DE112005000561B4 - Carbodiimides containing silane groups - Google Patents

Abstract

Carbodiimide containing the following structure: with the following meanings for n, R 1, R 2, R 3, R 4 and R 5: n: an integer from 0 to 20, R 1: aliphatic, cycloaliphatic, araliphatic or aromatic radical, R 2: aliphatic, cycloaliphatic, Araliphatic or aromatic radical, R3: methyl, ethyl, -O-CH3, -O-CH2-CH3, -O-CH (CH3) 2, -OC (CH3) 3 or -O-CH2-CH2-O-CH3 R4: methyl, ethyl, -O-CH3, -O-CH2-CH3, -O-CH (CH3) 2, -OC (CH3) 3 or -O-CH2-CH2-O-CH3 R5: methyl-, Ethyl, -O-CH3, -O-CH2-CH3, -O-CH (CH3) 2, -OC (CH3) 3, or -O-CH2-CH2-O-CH3

Description

mit den folgenden Bedeutungen für n, R₁, R₂, R₃, R₄ und R₅:
n: eine ganze Zahl von 0 bis 20, bevorzugt 2 bis 8, besonders bevorzugt im Mittel 4 bis 6,
R₁: aliphatischer, cycloaliphatischer, araliphatischer oder aromatischer, gegebenenfalls substituierter gegebenenfalls verzweigtkettiger Rest, bevorzugt Alkylenrest mit 1 bis 20, bevorzugt 2 bis 10, besonders bevorzugt 2 bis 4 Kohlenwasserstoffatomen,
R₂: aliphatischer, cycloaliphatischer, araliphatischer oder aromatischer, gegebenenfalls substituierter gegebenenfalls verzweigtkettiger Rest, bevorzugt Alkylenrest mit 1 bis 20, bevorzugt 2 bis 10, besonders bevorzugt 2 bis 4 Kohlenwasserstoffatomen,
R₃: Methyl-, Ethyl, -O-CH₃, -O-CH₂-CH₃, -O-CH(CH₃)₂, -O-C(CH₃)₃ oder -O-CH₂-CH₂-O-CH₃, bevorzugt -O-CH₃ oder -O-CH₂-CH₃, besonders bevorzugt -O-CH₃,
R₄: Methyl-, Ethyl, -O-CH₃, -O-CH₂-CH₃, -O-CH(CH₃)₂, -O-C(CH₃)₃ oder -O-CH₂-CH₂-O-CH₃, bevorzugt -O-CH₃ oder -O-CH₂-CH₃, besonders bevorzugt -O-CH₃,
R₅: Methyl-, Ethyl, -O-CH₃, -O-CH₂-CH₃, -O-CH(CH₃)₂, -O-C(CH₃)₃ oder -O-CH₂-CH₂-O-CH₃, bevorzugt -O-CH₃ oder -O-CH₂-CH₃, besonders bevorzugt -O-CH₃.The invention relates to carbodiimides containing the following structure:

with the following meanings for n, R ₁ , R ₂ , R ₃ , R ₄ and R ₅ :
n: an integer from 0 to 20, preferably 2 to 8, more preferably on average 4 to 6,
R ₁ : aliphatic, cycloaliphatic, araliphatic or aromatic, optionally substituted optionally branched-chain radical, preferably alkylene radical having 1 to 20, preferably 2 to 10, particularly preferably 2 to 4, hydrocarbon atoms,
R ₂ : aliphatic, cycloaliphatic, araliphatic or aromatic, optionally substituted optionally branched-chain radical, preferably alkylene radical having 1 to 20, preferably 2 to 10, particularly preferably 2 to 4, hydrocarbon atoms,
R ₃ : methyl, ethyl, -O-CH ₃ , -O-CH ₂ -CH ₃ , -O-CH (CH ₃ ) ₂ , -OC (CH ₃ ) ₃ or -O-CH ₂ -CH ₂ - O-CH ₃ , preferably -O-CH ₃ or -O-CH ₂ -CH ₃ , particularly preferably -O-CH ₃ ,
R ₄ : methyl, ethyl, -O-CH ₃ , -O-CH ₂ -CH ₃ , -O-CH (CH ₃ ) ₂ , -OC (CH ₃ ) ₃ or -O-CH ₂ -CH ₂ - O-CH ₃ , preferably -O-CH ₃ or -O-CH ₂ -CH ₃ , particularly preferably -O-CH ₃ ,
R ₅ : methyl, ethyl, -O-CH ₃ , -O-CH ₂ -CH ₃ , -O-CH (CH ₃ ) ₂ , -OC (CH ₃ ) ₃ or -O-CH ₂ -CH ₂ - O-CH ₃ , preferably -O-CH ₃ or -O-CH ₂ -CH ₃ , more preferably -O-CH ₃ .

The invention further relates to mixtures comprising the carbodiimides according to the invention and at least one compound from the following group: polyurethanes which have ester structures, polyethylene and / or butylene terephthalate, polyether esters, polyester amides, polycaprolactones, unsaturated polyester resins, polyamides, in particular thermoplastic polyurethanes containing the novel compounds Carbodiimides and preferably ester structures. By the term "silane groups" is meant in this document in particular silicon-organic groups.

Organic carbodiimides are known and are used, for example, as a stabilizer against the hydrolytic degradation of compounds containing ester groups, for example polyaddition and polycondensation products such as. As polyurethanes. Carbodiimides can be prepared by generally known processes, for example by the action of basic catalysts on mono- or polyisocyanates with elimination of carbon dioxide. Suitable catalysts are, for. As heterocyclic compounds containing phosphorus bound, metal carbonyls, phospholines, phospholene and phospholidines and their oxides and sulfides.

Such carbodiimides, their preparation and their use as stabilizers against the hydrolytic cleavage of polyester-based plastics are z. B. described in DE-A 4 318 979 . DE-A 4 442 724 and EP-A 460 481 , DE-A 4 318 979 describes carbodiimides and / or oligomeric polycarbodiimides based on 1,3-bis (1-methyl-1-isocyanatoethyl) benzene (TMXDI), which act as stabilizers against hydrolytic degradation of polyaddition or polycondensation products such as polyurethanes based on ester groups be used.

From the DE 4442 722 A1 are known thermoplastic molding compositions containing a thermoplastic polyurethane and at least one other thermoplastic polymer, wherein the thermoplastic polyurethane contains a carbodiimide as a stabilizer against hydrolytic degradation.

The DE 198 09 634 A1 discloses carbodiimides solid at room temperature, particularly derived from TMXDI, and the carbodiimide structures bonded to non-aromatic carbon atoms.

Subject of the DE 1 190 176 B is the use of carbodiimides together with organosilicon compounds as hydrolysis stabilizers, which leads to a temporal extension of the stabilizing effect, preferably in ester-group-containing polyurethanes.

From the prior art is also known to modify carbodiimides by alkoxysilanes. So describe EP-A 969 029 . EP-A 785 222 . EP-A 507 407 . EP-A 1 162 237 and US 4,118,536 the preparation of carbodiimides having alkoxysilane end groups.

The object of the present invention was to develop improved carbodiimides as stabilizers against the hydrolytic cleavage of polyester-based plastics, which have optimal incorporation into the starting components of the plastics or in the plastics themselves and also the dynamic and static properties of the plastics, in particular of polyurethane elastomers, not adversely affect. A particular aim was to obtain the property profile of the plastics to be stabilized, in particular of the thermoplastic polyurethane, even under conditions in which hydrolysis usually occurs.

This problem could be solved by the carbodiimides described above.

Purely statistically, in the hydrolytic degradation of a polyester from a molecule by cleavage, two molecules become. This is accompanied by a corresponding molar mass loss. When the carbodiimide is used, a scavenging of the acid-containing polymer residue results in a combination of these two molecules. However, this does not solve the problem of molecular weight degradation. The particular advantage of the carbodiimides according to the invention lies both in their outstanding effectiveness as hydrolysis stabilizers and in their ability to form crosslinks and thus higher molecular weights in the polymer via the siloxane groups at the end of the carbodiimide. This particular advantage is particularly advantageous in termoplastischen plastics, preferably thermoplastic polyurethane to bear.

By linking silane groups via the urea group to the carbodiimide, a very good crosslinking capacity is provided with the carbodiimides according to the invention by a simple and economical preparation process, which can bring about a significant increase in molecular weight in the polymer and thus ensures a high property profile of the polymer.

• • Leicht herstellbar
• • Ohne Nebenreaktionen in TPU einarbeitbar
• • Niedrige Viskositäten bei Verarbeitungstemperatur (60°C)
• • Pumpfähig bei Raumtemperatur
• • Lagerstabil
• • Wirksam als Hydrolyseschutzmittel, insbesondere wenn katalysatorfrei, d. h. mit deutlich reduziertem Gehalt z. B. an Phospholen-oxid
• • Geringe Flüchtigkeit
• • Kostengünstig
• • Reaktion in Masse, d. h. ohne Lösungsmittel

In addition, the carbodiimides according to the invention have the following advantages:

• • Easy to produce
• • Can be used without side reactions in TPU
• • Low viscosities at processing temperature (60 ° C)
• • Pumpable at room temperature
• • Shelf life
• • Effective as a hydrolysis, especially if catalyst-free, ie with significantly reduced content z. B. to phospholene oxide
• • Low volatility
• • Cost effective
• • Reaction in bulk, ie without solvent

• • Verbesserte hydrolytische Beständigkeit bei Lagerung in Wasser bei 80°C
• • Verbesserung (Erhöhung) der Zugfestigkeit und Reißdehnung bei Lagerung unter Wasser
• • Vernetzung der Siloxangruppen in-situ bei Anwendung unter feuchten Bedingungen, d. h. entfall des zusätzlichen Arbeitsschrittes der Vernetzung
• • Verringerung der Quelleigenschaften
• • Erhöhung der Wärmeformbeständigkeit
• • Erhöhung der HDT
• • Erhöhung des E-Modlus
• • Erhöhung der Vicat-Temperatur

The TPUs produced with the carbodiimides according to the invention have the following advantages over conventional carbodiimides:

• • Improved hydrolytic stability when stored in water at 80 ° C
• • improvement (increase) in tensile strength and elongation at break when stored under water
• • Crosslinking of the siloxane groups in situ when used under humid conditions, ie without the additional working step of crosslinking
• • Reduction of swelling properties
• • increase the heat resistance
• • increase the HDT
• • Increase the e-modus
• • increase the Vicat temperature

mit der folgenden Bedeutung für n: eine ganze Zahl von 1 bis 20, bevorzugt 2 bis 8, besonders bevorzugt im Mittel 4 bis 6.The following carbodiimides are preferred:

with the following meaning for n: an integer from 1 to 20, preferably from 2 to 8, particularly preferably from 4 to 6 on average.

The preparation of the carbodiimides according to the invention can be carried out by generally known reaction of the isocyanate groups with elimination of carbon dioxide in the presence of customary catalysts which are known for this reaction and have been described in the introduction.

For example, the carbodiimides according to the invention can be obtained in such a way that 1,3-bis (1-methyl-1-isocyanatoethyl) benzene is reacted in the presence of catalysts with carbon dioxide cleavage to give carbodiimides and subsequently the isocyanate-containing carbodiimide is reacted with a compound, which has at least one isocyanate group and at least one or two, preferably two, silane groups, preferably trialkoxysilane groups, in the presence of catalysts with elimination of carbon dioxide to give the carbodiimide. The molar ratio of the NCO groups of the isocyanate group-containing carbodiimide to the isocyanate groups of the silane is usually from 10: 1 to 0.2: 1, preferably from 5: 1 to 0.5: 1, particularly preferably from 1: 1 to 0.5: 1, in particular 1: 1.

Alternatively, the carbodiimides according to the invention can be obtained by mixing 1,3-bis (1-methyl-1-isocyanatoethyl) benzene in admixture with a compound containing at least one isocyanate group and at least one, preferably a silane, preferably trialkoxysilane has reacted in the presence of catalysts under carbon dioxide release to carbodiimides.

The preparation of the carbodiimides according to the invention by reacting the isocyanate groups can at elevated temperatures, for. B. at temperatures of 50 to 200 ° C, preferably from 150 to 185 ° C, advantageously in the presence of catalysts are condensed under carbon dioxide. For this purpose, suitable methods are described for example in the GB-A-1 083 410 , of the DE-B 1 130 594 ( GB-A-851 936 ) and the DE-A-11 56 401 ( US-A-3,502,722 ). As catalysts have proven excellent z. B. phosphorus compounds, which are preferably selected from the group of phospholens, phospholene oxides, phospholidines and phospholine oxides. When the reaction mixture has the desired level of NCO groups, polycarbodiimide formation is usually terminated. For this purpose, the catalysts can be distilled off under reduced pressure or by addition of a deactivator, such as. As phosphorus trichloride be deactivated. The polycarbodiimide preparation may also be carried out in the absence or presence of inert solvents under the reaction conditions.

By a suitable choice of reaction conditions such. As the reaction temperature, the type of catalyst and the amount of catalyst and the reaction time, the skilled person can adjust the degree of condensation in the usual way. The course of the reaction can be most easily followed by determining the NCO content. Other parameters such. B. Viscosity increase, color well or CO ₂ evolution can be used to track the process and control the reaction.

The diisocyanate used to prepare the carbodiimides according to the invention is 1,3-bis (1-methyl-1-isocyanatoethyl) benzene, also referred to below as TMXDI. The TMXDI can be used in mixtures with further, generally customary isocyanates, for example hexamethylene diisocyanate, 1-isocyanato-3,3,5-trimethyl-5-isocyanatomethyl cyclohexane (isophorone diisocyanate), di (cyclohexyl) methane diisocyanate, trimethylhexamethylene diisocyanate, dodecane diisocyanate, octane diisocyanate and or cyclohexane-1,4-diisocyanate. In this case, preferably at least 30 mol% TMXDI mitverwendet.

For incorporation of the silane group (s) into the carbodiimide, ie for reaction with the TMXDI or with the carbodiimide based TMXDI generally known isocyanates, preferably monoisocyanates containing at least one, preferably a silane group can be used. Preferably, the following compound is used, which is available from Osi Specialties:

The carbodiimides according to the invention containing at least one, preferably one to twenty carbodiimide, more preferably, the average degree of condensation (number average), d. H. the average number of carbodiimide structures in the carbodiimides according to the invention one to ten, particularly preferably 2 to 8, in particular 4 to 6.

The monocarbodiimides and / or oligomeric polycarbodiimides according to the invention are outstandingly suitable as acceptors for carboxyl compounds and therefore are preferably used as stabilizers against the hydrolytic degradation of ester group-containing compounds, for example, ester group-containing polymers, for. As polycondensation products such as thermoplastic polyesters such as polyethylene and butylene terephthalate, polyether esters, polyamides, polyester amides, polycaprolactones and unsaturated polyester resins and polyester esters such. B. block copolymers of polyethylene or butylene terephthalate and polycaprolactone. and polyaddition products, e.g. As polyurethanes, polyureas and polyurethane-polyurea elastomers containing ester groups. These ester group-containing compounds are well known. Their starting materials, preparation methods, structures and properties are described in manifold ways in the standard literature. Due to the good solubility in the synthesis components for the production of polyurethanes and the good compatibility with the polyurethanes formed, the (poly) carbodiimides of the invention are particularly suitable as stabilizers against the hydrolytic degradation of polyurethanes, preferably compact or cellular polyurethane elastomers and especially thermoplastic polyurethanes and cellular or compact elastomers.

The concentration of the carbodiimides according to the invention in the polycondensation or polyaddition products to be stabilized ester groups is generally 0.05 to 10 wt .-%, preferably 0.1 to 5 wt .-%, based on the total weight of the mixture. In individual cases, depending on the stress of the plastic by hydrolysis, the concentration may also be higher.

The carbodiimides which can be used according to the invention can be introduced by various methods into the products to be stabilized containing ester groups. For example, the carbodiimides according to the invention with one of the synthesis components for the preparation of the polyaddition products, for. As the polyisocyanates and / or polyhydroxyl compounds for the production of polyurethanes, or the carbodiimides can be added to the reaction mixture for the preparation of the polyurethanes. According to another procedure, the carbodiimides according to the invention can be incorporated into the melt of the fully reacted polyaddition or polycondensation products. However, it is also possible to coat granules of the polyaddition or polycondensation products with the carbodiimides according to the invention or to mix with the pulverized, pelletized or granulated carbodiimides of the invention and to introduce in a subsequent production of moldings by melt extrusion in the plastic compositions. For the production of polyurethane cast elastomers and TPU based on polyester, the carboxyl-containing polyester polyols are first treated with the carbodiimides according to the invention to reduce the acid contents and then, optionally with the addition of further amounts of carbodiimides, with polyisocyanates, optionally in the presence of additional Auxiliaries and additives, reacted. Furthermore, the carbodiimides according to the invention can be introduced into the polyurethane via the isocyanate component. However, the carbodiimides according to the invention are particularly useful if they are introduced into the ester-group-containing polymer during the customary preparation.

The carbodiimides of the invention are particularly preferably used in the preparation of polyurethanes, for. B. cellular, for example, microcellular polyurethanes, preferably polyurethane elastomers, in particular thermoplastic polyurethanes used. The preparation of these polyurethanes, in particular polyurethane elastomers, can be achieved by known reaction of customary starting components, ie. H. Isocyanates, isocyanate-reactive compounds, optionally propellants, preferably water and optionally catalysts, auxiliaries and / or additives in the presence of the carbodiimides of the invention take place. In this case, it is preferable to add the carbodiimides of the invention to the component containing the propellant, preferably water.

Preference is thus given to processes for the preparation of polyurethanes, preferably thermoplastic polyurethanes preferably by reacting isocyanates, isocyanate-reactive compounds, optionally blowing agents and optionally catalysts, auxiliaries and / or additives, wherein the reaction is carried out in the presence of the carbodiimides according to the invention.

In addition to the effectiveness as a stabilizer against the hydrolytic degradation of polyaddition or polycondensation products containing ester groups or for deacidification of polyesterols, which can be used for the production of polyester-containing plastics, especially polyurethane rubbers, the carbodiimides z. B. also for the termination of esterification reactions in the production of polyesters, when the desired degree of polycondensation is reached.

The thermoplastic polyurethane elastomers according to the invention can be used for extrusion, injection molding, calendar articles and powder-slush processes.

The carbodiimides of the invention are preferably used in thermoplastic polyurethanes. The present invention therefore also relates to processes for the preparation of silicon-organic groups, in this document also as silane-modified, ie silicon-organic groups thermoplastic polyurethane and thus obtainable crosslinkable TPU, in particular cable sheaths, fibers or hoses, in particular compressed air hoses , as well as the corresponding products crosslinked via the silane groups. In addition, the invention relates Kabelummantellungen, fibers or hoses, in particular compressed air hoses, based on thermoplastic polyurethane, which is crosslinked via silane groups, in particular siloxane, in particular Kabelummantellungen, fibers or hoses, in which the crosslinked thermoplastic polyurethane has a Shore A hardness between 85th and 98 and a Vicat temperature according to DIN EN ISO 306 (10 N / 120 K / h) greater than 130 ° C, more preferably greater than 140 ° C, in particular greater than 145 ° C.

The processing of the TPUs according to the invention, which are usually present as granules or in powder form, to injection molding and extrusion articles, for. As the desired films, moldings, rolls, fibers, linings in automobiles, hoses, cable connectors, bellows, trailing cables, cable sheathing, seals, belts or damping elements is carried out by conventional methods such. As injection molding or extrusion. Such injection molding and extrusion articles can also be made of compounds containing the TPU according to the invention and at least one further thermoplastic, especially a polyethylene, polypropylene, polyester, polyether, polystyrene, PVC, ABS, ASA, SAN, polyacrylonitrile, EVA, PBT, PET, polyoxymethylene, consist. In particular, the TPU produced according to the invention can be used for the production of the articles presented at the outset.

It is preferable to spin the silane-modified thermoplastic polyurethane to fibers by generally known methods or to extrude tubes, in particular compressed air hoses and then crosslink the thermoplastic polyurethane via the silane groups by means of moisture, optionally a catalyst which accelerates the crosslinking, is used. The crosslinking reactions via and through the silane groups are familiar to the person skilled in the art and generally known. This crosslinking is usually carried out by moisture and can by heat or catalysts known for this purpose, for. As Lewis acids, Lewis bases, Brönsted acids, Brönsted bases can be accelerated. Preference is given to using as the catalyst for the crosslinking preferably by means of moisture acetic acid, organic metal compounds such as titanic acid esters, iron compounds such. For example, iron (III) acetylacetonate, tin compounds, e.g. As tin diacetate, tin dioctoate, tin dilaurate or Zinndialkylsalze aliphatic carboxylic acids such as dibutyltin diacetate, dibutyltin dilaurate or the like, particularly preferably tin dilaurate and / or acetic acid.

Example 1:

Preparation of stabilizers according to the invention: isocyanate stage

1000 parts by weight (4.1 mol) of 1,3-bis (1-methyl-1-isocyanato-ethyl) -benzene with an NCO content of 34.4 wt .-% were in the presence of 2.0 Parts by weight of 1-methyl-2-phospholene-1-oxide solvent-free heated to 180 ° C and condensed at this temperature with moderate evolution of carbon dioxide. After reaching an NCO content of the reaction mixture of 10% by weight, which required a reaction time of about 24 hours, the carbodiimidization was terminated. The reaction mixture was cooled to 100 ° C.

Example 2 Preparation of Stabilizers According to the Invention: Carbodiimidization with the Isocyanato-Siloxane (Stabilizer 1)

To 500 g of the compound from Example 1 35 silanes was added dropwise with vigorous stirring over a period of about 10 min 117.9 g Silquest ^® A-Link ^™. The temperature was increased up to 120 ° C and the carbodiimidization up to an isocyanate content of max. 1 wt .-% continued. After reaching an NCO content of the reaction mixture of 1 wt .-%, this a reaction time of about 5 hours was required, the added catalyst and residues of unreacted 1,3-bis (1-methyl-1-isocyanato-ethyl ) benzene and Silquest ^® a-link 35 silane ^TM at a temperature of 190 ° C and under a pressure of 0.2 mbar distilled off.

The structure of the isocyanate-containing mixture of mono- and oligomeric polycarbodiimides with siloxane engroups was detected by ¹ H-NMR and IR spectrum.

Example 3: Preparation of TPU Samples

Polyol 1)

• Polyester polyol (butanediol / hexanediol adipate, molecular weight 2000, OH number = 56.1, BASF Aktiengesellschaft)

Polyol 2)

• Polyester polyol (butanediol / ethylene glycol adipate, molecular weight 2000, OH number = 56.1, BASF Aktiengesellschaft)

The polyols indicated in Table 1 were mixed at 80 ° C with 1,4-butanediol. Subsequently, the addition of the various hydrolysis stabilizers as listed in Table 1 was carried out with stirring. Table 1 attempt 1 2 3 4 Polyol 1 1000 g 1000 g 1000 g 1000 g butanediol 110 g 110 g 110 g 110 g Elastostab® H01 ^® 8 g - - - Stabaxol 1 ^® - 8 g - - Stabilizer 1 - - 8 g - attempt 5 6 7 8th Polyol 2 1000 g 1000 g 1000 g 1000 g butanediol 110 g 110 g 110 g 110 g Elastostab® H01 ^® 8 g - - - Stabaxol 1 ^® - 8 g - - Stabilizer 1 - - 8 g -
Elastostab® ^® H01: polymeric carbodiimide (hydrolysis stabilizer) Elastogran GmbH
Stabaxol ^® 1: monomeric carbodiimide (Antihydrolysis) of Rhein Chemie GmbH
Stabilizer 1: stabilizer prepared in Example 2

The glycol mixture was heated to 80 ° C. with stirring. Thereafter, 425 g of 4,4'-MDI (methylene diphenyl diisocyanate) was added and stirred until the reaction mixture was homogeneous. The mixture was then poured into a flat Teflon dish and annealed at 125 ° C on a hot plate for 10 min. The resulting TPU rind was tempered in a heating cabinet at 100 ° C for 24 h. After granulating the casting plates, they were processed on an injection molding machine into 2 mm spray plates. The mechanical values were determined and are listed in Table 2. Table 2 stabilization Shore hardness Tensile strength [mPas] Elongation at break [%] Tear resistance [N / mm] Abrasion [mm ³ ] Density [g / cm ³ ] Trial 1 82 49 580 65 35 1,183 Trial 2 82 52 600 68 34 1,183 Trial 3 85 53 560 71 33 1,181 Trial 4 84 44 630 75 33 1,185 stabilization Shore hardness Tensile strength [mPas] Elongation at break [%] Tear resistance [N / mm] Abrasion [mm ³ ] Density [g / cm ³ ] Trial 5 84 47 700 67 36 1,218 Trial 6 85 50 700 73 41 1,218 Trial 7 84 51 670 72 37 1,220 Trial 8 85 47 620 70 38 1,225 Table 3 characteristics unit DIN ISO hardness Shore A 53505 868 density kg / m ³ 53479 1183 tensile strenght MPa 53504 37 elongation at break % 53504 37 Tear strength N / mm 53515 34 abrasion mm ³ 53516 4649

Determination of hydrolysis resistance

Test specimens were punched out of the spray plates S2, placed in glasses (250 and 500 ml) with distilled water and placed in a temperature control cabinet of defined temperature (80 ° C.). At intervals (eg weekly) three specimens were taken. Thereafter, the samples were min. Stored for 30 minutes in standard climate 23/50 and determined tensile strength and elongation at break. Table 4: Measurement of tensile strength [MPa] as a function of time [days] Duration [d] Trial 1 Trial 2 Trial 3 Trial 4 0 49 52 53 44 7 44 44 47 25 14 45 46 46 7 21 44 44 45 destroyed 28 43 43 45 35 42 40 44 42 42 38 44 49 42 40 43 56 42 33 41 63 40 17 42 70 41 4.75 40 77 36 2 41 84 24 destroyed 39 91 6 35 98 destroyed 31 105 16 112 3 Table 5: Measurement of elongation at break [%] as a function of time [days] Duration [d] Trial 1 Trial 2 Trial 3 Trial 4 0 580 600 560 630 7 520 560 500 770 14 550 570 520 530 21 540 580 510 destroyed 28 550 600 530 35 540 580 550 42 620 650 590 49 590 650 620 56 620 730 630 63 590 780 650 70 610 275 660 77 610 40 650 84 750 Destroyed 680 91 450 710 98 Destroyed 790 105 220 112 30 Table 6: Measurement of tensile strength [MPa] as a function of time [days] Duration [d] Trial 5 Trial 6 Trial 7 Trial 8 0 47 50 51 47 7 42 41 47 27 14 - - # N 6 21 39 36 43 Destroyed 28 35 32 39 35 27 16 35 42 7 4 29 49 destroyed destroyed 18 56 3 63 destroyed 70 Table 7: Measurement of elongation at break [%] as a function of time [days] Duration [d] Trial 5 Trial 6 Trial 7 Trial 8 0 700 700 670 620 7 640 660 630 770 14 - - # N 420 21 690 700 650 Destroyed 28 680 780 680 35 840 900 700 42 580 280 750 49 destroyed destroyed 810 56 250 63 destroyed 70

Claims (7)

Carbodiimide containing the following structure:

with the following meanings for n, R ₁ , R ₂ , R ₃ , R ₄ and R ₅ : n: an integer from 0 to 20, R ₁ : aliphatic, cycloaliphatic, araliphatic or aromatic radical, R ₂ : aliphatic, cycloaliphatic , araliphatic or aromatic radical, R ₃ : methyl, ethyl, -O-CH ₃ , -O-CH ₂ -CH ₃ , -O-CH (CH ₃ ) ₂ , -OC (CH ₃ ) ₃ or -O- CH ₂ -CH ₂ -O-CH ₃ R ₄ : methyl, ethyl, -O-CH ₃ , -O-CH ₂ -CH ₃ , -O-CH (CH ₃ ) ₂ , -OC (CH ₃ ) ₃ or -O-CH ₂ -CH ₂ -O-CH ₃ R ₅ : methyl, ethyl, -O-CH ₃ , -O-CH ₂ -CH ₃ , -O-CH (CH ₃ ) ₂ , -OC ( CH ₃ ) ₃ or -O-CH ₂ -CH ₂ -O-CH ₃ Carbodiimide containing the following structure:

with the following meaning for n: an integer from 1 to 20. Mixtures containing carbodiimides according to claim 1 or 2 and at least one compound from the following group: polyurethanes having ester structures, polyethylene and / or butylene terephthalate, polyether esters, polyester amides, polycaprolactones, unsaturated polyester resins, polyamides. Thermoplastic polyurethanes containing carbodiimide according to claim 1 or 2 and preferably ester structures. A process for preparing carbodiimides, which comprises reacting 1,3-bis- (1-methyl-1-isocyanatoethyl) -benzene in the presence of catalysts with elimination of carbon dioxide to give carbodiimides and then reacting the isocyanate-containing carbodiimide with a compound, which comprises at least one isocyanate group and at least one or two silane groups, in the presence of catalysts with elimination of carbon dioxide to give the carbodiimide. Process for the preparation of carbodiimides, characterized in that 1,3-bis- (1-methyl-1-isocyanato-ethyl) -benzene is mixed with a compound which has at least one isocyanate group and at least one silane group in the presence of catalysts reacted under carbon dioxide release to carbodiimides. Process for the preparation of polyurethanes, characterized in that the reaction takes place in the presence of carbodiimides according to claim 1 or 2.