Imide-containing polyol, process for preparing imide-containing polyol, and process for using imide-containing polyol

Abstract

Embodiments of the present disclosure relate to imide-containing polyols, methods for making imide-containing polyols, and methods of using imide-containing polyols.

Description

Technical Field

[0001] The present disclosure relates to imide-containing polyols and methods for their preparation and use. Background Art

[0002] Rigid polyurethane and polyisocyanurate foams are used as insulation materials in buildings, vehicles, appliances, and the like. This type of foam is prepared by reacting a foam formulation comprising one or more isocyanates, one or more polyols, and one or more blowing agents. Summary of the Invention

[0003] The present disclosure provides various embodiments including: A method for preparing an imide-modified polyol composition, the method comprising: a) reacting trimellitic anhydride with an aliphatic diamine in the presence of 0 parts by weight to 3 parts by weight of another carboxylic anhydride and / or polycarboxylic acid per 100 parts by weight of trimellitic anhydride to form one or more imide group-containing compounds having terminal carboxylic acid groups; b) optionally combining one or more imide group-containing compounds having terminal carboxylic acid groups with one or more aromatic dicarboxylic acid derivatives without imide groups selected from aromatic carboxylic anhydrides, aromatic dicarboxylic acids, aromatic dicarboxylic acid halides, and aromatic dicarboxylic acid dialkyl esters, wherein the molar ratio of the imide group-containing compound to the aromatic dicarboxylic acid derivative is at least 25:75; c) esterifying one or more imide group-containing compounds having terminal carboxylic acid groups and one or more aromatic carboxylic acid derivatives (if present) by reacting with one or more polyols having a hydroxyl equivalent weight of 30 g / equivalent to 500 g / equivalent, wherein the imide-modified polyol composition has an acid value of not more than 5 mg KOH / g, a hydroxyl value of 100 mg KOH / g to 350 mg KOH / g, and contains 0.65 moles to 2.30 moles of imide groups per kilogram of the imide-modified polyol composition. Detailed Description

[0004] With the growth of global energy consumption, end-users strongly desire foam products with better insulation properties and that are easy to process and manufacture. This is becoming increasingly difficult to achieve industrially.

[0005] In addition, many polyurethane and polyisocyanurate foams typically need to be fire-resistant and require the use of large amounts of halogenated fire retardants, which face regulatory pressure in many jurisdictions. Therefore, it is desirable to reduce or even eliminate the use of these halogenated materials while maintaining the desired fire resistance in the foam. In summary, it would be advantageous to prepare foam products that can enhance insulation performance and have good fire resistance.

[0006] One or more embodiments provide a method for preparing an imide-modified polyol composition, the method comprising: a) reacting trimellitic anhydride with an aliphatic diamine in the presence of from 0 parts by weight to 3 parts by weight, per 100 parts by weight of trimellitic anhydride, of another carboxylic anhydride and / or polycarboxylic acid to form one or more imide group-containing compounds having terminal carboxylic acid groups; b) optionally combining one or more imide group-containing compounds having terminal carboxylic acid groups with one or more aromatic dicarboxylic acid derivatives free of imide groups selected from aromatic carboxylic anhydrides, aromatic dicarboxylic acids, aromatic dicarboxylic acid halides, and aromatic dicarboxylic acid dialkyl esters, wherein the molar ratio of the imide group-containing compound to the aromatic dicarboxylic acid derivative is at least 25:75; c) then esterifying one or more imide group-containing compounds having terminal carboxylic acid groups and one or more aromatic carboxylic acid derivatives (if present) by reacting with one or more polyols having a hydroxyl equivalent weight of from 30 g / equivalent to 500 g / equivalent to produce an imide-modified polyol composition, wherein the imide-modified polyol composition has an acid value of not more than 5 mg KOH / g, a hydroxyl value of from 100 mg KOH / g to 350 mg KOH / g, and contains from 0.65 moles to 2.30 moles of imide groups per kilogram of the imide-modified polyol composition.

[0007] One or more embodiments provide an imide-modified polyol composition produced in the foregoing process.

[0008] One or more embodiments provide a method for preparing a rigid isocyanate-based foam. One or more embodiments provide forming a reaction mixture and reacting the reaction mixture to produce a rigid isocyanate-based foam, wherein the reaction mixture comprises: a) at least one aromatic polyisocyanate in an amount providing an isocyanate index of from 100 to 600; b) a polyol, wherein the polyol comprises at least 25 wt% of the imide-modified polyol composition as discussed herein and from 0 wt% to 75 wt% of one or more non-imide-modified polyols, and wherein the imide content of the polyol is from 0.125 moles to 1.75 moles of imide groups per kilogram; c) at least one blowing agent; d) at least one halogenated flame retardant and / or a phosphorus-containing flame retardant; e) at least one foam-stabilizing surfactant; and f) at least one urethane trimerization catalyst and / or an isocyanate trimerization catalyst.

[0009] The imide-modified polyol composition is prepared by a method comprising a step of forming an imide group-containing compound having terminal carboxylic acid groups. This is achieved by reacting trimellitic anhydride with an aliphatic diamine.

[0010] The aliphatic diamine may have two primary amino groups. The aliphatic diamine can be a straight-chain aliphatic diamine, a branched-chain aliphatic diamine, a cyclic aliphatic diamine, a heteroaliphatic diamine, or a mixture thereof. The heteroaliphatic diamine has heteroatoms, such as oxygen, sulfur, and nitrogen, dispersed among the alkylene groups, where the primary amino groups are attached to the alkylene groups. The aliphatic diamine does not contain a carboxylic acid group and may also not contain other groups (except for amino groups) that react with carboxylic acid, amine, or hydroxyl groups under the reaction conditions for producing the imide-modified polyol composition. One or more embodiments provide that the aliphatic diamine may be selected from 4,4'-methylenebis(cyclohexylamine), 2,2'-[oxybis(2,1-ethanediyl-oxy)]bis(ethylamine), 2,2'-oxybis(ethylamine), 3,3'-[oxybis(2,1-ethanediyl-oxy)]bis(1-propylamine), 1,4-butanediamine, 1,5-pentanediamine, 1,3-pentanediamine, 1,6-hexanediamine, 1,7-heptanediamine, 1,8-octanediamine, 1,10-decanediamine, 1,11-undecanediamine, 1,12-dodecanediamine, 1,2-propanediamine, 2-methyl-1,3-propanediamine, 1,3-propanediamine, 1,3-cyclohexanediamine, 1,4-cyclohexanediamine, 3,3'-[1,4-butanediylbis(oxy)]bis(1-propylamine), 1,4-cyclohexanedimethanamine, 1,2-ethanediamine (also known as ethylenediamine (ED)), 2,2'-(ethylenedioxy)bis(ethylamine) (also known as 1,2-bis(2-aminoethoxy)ethane or diaminotriethylene glycol (DATEG)), 3,3'-[1,2-ethanediylbis(oxy)]bis(1-propylamine) (also known as ethylene glycol bis(3-aminopropyl) ether (EGAPE)), α-(2-aminomethylethyl)-ω-(2-aminomethylethoxy)-poly[oxy(methyl-1,2-ethanediyl)] (also known as polypropylene glycol diamine or polyoxypropylene diamine, or the trade name JEFFAMINE D230), 2-methyl-1,5-pentanediamine (also known as 2-methyl-1,5-diaminopentane (DYTEK A)), 1,3-cyclohexanedimethanamine (also known as 1,3-bis(aminomethyl)cyclohexane (1,3-CHDMA)), 1,2-cyclohexanediamine (also known as 1,2-diaminocyclohexane (1,2-CHDA)), 5-amino-1,3,3-trimethyl-cyclohexanemethanamine (also known as isophorone diamine (IPDA)), including their conformational isomers and positional isomers, or combinations thereof.One or more embodiments provide that the aliphatic diamine may be selected from 1,2-ethylenediamine (also known as ethylenediamine (ED)), 2,2'-(ethylenedioxy)bis(ethylamine) (also known as 1,2-bis(2-aminoethoxy)ethane or diaminotriethylene glycol (DATEG)), 3,3'-[1,2-ethanediylbis(oxy)]bis-1-propanamine (also known as ethylene glycol bis(3-aminopropyl) ether (EGAPE)), α-(2-aminomethylethyl)-ω-(2-aminomethylethoxy)-poly[oxy(methyl-1,2-ethanediyl)] (also known as polypropylene glycol diamine or polyoxypropylene diamine, or the trade name JEFFAMINE D230), 2-methyl-1,5-pentanediamine (also known as 2-methyl-1,5-diaminopentane (DYTEK A)), 1,3-cyclohexanedimethanamine (also known as 1,3-bis(aminomethyl)cyclohexane (1,3-CHDMA)), 1,2-cyclohexanediamine (also known as 1,2-diaminocyclohexane (1,2-CHDA)), 5-amino-1,3,3-trimethyl-cyclohexanemethanamine (also known as isophorone diamine (IPDA)), including their conformational isomers and positional isomers, or combinations thereof.

[0011] The imidization reaction is carried out in the presence of up to 3 parts by weight, up to 2 parts by weight, or up to 1 part by weight of another carboxylic anhydride and / or polycarboxylic acid per 100 parts by weight of trimellitic anhydride. Such other carboxylic anhydrides or polycarboxylic acids (if present) may be, for example, impurities in the trimellitic anhydride. The other carboxylic anhydride and / or polycarboxylic acid may be absent. The almost complete absence or complete absence of the other carboxylic anhydride and / or polycarboxylic acid allows for a more defined and predictable product in the imidization reaction.

[0012] Trimellitic anhydride and the aliphatic diamine may be combined in a ratio that provides 0.8 to 1.2 equivalents, 0.9 to 1.1 equivalents, or 0.95 to 1.05 equivalents of acid anhydride groups per equivalent of amino groups. One or more embodiments provide that the ratio is 0.98 to 1.02 equivalents or 0.99 to 1.01 equivalents of acid anhydride per equivalent of amino groups.

[0013] The reaction of trimellitic anhydride with the amino groups of the aliphatic diamine forms an amic acid intermediate, which is then cyclized / dehydrated chemically and / or thermally to form a diimide structure (e.g., an aromatic-aliphatic diimide), with the generation of water. The diimide structure may be represented by structure (I), where Aliph represents an aliphatic group.

[0014]

[0015] The diimide contains two imide groups and likewise contributes two imide groups to the imide-modified polyol composition as discussed herein.

[0016] The aliphatic group can be a straight-chain alkylene group having 2 to 18 carbon atoms; a branched-chain alkylene group having 3 to 18 carbon atoms; an alicyclic compound having at least one ring and no more than three rings and an independent ring size of 4 to 8 carbon atoms; –(CRR 1 ) n -[Z-(CR 2 R 3 ) n’ n” -Z-(CRR 1 ) n -type heteroaliphatic alkylene, where each R, R 1 , R 2 , R 3 is independently H, or a C1 to C6 alkyl group, n and n’ are independently integers from 2 to 4, n” is an integer from 0 to 18, and each Z is independently a heteroatom; and mixtures thereof. One or more embodiments provide that the aliphatic group can be 1,2-ethane, 1,2-cyclohexane, 2-methyl-1,5-pentane, 1,3-dimethylenecyclohexane, 1,3,3-trimethylcyclohexylmethylene, poly(oxypropylene) having on average at most 4 repeating units, 1,2-diethoxyethane, and 1,2-dipropoxyethane. The imidization reaction can be carried out, for example, at a temperature of 20°C to 180°C. Various pressures can be used (e.g., sufficient to prevent the reactants from boiling). In multiple embodiments, temperature and pressure conditions are preferably allowed such that the water released in the imidization reaction evaporates or distills (including azeotropic distillation) and is removed as the reaction proceeds. An inert purge gas can also be passed through the reaction vessel to remove water and / or aqueous azeotropes.

[0017] The imidization reaction can be carried out in a suitable solvent for trimellitic anhydride and aliphatic diamine. In some embodiments, the solvent does not react with any of the starting materials or reaction products. Examples of such non-reactive solvents include, for example, N,N-dimethylacetamide, N-methylpyrrolidone, N,N-dimethylformamide, toluene, xylene, benzene, various C6-C24 hydrocarbons, mixtures thereof, etc. When using such non-reactive solvents, the reaction can be carried out under reflux conditions. The imide group-containing compound having terminal carboxylic acid groups produced in the imidization can be separated from the non-reactive solvent and dried.

[0018] ​Alternatively, the imidization reaction can be carried out in the presence of a polyol having a hydroxyl equivalent weight of 30 g / equivalent to 500 g / equivalent, in which case the polyol can be used as a solvent and / or reaction medium. When a polyol is used, the imidization reaction can be carried out in the absence of an effective amount of an esterification catalyst (i.e., a catalyst for the reaction of an alcohol with a carboxylic acid). In the absence of such a catalyst, little or no esterification of the terminal carboxyl groups occurs during the imidization step. Although the imide group-containing product can be separated and dried from the polyol, it is generally preferred not to do so, and thus the imide group-containing product is left in the polyol.

[0019] The diimide having terminal carboxylic acid groups obtained in the imidization step is then esterified by reaction with a polyol having a hydroxyl equivalent weight of 30 g / equivalent to 500 g / equivalent. The polyol can be any of the polyols present during the imidization reaction or include any of the polyols present during the imidization reaction. Preferably, at least one polyol having a hydroxyl equivalent weight of at least 95 g / equivalent and at most 500 g / equivalent (such as 95 g / equivalent to 400 g / equivalent, 95 g / equivalent to 350 g / equivalent, or 150 g / equivalent to 250 g / equivalent) reacts with the diimide having terminal carboxylic acid groups. In some embodiments, such polyols having a hydroxyl equivalent weight of at least 95 and at most 500 account for at least 50%, at least 75%, at least 90%, or 100% of the total weight of the polyols having a hydroxyl equivalent weight of 30 g / equivalent to 500 g / equivalent. In other words, the polyols having a hydroxyl equivalent weight of at least 95 and at most 500 can be from 50%, 75%, or 90% of the lower limit to 100%, 99%, or 95% of the upper limit of the total weight of the polyols having a hydroxyl equivalent weight of 30 g / equivalent to 500 g / equivalent. The polyols having a hydroxyl equivalent weight of at least 95 and at most 500 are preferably bifunctional and are preferably polyethers, especially polyethylene glycol, poly(propylene glycol), or ethylene oxide / propylene oxide copolymer diols. Other useful polyols include diols such as ethylene glycol, diethylene glycol, triethylene glycol, 1,2-propanediol, 1,3-propanediol, dipropylene glycol, tripropylene glycol, cyclohexanedimethanol, neopentyl glycol, etc. For example, polyols having 3 or more hydroxyl groups can form all or part of the polyols having a hydroxyl equivalent weight of 30 to 500, but if used, can account for a small proportion thereof, such as at most 20 wt%, at most 10 wt%, or at most 5 wt%, to avoid excessive branching and / or crosslinking. Examples of such polyols include glycerol, trimethylolpropane, trimethylolethane, pentaerythritol, erythritol, triethanolamine, and polyethers having 3 to 6 hydroxyl groups per molecule and an equivalent weight of, for example, 100 g / equivalent to 500 g / equivalent.

[0020] Optionally, in one or more embodiments, a compound containing an imide group having a terminal carboxylic acid group is combined with one or more aromatic dicarboxylic acid derivatives without an imide group selected from aromatic carboxylic acid anhydrides, aromatic dicarboxylic acids, aromatic dicarboxylic acid halides, and aromatic dicarboxylic acid dialkyl esters, and the resulting mixture is simultaneously subjected to an esterification step. The aromatic dicarboxylic acid derivative does not contain an imide group and preferably has a molecular formula molecular weight of not more than 250 g / mol. Examples of such aromatic dicarboxylic acid derivatives include phthalic anhydride, phthalic acid, isophthalic acid, terephthalic acid, dimethyl terephthalate, dimethyl isophthalate, dimethyl phthalate, terephthaloyl chloride, isophthaloyl chloride, phthaloyl chloride, etc.; and mixtures of any two or more thereof. Preferred aromatic dicarboxylic acid derivatives are phthalic anhydride, phthalic acid, isophthalic acid, and especially phthalic anhydride. In such embodiments, the molar ratio of the diimide to the aromatic dicarboxylic acid derivative is at least 25:75 and can be any higher ratio up to 99.99:0.01. Examples of suitable ratios are at least 30:70 or at least 50:50. In certain embodiments, the ratio can be up to 95:5, up to 90:10, up to 80:20, or up to 70:30.

[0021] Alternatively, a compound containing an imide group having a terminal carboxylic acid group can undergo an esterification step in the absence of an added aromatic dicarboxylic acid derivative to produce an imide-modified polyol. Some of the starting polyol may remain unreacted during this step. In such embodiments, an aromatic dicarboxylic acid derivative can then be added and the resulting mixture subjected to esterification and / or transesterification conditions to produce an imide group-containing polyol composition as discussed herein.

[0022] The ratio of the polyol to the imidation reaction product can be selected to provide 1.5 to 3 equivalents of hydroxyl groups per equivalent of carboxyl groups provided by the diimide, plus carboxyl groups provided by the aromatic dicarboxylic acid derivative (if any). For the purposes of this calculation, an acid anhydride group is counted as two carboxylic acid groups, and a carboxylic acid alkyl ester and a halide group are each counted as one carboxylic acid group. The equivalent ratio can be at least 1.6, at least 1.75, or at least 1.9 and up to 2.5, up to 2.25, up to 2.10, or up to 2.05. When the equivalent ratio is greater than about 2, a portion of the polyol may remain unreacted during the esterification step.

[0023] The esterification reaction can be carried out in the presence of an esterification catalyst. Examples of esterification catalysts include Bronsted acids (such as sulfuric acid, p-toluenesulfonic acid); Lewis acids (such as SnCl4, AlCl3, and BF3), tin(II) compounds (such as SnCl2 and various tin dicarboxylates); organotin(IV) compounds (such as dialkyltin oxides, dialkyltin dicarboxylates, etc.), pyranone-coordinated Sn(II), Pb(II), Zn(II), and / or Hg(II) complexes, and various titanium compounds (such as titanium acetylacetonate, titanium(IV) oxyacetylacetonate, diisopropoxybis(acetylacetonate)titanium, tetra-isopropyltitanium, triethanolamine titanate, titanium(IV) isobutoxide), and other organotitanium catalysts and organozirconium catalysts as described in U.S. Patent No. 3,056,818. Other examples of catalysts that can be used in the present disclosure are described, for example, in U.S. Patent No. 10,619,000. The catalyst is used in a catalytically effective amount, such as 10 parts by weight to 10,000 parts by weight per million parts by weight of the combined weight of the diimide, polyol, and any added aromatic dicarboxylic acid derivative.

[0024] The esterification reaction can be carried out at a temperature of 100 °C to 270 °C. One or more embodiments specify a temperature of at least 180 °C, at least 200 °C, or at least 220 °C. Various pressures can be used, and the pressure is generally sufficient to prevent evaporation of the reactants, but temperature and pressure conditions that allow water and other volatile by-products of the esterification reaction to evaporate or distill and be removed as a vapor when the reaction proceeds can be preferred. One or more embodiments specify a pressure of about atmospheric pressure, such as about 90 kPa to 110 kPa. A negative pressure lower than atmospheric pressure down to 1 kPa can be used. The esterification reaction can be carried out in a suitable solvent for the starting materials (such as those described above for the imidization reaction). When a solvent is used, the reaction can be carried out under reflux conditions of the solvent, but it is preferred to carry out the esterification reaction in the absence of any solvent other than the reactants. The reaction can be continued until the acid value is reduced to less than 5 mg KOH / g, less than 2 mg KOH / g, less than 1 mg KOH / g, or less than 0.5 mg KOH / g, as measured by potentiometric titration with a standardized 0.01 N potassium hydroxide solution. One or more embodiments specify a lower limit of the acid value of 0.001 mg KOH / g or 0.01 mg KOH / g. If a portion of the polyol volatilizes, it can be replenished by adding a corresponding amount of additional polyol, optionally followed by an additional reaction under transesterification conditions.

[0025] The resulting imide-modified polyol composition comprises a reaction product of an imide group-containing compound and one or more hydroxy-terminated esters of a polyol. When an aromatic dicarboxylic acid derivative is present during all or part of the esterification step, the composition further contains a reaction product of an aromatic dicarboxylic acid derivative and one or more hydroxy-terminated esters of a polyol. The imide-modified polyol composition may contain an amount of unreacted starting polyol. The imide-modified polyol composition has a hydroxyl value of from 100 mg KOH / g to 350 mg KOH / g, from 125 mg KOH / g to 300 mg KOH / g, or from 150 mg KOH / g to 275 mg KOH / g, as measured according to ASTM E1899-16. The imide-modified polyol composition contains from 0.65 moles to 2.30 moles of imide groups per kilogram. In some embodiments, the imide-modified polyol composition contains at least 0.75 moles or at least 1.00 moles of imide groups per kilogram, and in specific embodiments contains at most 2.2 moles or at most 2.0 moles of imide groups per kilogram. The imide group-containing compound prepared by reacting two moles of trimellitic anhydride with one mole of an aliphatic diamine yields two moles of imide groups.

[0026] The imide-modified polyol composition may have an average hydroxyl functionality in the range of from 1.8 to 4, preferably from 1.8 to 3, more preferably from 1.8 to 2.5, or from 1.8 to 2.2. One or more embodiments provide that the imide-modified polyol composition is a liquid at room temperature. In some cases, some crystals may form upon prolonged standing at room temperature; these crystals typically disappear upon heating the imide-modified polyol composition. The imide-modified polyol composition may exhibit a viscosity of, for example, from 1 Pa·s to 300 Pa·s, from 5 Pa·s to 150 Pa·s, or from 5 Pa·s to 100 Pa·s, as measured according to ISO 3219 at 25 °C and a shear rate of 10 s−1. If crystals have formed in the imide-modified polyol composition, the viscosity is measured by heating the composition to 70 °C to melt the crystals, cooling to 25 °C over 4 hours, and then determining the viscosity.

[0027] The glass transition temperature (Tg) of the imide-modified polyol composition may be, for example, from −10 °C to −80 °C, or from −25 °C to −65 °C, as measured according to ASTM E1356-08(2014), taking the midpoint temperature as Tg.

[0028] For example, the imide-modified polyol composition can be used to prepare isocyanate-based polymers. The isocyanate-based polymers contain urethane groups produced in the reaction of the hydroxyl groups of the imide-modified polyol composition with the isocyanate groups of the polyisocyanate. The isocyanate-based polymers can also contain other groups formed in the reaction of the isocyanate groups, such as urea groups, isocyanurate groups, biuret groups, urethane groups, carbodiimide groups, and similar groups. Some polymers are polyurethane-isocyanurate polymers, especially foams, containing urethane and isocyanurate groups. The isocyanurate groups are formed in the trimerization reaction of three isocyanate groups.

[0029] Rigid isocyanate-based foams are prepared by forming a reaction mixture and reacting the reaction mixture to produce a rigid isocyanate-based foam. The reaction mixture comprises the imide-modified polyol composition discussed herein and at least one aromatic polyisocyanate. The aromatic polyisocyanate is provided in an amount sufficient to provide an isocyanate index of 100 to 600. The isocyanate index is 100 times the ratio of the isocyanate groups provided to the reaction mixture to the isocyanate-reactive groups (hydroxyl, primary or secondary amino, carboxylic acid, water, etc.). For the purpose of calculating the isocyanate index, water is considered to have two isocyanate-reactive groups. In some embodiments, the isocyanate index is at least 125, at least 150, or at least 180.

[0030] The polyisocyanate can have, for example, an isocyanate equivalent weight of at most 300 g / equivalent. The isocyanate equivalent weight can be at most 250, at most 175, and in some examples, 80 g / equivalent to 175 g / equivalent. If a mixture of polyisocyanate compounds is used, these equivalent weights apply to the mixture; each polyisocyanate compound in such a mixture can have an isocyanate equivalent weight above, within, or below those ranges.

[0031] Examples of polyisocyanates include m-phenylene diisocyanate, toluene-2,4-diisocyanate, toluene-2,6-diisocyanate, hexamethylene-1,6-diisocyanate, tetramethylene-1,4-diisocyanate, cyclohexane-1,4-diisocyanate, methylcyclohexane diisocyanate, naphthylene-1,5-diisocyanate, 1,3-bis(isocyanatomethyl)cyclohexane and / or 1,4-bis(isocyanatomethyl)cyclohexane (including cis isomers and / or trans isomers), methoxyphenyl-2,4-diisocyanate, diphenylmethane-4,4'-diisocyanate, diphenylmethane-2,4'-diisocyanate, hydrogenated diphenylmethane-4,4'-diisocyanate, hydrogenated diphenylmethane-2,4'-diisocyanate, 4,4'-biphenylene diisocyanate, 3,3'-dimethoxy-4,4'-biphenyl diisocyanate, 3,3'-dimethyl-4,4'-biphenyl diisocyanate, 3,3'-dimethyldiphenylmethane-4,4'-diisocyanate, 4,4',4''-triphenylmethane triisocyanate, polymethylene polyphenyl isocyanate (PMDI), toluene-2,4,6-triisocyanate and 4,4'-dimethyldiphenylmethane-2,2',5,5'-tetraisocyanate. Preferably, the polyisocyanate is diphenylmethane-4,4'-diisocyanate, diphenylmethane-2,4'-diisocyanate, PMDI, toluene-2,4-diisocyanate, toluene-2,6-diisocyanate or a mixture thereof. Diphenylmethane-4,4'-diisocyanate, diphenylmethane-2,4'-diisocyanate and mixtures thereof are collectively referred to as MDI, and all of them can be used. "Polymeric MDI", which is a mixture of PMDI and MDI, can be used. Toluene-2,4-diisocyanate, toluene-2,6-diisocyanate and mixtures thereof are collectively referred to as TDI, and all of them can be used.

[0032] The imide-modified polyol composition of the present disclosure comprises at least 25 wt% or at least 50 wt% of the polyols present in the foam-forming reaction mixture. In some embodiments, the imide-modified polyol composition comprises at least 60% or at least 70% of the total weight of all polyols. It can comprise up to 100%, up to 95%, up to 90% or up to 80% of the total weight of the polyol mixture. The polyols in the foam-forming reaction mixture optionally contain one or more non-imide-modified polyols, provided that the imide content of the polyols is from 0.125 moles to 1.75 moles, especially from 0.15 moles to 1.75 moles, or from 0.30 moles to 1.50 moles of imide groups per kilogram of the combined weight of all polyols. The non-imide-modified polyols (if present) can comprise, for example, from 1% to 75%, 1% to 50%, 1% to 40%, 1% to 30%, 1% to 20%, 1% to 10% or 1% to 5% of the total weight of all polyols (including the imide-modified polyol composition of the present disclosure).

[0033] The non-imide-modified polyols for the foam-forming reaction mixture of the present disclosure can have, for example, an average nominal hydroxyl functionality in the range of 1.8 to 8, 1.8 to 6.0, 1.8 to 4.5, or 1.8 to 3.0, and an average hydroxyl value of from 75 mg KOH / g to 750 mg KOH / g.

[0034] The non-imide-modified polyols (if present) can include, for example, chain extenders, i.e., compounds that react bifunctionally with isocyanate groups and have an equivalent weight of less than 200 (such as 30 to 125) per isocyanate-reactive group. Examples of chain extenders include ethylene glycol, diethylene glycol, triethylene glycol, propylene glycol, dipropylene glycol, tripropylene glycol, 1,4-butanediol, 1,6-hexanediol, ethylenediamine, propylenediamine, etc.

[0035] Other non-imide-modified polyols can include crosslinking agents, i.e., compounds having three or more isocyanate-reactive groups and an equivalent weight of less than 200 (such as 30 to 125) per isocyanate-reactive group. Examples of crosslinking agents include glycerol, trimethylolpropane, triethylolethane, pentaerythritol, erythritol, triethanolamine, diethanolamine, mannitol, sucrose, urea, sorbitol, etc.

[0036] Other non-imide modified polyols include polyether polyols having an equivalent weight greater than 75 g / equivalent per isocyanate-reactive group. The equivalent weight can be, for example, up to 2000 g / equivalent, up to 1000 g / equivalent, up to 500 g / equivalent, up to 400 g / equivalent, and / or up to 300 g / equivalent. These polyols can have an average of 2 to 8, 2 to 4, or 2.5 to 4 isocyanate-reactive groups per molecule. Polyether polyols include, for example, homopolymers of propylene oxide and random polymers of at least 70 mol% propylene oxide and up to 30 mol% ethylene oxide, as well as homopolymers of ethylene oxide, random and / or block copolymers of at least 50 mol% ethylene oxide and up to 50 mol% propylene oxide and / or butylene oxide.

[0037] Still other non-imide modified polyols include polyester polyols and polycarbonate polyols. When present, the non-imide modified polyols can include at least one aromatic polyester polyol that is not present in the imide modified polyol compositions of the present disclosure. Such aromatic polyester polyols can have, for example, a hydroxyl equivalent weight of 150 g / equivalent to 400 g / equivalent and a hydroxyl functionality of 2 to 3, 2 to 2.7, or 2 to 2.5. When present, such other aromatic polyester polyols can account for, for example, at least 5% or at least 10% and up to 75%, up to 35%, or up to 25% of the total weight of all polyols used.

[0038] The polyols present in the foam-forming reaction mixture can contain no more than 45 wt%, no more than 30 wt%, no more than 25 wt%, no more than 15 wt%, or no more than 10 wt% of polyether polyols (different from the imide modified polyol compositions).

[0039] In some embodiments, polyethylene glycol having a number average molecular weight of up to 400 g / mol accounts for 1% to 30% of the total weight of all polyols.

[0040] The foam-forming reaction mixture contains at least one blowing agent. The blowing agent can be or include a chemical blowing agent that reacts under the conditions of the foaming reaction to produce a gas. Examples of chemical blowing agents include water and formic acid. In one or more embodiments, the foam-forming reaction mixture contains water in an amount of 0.1 part by weight to 3 parts by weight, or 0.2 part by weight to 2.5 parts by weight, 0.5 part by weight to 2.5 parts by weight, or 0.8 part by weight to 2.0 parts by weight per 100 parts of the total polyols in the foam-forming reaction mixture.

[0041] The blowing agent can be or include one or more physical (endothermic) blowing agents, which can be used alone or in combination with one or more chemical blowing agents (e.g., water). Examples of physical blowing agents include methyl formate, low-boiling hydrocarbons (e.g., heptane, hexane, n-pentane, isopentane, butane, cyclopentane, cyclohexane, etc.; and mixtures thereof), low-boiling ketones (such as acetone and methyl ethyl ketone), hydrochlorofluorocarbons (HCFCs) (such as 1,1-dichloro-1-fluoroethane), hydrofluorocarbons (HFCs) (such as 1,1,1,3,3-pentafluoropropane), hydrofluoroolefins (HFOs) (such as trans-1,3,3,3-tetrafluoroprop-1-ene, 1,3,3,3-tetrafluoropropene), etc.; and mixtures thereof. Commercially available hydrofluorocarbon blowing agents include Solstice LBA and Solstice GBA from Honeywell; and Opteon 1100 and Opteon 1150 from Chemours. Straight-chain, branched-chain, and / or cyclic C4-C6 alkanes (such as cyclopentane, isopentane, n-pentane, and neopentane) are particularly useful. One or more embodiments provide that the physical blowing agent is n-pentane or a cyclopentane / isopentane blend. When present, the amount of the physical blowing agent can be from 0.1 parts by weight to 40 parts by weight per 100 parts of the total polyol in the foam-forming reaction mixture.

[0042] The foam-forming reaction mixture contains at least one halogenated flame retardant and / or a phosphorus-containing flame retardant, and the at least one halogenated flame retardant and / or phosphorus-containing flame retardant is preferably non-reactive towards isocyanate groups. Examples of non-reactive phosphorus-containing flame retardants include tris(1-chloropropyl) phosphate, triethyl phosphate, resorcinol bis(diphenyl phosphate), triphenyl phosphate, trimethyl phosphate, triphenylphosphine oxide, 9,10-dihydro-9-oxa-10-phosphaphenanthrene-10-oxide and its derivatives, red phosphorus, inorganic hypophosphites, aluminum phosphate, melamine orthophosphate, dicyandiamide orthophosphate, melamine pyrophosphate, melamine polyphosphate, oligoethylvinyl phosphate, dimethyl methylphosphonate, diethyl ethylphosphonate, diethyl propylphosphonate, tris(2-chloroethyl) phosphate, cyclic phosphonates, pentaerythritol phosphonates, cyclic neopentyl thionophosphoric anhydride, metal hypophosphites (such as zinc diethylphosphinate and aluminum diethylphosphinate), tricresyl phosphate, tert-butylphenyl phosphate (including tert-butylphenyl diphenyl phosphate), 2-ethylhexyl diphenyl phosphate, isodecyl diphenyl phosphate, and various phosphazene compounds. Polymeric or oligomeric phosphorus-containing compounds (such as oligoalkyl phosphates (e.g., Levagard 2000 and Levagard 3000 from Lanxess)) are also suitable. Phosphorus flame retardants containing one or more hydroxyl groups, such as Levagard 2100 and Levagard 4090N from Lanxess, Fyrol 6 and VeriQuel R100 from ICL Industrial Products, can also be used. The halogenated flame retardant can be omitted. When used, the flame retardant can be present in an amount of 0.1 to 30 parts by weight, 1 to 25 parts by weight, 2 to 25 parts by weight, or 5 to 25 parts by weight per 100 parts by weight of the total polyol amount in the foam-forming reaction mixture.

[0043] The foam-forming reaction mixture includes at least one surfactant (e.g., a foam-stabilizing surfactant). The surfactant helps to stabilize the bubbles formed by the blowing agent during the foaming process until the polymer cures. Examples of suitable surfactants include silicone-based surfactants such as the polysiloxane polyoxyalkylene block copolymers disclosed in U.S. Patent Nos. 2,834,748; 2,917,480, and 2,846,458; and organic-based surfactants containing polyoxyethylene-polyoxybutylene block copolymers such as those described in U.S. Patent No. 5,600,019. Examples of such silicone surfactants are commercially available under the trade names Tegostab (Evonik Industries AG), Niax (Momentive), and Vorasurf (The Dow Chemical Company). Specific examples of useful surfactants include VORASURF DC 193, VORASURF RF 5374, VORASURF DC5604, VORASURF SF 2937, VORASURF DC 5098, VORASURF 504, TEGOSTAB B8418, TEGOSTABB8491, TEGOSTAB B8421, TEGOSTAB B8461, and TEGOSTAB B8462, NIAX L-6988, NIAX L-6642, and NIAX L-6633 surfactants. When used, the amount of surfactant can be from 0.1 part to 10.0 parts per 100 parts of the total polyol present in the foam-forming reaction mixture.

[0044] The foam-forming reaction mixture contains one or more catalysts. The catalysts can include one or more urethane catalysts, which refers to compounds that catalyze one or both of the water-isocyanate reaction and the alcohol-isocyanate reaction. Suitable catalysts include, for example, tertiary amines, cyclic amidines, tertiary phosphines, various metal chelates, acidic metal salts, strong bases, various metal alkoxides and phenoxides, and metal salts of organic acids. Examples of metal-containing catalysts include tin salts, bismuth salts, cobalt salts, and zinc salts. The catalysts include tertiary amine catalysts, cyclic amidines, zinc catalysts, and tin catalysts. Examples of tertiary amine catalysts include: trimethylamine, triethylamine, tributylamine, N-methylmorpholine, N-ethylmorpholine, N,N-dimethylbenzylamine, N,N-dimethylethanolamine, N,N-dimethylaminopropylamine, N,N,N’,N’-tetramethyl-1,4-butanediamine, N,N,N’,N’-tetramethylethylenediamine, N,N,N’,N”,N”-pentamethyldiethylenetriamine, N,N-dimethylcyclohexylamine, N,N-dimethylpiperazine, 1,4-diazabicyclo-2,2,2-octane, bis(dimethylaminoethyl) ether, triethylenediamine, and dimethylalkylamines, where the alkyl group contains 4 to 18 carbon atoms. Mixtures of these tertiary amine catalysts can be used. When used, the tertiary amine catalyst can be present in an amount, for example, of 0.05 parts to 5 parts per 100 parts by weight of the polyol in the foam-forming reaction mixture.

[0045] Examples of metal-containing urethane catalysts include tin(II) salts of organic carboxylic acids, such as tin(II) diacetate, tin(II) ricinoleate, or tin(II) dioctoate, bismuth salts of organic carboxylic acids (such as bismuth octoate); organotin compounds, such as dimethyltin dilaurate, dibutyltin dilaurate, and other tin compounds of the formula SnRn(OR)4-n, where R is an alkyl or aryl group, and n is from 0 to 18, etc.; mercapto dialkyltin, etc. The metal-containing urethane catalyst can be used in an amount, for example, of 0.0015 parts by weight to 0.25 parts by weight per 100 parts of the total polyol present in the foam-forming reaction mixture.

[0046] For example, reactive amine catalysts (such as DMEA (dimethyl ethanolamine) or DMAPA (dimethylaminopropylamine) or amine-initiated polyols that act as self-catalyzing polyols) can also be used to reduce VOCs (volatile organic compounds).

[0047] The foam-forming reaction mixture can contain at least one isocyanate trimerization catalyst. An isocyanate trimerization catalyst is a material that promotes the reaction of isocyanate groups with other isocyanate groups to form isocyanurate rings. Useful isocyanate trimerization catalysts include strong bases such as alkali metal phenolates, alkali metal alkoxides, alkali metal hydroxides, alkali metal carboxylates, quaternary ammonium salts, etc. The alkali metal can be sodium or potassium. Specific examples of such trimerization catalysts include sodium p-nonylphenolate, sodium p-octylphenolate, sodium p-tert-butylphenolate, sodium acetate, sodium 2-ethylhexanoate, sodium propionate, sodium butyrate, potassium analogs of any of the foregoing, trimethyl-2-hydroxypropyl ammonium carboxylate salts, N,N’,N”-tris(3-dimethylaminopropyl) hexahydro-S-triazine, etc. Examples of commercially available trimerization catalysts include Dabco K15, Polycat 46, TMR 2, TMR18, etc. from Evonik, and DABCO K2097, etc. The isocyanate trimerization catalyst can be present in a catalytic amount such as 0.05 parts by weight to 10 parts by weight per 100 parts of the total polyol present in the foam-forming reaction mixture.

[0048] In addition to the foregoing components, the foam formulation can also contain various other optional ingredients such as, for example, liquid nucleating additives, solid nucleating agents, Ostwald ripening inhibitor additives, reactive or non-reactive diluents, expandable graphite, pigments, rheology modifiers, emulsifiers, antioxidants, mold release agents, dyes, pigments, and / or colorants such as titanium dioxide, iron oxide, chromium oxide, azo / diazo dyes, phthalocyanines, dioxazines, and carbon black; fillers or reinforcing agents such as glass fibers, carbon fibers, flake glass, mica, talc, etc.; and mixtures thereof.

[0049] Foams can be prepared by combining polyols, blowing agents, polyisocyanates, surfactants, flame retardants, and catalysts in the presence of various optional ingredients (if any) to form a foam-forming reaction mixture. The surfactant, catalyst, flame retardant, blowing agent, and various polyols can all be mixed together before they are combined with the polyisocyanate. Alternatively, they can be combined with the polyisocyanate individually (i.e., as separate streams), or they can be formed into any sub-mixture that is then combined with the polyisocyanate. The components can be mixed at a temperature of 5°C to 80°C. For example, equipment such as spray equipment, low-pressure impact mixers, high-pressure impact mixers, static mixers, liquid dispensing guns or mixing heads, or stirring vessels can be used to mix the components together.

[0050] Then the reaction mixture is reacted to form a foam. The methods of the present disclosure do not require special processing conditions; thus, the processing conditions and equipment described in the art for preparing rigid isocyanate-based foams are fully suitable. Generally, the components of the reaction mixture are combined and the well-mixed foam-forming reaction mixture is subjected to conditions sufficient to allow the foaming reaction to occur. In most cases, the isocyanate compound will react spontaneously with the chemical blowing agent (if present) and the polyol even at room temperature (22 °C). If desired, heat can be applied to the reaction mixture to accelerate the curing reaction. This can be done by heating some or all of the components before they are combined, or by applying heat to the reaction mixture or some combination of each component. The curing temperature can be, for example, 20 °C to 150 °C or 30 °C to 80 °C. Curing can be continued until the reaction mixture has expanded and cured sufficiently to form a stable foam.

[0051] In some embodiments, the curing step is carried out in a closed mold. In this method, the reaction mixture is either formed in the mold itself or formed outside the mold and then injected into the mold where it cures. Thus, the expansion of the reaction mixture during curing is constrained by the inner surface of the mold and also by the dimensions and geometry of the molded part.

[0052] In one or more embodiments, the curing step is carried out in a free rise (or slabstock) process. In the free rise process, the reaction mixture is poured into an open container such that expansion occurs against the atmosphere or a light surface (such as a film) in at least one direction (usually the vertical direction), and the resistance of the light surface to foam expansion is negligible. During the free rise process, the reaction mixture expands in at least one direction and is essentially unconstrained except by its own weight. The free rise process can be carried out by forming the reaction mixture and dispensing it into a trough or onto a conveyor for expansion and curing.

[0053] In one or more embodiments, the foam-forming reaction mixture is dispensed between facing panels (or on top of a single panel), metered into layers and cured to form a laminate. This can be done, for example, on a double belt laminator or similar equipment. Curing is conveniently carried out by passing the facing panels coated with a layer of the foam-forming reaction mixture through an oven that supplies heat to promote curing. This process can be used to produce sandwich panels for the construction or transportation industries.

[0054] In some embodiments, the cured foam has a foam density of 20 kg / m3 to 200 kg / m3, 25 kg / m3 to 150 kg / m3 or 25 kg / m3 to 100 kg / m3, as measured by ISO 3886.

[0055] In some embodiments, the cured foam exhibits a smoke density of no greater than 60, no greater than 50, or no more than 40. Generally, a relatively low smoke density indicates better combustion performance. One or more embodiments provide that the smoke density can have a lower limit of, for example, 0, 3, or 5. According to ASTM E 662, the smoke density generated when each foam sample is exposed to a flame is measured using an NBS smoke chamber at a heat flux of 25 kW / m 2 of the heat flux.

[0056] In some embodiments, the cured foam exhibits a favorable low thermal conductivity or k-factor (average plate temperature of 10 °C). In some embodiments, the k-factor is less than or equal to 19.5 mW / m-K, less than or equal to 19.2 mW / m-K, or less than or equal to 19.0 mW / m-K. In some embodiments with a hydrofluoroolefin (HFO) blowing agent (such as SOLSTICE LBA), the cured foam can achieve a thermal conductivity of less than or equal to 18.0 mW / m-K, less than or equal to 17.5 mW / m-K, even less than or equal to 17.0 mW / m-K, or even further less than or equal to 16.5 mW / m-K. The rigid isocyanate-based foam of this embodiment can have a thermal conductivity greater than 15.0 mW / m-K. Foams with lower thermal conductivity provide improved insulation performance.

[0057] The foams of the present disclosure can be used in various types of thermal insulation applications, such as for building and construction purposes, walk-in refrigerators, refrigerated shipping containers, cryogenic storage, and the like. The imide-containing polyol can be used to prepare non-porous isocyanate-based polymers that can be used, for example, in coatings, adhesives, and electronic devices.

[0058] The following examples are provided for illustration and are not intended to limit the scope. Unless otherwise indicated, all parts and percentages are by weight.

[0059] Embodiment

[0060] The following is Preparation Example 1-P (EX 1-P), an imide-modified polyol composition. The following is the preparation of 2,2'-(ethane-1,2-diyl)bis(1,3-dioxoisoindole-5-carboxylic acid). 1-Methyl-2-pyrrolidone (240 mL, NMP) and toluene (50 mL to the flask, 20 mL to the Dean-Stark collector) were added to a vessel (a magnetically stirred 3-neck 500 mL round-bottom flask equipped with an N2 inlet / outlet, a stopper, and a Dean-Stark type collector with a condenser); the toluene was refluxed and the collected water was drained from the collector. Trimellitic anhydride (64.04 g, 0.3333 mol) was added to the vessel in four equal portions over 1.25 hours. Under a positive pressure of N2, ethylenediamine (10.01 g, 0.1666 mol, EDA) was added dropwise to the vessel via a connected equalizing addition funnel over 20 minutes. The contents of the vessel were heated to 60 °C and held for 1 hour. The apparatus was switched to N2 purge, the toluene was refluxed for 3 hours, the collected water was drained from the collector, and then a large amount of toluene was removed through the collector. The contents of the vessel were cooled to about 20 °C and then cooled in ice water, the solid product was collected by filtration and the product was washed with 2 × 150 mL of methanol. The product was dried in a vacuum oven at 80 °C for about 12 hours. The product (2,2'-(ethane-1,2-diyl)bis(1,3-dioxoisoindoline-5-carboxylic acid)) was recrystallized from hot N,N-dimethylacetamide (177 grams), the solid product was collected by filtration after cooling, and washed with about 3 × 50 mL of methanol, then dried in a vacuum oven at 80 °C and then dried in a vacuum oven at 115 °C to constant weight. Yield = 51.4 grams, melting point 367 °C.

[0061] Polyethylene glycol 200 (83.77 g, 0.4168 mol), diethylene glycol (7.75 g, 0.0730 mol), phthalic anhydride (18.14 g, 0.1224 mol), and 2,2'-(ethane-1,2-diyl)bis(1,3-dioxoisoindoline-5-carboxylic acid) (50.00 g, 0.1224 mol) were added to a vessel (4-neck 500 mL round-bottom flask, with an N2 inlet adapter inserted together with an overhead stirrer, and the remaining necks stoppered). The apparatus was degassed by 3 cycles of N2 / vacuum (100 Torr) and maintained under N2 purge, with the flask outlet connected to a Dean-Stark type collector and condenser. The apparatus was insulated and the flask was heated with stirring for 2 h from room temperature to an initial setpoint of 200 °C, while TYZOR AA105 (0.0166 g) was injected into the flask at 102 °C; the flask was maintained at 200 °C for 1 h, then heated to / held at 210 °C for 1 h, heated to / held at 220 °C for 6 h, and the distillate was collected and drained. The Dean-Stark type collector and condenser were removed, and the apparatus was cooled to 200 °C under positive N2 pressure, and additional DEG (6.3 g) was added to the flask to compensate for the excess distillate, then at 200 °C / 180 °C for 1 h, then cooled and transferred. The final product had: a viscosity η of 31.2 Pa·s at 25 °C; a GPC molecular weight with Mn of 646; Mw of 1081; a polydispersity index of 1.67; a hydroxyl value OH# of 197 mg KOH / g (theoretical value 180 mg KOH / g); and an acid value (acid#) of 0.15 mg KOH / g; and a glass transition of Tg = -39 °C.

[0062] The following Preparation Example 2 - P imide - modified polyol composition was prepared. Polyethylene glycol 200 (150.53 g, 0.74891 mol), diethylene glycol (13.93 g, 0.1313 mol), and ethylenediamine (13.20 g, 0.2199 mol) were added to a vessel (a 4 - neck 500 mL round - bottom flask with an N2 inlet adapter inserted together with an overhead stirrer, and the remaining necks were stoppered). The flask was degassed three times by cycling between 200 Torr and atmospheric pressure N2. The flask was placed under a gentle N2 purge through a Dean - Stark type collector and condenser connected to the flask outlet. The apparatus was insulated. The flask was placed under a positive N2 pressure, and trimellitic anhydride (a total of 84.52 g, 0.4399 mol) was added to the stirred flask in three equal portions; the first portion was added at 50 °C and a mild exotherm occurred after 20 minutes, the second portion was added at 57 °C, the setpoint was raised to 75 °C, and after 30 minutes, the third portion was added at 75 °C, the setpoint was raised to and maintained at 95 °C, and held for 1.25 hours. Then, under a gentle N2 purge, the reaction mixture was heated to and maintained at 140 °C for 3 hours, the reaction mixture was heated and maintained at 160 °C for 2 hours, and the distillate was collected. The reaction mixture was cooled to 95 °C, and phthalic anhydride (32.60 g, 0.2201 mol) and TYZOR AA105 (0.0860 g) were added to the flask. The flask was heated with stirring for 0.75 hours to a setpoint of 200 °C and held for 1 hour, then heated to and maintained at 210 °C for 1 hour, and then cooled to room temperature. The flask was heated again to 220 °C within 1.5 hours (an additional feed of TYZOR AA105 (0.0489 g) was prepared at 90 °C), and held at 220 °C for 6 hours, and the distillate was collected and drained. The Dean - Stark type collector and condenser were removed, and under a positive N2 pressure, the apparatus was cooled to 200 °C, supplementary diethylene glycol (2.25 g) was added to the flask to compensate for the excess distillate, then held at 200 °C / 180 °C for 1 hour, and then cooled and transferred. The final product had: a viscosity η of 43.8 Pa·s at 25 °C; a GPC molecular weight with Mn of 677; Mw of 1243; a polydispersity index of 1.84; a hydroxyl value OH# of 176 mg KOH / g (the theoretical value is 180 mg KOH / g); and an acid value (acid#) of 0.17 mg KOH / g; and a glass transition temperature Tg of - 34 °C.

[0063] The following is Preparation Example 3-P - an imide-modified polyol composition. Polyethylene glycol 200 (333.12 g, 1.6573 mol), diethylene glycol (31.04 g, 0.2925 mol), and ethylenediamine (14.63 g, 0.2438 mol) were added to a vessel (a 4-neck 1000 mL round-bottom flask with an N2 inlet adapter inserted together with an overhead stirrer, and the remaining necks were stoppered). The flask was degassed three times by cycling between 200 Torr and atmospheric pressure N2. The flask was placed under a gentle N2 purge through a Dean-Stark type collector and condenser connected to the flask outlet. The apparatus was insulated. The flask was placed under a positive N2 pressure, and trimellitic anhydride (a total of 93.65 g, 0.4874 mol) was added to the stirred flask in three equal portions; the first portion was added at 51 °C and a gentle exotherm occurred after 25 minutes, the second portion was added at 56 °C and an exotherm occurred after 20 minutes, the third portion was added at 69 °C with a setpoint of 70 °C, and the setpoint was raised to and maintained at 95 °C for 50 minutes after 40 minutes. Then, under a gentle N2 purge, the reaction mixture was heated to and maintained at 140 °C for 3 hours, the reaction mixture was heated and maintained at 160 °C for 1 hour, and the distillate was collected. TYZOR AA105 (0.1079 g) was added to the flask, and the reaction mixture was heated and maintained at 220 °C for 3.5 hours. The reaction mixture was cooled, and phthalic anhydride (108.30 g, 0.73115 mol) and TYZOR AA105 (0.1244 g) were added to the flask at 96 °C. The flask was heated with stirring to a setpoint of 200 °C for 0.8 hour and maintained at 200 °C for 1 hour, then heated to and maintained at 220 °C for 6.5 hours, then cooled to 200 °C, and the distillate was collected and drained. The Dean-Stark type collector and condenser were removed, and with the apparatus under a positive N2 pressure, additional diethylene glycol (6.58 g) was added to the flask to compensate for the excess distillate, then maintained at 200 °C / 180 °C for 1 hour, then cooled and transferred. The final product had: a viscosity η of 6.54 Pa·s at 25 °C; a GPC molecular weight with Mn of 595; Mw of 947; a polydispersity index of 1.59; a hydroxyl value OH# of 212 mg KOH / g (the theoretical value was 199 mg KOH / g); and an acid value (acid#) of 1.40 mg KOH / g; and a glass transition temperature Tg of -47 °C.

[0064] Examples 4-P to 13-P (imide-modified polyol compositions) were prepared in a manner similar to Example 3-P, and the materials are shown in Tables 1 to 3.

[0065] TYZOR AA105 is titanium acetylacetonate (100% active); Dytek A is 2-methyl-1,5-pentanediamine; JEFFAMINE D230 is a polyoxypropylene diamine with a nominal molecular weight of 230; 1,3-CHDMA is 1,3-bis(aminomethyl)cyclohexane (a mixture of cis / trans isomers); 1,2-CHDA is 1,2-diaminocyclohexane (a mixture of cis / trans isomers); IDPA is isophorone diamine (a mixture of cis / trans isomers); EGAPE is ethylene glycol bis(3-aminopropyl) ether.

[0066] Determine many properties of the imide-modified polyol composition. The glass transition temperature (Tg) is determined according to ASTM E1356-08, and the midpoint temperature is taken as Tg. The hydroxyl value is determined according to ASTM E1899-16. The acid value is determined by potentiometric titration with a standardized 0.01N potassium hydroxide solution according to ASTM D664-18. The number average molecular weight (Mn), weight average molecular weight (Mw), and polydispersity index (PDI) = Mw / Mn are determined according to ASTM D5296-19, using polyethylene glycol calibration standards and an uninhibited tetrahydrofuran solvent.

[0067] Table 1

[0068]

[0069] Table 2

[0070]

[0071] Table 3

[0072]

[0073] Table 4

[0074]

[0075] The data in Table 4 show that each of Examples 1-P to 13-P has a Tg less than or equal to -20 °C; each of Examples 1-P to 13-P has a viscosity less than or equal to 300 Pa·s at 25 °C; the number average molecular weight (Mn) is less than or equal to 1,500 g / mol; and the hydroxyl value is from 100 KOH / g to 350 KOH / g.

[0076] Foams (Examples 1-F to 17-F, and Comparative Examples A-F to C-F) were prepared from the formulations listed in Tables 5, 6, 7, 10, and 13. For each foam, the polyol, surfactant, water, and catalyst were combined using a laboratory mixer. The imide-modified polyol composition was placed in an oven at 70 °C overnight and then mixed with the other polyols at room temperature while it was still warm, and then cooled to room temperature (18 °C to 25 °C). Then the physical blowing agent (pentane blend or SOLSICE LBA) was incorporated, followed by the polyisocyanate. The resulting reaction mixture was mixed at high speed for 5 seconds and then immediately poured into a vertically oriented mold (preheated to 55 °C) measuring 30 cm × 20 cm × 5 cm. The reaction mixture reacted in the mold for 20 minutes, at which point the resulting foam was demolded.

[0077] Polyol A is an aromatic polyester polyol having a functionality of 2.0 and a hydroxyl value of 220 mg KOH / g.

[0078] Polyol B is an aromatic polyester polyol having a functionality of 2.4 and a hydroxyl value of 315 mg KOH / g.

[0079] Polyol C is polyethylene glycol 200.

[0080] Triethyl phosphate is a flame retardant. The urethane catalyst is a commercially available product of 1,1,4,7,7-pentamethyldiethylenetriamine. The trimer catalyst is a commercially available material, DABCO K2097, purchased from Evonik. The pentane blend is an 80 / 20 mixture of cyclopentane and isopentane. The silicone surfactant is commercially available as VORASURF SF 2937. PMDI is a polymeric MDI product having an average isocyanate functionality of 3.0 and an isocyanate equivalent weight of 136.5. Multiple properties were measured for the foams. The results are reported in Tables 8, 9, 11, 12, and 14.

[0081] The cream time and gel time were determined according to the test procedures described in ASTM D7487 (2013). The cream time was visually observed; the gel time was evaluated by periodically contacting the surface of the curing reaction mixture with a wooden tongue depressor (the gel time is the time required for a draw to form when the wooden tongue depressor is pulled away after the polyisocyanate is mixed with the formulated polyol composition); the tack-free time is the time when the surface of the foam no longer feels sticky; the free-rise foam density was measured according to ASTM D6226;

[0082] Samples of fresh foam were conditioned overnight in room temperature air and then subjected to property testing. The K-factor (thermal conductivity) was measured according to ASTM C518; the foam core density was determined by weighing the K-factor test samples and measuring the physical dimensions of the K-factor plates. The compressive strength was measured according to ASTM D1621.

[0083] Table 5

[0084]

[0085] Table 6

[0086]

[0087] Table 7

[0088]

[0089] Table 8

[0090]

[0091] Table 9

[0092]

[0093] The data in Tables 8 and 9 show favorable thermal insulation performance characteristics while maintaining the required fire resistance performance characteristics. The data in Tables 8 and 9 show the required mechanical properties. In addition, the data in Table 9 show that the k-factor is reduced for each of Examples 1-F to 12-F compared to Comparative Examples A-F.

[0094] Table 10

[0095]

[0096] Table 11

[0097]

[0098] Table 12

[0099]

[0100] Table 13

[0101]

[0102] Table 14

[0103]

[0104] The data in Table 11 and Table 12 show favorable heat insulation performance characteristics while maintaining the required fire resistance performance characteristics. The data in Table 11 and Table 12 show the required mechanical properties. In addition, the data in Table 12 show that the k-factor of each of Examples 13-F to 16-F is reduced compared to both Comparative Examples A-F and Comparative Examples B-F.

[0105] The data in Table 14 show favorable heat insulation performance characteristics. In addition, the data in Table 14 show that the k-factor of Example 17-F is reduced compared to Comparative Example C-F.

Claims

1. A process for preparing an imide-modified polyol composition, the process comprising: a) reacting trimellitic anhydride with an aliphatic diamine in the presence of from 0 parts by weight to 3 parts by weight, per 100 parts by weight of said trimellitic anhydride, of another carboxylic anhydride and / or polycarboxylic acid to form one or more imide group-containing compounds having terminal carboxylic acid groups; b) optionally combining one or more imide group-containing compounds having terminal carboxylic acid groups with one or more aromatic dicarboxylic acid derivatives free of imide groups selected from aromatic carboxylic anhydrides, aromatic dicarboxylic acids, aromatic dicarboxylic acid halides, and aromatic dicarboxylic acid dialkyl esters, wherein the molar ratio of the imide group-containing compound to the aromatic dicarboxylic acid derivative is at least 25:75; c) then esterifying the one or more imide group-containing compounds having terminal carboxylic acid groups and the one or more aromatic carboxylic acid derivatives, if present, by reaction with one or more polyols having a hydroxyl equivalent weight of from 30 g / equivalent to 500 g / equivalent; wherein the imide-modified polyol composition has an acid value of not more than 5 mg KOH / g, a hydroxyl value of from 100 mg KOH / g to 350 mg KOH / g and contains from 0.65 moles to 2.30 moles of imide groups per kilogram of imide-modified polyol composition.

2. The process according to claim 1, wherein the aliphatic diamine is selected from 1,2-ethylenediamine, 2,2'-(ethylenedioxy)bis(ethylamine), 3,3'-[1,2-ethylenediylbis(oxy)]bis-1-propanamine, α-(2-aminomethylethyl)-ω-(2-aminomethylethoxy)-poly[oxy(methyl-1,2-ethylenediyl)], 2-methyl-1,5-pentanediamine, 1,3-cyclohexanedimethanamine, 1,2-cyclohexanediamine, 5-amino-1,3,3-trimethyl-cyclohexanemethanamine, including their conformational isomers and positional isomers, or combinations thereof.

3. The process according to claim 1 or 2, wherein at least 50% by weight of the one or more polyols having a hydroxyl equivalent weight of from 30 g / equivalent to 500 g / equivalent have a hydroxyl equivalent weight of from 95 to 500.

4. The process according to any one of the preceding claims, wherein a) is carried out in the presence of the one or more polyols having a hydroxyl equivalent weight of from 30 g / equivalent to 500 g / equivalent and in the absence of a catalytic amount of an esterification catalyst.

5. The process according to any one of the preceding claims, wherein b) is not carried out, and the product obtained in c) is combined with one or more aromatic dicarboxylic acid derivatives free of imide groups selected from aromatic carboxylic anhydrides, aromatic dicarboxylic acids, aromatic dicarboxylic acid halides, and aromatic dicarboxylic acid dialkyl esters, and the resulting combination is subjected to esterification and / or transesterification conditions to produce the imide-modified polyol composition.

6. A method according to any one of claims 1 to 4, wherein b) is carried out, the imide-modified polyol composition is obtained in c), and the imide-modified polyol composition comprises a mixture of an imide-modified polyol and a polyester polyol, the polyester polyol corresponding to the esterification product of the one or more aromatic dicarboxylic acid derivatives and the one or more polyols having a hydroxyl equivalent weight of from 30 g / equivalent to 500 g / equivalent.

7. An imide-modified polyol composition produced by a method according to any one of the preceding claims.

8. An imide-modified polyol composition according to claim 7, the imide-modified polyol composition comprising a mixture of an imide-modified polyol and a polyester polyol, the polyester polyol corresponding to the esterification product of the one or more aromatic dicarboxylic acid derivatives and the one or more polyols having a hydroxyl equivalent weight of from 30 g / equivalent to 500 g / equivalent.

9. A method for preparing a rigid isocyanate-based foam, the method comprising forming a reaction mixture and reacting the reaction mixture to produce the rigid isocyanate-based foam, wherein the reaction mixture comprises a) at least one aromatic polyisocyanate, the amount of the at least one aromatic polyisocyanate providing an isocyanate index of from 100 to 600; b) a polyol, wherein the polyol comprises at least 25% by weight of the imide-modified polyol composition according to claim 7 or 8 and from 0% to 75% by weight of one or more non-imide-modified polyols, and wherein the imide content of the polyol is from 0.125 to 1.75 moles of imide groups per kilogram; c) at least one blowing agent; d) at least one halogenated flame retardant and / or a phosphorus-containing flame retardant; e) at least one foam-stabilizing surfactant; and f) at least one urethane trimerization catalyst and / or an isocyanate trimerization catalyst.

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