NOVEL CARBODIIMIDES, METHOD FOR THE PRODUCTION AND USE THEREOF

Abstract

The invention relates to novel carbodiimides having terminal urea and/or urethane groups, to processes for the production thereof and to the use thereof as a stabilizer in ester-based polymers especially in films for protection from hydrolytic degradation.

Claims

1. A carbodiimide of formula (I) having terminal urea and/or urethane groups ##STR00004## wherein: each R may be identical or different and is selected from the group of —NHCONHR.sup.I, —NHCONR.sup.IR.sup.II and —NHCOOR.sup.III radicals, wherein R.sup.I and R.sup.II are identical or different and represent a C.sub.1-C.sub.22-alkyl, C.sub.6-C.sub.12-cycloalkyl, C.sub.6-C.sub.18-aryl, or C.sub.7-C.sub.18-aralkyl radical, and R.sup.III represents a C.sub.1-C.sub.22-alkyl, C.sub.6-C.sub.12-cyctoalkyl, C.sub.6-C.sub.18-aryl, C.sub.7-C.sub.18-aralkyl radical, an unsaturated alkyl radical having 2-22 carbon atoms, or an alkoxypolyoxyalkylene radical, and n=0 to 20.

2. The carbodiimide as claimed in claim 1, wherein: R is an —NHCOOR.sup.III radical where R.sup.III is an alkoxypolyoxyalkylene or an unsaturated alkyl radical having 18 carbon atoms, and n=0 to 20.

3. The carbodiimide as claimed in claim 1, wherein: R is an —NHCOOR.sup.III radical, wherein R.sup.III is C.sub.1-C.sub.22-alkyl, and n=0 to 15.

4. The carbodiimide as claimed in claim 2, wherein the NCN content in the carbodiimide is 2-8 wt %.

5. The carbodiimide as claimed in claim 3, wherein the NCN content in the carbodiimide is 2-10 wt %.

6. The carbodiimide as claimed in claim 1, wherein the carbodiimide has an average molar mass (Mw) of 1000-10,000 g/mol.

7. A process for producing the carbodiimides as claimed in claim 1, the process comprising: carbodiimidizing diisocyanates of formula (II) ##STR00005##  to eliminate carbon dioxide at temperatures of 80° C. to 200° C. in the presence of catalysts and optionally solvent, and subsequently, end-functionalizing free NCO functionalities with primary or secondary amines and/or alcohols.

8. A process for producing the carbodiimides as claimed in clam 1, the process comprising: end-functionalizing a portion of free NCO groups of aromatic diisocyanates of formula (II) ##STR00006##  with primary or secondary amines and/or alcohols and/or alkoxypolyoxyalkylene alcohols, and subsequently, carbodiimidizing to eliminate carbon dioxide at temperatures of 80° C. to 200° C. in the presence of catalysts and optionally solvent.

9. A process for producing the carbodiimides as claimed in claim 3, the process comprising end-functionalizing and carbodiimidizing aromatic diisocyanates of formula (II) ##STR00007## to produce a carbodiimide melt, and, after production of the melt, pelletizing the melt on pelletizing belts.

10. A composition comprising: at least one carbodiimide as claimed in claim 1; and at least one ester-based polymer selected from the group of polyester polyols, ester-based thermoplastic polyurethanes, polyurethane elastomers, PU adhesives, PU casting resins, polyamides (PA), 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 derivatives, and/or polyhydroxyalkanoates (PHA).

11. The composition as claimed in claim 10, wherein the concentration of the carbodiimide is 0.1-10 wt %, preferably 1-5 wt %, particularly preferably 1-3 wt %.

12. A process for producing the compositions as claimed in claim 10, the process comprising adding the carbodiimides by means of solids metering units to the ester-based polymers, wherein for the carbodiimides, R is an —NHCOOR.sup.III radical, wherein R.sup.III is C.sub.1-C.sub.22-alkyl, or C.sub.6-C.sub.12-cycloalkyl, and n=0 to 15; and the ester-based polymer is selected from the group consisting of polyethylene terephthalate (PET), polybutylene terephthalate (PBT), polytrimethylene terephthalate (PTT), polyamides (PA), thermoplastic polyurethanes (TPU), copolyesters, modified polyester made of cyclohexanediol and terephthalic acid (PCTA), thermoplastic polyester elastomers (TPE E), ethylene vinyl acetate (EVA), polylactic acid (PLA), polybutylene adipate terephthalate (PBAT), polybutylene succinate (PBS), PLA derivatives and/or polyhydroxyalkanoates (PHA).

13. The use of the carbodiimides as claimed in claim 1 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 thermoplastic polyurethanes (TPU), in polyurethane elastomers, in PU adhesives, in PU casting resins, in PU foams or in PU coatings for wood, leather, synthetic leather and textiles as protection from hydrolytic degradation.

14. The use of the carbodiimides as claimed in claim 1 in films, in particular in films for solar cells.

15. A film comprising at least one polyester selected from the group 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 as claimed in claim 1 based on the polyester.

16. A molding material made of polyamide (PA) and comprising: 1.0-3.0 wt % of the carbodiimide as claimed in claim 1 based on the polyamide, and optionally further additives, fillers and/or reinforcers.

17. The carbodiimide as claimed in claim 1, wherein: R is an —NHCOOR.sup.III radical where R.sup.III is an alkoxypolyoxyalkylene or an unsaturated alkyl radical having 18 carbon atoms, and n=1 to 10; the NCN content in the carbodiimide is 3-6 wt %; and the carbodiimide has an average molar mass (Mw) of 2000-8000 g/mol.

18. The carbodiimide as claimed in claim 1, wherein: R is an —NHCOOR.sup.III radical where R.sup.III is an alkoxypolyoxyalkylene or an unsaturated alkyl radical having 18 carbon atoms; n=3 to 6; the NCN content in the carbodiimide is 4-5 wt %; and the carbodiimide has an average molar mass (Mw) of 3000-6000 g/mol.

19. The carbodiimide as claimed in claim 1, wherein: R is an —NHCOOR.sup.III radical, wherein R.sup.III is C.sub.1-C.sub.6-alkyl, or C.sub.6-C.sub.12-cycloalkyl; n=1 to 15; and the NCN content in the carbodiimide is 3-10 wt %; and the carbodiimide has an average molar mass (Mw) of 2000-8000 g/mol.

20. The carbodiimide as claimed in claim 1, wherein: R is an —NHCOOR.sup.III radical, wherein R.sup.III is methyl, ethyl. i-propyl, or C.sub.6-cycloalkyl; n=3 to 8 and the NCN content in the carbodiimide is 4-5 wt %; and the carbodiimide has an average molar mass (Mw) of 3000-6000 g/mol.

Description

EXEMPLARY EMBODIMENTS

[0069] Tests were carried out on: [0070] 1) CDI (A): a carbodiimide according to formula (I) where R=NCO and n>20, having an NCN content of about 11 wt % and having an NCO content of <1 wt %, comparative. [0071] 2) CDI (B): a carbodiimide of formula (I) where R=—NHCOOR.sup.III and R.sup.III=cyclohexyl, having and NCN content of about 6 wt % and n=about 3, inventive.

[0072] Production of Carbodiimide CDI (A), Comparative

[0073] A baked-out and nitrogen-filled 250 ml four-necked flask was initially charged under a nitrogen stream with 92 g of the diisocyanate of formula (II), M-DIPI. 50 mg of 1-methylphospholene oxide were added and the mixture heated to 160° C. Carbodiimidization was then performed at 160° C. with elimination of carbon dioxide until an NCO content of about 1 wt % had been achieved. The products obtained was no longer stirrable at 160°. Viscosity at 140° C. was >1000 Pas and pelletization was therefore not possible.

[0074] Production of the Inventive Carbodiimide CD (B)

[0075] A baked-out and nitrogen-filled 250 ml four-necked flask was initially charged under a nitrogen stream with 92 g of the diisocyanate of formula (II), M-DIPI. 50 mg of 1-methylphospholene oxide were added and the mixture heated to 160° C. Carbodiimidization was then performed at 160° C. with elimination of carbon dioxide until an NCO content of about 6 wt % had been achieved. The reaction mixture was then cooled to about 90-100° C. and the terminal NCO groups were reacted with cyclohexanol in toluene as solvent (free NCO content <0.1%). Distiliative removal of the toluene afforded a product having an NCN content of about 6 wt %. Said product was still very readily stirrable at 160° and was pelletized without any issues. Viscosity at 140° C. was <10 Pas, The average molar mass was about 3000 g/mol.

[0076] The results show that compared to the prior art the inventive carbodiimides show handleable viscosities in the melt thus making large industrial scale production possible. Moreover, said carbodiimides have the advantage that they are based on less costly raw materials.