One-component polyurethane adhesive

Abstract

The present invention provides a one-component polyurethane adhesive composition that exhibits excellent mechanical properties, anti-sagging performance, product storage stability, and flame retardancy.

Description

[Technical Field]

[0001] The present invention relates to the field of one-component moisture-curing polyurethane adhesives. [Background technology]

[0002] One-component polyurethane adhesives are widely used in the automotive industry. Commercially available adhesives are designed to provide both strong adhesive performance and good physical properties. With the advent of electric vehicles, such adhesives are playing an increasing role in battery assembly components.

[0003] Flame retardancy is important in automotive applications, especially in battery assemblies where the adhesive is directly exposed to high voltages and currents.

[0004] There is a need for one-component polyurethane adhesives that can provide excellent mechanical properties and flame retardancy. Summary of the Invention [Means for solving the problem]

[0005] In a first aspect, the present invention provides a one-component moisture-curable polyurethane adhesive composition comprising: (A) at least one polyurethane prepolymer; (B) at least one amine catalyst and an optional organometallic catalyst; (C) the flame retardants / synergists aluminum hydroxide, melamine polyphosphate, and aluminum diethylphosphinate; and (D) optional adhesion promoters, fillers; A composition comprising:

[0006] In a second aspect, the present invention provides a method for bonding two substrates, comprising: (1) providing a one-component moisture-curing polyurethane adhesive according to the present invention; (2) applying an adhesive to the first substrate, the second substrate, or both; (3) placing the first substrate and the second substrate in adhesive contact, thereby sandwiching the adhesive therebetween; (4) curing the adhesive; The present invention provides a method comprising:

[0007] In a third aspect, the present invention provides a method for producing a medicament for the treatment of a pulmonary arthritis, comprising: (1) a first substrate; (2) a second substrate; (3) the one-component moisture-curing polyurethane adhesive of the present invention; A bonded assembly comprising: An assembly is provided in which first and second substrates are in adhesive contact with an adhesive sandwiched therebetween. [Brief explanation of the drawings]

[0008] [Figure 1] The method for measuring sagging used in the examples is shown, where 1 is the adhesive bead, 2 is the panel, and 3 is the bench. DETAILED DESCRIPTION OF THE INVENTION

[0009] The inventors have surprisingly found that (A) at least one urethane prepolymer resin; (B) at least one amine catalyst and an optional organometallic catalyst; (C) the flame retardants / synergists aluminum hydroxide, melamine polyphosphate, and aluminum diethylphosphinate; and (D) optional adhesion promoters, fillers; It has been found that compositions containing the compound exhibit excellent flame retardancy (passing the UL94 V0 flammability test), excellent adhesion properties, high electrical resistivity, and anti-sag performance.

[0010] Definitions and Abbreviations ATH: Aluminum hydroxide, Al(OH)3 MDI: 4,4'-methylenebis(phenylisocyanate) HDI: Hexamethylene diisocyanate IPDI: Isophorone diisocyanate MPP: melamine polyphosphate PU: Polyurethane SEC: Size Exclusion Chromatography RH: Relative humidity

[0011] Polymer molecular weights reported herein are reported in Daltons (Da) as number or weight average molecular weights as determined by size exclusion chromatography (SEC).

[0012] Polyurethane prepolymer (A) The composition of the present invention contains a polyurethane prepolymer.

[0013] Polyether prepolymers include polymers made by polymerizing one or more polyether polyols and / or polyester polyols in the presence of a polyisocyanate, preferably a diisocyanate.

[0014] Polyether polyols useful in the present invention include, for example, polyether polyols, poly(alkylene carbonate) polyols, hydroxyl-containing polythioethers, polymer polyols, and mixtures thereof. Polyether polyols are well known in the art and include, for example, polyoxyethylene, polyoxypropylene, polyoxybutylene, and polytetramethylene ether diols and triols, which are prepared by reacting unsubstituted, halogen-substituted, or aromatic-substituted ethylene oxide or propylene oxide with an initiator compound containing two or more active hydrogen groups, such as water, ammonia, a polyhydric alcohol, or an amine. Typically, polyether polyols can be prepared by polymerizing alkylene oxides in the presence of an active hydrogen-containing initiator compound. Preferred polyether polyols contain one or more alkylene oxide units in the polyol backbone. Preferred alkylene oxide units are ethylene oxide, propylene oxide, butylene oxide, and mixtures thereof. Preferably, the polyol contains propylene oxide units, ethylene oxide units, or mixtures thereof. In embodiments in which a mixture of alkylene oxide units is contained in the polyol, the different units can be arranged randomly or in blocks of each alkylene oxide. In a preferred embodiment, the polyol contains propylene oxide chains with ethylene oxide chains capping the polyol. In a preferred embodiment, the polyether polyol is a mixture of polyether diols and polyether triols. Preferably, the polyether polyol or mixture has a functionality of at least about 1.5, more preferably at least about 1.8, and most preferably at least about 2.0; it is preferably about 4.0 or less, more preferably about 3.5 or less, and most preferably about 3.0 or less. Preferably, the equivalent weight of the polyether polyol mixture is at least about 200, more preferably at least about 500, more preferably at least about 1,000; preferably about 5,000 or less, more preferably about 3,000 or less, and most preferably about 2,500 or less.

[0015] Polyester polyols include hydroxyl-terminated polyesters, and particularly preferred are hydroxyl-terminated aliphatic polyesters.

[0016] Polyester prepolymers include polymers prepared by reacting one or more linear copolyesters having primary hydroxyl functionality with a polyisocyanate, preferably a diisocyanate. Copolyesters having molecular weights of 3,000 to 4,000 Da, preferably 3,500 Da, are particularly preferred.

[0017] The diisocyanate that can be used to produce the polyester prepolymer is not particularly limited. Aliphatic and aromatic diisocyanates can be used. Examples of suitable diisocyanates include toluene diisocyanate (TDI), hexamethylene diisocyanate (HDI), naphthalene diisocyanate (NDI), methylene bis-cyclohexyl isocyanate (HMDI) (hydrogenated MDI), and isophorone diisocyanate (IPDI), with MDI being particularly preferred.

[0018] In a preferred embodiment, the polyester prepolymer is made by reacting a 3,500 Da molecular weight copolyester with MDI.

[0019] In a preferred embodiment, the polyester prepolymer is produced by reacting an aliphatic polyester having a molecular weight of 3,500 Da with MDI. In a particularly preferred embodiment, the polyester prepolymer is produced by reacting 65 to 80% by weight of a polyester diol with 5 to 15% by weight of MDI.

[0020] More specific examples of polyether polyols include the following: 1. Difunctional polyols (diols) such as poly(alkylene oxide) diols, in which the alkylene groups are C2-C4, particularly poly(ethylene oxide) diol, poly(propylene oxide) diol, and poly(tetramethylene oxide) diol, with poly(propylene oxide) diol being particularly preferred. In a particularly preferred embodiment, the polyether prepolymer comprises nominally difunctional poly(propylene oxide) (equivalent weight 1000) having a hydroxyl number of 56. 2. Trifunctional polyols (triols), such as those based on alkylene oxides initiated with a trifunctional polyol such as trimethylolpropane, where the alkylene groups are C2-C4, particularly ethylene oxide, propylene oxide, tetramethylene oxide, and butylene oxide, with propylene oxide being particularly preferred. In a particularly preferred embodiment, the polyether prepolymer comprises nominally trifunctional poly(propylene oxide) (equivalent weight 1558) with a hydroxyl number of 36; the polymer may or may not be capped with ethylene oxide to modify reactivity. 3. Mixtures of 1 and 2. Particularly preferred are mixtures of 1 and 2, and even more particularly preferred are mixtures of a) a nominally difunctional poly(propylene oxide) (equivalent weight 1000) having a hydroxyl number of 56 and b) a nominally trifunctional poly(propylene oxide) (equivalent weight 1558) having a hydroxyl number of 36, especially in a weight ratio b) / a) of 1:2 to 2:1.

[0021] The at least one polyurethane prepolymer may comprise a mixture of a polyether polyol-based prepolymer and a polyester-based prepolymer.

[0022] In a particularly preferred embodiment, the polyurethane prepolymer is a mixture of prepolymers based on polyether diols and polyether triols and prepolymers based on polyester diols.

[0023] The diisocyanate that can be used to produce the polyether prepolymer is not particularly limited. Aliphatic and aromatic diisocyanates can be used. Examples of suitable diisocyanates include toluene diisocyanate (TDI), hexamethylene diisocyanate (HDI), naphthalene diisocyanate (NDI), methylene bis-cyclohexyl isocyanate (HMDI) (hydrogenated MDI), and isophorone diisocyanate (IPDI), with MDI being particularly preferred.

[0024] In a particularly preferred embodiment, the polyether prepolymer comprises a nominally difunctional poly(propylene oxide) and a nominally trifunctional poly(propylene oxide) reacted with MDI.

[0025] In a particularly preferred embodiment, the polyether prepolymer comprises a nominally difunctional poly(propylene oxide) (equivalent weight 1000) having a hydroxyl number of 56 and a nominally trifunctional poly(propylene oxide) (equivalent weight 1558) having a hydroxyl number of 36 reacted with MDI.

[0026] The polyether prepolymer is produced by reacting at least one polyether polyol with a polyisocyanate using a catalyst capable of catalyzing the reaction of NCO groups with hydroxyl groups. Examples of such catalysts include tertiary amine catalysts, alkyltin carboxylates, oxides, and mercaptides. Specific examples include triethylenediamine, 1,4-diazabicyclo[2.2.2]octane, dimethylcyclohexylamine, dimethylethanolamine, bis-(2-dimethylaminoethyl)ether, dibutyltin dilaurate, and stannous octoate, with stannous octoate being particularly preferred.

[0027] The polymerization can be carried out in the presence of a plasticizer such as a high boiling ester or diester, for example, dialkyl phthalate, with diisononyl phthalate being particularly preferred.

[0028] An example of a method for making a polyurethane prepolymer included the following steps: 1. Heating at least one polyether polyol to 45-65°C under an inert atmosphere (e.g., nitrogen or argon), optionally in the presence of a plasticizer (e.g., diisononyl phthalate); 2. Add polyisocyanate; 3. Add catalyst; 4. After the reaction, if desired, a second amount of a plasticizer (eg, diisononyl phthalate) and a stabilizer such as a dialkyl malonate (eg, diethyl malonate) can be added.

[0029] In a preferred embodiment, the method for producing a polyurethane prepolymer comprises the steps of: 1. Heating polyether diols and polyether triols to 45-65°C under an inert atmosphere (e.g., nitrogen or argon), optionally in the presence of a plasticizer (e.g., diisononyl phthalate); 2. Add MDI and stir the mixture until uniform; 3. The catalyst stannous octoate is added slowly, preferably dropwise; 4. Keep the mixture at 75-85°C and add diisononyl phthalate along with diethyl malonate.

[0030] In a preferred embodiment, the polyurethane prepolymer comprises 18 to 30 wt. %, more preferably 19 to 25 wt. %, and more particularly preferably 22 to 23 wt. % of polyol diol, based on the total weight of the prepolymer.

[0031] In a preferred embodiment, the polyurethane prepolymer comprises 25 to 40 wt. %, 28 to 35 wt. %, more particularly preferably 32 to 33 wt. % of polyol triol, based on the total weight of the prepolymer.

[0032] In a preferred embodiment, the polyurethane prepolymer comprises 5 to 15 wt. %, more preferably 8 to 12 wt. %, and more particularly preferably 9 to 11 wt. % of diisocyanate, based on the total weight of the prepolymer.

[0033] In a particularly preferred embodiment, the polyurethane prepolymer comprises 22 to 23 weight percent polyol diol, 32 to 33 weight percent polyol triol, and 9 to 11 weight percent diisocyanate, based on the total weight of the prepolymer.

[0034] In a preferred embodiment, the polyurethane prepolymer comprises 18 to 30 wt. %, more preferably 19 to 25 wt. %, and even more particularly preferably 22 to 23 wt. %, based on the total weight of the prepolymer, of nominally difunctional poly(propylene oxide) (equivalent weight 1000) having a hydroxyl number of 56.

[0035] In a preferred embodiment, the polyurethane prepolymer comprises 25 to 40 wt. %, 28 to 35 wt. %, and more particularly preferably 32 to 33 wt. %, based on the total weight of the prepolymer, of nominally trifunctional poly(propylene oxide) having a hydroxyl number of 36 (equivalent weight 1558).

[0036] In a preferred embodiment, the polyurethane prepolymer comprises 5 to 15 wt. %, more preferably 8 to 12 wt. %, and most particularly preferably 9 to 11 wt. % MDI, based on the total weight of the prepolymer.

[0037] In a particularly preferred embodiment, the polyurethane prepolymer comprises 22-23 wt. % of a nominally difunctional poly(propylene oxide) (equivalent weight 1000) having a hydroxyl number of 56, 32-33 wt. % of a nominally trifunctional poly(propylene oxide) (equivalent weight 1558) having a hydroxyl number of 36, and 9-11 wt. % of MDI, based on the total weight of the prepolymer.

[0038] In a preferred embodiment, the polyether prepolymer has an isocyanate content of 1.25% by weight.

[0039] In a preferred embodiment, the polyurethane prepolymer has a viscosity of 16,000 cps at 23° C. as measured according to the procedure set forth in US Pat. No. 5,922,809, column 12, lines 38-49.

[0040] In a particularly preferred embodiment, the polyurethane prepolymer has an isocyanate content of 1.25 wt. % and a viscosity of 16,000 cps at 23° C. as measured according to the procedure set forth in U.S. Pat. No. 5,922,809, column 12, lines 38-49.

[0041] In a particularly preferred embodiment, the polyurethane prepolymer contains 22-23 wt. % of a nominally difunctional poly(propylene oxide) (1000 equivalent weight) having a hydroxyl number of 56, 32-33 wt. % of a nominally trifunctional poly(propylene oxide) (1558 equivalent weight) having a hydroxyl number of 36, and 9-11 wt. % of MDI, based on the total weight of the prepolymer; and has an isocyanate content of 1.25 wt. % and a viscosity of 16,000 cps at 23° C. as measured according to the procedure described in U.S. Pat. No. 5,922,809, column 12, lines 38-49.

[0042] The polyurethane prepolymer is preferably present in the one-component polyurethane adhesive at 20 to 70% by weight, more preferably 30 to 55% by weight, and most preferably 35 to 40% by weight, based on the total weight of the adhesive.

[0043] In a particularly preferred embodiment, the adhesive composition of the present invention comprises 20 to 70 wt. %, more preferably 35 to 40 wt. %, based on the total weight of the adhesive composition, of a polyurethane prepolymer comprising a nominally trifunctional poly(propylene oxide) (equivalent weight 1558) having a hydroxyl number of 36 and a nominally difunctional poly(propylene oxide) (equivalent weight 1000) having a hydroxyl number of 56 reacted with MDI, and having an isocyanate content of 1.25 wt. %.

[0044] If used, the polyester prepolymer is present at 0.5 to 5 weight percent, more preferably 0.75 to 1.5 weight percent, based on the total weight of the adhesive.

[0045] Preferably, the polyether-based prepolymer or prepolymer mixture has a Brookfield viscosity of at least 6,000 centipoise or at least about 8,000 centipoise, and as high as 30,000 centipoise or 20,000 centipoise. If the viscosity is too high, the final adhesive will be difficult to pump. If the viscosity is too low, the final adhesive will be too runny and / or sag.

[0046] The polyether prepolymer has an isocyanate equivalent weight of at least 840, corresponding to an NCO content of 5% by weight. The isocyanate equivalent weight of the prepolymer can be at least 1050 (4% NCO content), at least 1400 (3% NCO content), or at least 1680 (2.5% NCO content), and can be, for example, up to 10,000 (0.42% NCO content), up to 8400 (0.5% NCO content), up to 7000 (0.6% NCO content), or up to 5000 (0.84% ​​NCO content).

[0047] The polyether prepolymer has an average isocyanate functionality of at least about 2.0 and a molecular weight (weight average) of at least about 2,000. Preferably, the average isocyanate functionality of the prepolymer is at least about 2.2, more preferably at least about 2.4. Preferably, the isocyanate functionality is about 3.5 or less, more preferably about 3.0 or less, and most preferably about 2.8 or less. Preferably, the weight average molecular weight of the prepolymer is at least about 1,000, preferably at least about 2,500, more preferably at least about 3,000; preferably about 40,000 or less, even more preferably about 20,000 or less, more preferably about 15,000 or less, and most preferably about 10,000 or less. The prepolymer may be prepared by any suitable method, such as by reacting at least two highly isocyanate-reactive isocyanate-reactive compounds containing active hydrogen-containing groups with a stoichiometric excess of polyisocyanate under reaction conditions sufficient to form the corresponding prepolymer.

[0048] Prepolymer equivalent weight and molecular weight are determined according to the procedures disclosed in US Pat. No. 5,922,809, column 12, lines 50-64, which is incorporated herein by reference.

[0049] Amine and / or organometallic catalyst (B) The one-component polyurethane adhesive of the present invention comprises at least one amine catalyst and, optionally, at least one organometallic catalyst capable of catalyzing the reaction of an isocyanate with moisture.

[0050] The amine catalyst may be any amine catalyst capable of catalyzing the reaction of isocyanate with moisture.Preferably, tertiary amines include aliphatic cyclic and acyclic tertiary amines such as N,N-dimethylcyclohexaneamine, triethylenediamine, N,N,N,N-tetramethylalkylenediamine, N,N,N,N-pentamethyldiethylenetriamine, triethylamine, N,N-dimethylbenzylamine, N,N-dimethylhexadecylamine, N,N-dimethylbutylamine, di(2,6-dimethylmorpholinoethyl)ether, and 2,2'-dimorpholinodiethylether.

[0051] 2,2'-Dimorpholinodiethyl ether is particularly preferred.

[0052] The amine catalyst is preferably used in an amount of 0.05 to 2% by weight, more preferably 0.1 to 1% by weight, based on the total weight of the adhesive.

[0053] In a preferred embodiment, the amine catalyst is 2,2'-dimorpholinodiethyl ether used at 0.1 to 1 weight percent, based on the total weight of the adhesive composition.

[0054] When an organometallic catalyst is used, it can be any organometallic catalyst capable of catalyzing the reaction between an isocyanate and a functional group having at least one reactive hydrogen. Examples include metal carboxylates such as tin carboxylate and zinc carboxylate. Metal alkanoates include tin(II) octoate, bismuth octoate, or bismuth neodecanoate. Preferably, at least one organometallic catalyst is an organotin catalyst. Examples include dibutyltin dilaurate, stannous octoate, dimethyltin dineodecanoate, dimethyltin mercaptide, dimethyltin carboxylate, dimethyltin dioleate, dimethyltin dithioglycolate, dibutyltin mercaptide, dibutyltin bis(2-ethylhexyl thioglycolate), dibutyltin sulfide, dioctyltin dithioglycolate, dioctyltin mercaptide, dioctyltin dioctoate, dioctyltin dineodecanoate, and dioctyltin dilaurate. In a particularly preferred embodiment, this is dioctyltin dineodecanoate. The organometallic catalyst is preferably present in an amount of 0.001 to 2% by weight, more preferably 0.005 to 1% by weight, and especially preferably 0.01 to 0.5% by weight, based on the total weight of the adhesive.

[0055] Flame Retardants / Synergists The one-component polyurethane adhesive of the present invention contains the flame retardant / synergists aluminum hydroxide, melamine polyphosphate, and aluminum diethylphosphinate.

[0056] The aluminum hydroxide preferably has a median particle size of 2.6 microns.

[0057] The aluminum hydroxide is preferably present in an amount of 15 to 30% by weight, more preferably 20 to 28% by weight, and especially preferably 25% by weight, based on the total weight of the adhesive.

[0058] The melamine polyphosphate preferably has an average particle size of less than 20 microns, more preferably 15 microns or less, and most preferably 10 microns or less, as measured in acetone using laser diffraction techniques with a Malvern Mastersizer 2000 particle size analyzer. In a particularly preferred embodiment, the melamine polyphosphate has a D of 3 to 10 microns, more preferably 5 microns. 50 It has.

[0059] The melamine polyphosphate is preferably present at 10 to 20 wt %, more preferably 12 to 15 wt %, and especially preferably 13 wt %, based on the total weight of the adhesive.

[0060] The aluminum diethylphosphinate preferably has a D 50 (% by volume in acetone as measured using laser diffraction techniques with a Malvern Mastersizer 2000 particle size analyzer), and / or D of 10 microns or less 95 It has.

[0061] The aluminum diethylphosphinate is preferably present at 2 to 10 wt %, more preferably 2.5 to 5 wt %, and especially preferably 3.5 or 4.5 wt %, based on the total weight of the adhesive.

[0062] In a preferred embodiment, the adhesive has a D of 40 microns or less. 50 (% by volume in acetone as measured using laser diffraction techniques with a Malvern Mastersizer 2000 particle size analyzer), and / or D of 10 microns or less 95 The aluminum diethylphosphinate having the formula:

[0063] In a preferred embodiment, the adhesive contains 20 to 28 wt % aluminum hydroxide, 12 to 15 wt % melamine polyphosphate, and 2.5 to 5 wt % aluminum diethylphosphinate, based on the total weight of the adhesive.

[0064] In a particularly preferred embodiment, the adhesive comprises 20-28% by weight, based on the total weight of the adhesive, of aluminum hydroxide having a median particle size of 2.6 microns, 12-15% by weight of melamine polyphosphate having an average particle size of less than 20 microns, more preferably 15 microns or less, and more particularly preferably 10 microns or less, as measured in acetone using laser diffraction techniques with a Malvern Mastersizer 2000 particle size analyzer, and a D of 40 microns or less. 50 (% by volume measured using laser diffraction techniques with a Malvern Mastersizer 2000 particle size analyzer in acetone) and / or D of 10 microns or less 95 and 2.5 to 5 wt % of aluminum diethylphosphinate having the formula:

[0065] Optional Component (D) The adhesive composition of the present invention may contain 1 to 20% by weight, more preferably 2 to 10% by weight, of carbon black based on the total weight of the adhesive composition.

[0066] The carbon black is not particularly limited. Preferred carbon black has a molecular weight of at least 80, preferably at least 90, more preferably at least 95 cm3 of dibutyl phthalate per 100 g of carbon black as measured in accordance with ASTM D-2414-09. 3 In addition, the carbon black desirably has an iodine number of at least 80 as measured in accordance with ASTM D1510-11.

[0067] The adhesive composition of the present invention optionally contains 0 to 20 wt %, more preferably 5 to 15 wt %, and particularly preferably 9 to 10 wt %, of calcium carbonate, based on the total weight of the adhesive composition. The calcium carbonate particles may be untreated or may be surface-modified by treatment with a chemical substance such as an organic acid or an organic acid ester.

[0068] The adhesive composition of the present invention may optionally contain 0 to 1.5 wt %, more preferably 0.5 to 1 wt %, of fumed silica, based on the total weight of the adhesive.

[0069] When fumed silica is used, the particles may be untreated or may be surface modified by treatment with chemicals such as chlorosilanes, dichlorosilanes, alkyltrialkoxysilanes, or polydimethylsiloxanes.

[0070] Other optional ingredients The adhesive compositions of the present invention may further include other ingredients such as, for example, one or more plasticizers (such as diisononyl phthalate), one or more stabilizers, such as heat, visible light, and UV stabilizers.

[0071] Examples of heat stabilizers include alkyl-substituted phenols, phosphites, sebacates, and cinnamates. When present, a preferred heat stabilizer is an organic phosphite, more specifically, trisnonylphenyl phosphite, as disclosed in U.S. Patent No. 6,512,033, incorporated herein by reference. The heat stabilizer may comprise at least 0.01 weight percent or at least 0.3 weight percent, up to 5 weight percent, 2 weight percent or less, or 1.0 weight percent or less, based on the total weight of the adhesive composition. The adhesive composition may be free of such heat stabilizers.

[0072] Regarding UV light stabilizers, they include benzophenones and benzotriazoles. Specific UV light absorbers include those manufactured by BASF, such as TINUVIN® P, TINUVIN® 326, TINUVIN® 213, TINUVIN® 327, TINUVIN® 571, and TINUVIN® 328, and those manufactured by Cytec, such as CYASORB® UV-9, CYASORB® UV-24, CYASORB® UV-1164, CYASORB® UV-2337, CYASORB® UV-2908, CYASORB® UV-5337, CYASORB® UV-531, and CYASORB® UV-3638. Among these, TINUVIN® 571 is preferred. The one or more UV light absorbers may comprise at least 0.1 weight percent, at least 0.2 weight percent, or at least 0.3 weight parts, and may comprise no more than 3 weight percent, no more than 2 weight percent, or 1 weight percent of the weight of the adhesive composition.

[0073] The adhesive composition of the present invention may further comprise one or more visible light stabilizers. Preferred visible light stabilizers include hindered amine visible light stabilizers such as TINUVIN™ 144, TINUVIN™ 622, TINUVIN™ 77, TINUVIN™ 123, TINUVIN™ 765, and CHIMASSORB™ 944, all available from Cytec; and CYASORB™ UV-500, CYASORB™ UV-3581, and CYASORB™ UV-3346, all available from Ciba-Geigy. Of these, TINUVIN™ 765 is a preferred choice. The visible light stabilizer may comprise at least 0.1 weight percent, at least 0.2 weight percent, or at least 0.3 weight percent of the adhesive composition, and may comprise no more than 3 weight percent, no more than 2 weight percent, or no more than 1.5 weight percent.

[0074] In a preferred embodiment, the stabilizer comprises trisnonylphenyl phosphite, bis(1,2,2,6,6-pentamethyl-4-piperidyl) sebacate and methyl 1,2,2,6,6-pentamethyl-4-piperidyl sebacate, 2-(2H-benzotriazo-2-yl)-6-dodecyl-4-methyl-phenol, and mixtures thereof, and it is particularly preferred to use mixtures thereof.

[0075] NCO stabilizers, for example malonic acid diesters such as diethyl malonate, may also be added.

[0076] Manufacturing method The adhesive compositions of the present invention are prepared by mixing the ingredients under inert and dry conditions and / or under vacuum until a homogeneous mixture is obtained.

[0077] The resulting adhesive composition can be packaged, for example, in an airtight container, such as an airtight tube, which is stored in a sealed aluminum bag filled with nitrogen.

[0078] How to use In a second aspect, the present invention provides a method for bonding two substrates, comprising: (1) providing a one-component moisture-curing polyurethane adhesive according to the present invention; (2) applying an adhesive to the first substrate, the second substrate, or both; (3) placing the first substrate and the second substrate in adhesive contact, thereby sandwiching the adhesive therebetween; (4) curing the adhesive; The present invention provides a method comprising:

[0079] As previously mentioned, the preferred method of supplying the adhesive of the present invention is in an airtight container, such as an airtight tube, which is opened immediately prior to use.

[0080] The adhesive of the present invention can be applied by any application method, including, for example, application in the form of a bead using a pressurized flow gun through a nozzle, which can be applied by hand or robotically.

[0081] In a preferred embodiment, one or both of the first and second substrates is a metal, in particular coated or uncoated steel or aluminum, and in a particularly preferred embodiment, both substrates are electrically coated steel.

[0082] Curing is accomplished by exposing the adhesive to atmospheric moisture. Curing can occur at room temperature or at elevated temperatures, such as above 50° C. or above 70° C. Typical curing conditions include 23° C. and 50% RH for 3 to 7 days and 80° C. for 7 to 14 days.

[0083] Effect of the invention The adhesives of the present invention exhibit excellent adhesive properties, and using the Quick Knife Adhesion Test described in the Examples, the adhesives of the present invention exhibit a failure mode of preferably greater than 90% cohesive failure, more preferably greater than 95% cohesive failure, and even more particularly preferably 100% cohesive failure after curing for 7 days at 23°C and 50% RH.

[0084] Using the lap shear strength test described in the examples, the adhesives of the present invention preferably exhibit a lap shear strength of 360 psi or greater, more preferably 370 psi or greater, after curing for 7 days at 23° C. and 50% RH. Using the same test, the adhesives of the present invention also preferably exhibit a failure mode of greater than 90% cohesive failure, more preferably greater than 95% cohesive failure, and most particularly preferably 100% cohesive failure, after curing for 7 days at 50% RH.

[0085] Using the lap shear strength test described in the examples, the adhesives of the present invention preferably exhibit a lap shear strength of 400 psi or greater, more preferably 410 psi or greater, after curing for 7 days at 23° C. and 50% RH plus 14 days at 80° C. Using the same test, the adhesives of the present invention preferably exhibit a failure mode of greater than 90% cohesive failure, more preferably greater than 95% cohesive failure, and more especially preferably 100% cohesive failure, after curing for 7 days at 23° C. and 50% RH plus 14 days at 80° C.

[0086] The adhesives of the present invention exhibit excellent flame retardancy. Using the vertical flame test described in the examples, the adhesives of the present invention (after curing for 7 days at 23°C and 50% RH) preferably exhibit a fire extinguishing time after the first 10 seconds of burning of less than 2 seconds, more preferably less than 1 second, and especially preferably 0 seconds. The adhesives of the present invention preferably exhibit a fire extinguishing time after the second 10 seconds of burning of less than 6 seconds, more preferably 4 seconds or less.

[0087] The adhesives of the present invention preferably exhibit a UL94 rating of V0 (after curing for 7 days at 23° C. and 50% RH).

[0088] The uncured adhesives of the present invention also exhibit reduced sagging. Using the sagging test described in the Examples, the adhesives of the present invention preferably exhibit a sagging of less than 2 mm, more preferably less than 1 mm, and most preferably 0 mm when tested immediately after adhesive preparation. The adhesives of the present invention preferably exhibit a sagging of less than 3 mm, more preferably 2 mm or less, when tested after heat aging at 54°C for 3 days in the absence of moisture. This demonstrates that the adhesives of the present invention are relatively storage stable, even at high temperatures, when stored in the absence of moisture.

[0089] The adhesives of the present invention exhibit high electrical resistivity. Using the resistivity test described in the Examples, the adhesives of the present invention preferably exhibit a resistivity of 10 6 It exhibits a resistivity of greater than Ω (after curing for 7 days at 23°C and 50% RH).

[0090] use The adhesive composition of the present invention is particularly suitable for bonding substrates in environments where flame retardant performance is required, such as the area near the fuel tank of an internal combustion engine vehicle, and for bonding and sealing in battery assemblies, particularly the area around the battery box where flame retardancy is required.

[0091] Particularly preferred embodiments The following are particularly preferred embodiments of the adhesive composition of the present invention. 1. (A) at least one polyurethane prepolymer; (B) at least one amine catalyst and an optional organometallic catalyst; (C) the flame retardants / synergists aluminum hydroxide, melamine polyphosphate, and aluminum diethylphosphinate; and (D) optional adhesion promoters, fillers; One-component moisture-curing polyurethane adhesives, including: 2. The adhesive of embodiment 1, wherein the at least one polyurethane prepolymer is prepared by polymerizing one or more polyether polyols and / or polyester polyols in the presence of a polyisocyanate. 3. The adhesive of embodiment 2, wherein the at least one polyether polyol is a poly(C2-C6-alkylene oxide) diol. 4. The adhesive of embodiment 2 or 3, wherein the at least one polyether polyol is a poly(C2-C4-alkylene oxide) diol. 5. The adhesive of embodiment 2, 3, or 4, wherein the at least one polyether polyol is selected from poly(propylene oxide) diols, poly(propylene oxide) triols, and mixtures thereof. 6. The adhesive of any one of embodiments 1 to 5, wherein the at least one polyurethane prepolymer is a mixture of a polyether polyol-based prepolymer and a polyester polyol-based prepolymer. 7. The adhesive of any one of embodiments 1-6, wherein the at least one polyurethane prepolymer is made by reacting a poly(propylene oxide) diol, a poly(propylene oxide) triol, and a diisocyanate. 8. The adhesive of any one of embodiments 1-7, wherein the at least one polyurethane prepolymer is a mixture of a prepolymer made by reacting a poly(propylene oxide) diol, a poly(propylene oxide) triol, and a diisocyanate, and a prepolymer made by reacting an aliphatic polyester diol with a diisocyanate. 9. The adhesive of embodiment 7 or 8, wherein the diisocyanate is selected from IPDI, MDI, and mixtures thereof. 10. The adhesive of any one of embodiments 1-9, wherein the polyurethane prepolymer is present in an amount of 20-70 wt. %, more preferably 35-40 wt. % polyurethane prepolymer, based on the total weight of the adhesive composition. 11. The adhesive of any one of embodiments 1 to 10, comprising 20 to 70 wt. %, more preferably 35 to 40 wt. %, based on the total weight of the adhesive composition, of a polyurethane prepolymer comprising a nominally trifunctional poly(propylene oxide) (equivalent weight 1558) having a hydroxyl number of 36 and a nominally difunctional poly(propylene oxide) (equivalent weight 1000) having a hydroxyl number of 56, reacted with MDI, and having an isocyanate content of 1.25 wt. %. 12. The adhesive of any one of embodiments 1 to 11, wherein the at least one polyurethane prepolymer comprises 0.5 to 5 wt. %, more preferably 0.75 to 2.0 wt. %, based on the total weight of the adhesive, of a prepolymer made by reacting an aliphatic polyester diol with a diisocyanate. 13. The adhesive of any one of embodiments 1 to 12, wherein the amine catalyst is selected from aliphatic cyclic and acyclic tertiary amines. 14. The adhesive of any one of embodiments 1-13, wherein the amine catalyst is selected from N,N-dimethylcyclohexanamine, triethylenediamine, N,N,N,N-tetramethylalkylenediamine, N,N,N,N-pentamethyldiethylenetriamine, triethylamine, N,N-dimethylbenzylamine, N,N-dimethylhexadecylamine, N,N-dimethylbutylamine, di(2,6-dimethylmorpholinoethyl)ether, and 2,2'-dimorpholinodiethyl ether. 15. The adhesive of any one of embodiments 1-14, wherein the amine catalyst is 2,2'-dimorpholinodiethyl ether. 16. The adhesive of any one of embodiments 1 to 15, wherein the amine catalyst is used at 0.1 to 1 wt. %, based on the total weight of the adhesive composition. 17. The adhesive of any one of embodiments 1-16, wherein the aluminum hydroxide has a median particle size of 2.6 microns. 18. Melamine polyphosphate has a D of 20 microns in acetone as measured using laser diffraction techniques with a Malvern Mastersizer 2000 particle size analyzer. 50 , preferably 15 microns D 50 , more preferably 5 microns D 50 18. The adhesive of any one of embodiments 1 to 17, wherein 19. Aluminum diethylphosphinate is preferably 40 microns or less D 50 , and / or D less than 10 microns 95 19. The adhesive of any one of the preceding embodiments, having (volume % in acetone as measured using laser diffraction techniques with a Malvern Mastersizer 2000 particle size analyzer). 20. The adhesive of any one of embodiments 1-19, wherein the aluminum hydroxide is present in 15-30 wt. %, based on the total weight of the adhesive. 21. The adhesive of any one of embodiments 1-20, wherein the aluminum hydroxide is present in 20-28 wt. %, based on the total weight of the adhesive. 22. The adhesive of any one of embodiments 1-21, wherein the aluminum hydroxide is present at 25 wt. %, based on the total weight of the adhesive. 23. The adhesive of any one of embodiments 1-22, wherein the melamine polyphosphate is present in 10-20 wt. %, based on the total weight of the adhesive. 24. The adhesive of any one of embodiments 1-23, wherein the melamine polyphosphate is present in 12-15 wt. %, based on the total weight of the adhesive. 25. The adhesive of any one of embodiments 1-24, wherein the melamine polyphosphate is present at 13 wt.%, based on the total weight of the adhesive. 26. The adhesive of any one of embodiments 1-25, wherein the aluminum diethylphosphinate is present in 2-10 wt. %, based on the total weight of the adhesive. 27. The adhesive of any one of embodiments 1-26, wherein the aluminum diethylphosphinate is present in 2.5 to 5 wt. %, based on the total weight of the adhesive. 28. The adhesive of any one of embodiments 1-27, wherein the aluminum diethylphosphinate is present at 3.5 wt % or 4.5 wt %, based on the total weight of the adhesive. 29. The adhesive of any one of embodiments 1-28, further comprising carbon black. 30. The adhesive of any one of embodiments 1 to 29, further comprising 1 to 20 wt. %, more preferably 2 to 10 wt. %, of carbon black, based on the total weight of the adhesive composition. 31. The adhesive of any one of embodiments 1-30, further comprising calcium carbonate. 32. The adhesive of any one of embodiments 1-31, further comprising fumed silica. 33. The adhesive of any one of embodiments 1-32, further comprising fumed silica that has been surface-treated with a chlorosilane, a dichlorosilane, an alkyltrialkoxysilane, or a polydimethylsiloxane. 34. The adhesive of any one of embodiments 1-33, which exhibits a failure mode in the Quick Knife Adhesion Test (described herein) after curing for 7 days at 23°C and 50% RH of greater than 90% cohesive failure (CF), more preferably greater than 95% cohesive failure, and even more particularly preferably 100% cohesive failure. 35. The adhesive of any one of embodiments 1-34, which exhibits a lap shear strength of 360 psi or greater, more preferably 370 psi or greater, after curing for 7 days at 23°C and 50% RH in a Lap Shear Test (described herein). 36. The adhesive of any one of embodiments 1-35, which exhibits a failure mode in a lap shear test (described herein) after curing at 23°C and 50% RH for 7 days of greater than 90% cohesive failure, more preferably greater than 95% cohesive failure, and even more particularly preferably 100% cohesive failure. 37. The adhesive of any one of embodiments 1-36, which, after curing for 7 days at 23°C and 50% RH, exhibits an extinguishment time after the first 10 seconds of burning of less than 2 seconds, more preferably less than 1 second, and especially preferably 0 seconds, when using the Vertical Burn Test described herein. 38. The adhesive of any one of embodiments 1-37, which, after curing for 7 days at 23°C and 50% RH, exhibits an extinction time after a second 10-second burn of less than 6 seconds, more preferably 4 seconds or less, when using the Vertical Burn Test described herein. 39. The adhesive of any one of embodiments 1-38, which, when tested immediately after manufacture using the sag test described herein, exhibits a sag of less than 2 mm, more preferably less than 1 mm, and more particularly preferably 0 mm. 40. The adhesive of any one of embodiments 1-39, exhibiting a sag of less than 3 mm, more preferably 2 mm or less, when tested after heat aging at 54°C in dry conditions for 3 days using the sag test described herein. 41. Using the resistivity test described herein, after 7 days of curing at 23°C and 50% RH, 10 6 41. The adhesive of any one of embodiments 1 to 40, exhibiting a resistivity greater than Ω. 42. The adhesive of any one of embodiments 1-41, exhibiting a UL94 rating of V0 (after curing for 7 days at 23° C. and 50% RH). 43. A method for bonding two substrates, comprising: (1) supplying the one-component moisture-curing polyurethane adhesive according to any one of embodiments 1 to 42; (2) applying an adhesive to the first substrate, the second substrate, or both; (3) placing the first substrate and the second substrate in adhesive contact, thereby sandwiching the adhesive therebetween; (4) curing the adhesive; A method comprising: 44. The method of embodiment 43, wherein the first and second substrates are independently selected from metals. 45. The method of embodiment 43, wherein the first and second substrates are independently selected from coated steel and aluminum. 46. ​​The method of embodiment 43, 44, or 45, wherein curing is carried out at room temperature. [Example]

[0092] [Table 1]

[0093] Preparation of prepolymer Prepolymer 1 and Prepolymer 2 were prepared using the ingredients listed in Table 2.

[0094] [Table 2]

[0095] Prepolymer 1 1. The diol, triol, and diisononyl phthalate (1st batch) were placed in a dry reaction flask, mixed, and heated to 54°C under nitrogen. 2. When the temperature reached 54°C, the MDI was added. 3. Stannous octoate was added dropwise over 2 minutes. 4. The temperature was increased and held at 80°C for 30 minutes. 5. The temperature was reduced to 60° C. Diisononyl phthalate (second portion) and diethyl malonate were added and the mixture was stirred for 30 minutes. A sample of NCO was obtained. 6. The prepolymer was packaged under nitrogen.

[0096] Prepolymer 2 1. Diisononyl phthalate was placed in a dry reaction flask and heated to 50°C under N2. 2. When the temperature reached 50°C, MDI was added. 3. Molten polyester diol (Dynacol 17381) was slowly added to the above mixture. 4. The mixture was reacted in nitrogen at a temperature of 80-90°C for 40 minutes. 5. The prepolymer was stored in a dry glass container (airtight).

[0097] Preparation of adhesive composition The ingredients listed in Table 3 were mixed in a moisture-free atmosphere (vacuum) until homogeneous, packaged in an airtight tube, and stored in a sealed aluminum bag under nitrogen.

[0098] Examples of the present invention are designated "E1" and "E2", and comparative examples are designated "CE1" and "CE2".

[0099] Test Method Quick Knife Adhesion Test (QKA) The quick knife adhesion test (QKA) was performed by dispensing a 6 mm (width) x 6 mm (height) x 100 mm (length) bead onto a test substrate. The quick knife test was performed after a specified period of initial curing of the bead at 23°C and 50% RH (relative humidity) and after any additional environmental exposure. During testing, a slit (20-40 mm) was cut between the substrate and the end of the adhesive bead. The cured adhesive bead was then cut with a razor blade at a 60° angle back to the test substrate, while the end of the bead was pulled back at a >90° angle. Notches were cut approximately every 3-5 mm on the substrate. The degree of adhesion was evaluated as adhesive failure (AF), film failure (TF), and / or cohesive failure (CF). In AF, the cured bead can separate from the test substrate surface, while in CF, separation occurs within the adhesive bead as a result of cutting and pulling. TF is a special case of CF in which a thin film of cured adhesive remains on the substrate after cutting and testing.

[0100] The results for Examples 1 and 2 are set forth in Table 4.

[0101] Press Flow Viscosity The press flow viscosity for an adhesive sample was determined by recording the time (in seconds) for 20 g of the adhesive composition to pass through a 4.0 mm orifice under an applied pressure of 552 kPa at 23°C, unless otherwise specified.

[0102] The results are shown in Table 5.

[0103] Dripping Sag performance was evaluated by the following method: A metal panel 10 cm high and 30 cm long was placed perpendicular to its length. The adhesive composition, either freshly prepared or after 3 days of heat aging at 54°C in a nitrogen-filled aluminum bag, was dispensed along the top edge of the panel as a right-angled triangular bead 1.8 cm high and 0.6 cm long [as shown in Figure 1, (1) is the adhesive bead, (2) is the panel, and (3) is the bench]. After 30 minutes, the amount of drip or sag from the original position of the tip of the adhesive bead was measured in millimeters. If there was no sag from the tip of the bead, the sag test result was reported as zero millimeters.

[0104] The results are shown in Table 5.

[0105] Lap shear test Lap shear tests were performed according to the SAE J1529 test procedure described below. A triangular bead of adhesive composition, approximately 7 mm base and 9 mm height, was applied along the width of a 25 mm x 100 mm standard specimen and approximately 6 mm from the specimen edge. A second substrate, which may be a coated metal specimen, was immediately pressed onto the adhesive bead, resulting in a final height of 6 mm for the intermediate composition. Samples were cured for 7 days at 23°C and 50 percent relative humidity (RH) unless otherwise noted. The samples were then pulled at a rate of 50 mm / min using an Instron Tester, either immediately or after further environmental exposure. Sample area (in 2 The sample failure load (in pounds) divided by the test load (in pounds) gives the lap shear bond strength (in psi). Adhesion is rated as adhesive failure (AF), film failure (TF), and / or cohesive failure (CF). With AF, the cured bead can separate from the test substrate surface, while with CF, the separation occurs within the sealant adhesive, and TF is a special case of CF where there is a thin film of cured adhesive left on the substrate after testing.

[0106] The results are shown in Table 6.

[0107] Tensile and elongation properties Adhesive samples were dispensed between two sheets of release paper and then pressed to form 3 mm thick round patties. These round patties were cured for 7 days at 23°C and 50% relative humidity (RH). Test specimens were cut from these cured sample patties and tested for tensile strength, elongation, and Young's modulus (1-10% strain) using an Instron Tester, all according to ASTM D412 (Die C).

[0108] The results are shown in Table 7.

[0109] [Table 3]

[0110] electrical resistivity Two copper strips (50 mm long, 12 mm wide) were placed parallel to each other, 50 mm apart, on a non-conductive surface such as cardboard. A triangular adhesive bead (6 mm base, 12 mm height) was dispensed perpendicular to the two copper strips and through the center of the strips. The bead was allowed to cure for 3 days (or the specified time) at 23°C and 50% relative humidity. The resistivity of the bead was determined using an electrical multimeter by contacting its two probes to the two copper strips.

[0111] The results are shown in Table 8.

[0112] Vertical combustion test method The adhesive sample was dispensed between two sheets of release paper and then pressed to form a 4 mm (as specified) thick round patty. The patty was cured for 7 days at 23°C and 50% relative humidity (RH). Three test specimens, 13 mm wide and 125 mm long, were cut from the cured round patty. For the vertical burn test, the first test specimen was positioned vertically and its top edge was secured with a clip. A propane torch was ignited and the flame adjusted to a height of approximately 25 mm. The torch flame was set vertically and overlapped approximately 12 mm below the bottom edge of the test specimen. After 10 seconds of burning, the flame was quickly removed and a timer was started to count the time until the flame disappeared from the test specimen (defined as the extinction time after the first burn). The same test specimen was burned a second time for 10 seconds in the same manner, and the time until the flame disappeared was again recorded (the extinction time after the second burn). A total of three test specimens were tested from each adhesive sample. The overall short extinguishing times for both the first and second burns indicate the excellent flame retardancy of the test samples.

[0113] The results are shown in Table 9.

[0114] UL94 V0 Flammability Test The adhesive sample was dispensed between two sheets of release paper and then pressed to form a 4 mm thick (or as specified) round patty. The patties were cured for 7 days at 23°C and 50% relative humidity (RH). Ten test specimens, 13 mm wide and 125 mm long, were cut from the cured round patties. The first set of five test specimens was tested according to the conditions of UL94 V0. The second set of five test specimens was further conditioned at 70°C for 168 hours and then tested according to the conditions of UL94 V0. If the test results of both sets of specimens met the UL94 V0 criteria, the adhesive sample was rated as passing the requirements of UL94 V0.

[0115] The results are shown in Table 10.

[0116] [Table 4]

[0117] [Table 5]

[0118] [Table 6]

[0119] [Table 7]

[0120] [Table 8]

[0121] [Table 9]

[0122] [Table 10]

[0123] Discussion of results Quick Knife Adhesive (QKA), Table 4. Both Examples 1 and 2 exhibit 100% cohesive failure under the test conditions, indicating that the presence of the flame retardant / synergist does not adversely affect adhesive strength.

[0124] Press flow viscosity and sag, Table 5. Both Examples 1 and 2 exhibit acceptable viscosities immediately after preparation, making them suitable for application by many methods, such as a pressurized dispenser through a nozzle.

[0125] Viscosity increases after heat aging suggest a decrease and / or increase in molecular weight. Examples 1 and 2 both show acceptable viscosity increases after 3 days of storage at 54°C in an airtight container. Comparative Example 2 shows an unacceptable increase in viscosity of more than two-fold after heat aging.

[0126] When applying an adhesive bead to a substrate, ideally the adhesive bead should not move much and should stay in place before curing. Sag indicates the degree of movement that occurs after application. Comparative Examples 1 and 2 both exhibit significant sag immediately after preparation, while the inventive examples do not. Comparative Example 1 exhibited 7 mm of sag from testing the heat-aged material, while Comparative Example 2 was tested for sag after the first heat aging and was very poor, with the sagging bead completely disintegrating. In contrast, Examples 1 and 2 exhibited only 2 mm of sag after heat aging.

[0127] Lap shear strength, Table 6. Inventive Examples 1 and 2 exhibit excellent lap shear strength on steel specimens. Additionally, both samples exhibit 100% cohesive failure under both test conditions.

[0128] Tensile strength, elongation at break, and Young's modulus, Table 7. Inventive Examples 1 and 2 exhibit acceptable tensile strength, elongation at break, and Young's modulus.

[0129] Electrical resistivity, Table 8. Examples 1 and 2 are both 10 6 It exhibits a resistivity of over ohms, making it suitable for applications requiring electrical insulation in addition to excellent adhesion.

[0130] Vertical Burn Test, Table 9. Examples 1 and 2 of the present invention exhibited excellent flame retardancy, with both the first and second fires having an extinguishing time of less than 10 seconds. In contrast, the comparative example exhibited a relatively long extinguishing time after both the first and second fires.

[0131] UL94 Flammability Test Rating, Table 10. Inventive Examples 1 and 2 both have a UL94 rating of V0, the lowest flammability rating. The present specification includes the following aspects. Section 1: (A) at least one polyurethane prepolymer; (B) at least one amine catalyst and an optional organometallic catalyst; (C) the flame retardants / synergists aluminum hydroxide, melamine polyphosphate, and aluminum diethylphosphinate; and (D) optional adhesion promoters, fillers; One-component moisture-curing polyurethane adhesives, including: Section 2: Item 1. The adhesive according to item 1, wherein the at least one polyurethane prepolymer is produced by polymerizing one or more polyether polyols and / or polyester polyols in the presence of a polyisocyanate. Section 3: Item 3. The adhesive according to Item 2, wherein the at least one polyether polyol is a poly(C2-C6-alkylene oxide) diol. Section 4: Item 4. The adhesive according to Item 2 or 3, wherein the at least one polyether polyol is a poly(C2-C4-alkylene oxide) diol. Section 5: Item 5. The adhesive according to item 2, 3, or 4, wherein the at least one polyether polyol is selected from poly(propylene oxide) diols, poly(propylene oxide) triols, and mixtures thereof. Item 6: Item 6. The adhesive according to any one of items 1 to 5, wherein the at least one polyurethane prepolymer is a mixture of a polyether polyol-based prepolymer and a polyester polyol-based prepolymer. Section 7: Item 7. The adhesive according to any one of items 1 to 6, wherein the at least one polyurethane prepolymer is produced by reacting a poly(propylene oxide) diol, a poly(propylene oxide) triol, and a diisocyanate. Section 8: Item 8. The adhesive according to any one of items 1 to 7, wherein the at least one polyurethane prepolymer is a mixture of a prepolymer produced by reacting a poly(propylene oxide) diol, a poly(propylene oxide) triol, and a diisocyanate, and a prepolymer produced by reacting an aliphatic polyester diol with a diisocyanate. Section 9: Item 9. The adhesive according to item 7 or 8, wherein the diisocyanate is selected from IPDI, MDI, and mixtures thereof. Section 10: Item 10. The adhesive according to any one of items 1 to 9, wherein the polyurethane prepolymer is present in an amount of 20 to 70 wt %, more preferably 35 to 40 wt %, of polyurethane prepolymer based on the total weight of the adhesive composition. Section 11: 11. The adhesive of any one of items 1 to 10, comprising 20 to 70 wt. %, more preferably 35 to 40 wt. %, based on the total weight of the adhesive composition, of a polyurethane prepolymer comprising a nominally trifunctional poly(propylene oxide) (equivalent weight 1558) having a hydroxyl number of 36 and a nominally difunctional poly(propylene oxide) (equivalent weight 1000) having a hydroxyl number of 56, reacted with MDI, and having an isocyanate content of 1.25 wt. %. Section 12: Item 12. The adhesive according to any one of items 1 to 11, wherein the at least one polyurethane prepolymer comprises a prepolymer produced by reacting an aliphatic polyester diol with a diisocyanate in an amount of 0.5 to 5 wt %, more preferably 0.75 to 2.0 wt %, based on the total weight of the adhesive. Section 13: Item 13. The adhesive according to any one of items 1 to 12, wherein the amine catalyst is selected from aliphatic cyclic and acyclic tertiary amines. Section 14: Item 14. The adhesive according to any one of items 1 to 13, wherein the amine catalyst is selected from N,N-dimethylcyclohexaneamine, triethylenediamine, N,N,N,N-tetramethylalkylenediamine, N,N,N,N-pentamethyldiethylenetriamine, triethylamine, N,N-dimethylbenzylamine, N,N-dimethylhexadecylamine, N,N-dimethylbutylamine, di(2,6-dimethylmorpholinoethyl)ether, and 2,2'-dimorpholinodiethyl ether. Section 15: Item 15. The adhesive according to any one of items 1 to 14, wherein the amine catalyst is 2,2'-dimorpholinodiethyl ether. Section 16: Item 16. The adhesive according to any one of items 1 to 15, wherein the amine catalyst is used in an amount of 0.1 to 1 wt % based on the total weight of the adhesive composition. Section 17: Item 17. The adhesive according to any one of items 1 to 16, wherein the aluminum hydroxide has a median particle size of 2.6 microns. Section 18: The melamine polyphosphate has a D of 20 microns in acetone as measured using laser diffraction techniques with a Malvern Mastersizer 2000 particle size analyzer. 50 , preferably 15 microns D 50 , more preferably 5 microns D 50 Item 18. The adhesive according to any one of items 1 to 17, comprising: Section 19: The aluminum diethylphosphinate preferably has a D 50 , and / or D less than 10 microns 95 Item 19. The adhesive according to any one of items 1 to 18, having a volume percent (measured in acetone using laser diffraction techniques with a Malvern Mastersizer 2000 particle size analyzer). Section 20: Item 20. The adhesive according to any one of items 1 to 19, wherein the aluminum hydroxide is present in an amount of 15 to 30 wt % based on the total weight of the adhesive. Section 21: Item 21. The adhesive according to any one of items 1 to 20, wherein the aluminum hydroxide is present in an amount of 20 to 28 wt % based on the total weight of the adhesive. Section 22: Item 22. The adhesive according to any one of items 1 to 21, wherein the aluminum hydroxide is present in an amount of 25 wt % based on the total weight of the adhesive. Section 23: Item 23. The adhesive according to any one of items 1 to 22, wherein the melamine polyphosphate is present in an amount of 10 to 20 wt % based on the total weight of the adhesive. Section 24: Item 24. The adhesive according to any one of items 1 to 23, wherein the melamine polyphosphate is present in an amount of 12 to 15 wt % based on the total weight of the adhesive. Section 25: Item 25. The adhesive of any one of items 1 to 24, wherein the melamine polyphosphate is present at 13 wt % based on the total weight of the adhesive. Section 26: Item 26. The adhesive according to any one of items 1 to 25, wherein the aluminum diethylphosphinate is present in an amount of 2 to 10 wt % based on the total weight of the adhesive. Section 27: Item 27. The adhesive according to any one of items 1 to 26, wherein the aluminum diethylphosphinate is present in an amount of 2.5 to 5 wt % based on the total weight of the adhesive. Section 28: Item 28. The adhesive of any one of items 1 to 27, wherein the aluminum diethylphosphinate is present at 3.5 wt % or 4.5 wt % based on the total weight of the adhesive. Section 29: Item 29. The adhesive according to any one of items 1 to 28, further comprising carbon black. Section 30: Item 30. The adhesive according to any one of items 1 to 29, further comprising 1 to 20 wt %, more preferably 2 to 10 wt %, of carbon black based on the total weight of the adhesive composition. Section 31: Item 31. The adhesive according to any one of items 1 to 30, further comprising calcium carbonate. Section 32: Item 32. The adhesive according to any one of items 1 to 31, further comprising fumed silica. Section 33: Item 33. The adhesive according to any one of items 1 to 32, further comprising fumed silica surface-treated with chlorosilane, dichlorosilane, alkyltrialkoxysilane, or polydimethylsiloxane. Section 34: 34. The adhesive of any one of items 1 to 33, wherein the adhesive exhibits a failure mode in the Quick Knife Adhesion Test (described herein) after curing at 23° C. and 50% RH for 7 days that is greater than 90% cohesive failure (CF), more preferably greater than 95% cohesive failure, and more particularly preferably 100% cohesive failure. Section 35: Item 35. The adhesive according to any one of items 1 to 34, wherein the adhesive exhibits a lap shear strength of 360 psi or more, more preferably 370 psi or more, after curing for 7 days at 23°C and 50% RH in a lap shear test (described herein). Section 36: 36. The adhesive of any one of items 1 to 35, wherein the adhesive exhibits a failure mode in a lap shear test (described herein) after curing at 23°C and 50% RH for 7 days that is greater than 90% cohesive failure, more preferably greater than 95% cohesive failure, and even more particularly preferably 100% cohesive failure. Section 37: 37. The adhesive of any one of items 1 to 36, wherein after curing for 7 days at 23°C and 50% RH, the adhesive exhibits a fire extinguishing time after the first 10 seconds of burning of less than 2 seconds, more preferably less than 1 second, and particularly preferably 0 seconds, when using the Vertical Burn Test described herein. Section 38: 38. The adhesive of any one of items 1 to 37, wherein the adhesive exhibits a fire extinguishment time after a second 10-second burn of less than 6 seconds, more preferably 4 seconds or less, after curing for 7 days at 23°C and 50% RH, when using the Vertical Burn Test described herein. Section 39: Item 39. The adhesive of any one of items 1 to 38, which, when tested immediately after manufacture using the sag test described herein, exhibits a sag of less than 2 mm, more preferably less than 1 mm, and more particularly preferably 0 mm. Section 40: 40. The adhesive of any one of paragraphs 1 to 39, wherein the adhesive exhibits a sag of less than 3 mm, more preferably 2 mm or less, when tested after heat aging at 54° C. in dry conditions for 3 days using the sag test described herein. Section 41: Using the resistivity test described herein, after 7 days of curing at 23°C and 50% RH, 10 6 Item 41. The adhesive according to any one of items 1 to 40, which exhibits a resistivity greater than Ω. Section 42: 42. The adhesive of any one of items 1 to 41, which exhibits a UL94 rating of V0 (after curing for 7 days at 23° C. and 50% RH). Section 43: 1. A method for bonding two substrates, comprising: (1) A step of supplying the one-component moisture-curing polyurethane adhesive according to any one of items 1 to 42; (2) applying the adhesive to a first substrate, a second substrate, or both; (3) placing the first substrate and second substrate in adhesive contact, thereby sandwiching the adhesive therebetween; (4) curing the adhesive; A method comprising: Section 44: 44. The method of claim 43, wherein the first and second substrates are independently selected from metals. Section 45: 44. The method of claim 43, wherein the first and second substrates are independently selected from coated steel and aluminum. Section 46: 46. ​​The method of paragraph 43, 44, or 45, wherein curing is carried out at room temperature.

Claims

1. (A) at least one polyurethane prepolymer; (B) at least one amine catalyst and an optional organometallic catalyst; (C) the flame retardants / synergists aluminum hydroxide, melamine polyphosphate, and aluminum diethylphosphinate; and (D) optional adhesion promoters, fillers; One-component moisture-curing polyurethane adhesives, including:

2. The adhesive of claim 1 , wherein the at least one polyurethane prepolymer is prepared by polymerizing one or more polyether polyols and / or polyester polyols in the presence of a polyisocyanate.

3. The at least one polyether polyol is poly(C ２ ~C ６ 3. The adhesive of claim 2, wherein the diol is a hydroxybenzoate (hydroxybenzoate-alkylene oxide) diol.

4. The at least one polyether polyol is poly(C ２ ~C ４ 4. The adhesive according to claim 2, wherein the diol is a hydroxybenzoate (hydroxybenzoate)-alkylene oxide (hydroxybenzoate).

5. 5. The adhesive of claim 2, 3, or 4, wherein the at least one polyether polyol is selected from poly(propylene oxide) diols, poly(propylene oxide) triols, and mixtures thereof.

6. The adhesive of any one of claims 1 to 5, wherein the at least one polyurethane prepolymer is a mixture of a polyether polyol-based prepolymer and a polyester polyol-based prepolymer.

7. 7. The adhesive of any one of claims 1 to 6, wherein the at least one polyurethane prepolymer is produced by reacting a poly(propylene oxide) diol, a poly(propylene oxide) triol, and a diisocyanate.

8. 8. The adhesive of claim 1, wherein the at least one polyurethane prepolymer is a mixture of a prepolymer made by reacting a poly(propylene oxide) diol, a poly(propylene oxide) triol, and a diisocyanate, and a prepolymer made by reacting an aliphatic polyester diol with a diisocyanate.

9. 9. The adhesive of claim 7 or 8, wherein the diisocyanate is selected from IPDI, MDI, and mixtures thereof.

10. The adhesive of any one of claims 1 to 9, wherein the polyurethane prepolymer is present at 20 to 70 wt% polyurethane prepolymer, based on the total weight of the adhesive composition.

11. 11. The adhesive of any one of claims 1 to 10 comprising 20 to 70 wt%, based on the total weight of the adhesive composition, of a polyurethane prepolymer comprising a nominally trifunctional poly(propylene oxide) (equivalent weight 1558) having a hydroxyl number of 36 and a nominally difunctional poly(propylene oxide) (equivalent weight 1000) having a hydroxyl number of 56 reacted with MDI, and having an isocyanate content of 1.25 wt%.

12. 12. The adhesive of any one of claims 1 to 11, wherein the at least one polyurethane prepolymer comprises 0.5 to 5 wt%, based on the total weight of the adhesive, of a prepolymer made by reacting an aliphatic polyester diol with a diisocyanate.

13. The adhesive of any one of claims 1 to 12, wherein the amine catalyst is selected from aliphatic cyclic and acyclic tertiary amines.

14. 14. The adhesive of any one of claims 1 to 13, wherein the amine catalyst is selected from N,N-dimethylcyclohexanamine, triethylenediamine, N,N,N,N-tetramethylalkylenediamine, N,N,N,N-pentamethyldiethylenetriamine, triethylamine, N,N-dimethylbenzylamine, N,N-dimethylhexadecylamine, N,N-dimethylbutylamine, di(2,6-dimethylmorpholinoethyl)ether, and 2,2'-dimorpholinodiethyl ether.

15. The adhesive of any one of claims 1 to 14, wherein the amine catalyst is 2,2'-dimorpholinodiethyl ether.

16. The adhesive of any one of claims 1 to 15, wherein the amine catalyst is used at 0.1 to 1 wt%, based on the total weight of the adhesive composition.

17. The adhesive of any one of claims 1 to 16, wherein the aluminum hydroxide has a median particle size of 2.6 microns.

18. 18. The adhesive of any one of claims 1 to 17, wherein the melamine polyphosphate has a D50 of 20 microns measured in acetone using laser diffraction techniques with a Malvern Mastersizer 2000 particle size analyzer.

19. The aluminum diethylphosphinate has a D ５０ and / or D of 10 microns or less ９５ 19. The adhesive of any one of claims 1 to 18, having (volume % measured in acetone using laser diffraction techniques with a Malvern Mastersizer 2000 particle size analyzer).

20. 20. The adhesive of any one of claims 1 to 19, wherein the aluminum hydroxide is present at 15 to 30 wt%, based on the total weight of the adhesive.

21. 21. The adhesive of any one of claims 1 to 20, wherein the aluminum hydroxide is present at 20 to 28 wt%, based on the total weight of the adhesive.

22. The adhesive of any one of claims 1 to 21, wherein the aluminum hydroxide is present at 25% by weight, based on the total weight of the adhesive.

23. The adhesive of any one of claims 1 to 22, wherein the melamine polyphosphate is present at 10 to 20 wt%, based on the total weight of the adhesive.

24. The adhesive of any one of claims 1 to 23, wherein the melamine polyphosphate is present at 12 to 15 wt%, based on the total weight of the adhesive.

25. The adhesive of any one of claims 1 to 24, wherein the melamine polyphosphate is present at 13 wt%, based on the total weight of the adhesive.

26. The adhesive of any one of claims 1 to 25, wherein the aluminum diethylphosphinate is present at 2 to 10 wt%, based on the total weight of the adhesive.

27. The adhesive of any one of claims 1 to 26, wherein the aluminum diethylphosphinate is present at 2.5 to 5 wt%, based on the total weight of the adhesive.

28. The adhesive of any one of claims 1 to 27, wherein the aluminum diethylphosphinate is present at 3.5 wt% or 4.5 wt%, based on the total weight of the adhesive.

29. The adhesive of any one of claims 1 to 28, further comprising carbon black.

30. The adhesive of any one of claims 1 to 29, further comprising 1 to 20 wt% carbon black, based on the total weight of the adhesive composition.

31. The adhesive of any one of claims 1 to 30, further comprising calcium carbonate.

32. The adhesive of any one of claims 1 to 31, further comprising fumed silica.

33. The adhesive of any one of claims 1 to 32, further comprising fumed silica that has been surface treated with a chlorosilane, a dichlorosilane, an alkyltrialkoxysilane, or a polydimethylsiloxane.

34. 34. The adhesive of any one of claims 1 to 33, which exhibits a failure mode in the Quick Knife Adhesion Test (described herein) of greater than 90% Cohesive Failure (CF) after curing for 7 days at 23°C and 50% RH.

35. 35. The adhesive of any one of claims 1 to 34, which in the Lap Shear Test (described herein) exhibits a Lap Shear Strength of 360 psi or greater after curing for 7 days at 23°C and 50% RH.

36. 36. The adhesive of any one of claims 1 to 35, which in the Lap Shear Test (described herein) exhibits a failure mode of greater than 90% cohesive failure after curing for 7 days at 23°C and 50% RH.

37. 37. The adhesive of any one of claims 1 to 36, after curing for 7 days at 23°C and 50% RH, exhibiting a fire extinguishment time after the initial 10 seconds of burn of less than 2 seconds when using the Vertical Burn Test described herein.

38. 38. The adhesive of any one of claims 1 to 37, after curing for 7 days at 23°C and 50% RH exhibiting a fire extinguishment time after a second 10 second burn of less than 6 seconds when using the Vertical Burn Test described herein.

39. 39. The adhesive of any one of claims 1 to 38, when tested immediately after manufacture, exhibits a sag of less than 2 mm using the sag test described herein.

40. 40. The adhesive of any one of claims 1 to 39, which exhibits a sag of less than 3 mm when tested after heat aging at 54°C for 3 days in dry conditions using the sag test described herein.

41. Using the resistivity test described herein, after 7 days of curing at 23°C and 50% RH, 10 ６ 41. The adhesive of any one of claims 1 to 40, exhibiting a resistivity greater than Ω.

42. 42. The adhesive of any one of claims 1 to 41, exhibiting a UL94 rating of V0 (after curing for 7 days at 23°C and 50% RH).

43. 1. A method for bonding two substrates, comprising: (1) supplying the one-component moisture-curing polyurethane adhesive according to any one of claims 1 to 42; (2) applying the adhesive to a first substrate, a second substrate, or both; (3) placing the first substrate and second substrate in adhesive contact, thereby sandwiching the adhesive therebetween; (4) curing the adhesive; A method comprising:

44. 44. The method of claim 43, wherein the first and second substrates are independently selected from metals.

45. 44. The method of claim 43, wherein the first and second substrates are independently selected from coated steel and aluminum.

46. 46. ​​The method of claim 43, 44, or 45, wherein curing occurs at room temperature.

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