DE19936481A1 - Preparation of easily processed soft polyurethane foams, useful as noise damping materials, with good noise damping properties and high loss factor - Google Patents

Abstract

Easily processed soft PUR foams of good noise damping properties and high loss factor can be prepared from special polyurethane mixtures. Easily processed PUR foams of good noise damping properties and high loss factor can be prepared from special polyetherol mixtures, i.e. by: (a) reaction of organic and/or modified organic polyisocyanates; with (b) a polyetherol mixture; and optionally with (c) other compounds having a hydrogen atom reactive to isocyanates in the presence of water and/or other propellant, catalysts, and optionally adjuvants and additives. The polyether mixture (b) comprises: (1) at least 2-8-functional polyetherols based on ethylene oxide and propylene oxide and optionally butylene oxide, of OH number 20-80 mg KOH/g and more than 50% primary OH groups; and (2) at least one castor oil polyetherol based on ethylene oxide and optionally propylene oxide and/or butylene oxide of OH number 50-160 mg KOH/g. An Independent claim is included for a polyurethane foam material having noise damping properties prepared as above.

Description

The invention relates to a method for producing Soft polyurethane foams with sound-absorbing properties create by implementing organic and / or modified organic polyisocyanates (a) with a polyether mixture (b) and optionally further isocyanate-reactive ones Compounds (c) containing hydrogen atoms in the presence of water and / or other blowing agents (d), catalysts (e) and optionally further auxiliaries and additives (f), where a special polyether mixture is used.

The production of polyurethanes (PUR) by implementing organic polyisocyanates with compounds with at least two reactive hydrogen atoms, for example polyoxyalkylene polyamines and / or preferably organic polyhydroxyl compounds, especially polyetherols with molecular weights from Z. B. 300 to 6000, and optionally chain extension and / or crosslinking agents with molecular weights up to approx. 400 in the presence of catalysts, blowing agents, flame retardants, Aids and / or additives are known and have become a lot described above. A summary overview of the Her The position of PUR is e.g. B. in the plastics manual, volume VII, poly urethane, Carl-Hanser-Verlag, Munich, 1st edition 1966, out given by Dr. R. Vieweg and Dr. A. Höchtlen, as well as 2nd edition 1983 and 3rd edition 1993, published by Dr. G. Oertel, given.

The main area of application for cold-curing flexible foams are Upholstery elements for the furniture industry and seating elements for the Car industry. There are also numerous flexible PUR foams for sound-absorbing purposes, such as B. application in the automotive carpet.

The open-pore foam structure offers favorable conditions for airborne sound absorption. The damping behavior of the soft foams, the z. B. can be described by the so-called loss factor η, is considered in numerous writings as a parameter for optimizing the sound reduction index. The loss factor η

η = W _v / 2πW _r

expresses which sound component during a Oscillation period is irreversibly converted into heat. High loss factors therefore result in higher sound damping.

DE-A-27 51 774 discloses a sound-absorbing composite system Based on a combination of rigid foam and flexible foam polyols described, which contains high levels of heavy substances, what adversely affects the basis weight of the workpiece.

DE-A-37 10 731 describes a soft foam with soundproofing and droning properties presented. The one based on that at relatively high bulk densities manufactured wall cladding elements with carpet, castor oil can be used as an ingredient hold. The adhesive upper achieved as a special advantage surface properties require foaming in a characteristic number range from <80.

DE-A-33 16 652 describes a foam with noise-reducing properties. Significant proportions of castor oil are used here, especially in combination with an unspecified ethylene oxide-based polyether alcohol. The OH number of the A component is in the range from 150 to 250 mg KOH / g. Despite the addition of CFCs, bulk densities of greater than 120 kg / m ^{3 are} achieved. In addition, the foam piece must be glued to the thin-walled carrier material. Under current conditions, these restrictions do not allow for economical production of acoustics that is compatible with environmental protection requirements.

EP-A-433878 describes carpet foams with viscoelastic properties shown. These consist of a special combination nation of hydrophilic and hydrophobic polyols. These systems have good sound absorption behavior, segregate however, after a short while during storage if not is constantly stirred. DE-A-39 42 330 also describes special polyol mixtures for the production of such visco elastic foams.

EP-A-331941 describes acoustic foams with a loss factor claimed by <0.5. These foams are replaced by a Combination of special hydrophilic and hydrophobic poly etheroles manufactured.

DE-A-41 29 666 uses mutually incompatible polyols, that slowly separate out. Due to high proportions of ethylene oxide rich polyols and compliance with key figures <80 can be  achieve an adhesive carpet surface. Sound absorbing Eigen According to DE-A-400 10 444, a combination can be used of polyester and polyether alcohols. This too Systems tend to segregate very strongly.

Allow the inventions listed in the prior art definitely the production of soft foams with sound absorbent properties, with this class of substances still a considerable potential for improvement with regard to the properties and processability there.

The invention was based on the object of sound-absorbing, easy-to-use soft PUR foams with one Generate loss factor <0.2.

The object was achieved in that a polyether mixture (b), consisting of, for producing the flexible PUR foams

• 1. at least one two- to eight-functional polyetherol based on ethylene oxide and propylene oxide and optionally Butylene oxide with an OH number of 20 to 80 mg KOH / g and a proportion of primary OH groups greater than 50% and
• 2. at least one castor oil polyetherol based on ethylene oxide and optionally propylene oxide and / or butylene oxide an OH number of 50 to 160 mg KOH / g

is used.

The invention thus relates to a process for the manufacture of flexible PUR foams with sound-absorbing properties by reacting organic and / or rhiodified organic polyisocyanates (a) with a polyether mixture (b) and, if appropriate, further compounds (c) having isocyanate-reactive hydrogen atoms Presence of water and / or other blowing agents (d), catalysts (e) and optionally other auxiliaries and additives (f), which is characterized in that the polyether mixture (b) consists of

• 1. at least one two- to eight-functional polyetherol based on ethylene oxide and propylene oxide and optionally Butylene oxide with an OH number of 20 to 80 mg KOH / g and a proportion of primary OH groups greater than 50% and
• 2. at least one castor oil polyetherol based on ethylene oxide and optionally propylene oxide and / or butylene oxide an OH number of 50 to 160 mg KOH / g.

Objects of the invention are also those according to this Ver drive manufactured PUR soft foams with sound absorbing Properties as well as their use as damping material.

Surprisingly, in our investigations we found that by using the special polyetherol according to the invention It is possible to mix soft, sound-absorbing PUR foam to produce materials that are easy to work with and one high loss factor of <0.2, preferably 0.3 to 0.45 point.

The following is to be stated about the components used in the polyol mixture according to the invention:
The component (b1) consists of at least one two- to eight-functional polyetherol based on ethylene oxide and propylene oxide and optionally butylene oxide with an OH number of 20 to 80 mg KOH / g and a proportion of primary OH groups greater than 50%, preferably greater than 70%.

For example, polyetherols based on this come into consideration on glycerin or trimethylolpropane as starter. They point in usually a block structure. Polyethers are preferred ole used with an ethylene oxide endcap, particularly preferred become polyetherols based on glycerin or trimethylolpropane with a polypropylene oxide block and an ethylene oxide endcap.

Component b1) preferably comes in proportions of 20 to 70% by weight, preferably from 30 to 60% by weight, in each case based on the total weight of component b).

The component (b2) consists of at least one castor oil poly etherol based on ethylene oxide and optionally propylene oxide and / or butylene oxide with an OH number of 50 to 160 mg KOH / g, preferably from 80 to 160 mg KOH / g.

The castor oil polyetherol is obtained by the usual addition of ethylene oxide and optionally propylene oxide and / or butylene oxide Castor oil made. An addition is particularly preferred product of ethylene oxide on castor oil.

Component b2) preferably comes in proportions of 1 to 70% by weight, particularly preferably from 10 to 40% by weight on the total weight of component b).

Pure castor oil can optionally be added to the polyether mixture (b) (b3) are added.  

If pure castor oil is used, it will be preferred wise in proportions of 0.5 to 10 wt .-%, particularly preferred from 0.5 to 6% by weight, based in each case on the total weight component b) used.

The polyether mixture (b) can optionally also be the Be component (b4), consisting of one or more polyetherols based on propylene oxide and optionally ethylene oxide with a share of primary OH groups of less than 20%, be added.

For example, polyetherols based on this come into consideration on water, propylene glycol or ethylene glycol as a starter. she usually have a block structure. Preferably be Polyetherols used with a propylene oxide chain. In a Particularly preferred process variant is a poly as b4) propylene glycol used.

If a component b4) is used, it will be preferred in proportions of 0.5 to 7 wt .-%, preferably from 0.5 to 5% by weight, based in each case on the total weight of the component b), used.

The polyetherols mentioned are by known methods, such as they are, for example, described below.

The PUR flexible foams according to the invention with sound-absorbing Properties are achieved through the implementation of organic and / or modified organic polyisocyanates (a) with the above be written polyether mixture (b) and optionally further Ver having hydrogen atoms reactive toward isocyanates bonds (c) in the presence of water and / or other blowing agents agents (d), catalysts (e) and optionally other auxiliaries and additives (f) produced.

The following must be carried out in detail for the other starting components that can be used:
Suitable organic and / or modified organic polyisocyanates (a) are the aliphatic, cycloaliphatic, araliphatic and preferably aromatic polyvalent isocyanates known per se.

The following may be mentioned as examples: alkylene diisocyanates with 4 to 12 carbon atoms in the alkylene radical, such as 1,12-dodecanedi isocyanate, 2-ethyl-tetramethylene-1,4-diisocyanate, 2-methylpenta methylene diisocyanate 1,5, tetramethylene diisocyanate 1,4 and before  preferably 1,6-hexamethylene diisocyanate, cycloaliphatic diiso cyanates, such as cyclohexane-1,3- and -1,4-diisocyanate and any Mixtures of these isomers, 1-isocyanato-3,3,5-trimethyl-5-iso cyanatomethylcyclohexane (IPDI), 2,4- and 2,6-hexahydrotoluylene diisocyanate and the corresponding isomer mixtures, 4,4'-, 2,2'- and 2,4'-dicyclohexylmethane diisocyanate and the ent speaking isomer mixtures, and preferably aromatic di- and polyisocyanates, such as. B. 2,4- and 2,6-tolylene diisocyanate and the corresponding mixtures of isomers, 4,4'-, 2,4'- and 2,2'-diphenylmethane diisocyanate and the corresponding isomers mixtures, mixtures of 4,4'- and 2,2'-diphenylmethane diiso cyanates, polyphenylpolymethylene polyisocyanates, mixtures of 4,4'-, 2,4'- and 2,2'-diphenylmethane diisocyanates and poly phenylpolymethylene polyisocyanates (raw MDI) and mixtures of Crude MDI and tolylene diisocyanates. The organic di and poly Isocyanates can be used individually or in the form of their mixtures be set. Mixtures of poly are particularly preferred phenylpolymethylene polyisocyanate with MDI, preferably the The proportion of 2,4'-MDI is <30% by weight.

So-called modified polyvalent iso are also common cyanate, d. H. Products made by chemical conversion of organic Di- and / or polyisocyanates are obtained used. Example ester, urea, biuret, allophanate, Carbodiimide, isocyanurate, uretdione and / or urethane groups containing di- and / or polyisocyanates. In detail come with Examples include: modified 4,4'-diphenylmethane diiso cyanate, modified 4,4'- and 2,4'-diphenylmethane diisocyanate mixtures, modified raw MDI or 2,4- or 2,6-tolylene diisocyanate, urethane-containing organic, preferably aromatic polyisocyanates with NCO contents of 43 to 15% by weight, preferably from 31 to 21% by weight, based on the total weight, for example reaction products with low molecular weight diols, Triplets, dialkylene glycols, trialkylene glycols or polyoxy alkylene glycols with molecular weights up to 6000, in particular with molecular weights up to 1500, these as di- or poly oxyalkylene glycols can be used individually or as mixtures can. Examples include: diethylene and dipropylene glycol, polyoxyethylene, polyoxypropylene and polyoxypropylene polyoxyethylene glycols, triols and / or tetrols. Are suitable also prepolymers containing NCO groups with NCO contents of 25 up to 3.5% by weight, preferably from 21 to 14% by weight, based on the total weight made from those described below Polyester and / or preferably polyether polyols and 4,4'-di phenylmethane diisocyanate, mixtures of 2,4'- and 4,4'-diphenyl methane diisocyanate, 2,4- and / or 2,6-tolylene diisocyanates or Raw MDI. Liquid carbodiimide groups have also proven successful  and / or polyisocyanates containing isocyanurate rings with NCO Contained from 43 to 15, preferably 31 to 21 wt .-%, be moved to the total weight, e.g. B. based on 4,4'-, 2,4'- and / or 2,2'-diphenylmethane diisocyanate and / or 2,4- and / or 2,6-tolylene diisocyanate.

The modified polyisocyanates can be used together or with unmodified organic polyisocyanates, such as. B. 2,4'-, 4,4'-diphenylmethane diisocyanate, crude MDI, 2,4- and / or 2,6-tolylene diisocyanate can be mixed.

Organic polyisocyanates and are therefore preferably used: mixtures of toluene diisocyanates and raw MDI or mixtures of modified Organic polyisocyanates containing urethane groups an NCO content of 33.6 to 15 wt .-%, especially those based on tolylene diisocyanates, 4,4'-diphenylmethane diiso cyanate, diphenylmethane diisocyanate isomer mixtures or crude MDI and especially crude MDI with a diphenylmethane diisocyanate Isomer content of 30 to 80 wt .-%.

In addition to the polyether mixture according to the invention described above (b) optionally further reactive towards isocyanates Compounds (c) containing hydrogen atoms are used.

For this purpose, primarily connections with at least two reak tive hydrogen atoms used. It will be convenient those with a functionality of 2 to 8, preferably 2 to 3, and a molecular weight of 300 to 8000, preferably of 300 to 6000 and especially 1000 to 5000 used.

According to the invention, preference is given to using polyols, in particular Polyether polyols. In addition, polyethers can also be used, for example polyamines and / or other polyols selected from the group of Polyester polyols, polythioether polyols, polyester amides, hydroxyl group-containing polyacetals and hydroxyl-containing ali phatic polycarbonates or mixtures of at least two of the polyols mentioned. The hydroxyl number of the Polyhydroxyl compounds are usually 20 to 80 and preferably 28 to 56.

The polyether polyols used in components (b) and (c) are by known methods, for example by anionic Polymerization with alkali hydroxides, such as. B. sodium or Potassium hydroxide, or alkali alcoholates, such as. B. sodium methylate, Sodium or potassium ethylate or potassium isopropylate as kata lysators and with the addition of at least one starter molecule, the  2 to 8, preferably 2 to 3, reactive hydrogen atoms bound contains, or by cationic polymerization with Lewis acids, such as antimony pentachloride, boron fluoride etherate and the like. a., or bleach earth, (as catalysts from one or more alkylene oxides with 2 to 4 carbon atoms in the alkylene radical. For monofunctional starters can also be used for special purposes the polyether structure can be integrated.

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 one after the other or as mixtures be used.

Examples of suitable starter molecules are: water, organic dicarboxylic acids, such as succinic acid, adipic acid, Phthalic acid and terephthalic acid, aliphatic and aromatic, optionally N-mono-, N, N- and N, N'-dialkyl substituted Diamines with 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-hexa methylenediamine, phenylenediamine, 2,3-, 2,4- and 2,6-toluenediamine and 4,4 ', 2,4'- and 2,2'-diaminodiphenylmethane. As a starter Molecules are also suitable: alkanolamines, such as. B. Ethanolamine, N-methyl- and N-ethylethanolamine, dialkanolamines, such as B. diethanolamine, N-methyl and N-ethyldiethanolamine, and Trialkanolamines, such as. B. triethanolamine, and ammonia. Preferential wise are used, especially two and / or trihydric alcohols, such as ethanediol, 1,2-propanediol and 2,3, Diethylene glycol, dipropylene glycol, 1,4-butanediol, 1,6-hexanediol, Glycerin, trimethylolpropane, pentaerythritol. Particularly suitable for the proposed application, polyetherols are on Basis of propylene and / or ethylene oxide, optionally also Butylene oxide made using castor oil as a starter getting produced.

Polymer-modified are also suitable as polyether polyols Polyether polyols, preferably graft polyether polyols, ins especially those based on styrene and / or acrylonitrile by in situ polymerization of acrylonitrile, styrene or preferably mixtures of styrene and acrylonitrile, e.g. B. in Weight ratio 90: 10 to 10: 90, preferably 70: 30 to 30: 70, expediently analog in the aforementioned polyether polyols the details of German patent specifications 11 11 394, 12 22 669 (US 3304273, 3383351, 3523093), 11 52 536 (GB 1040452) and 11 52 537 (GB 987618) are produced, and polyether polyol  dispersions as a disperse phase, usually in a Amount of 1 to 50 wt .-%, preferably 2 to 25 wt .-% ent hold: e.g. B. polyureas, polyhydrazides, tert-amino groups bound containing polyurethanes and / or melamine and the z. B. are described in EP-B-011752 (US 4304708), US-A-4374209 and DE-A-32 31 497.

The polyether polyols can be used individually or in the form of mixtures be used.

Suitable polyester polyols can, for example, from organic Dicarboxylic acids with 2 to 12 carbon atoms, preferably ali phatic dicarboxylic acids with 4 to 6 carbon atoms, more valuable alcohols, preferably diols, with 2 to 12 carbons atoms, preferably 2 to 6 carbon atoms usual procedures are produced. Usually the organic polycarboxylic acids and / or derivatives and polyvalent Alcohols, advantageously in a molar ratio of 1: 1 to 1.8, preferably from 1: 1.05 to 1.2, catalyst-free or preferred wise in the presence of esterification catalysts, more appropriate as in an atmosphere of inert gas, such as. B. nitrogen, Carbon monoxide, helium, argon and the like. a., in the melt at tempera tures of 150 to 250 ° C, preferably 180 to 220 ° C, given if under reduced pressure up to the desired acid number, which are advantageously less than 10, preferably less than 2 is polycondensed.

The polyurethane foams can be used with or without of chain extenders and / or crosslinking agents are, but these are usually not required. Used as a chain extender and / or crosslinking agent diols and / or triols with molecular weights smaller than 400, preferably 60 to 300. For example aliphatic, cycloaliphatic and / or araliphatic diols with 2 to 14, preferably 4 to 10 carbon atoms, such as. B. Ethylene glycol, 1,3-propanediol, 1,10-decanediol, o-, m-, p-di hydroxycyclohexane, diethylene glycol, dipropylene glycol and preferred 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-containing polyalkylene oxides Based on ethylene and / or 1,2-propylene oxide and the aforementioned Diols and / or triols as starter molecules.

If chains are used to manufacture the polyurethane foams extenders, crosslinking agents or mixtures thereof Find application, they are expediently in a quantity  up to 5% by weight, based on the weight of the polyol compounds, for use.

As blowing agent (d) from polyurethane chemistry all Commonly known chlorofluorocarbons (CFCs) and highly and / or perfluorinated hydrocarbons can be used. The However, the use of these substances becomes strong for ecological reasons restricted or completely discontinued. In addition to HCFC and HFC offer in particular aliphatic and / or cycloaliphatic Hydrocarbons, especially pentane and cyclopentane, or Acetals such as B. methylal, as an alternative blowing agent. This Physical blowing agents are usually the polyol component of the system added. However, you can also in the isocyanate component or as a combination of both the polyol component and the isocyanate component are added. It is also possible to use them together with high and / or perfluorinated hydrocarbons in the form of an emulsion of Polyol component. As emulsifiers, if they are used, are usually oligomeric acrylates used as Side groups bound polyoxyalkylene and fluoroalkane contain and a fluorine content of about 5 to 30 wt .-% exhibit. Such products are from plastic chemistry well known, e.g. B. from EP-A-351614.

The amount of blowing agent or blowing agents used mixture is 1 to 25 wt .-%, preferably 1 to 15% by weight, based on the total weight of the components (b) to (f).

It is also possible and customary, particularly in soft foam, as a blowing agent of the polyol component water in an amount from 0.5 to 15% by weight, preferably 1 to 5% by weight add to the total weight of components (b) to (f). The water additive can be used in combination with the other described blowing agents take place.

As catalysts (e) for the production of polyurethane foam Compounds are used in particular that the Reaction of the reactive hydrogen atoms, especially hydroxyl group-containing compounds of components (b) and (c), with the organic, optionally modified polyisocyanates (a) speed up hard. Organic metals can be considered compounds, preferably organic tin compounds, such as Tin (II) salts of organic carboxylic acids, e.g. B. Tin (II) - acetate, tin (II) octoate, tin (II) ethylhexoate and tin (II) - laurat, and the dialkyltin (IV) salts of organic carbon acids, e.g. B. dibutyltin diacetate, dibutyltin dilaurate, dibutyl  tin maleate and dioctyltin diacetate. The organic metaliver bonds are used alone or preferably in combination with strongly basic amines. For example Amidines such as 2,3-dimethyl-3,4,5,6-tetrahydropyrimidine, tertiary Amines, such as triethylamine, tributylamine, dimethylbenzylamine, N-methyl, N-ethyl, N-cyclohexylmorpholine, N, N, N ', N'-tetra methyl ethylenediamine, N, N, N ', N'-tetramethylbutanediamine, N, N, N', N'- Tetramethyl-hexanediamine-1,6, pentamethyldiethylenetriamine, tetra methyldiaminoethyl ether, bis (dimethylaminopropyl) urea, Dimethylpiperazine, 1,2-dimethylimidazole, 1-azabicyclo- (3,3,0) - octane and preferably 1,4-diazabicyclo (2,2,2) octane, and amino alkanol compounds, such as triethanolamine, triisopropanolamine, N-methyl and N-ethyldiethanolamine and dimethylethanolamine. As Catalysts are also suitable: tris (dialkylamino alkyl) -s-hexahydrotriazines, especially tris- (N, N-dimethylamino propyl) -s-hexahydrotriazine, tetraalkylammonium hydroxides, such as Tetramethylammonium hydroxide, alkali hydroxide such as sodium hydroxide, and alkali alcoholates, such as sodium methylate and potassium isopropylate, and alkali salts of long-chain fatty acids with 10 to 20 carbon atoms and possibly pendant OH groups. 0.001 to 5% by weight are preferably used, in particular 0.05 to 2% by weight of catalyst or catalyst combination, based on the total weight of components (b) to (f).

The reaction mixture for the preparation of the invention sound absorbing polyurethane foams can be given if other aids and / or additives (f) be loved. Examples include surface-active ones Substances, foam stabilizers, cell regulators, fillers, colors substances, pigments, flame retardants, hydrolysis protection agents, fungistatic and bacteriostatic substances.

Suitable flame retardants are, for example, tricresyl phosphate, tris (2-chloroethyl) phosphate, tris (2-chloropropyl) - phosphate, tetrakis (2-chloroethyl) ethylene diphosphate, dimethyl methanephosphonate, diethanolaminomethylphosphonic acid diethyl ester as well as commercially available halogen-containing flame retardant polyols. Except the halogen-substituted phosphates already mentioned also inorganic or organic flame retardants, such as red phosphorus, aluminum oxide hydrate, antimony trioxide, arsenic oxide, Ammonium polyphosphate and calcium sulfate, expandable graphite or cyanur acid derivatives, such as. B. melamine, or mixtures of at least two flame retardants such as B. ammonium polyphosphates and Melamine and optionally corn starch or ammonium poly phosphate, melamine and expandable graphite and / or optionally aromatic polyester to flame retard the polyisocyanate polyaddition products are used. Particularly effective  Additions to melamine have been found. Generally it has proved to be expedient, 5 to 50 parts by weight, preferably 5 to 25 parts by weight of the flame retardants mentioned for each Use 100 parts by weight of components (b) to (f).

As surface-active substances such. B. Connections in Consider which to support the homogenization of the Aus serve and are also suitable, if necessary, the Regulate cell structure of plastics. May be mentioned at for example emulsifiers, such as the sodium salts of castor oil sulfates or fatty acids and salts of fatty acids with amines, e.g. B. oleic acid diethylamine, stearic acid diethanolamine, ricinol acidic diethanolamine, salts of sulfonic acids, e.g. B. alkali or Ammonium salts of dodecylbenzene or dinaphthylmethane disulfone acid and ricinoleic acid; Foam stabilizers, such as siloxane oxalkylene copolymers and other organopolylsiloxanes, ethoxylated alkylphenols, ethoxylated fatty alcohols, paraffin oils, castor oil or ricinoleic acid esters, Turkish red oil and earth nut oil, and cell regulators such as paraffins, fatty alcohols and dimethyl polysiloxanes. The surface-active substances are becoming more common wise in amounts of 0.01 to 5 parts by weight, based on 100 parts by weight Parts of components (b) to (f) applied.

As fillers, especially reinforcing fillers substances are the usual organic and known per se inorganic fillers, reinforcing agents, weighting agents, Agents for improving the abrasion behavior in paints, Understand coating agents, etc. In particular, be with Playfully called: inorganic fillers, such as silicate Minerals, for example layered silicates, such as antigorite, Serpentine, hornblende, ampibole, chrisotile and talc, metal oxides, such as kaolin, aluminum oxides, titanium oxides and iron oxides, Metal salts such as chalk, heavy spar and inorganic pigments, such as cadmium sulfide and zinc sulfide, and glass and. a. Preferably Kaolin (China Clay), aluminum silicate and Coprecipitates from barium sulfate and aluminum silicate as well as natural liche and synthetic fibrous minerals, such as wollastonite, Metal and in particular glass fibers of different lengths, the can optionally be arbitrated. As an organic filling For example, substances are considered: coal, rosin, Cyclopentadienyl resins and graft polymers as well as cellulose fibers, polyamide, polyacrylonitrile, polyurethane, polyester fibers based on aromatic and / or aliphatic Dicarboxylic acid esters and especially carbon fibers. The inorganic and organic fillers can be used individually or as Mixtures are used and are the reaction mixture before advantageously in amounts of 0.5 to 50% by weight  1 to 40 wt .-%, based on the total weight of the components (b) to (f), but the content of mats, Nonwovens and fabrics made from natural and synthetic fibers Can reach values up to 80.

Details of the other usual auxiliary and additives are in the specialist literature, for example the Monograph by J. H. Saunders and K. C. Frisch "High Polymers" Volume XVI, Polyurethanes, Parts 1 and 2, Verlag Interscience Publishers 1962 or 1964, or the plastic cited above manual, Polyurethane, Volume VII, Hanser-Verlag Munich, Vienna, 1. up to 3rd edition.

To produce the sound-absorbing PUR Foams become the organic and / or modified organic Polyisocyanates (a), the polyether mixture (b) and given if further isocyanate-reactive hydrogen atoms having compounds (c) in such amounts for reaction brought that the equivalence ratio of NCO groups of Polyisocyanates (a) to the sum of the reactive hydrogen atoms of components (b) and optionally (c) 0.70 to 1.25: 1, preferably 0.90 to 1.15: 1.

PUR foams according to the inventive method are before partly by the one-shot method, for example with Help of high pressure or low pressure technology in open or closed molds, for example metallic mold tools manufactured. Continuous is also common Application of the reaction mixture on suitable belt lines for the generation of foam blocks.

After two, it has proven to be particularly advantageous component process to work and the assembly components (b) to (f) to a so-called polyol component, often also as Component A referred to combine and as isocyanate component, often referred to as component B, the organic and / or modified organic polyisocyanates (a), especially preferably an NCO prepolymer or mixtures of this pre polymeric and other polyisocyanates, and optionally To use blowing agent (d).

The starting components are at a temperature of 15 to 90 ° C, preferably from 20 to 60 ° C and in particular from 20 to 35 ° C, mixed and in the open or optionally under it introduced high pressure in the closed mold or in a continuous work station on a belt that absorbs the reaction mass, applied. The mixing can  mechanically using a stirrer, using a stirring screw or carried out by high pressure mixing in a nozzle become. The mold temperature is expediently 20 up to 110 ° C, preferably 30 to 60 ° C and in particular 35 to 55 ° C.

The PUR foams (acoustic foams) produced by the process according to the invention have a density of 10 to 800 kg / m ³ , preferably of 60 to 100 kg / m ³ . They are particularly suitable as a material for sound insulation purposes.

The present invention is based on the examples given are explained, but without a corresponding one limit.

Examples

A polyol composition - see Table 1 - was with a Prepolymers based on diphenylmethane diisocyanate (MDI) - Derivatives and a polyetherol based on ethylene oxide and Propylene oxide with an NCO content of 28.9% by weight at each specified key figure (KZ) foamed.

Table 1

Composition of acoustic foams

Lupranol® 2040 OH number 28 mg KOH / g, polyether alcohol based on propylene and ethylene oxide (BASF),
Lupranol® 2043 OH number 29 mg KOH / g, polyether alcohol based on propylene and ethylene oxide (BASF),
Lupranol® 2042 OH number 27 mg KOH / g, polyether alcohol based on propylene and ethylene oxide (BASF),
Lupranol® 2047 OH number 42 mg KOH / g, polyether alcohol based on propylene and ethylene oxide (81% by weight) (BASF),
Lupranol® 1200 OH number 250 mg KOH / g, polyether alcohol based on propylene oxide (BASF),
Lupranol® 4100 OH number 25 mg KOH / g, graft polyether alcohol (BASF),
Lupragen® N 201 amine catalyst (BASF),
Lupragen® N 206 amine catalyst (BASF),
B 8680, B 8631 silicone stabilizer (Goldschmidt),
SH 209 silicone stabilizers (OSi),
Polyol A test product - OH number 150 mg KOH / g, polyether alcohol based on castor oil ethylene oxide (BASF),
Polyol B test product - OH number 110 mg KOH / g, polyether alcohol based on castor oil ethylene oxide (BASF),
Polyol C test product - OH number 87 mg KOH / g, polyether alcohol based on castor oil ethylene oxide (BASF),
Polyol D test product - OH number 145 mg KOH / g, polyether alcohol based on castor oil and propylene and ethylene oxide (BASF).

The characteristic values of the acoustic foams obtained are in Table 2 summarized.  

Table 2

Characteristic values of acoustic foams

The acoustic foams based on the castor oil derivatives or their Combination with castor oil have a very good foam structure and a good flow behavior. By using after growing raw materials can also sustainably protect the environment become.

Claims (14)

1. Process for the preparation of flexible polyurethane foam materials with sound-absorbing properties by reacting organic and / or modified organic poly isocyanates (a) with a polyether mixture (b) and, if appropriate, further compounds (c) which are reactive toward isocyanates in the presence of water and / or other blowing agents (d), catalysts (e) and optionally further auxiliaries and additives (f), characterized in that the polyether mixture (b) consists of

• 1. at least one two- to eight-functional polyetherol based on ethylene oxide and propylene oxide and optionally butylene oxide with an OH number of 20 to 80 mg KOH / g and a proportion of primary OH groups greater than 50% and
• 2. at least one castor oil polyetherol based on ethylene oxide and optionally propylene oxide and / or butylene oxide with an OH number of 50 to 160 mg KOH / g.

2. The method according to claim 1, characterized in that b) contains pure castor oil b3). 3. The method according to any one of claims 1 to 2, characterized records that b) at least one other polyetherol b4) the base of propylene oxide and optionally ethylene oxide a proportion of primary OH groups of less than 20% holds. 4. The method according to any one of claims 1 to 3, characterized records that b1) a proportion of primary OH groups larger than 70%. 5. The method according to any one of claims 1 to 4, characterized records that b2) has an OH number of 80 to 160 mg KOH / g has. 6. The method according to any one of claims 1 to 5, characterized records that b2) by adding ethylene oxide to castor oil will be produced.   7. The method according to any one of claims 1 to 6, characterized records that b2) in proportions of 1 to 70 wt .-%, preferably example from 10 to 40 wt .-%, based on the total weight component b) is used. 8. The method according to any one of claims 1 to 7, characterized records that b1) in proportions of 20 to 70 wt .-%, preferably as from 30 to 60 wt .-%, each based on the total weight of component b) is used. 9. The method according to any one of claims 1 to 8, characterized records that b3) in proportions of 0.5 to 10 wt .-%, preferably as from 0.5 to 6 wt .-%, each based on the total weight of component b) is used. 10. The method according to any one of claims 1 to 9, characterized records that b4) in proportions of 0.5 to 7 wt .-%, preferably as from 0.5 to 5 wt .-%, each based on the total weight of component b) is used. 11. The method according to any one of claims 1 to 10, characterized records that as organic and / or modified organic Polyisocyanates tolylene diisocyanate, mixtures of diphenyl methane diisocyanate isomers, mixtures of diphenylmethane diiso cyanate and polyphenylpolymethyl polyisocyanate or toluene diisocyanate with diphenylmethane diisocyanate and / or poly phenylpolymethyl polyisocyanate can be used. 12.Soft polyurethane foams with sound-absorbing properties, which can be produced by reacting organic and / or modified organic polyisocyanates (a) with a polyether mixture (b) and, if appropriate, other compounds which are reactive toward isocyanates (c) in the presence of water and / or other blowing agents ( d), catalysts (e) and optionally further auxiliaries and additives (f), characterized in that the polyether mixture (b) consists of

• 1. at least one two- to eight-functional polyetherol based on ethylene oxide and propylene oxide and optionally butylene oxide with an OH number of 20 to 80 mg KOH / g and a proportion of primary OH groups greater than 50% and
• 2. at least one castor oil polyetherol based on ethylene oxide and optionally propylene oxide and / or butylene oxide with an OH number of 50 to 160 mg KOH / g.

13. Flexible polyurethane foams with sound-absorbing properties shafts according to claim 12, characterized in that they have a loss factor of 0.20 to 0.50. 14. Use of flexible polyurethane foams with sound damping properties according to one of claims 12 or 13 as damping material.