Two-component polyurethane foam adhesive, process for preparing same and articles made therefrom

Abstract

The present invention relates to a two-component polyurethane foam adhesive, a process for preparing same and articles made therefrom.

Description

[Technical field]

[0001] The present invention relates to a two-component polyurethane foam adhesive, a process for preparing same and articles made therefrom. [Background technology]

[0002] Adhesive bonding is an essential technology without which many products could not be manufactured economically. Advantages of adhesive bonding include, but are not limited to, that the parts being joined are not damaged by thermal stress (e.g. due to welding), possible joining of dissimilar materials, and that the forces acting on the joining surfaces are widely distributed over the entire area.

[0003] Polyurethane (PU) foam adhesives are known in bonding substrates. Prepolymers, also known as isocyanate prepolymers, containing free isocyanate groups, play a major role in PU chemistry. Prepolymers are polyols reacted with excess isocyanate. One such adhesive based on prepolymers is described in US 7,622,187 B2 for roof structure applications. Adhesives with elongations (%) of about 200% and 150% at 20 psi were obtained by reacting polyols with molecular weights of at least 3000 g / mol with prepolymers with an isocyanate content of less than 25% by weight.

[0004] Another US 5,872,203A describes a PU adhesive composition for use in bonding together polymeric roofing membranes to roof deck substrates. The first component comprises a monomeric or polymeric isocyanate having an isocyanate content of about 33% by weight, or a prepolymer having an isocyanate content in the range of 0.2% to 10% by weight.

[0005] Another US 6,416,854 B2 describes a sprayable low-rise PU foam adhesive for monolithic roofing membranes. Using the low-rise adhesive in combination with a silicone-based coating, membrane thicknesses as low as 1 / 4 inch were obtained.

[0006] EP 0609982 A1 describes novel polyols and processes for preparing flexible polyurethane foams from special classes of polyols. Another US 6,130,268 describes two-component polyurethane adhesives and methods for bonding various types of building materials.

[0007] While PU foam adhesives for specific applications, e.g., fleeceback membranes for roofing, are known, PU foam adhesives that can be applied to a wide variety of substrates and that can be obtained through multiple equipment configurations, e.g., low pressure (about 100-200 psi) as well as high pressure (about 1000 psi), have not been disclosed. Existing adhesives can be obtained at either low pressure or high pressure, i.e., they are limited in terms of process and cannot be obtained using either of the two. Furthermore, existing PU foam adhesives lack the toughness and durability required to withstand high stress conditions without compromising mechanical properties such as, but not limited to, tensile strength, elongation (%), and tear strength.

[0008] It was therefore an object of the presently claimed invention to provide a PU foam adhesive that is universally applicable, i.e., can be applied to a wide variety of substrates, can be obtained through multiple equipment configurations, and has improved toughness and durability with acceptable mechanical properties. Summary of the Invention

[0009] Surprisingly, it has been found that the above objectives are met by the present invention as described hereinafter and as reflected in the claims.

[0010] Thus, in one aspect, the presently claimed invention relates to a two-component polyurethane foam adhesive, the two-component polyurethane foam adhesive comprising: (A) an isocyanate prepolymer component, (A1) at least one first polyether polyol having an average functionality of 1.9 to 3.5 and a hydroxyl number of 10 mg KOH / g to 100 mg KOH / g, and (A2) at least one polymeric isocyanate, an isocyanate prepolymer component, the isocyanate prepolymer having an isocyanate content of 15% to 28% by weight; (B) an isocyanate-reactive component, (B1) 50% to 90% by weight, based on the total weight of the isocyanate-reactive components, of a second polyether polyol having an average functionality of 1.9 to 3.5 and a hydroxyl number of 10 mg KOH / g to 40 mg KOH / g; and (B2) an isocyanate-reactive component comprising 0.5% to 30% by weight, based on the total weight of the isocyanate-reactive components, of a third polyether polyol having an average functionality of 1.9 to 8.0 and a hydroxyl number of 40 mg KOH / g to 1000 mg KOH / g.

[0011] In another aspect, the presently claimed invention relates to a process for preparing the above two-component polyurethane foam adhesive by mixing an isocyanate prepolymer component (A) with an isocyanate-reactive component (B) at an Isocyanate Index of 70 to 200.

[0012] In yet another aspect, the presently claimed invention relates to an article comprising at least one first substrate layer and one second substrate layer, wherein the two-component polyurethane foam adhesive layer described above is present between the first substrate layer and the second substrate layer and forms an adhesive bond therebetween.

[0013] In still yet another aspect, the presently claimed invention is a method for making the above article, said method comprising: (S1) applying a two-component polyurethane foam adhesive at least partially onto at least one first substrate layer; (S2) applying a second substrate layer onto the at least one first substrate layer and allowing the two-component polyurethane foam adhesive to solidify to obtain an article. DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS

[0014] Before describing the present compositions and formulations of the present invention, it is to be understood that the invention is not limited to the particular compositions and formulations described, as such compositions and formulations may, of course, vary. It is also to be understood that the terms used herein are not intended to be limiting, since the scope of the present invention will be limited only by the appended claims.

[0015] As used herein, the terms "comprising," "comprises," and "comprised of" are synonymous with "including," "includes," or "containing," "contains," and are inclusive or open-ended and do not exclude additional, unrecited members, elements, or method steps. As used herein, the terms "comprising," "comprises," and "comprised of" will be understood to include the terms "consisting of," "consists," and "(consists of).

[0016] Furthermore, terms such as "first", "second", "third", or "a", "b", "c", "d" and the like in the description and claims are used to distinguish between similar elements and do not necessarily describe a sequential or chronological order. It is to be understood that terms so used are interchangeable under appropriate circumstances and that the embodiments of the invention described herein can be performed in other orders than those described or illustrated herein. In the case of terms such as "first", "second", "third", or "(A)", "(B)", and "(C)", or "(a)", "(b)", "(c)", "(d)", "i", "ii", etc. relating to steps of a method or use or analysis, there is no consistency of time or time interval between the steps, i.e., the steps are performed simultaneously or there may be a time interval of seconds, minutes, hours, days, weeks, months, or even years between such steps, unless otherwise indicated in the application as described herein above or below.

[0017] In the following passages, various aspects of the invention are defined in more detail. Each aspect so defined may be combined with any other aspect or aspects, unless expressly indicated to the contrary. In particular, any feature indicated as being preferred or advantageous may be combined with any other feature or features indicated as being preferred or advantageous.

[0018] References throughout this specification to "an embodiment" or "one embodiment" mean that a particular feature, structure, or characteristic described in connection with that embodiment is included in at least one embodiment of the invention. Thus, the appearances of the phrase "an embodiment" or "one embodiment" in various places throughout this specification do not necessarily all refer to the same embodiment, but may. Furthermore, in one or more embodiments, particular features, structures, or characteristics may be combined in any suitable manner, as would be apparent to one of ordinary skill in the art from this disclosure. Furthermore, although some embodiments described herein include some features but not other features included in other embodiments, combinations of features of different embodiments are intended to be within the scope of the invention and form different embodiments, as would be understood by one of ordinary skill in the art. For example, in the appended claims, any of the claimed embodiments may be used in any combination.

[0019] Furthermore, ranges defined throughout the specification are inclusive, i.e., a range of 1 to 10 means that both 1 and 10 are included in the range. For the avoidance of doubt, Applicant reserves the right to any equivalents pursuant to applicable law.

[0020] One aspect of the present invention is embodiment 1, which relates to a two-component PU foam adhesive, (A) an isocyanate prepolymer component, (A1) at least one first polyether polyol having an average functionality of 1.9 to 3.5 and a hydroxyl number of 10 mg KOH / g to 100 mg KOH / g, and (A2) at least one polymeric isocyanate, an isocyanate prepolymer component, the isocyanate prepolymer having an isocyanate content of 15% to 28% by weight; (B) an isocyanate-reactive component, (B1) 50% to 90% by weight, based on the total weight of the isocyanate-reactive components, of a second polyether polyol having an average functionality of 1.9 to 3.5 and a hydroxyl number of 10 mg KOH / g to 40 mg KOH / g; and (B2) an isocyanate-reactive component comprising 0.5% to 30% by weight, based on the total weight of the isocyanate-reactive components, of a third polyether polyol having an average functionality of 1.9 to 8.0 and a hydroxyl number of 40 mg KOH / g to 1000 mg KOH / g.

[0021] In this context, the isocyanate prepolymer component (A) may alternatively be referred to as the A-side component, while the isocyanate-reactive component (B) may be referred to as the B-side component.

[0022] Isocyanate prepolymer component In one embodiment, the isocyanate prepolymer component of embodiment 1 is obtained by mixing a first polyether polyol with a polymeric isocyanate. The isocyanate prepolymer has an isocyanate content of 15% to 28% by weight. In another embodiment, the isocyanate content is 20% to 23% by weight.

[0023] First Polyether Polyol In another embodiment, the first polyether polyol of embodiment 1 has an average functionality of 1.9 to 3.5 and a hydroxyl number of 10 mg KOH / g to 100 mg KOH / g. In yet another embodiment, the first polyether polyol has an average functionality of 2.0 to 3.5, or 2.0 to 3.2. In yet another embodiment, the hydroxyl number is 15 mg KOH / g to 100 mg KOH / g, or 15 mg KOH / g to 90 mg KOH / g, or 20 mg KOH / g to 90 mg KOH, or 20 mg KOH / g to 80 mg KOH / g. In yet another embodiment it is from 20 mg KOH / g to 70 mg KOH / g, or from 20 mg KOH / g to 60 mg KOH / g, or from 20 mg KOH / g to 50 mg KOH / g, or from 20 mg KOH / g to 40 mg KOH / g, or from 20 mg KOH / g to 35 mg KOH / g, or from 25 mg KOH / g to 35 mg KOH / g.

[0024] In another embodiment, the first polyether polyol of embodiment 1 comprises a polyether polyol capped with at least one alkylene oxide. A suitable polyether polyol is formed by adding an alkylene oxide to a multifunctional starter molecule. The addition of the alkylene oxide is usually carried out in an alkaline medium using sodium hydroxide as a base. Such methods are known to those skilled in the art. The important properties of the first polyether polyol, such as melting point, viscosity, and compatibility, can be controlled by the ratio of various alkylene oxides.

[0025] In some embodiments, suitable starter molecules include amine-containing and hydroxyl-containing starter molecules, such as aliphatic and aromatic diamines, such as ethylenediamine, propylenediamine, butylenediamine, hexamethylenediamine, phenylenediamine, toluenediamine, diaminodiphenylmethane, and their isomers.

[0026] Other suitable starter molecules further include alkanolamines, such as ethanolamine, N-methylethanolamine and N-ethylethanolamine, dialkanolamines, such as diethanolamine, N-methyldiethanolamine and N-ethyldiethanolamine, and trialkanolamines, such as triethanolamine, and ammonia.

[0027] The hydroxyl-containing starter molecules are selected from sugars, sugar alcohols, e.g., glucose, mannitol, sucrose, pentaerythritol, sorbitol, polyhydric phenols, resoles, e.g., oligomeric condensation products formed from phenol and formaldehyde, glycols, such as trimethylolpropane, glycerol, ethylene glycol, propylene glycol, and condensation products thereof, such as polyethylene glycol and polypropylene glycol, e.g., diethylene glycol, triethylene glycol, dipropylene glycol, and water or combinations thereof.

[0028] In one embodiment, the hydroxyl-containing starter molecule is selected from sugars and sugar alcohols such as sucrose, sorbitol, glycerol, pentaerythritol, trimethylolpropane and mixtures thereof. In another embodiment, the hydroxyl-containing starter molecule is selected from sucrose, glycerol, pentaerythritol and trimethylolpropane.

[0029] In yet another embodiment, the hydroxyl-containing starter molecules include glycerol and / or propylene glycol.

[0030] Suitable alkylene oxides have 2 to 4 carbon atoms, such as ethylene oxide, propylene oxide, tetrahydrofuran, 1,2-butylene oxide, 2,3-butylene oxide and styrene oxide. The alkylene oxides can be used alone, alternately in succession, or as mixtures. In an embodiment, the alkylene oxide is propylene oxide and / or ethylene oxide.

[0031] In some embodiments, the at least one alkylene oxide capped polyether polyol has an alkylene oxide content of less than 25.0 wt.%, based on the total weight of the polyether polyol, hi other embodiments, the alkylene oxide content is from 5.0 wt.% to 25.0 wt.%, or from 10.0 wt.% to 25.0 wt.%.

[0032] In another embodiment, the first polyether polyol of embodiment 1 comprises glycerol as a starter molecule with propylene oxide and ethylene oxide end-capping, has an ethylene oxide content of 12.0% to 15.0% by weight, an average functionality of 3.0, and a hydroxyl number of 26 mg KOH / g to 30 mg KOH / g.

[0033] In yet another embodiment, the first polyether polyol of embodiment 1 comprises propylene glycol as a starter molecule with propylene oxide and ethylene oxide end-capping, has an ethylene oxide content of 18.0% to 23.0% by weight, an average functionality of 2.0, and a hydroxyl number of 28 mg KOH / g to 30 mg KOH / g.

[0034] In another embodiment, a mixture of first polyether polyols can also be used to obtain the isocyanate prepolymer of embodiment one.

[0035] In yet another embodiment, the isocyanate prepolymer component of embodiment 1 comprises other polyether polyols in addition to the first polyether polyol. Suitable other polyether polyols include, but are not limited to, the second polyether polyol and the third polyether polyol as described herein.

[0036] Polymeric Isocyanate Unlike existing two-component PU foam adhesives, the present invention uses a polymeric isocyanate to obtain the isocyanate prepolymer component of embodiment 1. The term "polymer" refers to the polymeric grades of isocyanates, including different oligomers and homologues, independent of each other.

[0037] In one embodiment, the polymeric isocyanate of embodiment 1 has an isocyanate functionality of 2.5 to 4.0. In another embodiment, it is 2.5 to 4.0, or 2.5 to 3.5, or 2.5 to 3.0.

[0038] In another embodiment, the polymeric isocyanate of embodiment 1 comprises a polymeric aromatic isocyanate.Suitable aromatic isocyanates include toluene diisocyanate, methylene diphenyl diisocyanate, m-phenylene diisocyanate, 1,5-naphthalene diisocyanate; 4-chloro-1; 3-phenylene diisocyanate; 2,4,6-toluylene triisocyanate; 1,3-diisopropylphenylene-2,4-diisocyanate; 1-methyl-3,5-diethylphenylene-2,4-diisocyanate; 1,3,5-triethylphenylene-2,4-diisocyanate; 1,3,5-triisopropyl-phenylene-2,4-diisocyanate; 3,3'-diethyl-bisphenyl-4,4' -diisocyanate; 3,5,3',5'-tetraethyl-diphenylmethane-4,4'-diisocyanate; 3,5,3',5'-tetraisopropyldiphenylmethane-4,4'-diisocyanate; 1-ethyl-4-ethoxy-phenyl-2,5-diisocyanate; 1,3,5-triethylbenzene-2,4,6-triisocyanate; 1-ethyl-3,5-diisopropylbenzene-2,4,6-triisocyanate, tolidine diisocyanate, and 1,3,5-triisopropylbenzene-2,4,6-triisocyanate are selected from the following polymer grades of aromatic isocyanates. Here, it should be understood that the polymeric isocyanate of embodiment 1 is not limited by the isocyanates listed above, and further includes other isomers not explicitly shown here. For example, methylene diphenyl diisocyanate means that the isomers are essentially included. Additionally, mixtures of polymeric isocyanates such as those listed above may also be used.

[0039] In yet another embodiment, the polymeric isocyanate of embodiment 1 is selected from the group consisting of toluene diisocyanate, methylene diphenyl diisocyanate, m-phenylene diisocyanate, 1,5-naphthalene diisocyanate; 4-chloro-1,3-phenylene diisocyanate; 2,4,6-toluylene triisocyanate, 1,3-diisopropylphenylene-2,4-diisocyanate; 1-methyl-3,5-diethylphenylene-2,4-diisocyanate; 1,3,5-triethyl The polymer grades are selected from phenylene-2,4-diisocyanate; 1,3,5-triisopropyl-phenylene-2,4-diisocyanate; 3,3'-diethyl-bisphenyl-4,4'-diisocyanate; 3,5,3',5'-tetraethyl-diphenylmethane-4,4'-diisocyanate; 3,5,3',5'-tetraisopropyldiphenylmethane-4,4'-diisocyanate, and 1-ethyl-4-ethoxy-phenyl-2,5-diisocyanate.

[0040] In a further embodiment, the polymeric isocyanate of embodiment 1 is selected from polymeric grades of toluene diisocyanate, methylene diphenyl diisocyanate, m-phenylene diisocyanate, 1,5-naphthalene diisocyanate; 4-chloro-1;3-phenylene diisocyanate; 2,4,6-toluylene triisocyanate, 1,3-diisopropylphenylene-2,4-diisocyanate; 1-methyl-3,5-diethylphenylene-2,4-diisocyanate, and 1,3,5-triethylphenylene-2,4-diisocyanate.

[0041] In yet a further embodiment, the polymeric isocyanate of embodiment 1 comprises polymeric methylene diphenyl diisocyanate (MDI). MDI is available in three different isomeric forms, namely, 2,2'-MDI, 2,4'-MDI, and 4,4'-MDI. Polymeric MDI comprises oligomeric and MDI isomers. Thus, polymeric MDI may contain a single MDI isomer, or an isomeric mixture of two or three MDI isomers, with the remainder being oligomeric species. The ratio of isomers as well as the amount of oligomeric species may vary widely in polymeric MDI. For example, polymeric MDI typically comprises 30% to 80% by weight of MDI isomers, including a mixture of 2,2'-MDI, 2,4'-MDI, and / or 4,4'-MDI, with the remainder being oligomeric species.

[0042] In addition, the polymeric isocyanate of embodiment 1 also includes isocyanates modified in known manner by the introduction of urethane, allophanate, urea, biuret, carbodiimide, uretonimine, isocyanurate and / or oxazolidone residues. These modified isocyanates are well known in the art and are prepared by reactions known to those skilled in the art. For example, uretonimine-carbodiimide modified polymeric isocyanates can be obtained by using well-known carbodiimide-promoting catalysts to convert isocyanates to carbodiimides at temperatures ranging from 50°C to 250°C, followed by further reaction with unconverted isocyanates at room temperature to form uretonimine modified isocyanates.

[0043] In one embodiment, the isocyanate prepolymer of embodiment 1 is obtained by mixing (A1) a first polyether polyol containing glycerol as a starter molecule with propylene oxide and ethylene oxide end-capping, with an ethylene oxide content of 12.0% to 15.0% by weight, with an average functionality of 3.0 and a hydroxyl value of 26 mg KOH / g to 30 mg KOH / g, with (A2) a polymeric MDI based mainly on 4,4'-MDI and containing higher functionality oligomers and isomers, with an isocyanate functionality of 2.5 to 3.1, to produce an isocyanate prepolymer with an isocyanate content of 20% to 23% by weight.

[0044] In another embodiment, the isocyanate prepolymer of embodiment 1 further comprises suitable components that can be added during or after the formation of the isocyanate prepolymer. In other words, the mixture for obtaining the isocyanate prepolymer can comprise, in addition to the first polyether polyol and the polymeric isocyanate, a surfactant and / or additive as described herein. In a further embodiment, the isocyanate prepolymer of embodiment 1 is obtained by mixing the first polyether polyol with the polymeric isocyanate, optionally in the presence of additives such as surfactants and / or flame retardants. Suitable amounts of these components are well known to those skilled in the art, and for example, they can be present in amounts similar to those in the isocyanate-reactive components as described herein.

[0045] Isocyanate-Reactive Components In one embodiment, the isocyanate-reactive component of embodiment 1 comprises a mixture of (B1) 50% to 90% by weight, based on the total weight of the isocyanate-reactive component, of a second polyether polyol having an average functionality of 1.9 to 3.5 and a hydroxyl value of 10 mg KOH / g to 40 mg KOH / g; (B2) 0.5% to 30% by weight, based on the total weight of the isocyanate-reactive component, of a third polyether polyol having an average functionality of 1.9 to 8.0 and a hydroxyl value of 40 mg KOH / g to 1000 mg KOH / g; and at least one selected from a crosslinker, a surfactant, and a catalyst. In another embodiment, the isocyanate-reactive component of embodiment 1 comprises a mixture of a second polyether polyol, a third polyether polyol, at least one selected from a crosslinker, a surfactant, and a catalyst, and, optionally, an additive.

[0046] Second Polyether Polyol In an embodiment, the second polyether polyol of embodiment 1 is the same as the first polyether polyol. In another embodiment, the second polyether polyol can be different from the first polyether polyol.

[0047] Suitable second polyether polyols may be selected from the first polyether polyols as described herein, including mixtures thereof. In one embodiment, the second polyether polyol of embodiment 1 has an average functionality of 2.0 to 3.5, or 2.0 to 3.2, or 2.2 to 3.2, or 2.5 to 3.2, or 2.8 to 3.2. In another embodiment, the hydroxyl number is 15 mg KOH / g to 40 mg KOH / g, or 15 mg KOH / g to 35 mg KOH / g, or 20 mg KOH / g to 35 mg KOH / g, or 20 mg KOH / g to 32 mg KOH / g. In yet another embodiment, it is 25 mg KOH / g to 32 mg KOH / g.

[0048] In another embodiment, the second polyether polyol of embodiment 1 comprises glycerol as a starter molecule with propylene oxide and ethylene oxide end-capping, has an ethylene oxide content of 12.0% to 15.0% by weight, an average functionality of 3.0, and a hydroxyl number of 26 mg KOH / g to 30 mg KOH / g.

[0049] In some embodiments, the second polyether polyol of embodiment 1 is present in an amount of 55% to 90% by weight, or 55% to 85% by weight, or 60% to 85% by weight, or 60% to 80% by weight. In yet other embodiments, it is present in an amount of 62% to 80% by weight, or 62% to 76% by weight.

[0050] Third Polyether Polyol Suitable third polyether polyols of embodiment 1 include conventional polyether polyols having an average functionality of 1.9 to 8.0 and a hydroxyl value of 40 mgKOH / g to 1000 mgKOH / g. In some embodiments, the average functionality is 1.9 to 7.5, or 1.9 to 6.0, or 1.9 to 5.5, or 1.9 to 5.0. In other embodiments, the average functionality is 1.9 to 4.5, or 2.0 to 4.5. The hydroxyl value of the third polyether polyol is 45 mgKOH / g to 1000 mgKOH / g, or 45 mgKOH / g to 950 mgKOH / g, or 50 mgKOH / g to 950 mgKOH / g, or 50 mgKOH / g to 900 mgKOH / g, or 50 mgKOH / g to 850 mgKOH / g.

[0051] Suitable third polyether polyols can be obtained by known methods, for example by anionic polymerization using an alkali metal hydroxide, such as sodium hydroxide or potassium hydroxide, or an alkali metal alkoxide, such as sodium methoxide, sodium ethoxide, potassium ethoxide or potassium isopropoxide, as catalyst and adding at least one amine-containing starter molecule, or by cationic polymerization with one or more alkylene oxides having 2 to 4 carbon atoms in the alkylene moiety, using a Lewis acid, such as antimony pentachloride, boron fluoride etherate, or fuller's earth as catalyst.

[0052] The starter molecules are generally selected such that their average functionality is from 2.0 to 8.0, or from 3.0 to 8.0. Optionally, a mixture of suitable starter molecules is used.

[0053] Starter molecules for the third polyether polyol include amine-containing and hydroxyl-containing starter molecules. Suitable amine-containing starter molecules include, for example, aliphatic and aromatic diamines such as ethylenediamine, propylenediamine, butylenediamine, hexamethylenediamine, phenylenediamine, toluenediamine, diaminodiphenylmethane and isomers thereof.

[0054] Other suitable starter molecules further include alkanolamines, such as ethanolamine, N-methylethanolamine and N-ethylethanolamine, dialkanolamines, such as diethanolamine, N-methyldiethanolamine and N-ethyldiethanolamine, and trialkanolamines, such as triethanolamine, and ammonia.

[0055] In some embodiments, the amine-containing starter molecule is selected from ethylenediamine, phenylenediamine, toluenediamine, and isomers thereof. In other embodiments, the amine-containing starter molecule comprises ethylenediamine.

[0056] The hydroxyl-containing starter molecules are selected from sugars, sugar alcohols, e.g., glucose, mannitol, sucrose, pentaerythritol, sorbitol, polyhydric phenols, resoles, e.g., oligomeric condensation products formed from phenol and formaldehyde, glycols, such as trimethylolpropane, glycerol, ethylene glycol, propylene glycol, and condensation products thereof, such as polyethylene glycol and polypropylene glycol, e.g., diethylene glycol, triethylene glycol, dipropylene glycol, and water or combinations thereof.

[0057] In one embodiment, the hydroxyl-containing starter molecule is selected from sugars and sugar alcohols such as sucrose, sorbitol, glycerol, pentaerythritol, trimethylolpropane and mixtures thereof. In another embodiment, the hydroxyl-containing starter molecule is selected from sucrose, glycerol, pentaerythritol and trimethylolpropane.

[0058] Suitable alkylene oxides having 2 to 4 carbon atoms are, for example, ethylene oxide, propylene oxide, tetrahydrofuran, 1,2-butylene oxide, 2,3-butylene oxide and styrene oxide. The alkylene oxides can be used alone, successively alternating, or as mixtures. In an embodiment, the alkylene oxide is propylene oxide and / or ethylene oxide. In another embodiment, the alkylene oxide is a mixture of ethylene oxide and propylene oxide containing more than 50% by weight of propylene oxide.

[0059] In an embodiment, the third polyether polyol of embodiment 1 is based on ethylenediamine having an average functionality of 4.0 and a hydroxyl number of 800 mg KOH / g.

[0060] In yet another embodiment, the third polyether polyol of embodiment 1 comprises propylene glycol and propylene oxide as starter molecules and has an average functionality of 2.0 and a hydroxyl number of 53 mg KOH / g to 58 mg KOH / g.

[0061] In another embodiment, a mixture of a third polyether polyol may also be used in the isocyanate-reactive component of embodiment one.

[0062] In still yet another embodiment, the third polyether polyol of embodiment 1 also includes other polyether polyols known to those of skill in the art. The third polyether polyol of embodiment 1 is present in an amount of 0.5% to 26% by weight, based on the total weight of the isocyanate-reactive components.

[0063] Crosslinking Agent In one embodiment, the isocyanate-reactive component of embodiment 1 includes a crosslinker. Suitable crosslinkers are compounds that contain at least two isocyanate-reactive groups and have a molecular weight of 100 g / mole to 150 g / mole. In another embodiment, the crosslinker has a molecular weight of 100 g / mole to 125 g / mole.

[0064] In another embodiment, the crosslinker in the isocyanate-reactive component of embodiment 1 is selected from monoethanolamine, diethanolamine, triethanolamine, diethylene glycol, dipropylene glycol, glycerin, trimethylolpropane, and pentaerythritol. In yet another embodiment, the crosslinker comprises diethylene glycol or dipropylene glycol.

[0065] In one embodiment, the crosslinker is present in the isocyanate-reactive component of embodiment 1 in an amount of 0.5% to 10.0% by weight, based on the total weight of the isocyanate-reactive component (B). In another embodiment, it is present at 0.5% to 9.0% by weight, or 0.5% to 8.0% by weight, or 0.5% to 7.0% by weight. In yet another embodiment, it is present at between 0.5% to 6.0% by weight, or 0.5% to 5.0% by weight.

[0066] Surfactants A variety of surfactants are known in the art and can be used in the present invention.One type of surfactant is silicone surfactant.The silicone surfactant for the present invention is selected from hydrolyzable polyether-polysiloxane block copolymer, non-hydrolyzable polyether-polysiloxane block copolymer, cyanoalkyl polysiloxane, polyether siloxane, polydimethyl siloxane, and polyether modified dimethyl polysiloxane.In one embodiment, the surfactant in the isocyanate reactive component of embodiment 1 comprises polyether polysiloxane and / or polyether siloxane.

[0067] In another embodiment, the polyether polysiloxane has the general formula (I):

[0068] [ka] is a polyether polysiloxane of the formula: R 1 , R 2 , R 3 and R 4 are each independently an alkyl, alkenyl, cycloalkyl, aryl, heteroaryl, alkylalkoxy, R 9 -C(=O)-, R 10 -NH-C(=O)-, R 11 Si(R 12 )(R 13 )-, R 14 -O-(-R 15 -O-) j-(C n H 2n -) k - selected from R 9 , R 10 , R 11 , R 12 , and R 13 are each independently selected from alkyl, alkenyl, cycloalkyl, aryl, heteroaryl, alkylalkoxy; R 14 and R 15 are independently selected from divalent alkylene, cycloalkylene, alkenyl, and aryl; n is an integer from 1 to 10; j and k are each independently an integer from 0 to 10; x and y are each independently an integer of 1 to 10,000.

[0069] The term “alkyl” as used herein refers to a group of the general formula C p H 2p+1

[0023] In the present invention, p refers to an acyclic saturated aliphatic group including a straight or branched chain alkyl saturated hydrocarbon radical represented by the formula: where p indicates the number of carbon atoms, such as 1, 2, 3, 4, etc.

[0070] In certain embodiments, alkyl is an unsubstituted, straight or branched chain C 1 -C 30 Refers to the alkyl group. Unsubstituted linear C 1 -C 30Alkyl is selected from methyl, ethyl, propyl, butyl, pentyl, hexyl, heptyl, octyl, nonyl, decyl, undecyl, dodecyl, tridecyl, tetradecyl, pentadecyl, hexadecyl, heptadecyl, octadecyl, nonadecyl, eicosyl, henicosyl, docosyl, tricosyl, tetracosyl, pentacosyl, hexacosyl, heptacosyl, octacosyl, noncosyl, and triacontyl. In another embodiment, it is selected from methyl, ethyl, propyl, butyl, pentyl, hexyl, heptyl, octyl, nonyl, decyl, undecyl, dodecyl, tridecyl, tetradecyl, pentadecyl, hexadecyl, heptadecyl, octadecyl, nonadecyl, and eicosyl.

[0071] The term "alkenyl" refers to a group of the general formula C p H 2p-1

[0023] This refers to unsubstituted straight chain acyclic unsaturated aliphatic groups including straight chain alkenyl unsaturated hydrocarbon radicals represented by the formula: where p indicates the number of carbon atoms, such as 1, 2, 3, 4, etc.

[0072] In certain embodiments, alkenyl is 1-propenyl, 1-butenyl, 1-pentenyl, 1-hexenyl, 2-hexenyl, 1-heptenyl, 2-heptenyl, 1-octenyl, 2-octenyl, 1-nonenyl, 2-nonenyl, 1-decenyl, 2-decenyl, 1-undecenyl, 2-undecenyl, 1-dodecenyl, 2-dodecenyl, 1-tridecenyl, 2-tridecenyl, 1-tetradecenyl, 2-tetradecenyl, 1-pentadecenyl, 2-pentadecen ... unsubstituted linear C selected from decenyl, 1-hexadecenyl, 2-hexadecenyl, 1-heptadecenyl, 2-heptadecenyl, 1-octadecenyl, 2-octadecenyl, 1-nonadecenyl, 2-nonadecenyl, 1-eicosenyl, 2-eicosenyl, 2-henicosenyl, 2-docosenyl, 2-tricosenyl, 2-tetracosenyl, 2-pentacosenyl, 2-hexacosenyl, 2-octacoenyl, 2-nonacosenyl and 2-triacontenyl 2 -C 30alkenyl. In another embodiment, it is selected from 1-propenyl, 1-butenyl, 1-pentenyl, 1-hexenyl, 2-hexenyl, 1-heptenyl, 2-heptenyl, 1-octenyl, 2-octenyl, 1-nonenyl, 2-nonenyl, 1-decenyl, 2-decenyl, 1-undecenyl, 2-undecenyl, 1-dodecenyl, 2-dodecenyl, 1-tridecenyl, 2-tridecenyl, 1-tetradecenyl, 2-tetradecenyl, 1-pentadecenyl, 2-pentadecenyl, 1-hexadecenyl, 2-hexadecenyl, 1-heptadecenyl, 2-heptadecenyl, and 1-octadecenyl. In another embodiment, an unsubstituted linear C alkyl group is selected from 1-propenyl, 1-butenyl, 1-pentenyl, 1-hexenyl, 2-hexenyl, 1-heptenyl, 2-heptenyl, 1-octenyl, 2-octenyl, 1-nonenyl, 2-nonenyl, 1-decenyl, 2-decenyl, 1-undecenyl, 2-undecenyl, 1-dodecenyl, 2-dodecenyl, 1-tridecenyl, 2-tridecenyl, 1-tetradecenyl, 2-tetradecenyl, 1-pentadecenyl, and 2-pentadecenyl. 2 -C 30 In yet another embodiment, an unsubstituted linear C alkyl group is selected from 1-propenyl, 1-butenyl, 1-pentenyl, 1-hexenyl, 2-hexenyl, 1-heptenyl, and 2-heptenyl. 2 -C 30 Alkenyl.

[0073] The term "cycloalkyl" refers to an unsubstituted or branched C alkyl group having a monocyclic or bicyclic 3- to 10-membered saturated alicyclic radical. 3 -C 10 Cycloalkyl refers to unsubstituted or branched C 3 -C 10 Cycloalkyl is a monocyclic or bicyclic C 3 -C 10 It is a compound with unsubstituted or branched C 3 -C 10Representative examples of monocyclic and bicyclic cycloalkyl are selected from cyclopropyl, cyclobutyl, cyclopentyl, cyclohexyl, cycloheptyl, bicyclo[2.2.1]heptyl and bicyclo[3.1.1]heptyl. 3 -C 10 The monocyclic and bicyclic cycloalkyls may be further branched with one or more of the same or different alkyl groups as described above. 3 -C 10 Representative examples of monocyclic and bicyclic cycloalkyls include, but are not limited to, methylcyclohexyl, dimethylcyclohexyl, and the like.

[0074] The term "aryl" refers to a monocyclic, bicyclic or tricyclic hydrocarbon ring system, preferably having 6 to 14 carbon atoms, in which at least one carbon ring has a 4p+2 π electron system, where "p" is the number of aromatic rings. The aryl moieties may be unsubstituted, monosubstituted, or polysubstituted, either the same or different. Examples of aryl moieties include, but are not limited to, phenyl, 1-naphthyl, 2-naphthyl, or anthracenyl.

[0075] The term "heteroaryl" refers to an aromatic monocyclic, bicyclic or tricyclic hydrocarbon having 5, 6, 7, 8, 9, 10, 11, 12, 13 or 14 carbon atoms, or 5, 6, 9 or 10 atoms, in which 1 to 4 carbon atoms are replaced by the same or different heteroatoms, including oxygen, sulfur and nitrogen. The heteroaryl moiety may contain 1, 2, 3, 4 or 5, or 1, 2 or 3 heteroatoms, independently selected from oxygen, sulfur and nitrogen. The heteroaryl moiety may be unsubstituted or monosubstituted, or the same or different polysubstituted. Representative examples of suitable heteroaryl moieties are selected from furyl, pyridyl, oxazolyl, thiazolyl, pyrazolyl, pyrimidinyl, pyrrolyl, isoxazolyl, triazolyl, tetrazolyl, pyridazinyl, isothiazolyl, benzothiazolyl, benzoxazolyl, benzimidazolyl, quinolinyl and isoquinolinyl.

[0076] The term "alkylene" refers to an acyclic saturated hydrocarbon chain that combines different moieties. A representative example of an alkylene group is -CH 2 -CH 2 -, -CH 2 -CH(CH 3 )-, -CH 2 -CH(CH 2 CH 3 )-, -CH 2 -CH(nC 3 H 7 )-, -CH 2 -CH(nC 4 H 9 )-, -CH 2 -CH(nC 5 H 11 )-, -CH 2 -CH(nC 6 H 13 )-, -CH 2 -CH(nC 7 H 15 )-, -CH 2 -CH(nC 8 H 17 )-, -CH(CH 3 )-CH(CH 3 )-, -(CH 2 ) 3 -, -(CH 2 ) 4 -, -(CH 2 ) 5 -, -(CH 2 ) 6 -, -(CH 2 ) 8 -, -(CH 2 ) 10 -, -C(CH 3 ) 2 -, -CH 2 -C(CH 3 ) 2 -CH 2 - and -CH 2 -[C(CH 3 ) 2 ] 2 -CH 2 In one embodiment, the compound is selected from C 2 -C 10 Alkylene is -CH 2-CH 2 -, CH 2 -CH(CH 3 )-, -CH 2 -CH(CH 2 CH 3 )-, -CH 2 -CH(nC 3 H 7 )-, -CH 2 -CH(nC 4 H 9 )-, -CH 2 -CH(nC 6 H 13 )-, and -(CH 2 ) 4 -One or more of the following may be selected.

[0077] In one embodiment, the polyether polysiloxane of general formula (I) has the general formula (I)(a) [ka] is a polyether polysiloxane of the formula: R 1 , R 2 , R 3 and R 4 are each independently an alkyl, an alkenyl, R 14 -O-(-R 15 -O-) j -(C n H 2n -) k - selected from R 14 and R 15 are independently selected from divalent alkylene, cycloalkylene, alkenyl, and aryl; n is an integer from 1 to 10; j and k are each independently an integer from 0 to 10; z is an integer from 1 to 10,000.

[0078] In one embodiment, R 2 and R 3are each independently selected from methyl, ethyl, propyl, butyl, pentyl, hexyl, heptyl, octyl, nonyl, and decyl. In another embodiment, they are selected from methyl, ethyl, propyl, butyl, pentyl, and hexyl. In yet another embodiment, R 2 and R 3 are the same and are selected from methyl, ethyl, propyl, butyl, pentyl, and hexyl. 2 and R 3 contains methyl.

[0079] In another embodiment, n is an integer from 1 to 8, or from 1 to 6, or from 1 to 4 in general formula (I)(a).

[0080] In another embodiment, x and y are independently from each other an integer from 1 to 10000, or from 1 to 5000, or from 1 to 1000, or from 1 to 500, or from 10 to 500, or from 10 to 250, or even from 10 to 100 in general formula (I)(a).

[0081] In the present context, as will be understood by the skilled artisan, the linkages denoted by x and y are distributed so as to form a block polymer structure or a random polymer structure.

[0082] In another embodiment, the nonionic surfactant has the general formula (II): [ka] The polyether siloxane includes a polyether siloxane represented by the formula: R 5 , R 6 , R 7 and R 8 are each independently an alkyl, alkenyl, cycloalkyl, aryl, heteroaryl, alkylalkoxy, R 9 -C(=O)-, R 10 -NH-C(=O)-, R 11 Si(R 12 )(R 13 )-, R14 -O-(-R 15 -O-) j -(C n H 2n -) k - selected from R 9 , R 10 , R 11 , R 12 , and R 13 are each independently selected from alkyl, alkenyl, cycloalkyl, aryl, heteroaryl, alkylalkoxy; R 14 and R 15 are independently selected from divalent alkylene, cycloalkylene, alkenyl, and aryl; m is an integer from 1 to 10; j and k are each independently an integer from 0 to 10; z is an integer from 1 to 10,000.

[0083] In one embodiment, the polyether siloxane has the general formula (II)(a): [ka] wherein: R 5 , R 6 , R 7 and R 8 are each independently an alkyl, an alkenyl, R 14 -O-(-R 15 -O-) j -(C n H 2n -) k - selected from R 14 and R 15 are independently selected from divalent alkylene, cycloalkylene, alkenyl, and aryl; m is an integer from 1 to 10; j and k are each independently an integer from 0 to 10; z is an integer from 1 to 10,000.

[0084] Other surfactants that may be used in this context include, but are not limited to, salts of fatty acids, salts of sulfate esters, salts of phosphate esters, and sulfonates.

[0085] In one embodiment, the surfactant is present in the isocyanate-reactive component of embodiment 1 in an amount of 0.1 wt% to 10.0 wt%, based on the total weight of the isocyanate-reactive component. In another embodiment, it is present from 0.1 wt% to 9.0 wt%, or from 0.1 wt% to 8.0 wt%, or from 0.1 wt% to 7.0 wt%, or from 0.1 wt% to 6.0 wt%, or from 0.1 wt% to 5.0 wt%, or from 0.1 wt% to 4.0 wt%. In another embodiment, it is present from 0.1 wt% to 3.0 wt%, or from 0.5 wt% to 3.0 wt%, or from 0.5 wt% to 2.0 wt%.

[0086] In another embodiment, a surfactant may also be present in the isocyanate prepolymer component of embodiment 1. If present, the amount of surfactant is 0.1% to 10.0% by weight, based on the total weight of the isocyanate prepolymer component. In another embodiment, it is present at 0.1% to 9.0% by weight, or 0.1% to 8.0% by weight, or 0.1% to 7.0% by weight, or 0.1% to 6.0% by weight, or 0.1% to 5.0% by weight, or 0.1% to 4.0% by weight. In another embodiment, it is present at 0.1% to 3.0% by weight, or 0.5% to 3.0% by weight, or 0.5% to 2.0% by weight.

[0087] catalyst In one embodiment, the isocyanate-reactive component of embodiment 1 comprises a catalyst. In another embodiment, the catalyst comprises an amine catalyst. The amine catalyst is a tertiary amine catalyst.

[0088] Suitable catalysts of embodiment 1 include trimethylamine, triethylamine, dimethylethanolamine, N-methylmorpholine, N,N-dimethylbenzylamine, N,N-dimethylethanolamine, N,N,N',N'-tetramethyl-1,4-butanediamine, N,N-dimethylpiperazine, bis(dimethylaminoethyl)ether, bis(2-dimethylaminoethyl)ether, morpholine,4,4'-(oxydi-2,l-ethanediyl)bis, triethylenediamine, pentamethyldiethylenetriamine, dimethylcyclohexylamine, N-acetyl-N,N-dimethylamine, N-coco-morpholine, N,N-dimethylaminomethyl-N-methylethanolamine, N,N,N'-trimethyl-N'-hydroxyethylbis(aminoethyl)ether, N,N-bis(3-dimethyl-aminopropyl)-N-isopropanolamine, (N,N-di ... methyl)amino-ethoxyethanol, N,N,N',N'-tetramethylhexanediamine, 1,8-diazabicyclo-5,4,0-undecene-7, N,N-dimorpholinodiethyl ether, N-methylimidazole, dimethylaminopropyldipropanolamine, bis(dimethylaminopropyl)amino-2-propanol, tetramethylaminobis(propylamine), (dimethyl(aminoethoxyethyl))((dimethylamine)ethyl)ether, tris(dimethylaminopropyl)amine, dicyclohexylmethylamine, bis(N,N-dimethyl-3-aminopropyl)amine, and 1,2-ethylenepiperidine, and methyl-hydroxyethylpiperazine, 1,4-diazabicyclo[2.2.2]octane-2-methanol, and N-(3-dimethylaminopropyl)-N,N-diisopropanolamine.

[0089] In another embodiment, the catalyst is trimethylamine, triethylamine, dimethylethanolamine, N-methylmorpholine, N,N-dimethylbenzylamine, N,N-dimethylethanolamine, N,N,N',N'-tetramethyl-1,4-butanediamine, N,N-dimethylpiperazine, bis(dimethylaminoethyl)ether, bis(2-dimethylaminoethyl)ether, morpholine,4,4'-(oxydi-2,l-ethanediyl)bis, triethylenediamine, pentamethyldiethylenetriamine, dimethylcyclohexylamine, N-acetyl-N,N-dimethylamine, N-coco-morpholine, N,N-dimethylaminomethyl-N-methylethanolamine ...-dimethylbenzylamine, N,N-dimethylethanolamine, N,N-dimethylethanolamine, N,N-dimethylethanolamine, N,N-dimethylethanolamine, N,N-dimethylethanolamine, N,N-dimethylethanolamine, N,N-dimethylethanolamine, N,N-dimethylethanolamine, N,N-dimethylethanolamine, N,N-dimethylethanolamine, N,N-dimethylethanolamine, N,N-dimethylethanolamine, N,N-dimethylethanolamine, N,N-dimethylethanolamine, N,N-dimethylethanolamine, N,N-dimethylethanolamine, N,N-dimethylethanolamine, N,N-dimethylethanolamine, N,N-dimethylethanolamine, N,N-dimethylethanolamine, N, The amine is selected from N,N,N'-trimethyl-N'-hydroxyethyl bis(aminoethyl)ether, N,N-bis(3-dimethyl-aminopropyl)N-isopropanolamine, (N,N-dimethyl)amino-ethoxyethanol, N,N,N',N'-tetramethylhexanediamine, 1,8-diazabicyclo-5,4,0-undecene-7, N,N-dimorpholinodiethyl ether, N-methylimidazole, dimethylaminopropyl dipropanolamine, bis(dimethylaminopropyl)amino-2-propanol, tetramethylaminobis(propylamine), and (dimethyl(aminoethoxyethyl))((dimethylamine)ethyl)ether.

[0090] In yet another embodiment, the catalyst is selected from trimethylamine, triethylamine, dimethylethanolamine, N-methylmorpholine, N,N-dimethylbenzylamine, N,N-dimethylethanolamine, N,N,N′,N′-tetramethyl-1,4-butanediamine, N,N-dimethylpiperazine, bis(dimethylaminoethyl)ether, bis(2-dimethylaminoethyl)ether, morpholine,4,4′-(oxydi-2,1-ethanediyl)bis, triethylenediamine, pentamethyldiethylenetriamine, dimethylcyclohexylamine, N-acetyl-N,N-dimethylamine, N-coco-morpholine, N,N-dimethylaminomethyl-N-methylethanolamine, N,N,N′-trimethyl-N′-hydroxyethylbis(aminoethyl)ether, N,N-bis(3-dimethyl-aminopropyl)N-isopropanolamine, and (N,N-dimethyl)amino-ethoxyethanol.

[0091] In still yet another embodiment, the catalyst is selected from trimethylamine, triethylamine, dimethylethanolamine, N-methylmorpholine, N,N-dimethylbenzylamine, N,N-dimethylethanolamine, N,N,N′,N′-tetramethylene-1,4-butanediamine, N,N-dimethylpiperazine, bis(dimethylaminoethyl)ether, bis(2-dimethylaminoethyl)ether, morpholine,4,4′-(oxydi-2,l-ethanediyl)bis, triethylenediamine, pentamethyldiethylenetriamine, and dimethylcyclohexylamine.

[0092] In another embodiment, the catalyst is selected from N,N,N′,N′-tetramethyl-1,4-butanediamine, N,N-dimethylpiperazine, bis(dimethylaminoethyl)ether, bis(2-dimethylaminoethyl)ether, morpholine, 4,4′-(oxydi-2,1-ethanediyl)bis, triethylenediamine, pentamethyldiethylenetriamine, and dimethylcyclohexylamine.

[0093] In a further embodiment, the catalyst of embodiment 1 comprises triethylenediamine.

[0094] Suitable amounts of catalyst are well known to those skilled in the art. However, in some embodiments, the catalyst of embodiment 1 is present in an amount of 0.01 wt% to 5.0 wt%, based on the total weight of the isocyanate-reactive components. In other embodiments, it is present from 0.01 wt% to 5.0 wt%, or from 0.01 wt% to 4.5 wt%, or from 0.05 wt% to 4.5 wt%. In still other embodiments, it is present from 0.05 wt% to 4.0 wt%, or from 0.1 wt% to 4.0 wt%, or from 0.1 wt% to 3.5 wt%. In still other embodiments, it is present from 0.3 wt% to 3.5 wt%, or from 0.3 wt% to 3.0 wt%, or from 0.5 wt% to 3.0 wt%. In other embodiments, it is present from 0.5 wt% to 2.5 wt%, or from 0.5 wt% to 2.0 wt%.

[0095] Additives In an embodiment, the isocyanate-reactive component of embodiment 1 further comprises at least one additive.Suitable additives can be selected from water scavengers, blowing agents, cell opening agents, flame retardants, dyes, pigments, IR absorbing materials, stabilizers, plasticizers, antistatic agents, fungistatic agents, bacteriostatic agents, hydrolysis control agents, curing agents, antioxidants, alkylene carbonates, carbonamides and pyrrolidones.The additives used herein are known and used in the polyurethane chemistry field to produce two-component polyurethane adhesives.

[0096] In one embodiment, the at least one additive is present in the isocyanate-reactive component of embodiment 1 in an amount of from 0.1 weight percent to 20.0 weight percent, based on the total weight of the isocyanate-reactive component.

[0097] In another embodiment, at least one additive may also be present in the isocyanate prepolymer component of embodiment 1. Suitable additives include compounds that do not react with the prepolymer component, such as, but not limited to, water scavengers, blowing agents, and flame retardants. If present, the amount of additive is 0.1% to 20.0% by weight, based on the total weight of the isocyanate prepolymer component.

[0098] In an embodiment, the two-component PU foam adhesive of embodiment 1 as described herein is a low-rise PU foam adhesive. The low-rise PU foam adhesive can be used for drawdown or in-situ injection, as well as spray applications. The low-rise PU foam adhesive often behaves as an elastomer, especially in drawdown applications, so a blowing agent (water) is not required. However, in spray applications, a small amount of water may be added as a blowing agent.

[0099] In an embodiment, the two-component PU foam adhesive of embodiment 1 does not contain any blowing agent other than water. In other words, no chemical or physical blowing agent, except for water, is introduced into either the A-side and / or the B-side.

[0100] The two-component PU foam adhesive of embodiment 1 as described herein is universally applicable, i.e., can be applied to a wide variety of substrates, can be obtained through multiple equipment configurations, and has improved toughness and durability with acceptable mechanical properties. In particular, the two-component PU foam adhesive has acceptable tear strength as determined according to ASTM D-624, acceptable tensile strength and elongation at break, both as determined according to ASTM D-638.

[0101] Process for Preparing Two-Component PU Foam Adhesive

[0102] Another aspect of the present invention is embodiment 2, which relates to a process for preparing the two-component PU foam adhesive of embodiment 1 by mixing an isocyanate prepolymer component (A) with an isocyanate-reactive component (B) at an isocyanate index of 70-200.

[0103] In one embodiment, the isocyanate prepolymer component (A) and the isocyanate-reactive component (B) of embodiment 2 are mixed at an index of 70 to 180. In another embodiment, the index is 80 to 180, or 80 to 160. In yet another embodiment, the index is 90 to 160, or 90 to 150, or 100 to 150. In yet another embodiment, the index is 100 to 130, or 105 to 130. The isocyanate index represents the molar ratio of NCO groups to isocyanate-reactive groups. An index of 100 relates to a 1:1 ratio.

[0104] In another embodiment, embodiment 2 comprises: (S1) preparing an isocyanate prepolymer component by mixing at least one first polyether polyol and at least one polymeric isocyanate with an isocyanate content of 15% to 28% by weight; (S2) mixing an isocyanate-reactive component with an isocyanate prepolymer component to obtain a reaction mixture; (S3) spraying or pouring the reaction mixture onto at least one substrate layer and allowing it to harden.

[0105] In another embodiment, the mixing of embodiment 1 can be carried out using a suitable mixing device. Suitable mixing devices for the purpose of the present invention, such as mixing heads, are known to those skilled in the art. In an embodiment, the isocyanate prepolymer component and the isocyanate reactive component are fed into the mixing device as separate streams. The streams are mixed in the mixing device, thus obtaining a reaction mixture. Although it is preferred that each stream enters the mixing device separately, the isocyanate prepolymer component and the isocyanate reactive component can be thoroughly mixed by a suitable mixing means, such as a static mixer or a dynamic mixer. Furthermore, the mixing can be continuous or discontinuous.

[0106] In another embodiment, the mixing of embodiment 2 as described herein can be controlled by any suitable means known to one of skill in the art, such as by simply switching it on and off, or even by process control software equipped with flow meters so that parameters such as mix ratio, temperature and pressure can be controlled.

[0107] Other suitable techniques, such as those described in WO2019 / 089237A1, may also be used to obtain the two-component PU foam adhesive of embodiment 2.

[0108] Suitable mixing temperatures are well known to those skilled in the art. However, in one embodiment, the mixing of embodiment 2 is carried out at a temperature between 30° C. and 120° C. Similarly, curing of the reaction mixture is carried out at room temperature. "Room temperature" refers to a temperature of 25° C.

[0109] In another embodiment, the isocyanate prepolymer component (A) and the isocyanate reactive component (B) are mixed at a mixing ratio (A):(B) of 1.0:4.0 to 4.0:1.0 in embodiment 2. The mixing ratio is determined as the weight ratio between the isocyanate prepolymer component (A) and the isocyanate reactive component (B). In one embodiment, the ratio is 1.0:3.0 to 3.0:1.0. In another embodiment, it is 1.0:3.0.

[0110] In one embodiment, the mixing ratio (A):(B) is 1.0:4.0 to 4.0:1.0 by volume. In another embodiment, the mixing ratio (A):(B) is 1.0:1.0 by volume.

[0111] The two-component PU foam adhesive of embodiment 1 of the present invention or the two-component PU foam adhesive obtained according to embodiment 2 can be obtained through multiple equipment configurations, so that the mixing can be carried out at a pressure ranging from 0.1 MPa to 10 MPa. Therefore, the two-component PU foam adhesive can be easily used for spraying or drawdown applications, and a suitable pressure range can be selected for this purpose.

[0112] Goods Another aspect of the invention is embodiment 3, which relates to an article comprising at least one first and one second substrate layer, wherein the two-component PU foam adhesive of embodiment 1 or the two-component PU foam adhesive obtained according to embodiment 2 is present between the first and second substrate layers of the article and forms an adhesive bond therebetween.

[0113] In an embodiment, the first and second substrate layers are independently selected from wood, ceramic, steel, paper, fabric, nonwoven, concrete, and polymeric materials. The two-component PU foam adhesive can be applied to a wide variety of applications, can be easily obtained using multiple equipment configurations, and the substrate layers can be selected based on the intended application.

[0114] In one embodiment, the first substrate layer of embodiment 3 is the same as the second substrate layer. In another embodiment, the first substrate layer and the second substrate layer of embodiment 3 are different. In another embodiment, the multiple layers of each of the first substrate layer and the second substrate layer can also be joined using a two-component PU foam adhesive as described herein.

[0115] Suitable articles that can be obtained using the two-component PU foam adhesive include, but are not limited to, roof structures, etc. In some embodiments, the roof structure is selected from board-to-board (e.g., oriented strand board (OSB), gypsum, plywood, fiberboard, high density board, board stock, polyisocyanurate (PIR), expanded polystyrene (EPS), extruded polystyrene (XPS) and Neopore), and board-to-fleece modified membrane (e.g., ethylene propylene diene terpolymer (EPDM), thermoplastic olefin (TPO) and polyvinyl chloride (PVC)).

[0116] The article of embodiment 3 can be obtained at the installation site itself by spraying or injecting the two-component PU foam adhesive. For example, the article can be obtained by pouring or spraying the two-component PU foam adhesive onto the substrate layer and allowing it to harden for a sufficient time. When the adhesive hardens, the article obtained is durable and tough, and has the necessary strength to withstand adverse conditions.

[0117] Method for manufacturing an article Another aspect of the invention is embodiment 4, which relates to a method for producing an article as described in embodiment 3, the method comprising: (S1) applying a two-component PU foam adhesive at least partially onto at least one first substrate layer; (S2) applying a second substrate layer onto the at least one first substrate layer and allowing the two-component polyurethane foam adhesive to solidify to obtain an article.

[0118] Suitable techniques for applying the two-component PU foam adhesive onto at least one first substrate layer are well known to those skilled in the art. For example, the two-component PU foam adhesive can be applied onto at least one first substrate layer of embodiment 4 using a roller, a squeegee, a brush, a doctor blade, an air knife, a vibrator, gravity, ultrasonic, a spray nozzle, or multiple dispensing nozzles.

[0119] In one embodiment, the two-component PU foam adhesive of embodiment 4 is at least partially applied onto a first substrate layer. In another embodiment, at least one first substrate layer of embodiment 4 is completely covered by the two-component PU foam adhesive.

[0120] In another embodiment, a second substrate layer is applied over the first substrate layer of embodiment 4 and allowed sufficient time for the two-component PU foam adhesive to set or cure. In one embodiment, the adhesive cures with a set time ranging from 1 minute to 15 minutes at room temperature. "Set time" refers to the time it takes for the adhesive to finally cure and bond the substrates.

[0121] Alternatively, the second substrate layer of embodiment 4 can also be at least partially covered by the two-component PU foam adhesive and then applied onto the first substrate layer to obtain the article.

[0122] The invention is illustrated in more detail by the following embodiments and combinations of embodiments which can be taken from the corresponding dependency references and links. I. A two-component polyurethane foam adhesive comprising: (A) an isocyanate prepolymer component, (A1) at least one first polyether polyol having an average functionality of 1.9 to 3.5 and a hydroxyl number of 10 mg KOH / g to 100 mg KOH / g, and (A2) at least one polymeric isocyanate, an isocyanate prepolymer component, the isocyanate prepolymer having an isocyanate content of 15% to 28% by weight; (B) an isocyanate-reactive component, (B1) 50% to 90% by weight, based on the total weight of the isocyanate-reactive components, of a second polyether polyol having an average functionality of 1.9 to 3.5 and a hydroxyl number of 10 mg KOH / g to 40 mg KOH / g; and (B2) an isocyanate-reactive component comprising 0.5% to 30% by weight, based on the total weight of the isocyanate-reactive components, of a third polyether polyol having an average functionality of 1.9 to 8.0 and a hydroxyl number of 40 mg KOH / g to 1000 mg KOH / g.

[0123] II. The two-component polyurethane foam adhesive of embodiment I, wherein the isocyanate prepolymer has an isocyanate content of 20% to 23% by weight.

[0124] III. The two-component polyurethane foam adhesive of embodiment I or II, wherein the at least one first polyether polyol comprises at least one alkylene oxide-capped polyether polyol.

[0125] IV. The two-component polyurethane foam adhesive of embodiment III, wherein the at least one alkylene oxide-capped polyether polyol has an alkylene oxide content of less than 25.0 wt.%, based on the total weight of the alkylene oxide-capped polyether polyols.

[0126] V. The two-component polyurethane foam adhesive of embodiment III or IV, wherein the alkylene oxide content is 5.0% to 25.0% by weight.

[0127] VI. The two-component polyurethane foam adhesive of any one of embodiments III-V, wherein the alkylene oxide comprises propylene oxide and / or ethylene oxide.

[0128] VII. The two-component polyurethane foam adhesive of any one of embodiments I-VI, wherein the polymeric isocyanate has an isocyanate functionality of 2.5 to 4.0.

[0129] VIII. The two-component polyurethane foam adhesive of any one of embodiments I-VII, wherein the polymeric isocyanate comprises a polymeric methylene diphenyl diisocyanate.

[0130] IX. The two-component polyurethane foam adhesive of any one of embodiments 1-VIII, wherein the second polyether polyol has an average functionality of 2.0 to 3.5 and a hydroxyl number of 20 mg KOH / g to 40 mg KOH / g.

[0131] X. The two-component polyurethane foam adhesive of any one of embodiments I-IX, wherein the second polyether polyol is present in an amount of 60% to 80% by weight, based on the total weight of the isocyanate-reactive components.

[0132] XI. The two-component polyurethane foam adhesive of any one of embodiments I-X, wherein the second polyether polyol comprises an alkylene oxide-capped polyether polyol having an alkylene oxide content of less than 25.0 wt.%, based on the total weight of the alkylene oxide-capped polyether polyol.

[0133] XII. The two-component polyurethane foam adhesive of embodiment XI, wherein the alkylene oxide content is 5.0% to 25.0% by weight.

[0134] XIII. The two-component polyurethane foam adhesive of embodiment XI or XII, wherein the alkylene oxide comprises propylene oxide or ethylene oxide.

[0135] XIV. The two-component polyurethane foam adhesive of any one of embodiments I-XIII, wherein the third polyether polyol has an average functionality of 1.9 to 5.0 and a hydroxyl number of 50 mg KOH / g to 900 mg KOH / g.

[0136] XV. The two-component polyurethane foam adhesive of any one of embodiments I-XIV, wherein the isocyanate-reactive component further comprises at least one selected from a crosslinker, a surfactant, and a catalyst.

[0137] XVI. The two-component polyurethane foam adhesive of embodiment XV, wherein the crosslinker comprises a compound containing at least two isocyanate-reactive groups and having a molecular weight from 30 g / mole to 150 g / mole.

[0138] XVII. The two-component polyurethane foam adhesive of embodiment XV or XVI, wherein the crosslinker comprises a compound containing at least two isocyanate-reactive groups and having a molecular weight from 100 g / mole to 150 g / mole.

[0139] XVIII. The two-component polyurethane foam adhesive of any one of embodiments XV-XVII, wherein the crosslinker is selected from monoethanolamine, diethanolamine, triethanolamine, diethylene glycol, dipropylene glycol, glycerin, trimethylolpropane, and pentaerythritol.

[0140] XIX. The two-component polyurethane foam adhesive of any one of embodiments XV-XVIII, wherein the crosslinker is present in an amount of 0.5% to 10.0% by weight, based on the total weight of the isocyanate-reactive components.

[0141] XX. The two-component polyurethane foam adhesive of any one of embodiments XV-XIX, wherein the crosslinker is present in an amount of 0.5% to 5.0% by weight, based on the total weight of the isocyanate-reactive components.

[0142] XXI. The two-component polyurethane foam adhesive of any one of embodiments XV-XX, wherein the surfactant comprises a polyether polysiloxane and / or a polyether siloxane.

[0143] XXII. The two-component polyurethane foam adhesive of any one of embodiments XV-XXI, wherein the surfactant is present in an amount of 0.1 wt.% to 10.0 wt.%, based on the total weight of the isocyanate-reactive components.

[0144] XXIII. The two-component polyurethane foam adhesive of any one of embodiments XV-XXII, wherein the surfactant is present in an amount of 0.1 wt.% to 5.0 wt.%, based on the total weight of the isocyanate-reactive components.

[0145] XXIV. The two-component polyurethane foam adhesive of any one of embodiments XV-XXIII, wherein the catalyst comprises an amine catalyst.

[0146] XXV. The two-component polyurethane foam adhesive of embodiment XXIV, wherein the amine catalyst is a tertiary amine catalyst.

[0147] XXVI. The catalyst is selected from the group consisting of trimethylamine, triethylamine, dimethylethanolamine, N-methylmorpholine, N,N-dimethylbenzylamine, N,N-dimethylethanolamine, N,N,N′,N′-tetramethyl-1,4-butanediamine, N,N-dimethylpiperazine, bis(dimethylaminoethyl)ether, bis(2-dimethylaminoethyl)ether, morpholine, 4,4′-(oxydi-2,l-ethanediyl)bis, triethylenediamine, pentamethyldiethylenetriamine, dimethylcyclohexylamine, N-acetyl-N,N-dimethylamine, N-coco-morpholine, N,N-dimethylaminomethyl-N-methylethanolamine, N,N,N′-trimethyl-N′-hydroxyethylbis(aminoethyl)ether, N,N-bis(3-dimethyl-aminopropyl)-N-isopropanolamine, (N,N-dimethyl)amino-ethoxyethanol, N, The two-component polyurethane foam adhesive of any one of embodiments XV-XXV, wherein the active ingredient is selected from N,N',N'-tetramethylhexanediamine, 1,8-diazabicyclo-5,4,0-undecene-7, N,N-dimorpholinodiethyl ether, N-methylimidazole, dimethylaminopropyldipropanolamine, bis(dimethylaminopropyl)amino-2-propanol, tetramethylaminobis(propylamine), (dimethyl(aminoethoxyethyl))((dimethylamine)ethyl)ether, tris(dimethylaminopropyl)amine, dicyclohexylmethylamine, bis(N,N-dimethyl-3-aminopropyl)amine, and 1,2-ethylenepiperidine, and methyl-hydroxyethylpiperazine, 1,4-diazabicyclo[2.2.2]octane-2-methanol, and N-(3-dimethylaminopropyl)-N,N-diisopropanolamine.

[0148] XXVII. The two-component polyurethane foam adhesive of any one of embodiments XV-XXVI, wherein the catalyst is present in an amount of 0.01% to 5.0% by weight, based on the total weight of the isocyanate-reactive components.

[0149] XXVIII. The two-component polyurethane foam adhesive of any one of embodiments I-XXVII, wherein the isocyanate-reactive component further comprises at least one additive.

[0150] XXIX. The two-component polyurethane foam adhesive of embodiment XXVIII, wherein the at least one additive is selected from water scavengers, blowing agents, cell openers, flame retardants, dyes, pigments, IR absorbing materials, stabilizers, plasticizers, antistatic agents, fungistatic agents, bacteriostatic agents, hydrolysis control agents, curing agents, antioxidants, alkylene carbonates, carbonamides, and pyrrolidones.

[0151] XXX. The two-component polyurethane foam adhesive of embodiment XXVIII or XXIX, wherein the at least one additive is present in an amount of 0.1 wt.% to 20.0 wt.%, based on the total weight of the isocyanate-reactive components.

[0152] XXXI. A process for preparing a two-component polyurethane foam adhesive according to any one of embodiments I-XXX by mixing an isocyanate prepolymer component (A) with an isocyanate-reactive component (B) at an Isocyanate Index of 70 to 200.

[0153] XXXII. The process of embodiment XXXI, wherein the mixing is carried out at a pressure ranging from 0.1 MPa to 10 MPa.

[0154] XXXIII. An article comprising at least one first substrate layer and one second substrate layer, wherein a two-component polyurethane foam adhesive layer according to any one of embodiments I-XXX or obtained according to embodiment XXXI or XXXII is present between the first substrate layer and the second substrate layer of the article and forms an adhesive bond therebetween.

[0155] XXXIV. The article of embodiment XXXIII, wherein at least one of the first substrate layer and the second substrate layer are independently selected from wood, ceramic, steel, paper, fabric, nonwoven fabric, concrete, and a polymeric material.

[0156] XXXV. The article of embodiment XXXIII or XXXIV, wherein the article is a roof structure.

[0157] XXXVI. A method for producing an article according to any one of embodiments XXXIII-XXXV, the method comprising: (S1) applying a two-component polyurethane foam adhesive at least partially onto at least one first substrate layer; (S2) applying a second substrate layer onto the at least one first substrate layer and allowing the two-component polyurethane foam adhesive to solidify to obtain an article.

[0158] XXXVII. The method of embodiment XXXVII, wherein in step (S2), the two-component polyurethane foam adhesive has a set time of from 1 minute to 15 minutes. EXAMPLES

[0159] The presently claimed invention is illustrated by the following non-limiting examples. [Table 1] [Table 2]

[0160] General synthesis of isocyanate prepolymer components The prepolymer component was obtained using the aforementioned components. The components were mixed in a 7 gallon reactor and heated to 60°C. The isocyanate was added first, followed by the first polyether polyol with stirring, where the temperature was maintained below 80°C. After the first polyether polyol was added, the reactor was set to 80°C for 1 hour and 45 minutes under nitrogen atmosphere. The resulting prepolymer was then cooled to 40°C and poured into a container. A summary of the components used and their amounts (all in weight %) is given in Table 1. [Table 3]

[0161] General synthesis of reaction mixture The aforementioned isocyanate prepolymer component (A) was mixed with the isocyanate-reactive component (B) at an index of 120. The reaction mixture was obtained at a mix ratio of 1.0:3.0 (A:B) by weight. An overview of the components used and their amounts (all in weight %) is given in Table 2. [Table 4]

[0162] Spray application The aforementioned reactive mixtures, specifically IE4 and IE5, were sprayed onto a polyethylene board having dimensions of 16" x 16". Polyethylene was used to ensure easy removal of the adhesive after curing. Spraying was completed using a Graco E-30 proportioner with an attached Fusion spray gun. The machine spray pressure was set at 6.89 MPa with a reactive mixture temperature of 54.4°C.

[0163] Drawdown application IE1, IE2, and IE3 were applied onto a polyethylene sheet using a KTQ-II Adjustable Film Applicator. The isocyanate prepolymer component (A) and the isocyanate-reactive component (B) of the inventive examples were weighed separately and mixed together at high speed, and the mixture was poured onto the polyethylene sheet. Before the mixture was allowed to fully cure, the KTQ-II was used to spread the material across the polyethylene to create a uniform sample.

[0164] Both the spray and drawdown applied adhesives were tested for their mechanical properties and a summary of the test results is shown in Table 3. [Table 5]

[0165] As is evident from the above, the adhesives of the present invention have acceptable properties, especially tensile strength, elongation at break and tear strength, compared to the commercially available non-prepolymer grade (CE1).Furthermore, the adhesives of the present invention have improved toughness, are durable enough for use on a wide variety of substrates, and can be easily obtained through multiple equipment configurations, for example by spraying or pouring.

Claims

1. 1. A two-component polyurethane foam adhesive comprising: (A) an isocyanate prepolymer component, (A1) at least one first polyether polyol having an average functionality of 1.9 to 3.5 and a hydroxyl number of 10 mg KOH / g to 100 mg KOH / g; and (A2) at least one polymeric isocyanate, an isocyanate prepolymer component, the isocyanate prepolymer having an isocyanate content of 15% to 28% by weight; (B) an isocyanate-reactive component, (B1) 50% to 90% by weight, based on the total weight of the isocyanate-reactive components, of a second polyether polyol having an average functionality of 1.9 to 3.5 and a hydroxyl number of 10 mg KOH / g to 40 mg KOH / g; and (B2) an isocyanate-reactive component comprising 0.5% to 30% by weight, based on the total weight of the isocyanate-reactive component, of a third polyether polyol having an average functionality of 1.9 to 8.0 and a hydroxyl number of 40 mg KOH / g to 1000 mg KOH / g.

2. 10. The two-component polyurethane foam adhesive of claim 1 , wherein the at least one first polyether polyol comprises at least one alkylene oxide-capped polyether polyol.

3. 3. The two-component polyurethane foam adhesive of claim 2, wherein the at least one alkylene oxide-capped polyether polyol has an alkylene oxide content of less than 25.0 wt.%, based on the total weight of the at least one alkylene oxide-capped polyether polyol.

4. The two-component polyurethane foam adhesive of any one of claims 1 to 3, wherein the polymeric isocyanate comprises polymeric methylene diphenyl diisocyanate.

5. 5. The two-component polyurethane foam adhesive of any one of claims 1 to 4, wherein the second polyether polyol comprises an alkylene oxide-capped polyether polyol having an alkylene oxide content of less than 25.0 wt%, based on the total weight of the alkylene oxide-capped polyether polyol.

6. The two-component polyurethane foam adhesive of any one of claims 1 to 5, wherein the isocyanate-reactive component further comprises at least one selected from a crosslinker, a surfactant, and a catalyst.

7. The two-component polyurethane foam adhesive of any one of claims 1 to 6, wherein the isocyanate-reactive component further comprises at least one additive.

8. 8. The two-component polyurethane foam adhesive of claim 7, wherein the at least one additive is selected from water scavengers, blowing agents, cell openers, flame retardants, dyes, pigments, IR absorbing materials, stabilizers, plasticizers, antistatic agents, fungistatic agents, bacteriostatic agents, hydrolysis control agents, curing agents, antioxidants, alkylene carbonates, carbonamides, and pyrrolidones.

9. 9. A process for preparing the two-component polyurethane foam adhesive according to any one of claims 1 to 8 by mixing the isocyanate prepolymer component (A) with the isocyanate-reactive component (B) at an Isocyanate Index of 70 to 200.

10. 10. An article comprising at least one first and one second substrate layer, wherein a two-component polyurethane foam adhesive layer according to any one of claims 1 to 8 or obtained according to claim 9 is present between the first and second substrate layers of the article and forms an adhesive bond therebetween.

11. 11. The article of claim 10, wherein at least one of the first substrate layer and the second substrate layer are independently selected from wood, ceramic, steel, paper, fabric, nonwoven fabric, concrete, and polymeric materials.

12. 12. A method for manufacturing an article according to claim 10 or 11, said method comprising: (S1) applying the two-component polyurethane foam adhesive at least partially onto the at least one first substrate layer; (S2) applying the second substrate layer onto the at least one first substrate layer and allowing the two-component polyurethane foam adhesive to solidify to obtain the article.

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