DE102021003264A1 - TWO-COMPONENT POLYURETHANE COMPOSITIONS - Google Patents

Abstract

The present invention relates to a two-component (2K) polyurethane composition comprising: (i) a first component comprising (i-1) one or more benzyl ether type phenolic resins; and(ii-1) one or more polymeric polyols other than the one or more benzyl ether-type phenolic resins;(ii) a second component comprising an isocyanate formulation consisting of one or more isocyanate compounds, wherein at least one isocyanate compound has at least 2 isocyanate groups per molecule.The two-component (2K) polyurethane composition can be used for coating surfaces. It is particularly suitable as a casting compound, as a cavity seal, as a filling resin, in mold construction, for the production of a prepreg, as a repair resin or as an adhesive.

Description

technical field

The present invention relates to a two-component (2K) polyurethane composition. The two-component (2K) polyurethane composition can be used for coating surfaces. It is particularly suitable as a casting compound, as a cavity seal, as a filling resin, in mold construction, for the production of a prepreg, as a repair resin, or as an adhesive.

State of the art

2K polyurethane compositions based on polyols are known. Addition products of ethylene and/or propylene oxide with polyhydric alcohols or polyester polyols, polyhydric amines and thiol compounds or mixtures of the respective components are used as the polyol component. Typical starter molecules are also polyols such as glycerol, sorbitol, sucrose, trimethylolpropane, pentaerythritol or triethanolamine.

JP S61-223035 A describes a foam composition based on a phenolic benzyl ether type resin, polyisocyanate, an aromatic sulfonic acid, boron trifluoride and water for primary use in thermal insulation. JP S61-223035 A describes the addition of a curing agent and reports strong heat development and foaming when using benzyl ether resins. There is no talk of curing without a curing agent. The foam is particularly foamed and brittle. Boron trifluoride is added to improve corrosion protection, and resorcinol is used to increase mechanical strength and adhesion. Water must be added to improve the foam quality in the molding.

EP 0 590 638 A describes a process for preparing a polyurethane-polycarbodiimide foam, the process comprising reacting a polyol component comprising a benzyl ether-type phenolic resin having hydroxymethylene groups with an organic polyisocyanate component in the presence of an organotin catalyst and a carbodiimidation catalyst. It is noted here that the hydroxymethylene group in the benzyl ether resin used with isocyanates splits off gaseous CO ₂ in the presence of tin and “automatically” foams up in the process. The simultaneous carbodiimidation step of two NCO groups releases additional CO ₂ , which further contributes to foaming. The benzyl ether resin has an OHN of 300 to 700, preferably 450 to 600 mg KOH/g. To reduce the curing rate, the benzyl ether resins can be mixed with polyols, using 20 to 100% by weight of benzyl ether resin, preferably 30 to 80% by weight, based on the total weight of the polyols. It can contain from 0.1 to 4% by weight, preferably from 0.5 to 2% by weight, of water, based on the polyisocyanate.

EP 0 650 991 A describes a process for preparing a polyurethane foam by reacting a polyol component containing a benzylic ether-type phenolic resin having hydroxymethylene groups with an organic polyisocyanate component in the presence of an organotin-type urethanization catalyst, a tertiary amine-type blowing catalyst and water. The benzyl ether resin preferably has a free water content of at most 0.5% by weight and a viscosity of 1 to 20 Pas. Not more than 4% by weight, preferably not more than 2% by weight, of water, based on the polyisocyanate, can be present.

GB 2 074 176 A describes a polyurethane-modified polyisocyanurate foam obtained by reacting a specific benzyl ether resin with a polyisocyanate component in the presence of a trimerization catalyst for the polyisocyanate compound(s) and a blowing agent. Dibutyltin dilaurate can be used as a reaction accelerator.

US Pat. No. 3,948,824 A describes foams based on a phenolaldehyde benzyl ether resin, a polyisocyanate and a gaseous foaming agent. Example 3 shows a condensation product between a benzyl ether resin and an adipic acid polyol as the polyol component. The benzyl ether resin obtained contains approx. 1% free formaldehyde.

US 4,448,951A describes foams based on modified benzyl ether-containing resole polyols obtained from phenol, paraformaldehyde and an aliphatic hydroxyl compound using a metal catalyst.

US 3,242,107A describes special novolaks from para-tert. Butylphenol-formaldehyde resin or its adducts with alkylene oxides, which are proposed with isocyanates for use in foams, casting compounds and coatings. It is mentioned that solvents and other polyols can be added.

GB 2 033 413 A describes a process for preparing a phenol-aldehyde condensate by reacting a phenol with an aliphatic aldehyde under non-aqueous conditions in the presence of an aliphatic polyol. In one embodiment, the reaction can be conducted at a pH of less than 6 using an organic acid to adjust the pH.

None of the documents mentioned describe the use of benzyl ether resins and/or novolaks (without para-tertiary butyl phenol) as a component of PU casting compounds or PU coatings.

WO 2018/113853 discloses binders that can be used for curing molding mixtures. Cores, molds and feeders for metal casting can be produced with the mold material mixtures.

DE 10 2015 107 016 discloses a process for reducing free formaldehyde in benzyl ether resins useful in the manufacture of cores and molds for metal casting and for coating fertilizers, respectively.

The inventors have set themselves the task of developing new PU compositions which cure quickly and/or provide moldings/coatings which have increased strength.

Disclosure of Invention

• (i) eine erste Komponente, umfassend
  • (i-1) ein oder mehrere Phenolharze vom Benzylethertyp; und
  • (ii-1) ein oder mehrere polymere Polyole, die von dem einen oder mehreren Phenolharz(en) vom Benzylethertyp verschieden ist;
• (ii) eine zweite Komponente, umfassend eine Isocyanatformulierung, die aus einem oder mehreren Isocyanat-Verbindungen besteht, wobei mindestens eine Isocyanat-Verbindung zumindest 2 Isocyanat-Gruppen pro Molekül aufweist.

Accordingly, the present invention relates to a two-component (2K) polyurethane composition comprising:

• (i) a first component comprising
  • (i-1) one or more benzyl ether type phenolic resins; and
  • (ii-1) one or more polymeric polyols other than the one or more benzyl ether-type phenolic resins;
• (ii) a second component comprising an isocyanate formulation consisting of one or more isocyanate compounds, wherein at least one isocyanate compound has at least 2 isocyanate groups per molecule.

1. a) die erste Komponente enthält freies Phenol und freien Hydroxybenzylalkohol, wobei mindestens etwa 1,2 Gewichtsteile freier Hydroxybenzylalkohol pro 1 Gewichtsteil freies Phenol in der ersten Komponente enthalten sind;
2. b) die erste Komponente enthält freies Phenol und freies Saligenin (o-Hydroxybenzylalkohol), wobei mindestens etwa 1,1 Gewichtsteile freies Saligenin (o-Hydroxybenzylalkohol) pro 1 Gewichtsteil freies Phenol in der ersten Komponente enthalten sind.

In a second aspect, the two-component (2K) polyurethane composition according to the invention is preferably characterized by one or both of the following features:

1. a) the first component contains free phenol and free hydroxybenzyl alcohol, there being at least about 1.2 parts by weight of free hydroxybenzyl alcohol per 1 part by weight of free phenol in the first component;
2. b) the first component contains free phenol and free saligenin (o-hydroxybenzyl alcohol) with at least about 1.1 parts by weight free saligenin (o-hydroxybenzyl alcohol) per 1 part by weight free phenol in the first component.

• • 1 zu größer als 1,2 bis 1 zu 30,
• • bevorzugt 1 zu 1,3 bis 1 zu 20, und
• • besonders bevorzugt 1 zu 1,6 bis 1 zu 15, und
• • ganz besonders bevorzugt 1 zu 1,8 bis 1 zu 13.

In a third aspect, the weight ratio of free phenol to free hydroxybenzyl alcohol in the first component is preferred

• • 1 in greater than 1.2 to 1 in 30,
• • preferably 1 to 1.3 to 1 to 20, and
• • particularly preferably 1:1.6 to 1:15, and
• • very particularly preferably 1 to 1.8 to 1 to 13.

• • 1 zu größer als 1,1 bis 1 zu 25,
• • bevorzugt 1 zu 1,2 bis 1 zu 15, und
• • besonders bevorzugt 1 zu 1,5 bis 1 zu 10,
• • ganz besonders bevorzugt 1 zu 1,8 bis 1 zu 8.

In a fourth aspect, the weight ratio of free phenol to free saligenin in the first component is preferred

• • 1 in greater than 1.1 to 1 in 25,
• • preferably 1 to 1.2 to 1 to 15, and
• • particularly preferably 1 to 1.5 to 1 to 10,
• • very particularly preferably 1 to 1.8 to 1 to 8.

In a fifth aspect, the two-part (2K) polyurethane composition of the present invention typically contains at most about 10.0% by weight free phenol, preferably at most about 8.0% by weight free phenol, based on the weight of the benzyl ether-type phenolic resin preferably at most about 4.0 wt%, even more preferably at most about 2.0 wt% free phenol.

In a sixth aspect, the first component preferably contains at most about 1.0% by weight free phenol.

In a seventh aspect, in addition to free phenol, the first component preferably also contains free cresol and/or cardanol and/or cardol.

• • etwa 8 bis etwa 70 Gew.%, insbesondere etwa 10 bis etwa 62 Gew.%, Phenolharz vom Benzylethertyp; und/oder
• • etwa 13 bis etwa 78 Gew.%, insbesondere etwa 17 bis etwa 70 Gew.%, Isocyanatformulierung.

In an eighth aspect, the two-component (2K) polyurethane composition according to the invention preferably contains, based on the total weight of the two-component (2K) polyurethane composition:

• • from about 8% to about 70% by weight, more preferably from about 10% to about 62% by weight, of benzyl ether-type phenolic resin; and or
• • about 13 to about 78% by weight, especially about 17 to about 70% by weight, isocyanate formulation.

In a ninth aspect, the molar ratio of the isocyanate-reactive groups to the isocyanate groups is preferably from about 1.5: 1 to about 1: 1.5, preferably from about 1.3: 1 to about 1: 1.3, more preferably about 1 .2:1 to about 1:1.2.

In a tenth aspect, the one or more polymeric polyol(s) is selected from polyether polyols, polyester polyols, polycarbonate polyols, and combinations thereof.

In an eleventh aspect, the one or more polymeric polyols has a weight average molecular weight of from about 500 to about 10,000 Da, preferably from about 750 to about 9000 Da, more preferably from about 1000 to about 5000 Da, even more preferably from about 1500 to about 4500 on.

The invention also relates to a method for coating a surface of a substrate, wherein the first component and the second component of the two-component (2K) polyurethane composition according to the invention are mixed into a mixture and the mixture is applied to the surface of the substrate. The substrate is preferably selected from metals, ceramics, wood, fabrics, fleece, glass, artificial stone, natural stone or plastic.

The invention also relates to the use of the two-component (2K) polyurethane composition according to the invention as a casting compound (in particular for electrical components), as a cavity seal (in particular for motor vehicles), as a filling resin, in mold construction, for the production of a prepreg, as a repair resin or as an adhesive. The surface area of the substrate is preferably at least 1 cm ² .

For the purposes of this invention, two-component (2K) polyurethane compositions are understood as meaning all compositions which comprise at least two components which, after mixing, polymerize to form a polyurethane. Upon reaction, the reactive components of the composition convert to a solid state.

Detailed description

• - die Härtungsgeschwindigkeit der Reaktionsmischung deutlich beschleunigen; und/oder
• - die Festigkeiten der daraus hergestellten Formkörper/Beschichtungen deutlich erhöhen.

It has been found that the benzyl ether type phenolic resins in the compositions of this invention:

• - significantly accelerate the rate of hardening of the reaction mixture; and or
• - Significantly increase the strength of the moldings/coatings produced therefrom.

These effects are surprising and could not have been foreseen by a person skilled in the art or derived from the prior art.

• - den Korrosionsschutz auf metallischen Oberflächen verbessern;
• - die Herstellung blasenfreier Formkörper/Beschichtungen ermöglichen; und/oder
• - die Haftung auf (bspw. metallischen) Oberflächen signifikant verbessern.

In some preferred embodiments, the compositions of the present invention can:

• - improve protection against corrosion on metallic surfaces;
• - enable the production of bubble-free moldings/coatings; and or
• - Significantly improve adhesion to (e.g. metallic) surfaces.

curing speed:

In the present invention, it has been found that benzyl ether type phenolic resins can self-catalyze the reaction without adding any organic or inorganic metal or amine compound. The curing reaction or rate is independent of the residual synthesis catalyst remaining in the benzyl ether type phenolic resin which enables the condensation reaction between phenol and formaldehyde (e.g. zinc acetate). Furthermore, it was surprisingly found that the compositions according to the invention result in a homogeneously cured molding composition. Partial curing between phenolic resin of the benzyl ether type and isocyanate would be expected, i.e. an inhomogeneous molded body with cured (phenolic resin of the benzyl ether type) and soft parts (polymeric polyol). In addition, it would have been expected that the molded body obtained would show a high level of foaming.

It is believed that the benzyl ether type phenolic resin has the ability to activate the less reactive polyol to also react with the isocyanate. The reaction time shortens as the content of the benzyl ether type phenolic resin increases. Depending on the polyol used, the reaction time (room temperature) can be less than one minute with the addition of about 40 to about 60 weight percent benzyl ether phenolic resin based on the polyol component (benzyl ether phenolic resin plus polymeric polyol). It is immaterial for the rate of curing whether the polyisocyanate contains aromatically bound isocyanate groups or aliphatically bound isocyanate groups. That is, even the more sluggish aliphatic isocyanates can be cured using phenolic resin of the benzyl ether type even without adding a catalyst. This was not foreseeable and is surprising.

Strengths:

The compositions of the present invention can react quickly, so that it is possible to blend the benzyl ether type phenolic resin with a polymeric polyol. The mixing ratio of polyol and benzyl ether type phenolic resin can be appropriately adjusted to optimize strength. Typically, the optimum strength is from about 20 to about 45 weight percent benzyl ether-type phenolic resin based on the sum of benzyl ether-type phenolic resin and polymeric polyol.

Corrosion protection:

Coatings made from the compositions according to the invention can improve the protection against corrosion by preventing, for example, a salt solution from penetrating between the sheet metal and the coating. It is believed that the benzyl ether type phenolic resin increases adhesion to the metal surface. Furthermore, it has been found that the benzyl ether type phenolic resin makes the coated layer less vulnerable, e.g., without the benzyl ether type phenolic resin, the coated film swells in a saline solution, becomes soft, and releases from the substrate more easily. These effects can be significantly reduced by the compositions according to the invention or do not occur at all.

Plasticity:

The compositions according to the invention preferably show no increase in plasticity. At the same time, however, it is also not evident that they show increased brittleness in bubble-free moldings. The addition of ester solvents can bring about a significant increase in plasticity while at the same time increasing strength. Those skilled in the art know that it is very difficult to increase plasticity and strength at the same time.

First component

• (i-1) ein oder mehrere Phenolharze vom Benzylethertyp; und
• (ii-1) ein oder mehrere polymere Polyole, die von dem einem oder mehreren Phenolharzen vom Benzylethertyp verschieden ist.

The first component includes

• (i-1) one or more benzyl ether type phenolic resins; and
• (ii-1) one or more polymeric polyols other than the one or more benzyl ether type phenolic resins.

The first component preferably does not contain isocyanate compounds since they tend to react prematurely with the benzyl ether-type phenolic resin and with the polymeric polyol.

Benzyl ether type phenolic resin

At least one phenolic resin of the benzyl ether type is used in the first component. Hereinafter, for convenience, this component is referred to as “benzyl ether type phenolic resin”. However, it should be understood that mixtures of several benzyl ether type phenolic resins are encompassed by this term.

All conventionally used phenolic compounds are suitable for the preparation of the phenolic resins of the benzyl ether type. In addition to unsubstituted phenols, substituted phenols or mixtures thereof can be used. The phenolic compounds are preferably unsubstituted either in both ortho positions or in one ortho and para position. The remaining ring carbons can be substituted. The choice of substituent is not particularly limited as long as the substituent does not adversely affect the reaction of the phenol with the aldehyde.

Examples of substituted phenols are alkyl substituted, alkoxy substituted, aryl substituted and aryloxy substituted phenols.

The basic structure of a phenolic resin of the benzyl ether type has -CH ₂ -linked phenol units -CH ₂ -O-CH ₂ - linked phenol units in addition to -CH 2 -linked phenol units and can be represented by way of example (in relation to a product reacted only with formaldehyde) as follows:

The different units are typically statistically distributed (ie also linked in a different order than shown above). Some of the phenol unit can also be para-linked. Herein each R ¹ is independently (especially m and n) hydrogen or a C1-C26 alkyl and/or alkenyl substituent (saturated or unsaturated, straight chain or branched) ortho, meta or para to the phenolic hydroxy -Group; the sum of m and n is at least about 2 and the ratio m/n is at least about 1, preferably from about 9:1 to about 1:9 (mol:mol); R is independently hydrogen, -CH ₃ , -CH ₂ OH or -CH ₂ OR ² with R ² = a C1 to C9 hydrocarbon. The radical R ² can be straight-chain or branched, saturated or unsaturated. In a preferred embodiment, R ² is methyl, ethyl, or n-butyl, or mixtures thereof. About 5 to about 40 mol%, preferably about 6 to about 35% and more preferably about 8 to about 25 mol% of the —CH ₂ OH groups can be etherified with R ² .

The substituents mentioned above have, for example, about 1 to about 26, preferably about 1 to about 15 carbon atoms. Examples of suitable phenols are o-cresol, m-cresol, p-cresol, 3,5-xylenol, 3,4-xylenol, 3,4,5-trimethylphenol, 3-ethylphenol, 3,5-diethylphenol, p-butylphenol, 3,5-dibutyl phenol, p-amyl phenol, cyclohexyl phenol, p-octyl phenol, p-nonyl phenol, cardanol, 3,5-dicyclohexyl phenol, p-crotyl phenol, p-phenyl phenol, 3,5-dimethoxy phenol and p-phenoxy phenol.

Particularly preferred phenolic components for the synthesis of the benzyl ether resin are phenol and/or o-cresol and/or cardanol and/or cardol.

Higher condensed phenols such as bisphenol A are also suitable. In addition, polyhydric phenols which have more than one phenolic hydroxyl group are also suitable.

Preferred polyhydric phenols have 2 to 4 phenolic hydroxyl groups. Specific examples of suitable polyhydric phenols are catechol, resorcinol, hydroquinone, pyrogallol, phloroglucinol, 2,5-dimethylresorcinol, 4,5-dimethylresorcinol, 5-methylresorcinol, cardol or 5-ethylresorcinol. Mixtures of various mono- and polyhydric and/or substituted and/or condensed phenolic components can also be used in the preparation of the benzyl ether type phenolic resin.

zur Herstellung der Phenol-Formaldehyd-Harzkomponente verwendet, wobei A, B und C unabhängig voneinander ausgewählt sind aus: einem Wasserstoffatom, einem verzweigten oder unverzweigten Alkyl- oder Alkenylrest, der beispielsweise etwa 1 bis etwa 26, vorzugsweise etwa 1 bis etwa 15 Kohlenstoffatome aufweisen kann (wobei der Alkenylrest bis zu etwa 3 konjugierte und/oder isolierte Doppelbindungen enthalten kann), einem verzweigten oder unverzweigten Alkoxyrest, der beispielsweise etwa 1 bis etwa 26, vorzugsweise etwa 1 bis etwa 15 Kohlenstoffatome aufweisen kann, einem verzweigten oder unverzweigten Alkenoxyrest, der beispielsweise etwa 1 bis etwa 26, vorzugsweise etwa 1 bis etwa 15 Kohlenstoffatome aufweisen kann (wobei der Alkenoxyrest bis zu etwa 3 konjugierte und/oder isolierte Doppelbindungen enthalten kann).In one embodiment, phenols of general formula I:

used to prepare the phenol-formaldehyde resin component, wherein A, B and C are independently selected from: a hydrogen atom, a branched or unbranched alkyl or alkenyl radical having, for example, about 1 to about 26, preferably about 1 to about 15 carbon atoms (wherein the alkenyl radical can contain up to about 3 conjugated and/or isolated double bonds), a branched or unbranched alkoxy radical which can have, for example, about 1 to about 26, preferably about 1 to about 15 carbon atoms, a branched or unbranched alkenoxy radical which for example, from about 1 to about 26, preferably from about 1 to about 15, carbon atoms (where the alkenoxy radical may contain up to about 3 conjugated and/or isolated double bonds).

• Phenol zu Cardanol im Bereich von etwa 10 : 1 bis etwa 99 : 1, bevorzugt von etwa 15 : 1 bis etwa 60 : 1; und/oder
• Phenol zu o-Kresol im Bereich von etwa 1 : 1 bis etwa 10 : 1, bevorzugt von etwa 1,5 : 1 bis etwa 3,5 : 1; und/oder
• o-Kresol zu Cardanol im Bereich von etwa 5 : 1 bis etwa 30 : 1, bevorzugt von etwa 10 : 1 bis etwa 20: 1.

In a preferred embodiment, the benzyl ether type phenolic resin consists of phenol, o-cresol and cardanol moieties. The preferred molar ratios of the individual structural units in the benzyl ether resin structure are as follows:

• phenol to cardanol ranging from about 10:1 to about 99:1, preferably from about 15:1 to about 60:1; and or
• phenol to o-cresol ranging from about 1:1 to about 10:1, preferably from about 1.5:1 to about 3.5:1; and or
• o-cresol to cardanol ranging from about 5:1 to about 30:1, preferably from about 10:1 to about 20:1.

In addition to formaldehyde, aldehydes of the formula: R-CHO where R is a carbon atom radical containing from 1 to 3 carbon atoms, preferably one carbon atom. Specific examples are acetaldehyde and propionaldehyde. Formaldehyde is particularly preferably used, either in its aqueous form, as paraformaldehyde or trioxane.

In order to obtain benzyl ether type phenolic resins, it is preferable to use at least an equivalent number of moles of aldehyde compound to the number of moles of phenol compounds. The molar ratio of aldehyde compound to phenol compound is preferably about 1.05:1.0 to about 2.5:1, particularly preferably about 1.1:1 to about 2.2:1, particularly preferably about 1.2: 1 to about 2.0:1.

The phenolic resin of the benzyl ether type is prepared according to methods known to those skilled in the art. In this case, the phenol and the aldehyde are reacted in the presence of a divalent metal ion, at temperatures of preferably at most about 130.degree. The water formed is distilled off. For this purpose, a suitable entraining agent, for example toluene or xylene, can be added to the reaction mixture, or the distillation is carried out under reduced pressure.

Catalysts suitable for the production of phenolic resins of the benzyl ether type are salts of divalent ions of metals such as Mn, Zn, Cd, Mg, Co, Ni, Fe, Pb, Ca and Ba, especially Zn salts. Zinc acetate is preferably used. The amount used is not critical. Typical amounts of metal catalyst are about 0.02 to about 0.3% by weight, preferably about 0.02 to about 0.18% by weight, based on the total amount of phenolic compound and aldehyde compound.

Such resins are, for example, in U.S. 3,485,797 and in EP 1 137 500 described, the disclosure of which is hereby expressly referred to both with regard to the phenolic resins of the benzyl ether type themselves and with regard to their preparation. Analyzes of these resins show that the weight ratio of free phenol (hydroxybenzene) to free hydroxybenzyl alcohol is always 1:less than 1.

• Die erste Reaktionsstufe der Formaldehyd-Addition, bestehend aus einem Mol Phenol und einem Mol Formaldehyd, bildet Hydroxybenzylalkohol, insbesondere Saligenin. Aufgrund der orthoortho dirigierenden Wirkung des Metallkatalysators wird hauptsächlich
  
  gebildet. Allerdings ist die Bildung von
  
  ebenso möglich. Es sind auch Mischungen der Stellungsisomeren möglich, so kann die -CH₂-OH Gruppe sich an ortho- und/oder para-Position befinden, bspw. an der ortho- und ortho-, an ortho- und para- und an ortho-, ortho- und para- Stellung geknüpft sein. In einer weiteren Ausführungsform kann eine, zwei oder drei -CH₂-OH Gruppen mit einem C1 bis C9 Monoalkohol verethert sein. Dieser Monoalkohol kann geradkettig oder verzweigt, gesättigt oder ungesättigt sein.

In another preferred embodiment for the benzyl ether type phenolic resin, the ratio of free phenol to saligenin can be adjusted:

• The first reaction stage of formaldehyde addition, consisting of one mole of phenol and one mole of formaldehyde, forms hydroxybenzyl alcohol, in particular saligenin. Due to the orthoortho directing effect of the metal catalyst,
  
  educated. However, the formation of
  
  also possible. Mixtures of the positional isomers are also possible, so the -CH ₂ -OH group can be in the ortho and/or para position, for example in the ortho and ortho, in ortho and para and in the ortho, be linked in the ortho and para position. In a further embodiment, one, two or three -CH ₂ -OH groups can be etherified with a C1 to C9 monoalcohol. This monoalcohol can be straight-chain or branched, saturated or unsaturated.

What is mentioned for the phenol example also applies to the phenolic base o-cresol and m-cresol. Possible mixtures of positional isomers of the -CH ₂ -OH group are at the ortho or para and at the ortho and para position. In a further embodiment, one or two -CH ₂ -OH groups can be etherified with a C1 to C9 monoalcohol. This monoalcohol can be straight-chain or branched, saturated or unsaturated. In a preferred embodiment, it is methanol, ethanol or n-butanol.

If cardanol and/or cardol is used as the phenolic base, the —CH ₂ —OH group can be in the ortho and/or para position, for example in the ortho and ortho, in the ortho and para and in be linked ortho, ortho and para positions. In a further embodiment, one, two or three -CH ₂ -OH groups can be etherified with a C1 to C9 monoalcohol.

This monoalcohol can be straight-chain or branched, saturated or unsaturated. In a preferred embodiment, it is methanol, ethanol or n-butanol.

Monomeric addition products are defined as the first reaction stage of a phenolic base with formaldehyde, where up to three ring hydrogens of the phenolic base can be substituted by a —CH ₂ —OH group. Monomeric addition products based on phenol have a molar mass of 124 g/mol (hydroxybenzyl alcohol) to 184 g/mol (phenol plus up to 3 -CH ₂ OH). Any C1 to C26 alkyl radicals which are bonded to the phenolic parent structure and/or as an alkyl radical to an etherified -CH ₂ -OH group are not included in the stated molecular weights.

The two-pack (2K) polyurethane composition preferably contains free phenol and free hydroxybenzyl alcohol, with at least about 1.2 parts by weight of free hydroxybenzyl alcohol per 1 part by weight of free phenol in the two-pack (2K) polyurethane composition. More preferably, there are from about 1.2 to about 30, even more preferably from about 1.3 to about 20, more preferably from about 1.6 to about 15, and most preferably from about 1.8 to about 13 parts by weight of free hydroxybenzyl alcohol per 1 part by weight free phenol contained in the two-component (2K) polyurethane composition.

In the context of the invention, “hydroxybenzyl alcohol” means ortho-hydroxybenzyl alcohol, meta-hydroxybenzyl alcohol and para-hydroxybenzyl alcohol:

In another preferred embodiment, the two-part (2K) polyurethane composition contains free phenol and free saligenin (o-hydroxybenzyl alcohol) with at least about 1.1 parts by weight free saligenin (o-hydroxybenzyl alcohol) per 1 part by weight free phenol in the two-part (2K) polyurethane composition are included. Preferably there are from about 1.1 to about 25, preferably from about 1.2 to about 15, more preferably from about 1.5 to about 10, and most preferably from about 1.8 to about 8 parts by weight of free saligenin (o-hydroxybenzyl alcohol) per 1 part by weight of free phenol included in the two-component (2K) polyurethane composition.

Specifically, the weight of the phenolic resin of the benzyl ether type means the sum of the weights of the phenolic resin and the associated (free) monomers and hydroxybenzyl alcohols, the phenolic resin being the reaction product of at least one formaldehyde compound and a phenolic compound, including polymer-analogous reaction products such as alkoxylation the end groups.

The free phenol content is preferably at most about 10.0% by weight, more preferably at most about 8.0% by weight, more preferably at most about 4.0% by weight, based on the weight of the benzyl ether type phenolic resin at most about 2.0% by weight.

In one embodiment, the first component of the 2K polyurethane composition contains at most about 1.0% by weight free phenol, preferably at most about 0.8% by weight free phenol, and more preferably about 0.6% by weight free phenol.

Accordingly, in a preferred embodiment, the level of free saligenin (o-hydroxybenzyl alcohol) in the two-component (2K) polyurethane composition is, e.g., about 3.5 to about 16.0% by weight, or about 1.6 to about 12. 0% by weight and the free hydroxybenzyl alcohol content, for example, about 4.0 to about 26.0% by weight or about 2.0 to about 13.0% by weight, each based on the weight of the benzyl ether type phenolic resin.

Accordingly, in a preferred embodiment, the free saligenin (o-hydroxybenzyl alcohol) content is, for example, about 0.2 to about 15.0% by weight, or about 0.25 to about 12.0% by weight and the free hydroxybenzyl alcohol content for example about 0.30 to about 20.0% by weight or about 0.40 to about 15.0% by weight, in each case based on the first component.

Accordingly, in a preferred embodiment, the content of free saligenin is, for example, about 0.10 to about 10.0% by weight or about 0.12 to about 6.0% by weight and the content of free hydroxybenzyl alcohol is, for example, about 0.15 to about 15.0% by weight or about 0.20 to about 10.0% by weight, in each case based on the two-component (2K) polyurethane composition.

The benzyl ether type phenolic resins can contain the required level of free hydroxybenzyl alcohol, especially free saligenin, either by controlling during or after the formation reaction of the benzyl ether type phenolic resin, or by adding hydroxybenzyl alcohol, especially saligenin, before, after or during the formation of the phenolic resin, especially after the formation of the phenolic resin or by addition to the first component.

It is also possible to control the ratio of free phenol to free hydroxybenzyl alcohol, in particular to saligenin, in the benzyl ether type phenolic resin by subsequently removing the free phenol (or preferably the free phenol) from the benzyl ether type phenolic resin, e.g Steam distillation, azeotrope distillation or leaching with water according to DIN 53704 and e.g. filtration. If desired, hydroxybenzyl alcohol, in particular saligenin, can also be added after this step. The phenol:saligenin ratio is preferably adjusted via control of the benzyl ether resin synthesis.

If other phenolic bases are used in addition to phenol, these can also be present in small amounts, based on the monomeric benzyl ether resin. It is possible, for example, for the two-component (2K) polyurethane composition to contain free cresol and/or cardanol and/or cardol or other monomers in addition to free phenol.

The phenolic resin of the benzyl ether type still contains water due to the reaction. This water can interfere with curing and is preferably removed as completely as possible. Therefore, in a preferred embodiment, the water content of the two-component (2K) polyurethane composition based on the phenolic resin of the benzyl ether type is at most about 0.90% by weight, more preferably at most about 0.85% by weight and particularly preferably at most about 0.85% by weight 0.750% by weight. Based on the first component, the water content is preferably at most about 0.35% by weight, more preferably at most about 0.32% by weight and particularly preferably at most about 0.25% by weight. The information relates to the weight of the first component without the addition of a drying agent. The water content can be quantified using Karl Fischer titration. The free water content can be reduced further by adding an optional drying agent (for example zeolites/layered silicates or other molecular sieves or orthoformic esters).

Depending on the reaction, the phenolic resin of the benzyl ether type optionally also contains free alcohol from, for example, R ² . This free alcohol content should preferably be low. The content of free alcohol, based on the phenolic resin of the benzyl ether type, is preferably at most about 3.0% by weight, preferably at most about 2.0% by weight and particularly preferably at most about 1.5% by weight. Based on the first component, the content of free alcohol is preferably at most about 1.0% by weight, more preferably at most about 0.75% by weight and particularly preferably at most about 0.50% by weight. The content of free alcohol can be determined, for example, by means of gas chromatography (injector temperature 250°C, Agilent 7890A, capillary column HP5MS, 50m=l, 0.2mm=d, 0.3µm coating, temperature ramp T=50°C-325°C). .

The free formaldehyde content is preferably at most about 0.9% by weight, more preferably at most about 0.7% by weight, more preferably at most about 0.5% by weight, based on the weight of the benzyl ether type phenolic resin preferably at most about 0.3% by weight (KCN method, DIN EN ISO 11402)

The content of free formaldehyde, based on the first component, is preferably at most about 0.10% by weight, more preferably at most about 0.06% by weight and particularly preferably at most about 0.01% by weight. This can be kept within this range by the reaction control of the benzyl ether resin. However, it is also possible to subsequently reduce the free formaldehyde content by means of a suitable formaldehyde scavenger in the first component.

CH-acidic compounds such as malonic acid esters, acetoacetates (with different alkyl or aryl groups, e.g. ethyl acetoacetate), but also amino-functional compounds such as urea, ethylene urea, monoethanolamine, aminosilanes or certain amino acids have proven to be suitable formaldehyde scavengers.

The weight average molar mass (HPLC Agilent 1100, RI Detector, PSS SDV pre-column 5 µm, PSS SDV column 5 µm 1000 Å, PSS SDV column 5 µm 100 Å, flux THF, column temperature 35°C, calibration against PSS polystyrene ReadyCal-Kit low ( Mp 266-67500 D, Internal Standard PSS Polystyrene ReadyCal-Kit low (Mp 266-67500 D) of the phenolic resin of the benzyl ether type, without phenol and without monomeric condensation products, is preferably from about 350 to about 4000 g/mol, particularly preferably from about 400 to about 3000 g/mol and more preferably from about 500 to about 2000 g/mol.

The OHN (OH number, determined according to DIN 53240) of the phenolic resin of the benzyl ether type can serve as a further characterization, which is preferably from about 500 to about 900 mg KOH/g, particularly preferably from about 550 to about 850 mg KOH/g from about 560 to about 750 mg KOH/g.

polyol

Polyols are divided into polymeric polyols and non-polymeric polyols.

The first component contains one or more polyols other than the one or more benzyl ether-type phenolic resins and typically contains at least two primary and/or secondary hydroxyl groups.

The polymeric polyols are not particularly limited and can be selected from polyether polyols, polyester polyols, polycarbonate polyols, polylactides, hydroxy-functional polybutadienes, acrylate polyols, polytetramethylene glycols, polysiloxane polyols, novolaks, and combinations thereof. Preferably, the polyols are selected from polyether polyols, polyester polyols, polycarbonate polyols, and combinations thereof. Polyether polyols are particularly preferred.

Polymer polyols are made up of at least 4 monomer units (3+1 rule). The weight average molecular weight of the polymeric polyols is preferably from about 500 to about 10,000 Da, more preferably from about 750 to about 9000 Da, even more preferably from about 1000 to about 5000 Da, even more preferably from about 1500 to about 4500. The weight average The molecular weight can be determined using HPLC (Agilent 1100, RI Detector, PSS SDV pre-column 5 µm, PSS SDV column 5 µm 1000 Å, PSS SDV column 5 µm 100 Å, flux THF, column temperature 35°C, calibration against PSS polystyrene ReadyCal kit low (Mp 266-67500 D), internal standard PSS polystyrene ReadyCal kit low (Mp 266-67500 D)).

polyether polyols

Suitable polymeric polyols are polyether polyols, such as hydroxy-functional polyethers, which are obtained by alkoxylating polyfunctional alcohols (such as glycerol, glycols, trimethylolpropane, sorbitol, sucrose or pentaerythritol) with alkylene oxide (such as ethylene oxide (EO), propylene oxide (PO) or butylene oxide (BO)) under anhydrous alkaline conditions (e.g. KOH). Aminic compounds, such as ethylenediamine and triethanolamine, or mixtures with one another can also serve as the starter molecule. The molecular weight can be influenced by the concentration of the alkali (e.g. KOH). Water can also be used as a starter molecule, thereby obtaining, for example, polyethylene glycols or polypropylene glycols. The weight average molecular weight is, for example, from about 500 to about 10,000 Da, preferably from about 750 to about 9000 Da, more preferably from about 1000 to about 5000 Da, even more preferably from about 1500 to about 4500.

Numerous compounds can be obtained by varying the starter molecule and the alkoxylation components. Thus, homopolymers can be formed using only one alkoxylating agent. Mixtures of EO and/or PO and/or BO with one another result in randomly distributed copolymers. Block copolymers are obtained by adding an alkoxylating agent at different times. In addition to anionic polymerization using KOH, the use of DMC catalysts is also possible.

The polyether polyols can contain from about 1.5 to about 8 primary and/or secondary hydroxyl groups, preferably from about 2 to about 8 primary and/or secondary hydroxyl groups per molecule.

The OHN (mg KOH/g) can be, for example, in the range from about 30 to about 800, preferably from about 60 to about 750 and particularly preferably from about 100 to about 700.

polyester polyols

Suitable polyester polyols can be obtained by esterifying polybasic carboxylic acids (e.g. phthalic acid, isophthalic acid, terephthalic acid, maleic acid, adipic acid, sebacic acid, fumaric acid, hexahydrophthalic acid or tetrahydrophthalic acid) or their anhydrides with polyhydric alcohols, ring opening of cyclic esters such as lactones or cyclic carbonates or from the Transesterification of, for example, dimethyl esters of dicarboxylic acids with polyhydric alcohols. Sometimes the reaction is self-catalyzing or metal catalysts or organic sulfonic acids are used as catalyst,

The polyester polyols have at least two OH groups so that a network can form. Preferably, the average number of OH groups per polyester polyol molecule is from about 2.1 to about 3.5. The remaining amount of residual acid (calculated as the acid number AN in mg KOH/g) should be kept low, as this can lead to undesirable bubble formation with NCO groups. It is desirable to strive for an SZ (determined according to EN ISO 2114) of at most about 2.0, preferably at most about 1.5.

The weight average molecular weight is, for example, from about 500 to about 10,000 Da, preferably from about 750 to about 9000 Da, more preferably from about 1000 to about 5000 Da, even more preferably from about 1500 to about 4500.

polycarbonate polyols

Polycarbonate polyols are also useful as the polymeric polyol. They can be prepared from polyols and dialkyl, cycloalkyl or diaryl carbonates in the presence of suitable Sn and Ti compounds or DMC catalysts and elevated temperatures in the range of 200°C. The molar ratio of the carbonate and polyol components used here determines the resulting molar mass distribution of the polycarbonate polyol. Common carbonate compounds are diphenyl carbonate, trimethylene carbonate, neopentyl glycol carbonate, 2,2,4-trimethyl-1,3-pentanediol carbonate, 2,2-dimethyl-1,3-butanediol carbonate, 1,3-butanediol carbonate, 2-methyl-1,3-propanediol carbonate , 2,4-pentanediol carbonate, 2-methylbutane-1,3-diol carbonate, TMP monoallyl ether carbonate and pentaerythritol diallyl ether carbonate. Classic polyols for producing polycarbonate polyols are, for example, aliphatic or cycloaliphatic dihydroxy compounds such as diethylene glycol, triethylene glycol, oligoethylene glycol, thiodiglycol, the di- or polyglycols produced from 1,2-propylene oxide, propylene glycols, di-, tri- and tetrabutylene glycol, 1,5-pentanediol , 1,6-hexanediol, di-, tri- and tetrahexylene ether glycol, 1,8-octanediol, neopentyl glycol, 2-ethyl-1,6-hexanediol, 3-methyl-1,5-pentanediol, 1,4-cyclohexanediol, 1 ,3-cyclohexanediol, trimethylolpropane, trimethylolethane, glycerol and their reaction products with ethylene oxide and propylene oxide or aromatic diols such as p-xylylene glycol. Excess polyol provides OH functionalization of the final polycarbonate polyol.

The weight average molecular weight is, for example, from about 500 to about 10,000 Da, preferably from about 750 to about 9000 Da, more preferably from about 1000 to about 5000 Da, even more preferably from about 1500 to about 4500.

Other polymeric polyols

Furthermore, polylactides, hydroxy-functional polybutadienes, acrylate polyols, polytetramethylene glycols, polysiloxane polyols and urea resins can be used as polymeric polyols in the first component. The above compounds typically contain 2 to 8 aliphatic hydroxyl groups.

Mixtures of different polymeric polyols are of course possible.

Non-polymeric hydroxy-functional natural or ring-opened epoxidation products of triglycerides such as castor oil. These can be added as needed to achieve desired properties. These contain at least 2 to 8 hydroxyl groups.

For the characterization and preparation of the polyol classes mentioned, reference is made to the book "Chemistry and Technology of Polyols for Polyurethanes, 2nd Edition" Volume 1 by Mihail Ionescu.

The amounts of polymeric polyols used are not particularly limited. The amounts of polymeric polyols, optional inert and optional reactive solvents, and optional non-polymeric polyols and other additives together with the benzyl ether type phenolic resin discussed above constitute a first component.

The polymeric polyols are preferably present in the first component in an amount of from about 2% to about 95% by weight, more preferably from about 5% to about 95% by weight, and most preferably from about 10% to about 95% by weight. The first component preferably contains from about 2 to about 60% by weight of one or more benzyl ether-type phenolic resins, more preferably from about 5 to about 55% by weight, most preferably from about 5 to about 50% by weight. Optionally, the first component can also contain inert and/or reactive solvents in an amount of 0 to about 50% by weight, preferably from about 1 to about 45% by weight and particularly preferably from about 2 to about 40% by weight. It is also possible to mix several inert and/or reactive solvents, polyols or phenolic resins of the benzyl ether type from each of the classes of substances mentioned.

second component

The second component comprises an isocyanate formulation consisting of one or more isocyanate compounds, with at least one isocyanate compound having at least 2 isocyanate groups per molecule.

The second component preferably does not contain a benzyl ether type phenolic resin or polyol because they tend to react prematurely with the isocyanate compound.

isocyanate formulation

The isocyanate formulation consists of one or more isocyanate compounds and includes one or more isocyanate compounds having at least 2 isocyanate groups per molecule.

The isocyanate compounds with at least 2 isocyanate groups per molecule can be monomeric, oligomeric or polymeric and have the general formula R(NCO) _z , where R is a polyvalent organic radical which has an aromatic, aliphatic, cycloaliphatic or araliphatic radical and z is an integer of at least 2 (e.g. 2 to 4). Examples are ethylene diisocyanate, 1,4-butylene diisocyanate, 1,5-pentane diisocyanate, 1,6-hexamethylene diisocyanate, 1,12-dedecane diisocyanate, cyclobutane-1,3-diisocyanate, cyclohexane-1,3-diisocyanate and cyclohexane-1,4- diisocyanate and mixtures of these isomers, isophorone diisocyanate, 2,4- and 2,6-hexanehydrotoluylene diisocyanate and mixtures of these isomers, 2,2,4- and/or 2,4,4-trimethylhexamethylene diisocyanate, bis(4,4',2,4 'And 2,2'isocyanatocyclohexyl)methane or mixtures of these isomers, 1,3-diisocyanato-o-xylene and mixtures of other xylene isomers, m-phenylene diisocyanate, p-phenylene diisocyanate, 2,4-tolylene diisocyanate, 2,2'-diphenylmethane isocyanate, 2 ,4'-diphenylmethane isocyanate, 4,4'-diphenylmethane isocyanate, oligomeric MDI having at least three aromatic nuclei, 1,5-naphthalene diisocyanate, 4,4'-biphenylene diisocyanate, 3,3'-dimethyl-4,4'-diphenylmethane diisocyanate, 3,3 '-dimethyldiphenylmethane-4,4'-diisocyanate, triisocyanates such as 4,4,4'''-triphenylmethane triisocyanate and 2,4,6-toluene triisocyanate, tetraisocyanates such as 4,4'-dimethyl-2,2'-5,5'-diphenylmethane tetraisocyanate and 1,3- and/or 1,4-bis-(2-isocyanato-prop-2-yl)-benzene (TMXDI) and 1,3-bis(isocyanatomethyl)benzene (XDI).

The NCO content of the polyisocyanate used (weight of the NCO group based on the weight of the isocyanate molecule) is preferably at least about 17% by weight, more preferably at least about 27% by weight and most preferably at least about 30% by weight. The viscosity (25° C., according to DIN 53019-1) of the isocyanate should be at most about 3000 mPas, preferably at most about 2500 mPas and particularly preferably at most about 1500 mPas.

Depending on the desired properties, mixtures of isocyanates can also be used.

The isocyanates can also be derivatized by reacting difunctional isocyanates with one another in such a way that some of their isocyanate groups are derivatized to biuret, allophanate, uretdione, isocyanurate, carbodiimide, urethonimine groups. Interesting are, for example, dimerization products containing uretdione groups, e.g. of MDI or TDI. Such derivatized isocyanates are preferably used only as a component in addition to the above non-derivatized isocyanates.

Isocyanate terminated prepolymers

In addition to monomeric and polymeric polyisocyanates, isocyanate-terminated prepolymers can also be used. For example, such prepolymers are obtained by reacting OH-, NH-, NH ₂ and SH-containing polymers or monomers with an excess of diisocyanate. These prepolymers feature excellent compatibility with other isocyanates or other reaction components and can also increase the degree of crosslinking of the isocyanate component. As a result, a robust and homogeneous polyurethane network is formed. These prepolymers can be produced, for example, from monomers containing HO, HN, H ₂ N and/or HS components such as castor oil, and from polymers containing HO, HN, H ₂ N and/or HS by reaction with polyisocyanates. The following types of isocyanate termination are conceivable here, such as, for example, aliphatic and/or cycloaliphatic and/or aromatic or mixtures thereof. Partial isocyanate terminations are also conceivable. For example, the amount of isocyanate-terminated prepolymers can be up to 100%. Mixtures of different prepolymers with isocyanate termination with each other and with other isocyanate compounds or derivatizations are possible.

The isocyanate formulation can also contain blocked isocyanates and/or monoisocyanates, in which case the amount should generally not exceed about 10% by weight, based on the weight of the isocyanate formulation.

The ratio of the isocyanate-reactive groups (ie the sum of the HO, H ₂ N, HN and HS groups) to isocyanate groups in the two-component (2K) polyurethane composition is usually chosen so that the molar ratio of isocyanate reactive groups to isocyanate groups is from about 1.5:1 to about 1:1.5, preferably from about 1.3:1 to about 1:1.3, more preferably from about 1.2:1 to about 1:1.2 .

The weight ratio of the first to second components in the two-component (2K) polyurethane composition is typically increased from about 1.8:1 to about 1:1.8, preferably from about 1.5:1 to about 1:1.5 preferably chosen from about 1.4:1 to about 1:1.4.

The second component preferably contains from about 50% to about 100%, more preferably from about 60% to about 100% by weight isocyanate formulation. Optionally, inert and/or reactive solvents can also be present in the second component in an amount of from 0 to about 50% by weight, preferably from about 0% by weight to about 40% by weight and particularly preferably from about 0% by weight to about 30% by weight. It is also possible to mix several inert and/or reactive solvents or isocyanates from each of the classes of substances mentioned.

solvent

The addition of high-boiling solvents can result in an increase in strength and a significant increase in plasticity. Those skilled in the art know that it is very difficult to increase plasticity and strength at the same time. High-boiling esters have proven to be particularly suitable in this regard.

Both the first and the second component can contain solvents. This affects later properties of the cured two-component (2K) polyurethane composition and e.g. the viscosities of the two components.

Inert solvents

The solvents can be inert solvents. Inert solvents are solvents that cannot be incorporated directly into the polyurethane network, i.e. they are free of hydroxyl, mercaptan, epoxy, amino and isocyanate groups. Suitable solvents are polar and/or non-polar solvents or mixtures thereof. Suitable solvents are, for example, the aromatic solvents known under the name Solvent Naphtha. Starting from benzene, alkyl and/or alkenyl groups are substituted independently of one another on the aromatic ring and have a chain length of C1 to C30, preferably C1 to C20 and particularly preferably C1 to C16. Independently of one another, one to six ring hydrogens of the benzene can be substituted by an alkyl and/or alkenyl radical, preference being given to 1 to 4, particularly preferably 1 to 3, ring hydrogens being substituted. Irrespective of this, the alkyl or alkenyl chain can be straight-chain or branched.

Furthermore, oxygen-rich, organic solvents can be used. Above all, aliphatic, aromatic or cycloaliphatic dicarboxylic acid esters, glycol ether esters, glycol diesters, glycol diethers, cyclic ketones, cyclic esters (lactones), cyclic carbonates, acetals, hemiacetals and silicic acid esters are suitable.

Suitable are, for example, mono- and dicarboxylic acid esters with a carbon chain in the carboxylic acid from C6 to C22 and a carbon chain in the esterified alcohol from C1-C18 such as fatty acid methyl ester, ethylhexyl fatty acid ester, fatty acid butyl ester, dioctyl adipate, fatty acid isopropyl ester or hexahydrophthalic ester. However, dimeric fatty acid esters, Guerbet alcohol esters and triglycerides are also suitable. Surprisingly, these high-boiling ester solvents can increase plasticity.

Preferred solvents have a boiling point (at 1013 mbar) of at least about 100°C, more preferably at least about 170°C and most preferably at least about 185°C. Solvents which do not migrate to the surface in the cured polymer matrix are preferred.

Different classes of inert solvents can be mixed with each other and in the respective component of the two-component (2K) polyurethane composition.

Based on the two-component (2K) polyurethane composition, 0 to about 40% by weight of inert solvents, preferably 0 to about 30% by weight and particularly preferably 0 to about 25% by weight of inert solvents can be present. In one embodiment, the two-component (2K) polyurethane composition contains inert solvents.

If an inert solvent is used in the first component, 0 to about 50% by weight inert solvent, preferably about 1 to about 45% by weight and more preferably about 2 to about 40% by weight inert solvent, based on the first component, are used. In one embodiment, the first component contains inert solvent.

Reactive solvents

In addition to the benzyl ether resin and the polymeric polyol, the first component may optionally contain a reactive solvent. A reactive solvent is understood to mean solvents which can be incorporated into the polyurethane network, reduce the viscosity and possibly improve flow, i.e. these contain hydroxyl and/or mercaptan and/or amino groups.

Examples of suitable reactive solvents are diacetone alcohol, glycerol, polyglycerols, partially esterified glycerols, ethylene glycol, diethylene glycol, propylene glycol, dipropylene glycol, butanediol, methylpropanediol, free cardanol, free cardol or castor oil fatty acid esters. Also suitable are monoalcohols having a hydroxyl group and a saturated or unsaturated, straight-chain or branched chain of about 2 to about 36 carbon atoms, such as ethanol, ethylhexanol, oleyl alcohol, Guerbet alcohols or dimer diols.

Different classes of inert or reactive solvents can be mixed with one another and in the respective component of the two-component (2K) polyurethane composition.

Optional additives

The two-component (2K) polyurethane composition can contain additives if necessary. The optional additives can be present in the first component and/or in the second component or added separately from the first and second components.

To improve the processing properties, other customary additives such as wetting agents (e.g. surfactants), leveling agents (e.g. silicone-based additives such as polysiloxanes or silicone additives), processing time regulators (acids and bases), or hydrophobing agents (waxes), defoamers or deaerators can optionally be used. It is also possible to add pigments and/or color pastes for color identification.

To extend the pot life of the two-component (2K) polyurethane composition, customary reaction retarders can be added to the first and/or second component, such as Phosphoro xychloride, phenylphosphonic acid dichloride, acid chlorides, salicylic acid, sulfonic acids, carboxylic acids or phosphoric acid monoesters.

To increase adhesion on inorganic, organic or hybrid surfaces, it can be advantageous to use e.g. silane compounds as adhesion promoters in the two-component (2K) polyurethane composition. All common silanes that can be dissolved in the composition are suitable here. Mention may be made here of gamma-propyl or alpha-silanes containing one or two silyl groups and having at least one organic functional group, such as epoxy, isocyanate, vinyl, primary or secondary amino, ureido, mercapto or methacrylic groups.

To improve flame retardancy, an organic and/or inorganic flame retardant can be added to the two-component (2K) polyurethane composition. These can be, for example, bromine- and/or phosphorus-containing, intumescent compounds or inorganic solids.

It is preferred that the 2K polyurethane composition does not contain any compound that has epoxy groups.

Optional fillers

The two-component (2K) polyurethane composition according to the invention can optionally contain one or more fillers. The fillers enable adjustment of strength, plasticity, shrinkage and thermal and electrical conductivity as well as corrosion protection. Suitable fillers are finely ground or powdery inorganic or organic solids that can be dispersed in the two-component (2K) polyurethane composition and are difficult or impossible to dissolve. Examples of organic fillers are, for example, wood flour, lignin, cellulose, cork flour and ground plastics. Examples of inorganic fillers are, for example, oxides, sulfates, silicates, carbonates, phosphates or hydroxides or mixed salts of alkali or alkaline earth elements, silicon, titanium or aluminum. Mixed crystals/shapes are also possible. These can be of natural or synthetic origin.

Carbon black or amorphous or crystalline silica, glass beads or glass powder, asbestos, mineral powder, metal powder, quartz powder, talc, lime, baryte, heavy spar, gypsum, zinc phosphate, iron oxides or carbon fiber powder are also suitable. Based on the two-component (2K) polyurethane composition, up to about 50% by weight, preferably up to about 45% by weight and particularly preferably up to about 30% by weight, of fillers or granular substances are present.

In a preferred embodiment, the two-component (2K) polyurethane composition contains no fillers or granular substances.

Optional fiber reinforcement

Furthermore, it is possible to influence the mechanical properties of the composition by introducing fibers. Suitable fibers are synthetic fibers such as glass, aramid or carbon fibers. Natural plant fibers e.g. based on wood, hemp, flax, sisal or cotton are also possible. If short fibers are used, they are dispersed in the resin matrix, e.g. in the same way as the fillers. Long fibers, fleece or mats can be placed in the mold beforehand and wetted with the two-component (2K) polyurethane composition and cured using suitable methods. Nonwovens, mats, and fabrics impregnated with polymer are referred to in the art as prepregs.

Harder

Catalysts known from polyurethane coatings can be used to cure the two-component (2K) polyurethane composition. Amine catalysts and metal catalysts can be mentioned as examples, preference being given to amine catalysts. The amine catalysts can be substances that can react in the resin or substances whose chemical structure does not allow this.

In principle, all amino-functional substances such as aliphatic, cycloaliphatic, heterocyclic and/or aromatic amines are suitable as amine catalysts. There are both primary and secondary and tertiary monoamines as well as polyamines with primary, secondary and tertiary amino groups. Mixtures of the individual amines with one another are also possible.

Wobei R¹, R², R³, R^1* und R^2* unabhängig von einander aus H, C6-C12 Aryl, C1-C18 Alkyl, C1 - C18 Alkylen-C6-C12 Aryl, C1-C8 Alkylen-O-C1-C8 Alkyl, C1-C8 Alkylen-O-C1-C8 Alkyl-OH, C2-C18 Alkenyl, C1-C18 Hydroxyalkyl, C2-C18 Hydroxyalkenyl, C1-C18 Aminoalkyl, C2-C18 Aminoalkenyl, C6-C12 Aminoaryl, C5-C18 Cycloalkyl, C5-C18 Cycloalkenyl, C1-C18 Aminoalkylalkohol, C1-C18 Alkylaminoalkylalkohol, C2-C18 Aminoalkenylalkohol und C6-C12 Aminoarylalkohol ausgewählt sind. In einer weiteren Ausführungsform können R¹ und R² bzw. R^1* und R^2* zu einem Ring verbunden sein, der 3 bis 10 Ringatome aufweist, wobei die Ringatome (außer dem N des Amins) aus C, N, O und S ausgewählt sind. Bevorzugte Aminkatalysatoren sind Verbindungen der vorstehenden Strukturformel, wobei R¹, R², R³, R^1* und R^2* unabhängig von einander aus H, C1-C18 Alkyl, C1-C18 Hydroxyalkyl, C1-C18 Alkylen-C6-C12 Aryl und C5-C18 Cycloalkyl oder Verbindungen, in denen R¹ und R² bzw. R^1* und R^2* zu einem Ring verbunden sind. Besonders bevorzugt sind Verbindungen, in denen R¹, R², R³, R^1* und R^2* unabhängig von einander aus H, C1-C18 Alkyl, und C1-C18 Hydroxyalkyl ausgewählt sind.Non-limiting examples of liquid amine catalysts are triethanolamine, dimethylethanolamine, vinylimidazole, 2-(2-dimethylaminoethoxy)ethanol, 1,3-propanediamine, 3'-iminobis(N,N-dimethylpropylamine), tetramethylguanidine, N,N,N'-trimethylaminoethyl -ethanolamine 4,4-phenylpropylpyridine, 1,3,5-tris(3-(dimethylamino)propyl)-hexahydro-s-triazine, 2,2'-dimorpholinodiethyl ether, N-methylmorpholine, N-ethylmorpholine, benzyldimethylamine, N,N -dimethylcyclohexylamine, pentamethyldiethylenetriamine, N,N,N',N'',N''-pentamethyldipropylenetriamine, bis(2-methylaminoethyl)ether, diazabicyclooctane, and N,N-diisopropylamine. A general definition can be derived, for example, from the following structure, in which only the catalytically active centers are shown:

Where R ¹ , R ² , R ³ , R ^1* and R ^2* are independently selected from H, C6-C12 aryl, C1-C18 alkyl, C1 - C18 alkylene-C6-C12 aryl, C1-C8 alkylene-O- C1-C8 alkyl, C1-C8 alkylene-O-C1-C8 alkyl-OH, C2-C18 alkenyl, C1-C18 hydroxyalkyl, C2-C18 hydroxyalkenyl, C1-C18 aminoalkyl, C2-C18 aminoalkenyl, C6-C12 aminoaryl, C5 -C18 cycloalkyl, C5-C18 cycloalkenyl, C1-C18 aminoalkyl alcohol, C1-C18 alkylaminoalkyl alcohol, C2-C18 aminoalkenyl alcohol and C6-C12 aminoaryl alcohol. In a further embodiment, R ¹ and R ² or R ^1* and R ^2* can be connected to form a ring which has 3 to 10 ring atoms, the ring atoms (apart from the N of the amine) being selected from C, N, O and S are selected. Preferred amine catalysts are compounds of the above structural formula where R ¹ , R ² , R ³ , R ^1* and R ^2* are independently selected from H, C1-C18 alkyl, C1-C18 hydroxyalkyl, C1-C18 alkylene-C6-C12 aryl and C5-C18 cycloalkyl or compounds in which R ¹ and R ² or R ^1* and R ^2* are connected to form a ring. Particularly preferred are compounds in which R ¹ , R ² , R ³ , R ^1* and R ^2* are independently selected from H, C1-C18 alkyl, and C1-C18 hydroxyalkyl.

L is selected from C1-C12 alkylene, C1-C6 alkylene-O-C1-C6 alkylene, C1-C6 alkylene-NH-C1-C6 alkylene, C1-C6 alkylene-N(C1-C6 alkyl)-C1-C6 alkylene , and -C(=NH)-. L is preferably selected from C1-C12 alkylene. Gaseous amines are amines that can be vaporized by flowing and/or vaporizing through a carrier gas (usually air or an inert gas). Depending on the boiling point and vapor pressure of the amine, this can take place from about +10 °C to about +120 °C. Typically, the vaporizable amines have a boiling point less than about 95°C (1013 mbar). These include, for example, trimethylamine, triethylamine, dimethylethylamine, dimethylpropylamine and dimethylisopropylamine or mixtures thereof.

In a preferred embodiment, the amines used are N,N,N'-trimethylaminoethylethanolamine, dimethylethanolamine, dimethylisopropylamine or mixtures thereof.

Blocked amines can also be used. These have the advantage of a "switching temperature" and only start the reaction above a certain temperature. A suitable blocking agent is formic acid, for example.

Such blocked amines are, for example, from WO 2011/095440 known and include the Tosoh Corporation, Tokyo, commercially available products Toyocat DB 30, Toyocat DB 40, Toyocat DB 41, Toyocat DB 60 and Toyocat DB 70, which differ in terms of application by the degree of their thermal latency.

Curing can also take place exclusively with metal catalysts.

In principle, organic or inorganic salts of the elements tin, bismuth, iron, zinc, preferably in combination with organic carboxylates, are suitable as metal catalysts. Examples of suitable metal catalysts are: dibutyltin laurate, dioctyltin dilaurate, dioctyltin acetate, zinc neodecanoate, ferrous chloride, ferric chloride, zinc chloride, and bismuth octoate.

In order to achieve specific curing properties, two or more catalysts can also be mixed with one another, and these can belong to different classes of compounds. Different hardening processes can also be combined. To increase the activity, one or more catalysts in addition to the first component and / or the second component and / or are added to the two-component (2K) polyurethane composition, and these can belong to different classes of compounds.

Solvents can be added to catalysts that are liquid or solid at the working temperature, e.g. in order to influence the reaction rate in this way. This can be used to convert solid amines to the liquid state at the working temperature.

The exact amount of the catalyst depends on the type of catalyst and can be selected appropriately by a person skilled in the art. The amount of catalyst required for curing depends on the reactivity of the two-component (2K) polyurethane composition, the desired curing time and the working temperature. With an amine catalyst, generally from about 0.05% to about 20% by weight is employed, preferably from about 0.1 to about 10% by weight, and more preferably from about 0.15 to about 6% by weight, based on the total amount of two-component (2K) polyurethane composition used.

If the reaction speed is not important, the two-component (2K) polyurethane composition can also be applied and cured without the addition of a catalyst.

Since the reaction between the benzyl ether type phenolic resin, the polyol and the isocyanate compound proceeds rapidly, the curing conditions are not critical. This can take place, for example, in a temperature range of about -40°C to about +130°C and/or at a relative humidity of up to about 98%. The curing of the two-component (2K) polyurethane composition is also possible under reduced as well as under increased pressure.

Process for coating a surface of a substrate

The two-part (2K) polyurethane composition can be used to coat a surface of a substrate.

The substrate is not particularly limited. Examples of substrates include metals, ceramics, fabrics, non-woven fabrics, wood, glass, artificial stone, natural stone, and plastic. In one embodiment, the substrate includes metals, fabrics, nonwovens, wood, glass, and plastic. In a preferred embodiment, the substrate comprises metal.

The substrate is preferably non-particulate. The substrate is preferably not a molding material such as quartz sand and not an agrochemical. The substrate preferably has a flat shape. The surface area of the substrate is preferably at least about 1 cm ² , more preferably at least about 1.5 cm ² , even more preferably at least about 2.0 cm ² . When the substrate consists of multiple objects (such as multiple particles), the above term "surface of the substrate" refers to the smallest sub-unit thereof, namely a single particle.

The substrate preferably has a size of at least about 0.4 mm, more preferably about 0.8 mm, even more preferably about 1.5 mm. If the substrate is spherical, the size refers to the sphere diameter. If the substrate is not spherical, the size refers to the smallest linear expansion, e.g. to the sheet thickness in the case of sheet metal.

The first component and the second component of the two-component (2K) polyurethane composition are first mixed. The mixture is then applied to the surface of the substrate. The homogeneous mixing can take place, for example, by means of a suitable mixing apparatus or manually. The length of time between mixing the first and second component and optional additives until application to the substrate depends on the choice of the first and second component and, above all, on their reactivity. It is generally from about 30 seconds to about 2 hours, preferably from about 40 seconds to about 1.5 hours.

The viscosity of the mixture is not particularly limited and can be, for example, in the range from about 50 mPas to about 50 Pas, preferably from about 60 mPas to about 40 Pas. The viscosity can be measured with a CAP-2000 rotational viscometer (measurement conditions: 25°C, spindle and revolutions are selected such that the utilization is between about 40 and about 60%).

After application, the mixture can be cured. Possible hardeners are mentioned above.

The cured composition of the present invention is visually substantially free of bubbles. The density of the cured composition (measured at 20° C.) is at least about 0.850 g/cm ³ , preferably at least about 0.950 g/cm ³ and more preferably at least about 0.980 g/cm ³ , each measured without fillers. Density can be measured by water displacement.

use

The two-component (2K) polyurethane composition according to the invention can be used in many different ways. Examples of possible applications are as a casting compound (especially for electrical components), as a cavity seal (especially for motor vehicles), as a filling resin (especially for cable sleeves), in mold construction, for the production of a prepreg (especially for wind turbines (see e.g. EP 3 313 910 or for oil or gas pipelines), as a repair resin or as an adhesive.

The two-component (2K) polyurethane composition according to the invention is also suitable as a surface coating. In particular, it can be used as a protective layer to protect substrates against mechanical influences and/or oxidation, for example. In a particularly preferred embodiment, it can be used as a surface coating for metals, for example to protect them from corrosion.

EXAMPLES

Chemicals used

acetone Supplier Sigma Aldrich Byc 088 Fluorosilicone based defoamer, supplier Byk Chemie Desmophen 4011 T Trifunctional polyether polyol, TMP starter based on propylene oxide, OHZ: 525 - 570, supplier Covestro AG Desmophen SC 01 trifunctional polyether polyol, glycerin starter based on propylene oxide, OHZ 560 - 584, supplier Covestro AG Desmophen ultra 3600 N HDI trimer, NCO content 22.5 - 23.5%, supplier Covestro AG DINCH Diisononyl 1,2-cyclohexanedicarboxylate dioctyl adipate (DOA) Supplier Sigma Aldrich IRIS (Rhodiasolv IRIS) Branched dimethyl glutarate, supplier Rhodia Operations Isopropyl laurate (IPL) Supplier Oleon GmbH Lupranate M 70 R polymeric MDI, functionality 2.9, NCO content approx. 31.4%, supplier BASF AG Molecular sieve 3A, montmorillonite Supplier Sigma Aldrich SNL (Light Solvent Naphtha) Supplier Exxon zinc acetate dihydrate Supplier Sigma Aldrich

• Molgewicht (Mn) 434 g/mol, Molgewicht (Mw) 1987 g/mol, Molgewicht (Mz) 6255 g/mol OHZ: ca. 580 mg KOH/g
• Gehalt an freiem Phenol: 11,8 Gew. %
• Gehalt an freiem Saligenin: 7 Gew. %
• Verhältnis freies Phenol : freiem Saligenin = 1:0,6

Benzyl ether resin 1 (phenol/cardanol copolymer) according to Example 1 of DE10158693A1 , which is characterized by the following analytical key figures:

• Molecular weight (Mn) 434 g/mol, molecular weight (Mw) 1987 g/mol, molecular weight (Mz) 6255 g/mol OHZ: approx. 580 mg KOH/g
• Free phenol content: 11.8% by weight
• Content of free saligenin: 7% by weight
• Ratio free phenol: free saligenin = 1:0.6

• Molgewicht (Mn) 525 g/mol, Molgewicht (Mw) 1400 g/mol, Molgewicht (Mz) 3570 g/mol OHZ: ca. 560 mg KOH/g
• Gehalt an freiem Phenol: 1,8 Gew. %
• Gehalt an freiem Saligenin: 3,8 Gew. %
• Verhältnis freies Phenol : freiem Saligenin = 1:2,1

Benzyl ether resin 2 (o-cresol/phenol/cardanol copolymer), which is characterized by the following analytical parameters:

• Molecular weight (Mn) 525 g/mol, molecular weight (Mw) 1400 g/mol, molecular weight (Mz) 3570 g/mol OHZ: approx. 560 mg KOH/g
• Free phenol content: 1.8% by weight
• Content of free saligenin: 3.8% by weight
• Ratio free phenol: free saligenin = 1:2.1

Benzyl Ether Resin 3 (Synthesis Example)

648.4 g of phenol (99%), 352.6 g of paraformaldehyde (91%) and 0.6 g of zinc acetate dihydrate were placed in a reaction vessel equipped with a stirrer, reflux condenser and thermometer. With stirring, the temperature was increased uniformly within 60 minutes to 105 to 115° C. and held until a refractive index (25° C.) of 1.5590 was reached. Then 50 g of cardanol were added, the condenser was switched to atmospheric distillation and the temperature was brought to 120 to 125° C. within an hour. Distillation was continued at this temperature until a refractive index (25° C.) of 1.5940 was reached. Thereafter, vacuum was applied and distilled at reduced pressure to a refractive index (25°C) of about 1.6020. Then, per 90 parts by weight of the resin obtained, 8 parts by weight of n-butanol and 2 parts by weight of water were added and refluxed at 100-112° C. for 60 minutes. The unreacted butanol was then removed under reduced pressure. The resin had a refractive index (25°) of about 1.5980. The free phenol content, determined by GC, was 3.8% by weight and the saligenin content was 6.7%. A phenol to saligenin ratio of 1:1.76

First components used

Table 1 shows the first components used. A1 and A2 are comparative examples. A1 A2 A3 A4 A5 A6 A7 A8 A9 A10 A11 A12 Desmophen 30SC01 99.9 94.9 89.9 79.9 69.9 59.9 Desmophen 401 1T 99.9 94.9 89.9 79.9 69.9 59.9 Benzyl ether resin 1 5 10 20 30 40 5 10 20 30 40 molecular sieve 3A 0.1 0.1 0.1 0.1 0.1 0.1 0.1 0.1 0.1 0.1 0.1 0.1 A 13 A 14 A 15 A 16 Desmophen 30SC01 97.9 79.9 59.9 39.9 benzyl ether resin 2 2 20 40 60 molecular sieve 3A 0.1 0.1 0.1 0.1

Production of the first components:

The amount of Desmophen heated to 50-70°C was placed in a suitable vessel and the benzyl ether resin heated to 80-90°C was added with stirring. Clear, viscous solutions were obtained. The molecular sieve was then stirred in at a temperature below 40°C, which made the solutions cloudy. Before mixing with the second component, there was a wait of at least 24 hours so that the molecular sieve had enough time to bind any water that might be present. It was also necessary to stir the mixtures before mixing with the second component in order to distribute the insoluble molecular sieve homogeneously.

Determination of gel time

The gel time was determined using a device for determining the gel time (Model Geltimer m, from Gel Instruments AG). For this purpose, 20 g of each of the first components listed above were weighed into a paper cup and mixed homogeneously with 20 g of Lupranat M 70 R using a wooden spatula so that little air was stirred in. 4 g of each of these mixtures were filled into a test tube, the measuring wire was connected and the test tube was hung in the measuring apparatus. The outside temperature of the test tube was kept constant at 25° C. by means of a water bath thermostat. When the viscosity of the mixture being tested increased so much that the cured composition pulled the test tube up through the gauge wire, the gel timer turned off and time was stopped. Table 2 shows the curing times in minutes for some of the first components with Lupranat M 70 R 1st comp. A1 A2 A3 A4 A5 A6 A7 A8 A9 A10 A11 A12 minutes 94 46 90 86 65 59 6 38 29 16 7 2 1st comp. A 13 A 14 A 15 A 16 minutes 62 46 5 1

The gel time for mixtures with Desmodur ultra N 3600 was determined in the same way as described above. For this purpose, the Lupranat M 70 R 1:2 was replaced by Desmodur ultra N 3600 by weight. Table 3 shows the curing times in hours of some of the first components with Desmodur ultra N 3600 1st component A2 A9 a 10 A 11 A 12 hours >48 6.5 2.5 0.5 0.15

It can be seen from Tables 1, 2 and 3 that the addition of a benzyl ether resin significantly increases the rate of reaction. This is surprising in that both the benzyl ether resin and the desmophen are in the same hydroxyl number range. C1 C2 Desmophen 30 SC 01 99.86 Desmophen 4011 T 99.86 zinc acetate dihydrate 0.04 0.04 molecular sieve 3A 0.1 0.1 gel time > 48h > 48h

Comparative experiments in which 0.04% zinc acetate dihydrate was added to A 1 and A 2 show no catalytic effect in the reaction between the first component and the second component. Residual zinc acetate dihydrate is used as a catalyst for the benzyl ether resin synthesis and may be present as a residue in the benzyl ether resin.

Determination of strengths of compositions

Production of the test specimens from the first and second component in a weight ratio of 1:1

40 g of each of the first components listed above were weighed into a paper cup and mixed homogeneously with 40 g of Lupranat M 70 R using a wooden spatula so that little air was stirred in. 2 drops of Byk 088 were added to reduce foaming. 34 g of this mixture were filled into a silicone mold measuring 171 mm*22 mm*9 mm and allowed to harden at room temperature. After 24 hours the received bars measured. The ledger was placed on the two support points on the 22 mm thick side and measured. The results given are the mean of a duplicate determination. Table 4 shows the strengths found in N/cm ² of 24-hour-old test specimens 1st comp. A1 A2 A3 A4 A5 A6 A7 A8 A9 a 10 A 11 A 12 Newtons/ ^cm2 soft soft 250 275 300 320 336 394 527 556 634 482

The results in Table 4 show that the addition of just 5% benzyl ether resin to the first component significantly increases strength after 24 hours.

Production of the test specimens from the first and second component with changed weight ratios

40 g of component A 6 were weighed into a paper cup and mixed homogeneously with the amounts of Lupranat M 70 R specified in Table 5 using a wooden spatula, so that little air was stirred in. 2 drops of Byk 088 were added to reduce foaming. 34 g of this mixture were filled into a silicone mold measuring 171 mm*22 mm*9 mm and allowed to harden at room temperature. After 24 hours, it was shaped and the bar obtained was measured using a bending device from Jung Instruments Model SJ-1. The ledger was placed on the two support points on the 22 mm thick side and measured. The results given are the mean of a duplicate determination. Table 5 shows the strength in N/cm ² of 24-hour-old test specimens. The specified weight ratio relates to the amount by weight of first component A 6 to second component. weight ratio 1:0.7 1:0.8 1:0.9 1:1 1:1.1 Lupranate M 70 R 28g 32g 36g 40g 44g Newtons/ ^cm2 551 475 257 320 372

Production of the test specimens from the first and second component in a weight ratio of 1:1 and solvent

40 g of the first component A 11 were weighed into a paper cup and mixed homogeneously with 40 g of Lupranat M 70 R using the amounts and solvents specified in Table 6 using a wooden spatula, so that a little air was stirred in. 2 drops of Byk 088 were added to reduce foaming. 34 g of this mixture were filled into a silicone mold measuring 171 mm*22 mm*9 mm and allowed to harden at room temperature. After 24 hours, it was shaped and the bar obtained was measured using a bending device from Jung Instruments Model SJ-1. The ledger was placed on the two support points on the 22 mm thick side and measured. The results given are the mean of a duplicate determination. In addition, the plasticity of the bars, given in mm elongation at break, was also measured in these measurements. solvent acetone SNL IPL IRIS DINCH DOA Amount added 14g 14g 14g 14g 14g 14g Newtons/ ^cm2 783 733 570 780 700 920 mm 2.6 1.8 2.2 2.5 2.4 4.7

Table 6 shows the strength and elongation at break in mm of the cast test bars after 24 hours. It can be seen that the strength can be significantly increased by adding solvents. Furthermore, the test specimens show a very high elongation at break, which is further explained by the following test.

Production of the test specimens from the first and second component in a weight ratio of 1:1 and different proportions of benzyl ether resin

40 g of the first component were weighed into a paper cup and mixed homogeneously with 40 g of Lupranat M 70 R and an additional 11.2 g of diocytladipate (DOA) using a wooden spatula, so that little air was stirred in. 2 drops of Byk 088 were added to reduce foaming. 34 g of this mixture were each filled into a silicone mold measuring 171 mm*22 mm*9 mm and at room temperature left to harden. After 24 hours, it was shaped and the bar obtained was measured using a bending device from Jung Instruments Model SJ-1. The ledger was placed on the two support points on the 22 mm thick side and measured. The results given are the mean of a duplicate determination. In addition, the plasticity of the bars, given in mm elongation at break, was also measured in these measurements. first component A2 A9 A10 A11 A12 Newtons/ ^cm2 340 920 960 1050 1260 mm 4.1 6.3 4.5 5.1 5.3

Table 7 shows the strength and elongation at break of the test specimens as a function of the proportion of benzyl ether resin with a constant proportion of dioctyl adipate

Table 7 shows that dioctyl adipate increases the strength of the mixtures. This can also be seen in sample A 2, although the increase in strength with benzyl ether resin is greater. The increase in elongation at break with a simultaneous increase in strength is surprising.

Production of the test specimens from the first and second component in a weight ratio of 1:1 and different proportions of dioctyl adipate (DOA)

40 g of the first component A11 were weighed into a paper cup and mixed homogeneously with 40 g of Lupranat M 70 R and the amounts of dioctyl adipate specified in Table 8 using a wooden spatula, so that little air was stirred in. 2 drops of Byk 088 were added to reduce foaming. 34 g of this mixture were filled into a silicone mold measuring 171 mm*22 mm*9 mm and allowed to harden at room temperature. After 24 hours, it was shaped and the bar obtained was measured using a bending device from Jung Instruments Model SJ-1. The ledger was placed on the two support points on the 22 mm thick side and measured. The results given are the mean of a duplicate determination. In addition, the plasticity of the bars, given in mm elongation at break, was also measured in these measurements. first component A10 A11 A12 A10 A11 A12 Added amount DOA 4g 4g 4g 8g 8g 8g Newtons/ ^cm2 570 1290 491 1050 1351 860 mm 1.5 5.1 1 4.9 5.1 2.4

Table 8 shows the strength and elongation at break of the test specimens as a function of the benzyl ether resin content and the amount of dioctyl adipate.

anti-corrosion test

Coating of the test panels with a composition of the first and second component in a weight ratio of 1:1.5

40 g of each of the first components A 1 or A 4 to A 7 were weighed into a paper cup and mixed homogeneously with 60 g of Lupranat M 70 R using a wooden spatula so that a little air was stirred in. This mixture was poured into a doctor blade and a layer 150 μm thick was applied centrally to a degreased sheet steel (type Stahl DC01 C290, R-036, 79 mm×152 mm×0.8 mm, from Rocholl GmbH). The coated metal sheet was then thermally cured directly in a circulating air oven at 70° C. for 30 minutes, so that transparent, bubble-free, adhesive films were obtained. After a post-conditioning time of 3 days at room temperature, the panels were placed halfway up in a 3% sodium chloride solution (ie the lower half of the coating was in the liquid, the upper half was exposed to the gas space) and stored at room temperature. The storage vessel was sealed so that a saturated relative humidity of 98% was established in the gas space. At certain times, the test panels were assessed visually. After 7 days, the elastic hardness was determined by means of the König pendulum damping method (DIN 53157). For this purpose, the removed panels were rinsed with water, the residual moisture was carefully removed with a cloth and measured after 2 days of conditioning. Both the measurement and the conditioning took place at room temperature. The specified oscillation time (Pen deflection) refers to the deflection from 6 degrees to 3 degrees and is given in seconds (sec). The higher the oscillation time, the harder the coating. The initial value was determined before storage began. Table 9 shows the visual assessment of the coated test panels divided into gas phase and liquid phase after certain periods of time. 1st component a 1 A4 A 5 judged phase fluid gas fluid gas fluid gas 1 day - Visual milky clear milky clear milky clear 1 day liability fixed fixed fixed fixed fixed fixed 2 days - Visual milky clear milky clear milky clear 2 days liability detachment fixed fixed fixed fixed fixed 7 days - Visual milky clear milky clear milky clear 7 days liability detachment detachment fixed fixed fixed fixed 1st component A6 A 7 judged phase fluid gas fluid gas 1 day - Visual clear clear clear clear 1 day liability fixed fixed fixed fixed 2 days - Visual clear clear clear clear 2 days liability fixed fixed fixed fixed 7 days - Visual clear clear clear clear 7 days liability fixed fixed fixed fixed Table 10 shows the König pendulum damping, given in seconds (sec) 1st component a 1 A4 A 5 A6 A 7 Initial value (sec) 150 150 155 180 180 gas phase (sec) 140 145 150 180 180 liquid phase (sec) 66 115 150 180 180

Both tables of results show that the addition of a benzyl ether resin in the first component significantly improves resistance and adhesion to salt water and protects the substrate from corrosion. An addition of 30% or more benzyl ether resin shows no differences between the initial value and gas and liquid phase storage.

QUOTES INCLUDED IN DESCRIPTION

This list of the documents cited by the applicant was generated automatically and is included solely for the better information of the reader. The list is not part of the German patent or utility model application. The DPMA assumes no liability for any errors or omissions.

Patent Literature Cited

• JP S61223035 A [0003]
• EP0590638A [0004]
• EP0650991A [0005]
• GB 2074176A [0006]
• US4448951A [0008]
• US3242107A [0009]
• GB 2033413A [0010]
• WO 2018113853 [0012]
• DE 102015107016 [0013]
• US3485797 [0054]
• EP 1137500 [0054]
• WO 2011095440 [0138]
• EP 3313910 [0154]
• DE 10158693 A1 [0156]

Claims (15)

A two-component (2K) polyurethane composition comprising: (i) a first component comprising (i-1) one or more benzyl ether type phenolic resins; and (ii-1) one or more polymeric polyols other than the one or more benzyl ether-type phenolic resins; (ii) a second component comprising an isocyanate formulation consisting of one or more isocyanate compounds, wherein at least one isocyanate compound has at least 2 isocyanate groups per molecule. The two-component (2K) polyurethane composition according to claim 1 , wherein the two-component (2K) polyurethane composition is further characterized by one or both of the following features: a) the first component contains free phenol and free hydroxybenzyl alcohol, with at least about 1.2 parts by weight of free hydroxybenzyl alcohol per 1 part by weight of free phenol in the first component included; b) the first component contains free phenol and free saligenin (o-hydroxybenzyl alcohol) with at least about 1.1 parts by weight free saligenin (o-hydroxybenzyl alcohol) per 1 part by weight free phenol in the first component. The two-component (2K) polyurethane composition according to claim 2 , wherein the weight ratio of free phenol to free hydroxybenzyl alcohol in the first component • 1 to greater than 1.2 to 1 to 30, • preferably 1 to 1.3 to 1 to 20, and • particularly preferably 1 to 1.6 to 1 to 15, and • very particularly preferably from 1 to 1.8 to 1 to 13. The two-component (2K) polyurethane composition according to claim 2 or 3 , wherein the weight ratio of free phenol to free saligenin in the first component is • 1 to greater than 1.1 to 1 to 25, • preferably 1 to 1.2 to 1 to 15, and • particularly preferably 1 to 1.5 to 1 to 10, • most preferably 1 to 1.8 to 1 to 8. The two-component (2K) polyurethane composition according to one of claims 2 until 4 wherein the two-component (2K) polyurethane composition contains at most about 10.0% by weight free phenol, preferably contains at most about 8.0% by weight free phenol, more preferably at most about 4.0% by weight, more preferably at most about 2.0% by weight, free phenol. The two-component (2K) polyurethane composition according to one of Claims 1 until 4 , wherein the first component contains at most about 1.0% by weight of free phenol. The two-component (2K) polyurethane composition according to one of Claims 1 until 5 , wherein the first component also contains free cresol and/or cardanol and/or cardol in addition to free phenol. The two-component (2K) polyurethane composition according to one of Claims 1 until 6 wherein the two-component (2K) polyurethane composition comprises, based on the total weight of the two-component (2K) polyurethane composition: • about 8 to about 70% by weight, more preferably about 10 to about 62% by weight, of phenolic resin of the benzyl ether type; and/or • about 13 to about 78% by weight, in particular about 17 to about 70% by weight, of isocyanate formulation; contains. The two-component (2K) polyurethane composition according to one of Claims 1 until 7 wherein the molar ratio of isocyanate-reactive groups to isocyanate groups is from about 1.5:1 to about 1:1.5, preferably from about 1.3:1 to about 1:1.3, more preferably about 1.2:1 to about 1:1.2. The two-component (2K) polyurethane composition according to one of Claims 1 until 9 wherein the one or more polymeric polyol(s) is selected from polyether polyols, polyester polyols, polycarbonate polyols, and combinations thereof. The two-component (2K) polyurethane composition according to one of Claims 1 until 10 wherein the one or more polymeric polyols have a weight average molecular weight of from about 500 to about 10,000 Da, preferably from about 750 to about 9000 Da, more preferably from about 1000 to about 5000 Da, even more preferably from about 1500 to about 4500 . A method of coating a surface of a substrate, wherein the first component and the second component of the two-component (2K) polyurethane composition according to any one of Claims 1 until 11 are mixed into a mixture and the mixture is applied to the surface of the substrate. The procedure according to claim 12 , wherein the substrate is selected from metals, ceramics, wood, fabrics, fleece, glass, artificial stone, natural stone or plastic. Use of the two-component (2K) polyurethane composition according to one of Claims 1 until 11 as a casting compound (in particular for electrical components), as a cavity seal (in particular for motor vehicles), as a filling resin, in mold making, for the production of a prepreg, as a repair resin or as an adhesive. Use of the two-component (2K) polyurethane composition according to one of Claims 1 until 11 for coating the surface of a substrate, the surface area of the substrate being at least 1 cm ² .