Use of epoxy compounds as carbon dioxide scavengers in PIR-containing foams for excellent thermal insulation properties

Abstract

A reactive composition for preparing a PIR-containing foam at an isocyanate index of at least 120, the composition comprising at least an isocyanate composition comprising one or more isocyanate compounds; an isocyanate-reactive composition comprising one or more isocyanate-reactive compounds; at least one PIR-promoting catalyst; at least one physical blowing agent having a lambda gas of ≤12 mW / m·K at 10° C.; at least one CO 2 scavenging compound selected from at least one epoxy compound; and an optional catalyst for promoting the reaction of the epoxy compound with CO 2 , characterized in that the amount of the isocyanate-reactive compound in the reactive composition is at least 10% by weight, calculated on the total weight of the reactive composition, or is at least greater than the amount of the epoxy compound, and the molar amount of the epoxy compound in the reactive composition is at least 7.8 times the molar amount of CO 2 formed after the reaction of water present in the reactive composition with the isocyanate.

Description

Technical Field

[0001] The present invention relates to polyisocyanurate (PIR) containing thermal insulation foams, and more particularly to semi-rigid and rigid PIR containing thermal insulation foams having significantly improved long term thermal insulation values ​​when used under diffusion tight conditions, such that low thermal conductivity (λ value) is achieved during the average economic life of the foam.

[0002] The present invention further relates to reactive compositions and methods for producing PIR-containing insulating foams having significantly improved insulating properties that are maintained over the average economic life of the foam, using a blowing agent with a low lambda gas value (≤12 mW / m·K at 10° C.) in combination with a predetermined amount of a CO 2 scavenger.

[0003] The present invention further relates to the use of epoxy compounds as CO2 scavengers in thermal insulation foams containing PIR. Background Art

[0004] After manufacture, it is known that closed-cell rigid insulation foams comprising polyisocyanurate (PIR) and polyurethane (PUR) generally contain CO2 which is released during the foaming process.

[0005] Because the thermal conductivity of CO2 gas (expressed in mW / m·K and recorded as "λ" or "λ" value) is higher than that of common physical blowing agents, the overall λ value of a given foam containing PUR and PIR is generally higher than it would be in the absence of CO2 gas.

[0006] To address this problem, CO2 can be removed from the cell gas mixture after the foam is generated, for example by using a CO2 scavenger incorporated into the foam.

[0007] Various CO2 scavengers have been previously identified and successfully used in isocyanate-based foams (EP 1031601 and EP 0618253), such as zeolites, calcium hydroxide, sodium hydroxide, lithium hydroxide, ...

[0008] WO2019 / 211259 discloses the use of NaOH and KOH compounds as CO2 scavengers. Due to their low cost (commodity chemicals) and their quantitative reaction with CO2, these compounds result in effective scavenging. However, they are used in the form of solid particles, which is not ideal in terms of processing. In addition, they are only suitable for aging conditions where some moisture diffusion within the foam can occur (i.e., moisture-catalyzed scavenging), which precludes their use in applications such as composite panels, appliances, or pipes unless specific moisture-permeable surfaces are used.

[0009] EP0723989 discloses the use of an epoxy compound as a CO2 scavenger in a method for producing polyurethane (PUR) thermal insulation foam, wherein the amount of the epoxy compound is not less than 2.5 molar equivalents and not more than 4 molar equivalents relative to the stoichiometric molar amount of carbon dioxide generated from water used as a reactive blowing agent. However, EP0723989 is limited to polyurethane thermal insulation foams and does not disclose thermal insulation foams (primarily) containing PIR.

[0010] On the other hand, standards for insulating foams, especially for use in construction and consumer products, are becoming increasingly stringent, requiring further improvement (i.e., reduction) of the lambda value (thermal conductivity) of foams containing primarily PIR and maintaining a low lambda value throughout the life of the foam.

[0011] To further improve the lambda value of PIR-containing foams, alternative blowing agents with very low thermal conductivity are used, such as hydrofluorocarbons (HFCs). More recently, hydrofluoroolefins (HFOs) and hydrochlorofluoroolefins (HCFOs) have also been used.

[0012] However, the challenge is to achieve the removal of CO gas in insulating foams (predominantly) comprising PIR and at the same time significantly improve the lambda value, thereby avoiding the negative influence of excess and / or residual amounts of scavengers and obtaining foams predominantly comprising PIR which have a very low thermal conductivity and which also remains low over a long period of time (at least during the average economic life of the foam).

[0013] Purpose of the Invention

[0014] The object of the present invention is to significantly improve the thermal insulation properties of thermal insulation foams comprising polyisocyanurates (PIR) produced with an isocyanate index >120 and to maintain the excellent thermal insulation properties (ie low lambda values) over a long period of time.

[0015] The objects of the present invention are achieved by capturing the CO2 released during the foaming and aging process, in combination with the use and presence of a blowing agent with low thermal conductivity.

[0016] The present invention therefore relates to novel thermal insulation foams comprising polyisocyanurates (PIRs) having significantly improved thermal insulation values ​​which are retained over the average economic life of the foam, as well as to novel reactive mixtures and a process for producing said improved thermal insulation foams, and to the use of the improved thermal insulation foams for thermal insulation. Summary of the Invention

[0017] Disclosed are reactive compositions for preparing PIR-containing foams at an isocyanate index of at least 120, wherein the foams have significantly improved thermal insulation values ​​that are maintained over the average economic life of the foam. The reactive compositions comprise at least:

[0018] a) an isocyanate composition comprising one or more isocyanate compounds, and

[0019] b) an isocyanate-reactive composition comprising one or more isocyanate-reactive compounds, and

[0020] c) at least one PIR promoting catalyst, and

[0021] d) at least one physical blowing agent having a lambda gas ≤ 12 mW / m·K at 10°C, and

[0022] e) at least one CO2 scavenging compound selected from at least one epoxy compound having an equivalent weight of less than 300 g / mol, and

[0023] f) optionally, a catalyst to promote the reaction of the epoxy compound with CO2

[0024] Characterized in that the amount of isocyanate-reactive compound b) in the reactive composition is at least 10% by weight, based on the total weight of the reactive composition, or is at least greater than the amount of the epoxy compound, and the molar amount of the epoxy compound in the reactive composition is at least 7.8 times the molar amount of CO2 formed after the reaction of water present in the reactive composition with the isocyanate.

[0025] According to an embodiment, the amount of isocyanate-reactive compound b) in the reactive composition is at least 10 wt.-%, preferably at least 15 wt.-%, more preferably at least 20 wt.-%, based on the total weight of the reactive composition.

[0026] According to an embodiment, the molar amount of the epoxy compound in the reactive composition is preferably at least 10 times, more preferably at least 15 times, the molar amount of CO formed after the reaction of water present in the reactive composition with the isocyanate. The ratio of the molar amount of the epoxy compound in the reactive composition to the molar amount of CO formed from water is also referred to herein as the molar ratio of epoxy groups to water in the reactive composition.

[0027] According to an embodiment, the maximum amount of all epoxy compounds in the reactive composition is <25 wt%, preferably <20 wt%, based on the total weight of the reactive composition.

[0028] According to an embodiment, the at least one epoxy compound in the reactive composition is selected from epoxy compounds having an equivalent weight below 300 g / mol, preferably below 250 g / mol, more preferably below 200 g / mol, and wherein the at least one epoxy compound used is liquid at 20°C.

[0029] According to an embodiment, the catalyst used to promote the reaction of the epoxy compound with CO2 is selected from ammonium salts, more preferably from tetrabutylammonium bromide and / or tetrabutylammonium iodide.

[0030] According to an embodiment, the at least one physical blowing agent having a lambda gas value ≤ 12 mW / m·K@10° C. is selected from HFO blowing agents and / or HCFO blowing agents and / or hydrocarbon blowing agents such as cyclopentane and mixtures thereof.

[0031] According to an embodiment, the at least one physical blowing agent having a lambda gas value ≤ 12 mW / m·K@10° C. is selected from chlorofluorocarbons (CFCs) and / or hydrofluorocarbons (HFCs) and / or hydrochlorofluorocarbons (HCFCs).

[0032] According to an embodiment, the polyisocyanate compound in the reactive composition is selected from toluene diisocyanate, methylene diphenyl diisocyanate or a polyisocyanate composition comprising methylene diphenyl diisocyanate or a mixture of such polyisocyanates.

[0033] According to an embodiment, the one or more isocyanate-reactive compounds in the reactive composition comprise polyols and polyol mixtures having an average hydroxyl number of 50 to 1000, especially 150 to 700 mg KOH / g, and a hydroxyl functionality of 2 to 8, especially 3 to 8.

[0034] According to an embodiment, the blowing agent is present in the reactive composition in an amount of 1 to 60 parts by weight, preferably 2 to 45 parts by weight per one hundred parts by weight of the isocyanate-reactive compound.

[0035] According to an embodiment, the reactive composition further comprises, in addition to the blowing agent having a lambda gas value ≤ 12 mW / m·K at 10°C, an additional blowing agent having a lambda gas value > 12 mW / m·K at 10°C, and wherein the ratio of the blowing agent having a lambda gas value ≤ 12 mW / m·K at 10°C to the additional blowing agent is a weight ratio of 95 / 5 to 5 / 95, calculated based on the total weight of all blowing agents.

[0036] Furthermore, the present invention discloses a method for preparing a thermal insulation foam comprising PIR having significantly improved thermal insulation values ​​that are maintained during the average economic life of the foam, the method comprising combining and / or mixing the ingredients of the reactive composition at an Isocyanate Index of at least 120, preferably at least 150, more preferably at least 200, and most preferably at least 250.

[0037] According to an embodiment, the method of the present invention for preparing a PIR-containing insulating foam further comprises the step of sealing the foam with a gas diffusion tight seal, wherein at least 50%, preferably at least 90%, more preferably 95%, and most preferably 90-100% of the foam surface is covered by the gas diffusion tight seal.

[0038] According to an embodiment, the gas diffusion tight seal in the PIR-containing insulating foam of the present invention is selected from metal foils such as aluminum foil or metal multilayers comprising aluminum foil and / or gas barrier polymer layers such as ethylene vinyl alcohol copolymer (EVOH), polyvinyl alcohol (PVOH) and copolymers thereof, polyvinylidene chloride (PVDC), polyamide (PA), polyethylene terephthalate (PET), polyketone (PK), polyacrylonitrile (PAN) and combinations thereof and / or thermoplastic polymers such as polyethylene and / or polypropylene.

[0039] According to an embodiment, the method of preparing a thermal insulation foam comprising PIR according to the present invention further comprises a step of aging the foam after sealing the foam, said aging step comprising keeping the foam at a given temperature above room temperature until a stable low lambda value is obtained, preferably at a temperature of 25-100°C, more preferably 40-80°C, even more preferably 55-70°C for less than one month, more preferably less than one week, even more preferably less than one day.

[0040] Furthermore, the present invention discloses a stabilized PIR-containing thermal insulation foam produced using the method according to the present invention, wherein the weight percent of CO2 in the stabilized aged foam is 0-2 weight percent, preferably 0-1 weight percent, more preferably 0-0.5 weight percent, calculated on the total weight of the stabilized aged foam.

[0041] According to an embodiment, the stabilized PIR-containing insulation foam according to the invention has a thermal conductivity of <45 kg / m 3 The foam density is 0.1% and the stable thermal conductivity is <20 mW / m·K at 10°C, preferably 14-20 mW / m·K at 10°C.

[0042] According to an embodiment, the stabilized PIR-containing insulation foam according to the invention has a thermal conductivity of >45 kg / m 3 The foam density is 0.1% and the stable thermal conductivity is <25 mW / m·K at 10°C, preferably 14-25 mW / m·K at 10°C.

[0043] The stabilized PIR-containing insulating foam according to the invention is suitable for use as thermal insulation, for example as building insulation foam, appliance insulation foam or pipe insulation.

[0044] The independent and dependent claims set out particular and preferred features of the invention. Features of the dependent claims may be combined with features of the independent claim or other dependent claims as appropriate.

[0045] The above and other characteristics, features and advantages of the present invention will become apparent from the following detailed description taken in conjunction with the accompanying drawings, which illustrate the principles of the present invention by way of example. This description is given for illustrative purposes only and does not limit the scope of the present invention.

[0046] Definitions and Terminology

[0047] In the context of the present invention, the following terms have the following meanings:

[0048] 1) The expression "isocyanate index" or "NCO index" or "index" as used herein refers to the ratio of NCO groups to isocyanate-reactive hydrogen atoms present in a formulation, given as a percentage:

[0049]

[0050] In other words, the NCO index expresses the percentage of isocyanate groups actually used in the formulation relative to the amount of isocyanate groups theoretically required to react with the amount of isocyanate-reactive hydrogen used in the formulation.

[0051] It should be observed that the isocyanate index used herein is considered from the perspective of the actual polymerization process for preparing the material comprising the isocyanate component and the isocyanate-reactive component. Any isocyanate groups consumed in the preliminary steps for producing modified polyisocyanates (including such isocyanate derivatives known in the art as prepolymers) or any active hydrogens consumed in the preliminary steps (e.g., reaction with isocyanates to produce modified polyols or polyamines) are not taken into account in the calculation of the isocyanate index. Only the free isocyanate groups and free isocyanate-reactive hydrogens (including those of water, if water is used) present during the actual polymerization stage are taken into account.

[0052] During foaming, a portion of the epoxy compound used as CO2 scavenger may also react to some extent with the isocyanate to form oxazolidone / oxazolidinone groups in situ, but these reactions are not taken into account for the index calculation herein.

[0053] 2) The expressions "isocyanate-reactive compound" (also referred to as iso-reactive compound) and "isocyanate-reactive hydrogen atoms" used herein for calculating the isocyanate index refer to the sum of the active hydrogen atoms in the hydroxyl groups and amine groups present in the isocyanate-reactive compound; this means that for the purpose of calculating the isocyanate index in an actual polymerization process, one hydroxyl group is considered to contain one reactive hydrogen, one primary amine group is considered to contain one reactive hydrogen, and one water molecule is considered to contain two reactive hydrogens.

[0054] 3) As used herein, "reactive composition" or "reaction mixture" refers to a combination of compounds wherein the polyisocyanate is maintained separately from the isocyanate-reactive components in one or more containers.

[0055] 4) The term "average nominal functionality" (or simply "functionality") is used herein to refer to the number average functionality. For example, the average nominal hydroxyl functionality of a polyol or polyol composition refers to the number average of the hydroxyl groups per molecule of the polyol or polyol composition, assuming that this is the number average functionality (number of active hydrogen atoms per molecule) of the initiator or initiators used in their preparation, although in practice it is typically slightly less due to some terminal unsaturation. The average nominal epoxy functionality of an epoxy compound or epoxy composition refers to the number average of the epoxide groups per molecule of the epoxy compound or epoxy composition.

[0056] 5) Unless otherwise indicated, the word "average" refers to the digital mean.

[0057] 6) The term "equivalent molecular weight" of a compound refers to the molecular weight of the compound divided by its functionality.

[0058] 7) As used herein, "trimerization catalyst" refers to a catalyst that catalyzes (promotes) the formation of isocyanurate groups from polyisocyanates. This means that isocyanates can react with each other to form macromolecules with isocyanurate structures (polyisocyanurates = PIRs). Isocyanate-polyol and isocyanate-isocyanate reactions (homopolymerization) can occur simultaneously or directly sequentially to form macromolecules with urethane and isocyanurate structures.

[0059] 8) As used herein, "polyisocyanurate-containing foam", "PIR-containing foam" and "thermal insulation foam mainly containing PIR" refer to foams prepared at an isocyanate index of at least 120, more preferably an isocyanate index above 180, and most preferably an isocyanate index above 250 and mainly containing polyisocyanurate (PIR) compounds.

[0060] 9) "Foam density" as used herein refers to the density measured on a foam sample according to ISO 845 and is calculated on a weight / volume basis and expressed in kg / m 3 express.

[0061] 10) "Thermal conductivity" is measured using a heat flow meter (HFM) at 10°C according to ISO 8301. "λ value," "λ value," or "k value" as used herein refers to the thermal conductivity of a material, typically expressed in mW / m·K. The lower the λ value, the better the thermal insulation performance.

[0062] 11) The "closed cell content" of the foam is measured using a pycnometer according to ISO 4590.

[0063] 12) As used herein, the terms "stable lambda value," "stable λ value," and "stable k value" of a foam refer to a thermal conductivity value (according to ISO 8301) that does not change over time (change ≤ 0.5 mW / m·K) at 10°C. For the foam according to the present invention, a stable lambda value is achieved after the time required for CO2 to be captured by the CO2 scavenging compound according to the present invention (after completion of the CO2 scavenging process). Depending on the type of formulation, completion of the CO2 scavenging process may take from several hours to several months.

[0064] 13) "Aging" refers to the treatment of a foam wherein the foam is maintained at a certain temperature for a given period of time.

[0065] 14) The expression "the molar amount of epoxy compound in the reactive composition relative to the molar amount of CO formed upon reaction of water present in the reactive composition with isocyanate" is also referred to herein as the "molar ratio of epoxy groups to water" present in the reactive composition. At an isocyanate index >120, it is assumed that all water present in the reactive composition is converted to CO by reaction with free NCO groups. Detailed Description of the Invention

[0067] The invention will be described with reference to specific embodiments.

[0068] It should be noted that the term "comprising" used in the claims should not be interpreted as being limited to the components listed thereafter; it does not exclude other elements or steps. Thus, it should be interpreted as specifying the presence of the features, steps, or components mentioned, but not excluding the presence or addition of one or more other features, steps, or components, or groups thereof. Thus, the scope of the expression "a device comprising components A and B" should not be limited to devices consisting solely of components A and B. It means that for the present invention, the only relevant components of the device are A and B.

[0069] Throughout this specification, reference is made to "one embodiment" or "an embodiment." Such reference means that a particular feature described in connection with the embodiment is included in at least one embodiment of the invention. Thus, appearances of the phrases "in one embodiment" or "in an embodiment" in various places throughout this specification are not necessarily all referring to the same embodiment, although they may. Furthermore, as will be apparent to those skilled in the art, the particular features or characteristics may be combined in any suitable manner in one or more embodiments.

[0070] It will be appreciated that although preferred embodiments and / or materials have been discussed to provide embodiments in accordance with the present invention, various modifications or changes may be made without departing from the scope and spirit of the invention.

[0071] The present invention relates to thermal insulation foams comprising polyisocyanurate (PIR) which suffer from deteriorated insulation values ​​due to the formation of CO 2 .

[0072] The present invention develops a process wherein an optimal amount of a CO2 scavenger compound is added to the reactive composition for the preparation of PIR-containing foams, said CO2 scavenger compound capturing most of the CO2 formed during foaming and aging, in combination with a blowing agent having a λ ≤ 12 mW / m·K at 10°C.

[0073] The present invention therefore relates to novel thermal insulation foams comprising polyisocyanurate (PIR) having significantly improved thermal insulation values ​​which are retained during the average economic life of the foam, to a novel process for preparing said improved thermal insulation foams and to the use of the improved thermal insulation foams for thermal insulation.

[0074] According to a first aspect, a reactive composition for preparing a thermal insulation foam comprising polyisocyanurate (PIR) having significantly improved thermal insulation properties that are maintained during the average economic life of the foam is disclosed.

[0075] The reactive composition for preparing the PIR-containing foam of the present invention at an isocyanate index of at least 120 comprises:

[0076] a) an isocyanate composition comprising one or more isocyanate compounds,

[0077] b) an isocyanate-reactive composition comprising one or more isocyanate-reactive compounds, and

[0078] c) at least one PIR promoting catalyst, and

[0079] d) at least one physical blowing agent having a lambda gas ≤ 12 mW / m·K at 10°C, and

[0080] e) at least one CO2 scavenging compound selected from at least one epoxy compound having an equivalent weight of less than 300 g / mol, and

[0081] f) optionally, a catalyst to promote the reaction of the epoxy compound with CO2

[0082] Characterized in that the amount of isocyanate-reactive compound b) in the reactive composition is at least 10% by weight, based on the total weight of the reactive composition, or is at least greater than the amount of the epoxy compound, and the molar amount of epoxy groups in the reactive composition is at least 7.8 times the molar amount of CO2 formed after the reaction of water present in the reactive composition with the isocyanate.

[0083] According to an embodiment, the amount of isocyanate-reactive compound b) in the reactive composition is at least 10 wt.-%, preferably at least 15 wt.-%, more preferably at least 20 wt.-%, based on the total weight of the reactive composition.

[0084] According to an embodiment, the molar amount of epoxy groups in the reactive composition is preferably at least 10 times, more preferably at least 15 times, the molar amount of CO2 formed after the reaction of water present in the reactive composition with the isocyanate.

[0085] According to an embodiment, the total amount of epoxy compounds in the reactive composition should be at least several weight percent, preferably >2 weight percent, more preferably >5 weight percent, most preferably >10 weight percent, calculated based on the total weight of the reactive composition and independently of the amount of water present in the reactive composition, in order to be able to scavenge CO2 formed by the reaction of the carbodiimide and / or additional CO2 formed by the reaction between residual NCO and moisture.

[0086] According to an embodiment, the maximum amount of all epoxy compounds in the reactive composition should be <25 wt%, preferably <20 wt%, based on the total weight of the reactive composition, to avoid problems such as excessive reaction with isocyanate, increased exotherm, dimensional stability issues, too much unreacted epoxy compound, etc.

[0087] According to an embodiment, the at least one epoxy compound is selected from epoxy compounds having an equivalent weight of less than 300 g / mol, preferably less than 250 g / mol, more preferably less than 200 g / mol. The use of epoxy compounds with a low equivalent weight is advantageous in ensuring that as little epoxy compound as possible (in terms of weight % of the total formulation) is used to obtain optimal CO 2 removal.

[0088] According to an embodiment, the one or more epoxy compounds used are liquid at 20°C.

[0089] Examples of suitable (poly)epoxides are:

[0090] 1) Polyglycidyl and poly(β-methylglycidyl) esters can be obtained by reacting a compound having at least one carboxyl group in the molecule with epichlorohydrin and β-methylepichlorohydrin, respectively. The reaction is conveniently carried out in the presence of a base. Aliphatic monocarboxylic acids and polycarboxylic acids can be used as compounds having at least one carboxyl group in the molecule. Examples of such monocarboxylic acids are propionic acid, butyric acid and valeric acid. Examples of such polycarboxylic acids are oxalic acid, succinic acid, glutaric acid, adipic acid, pimelic acid, suberic acid and azelaic acid. However, alicyclic polycarboxylic acids such as tetrahydrophthalic acid, 4-methyltetrahydrophthalic acid, hexahydrophthalic acid or 4-methylhexahydrophthalic acid can also be used. In addition, aromatic polycarboxylic acids such as phthalic acid, isophthalic acid or terephthalic acid can be used.

[0091] 2) Polyglycidyl or poly(β-methylglycidyl) ethers, which can be obtained by reacting a compound having at least one free alcoholic and / or phenolic hydroxyl group with epichlorohydrin or β-methylepichlorohydrin under alkaline conditions or in the presence of an acidic catalyst, followed by treatment with a base. Glycidyl ethers of this type are derived, for example, from acyclic alcohols such as butanol, pentanol, ethylene glycol, diethylene glycol or higher poly(oxyethylene) glycols, propylene-1,2-diol or poly(oxypropylene) glycol, propylene-1,3-diol, butane-1,4-diol, poly(oxytetramethylene) glycol, pentane-1,5-diol, hexane-1,6-diol, hexane-2,4,6-triol, glycerol, 1,1,1-trimethylolpropane, pentaerythritol or sorbitol, and from polyepichlorohydrin. Glycidyl ethers of this type are also derived from cycloaliphatic alcohols, such as 1,4-cyclohexanedimethanol, bis(4-hydroxycyclohexyl)methane or 2,2-bis(4-hydroxycyclohexyl)propane, or from alcohols containing aromatic groups and / or other functional groups, such as N,N-bis(2-hydroxyethyl)aniline or p,p'-bis(2-hydroxyethylamino)-diphenylmethane. Glycidyl ethers can also be based on mononuclear phenols, such as phenol, p-tert-butylphenol, resorcinol or hydroquinone, or on polynuclear phenols, such as bis(4-hydroxyphenyl)methane, 4,4'-dihydroxybiphenyl, bis(4-hydroxyphenyl)sulfone, 1,1,2,2-tetrakis(4-hydroxyphenyl)ethane, 2,2-bis(4-hydroxyphenyl)propane or 2,2-bis(3,5-dibromo-4-hydroxyphenyl)propane. Other suitable hydroxy compounds for preparing glycidyl ethers are novolacs, which are obtainable by condensing aldehydes such as formaldehyde, acetaldehyde, chloral or furfural with phenols or bisphenols which are unsubstituted or substituted by chlorine atoms or C1-C9-alkyl groups, for example phenol, 4-chlorophenol, 2-methylphenol or 4-tert-butylphenol.

[0092] 3) Poly(N-glycidyl) compounds, which can be obtained by dehydrochlorination of the reaction products of epichlorohydrin with amines containing at least one amino hydrogen atom. These amines are, for example, aniline, n-butylamine, bis(4-aminophenyl)methane, m-xylenediamine, or bis(4-methylaminophenyl)methane. Poly(N-glycidyl) compounds also include triglycidyl isocyanurate, N,N′-diglycidyl derivatives of cycloalkylene ureas, such as ethylene urea or 1,3-propylene urea, and diglycidyl derivatives of hydantoins, such as 5,5-dimethylhydantoin.

[0093] 4) Poly(S-glycidyl) compounds, for example S-glycidyl derivatives derived from thiols, for example ethane-1,2-dithiol or bis(4-mercaptomethylphenyl)ether.

[0094] 5) One or more cycloaliphatic epoxy compounds, for example bis(2,3-epoxycyclopentyl)ether, 2,3-epoxycyclopentyl glycidyl ether, 1,2-bis(2,3-epoxycyclopentyloxy)ethane or 3,4-epoxycyclohexylmethyl-3',4'-epoxycyclohexanecarboxylate.

[0095] It is also possible to use one or more (poly)epoxy compounds in which the 1,2-epoxy group is bonded to different heteroatoms or functional groups; these compounds include, for example, N,N,O-triglycidyl derivatives of 4-aminophenol, glycidyl ethers of salicylic acid - glycidyl esters, N-glycidyl-N'-(2-glycidyloxypropyl)-5,5-dimethylhydantoin or 2-glycidyloxy-1,3-bis(5,5-dimethyl-1-glycidylhydantoin-3-yl)propane.

[0096] Particularly preferred are one or more of those (poly)epoxides mentioned under 1) and 2), most preferred are those mentioned under 2).

[0097] Suitable commercially available epoxy compounds include phenyl glycidyl ether, butanediol diglycidyl ether (as DY-D was obtained from Huntsman) and bisphenol A diglycidyl ether (as GY240 was obtained from Huntsman).

[0098] According to the embodiment, the catalyst for promoting the reaction of epoxy compound and CO2 can be selected from ammonium salts represented by tetrabutylammonium bromide, tetrabutylammonium iodide, etc. Other preferred onium salts are phosphonium salts represented by tetraphenylphosphonium bromide and triphenylmethylphosphonium bromide, and sulfonium salts represented by tributylsulfonium bromide. For example, a complex, ammonium salt or quaternary ammonium salt of iodofluorocarbon and non-conjugated amine can be used. Metal halides and alkali metal halides can also be used alone or in combination with other catalysts. Examples of metal halides include zinc chloride, zinc bromide and zinc iodide. Examples of alkali metal halides include lithium chloride, lithium bromide, lithium iodide and sodium iodide. By using a catalyst that promotes the reaction of epoxy compound and CO2, carbon dioxide will react chemically with the epoxy group of the epoxy compound more quickly to form a solid or liquid cyclic carbonate.

[0099] According to a preferred embodiment, the blowing agent in the reactive composition is selected from at least HFO blowing agents and / or HCFO blowing agents and / or hydrocarbons having a lambda gas value ≤ 12 mW / m·K at 10° C., such as cyclopentane.

[0100] According to a preferred embodiment, the blowing agent comprises at least an HFO blowing agent and / or an HCFO blowing agent having a lambda gas value of ≤12 mW / m·K at 10° C. and / or a hydrocarbon, such as cyclopentane.

[0101] According to an embodiment, the blowing agent in the reactive composition comprises at least 3,3,3-trifluoropropene, 1,2,3,3,3-pentafluoropropene, cis- and / or trans-1,3,3,3-tetrafluoropropene and / or 2,3,3,3-tetrafluoropropene, and / or 1,1,1,4,4,4-hexafluorobut-2-ene, and / or 1-chloro-3,3,3-trifluoropropene, and / or 2-chloro-3,3,3-trifluoropropene and mixtures thereof.

[0102] Preferred examples of suitable commercially available HFO foaming gases are Honeywell HFO-1234ze (Honeywell's trade name for trans-1,3,3,3-tetrafluoropropene) or 1100 (trade name of Chemours for cis-1,1,1,4,4,4-hexafluorobut-2-ene, CF3CH=CHCF3).

[0103] A preferred example of a suitable commercially available HCFO foaming gas is Honeywell LBA 1233zd (Honeywell's trade name for trans-1-chloro-3,3,3-trifluoropropene, CHCl=CHCF3) or 1233zd (trade name of trans-1-chloro-3,3,3-trifluoropropene, CHCl=CHCF3 from Arkema).

[0104] According to an embodiment, the reactive composition may comprise a blowing agent selected from hydrofluorocarbons (HFCs) and / or hydrocarbons such as cyclopentane and mixtures thereof having a lambda gas value ≤ 12 mW / m·K at 10°C.

[0105] According to an embodiment, the reactive composition may further comprise a blowing agent having a lambda gas value > 12 mW / m·K at 10° C., such as a hydrocarbon selected from isopentane, isobutane, n-pentane and mixtures thereof.

[0106] According to an embodiment, the reactive composition may further comprise an additional blowing agent selected from the group consisting of formic acid, methyl formate, dimethyl ether, water, dichloromethane, acetone, tert-butanol, argon, krypton, xenon, and mixtures thereof.

[0107] According to an embodiment, the reactive composition may further comprise (optionally) one or more surfactants, one or more flame retardants, one or more antioxidants, one or more auxiliary blowing agents, one or more auxiliary polyurethane catalysts, one or more auxiliary trimerization catalysts, or combinations thereof.

[0108] According to a second aspect, a method is disclosed for preparing a thermal insulation foam comprising polyisocyanurate (PIR) having significantly improved thermal insulation properties that are maintained during the average economic life of the foam, utilizing the reactive composition of the first aspect of the invention.

[0109] The method of preparing a thermal insulation foam comprising polyisocyanurate (PIR) according to the present invention may comprise combining and / or mixing at least the following compounds at an isocyanate index of at least 120 to form a reactive composition:

[0110] a) an isocyanate composition comprising one or more isocyanate compounds,

[0111] b) an isocyanate-reactive composition comprising one or more isocyanate-reactive compounds, and

[0112] c) at least one PIR promoting catalyst, and

[0113] d) at least one physical blowing agent having a lambda gas ≤ 12 mW / m·K at 10°C, and

[0114] e) at least one CO2 scavenging compound selected from at least one epoxy compound having an equivalent weight of less than 300 g / mol, and

[0115] f) optionally, a catalyst to promote the reaction of the epoxy compound with CO2

[0116] Characterized in that the amount of isocyanate-reactive compound b) in the reactive composition is at least 10% by weight, based on the total weight of the reactive composition, or is at least greater than the amount of the epoxy compound, and the molar amount of epoxy groups in the reactive composition is at least 7.8 times the molar amount of CO2 formed after the reaction of water present in the reactive composition with the isocyanate.

[0117] According to the present invention, an optimal amount of CO 2 scavenger compound needs to be added to the formulation used to prepare the PIR-containing insulation foam of the present invention, wherein the optimal amount of CO 2 scavenger compound captures the CO 2 formed during foaming and aging, and which minimizes the amount of residual unreacted CO 2 scavenger compound.

[0118] According to an embodiment, the amount of isocyanate-reactive compound b) in the reactive composition is at least 10 wt.-%, preferably at least 15 wt.-%, more preferably at least 20 wt.-%, based on the total weight of the reactive composition.

[0119] According to an embodiment, the molar amount of epoxy groups in the reactive composition is preferably at least 10 times, more preferably at least 15 times, the molar amount of CO2 formed after the reaction of water present in the reactive composition with the isocyanate.

[0120] According to an embodiment, the total amount of epoxy compounds in the reactive composition should be at least several weight percent, preferably >2 weight percent, more preferably >5 weight percent, most preferably >10 weight percent, calculated based on the total weight of the reactive composition and independently of the amount of water present in the reactive composition, in order to be able to scavenge CO2 formed by the reaction of the carbodiimide and / or additional CO2 formed by the reaction between residual NCO and moisture.

[0121] According to an embodiment, the maximum amount of all epoxy compounds in the reactive composition should be <25 wt%, preferably <20 wt%, based on the total weight of the reactive composition, to avoid problems such as excessive reaction with isocyanate, increased exotherm, dimensional stability issues, too much unreacted epoxy compound, etc.

[0122] According to an embodiment, the method for preparing a thermal insulation foam comprising polyisocyanurate (PIR) according to the present invention may further include combining and mixing one or more surfactants, one or more additives such as a nucleating agent, an adhesion promoter, one or more flame retardants, water, one or more antioxidants, one or more auxiliary blowing agents, one or more auxiliary polyurethane catalysts, one or more auxiliary trimerization catalysts, one or more blowing catalysts, or a combination thereof.

[0123] According to an embodiment, the process for preparing a thermal insulation foam comprising polyisocyanurate (PIR) according to the invention is carried out at an isocyanate index of at least 120, preferably at least 150, more preferably above 200, most preferably above 250.

[0124] According to an embodiment, the PIR-promoting catalyst compound is selected from at least one trimerization catalyst compound. Any compound that catalyzes the trimerization of isocyanates can be used as the trimerization catalyst compound, such as tertiary amines, triazines, and most preferably metal salt trimerization catalysts. Two or more different metal salt trimerization catalysts can be used in the method of the present invention.

[0125] According to an embodiment, the trimerization catalyst compound is a metal salt trimerization catalyst selected from one or more organic salts, preferably the organic salt is selected from alkali metal, alkaline earth metal and / or quaternary ammonium organic salts, more preferably selected from carboxylates and / or alkoxides, such as potassium acetate, potassium hexanoate, potassium ethylhexanoate, potassium octoate, potassium lactate, sodium ethoxide, sodium formate, potassium formate, sodium acetate, potassium benzoate and mixtures thereof. A preferred metal salt trimerization catalyst is potassium acetate, such as commercially available K-Tron® from Air Products. 46 catalyst, Catalyst LB from Huntsman and Catalyst LB from Air Products K15 catalyst.

[0126] According to an embodiment, the trimerization catalyst compound is a metal salt trimerization catalyst selected from lithium halide salts, preferably LiCl compounds. Said lithium halide (LiCl) compounds form active trimerization catalysts upon combination with one or more epoxy compounds.

[0127] According to an embodiment, the trimerization catalyst compound is a metal salt trimerization catalyst selected from potassium ethoxide, sodium ethoxide, potassium methoxide, sodium methoxide, potassium t-butoxide, titanium isopropoxide, and mixtures thereof dissolved in a suitable carrier such as a monool / polyol composition.

[0128] According to a preferred embodiment, the method for preparing a thermal insulation foam comprising polyisocyanurate (PIR) according to the present invention further comprises the step of sealing the foam with a gas diffusion tight seal, wherein at least 50%, at least 75%, preferably at least 90%, more preferably 95%, most preferably 90-100% of the foam surface is covered by the gas diffusion tight seal.

[0129] According to an embodiment, the gas diffusion tight seal is selected from a metal foil, such as aluminum foil or a metal multilayer including aluminum foil, and at least 50%, preferably 50-95%, more preferably 50-85%, most preferably 50-75% of the foam surface is covered by the gas diffusion tight seal.

[0130] According to a preferred embodiment, the gas diffusion tight seal is a moisture permeable layer, preferably comprising at least a layer of ethylene vinyl alcohol (EVOH) copolymer resin as a gas barrier polymer.

[0131] According to an embodiment, the gas diffusion tight seal may comprise at least one layer of a gas barrier polymer selected from the group consisting of ethylene vinyl alcohol copolymer (EVOH), polyvinyl alcohol (PVOH) and copolymers thereof, polyvinylidene chloride (PVDC), polyamide (PA), polyethylene terephthalate (PET), polyketone (PK), polyacrylonitrile (PAN), and combinations thereof. The gas barrier polymer layer may also comprise one or more additional layers, which may, for example, comprise or consist of a thermoplastic polymer, such as polyethylene and / or polypropylene. Other suitable seals for use in the present invention are disclosed in EP 3000592.

[0132] According to a preferred embodiment, the method for preparing a thermal insulation foam comprising polyisocyanurate (PIR) according to the present invention further comprises a step of aging the foam after the step of sealing the foam with a gas diffusion-tight seal. The aging step comprises keeping the foam at a given temperature above room temperature until a stable low lambda value is obtained, which indicates that a significant reaction between the epoxy compound and CO2 has occurred. The foam is preferably aged at 25-100°C, more preferably at 40-80°C, even more preferably at 55-70°C, for preferably less than one month, more preferably less than one week, even more preferably less than one day.

[0133] According to an embodiment, the polyisocyanate compound used in the method for preparing a thermal insulation foam comprising polyisocyanurate (PIR) according to the present invention is selected from organic isocyanates containing a plurality of isocyanate groups, including aliphatic isocyanates such as hexamethylene diisocyanate, more preferably aromatic isocyanates such as m- and p-phenylene diisocyanate, toluene-2,4- and 2,6-diisocyanate, diphenylmethane-4,4'-diisocyanate, chlorobenzene-2,4-diisocyanate, naphthalene-1,5-diisocyanate, diphenylene- 4,4'-diisocyanate, 4,4'-diisocyanate-3,3'-dimethyldiphenyl, 3-methyldiphenylmethane-4,4'-diisocyanate and diphenylether diisocyanate, cycloaliphatic diisocyanates such as cyclohexane-2,4- and 2,3-diisocyanate, 1-methylcyclohexyl-2,4- and 2,6-diisocyanate and mixtures thereof, and bis-(isocyanatocyclohexyl)methane and triisocyanates such as 2,4,6-triisocyanatotoluene and 2,4,4'-triisocyanatodiphenyl ether.

[0134] According to embodiments, the polyisocyanate composition comprises a mixture of polyisocyanates. For example, a mixture of toluene diisocyanate isomers, such as a commercially available mixture of 2,4- and 2,6-isomers, and a mixture of di- and higher polyisocyanates prepared by phosgenation of aniline / formaldehyde condensates. Such mixtures are well known in the art and include crude phosgenation products of a mixture of methylene-bridged polyphenyl polyisocyanates, comprising diisocyanates, triisocyanates, and higher polyisocyanates, as well as any phosgenation by-products.

[0135] Preferred polyisocyanate compositions of the present invention are those in which the polyisocyanate is an aromatic diisocyanate or a higher functionality polyisocyanate, in particular a crude mixture of methylene-bridged polyphenyl polyisocyanates containing diisocyanates, triisocyanates and higher functionality polyisocyanates. Methylene-bridged polyphenyl polyisocyanates (e.g., methylene diphenyl diisocyanate, abbreviated as MDI) are well known in the art and have the general formula I, wherein n is 1 or greater and, in the case of a crude mixture, represents an average value greater than 1. They are prepared by phosgenation of the corresponding polyamine mixtures obtained by condensation of aniline and formaldehyde.

[0136]

[0137] Other suitable polyisocyanate compositions may include isocyanate-terminated prepolymers prepared by reacting an excess of diisocyanate or a higher functionality polyisocyanate with a hydroxyl-terminated polyester or hydroxyl-terminated polyether, and products obtained by reacting an excess of diisocyanate or a higher functionality polyisocyanate with a monomeric polyol or a mixture of monomeric polyols such as ethylene glycol, trimethylolpropane or butanediol. A preferred class of isocyanate-terminated prepolymers is an isocyanate-terminated prepolymer comprising a crude mixture of methylene-bridged polyphenyl polyisocyanates of diisocyanates, triisocyanates and higher functionality polyisocyanates.

[0138] According to an embodiment, the polyisocyanate compound in the polyisocyanate composition is selected from toluene diisocyanate, methylene diphenyl diisocyanate or a polyisocyanate composition comprising methylene diphenyl diisocyanate or a mixture of such polyisocyanates.

[0139] According to an embodiment, the one or more isocyanate-reactive compounds used in the method for preparing an insulating foam comprising polyisocyanurate (PIR) according to the present invention include any of those known in the art for preparing the foam. Of particular importance for the preparation of rigid foams are polyols and polyol mixtures having an average hydroxyl number of 50-1000, especially 150-700 mg KOH / g and a hydroxyl functionality of 2-8, especially 3-8. Suitable polyols have been fully described in the prior art and include reaction products of alkylene oxides, such as ethylene oxide and / or propylene oxide, with initiators having 2-8 active hydrogen atoms per molecule. Suitable initiators include: polyols, such as glycerol, trimethylolpropane, triethanolamine, pentaerythritol, sorbitol and sucrose; polyamines, such as ethylenediamine, toluenediamine (TDA), diaminodiphenylmethane (DADPM) and polymethylenepolyphenylenepolyamines; and amino alcohols, such as ethanolamine and diethanolamine; and mixtures of such initiators. Other suitable polymeric polyols include polyesters obtained by condensing diols and higher functionality polyols with dicarboxylic acids or polycarboxylic acids in appropriate proportions. Other suitable polymeric polyols include hydroxyl terminated polythioethers, polyamides, polyesteramides, polycarbonates, polyacetals, polyolefins and polysiloxanes.

[0140] The amounts of the polyisocyanate composition and the isocyanate-reactive compound(s) to be reacted depend on the properties of the polyisocyanurate (PIR)-containing thermal insulation foam to be produced and can be readily determined by a person skilled in the art.

[0141] According to a preferred embodiment, the physical blowing agent with a lambda gas value of ≤12 mW / m·K at 10°C is selected from at least HFO blowing agents and / or HCFO blowing agents and / or hydrocarbons with a lambda gas value of ≤12 mW / m·K at 10°C, such as cyclopentane.

[0142] According to a preferred embodiment, the physical blowing agent with a lambda gas value of ≤12 mW / m·K at 10°C includes at least an HFO blowing agent and / or an HCFO blowing agent and / or a hydrocarbon, such as cyclopentane, having a lambda gas value of ≤12 mW / m·K at 10°C.

[0143] According to an embodiment, the physical blowing agent with λ gas ≤ 12 mW / m·K at 10° C. comprises at least 3,3,3-trifluoropropene, 1,2,3,3,3-pentafluoropropene, cis- and / or trans-1,3,3,3-tetrafluoropropene and / or 2,3,3,3-tetrafluoropropene, and / or 1,1,1,4,4,4-hexafluorobut-2-ene, and / or 1-chloro-3,3,3-trifluoropropene, and / or 2-chloro-3,3,3-trifluoropropene and mixtures thereof.

[0144] Preferred examples of suitable commercially available HFO foaming gases are Honeywell HFO-1234ze (Honeywell's trade name for trans-1,3,3,3-tetrafluoropropene) or 1100 (trade name of Chemours for cis-1,1,1,4,4,4-hexafluorobut-2-ene, CF3CH=CHCF3).

[0145] A preferred example of a suitable commercially available HCFO foaming gas is Honeywell LBA 1233zd (Honeywell's trade name for trans-1-chloro-3,3,3-trifluoropropene, CHCl=CHCF3) or 1233zd (trade name of trans-1-chloro-3,3,3-trifluoropropene, CHCl=CHCF3 from Arkema).

[0146] According to an embodiment, the reactive composition may further comprise a blowing agent selected from hydrofluorocarbons (HFCs) and / or hydrocarbons such as cyclopentane and mixtures thereof having a lambda gas value ≤ 12 mW / m·K at 10°C.

[0147] According to an embodiment, the reactive composition may further comprise an additional blowing agent having a lambda gas value > 12 mW / m·K at 10° C., such as a hydrocarbon selected from isopentane, isobutane, n-pentane and mixtures thereof.

[0148] According to an embodiment, the reactive composition may further comprise an additional blowing agent selected from the group consisting of formic acid, methyl formate, dimethyl ether, water, dichloromethane, acetone, tert-butanol, argon, krypton, xenon, and mixtures thereof.

[0149] The amount of blowing agent used can vary depending on, for example, the intended use and application of the foam product and the desired foam properties and density. The blowing agent can be present in an amount of 1 to 60 parts by weight (pbw) per one hundred parts by weight of the isocyanate-reactive compound (polyol), more preferably 2 to 45 pbw. If (optional) water is used as one of the blowing agents in the foam formulation, the amount of water is preferably limited to an amount of up to 15 pbw, preferably <5 pbw, and more preferably <3 pbw.

[0150] According to an embodiment, at least one blowing agent having a λ gas value ≤12 mW / m·K at 10° C. may contain an additional blowing agent having a λ gas value >12 mW / m·K at 10° C., and the ratio of the blowing agent having a λ gas value ≤12 mW / m·K at 10° C. to the additional blowing agent is a weight ratio of 95 / 5 to 5 / 95 calculated based on the total weight of all blowing agents.

[0151] According to an embodiment, the physical blowing agent having a lambda gas ≤ 12 mW / m·K at 10° C. is selected from HCFO and / or HFO blowing agents, and contains cyclopentane or a mixture of cyclopentane and isopentane as an additional blowing agent, and the ratio of the HCFO and / or HFO blowing agent to the cyclopentane blowing agent is a weight ratio of 95 / 5 to 5 / 95 calculated based on the total weight of all blowing agents.

[0152] There are many different orders in which the compounds of the reactive composition required to prepare the PIR-containing foam of the present invention may be contacted or combined. One skilled in the art will recognize that varying the order of addition of the compounds falls within the scope of the present invention.

[0153] According to embodiments, combining and mixing the one or more CO2 scavenging compounds may be performed by adding the one or more CO2 scavenging compounds to the isocyanate-reactive composition prior to combining and / or mixing with the polyisocyanate composition (in other words, adding the one or more CO2 scavenging compounds to the polyisocyanate-reactive composition prior to reacting the polyisocyanate-reactive composition with the polyisocyanate composition).

[0154] According to embodiments, combining and mixing the one or more CO2 scavenging compounds may be performed by adding the one or more CO2 scavenging compounds to the polyisocyanate composition prior to combining and / or mixing with the isocyanate-reactive composition (in other words, the one or more CO2 scavenging compounds are added to the polyisocyanate composition prior to reacting the polyisocyanate composition with the polyisocyanate-reactive composition).

[0155] According to embodiments, combining and mixing one or more CO2 scavenging compounds may be performed by adding the one or more CO2 scavenging compounds after placing the reactive composition produced by combining and / or mixing the polyisocyanate composition, the isocyanate-reactive composition, the one or more catalyst compounds, the one or more blowing agents, and optionally other ingredients.

[0156] According to embodiments, combining and mixing one or more CO 2 scavenging compounds may be performed by adding the one or more CO 2 scavenging compounds to a reactive composition already present in a mold, the reactive composition being produced by combining and / or mixing a polyisocyanate composition, an isocyanate-reactive composition, one or more catalyst compounds, one or more blowing agents, and optionally other ingredients.

[0157] According to embodiments, combining and mixing one or more CO2 scavenging compounds may be performed by adding the one or more CO2 scavenging compounds to the mold prior to injecting the reactive composition produced by combining and / or mixing the polyisocyanate composition, the isocyanate-reactive composition, the one or more catalyst compounds, the one or more blowing agents, and optionally other ingredients into the mold.

[0158] According to a third aspect, there is disclosed a thermal insulation foam comprising polyisocyanurate (PIR) having significantly improved thermal insulation properties that are maintained during the average economic life of the foam and prepared by the method according to the second aspect of the invention and using the reactive composition of the first aspect of the invention.

[0159] According to an embodiment, the PIR-containing foam according to the present invention preferably has an amount of residual scavenging compounds in the stabilized aged foam of 0-10 wt.-%, more preferably 0-5 wt.-%, even more preferably 0-3 wt.-%, calculated on the total weight of the stabilized aged foam.

[0160] According to an embodiment, the PIR-containing insulation foam of the present invention has a stable aged lambda value that is at least 1 mW / m·K lower at 10° C. after the same period of time than a prior art polyisocyanurate (PIR) insulation foam using the same amount and type of blowing agent but without a CO 2 scavenger.

[0161] According to an embodiment, the weight percent of CO2 in the stabilized aged foam is 0-2 weight percent, preferably 0-1 weight percent, more preferably 0-0.5 weight percent, calculated based on the total weight of the stabilized aged foam.

[0162] According to an embodiment, the amount of residual epoxy compounds in the stabilized aged foam is 0 to 10 wt%, more preferably 0 to 5 wt%, even more preferably 0 to 3 wt%, calculated based on the total weight of the stabilized aged foam.

[0163] According to an embodiment, the thermal insulation foam comprising polyisocyanurate (PIR) according to the present invention is maintained in an air diffusion sealed condition with a gas diffusion tight seal and at least 50%, at least 75%, preferably at least 90%, more preferably 95%, most preferably 90-100% of the foam surface is covered by the gas diffusion tight seal.

[0164] According to a preferred embodiment, the gas diffusion tight seal is a moisture permeable layer, preferably comprising at least a layer of ethylene vinyl alcohol (EVOH) copolymer resin as a gas barrier polymer.

[0165] According to an embodiment, the gas diffusion tight seal may comprise at least one layer of a gas barrier polymer selected from the group consisting of ethylene vinyl alcohol copolymer (EVOH), polyvinyl alcohol (PVOH) and copolymers thereof, polyvinylidene chloride (PVDC), polyamide (PA), polyethylene terephthalate (PET), polyketone (PK), polyacrylonitrile (PAN), and combinations thereof. The gas barrier polymer layer may also comprise one or more additional layers, which may, for example, comprise or consist of a thermoplastic polymer, such as polyethylene and / or polypropylene. Other suitable seals for use in the present invention are disclosed in EP 3000592.

[0166] According to an embodiment, the thermal insulation foam comprising polyisocyanurate (PIR) according to the present invention is maintained in an air diffusion tight condition, and the gas diffusion tight seal is selected from a metal foil such as aluminum foil or a metal multilayer including aluminum foil, and wherein at least 50%, preferably 50-95%, more preferably 50-85%, most preferably 50-75% of the foam surface is covered by the gas diffusion tight seal.

[0167] The PIR-containing insulation foam according to the present invention will produce an insulation foam having a significantly low thermal conductivity (after a stabilization period in which the scavenger captures CO 2 ). The polyisocyanurate (PIR)-containing insulation foam can have a stable aged thermal conductivity over time that is lower than the initial thermal conductivity immediately after the foam is produced due to the CO 2 scavenger consuming CO 2 , using a blowing agent having a lambda gas value of ≤12 mW / m·K at 10° C., such as a blowing agent containing HFO / HCFO, and diffusion sealing conditions.

[0168] According to an embodiment, the thermal insulation foam comprising polyisocyanurate (PIR) according to the invention is a rigid thermal insulation foam.

[0169] According to an embodiment, the thermal insulation foam comprising polyisocyanurate (PIR) according to the invention has a thermal conductivity of <45 kg / m 3 The foam density is 0.1% and the stable thermal conductivity is <20 mW / m·K at 10°C, preferably 14-20 mW / m·K at 10°C.

[0170] According to an embodiment, the thermal insulation foam comprising polyisocyanurate (PIR) according to the invention has a thermal conductivity of >45 kg / m 3 The foam density is 0.1% and the stable thermal conductivity is <25 mW / m·K at 10°C, preferably 14-25 mW / m·K at 10°C.

[0171] According to an embodiment, the thermal insulation foam comprising polyisocyanurate (PIR) according to the invention has a closed cell content greater than 70%, calculated on the basis of the total amount of closed and open cells present in the material.

[0172] According to an embodiment, the PIR-containing foam of the present invention can be used as a thermal insulation such as a building insulation foam, an appliance insulation foam or a pipe insulation. The polyisocyanurate (PIR)-containing thermal insulation foam of the present invention meets all requirements for use as a thermal insulation material, in particular due to its low thermal conductivity values. BRIEF DESCRIPTION OF THE DRAWINGS

[0173] Figure 1 The graph illustrates the effect of CO2 scavengers on the lambda value (measured at 10°C) as a function of time (room temperature aging) for foams prepared according to the invention (Examples 1 and 2) and comparative foams (Comparative Examples 1 and 2). DETAILED DESCRIPTION

[0174] Chemicals used:

[0175] - Polyol: Aromatic polyester polyol with OHv=240 mg KOH / g (Stepanpol PS2352 from Stepan)

[0176] -Flame retardant tris(chloroisopropyl) phosphate (TCPP)

[0177] -Catalyst 1: Pentamethyldiethylenetriamine (PMDETA)

[0178] - Catalyst 2: Potassium octoate based catalyst ( K15)

[0179] - Catalyst 3: Potassium acetate-based catalyst (LB catalyst)

[0180] -Catalyst 4: Tetrabutylammonium bromide (TBAB, Sigma-Aldrich)

[0181] - Foam stabilizer: Silicone surfactant (from Evonik 8494)

[0182] -Foaming agent: Cyclopentane (CP, Alfa-Aesar)

[0183] -water

[0184] -Epoxide: Phenyl glycidyl ether (PGE, Sigma-Aldrich)

[0185] -Polyisocyanate 2085 (S2085, from Huntsman), a high functionality polymeric MDI composition with NCO% = 30.5 and average functionality = 2.9.

[0186] Insulation foams containing PIR were made using CO2 scavengers and cyclopentane blowing agents (Examples 1 and 2) and without Or comparative examples 1 and 2 using limited amounts of CO2 scavengers (illustrating the effect of CO2 scavengers)

[0187] In a closed metal mold (20×20×4cm 3 The following PIR formulation (Table 1) was foamed in a mold having its inner surface previously covered with a gas diffusion tight seal (air-impermeable multilayer aluminum containing foil). Demolding was performed after 1 hour, and the seals were removed from the sides of the foam, leaving them open. The top and bottom surfaces of the resulting foam were thus covered with a gas diffusion tight seal (71.4% of the foam surface).

[0188] For foams containing epoxy compounds (PGE), the CO2 / epoxy reaction catalyst (TBAB) was first dissolved in the epoxy compound, and the resulting solution was then mixed with the remaining polyol blend and then reacted with the isocyanate, keeping the TBAB / PGE weight ratio constant at 0.33.

[0189] The amount of reaction mixture injected into the mold was adjusted to ensure good mold filling and minimized overfilling. The foams were aged at room temperature and their lambda values ​​at 10°C were measured in a LaserComp Fox 200 at regular time intervals until a constant value was reached (stable lambda value, ~100 days). The CO2 content in the foams was then determined by cell gas analysis (method developed in-house). FTIR (Fourier Transform Infrared) spectra were also recorded to qualitatively demonstrate the presence or absence of carbonate adducts in the foams (wave number ~1798 cm -1 ).

[0190]

[0191]

[0192] Table 1. Rigid PIR foam formulations.

[0193] The lambda values ​​of the four foams are plotted on Figure 1 Additional foam properties are summarized in Table 2. Comparative Example 1, which does not contain a CO2 scavenger epoxy compound, has the highest aged λ value and the largest amount of CO2. Comparative Example 2, which includes a small amount of epoxy compound in its formulation, shows only a negligible decrease in its aged λ value and a significant residual CO2 level compared to Comparative Example 1, which does not contain an epoxy compound. Examples 1 and 2 according to the present invention have a higher amount of epoxy compound and ultimately show lower aged λ values ​​and significantly lower CO2 levels compared to Comparative Examples 1 and 2, indicating successful CO2 scavenging. -1 The obvious presence of FTIR absorption peaks also confirmed the formation of carbonate groups.

[0194] These results demonstrate that the proper amount of epoxy compound is critical to significant CO scavenging and ultimately achieving improved thermal insulation properties (i.e., lower lambda values), and therefore an epoxy / water molar ratio greater than 7.8 must be used (or in other words, the molar amount of epoxy compound in the reactive composition needs to be at least 7.8 times the molar amount of CO formed from water).

[0195]

[0196] Table 2. PIR foam properties.

Claims

1. A reactive composition for preparing a PIR-containing foam at an isocyanate index of at least 120, said composition comprising at least: a) an isocyanate composition comprising one or more isocyanate compounds, and b) an isocyanate-reactive composition comprising one or more isocyanate-reactive compounds, and c) at least one PIR promoting catalyst, and d) at least one physical blowing agent having a lambda gas value ≤ 12 mW / m·K at 10°C, and e) at least one CO2 scavenging compound selected from at least one epoxy compound having an equivalent weight of less than 300 g / mol, and f) optionally, a catalyst to promote the reaction of the epoxy compound with CO2 It is characterized by: The amount of isocyanate-reactive compound b) in the reactive composition is at least 10 wt.-%, calculated on the total weight of the reactive composition, or at least greater than the amount of the epoxy compound, and the molar amount of the epoxy compound in the reactive composition is at least 7.8 times the molar amount of CO formed after the reaction of water present in the reactive composition with the isocyanate.

2. The reactive composition according to claim 1, wherein the amount of isocyanate-reactive compound b) in the reactive composition is at least 15% by weight, based on the total weight of the reactive composition.

3. The reactive composition according to claim 1, wherein the amount of isocyanate-reactive compound b) in the reactive composition is at least 20% by weight, based on the total weight of the reactive composition.

4. The reactive composition according to any one of claims 1 to 3, wherein the molar amount of the epoxy compound in the reactive composition is at least 10 times the molar amount of CO2 formed after the reaction of water present in the reactive composition with the isocyanate.

5. The reactive composition according to any one of claims 1 to 3, wherein the molar amount of the epoxy compound in the reactive composition is at least 15 times the molar amount of CO2 formed after the reaction of water present in the reactive composition with the isocyanate.

6. The reactive composition according to any one of claims 1 to 3, wherein the maximum amount of all epoxy compounds in the reactive composition is <25 wt.-%, calculated based on the total weight of the reactive composition.

7. The reactive composition according to any one of claims 1 to 3, wherein the maximum amount of all epoxy compounds in the reactive composition is <20 wt.-%, calculated based on the total weight of the reactive composition.

8. The reactive composition according to any one of claims 1 to 3, wherein the at least one epoxy compound is selected from epoxy compounds having an equivalent weight of less than 250 g / mol, and wherein the at least one epoxy compound used is liquid at 20°C.

9. The reactive composition according to claim 8, wherein the at least one epoxy compound is selected from epoxy compounds having an equivalent weight of less than 200 g / mol.

10. The reactive composition according to any one of claims 1 to 3, wherein the catalyst for promoting the reaction of the epoxy compound with CO2 is selected from ammonium salts.

11. The reactive composition according to claim 10, wherein the catalyst for promoting the reaction of the epoxy compound with CO2 is selected from tetrabutylammonium bromide and / or tetrabutylammonium iodide.

12. The reactive composition according to any one of claims 1 to 3, wherein the at least one physical blowing agent having a lambda gas value ≤ 12 mW / m·K at 10°C is selected from HFO blowing agents and / or HCFO blowing agents and / or hydrocarbon blowing agents and mixtures thereof.

13. The reactive composition according to any one of claims 1 to 3, wherein the at least one physical blowing agent having a lambda gas value ≤ 12 mW / m·K at 10°C is selected from chlorofluorocarbons and / or hydrofluorocarbons and / or hydrochlorofluorocarbons.

14. The reactive composition according to any one of claims 1 to 3, wherein the isocyanate compound is selected from toluene diisocyanate, methylene diphenyl diisocyanate or a polyisocyanate composition comprising methylene diphenyl diisocyanate or a mixture of such polyisocyanates.

15. The reactive composition of any one of claims 1 to 3, wherein the one or more isocyanate-reactive compounds comprise polyols and polyol mixtures having an average hydroxyl number of 50 to 1000 mg KOH / g and a hydroxyl functionality of 2 to 8.

16. The reactive composition of any one of claims 1 to 3, wherein the one or more isocyanate-reactive compounds comprise polyols and polyol mixtures having an average hydroxyl number of 150 to 700 mg KOH / g and a hydroxyl functionality of 3 to 8.

17. The reactive composition of any one of claims 1 to 3, wherein the blowing agent is present in an amount of 1 to 60 parts by weight per one hundred parts by weight of the isocyanate-reactive compound.

18. The reactive composition of any one of claims 1 to 3, wherein the blowing agent is present in an amount of 2 to 45 parts by weight per one hundred parts by weight of the isocyanate-reactive compound.

19. The reactive composition according to any one of claims 1 to 3, further comprising, in addition to the blowing agent having a lambda gas value ≤ 12 mW / m·K at 10°C, an additional blowing agent having a lambda gas value > 12 mW / m·K at 10°C, wherein the ratio of the blowing agent having a lambda gas value ≤ 12 mW / m·K at 10°C to the additional blowing agent is a weight ratio of 95 / 5 to 5 / 95, calculated based on the total weight of all blowing agents.

20. A method of preparing a thermal insulation foam comprising PIR, the method comprising combining and / or mixing the ingredients of the reactive composition according to any one of the preceding claims 1 to 19 at an isocyanate index of at least 120.

21. The method of claim 20, further comprising the step of sealing the foam with a gas diffusion tight seal, wherein at least 50% of the foam surface is covered by the gas diffusion tight seal.

22. The method according to claim 20 or 21, wherein the gas diffusion tight seal is selected from a metal foil or a metal multilayer comprising an aluminum foil and / or a gas barrier polymer layer.

23. The method according to claim 20 or 21, further comprising the step of aging the foam after sealing the foam, said aging step comprising maintaining the foam at a given temperature above room temperature until a stable low lambda value is obtained, at a temperature of 25-100°C for less than one month.

24. A stabilized PIR-containing thermal insulation foam prepared using the method according to any one of claims 20 to 23, wherein the weight percent of CO2 in the stabilized aged foam is 0-2 weight percent, based on the total weight of the stabilized aged foam.

25. The stabilized PIR-containing insulating foam of claim 24, wherein the weight percent of CO2 in the stabilized aged foam is 0-0.5 weight percent, based on the total weight of the stabilized aged foam.

26. The stabilized PIR-containing thermal insulation foam according to claim 24, having a foam density of <45 kg / m³ and a stabilized thermal conductivity of <20 mW / m·K at 10°C.

27. The stabilized PIR-containing insulation foam of claim 26, having a stabilized thermal conductivity of 14-20 mW / m·K at 10°C.

28. The stabilized PIR-containing thermal insulation foam according to claim 24, having a foam density of > 45 kg / m³ and a stabilized thermal conductivity of < 25 mW / m·K at 10°C.

29. The stabilized PIR-containing insulation foam of claim 28, having a stabilized thermal conductivity of 14-25 mW / m·K at 10°C.

30. Use of the PIR-containing insulating foam according to any one of claims 24 to 29 as a thermal insulator.

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