EP4323420A1

EP4323420A1 - Production of hard polyurethane or polyisocyanurate foam

Info

Publication number: EP4323420A1
Application number: EP22716950.5A
Authority: EP
Inventors: Martin Glos; Jobst Grimminger
Original assignee: Evonik Operations GmbH
Current assignee: Evonik Operations GmbH
Priority date: 2021-04-14
Filing date: 2022-03-22
Publication date: 2024-02-21
Also published as: WO2022218657A1; KR20230169180A; CA3208550A1; JP2024514003A; CN117120500A

Abstract

The invention relates to a composition for producing hard polyurethane or polyisocyanurate foam, comprising at least one isocyanate component, a polyol component, optionally a foam stabilizer, and optionally blowing agents, wherein the composition contains at least one catalyst that catalyzes the formation of a urethane or isocyanurate bond, said catalyst comprising zinc salts and/or a zinc-containing preparation.

Description

Production of rigid polyurethane or polyisocyanurate foam

The present invention is in the field of polyurethanes (PU) and polyisocyanurates (PIR), in particular PU or PIR rigid foams. In particular, it relates to the production of PU or PIR rigid foams using zinc salts, and also to the use of the foams that have been produced therewith. In the context of the present invention, these are PU or PIR rigid foams.

In the context of the present invention, polyurethane (PU) is understood in particular as meaning a product obtainable by reaction of polyisocyanates and polyols or compounds having isocyanate-reactive groups. In addition to the polyurethane, other functional groups can also be formed, such as uretdiones, carbodiimides, isocyanurates, allophanates, biurets, ureas and/or uretimines. For the purposes of the present invention, PU is therefore understood to mean both polyurethane and polyisocyanurate, polyureas and polyisocyanate reaction products containing uretdione, carbodiimide, allophanate, biuret and uretimine groups. In the context of the present invention, polyurethane foam (PU foam) is understood to mean, in particular, foam which is obtained as a reaction product based on polyisocyanates and polyols or compounds with isocyanate-reactive groups. In addition to the polyurethane that gives the product its name, other functional groups can also be formed, such as allophanates, biurets, ureas, carbodiimides, uretdiones, isocyanurates or uretimines.

In the context of the present invention, the formation of polyisocyanurates is particularly important. This reaction is known as trimerization, since formally three isocyanate groups react to form an isocyanurate ring. The production of PIR rigid foam is described in the literature and is usually carried out by reacting polyisocyanates with compounds having hydrogen atoms which are reactive toward isocyanate groups, mostly polyether oils, polyester oils or both, the isocyanate index preferably being 180 or greater. As a result, in addition to the urethane structures that result from the reaction of isocyanates with compounds containing reactive hydrogen atoms, isocyanurate structures or other structures that result from the reaction of isocyanate groups with other groups, such as polyurethane groups, form as a result of the reaction of the isocyanate groups with one another.

Various catalysts are used in the production of rigid polyurethane and polyisocyanurate foams in order to positively influence the foaming reaction profile and the performance properties of the foam. The formation of polyisocyanurates is advantageous here, since these lead to good mechanical properties (high compression hardness) and improved flame-retardant properties. Various publications relating to the use of catalysts to improve compression hardness by supporting the trimerization reaction in the production of PU or PIR rigid foams are known.

EP 1878493 A1 describes the use of carbocation compounds as trimerization catalysts, the anions being based on di-carbonyl compounds. The use of zinc carboxylates is not described.

US Pat. No. 4,452,829 describes the production of spray foam using triols with molar masses of more than 1000 g/mol. Here, Zn salts are used in combination with K salts to accelerate the creaming, i.e. the start of the PU reaction with water. A Zn-containing catalyst (zinc octoate) is added to a K-containing catalyst in order to shorten the creaming time, i.e. to accelerate the reaction.

US Pat. No. 4,200,699 describes gel catalyst compositions for the production of rigid PU foams containing Zn, K and Sb carboxylates, with another gel catalyst from the group consisting of tertiary amines, inorganic tin compounds or organotin compounds preferably being used.

EP 1745847 A1 describes trimerization catalysts based on potassium octoate and solvents which are inert to the reaction with isocyanates.

WO 2016/201675 describes trimerization catalysts consisting of compositions based on sterically hindered carboxylates and tert. Amines bearing an isocyanate-reactive group.

WO 2010/054317 describes iminium salts as trimerization catalysts.

WO 2013/074907 A1 describes the use of tetraalkylguanidine salts of aromatic carboxylic acids as catalysts for polyurethane foams.

The object of the present invention was to make it possible to provide rigid polyurethane or polyisocyanurate foams which have particularly advantageous performance properties, such as in particular good compression hardness and/or indentation hardness after a short reaction time. However, the influence on the climbing profile should preferably be kept as low as possible.

Surprisingly, it has now been found that the use of zinc salts and/or zinc-containing preparations makes it possible to solve this problem. The present invention is therefore a composition for the production of rigid polyurethane or polyisocyanurate foam, comprising at least one isocyanate component, a polyol component, optionally a foam stabilizer, optionally blowing agent, the composition containing at least one catalyst which forms a urethane or isocyanurate - Bond catalyzed, contains, and wherein this catalyst comprises zinc salts and / or a zinc-containing preparation.

For the purposes of this invention, a zinc-containing preparation is a preparation that contains zinc. A preparation, in turn, is a mixture, mixture or solution that consists of two or more substances. A zinc-containing preparation within the meaning of this invention is therefore a preparation that contains zinc and at least one other component.

This zinc-containing preparation can include any other components, but preferably solvents and at least one nitrogen-containing compound.

Solvents and the at least one nitrogen-containing compound are described in more detail below. A preferred zinc-containing preparation within the meaning of this invention therefore includes zinc salts, solvents and at least one nitrogen-containing compound, in particular as defined further below.

It has been found that the use of compositions according to the invention in the production of PU or PIR rigid foam leads to corresponding rigid foams with improved performance properties. In particular, the trimming is improved, as a result of which the foams harden quickly, ie already have a high compressive strength and high indentation hardness at an early point in time. A particular advantage of the invention lies in the fact that the use of the compositions according to the invention nevertheless makes it possible for the influence on the climbing profile to be kept as low as possible. This is very advantageous, since otherwise one can have problems with the flowability of the reaction mixture, which leads to significant processing problems. With the compositions according to the invention, the rise profiles can also be slowed down, if necessary, which opens up a wide range of options for adapting the reactivity of a foam system.

The effect that a PU reaction can be slowed down by adding zinc-containing compounds is surprising and new. According to the prior art, zinc-containing compounds for accelerating the reaction therefore lead to shorter cream or gel times, as described, for example, in US Pat. No. 4,428,29.

With the solution according to the invention, PU or PIR rigid foam-based products such as, for example, insulation panels or refrigerated cabinets can thus be produced with a particularly high quality, and the processes for producing the PU or PIR rigid foams can be made more efficient. An additional advantage of the invention is the good ecotoxicological classification of the chemicals that can be used, in particular the zinc salts or zinc-containing preparation. This is because metal compounds with problematic toxicological properties (Sn, Pb, etc.) are often used in the prior art.

The invention has the further advantage that it can be used to produce PU or PIR rigid foams which have few foam defects.

According to a preferred embodiment of the invention, the zinc salts and/or zinc-containing preparations comprise zinc(II) salts, preferably zinc(II) carboxylates, where the carboxylates are based on carboxylic acids containing 1 to 34 carbons, which can also contain unsaturated or aromatic units, in particular comprising zinc(II) acetate, zinc(II) propionate, zinc(II) pivalate, zinc(II) 2-ethylhexanoate (zinc(II) octoate), zinc(II) isononanoate (zinc(II )-3,5,5- trimethylhexanoate), zinc(II) neodecanoate, zinc(II) ricinoleate, zinc(II) palmitate, zinc(II) stearate, zinc(II) oleate, zinc(II) -laurate, zinc (II) napthenate and/or zinc (II) benzoate, with zinc (II) acetate and/or zinc (II) ricinoleate being most preferred, and/or where the carboxylates also contain N and O may have as hetero atoms, in particular comprising zinc(II) lactate, zinc(II) glycinate, zinc(II) hippurate and/or zinc(II) citrate, and/or zinc(II) soaps, such as in particular zinc oleate, zinc palmitate and/or zinc stearate .

The compositions according to the invention preferably contain the zinc carboxylate in stoichiometric form, ie Zn and carboxylate in a molar ratio of 1 to 2, ie in particular no excess of carboxylate or carboxylic acid. The acid on which it is based is often used in excess in technical production processes for zinc salts, so that the end product still contains an excess of the acid. This is not advantageous here.

The total amount of zinc salts used is preferably in the range from 0.025 to 2% by weight, preferably 0.05 to 1.6% by weight, particularly preferably 0.1 to 1.2% by weight, based on the composition as a whole.

For the purposes of the present invention, it is very particularly preferred to introduce the zinc salts and/or zinc-containing preparation for use in PU or PIR reaction mixtures in dissolved form.

Therefore, according to a preferred embodiment of the invention, the zinc salts and/or zinc-containing preparation according to the invention are added to the reaction mixture in a carrier medium or the zinc-containing preparation preferably comprises a carrier medium. The terms carrier medium and solvent are used synonymously in the context of this invention. In particular, a preferred zinc-containing preparation comprises zinc salts, preferably zinc(II) salts, in particular zinc(II) carboxylate, in a carrier medium, in particular comprising glycols, alkoxylates and/or oils of synthetic and/or natural origin. This corresponds to a preferred embodiment of the invention.

In principle, all substances suitable as solvents can be used as carrier media. For example, glycols, alkoxylates and/or oils of synthetic and/or natural origin are preferably used. Protic or aprotic solvents can be used.

The zinc-containing preparations according to the invention can also be used as part of compositions with various carrier media.

The use of the carrier media is preferred in order to provide a zinc-containing preparation that can be used in an uncomplicated manner. The lowest possible viscosity is preferred here, so that the preparation does not make any special demands on pumps or other technical equipment for processing. Preferred viscosities are less than 10 Pas, preferably less than 8 Pas, particularly preferably less than 6 Pas, measured at 25° C. by the Hoppler method described in DIN 53655.

Furthermore, it is very particularly preferred for the purposes of the present invention if the composition according to the invention additionally contains at least one nitrogen-containing compound. This can optimally support the solubility of the zinc salt in the respective carrier medium. Amines, amine alkoxylates, amino acids and/or amines with several acid functions can preferably be used here, but in particular N,N,N',N'-tetrakis(2-hydroxypropyl)ethylenediamine, N,N,N', N'-tetrakis(2-hydroxyethyl)ethylenediamine, 2-[[2-[2-(dimethylamino)ethoxy]ethyl]methylamino]ethanol, fatty amine ethoxylates such as tallow fatty amine ethoxylate, cocoamine ethoxylate, cetyl/stearyl Amine ethoxylate, PEG-3-tallow-aminopropylamine, PPG-3-tallow-aminopropylamine, glycine, lysine, arginine, sarcosine, ethylenediaminetetraacetate and/or ethylenediaminetriacetate-cocoalkylacetamide, fatty amine alkoxylates being particularly preferred, the at least one nitrogen containing compound is contained in particular in the zinc-containing preparation. N,N,N',N'-tetrakis(2-hydroxypropyl)ethylenediamine and/or N,N,N',N'-tetrakis(2-hydroxyethyl)ethylenediamine are most preferred.

These nitrogen-containing compounds that can also be used are preferably present in amounts of 0.01 to 3% by weight, preferably 0.02 to 2% by weight, particularly preferably 0.1 to 1.5% by weight, based on the entire composition according to the invention.

A very particularly preferred zinc-containing preparation therefore includes (a) Zinc salt (preferably zinc(II) salt, in particular zinc(II) carboxylate, in particular as described above,

(b) carrier medium (in particular comprising glycols, alkoxylates or oils of synthetic and/or natural origin) and

(c) Nitrogen-containing compound, in particular as described above, wherein the nitrogen-containing compound is N,N,N',N'-tetrakis(2-hydroxypropyl)ethylenediamine and/or N,N,N',N'-tetrakis(2 -hydroxyethyl)ethylenediamine are very particularly preferred.

Furthermore, it corresponds to a preferred embodiment of the invention if at least one additional trimerization catalyst is additionally contained in the composition according to the invention. The additional trimerization catalysts as such do not themselves contain any zinc, but are additionally added according to a preferred embodiment of the invention.

If desired, the reaction rate can be adjusted to the desired extent with the additional trimerization catalysts. The additional trimerization catalyst can also be part of the zinc-containing preparation, which corresponds to a preferred embodiment. In another preferred embodiment, it is not a component of the zinc-containing preparation but is added separately to the composition according to the invention.

In principle, all known trimerization catalysts can be used. Particularly suitable additional trimerization catalysts are, for example, carboxylates of ammonium cations such as tetramethylammonium, tetraethylammonium, tetrapropylammonium, tetrabutylammonium, dimethyldiallylammonium, trimethyl-(2-hydroxypropyl)ammonium, triethyl-(2-hydroxypropyl)ammonium, tripropyl-(2-hydroxypropyl)ammonium, Tributyl-(2-hydroxypropyl) ammonium, Trimethyl-(2-hydroxyethyl) ammonium, Triethyl-(2-hydroxyethyl) ammonium, Tripropyl-(2-hydroxyethyl) ammonium, Tributyl-(2-hydroxyethyl) ammonium, dimethylbenzyl-(2- hydroxyethyl) ammonium, dimethylbenzyl-(2-hydroxypropyl) ammonium, or the like. Also suitable as cations are potassium or other alkali or alkaline earth metals, in particular as described in the documents EP1 745 847 A1 and WO 2016/201675 and the citations contained therein. A potassium carboxylate, in particular potassium acetate, potassium formate, potassium propionate, potassium butanoate, potassium pentanoate, potassium hexanoate, potassium heptanoate, potassium 2-ethylhexanoate, potassium pivalate, potassium octoate, potassium butyrate, potassium isobutyrate, potassium nonanoate, potassium decanoate, potassium ricinoleate, potassium stearate and/or potassium neodecanoate is preferably used .

A preferred composition according to the invention comprises additional trimerization catalysts in amounts of from 0.2 to 9% by weight, preferably from 0.5 to 7% by weight, based on the total composition according to the invention. A preferred composition according to the invention therefore comprises zinc salt (preferably zinc(II) salt, in particular zinc(II) carboxylate, carrier medium, nitrogen-containing compound and optional (preferably obligatory) additional trimerization catalyst. It is preferred that the optional ( preferably obligatory) usable, additional trimerization catalyst is not part of the zinc-containing preparation.

Furthermore, it corresponds to a preferred embodiment of the invention if the compositions according to the invention are free from Sb carboxylates and/or Sn carboxylates.

It corresponds to a further preferred embodiment of the invention if the composition according to the invention also comprises a tertiary amine (ie additional tertiary amine) as further catalysts, these additional tertiary amines preferably containing at least 2 nitrogen atoms per molecule.

Additional tertiary amines that can be used with particular preference are selected from group 1. This group 1 consists of the following amines: pentamethyldiethylenetriamine, bis(2-dimethylaminoethyl)ether, tris(dimethylaminopropyl)amine, N-[2-[2-(dimethylamino)ethoxy]ethyl]-N-methyl-1,3- propanediamine, 2-{[2-(dimethylamino)ethyl]methylamino}ethanol, 2-[[2-[2-(dimethylamino)ethoxy]ethyl]methylamino]ethanol, N-methyl-N-(N,N- dimethylaminopropyl)aminopropanol, N-methyl-N-(N,N-dimethylaminopropyl)aminoethanol, 1-bis[3-(dimethylamino)propyl]amino]2-propanol, 1,T[[3-(dimethylamino)propyl] amino]-2-propanol, 3,3'-iminobis(N,N-dimethylpropylamine), Diisopropyltrimethyldiethylenetriamine, Bis-(dimethylaminopropyl)methylamine Trimethylaminoethyl- ethanolamine, 3-dimethylamino-N,N-dimethylpropionamide, dimethylaminopropylamine, 1-(3- Amino- propyl)pyrrolidine, 1-(2-aminoethyl)pyrrolidine, 1-(1-pyrrolidinyl)-2-propanamine, N,N-dimethyl-1-(pyrrolidin-1-yl)propan-2-amine, tris( dimethylaminopropyl)amine, N,N,N'N'-tetramethylethylenediamine, 1,3,5-tris(dimethylaminopropyl)hexahydrotriazine, N, N'-bis[3-(dimethylamino)propyl]urea, N-[3-(dimethylamino)propyl]urea, 1,3-bis(dimethylamino)propane and N,N,N'N'-tetramethylhexymethylenediamine, wherein mixtures of the aforementioned amines can also be used. This means that preferably, for example, each of the aforementioned group 1 amines or mixtures of the aforementioned group 1 amines can be used. This corresponds to a preferred embodiment of the invention.

Additional tertiary amines which can preferably be used are also tertiary amines which satisfy the structural formula (III): (Formula III) with m equals 1 or 2,

A equals O, S or NR ^e ,

R ^a , R ^b , R ^c , R ^d and R ^e are alkyl or functionalized alkyl of 1 to 20 carbons. The use of tertiary amines of the structural formula (III) corresponds to a preferred embodiment of the invention.

Other additional tertiary amines that can preferably be used satisfy the following structural formula IV, V or VI: with m equal to 1 or 2,

R ^f is H, methyl, ethyl, isopropyl, 3-hydroxypropyl, 2-hydroxypropyl, hydroxyethyl, 3-aminopropyl, 2-aminopropyl or aminoethyl, where the two radicals can be different or identical. The use of amines of the structural formula IV, V or VI corresponds to a preferred embodiment of the invention. Appropriate amine mixtures can also be used here.

The tertiary amines that can also be used, preferably as described above, in particular selected from group 1 and/or according to formula III, IV, V or VI, have the function of acting as a catalyst, while the nitrogen-containing compounds mentioned above, in particular N ,N,N',N'-tetrakis(2-hydroxypropyl)ethylenediamine and/or N,N,N',N'-tetrakis(2-hydroxyethyl)ethylenediamine, serve to further improve the solubility of the zinc salt.

A very particularly preferred composition according to the invention comprises a tertiary amine that can also be used, preferably as described above, preferably selected from Group 1 and/or according to formula III, IV, V or VI, in amounts of 0.05 to 3% by weight, preferably 0.1 to 2% by weight, based on the total composition according to the invention.

A very particularly preferred composition according to the invention thus comprises zinc salt (preferably zinc(II) salt, in particular zinc(II) carboxylate), carrier medium, nitrogen-containing compound, optional, preferably obligatory, additional trimerization catalyst and additional tertiary amine, preferably as described above , preferably selected from group 1 and/or according to formula III, IV, V or VI. It is preferred that the additional tertiary amine is not part of the zinc-containing preparation.

A very particularly preferred composition according to the invention thus comprises

(i) a zinc-containing preparation comprising zinc(II) salt, in particular zinc(II) carboxylate, carrier medium and nitrogen-containing compound, preferably as described above, and as further components the preferred composition additionally comprises additional trimerization catalyst, preferably such as previously described, and additional tertiary amine, preferably as previously described, preferably selected from group 1 and/or according to formula III, IV, V or VI.

According to a further preferred embodiment of the invention, the compositions according to the invention additionally contain salts of amino acids and/or amino acid derivatives.

These salts of amino acids or amino acid derivatives can be formally derived from the reaction of aromatic carboxylic acids and amino acids, in particular they can also be obtained by reacting amino acids and aromatic carboxylic acids, aromatic carboxylic acid esters, aromatic carboxylic acid halides and/or aromatic carboxylic acid anhydrides, which is a preferred embodiment of the Invention corresponds. The conversion into the salt can be carried out by conventional methods, for example by reaction with conventional bases such as KOH, NaOH or corresponding ammonium hydroxides.

Particularly preferred salts of amino acids or amino acid derivatives according to the invention satisfy the following formula (I) wherein

R ³ is an aromatic radical, possibly a polynuclear aromatic radical, which can have substitutions, optionally also further carboxy functions to which further amino acids can be attached, R ³ preferably is,

R ¹ , R ² , R ⁴ are independently H, Ci to Cie alkyl, alkenyl, aryl or alkylaryl, which can also be substituted,

M ⁺ represents a cation, such as preferably alkali metal cation or ammonium cation or a substituted ammonium cation, preferably Li ⁺ , Na ⁺ , K ⁺ , Rb ⁺ , Cs ⁺ or ammonium compounds such as advantageously tetraalkylammonium, trialkylhydroxyalkylammonium, benzyltrialkylammonium, Tetramethylammonium, Tetraethylammonium, Tetrabutylammonium, Tetrapropylammonium, dimethyldiallylammonium, Trimethyl(2-hydroxypropyl)ammonium, Triethyl(2-hydroxypropyl)ammonium, Tripropyl(2-hydroxypropyl)ammonium, Tributyl(2-hydroxypropyl)ammonium, dimethylbenzyl(2-hydroxypropyl) ammonium or dimethylbenzyl(2-hydroxyethyl)ammonium and combinations thereof.

It is particularly preferred that R ³ is phenyl, alkyl-phenyl, or is a radical derived from phthalic acid, isophthalic acid, terephthalic acid or pyrrometic acid.

A particularly preferred embodiment is when the salts of amino acid derivatives satisfy the following formula (II), With

R ¹ , R ² , M ⁺ as defined above, wherein preferably R ² are each H, more preferably R ¹ and R ² are each H, wherein in particular R ¹ and R ² are each H and M ⁺ is Na ⁺ , K ⁺ or NRV stands,

R ¹ as previously defined. Accordingly, particularly preferred structures are: With

M ⁺ and R ¹ as previously defined.

The salts of hippuric acid are particularly preferred With

M ⁺ as defined above, preferably sodium, potassium or ammonium as cation, particularly preferably the sodium salt

The salts which can be used according to the invention can be prepared by known methods.

Hippuric acid and its salts are commercially available. The preparation is known to those skilled in the art. For example, hippuric acid can be produced by reacting benzoyl chloride with glycine (Schotten Baumann method). The amidation can also be based on benzoic acid ester (methyl ester) and glycine. The salts are then prepared, for example, using the appropriate bases such as, for example, KOH, NaOH or appropriate ammonium hydroxides.

A preferred composition according to the invention can comprise the salts of amino acids and/or amino acid derivatives that can also be used in amounts of 2 to 50% by weight, preferably 4 to 45% by weight, based on the entire composition according to the invention. Technical quality is often sufficient for use in PU or PIR foams, since any secondary components from the manufacturing processes do not affect the foam production. This is another significant advantage of the invention.

According to a preferred embodiment of the invention, the salts of amino acids and/or amino acid derivatives can be added to the reaction mixture in a carrier medium. All substances suitable as solvents can be used as carrier media. For example, glycols, alkoxylates or oils of synthetic and/or natural origin are suitable. The use of a carrier medium for the salts of amino acid derivatives corresponds to a preferred embodiment of the invention. The salts according to the invention can also be used as part of compositions with various carrier media.

It corresponds to a preferred embodiment of the invention if the total mass fraction of zinc-containing preparation according to the invention in the finished polyurethane foam is from 0.01 to 10% by weight, preferably from 0.1 to 5% by weight.

It corresponds to a preferred embodiment of the invention if the composition according to the invention comprises water and/or blowing agent, optionally at least one flame retardant and/or further additives which can be used advantageously in the production of rigid polyurethane or polyisocyanurate foam. In addition to the zinc-containing preparation according to the invention, other catalysts can also be present.

A particularly preferred composition according to the invention contains the following components: a) at least one isocyanate-reactive component, in particular polyols, b) at least one polyisocyanate and/or polyisocyanate prepolymer, c) a catalyst according to the invention as described above (in particular zinc-containing preparation according to the invention) , d) (optional) further catalysts, e) (optional) a foam-stabilizing component based on siloxanes or other surfactants, f) one or more blowing agents, g) further additives, fillers, flame retardants, etc.

A preferred zinc-containing preparation that can be used within the scope of this invention comprises, based on this preparation: (i) Zinc(II) carboxylate, preferably as defined above, in amounts of 2 to 50% by weight, preferably 5 to 45% by weight, particularly preferably 10 to 40% by weight,

(ii) carrier media, preferably as defined above, in amounts of 10 to 95% by weight, preferably 15 to 90% by weight, particularly preferably 20 to 70% by weight,

(iii) nitrogen-containing compound, preferably as defined above, in amounts of 1 to 70% by weight, preferably 2 to 60% by weight, particularly preferably 5 to 30% by weight,

% by weight in each case based on this total zinc-containing preparation.

A particularly preferred zinc-containing preparation that can be used within the scope of this invention comprises, based on this preparation:

(i) Zinc(II) carboxylate, preferably as defined above, in amounts of 2 to 50% by weight, preferably 5 to 45% by weight, particularly preferably 10 to 40% by weight,

(iv) Additional trimerization catalysts as defined above in amounts of 5 to 75% by weight, preferably 10 to 70% by weight, more preferably 15 to 60% by weight

% by weight in each case based on this total zinc-containing preparation.

A very particularly preferred composition according to the invention comprises the zinc-containing preparation just specified and also an additional tertiary amine, preferably as defined above, preferably selected from group 1 and/or according to formula III, IV, V or VI.

Another object of the invention is a process for producing rigid polyurethane or polyisocyanurate foam by reacting one or more polyol components with one or more isocyanate components, the reaction taking place in the presence of a catalyst which catalyzes the formation of a urethane or isocyanurate bond , wherein the catalyst comprises zinc salts and/or a zinc-containing preparation, in particular as described above, preferably using a composition according to the invention, as described above. In addition to the zinc-containing preparation according to the invention which can be used with preference, other catalysts can also be used.

It is preferred that the zinc-containing preparations are added to the reaction mixture for producing the PU or PIR rigid foam in a carrier medium, preferably comprising glycols, alkoxylates or oils of synthetic and/or natural origin.

Another object of the invention is the use of zinc salts and/or zinc-containing preparations, in particular using a composition according to the invention as above described as a catalyst in the production of rigid polyurethane or polyisocyanurate foams, preferably for improving the performance properties of the rigid polyurethane or polyisocyanurate foam, in particular for increasing the compressive strength of the rigid polyurethane or polyisocyanurate foam at an early stage, compared to polyurethane or polyisocyanurate -Rigid foams that were produced without zinc salts and/or zinc-containing preparations, compressive strength can be determined according to DIN EN ISO 844:2014-11.

A further object of the invention is a polyurethane or polyisocyanurate rigid foam obtainable by the process according to the invention, as described above.

The present invention also relates to the use of rigid polyurethane or polyisocyanurate foams according to the invention for thermal insulation purposes, preferably as insulating panels and insulating materials and for cooling apparatus which has a rigid polyurethane or polyisocyanurate foam according to the invention as insulating material.

Individual components that can be used (designated here with a) to g)) are described in more detail below. Component c) has already been described.

Polyols suitable as polyol component a) for the purposes of the present invention are all organic substances having two or more isocyanate-reactive groups, preferably OH groups, and preparations thereof. Preferred polyols are all for the production of polyurethane systems, in particular polyurethane coatings, polyurethane elastomers or foams; commonly used polyether polyols and/or polyester polyols and/or aliphatic polycarbonates containing hydroxyl groups, in particular polyether polycarbonate polyols and/or polyols of natural origin, so-called “natural oil based polyols” (NOPs). The polyols usually have a functionality of 1.8 to 8 and number-average molecular weights in the range from 500 to 15,000. The polyols with OH numbers in the range from 10 to 1200 mg KOH/g are usually used.

Polyether polyols can be used. These can be prepared by known methods, for example by anionic polymerization of alkylene oxides in the presence of alkali metal hydroxides, alkali metal alcoholates or amines as catalysts and with the addition of at least one starter molecule that preferably contains 2 or 3 reactive hydrogen atoms or by cationic polymerization of alkylene oxides in the presence of Lewis -Acids such as antimony pentachloride or boron trifluoride etherate or by double metal cyanide catalysis. Suitable alkylene oxides contain 2 to 4 carbon atoms in the alkylene radical. Examples are tetrahydrofuran, 1,3-propylene oxide, 1,2- or 2,3-butylene oxide; ethylene oxide and 1,2-propylene oxide are preferably used. The alkylene oxides can be used individually, cumulatively, in blocks, alternately one after the other, or as mixtures. In particular, compounds with at least 2, preferably 2 to 8, hydroxyl groups or with at least two primary amino groups in the molecule are used as starter molecules. Examples of starter molecules that can be used are water, di-, tri- or tetrahydric alcohols such as ethylene glycol, 1,2- and 1,3-propanediol, diethylene glycol, dipropylene glycol, glycerol, trimethylolpropane, pentaerythritol, castor oil, etc., higher polyfunctional alcohols Polyols, in particular sugar compounds such as glucose, sorbitol, mannitol and sucrose, polyhydric phenols, resols such as oligomer condensation products of phenol and formaldehyde and Mannich condensates of phenols, formaldehyde and dialkanolamines and melamine, or amines such as aniline, EDA, TDA, MDA and PMDA, particularly preferably TDA and PMDA. The selection of the suitable starter molecule depends on the respective field of application of the resulting polyether polyol in the production of polyurethane.

Polyester polyols can be used. These are based on esters of polybasic aliphatic or aromatic carboxylic acids, preferably with 2 to 12 carbon atoms. Examples of aliphatic carboxylic acids are succinic acid, glutaric acid, adipic acid, suberic acid, azelaic acid, sebacic acid, decanedioic acid, maleic acid and fumaric acid. Examples of aromatic carboxylic acids are phthalic acid, isophthalic acid, terephthalic acid and the isomeric naphthalenedicarboxylic acids. The polyester polyols are obtained by condensing these polybasic carboxylic acids with polyhydric alcohols, preferably diols or triols having 2 to 12, particularly preferably 2 to 6, carbon atoms, preferably trimethylolpropane and glycerol.

Polyether polycarbonate polyols can be used. These are polyols containing carbon dioxide bound as a carbonate. Since carbon dioxide is produced in large quantities as a by-product in many processes in the chemical industry, the use of carbon dioxide as a comonomer in alkylene oxide polymerizations is of particular commercial interest. Partial replacement of alkylene oxides in polyols with carbon dioxide has the potential to significantly reduce the cost of polyol production. In addition, the use of CO2 as a comonomer is ecologically very advantageous, since this reaction represents the conversion of a greenhouse gas into a polymer. The production of polyether polycarbonate polyols by addition of alkylene oxides and carbon dioxide onto H-functional starter substances using catalysts has been known for a long time. Various catalyst systems can be used here: the first generation represented heterogeneous zinc or aluminum salts, as described, for example, in US Pat. No. 3,900,424 or US Pat. No. 3,953,383. Furthermore, mono- and binuclear metal complexes have been used successfully for the copolymerization of CO 2 and alkylene oxides (WO 2010/028362, WO 2009/130470, WO 2013/022932 or WO 2011/163133). The most important class of catalyst systems for the copolymerization of carbon dioxide and alkylene oxides are the double metal cyanide catalysts, also referred to as DMC catalysts (US-A 4500704, WO 2008/058913). Suitable alkylene oxides and H-functional Starter substances are those which are also used for the production of carbonate-free polyether polyols, as described above.

Polyols based on renewable raw materials "natural oil-based polyols" (NOPs) can be used. NOPs for the production of polyurethane foams are of increasing interest in view of the limited long-term availability of fossil resources, namely oil, coal and gas, and against the background of rising crude oil prices and have already been described many times in such applications (WO 2005/033167; US 2006/0293400, WO 2006/094227, WO 2004/096882, US 2002/0103091, WO 2006/116456 and EP 1678232). A number of these polyols from various manufacturers are now available on the market (WO2004/020497, US2006/0229375, WO2009/058367). Depending on the basic raw material (e.g. soybean oil, palm oil or castor oil) and the subsequent processing, polyols with different properties result. A distinction can essentially be made here between two groups: a) polyols based on renewable raw materials, which are modified to such an extent that they can be used 100% for the production of polyurethanes (WO2004/020497, US2006/0229375); b) Polyols based on renewable raw materials which, due to their processing and properties, can only replace the petrochemical-based polyol to a certain extent (WO2009/058367).

The so-called packed polyols (polymer polyols) represent a further class of usable polyols. These are characterized in that they contain solid organic fillers up to a solids content of 40% or more in disperse distribution. Among others, SAN, PHD and PIPA polyols can be used. SAN polyols are highly reactive polyols containing a dispersed styrene/acrylonitrile (SAN)-based copolymer. PHD polyols are highly reactive polyols which also contain polyurea in dispersed form. PIPA polyols are highly reactive polyols containing a polyurethane in dispersed form, for example formed by the in situ reaction of an isocyanate with an alkanolamine in a conventional polyol.

Polyols are preferably used which have a molar mass of less than 1000 g/mol. Polyols with a functionality of less than 3 are further preferred. In particular, it is preferable not to use any triols with molar masses above 1000 g/mol. This corresponds in each case to a particularly preferred form of the invention.

A preferred ratio of isocyanate and polyol, expressed as the index of the formulation, ie as the stoichiometric ratio of isocyanate groups to isocyanate-reactive groups (eg OH groups, NH groups) multiplied by 100, is in the range from 10 to 1000, preferably 40 to 700, more preferably 60 to 600, more preferably 150 to 550. A more preferred range is 250 to 500 and even more preferably 300 to 450. An index of 100 represents a 1 to 1 molar ratio of the reactive groups.

PIR formulations based on at least 70%, 80% or 90% polyester in the polyol component are preferred according to the invention.

In a particularly preferred embodiment, polyester polyols based on aromatic carboxylic acids are used in more than 50 pphp, preferably more than 70 pphp, based on 100 parts by mass of polyol component.

Preferred aromatic polyester polyols have OH numbers in the range from 150 to 400 mg KOH/g, preferably 170 to 350, very particularly preferably 180 to 300 mg KOH/g

One or more organic polyisocyanates having two or more isocyanate functions are preferably used as isocyanate components b). One or more polyols having two or more isocyanate-reactive groups are preferably used as polyol components.

Isocyanates suitable as isocyanate components for the purposes of this invention are all isocyanates which contain at least two isocyanate groups. In general, all aliphatic, cycloaliphatic, arylaliphatic and preferably aromatic polyfunctional isocyanates known per se can be used. Isocyanates are particularly preferably used in a range from 60 to 200 mol % relative to the sum of the isocyanate-consuming components.

Examples which may be mentioned here are alkylene diisocyanates having 4 to 12 carbon atoms in the alkylene radical, such as 1,12-dodecane diisocyanate, 2-ethyltetramethylene 1,4-diisocyanate, 2-methylpentamethylene 1,5-diisocyanate, tetramethylene 1,4-diisocyanate and preferably hexa - 1,6-methylene diisocyanate (HMDI), cycloaliphatic diisocyanates, such as cyclohexane-1,3- and 1-4-diisocyanate and any mixtures of these isomers, 1-isocyanato-3,35-trimethyl-5-isocyanato-rmethylcyclohexane ( Isophorone diisocyanate or IPDI for short), 2,4- and 2,6-hexahydro-'toluene-'diisocyanate and the corresponding isomer mixtures, and preferably aromatic di- and polyisocyanates, such as 2,4- and 2,6-toluene diisocyanate ( TDI) and the corresponding isomer mixtures, naphthalene diisocyanate, diethyltoluene diisocyanate, mixtures of 2,4'- and 2,2'-diphenylmethane diisocyanates (MDI) and polyphenylpolymethylene polyisocyanates (crude MDI) and mixtures of crude MDI and toluene diisocyanates (TDI). The organic di- and polyisocyanates can be used individually or in the form of their mixtures. Corresponding “oligomers” of the diisocyanates can also be used (IPDI trimer based on isocyanurate, biurete-urethdione.) It is also possible to use prepolymers based on the isocyanates mentioned above. It is also possible to use isocyanates which have been modified by the incorporation of urethane, uretdione, isocyanurate, allophanate and other groups, so-called modified isocyanates.

Particularly suitable organic polyisocyanates and therefore particularly preferably used are various isomers of toluene diisocyanate (2,4- and 2,6-toluene diisocyanate (TDI), in pure form or as isomer mixtures of different composition), 4,4'-diphenylmethane diisocyanate (MDI) , the so-called "crude MDI" or "polymeric MDI" (contains not only the 4,4'- but also the 2,4'- and 2,2'-isomers of MDI and higher-nuclear products) as well as what is known as "pure MDI". binuclear product from predominantly 2,4'- and 4,4'-isomer mixtures or their prepolymers. Examples of particularly suitable isocyanates are listed, for example, in EP 1712578, EP 1161474, WO 00/58383, US 2007/0072951, EP 1678232 and WO 2005/085310, to which reference is made here in its entirety.

Optional catalysts d) can be used in addition to the catalyst according to the invention, ie the zinc salts and/or zinc-containing preparations, as described above.

Suitable additional optional catalysts d) for the purposes of the present invention are all compounds which are able to accelerate the reaction of isocyanates with OH functions, NH functions or other isocyanate-reactive groups and with isocyanates themselves. The usual catalysts known from the prior art can be used here, including e.g. amines (cyclic, acyclic; monoamines, diamines, oligomers with one or more amino groups), ammonium compounds, organometallic compounds and metal salts, preferably those of potassium, tin , iron, bismuth. In particular, mixtures of several components can be used as catalysts.

Si-free surfactants or also organomodified siloxanes can be used as component e).

The use of such substances in rigid foams is known. Within the scope of this invention, all compounds that support foam production (stabilization, cell regulation, cell opening, etc.) can be used here. These compounds are well known from the prior art.

Corresponding siloxanes which can be used for the purposes of this invention are described, for example, in the following patent specifications: CN 103665385, CN 103657518, CN 103055759, CN 103044687, US 2008/0125503, US 2015/0057384, EP 1520870 A1, EP 14610879, EP 6074, EP 674, EP 12610879 , EP 0275563. These aforementioned documents are hereby introduced as a reference and are considered part of the disclosure content of the present invention. The use of polyether-modified siloxanes is particularly preferred. The use of blowing agents f) is optional, depending on which foaming process is used. Chemical and physical blowing agents can be used. The choice of propellant depends heavily on the type of system.

In a particularly preferred embodiment, no HFO is used as blowing agent.

Depending on the amount of blowing agent used, a high or low density foam is produced. In this way, foams with densities of 5 kg/m ³ to 900 kg/m ³ can be produced. Preferred densities are 8 to 800, particularly preferably 10 to 600 kg/m ³ , in particular 30 to 150 kg/m ³ .

Corresponding compounds with suitable boiling points can be used as physical blowing agents. Likewise, chemical blowing agents can be used, which react with NCO groups and release gases, such as water or formic acid. Examples of blowing agents are liquefied CO 2 , nitrogen, air, volatile liquids, for example hydrocarbons with 3, 4 or 5 carbon atoms, preferably cyclo-, iso- and n-pentane, fluorocarbons, preferably HFC 245fa, HFC 134a or HFC 365mfc, fluorochlorohydrocarbons, preferably HCFC 141b, hydrofluoroolefins (HFO) or hydrohaloolefins such as 1234ze, 1234yf, 1233zd(E) or 1336mzz, oxygen-containing compounds such as methyl formate, acetone and dimethoxymethane, or chlorinated hydrocarbons, preferably dichloromethane and 1,2-dichloroethane.

Suitable water contents for the purposes of this invention depend on whether or not one or more blowing agents are used in addition to the water. In the case of purely water-blown foams, the values are preferably from 1 to 20 pphp; if other blowing agents are also used, the amount used is reduced to preferably 0.1 to 5 pphp.

All substances known from the prior art which are used in the production of polyurethanes, in particular polyurethane foams, can be used as additives g), such as, for example, crosslinkers and chain extenders, stabilizers against oxidative degradation (so-called antioxidants), Flame retardants, surfactants, biocides, cell-refining additives, cell openers, solid fillers, antistatic additives, nucleating agents, thickeners, dyes, pigments, color pastes, fragrances, emulsifiers, etc.

The process according to the invention for the production of PU or PIR rigid foams can be carried out by known methods, for example by hand mixing or preferably with the aid of foaming machines. If the process is carried out using foaming machines, high-pressure or low-pressure machines can be used. The process according to the invention can be carried out either batchwise or continuously. A preferred rigid polyurethane or polyisocyanurate foam formulation for the purposes of this invention has a density of 5 to 900 kg/m 3 and preferably has the composition given in Table 1.

Table 1 :

Composition of a preferred rigid polyurethane or polyisocyanurate foam formulation

For further preferred embodiments and configurations of the method according to the invention, reference is also made to the statements made above in connection with the composition according to the invention.

As already mentioned, a further object of the invention is a PU or PIR rigid foam obtainable by the process mentioned.

PU or PIR rigid foam is an established technical term. The well-known and fundamental difference between flexible foam and rigid foam is that flexible foam shows elastic behavior and the deformation is therefore reversible. Hard foam, on the other hand, is permanently deformed. In the context of the present invention, PU or PIR rigid foam is understood in particular as a foam according to DIN 7726:1982-05, which has a compressive strength according to DIN 53 421/DIN EN ISO 604:2003-12 of advantageously >20 kPa, preferably >80 kPa, preferably >100 kPa, more preferably >150 kPa, particularly preferably >180 kPa. Furthermore, according to DIN EN ISO 4590:2016-12, the PU or PIR rigid foam advantageously has a closed-cell content of greater than 50%, preferably greater than 80% and particularly preferably greater than 90%. According to a preferred embodiment of the invention, the polyurethane foam has a density of preferably 5 to 900 kg/m ³ , preferably 8 to 800, particularly preferably 10 to 600 kg/m ³ , in particular 30 to 150 kg/m ³ .

In particular, predominantly closed-cell foams can be produced. The closed-cell content is advantageously >80%, preferably >90%.

The PU or PIR rigid foams according to the invention can be used as or for the production of insulating materials, preferably insulating boards, refrigerators, insulating foams, headliners, packaging foams or spray foams.

Especially in the cold store, refrigerator and household appliance industry; e.g. B. for the production of insulating boards for roofs and walls, as insulating material in containers and warehouses for frozen goods and for refrigerators and freezers, the PU or PIR foams according to the invention can be used with advantage.

Other preferred fields of application are in vehicle construction, in particular for the production of vehicle headliners, body parts, interior panels, refrigerated vehicles, large containers, transport pallets, packaging laminates, in the furniture industry, e.g. for furniture parts, doors, panels, in electronics applications.

Cooling apparatuses according to the invention have a PU or PIR foam (polyurethane or polyisocyanurate foam) according to the invention as insulating material.

Another object of the invention is the use of PU or PIR rigid foam as insulation material in refrigeration technology, in refrigerated cabinets, in construction, automotive, shipbuilding and/or electronics, as insulation panels, as spray foam, as one-component foam.

The objects according to the invention have been described above and are described below by way of example, without the invention being limited to these exemplary embodiments. If ranges, general formulas or compound classes are given, they should not only include the corresponding ranges or groups of compounds that are explicitly mentioned, but also all sub-ranges and sub-groups of compounds that are obtained by removing individual values (ranges) or compounds be able. If documents are cited in the context of the present description, their content, in particular with regard to the facts in which the document was cited, should belong entirely to the disclosure content of the present invention. Unless otherwise stated, percentages are percentages by weight. If mean values are given, they are weight averages unless otherwise stated. If parameters are specified, determined by measurement, unless otherwise stated, the measurements were carried out at a temperature of 25 °C and a pressure of 101325 Pa.

The present invention is described by way of example in the examples listed below, without the invention, the scope of which results from the entire description and the claims, being restricted to the embodiments mentioned in the examples.

EXAMPLES:

The following raw materials were used to produce foams.

Stepanpol® PS 2352: polyester polyol from Stepan Daltolac® R 471: polyether polyol from Huntsman TCPP: tris(2-chloroisopropyl) phosphate from ICL

KOSMOS® 75 from Evonik Operations GmbH, catalyst based on potassium octoate

KOSMOS® 45 MEG from Evonik Operations GmbH, catalyst based on potassium octoate

POLYCAT® 5 from Evonik Operations GmbH, amine catalyst

POLYCAT® DP from Evonik Operations GmbH, amine catalyst

POLYCAT® 9 from Evonik Operations GmbH, amine catalyst

POLYCAT® 206 from Evonik Operations GmbH, amine catalyst

POLYCAT® 77 from Evonik Operations GmbH, amine catalyst

TEGOAMIN® BDE from Evonik Operations GmbH, amine catalyst

DABCO® T from Evonik Operations GmbH, amine catalyst

DABCO® NE 300 from Evonik Operations GmbH, amine catalyst

DABCO® TMR 31 from Evonik Operations GmbH, catalyst for final curing.

MDI (44V20): Desmodur® 44V20L from Covestro, diphenylmethane-4,4'-diisocyanate (MDI) with isomers and higher-functional homologues

Tegostab® B 8460 from Evonik Operations GmbH, foam-stabilizing surfactant.

Production of the zinc-containing preparations according to the invention:

Various components are prepared which can then be combined in the foams to form compositions of the invention (or not of the invention).

The corresponding components/compositions can be pre-formulated or added as individual components to the reaction mixture to be foamed.

According to the invention are the examples containing zinc.

Component A: Zinc acetate based

Zinc acetate dihydrate, 12.5 g (available from Sigma-Aldrich) was dissolved in monoethylene glycol containing 11% zinc acetate along with 15 g of N,N,N',N'-tetrakis(2-hydroxypropyl)ethylenediamine. Component B: zinc propionate based

Zinc propionate, 12g (available from Sigma-Aldrich) was added along with 15g of N,N,N',N'-tetrakis(2-hydroxypropyl)ethylenediamine; dissolved in monoethylene glycol containing 12% zinc propionate.

Component C: zinc ricinoleate-based: Kosmos® 54 Evonik Operations GmbH.

Other non-Zn containing components used in the examples:

Component D:

Na hippurate (available from Sigma-Aldrich) was dissolved in monoethylene glycol containing 25% Na hippurate.

Component E: Potassium acetate based: Kosmos® 45 MEG from Evonik Operations GmbH. Component F: Potassium Propionate based:

Potassium propionate (available from Sigma-Aldrich) was dissolved in monoethylene glycol containing 30% potassium propionate.

Component G: Potassium octoate based: Kosmos® 75 from Evonik Operations GmbH.

Component H: Potassium pivalate based: DABCO® TMR 20 from Evonik Operations GmbH. Component I: DABCO® TMR 31 from Evonik Operations GmbH.

Examples:

Production of PU foams:

The foaming was carried out using the hand mixing method. For this purpose, the compounds according to the invention, polyols, flame retardants, catalysts according to the invention or not, water, siloxane surfactant and blowing agent were weighed into a beaker and mixed with a plate stirrer (6 cm diameter) at 1000 rpm for 30 s. The amount of propellant evaporated during the mixing process was determined by weighing again and replenished. The isocyanate (MDI) was then added, and the reaction mixture was stirred with the stirrer described for 5 s at 3000 rpm.

The reaction mixtures were poured into appropriate beakers with a top diameter of 20 cm to obtain free-rising foams. The amount of reaction mixture was chosen so that the tip of the foam dome was 10 to 15 cm above the top edge of the beaker. During foaming, the gel time was determined in order to assess the influence of the catalysts on the foaming rate.

After 3 minutes, the foam caps were cut off at the top edge of the beaker, giving a round foam surface. The indentation hardness of the foams was determined on this surface.

Method of determining the indentation hardness:

For this purpose, the force was measured to press a stamp with a diameter of 4 cm into the foam. The indentation forces were measured at an indentation depth of 5 mm. The measurement was carried out after 4, 6, 8 and 10 minutes, with the stamp being pressed in at 4 different points on the cut surface in a circular arrangement.

Compression hardness determination method:

The compressive strength of the foams is measured on cube-shaped specimens with an edge length of 5 cm in accordance with DIN EN ISO 844:2014-11 up to a compression of 10% (the maximum compressive stress that occurs in this measurement range is given). Table 2 summarizes the foam formulations used (form 1 to form 9).

Table 2:

Foam formulations (PIR and PUR)

Table 2

(continued) Formulations

Foaming results with the trimerization catalysts according to the invention.

Table 3: Summary of the foaming tests with various catalysts and foam formulations according to the invention.

The components used are specified (comp. A-1, inventive or not depending on the composition), their dosage in (dos. pphp), the formulation used from Table 2, the gel time (GZ) in seconds, and the indentation hardness in Newton according to the specified Time in minutes (after mixing with MDI).

The catalyst compositions without Zn are not inventive. Table 3:

The foams according to the invention each show significantly higher indentation hardnesses than the comparative examples. It can be seen from this that the trimer catalysts according to the invention in various formulations enable improved curing of the foam. In some cases, the gel times can even be extended or the positive effects on curing can be further improved by keeping the gel times the same. This is an enormous advantage, since the processability of the reaction mixture is retained due to the low influence on the gel time, for example with regard to the flowability of the foaming mixture, and at the same time the curing of the foam is accelerated. It is clearly evident from the experiments that the trimerization catalysts according to the invention lead to improved curing of the foam. The very good results described above for the indentation hardness of the foams according to the invention correspond to those of the compression hardness.

Claims

Patent Claims:

1. Composition for producing rigid polyurethane or polyisocyanurate foam, comprising at least one isocyanate component, a polyol component, optionally a foam stabilizer, optionally blowing agent, the composition containing at least one catalyst which catalyzes the formation of a urethane or isocyanurate bond , characterized in that this catalyst comprises zinc salts and/or a zinc-containing preparation.

2. Composition according to claim 1, characterized in that the zinc salts and / or zinc-containing preparations comprise zinc (II) salts, preferably zinc (II) carboxylates, wherein the carboxylates are based on carboxylic acids containing 1 to 34 carbons, which also unsaturated or aromatic units, in particular comprising zinc(II) acetate, zinc(II) propionate, zinc(II) pivalate, zinc(II) 2-ethylhexanoate (zinc(II) octoate), zinc(II )- isononanoate (zinc(II)-3,5,5-trimethylhexanoate), zinc(II) neodecanoate, zinc(II) ricinoleate, zinc(II) palmitate, zinc(II) stearate, zinc(II) oleate, zinc (II) laurate, zinc (II) napthenate and/or zinc (II) benzoate, with zinc (II) acetate and/or zinc (II) ricinoleate being most preferred, and/or where the carboxylates can also have N and O as hetero atoms, in particular including zinc(II) lactate, zinc(II) glycinate, zinc(II) hippurate, zinc(II) citrate, and/or zinc(II ) soaps, such as in particular zinc oleate, zinc palmitate, and / or zinc earat.

3. Composition according to claim 2, characterized in that the zinc(II) carboxylate used is present in stoichiometric form, ie Zn and carboxylate in a molar ratio of 1 to 2, ie in particular no excess of carboxylate or carboxylic acid.

4. Composition according to one of Claims 1 to 3, characterized in that the zinc-containing preparation contains zinc salts, preferably zinc(II) salts, in particular zinc(II) carboxylate in a carrier medium, in particular comprising glycols, alkoxylates and/or oils synthetic and/or natural origin.

5. The composition as claimed in any of claims 1 to 4, characterized in that at least one nitrogen-containing compound is additionally present, preferably comprising amines, amine alkoxylates, amino acids and/or amines with several acid functions, in particular comprising N,N, N',N'-tetrakis(2-hydroxypropyl)ethylenediamine, N,N,N',N'-tetrakis(2-hydroxyethyl)ethylenediamine, 2-[[2-[2-(dimethylamino)ethoxy]ethyl]me- ethylamino]ethanol, fatty amine ethoxylates such as tallow fatty amine ethoxylate, cocoamine ethoxylate, cetyl/stearylamine ethoxylate or PEG-3-tallow aminopropylamine, PPG-3-tallow aminopropylamine, glycine, lysine, arginine, sarcosine, Ethylenediamine tetraacetate and/or ethylenediamine triacetate coconut alkylacetamide, fatty amine alkoxylates being particularly preferred can be used, the at least one nitrogen-containing compound being contained in particular in the zinc-containing preparation.

6. The composition according to any one of claims 1 to 5, characterized in that at least one additional trimerization catalyst is additionally present, preferably carboxylates of ammonium, potassium and/or other alkali metals or alkaline earth metals, more preferably potassium carboxylates, in particular potassium acetate, potassium formate, Potassium propionate, potassium butanoate, potassium pentanoate, potassium hexanoate, potassium heptanoate, potassium 2-ethylhexanoate, potassium pivalate, potassium octoate, potassium butyrate, potassium isobutyrate, potassium nonanoate, potassium decanoate, potassium ricinoleate, potassium stearate, and/or potassium neodecanoate, and/or carboxylates of ammonium cations such as in particular carboxylates of Tetramethylammonium, Tetraethylammonium, Tetrapropylammonium, Tetrabutylammonium, dimethyldiallylammonium, Trimethyl-(2-hydroxypropyl)ammonium, Triethyl-(2-hydroxypropyl)ammonium, Tripropyl-(2-hydroxypropyl)ammonium, Tributyl-(2-hydroxypropyl)ammonium, Trimethyl-(2 -hydroxyethyl) ammonium, triethyl-(2-hydroxyethyl) ammonium, tripropyl-(2-hydroxyethyl) ammonium, tributyl-(2-hydroxyethyl) ammonium, dimethylbenzyl-(2-hydroxyethyl) ammonium and/or dimethylbenzyl-(2-hydroxypropyl) ammonium.

7. Composition according to one of Claims 1 to 6, characterized in that salts of amino acids and/or amino acid derivatives are additionally used, these being formally derivable from the reaction of aromatic carboxylic acids and amino acids, in particular they can be obtained by reacting amino acids and aromatic Carboxylic acids, aromatic carboxylic acid esters, aromatic carboxylic acid halides and/or aromatic carboxylic acid anhydrides.

8. The composition as claimed in any of claims 1 to 7, characterized in that a tertiary amine is additionally present as a further catalyst, the additional tertiary amine preferably containing at least 2 nitrogen atoms per molecule, and additional tertiary amines which can be used particularly preferably being selected from from group 1, consisting of pentamethyldiethylenetriamine, bis(2-dimethylaminoethyl)ether, tris(dimethylaminopropyl)amine, N-[2-[2-(dimethylamino)ethoxy]ethyl]-N-methyl-1,3-propanediamine , 2-{[2-(dimethylamino)ethyl]methylamino}ethanol, 2-[[2-[2-(dimethylamino)ethoxy]ethyl]methylamino]ethanol, N-methyl-N-(N,N-dimethylaminopropyl )aminopropanol, N-methyl-N-(N,N-dimethylaminopropyl)aminoethanol, 1-bis[3-(dimethylamino)propyl]amino]2-propanol, 1,1'[[3-(dimethylamino)propyl]amino] -2-propanol, 3,3'-iminobis(N,N-dimethylpropylamine), diisopropyltrimethyldiethylenetriamine, bis(dimethylaminopropyl)methylamine trimethylaminoethylethanolamine, 3-dime thylamino-N,N-dimethylpropionamide , dimethylaminopropylamine, 1-(3-aminopropyl)pyrrolidine, 1-(2-aminoethyl)pyrrolidine, 1-(1-pyrrolidinyl)-2-propanamine, N,N-dimethyl-1-(pyrrolidine -1-yl)propan-2-amine, tris(dimethylaminopropyl)amine, N,N,N'N'-tetramethylethylenediamine, 1,3,5-tris(dimethylaminopropyl)hexahydrotriazine, N,N'-bis[ 3-(dimethyl- amino)propyl]urea, N-[3-(dimethylamino)propyl]urea, 1,3-bis(dimethylamino)propane and N,N,N'N'-tetramethylhexymethylenediamine, mixtures of the aforementioned amines also being usable, and/or , preferably or, where the additional tertiary amine that can be used with particular preference satisfies the structural formula (III): (formula III) with m equal to 1 or 2,

A equals O, S or NR ^e ,

R ^a , R ^b , R ^c , R ^d and R ^e are alkyl or functionalized alkyl having 1 to 20 carbons and/or, preferably or, where the additional tertiary amine that can be used particularly preferably satisfies structural formula IV, V or VI: with m equal to 1 or 2,

R ^f is H, methyl, ethyl, isopropyl, 3-hydroxypropyl, 2-hydroxypropyl, hydroxyethyl, 3-aminopropyl, 2-aminopropyl or aminoethyl, where the two radicals can be different or identical.

9. The composition as claimed in any of claims 1 to 8, characterized in that the total mass fraction of zinc-containing preparation in the finished polyurethane foam is from 0.01 to 10% by weight, preferably from 0.1 to 5% by weight.

10. Composition according to any one of claims 1 to 9, characterized in that it contains a zinc-containing preparation which comprises:

(i) Zinc(II) carboxylate, preferably as defined in claim 2 and/or 3, in amounts of 2 to 50% by weight, preferably 5 to 45% by weight, particularly preferably 10 to 40% by weight,

(ii) carrier media, preferably as defined in claim 4, in amounts of 10 to 95% by weight, preferably 15 to 90% by weight, particularly preferably 20 to 70% by weight,

(iii) nitrogen-containing compound, preferably as defined in claim 5, in amounts of 1 to 70% by weight, preferably 2 to 60% by weight, particularly preferably 5 to 50% by weight,

% by weight based on this total zinc-containing preparation.

11. The composition according to any one of claims 1 to 10, characterized in that it comprises: a zinc-containing preparation, comprising zinc(II) salt, carrier medium and nitrogen-containing

Compound, in particular as defined in claim 10, and as further components, the composition additionally comprises

(i) additional trimerization catalyst, in particular as defined in claim 6, and

(ii) additional tertiary amine, in particular as defined in claim 8.

12. The composition as claimed in any of claims 1 to 11, characterized in that it additionally comprises water and/or blowing agent, optionally at least one flame retardant and/or other additives which can be used advantageously in the production of rigid polyurethane or polyisocyanurate foam.

13. A process for producing rigid polyurethane or polyisocyanurate foam by reacting one or more polyol components with one or more isocyanate components, the reaction taking place in the presence of a catalyst which catalyzes the formation of a urethane or isocyanurate bond, characterized in that this catalyst comprises zinc salts and/or a zinc-containing preparation, preferably using a composition as defined in any one of claims 1 to 12, in particular using a zinc-containing preparation as characterized in claim 10.

14. Use of zinc salts and/or zinc-containing preparations, in particular using a composition according to the invention as defined in one of claims 1 to 12, as a catalyst in the production of rigid polyurethane or polyisocyanurate foams, preferably for improving the performance properties of the polyurethane or polyisocyanurate rigid foam, in particular to increase the Compression hardness of the rigid polyurethane or polyisocyanurate foam at an early stage, compared to rigid polyurethane or polyisocyanurate foams that were produced without the zinc salts and/or zinc-containing preparations, compression hardness can be determined according to DIN EN ISO 844:2014-11.

15. Rigid polyurethane or polyisocyanurate foam obtainable by the process according to the invention as claimed in claim 13.

16. The use of rigid polyurethane or polyisocyanurate foams as claimed in claim 15 for thermal insulation purposes, preferably as insulating boards and insulating materials and for cooling apparatus.