New type of Anti-hydrolysis agent, process for preparation, and the use thereof

Abstract

The invention relates to a process for preparing new, functionalized, end-capped polycarbodiimides, comprising the following steps: 1. preparing end-capped polycarbodiimides by carbodiimidization of diisocyanates of formula (Ia) and / or diisocyanates of formula (IIa) and monoisocyanates; and 2. functionalizing some of the carbodiimide groups of the polycarbodiimides by reacting with acids, alcohols, thiols or amines. The end-capped polycarbodiimides obtainable thereby protect particularly well against the hydrolytic cleavage of esters and polyamide and can be easily prepared.

Description

[0001] P001 01126A

[0002] Procedures for and their

[0003] The invention relates to a method for producing new, end-capped polycarbodiimides that offer particularly good protection against the hydrolytic cleavage of esters and polyamides and are easy to produce, these new end-capped polycarbodiimides and their use.

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

[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] The carbodiimidation of diisocyanates yields polycarbodiimides with terminal, unreacted isocyanate groups. Their undesired reactivity can be avoided by adding monoisocyanates during or at the end of the carbodiimidation process. These monoisocyanates react with the terminal isocyanate groups to form further carbodiimide groups, creating the chain ends on both sides of the polycarbodiimide. The polycarbodiimides obtained in this way are subsequently referred to as end-capped polycarbodiimides.

[0007] Alkali or alkaline earth compounds, as well as heterocyclic compounds containing phosphorus, are typically used as catalysts. Suitable catalysts are described, for example, in Angew. Chem. 1962, 74, 801-806 and Angew. Chem. 1981, 93, 855-866.

[0008] End-capped polycarbodiimides (WO2014184116) very effectively stabilize polyesters against hydrolysis and exhibit low isocyanate emissions during processing. However, a disadvantage is their low thermal stability at high temperatures, where they can fully polymerize due to upstream decomposition and rearrangement reactions. This behavior prevents trouble-free production of these compounds. For example, 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 P001 01126A

[0009] - 2 -

[0010] Polymerizations are, have a tough-soft or sticky consistency and cannot be packaged, stored or dosed during application.

[0011] US 2024 / 209136 A1 discloses a process for reducing the residual content of monomeric isocyanates in the production of carbodiimides, comprising the carbodiimidation of isocyanates using a catalyst, followed by distillation or extraction to separate the catalyst and a portion of the monomeric isocyanate, and the addition of alcohols for reaction with the remaining isocyanate. In the examples, the carbodiimidation was carried out until the NCO content fell below 1% and then reacted with up to 2.0% ethylhexanol. From the ratio of the molar masses of isocyanate (42 g / mol) and ethylhexanol (130 g / mol), it is clearly evident that at an NCO content of just under 1%, all of the alcohol reacted with the significantly more reactive isocyanate groups and not with the far less reactive carbodiimide functionalities.

[0012] The object of the present invention was therefore to provide new polycarbodiimides which do not have the above disadvantages of the prior art, show very good results in hydrolysis protection, meet the requirements for plant safety and enable economical production.

[0013] Surprisingly, it has now been found that the aforementioned problem is solved by special end-capped polycarbodiimides of formulas (I) or (II)

[0014]

[0015] where P001 01126A

[0016] - 3 -

[0017] A for -N=C=N- and for groups of formula (III)

[0018]

[0019] where the ratio of -N=C=N- units to groups of formula (III) is greater than or equal to 1,

[0020] R at least one remainder is selected from -OR 2 , -SR 2 , -OC(O)R 2 , -NHR 2 , -NR 2 2 ,

[0021] R 2 is an alkyl, cycloalkyl, aralkyl, alkylaryl or aryl radical

[0022] R 1 for Ci-C24-alkyl, Cs-C24-cyclo- or Ci-Ci2-alkyl-substituted or Ci-C24-oxyalkyl-substituted cycloalkyl, Ci-Ci2-alkyl-substituted or Ci-C24-oxyalkyl-substituted aryl, C7-Ci8-alkylaryl-substituted aryl, and optionally for Ci-Ci2-alkyl-substituted aryl bridged with A via Ci-Cs-alkylene groups, which has a total of 7 to 30 carbon atoms, as well as for CyCis-aryl,

[0023] R 3 for ethyl,

[0024] R 4 for ethyl,

[0025] R 5 for methyl, and

[0026] n represents a number from 2 to 50, preferably 4 to 30, and most preferably 5 to 20.

[0027] The present invention therefore relates to end-capped polycarbodiimides of formula (I) or (II)

[0028]

[0029] where

[0030] A for -N=C=N- and for groups of formula (III)

[0031] RH

[0032] N=CN -P001 01126A

[0033] - 4 -

[0034] where the ratio of -N=C=N- units to groups of formula (III) is greater than or equal to 1,

[0035] R at least one remainder is selected from -OR 2 , -SR 2 , -OC(O)R 2 , -NHR 2 , -NR 2 2 ,

[0036] R 2 is an alkyl, cycloalkyl, aralkyl, alkylaryl or aryl radical

[0037] R 1for Ci-C24-alkyl, Cs-C24-cyclo- or Ci-Ci2-alkyl-substituted or Ci-C24-oxyalkyl-substituted cycloalkyl, Ci-Ci2-alkyl-substituted or Ci-C24-oxyalkyl-substituted aryl, C7-Ci8-alkylaryl-substituted aryl, and optionally for Ci-Ci2-alkyl-substituted aryl bridged with A via Ci-Cs-alkylene groups, which has a total of 7 to 30 carbon atoms, as well as for CyCis-aryl,

[0038] R 3 for ethyl,

[0039] R 4 for ethyl,

[0040] R 5 for methyl and

[0041] n represents a number from 2 to 50, preferably 4 to 30, and most preferably 5 to 20.

[0042] In a further preferred embodiment, R 2 and R 3 independently of each other for di- and / or triisopropylphenyl and group A stands for -N=C=N- and for groups of formula (III), especially preferably isourea ether groups with R as cyclohexanolate.

[0043] In the aforementioned embodiments of the invention, mixtures of compounds of formula (I) and / or (II) with different values ​​for n can also occur. In this case, fractional numbers may result when determining the mean value for n.

[0044] The carbodiimidation of isocyanates in the presence of a catalyst in step a) 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.

[0045] 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 a person skilled in the art. Examples of such solvents include petroleum ethers, benzene, and / or alkylbenzenes. P001 01126A

[0046] - 5 -

[0047] The isocyanates 2,4-Diethyltoluyl diisocyanate (DETDI) and 2,4,6-Triisopropylphenyl isocyanate (TRI PI) are particularly preferred.

[0048]

[0049] In one embodiment of the invention, strong bases or phosphorus compounds are preferred as catalysts for the carbodiimidation of the isocyanates to end-capped polycarbodiimides of formula (I). Phosphoium 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. Alkylphospholene oxides, such as methylphospholene oxide, are particularly preferred as catalysts.

[0050] The reaction (carbodiimidation) is preferably carried out in a temperature range of 140 °C to 200 °C, particularly preferably at 160 - 180 °C.

[0051] Another object of the present invention is a method for producing functionalized, end-capped polycarbodiimides, comprising the steps of:

[0052] 1. Preparation of end-capped polycarbodiimides by carbodiimidation of diisocyanates and monoisocyanates, and

[0053] 2. Functionalization of some of the carbodiimide groups of end-capped polycarbodiimides by reaction with acids, alcohols, thiols, or amines. P001 01126A

[0054] - 6 -

[0055] Preferably, diisocyanates of formulas (1a) or (Ha) are used in the process:

[0056]

[0057] In the process according to the invention, monoisocyanates of formula R are preferred. 1 -NCO is used, where R 1for Ci-C24-alkyl, Cs-C24-cyclo- or Ci-Ci2-alkyl-substituted or Ci-C24-oxyalkyl-substituted cycloalkyl, Ci-Ci2-alkyl-substituted or C1-C24-oxyalkyl-substituted aryl, CyCis-alkylaryl-substituted aryl and optionally for Ci-Ci2-alkyl-substituted aryl bridged with A via Ci-Cs-alkylene groups, which has a total of 7 to 30 carbon atoms, as well as for CyCis-aryl.

[0058] Following polycarbodiimide formation, one or more nucleophilic components, preferably alcohol and / or amine, are added to the capped polycarbodiimides and stirred. The nucleophilic component reacts with some of the carbodiimide functional groups, thus achieving functionalization. Functionalization preferably takes place at temperatures of 140–200 °C, particularly preferably at 160–180 °C.

[0059] Preferred nucleophilic components include alcohols such as cyclohexanol, 2-ethylhexyl ethanol, or benzyl alcohol.

[0060] Typically, 2-50 wt%, preferably 5-20 wt%, particularly preferably 10-15 wt% of the nuclephilic component such as alcohol, thiol or amine are added, relative to the amount of carbodiimide contained.

[0061] In a preferred embodiment, after functionalization of the polycarbodiimide, it is processed, i.e., pastillated or scaled. Optionally, one or more purification steps may be included between the functionalization and processing of the polycarbodiimide. P001 01126A

[0062] - 7 -

[0063] For optimal reaction between the carbodiimide groups and alcohol or amine, catalysts known from polyurethane synthesis can also be used, preferably triethylenediamine (TEDA).

[0064] A distillation can then be carried out to remove any excess alcohol that may be present.

[0065] Preferably, following functionalization or the removal of excess alcohol or catalyst, the end-capped polycarbo-diimides are pastillated, e.g., on pastillating strips.

[0066] Another aspect of the invention is therefore pastilled end-capped polycarbodiimides with the structure according to the invention.

[0067] Furthermore, the invention relates to a composition containing

[0068] 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 E), 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

[0069] at least one end-capped polycarbodiimide according to the invention, preferably in an amount of 0.1 - 10 wt.%, particularly preferably 1 - 5 wt.%, particularly preferably 1 - 3 wt.% end-capped polycarbodiimide based on the content of ester-based polymer and / or polyamide.

[0070] These compositions are advantageously obtainable by a process in which the end-capped polycarbodiimides are combined with 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.

[0071] - 8 -

[0072] and polyhydroxyalkanoates (PHA) and / or polyamide (PA) are added using a solid dosing unit.

[0073] The invention further relates to the use of the end-capped polycarbodiimides 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.

[0074] 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.% end-capped polycarbodiimides according to the invention, based on the content of the at least one polyester.

[0075] Furthermore, the invention comprises molding compounds made of polyamide (PA) containing 1.0 - 3.0 wt.% of end-capped polycarbodiimides according to the invention, based on the polyamide, and optionally further additives, fillers and / or reinforcing agents.

[0076] The following examples serve to illustrate the invention without limiting it. P001 01126A

[0077] - 9 -

[0078] Carbodiimide 1: End-capped polycarbodiimide based on 1,3,5-triisopropylphenyl diisocyanate (TRI DI) and 2,4,6-triisopropylphenyl diisocyanate (TRI PI) with Mw approx. 3500 g / mol.

[0079] Carbodiimide 2: Polycarbodiimide based on 2,4-diethyltolyl diisocyanate (DETDI) and cyclohexanol with Mw = approx. 2000 g / mol.

[0080] Carbodiimide 3: End-capped polycarbodiimide based on 2,4-diethyltolyl diisocyanate (DETDI) and 2,4,6-triisopropylphenyl diisocyanate (TRI PI) with a molecular weight of approximately 4000 g / mol.

[0081] Carbodiimide 4: End-capped polycarbodiimide based on 2,4-diethyltolyl diisocyanate (DETDI) and 2,4,6-triisopropylphenyl isocyanate (TRI PI) with a molecular weight of approximately 4000 g / mol, reacted with 15 wt.% cyclohexanol based on the carbodiimide or carbodiimide of formula (I) with R 1 , R 2 = Triisopropylphenyl

[0082]

[0083] with R = cyclohexyl alholate and

[0084] R 3 for ethyl, R 4for ethyl and R 5 stands for methyl.

[0085] Production of the end-capped polycarbodiimide according to the invention

[0086] A mixture of 85 wt% 2,4-diethyltolyl diisocyanate (DETDI) and 15 wt% 2,4,6-triisopropylphenyl isocyanate (TRIPI) was carbodiimidated in the presence of approximately 0.2% methylphospholene oxide at 180 °C until a residual isocyanate content of < 0.1% was achieved. Subsequently, approximately 15 wt% cyclohexanol (based on the carbodiimide) was added at 160 °C, and the mixture was stirred for a further 5 hours. Finally, the unreacted cyclohexanol was distilled off for approximately 2 hours at 160 °C and 10 mbar.

[0087] Hydrolysis protection in polylactic acid (PLA)

[0088] To evaluate the hydrolysis protection effect in PLA, 1.0 wt.% of each end-capped polycarbodiimide was mixed into PLA using a Werner & Pfleiderer ZSK 25 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. P001 01126A

[0089] - 10-

[0090] For the hydrolysis test, these F3 test specimens were stored in water at 65 °C and their tensile strength was measured.

[0091] The results are listed in Table 1.

[0092] Table 1:

[0093]

[0094] See: Comparative example, Inventive: According to the invention

[0095] As can be seen from Table 1, the carbodiimide according to the invention exhibits an excellent stabilizing effect in PLA, can be produced safely (no risk of through-polymerization of the reaction mixture) and can be optimally processed (pasteled or scaled).

Claims

P001 01126A - 11 - 1. Method for the production of functionalized, end-capped polycarbodiimides, comprising the steps: 1) Preparation of end-capped polycarbodiimides by carbodiimidation of diisocyanates of formula (1a) and / or of diisocyanates of formula (Ha) and monoisocyanates, and 2) Functionalization of some of the carbodiimide groups of polycarbodiimides by reaction with acids, alcohols, thiols or amines.

2. Method according to claim 1, wherein the residual isocyanate content of the polycarbodiimides used in step 2) is < 0.1%.

3. Method according to claim 1 or 2, wherein the monoisocyanates are of formula R 1 -NCO is involved, where R 1for Ci-C24-alkyl, Cs-C24-cyclo- or Ci-Ci2-alkyl-substituted or Ci-C24-oxyalkyl-substituted cycloalkyl, C1-C12-alkyl-substituted or Ci-C24-oxyalkyl-substituted aryl, CyCis-alkylaryl-substituted aryl and optionally for Ci-Ci2-alkyl-substituted aryl bridged with A via Ci-Cs-alkylene groups, which has a total of 7 to 30 carbon atoms, as well as for CyCis-aryl.

4. Method according to one or more of claims 1 to 3, wherein the end-capped polycarbodiimides correspond to formula (I) or (II) P001 01126A - 12- where A for -N=C=N- or for groups of formula (III) J - N— CN - (in) where the ratio of -N=C=N- units to groups of formula (III) is greater than or equal to 1, R at least one remainder is selected from -OR 2 , -SR 2 , -OC(O)R 2 , -NHR 2 , -NR 2 2, R2 is an alkyl, cycloalkyl, aralkyl, alkylaryl or aryl radical R 1 for Ci-C24-alkyl, Cs-C24-cyclo- or Ci-Ci2-alkyl-substituted or C1-C24-oxyalkyl-substituted cycloalkyl, Ci-Ci2-alkyl-substituted or Ci-C24-oxyalkyl-substituted aryl, CyCis-alkylaryl-substituted aryl, and optionally for C1-Ci2-alkyl-substituted aryl bridged with A via Ci-Cs-alkylene groups, which has a total of 7 to 30 carbon atoms, as well as for CyCis-aryl R 3 for ethyl, R 4 for ethyl, R 5 for methyl, n represents a number from 2 to 50, preferably 4 to 30, most preferably 5 to 20. P001 01126A - 13- 5. Method according to claim 4, wherein in the end-capped polycarbodiimides the ratio of -N=C=N- groups to groups of formula (III) is from 99:1 to 1:1, preferably from 30:1 to 2:1 and more preferably from 20:1 to 5:

1.

6. Method according to one or more of claims 1 to 5, wherein the carbodiimidation is carried out in a temperature range of 140 °C to 200 °C, preferably from 160 - 180 °C and the functionalization is carried out at temperatures of 140 to 200 °C, preferably at 160 - 180 °C.

7. Method according to one or more of claims 1 to 6, wherein after functionalization of the polycarbodiimide a preparation in the form of a pastille or scaling takes place.

8. End-capped polycarbodiimides of formula (I) or (II) where A for-N=C=N- and for further groups of formula (III) stands, R at least one remainder is selected from -OR 2 , -SR 2 , -OC(O)R 2 , -NHR 2 , -NR 2 2, R 2 is an alkyl, cycloalkyl, aralkyl, alkylaryl or aryl radical R 1for Ci-C24-alkyl, Cs-C24-cyclo- or Ci-Ci2-alkyl-substituted or C1-C24-oxyalkyl-substituted cycloalkyl, Ci-Ci2-alkyl-substituted or Ci-C24-oxyalkyl-substituted aryl, CyCis-alkylaryl-substituted aryl and optionally for C1-P001 01126A - 14- Ci2-alkyl-substituted aryl bridged with A via Ci-Cs alkylene groups, which has a total of 7 to 30 carbon atoms, and also stands for CyCis-aryl, R 3 for ethyl, R 4 for ethyl, R 5 for methyl, and n represents a number from 2 to 50, preferably 4 to 30, and most preferably 5 to 20.

9. End-capped polycarbodiimides according to claim 8, wherein the ratio of -N=C=N- groups to groups of formula (III) is from 100:1 to 1:50, preferably from 50:1 to 1:30, more preferably from 20:1 to 1:20 and particularly preferably from 10:1 to 1:

10.

10. End-capped polycarbodiimides according to claim 8 or 9, wherein R 1 for C5-C10 cycloalkyls or Ci-Ci2-alkyl-substituted aryls, preferably for cyclohexyl or C1-C4-alkyl-substituted aryls.

11. Composition comprising 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 terephthalates (PET), polybutylene terephthalates (PBT), polytrimethylene terephthalates (PTT), copolyesters, thermoplastic polyester elastomers (TPE E), 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 (PA) and at least one end-capped polycarbodiimide according to any one of claims 8 to 10, 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.

12. A process for producing the compositions according to claim 11, characterized in that end-capped polycarbodiimides according to any one of claims 8 to 10 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. - 15- 13. Use of the end-capped polycarbodiimides according to any one of claims 8 to 10 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 (TPEs), 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.

14. Films comprising 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.% end-capped polycarbodiimides according to any one of claims 8 to 10, based on the at least one polyester.

15. Molding compounds made of polyamide (PA) containing 1.0 - 3.0 wt.% of at least one end-capped polycarbodiimide according to any one of claims 8 to 10, based on the polyamide, and optionally further additives, fillers and / or reinforcing agents.

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