Compositions containing isocyanate and isocyanurate groups, and rigid PUR / PIR foams produced therefrom

Abstract

The present invention relates to compositions containing isocyanate and isocyanurate groups, and methods for producing rigid PUR / PIR foams from these compositions by reacting pMDI in the presence of a trimerization catalyst. The present invention further relates to methods for producing compositions containing isocyanate and isocyanurate groups, the production of rigid PUR / PIR foams from these compositions, the rigid foams themselves, and uses of such rigid foams.

Description

[Technical Field]

[0001] The present invention relates to compositions containing isocyanates and isocyanurates for producing rigid PUR / PIR foams, and to the production of compositions containing isocyanates and isocyanurates by partial trimerization of polymeric MDI (pMDI). The invention further relates to the production of rigid PUR / PIR foams from these compositions, the rigid foams themselves, and uses of such rigid foams. [Background technology]

[0002] To produce thermally insulating foams, such as those used for facade cladding, polyisocyanurate-polyurethane foam systems (PUR / PIR foams), which are produced by using a polymeric polyisocyanate commonly used in rigid foam production in a significant stoichiometric excess relative to the polyol component, are increasingly being used to improve fire protection. Therefore, the polymeric polyisocyanate used has a decisive influence on the properties of the rigid foam. In addition to the final properties, such as insulating efficiency and final strength, the mechanical strength of the rigid foam immediately after production is also an important technical property, determining the time until the rigid foam can be mechanically handled and stacked.

[0003] It is known that the time required to cure PUR / PIR foams can be affected by various factors, particularly through the use of oligomeric (polynuclear) polyisocyanates. The synthesis of polynuclear isocyanurate structures is achieved by the trimerization of polyisocyanates.

[0004] Patent Document 1 describes a particularly low-color PUR / PIR foam from a composition containing isocyanate and isocyanurate groups. The process described therein includes (a) trimerizing polymeric MDI in the presence of a trimerization catalyst to obtain an isocyanurate-containing polyisocyanate, (b) deactivating the trimerization catalyst, and (c) blending the isocyanurate-containing polyisocyanate with monomeric MDI to form a final product having a viscosity similar to that of standard pMDI and a binuclear content of at least 60% by weight. The final product is used to produce foams with lighter colors than foams based on standard pMDI. The disadvantage of blending with monomeric MDI in step c) is that the isocyanate functionality of the blend is reduced, which adversely affects the final properties, such as strength, of the rigid PUR / PIR foam produced therefrom.

[0005] Patent Document 2 relates to a method for producing liquid isocyanurate-modified pMDI with controlled viscosity. This method comprises the steps of: (a) trimerizing "conventional pMDI," which is a trimer-free mixture of monomeric and oligomeric MDI having a viscosity of 30 mPa·s to 300 mPa·s, in the presence of a trimerization catalyst to obtain isocyanurate-containing pMDI having a viscosity at 25°C in the range of 2000 mPa·s to 200,000 mPa·s; (b) deactivating the catalyst with a catalyst deactivator to obtain a mixture containing the isocyanurate-modified pMDI and the deactivated catalyst; and (c) mixing the mixture from step (b) with trimer-free pMDI in an amount sufficient to obtain a mixture having a viscosity at 25°C in the range of 400 mPa·s to 20,000 mPa·s and a content of free NCO groups equivalent to conventional pMDI having a viscosity of 30 mPa·s to 1,000 mPa·s.

[0006] The drawback is that this three-stage process for producing isocyanurate-containing pMDI, via the intermediate high viscosity pMDI, creates deficiencies in the production of insulating panels.

[0007] Patent Document 3 discloses a method for producing rigid polyurethane-polyisocyanurate foams (rigid PUR / PIR foams) using isocyanate blends of mainly monomeric and polymeric MDI followed by partial trimerization. The isocyanate blends used in this invention contain 15% to 25% by weight of isocyanurate groups and have a viscosity of more than 1000 mPa·s at 25°C. However, blends with low viscosity and / or high isocyanurate content have proven to be detrimental, for example, from the standpoint of storage stability.

[0008] Patent Documents 4, 5, 6, 7, and 8 disclose isocyanurate-modified polyisocyanates and foams produced therefrom. Relatively high catalyst concentrations (greater than 0.5 wt%) are used to produce the modified polyisocyanates, and the results do not show a linear relationship between NCO content, viscosity, and isocyanurate content. In each case, MDI with a viscosity of 130 mPa·s (25°C) is used. At catalyst concentrations greater than 0.5 wt%, it becomes difficult to control reactivity.

[0009] Patent Document 9 also discloses the production of modified polyisocyanates using high catalyst loadings, which are terminated thermally rather than chemically. However, this method has the disadvantage that catalyst residues that are not chemically inactivated may adversely affect the further reaction leading to polyurethane. Furthermore, the trimerization reaction continues for a certain period of time during thermal termination, making it nearly impossible to establish a specific product viscosity in a controlled manner.

[0010] Patent Document 10 discloses the trimerization of polyisocyanates using a catalyst, tetramethylguanidine, an iminourea derivative, which cannot be terminated with acid chlorides or hydrochloric acid, and therefore requires the use of methylsulfonic acid as a terminator, which adversely affects the corrosiveness of the composition.

[0011] Patent Document 11 discloses an isocyanate formulation containing a free radical initiator (tert-butyl peroxybenzoate) and an inhibitor (dibutylhydroxytoluene), the inhibitor being added simultaneously with the free radical initiator. During the reaction of the isocyanate formulation with a polyol, the free radical initiator is thermally decomposed at high temperatures to form free radicals, which initiate the free radical polymerization of olefins. To ensure the stability of the isocyanate formulation, the inhibitor is added together with the free radical initiator before use, i.e., to prevent the viscosity from increasing and ultimately solidifying during storage. Furthermore, this invention does not describe free radical initiators, particularly peroxides or azo compounds.

[0012] Patent Document 12 similarly discloses the trimerization of isocyanates using a free radical initiator. The reaction is not terminated, and no terminator is added. As a result, the trimerization reaction is believed to continue indefinitely until gelation occurs and the resulting isocyanate cannot be used in the foaming reaction. [Prior art documents] [Patent documents]

[0013] [Patent Document 1] U.S. Patent No. 4,743,627 [Patent Document 2] U.S. Patent Application Publication No. 2009 / 105359 [Patent Document 3] International Publication No. 2017 / 046274 [Patent Document 4] Japanese Patent Publication No. 06-256460 [Patent Document 5] Patent Publication No. 2008-260843 [Patent Document 6] Japanese Patent Publication No. 08-73557 [Patent Document 7] Japanese Patent Publication No. 08-92346 [Patent Document 8] Japanese Patent Publication No. 08-120048 [Patent Document 9] Japanese Patent Publication No. 59-163357 [Patent Document 10] German patent no. 69116583 [Patent Document 11] European Patent Application Publication No. 3974460 [Patent Document 12] International Publication No. 2020 / 221662 Summary of the Invention [Problem to be solved by the invention]

[0014] In light of the above-mentioned prior art, the object of the present invention was to provide a polyisocyanate component that allows the production of rigid PUR / PIR foams that have good early strength, allow for fast handling and stacking of the insulation panels produced from the rigid PUR / PIR foams, and exhibit good flame retardancy, while at the same time overcoming the drawbacks of the methods described in the prior art (lack of storage stability, poor foam properties, defects in the produced panels). [Means for solving the problem]

[0015] Surprisingly, this object has been achieved by an isocyanurate-containing pMDI having a viscosity of less than 2000 mPa·s at 25°C, in particular less than 1000 mPa·s at 25°C, and a number average molecular weight Mn of more than 350 g / mol, which can be obtained directly by trimerization of conventional polymeric MDI having a monomeric MDI content of less than 55% by weight, in particular less than 50% by weight, a viscosity of 130 mPa·s to 400 mPa·s at 25°C, preferably 140 mPa·s to 400 mPa·s, more preferably 140 mPa·s to 300 mPa·s at 25°C, and containing 5% to less than 13% by weight of isocyanurate groups.

[0016] The present invention therefore relates to a method for producing a composition A2 containing an isocyanate and an isocyanurate, which method comprises the steps of: 1) reacting polyisocyanate A1 in the presence of a trimerization catalyst; 2) terminating the reaction from step 1) using a suitable terminating agent to obtain composition A2; Including, the trimerization catalyst is not an iminourea, a derivative of an iminourea or a free radical initiator, and the concentration of trimerization catalyst used is less than 0.50% by weight, in particular less than 0.45% by weight, more preferably less than 0.40% by weight and very particularly preferably less than 0.30% by weight, based on A1, The polyisocyanate A1 used in step 1) is a polymeric MDI having a monomeric diphenylmethane diisocyanate content of less than 55% by weight, particularly preferably 30% to 50% by weight, and a viscosity of 140 mPa·s to 400 mPa·s (solvent-free according to DIN 53019-1:2008-09), Step 2) is carried out when the reaction mixture from step 1) contains 5% by weight to less than 13% by weight of isocyanurate groups and has a viscosity at 25°C of less than 2000 mPa·s (solvent-free according to DIN 53019-1:2008-09).

[0017] In the context of the present application, "oligomeric MDI" is understood to mean polyisocyanate mixtures composed of polynuclear homologues of MDI having at least three aromatic nuclei and an NCO functionality of at least three.

[0018] In the context of the present invention, the terms "polymeric diphenylmethane diisocyanate", "polymeric MDI" or pMDI are used to describe a mixture of oligomeric MDI and, optionally, monomeric MDI. The monomer content of polymeric MDI is typically in the range of 30% to 50% by weight relative to the total mass of the pMDI.

[0019] Polyisocyanate A1 contains less than 55% by weight, particularly preferably 30% to 50% by weight or less, of monomeric MDI and has a viscosity at 25°C of 130 to 400 mPa·s, preferably 140 to 400 mPa·s at 25°C, particularly preferably 140 to 300 mPa·s at 25°C (solvent-free according to DIN 53019-1:2008-09). It is particularly preferred to use a polymeric MDI having 35 to 50% by weight of 4,4'-methylidene diphenyl diisocyanate, 1 to 10% by weight of 2,4'-methylidene diphenyl diisocyanate, more than 0 to 5% by weight of 2,2'-methylidene diphenyl diisocyanate, and 45 to less than 64% by weight of a higher homologue (having three or more aromatic nuclei) of methylidene diphenyl diisocyanate. It is particularly preferred to use a composition containing 40% to 50% by weight, especially 40% to 46% by weight, of 4,4'-methylidene diphenyl diisocyanate, 1% to 5% by weight of 2,4'-methylidene diphenyl diisocyanate, more than 0% but not more than 5% by weight of 2,2'-methylidene diphenyl diisocyanate, and 45% to less than 60% by weight of a higher homologue (having three or more aromatic nuclei) of methylidene diphenyl diisocyanate.

[0020] Polyisocyanate A1 is subjected to a trimerization reaction [step (1)]. The trimerization reaction is known per se, and is described, for example, in

[0015] to

[0016] of WO 2009 / 039332.

[0021] (incorporated herein by reference). Suitable trimerization catalysts include, for example, Mannich bases of phenols or phenol derivatives (e.g., 2,4,6-tris(dimethylaminomethyl)phenol and 4,4'-isopropylidenebis[2,6-bis(dimethylaminomethyl)phenol]), potassium acetate, and / or aliphatic quaternary ammonium salts. Iminoureas, such as 1,1,3,3-tetramethylguanidine, are unsuitable as catalysts because of the subsequent difficulty in terminating the trimerization reaction with acid chlorides. Similarly, free radical initiators, particularly peroxy compounds and azo compounds, are also unsuitable as catalysts because of the similar difficulty in terminating the free radical-induced trimerization reaction.

[0021] The concentration of trimerization catalyst used is less than 0.50% by weight, in particular less than 0.45% by weight, more preferably less than 0.40% by weight, and very particularly preferably less than 0.30% by weight, based on A1, as at higher concentrations the trimerization reaction proceeds too rapidly and is difficult to stop in time.

[0022] The content (wt%) of isocyanurate groups in the composition A2 containing isocyanate and isocyanurate obtained after the trimerization reaction can be determined as follows: Isocyanurate%(A2)=(NCO%(A1)-NCO%(A2)) / (NCO%(A1) / 2)×100

[0023] The determination of the weight fraction of NCO groups is carried out in accordance with DIN EN 1242:2013.

[0024] Viscosity specifications in this application refer to viscosities determined in accordance with DIN 53019-1(2008-09) (solvent-free).

[0025] The composition of the isocyanate and isocyanurate-containing composition A2 and the composition of the isocyanate component A can be determined by gel permeation chromatography (GPC) in accordance with DIN 55672-1:2016-03 at 35° C. using tetrahydrofuran as solvent.

[0026] Composition A2 or isocyanate component A preferably has a seventh peak ("Peak G" corresponding to the seventh smallest molecular weight fraction) with a peak area exceeding 4.6 area % in GPC.

[0027] Composition A2 or isocyanate component A preferably has a number average molecular weight Mn of more than 350 g / mol.

[0028] Composition A2 is The content of isocyanurate groups is 5% by weight to less than 13% by weight of isocyanurate groups, The number average molecular weight Mn exceeds 350 g / mol, In GPC, there is a seventh peak corresponding to the seventh smallest molecular weight fraction, and the peak area preferably exceeds 4.6 area %; The viscosity at 25°C is less than 2000 mPa·s, preferably less than 1000 mPa·s at 25°C.

[0029] Compared to compositions according to the prior art, composition A2 produced by the process according to the invention has a lower content of trimerization catalyst and an advantageous molecular weight distribution, which leads to advantageous properties in the subsequent processing to obtain rigid PUR / PIR foams, such as better surface quality.

[0030] According to the present invention, the trimerization reaction is terminated in a controlled manner by adding a deactivating agent ("terminator"). In principle, any acid chloride or any Brønsted acid can be used except for sulfonic acid, sulfuric acid, or their derivatives (because these compounds are highly corrosive). Usable acid chlorides include, inter alia, acetyl chloride and benzoyl chloride, and mixtures thereof. A preferred example of an acid chloride is benzoyl chloride, and a more preferred example is isophthaloyl chloride. Usable acids include, inter alia, hydrochloric acid, acetic acid, oxalic acid, and phosphoric acid. Preferred are hydrochloric acid, acetic acid, and oxalic acid. A particularly preferred example of an acid is hydrochloric acid. The acid chloride or Brønsted acid can also be used as a solution or dispersion in an organic solvent, monomeric MDI, or polymeric MDI.

[0031] The isocyanate- and isocyanurate-containing composition A2 obtained after step 2) can be used alone or in admixture with additional isocyanates to produce polymers, especially rigid PUR foams and rigid PUR / PIR foams. For example, it is possible to establish a specific viscosity by blending with additional polyisocyanates. Aliphatic, cycloaliphatic, and araliphatic diisocyanates and / or polyisocyanates, especially aromatic isocyanates, known in polyurethane chemistry are suitable here. In particular, isomers and oligomers of MDI and TDI can be used.

[0032] Further aspects of the present invention are a composition A2 containing an isocyanate and an isocyanurate, and an isocyanate component A comprising composition A2, which can be obtained by the process according to the invention.

[0033] The present invention also relates to a method for producing rigid PUR / PIR foams by reacting a PUR / PIR system composed of an isocyanate component A and a polyol formulation B in the presence of a blowing agent C and a catalyst D, wherein the isocyanate component A comprises a composition A2 containing an isocyanate and an isocyanurate according to the present invention.

[0034] PUR / PIR systems are preferably used to manufacture component composites. Foaming is typically carried out continuously or discontinuously for at least one outer layer.

[0035] Rigid PUR / PIR foams can be obtained by reacting a PUR / PIR system, wherein the isocyanate component A and the polyol formulation B are generally reacted in amounts such that the foam has an isocyanate index of 250 or greater and 450 or less, preferably 320 or greater and 400 or less.

[0036] The isocyanate index in this specification is the quotient calculated from the molar amount [mol] of isocyanate groups actually used and the molar amount [mol] of isocyanate groups stoichiometrically required for complete conversion of the isocyanate-reactive groups, multiplied by 100. Since one mole of isocyanate groups is required to convert one mole of isocyanate-reactive groups, the following formula applies: Index = (number of moles of isocyanate groups / number of moles of isocyanate-reactive groups) x 100

[0037] The isocyanate component A has in particular the following properties: less than 13% by weight of isocyanurate groups, Monomeric MDI 20% by weight to 50% by weight, preferably 20% by weight to 40% by weight, NCO content 23% to 30% by weight (DIN EN 1242:2013), In each case, the weight is based on the total weight of component A. The viscosity at 25°C is less than 2000 mPa·s, preferably less than 1000 mPa·s at 25°C.

[0038] To produce the isocyanate component A, the isocyanate- and isocyanurate-containing composition A2 of the present invention may optionally be blended with additional isocyanates, for example to achieve a lower or higher viscosity. In a preferred embodiment, the isocyanate- and isocyanurate-containing composition A2 of the present invention is used without blending with additional isocyanates. Suitable isocyanates for blending with the isocyanate- and isocyanurate-containing composition A2 of the present invention include conventional aliphatic, cycloaliphatic, and araliphatic diisocyanates and / or polyisocyanates known from polyurethane chemistry, especially aromatic isocyanates. Aromatic isocyanates, especially homologs and isomers of the MDI series, are particularly preferred. Suitable isocyanates for blending can also be selected from polyurethane prepolymers and modified isocyanates. The term "polyurethane prepolymer" refers specifically to a reactive intermediate in the reaction from isocyanates to polyurethane polymers. They are produced by reacting a polyol component with an excess of an isocyanate component. Preferred modified isocyanates include urea-, biuret-, urethane-, isocyanurate-, allophanate-, carbodiimide-, uretdione-, and uretonimine-modified isocyanates. Such modified isocyanates are commercially available and are produced by reacting an isocyanate with a substoichiometric amount of an isocyanate-reactive compound or with itself.

[0039] It is especially possible to use isomers and oligomers of MDI and TDI in the formulation.

[0040] Compounds based on polyesterols or polyetherols are preferably used as the polyol in polyol blend B. The functionality of the polyetherols and / or polyesterols is generally 1.9 to 8, preferably 1.9 to 7, and particularly preferably 1.9 to 6.

[0041] The polyols in particular have a hydroxyl number of more than 70 mg KOH / g, preferably more than 100 mg KOH / g, particularly preferably more than 120 mg KOH / g. The upper limit of the hydroxyl number that has proven advantageous is generally 1000 mg KOH / g, preferably 900 mg KOH / g, in particular 800 mg KOH / g. The above-mentioned OH numbers relate to the polyols in polyol blend B as a whole, and do not prevent the individual components of the mixture from having higher or lower values.

[0042] The polyol formulation B preferably contains a polyether polyol produced by anionic polymerization of one or more alkylene oxides having 2 to 4 carbon atoms in the alkylene radical using a known method, for example, an alkali metal hydroxide (such as sodium hydroxide or potassium hydroxide) or an alkali metal alkoxide (such as sodium methoxide, sodium ethoxide, or potassium ethoxide, or potassium isopropoxide) as a catalyst, with the addition of at least one starter molecule containing 2 to 8, preferably 2 to 6, reactive hydrogen atoms in bond form, or by cationic polymerization using a Lewis acid (e.g., antimony pentachloride, boron fluoride etherate, or fuller's earth, among others) as a catalyst. Suitable alkylene oxides include, for example, tetrahydrofuran, 1,3-propylene oxide, 1,2-butylene oxide, and 2,3-butylene oxide, styrene oxide, and preferably ethylene oxide and 1,2-propylene oxide. These alkylene oxides can be used individually, alternately in succession, or as a mixture. Possible starter molecules include alcohols such as glycerol, trimethylolpropane (TMP), pentaerythritol, sucrose, sorbitol; and amines such as methylamine, ethylamine, isopropyleneamine, butylamine, benzylamine, aniline, toluidine, toluenediamine, naphthylamine, ethylenediamine, diethylenetriamine, 4,4'-methylenedianiline, 1,3-propanediamine, 1,6-hexanediamine, ethanolamine, diethanolamine, triethanolamine, etc.The starting molecules may also be condensation products of formaldehyde, phenol, and diethanolamine / ethanolamine; condensation products of formaldehyde, alkylphenol, and diethanolamine / ethanolamine; condensation products of formaldehyde, bisphenol A, and diethanolamine / ethanolamine; condensation products of formaldehyde, aniline, and diethanolamine / ethanolamine; condensation products of formaldehyde, cresol, and diethanolamine / ethanolamine; condensation products of formaldehyde, toluidine, and diethanolamine / ethanolamine; and condensation products of formaldehyde, toluenediamine (TDA), and diethanolamine / ethanolamine. Preferably, the starting molecules used are TMP and TDA.

[0043] Polyol formulation B may contain a crosslinking agent as a further constituent. A crosslinking agent is understood to be a compound having a molecular weight of 60 g / mol to less than 400 g / mol and having at least three hydrogen atoms reactive with isocyanates. An example is glycerol. The crosslinking agent is generally used in an amount of 1% to 10% by weight, preferably 2% to 6% by weight, based on the total weight of polyol formulation B (excluding the physical blowing agent).

[0044] Polyol formulation B may also contain a chain extender, which serves to increase the crosslink density. Chain extenders are understood to be compounds having a molecular weight of 60 g / mol to less than 400 g / mol and having at least two hydrogen atoms reactive with isocyanates. Examples include butanediol, diethylene glycol, dipropylene glycol, and ethylene glycol. The chain extender is generally used in an amount of 2% to 20% by weight, preferably 4% to 15% by weight, based on the total weight of polyol formulation B (excluding the physical blowing agent).

[0045] The crosslinkers and chain extenders can be used individually or in combination in the polyol mixture.

[0046] The production of rigid PUR / PIR foams further uses chemical and / or physical blowing agents (C).

[0047] Preferred chemical blowing agents include water or carboxylic acids, especially formic acid. The chemical blowing agents are generally used in an amount of 0.1% to 5% by weight, especially 1.0% to 3.0% by weight, based on the weight of component B.

[0048] The term physical blowing agent is understood to mean a compound that dissolves or emulsifies in the starting materials for polyurethane production and vaporizes under polyurethane-forming conditions. Examples include hydrocarbons, halogenated hydrocarbons, and other compounds, such as perfluorinated alkanes such as perfluorohexane, hydrochlorofluorocarbons, and ethers, esters, ketones, and / or acetals. These are typically used in an amount of 1% to 30% by weight, preferably 2% to 25% by weight, and particularly preferably 3% to 20% by weight, based on the total weight of component B.

[0049] The production of rigid PUR / PIR foams further utilizes catalyst D. Catalyst D, used to promote the reaction between the hydroxyl-containing compound of Component B and the isocyanate groups of Component A, is typically preferably an organotin compound, such as a tin(II) salt of an organic carboxylic acid, and / or a basic amine compound, preferably a tertiary amine, such as triethylamine, and / or 1,4-diaza-bicyclo-(2,2,2)-octane. Catalyst D, used to form isocyanurate groups in the production of rigid PUR / PIR foams, is typically selected from metal carboxylates, preferably potassium acetate or potassium octanoate, and solutions thereof. Rigid PUR / PIR foams utilize a mixture of a catalyst promoting the reaction between the hydroxyl-containing compound of Component B and the isocyanate groups of Component A and a catalyst to form isocyanurate groups. The catalyst is generally used in an amount of 0.001% to 5% by weight, based on the weight of Component B.

[0050] The PUR / PIR system may also optionally be admixed with further auxiliary and / or additive substances E. These are understood to mean the customary auxiliary and additive substances known in the prior art. These can be added to the polyol component B or directly to the reaction mixture. These include, for example, surface-active substances, foam stabilizers, cell regulators, fillers, dyes, pigments, flame retardants, antistatic agents, hydrolysis inhibitors, and / or fungistatic and bacteriostatic substances.

[0051] The present invention also relates to rigid PUR / PIR foams obtainable by the process according to the invention. In the context of the present invention, rigid PUR / PIR foams are in particular those having an apparent density of 15 kg / m according to DIN EN ISO 3386-1-98 (September 2010). 3 ~300kg / m 3 and a compressive strength according to DIN EN 826 (May 1996) in the range of 0.1 MPa to 3 MPa.

[0052] Surprisingly, these rigid PUR / PIR foams have been found to have improved stackability compared to rigid foams produced using conventional MDI or pMDI with a relatively high isocyanurate content. This is measured after production in the form of an indentation depth at a specified weight and specified piston area (see the experimental part for an explanation) and is related to the cure rate. At the same time, the rigid PUR / PIR foams also exhibit very good storage stability and foam properties, improved flame retardancy, and the produced panels are almost free of defects. The rigid PUR / PIR foams according to the invention also have advantages in terms of water absorption.

[0053] Therefore, the rigid PUR / PIR foam according to the invention can be advantageously used as a thermal insulating foam in the manufacture of elemental composite articles.

[0054] The present invention also relates to an elementary composite comprising a rigid foam layer containing a rigid PUR / PIR foam according to the invention and at least one outer layer, where the outer layer is at least partially in contact with the layer containing the rigid PUR / PIR foam according to the invention, and the material of the outer layer is typically aluminum, steel, bitumen, paper, mineral nonwovens, nonwovens containing organic fibers, plastic sheets, plastic films, and / or wood sheets.

[0055] In another embodiment of the element composite article, it is in the form of an insulating panel. DETAILED DESCRIPTION OF THE INVENTION

[0056] Experimental Section: How to use: Mold temperature: Temperature of the mold used for foaming (℃) Mixing time: The time (in seconds) to mix the reaction mixture. Cream time: The time (seconds) elapsed from the start of mixing until the start of the reaction is detected Fiber time: The time (seconds) elapsed from the start of mixing until the foam surface solidifies Tack-free time: The time (seconds) elapsed from the start of mixing until the foam surface becomes tacky. Indentation depth (after a certain time): Indentation depth test is performed on a 20 x 20 cm 2 The test is carried out on freshly prepared laboratory foams in test packages with a base area of ​​1000 mm. After a specified time in the curing stage, the penetration depth of a piston with a diameter of 3.5 cm and a piston weight of 6 kg is determined. Cell size: Scale of 1 to 6; 1 means very fine or very uniform, 6 means very coarse or irregular. Surface / foam interior: qualitative differentiation of brittle, sandy and tough Apparent core density: DIN EN ISO 845:2009 "Foams of rubber and plastics - Determination of apparent density" Isocyanate content: DIN EN 1242:2013 "Determination of isocyanate content" Viscosity: DIN 53019-1:2008 "Viscometry - Measurement of viscosities and flow curves with rotational viscometers". Measurements were carried out without solvent. Hydroxyl number (OH number): The determination of the OH number was carried out in accordance with the standard DIN 53240-2:2007. Dimensional stability (dim.stab.): After storing foam specimens at 20°C to 25°C for at least 24 hours, the dimensional stability of 10 x 10 x 10 cm 3 Two foam cubes with dimensions of 1.0 mm are removed from the core. The three spatial directions of each cube are marked, then measured with a caliper and stored at -22°C and 100°C, respectively, for 24 hours. The cubes are then measured again at room temperature. The dimensional stability is the percentage change ΔL in edge length in all three spatial directions A, B, and C, where C always corresponds to the foaming direction: ΔL = (L - OL) / OL x 100%, where L = edge length of the test specimen after storage and OL = edge length of the test specimen before storage. A foam passes this test if the change in each direction at -22°C and 100°C is less than 1%. Water absorption: A cube of 90 mm x 90 mm x 60 mm is weighed and immersed in water in a desiccator, and the pressure is reduced to 100 mbar for 60 seconds. After that, the excess water is drained and the cube is weighed to determine the water absorption. Swiss fire resistance test: Tested in accordance with Fire Protection Directive No. 585.113 of the Association of Cantonal Fire Insurance Companies (VKF) (SAR 585.113, Switzerland, 23 March 2015, Annex 5 of the Fire Protection Ordinance). SBT (Small Burner Test): Flame retardancy test according to DIN EN ISO 11925-2 (2020-07) for flame retardancy classification. Compression strength: Compression strength in the direction of travel at 10% compression according to DIN EN 826-01 (2013-05). Thermal conductivity: Thermal conductivity according to DIN EN 12667-01 (2001-05) (10°C or 70°C, 0 value); 0 value is understood to mean that the measurement was carried out immediately after production, without prior storage. The content of isocyanurate groups in Isocyanate 1, Isocyanate 2 and Isocyanate 3 is determined by the following formula: Isocyanurate % (Isocyanate 1, Isocyanate 2, or Isocyanate 3) = (NCO % (input material) - NCO % (Isocyanate 1, Isocyanate 2, or Isocyanate 3)) / (NCO % (input material) / 2) x 100 where NCO% (input) is the NCO content of the polyisocyanate A1 (MDI200 / MDI100) used. Storage Test: The storage stability of the isocyanates was qualitatively assessed by storing test specimens in the laboratory at room temperature for 3 months and visually assessing them. GPC gel permeation chromatography: The content of various substances was determined by gel permeation chromatography (GPC) in tetrahydrofuran at 35 °C according to DIN 55672-1:2016-03 (PSS Polymer Services SECurity GPC system, flow rate 0.6 ml / min; columns: 2 x PSS SDV 50A 5 μm, 2 x PSS SDV 100A 5 μm, 8 x 300 mm; RI detector). Polystyrene standards of known molecular weight were used for calibration. Number-average molecular weights were calculated using PSS WinGPC software. In the chromatogram, peaks are labeled as shown in Figure 1. The seventh lowest molecular weight peak is designated "Peak G."

[0057] Materials used: MDI100: Desmodur 44V10L, polymeric diphenylmethane diisocyanate (Covestro Deutschland AG); isocyanate content 31.8% by weight, viscosity at 25°C approximately 100 mPa·s MDI200: Desmodur 44V20L, polymeric diphenylmethane diisocyanate (Covestro Deutschland AG); isocyanate content 31.5% by weight, viscosity at 25°C approximately 200 mPa·s MDI700: Desmodur 44V70L, polymeric diphenylmethane diisocyanate (Covestro Deutschland AG); isocyanate content 30.9% by weight, viscosity at 25°C approximately 700 mPa·s Benzoyl chloride: Obtained from Sigma-Aldrich; 99.5%; boiling point 198°C Tris(dimethylaminomethyl)phenol: Obtained from Sigma-Aldrich; 95%; Refractive index n20 / D 1.516; Boiling point: 130°C to 135°C Polyol 1: Aromatic polyester polyol (Synthesia Technology) with an OH value of 240 mg / kg KOH, a functionality determined from raw materials of 1.9, and a viscosity of 1500 mPa·s at 25°C. Polyol 2: A polyether diol (Covestro) with an OH value of 28 mg / kg KOH and a viscosity of 860 mPa·s at 25°C, produced using 1,2-propylene glycol as the starter and a mixture of ethylene oxide and propylene oxide in a ratio of 30 parts by weight to 70 parts by weight. Polyol 3: Aromatic polyester polyol (Covestro) with an OH value of 370 mg / kg KOH, a raw material functionality of 1.9, and a viscosity of 1400 mPa·s at 25°C. Polyol 4: Aromatic polyester polyol (Covestro) with an OH value of 795 mg / kg KOH, a functionality determined from raw materials of 2.0, and a viscosity of 1400 mPa·s at 25°C. Polyol 5: Aromatic polyester polyol (Stepan Company) having an OH number of 240 mg / kg KOH, an acid number of 0.8, and a viscosity of 3000 mPa·s at 25°C. Polyol 6: A polyether diol (Covestro) produced using glycerol as the starting material and ethylene oxide and propylene oxide in a ratio of 13 parts by weight to 87 parts by weight, with ethylene oxide added as the second block, having an OH value of 35 mg / kg KOH and a viscosity of 860 mPa·s at 25°C. Diethylene glycol: Diethylene glycol (Aldrich) Triethyl phosphate: flame retardant (Lanxess) Disflamoll DPK: Flame retardant (Lanxess) Tegostab B8443: Foam stabilizer (Evonik) DABCO LK443: Foam stabilizer (Evonik) Desmorapid 1792: Potassium acetate catalyst (Covestro) Desmorapid DB: benzyldimethylamine catalyst (Covestro) Desmorapid VP.PU1221 VN: Catalyst (Covestro) Desmorapid 1118: Catalyst (Covestro) Tetramethylguanidine: 1,1,3,3-tetramethylguanidine (Aldrich) n-Pentane: n-Pentane blowing agent (Aldrich) Cyclopentane: Cyclopentane blowing agent (Aldrich) Isopentane: Isopentane blowing agent (Aldrich) Adhesion promoter: 2K adhesion promoter (Covestro) TCPP: Fyrol PCF flame retardant (ICL) Tegostab B8421: Foam stabilizer (Evonik) Desmorapid PV: pentamethyldiethylenamine catalyst (Covestro) Kosmos 75 MEG: Potassium octanoate catalyst (Biesterfeld) Polyol Mixture 1: A mixture consisting of the following components:

[0058] TIFF2026500501000001.tif34170 [Example]

[0059] Example 1: Preparation of Isocyanate 1 (Invention) Under dry nitrogen, 99.80 parts by weight of MDI 200 is initially charged and heated to 60°C. 0.17 parts by weight of tris(dimethylaminomethyl)phenol is added. The reaction temperature is maintained constant at 60±2°C. When the target viscosity of 700 mPa·s at 25°C is reached, 0.03 parts by weight of benzoyl chloride is added and the mixture is stirred at 60°C for 20 minutes. The viscosity, NCO content, and isocyanurate group content of Isocyanate 1 are 678 mPa·s at 25°C, NCO content: 29.92%, and isocyanurate group content: 10.0% by weight.

[0060] The GPC of Isocyanate 1 is shown in Figure 1. Table 1 shows a comparison of the peak areas and number average molecular weights obtained from the gel permeation chromatograms of Isocyanate 1 and Isocyanate 2. TIFF2026500501000002.tif116170

[0061] The area corresponding to peak G is 5.0 area %.

[0062] The number average molecular weight Mn is 356 g / mol.

[0063] Example 2a * : Formation of Isocyanate 2 (Comparison of Redilution, Non-invention) Under dry nitrogen, 99.80 parts by weight of MDI200 are initially charged and heated to 60°C. 0.17 parts by weight of tris(dimethylaminomethyl)phenol are added. The reaction temperature is kept constant at 60±2°C. When the target viscosity of 3000 mPa·s at 25°C is reached, 0.03 parts by weight of benzoyl chloride is added and the mixture is stirred at 60°C for 20 minutes. Viscosity of the intermediate product: 3360 mPa·s at 25°C; NCO content of the intermediate: 28.52% NCO.

[0064] After the trimerization reaction was completed, 94.97 parts by weight of MDI 200 was added to obtain the same viscosity and trimer content as Isocyanate 1. Isocyanate 2 obtained after mixing had a viscosity of 705 mPa·s at 25°C, an NCO content of 29.91% NCO, and 10.0% by weight of isocyanurate groups.

[0065] The area corresponding to peak G is 4.4 area %.

[0066] The number average molecular weight Mn is 346 g / mol.

[0067] Example 2b * : Formation of isocyanate 3 (relatively low viscosity comparison, Patent Document 10, non-invention) Under dry nitrogen, 99.80 parts by weight of MDI100 is initially charged and heated to 60°C. 0.17 parts by weight of tris(dimethylaminomethyl)phenol is added. The reaction temperature is maintained at 60±2°C. When the NCO content drops by approximately 1.5% (corresponding to approximately 10% by weight of isocyanurate groups), 0.03 parts by weight of benzoyl chloride is added and the resulting mixture is stirred at 60°C for 20 minutes. The viscosity, NCO content, and isocyanurate group content of Isocyanate 3 at 25°C are 355 mPa·s, NCO content: 29.98% NCO, and isocyanurate group content: 11.4% by weight.

[0068] Example 2c * : Formation of isocyanate 4 (comparison of iminourea catalyst, Patent Document 10, non-invention) Under dry nitrogen, 99.80 parts by weight of MDI200 was initially charged and heated to 60°C. 0.17 parts by weight of tetramethylguanidine was added. The reaction temperature was kept constant at 60±2°C. When the NCO content decreased by approximately 1.5% (corresponding to approximately 10% by weight of isocyanurate groups), 0.03 parts by weight of benzoyl chloride was added and the resulting mixture was stirred at 60°C for 20 minutes. The reaction did not stop after the addition of benzoyl chloride. The reaction mixture was then cooled to room temperature. In this case, the reaction did not stop and continued until a solid was formed after 24 hours.

[0069] TIFF2026500501000003.tif81170

[0070] Examples 3 to 6: Preparation of PUR / PIR foams The resulting isocyanate- and isocyanurate-containing compositions, Isocyanate 1 and Isocyanate 2, were used to make rigid PUR / PIR foams and compared to a standard polyisocyanate composition of similar viscosity that did not contain isocyanurate. Table 2 below shows the results of the comparison of the isocyanate- and isocyanurate-containing compositions, Isocyanate 1, used in inventive Example 5 and Comparative Example 3. * and Example 4 * In Comparative Example 6, the composition MDI700 containing only isocyanate groups was used. * In each case, the same polyol formulation is foamed using Isocyanate 2, a composition containing isocyanate and isocyanurate. For ease of comparison, the isocyanate composition was substituted in equal parts by weight in each case, resulting in some variation in the index.

[0071] TIFF2026500501000004.tif221170

[0072] Experiments have shown that the use of Isocyanate 1, a composition containing an isocyanate and an isocyanurate according to the present invention, can be used to produce rigid PUR / PIR foams by substituting conventional pMDI by weight fraction (i.e., without index matching), and the rigid PUR / PIR foams are comparable to those produced from conventional pMDI when comparing their physical / mechanical properties and performance characteristics, and are clearly superior in terms of penetration depth after 2.5 minutes and 5 minutes (Example 5). Non-inventive Example 6 * showed that rediluting a very viscous trimerized pMDI (viscosity at 25 °C before dilution greater than 2000 mPa·s, see the production of Isocyanate 2) to obtain a composition containing approximately 700 mPa·s of isocyanate and isocyanurate (Isocyanate 2) gave similar advantages in terms of penetration depth after 2.5 and 5 minutes, but the rigid PUR / PIR foam did not perform as well in fire tests.

[0073] Examples 7 to 9: Fabrication of element composites with a steel outer layer on a double belt The isocyanate components Isocyanate 1, Isocyanate 2 and MDI 700 were in each case subjected to industrial-scale testing on a double conveyor belt with a steel outer layer (so-called metal panel; Table 3). The test conditions, input materials and results are summarized in Table 3.

[0074] The results show that the isocyanate and isocyanurate-containing composition of the present invention, Isocyanate 1, can be used to create component composites with rigid PUR / PIR foams that have comparable physical / mechanical and performance properties by substituting conventional pMDI by weight fraction (i.e., without index matching) (Example 8). Non-inventive Example 9 *also showed that redilution of very viscous trimerized pMDI (viscosity at 25 °C before dilution > 2000 mPa·s, see preparation of Isocyanate 2) to obtain a composition containing approximately 700 mPa·s of isocyanate and isocyanurate (Isocyanate 2) gave identical mechanical properties, but produced undesirable defects on the backside of the sheet metal and significantly worse fire test results.

[0075] TIFF2026500501000005.tif254170

[0076] Examples 10 to 12: Fabrication of element composites with an aluminum upper layer on a double belt Industrial-scale tests using a double conveyor belt with an aluminum outer layer (so-called insulation board, Table 4) show that the use of the inventive isocyanate- and isocyanurate-containing composition, Isocyanate 1, can be used to produce component composites with rigid PUR / PIR foams with comparable physical / mechanical and performance properties (Example 11) by substituting conventional pMDI by weight fraction (i.e., without index matching). Non-inventive Example 12 * However, when rediluted trimerized pMDI with a very high viscosity before redilution (viscosity at 25°C before dilution greater than 2000 mPa·s, see the production of Isocyanate 2) was used to obtain a composition containing approximately 700 mPa·s of isocyanate and isocyanurate (Isocyanate 2), the same mechanical properties were obtained, but undesirable defects occurred in the outer layer, and the compressive strength of Inventive Example 11 was significantly lower than that of Comparative Example 10 using conventional pMDI. * and Comparative Example 12 * It also shows that it is superior to both

[0077] From laboratory-scale tests (so-called thermal insulation boards, Table 5), the use of Isocyanate 1, an isocyanate- and isocyanurate-containing composition of the present invention, showed significantly improved indentation depth and water absorption after 3 and 5 minutes (Example 13) compared with non-invention Isocyanate 3 (Patent Document 10, Example 14). *This is due to the high content of monomeric diphenylmethane diisocyanate. The MDI 100 used here is similar to the isocyanate used as an input material in Patent Document 10. Comparative Example 14 * In the non-invention, the functionality of the isocyanate 3 is reduced by using MDI 100.

[0078] In summary, it should be recognized that the use of the inventive isocyanate and isocyanurate containing composition, Isocyanate 1, compared to conventional MDI 700 and the non-inventive isocyanurate containing composition, Isocyanate 2, provides advantages in terms of foam sheet stackability / early strength measured as indentation depth after 2.5 minutes and 5 minutes, element composite quality (especially the surface), and flame retardancy.

[0079] TIFF2026500501000006.tif249170

[0080] TIFF2026500501000007.tif148170

Claims

1. 1. A method for producing a composition A2 containing an isocyanate and an isocyanurate, comprising the steps of: 1) reacting polyisocyanate A1 in the presence of a trimerization catalyst; 2) terminating the reaction according to step 1) using a suitable terminating agent to obtain composition A2; Including, the trimerization catalyst is not an iminourea, an iminourea derivative, or a free radical initiator, and the concentration of the trimerization catalyst used is less than 0.50% by weight based on A1; the polyisocyanate A1 used in step 1) is a polymeric MDI having a monomeric diphenylmethane diisocyanate content of less than 55% by weight and a viscosity at 25°C of 130 mPa s to 400 mPa s, preferably 140 mPa s to 400 mPa s (solvent-free according to DIN 53019-1:2008-09); 2) is carried out when the reaction mixture from step 1) contains 5% by weight to less than 13% by weight of isocyanurate groups and has a viscosity at 25°C of less than 2000 mPa s (solvent-free according to DIN 53019-1:2008-09).

2. 2. The method according to claim 1, wherein the polyisocyanate A1 used comprises up to 50% by weight of monomeric MDI and / or has a viscosity at 25°C of 140 mPa·s to 300 mPa·s (solvent-free according to DIN 53019-1:2008-09).

3. 10. The method of claim 1, wherein the terminator is a compound selected from an acid chloride or a Bronsted acid, with the proviso that it is not a sulfonic acid, sulfuric acid, or a derivative of these acids.

4. Composition A2 containing an isocyanate and an isocyanurate, obtainable by the method according to any one of claims 1 to 3.

5. Composition A2 according to claim 4, characterized in that in GPC it has a seventh peak corresponding to the seventh smallest molecular weight fraction, with a peak area of ​​more than 4.6 area %.

6. 6. Composition A2 according to claim 4 or 5, having a number average molecular weight Mn of more than 350 g / mol.

7. Composition A2 according to any one of claims 4 to 6, characterized in that it has a viscosity at 25°C of less than 1000 mPa·s (solvent-free according to DIN 53019-1:2008-09).

8. An isocyanate component A comprising a composition A2 according to any one of claims 4 to 7.

9. 10. A PUR / PIR system for producing rigid PUR / PIR foams from the isocyanate component A of claim 8 and the polyol formulation B in the presence of a blowing agent C, and optionally catalyst D, auxiliary substances and additive substances E.

10. 10. The PUR / PIR system according to claim 9, characterized in that the foam has an isocyanate index of 250 to 450, preferably 320 to 400.

11. 11. A method for producing rigid PUR / PIR foam by reacting the PUR / PIR system of claim 9 or 10.

12. 12. Rigid PUR / PIR foam obtainable by the method according to claim 11.

13. 13. Use of the rigid PUR / PIR foam according to claim 12 as a thermal insulating foam in the manufacture of elementary composite articles.

14. 13. A component composite article comprising a rigid foam layer comprising the rigid PUR / PIR foam of claim 12 and at least one outer layer.

15. 15. The elementary composite article according to claim 14, wherein the material of the outer layer is aluminum, steel, bitumen, paper, mineral nonwoven fabric, nonwoven fabric containing organic fibers, plastic sheet, plastic film, and / or wood sheet.

Images