DE102007015891A1 - Production of polyurethane, involves reacting polyisocyanate with compounds containing at least two isocyanate-reactive hydrogen atoms and at least one urethane group - Google Patents

Abstract

A method for the production of polyurethanes (I) by reacting (a) polyisocyanates with (b) compounds with at least 2 NCO-reactive hydrogen atoms, in which (b) contains at least one compound (bi) with at least 2 NCO-reactive hydrogens and at least one urethane group, obtained by reacting (bi1) compounds with at least 2 amino groups with (bi2) compounds with hydroxyl groups and (bi3) urea, or by reacting non-functional urethanes with (bi4) compounds containing hydroxyl groups.

Description

object The invention is a process for the preparation of polyurethanes by reacting polyisocyanates with compounds having at least two hydrogen atoms reactive with isocyanate groups and at least a urethane group in the molecule.

The Production of polyurethanes by reaction of polyisocyanates with compounds having at least two isocyanate-reactive Hydrogen atoms has long been known and widely used in the literature described.

When Compounds having at least two isocyanate-reactive Hydrogen atoms are mostly polyols, in particular polycarbonates, Polyether alcohols and / or polyester alcohols used.

One Advantage in the use of polyurethanes is that through targeted variation of the starting materials the properties of the final products depending on the desired Purpose can be set.

there exists as a permanent one Task to provide new products with improved properties. There in the case of the polyisocyanates only limited possibilities of variation most of the time, the connections are made with at least two prepared with isocyanate-reactive hydrogen atoms. So can by changes the composition of these compounds and / or by their mixing influence on the properties of the polyurethanes.

task The invention was novel compounds with at least two active To provide hydrogen atoms for the production of polyurethanes can be used with improved properties.

The Task was solved be prepared by as compounds having at least two with isocyanate groups reactive hydrogen atoms are used by Reaction of at least two amino-containing compounds with hydroxyl-containing compounds and urea or by Reaction of non-functional urethanes with hydroxyl-containing Connections are made.

• a) Polyisocyanaten mit
• b) Verbindungen mit mindestens zwei mit Isocyanatgruppen reaktiven Wasserstoffatomen,

dadurch gekennzeichnet, dass die Verbindungen mit mindestens zwei mit Isocyanatgruppen reaktiven Wasserstoffatomen b) mindestens eine Verbindung bi) mit mindestens zwei mit Isocyantgruppen reaktiven Wasserstoffatomen und mindestens einer Urethangruppe enthalten, die hergestellt wurde durch Umsetzung von bi1) mindestens zwei Aminogruppen enthaltenden Verbindungen mit bi2) Hydroxylgruppen enthaltenden Verbindungen und bi3) Harnstoff oder durch Umsetzung von nichtfunktionellen Verbindungen mit mindestens einer Urethangruppe mit bi4) hydroxylgruppenhaltigen Verbindungen.The invention accordingly provides a process for the preparation of polyurethanes by reacting

• a) polyisocyanates with
• b) compounds having at least two isocyanate-reactive hydrogen atoms,

characterized in that the compounds having at least two isocyanate-reactive hydrogen atoms b) at least one compound bi) containing at least two isocyanate-reactive hydrogen atoms and at least one urethane group which has been prepared by reacting bi1) containing at least two amino groups compounds with bi2) hydroxyl groups containing compounds and bi3) urea or by reacting non-functional compounds having at least one urethane group with bi4) hydroxyl-containing compounds.

The for the inventive method used compounds bi) are known per se. They usually become in the preparation of diisocyanates by the phosgene-free process used.

These methods are known and, for example, in DE 102 09 096 . EP 521 554 and DE 33 14 788 described. They are prepared by reacting monofunctional alcohols with a diamine and urea. The urethanes thus prepared are then reacted by thermal cleavage in the diisocyanates and the monofunctional alcohols.

The Urethane mentioned have no reactive groups and therefore can not as starting compounds for the production of polyurethanes are used.

Surprisingly It has been shown that such urethanes containing isocyanate groups contain reactive groups with polyisocyanates to polyurethanes can be implemented with improved properties.

The preparation of the compounds bi) can be carried out in various ways. For one thing, too next in a known way by reacting monools as component bi2), diamines bi1) and urea bi3) a non-functional urethane can be prepared. This is reacted in a second step with a polyhydric alcohol bi4) to an OH-functional urethane. In this case, the polyfunctional alcohol should be present in particular in stoichiometric excess in order to shift the reaction equilibrium in the direction of the end products. The unreacted compounds bi2a) and bi4) can remain in the product after the reaction and participate in the further processing into polyurethanes. However, it is also possible to separate them and return them to the reaction.

In a further embodiment the method according to the invention becomes in place of the monofunctional alcohol bi2) a mehrfunktioneller Alcohol bi4) used. As polyfunctional alcohols preferably those are used which have a hydroxyl number of 20-2000 mg KOH / g, especially 40 - 2000 mgKOH / g. The used for the preparation of the compounds bi) Polyfunctional alcohols are 2- to 4-functional. With higher functionalities increases the viscosity The compounds too strong, so that they are no longer processable are. Preferably, the polyfunctional alcohols are 2- to 3-functional. Particularly preferred polyfunctional alcohols are alkanediols used with a maximum of 8 carbon atoms in the main chain. The In particular, alkanediols used exclusively have primary hydroxyl groups on. Examples of this are ethylene glycol, diethylene glycol, propylene glycol, dipropylene glycol, Butanediol-1,4, pentanediol-1,5, 1,6-hexanediol and any mixtures from at least two of said diols.

When difunctional alcohols can also, individually or mixed with each other or in admixture with the mentioned alkanediols, difunctional polyether used become. Preferred are higher Homologs of ethylene glycol or propylene glycol, preferably having a molecular weight of at most 1500 g / mol, in particular 200 to 1000 g / mol.

It can for both method variants described above, in principle, the same or different polyfunctional alcohols bi2) or bi4) used become.

The Compounds having at least two amino groups bi1) preferably have a molecular weight of less than 2000 g / mol, preferably in the range between 200 and 2000 g / mol.

Preferably Such amines are used as starting materials for the preparation of polyurethanes, for example aromatic diamines such as tolylenediamine or diphenylmethanediamine. Preferably used are aliphatic amines, especially hexamethylenediamine and isophoronediamine.

When Urea bi3) can preferably be used formula-pure urea become. It is also possible with Use alkyl groups modified urea.

The Reaction of the diamines bi1) with the alcohols bi2) or bi4) takes place preferably at temperatures in the range between 180 and 220 ° C and atmospheric pressure or overpressure. The ammonia formed is discharged from the reaction mixture. The molar ratio from urea bi3) to the at least two primary amino groups Compounds bi1) is 2: 1 to 10: 1.

The Compounds bi) preferably have a molecular weight in the range between 300 and 2000 g / mol. They preferably have a functionality of 2 up to 4. In particular, they are difunctional. The using Hexamethylenediamine compounds bi) are usually at processing temperature liquid, the compounds prepared using isophorone diamine bi) are usually solid at the processing temperature.

The Preparation of the polyurethanes, as described, by reaction the compound containing bi) with at least two isocyanate-reactive hydrogen atoms b) with polyisocyanates a).

The Compounds bi) can in the preparation of the polyurethanes alone or together with other compounds with at least two isocyanate-reactive hydrogen atoms bii) are used for the production of polyurethanes. This depends first Line of the kind and the aimed properties of the polyurethanes from.

The Compounds bii) are in particular selected from the group containing Polyether alcohols, polyester alcohols, alkanediols and alkanetriols.

Preferably the compounds are bi) in an amount of at most 50 wt .-%, based on the weight of component b) used. Especially they are preferably used in an amount of from 2 to 50% by weight, from 2 to 30 wt .-%, and in particular from 2 to 25 wt .-% and in particular from 5 to 20 wt .-%, each based on the weight of the component b) used. The compounds of the invention can for the production of rigid polyurethane foams, flexible foams, Elastomers, coatings and adhesives and sealants are used.

Specifically, the starting components used to prepare the polyurethanes are as follows:
Suitable polyisocyanates a) for the preparation are the known aliphatic, cycloaliphatic, araliphatic and preferably aromatic polyfunctional isocyanates.

in the Specific examples are: alkylenediisocyanates with 4 to 12 carbon atoms in the alkylene radical, such as 1,12-dodecane diisocyanate, 2-ethyl-tetramethylene-1,4,2-methylpentamethylene-1,5, Tetramethylene diisocyanate-1,4 and preferably hexamethylene diisocyanate-1,6; cycloaliphatic diisocyanates, such as cyclohexane-1,3- and 1,4-diisocyanate as well as any mixtures of these isomers, 1-isocyanato-3,3,5-trimethyl-5-isocyanatomethylcyclohexane (IPDI), 2,4- and 2,6-hexahydrotoluylene diisocyanate and the corresponding isomer mixtures, 4,4'-, 2,2'- and 2,4'-dicyclohexylmethane diisocyanate and the corresponding isomer mixtures, and preferably aromatic Di- and polyisocyanates, e.g. 2,4- and 2,6-toluene diisocyanate and the corresponding Isomer mixtures, 4,4'-, 2,4'- and 2,2'-diphenylmethane diisocyanate and the corresponding Isomer mixtures, mixtures of 4,4'- and 2,2'-diphenylmethane diisocyanates, polyphenylpolymethylene polyisocyanates, Mixtures of 4,4'-, 2,4'- and 2,2'-diphenylmethane diisocyanates and Polyphenylpolymethylenpolyisocyanaten (crude MDI) and mixtures of Crude MDI and tolylene diisocyanates. The organic di- and polyisocyanates can used individually or in the form of their mixtures.

When Compounds having at least two isocyanate-reactive Hydrogen atoms bii), which are used together with the compounds bi) are mostly multifunctional alcohols, preferably polyether alcohols and / or polyester alcohols used.

Especially are as polyether alcohols and / or polyester alcohols such a functionality from 2 to 8, preferably 2 to 3, and an average molecular weight from 300 to 8,000, preferably from 300 to 5,000.

The used polyether alcohols are prepared by known methods, for example by anionic polymerization with alkali metal hydroxides, such as. B. Sodium or potassium hydroxide or alkali metal such as. For example, 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 Contains 2 to 3, bonded to reactive hydrogen atoms, or by cationic Polymerization with Lewis acids, such as antimony pentachloride, borofluoride etherate and. a., or bleaching earth as catalysts or by Doppelmetallcyanidkatalyse from a or more alkylene oxides having 2 to 4 carbon atoms in the alkylene radical produced. For Special uses can also monofunctional starters are incorporated into the polyether structure.

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 individually, alternating successively or used as mixtures become.

When starter molecules For example: water, organic dicarboxylic acids, aliphatic and aromatic 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- 1,4-butylenediamine, 1,2-, 1,3-, 1,4-, 1,5- and 1,6-hexamethylenediamine, Phenylenediamine, 2,3-, 2,4- and 2,6-toluenediamine and 4,4 '; 2,4'- and 2,2'-diaminodiphenylmethane. As starter molecules Also suitable: alkanolamines, and ammonia. Preferably used are polyvalent, especially bivalent and / or trivalent Alcohols, such as ethanediol, 1,2-propanediol and -2,3, diethylene glycol, Dipropylene glycol, 1,4-butanediol, 1,6-hexanediol, glycerol, trimethylolpropane, Pentaerythritol.

The Polyether alcohols, preferably polyoxypropylene and Polyoxypropylenpolyoxyethylenpolyole possess a functionality of preferably 2 to 8 and in particular 2 to 3 and molecular weights from 300 to 8000, preferably 300 to 6000.

Other 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, and polyetherpolyol dispersions which are used as the disperse phase, usually in an amount of from 1 to 50% by weight .-%, preferably 2 to 25 wt .-%, contain: z. As polyureas, polyhydrazides, tert-amino groups bound polyurethanes and / or melamine and z. B. be described in EP-B 011 752 ( US 4,304,708 ) US 4,374,209 and DE-A 32 31 497.

The Polyether polyols can used singly or in the form of mixtures.

suitable Polyester polyols can for example, from organic dicarboxylic acids having 2 to 12 carbon atoms, preferably aliphatic dicarboxylic acids having 4 to 6 carbon atoms, polyhydric alcohols, preferably diols, having 2 to 12 carbon atoms, preferably 2 to 6 carbon atoms, prepared by conventional methods become. Usually be the organic polycarboxylic acids and / or derivatives and polyhydric alcohols, preferably in the molar ratio of 1: 1 to 1.8, preferably from 1: 1.05 to 1.2, catalyst free or preferably in the presence esterification catalysts, conveniently in an inert gas atmosphere, polycondensed.

To the compounds having at least two isocyanate-reactive Include hydrogen atoms also chain extension and / or crosslinking agents, which are optionally used can. As chain extension and / or crosslinking agents are mostly used diols and / or Triols with molecular weights less than 400, preferably 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, 1,3-propanediol, dexanediol-1,10, om, p-dihydroxycyclohexane, diethylene glycol, dipropylene glycol and preferably 1,4-butanediol, 1,6-hexanediol and bis (2-hydroxyethyl) hydroquinone, Triols, such as 1,2,4- and 1,3,5-trihydroxycyclohexane, triethanolamine, diethanolamine, glycerin and trimethylolpropane and low molecular weight hydroxyl groups Polyalkylene oxides based on ethylene and / or 1,2-propylene oxide and the aforementioned diols and / or triols as starter molecules.

Provided for preparing the polyurethanes, chain extenders, crosslinking agents or mixtures thereof are used, they come expediently in an amount of up to 10% by weight, based on the weight of the polyol compounds, for use.

For foamed polyurethanes propellants are used. The blowing agent is mostly water, preferably in proportions of 1 to 10 wt .-%, more preferably in an amount of 1 to 5 wt .-% and in particular from 2 to 4 wt .-%, in each case based on the total weight of components (b) to (g) used.

Of the Adding water can be done in combination with other common propellants. Therefor For example, those commonly known from polyurethane chemistry Chlorofluorocarbons (CFCs) as well as highly fluorinated and / or perfluorinated ones Hydrocarbons in question. The use of these substances, however, will from ecological establish highly limited or completely adjusted. In addition to HCFC and HFCs are particularly suitable aliphatic and / or cycloaliphatic hydrocarbons, in particular Pentane and cyclopentane or acetates, such as. As methylal, as an alternative blowing agent at. These physical blowing agents usually become the polyol component added to the system. You can however, also in the isocyanate component or as a combination both the polyol component and the isocyanate component added become.

Farther can the reaction in the presence of catalysts, flame retardants as well as usual auxiliary and / or additives become.

When Catalysts for the production of polyurethane foams are In particular, compounds used that promote the reaction of the reactive Hydrogen atoms, with the organic, optionally modified Strongly accelerate polyisocyanates. Organic are possible Metal compounds, preferably organic tin compounds. The organic metal compounds are used alone or preferably in Used in combination with strong basic amines.

to Production of polyurethane foams are often also flame retardants, preferably halogen-free flame retardants used. Come for this in particular: ammonium polyphosphate, aluminum hydroxide, Isocyanurate derivatives and carbonates of alkaline earth metals.

The reaction mixture for the preparation of polyurethane foams may optionally still additional aids and / or additives are incorporated. Examples which may be mentioned are stabilizers, fillers, dyes, pigments and hydrolysis protection agents as well as fungistatic and bacteriostatic substances.

When Stabilizers are especially surface-active substances, i. H. Used compounds to assist the homogenization of the Serve starting materials and, where appropriate, are also suitable, the Cell structure of plastics regulate. Examples include Emulsifiers, such as the sodium salts of castor oil sulfates or fatty acids, and Salts of fatty acids with amines.

More details about the above other usual Auxiliaries and additives are the specialist literature, such as Monograph by J.H. Saunders and K.C. Frisch "High Polymers" Vol. XVI, Polyurethanes, Part 1 and 2, Interscience Publishers 1962 and 1964, or the above cited Plastics Handbook, Polyurethane, Volume VII, Hanser-Verlag Munich, Vienna, 1st to 3rd edition.

The Invention will be described in more detail in the following examples.

Examples:

Example 1:

92,76g Urea, 89.73 g hexamethylenediamine, 417.54 g BDO-1.4 and 1 ml of a Catalyst solution, consisting from a 5.26% solution of zirconium tetrabutylate in ethyl methyl ketone were combined in one 4-necked flask and stirred at 210 ° C for about 6h. The 4-neck piston, the with blade stirrer, Reflux cooler and an oil bath equipped was, was during the entire reaction with nitrogen. That in the reaction formed ammonia went over Chop the head off.

The formed reaction product was white and solid and melted about 115 ° C and owned one OH number of 821 mg KOH / g.

Example 2:

115.61 g urea, 163.91 g isophoronediamine, 520.42 g butanediol-1,4 and 1 ml of a catalyst solution, consisting of a 5.26% solution of zirconium tetrabutylate in ethyl methyl ketone were combined in one 4-necked flask and stirred at 210 ° C for about 6h. The 4-neck piston, the with blade stirrer, Reflux cooler and an oil bath equipped was, was during the entire reaction with nitrogen. That in the reaction formed ammonia went over Chop the head off.

The formed reaction product was white and solid and melted about 115 ° C and owned one OH number of 821 mg KOH / g.

The formed reaction product was yellowish, clear and liquid.
OH: 785.0 mg KOH / g

Example 3:

221.5 Hexamethylenedibutylurethan, 378.5 g of 1,4-butanediol and 1 ml of a Catalyst solution consisting of a 5.26% solution of zirconium tetrabutylate in ethyl methyl ketone were combined in a 4-necked flask submitted and at 210 ° C. stirred for about 6h. The 4-necked flask equipped with blade stirrer, Reflux cooler and an oil bath equipped was, was during the entire reaction with nitrogen. The above-mentioned in the transesterification outgoing n-butanol was collected in the distillation receiver.

The formed reaction product was white and solid and melts at about 115 ° C, OH: 815.0 mg KOH / g.

Example 4:

325.28 g Isophorondibutylurethan, 474.69 g of 1,4-butanediol and 1 ml of a Catalyst solution consisting of a 5.26% solution of zirconium tetrabutylate in ethyl methyl ketone were combined in a 4-necked flask submitted and at 210 ° C. stirred for about 6h. The 4-necked flask equipped with blade stirrer, Reflux cooler and an oil bath equipped was, was during the entire reaction with nitrogen. The above-mentioned in the transesterification outgoing n-butanol was collected in the distillation receiver.

The formed reaction product was yellowish, clear and liquid;
OH: 778.0 mg KOH / g.

Example 5 (comparison):

A polyol component consisting of Lupraphen ^® 8101 90.7 parts by weight Zeolite paste 3.0 parts by weight 1,4-butanediol 9.3 parts by weight Thorcat 535 0.2 parts by weight was homogenized at a temperature of 90 ° C and then with 56 TI. a B component (MP102) mixed at a ratio of 103.

This Mixture was potted at a mold temperature of: 90 ° C.

Example 6:

A polyol component consisting of Lupraphen ^® 8101 81.4 parts by weight Zeolite paste 3.0 parts by weight Product from Ex.2 18.6 parts by weight Thorcat 535 0.2 parts by weight was homogenized at a temperature of 90 ° C and then with 54 TI. a B component (MP102) mixed at a ratio of 103.

This Mixture was potted at a mold temperature of: 90 ° C.

Example 7:

A polyol component consisting of Lupraphen ^® 8101 81.4 parts by weight Zeolite paste 3.0 parts by weight Product of Ex.4 18.6 parts by weight Thorcat 535 0.2 parts by weight was homogenized at a temperature of 90 ° C and then with 54 TI. a B component (MP102) mixed at a ratio of 103.

This Mixture was potted at a mold temperature of: 90 ° C.

there were the mechanical properties shown in the following table receive:

Results of the mechanical test:

The Level of mechanical properties could be significantly improved become.

Example 7 (comparison):

A polyol component consisting of Lupranol® ^® 2043 70.05 parts by weight VP 9343 20.00 parts by weight DC 193 0.20 parts by weight Lupragen N 202 1.75 parts by weight water 0.50 parts by weight 1,4-butanediol 7.50 parts by weight was homogenized and then with 53.2 TI. of a B component (MP102) mixed at a ratio of 98.

This Mixture was potted at a mold temperature of: 45 ° C.

Example 8:

A polyol component consisting of Lupranol® ^® 2043 66.05 parts by weight VP 9343 19.00 parts by weight DC 193 0.20 parts by weight Lupragen N 202 1.75 parts by weight water 0.50 parts by weight Product from Ex. 2 10.00 parts by weight was homogenized and then 55.5 TI. of a B component (MP102) mixed at a ratio of 98.

This Mixture was potted at a mold temperature of: 45 ° C.

The following table shows the results of the mechanical test obtained:

The Tensile strength could be increased significantly.

Claims (16)

A process for the preparation of polyurethanes by reacting a) polyisocyanates with b) compounds having at least two isocyanate-reactive hydrogen atoms, characterized in that the compounds having at least two isocyanate-reactive hydrogen atoms b) at least one compound bi) having at least two isocyanate-reactive hydrogen atoms and at least one urethane group which has been prepared by reacting bi1) compounds containing at least two amino groups with bi2) hydroxyl-containing compounds and bi3) urea or by reacting non-functional urethanes with bi4) hydroxyl-containing compounds. Method according to claim 1, characterized in that that the compound bi) in an amount of not more than 50 wt .-%, based on the weight of component b) is used. A process according to claim 1, characterized in that in the preparation of bi) the compounds bi2) and bi4) are used in excess and the unreacted part of the compounds bi2) and bi4) remains in the reaction mixture. Method according to claim 1, characterized in that that the compounds bi) contain hydroxyl groups. Method according to claim 1, characterized in that the compounds bi) contain 2 to 4 hydroxyl groups. Method according to claim 1, characterized in that that the compounds bi) have a molecular weight in the range between 300 and 2000 g / mol. Method according to claim 1, characterized in that that the compounds bi2) and bi4) are the same. Method according to claim 1, characterized in that that the compounds bi2) and bi4) are different. Method according to claim 1, characterized in that that the compounds bi2) and bi4) have a hydroxyl number of 20-2000 mg KOH / g have. Method according to claim 1, characterized in that that compounds bi2) and bi4) have a hydroxyl number of 40-2000 mg KOH / g. Method according to claim 1, characterized in that that the at least two primary Amino-containing compounds bi1) a molecular weight less than 2000 g / mol. Method according to claim 1, characterized in that that at least two primary Amino-containing compounds bi1) a molecular weight between 200 and 2000 g / mol. Method according to claim 1, characterized in that that in the preparation of the compounds bi) the molar ratio of Urea to the at least two primary amino groups Compounds 2: 1 to 10: 1. Method according to claim 1, characterized in that that component b) consists exclusively of compounds bi) consists. Method according to claim 1, characterized in that that component b) further compounds having at least two containing isocyanate-reactive hydrogen atoms bii). Method according to claim 1, characterized in that that the compounds bii) are selected from the group comprising Polyether alcohols, polyester alcohols, alkanediols and alkanetriols.