[2.2.2]octane. Preference is given to esters of β-(3,5-di-tert-butyl-4-hydroxyphenyl)propionic acid, in particular with octadecyl alcohol, such as the addition of octadecyl-3-(3,5-di-tert-butyl-4-hydroxyphenyl)propionic acid, which is available as, for example, Irganox 1076 TM Commercially available.

[0041] 1.14. Esters of β-(5-tert-butyl-4-hydroxy-3-methylphenyl)propionic acid with mono- or polyols, for example esters with methanol, ethanol, n-octanol, isooctyl alcohol, octadecanol, 1,6-hexanediol, 1,9-nonanediol, ethylene glycol, 1,2-propylene glycol, neopentyl glycol, thiodiethylene glycol, diethylene glycol, triethylene glycol, pentaerythritol, tris(hydroxyethyl)isocyanurate, N,N'-bis( hydroxyethyl)oxalamide, 3-thiaundecanol, 3-thiapentadecanol, trimethyl hexanediol, trimethylolpropane, 4-hydroxymethyl-1-phospha-2,6,7-trioxabicyclo[2.2.2]octane; 3,9-bis[2-{3-(3-tert-butyl-4-hydroxy-5-methylphenyl)propionyloxy}-1,1-dimethylethyl]-2,4,8,10-tetraoxaspiro[5.5]undecane.

[0042] 1.15. Esters of β-(3,5-dicyclohexyl-4-hydroxyphenyl)propionic acid with mono- or polyhydric alcohols, for example esters with methanol, ethanol, octanol, octadecanol, 1,6-hexanediol, 1,9-nonanediol, ethylene glycol, 1,2-propylene glycol, neopentyl glycol, thiodiethylene glycol, diethylene glycol, triethylene glycol, pentaerythritol, tris(hydroxyethyl)isocyanurate, N,N'-bis(hydroxyethyl)oxamide, 3-thiaundecanol, 3-thiapentadecanol, trimethylhexanediol, trimethylolpropane, 4-hydroxymethyl-1-phospha-2,6,7-trioxabicyclo[2.2.2]octane.

[0043] 1.16. Esters of 3,5-di-tert-butyl-4-hydroxyphenylacetic acid with mono- or polyhydric alcohols, for example esters with methanol, ethanol, octanol, octadecanol, 1,6-hexanediol, 1,9-nonanediol, ethylene glycol, 1,2-propylene glycol, neopentyl glycol, thiodiethylene glycol, diethylene glycol, triethylene glycol, pentaerythritol, tris(hydroxyethyl)isocyanurate, N,N'-bis(hydroxyethyl)oxamide, 3-thiaundecanol, 3-thiapentadecanol, trimethylhexanediol, trimethylolpropane, 4-hydroxymethyl-1-phospha-2,6,7-trioxabicyclo[2.2.2]octane.

[0044] 1.17. Amides of β-(3,5-di-tert-butyl-4-hydroxyphenyl)propionic acid, for example N,N′-bis(3,5-di-tert-butyl-4-hydroxyphenylpropionyl)hexamethylene diamide, N,N′-bis(3,5-di-tert-butyl-4-hydroxyphenylpropionyl)trimethylene diamide, N,N′-bis(3,5-di-tert-butyl-4-hydroxyphenylpropionyl)hydrazine, N,N′-bis[2-(3-[3,5-di-tert-butyl-4-hydroxyphenyl]propionyloxy)ethyl]oxalamide (Naugard XL-1).

[0045] 1.18. Ascorbic acid (vitamin C)

[0046] 1.19. Amine antioxidants, for example, N,N'-diisopropyl-p-phenylenediamine, N,N'-di-sec-butyl-p-phenylenediamine, N,N'-bis(1,4-dimethylpentyl)-p-phenylenediamine, N,N'-bis(1-ethyl-3-methylpentyl)-p-phenylenediamine, N,N'-bis(1-methylheptyl)-p-phenylenediamine, N,N'-dicyclohexyl-p-phenylenediamine, N,N'-diphenyl-p-phenylenediamine, N,N'-bis(2-naphthyl)-p-phenylenediamine, N-isopropyl-N'-phenyl-p-phenylenediamine, N-(1,3-dimethylbutyl)-N'-phenyl-p-phenylenediamine, N-(1-methylheptyl)-N'- phenyl-p-phenylenediamine, N-cyclohexyl-N'-phenyl-p-phenylenediamine, 4-(p-toluenesulfamoyl)diphenylamine, N,N'-dimethyl-N,N'-di-sec-butyl-p-phenylenediamine, diphenylamine, N-allyldiphenylamine, 4-isopropoxydiphenylamine, N-phenyl-1-naphthylamine, N-(4-tert-octylphenyl)-1-naphthylamine, N-phenyl-2-naphthylamine, octylated diphenylamines such as p-, p-'-di-tert-octyldiphenylamine, 4-n-butylaminophenol, 4-butyrylaminophenol, 4-nonanoylaminophenol, 4-dodecanoylaminophenol, 4-octadecanoylaminophenol, bis(4-methoxyphenyl)- 1,2-bis[(2-methylphenyl)amino]ethane, 1,2-bis(phenylamino)propane, (o-tolyl)biguanide, bis[4-(1',3'-dimethylbutyl)phenyl]amine, tert-octylated N-phenyl-1-naphthylamine, mixtures of mono- and di-alkylated tert-butyl / tert-octyl diphenylamines, mixtures of mono- and di-alkylated nonyl diphenylamines, mixtures of mono- and di-alkylated nonyl diphenylamines, mixtures of monoalkylated dodecyldiphenylamines, mixtures of mono- and dialkylated isopropyl / isohexyldiphenylamines, mixtures of mono- and dialkylated tert-butyldiphenylamines, 2,3-dihydro-3,3-dimethyl-4H-1,4-benzothiazine, phenothiazine, mixtures of mono- and dialkylated tert-butyl / tert-octyl phenothiazines or mixtures of mono- and dialkylated tert-octyl phenothiazines, N-allyl phenothiazine, N,N,N',N'-tetraphenyl-1,4-diaminobut-2-ene, N-[(1,1,3,3-tetramethylbutyl)phenyl]-1-naphthylamine] (as Irganox L06 TM Commercially available).

[0047] Suitable UV absorbers and light stabilizers are:

[0048] 2.UV absorbers and light stabilizers

[0049] 2.1.2-(2'-Hydroxyphenyl)benzotriazoles, for example 2-(2'-hydroxy-5'-methylphenyl)benzotriazole, 2-(3',5'-di-tert-butyl-2'-hydroxyphenyl)benzotriazole, 2-(5'-tert-butyl-2'-hydroxyphenyl)benzotriazole, 2-(2'-hydroxy-5'-(1,1,3,3-tetramethylbutyl)phenyl)benzotriazole, 2-(3',5'-di-tert-butyl-2'-hydroxyphenyl)-5-chlorobenzotriazole, 2-(3'-tert-butyl-2'-hydroxy-5'-methylphenyl)-5-chlorobenzotriazole, 2-(3'-sec-butyl-5'-tert-butyl-2'-hydroxyphenyl)benzotriazole 2-(2'-hydroxy-4'-octyloxyphenyl)benzotriazole, 2-(3',5'-di-tert-amyl-2'-hydroxyphenyl)benzotriazole, 2-(3',5'-di(α,α-dimethylbenzyl)-2'-hydroxyphenyl)benzotriazole, 2-(3'-tert-butyl-2'-hydroxy-5'-(2-octyloxycarbonylethyl)phenyl)-5-chlorobenzotriazole, 2-(3'-tert-butyl-5'-[2-(2-ethylhexyloxy)carbonylethyl]-2'-hydroxyphenyl)-5-chlorobenzotriazole, 2-(3'-tert-butyl-2'-hydroxy-5'-(2-methoxycarbonylethyl)phenyl)-5-chlorobenzotriazole, '-tert-butyl-2'-hydroxy-5'-(2-methoxycarbonylethyl)phenyl)benzotriazole, 2-(3'-tert-butyl-2'-hydroxy-5'-(2-octyloxycarbonylethyl)phenyl)benzotriazole, 2-(3'-tert-butyl-5'-[2-(2-ethylhexyloxy)carbonylethyl]-2'-hydroxyphenyl)benzotriazole, 2-(3'-dodecyl-2'-hydroxy-5'-methylphenyl)benzotriazole, 2-(3'-tert-butyl-2'-hydroxy-5'-(2-isooctyloxycarbonylethyl)phenylbenzotriazole, 2,2'-methylenebis[4-(1,1,3,3-tetramethylbutyl)-6-benzotriazol-2-ylphenyl] Phenol]; ester exchange product of 2-[3'-tert-butyl-5'-(2-methoxycarbonylethyl)-2'-hydroxyphenyl]-2H-benzotriazole and polyethylene glycol 300; [R'-CH2-CH2-CO-O-CH2-CH2-]2——wherein R'=3'-tert-butyl-4'-hydroxy-5'-2H-benzotriazol-2-ylphenyl, 2-[2'-hydroxy-3'-(α,α-dimethylbenzyl)-5'-(1,1,3,3-tetramethylbutyl)phenyl]benzotriazole; 2-[2'-hydroxy-3'-(1,1,3,3-tetramethylbutyl)-5'-(α,α-dimethylbenzyl)phenyl]benzotriazole.

[0050] 2.2.2-Hydroxybenzophenones, for example 4-hydroxy, 4-methoxy, 4-octyloxy, 4-decyloxy, 4-dodecyloxy, 4-benzyloxy, 4,2',4'-trihydroxy and 2'-hydroxy-4,4'-dimethoxy derivatives.

[0051] 2.3. Esters of substituted and unsubstituted benzoic acid, for example 4-tert-butylphenyl salicylate, phenyl salicylate, octylphenyl salicylate, dibenzoylresorcinol, bis(4-tert-butylbenzoyl)resorcinol, benzoylresorcinol, 2,4-di-tert-butylphenyl 3,5-di-tert-butyl-4-hydroxybenzoate, hexadecyl 3,5-di-tert-butyl-4-hydroxybenzoate, octadecyl 3,5-di-tert-butyl-4-hydroxybenzoate, 2-methyl-4,6-di-tert-butylphenyl 3,5-di-tert-butyl-4-hydroxybenzoate.

[0052] 2.4. Acrylic esters, for example ethyl α-cyano-β,β-diphenylacrylate, isooctyl α-cyano-β,β-diphenylacrylate, methyl α-carbonylmethoxycinnamate, methyl α-cyano-β-methyl-p-methoxycinnamate, butyl α-cyano-β-methyl-p-methoxycinnamate, methyl α-carbonylmethoxy-p-methoxycinnamate, N-(β-carbonylmethoxy-β-cyanovinyl)-2-methylindoline and neopentyl tetrakis(α-cyano-β,β-diphenylacrylate), or sterically hindered acrylates, As disclosed in EP-A-3587425, such as, for example, (2E,2'E)-2,4,8,10-tetraoxaspiro[5.5]undecane-3,9-diylbis(2-methylpropane-2,1-diyl)bis(2-cyano-3-(3,4-dimethoxyphenyl)acrylate) [CAS Reg. No. 2233585-18-5], or similar derivatives, wherein one of the two OCH3 groups (methoxy) of each (2-cyano-3-(3,4-dimethoxyphenyl)acrylate) moiety is replaced by OC6H 13 The group is replaced to obtain a bis(2-cyano-3-(3-methoxy-4-hexyloxyphenyl)acrylate) derivative.

[0053] 2.5. Nickel compounds, for example nickel complexes of 2,2′-thiobis[4-(1,1,3,3-tetramethylbutyl)phenol], such as the 1:1 or 1:2 complex, with or without additional ligands such as n-butylamine, triethanolamine or N-cyclohexyldiethanolamine, nickel dibutyldithiocarbamate, the nickel salt of a monoalkyl ester, for example the methyl or ethyl ester, of 4-hydroxy-3,5-di-tert-butylbenzylphosphonic acid, nickel complexes of ketoximes, for example 2-hydroxy-4-methylphenylundecylketoxime, nickel complexes of 1-phenyl-4-lauroyl-5-hydroxypyrazole with or without additional ligands.

[0054] 2.6. Sterically hindered amines (also called HALS), for example bis(2,2,6,6-tetramethyl-4-piperidinyl) sebacate, bis(2,2,6,6-tetramethyl-4-piperidinyl) succinate, bis(1,2,2,6,6-pentamethyl-4-piperidinyl) sebacate, bis(1,2,2,6,6-pentamethyl-4-piperidinyl) n-butyl-3,5-di-tert-butyl-4-hydroxybenzylmalonate, condensate of 1-(2-hydroxyethyl)-2,2,6,6-tetramethyl-4-hydroxypiperidine and succinic acid, linear or cyclic condensate of N,N'-bis(2,2,6,6-tetramethyl-4-piperidinyl)hexamethylenediamine and 4-tert-octylamino-2,6-dichloro-1,3,5-triazine, secondary Tris(2,2,6,6-tetramethyl-4-piperidinyl)nitrilotriacetate, tetra(2,2,6,6-tetramethyl-4-piperidinyl)1,2,3,4-butanetetracarboxylate, 1,1'-(1,2-ethanediyl)-bis(3,3,5,5-tetramethylpiperazinone), 4-benzoyl-2,2,6,6-tetramethylpiperidine, 4-stearyloxy-2,2,6,6-tetramethylpiperidine, bis(1,2,2,6,6-pentamethylpiperidinyl)-2-n-butyl-2-(2-hydroxy-3,5-di-tert-butylbenzyl)malonate, 3-n-octyl-7,7,9,9-tetramethyl-1,3,8-triazaspiro[4.5]decane-2,4-dione, bis(1-octyloxy-2,2,6,6-tetramethylpiperidinone)sebacate bis(1-octyloxy-2,2,6,6-tetramethylpiperidin-4-yl) succinate, bis[2,2,6,6-tetramethyl-1-(undecyloxy)-piperidin-4-yl] carbonate, linear or cyclic condensate of N,N'-bis(2,2,6,6-tetramethyl-4-piperidinyl)-hexamethylenediamine and 4-morpholino-2,6-dichloro-1,3,5-triazine, condensate of 2-chloro-4,6-bis(4-n-butylamino-2,2,6,6-tetramethylpiperidinyl)-1,3,5-triazine and 1,2-bis(3-aminopropylamino)ethane, 2-chloro-4,6-bis(4-n-butylamino-1,2,2,6,6-pentamethylpiperidinyl)-1,3,5-triazine 1,2-bis(3-aminopropylamino)ethane condensate, 8-acetyl-3-dodecyl-7,7,9,9-tetramethyl-1,3,8-triazaspiro[4.5]decane-2,4-dione, 3-dodecyl-1-(2,2,6,6-tetramethyl-4-piperidinyl)pyrrolidine-2,5-dione, 3-dodecyl-1-(1,2,2,6,6-pentamethyl-4-piperidinyl)pyrrolidine-2,5-dione, a mixture of 4-hexadecyloxy- and 4-stearyloxy-2,2,6,6-tetramethylpiperidine, a condensate of N,N'-bis(2,2,6,6-tetramethyl-4-piperidinyl)hexamethylenediamine and 4-cyclohexylamino-2,6-dichloro-1,3,5-triazine, 1,2-bis(3-aminopropylamino)ethane, condensate of 2,4,6-trichloro-1,3,5-triazine and 4-butylamino-2,2,6,6-tetramethylpiperidine (CAS Registry No. [136504-96-6]); 1,6-hexanediamine, 2,4,6-trichloro-1,3,5-triazine, N,N-dibutylamine and 4-butylamino-2,2,6,6-tetramethylpiperidine (CAS Registry No. [192268-64-7]); N6,N6'-hexane-1,6-diylbis[N2,N4-dibutyl-N2,N4,N6-tris(2,2,6,6-tetramethylpiperidin-4-yl)-1,3,5-triazine-2,4,6-triamine], butyraldehyde and hydrogen peroxide reaction products; N-(2,2,6,6-tetramethyl-4-piperidinyl)-n-dodecylsuccinimide, N-(1,2,2,6,6-pentamethyl-4-piperidinyl)-n-dodecylsuccinimide, 2-undecyl-7,7,9,9-tetramethyl-1-oxa-3,8-diaza-4-oxospiro[4,5]decane, reaction products of 7,7,9,9-tetramethyl-2-cycloundecyl-1-oxa-3,8-diaza-4-oxospiro[4,5]decane and epichlorohydrin, 1,1-bis(1,2,2,6,6-pentamethyl-4-piperidinyloxycarbonyl)-2-(4-methoxyphenyl)ethylene, N,N'-bisformyl-N,N'-bis(2,2,6,6-tetramethyl-4-piperidinyloxycarbonyl)- 1,2,2,6,6-pentamethyl-4-aminopiperidine, the reaction product of N,N'-bis(2,2,6,6-tetramethyl-1-propoxypiperidin-4-yl)-hexane-1,6-diamine and 2,4-dichloro-6-{n-butyl-(2,2,6,6-tetramethyl-1-propoxypiperidin-4-yl)amino}-[1,3,5]triazine with 2-chloro-4,6-dichloro-6-{n-butyl-(2,2,6,6-tetramethyl-1-propoxypiperidin-4-yl)amino}-[1,3,5]triazine. A mixture of oligomeric compounds of dimethylol formal condensation products terminated with (di-n-butylamino)-[1,3,5]triazine, which is a mixture of oligomeric compounds of dimethylol formal condensation products terminated with 2-chloro-4,6-bis(di-n-butylamino)-[1,3,5]triazine and N,N'-bis(2,2,6,6-tetramethylpiperidin-4-yl)-hexane-1,6-diamine and 2,4-dichloro-6-{n-butyl-(2,2,6,6-tetramethylpiperidin-4-yl)amino}-[1,3,5]triazine, (N2,N4-dibutyl-N2,N4-bis(1,2,2,6,6-pentamethyl-4-piperidinyl)-6-(1-pyrrolidinyl)-[1,3,5]-triazine-2,4-diamine, 2,4-Bis[N-(1-cyclohexyloxy-2,2,6,6-tetramethylpiperidin-4-yl)-N-butylamino]-6-(2-hydroxyethyl)amino-1,3,5-triazine, 1-(2-hydroxy-2-methylpropoxy)-4-octadecanoyloxy-2,2,6,6-tetramethylpiperidine, 5-(2-ethylhexanoyl)oxymethyl-3,3,5-trimethyl-2-morpholinone, Sanduvor (Clariant; CAS Reg. No. [106917-31-1]), 5-(2-ethylhexanoyl)oxymethyl-3,3,5-trimethyl-2-morpholinone 1,3,5-tri(N-cyclohexyl-N-(2,2,6,6-tetramethylpiperazin-3-one-4-yl)amino)-s-triazine, 1,3,5-tri(N-cyclohexyl-N-(1,2,2,6,6-pentamethylpiperazin-3-one-4-yl)amino)-s-triazine,

[0055] Dimethyl succinate, polymer with 4-hydroxy-2,2,6,6-tetramethyl-1-piperidinylethanol (CAS 65447-77-0),

[0056] Poly[[6-[(1,1,3,3-tetramethylbutyl)amino]-1,3,5-triazine-2,4-diyl][(2,2,6,6-tetramethyl-4-piperidinyl)imino]-1,6-hexanediyl[(2,2,6,6-tetramethyl-4-piperidinyl)imino]])(CAS 71878-19-8),

[0057] 2,2,4,4-Tetramethyl-7-oxa-3,20-diazabispiro[5.1.11.2]heneicosan-21-one hydrochloride and hydrolyzed epichlorohydrin polymer (CAS 202483-55-4),

[0058] N,N'-Bis(2,2,6,6-tetramethyl-4-piperidinyl)-1,6-hexanediamine polymer with morpholine-2,4,6-trichloro-1,3,5-triazine (CAS 193098-40-7)

[0059] 1,2,3,4-Butanetetracarboxylic acid, polymer with 2,2-bis(hydroxymethyl)-1,3-propanediol, 3-hydroxy-2,2-dimethylpropanal, 1,2,2,6,6-pentamethyl-4-piperidinyl ester (CAS 101357-36-2)

[0060] Tetrakis(1,2,2,6,6-pentamethyl-4-piperidinyl)1,2,3,4-butanetetracarboxylate (91788-83-9),

[0061] N,N"'-[1,2-ethane-diyl-bis[[[4,6-bis-[butyl(1,2,2,6,6-pentamethyl-4-piperidinyl)amino]-1,3,5-triazine-2-yl]imino]-3,1-propanediyl]]bis[N',N"-dibutyl-N',N"-bis(1,2,2,6,6-pentamethyl-4-piperidinyl)-1,3,5-triazine-2,4,6-triamine (CAS 106990-43-6), or

[0062] A light stabilizer having formula (II) wherein X2 is n-butyl

[0063]

[0064] 2.7. Oxamides, for example 4,4'-dioctyloxyoxalanilide, 2,2'-diethoxyoxalanilide, 2,2'-dioctyloxy-5,5'-di-tert-butyloxalanilide, 2,2'-di-dodecyloxy-5,5'-di-tert-butyloxalanilide, 2-ethoxy-2'-ethyloxalanilide, N,N'-bis(3-dimethylaminopropyl)oxalamide, 2-ethoxy-5-tert-butyl-2'-ethyloxalanilide and mixtures thereof with 2-ethoxy-2'-ethyl-5,4'-di-tert-butyloxalanilide, mixtures of o- and p-methoxy disubstituted oxalanilides and mixtures of o- and p-ethoxy disubstituted oxalanilides.

[0065] 2.8. 2-(2-Hydroxyphenyl)-1,3,5-triazines, for example 2,4,6-tris(2-hydroxy-4-octyloxyphenyl)-1,3,5-triazine, 2-(2-hydroxy-4-octyloxyphenyl)-4,6-bis(2,4-dimethylphenyl)-1,3,5-triazine, 2-(2,4-dihydroxyphenyl)-4,6-bis(2,4-dimethylphenyl)-1,3,5-triazine, 2,4-bis(2-hydroxy-4-propoxyphenyl)-6-(2,4-dimethylphenyl)-1,3,5-triazine, 2-( 2-Hydroxy-4-octyloxyphenyl)-4,6-bis(4-methylphenyl)-1,3,5-triazine, 2-(2-hydroxy-4-dodecyloxyphenyl)-4,6-bis(2,4-dimethylphenyl)-1,3,5-triazine, 2-(2-hydroxy-4-tridecyloxyphenyl)-4,6-bis(2,4-dimethylphenyl)-1,3,5-triazine, 2-[2-hydroxy-4-(2-hydroxy-3-butoxypropoxy)phenyl]-4,6-bis(2,4-dimethyl)-1,3,5-triazine, 2-[2-hydroxy- 4-(2-hydroxy-3-octyloxypropoxy)phenyl]-4,6-bis(2,4-dimethyl)-1,3,5-triazine, 2-[4-(dodecyloxy / tridecyloxy-2-hydroxypropoxy)-2-hydroxyphenyl]-4,6-bis(2,4-dimethylphenyl)-1,3,5-triazine, 2-[2-hydroxy-4-(2-hydroxy-3-dodecyloxypropoxy)phenyl]-4,6-bis(2,4-dimethylphenyl)-1,3,5-triazine, 2-(2-hydroxy-4-hexyloxy)phenyl-4,6-diphenyl- 1,3,5-triazine, 2-(2-hydroxy-4-methoxyphenyl)-4,6-diphenyl-1,3,5-triazine, 2,4,6-tris[2-hydroxy-4-(3-butoxy-2-hydroxypropoxy)phenyl]-1,3,5-triazine, 2-(2-hydroxyphenyl)-4-(4-methoxyphenyl)-6-phenyl-1,3,5-triazine, 2-{2-hydroxy-4-[3-(2-ethylhexyl-1-oxy)-2-hydroxypropoxy]phenyl}-4,6-bis(2,4-dimethylphenyl)-1,3,5-triazine.

[0066] The plastic additive is preferably an oxidation and hydrogenation reaction product of a polymer of N1,N6-bis(2,2,6,6-tetramethyl-4-piperidinyl)-1,6-hexanediamine and 2,4,6-trichloro-1,3,5-triazine with 3-bromo-1-propylene, N-butyl-1-butylamine and N-butyl-2,2,6,6-tetramethyl-4-piperidinamine, which has a CAS number of 247243-62-5.

[0067] The plastic additive preferably comprises a light stabilizer, a UV stabilizer or a mixture thereof.

[0068] The plastic additive is preferably a condensate of 1,6-hexanediamine and 2,4,6-trichloro-1,3,5-triazine and N,N-dibutylamine and 4-butylamino-2,2,6,6-tetramethylpiperidine or a light stabilizer having the formula (I)

[0069]

[0070] In particular, the plastic additives include light stabilizers having formula (I).

[0071] In another preferred form, the plastic additive comprises a light stabilizer having formula (I) and a light stabilizer selected from sterically hindered amines (eg, the sterically hindered amines described in Section 2.6 above).

[0072] In another preferred form, the plastic additive comprises a light stabilizer having formula (I) and a light stabilizer selected from the following

[0073] -Dimethyl succinate, polymer with 4-hydroxy-2,2,6,6-tetramethyl-1-piperidinylethanol (CAS 65447-77-0),

[0074] -poly[[6-[(1,1,3,3-tetramethylbutyl)amino]-1,3,5-triazine-2,4-diyl][(2,2,6,6-tetramethyl-4-piperidinyl)imino]-1,6-hexanediyl[(2,2,6,6-tetramethyl-4-piperidinyl)imino]])(CAS 71878-19-8),

[0075] -2,2,4,4-tetramethyl-7-oxa-3,20-diazadispiro[5.1.11.2]heneicosan-21-one hydrochloride and hydrolyzed epichlorohydrin polymer (CAS 202483-55-4),

[0076] -N,N'-Bis(2,2,6,6-tetramethyl-4-piperidinyl)-1,6-hexanediamine polymer with morpholine-2,4,6-trichloro-1,3,5-triazine (CAS 193098-40-7)

[0077] -1,2,3,4-Butanetetracarboxylic acid, polymer with 2,2-bis(hydroxymethyl)-1,3-propanediol and 3-hydroxy-2,2-dimethylpropanal, 1,2,2,6,6-pentamethyl-4-piperidinyl ester (CAS 101357-36-2),

[0078] -1,2,3,4-butanetetracarboxylic acid tetrakis (1,2,2,6,6-pentamethyl-4-piperidinyl) ester (91788-83-9),

[0079] -1,2,3,4-butanetetracarboxylic acid tetrakis(2,2,6,6-tetramethyl-4-piperidinyl) ester,

[0080] - a linear or cyclic condensate of N,N'-bis(2,2,6,6-tetramethyl-4-piperidinyl)-hexamethylenediamine and 4-morpholino-2,6-dichloro-1,3,5-triazine,

[0081] -1,2-bis(3-aminopropylamino)ethane, condensate of 2,4,6-trichloro-1,3,5-triazine and 4-butylamino-2,2,6,6-tetramethylpiperidine (CAS Registry Number [136504-96-6]),

[0082] -1,6-hexanediamine and 2,4,6-trichloro-1,3,5-triazine and condensation product of N,N-dibutylamine and 4-butylamino-2,2,6,6-tetramethylpiperidine (CAS Registry Number [192268-64-7]),

[0083] - the reaction product of a maleic anhydride-alpha-olefin copolymer and 2,2,6,6-tetramethyl-4-aminopiperidine,

[0084] -N,N"'-[1,2-ethane-diyl-bis[[[4,6-bis-[butyl(1,2,2,6,6-pentamethyl-4-piperidinyl)amino]-1,3,5-triazine-2-yl]imino]-3,1-propanediyl]]bis[N',N"-dibutyl-N',N"-bis(1,2,2,6,6-pentamethyl-4-piperidinyl)-1,3,5-triazine-2,4,6-triamine (CAS 106990-43-6), and

[0085] - a light stabilizer having formula (II).

[0086] Step b)

[0087] Step b) is optionally mixing the additive solutions.

[0088] The additive solutions are typically those obtainable from step a).In a preferred form, an additive solution is provided in step a) and the optional step b) is not applied.

[0089] In another preferred form, at least two additive solutions are provided in step a) and step b) is applied. In another preferred form, at least two additive solutions are provided in step a) and they are mixed in step b).

[0090] The mixing of the additive solution can be achieved in batches or continuously. The mixing of the additive solution can be achieved continuously by a static mixer, for example while feeding to the next step (c). Alternatively, the mixing can be carried out in batches or continuously in a mixing vessel (from which the feed to (c) is continuously drawn).

[0091] The mixing of the additive solutions can be carried out at room temperature or at an elevated temperature (eg, up to a few degrees below the boiling point of the solution, eg, 10°C to 100°C).

[0092] The additive solutions may be mixed in any desired weight ratio.

[0093] Step c)

[0094] Step c) is to subject the additive solution to thin film evaporation to produce a concentrated additive.

[0095] The additive concentrate is usually liquid.The additive concentrate may contain 0.5 to 20 wt%, preferably 1 to 15 wt% and in particular 2 to 10 wt% of a solvent, such as the solvent or solvents used in the additive solution of step a).

[0096] During thin film evaporation, the solvent concentration preferably decreases to produce a concentrated additive containing less than 10 wt%, preferably less than 5 wt% solvent. In another form, during thin film evaporation, the solvent concentration preferably decreases to produce a concentrated additive containing less than 8 wt%, preferably less than 7 wt% solvent.

[0097] Thin film evaporation can refer to the method for continuously evaporating solvent from the thin film of additive solution under reduced pressure and the temperature that optionally rises.The thin film of additive solution can be formed inside or outside on horizontal, inclined, spiral or vertical tube, plate, cylinder or cone shape.Direct current or countercurrent solvent vapor flow can be applied.The thin film can have the thickness of 0.01 to 10mm or 0.1 to 5mm.

[0098] Suitable devices for thin film evaporation are thin film evaporators, spiral tube evaporators, falling film evaporators or rising film evaporators. Suitable designs of these devices are rotary evaporators, which include self-circulation evaporators or forced circulation evaporators, tubular evaporators, full-circulation evaporators or plate evaporators. Devices for thin film evaporation may include additional mechanical elements such as wipers that can support the formation and maintenance of thin films. Such wipers may be used in shell and tube evaporators, wherein the wipers may be fixed to the surface of the rotating inner tube, and the film may be transported on the inner surface of the outer cylinder.

[0099] The temperature and vacuum of the thin film evaporation can be adjusted to the boiling point of the solvent being evaporated. Typically, the temperature of the thin film evaporation is 20°C to 350°C, preferably 40°C to 270°C. In another form, the temperature of the thin film evaporation is 110°C to 220°C, preferably 140°C to 190°C. Often, a heating jacket is used to adjust the temperature. Typically, the vacuum of the thin film evaporation is 1 to 900 mbar, preferably 10 to 500 mbar. The residence time in the evaporator can be 10 seconds to 10 minutes and preferably 10 seconds to 5 minutes.

[0100] Step d)

[0101] Step d) is to stir the concentrated additive under vacuum to produce a hot melt.

[0102] The additive concentrate can be stirred by extrusion or kneading, preferably by extrusion.

[0103] The stirring can be carried out by known apparatuses such as in a single-screw extruder, a multi-screw extruder or a kneader, with a multi-screw extruder being preferred.

[0104] Single screw extruders include, for example, those having an axially oscillating screw.

[0105] Suitable multi-screw extruders are twin-screw extruders, annular extruders and planetary roller extruders, with planetary roller extruders being preferred.

[0106] Twin screw extruders are, for example, counter-rotating intermeshing, counter-rotating non-intermeshing, co-rotating intermeshing and co-rotating non-intermeshing twin screw extruders.

[0107] The planetary roller extruder may have kneading elements like toothed rollers or rollers with grooves and gaps.The extruder unit may comprise one or more conveying sections and one or more accumulating sections.

[0108] In a preferred form, the stirring of the concentrated additive is carried out by extrusion in a single screw extruder. In another preferred form, the stirring of the concentrated additive is carried out by extrusion in a multi-screw extruder. In another preferred form, the stirring of the concentrated additive is carried out by extrusion in a twin-screw extruder. In another preferred form, the stirring of the concentrated additive is carried out by extrusion in a ring extruder. In another preferred form, the stirring of the concentrated additive is carried out by extrusion in a planetary roller extruder.

[0109] The device for stirring (e.g. a multi-screw extruder) is usually temperature controlled. For example, the housing and screws of the device can be heated separately in multiple zones, for example using double jacket heating. Stirring (preferably extruding) is usually carried out at a temperature of 20°C to 300°C, preferably 80°C to 200°C. In another form, stirring (preferably extruding) is carried out at a temperature of 120°C to 250°C, preferably 140°C to 200°C. The temperature during stirring can be adapted to the boiling point of the solvent that may be removed during stirring.

[0110] The stirring (preferably extrusion) is usually carried out under vacuum, for example 0.1 to 500 mbar, preferably 1 to 100 mbar. In another form, the stirring (preferably extrusion) is carried out under a vacuum below 80 mbar, preferably below 50 mbar. The temperature during stirring can also be adapted to the vacuum that may be applied during stirring.

[0111] The solvent concentration can be reduced during stirring (preferably extrusion) under vacuum. During stirring, the solvent concentration can be reduced to produce a hot melt containing less than 10.000 ppm, preferably less than 5000 ppm of solvent. The solvent concentration in the hot melt is generally the same as in the granular plastic additive.

[0112] Preferably, the agitation is performed by extruding the additive concentrate under vacuum to produce a hot melt.

[0113] In another preferred form, the agitation is performed by extruding the additive concentrate under vacuum using a multi-screw extruder to produce a hot melt.

[0114] In another preferred form, the agitation is carried out by extruding the additive concentrate under a vacuum of 1 to 100 mbar to produce a hot melt.

[0115] In another preferred form, the agitation is carried out by extruding the additive concentrate using a multi-screw extruder under a vacuum of 1 to 100 mbar to produce a hot melt.

[0116] In another preferred form, the stirring is carried out by extruding the additive concentrate under a vacuum of 1 to 100 mbar to produce a hot melt, wherein during extrusion the solvent concentration may be reduced to produce a hot melt containing less than 10.000 ppm, preferably less than 5000 ppm, of solvent.

[0117] In another preferred form, the stirring is carried out by extruding the additive concentrate with a multi-screw extruder under a vacuum of 1 to 100 mbar to produce a hot melt, wherein during extrusion the solvent concentration can be reduced to produce a hot melt containing less than 10.000 ppm, preferably less than 5000 ppm of solvent.

[0118] In another preferred form, the stirring is carried out by extruding the concentrated additive under a vacuum of 1 to 100 mbar to produce a hot melt, wherein during extrusion the solvent concentration can be reduced to produce a hot melt containing less than 20.000 ppm, preferably less than 8000 ppm of solvent.

[0119] In another preferred form, the stirring is carried out by extruding the concentrated additive with a multi-screw extruder under a vacuum of 1 to 100 mbar to produce a hot melt, wherein during extrusion the solvent concentration can be reduced to produce a hot melt containing less than 20.000 ppm, preferably less than 8000 ppm of solvent.

[0120] Step e)

[0121] Step e) is the mixing of the molten carrier polymer with the concentrated additive during stirring, which is preferably extrusion. Typically, step d) and step e) are carried out simultaneously.

[0122] The mixing of the molten carrier polymer can be carried out by extruding the carrier polymer and feeding it into the hot melt in step d). The extrusion of the carrier polymer can be carried out by known devices, such as in a single screw extruder or a multi-screw extruder. The extrusion of the carrier polymer is generally carried out at a temperature of 20°C to 300°C, preferably 80°C to 200°C. In another form, the extrusion of the carrier polymer can be carried out at a temperature of 100°C to 200°C, preferably 120°C to 180°C. The temperature during the extrusion of the carrier polymer can be adjusted to the melting point of the carrier polymer. The temperature during the extrusion of the carrier polymer is generally adjusted to melt the carrier polymer.

[0123] The granular plastic additive can contain 1 to 25 wt%, preferably 8-12 wt% of the carrier polymer. The weight ratio of the carrier polymer and the concentrated additive mixed during extrusion can be adjusted to achieve the desired wt%, such as 1 to 25 wt%, preferably 8-12 wt% of the carrier polymer in the granular plastic additive.

[0124] Suitable carrier polymers are polyolefins, such as polypropylene or polyethylene, with polyethylene being preferred. Preferred carrier polymers are low density polyethylene, for example having a density of 0.915 to 0.930 g / cm 3 of low-density polyethylene.

[0125] Suitable polyethylenes are low density polyethylenes; homopolymeric polyethylene waxes (e.g., having an average molecular weight of 2000 to 10,000, preferably 3000 to 8000); copolymeric polyethylene waxes of ethylene and vinyl acetate (VAC), which may have a VAC content of 2% to 30% by weight, preferably 5% to 20% by weight, and may have an average molecular weight of 2,000 to 10,000, preferably 3,000 to 8,000.

[0126] Suitable polypropylenes are homopolymeric polypropylene waxes (eg, having an average molecular weight of 2,000 to 10,000, preferably 3,000 to 8,000) and copolymeric polypropylene waxes.

[0127] Step f)

[0128] Step f) is to cool and shape the hot melt containing the plastic additive and the carrier polymer to produce a granular plastic additive.

[0129] The outlet nozzle of the kneader or extruder may have a plurality of orifices, preferably only one orifice, at which the hot melt can leave the device.

[0130] The cooling of the hot melt can be carried out with a drum cooler or a belt cooler, wherein a drum cooler is preferred. The hot melt can be spread into a film, which is then pressed against the surface of a cooling drum. The hot melt can solidify during cooling. The hot melt can be cooled to a temperature below 60° C., preferably below 40° C.

[0131] The shaping of the hot melt can be carried out before, during or after cooling, preferably after cooling. Preferably, the hot melt solidifies before shaping.

[0132] Shaping can be carried out by rolling, stamping, crushing or pulverizing, wherein crushing is preferred. Crushing can be achieved in a roll crusher or a roll mill. The combination of a roll crusher or a roll mill with a screen granulator is also possible.

[0133] After forming the granular plastic additive, sieving can be performed to achieve the desired particle size, for example by selecting an appropriate sieve width. Sieving of the granular plastic additive can produce fine particles or dust. The fine particles or dust can be recycled, for example by introducing it into the stirring of step d). In another form, the fine particles or dust are recycled by introducing it into the stirring of step d) via step e), for example by mixing the fine particles or dust with a carrier polymer.

[0134] The granular plastic additive can have any shape. The granular plastic additive can have the shape of regular or irregular particles, spheres, cubes, prisms, pyramids. The granular plastic additive can have a particle size of 0.1 to 10.0 mm, preferably 0.5 to 5 mm.

[0135] In a preferred form, the method for preparing a granular plastic additive comprises the following steps:

[0136] a) providing two additive solutions, the two additive solutions comprising a plastic additive and a solvent, wherein each additive solution contains a different plastic additive and the same or different solvents,

[0137] b) mixing the two additive solutions (for example in a static mixer),

[0138] c) subjecting the additive solution to thin film evaporation to produce a concentrated additive,

[0139] d) extruding the additive concentrate under vacuum (e.g. in a multi-screw extruder) to produce a hot melt, wherein the solvent concentration is removed during extrusion under vacuum,

[0140] e) mixing a molten carrier polymer (e.g. a polyolefin) with the concentrated additive during extrusion, wherein the mixing is performed by extruding the carrier polymer and feeding it into a hot melt, and

[0141] f) cooling and shaping the hot melt comprising the plastic additive and the carrier polymer to produce the granulated plastic additive.

[0142] In another preferred form, the method for preparing a granular plastic additive comprises the following steps:

[0143] a) providing two additive solutions, the two additive solutions comprising a plastic additive and a solvent, wherein each additive solution contains a different plastic additive and the same or different solvents, wherein both additive solutions contain at least 25 wt % of the solvent,

[0144] b) mixing the two additive solutions,

[0145] c) subjecting the additive solution to thin film evaporation to produce an additive concentrate, wherein during the thin film evaporation the solvent concentration is reduced to produce an additive concentrate comprising less than 10 wt % solvent,

[0146] d) extruding the additive concentrate under vacuum (e.g. in a multi-screw extruder) to produce a hot melt, wherein the solvent concentration is removed during extrusion under vacuum,

[0147] e) mixing a molten carrier polymer (e.g. a polyolefin) with the concentrated additive during extrusion, wherein the mixing is performed by extruding the carrier polymer and feeding it into a hot melt, and

[0148] f) cooling and shaping the hot melt comprising the plastic additive and the carrier polymer to produce a granular plastic additive, wherein the granular plastic additive comprises 1 to 25 wt % of the carrier polymer.

[0149] In another preferred form, the method for preparing a granular plastic additive comprises the following steps:

[0150] a) providing two additive solutions, the two additive solutions comprising a plastic additive and a solvent, wherein each additive solution contains a different plastic additive and the same or different solvent, wherein the solvent comprises toluene, xylene, ethylbenzol, trimethylbenzene, isopropylbenzene, diisopropylbenzene, a water-insoluble organic ketone or a mixture thereof, wherein both additive solutions contain at least 25 wt % of the solvent,

[0151] b) mixing the two additive solutions,

[0152] c) subjecting the additive solution to thin film evaporation to produce an additive concentrate, wherein during the thin film evaporation the solvent concentration is reduced to produce an additive concentrate comprising less than 10 wt % solvent,

[0153] d) extruding the additive concentrate under vacuum (e.g. in a multi-screw extruder) to produce a hot melt, wherein the solvent concentration is removed during extrusion under vacuum,

[0154] e) mixing a molten carrier polymer which is a polyolefin with the concentrated additive during extrusion, wherein the mixing is performed by extruding the carrier polymer and feeding it into the hot melt, and

[0155] f) cooling and shaping the hot melt comprising the plastic additive and the carrier polymer to produce a granular plastic additive, wherein the granular plastic additive comprises 1 to 25 wt % of the carrier polymer, and wherein the plastic additive comprises a light stabilizer, a UV stabilizer or a mixture thereof.

[0156] In another preferred form, the method for preparing a granular plastic additive comprises the following steps:

[0157] a) providing two additive solutions, the two additive solutions comprising a plastic additive and a solvent, wherein each additive solution contains a different plastic additive and the same or different solvent, wherein the solvent comprises toluene, xylene, ethylbenzol, trimethylbenzene, isopropylbenzene, diisopropylbenzene, a water-insoluble organic ketone or a mixture thereof, wherein both additive solutions contain at least 25 wt % of the solvent,

[0158] b) mixing the two additive solutions,

[0159] c) subjecting the additive solution to thin film evaporation to produce an additive concentrate, wherein during the thin film evaporation the solvent concentration is reduced to produce an additive concentrate comprising less than 10 wt % solvent,

[0160] d) extruding the additive concentrate under vacuum (e.g. in a multi-screw extruder) to produce a hot melt, wherein the solvent concentration is removed during extrusion under vacuum,

[0161] e) mixing a molten carrier polymer which is a polyolefin with the concentrated additive during extrusion, wherein the mixing is performed by extruding the carrier polymer and feeding it into the hot melt, and

[0162] f) cooling and shaping the hot melt comprising the plastic additive and the carrier polymer to produce a granular plastic additive, wherein the granular plastic additive comprises 1 to 25 wt % of the carrier polymer, and wherein the plastic additive comprises

[0163] - a condensate of 1,6-hexanediamine and 2,4,6-trichloro-1,3,5-triazine and N,N-dibutylamine and 4-butylamino-2,2,6,6-tetramethylpiperidine, and / or

[0164] - a light stabilizer of formula (I).

[0165] Steps a) to f) are generally carried out in alphabetical order. Steps c) to f) can be carried out batchwise or continuously, preferably continuously.

[0166] The present invention also relates to a granulated plastic additive obtainable by a process for preparing a granulated plastic additive, the process comprising the following steps

[0167] a) providing at least one additive solution, the at least one additive solution comprising a plastic additive and a solvent,

[0168] b) optionally mixing these additive solutions,

[0169] c) subjecting the additive solution to thin film evaporation to produce a concentrated additive,

[0170] d) stirring the additive concentrate under vacuum to produce a hot melt,

[0171] e) mixing the molten carrier polymer with the additive concentrate during stirring, and

[0172] f) cooling and shaping the hot melt comprising the plastic additive and the carrier polymer to produce a granular plastic additive.

[0173] Preferably, the granular plastic additive is obtainable by the process wherein the solvent is toluene, xylene, ethylbenzene, trimethylbenzene, isopropylbenzene or diisopropylbenzene, and the concentration of the solvent in the granular plastic additive is less than 5000 ppm.

[0174] In another preferred form, the granular plastic additive is obtainable by the process wherein the solvent is toluene, xylene, ethylbenzene, trimethylbenzene, isopropylbenzene or diisopropylbenzene, and the concentration of the solvent in the granular plastic additive is less than 10.000 ppm.

[0175] Preferably, the granular plastic additive is obtainable by the process wherein the solvent is xylene and the solvent concentration in the granular plastic additive is less than 5000 ppm. In another preferred form, the granular plastic additive is obtainable by the process wherein the solvent is xylene and the solvent concentration in the granular plastic additive is less than 10.000 ppm.

[0176] Figure 1 A suitable flow chart for a method for preparing a granular plastic additive is shown: an additive solution A and an optional additive solution B are provided, both of which contain a plastic additive and a solvent. Additive solution A is optionally mixed with additive solution B (if present) (e.g., in a static mixer). The additive solution can be subjected to thin film evaporation, and the evaporated solvent can be recovered. The resulting concentrated additive can then be extruded or kneaded under vacuum, and the evaporated solvent can be recovered. The carrier polymer can be melted in a side extruder and mixed with the concentrated additive. The hot melt can be cooled, granulated and sieved to produce a granular plastic additive. The fines from the sieving can be recycled, for example, by adding to an extruder.

[0177] Examples

[0178] Example 1

[0179] A solution of about 44 wt% of a light stabilizer of formula (I) in xylene is prepared and heated to 85°C. The solution is pumped continuously at 560 kg / h in a wiped film evaporator. The thin film evaporator is operated under vacuum (about 290 mbar) and the jacket is heated with steam; the evaporator and the conical heating jacket section are heated under controlled pressure of 6 bar gauge and 8 bar gauge, respectively. This results in a tank temperature of 162°C. The tank contains a liquid concentrated additive containing 2-3 wt% of volatiles.

[0180] The tank was then continuously pumped at 250 kg / h to a planetary roller extruder. The extruder was operated at 150 rpm; the vacuum was maintained at 16 mbar, 18 mbar respectively in two sections of the extruder separated by a stop ring, while the temperature of the jacket was maintained at an average of 162° C. over the length to produce a hot melt.

[0181] A side stream of 25 kg / h of molten (extruder temperature 145°C-155°C) low density polyethylene (LDPE, density 0.920 at 23°C (ISO 1183), melt flow index about 7.8 g / 10 min (190°C, 2.16 kg, ISO 1133)) was mixed into the hot melt in the planetary roll extruder via a side feeder extruder.

[0182] The resulting melt at the extruder outlet was cooled on a cooling drum. Granulation was performed using a crusher at the cooling drum outlet and then a screen granulator. The final granules of the light stabilizer of formula (I) contained 8.9 wt% of LDPE and 0.49 wt% of volatiles.

[0183] Example 2

[0184] A solution of about 44 wt% of a light stabilizer of formula (I) in xylene is prepared and heated to 85°C. The solution is continuously pumped at 780 kg / h in a wiped film evaporator. The thin film evaporator is operated under vacuum (about 290 mbar) and the jacket is heated with steam; the evaporator and the conical heating jacket section are heated under controlled pressure of 6 bar gauge and 5 bar gauge, respectively. This results in a tank temperature of 150°C. The tank contains a liquid concentrated additive containing 5-5.5 wt% of volatiles.

[0185] The tank was then continuously pumped at 360 kg / h to a planetary roller extruder. The extruder was operated at 150 rpm; the vacuum was maintained at 20 mbar, 27 mbar respectively in two sections of the extruder separated by a stop ring, while the temperature of the jacket was maintained at an average of 172° C. over the length to produce a hot melt.

[0186] A side stream of 36 kg / h of molten (extruder temperature 145°C-155°C) low density polyethylene (LDPE, density 0.920 at 23°C (ISO 1183), melt flow index about 7.8 g / 10 min (190°C, 2.16 kg, ISO 1133)) was mixed into the hot melt in the planetary roll extruder via a side feeder extruder.

[0187] The resulting melt at the extruder outlet is cooled on a cooling drum. Granulation is performed with a crusher at the cooling drum outlet and then with a screen granulator. Subsequently, the product is sieved and the fine fraction <1 mm is recycled into the extruder via the same side feeder as the LDPE (flow rate is 40 kg / h).

[0188] The final granules of the light stabilizer having formula (I) contained 9.5 wt% LDPE and 0.33 wt% volatiles.

[0189] Example 3

[0190] A solution of about 43 wt% of a light stabilizer of formula (I) in xylene is prepared and heated to 85°C. The solution is continuously pumped at 770 kg / h in a wiped film evaporator. The thin film evaporator is operated under vacuum (about 290 mbar) and the jacket is heated with steam; the evaporator and the conical heating jacket section are heated under controlled pressure of 6 bar gauge and 8 bar gauge, respectively. This results in a tank temperature of 148°C. The tank contains a liquid concentrated additive containing 5.5-6 wt% of volatiles.

[0191] The tank was then continuously pumped at 350 kg / h to a planetary roller extruder. The extruder was operated at 150 rpm; the vacuum was maintained at 7 mbar, 23 mbar respectively in two sections of the extruder separated by a stop ring, while the temperature of the jacket was maintained at an average of 166° C. over the length to produce a hot melt.

[0192] A side stream of 37.5 kg / h of molten (extruder temperature 145°C-155°C) low density polyethylene (LDPE, density 0.920 at 23°C (ISO 1183), melt flow index about 7.8 g / 10 min (190°C, 2.16 kg, ISO 1133)) was mixed into the hot melt in the planetary roll extruder via a side feeder extruder.

[0193] The resulting melt at the extruder outlet was cooled on a cooling drum. Granulation was performed using a crusher at the cooling drum outlet followed by a screen granulator. The final granules of the light stabilizer of formula (I) contained 10.2 wt% of LDPE and 0.25 wt% of volatiles.

Claims

1. A method for preparing a granular plastic additive, the method comprising the following steps a) providing at least one additive solution, the at least one additive solution comprising a plastic additive and a solvent, b) optionally mixing these additive solutions, c) subjecting the additive solution to thin film evaporation to produce a concentrated additive, d) stirring the additive concentrate under vacuum to produce a hot melt, e) mixing molten carrier polymer with the additive concentrate during the stirring, and f) cooling and shaping the hot melt comprising the plastic additive and the carrier polymer to produce the granulated plastic additive.

2. The method according to claim 1, wherein: The stirring is performed by extrusion or kneading.

3. The method according to claim 1 or 2, wherein: The stirring is carried out in a single-screw extruder, a multi-screw extruder or a kneader.

4. A method according to any one of the preceding claims, wherein: The solvent concentration decreased during stirring under the vacuum.

5. A method according to any one of the preceding claims, wherein: During the stirring, the solvent concentration decreases to produce a hot melt containing less than 10.000 ppm, preferably less than 5000 ppm of the solvent.

6. A method according to any one of the preceding claims, wherein: The mixing of the molten carrier polymer is carried out by extruding the carrier polymer and feeding it into the hot melt in step d).

7. A method according to any one of the preceding claims, wherein: The carrier polymer is a polyolefin.

8. A method according to any one of the preceding claims, wherein: The granular plastic additive comprises 1 to 25 wt %, preferably 8 to 12 wt % of the carrier polymer.

9. A method according to any one of the preceding claims, wherein: The solvent includes toluene, xylene, ethylbenzene, trimethylbenzene, isopropylbenzene, diisopropylbenzene, water-insoluble organic ketone or a mixture thereof.

10. A method according to any one of the preceding claims, wherein: During the thin film evaporation, the solvent concentration decreases to produce the concentrated additive comprising less than 10 wt%, preferably less than 5 wt% of the solvent.

11. A method according to any one of the preceding claims, wherein: At least two additive solutions are provided in step a) and are mixed in step b).

12. A method according to any one of the preceding claims, wherein: The plastic additive includes a light stabilizer, a UV stabilizer or a mixture thereof.

13. A method according to any one of the preceding claims, wherein: The plastic additive comprises a light stabilizer having formula (I) and optionally a light stabilizer selected from sterically hindered amines.

14. A method according to any one of the preceding claims, wherein: The shaping is carried out after cooling by comminution, preferably by grinding.

15. A granular plastic additive obtainable by the process as claimed in any one of claims 1 to 14.

16. The granular plastic additive according to claim 15, wherein The solvent is xylene and the concentration of the solvent in the granulated plastic additive is below 10.000 ppm, preferably below 5000 ppm.

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