EP3649178A1

EP3649178A1 - Sulphur-containing polyester polyols, their production and use

Info

Publication number: EP3649178A1
Application number: EP18737577.9A
Authority: EP
Inventors: Martin Ruebenacker; Kathrin COHEN; Sirus Zarbakhsh; Sindhu MENON; Sabrina KRONIG
Original assignee: BASF SE
Current assignee: BASF SE
Priority date: 2017-07-05
Filing date: 2018-07-03
Publication date: 2020-05-13
Also published as: US20210095072A1; CN110753713B; WO2019007937A1; US11578167B2; BR112019025063A2; KR20200027977A; CN110753713A

Abstract

The present invention relates to sulphur-containing polyester polyols, their production and use.

Description

Sulfur-containing polyesterpolyols (PESOLs), their preparation and their use.

In the context of the present disclosure, the terms "polyester polyol" and the abbreviation "PESOL" are used to mean a compound having at least two reactive OH groups and at least two, preferably more than two, ester bonds. The barrier properties of polyurethane systems z. B. insulating foams or thermoplastic polyurethane (PU) are determined mainly by the structure of the polymer matrix. Reduced thermal conductivity and lower gas diffusion can thus only be achieved if the polymer matrix has particularly low gas permeabilities. For this, it has been necessary to develop new polyol structures that reduce the gas permeability of polyurethane materials, particularly with respect to the gases carbon dioxide, nitrogen, oxygen, water, methane and pentane derivatives.

The use of polyurethanes in which a good gas barrier is required is limited by the high permeability of the PU polyurethane matrix. It is therefore desirable to produce polyurethanes which have a high barrier to gases such as CO 2, O 2, H 2 O and N 2. Furthermore, the thermal conductivity of polyurethane foams can be significantly improved by increasing the gas barrier. (US 5,532,284)

Known methods of producing polyurethanes with high barrier properties are, for example, the formulation with nanoscale fillers in order to extend diffusion paths. Older applications describe here, for example, the use of nanoscale clay (US 6,403,231). Such methods require the handling of solids, which make processing significantly more difficult and cause a sharp increase in viscosity.

Furthermore, US Pat. No. 5,532,284 describes that polymers such as ethylene / vinyl acetate copolymer or ethylene / acrylic ester copolymer, which are known for a high gas barrier, can markedly lower the thermal conductivity of polyurethane systems. This is due to a lower cell gas diffusion. By means of this method one can effectively increase the gas barrier, however, one must first prepare a stable dispersion of the barrier polymer in the continuous polymer phase. This requires a further process step. It is therefore desirable to produce polyurethane systems which have a high barrier but manage without a further process step.

This can be accomplished by the present invention by preparing sulfur-containing polyester polyols. Poly (thio) ester polyols can be prepared in various ways, for example by condensation of di (hydroxyethyl) polysulfides. US 8,158,726 describes the preparation of hydroxy- and carboxy-functional polyesters, for. By reacting di (hydroxyethyl) disulphide with a monobasic or dibasic carboxylic acid in the presence of a protic acid catalyst. lysators, and their use in polyurethane prepolymers based on the previously named compounds. However, no polysulfidic dicarboxylic acids are used here. In addition, a strong acid is preferably used as protic catalyst, such as methanesulfonic acid. This increasingly leads to the formation of unwanted cyclic by-products.

Sulfur-containing dicarboxylic acids have the advantage of increased reactivity towards esterification due to the activation of the COOH groups. Thus, it is possible according to the present invention by the use of sulfur-containing dicarboxylic acids to obtain polyester polyols, which can be prepared without the addition of a catalyst.

While US 8,158,726 describes the synthesis of prepolymers, no properties of the resulting polyurethane materials are described.

Older applications describe the preparation and properties of high molecular weight polyesters based on the diacids 2- [4- [4- (carboxymethoxy) phenyl] sulfanylphenoxy] acetic acid, 2- [4- [4- (carboxymethoxy) phenyl] sulfonyl-phenoxy ] acetic acid and terephthalic acid with ethylene glycol. The polyesters produced in the synthesis described, in which transition metal catalysts are used, can be processed by extrusion into materials which have an increased oxygen barrier (US Pat. No. 4,426,512). However, the structures described are each aromatic thioethers which have an improved barrier property by the combination of sulfur and aromatic carboxylic acids. In the case of aromatic compounds, it is to be expected that the barrier properties will be improved due to the "pi-stacking" effect, but this can not be predicted for aliphatic compounds.

In the literature, it has also not been described yet that disulfidic, aliphatic Q-bonds such as diacids (eg 3,3-dithiodipropionic acid also called 3- (2-carboxyethyl-disulfanyl) propanoic acid (CAS 1 1 19-62-9 ) may also have improved barrier properties by skillful combination, for example with glycols.

Sulfur-based foams, as described in US Pat. No. 3,892,686, could be prepared by reaction of aromatic dicarboxylic acids or heterocycles with elemental sulfur. Thus, aromatic polysulfides are obtained. The use of dithiodipropionic acid is described in this publication only as an additive. Furthermore, no statements were made about the resulting properties of the foams. Further relevant literature describes the preparation of sulfur-containing polyesters (US Pat. No. 3,459,787) based on monothio and dithiocarboxylic acids by means of catalyzed esterification, with, for example, lead oxide. The use of cyclohexanedimethanol is not disclosed. The resulting polymers are polyesterols having a molecular weight of from 2,000 to 10,000 gmol and have been further processed in part by heating with elemental sulfur and tested for their properties, eg crystallinity and viscosity. However, no use of these products in polyurethane applications has been described. It was therefore the desire of the art to produce polyurethane systems based on polyester polyols, which result in an improved gas barrier. The polyester polyols should be as simple as possible, for. Example, without the use of an additional catalyst, be produced, and it should be as few by-products arise.

Surprisingly, it has now been found that, inter alia, by reaction of dithiodipropionic acid with cyclohexanedimethanol and optionally further polyols, polymers are formed which lead to an improvement of the gas barrier in Polyurethanmaterialiensystomon and thus reduce the thermal conductivity, for the preparation of the polyester polyols on the addition of a catalyst can be waived.

It is assumed that the sulfur-containing dicarboxylic acid as starting material also has a catalytic effect on the reaction with the alcohol.

Therefore, in a preferred embodiment of the invention, no further catalyst is used. By waiving an additional, z. B. protic (acid) catalyst and the number and amount of unwanted by-products in the PESOL product are reduced.

An object of the present invention is thus a polyesterpolyol comprising the esterification product of:

a. at least one dicarboxylic acid component (A), wherein the dicarboxylic acid components (A)

b. at least one disulfide-containing dicarboxylic acid a-1; and

c. a polyol component (K), the

i. at least one diol (D), wherein the diol (D)

ii. at least one diol b-1, which is selected from the group consisting of cyclohexanedimethanol and 1, 6 hexanediol

In this case, preferably 45-50 mol% of the dicarboxylic acid component A) and 50-55% of a polyol component (K) are used, the sum of the mol% of A and K being 100 mol%. In one embodiment of the present invention, the dicarboxylic acid component A ) also comprise at least one non-sulfuric dicarboxylic acid a-2. In this embodiment, the dicarboxylic acid component A) preferably comprises

a. 50 to 100 mol% of at least one disulfide-containing dicarboxylic acid a-1; and

b. 0-50 mol% of a non-sulfur dicarboxylic acid a-2, wherein the sum of the mol% of the components a-1 and a-2 in the dicarboxylic acid component A) is 100 mol%.

Examples of suitable non-sulfuric dicarboxylic acid a-2 are: succinic acid, glutaric acid, adipic acid, suberic acid, azelaic acid, sebacic acid, decanedicarboxylic acid, maleic acid, fumaric acid, phthalic acid, isophthalic acid and terephthalic acid. The dicarboxylic acids a-2 can be used both individually and as a mixture with one another. Instead of the free dicarboxylic acids, the corresponding dicarboxylic acid derivatives, such as dicarboxylic acid esters of alcohols having 1 to 4 carbon atoms or dicarboxylic anhydrides such as phthalic anhydride are used. As the aromatic dicarboxylic acids, phthalic acid, terephthalic acid and / or isophthalic acid are preferably used in admixture or alone. The aliphatic dicarboxylic acids used are preferably dicarboxylic acid mixtures of succinic, glutaric and adipic acid. Here, the mixtures in proportions of, for example, 20 to 35: 35 to 50: 20 to 32 parts by weight, and in particular adipic acid used.

Very particular preference wtfd phthalic acid and terephthalic acid are used as non-sulfuric dicarboxylic acid a-2.

In one embodiment of the present invention, at least one, preferably all, of the at least one disulfide-containing dicarboxylic acids a-1) is selected from the group consisting of aliphatic disulfide-containing dicarboxylic acids. In one embodiment of the present invention, at least one of the disulfide-containing dicarboxylic acids is a-1), preferably all of the disulfide-containing dicarboxylic acids a-1) selected from the group consisting of 3,3-dithiodipropionic acid, 2- (carboxymethyldisulfanyl) acetic acid, 3- (2 -Carboxyethyl-disulfanyl) propanoic acid, 4- (3-carboxypropyldisulfanyl) butanoic acid, and their alkyl esters, preferably dimethyl and diethyl esters and mixtures of the above-mentioned dicarboxylic acids.

In a particularly preferred embodiment, dicarboxylic acid component A) consists of only one disulfide-containing dicarboxylic acid, this disulfide-containing dicarboxylic acid being 3- (2-carboxyethyl-disulfanyl) -propanoic acid (3,3-dithiodipropionic acid).

The diol component D may comprise, in addition to the diol b-1) yet another diol b-2. Preferably, the diol b-2 is selected from the group consisting of ethylene glycol, diethylene glycol, 1, 2-propanediol, 1, 3-propanediol, monopropylene glycol, dipropylene glycol, 1, 4-butanediol, 1, 5-pentanediol or mixtures the above components.

In this case, the diol component D) comprises

a. From 10 mol% to 100 mol% of diol b-1;

b. 0 mol% to 90 mol% of diol b-2

wherein the sum of the mol% of component b-1 and b-2 is 100 mol%

In a further embodiment of the present invention, component b-1) is the sole diol component D.

In a preferred embodiment of the present invention, component b-1) is 1,4-cyclohexanedimethanol.

In a further embodiment of the present invention, at least one higher-order alcohol C) is present in the polyol component K, preferably exactly one higher-order alcohol C) is present, the higher-order alcohol C having a functionality of greater than 2. Preferably, in this embodiment, polyol component (K) comprises

a. 10 to 100 mol% of the diol (D); such as

b. 0 to 90 mol% of at least one higher-grade alcohol C) having a functionality greater than 2; The polyol component (K) particularly preferably comprises the higher-order alcohol C) in an amount of 0.1 to 40 mol%, preferably 0.2 to 30 mol%, particularly preferably 0.5 to 10 mol%, based on the sum of all in the polyol component (K) existing alcohols.

In one embodiment of the present invention, the polyhydric alcohol C) is selected from the group of glycerol, trimethylolpropane (TMP), pentaerythritol, mixtures of the abovementioned compounds and alkylene oxides of the abovementioned compounds.

Alkylene oxides in the context of the present invention are preferably ethylene oxide, propylene oxide or butylene oxide, preferably ethylene oxide or propylene oxide.

In a preferred embodiment of the present invention, the polyhydric alcohol C) is prepared by reacting a polyol selected from the group consisting of the group of glycerol, trimethylolpropane (TMP), pentaerythritol with ethylene oxide and / or propylene oxide, preferably ethylene oxide.

In a further preferred embodiment of the present invention, the polyhydric alcohol C) consists of the reaction product of TMP with ethylene oxide. In one embodiment of the present invention, the polyhydric alcohol C) has a

OH number in the range of 1800 mg KOH / g to 100 mg KOH / g, preferably 1400 mg KOH / g to 150 mg KOH / g, more preferably 1250 mg KOH / g to 200 mg KOH / g.

In a preferred embodiment of the present invention, the polyhydric alcohol C) consists of TMP.

In a preferred embodiment of the present invention, the polyhydric alcohol C) consists of the reaction product of trimethylolpropane (TMP) or glycerol with ethylene oxide and / or propylene oxide, preferably ethylene oxide, TMP.

A particularly preferred embodiment of the invention is a polyester polyol consisting of the esterification product of i) 45-50 mol% of the dicarboxylic acid component (D) comprising 3- (2-carboxyethyl-disulfanyl) propanoic acid and ii) 50-55% of a polyol component (P) comprising 1, 4-cyclohexanedimethanol, wherein the mol% of components i) and ii) add up to 100%.

A further preferred embodiment of the invention is a polyester polyol consisting of the esterification product of a) 10 to 70 mol% of 3- (2-carboxyethyl-disulfanyl) propanoic acid and b) 10 to 70 mol% of 1, 4-cyclohexanedimethanol, where the mol% the components i) and ii) add to 100%, and wherein the esterification no additional catalyst is used.

A further particularly preferred embodiment of the invention is a polyesterpolyol consisting of the esterification product of i) 45 to 55 mol% of 3- (2-carboxyethyldisulfanyl) propanoic acid, ii) 50 to 55% of a polyol component K, which consists of

b-1) 10 to 70 mol% of 1,4-cyclohexanedimethanol and c) 0.5 to 20 mol% of trimethylolpropane, the molar% of components a) to c) adding to 100%.

b-1) from 10 to 70 mol% of 1,4-cyclohexanedimethanol; and c) from 0.5 to 20 mol% of trimethylolpropane, wherein the mol% of components a) to c) add up to 100% and in the esterification no additional catalyst is used.

A further subject of the present invention is also a process for the preparation of a polyester polyol by reacting the dicarboxylic acid component (D) as defined above in the amounts indicated above with the polyol component (P). For the preparation of the polyester polyols according to the invention, the disulfide-containing polycarboxylic acids and / or derivatives and polyhydric alcohols are preferably free from catalyst, advantageously in an atmosphere of inert gas, such as e.g. Nitrogen, carbon monoxide, helium, argon and the like. in the melt at temperatures of 150 to 220 ° C, preferably 160 to 190 ° C, optionally under reduced pressure to the desired acid number, which is advantageously less than 10, preferably less than 2, polycondensed. According to a preferred embodiment, the esterification mixture at the abovementioned temperatures to an acid number of 80 to 20, preferably 40 to 20, under normal pressure and then under a pressure of less than 500 mbar, preferably 40 to 400 mbar, polycondensed. The polyesterpolyols obtained preferably have a functionality of 1.8 to 4, in particular 2 to 3, and a molecular weight of 300 to 3000, preferably 400 to 2500 and in particular 450 to 2000.

A further embodiment of the process comprises a variant in which no additional catalyst is used to prepare a polyester polyol according to the invention.

Some suitable sulfur-containing educts (dicarboxylic acids), which can be reacted according to the invention in each case with a suitable reactant, are shown schematically in Figure 2 as chemical formulas purely for illustration. Furthermore, the invention also relates to the use of the polyester polyols according to the invention or to prepare according to the invention for preparing a polyurethane by reaction with at least one di- or polyisocyanate and at least one aliphatic diol and optionally at least one blowing agent. In particular, the invention relates to the use of the polyester polyols according to the invention in rigid polyurethane foams.

Therefore, the present invention also includes a process for producing a rigid polyurethane foam by reacting a reaction mixture comprising

A. organic and / or modified organic di- and / or polyisocyanates with

B. the specific polyester polyols of the invention,

F. one or more propellants; and

G. Catalysts.

Here, the reaction mixture in a further embodiment also

C. other polyester polyols and / or

D. optionally polyetherols and / or other compounds having at least two isocyanate-reactive groups and / or

E. and optionally chain extenders and / or crosslinking agents and / or

H. optionally further auxiliaries and / or additives, and / or

I. optionally at least one flame retardant and / or

J. optionally with foam stabilizers. Accordingly, the invention particularly relates to the use of the polyester polyols according to the invention in rigid polyurethane foams prepared from:

A. organic and / or modified organic di- and / or polyisocyanates with

B. the specific polyester polyols of the invention,

C. optionally further polyesterpolyols,

D. optionally polyetherols and / or further compounds having at least two isocyanate-reactive groups,

E. and optionally chain extenders and / or crosslinkers,

F. one or more propellants,

G. catalysts, as well

H. optionally further auxiliaries and / or additives, and

I. if appropriate, at least one flame retardant.

Here, optional foam stabilizers (J) can be used.

For the production of rigid polyurethane foams by the process according to the invention, in addition to the above-described special polyester polyols, use is made of structural components known per se, to which the following details are to be stated.

Suitable organic and / or modified organic polyisocyanates A) are the per se known aliphatic, cycloaliphatic, araliphatic and preferably aromatic polyfunctional isocyanates.

Specific examples which may be mentioned are: alkylenediisocyanates having 4 to 12 carbon atoms in the alkylene radical, such as 1,12-dodecanediisocyanate, 2-ethyltetramethylenediisocyanate 1, 4, 2-methylpentamethylene diisocyanate-1, 5, tetramethylene diisocyanate-1, 4, and preferably hexamethylene diiso- cyanate-1, 6; Cycloaliphatic diisocyanates such as cyclohexane-1, 3- and 1, 4-diisocyanate and any mixtures of these isomers, 1 -lsocyanato-3,3,5-trimethyl-5-isocyanatomethylcyclohexane (IPDI), 2,4- and 2,6-Hexahydrotoluylendiisocyanat and the corresponding isomer mixtures, 4,4'-, 2,2'- and 2,4'-dicyclohexylmethane diisocyanate and the corresponding mixtures of isomers, and preferably aromatic di- and polyisocyanates, such as 2,4- and 2,6-toluene - Diisocyanate and the corresponding mixtures of isomers, 4,4'-, 2,4'- and 2,2'-diphenylmethane diisocyanate and the corresponding isomer mixtures, mixtures of 4,4'- and 2,2'-diphenylmethane diisocyanates, Polyphenylpolymethylenpolyisocyanate, mixtures from 2,4'-, 2,4'- and 2,2'-diphenylmethane diisocyanates and Polyphenylpolymethylenpolyisocyanaten (crude MDI) and mixtures of crude MDI and toluene diisocyanates.

The organic di- and polyisocyanates can be used individually or in the form of their mixtures. Preferred diisocyanates and polyisocyanates are tolylene diisocyanate (TDI), diphenylmethane diisocyanate (MDI) and, in particular, mixtures of diphenylmethane diisocyanate and polyphenylene polyethylene polyisocyanates (polymeric MDI or PMDI).

Often, so-called modified polyvalent isocyanates, i. Products obtained by chemical reaction of organic di- and / or polyisocyanates used. Examples include ester, urea, biuret, allophanate, carbodiimide, isocyanurate, uretdione, carbamate, and / or urethane groups-containing di- and / or polyisocyanates. For the production of rigid polyurethane foams, very particular preference is given to using polymer MDI. Suitable further polyester polyols C) can be prepared, for example, from organic dicarboxylic acids having 2 to 12 carbon atoms, preferably aromatic or a mixture of aromatic and aliphatic dicarboxylic acids, and polyhydric alcohols, preferably diols, having 2 to 12 carbon atoms, preferably 2 to 6 carbon atoms. Suitable dicarboxylic acids are, for example: succinic acid, glutaric acid, adipic acid, suberic acid, azelaic acid, sebacic acid, decanedicarboxylic acid, maleic acid, fumaric acid, phthalic acid, isophthalic acid and terephthalic acid. The dicarboxylic acids can be used both individually and in admixture with each other. Instead of the free dicarboxylic acids, the corresponding dicarboxylic acid derivatives, e.g. Dicarboxylic ter of alcohols having 1 to 4 carbon atoms or dicarboxylic anhydrides such as phthalic anhydride are used. As the aromatic dicarboxylic acids, phthalic acid, terephthalic acid and / or isophthalic acid are preferably used in admixture or alone. The aliphatic dicarboxylic acids used are preferably dicarboxylic acid mixtures of succinic, glutaric and adipic acid in proportions of, for example, from 20 to 35:35 to 50:20 to 32 parts by weight, and in particular adipic acid. Examples of dihydric and polyhydric alcohols, in particular diols, are: ethanediol, diethylene glycol, 1,2-or 1,3-propanediol,

Dipropylene glycol, 1, 4-butanediol, 1, 5-pentanediol, 1, 6-hexanediol, 1, 10-decanediol, glycerol, trimethylolpropane and pentaerythritol. Preferably used are ethanediol, diethylene glycol, 1, 4-butanediol, 1, 5-pentanediol, 1, 6-hexanediol or mixtures of at least two of said diols, in particular mixtures of 1, 4-butanediol, 1, 5-pentanediol and 1, 6-hexanediol. It is also possible to use polyester polyols from lactones, for example ε-caprolactone or hydroxycarboxylic acids, for example ω-hydroxycaproic acid.

It is also possible to use polyether polyols D) which have been prepared by known processes, for example by anionic polymerization with alkali metal hydroxides, e.g. Sodium or potassium hydroxide or alkali alcoholates, e.g. Sodium methylate, sodium or potassium ethylate or potassium isopropylate, as catalysts and with the addition of at least one starter molecule containing 2 to 8, preferably 2 to 6, bonded reactive hydrogen atoms, or by cationic polymerization with Lewis acids such as antimony pentachloride, borofluoride etherate u.a. or bleaching earth, are prepared as catalysts from one or more alkylene oxides having 2 to 4 carbon atoms in the alkylene radical.

Suitable alkylene oxides are, for example, tetrahydrofuran, 1, 3-propylene oxide, 1, 2 or 2,3-butylene oxide, styrene oxide and preferably ethylene oxide and 1, 2-propylene oxide. The alkylene oxides can be used individually, alternately in succession or as mixtures. Preferred alkylene oxides are propylene oxide and ethylene oxide, particularly preferred is ethylene oxide. Suitable starter molecules are, for example: water, organic dicarboxylic acids such as succinic acid, adipic acid, phthalic acid and terephthalic acid, aliphatic and aromatic, optionally N-mono-, N, N- and Ν, Ν'-dialkyl-substituted diamines having 1 to 4 carbon atoms in the alkyl radical , such as optionally mono- and dialkyl-substituted ethylenediamine, diethylenetriamine, triethylenetetramine, 1, 3-propylenediamine, 1, 3 or 1, 4-butylenediamine, 1, 2, 1, 3, 1, 4, 1, 5- and 1,6-hexamethylenediamine, phenylenediamines, 2,3-, 2,4- and 2,6-toluenediamine and 4,4'-, 2,4'- and 2,2'-diaminodiphenylmethane.

Also suitable as starter molecules are: alkanolamines, e.g. Ethanolamine, N-methyl and N-ethylethanolamine, dialkanolamines, e.g. Diethanolamine, N-methyl- and N-ethyldiethanolamine, and trialkanolamines, e.g. Triethanolamine, and ammonia.

Preference is given to using dihydric or polyhydric alcohols, such as ethanediol, propanediol 1, 2 and 1, 3, diethylene glycol, dipropylene glycol, butanediol 1, 4, hexanediol 1, 6, glycerol, trimethylolpropane, pentaerythritol, sorbitol and sucrose ,

The polyether polyols, preferably polyoxypropylene polyols and / or polyoxyethylene polyols, have a functionality of preferably 2 to 6 and in particular 2 to 5 and molecular weights of 150 to 3000, preferably 200 to 2000 and in particular 250 to 1000.

Further suitable polyether polyols are polymer-modified polyether polyols, preferably graft polyether polyols, in particular those based on styrene and / or acrylonitrile, which are prepared by in situ polymerization of acrylonitrile, styrene or preferably mixtures of styrene and acrylonitrile, for example in a weight ratio of 90:10 to 10:90 , preferably 70:30 to 30:70, in expediently the abovementioned polyether polyols analogously to the specifications of German Patent Specifications 1,131,194, 12,222,669 (US 3,304,273, 3,383,351, 3,523,093), 1,152,536 (GB 10 40452) and 1 1 52 537 (GB 987.618), and polyetherpolyol dispersions containing as a disperse phase, usually in an amount of 1 to 50 wt .-%, preferably 2 to 25% by weight: eg polyureas, polyhydrazides, tert . Amino groups bound containing Polyurethanes and / or melamine and those described, for example, in EP-B 01 1 752 (US 4,304,708), US-A, 4,374,209 and DE-A, 32 31 497.

The polyether polyols, like the polyester polyols, may be used singly or in the form of mixtures. Furthermore, they can be mixed with the graft polyether polyols or polyester polyols and with the hydroxyl-containing polyester amides, polyacetals, polycarbonates and / or polyether polyamines.

As hydroxyl-containing polyacetals are e.g. the compounds which can be prepared from glycols, such as diethylene glycol, triethylene glycol, 4,4'-dihydroxyethoxydiphenyldimethylmethane, hexanediol and formaldehyde. It is also possible to prepare suitable polyacetals by polymerization of cyclic acetals.

Suitable hydroxyl-containing polycarbonates are those of the type known per se which can be obtained, for example, by reacting diols, such as propanediol 1, 3, butanediol 1, 4 and / or hexanediol 1, 6, diethylene glycol, triethylene glycol or tetraethylene glycol with diarylcarboxylic acid. boning, eg Diphenyl carbonate, alkylene carbonate or phosgene can be prepared. The polyester amides include e.g. the predominantly linear condensates obtained from polybasic, saturated and / or unsaturated carboxylic acids or their anhydrides and polybasic saturated and / or unsaturated aminoalcohols or mixtures of polyhydric alcohols and aminoalcohols and / or polyamines. Suitable polyether polyamines can be prepared from the above polyether polyols by known methods. Examples include the cyanoalkylation of polyoxyalkylene and subsequent hydrogenation of the nitrile formed (US 3,267,050) or the partial or complete A- minierung of polyoxyalkylene with amines or ammonia in the presence of hydrogen and catalysts (DE 12 15 373).

The rigid polyurethane foams according to the invention can be prepared with the concomitant use of chain extenders and / or crosslinking agents (E). To modify the mechanical properties, e.g. However, the hardness, the addition of chain extenders, crosslinking agents or optionally mixtures thereof may prove advantageous.

As chain extenders and / or crosslinking agents are used diols and / or triols having molecular weights less than 400, preferably from 60 to 300. Suitable examples include aliphatic, cycloaliphatic and / or araliphatic diols having 2 to 14, preferably 4 to 10 carbon atoms , such as ethylene glycol, propanediol-1, 3, decanediol-1, 10, o-, m-, p-dihydroxycyclohexane, diethylene glycol, dipropylene glycol and preferably butanediol-1, 4, hexanediol-1, 6 and bis (2-hydroxy -ethyl) -hydroquinone, triols such as 1, 2,4-, 1, 3,5-trihydroxycyclohexane, glycerol and trimethylolpropane and low molecular weight hydroxyl-containing polyalkylene oxides based on ethylene and / or 1, 2-propylene oxide and the aforementioned Diols and / or triols as starter molecules. Further compounds (D) having at least two isocyanate-reactive groups, ie having at least two hydrogen atoms which are reactive toward isocyanate groups, are in particular those which contain two or more reactive groups selected from OH groups, SH groups, NH groups and Groups, NH2 groups and CH-acidic groups, such as ß-diketo groups have.

If chain extenders, crosslinking agents or mixtures thereof are used for producing the rigid polyurethane foams, these are expediently used in an amount of from 0 to 20% by weight, preferably from 0.5 to 5% by weight, based on the weight of component B), for use.

Propellants (F) used to prepare the rigid polyurethane foams preferably include water, formic acid and mixtures thereof. These react with isocyanate groups to form carbon dioxide and in the case of formic acid to carbon dioxide and carbon monoxide. In addition, physical blowing agents such as low-boiling hydrocarbons and aromatic and aliphatic halogenated hydrocarbons can be used. Suitable liquids are those which are inert to the organic, optionally modified polyisocyanates and have boiling points below 100 ° C., preferably below 50 ° C. at atmospheric pressure, so that they evaporate under the influence of the exothermic polyaddition reaction.

Examples of such preferably usable liquids are alkanes, such as heptane, hexane, n- and iso-pentane, preferably technical mixtures of n- and iso-pentanes, n- and iso-butane and propane, cycloalkanes, such as cyclopentane and / or Cyclohexane, ethers, such as furan, dimethyl ether and diethyl ether, ketones, such as acetone and methyl ethyl ketone, alkyl carboxylates, such as methyl formate, dimethyl oxalate and ethyl acetate, and halogenated hydrocarbons, such as

Methylene chloride, dichloromonofluoromethane, difluoromethane, trifluoromethane, difluoroethane, tetrafluoroethane, chlorodifluoroethanes, 1,1-dichloro-2,2,2-trifluoroethane, 2,2-dichloro-2-fluoroethane and hepafluoropropane. It is also possible to use mixtures of these low-boiling liquids with one another and / or with other substituted or unsubstituted hydrocarbons. Furthermore, halogenated olefins can be used.

Also suitable are organic carboxylic acids, e.g. Formic acid, acetic acid, oxalic acid, ricinoleic acid and carboxyl group-containing compounds.

Preferably used are water, formic acid, all pentane isomers and their mixtures, and mixtures of at least two of these blowing agents, e.g. Mixtures of water and Cyclobexaftpentan and optionally water formic acid.

The blowing agents are either wholly or partially in the polyol component (i.e.

B + C + D + E + F + G + H + l) are dissolved or are metered in directly before the foaming of the polyol component via a static mixer. The polyol component is in situ pentane, possibly parts of the chemical blowing agent, partially or completely added to the catalysts, but usually this already contains at least parts thereof (with the exception of the pentane). The auxiliaries and additives, as well as the flame retardants are - if present - preferably already in the polyol blend. The amount of blowing agent or propellant mixture used is 1 to 45 wt .-%, preferably 1 to 30 wt .-%, particularly preferably 1, 5 to 20 wt .-%, each based on the sum of components B) to G).

Serves water as a blowing agent, it is used in an amount of 0.2 to 5 wt .-%, based on the synthesis components B, F, C, D, E, H, I, G and J.

The water can be contained separately or in one of the components B, F, C, D, E, H, I, G or J. The addition of water can be done in combination with the use of the other blowing agents described. As catalysts (G) for the preparation of rigid polyurethane foams in particular compounds are used which greatly accelerate the reaction of the reactive hydrogen atoms, in particular hydroxyl groups, containing compounds of component B) and optionally C) with the organic, optionally modified polyisocyanates A).

It is expedient to use basic polyurethane catalysts, for example tertiary amines, such as triethylamine, tributylamine, dimethylbenzylamine, dicyclohexylmethylamine, dimethylcyclohexylamine, Ν, Ν, Ν ', Ν'-tetramethyldiaminodiethyl ether, bis (dimethylaminopropyl) urea, N-methyl- or triethylamine N-ethylmorpholine, N-cyclohexylmorpholine, Ν, Ν, Ν ', Ν'-tetramethylethylenediamine, Ν, Ν, Ν', Ν'-tetramethylbutanediamine, N, N, N ', N'-tetramethylhexanediamine-1, 6 , Pentamethyldiethylenetriamine, dimethylpiperazine, N-dimethylaminoethylpiperidine, 1, 2-dimethylimidazole, 1-azabicyclo [2.2.0] octane, 1, 4-diazabicyclo [2.2.2] octane (DABCO, synonym: triethylenediamine) and Alkanolamine compounds, such as triethanolamine, triisopropanolamine, N-methyl- and N-ethyldiethanolamine, dimethylaminoethanol, 2- (N, N-dimethylaminoethoxy) ethanol, N, N ', N "-tris- (dialkylaminoalkyl) hexahydrotriazines, eg N, N', N "tris (dimethylaminopropyl) -s-hexahydrotriazine, 1,8-diazabicyclo [5.4.0] undec-7-ene. However, metal salts are also suitable, such as iron (II) chloride, zinc chloride, lead octoate and preferably tin salts, such as tin dioctoate, tin diethylhexoate and dibutyltin dilaurate, and in particular mixtures of tertiary amines and organic tin salts.

Other important catalysts are carboxylates, often in the form of their potassium or ammonium salts, such as formate, acetate, octoate, or in zwitterionic form, for example in the form of substituted amino acids.

Further suitable catalysts are: amidines, such as 2,3-dimethyl-3,4,5,6-tetrahydropyrimidine ,. and alkali salts of long-chain fatty acids having 10 to 20 carbon atoms and optionally pendant OH groups. Preferably used are 0.001 to 5 wt .-%, in particular 0.05 to 2 wt .-%, catalyst or catalyst combination, based on the weight of components B) to I). It is also possible to run the reactions without catalysis. In this case, the catalytic activity of amines started polyols is exploited. If a larger excess of polyisocyanate is used during foaming, the catalysts for the trimerization reaction are the excess NCO- Other groups are also contemplated: isocyanurate group-forming catalysts, for example ammonium ions or alkali metal salts alone or in combination with tertiary amines. The formation of isocyanurate leads to flame-resistant PIR foams, which are preferably used in industrial rigid foam, for example in construction as an insulating board or sandwich elements.

Further information on the above-mentioned and further starting materials can be found in the specialist literature, for example the Kunststoffhandbuch, Volume VII, Polyurethane, Carl Hanser Verlag Munich, Vienna, 1st, 2nd and 3rd Edition 1966, 1983 and 1993.

If appropriate, further auxiliaries and / or additives (H) may also be added to the reaction mixture for the preparation of the rigid polyurethane foams. Mention may be made, for example, of surface-active substances, foam stabilizers, cell regulators, fillers, dyes, pigments, flame retardants, hydrolysis protectants, fungistatic and bacteriostatic substances.

As surface-active substances are e.g. Compounds which serve to assist the homogenization of the starting materials and, if appropriate, are also suitable for regulating the cell structure of the plastics. Mention may be made, for example, of emulsifiers, such as the sodium salts of castor sulfinates or fatty acids, and salts of fatty acids with amines, e.g. diethylamine, stearic acid diethanolamine, diethanolamine ricinoleic acid, salts of sulfonic acids, e.g. Alkali or ammonium salts of dodecylbenzene or dinaphthylmethanedisulfonic acid and ricinoleic acid; Foam stabilizers, such as siloxane-oxalkylene mixed polymers and other organopolysiloxanes, oxyethylated alkylphenols, oxyethylated fatty alcohols, paraffin oils, castor oil or ricinoleic acid esters, Turkish red oil and peanut oil, and cell regulators, such as paraffins, fatty alcohols and dimethylpolysiloxanes. To improve the emulsifying effect, the cell structure and / or stabilization of the foam, the above-described oligomeric acrylates having polyoxyalkylene and fluoroalkane radicals are also suitable as side groups. The surface-active substances are usually used in amounts of from 0.01 to 10% by weight, based on 100% by weight of component B). Fillers, in particular reinforcing fillers, are the conventional, customary organic and inorganic fillers, reinforcing agents, weighting agents, agents for improving the abrasion behavior in paints, coating compositions, etc.

Specific examples are: inorganic fillers such as silicate minerals, for example phyllosilicates such as antigorite, serpentine, hornblende, amphiboles, chrysotile and talc, metal oxides such as kaolin, aluminas, titanium oxides and iron oxides, metal salts such as chalk, barite and inorganic pigments such as cadmium sulfide and zinc sulfide, as well as glass, etc. Preferably used are kaolin (China Clay), aluminum silicate and coprecipitates of barium sulfate and aluminum silicate and natural and synthetic fibrous minerals such as wollastonite, metal and in particular glass fibers of various 5 length, which may optionally be finished. Suitable organic fillers are, for example: carbon, melamine, rosin, cyclopentadienyl resins and graft polymers and also cellulosic fibers, polyamide, polyacrylonitrile, polyurethane, polyester fibers based on aromatic and / or aliphatic dicarboxylic acid esters and in particular carbon fibers. The inorganic and organic fillers can be used individually or as mixtures and are advantageously added to the reaction mixture in amounts of 0.5 to 50% by weight, preferably 1 to 40% by weight, based on the weight of components A) to C). , but the content of mats, fleeces and fabrics made of natural and synthetic fibers can reach values of up to 80% by weight.

As flame retardants (I) it is generally possible to use the flame retardants known from the prior art. Suitable flame retardants are, for example, non-incorporable brominated substances, brominated esters, brominated ethers (xxol), or brominated alcohols such as dibromoneopentyl alcohol, tribromoneopentyl alcohol and PHT-4-diol, and chlorinated phosphates, e.g. Tris (2-chloroethyl) phosphate, tris (2-chloropropyl) phosphate, tris (1,3-dichloropropyl) phosphate, tricresyl phosphate, tris (2,3-dibromopropyl) phosphate, tetrakis (2-chloroethyl) - Ethylendiphosphat, Dimethylmethanphosphonat Diethanolaminomethylphosphonsäurediethyl- and commercially available halogen-containing flame retardant.

As further liquid flame retardants it is possible to use phosphates or phosphonates such as diethylethane phosphonate (DEEP), triethyl phosphate (TEP), dimethyl propyl phosphonate (DMPP), diphenyl cresyl phosphate (DPK) and others.

In addition to the flame retardants already mentioned, inorganic or organic flame retardants, such as red phosphorus, red phosphorus-containing finishes, alumina hydrate, antimony trioxide, arsenic oxide, ammonium polyphosphate and calcium sulfate, expandable graphite or cyanuric acid derivatives, e.g. Melamine, or mixtures of at least two flame retardants, e.g. Ammonium polyphosphates and melamine and optionally corn starch or ammonium polyphosphate, melamine and expandable graphite and / or optionally aromatic polyester for flame retardancy of the rigid polyurethane foams can be used. In general, it has proven expedient, 1 to 70 wt .-%, preferably 5 to 40 wt .-%., Particularly preferably 10 to 30 wt .-% of said flame retardants, based on the polyol system (ie components B + C + D + E + F + G + H + 1).

Further details of the abovementioned other customary auxiliaries and additives can be found in the specialist literature, for example the monograph by J.H. Saunders and K.C. Frisch "High Polymers" Volume XVI, Polyurethanes, Part 1 and 2, published by Interscience Publishers 1962 and 1964 respectively, or the Kunststoff-Handbuch, Polyurethane, Volume VII, Hanser-Verlag, Munich, Vienna, 1st and 2nd editions, 1966 and 1983. The rigid polyurethane foams obtainable by the abovementioned processes and the components defined above are likewise provided by the present invention.

Here, the corresponding rigid polyurethane foams for thermal insulation in refrigerators (refrigerators) and in the construction industry can be used.

It should be noted in the production of rigid polyurethane foams that polyurethane rigid foams for use in the construction and rigid polyurethane foams for cooling systems usually contain flame retardants Another object of the invention relates to the use of the polyester polyols according to the invention in thermoplastic polyurethanes by reacting a polyester polyol prepared by the process according to the invention with one or more organic diisocyanates (or polyisocyanates), which have already been described in previous versions. The preparation of the polyurethanes can in principle by the known methods, batchwise or continuously, for example with reaction extruders or the tape method according to "one-shot" or the prepolymer method (also multi-stage prepolymer method, see for example US 6,790,916), but preferably after the "one-shot "Procedures are carried out. In these processes, the components to be reacted polyesterpolyols, chain extenders, isocyanates and, if appropriate, auxiliaries and additives (in particular UV stabilizers) can be mixed successively or simultaneously with one another, the reaction starting immediately.

The polyurethane which is obtained from a polyesterpolyol prepared by the process according to the invention is in particular a thermoplastic polyurethane. Thermoplastic polyurethanes are also referred to below as TPU.

The production of TPU can be carried out by the methods known to those skilled in the art. Another object of the present invention relates to a molding, a film, a hose, z. As a bicycle tube, or a fiber made of a thermoplastic polyurethane based on the polyester polyol according to the invention.

The production of TPU can be carried out by the methods known to those skilled in the art.

Listed below are exemplary embodiments of the present invention, which are not limitative of the present invention. In particular, the present invention also encompasses those embodiments which result from the following references and combinations thereof:

1 . Polyester polyol comprising the esterification product of

a. at least one dicarboxylic acid component A), wherein the dicarboxylic acid components A)

b. at least one disulfide-containing dicarboxylic acid a-1; and

c. a polyol component (K), the

i. at least one diol (D), wherein the diol (D)

ii. at least one diol b-1 which is selected from the group consisting of cyclohexanedimethanol, 1 -6-hexanediol 2. Polyester polyol according to embodiment 1, characterized in that the dicarboxylic acid component A) additionally contains a non-sulfur-containing dicarboxylic acid a-2; includes.

3. Polyester polyol according to embodiment 1, characterized in that the non-sulfur-containing dicarboxylic acid is a-2 terephthalic acid. Polyester polyol according to embodiment 1 or 2, characterized in that the dicarboxylic acid component A)

a. 50 to 100 mol% of at least one disulfide-containing dicarboxylic acid a-1; and b. 0-50 mol% of a non-sulfuric dicarboxylic acid a-2,

wherein the sum of the mol% of the components a-1 and a-2 in the dicarboxylic acid component A) is 100 mol%. Polyester polyol according to one of embodiments 1 to 4, characterized in that the diol (D) comprises a further diol b-2. Polyesterpolyol according to embodiment 5, characterized in that the further diol b- 2 from the group consisting of ethylene glycol, diethlyeneglycol, 1, 2-propanediol, 1, 3-propanediol, monopropylene glycol, dipropylene glycol, 1, 4-butanediol, 1, 5-pentanediol is selected. Polyester polyol according to one of embodiments 5 to 6, characterized in that the diol D)

a. 10mol% to 100mol% diol b-1

b. 0mol% to 90 mol% of diol b-2

wherein the sum of the mol% of component b-1 and b-2 is 100 mol% Polyesterpolyol according to any one of embodiments 1 to 7, characterized in that the polyol component (K) the diol (D) and at least one higher-grade alcohol C) with a functionality greater than 2 includes. Polyester polyol according to embodiment 8, characterized in that the polyol component (K).

a. 10 to 100 mol% of the diol (D); such as

b. 0 to 90 mol% of at least one higher-grade alcohol C) having a functionality greater than 2;

wherein the sum of the mol% of D and C is 100 mol%. Polyester polyol according to embodiment 8, characterized in that the polyol component (K).

a. 60 to 99.9 mol% of the diol (D); such as

b. 0.1 to 40 mol% of at least one higher-grade alcohol C) having a functionality greater than 2;

a. 90 to 99.5 mol% of the diol (D); such as

b. 0.5 to 10 mol% of at least one higher-grade alcohol C) having a functionality greater than 2; wherein the sum of the mol% of D and C is 100 mol%.

12. Polyester polyol according to one of embodiments 1 to 1 1, characterized in that it

a. 45-50 mol% of the dicarboxylic acid component A) and

b. 50-55% of a polyol component (K),

wherein the sum of the mol% of A and K is 100 mol%

13. Polyesterpolyol according to any one of embodiments 1 to 12, wherein at least one of the disulfide-containing dicarboxylic acids a-1) are selected from the group consisting of aliphatic disulfide-containing dicarboxylic acids.

14. Polyesterpolyol according to any one of embodiments 1 to 12, wherein the disulfide-containing dicarboxylic acid a-1) is an aliphatic disulfide-containing dicarboxylic acid.

15. polyester polyol according to embodiment 14, wherein at least one of the disulfide-containing dicarboxylic acids a-1) is selected from the group consisting of 2- (carboxymethyldisulfanyl) acetic acid, 3- (2-carboxyethyl-disulfanyl) propanoic acid, 4- (3-Carboxypropyldisul - Fanyl) butanoic acid, 2 - [(2-carboxyphenyl) disulfanyl] benzoic acid and their alkyl esters, preferably dimethyl and diethyl esters or mixtures of the abovementioned acids.

16. A polyester polyol according to embodiment 14, wherein the disulfide-containing dicarboxylic acid a-1) is selected from the group consisting of 2- (carboxymethyldisulfanyl) acetic acid, 3- (2-carboxyethyl-disulfanyl) propanoic acid, 4- (3-carboxypropyldisulfanyl) butanoic acid, and their alkyl esters, preferably dimethyl and diethyl esters or mixtures of the abovementioned acids.

17. A polyester polyol according to embodiment 14, which is disulfide-containing dicarboxylic acid a-1) 3- (2-carboxyethyl-disulfanyl) propanoic acid.

18. Polyesterpolyol according to any one of embodiments 8 to 17, wherein the higher alcohol C) is selected from the group consisting of glycerol, trimethylolpropane (TMP), pentaerythritol, reaction products thereof with an alkylene oxide, and mixtures thereof. 19. A polyester polyol according to any one of embodiments 8 to 17, wherein the higher alcohol C) is selected from the group consisting of TMP and the reaction product of TMP with ethylene oxide.

20. A process for preparing a polyesterpolyol according to any one of embodiments 1 to 19 by reacting component D) with component K).

21. A process for producing a polyester polyol according to embodiment 20, wherein no additional catalyst is used during the reaction. 22. A process for producing a polyester polyol according to any one of embodiments 1 to 19, wherein no higher alcohol C) is used.

23. A process for producing a polyester polyol according to any one of embodiments 1 to 19, wherein the reaction is carried out at a temperature in the range of 150 ° to 220 ° C.

24. A process for producing a polyester polyol according to any one of embodiments 1 to 19, wherein the reaction is carried out at a temperature in the range of 160 ° to 190 ° C.

25. A process for preparing a polyester polyol according to any one of embodiments 20 to 24, wherein the reaction first

a. at normal pressure up to an acid number of 80 to 20 mg KOH / g - determined according to DIN EN 1241 is performed, and then

b. is continued at a pressure of less than 500 mbar to an acid number of less than 10 mg KOH / g.

26. A process for the preparation of a polyester polyol according to embodiment 25, wherein the reaction is carried out initially at atmospheric pressure up to an acid number of 40 to 20 mg KOH / g.

27. A process for preparing a polyester polyol according to any one of embodiments 25 to 21, wherein in step b at a pressure of 40 to 400 mbar is used.

28. A process for preparing a polyester polyol according to any of embodiments 25 to 22, wherein the reaction in step b is continued to an acid number of less than 2 mg KOH / g. 29. A process for producing a polyester polyol according to any one of embodiments 25 to 23, wherein the reaction is carried out under an inert atmosphere.

30. A process for producing a rigid polyurethane foam by reacting a reaction mixture comprising

a. organic and / or modified organic di- and / or polyisocyanates with b. at least one polyester polyol according to any of embodiments 1 to 19, c. one or more propellants as well

d. Catalysts. 31. The method of embodiment 30, wherein the reaction mixture further comprises other polyester polyols and / or polyether polyols.

32. The method according to any one of embodiments 30 to 31, wherein the reaction mixture further comprises further polyetherols and / or other compounds having at least two isocyanate-reactive groups. 33. The method of any of embodiments 30 to 32, wherein the reaction mixture further comprises chain extenders and / or crosslinkers.

34. The process according to any one of embodiments 30 to 33, wherein the reaction mixture additionally comprises chain extender and / or flame retardant.

35. Polyurethane rigid foam obtainable by a process according to embodiments 30 to 34. 36. Use Polyester polyol according to one of embodiments 1 to 19 for producing a rigid polyurethane foam.

The following examples are illustrative of the invention, but are in no way limiting as to the subject matter of the present invention.

Examples

The following examples are intended to illustrate some aspects of the present invention. In no way should the examples limit the scope of the invention. methods

Viscosity determination:

Unless stated otherwise, the viscosity of the polyols was determined at 25 ° C. in accordance with DIN EN ISO 3219 (October 1994) using a Rheotec RC 20 rotational viscometer using the spindle CC 25 DIN (spindle diameter: 12.5 mm; : 13.56 mm) at a shear rate of 50 1 / s.

Measurement of the hydroxyl number:

The hydroxyl numbers were determined by the phthalic anhydride method DIN 53240 (December 1971) and reported in mg KOH / g.

Measurement of the acid number:

The acid number was determined according to DIN EN 1241 (May 1998) and is given in mg KOH / g. Permeability measurement on polyurethane films

The permeability of polyurethane films was determined against each 4 gases. The transmissions against nitrogen, methane, and carbon dioxide were measured with a Brugger gas permeability tester according to ASTM D 1434 82 (1982 original, 2015 rev.). The measuring area is 78 cm ² . The oxygen permeability was determined in a Mocon Oxtran 2/21 according to ASTM D 3985 (2005 orig., 2010 rev.). Here the measuring area is 50 cm ² . The water permeability was determined according to ASTM F-1249 (2013 original).

Inventive Example 1

565.3 g of 3- (2-carboxyethyldisulfanyl) propanoic acid and 531.6 g of cyclohexanedimethanol are introduced into a round-bottomed flask equipped with thermometer, nitrogen inlet, heating paddle, distillation column and stirrer and heated to 120.degree. Upon further heating to 140 ° C results in reaching a temperature of 135 ° C water, which is separated by distillation. After 80% of the calculated condensation water is separated, the pressure in the apparatus is reduced to 60 mbar and the mixture is heated further until an acid value of less than 2 mg KOH / g is reached. There is obtained a polyester polyol having a hydroxyl number of 1 1 1 mg KOH / g, an acid number of 1.17 mg KOH / g and a viscosity of 1719 mPas at 75 ° C.

Inventive Example 2

1557 g of 3- (2-carboxyethyldisulfanyl) propanoic acid, 1 127 g of cyclohexanedimethanol and 82.8 g of trimethylolpropane are placed in a 41 round-bottomed flask equipped with thermometer, nitrogen inlet, heater, distillation column and stirrer and heated to 120.degree. Upon further heating to 210 ° C, the resulting condensation water is distilled off continuously until an acid value of less than 2 mg KOH / g is reached. From the reaction, a polyester polyol having a hydroxyl value of 61, 5 mg KOH / g, an acid number of 0.6 mg KOH / g and a viscosity of 13090 mPas at 75 ° C was obtained.

Inventive Example 3

1563 g of 3- (2-carboxyethyldisulfanyl) -propanoic acid, 1,127 g of cyclohexanedimethanol and 77.4 g of trimethylolpropane are introduced into a round-bottomed flask equipped with thermometer, nitrogen inlet, heating mushroom, distillation column and stirrer and heated to 120.degree. Upon further heating to 210 ° C, the resulting condensation water is distilled off continuously until an acid value of less than 2 mg KOH / g is reached. From the reaction, a polyester polyol having a hydroxyl value of 55.5 mg KOH / g, an acid number of 0.526 mg KOH / g and a viscosity of 16540 mPas at 75 ° C was obtained. Inventive Example 4

Into a round-bottomed flask equipped with thermometer, nitrogen inlet, heater, distillation column and stirrer are charged 1317 g of 3- (2-carboxyethyldisulfanyl) propanoic acid, 121 1, 7 g of cyclohexanedimethanol and 197 g of glycerol and heated to 120 ° C. On further heating up to 210 ° C., the condensation water formed is continuously distilled off until an acid number of less than 2 mg KOH / g is reached. From the reaction, a polyester polyol having a hydroxyl value of 234.5 mg KOH / g, an acid number of 0.028 mg KOH / g and a viscosity of 807 mPas at 75 ° C was obtained.

Comparative Example 1

Provided in a 41 round bottom flask equipped with thermometer, nitrogen inlet, heater, distillation column and stirrer 1230 g of adipic acid and 1605 g of cyclohexanedimethanol and heated to 120 ° C. After adding 1 ppm of titanium tetrabutoxide as catalyst, the mixture is stirred and heated to 240 ° C, wherein the released water is distilled off continuously. After 80% of the calculated water of reaction is removed, a vacuum of 60 mbar is applied and the reaction is continued until an acid value of less than 2 mg KOH / g is measured. The resulting polyester polyol had a hydroxyl number of 1.14.8 mg KOH / g, an acid number of <0.1 mg KOH / g and a viscosity of 420 mPas at 100 ° C.

Comparative Example 2

1660 g of adipic acid and 1249 g of butanediol are placed in a 41 round-bottomed flask equipped with thermometer, nitrogen inlet, heated mushroom, distillation column and stirrer and heated to 120.degree. After adding 1 ppm of titanium tetrabutoxide as a catalyst, the mixture is stirred and heated to 240 ° C, wherein the released water is continuously distilled off.

After 80% of the calculated water of reaction is removed, a vacuum of 60 mbar is applied and the reaction is continued until an acid value of less than 2 mg KOH / g is measured. The polyesterpolyol obtained had a hydroxyl number of 56 mg KOH / g, an acid number of 0.6 mg KOH / g and a viscosity of 670 mPas at 75.degree. Application Example 1 - Production of TPU Films

TPUs were produced from the polyester polyols prepared in Inventive Example 1 and Comparative Example 2 and made into flat films. The TPU production was carried out by methods known to the person skilled in the art. The flat films were produced on a 30-point bend with a three-zone screw with mixing part (screw ratio 1: 3) and a 250 mm slot die.

The resulting films were tested for their permeability characteristics as described under Permeability Measurement. (In the following tables, "E" means: to power of ten.) Table 1: Use of the PESOL according to the invention

Based on the permeability measurements presented above, it can be seen that TPU flat films based on polyesterols without dithio-di-propionic acid have a significantly higher permeability compared to the gases tested.

This is accompanied by an increased thermal conductivity of those polyurethane systems which are not based on the sulfur-containing PESOLs according to the invention.

Further application examples: Production of rigid polyurethane foams for thermal insulation

To prepare the rigid polyurethane foams according to the invention on a laboratory scale, the components of Comparative Examples X and Y listed in Tables 3 and 4 and Examples A and B according to the invention in the proportions indicated are at 20 ° C. mixed. The reaction mixture either remains in the mixing vessel (beaker) or is transferred into an open cube shape of dimensions 22 × 22 × 22 cm in which the foam rises freely. Test specimens for determining the thermal conductivity (WLF), compressive strength and closed cell count were taken from the cube foam block. Cell size and cell gas content were determined on cup foams.

Table 3.

Table 4.

Polyol 1: polyester polyol based on terephthalic acid, diethylene glycol, cis

Fatty acid and alkoxylated glycerol, OH number 240 mg KOH / g.

Polyol 2: polyester polyol based on 3,3'-dithiodipropionic acid, cyclohexanedimethanol and trimethylolpropane, OH number 55 mg KOH / g.

Polyol 3: Polyester polyol based on 3,3-dithiodipropionic acid, cyclohexanedimethanol and glycerol, OH number 235 mg KOH / g.

Polyol 4: polyether polyol based on diethylene glycol and ethylene oxide, OH number

190 mg KOH / g.

Additives: Mixture of flame retardant Tris (1-chloro-2-propyl) phosphate, a

Silicon-based copolymer from Evonik Goldschmidt as foam stabilizer and a catalyst mixture consisting of a formate salt and a tertiary amine.

Isocyanate: Polymeric MDI with an NCO content of 31.5% by weight

The thermal conductivity is determined using a λ-meter EP500e from Lambda Messtechnik GmbH Dresden at an average temperature of 10 ° C. on PU test specimens of dimensions 200 × 200 × 50 mm, which were taken from the cube foam block described above 24 hours after its production , To determine the cell size, a sample body approximately 10 × 10 × 10 cm larger is taken from the interior of a cup foam. For the measurement, a clean cut surface perpendicular to the direction of the foam is generated and contrasted with soot spray. Then the cut surface is taken up with a light microscope and the evaluation with the software PORE! SCAN from Goldlücke. This generates over the area a size class distribution of the cells and the arithmetic mean value.

The determination of the cell gases is carried out according to the method of M. Svanström and O. Ramnäs described in the Journal of Cellular Plastics, Vol. 31, 1995, pages 375-388, in which from the intak- th cup foams under an inert gas atmosphere with a gas sample from the foam interior a brass syringe is removed.

In Tables 3 and 4 examples are shown in which the polyols 2 and 3 of the invention to different proportions replace the polyol 1 in the A component of a representative PIR formulation. Both examples show that the use of the polyols of the invention reduce the thermal conductivity of the foam after 24 hours and after aging for 21 days at 70 ° C. Furthermore, the compressive strength improves when replacing 50 parts by weight of polyol 1 by 7% polyol 3. The improvement of the thermal conductivities can be explained by the slower exchange mainly of CO2 against air in the foam cells. These results confirm the results of permeability measurements on TPU films of Tables 1 and 2.

From these other application examples, it can be seen that when using the polyester polyols according to the invention, the thermal conductivity in the resulting polyurethanes before and after aging can be reduced.

formulas

2- (carboxymethyldisulfanyl) acetic acid

3- (2-Carboxyethyldisulfanyl) propanoic acid

H

4- (3-carboxypropyldisulfanyl) butanoic acid

Claims

claims

1 . Polyester polyol comprising the esterification product of

b. at least one disulfide-containing dicarboxylic acid a-1; and

c. a polyol component (K), the

i. at least one diol (D), wherein the diol (D)

ii. at least one diol b-1, which is selected from the group consisting of cyclohexanedimethanol, 1, 6 hexanediol

2. Polyester polyol according to claim 1, characterized in that the dicarboxylic acid components A) additionally contain a non-sulfur-containing dicarboxylic acid a-2; includes.

3. Polyester polyol according to claim 1, characterized in that the non-sulfur-containing dicarboxylic acid is a-2 terephthalic acid.

4. Polyester polyol according to one of claims 1 to 3, characterized in that the diol (D) comprises a further diol b-2.

5. Polyester polyol according to one of claims 1 to 4, characterized in that the polyol component (K) comprises the diol (D) and at least one higher-value alcohol C having a functionality greater than 2.

6. A polyester polyol according to any one of claims 1 to 5, wherein at least one of the disulfide-containing dicarboxylic acids a-1) are selected from the group consisting of aliphatic disulfide-containing dicarboxylic acids.

A polyester polyol according to claim 6, wherein the disulfide-containing dicarboxylic acid a-1) is 3- (2-carboxyethyl-disulfanyl) propanoic acid.

8. Polyesterpolyol according to any one of claims 5 to 7, wherein the higher alcohol C) is selected from the group consisting of glycerol, trimethylolpropane (TMP), pentaerythritol, reaction products thereof with an alkylene oxide, and mixtures thereof.

9. A process for preparing a polyester polyol according to any one of claims 1 to 8 by reacting the component D) with the component K).

A process for the preparation of a polyester polyol according to claim 9, wherein no additional catalyst is used during the reaction.

1 1. A process for preparing a polyester polyol according to any one of claims 1 to 8, wherein the reaction first a. at normal pressure up to an acid number of 80 to 20 mg KOH / g - determined according to DIN EN 1241, and then

12. A process for producing a rigid polyurethane foam by reacting a reaction mixture comprising

a. organic and / or modified organic di- and / or polyisocyanates with b. at least one polyester polyol according to one of claims 1 to 8,

c. one or more propellants as well

d. Catalysts.

13. The method of claim 12, wherein the reaction mixture further comprises other polyester polyols and / or polyether polyols.

14. rigid polyurethane foam obtainable by a process according to claim 12 to 13.

15. Use of a polyester polyol according to any one of claims 1 to 8 for the production of a rigid polyurethane foam.