DE19706452A1 - Reducing absorption/desorption tendency of poly:isocyanate polyaddition products eg poly:urethane(s) - Google Patents

Abstract

Use is claimed of 24-34C fatty acids (and/or their amides and/or esters) in the production of polyisocyanate-polyaddition products with reduced tendency to absorb and/or desorb substances, the production comprising reacting (a) a polyisocyanate with (b) an NCO-reactive compound of mol. wt. 500-8,000, (c) optionally also a chain extender and/or crosslinker of mol. wt. below 500, (d) a catalyst and (e) conventional additives etc in presence of the fatty acid and/or derivative.

Description

The invention relates to the use of fatty acids 24 to 34 carbon atoms and / or derivatives of these fatty acids for the production of polyisocyanate polyadducts with ver reduced tendency to take up and / or release substances.

The manufacture of polyisocyanate polyadducts by Implementation of polyisocyanates with reactive towards isocyanates Connections are known and z. B. in the "plastic manual", volume 7, Polyurethane, 3rd edition, 1993, edited by G. Oertel, Carl-Hanser-Verlag, Munich and 1st edition, 1966, published by R. Vieweg and A. Höchtlen, Carl-Hanser-Verlag, Munich be wrote. Due to the reaction conditions such. B. the Kata lysing or the reaction partner can allophanates, biurethe, Carbodiimides and their isocyanate adducts, oxazolidones, polyimides, Polyamides, polyureas, polyisocyanurates and especially as most important and most common substance group Polyurethanes as isocyanate Adducts are present, which are generally referred to below as polyurethanes or abbreviated PUR. Also the structural up construction of the polyurethanes as well as their properties can be within vary over a wide range. So depending on the reaction conditions thermoplastic or cross-linked, cellular, z. B. micro cellular or compact polyurethanes, soft, elastic or hard Polyurethane foams are made.

Common to all polyurethanes is that they are due to of the isocyanate adducts contain polar functions and thus one Affinity to polar, for example hydrophilic substances be to sit. The polarity of the polyurethanes on the one hand justifies them relative insensitivity to non-polar solvents, which the area of application of the polyurethanes z. B. compared to poly olefins or similar non-polar polymers significantly expanded. On the other hand, the polarity causes the polyurethanes to have a Tendency to absorb polar substances, for example what possess water, inorganic or organic acids and bases. Also substances that lead to discoloration of the polyurethane and halogens such as chlorine, e.g. B. from drinking water, who due to this tendency absorbed by the polyurethanes.

Since the recording processes are reversible processes delt, numerous processes are known in which the poly urethanes not only absorb substances from the environment, but also  these or unreacted raw materials, additives or degradation Deliver polyurethane products to the environment. These processes are z. B. for efflorescence, washouts or the "fogging" of Responsible for polyurethanes.

The use of fatty acids with 24 to 34 carbon atoms and / or their esters and / or amides, e.g. B. as mixtures in the form of montan waxes in the production of polyurethanes, ins special thermoplastic polyurethanes, as a release agent e.g. B. from EP-A-563 918 and from the company documents of Hoechst Joint-stock company "Montan waxes for plastics processing" and "Hoechst waxes" known. The advantages known so far through the use of these compounds are improved De-molding of the molded polyurethane body because it adheres to the For men or a glue z. B. thermoplastic polyurethane nulate is prevented. The Montan waxes can be used for this purpose both as raw products and as in the company letter of Höchst Aktiengesellschaft "Höchst waxes" described as part synthetic or refined, bleached products used will.

The object of the present invention was therefore to poly Isocyanate polyadducts with a reduced tendency to open developing and / or dispensing substances.

This object could be achieved according to the invention in that fatty acids with 24 to 34 carbon atoms and / or esters and / or amides of these fatty acids for the production of polyisocya nat polyadducts with a reduced tendency to absorb and / or dispensing substances by reacting (a) polyiso cyanates, (b) isocyanate-reactive compounds with a molecular weight of 500 to 8000 g / mol and optionally (c) chain extenders and / or crosslinking agents with a Molecular weight of less than 500 g / mol, (d) catalysts and (e) usual auxiliaries and additives in the presence of the fatty acids and / or derivatives of these fatty acids.

The fatty acids and / or their derivatives according to the invention can individually or as a mixture of at least two of the fatty acids and / or whose derivatives are used.

As fatty acids according to the invention, which also include wax acids or acid waxes can be mentioned, those with at least 24, are preferred 24 to 36, particularly preferably 26 to 30 carbon atoms can be used, such as those contained in Montan waxes are. The fatty acids can be branched or preferably linear built up, saturated or unsaturated and for example  Contain hydroxyl groups. Partially synthetic, refined or bleached acid waxes can be used, such as they z. B. from raw montan wax after extraction with suitable Lö solvents and subsequent oxidation with, for example Chromic acid can be obtained. These procedures for working up Rohmontanwachs z. B. in the company lettering Hoechst Joint-stock company "Montan-Wachsen" described. The worked up The advantages of acid waxes are of uniform quality and a small proportion of short-chain carboxylic acids. In addition these products are almost colorless and therefore lead to their Use in polyurethanes not to discolour them.

The fatty acids preferably have a melting point of greater than 85.degree on. Examples of suitable wax acids are lignoceric acid, Cerotinic acid, melissic acid (triacontanoic acid), hentriacontanoic acid (Melissylic acid), octacosanoic acid, myricylic acid, dotriacontanoic acid, Called tetrakontanoic acid.

The wax acids can preferably also be used as derivatives, for example as esters or amides, or modified, for example can be used alkoxylated. For example, the acid wax with linear or branched mono-, di- or poly alcohols or mono-, di- or polyamines esterified or amidated be. The monoalcohols or monoamines 2 preferably have to 36, particularly preferably 16 to 32 carbon atoms. As Alcohols are preferably used as di- or polyalcohols or amines get or amines with 2 to 10, particularly preferably 2 to 6 carbons atoms of matter.

Examples of preferred ester waxes are ethylene dice rotinate (ethylene glycol cerotic diester), butylene dicerotinate (Butylene glycol-cerotinic acid diester) or butyleneditriacontanate (Butylene glycol triacontanoic acid diester), butylene octocosanate, Hen triacont wax, cerotin and / or melissin wax, ethylene glycol Octakosanoic acid and / or triacontanoic acid ester, 1,6-hexanediol cero tic acid diesters as well as those in bleached and / or refined montan waxes containing ester and / or amides.

The fatty acids and / or their derivatives according to the invention can individually or in mixtures containing two or more of these Compounds are used and are preferred in one Weight fraction from 0.001 to 15 wt .-%, particularly preferably 0.05 up to 10 wt .-%, in particular 0.05 to 3 wt .-% based on the Ge total weight of the polyisocyanate polyaddition products used.  

The using the fatty acids and / or their derivatives produced polyisocyanate polyadducts show a reduced tendency to take up and release sub punch on. For example, the inclusion of halogens, sub punches that lead to discoloration of the polyaddition products or polar compounds, d. H. Substances that, for example, in Solution at least partially present as ions or Substan zen that have a dipole moment and / or hydrogen bonds ties, e.g. B. with water, for example what water, bases, salts and / or acids, for example acetic acid in the polyisocyanate polyadducts by using Fatty acids with 24 to 34 carbon atoms and / or esters and / or Amides of these fatty acids in the manufacture of polyisocya nat polyadducts can be reduced. Furthermore, the release of substances from the polyaddition products, for example plasticizers and / or amines, especially sub punch with a molecular weight of less than 10,000 g / mol redu be decorated.

The wax acids can be added to one of the components (a) to (e) or, for example, if you use the two-component Ver drive works, in the polyol component (A) containing the up structural components (b) and optionally (c), (d), (e) and / or (f) or in the isocyanate component (B) containing the optionally modified isocyanates and optionally (e) take place. Also an addition directly into the reaction mixture, for example the production of the polyurethanes by means of a reaction extruder or using the one-shot process is possible. One uses the wax acids according to the invention for the production of thermoplastic polyurethanes, so can the addition of wax acids and / or their derivatives in one of the components or in the reaction mixture or in a confectioning cut respectively.

Adequate mixing of the wax acids and / or their Derivatives with the components are advantageous in any case.

The wax acids and / or their derivatives can be obtained from the manufacturer tion of conventional polyurethanes are used, for example the production of thermoplastic or cross-linked polyurethane NEN, compact or cellular, for example microcellular poly urethanes. The particularities in the manufacture of the Different polyurethane forms are known and varied, e.g. B. in the plastics manual loc. cit. described. So become more common way for the production of thermoplastic polyisocyanate poly addition products to isocyanate-reactive compounds used with a molecular weight of 500 to 8000 g / mol, the  a functionality of 1.5 to less than 3, preferably 1.7 to 2.5 have and are therefore predominantly bifunctional. Like this with it is advantageous to use no crosslinking agents for the implementation to use. In the manufacture of cross-linked, if necessary cellular polyisocyanate polyadducts are preferred wise crosslinking agents, for example against isocyanates active connections that have a functionality of 3 to 8 have, and optionally blowing agents.

The following are based on the production of thermoplastic Polyurethanes, hereinafter also abbreviated TPU, the components (a) to (e) and the processes for producing the PUR are exemplary being represented. The molecular weight given below Unless stated, weights have the unit g / mol.

• a) Suitable organic isocyanates (a) are preferably aliphatic, cycloaliphatic and in particular aromatic diisocyanates. The following may be mentioned by way of example: aliphatic diisocyanates, such as 1,6-hexamethylene-diiso cyanate, 1,5-2-methyl-pentamethylene-diisocyanate, 1,4-2-ethylbutylene or mixtures of at least 2 of the C _{6 mentioned} Alkylene diisocyanates, pentamethylene diiso cyanate 1,5 and butylene diisocyanate 1,4, cycloaliphatic diisocyanates, such as 1-isocyanato-3,3,5-trimethyl-5-isocyanato methylcyclohexane (isophorone diisocyanate), 1,4-cyclohexane diisocyanate, 1-methyl-2,4- and -2,6-cyclohexane diisocyanate and the corresponding isomer mixtures, 4,4'-, 2,4'- and 2,2'-dicyclohexylmethane diisocyanate and the corresponding isomer mixtures and preferably aromatic diisocyanates, such as 2,4'-tolylene diisocyanate, mixtures of 2,4- and 2,6-tolylene diisocyanate, 4,4'-, 2,4'- and / or 2, 2'-diphenylmethane diisocyanate (MDI), mixtures of 2,4'- and 4,4'-diphenylmethane diisocyanate, urethane-modified liquid 4,4'- and / or 2,4-diphenylmethane diisocyanates, 4,4 '-Diisocyanato-di phenylethane (1,2 ) and 1,5-naphthylene diisocyanate. Preference is given to using 1,6-hexamethylene diisocyanate, 4,4'-dicyclohexylmethane diisocyanate, isophorone diisocyanate, diphenylmethane diisocyanate isomer mixtures with a 4,4'-diphenylmethane diisocyanate content of greater than 96% by weight. % and in particular 4,4'-diphenylmethane diisocyanate.
• b) Suitable as substances (b) reactive towards isocyanates for example, polyhydroxyl compounds with molecular weights from 500 to 8000, preferably polyetherols and Polyesterols. However, hydroxyl groups are also suitable containing polymers, for example polyacetals, such as polyoxy methylene and especially water-insoluble formals, e.g. B. Poly  butanediol formal and polyhexanediol formal, and aliphatic Polycarbonates, especially those made from diphenyl carbonate and Hexanediol-1,6, made by transesterification, with the above mentioned molecular weights. The polyhydroxyl mentioned Connections can be made as individual components or in the form of Mixtures are used.

The mixtures for the production of the TPU or the TPU must at least predominantly on difunctional versus iso cyanate-reactive substances are based. The one with these Mixtures of TPUs are therefore predominantly not branches, d. H. mostly not networked, built up.

Suitable polyetherols can be prepared according to known ones Processes, for example by anionic polymerization with Alkali hydroxides, such as sodium or potassium hydroxide, or alkali alcoholates, such as sodium methylate, sodium or potassium ethylate or potassium isopropylate as catalysts or by cationic Polymerization with Lewis acids, such as antimony pentachloride, boron fluoride etherate u. a. or bleaching earth as catalysts from one or more alkylene oxides having 2 to 4 carbon atoms in the Alkylene radical and optionally a starter molecule, the 2 reak tive contains hydrogen atoms bound. As alkylene oxides e.g. B. called: ethylene oxide, 1,2-propylene oxide, tetrahydrofuran, 1,2- and 2,3-butylene oxide. Ethylene is preferably used oxide and mixtures of 1,2-propylene oxide and ethylene oxide. The Alkylene oxides can be used individually, alternately in succession or as Mixture can be used. As a starter molecule come for example Wise into consideration: water, amino alcohols, such as N-alkyl-dialkanol amines, for example N-methyl-diethanolamine and diols, e.g. B. Alkanediols or dialkylene glycols with 2 to 12 C, atoms, preferred quiet 2 to 6 carbon atoms, such as ethanediol, 1,3-propanediol, butane diol-1,4 and hexanediol-1,6. If necessary, mixtures can also be used of starter molecules are used. Suitable polyetherols are also the hydroxyl-containing polymerization products of tetrahydrofuran (polyoxytetramethylene glycols).

Polyetherols of 1,2-propylene oxide are preferably used and ethylene oxide in which more than 50%, preferably 60 to 80% of the OH groups are primary hydroxyl groups and in which at least least part of the ethylene oxide arranged as a terminal block is and especially polyoxytetramethylene glycols.

Such polyetherols can be obtained by e.g. B. to the starter molecule, propylene oxide-1,2 and then then polymerized the ethylene oxide or first that total 1,2-propylene oxide mixed with part of the ethylene  copolymerized oxide and then the rest of the ethylene oxide polymerized or gradually part of the Ethylene oxide, then all of 1,2-propylene oxide and then that Polymerized rest of the ethylene oxide onto the starter molecule.

The essentially linear polyetherols in the case of TPU zen usually molecular weights of 500 to 8000, preferably example, 600 to 6000 and especially 800 to 3500. You can probably individually as well as in the form of mixtures with each other Application come.

Suitable polyesterols can, for example, from dicarboxylic acids with 2 to 12 carbon atoms, preferably 4 to 8 carbons atoms, and polyhydric alcohols are produced. As Dicarboxylic acids are suitable, for example: aliphatic Dicarboxylic acids, such as succinic acid, glutaric acid, suberic acid, Azelaic acid, sebacic acid and preferably adipic acid and aromatic dicarboxylic acids, such as phthalic acid, isophthalic acid and terephthalic acid. The dicarboxylic acids can be used individually or as Mixtures, e.g. B. in the form of a succinic, glutaric and adipic acid mixture, can be used. Likewise, mixtures of aro Matic and aliphatic dicarboxylic acids can be used. To Her position of the polyesterols it may be advantageous be, instead of the dicarboxylic acids, the corresponding dicarbon acid derivatives, such as dicarboxylic acid esters with 1 to 4 carbon atoms in the alcohol residue, dicarboxylic acid anhydrides or dicarboxylic acid chloride to use. Examples of polyhydric alcohols are Alkanediols having 2 to 10, preferably 2 to 6, carbon atoms, such as ethanediol, 1,3-propanediol, 1,4-butanediol, 1,5-pentanediol, 1,6-hexanediol, 1,10-decanediol, 1,3-2,2-dimethylpropanediol, 1,2-propanediol and dialkylene ether glycols such as diethylene glycol and dipropylene glycol. Depending on the desired properties can the polyhydric alcohols alone or optionally can be used in mixtures with each other.

Also suitable are esters of carbonic acid with the above Diols, especially those with 4 to 6 carbon atoms, such as 1,4-butanediol and / or 1,6-hexanediol, condensation products of ω-hydroxycarboxylic acids, for example (ω-hydroxycaproic acid and preferably polymerization products of lactones, for example optionally substituted ω-caprolactones.

Alkane diol poly are preferably used as polyesterols adipates with 2 to 6 carbon atoms in the alkylene radical, such as. B. Ethanediol polyadipate, 1,4-butanediol polyadipate, ethanediol butanediol-1,4-polyadipate, 1,6-hexanediol-neopentylglycol-poly  adipates, polycaprolactones and especially 1,6-hexanediol 1,4-butanediol polyadipates.

The polyesterols usually have molecular weights Weight average) from 500 to 6000, preferably from 800 to 3500.

• c) As chain extenders (c), which are usually moles molecular weights of less than 500 g / mol, preferably 60 to 499, particularly preferably have 60 to 300, preferably come Alkanediols with 2 to 12 carbon atoms, preferably with 2,4 or 6 carbon atoms, such as. B. ethanediol, hexane diol-1,6, and especially 1,4-butanediol and dialkylene ether glycols such as B. diethylene glycol and dipropylene glycol in Be dress. However, diesters of terephthalic acid are also suitable with alkanediols with 2 to 4 carbon atoms, such as. B. Te bis-ethanediol or 1,4-butanediol, hydroxy alkylene ethers of hydroquinone, such as. B. 1,4-Di- (β-hydroxy thyl) hydroquinone, (cyclo) aliphatic diamines, such as. B. 4,4'-diaminodicyclohexylmethane, 3,3'-dimethyl-4,4'-diaminodi ocyclohexylmethane, 1-amino-3,3,5-trimethyl-5-aminomethyl-cy clohexane, ethylenediamine, 1,2-, 1,3-propylene diamine, N-methyl propylenediamine-1,3, N, N'-dimethylethylenediamine and aromati cal diamines, such as B. 2,4- and 2,6-tolylene diamine, 3,5-diethyl-2,4- and -2,6-toluenediamine and primary, location ho-di-, tri- and / or tetraalkyl-substituted 4,4'-diamino diphenylmethane.

Chain extenders are preferably used Alkanediols with 2 to 6 carbon atoms in the alkylene radical, in particular 1,4-butanediol and / or dialkylene glycols with 4 to 8 carbons atoms of matter.

To adjust the hardness and melting point of the TPU, the Build-up components (b) and (c) in a relatively wide molar ratio can be varied. Molar ratios have proven successful from polyhydroxyl compounds (b) to chain extenders (c) from 1: 1 to 1:12, in particular from 1: 1.8 to 1: 6.4, the hardness and melting point of the TPU increasing Diols content increases.

• d) Suitable catalysts, which in particular the reaction between the NCO groups of the diisocyanates (a) and the Accelerate hydroxyl groups of structural components (b) and (c) nigen, are the known according to the prior art and usual tertiary amines, such as. B. triethylamine, dimethyl cyclohexylamine, N-methylmorpholine, N, N'-dimethylpiperazine, 2- (dimethylaminoethoxy) ethanol, diazabicyclo (2,2,2) octane and similar and in particular organic metal compounds  such as titanium acid esters, iron compounds such. B. iron (III) - acetylacetonate, tin compounds, e.g. B. tin diacetate, tin dioctoate, tin dilaurate or the tin dialkyl salts alipha table carboxylic acids such as dibutyltin diacetate, dibutyltin dilaurat or similar. The catalysts are becoming more common wise in amounts of 0.002 to 0.1 parts per 100 parts of poly hydroxyl compound (b) used.
• e) In addition to catalysts, structural components (a) to (c) also conventional auxiliaries and / or additives (e) be added. Examples include surface-active ones Substances, foam stabilizers, cell regulators, fillers, Flame retardants, nucleating agents, oxidation retardants, Stabilizers, lubricants and mold release agents, dyes and Pigments, inhibitors, stabilizers against hydrolysis, light, Heat or discoloration, dyes, inorganic and / or organic fillers, reinforcing agents and plasticizers.

More information about the above-mentioned auxiliary and additive substances are in the specialist literature, for example in monographs by J.H. Saunders and K.C. Fresh "High Polymers", Volume XVI, Polyurethanes, parts 1 and 2, published by Interscience Publishers 1962 or 1964, the aforementioned plastics manual, volume XII, poly urethane or DES 29 01 774.

The processing of the fatty acids according to the invention and / or their Derivatives with the TPU, usually in granules or in pul are present in a deformed manner using customary methods. Example wise you mix the TPU with the fatty acids of the invention and / or their derivatives z. B. at temperatures from 0 to 150 ° C, preferably 10 to 100 ° C and in particular 10 to 35 ° C. Then You can eat the mixture at a temperature in the range of 150 up to 250 ° C, preferably 160 to 230 ° C and in particular 180 to 220 ° C, for example flowable, softened or melted NEN state, preferably with degassing, e.g. B. by stirring, whale zen, kneading or extruding, for example using a rolling device, a kneader or an extruder homogeneous nize and process to the desired TPU. Preferably become the fatty acids and / or their derivatives according to the invention and the TPU in mixtures or individually in an extruder brings, e.g. B. at temperatures of 150 to 250 ° C, preferably from 160 to 230 ° C and in particular from 180 to 220 ° C, partially ge melted, the mixture extruded, e.g. B. on a one or Twin shaft machine, preferably with degassing, cooled down and on closing granulated. The granules can be stored or processed directly to the desired products.  

Furthermore, the reaction mixture containing (a), (b) and optionally (c), (d) and / or (e) can be experienced in the presence of the fatty acids and / or their derivatives according to the invention after the extruder or preferably implemented by the belt process the. In detail, the belt procedure is as follows:
The structural components (a) to (c) and the fatty acids and / or their derivatives according to the invention and optionally (d) and / or (e) are at temperatures above the melting point of the structural components (a) to (c) with the aid of a mixing head continuously mixed. The reaction mixture is applied to a carrier, preferably a conveyor belt, and passed through a tempered zone. The reaction temperature in the temperature-controlled zone can be 60 to 200 ° C., preferably 100 to 180 ° C., and the residence time is generally 0.05 to 0.5 hours, preferably 0.1 to 0.3 hours. After the reaction has ended, the TPU is allowed to cool and is then comminuted or granulated.

In the extruder process, the structural components (a) to (c) and the fatty acids and / or their derivatives according to the invention as optionally (d) and (e) individually or as a mixture in the Extruder introduced, e.g. B. at temperatures from 100 to 250 ° C, preferably reacted 140 to 220 ° C, the obtained TPU is extruded, cooled and granulated.

Furthermore, the fatty acid compounds according to the invention by storing the TPU in mixtures, for example aqueous, e.g. B. in the extrusion water bath, or in solutions containing the Fatty acid compounds or for example by treatment of the TPU granules in a blending silo with the fatty acid compounds at temperatures above the melting point of the fat used acidic compounds are applied to the TPU.

The reduced tendency of the polyurethanes according to the invention to Intake and / or release of substances should be based on the following Examples are shown.

example 1 Inclusion of substances that cause discoloration of thermoplastic polyurethanes

Thermoplastic polyurethanes were produced according to the following basic recipe:

1000 parts of polytetrahydrofuran with an average molecular weight of 1000
950 parts 4,4'MDI
252 parts of butane (1.4) diol
22 parts phenolic antioxidant.

One product each with no additives, one product with 0.4% one usual mold release agent and an inventive Product manufactured.

Table 1

The polyurethanes were hand-cast from the above raw materials. The additives were made before position in the polyol component. On an injection molding machine were 2 mm thick test specimens with a polymer mass meter temperature of 220 ° C and then at 20 hours 100 ° C annealed in a forced air oven.

Mechanical properties of the injection molded plates

There were no significant differences in the mechanical egg properties of the test plates found.

Table 2

The tendency to ingest substances that cause discoloration of the thermoplastic polyurethanes was based on the Staining of the samples measured after 7 days of storage in cow manure.  

After washing the samples under water and measuring the Pro In an Ultrascan color measuring device, a clear ge is shown less discoloration of the sample according to the invention as with the smaller values can be seen in Table 3.

Table 3

Example 2 Dispensing substances from thermoplastic polyurethanes

There were thermoplastic polyurethanes according to the following basic recipe

1000 parts of polytetrahydrofuran with an average molecular weight of 1000
600 parts 4.4'MDI
121 parts of butane-1,4-diol
17 parts phenolic antioxidant

as well as with the additions or characteristics given in Table 4 produced:

Table 4

The products were used to produce 2 mm thick test plates on an injection molding machine, which were annealed at 100 ° C. for 20 hours and then stored in a standard atmosphere. Test plates, each with a total surface area of 2 dm ² and a weight of 23 g, were stored in 400 ml of 3% acetic acid at 40 ° C. for 10 days. After removal of the test specimens and cooling of the solution, the amine content in 40 ml of the solution was determined on the same day photometrically on a dye produced by diazo and coupling with naphthylethylenediamine dihydrochloride at 550 nm wavelength.

Table 5

The thermoplastic polyurethanes produced according to the invention show a significantly lower tendency to deliver for example amines in the extraction experiment.

Example 3 Acetic acid absorption

On thermoplastic polyurethanes as described in Example 2 In addition, the consistency towards Acetic acid checked. Transparent polyurethanes show by location usually a milky cloudiness. All samples were clear transparent before storage in acetic acid.

Table 6

The sample according to the invention showed, in contrast to the Comparative samples, no cloudiness due to an intake of Acetic acid.

Example 4 Absorption of water

Thermoplastic polyurethanes were produced according to the following basic recipe:

Polyether polyurethane
1000 parts of polytetrahydrofuran with an average molecular weight of 1000
600 parts 4.4'MDI
121 parts of butane (1.4) diol
17 parts phenolic antioxidant

and the additives shown in Table 7.

Table 7

Polyester polyurethane

1000 parts of polybutylene adipate with an average molecular weight of 2500
880 parts 4,4'MDI
278 parts butane (1,4) diol
10 parts of a carbodiimide as hydrolysis protection agent

as well as the additives shown in Table 8.

Table 8

The products became uniform granules on an extruder made late.

The moisture content after storage at 23 ° C / 50% rel. Humidity of predried samples of the same grain size became after 30 minutes measured and is shown in Table 9.  

Table 9

A significantly lower moisture absorption is with the products according to the invention ascertainable.

Example 5 Intake of chlorine

Thermoplastic polyurethanes were produced according to the following basic recipe:

Polyether polyurethane

1000 parts of polytetrahydrofuran with an average molecular weight of 1000
600 parts 4.4'MDI
121 parts of butane (1.4) diol
17 parts phenolic antioxidant

as well as the additives shown in Table 10.

Table 10

The products became 2 mm thick on an injection molding machine Test plates produced, which was annealed at 100 ° C for 20 hours the. The test plates became the same for storage voluminous test bars of format S2 punched out.

The test rods were placed in 200 ml of chlorine water solution (w (Cl ₂ )) = 10 ppm) at 23 ° C; the residual chlorine content of the solution was determined after 24 hours by iodometric titration of the solution with sodium thiosulfate against a blank sample. As a result, the relative chlorine uptake of the sample is used.

Table 11

A significantly lower chlorine uptake is the fiction according to the products.

Claims (9)

1. Use of fatty acids with 24 to 34 carbon atoms and / or esters and / or amides of these fatty acids for the manufacture development of polyisocyanate polyadducts with a reduction ter tendency to take up and / or release substances Reaction of (a) polyisocyanates, (b) against isocyanates reactive compounds with a molecular weight of 500 to 8000 g / mol and optionally (c) chain extension and / or Crosslinking agents with a molecular weight of small ner 500 g / mol, (d) catalysts and (e) usual auxiliaries and Additives in the presence of the fatty acids and / or derivatives of these fatty acids. 2. Use according to claim 1, characterized in that the Fatty acids and / or their derivatives in a proportion by weight from 0.001 to 15% by weight, based on the total weight of the Polyisocyanate polyadducts are used. 3. Use according to one of claims 1 or 2 for the production of polyisocyanate polyadducts with a diminished tendency to adopt polar compounds. 4. Use according to one of claims 1 or 2 for the production of polyisocyanate polyadducts with a diminished tendency to ingest substances that lead to discoloration exercise of polyaddition products. 5. Use according to one of claims 1 or 2 for the production of polyisocyanate polyadducts with a diminished ten tendency to release substances from the polyadditions products. 6. Use according to claim 5 for the production of polyisocya nat polyadducts with a reduced tendency to Delivery of substances with a molecular weight of less 10,000 g / mol. 7. Use according to claim 5 for the production of polyisocya nat polyadducts with a reduced tendency to Dispensing plasticizers.   8. Use according to one of claims 1 to 7 for the manufacture of thermoplastic polyisocyanate polyaddition products, characterized in that the implementation is compared with Isocyanate-reactive compounds with a molecular weight from 500 to 8000 g / mol, the one Have functionality from 1.5 to less than 3 and for that Implementation uses no crosslinking agents. 9. Use according to one of claims 1 to 7 for the production of cross-linked, optionally cellular polyisocyanate poly addition products, characterized in that the Um settlement in the presence of isocyanate-reactive Compounds that have functionality from 3 to 8 and, if necessary, of blowing agents.