RU2575124C2 - Polyurethane and polyisocyanurate foam plastics - Google Patents

Abstract

FIELD: chemistry.

SUBSTANCE: versions of invention realisation relate to compositions of foam-urethane or polyisocyanurate foam plastics. Described is composition for obtaining polyurethane or polyisocyanurate foam plastic, which includes (a) combined polyol, including (i) from approximately 30 to approximately 60 wt % of aromatic polyesterpolyol, which has hydroxyl number higher than approximately 50 mg KOH/g and functionality, at least, approximately 2; (ii) from approximately 10 to approximately 30 wt % of polyetherpolyol of novolac type, which has hydroxyl number higher than approximately 100 mg KOH/g and functionality, at least, approximately 2.2 and (iii) from approximately 10 to approximately 40 wt %. of polyetherpolyol, which includes polyol, initiated by sucrose or sorbite, which has average hydroxyl number higher than approximately 200 mg KOH/g and average functionality, at least, approximately 4; all percentage values are calculated of the total g weight of combined polyol, and wherein components (i), (ii) and (iii) are selected in such a way, that combined polyol in total has average functionality, at least, approximately 2.4; (b) polyisocyanate and (c) foaming agent; so that stoichiometric index of polyisocyanate to combined polyol constitutes more than 250. Disclosed is polyurethane or polyisocyanurate foam plastic, obtained according to said composition and method for obtaining polyurethane or polyisocyanurate foam plastic, which includes interaction under conditions of foam generation of components of said composition with obtaining rigid polyurethane or polyisocyanurate foam plastic. Also described is polyurethane or polyisocyanurate foam plastic, obtained by claimed method.

EFFECT: obtaining polyurethane and polyisocyanurate foam plastics, which have improved hardening characteristics.

16 cl, 3 ex, 1 tbl

Description

Technical field

Embodiments of the present invention relate to polyurethane and polyisocyanurate foams. In particular, embodiments of the present invention relate to these foams made from aromatic polyester polyols that exhibit improved processing properties over a wide range of thicknesses.

State of the art

Polyurethane and polyisocyanurate foams are widely used as insulation materials in the construction industry. Typically, these foams are solid closed-cell foams containing low heat conductive gas such as a hydrocarbon, such as pentane, in the cells. Foaming compositions, being liquid, can be used in on-site applications with hard foam sheets or panels. The panels, which can be obtained by a continuous process, may include a lining, such as a metal foil, to which the foam is glued. These panels may refer to layered panels.

The foams used in the preparation of these multi-layer panels with a polyisocyanurate core may have poor curability, resulting in defects such as shrinkage and deformation.

Therefore, there is a need for polyurethane and polyisocyanurate foams having improved curing characteristics.

SUMMARY OF THE INVENTION

Embodiments of the invention relate to compositions of polyurethane or polyisocyanurate foams. The compositions include a combined polyol, a polyisocyanate and a blowing agent, the stoichiometric index of the polyisocyanate to the combined polyol being more than 250. The combined polyol comprises (i) from about 20 to about 60% by weight. aromatic complex polyether polyol having a hydroxyl number greater than about 50 mg KOH / g and a functionality of at least about 2, (ii) from about 10 to about 30% of the mass. simple polyester polyol novolac type having a hydroxyl number greater than about 100 mg KOH / g and a functionality of at least about 2.2, and (iii) from about 5 to about 40% of the mass. polyether polyol, including sucrose or sorbitol-initiated polyol having an average hydroxyl number greater than about 200 mg KOH / g and an average functionality of at least about 4. All percentages are based on the total weight of the combined polyol, and components (i), (ii ) and (iii) are selected so that the combined polyol as a whole has an average functionality of at least about 2.4.

Embodiments of the invention also relate to methods for making polyurethane or polyisocyanurate foam formulations. The methods include reacting under conditions of foaming the combined polyol, polyisocinate and blowing agent, so that the stoichiometric index of the polyisociant to the combined polyol is more than 250. The combined polyol comprises (i) from about 20 to about 60% by weight. aromatic complex polyether polyol having a hydroxyl number greater than about 50 mg KOH / g and a functionality of at least about 2, (ii) from about 10 to about 30% of the mass. simple novolac type polyether polyol having a hydroxyl number greater than about 100 mg KOH / g and a functionality of at least about 2.2, and (iii) from about 5 to about 40% of the mass. a polyether polyol comprising a sucrose or sorbitol initiated polyol having an average hydroxyl number greater than about 200 mg KOH / g and an average functionality of at least about 4. All percentages are based on the total weight of the combined polyol, and components (i), ( ii) and (iii) are selected so that the combined polyol as a whole has an average functionality of at least about 2.4.

DETAILED DESCRIPTION OF THE INVENTION

Embodiments of the invention relate to both a method and an improvement in properties that are advantageous in a polyisocyanurate core laminate panel industry. As used herein, the term “polyurethane and polyisocyanurate” includes both polyisocyanurate foams and urethane-modified polyisocyanurate foams (PU-PIRs) resulting from the interaction of an isocyanate with a reactive to isocyanate component, such that the ratio of isocyanate groups to reactive to isocyanate is 1.8 or higher, and in the presence of suitable catalysts that favor the polyisocyanurate ring formation reaction.

Combined Polyol

1) Aromatic polyester polyol

The first component is an aromatic polyester polyol. As used herein, “aromatic” refers to organic compounds containing at least one conjugated ring with alternating single and double bonds that give the compounds overall stability. The term "polyester polyol", as used herein, includes any small amounts of unreacted polyol remaining after the polyester polyol and / or non-esterified polyol (e.g. glycerol) is charged to the reactor as part of the polyester polyol production process. Although the aromatic complex polyester polyol can be obtained from essentially pure reagents, more complex starting materials such as polyethylene terephthalate can be used. Other residues that can be used are dimethyl terephthalate (DMT) process residues, which are waste from DMT production.

The aromatic polyester polyol may optionally contain, for example, halogen atoms and / or may be unsaturated and may, in general, be obtained from the same starting materials as discussed above, but at least one polyol or polycarboxylic acid, preferably an acid is an aromatic compound having an aromatic ring content (expressed in weight percent of groups containing at least one aromatic ring per molecule), which is at least about 30% wt., calculated on the total weight of the compound, and preferably more than approximately 35% of the mass. Especially used complex polyether polyols having an acid component, which mainly includes at least 30% of the mass. residues of phthalic acid or residues of their isomers.

The aromatic polyester polyol is also characterized in that it has a hydroxyl number greater than about 50 mg KOH / g and, in some embodiments, a functionality that is equal to or greater than about 2. In some embodiments, the hydroxyl number ranges from more than about 50 to about 400 mg KOH / g, and in other embodiments, the hydroxyl number is in the range of about 150 to about 350 mg KOH / g. The functionality may range from about 1.5 to about 8, but in some non-limiting embodiments of the invention, it may lie in the range from about 2 to about 8, and in other, non-limiting embodiments, it may lie in the range from about 2 to about 6.

2) Simple polyester polyol novolac type

The second component is a simple novolac type polyether polyol. The novolac type polyether polyols are alkoxylation products of a phenol-formaldehyde resin, which is formed by the reaction of phenol with formaldehyde in the presence of an acid catalyst such as glacial acetic acid, followed by treatment with concentrated hydrochloric acid. Typically, a small amount of an acid catalyst or catalysts is added to a miscible phenol, such as p-toluenesulfonic acid, followed by formaldehyde. Formaldehyde will interact with two phenolic groups to form a methylene bridge, creating a dimer due to electrophilic aromatic substitution between the ortho and para positions of phenol and protonated formaldehyde. Another example is bisphenol A, which represents the condensation product of acetone with two phenols. As the concentration of dimers increases, trimers, tetramers and higher oligomers can also form. However, since the molar ratio of formaldehyde to phenol is regulated at a value of somewhere less than 1, the polymerization does not proceed completely. Thus, novolak can then be alkoxylated to a molecular weight of the desired value, preferably from about 300 to about 2000, and in some non-limiting embodiments of the invention, from about 500 to about 1500.

Phenols that can be used to prepare the novolac initiator include o-, m- or p-cresols, ethylphenol, nonylphenol, p-phenylphenol, 2,2-bis (4-hydroxyphenol) propane, beta-naphthol, beta-hydroxyanthracene, p-chlorophenol, o-bromophenol, 2,6-dichlorophenol, p-nitrophenol, 4-nitro-6-phenylphenol, 2-nitro-4-methylphenol, 3,5-dimethylphenol, p-isopropylphenol, 2-bromo-4- cyclohexylphenol, 4-t-butylphenol, 2-mentyl-4-bromophenol, 2- (2-hydroxypropyl) phenol, 2- (4-hydroxyphenol) ethanol, 2-carbetoxyphenol, 4-chloromethylphenol and mixtures thereof. In some embodiments, the phenols used to make the novolac type polyether polyols are unsubstituted.

Suitable novolac-type polyether polyols can be obtained, for example, by reacting a condensation adduct of phenol and formaldehyde with one or more alkylene oxides including ethylene oxide, propylene oxide and butylene oxide. These polyols, sometimes referred to as novolak initiated polyols, are known to those skilled in the art and can be prepared by methods such as those disclosed, for example, in US Pat. Nos. 2,838,473, 2,938,884, 3,470,118, 3,686,101 and 4,046,721, the entirety of which is incorporated herein by reference link order. Typically, novolac starting materials are prepared by reacting phenol (e.g., cresol) with formaldehyde, where the molar ratio of formaldehyde to phenol is less than one in the presence of an acid catalyst to form a multicore condensation product containing from 2.1 to 12, for example, from 2.2 to 6 or 2.5 to 4.5 units of phenol per molecule. Then, the novolac resin is reacted with an alkylene oxide such as ethylene oxide, propylene oxide, butylene oxide or isobutylene oxide to form an oxyalkylated product containing many hydroxyl groups. Some embodiments of the invention encompass novolac polyols that contain an average of 2.2 to 6 hydroxyl residues per molecule and have an average hydroxyl number of from about 100 to about 400 mg KOH / g or from about 100 to about 300 mg KOH / g.

3) Polyol initiated by sucrose or sorbitol

A third necessary component of the combined polyol is a sucrose and / or sorbitol initiated polyol. This polyol is a polyether polyol and may have a hydroxyl number greater than about 200 mg KOH / g. The nominal functionality of the pure sucrose-initiated polyol is 8, and for the pure sorbitol-initiated polyol, the nominal functionality is 6. Embodiments of the invention encompass initiator mixtures that include, in addition to sucrose and / or sorbitol, diols or triols (initiated, respectively, for example , water or glycerol), so that the initiator mixture has an average functionality lying in the range from about 3.5 to about 7.

Sucrose can be obtained from sugarcane or sugar beets, honey, sorghum, sugar maple, fruits, and the like. Means of extraction, separation and preparation of the sucrose component vary depending on the source, but are widely known and used on an industrial scale by specialists in this field.

Sorbitol can be obtained by hydrogenating D-glucose over a suitable hydrogenation catalyst. Fixed layers and equipment of a similar type are particularly suitable for use in carrying out this reaction. Suitable catalysts may include, for example, Raney ™ catalysts (Grace-Davison), such as those used by Wen, Jian-Ping et al., “Preparation of Sorbitol from D-glucose hydrogenation in gas-liquid-solid three- phase flow airlift loop reactor ”, The Journal of Chemical Technology and Biotachnology, vol. 4, pp. 403-406 (Wiley Interscience, 2004), whose publication is incorporated herein by reference in its entirety. Nickel-aluminum and ruthenium-carbon catalysts are just two of many possible catalysts.

In an alternative embodiment, sorbitol production may begin with a starch hydrolyzate that has been hydrogenated. Starch is a natural material derived from corn, wheat and other starch-containing plants. In order to obtain a hydrolyzate, the starch polymer molecule can be split into smaller oligomers at any bond between the glucose rings to produce glucose, maltose and higher molecular weight oligo- and polysaccharides. The resulting molecules containing hemiacetal glucose nuclei as terminal units can be hydrogenated to produce sorbitol, maltitol and hydrogenated oligo- and polysaccharides. Hydrogenated starch hydrolysates are commercially available and inexpensive products, often in the form of syrups, and provide an additional advantage as a renewable source. This method may additionally require either separation of glucose before hydrogenation, or sorbitol after hydrogenation to obtain a suitable polyol initiated by sorbitol from it. In general, hydrogenation reduces or eliminates the tendency to form a hydroxyaldehyde form of glucose from the terminal units. Therefore, fewer side reactions of sorbitol, such as aldol condensation and Canizzaro reactions, can occur. In addition, the final polyol will include reduced amounts of by-products.

A sucrose or sorbitol initiated polyol can be prepared by polymerizing alkylene oxides on a specific initiator in the presence of a suitable catalyst. A specific initiator may be pure sucrose or a sorbitol-based initiator, or it may be a mixture of sucrose and / or sorbitol plus one or more other initiators, the latter intended to control the final average functionality of the resulting polyether polyol. Possible co-initiators are water, short chain diols, such as monoethylene glycol, diethylene glycol, polyethylene glycol, or triols, such as glycerol or trimethylolpropane. In one embodiment of the invention, each of the initiators may be individually alkoxylated, and the resulting polyols are mixed to obtain the desired component of the combined polyol. In another embodiment, the initiators may be mixed together before alkoxylation, thereby acting as co-initiators, to form a polyol component having a desired hydroxyl number and functionality.

For alkoxylation, an alkylene oxide or mixture of alkylene oxides may be added to the initiator (s) in any order and may be added in any number of portions or may be administered periodically. The introduction of more than one alkylene oxide into the reactor at the same time leads to the production of a block having a statistical distribution of alkylene oxide molecules, the so-called hetero chain block. In order to obtain a polyoxyalkylene block of a selected alkylene oxide, a first charge of alkylene oxide is introduced into a reaction vessel containing initiator molecules. After the first download, you can enter the second download and bring the reaction to completion. If the first charge and the second charge have different relative alkylene oxide compositions, the result is a polyoxyalkylene block. You can get the blocks of polyols in this way, when the blocks thus formed are either all ethylene oxide or all propylene oxide or all butylene oxide, but intermediate compositions are also possible. Blocks can be entered in any order, and the number of blocks can be any. For example, you can enter the first block of ethylene oxide, and then the second block of propylene oxide. Alternatively, a first propylene oxide block and then an ethylene oxide block may be introduced. The third and subsequent blocks may be entered. The composition of all blocks should be chosen so as to obtain the final material with the properties required for its intended application.

Foaming Agent (s)

The composition of the polyol also includes a chemical blowing agent, which can be selected in part based on the desired density of the final foam. In some non-limiting embodiments, a hydrocarbon blowing agent may be selected. For example, hydrocarbon or fluorine-containing halogenated hydrocarbon blowing agents can be used, and in some cases they can serve to reduce or further reduce viscosity and thereby improve process properties. These include, for example, butane, isobutane, 2,3-dimethylbutane, n- and i-pentane isomers, hexane isomers, heptane isomers, cycloalkanes, including cyclopentane, cyclohexane, cycloheptane and combinations thereof, HFC-245fa (1,1 , 1,3,3-pentafluoropropane), HFC-365mfc (1,1,1,3,3-pentafluorobutane), HFC-227ea (1,1,1,2,3,3,3-heptafluoropropane), HFC- 134a (1,1,1,2-tetrafluoroethane), combinations of two or more of the foregoing, and the like. These hydrocarbons and / or fluorine-free halogenated hydrocarbons can be used in such an amount that, in general, a blowing agent, including fluorocarbon, is not more than about 20 parts or not more than about 15 parts per 100 parts of the entire polyol as one composition.

An optional chemical blowing agent that can be selected is formic acid or another carboxylic acid. Formic acid may be used in an amount of from about 0.5 to about 8 parts per 100 parts by weight of the polyol as one composition. In some non-limiting embodiments of the invention, formic acid is present in an amount of from about 0.5 parts and / or from about 1 part to about 6 parts or to about 3.5 parts by weight. It is also contemplated that other aliphatic mono- and polycarboxylic acids may be used, such as those disclosed in US Pat. No. 5,143,945, which is incorporated herein by reference in its entirety and including isobutyric acid, ethylbutyric acid, ethylhexanoic acid, and their combinations.

In addition to formic acid or other carboxylic acid, water may also optionally be selected as a blowing agent. Water is used in some non-limiting embodiments of the invention in an amount of from about 0.5 to about 10 parts, or from about 0.7 to about 5 parts per 100 parts by weight of the combined polyol. In some non-limiting embodiments of the invention, upon receipt of a polyurethane or polyisocyanurate foam to accelerate and give the desired process parameters, the amount of water used may not exceed 4 parts by weight or not more than 2.5 parts water or not more than 1.5 parts water per 100 parts of a polyol as one composition. In some non-limiting embodiments, it is preferred not to use water.

Finally, as optional additional chemical blowing agents, carbamates that emit carbon dioxide during the blowing process and their adducts can also be advantageously used. They are discussed in more detail, for example, in US patents 5789451 and 6316662 and European patent EP 1097954, which are incorporated herein by reference in their entirety.

The ratio of components in the combined polyol

The three minimally required components of the combined polyol (with the exception of the blowing agent (s)) in some non-limiting embodiments of the invention are contained in specific ranges of ratios in order to improve their storage stability after combining them. And if the content of the aromatic complex polyester polyol can lie in the range from about 20 to about 60% of the mass. calculated on the basis of the total mass of the combined polyol, the content of the polyether polyol may lie in the range from about 10 to about 30 wt. -%, for example, from about 20 to about 30% of the mass. In some embodiments, it is desirable that the aromatic polyester polyol content is limited to a range of from about 20 to about 40% by weight. The polyol initiated by sucrose or sorbitol may be contained in an amount lying in the range from about 5 to about 40 wt. -%, in the same calculation. Combinations of more than one of each type of polyol may also be selected, provided that their combined percentage in the combined polyol generally corresponds to the indicated ranges. In addition, the proportion of aromatic polyester polyol, novolac type polyether polyol, the proportion of sucrose or sorbitol initiated polyol, and the proportion of the remaining polyether polyol can be selected so that the combined polyol as a whole has an average functionality of at least about 2 or, at least about 2.5. The hydrocarbon or halogen hydrocarbon blowing agent, either incorporated into the combined polyol or added separately during the foaming process, is preferably contained in an amount of from about 2 to about 20 parts, based on 100 parts of the combined polyol, and more preferably in an amount of from about 2 to about 15 parts according to the same calculation.

Polyisocyanate

In order to obtain a polyurethane or polyisocyanurate foam according to embodiments of the invention, the polyol composition must be reacted with a suitable stoichiometric excess of the polyisocyanate component under appropriate foaming conditions. The polyisocyanate component is called the “A-component” in the United States (in Europe, the “B-component”). The selection of the A component can be made from a wide range of polyisocyanates, including but not limited to those well known to those skilled in the art. For example, organic polyisocyanates, modified polyisocyanates, isocyanate prepolymers and mixtures thereof can be used. They may further include aliphatic and cycloaliphatic isocyanates and, in particular, aromatic and, more specifically polyfunctional aromatic isocyanates. Polyphenylpolymethylene polyisocyanates (PMDI) may also be used.

Other polyisocyanates that may be used in the present invention include 2,4- and 2,6-toluene diisocyanate and the corresponding isomeric mixtures of 4,4'-, 2,4 'and 2,2'-diphenylmethanediisocyanate; mixtures of 4,4'-, 2,4 'and 2,2'-diphenylmethanediisocyanates and polyphenylpolymethylene polyisocyanates (PMDI); and mixtures of PMDI and toluene diisocyanates. In addition, aliphatic and cycloaliphatic isocyanate compounds such as 1,6-hexamethylene diisocyanate can be used in the present invention; 1-isocyanato-3,5,5-trimethyl-1,3-isocyanatomethylcyclohexane; 2,4- and 2,6-hexahydrotoluene diisocyanate and their corresponding isomeric mixtures; and 4,4'-, 2,2 'and 2,4'-dicyclohexylmethanediisocyanate and their corresponding isomeric mixtures. Also suitable for use in the present invention is 1,3-tetramethylene xylene diisocyanate.

Also preferred for use as an A component are the so-called modified multifunctional isocyanates, that is, those resulting from chemical reactions of the above diisocyanates and / or polyisocyanates. Examples are polyisocyanates containing esters, ureas, biurets, allophanates and, preferably, carbodiimides and / or uretonomine, and diisocyanates and polyisocyanates containing isocyanurate and / or urethane groups. Liquid polyisocyanates containing carbodiimide groups, uretonomine groups and / or isocyanurate nuclei having an isocyanate group (NCO) content of from 120 to 40 weight percent or from 20 to 35 weight percent can also be used. These include, for example, 4,4'-, 2,4'- and / or 2,2'-diphenylmethanediisocyanate polyisocyanates and the corresponding isomeric mixtures, 2,4- and / or 2,6-toluene diisocyanate and the corresponding isomeric mixtures, mixtures of diphenylmethanediisocyanates and PMDI; and mixtures of toluene diisocyanates and PMDI and / or diphenylmethanediisocyanates.

Suitable prepolymers for use as the polyisocyanate component in the compositions of the present invention are prepolymers having an NCO content of from 2 to 40 weight percent or from 4 to 30 weight percent. These prepolymers are prepared by reacting di- and / or polyisocyanates with materials including low molecular weight diols and triols, but can also be prepared with multivalent compounds containing an active hydrogen atom, such as di- and triamines and di- and tritiols. Specific examples include aromatic polyisocyanates containing urethane groups, which may have an NCO content of 5 to 40 weight percent or 20 to 35 weight percent, obtained by reacting diisocyanates and / or polyisocyanates with polyols such as, for example, low molecular weight diols, triols, oxyalkylene glycols, dioxyalkylene glycols or polyoxyalkylene glycols having molecular weights of up to about 800. These polyols can be used individually or in mixtures as di- and / or polyoxyalkylene glycols. For example, diethylene glycols, dipropylene glycols, polyoxyethylene glycols, ethylene glycols, propylene glycols, butylene glycols, polyoxypropylene glycols and polyoxypropylene polyoxyethylene glycols can be used. Polyester polyols as well as alkyldiols such as butanediol can also be used. Other diols also suitable for use include bishydroxyethyl or bishydroxypropyl bisphenol A, cyclohexanedimethanol and bishydroxyethylhydroquinone.

Suitable materials for use as the polyisocyanate component in the prepolymer compositions that can be used in the present invention are the same materials as mentioned above as suitable polyisocyanates.

PMDI in any of its forms can be used as a polyisocyanate for use in embodiments of the invention. When used, it can have an equivalent weight between 125 and 300, for example, from 130 to 175, and the average functionality is greater than about 1.5. Embodiments of the invention encompass average functionality from 1.75 to 3.5. The viscosity of the polyisocyanate component can range from 25 to 5000 centipoise (cP) (0.025 to about 5 Pa), but values from 100 to 1000 cP at 25 ° C (0.1 Pa · s) may be acceptable for ease of processing. Embodiments of the invention encompass similar viscosities when alternative polyisocyanate components are selected. In some embodiments, the polyisocyanate component in the compositions of the present invention is selected from the group consisting of MDI, PMDI, MDI prepolymer, PMDI modified prepolymer, modified MDI, and mixtures thereof.

For the purposes of the embodiments of the invention, the ratio of the isocyanate indices of the A component to the B component (polyisocyanate to combined polyol) may be greater than 250, namely, depending on the conditions used, greater than 2.5, i.e., the foam is produced by reacting at least 2.5 NCO groups for each isocyanate-reactive group; in some non-limiting embodiments, the isocyanate index exceeds 270, namely, depending on the conditions used, exceeds 2.7.

Optional ingredients

Other polyols may also be included in the combined polyol and / or in the final composition, in addition to the three above, and, if included, are considered part of the composition of the B-component. Although these additional materials are usually included as part of the B-component during the preparation process, they are processed separately, as they are considered optional. Other polyols can be selected so that the combined polyol as a whole will have an average functionality of at least about 2.4 (excluding the contribution to the functionality due to the presence of water in the foaming composition). Embodiments of the invention include average functionality of at least 2.5; 2.6; 2.7; 2.8; 2.9; 3.0; 3.1; 3.2 or at least 3.3. Other polyols may include one or more other simple or complex polyether polyols of the type commonly used in the processes for producing polyurethane and / or polyisocyanurate foams. Other compounds may also be present containing at least two isocyanate-reactive hydrogen atoms, for example, simple polythioether polyols, polyether amides and polyacetals containing hydroxyl groups, aliphatic polycarbonates containing hydroxyl groups, polyoxyalkylene polyethers with terminal amine groups and preferably polyester polyols , polyoxyalkylene simple polyether polyols and dispersion grafted polyols. Mixtures of two or more of the above materials may also be used. In many embodiments, these polyols contain from about 2 to about 8 hydroxyl groups per molecule and have a hydroxyl number greater than 100 mg KOH / g, and in some embodiments more than 300 mg KOH / g.

In some non-limiting embodiments, the combination polyol may also include one or more chain extenders and / or crosslinking agents. If selected, chain extenders can be bifunctional, low molecular weight alcohols, in particular those having a molecular weight of up to 400, for example, ethylene glycol, propylene glycol, butanediol, hexanediol, and mixtures thereof. Crosslinking agents in many embodiments of the invention are at least trifunctional and can be selected, for example, from such low molecular weight alcohols as glycerol, trimethylolpropane, pentaerythritol, sucrose, sorbitol, or mixtures thereof.

The composition of the present invention may include additional additives or modifiers, such as those that are well known in this field. For example, surfactants, catalysts, flame retardants and / or fillers may be used. Of particular importance are one or more trimerization catalysts. The trimerization catalysts used may be any known to those skilled in the art that will catalyze the trimerization of an organic isocyanate compound to form an isocyanurate fragment. For typical isocyanate trimerization catalysts, see The Journal of Cellular Plastics, November / December 1975, page 329 and US Patents 3,745,133; 3,896,052; 3,899,443; 3,903,018; 3954684 and 4101465, the essence of which is incorporated herein by reference in its entirety. Typical trimerization catalysts include glycine salts, tertiary amine trimerization catalysts, alkaline carboxylic acid salts, and mixtures of these classes of catalysts. Suitable trimerization catalysts include N-2-hydroxy-5-nonylphenylmethyl-N-methylglycinate. Also included are epoxides disclosed in US Pat. No. 3,745,133. Trimerization catalysts are available from, for example, Air Products under the trademarks DABCO K2097, DABCO K15, DABCO TMR and CURITHANE 52.

Another category of catalysts that can be included is the class of amine catalysts, including any organic compounds that contain at least a tertiary nitrogen atom and are capable of catalyzing the hydroxyl / isocyanate reaction between the A component and the B component. Typical classes of amines include N-alkylmorpholines, N-alkylalkonolamines, N, N-dialkylcyclohexylamines and alkylamines, where the alkyl groups are methyl, ethyl, propyl, butyl and their isomeric forms, and heterocyclic amines. Typical but non-limiting examples are triethylenediamine, tetramethylenediamine, bis (2-dimethylaminoethyl) ether, triethylamine, tripropylamine, tributylamine, triamylamine, pyridine, quinoline, dimethylpiperazine, piperazine, N, N-ethylamine-dimethyl-dimethyl-dimethyl-dimethyl-dimethyl-dimethyl-dimethyl-dimethyl-dimethyl-dimethyl-dimethyl-dimethyl-dimethyl-dimethyl-dimethyl-dimethyl-dimethyl-dimethyl-dimethyl-dimethyl-dimethyl-dimethyl-dimethyl-dimethyl-dimethyl-dimethyl-dimethyl-dimethyl-dimethyl-dimethyl-dimethyl-dimethyl-dimethyl-dimethyl-dimethyl-2-dimethyl-dimethyl-dimethyl-dimethyl , methyltriethylenediamine, 2,4,6-tridimethylaminomethylphenol, N, N ', N ”-tris (dimethylaminoporpyl) sim-hexahydrotriazine and mixtures thereof. Tertiary amines that may be selected may include bis (2-dimethylaminoethyl) ether, dimethylcyclohexylamine, N, N-dimethylethanolamine, triethylenediamine, triethylamine, 2,4,6-tri (dimethylaminomethyl) phenol, N, N, N-ethylmorpholine and mixtures thereof.

A non-amine catalyst may also be used in the present invention. Typical of these catalysts are organometallic compounds of bismuth, lead, tin, titanium, iron, antimony, uranium, cadmium, cobalt, thorium, aluminum, mercury, zinc, nickel, cerium, molybdenum, vanadium, copper, manganese, zirconium, and combinations thereof. Included for illustrative purposes only are bismuth nitrate, lead 2-ethylhexoate, lead benzoate, lead naphthalate, ferric chloride, antimony trichloride, antimony glycolate, combinations thereof, and the like. Embodiments of the invention include tin salts of carboxylic acids, such as tin acetate, tin octoate, tin 2-ethylhexoate, 1-methylimidazole and tin laurate, as well as salts of dialkyltin carboxylic acids, such as dibutyltin diacetate, dibutyltin diacetate, dimethyl dialet, combinations thereof, etc. Catalysts such as NIAX ^T A-1, POLYCAT 9 and / or POLYCAT 77 (NIAX A-1 is available from Momentive Performance Materials. POLYCAT 9 and POLYCATR 77 are available from Air Products and Chemicals, Inc.). Additional catalysts such as TOYOCAT ™ DM 70, POLYCAT 8 or other gelation catalysts. (TOYOCAT ™ DM 70 is available from Tosoh Corporation). Catalysts may be included in amounts of from about 0.5 to about 8 parts, in total, from the B component.

Although the basic composition allows to obtain foams having improved combustion properties, as defined below, in some embodiments of the invention it may be desirable to further improve fire resistance by including as additives one or more halogen-free or halogen-free flame retardants, such as Tris ( 2-chloroethyl) phosphate, tris-ethyl phosphate, tris (2-chloropropyl) phosphate, tris (1,3-dichloropropyl) phosphate, ammonium phosphate, various halogen-containing aromatic compounds, antimony oxide, alumina tricrystal hydrate, polyvinyl chloride and combinations thereof. Dispersants, cell stabilizers and surfactants may also be included.

Surfactants including organic surfactants and silicone-based surfactants can be added to stabilize the cells. Some typical materials are marketed under the designations SF-1109, L-520, L-521 and DC-193, which are typically polysiloxane-polyoxyalkylene block copolymers, such as those disclosed in US Pat. Nos. 2,834,748; 2917480 and 2846458, the substance of which is incorporated herein by reference in its entirety. Also included are organic surfactants containing polyoxyethylene-polyoxybutylene block copolymers, such as those described in US Pat. No. 5,600,019, the disclosure of which is incorporated herein by reference in its entirety. It is especially desirable to use a small amount of a surfactant to stabilize the reaction expandable mixture until it hardens. Other surfactants include polyethylene glycol ethers and long chain alcohols, tertiary amines or alkanolamine salts of long chain sulfate allylic acid esters, alkyl sulfonic esters, alkylaryl sulfonic acids, and combinations thereof.

These surfactants are used in amounts sufficient to stabilize the foaming reaction and to prevent destruction and the formation of large, uneven cells. Typically, from about 0.2 to about 3 parts of a surfactant per 100 parts by weight of the combined polyol is sufficient for this purpose.

Other additives may include, but are not limited to, carbon black and coloring agents, fillers, and pigments. Examples may include barium sulfate, calcium carbonate, graphite, carbon black, titanium dioxide, iron oxide, microspheres, alumina tricrystal hydrate, wollastonite, marketable glass fiber (ground or continuous) and polyester fibers and other polymer fibers, as well as various combinations thereof.

Foam Production

The polyurethane or polyisocyanurate polymer obtained by the method of the present invention, in some non-limiting embodiments, is a rigid, closed-cell, foamed polymer. This polymer is usually prepared by thoroughly mixing the reaction components, i.e. a polyol / blowing agent component (consisting essentially of or comprising a combined polyol and blowing agent as defined above), along with an isocyanate component, i.e. at least two streams; or a polyol component (consisting essentially of or comprising a combined polyol as defined above), a blowing agent component, and an isocyanate component, i.e. at least three streams, where, for example, the combined polyol and the component blowing agent are mixed before contact with the isocyanate component at room temperature or at a slightly elevated temperature for a short period of time. If desired, additional streams may be included to introduce various catalysts and other additives. The mixing of flows can be carried out either in a high-pressure apparatus or in a low-pressure apparatus, a mixing head with or without a static mixer for combining the flows, and then applying the reaction mixture to the substrate. This substrate may be, for example, a rigid or flexible facing sheet made from foil or other material, including another layer of the same or different polyurethane or polyisocyanurate, which moves, periodically or continuously, along the production line, or directly onto a conveyor belt. The type of facing material specifically included within the scope of the embodiments of the invention is a thin metal sheet, for example made of steel, optionally coated with a suitable material, such as polyester or epoxy, to slow down the formation of rust.

In alternative embodiments of the invention, the reaction mixture may be poured into an open form or distributed by special equipment in an open form or simply applied to the place for which it is intended, i.e. place of use with in-place filling, such as between the inner and outer walls of the structure. In the case of applying inwardly the form on the facing sheet, the second sheet may be applied on top of the applied mixture. In other embodiments, the mixture may be injected into a closed mold, with or without vacuum, to fill cavities. In both cases, when a mold is used, and also when a continuous production line is used, the mold or the continuous production line is usually heated to speed up the polyol-isocyanate reaction process.

In general, these applications may be accompanied by the use of known single-prepolymer or quasi-prepolymer methods used in conjunction with traditional mixing methods. Upon interaction, the mixture takes the shape configuration or adheres to the substrate to produce a polyurethane or polyisocyanurate polymer of a more or less predetermined structure, which is then allowed to solidify at the application site either in the form, either partially or completely. Suitable conditions for accelerating the curing of the polymer include a temperature typically from 20 ° C to 150 ° C, such as from 35 ° C to 75 ° C or from 40 ° C to 70 ° C. Curing temperatures can be achieved by heating the mold and / or it can develop within the system due to the exothermic nature of the reaction. These temperatures will usually allow the polymer to solidify sufficiently so that it can be removed from the mold, if used, or from the production line, usually in the range of about 3 to 20 minutes, and more typically in the range of 4 to 15 minutes after mixing the reagents. Optimum curing conditions will depend on the specific components, including the catalysts and amounts used in the preparation of the polymer, as well as the size and configuration of the manufactured product.

The result can be a rigid foam in the form of foam blocks, a molded product, a filled cavity, including, but not limited to, a pipe or insulating wall or shell, spray foam, foamed foam or laminated product of periodic or continuous production, including, but not limited to, laminate or laminate obtained with other materials, such as cardboard, drywall, thermoplastics, paper, metal, or combinations thereof. Advantageously, the foams obtained according to the embodiments of the present invention can have improved processing properties compared to foams obtained by similar compositions and preparation methods, except that the compositions do not include the specific combination polyol used in the present invention. As used herein, the term "improved technological properties" refers to the ability of a foam to have fewer defects, which may include, but are not limited to, shrinkage and deformability. This improvement may be particularly advantageous when embodiments of the invention are used in the manufacture of laminate panels. Laminate panels can be defined, in some embodiments, as comprising at least one relatively flat layer (i.e., a layer having two relatively large sizes and one relatively small size) of rigid foam, on which a large size side is coated at least one layer of flexible or rigid material, such as a foil or a thicker layer of metal or other structure-forming material. This layer may, in some embodiments of the invention, serve as a substrate during the preparation of the foam.

In addition, polyisocyanurate and polyurethane foams according to embodiments of the invention can exhibit improved cure parameters, including improved compressive strength in the uncured state. The test method for determining the compressive strength in the uncured state is described in the note to table 1. This feature may be particularly advantageous when embodiments of the present invention are used in the manufacture of insulating laminated panels.

The above description is intended as a general one and is not intended to include all possible embodiments of the invention. Similarly, the examples below are illustrative only and are not intended to define or limit the invention in any way. Specialists in this field will be absolutely sure that other embodiments of the invention will be apparent within the scope of the claims set forth in the claims when considering the description and / or practical embodiment of the invention, as discussed herein. These other embodiments of the invention may include the selection of specific components and their proportions; mixing and reaction conditions, containers, used equipment and test reports; operational parameters and selectivity; identification of products and by-products; subsequent processing and its use, etc .; and those skilled in the art will understand that they can vary within the scope of the claims defined in the appended claims.

EXAMPLES

The materials used in the examples and / or comparative examples include the following, which are listed in alphabetical order.

CURATHANE 52 is glycine, an N - {[2-hydroxy-5-nonylphenyl) methyl] -N-methyl monosodium salt in diethylene glycol, available from Air Products and Chemicals, Inc.

DABCO K15 is a potassium octoate-based catalyst in diethylene glycol, available from Air Products and Chemicals, Inc.

IP 585 is a polyol IP 585, a polyol polyoxypropylene-polyoxyethylene, initiated by an aromatic resin (polyol bead type) with a hydroxyl number of 195 mg KOH / g, an equivalent weight of 286 and an average functionality of 3.3, available from The Dow Chemical Company.

NIAX A-1 is a catalyst based on 70% bis (2-dimethylaminoethyl) ether and 30% dipropylene glycol, available from Momentive Performance Materials.

NIAX L-6633 is a silicone based surfactant from Momentive Performance Materials.

POLYCAT 8 represents N, N-dimethylcyclohexylamine, available from Air Products and Chemicals, Inc.

Polyester 1 is a terephthalic acid, diethylene glycol and PEG200 polyester, and is prepared as described in WO / 2010/015642, has a hydroxyl number of 240, a nominal functionality of 2, and an equivalent weight of 234.

PEG 400 is a polyethylene glycol having an average molecular weight of approximately 400.

TCPR is tris (chlorisopropyl) phosphate available from Albemrle.

VORANATE M600 is a highly viscous crude diphenylmethanediisocyanate (viscosity of approximately 600 mPa at 25 ° C.) available from The Dow Chemical Company.

VORANOL 280 is a high functional sucrose / glycerin initiated polyol (6.9) having an equivalent weight of approximately 200, OH number 280, and number average molecular weight 1402, available from The Dow Chemical Company.

VORANOL RN 482 is a sucrose-initiated polyether polyoxypolyethylene polyol having a hydroxyl number of 482, a nominal functionality of 6, and an equivalent weight of 117, available from The Dow Chemical Company.

Example 1 and comparative example 2

Two combined polyols were prepared, including the components listed in table 1 (quantities are presented in parts by weight). The first polyol was prepared by mixing the polyol components. Then the mixture was reacted with isocyanate (VORANATE ™ M600) and n-pentane, at an index of 280, to obtain a spontaneously expandable foam. Curing parameters were determined by measuring the compressive strength in the uncured state after four (4) minutes, and the results are also shown in table 1.

Table 1 Example 1 Example 2 Reference Example 2 Polyol Polyester 1 20,23 43.95 45,2 IP 585 29.18 fifteen VORANOL RN 482 9.73 13 VORANOL 280 10,4 Peg 400 12.65 17.3 TCPP 21.13 21 20.57 CURITHANE 52 1.75 1.7 1.7 Dabco k15 one one 0.76

NIAX A-1 0.56 0.58 NIAX L-6633 3 3 3 POLYCAT 8 Water 0.77 0.77 0.77 Polyol, total parts one hundred one hundred one hundred Polyol, medium functionality * 2.9 2,8 2,3 VORANATE M600 per 100 parts polyol 168.5 170 159.6 Index 280 280 280 n-pentane 12.1 12.1 11.7 Density of spontaneously foaming foam About 36 About 36 About 36 GCS ** (kPa) 150 145 110 * average functionality based on a combination of polyester 1, IP 585, VORANOL RN 482 and PEG 400 for example 1, a combination of polyester 1, IP 585 and VORANOL RN 482 for example 2, and a combination of polyester 1, VORANOL 280 and PEG 400 for comparative example 3.
** GCS (compressive strength in the uncured state): this is a measure of spontaneous foaming of the foam obtained inside a wooden box (20 × 20 × 20cm), removed 2 minutes after the start of the reaction and placed (perpendicular to the direction of foaming) on a 5 × wooden piece 5 cm held on the bottom plate of an Instron 10 kN tensile testing machine. The top plate of the machine moves for 4 minutes with compression of the foam at a constant speed (20 mm per minute) in a direction identical to a wooden piece. The resulting GCS value is expressed in kPa.

It can be seen that example 1 and example 2 show improved curing (compressive strength in the uncured state, GCS test).

Claims (16)

1. The composition for producing polyurethane or polyisocyanurate foam, including
(a) a combined polyol comprising
(i) from about 30 to about 60 wt.% aromatic polyester polyol having a hydroxyl number greater than about 50 mg KOH / g and a functionality of at least about 2;
(ii) from about 10 to about 30 wt.% novolac type polyether polyol having a hydroxyl number greater than about 100 mg KOH / g and a functionality of at least about 2.2, and
(iii) from about 10 to about 40 wt.% a polyether polyol comprising a sucrose or sorbitol initiated polyol having an average hydroxyl number greater than about 200 mg KOH / g and an average functionality of at least about 4;
all percentages are based on the total weight of the combined polyol, and where components (i), (ii) and (iii) are selected such that the combined polyol as a whole has an average functionality of at least about 2.4;
(b) a polyisocyanate and
(c) a blowing agent;
so that the stoichiometric index of the polyisocyanate to the combined polyol is more than 250. 2. The composition of claim 1, wherein the aromatic polyester polyol is selected from aromatic polyester polyols having
an acid component comprising at least about 30 wt.% residues of phthalic acid or residues of its isomers. 3. The composition of claim 1, wherein the aromatic polyester polyol is obtained by transesterification of crude reaction residues or wastes. 4. The composition of claim 1, wherein the aromatic polyester polyol has a hydroxyl number in the range of from more than about 50 mg KOH / g to about 400 mg KOH / g. 5. The composition according to p. 4, where the hydroxyl number lies in the range from about 150 to about 300. 6. The composition according to p. 1, where the aromatic complex polyether polyol has a functionality in the range from about 2 to about 8. 7. The composition according to claim 1, wherein the polyol novolac type has a molecular weight of from about 300 to about 1500. 8. Polyurethane or polyisocyanurate foam obtained according to the composition according to p. 1 9. A method of obtaining a polyurethane or polyisocyanurate foam, including interaction under conditions of foaming
(a) a combined polyol comprising
(i) from about 30 to about 60 wt.% aromatic polyester polyol having a hydroxyl number greater than about 50 mg KOH / g and a functionality of at least about 2;
(ii) from about 10 to about 30 wt.% simple novolac type polyether polyol having a hydroxyl number greater than about 100 mg KOH / g and
functionality of at least about 2.2, and
(iii) from about 10 to about 40 wt.% a polyether polyol comprising a sucrose or sorbitol initiated polyol having an average hydroxyl number greater than about 200 mg KOH / g and an average functionality of at least about 4;
all percentages are based on the total weight of the combined polyol and where components (i), (ii) and (iii) are selected so that the combined polyol as a whole has an average functionality of at least about 2.4;
(b) a polyisocyanate and
(c) a blowing agent;
so that the stoichiometric index of the polyisocyanate to the combined polyol is more than 250; to obtain a rigid polyurethane or polyisocyanurate foam. 10. The method of claim 9, wherein the combined polyol, polyisocyanate, and blowing agent are contacted as two streams, three streams, or more than three streams. 11. The method of claim 10, wherein the mixed streams are sprayed or coated onto a substrate. 12. The method according to p. 11, where the substrate is selected from the group consisting of a hard facing sheet, a flexible facing sheet, a layer of a similar or other polyurethane or polyisocyanurate or conveyor belt. 13. The method according to p. 12, where a laminated panel. 14. Polyurethane or polyisocyanurate foam obtained by the method according to p. 9. 15. The foam according to claim 14, where the foam is a layer in a laminated panel. 16. The foam of claim 15, further comprising at least one hard facing sheet, at least one flexible facing sheet, at least one layer of the same or different polyurethane or polyisocyanurate, or a combination thereof.