Novel hydrolysis inhibitor, method for production, and use thereof

Abstract

The invention relates to novel, easily producible carbodiimides of formula (I) R2-R1-(-N=C=N-R1-)m-R2 (I), in which m corresponds to an integer from 2 to 500, R1 was introduced by carbodiimidisation of 1,3-diethyl -2,4-diisocyanato-5-methylbenzene, 1,5-diethyl-2,4-diisocyanato-3-methylbenzene, 2,4,6-triisopropylphenyl diisocyanate, 1,3-diisopropyl -2,4-diisocyanato-5-methylbenzene, 1,5-diisopropyl -2,4-diisocyanato-3-methylbenzene and / or 4,4'-methylenebis(2,6-diisopropylphenyl isocyanate), R2 is -NHCONHR3, -NHCOOR3 or -NHCOSR3, wherein R3 stands for R5-X-R6 and X is selected from O, NH, N(R7), S and P(O)(R7), wherein R5, R6, R7 are the same or different and stand for C1-C12 alkylene-, C5-C12-cycloalkylene-, C6-C12-arylenes, C7-C18-alkylaryl-substituted arylenes, unsubstituted or C1-C12-alkyl-substituted arylenes bridged via alkylene groups which in total have 7 to 30 carbon atoms, C7-C18-alkylaryl-substituted alkylenes, or unsubstituted or C1-C12-alkyl-substituted cycloalkylenes bridged via alkylene groups, which in total have 7 to 30 carbon atoms. These are particularly suitable as stabilisers against the hydrolytic cleavage of esters and polyamide.

Description

[0001] P001 01255A

[0002] - 1 - Novel hydrolysis inhibitors, methods for their production and their use

[0003] The invention relates to new, easily produced stabilizers that offer particularly good protection against the hydrolytic cleavage of esters and polyamides, as well as their production and use.

[0004] Carbodiimides have proven their worth in many applications, e.g. as hydrolysis inhibitors for thermoplastic polymers, polyols, polyurethanes, triglycerides and lubricating oils, etc.

[0005] According to current technology, carbodiimides are typically synthesized from isocyanates, which are carbodiimidated by basic or heterocyclic catalysis with the release of CO2. Mono- or polyfunctional isocyanates can be converted to monomeric or polymeric carbodiimides.

[0006] Alkali or alkaline earth compounds, as well as heterocyclic compounds containing phosphorus, are typically used as catalysts. Examples of such catalysts can be found in Angew. Chem. 1962, 74, 801-806 and Angew. Chem.

[0007] Described in 1981, 93, 855-866.

[0008] Carbodiimides from WO2014184116, WO2016071347, or WO2023285310 effectively stabilize polyesters against hydrolysis. They can be formed into granules, but these are not homogeneous (not uniformly round) and can cause problems (blockages) when used in dosing systems. A further disadvantage is the low thermal stability of these stabilizers at high temperatures, where they can fully polymerize due to upstream decomposition and rearrangement reactions. This behavior prevents trouble-free production of these compounds. They can polymerize in the furnace and on the pastillation line at the required temperatures, a behavior that can lead to economic disadvantages due to damage to the production equipment.Alternative products that show comparable results in hydrolysis protection and are stable against polymerization usually have a tough-soft or sticky consistency and cannot be packaged, stored or dosed in solid form during application.

[0009] The object of the present invention was therefore to provide new carbodiimides that do not have the above disadvantages of the prior art, achieving very good results in P001 01255A

[0010] - 2 -

[0011] Provide hydrolysis protection, meet the requirements for plant safety and enable the economical production of homogeneous granules / pastilles.

[0012] Surprisingly, it has now been found that the aforementioned problem is solved by carbodiimides of formula (I)

[0013] R 2 -R 1 -(-N=C=NR 1 -)mR 2 (I),

[0014] in the

[0015] m corresponds to an integer from 2 to 500, preferably 3 to 20, most preferably 4 to 10,

[0016] R 1 was introduced by carbodiimidation of 1,3-diethyl-2,4-diisocyanato-5-methylbenzene, 1,5-diethyl-2,4-diisocyanato-3-methylbenzene, 2,4,6-triisopropylphenyl diisocyanate, 1,3-diisopropyl-2,4-diisocyanato-5-methylbenzene, 1,5-diisopropyl-2,4-diisocyanato-3-methylbenzene and / or 4,4'-methylenebis(2,6-diisopropylphenyl isocyanate),

[0017] R 2 -NHCONHR 3 , -NHCOOR 3 or -NHCOSR 3 is,

[0018] where R 3 for R 5 -XR 6 stands and X is selected from O, NH, N(R 7 ), S and P(O)(R 7 ), where R 5 , R 6 , R 7are the same or different and stand for Ci-Ci2-alkylene, Cs-Ci2-cycloalkylene, Ce-Ci2-arylenes, CyCis-alkylaryl-substituted arylenes, unsubstituted or Ci-Ci2-alkyl-substituted arylenes bridged via alkylene groups which have a total of 7 to 30 carbon atoms, CyCis-alkylaryl-substituted alkylenes, or unsubstituted or Ci-Ci2-alkyl-substituted cycloalkylenes bridged via alkylene groups which have a total of 7 to 30 carbon atoms.

[0019] The remains R 1 The following structural formulas have been introduced by carbodiimidation of:

[0020] 1,3-Diethyl-2,4-diisocyanato-5-methylbenzene:

[0021]

[0022] P001 01255A

[0023] - 3 - 1,5-Diethyl-2,4-diisocyanato-3-methylbenzene:

[0024] ldiisocyanate:

[0025]

[0026] 1,3-Diisopropyl-2,4-diisocyanato-5-methylbenzene:

[0027]

[0028] P001 01255A

[0029] - 4 -

[0030] 4,4'-Methylenebis(2,6-diisopropylphenyl isocyanate):

[0031]

[0032] Carbodiimides are also preferred, in which R 2 selected from NHCONHR 3 and NHCOOR 3 , where R 3 for R 5 -XR 6 X is selected from O, NH and N(R). 7 ) and R 5 , R 6 , R 7 are the same or different and stands for Ci-Ci2-alkylene or Cs-Ci2-cycloalkylene.

[0033] A further preferred embodiment relates to carbodiimides in which R 2 -NHCOOR 3 is, where R 3 for R 5 -OR 6 stands, R 5 and R 6are the same or different and stand for C1-C12 alkylene or Cs-Ci2 cycloalkylenes, preferably for Ci-Cs alkylene or Cs-Ce cycloalkylenes and particularly preferably for Ci-Ce alkylene.

[0034] For the production of the carbodiimides according to the invention, sterically hindered diisocyanates such as DETDI: 1,3-diethyl-2,4-diisocyanato-5-methylbenzene and / or 1,5-diethyl-2,4-diisocyanato-3-methylbenzene are particularly preferably used as isocyanates.

[0035]

[0036] DETDI

[0037] 2,4,6 triisopropylphenyl diisocyanate (TRIDI),

[0038]

[0039] TRIDIP001 01255A

[0040] - 5 -

[0041] DIPTDI: 1,3-Diisopropyl-2,4-diisocyanato-5-methylbenzene and / or 1,5-Diisopropyl-2,4-diisocyanato-3-methylbenzene

[0042]

[0043] DIPTDI

[0044] or 4,4'-Methylenebis(2,6-diisopropylphenyl isocyanate) (M-DIPI)

[0045]

[0046] M-DIPI

[0047] used.

[0048] Thus, the present invention relates in particular to carbodiimides in which the R residues are 1 derived from 1,3-diethyl-2,4-diisocyanato-5-methylbenzene, 1,5-diethyl-2,4-diisocyanato-3-methylbenzene, 2,4,6-triisopropylphenyl diisocyanate, 1,3-diisopropyl-2,4-diisocyanato-5-methylbenzene, 1,5-diisopropyl-2,4-diisocyanato-3-methylbenzene and / or 4,4'-methylene-bis(2,6-diisopropylphenyl isocyanate), i.e., obtained by carbodiimidation of these diisocyanates.

[0049] A preferred embodiment also comprises carbodiimides in which the R2 groups represent n-propoxyethoxy, i-propoxyethoxy, n-butoxyethoxy, i-butoxyethoxy, t-butoxyethoxy, phenoxyethanol, phenoxy-n-butoxy, phenoxy-n-propoxy and / or phenoxy-i-propoxy, preferably n-propoxyethoxy, i-propoxyethoxy, n-butoxyethoxy, i-butoxyethoxy and / or t-butoxyethoxy and most preferably n-butoxyethoxy, i.e., which are obtainable by reacting terminal isocyanate groups of the carbodiimides with the associated alkoxy alcohols. P001 01255A

[0050] - 6 -

[0051] Preferably the NCN content in the carbodiimide is 2 - 10 wt.%, particularly preferably 3 - 8 wt.% and most preferably 3 - 6 wt.%.

[0052] The average molar mass (M w The amount of carbodiimide is preferably 1000-10000 g / mol, more preferably 2000-8000 g / mol and most preferably 3000-6000 g / mol.

[0053] The carbodiimidation of isocyanates in the presence of a catalyst of the process according to the invention typically takes place in a condensation reaction with elimination of CO2, as described, for example, in Angew. Chem. 93, pp. 855-866 (1981) or DE-A-11 30594 or Tetrahedron Letters 48 (2007), pp. 6002-6004.

[0054] Carbodiimidation can be carried out in the substance or in a solvent. It is also possible to start the carbodiimidation in the substance and add a solvent during the reaction. Suitable solvents can be easily identified by those skilled in the art. Examples of such solvents include petroleum ethers, benzene, and / or alkylbenzenes.

[0055] In one embodiment of the invention, strong bases or phosphorus compounds are preferred as catalysts for the carbodiimidation of the isocyanates to carbodiimides of formula (I). Phosphoene oxides, phospholidines, or phospholine oxides, as well as the corresponding sulfides, are preferably used. Furthermore, tertiary amines, basic metal compounds, alkali or alkaline earth oxides or hydroxides, alcoholates or phenolates, carboxylic acid metal salts, and non-basic organometallic compounds can be used as catalysts. Alkylphosphone oxides, such as methylphospholene oxide, are particularly preferred as catalysts.

[0056] The reaction (carbodiimidation) is preferably carried out in a temperature range of 140 °C to 200 °C, particularly preferably at 160 - 180 °C.

[0057] An object of the present invention is a process for the production of carbodiimides according to the invention, in which diisocyanates are carbodiimidated at temperatures of 140 to 200°C, preferably at 160 to 180°C, in the presence of catalysts and optionally solvents and with the elimination of carbon dioxide (preferably to a certain NCO content), and the terminal NCO functionalities are subsequently reacted with alcohols, primary amines, secondary amines and / or thiols (final functionalization), preferably at temperatures of 60 to 140°C, particularly preferably at 80 to 120°C. P001 01255A

[0058] - 7 -

[0059] A further object of the invention is an alternative process for the production of the carbodiimides according to the invention in which diisocyanates are carbodiimidated and end-functionalized at temperatures of 140°C to 200°C, preferably at 160-180°C, in the presence of catalysts and at least one substance selected from the group containing alcohols, primary amines, secondary amines and thiols, optionally in the presence of solvents, with the elimination of carbon dioxide.

[0060] Alcohols are preferably used for the final functionalization, especially n-propoxyethanol, i-propoxyethanol, n-butoxyethanol, i-butoxyethanol and t-butoxyethanol, phenoxyethanol, phenoxy-n-butanol, phenoxy-n-propanol and / or phenoxy-i-propanol.

[0061] To optimize the reaction of the carbodiimide groups with the alcohol, catalysts known from polyurethane synthesis can also be used, preferably triethylenediamine (TEDA).

[0062] A distillation can then be carried out to remove any excess alcohol that may be present.

[0063] Preferably, the processes according to the invention for the production of the carbodiimides comprise a pastillation of the carbodiimides, e.g. on pastillating belts, following the final functionalization or the separation of excess alcohol or catalyst.

[0064] Another aspect of the invention is therefore pastillated carbodiimides with the structure according to the invention.

[0065] Furthermore, the invention relates to a composition containing

[0066] at least one ester-based polymer, preferably selected from the group consisting of polyester polyols, ester-based thermoplastic polyurethanes, ester-based PU adhesives, ester-based PU casting resins, polyethylene terephthalates (PET), polybutylene terephthalates (PBT), polytrimethylene terephthalates (PTT), copolyesters, thermoplastic polyester elastomers (TPE), ethylene vinyl acetates (EVA), polylactic acids (PLA), polybutylene adipate terephthalates (PBAT), polybutylene succinates (PBS), PLA blends and polyhydroxyalkanoates (PHA) and / or at least one polyamide and P001 01255A

[0067] - 8 -

[0068] at least one carbodiimide according to the invention, preferably in an amount of 0.1 - 10 wt.%, particularly preferably 1 - 5 wt.%, particularly preferably 1 - 3 wt.% carbodiimide based on the content of ester-based polymer and / or polyamide. These compositions are advantageously obtainable by a process in which the carbodiimides are added to the ester-based polymers, preferably selected from the group comprising polyethylene terephthalate (PET), polybutylene terephthalate (PBT), polytrimethylene terephthalate (PTT), ester-based thermoplastic polyurethanes (TPU), copolyesters, modified polyesters of cyclohexanediol and terephthalic acid (PCTA), thermoplastic polyester elastomers (TPE E), ethylene vinyl acetate (EVA), polylactic acid (PLA), polybutylene adipate terephthalates (PBAT), polybutylene succinates (PBS), PLA blends and polyhydroxyalkanoates (PHA) and / or to polyamide (PA) by means of a solid dosing unit.

[0069] The invention further relates to the use of the carbodiimides according to the invention in ester-based polyols, in polyamides (PA), in polyethylene terephthalate (PET), in polybutylene terephthalate (PBT), in polytrimethylene terephthalate (PTT), in copolyesters, in thermoplastic polyester elastomers (TPE E), in ethylene vinyl acetate (EVA), in polylactic acid (PLA) and / or in PLA derivatives, in polybutylene adipate terephthalates (PBAT), in polybutylene succinates (PBS), in polyhydroxyalkanoates (PHA), in blends, in ester-based thermoplastic polyurethanes (TPU), in ester-based polyurethane elastomers, in ester-based PU adhesives, in ester-based PU casting resins, in ester-based PU foams or in ester-based PU coatings for wood, leather, artificial leather and textiles, as protection against hydrolytic degradation.

[0070] A particular aspect of the invention is films containing at least one polyester selected from the group consisting of polyethylene terephthalate (PET), ethylene vinyl acetate (EVA), polyethylene naphthalate (PEN), polybutylene terephthalate (PBT), polytrimethylene terephthalate (PTT) and / or polycyclohexanedimethanol terephthalate (PCT) and 1.0 - 3.0 wt.% of at least one carbodiimide according to the invention, based on the content of the at least one polyester.

[0071] Furthermore, the invention comprises molding compounds made of polyamide (PA) containing 1.0 - 3.0 wt.% of at least one carbodiimide according to the invention, based on the polyamide, and optionally further additives, fillers and / or reinforcing agents.

[0072] The following examples serve to illustrate the invention without limiting it. P001 01255A

[0073] - 9 -

[0074] Carbodiimide 1: Carbodiimide (Mw = approx. 2500 g / mol) based on DETDI) and cyclohexanol.

[0075] Carbodiimide 2: Carbodiimide (Mw = approx. 10000 g / mol) based on M-DIPI and cyclohexanol.

[0076] Carbodiimide 3: Carbodiimide (Mw approx. 2500 g / mol) based on DETDI and polyethylene glycol methyl ether with Mw = 500 g / mol.

[0077] Carbodiimide 4: Carbodiimide (Mw approx. 2500 g / mol) based on DETDI and n-butoxyethanol

[0078] Carbodiimide 5: Carbodiimide (Mw = approx. 10,000 g / mol) based on M-DIPI and n-butoxyethanol

[0079] Production of carbodiimides

[0080] A mixture of 85 wt.% of the isocyanate and 14.8 wt.% alcohol was carbodiimidated in the presence of approximately 0.2% methylphospholene oxide at 180 °C until a residual isocyanate content of < 0.1% was achieved.

[0081] Hydrolysis protection in polylactic acid (PLA)

[0082] To evaluate the hydrolysis protection effect in PLA, 1.0 wt.% of each of the different carbodiimides was mixed into PLA using a Werner & Pfleiderer ZSK25 laboratory twin-screw extruder prior to the measurement described below. The resulting granules were then used to produce the F3 standard test specimens for measuring tear strength on an Arburg Allrounder 320 S 150-500 injection molding machine.

[0083] For the hydrolysis test, these F3 test specimens were stored in water at 65 °C and their tensile strength was measured. P001 01255A

[0084] - 10-

[0085] The results are listed in Table 1.

[0086] Table 1:

[0087]

[0088] See: Comparative example, Inventive: According to the invention

[0089] As can be seen from Table 1, the carbodiimides according to the invention show an improved stabilizing effect in PLA and can be produced in uniform pastille form without effort.

Claims

P001 01255A - 11 - 1. Carbodiimides of the formula (I) R 2 -R 1 -(-N=C=NR 1 -) m -R 2 (I), in the m corresponds to an integer from 2 to 500, preferably 3 to 20, most preferably 4 to 10, R 1 was introduced by carbodiimidation of 1,3-diethyl-2,4-diisocyanato-5-methylbenzene, 1,5-diethyl-2,4-diisocyanato-3-methylbenzene, 2,4,6-triisopropylphenyl diisocyanate, 1,3-diisopropyl-2,4-diisocyanato-5-methylbenzene, 1,5-diisopropyl-2,4-diisocyanato-3-methylbenzene and / or 4,4'-methylene-bis(2,6-diisopropylphenyl isocyanate), R 2 -NHCONHR 3 , -NHCOOR 3 or -NHCOSR 3 is, where R 3 for R 5 -XR 6 stands and X is selected from O, NH, N(R 7 ), S and P(O)(R 7 ), where R 5 , R 6 , R 7are the same or different and stand for Ci-Ci2-alkylene, C5-C12-cycloalkylene, C6-Ci2-arylenes, CyCis-alkylaryl-substituted arylenes, unsubstituted or Ci-Ci2-alkyl-substituted arylenes bridged via alkylene groups which have a total of 7 to 30 carbon atoms, CyCis-alkylaryl-substituted alkylenes, or unsubstituted or Ci-Ci2-alkyl-substituted cycloalkylenes bridged via alkylene groups which have a total of 7 to 30 carbon atoms.

2. Carbodiimide according to claim 1, characterized in that R 2 selected from NHCONHR 3 and -NHCOOR 3 , where R 3 for R 5 -XR 6 X is selected from O, NH and N(R). 7 ) and R 5 , R 6 , R 7 are the same or different and stands for Ci-Ci2-alkylene or Cs-Ci2-cycloalkylene.

3. Carbodiimides according to claim 1 or 2, characterized in that R 2 -NHCOOR 3 is, where R3 for R 5 -OR 6 stands, where R 5 and R 6 are the same or different and stand for Ci-Ci2-alkylene or Cs-Ci2-cycloalkylenes, preferably for Ci-Cs-alkylene or Cs-Ce-cycloalkylenes and particularly preferably for Ci-Ce-alkylene.

4. Carbodiimides according to one or more of claims 1 to 3, characterized in that the residues R2 are for n-propoxyethoxy, i-propoxyethoxy, n-butoxyethoxy, i-butoxyethoxy, t-butoxyethoxy, phenoxyethanol, phenoxy-n-butoxy,P001 01255A - 12- Phenoxy-n-propoxy and / or phenoxy-i-propoxy, preferably for n-propoxyethoxy, i-propoxyethoxy, n-butoxyethoxy, i-butoxyethoxy and / or t-butoxyethoxy and most preferably for n-butoxyethoxy.

5. A process for the preparation of carbodiimides according to any one of claims 1 to 4, characterized in that diisocyanates are carbodiimidated at temperatures of 140°C to 200°C, preferably at 160-180°C, in the presence of catalysts and optionally solvents and with the elimination of carbon dioxide, and the terminal NCO functionalities are subsequently reacted with alcohols, primary amines, secondary amines and / or thiols, preferably at temperatures of 60-140°C, particularly preferably at 80-120°C.

6. A process for the production of carbodiimides according to any one of claims 1 to 4, characterized in that diisocyanates are carbodiimidated and end-functionalized at temperatures of 140°C to 200°C, preferably at 160-180°C, in the presence of catalysts and at least one substance selected from the group comprising alcohols, primary amines, secondary amines and thiols, optionally in the presence of solvent, with the elimination of carbon dioxide.

7. Method for producing the carbodiimides according to claim 5, characterized in that the product obtained is pastillated onto pastillating strips.

8. Composition containing at least one ester-based polymer, preferably selected from the group comprising polyester polyols, ester-based thermoplastic polyurethanes, ester-based PU adhesives, ester-based PU casting resins, polyethylene terephthalate (PET), polybutylene terephthalate (PBT), polytrimethylene terephthalate (PTT), copolyesters, thermoplastic polyester elastomers (TPE E), ethylene vinyl acetate (EVA), polylactic acid (PLA), polybutylene adipate terephthalate (PBAT), polybutylene succinate (PBS), PLA blends and polyhydroxyalkanoates (PHA), and / or at least one polyamide and at least one carbodiimide according to any one of claims 1 to 4, preferably in an amount of 0.1–10 wt.%, particularly preferably 1–5 wt.%, particularly preferably 1–3 wt.% carbodiimide based on the content of ester-based polymer and / or polyamide. P001 01255A - 13- 9. A method for producing the compositions according to claim 8, characterized in that carbodiimides according to one of claims 1 to 4 are added to the ester-based polymers, preferably selected from the group comprising polyethylene terephthalate (PET), polybutylene terephthalate (PBT), polytrimethylene terephthalate (PTT), ester-based thermoplastic polyurethanes (TPU), copolyesters, modified polyesters of cyclohexanediol and terephthalic acid (PCTA), thermoplastic polyester elastomers (TPE E), ethylene vinyl acetate (EVA), polylactic acid (PLA), polybutylene adipate terephthalates (PBAT), polybutylene succinates (PBS), PLA blends and polyhydroxyalkanoates (PHA), and / or to polyamide (PA), by means of a solid dosing unit.

10. Use of the carbodiimides according to any one of claims 1 to 4 in ester-based polyols, in polyamides (PA), in polyethylene terephthalate (PET), in polybutylene terephthalate (PBT), in polytrimethylene terephthalate (PTT), in copolyesters, in thermoplastic polyester elastomers (TPE), in ethylene vinyl acetate (EVA), in polylactic acid (PLA) and / or in PLA derivatives, in polybutylene adipate terephthalates (PBAT), in polybutylene succinates (PBS), in polyhydroxyalkanoates (PHA), in blends, in ester-based thermoplastic polyurethanes (TPU), in ester-based polyurethane elastomers, in ester-based PU adhesives, in ester-based PU casting resins, in ester-based PU foams or in ester-based PU coatings for wood, leather, artificial leather and textiles, as protection against hydrolytic Dismantling.

11. Films containing at least one polyester selected from the group consisting of polyethylene terephthalate (PET), ethylene vinyl acetate (EVA), polyethylene naphthalate (PEN), polybutylene terephthalate (PBT), polytrimethylene terephthalate (PTT) and / or polycyclohexanedimethanol terephthalate (PCT) and 1.0 - 3.0 wt.% of the carbodiimides according to any one of claims 1 to 4, based on the at least one polyester.

12. Molding compounds made of polyamide (PA) containing 1.0 - 3.0 wt.% of the carbodiimides according to any one of claims 1 to 4, based on the polyamide, and optionally further additives, fillers and / or reinforcing agents.

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