Two-component polyurethane adhesive composition

Abstract

The two-part thermally conductive polyurethane adhesive comprises component A and component B. Component A is an NCO-terminated prepolymer made by reacting at least one polyol having an Mn greater than 2,000 Da and an OH functionality of 2-3 with 30-45 wt. %, based on the total weight of component A, of at least one polyisocyanate selected from aliphatic polyisocyanates and mixtures of 2,4'-MDI and 4,4'-MDI. Component B comprises at least one polyol having an Mn less than 1,000 Da and an OH functionality of at least 2. The bonded assembly comprises a first substrate and a second substrate bonded to the first substrate by the polyurethane adhesive made by mixing components A and B.

Description

[Technical Field]

[0001] This invention relates to the field of two-component polyurethane adhesive compositions. [Background technology]

[0002] Two-component polyurethane adhesives offer a versatile bonding solution. Their use is increasing in the automotive industry, partly due to the need to reduce weight associated with conventional fastening methods such as rivets.

[0003] Two-component polyurethanes consist of an isocyanate component and a polyol component. The isocyanate component contains at least one isocyanate-terminated molecule, and the polyol component contains at least one polyol. When the two components are mixed immediately before use, the OH groups of the polyol react with the NCO groups of the isocyanate-terminated molecules to form a high molecular weight polyurethane that can be linear or branched (i.e., crosslinked). As the components are mixed and the molecular weight begins to increase, the viscosity of the mixture also increases. The adhesive mixture and the parts to be bonded using the mixture have a limited viscosity that allows them to be manipulated. The time from mixing to reaching a predetermined degree of curing (and / or viscosity) is called the "working time." In some applications, a longer working time is desired. [Overview of the project] [Means for solving the problem]

[0004] In a first aspect, the present invention provides a two-component thermally conductive polyurethane adhesive, which is a (A) Component A: (ai) Molecular weight (M nAn NCO-terminated prepolymer produced by reacting at least one polyol having a functional value of 2-3 and a OH value of over 2,000 Da with at least one polyisocyanate selected from aliphatic polyisocyanates and a mixture of 2,4'-methylene-bis-(phenylisocyanate) (MDI) and 4,4'-MDI, in an amount of 30-45% by weight based on the total weight of component A, (B) Component B: (bi) Molecular weight (M n ) is less than 1,000 Da, and at least one polyol having an OH functional value of at least 2, (bii) A catalyst capable of selectively catalyzing the reaction between an OH group and an NCO group, and

[0005] In a second aspect, the present invention provides a kit for producing a thermally conductive polyurethane adhesive, the kit comprising: (A) Component A: (ai) Molecular weight (M n An NCO-terminated prepolymer produced by reacting at least one polyol having a functional value of 2-3 and a OH value of over 2,000 Da with at least one polyisocyanate selected from aliphatic polyisocyanates and a mixture of 2,4'-methylene-bis-(phenylisocyanate) (MDI) and 4,4'-MDI, in an amount of 30-45% by weight based on the total weight of component A, (B) Component B: (bi) Molecular weight (M n ) is less than 1,000 Da, and at least one polyol having an OH functional value of at least 2, (bii) A catalyst capable of selectively catalyzing the reaction between an OH group and an NCO group, and

[0006] In a third aspect, the present invention provides a method for bonding two or more substrates, the method being: (1) (A) Component A: (ai) Molecular weight (M nAn NCO-terminated prepolymer produced by reacting at least one polyol having a functional value of 2-3 and a OH value of over 2,000 Da with at least one polyisocyanate selected from aliphatic polyisocyanates and a mixture of 2,4'-methylene-bis-(phenylisocyanate) (MDI) and 4,4'-MDI, in an amount of 30-45% by weight based on the total weight of component A, (B) Component B: (bi) Molecular weight (M n ) is less than 1,000 Da, and at least one polyol having an OH functional value of at least 2, (bii) A step of providing an adhesive comprising a catalyst capable of selectively catalyzing the reaction between an OH group and an NCO group, (2) A step of mixing component A and component B to produce an adhesive mixture, (3) A step of applying the adhesive mixture to the first substrate, (4) A step of bringing the first substrate into adhesive contact with the second substrate, (5) A step of curing the adhesive mixture.

[0007] In a fourth aspect, the present invention provides a bonded assembly, the assembly is (1) A first substrate and (2) A second substrate bonded to the first substrate, The first substrate and the second substrate are, (A) Component A: (ai) Molecular weight (M n An NCO-terminated prepolymer produced by reacting at least one polyol having a functional value of 2-3 and a OH value of over 2,000 Da with at least one polyisocyanate selected from aliphatic polyisocyanates and a mixture of 2,4'-methylene-bis-(phenylisocyanate) (MDI) and 4,4'-MDI, in an amount of 30-45% by weight based on the total weight of component A, (B) Component B: (bi) Molecular weight (M n ) is less than 1,000 Da, and at least one polyol having an OH functional value of at least 2, (bii) They are adhered to each other by an adhesive produced by mixing a catalyst capable of catalyzing the reaction between an OH group and an NCO group.

Mode for Carrying Out the Invention

[0008] The inventors of the present invention found that a prepolymer having a molecular weight (M n ) of more than 2,000 Da and an OH functionality of at least 2 to 3 is reacted with at least one polyisocyanate selected from aliphatic polyisocyanates and a mixture of 2,4'-methylene-bis-(phenyl isocyanate) (MDI) and 4,4'-MDI in an amount of 30 to 45% by weight based on the total weight of component A, and by using a polyol component containing at least one polyol having a molecular weight (M n ) of less than 1,000 Da and an OH functionality of at least 2, it is possible to achieve a longer pot life and a gentle viscosity development in a polyurethane adhesive.

[0009] Definitions and Abbreviations MDI: Methylene-bis-(phenyl isocyanate) HDI: Hexamethylene diisocyanate IPDI: Isophorone diisocyanate PU: Polyurethane GPC: Gel permeation chromatography RH: Relative humidity

[0010] The equivalent weight and molecular weight were measured by gel permeation chromatography (GPC) using a Malvern Viscothek GPC max apparatus. Tetrahydrofuran (THF) was used as the eluent, PL GEL MIXED D (Agilent, 300×7.5 mm, 5 μm) was used as the column, and MALVERN Viscothek TDA (integrated refractive index viscometer and light scattering) was used as the detector.

[0011] Component A (Isocyanate) Component A has a molecular weight (M n The present invention comprises an NCO-terminated prepolymer produced by reacting at least one polyol having a OH functional value of 2-3 and a OH functional value of over 2,000 Da with at least one polyisocyanate selected from aliphatic polyisocyanates and a mixture of 2,4'-methylene-bis-(phenylisocyanate) (MDI) and 4,4'-MDI, in an amount of 30-45% by weight based on the total weight of component A.

[0012] The polyol is preferably a polyether polyol, and more particularly a poly(C) 2~4 Selected from alkylene oxide polyols.

[0013] In a preferred embodiment, the polyol is selected from poly(propylene oxide) polyols.

[0014] The polyol used to produce the prepolymer preferably has a functional value of 2.5 to 3, more preferably 3.

[0015] In a preferred embodiment, the polyol used to produce the prepolymer is a polyether polyol having a functional value of 2.5 to 3, more preferably 3.

[0016] In a more preferred embodiment, the polyol used to produce the prepolymer is a poly(C) having a functional value of 2.5 to 3, more preferably 3. 2~4 It is an alkylene oxide polyol.

[0017] In another preferred embodiment, the polyol used to produce the prepolymer is a poly(propylene oxide) polyol having a functional value of 2.5 to 3, more preferably 3.

[0018] In another preferred embodiment, the polyol used to produce the prepolymer has a molecular weight greater than 2,500 Da (M n) has, more preferably, a molecular weight (M) of 3,000 Da. n ) has.

[0019] In preferred embodiments, the polyol used to produce the prepolymer has a molecular weight greater than 2,500 Da (M n ) Polyether polyols having ), especially poly(C 2~4 Selected from alkylene oxide polyols, more preferably having a molecular weight of 3,000 Da (M n ) has.

[0020] In a preferred embodiment, the polyol has a molecular weight greater than 2,500 Da (M n Selected from poly(propylene oxide) polyols having ) and more preferably having a molecular weight (M) of 3,000 Da. n ) has.

[0021] The polyol used to produce the prepolymer preferably has a functional value of 2.5 to 3, more preferably 3, and a molecular weight greater than 2,500 Da (M n ) has, more preferably, a molecular weight (M) of 3,000 Da. n ) has.

[0022] In preferred embodiments, the polyol used to produce the prepolymer has a functional value of 2.5 to 3, more preferably 3, and a molecular weight greater than 2,500 Da (M n A polyether polyol having ) and more preferably having a molecular weight (M) of 3,000 Da. n ) has.

[0023] In a more preferred embodiment, the polyol used to produce the prepolymer has a functional value of 2.5 to 3, more preferably 3, and a molecular weight greater than 2,500 Da (M n ) has poly(C 2~4 It is an alkylene oxide polyol, more preferably one with a molecular weight of 3,000 Da (M n ) has.

[0024] In another preferred embodiment, the polyol used to produce the prepolymer has a functional value of 2.5 to 3, more preferably 3, and a molecular weight greater than 2,500 Da (M n A poly(propylene oxide) polyol having ) and more preferably having a molecular weight (M) of 3,000 Da. n ) has.

[0025] The prepolymer may be prepared from a mixture of polyols selected from those described herein.

[0026] The polyisocyanate is selected from aliphatic polyisocyanates and mixtures of 2,4'-MDI and 4,4'-MDI.

[0027] In preferred embodiments, the polyisocyanate is aliphatic, and isophorone diisocyanate (IPDI), dicyclohexylmethane diisocyanate (HMDI), hexamethylene diisocyanate (HDI), and mixtures thereof are particularly preferred.

[0028] In another preferred embodiment, the polyisocyanate is a mixture of 2,4'-MDI and 4,4'-MDI. More preferably, the weight ratio of 2,4'-MDI to 4,4'-MDI is 0.667 to 1.5, more preferably 0.8 to 1.5, and even more preferably 1 to 1.5.

[0029] A mixture of 2,4'-MDI and 4,4-MDI in a weight ratio of 1:1 is particularly preferred.

[0030] The NCO-terminated prepolymer of component A is produced by reacting at least one polyol with at least one polyisocyanate. This reaction is preferably carried out under dry, inert conditions, particularly under vacuum. In a preferred embodiment, at least one polyol is first dried under vacuum and high temperature (>100°C), then cooled (e.g., to 80°C), and then at least one polyisocyanate is added under vacuum. The mixture is reacted under vacuum for 1-2 hours. The prepolymer may be purified, but preferably the resulting reaction mixture is used without purification.

[0031] At least one polyisocyanate is used in an amount such that there is an excess of NCO groups relative to the OH groups of the polyol. In a preferred embodiment, at least one polyisocyanate is used in a stoichiometric excess of 2 to 15 times, more preferably 8 to 12 times, and particularly preferably 10 times, relative to the polyol.

[0032] In a preferred embodiment, the prepolymer is produced by reacting a polyether polyol with a mixture of 2,4'-MDI and 4,4'-MDI.

[0033] In another preferred embodiment, the prepolymer is poly(C) 2~4 It is produced by reacting an alkylene oxide polyol with a mixture of 2,4'-MDI and 4,4'-MDI.

[0034] In another preferred embodiment, the prepolymer is produced by reacting a poly(propylene oxide) polyol with a mixture of 2,4'-MDI and 4,4'-MDI.

[0035] In another preferred embodiment, the prepolymer is produced by reacting a polyether polyol having a functional value of 2.5 to 3, more preferably 3, with a mixture of 2,4'-MDI and 4,4'-MDI.

[0036] In another preferred embodiment, the prepolymer is a poly(C) having a functional value of 2.5 to 3, more preferably 3. 2~4 It is produced by reacting an alkylene oxide polyol with a mixture of 2,4'-MDI and 4,4'-MDI.

[0037] In another preferred embodiment, the prepolymer is produced by reacting a poly(propylene oxide) polyol having a functional value of 2.5 to 3, more preferably 3, with a mixture of 2,4'-MDI and 4,4'-MDI.

[0038] In another preferred embodiment, the prepolymer has a molecular weight greater than 2,500 Da (M n ), more preferably a molecular weight of 3,000 Da (M n It is produced by reacting a polyether polyol having ) with a mixture of 2,4'-MDI and 4,4'-MDI.

[0039] In another preferred embodiment, the prepolymer has a molecular weight greater than 2,500 Da (M n ), more preferably a molecular weight of 3,000 Da (M n ) has poly(C 2~4 It is produced by reacting an alkylene oxide polyol with a mixture of 2,4'-MDI and 4,4'-MDI.

[0040] In another preferred embodiment, the prepolymer has a molecular weight greater than 2,500 Da (M n ), more preferably a molecular weight of 3,000 Da (M n It is produced by reacting a poly(propylene oxide) polyol having ) with a mixture of 2,4'-MDI and 4,4'-MDI.

[0041] In another preferred embodiment, the prepolymer has a molecular weight greater than 2,500 Da (M n ), more preferably a molecular weight of 3,000 Da (M nIt is produced by reacting a polyether polyol having a functional value of 2.5 to 3, preferably 3, with a mixture of 2,4'-MDI and 4,4'-MDI.

[0042] In another preferred embodiment, the prepolymer has a molecular weight greater than 2,500 Da (M n ), more preferably a molecular weight of 3,000 Da (M n It is produced by reacting a polyether polyol having a functional value of 2.5 to 3, preferably 3, with a mixture of 2,4'-MDI and 4,4'-MDI.

[0043] In another preferred embodiment, the prepolymer has a molecular weight greater than 2,500 Da (M n ), more preferably a molecular weight of 3,000 Da (M n ), and poly(C) having a functional value of 2.5 to 3, preferably 3. 2~4 It is produced by reacting an alkylene oxide polyol with a mixture of 2,4'-MDI and 4,4'-MDI.

[0044] In another preferred embodiment, the prepolymer has a molecular weight greater than 2,500 Da (M n ), more preferably a molecular weight of 3,000 Da (M n It is produced by reacting a poly(propylene oxide) polyol having a functional value of 2.5 to 3, preferably 3, with a mixture of 2,4'-MDI and 4,4'-MDI.

[0045] In another preferred embodiment, the prepolymer has a molecular weight greater than 2,500 Da (M n ), more preferably a molecular weight of 3,000 Da (M n It is produced by reacting a polyether polyol having a functional value of 2.5 to 3, preferably 3, with a mixture of 2,4'-MDI and 4,4'-MDI.

[0046] In a particularly preferred embodiment, the prepolymer is produced by reacting a poly(propylene oxide) polyol having a molecular weight (Mn) of 3,000 Da and a functional value of 3 with a 1:1 (weight:weight) mixture of 2,4'-MDI and 4,4'-MDI.

[0047] At least one polyol is used in component A, preferably in an amount of 10-40% by weight, more preferably 25-35% by weight, and particularly preferably 28-29% by weight, based on the total weight of component A. It should be understood that the polyol is in a prepolymer form.

[0048] At least one polyisocyanate is used in component A at an amount of 20-50% by weight, more preferably 30-40% by weight, and even more preferably 34-36% by weight, based on the total weight of component A.

[0049] The NCO-terminated prepolymer preferably contains 40-50% by weight, more preferably 42-48% by weight, and particularly preferably 43-45% by weight of polyol, based on the total weight of the prepolymer.

[0050] The NCO-terminated prepolymer preferably contains 50-60% by weight, more preferably 52-58% by weight, and particularly preferably 54-56% by weight of diisocyanate based on the total weight of the prepolymer.

[0051] The prepolymer is preferably used without purification. The prepolymer mixture is preferably used in component A at an amount of 50-75% by weight, more preferably 55-70% by weight, and even more preferably 60-66% by weight, based on the total weight of component A.

[0052] Component A may additionally contain talc. If used, the talc is preferably present in an amount of 25-40% by weight, more preferably 30-40% by weight, and particularly preferably 32-37% by weight, based on the total weight of component A.

[0053] Component A may additionally contain fumed silica. If used, the fumed silica is preferably present in an amount of 0.75 to 2% by weight, more preferably 1 to 2% by weight, based on the total weight of component A.

[0054] Component A is typically formulated by drying solid raw materials such as talc and fumed silica at high temperatures under vacuum. Preferably, drying is carried out until the moisture content is 300 ppm or less. The prepolymer is added to the dried raw materials and mixed under reduced pressure until homogeneous, after which component A is stored in a moisture-proof container.

[0055] Component B (Polyol) Component B has (bi) molecular weight (M n (bii) comprising at least one polyol having a density of less than 1,000 Da and an OH functional value of at least 2, and a catalyst capable of optionally catalyzing the reaction between an OH group and an NCO group.

[0056] At least one polyol preferably comprises a polyol having a molecular weight (Mn) greater than 400 Da. At least one polyol comprises a polyol having a molecular weight (Mn) of 400 to 1,000 Da, more preferably 500 to 1,000 Da.

[0057] In a preferred embodiment, at least one polyol comprises a polyol having a functional value of 3 or more.

[0058] In a more preferred embodiment, at least one polyol comprises a polyol having a functional value of 3 or more and a molecular weight (Mn) of 400 to 1,000 Da, more preferably 500 to 1,000 Da.

[0059] In a more preferred embodiment, at least one polyol includes a mixed polyol, particularly a mixture of a polyol having a functional value of 3 and a polyol having a functional value greater than 3.

[0060] In a preferred embodiment, at least one polyol comprises a polyether polyol. A preferred polyether polyol is poly(C 2~4 The polyols are selected from alkylene oxide-based polyols, particularly poly(ethylene oxide)-based, poly(propylene oxide)-based, poly(butylene oxide)-based polyols, and mixtures thereof. In a particularly preferred embodiment, the polyether polyol is selected from poly(propylene oxide)-based polyols.

[0061] In another preferred embodiment, at least one polyol comprises a triol. The triol is, for example, poly(C) 2~4 The triol may be an alkylene oxide, particularly a poly(propylene oxide) type, or it may be, for example, castor oil. In a particularly preferred embodiment, the triol is castor oil.

[0062] In preferred embodiments, at least one polyol comprises a mixture of a polyether polyol and castor oil, particularly having a functional value of greater than 3, more preferably greater than 4, and most preferably greater than 5.

[0063] In preferred embodiments, the polyether polyol having a functional value of more than 3, more preferably more than 4, and particularly preferably more than 5, is a poly(propylene oxide) polyol.

[0064] In a preferred embodiment, component B contains 40 to 60% by weight of triol based on the total weight of component B.

[0065] In a preferred embodiment, component B comprises 0 to 10% by weight of a polyol having a functional value greater than 3, more preferably greater than 4.

[0066] In preferred embodiments, component B comprises 0 to 20% by weight of a polyol having a functional value greater than 2, more preferably 3, and a molecular weight of less than 500 Da, more preferably less than 400 Da.

[0067] In another preferred embodiment, component B comprises 40 to 60% by weight of a triol based on the total weight of component B, 0 to 10% by weight of a polyol having a functional value greater than 3, more preferably greater than 4, and 0 to 20% by weight of a polyol having a functional value greater than 2, more preferably 3, and a molecular weight of less than 500 Da, more preferably less than 400 Da.

[0068] In another preferred embodiment, at least one polyol comprises a mixture of 80-97% by weight, more preferably 85-95% by weight, and particularly preferably 91-94% by weight of castor oil and 3-20% by weight, more preferably 5-15% by weight, and particularly preferably 6-9% by weight of a polyether polyol, particularly having a functional value of greater than 3, more preferably greater than 4, and particularly preferably greater than 5 (where weight % is based on the total weight of the polyol in component B).

[0069] In another preferred embodiment, the polyol comprises a mixture of a triol in 80-97% by weight, more preferably 85-95% by weight, and particularly preferably 91-94% by weight, and a polyether polyol having a functional value greater than 3, more preferably greater than 4, and particularly preferably greater than 5, in 3-20% by weight, more preferably 5-15% by weight, and particularly preferably 6-9% by weight, based on the total weight of the polyol in component B.

[0070] In a particularly preferred embodiment, at least one polyol comprises a mixture of poly(propylene oxide) having a functional value of 6 and castor oil.

[0071] In another particularly preferred embodiment, at least one polyol comprises a mixture of 80-97% by weight, more preferably 85-95% by weight, and especially preferably 91-94% by weight of castor oil and 3-20% by weight, more preferably 5-15% by weight, and especially preferably 6-9% by weight of a poly(propylene oxide) polyol having a functional value of 6 (where weight % is based on the total weight of the polyol in component B).

[0072] Component B optionally includes a catalyst capable of catalyzing the reaction between an isocyanate group and an OH group.

[0073] Examples of such catalysts include tertiary amine catalysts, organometallic catalysts, such as bismuth catalysts, alkyltin carboxylates, oxides, and tin mercaptides.

[0074] Specific examples of tertiary amine catalysts include N-methylmorpholine, N-methylimidazole, triethylenediamine, bis-(2-dimethylaminoethyl)-ether, 1,4-diazabicyclo[2.2.2]octane (DABCO), dimethylcyclohexylamine, dimethylethanolamine, 2,2-dimorpholinyldiethyl ether (DMDEE), N,N,N-dimethylaminopropylhexahydrotriazine, dimethyltetrahydropyrimidine, tetramethylethylenediamine, dimethylcyclohexylamine, and 2,2-N,N-benzyldimethylamine. Examples include dimethylethanolamine, dimethylaminopropylamine, pentadimethyldiethylenetriamine, N,N,N',N'-tetramethyl-1,6-hexanediamine, N,N',N'-trimethylaminoethylpiperazine, 1,1'-[[3-(dimethylamino)propyl]imino]bispropan-2-ol, 1,3,5-tris[3-(dimethylamino)propyl]hexahydro-1,3,5-triazine, NN-dimethyldipropylenetriamine, and N,N,N'-trimethylaminoethylethanolamine, with DMDEE being particularly preferred.

[0075] When an organometallic catalyst is used, it is any organometallic catalyst capable of catalyzing the reaction between an isocyanate and a functional group having at least one reactive hydrogen. Examples include bismuth catalysts, metal carboxylates such as tin carboxylate and zinc carboxylate. Examples of metal alkanoates include stannous octanoate, bismuth octanoate, or bismuth neodecanoate. Preferably, at least one organometallic catalyst is a bismuth catalyst or an organotin catalyst. Examples include dibutyltin dilaurate, dimethyltin dineodecanoate, dimethyltin mercaptide, dimethyltin carboxylate, dimethyltin dioleate, dimethyltin dithioglycolate, dibutyltin mercaptide, dibutyltin bis(2-ethylhexylthioglycolate), dibutyltin sulfide, dioctyltin dithioglycolate, dioctyltin mercaptide, dioctyltin dioctoate, dioctyltin dineodecanoate, and dioctyltin dilaurate. In preferred embodiments, the catalyst is a tin catalyst, particularly preferably dioctyltin mercaptide and / or dimethyltin dithioglycolate. In particularly preferred embodiments, the catalyst is dioctyltin mercaptide.

[0076] The catalyst is preferably used in an amount of 0.0005 to 0.002% by weight, more preferably 0.00075 to 0.0015% by weight, based on the total weight of component B.

[0077] In preferred embodiments, the catalyst is dioctyl tin mercaptide, used in an amount of 0.0005 to 0.002% by weight, more preferably 0.00075 to 0.0015% by weight, based on the total weight of component B.

[0078] Component B may additionally contain talc. If used, the talc is preferably present in an amount of 20-50% by weight, more preferably 30-40% by weight, and particularly preferably 30-34% by weight, based on the total weight of component B.

[0079] Component B may additionally contain fumed silica. If used, the fumed silica is preferably present in an amount of 0.75 to 2% by weight, more preferably 1 to 2% by weight, based on the total weight of component A.

[0080] Component B may additionally contain a water-scavenging agent such as a molecular sieve. If used, the molecular sieve is preferably used in an amount of 1 to 5% by weight, more preferably 2 to 4% by weight, based on the total weight of component B.

[0081] Component B is typically formulated by drying solid raw materials such as talc and fumed silica at high temperatures under vacuum. Preferably, drying is carried out until the moisture content is 300 ppm or less. At least one polyol and a catalyst are added to the dried raw materials and mixed under reduced pressure until homogeneous, after which component B is stored in a moisture-proof container.

[0082] Manufacturing method The adhesive composition of the present invention is prepared by mixing the raw materials of each component separately, preferably under inert and dry conditions and / or under vacuum, until a homogeneous mixture is obtained. Once the components are prepared, they are stored in separate containers until use.

[0083] How to use In one embodiment, the present invention provides a method for bonding two or more substrates, the method being: (1) (A) Component A: (ai) Molecular weight (M n An NCO-terminated prepolymer produced by reacting at least one polyol having a functional value of 2-3 and a OH value of over 2,000 Da with at least one polyisocyanate selected from aliphatic polyisocyanates and a mixture of 2,4'-methylene-bis-(phenylisocyanate) (MDI) and 4,4'-MDI, in an amount of 30-45% by weight based on the total weight of component A, (B) Component B: (bi) Molecular weight (M n) is less than 1,000 Da, and at least one polyol having an OH functional value of at least 2, (bii) A step of providing an adhesive comprising a catalyst capable of selectively catalyzing the reaction between an OH group and an NCO group, (2) A step of mixing component A and component B to produce an adhesive mixture, (3) A step of applying the adhesive mixture to the first substrate, (4) A step of bringing the first substrate into adhesive contact with the second substrate, (5) A step of curing the adhesive mixture.

[0084] The raw materials for components A and B, which are useful in the method of the present invention, are as described with respect to adhesives.

[0085] The mixing of component A and component B is carried out by any method that allows for a fairly rapid acquisition of a homogeneous mixture. Typically, the mixing is achieved by simultaneously introducing both components into a mixing vessel or mixing channel. The mixing of component A and component B may be in any desired ratio, but is typically carried out using an A:B volume ratio of 0.8 to 1.2, more preferably 1.

[0086] The application of the adhesive mixture to the substrate is typically carried out using a suitable application gun and static mixer. The adhesive is filled into a cartridge that ensures a suitable mixing ratio. The cartridge is placed in the application gun and fitted with a suitable static mixer. The adhesive is then extruded through the static mixer onto the surface to be bonded.

[0087] Curing typically occurs at ambient temperature (e.g., 23°C) and humidity (e.g., 50% relative humidity). Complete curing using the adhesive of the present invention usually occurs in 7 to 10 days.

[0088] There are no particular limitations on the substrate, which can include metals and plastics. The adhesive of the present invention is particularly suitable for bonding e-coated steel, PET film, aluminum-metallized plastic film, and aluminum.

[0089] Preferred applications include thermally conductive materials used in any application requiring thermal conductivity, with a primary application being thermal management of EV batteries in the automotive industry, particularly for bonding modules or cells to cooling plates.

[0090] [Effects of the invention] The curing adhesive of the present invention (7 days, 23°C, 50%RH) preferably has a bonding area of ​​250 mm² when measured according to DIN EN 1465. 2 (10 x 25 mm), adhesive layer thickness: 1 mm, using e-coated steel on both substrates, exhibits a lap shear strength of 4 MPa or more.

[0091] The pot life of the adhesive mixture obtained by mixing component A and component B (preferably in a volume ratio of 0.8:1 to 1.2:1, more preferably 1:1) is preferably more than 60 minutes, more preferably more than 65 minutes. The pot life is the time it takes for the rheological viscosity to simultaneously reach 900 Pas at a shear rate of 0.25 / second, 500 Pas at a shear rate of 1 / second, and 300 Pas at a shear rate of 2.5 / second. The rheological viscosity is measured using a TA rheometer with a 25 mm parallel plate and a 0.2 mm gap.

[0092] The adhesive mixture obtained by mixing component A and component B (preferably in a volume ratio of 0.8:1 to 1.2:1, more preferably 1:1) preferably has a tensile strength of 5 MPa or less when the sample is pulled at 50 mm / min, as measured according to DIN EN ISO 527-2 after curing at 23°C and 50% RH for 7 days.

[0093] The adhesive mixture obtained by mixing component A and component B (preferably in a volume ratio of 0.8:1 to 1.2:1, more preferably 1:1) preferably has an E modulus of 15 or less when the sample is pulled at 50 mm / min, after being cured at 23°C and 50% RH for 7 days, as measured according to DIN EN ISO 527-2.

[0094] The adhesive mixture obtained by mixing component A and component B (preferably in a volume ratio of 0.8:1 to 1.2:1, more preferably 1:1) preferably has a breaking elongation of 100% or more when the sample is pulled at 50 mm / min, as measured according to DIN EN ISO 527-2 after curing at 23°C and 50% RH for 7 days.

[0095] Particularly Preferred Embodiment The following are particularly preferred embodiments of the adhesive composition of the present invention.

[0096] 1. A two-component thermally conductive polyurethane adhesive, (A) Component A: (ai) Molecular weight (M n An NCO-terminated prepolymer produced by reacting at least one polyol having a functional value of 2-3 and a OH value of over 2,000 Da with at least one polyisocyanate selected from aliphatic polyisocyanates and a mixture of 2,4'-methylene-bis-(phenylisocyanate) (MDI) and 4,4'-MDI, in an amount of 30-45% by weight based on the total weight of component A, (B) Component B: (bi) Molecular weight (M n ) is less than 1,000 Da, and at least one polyol having an OH functional value of at least 2, (bii) An adhesive comprising a catalyst capable of selectively catalyzing the reaction between an OH group and an NCO group.

[0097] 2. A kit for producing a thermally conductive polyurethane adhesive, (A) Component A: (ai) Molecular weight (M nAn NCO-terminated prepolymer produced by reacting at least one polyol having a functional value of 2-3 and a OH value of over 2,000 Da with at least one polyisocyanate selected from aliphatic polyisocyanates and a mixture of 2,4'-methylene-bis-(phenylisocyanate) (MDI) and 4,4'-MDI, in an amount of 30-45% by weight based on the total weight of component A, (B) Component B: (bi) Molecular weight (M n ) is less than 1,000 Da, and at least one polyol having an OH functional value of at least 2, (bii) A kit comprising a catalyst capable of selectively catalyzing the reaction between an OH group and an NCO group.

[0098] 3. A method for bonding two or more substrates, (1) (A) Component A: (ai) Molecular weight (M n An NCO-terminated prepolymer produced by reacting at least one polyol having a functional value of 2-3 and a OH value of over 2,000 Da with at least one polyisocyanate selected from aliphatic polyisocyanates and a mixture of 2,4'-methylene-bis-(phenylisocyanate) (MDI) and 4,4'-MDI, in an amount of 30-45% by weight based on the total weight of component A, (B) Component B: (bi) Molecular weight (M n ) is less than 1,000 Da, and at least one polyol having an OH functional value of at least 2, (bii) A step of providing an adhesive comprising a catalyst capable of selectively catalyzing the reaction between an OH group and an NCO group, (2) A step of mixing component A and component B to produce an adhesive mixture, (3) A step of applying the adhesive mixture to the first substrate, (4) A step of bringing the first substrate into adhesive contact with the second substrate, (5) A method comprising the step of curing an adhesive mixture.

[0099] 4. (1) A first substrate and (2) A bonded assembly comprising a second substrate bonded to a first substrate, The first substrate and the second substrate are, (A) Component A: (ai) Molecular weight (M n An NCO-terminated prepolymer produced by reacting at least one polyol having a functional value of 2-3 and a OH value of over 2,000 Da with at least one polyisocyanate selected from aliphatic polyisocyanates and a mixture of 2,4'-methylene-bis-(phenylisocyanate) (MDI) and 4,4'-MDI, in an amount of 30-45% by weight based on the total weight of component A, (B) Component B: (bi) Molecular weight (M n ) is less than 1,000 Da, and at least one polyol having an OH functional value of at least 2, (bii) An assembly bonded together by an adhesive prepared by mixing a catalyst capable of selectively catalyzing the reaction between an OH group and an NCO group.

[0100] 5. The polyols used to manufacture the prepolymer are polyether polyols, especially poly(C) 2~4 One of the prior embodiments, selected from alkylene oxide polyols.

[0101] 6. The polyol used to produce the prepolymer is selected from any one of the prior embodiments, from poly(propylene oxide) polyols.

[0102] 7. The polyol used to produce the prepolymer is any one of the prior embodiments having a functional value of 2.5 to 3, more preferably 3.

[0103] 8. The polyol used to produce the prepolymer is a polyether polyol having a functional value of 2.5 to 3, more preferably 3, as in any one of the prior embodiments.

[0104] 9. The polyol used to produce the prepolymer is a poly(C) having a functional value of 2.5 to 3, more preferably 3. 2~4 Any one of the prior embodiments, which is an alkylene oxide polyol.

[0105] 10. The polyol used to produce the prepolymer is a poly(propylene oxide) polyol having a functional value of 2.5 to 3, more preferably 3, as in any one of the prior embodiments.

[0106] 11. The polyols used to manufacture the prepolymers have a molecular weight (M) greater than 2,500 Da. n ) and more preferably the polyol has a molecular weight (M) of 3,000 Da n Any one of the prior embodiments having )

[0107] 12. The polyols used to manufacture the prepolymers have a molecular weight (M) greater than 2,500 Da. n ) Polyether polyols having ), especially poly(C 2~4 Selected from alkylene oxide polyols, more preferably having a molecular weight of 3,000 Da (M n Any one of the prior embodiments having )

[0108] 13. The polyols used to manufacture the prepolymers have a molecular weight (M) greater than 2,500 Da. n Selected from poly(propylene oxide) polyols having ) and more preferably having a molecular weight (M) of 3,000 Da. n Any one of the prior embodiments having )

[0109] 14. The polyol used to produce the prepolymer has a functional value of 2.5 to 3, more preferably 3, and a molecular weight greater than 2,500 Da (M n ) has, more preferably, a molecular weight (M) of 3,000 Da. n Any one of the prior embodiments having )

[0110] 15. The polyol used to produce the prepolymer has a functional value of 2.5 to 3, more preferably 3, and a molecular weight greater than 2,500 Da (M n A polyether polyol having ) and more preferably having a molecular weight (M) of 3,000 Da. n Any one of the prior embodiments having )

[0111] 16. The polyol used to produce the prepolymer has a functional value of 2.5 to 3, more preferably 3, and a molecular weight greater than 2,500 Da (M n ) has poly(C 2~4 It is an alkylene oxide polyol, more preferably one with a molecular weight of 3,000 Da (M n Any one of the prior embodiments having )

[0112] 17. The polyol used to produce the prepolymer has a functional value of 2.5 to 3, more preferably 3, and a molecular weight greater than 2,500 Da (M n A poly(propylene oxide) polyol having ) and more preferably having a molecular weight (M) of 3,000 Da. n Any one of the prior embodiments having )

[0113] 18. The prepolymer is one of the prior embodiments, prepared from a mixture of polyols selected from those described herein.

[0114] 19. The polyisocyanate is selected from any one of the prior embodiments, which includes aliphatic polyisocyanates and mixtures of 2,4'-MDI and 4,4'-MDI.

[0115] 20. The polyisocyanate is aliphatic, and isophorone diisocyanate (IPDI), dicyclohexylmethane diisocyanate (HMDI), and hexamethylene diisocyanate (HDI), as well as mixtures thereof, are particularly preferred, according to any one of the prior embodiments.

[0116] 21. The polyisocyanate is a mixture of 2,4'-MDI and 4,4'-MDI, one of the prior embodiments.

[0117] 22. The polyisocyanate is a mixture of 2,4'-MDI and 4,4'-MDI, and the weight ratio of 2,4'-MDI to 4,4'-MDI is 0.667 to 1.5, more preferably 0.8 to 1.5, and even more preferably 1 to 1.5, according to any one of the prior embodiments.

[0118] 23. Any one of the prior embodiments, wherein the polyisocyanate is a mixture of 2,4'-MDI and 4,4-MDI in a weight ratio of 1:1 between 2,4'-MDI and 4,4-MDI.

[0119] 24. Any one of the prior embodiments, in which the prepolymer reaction mixture is used without purification.

[0120] 25. Any one of the prior embodiments, wherein at least one polyisocyanate is used in an amount that is 2 to 15 times, more preferably 8 to 12 times, and particularly preferably 10 times, a stoichiometric excess relative to the polyol.

[0121] 26. The prepolymer is produced by reacting a polyether polyol with a mixture of 2,4'-MDI and 4,4'-MDI, one of the prior embodiments.

[0122] 27. The prepolymer is poly(C) 2~4 One of the prior embodiments, produced by reacting an alkylene oxide polyol with a mixture of 2,4'-MDI and 4,4'-MDI.

[0123] 28. The prepolymer is produced by reacting a poly(propylene oxide) polyol with a mixture of 2,4'-MDI and 4,4'-MDI, one of the prior embodiments.

[0124] 29. The prepolymer is any one of the previous embodiments produced by reacting a polyether polyol having a functionality of 2.5 to 3, more preferably 3, with a mixture of 2,4'-MDI and 4,4'-MDI.

[0125] 30. The prepolymer is any one of the previous embodiments produced by reacting a poly(C 2~4 alkylene oxide) polyol having a functionality of 2.5 to 3, more preferably 3, with a mixture of 2,4'-MDI and 4,4'-MDI.

[0126] 31. The prepolymer is any one of the previous embodiments produced by reacting a poly(propylene oxide) polyol having a functionality of 2.5 to 3, more preferably 3, with a mixture of 2,4'-MDI and 4,4'-MDI.

[0127] 32. The prepolymer is any one of the previous embodiments produced by reacting a polyether polyol having a molecular weight (M n ) of more than 2,500 Da, more preferably a molecular weight (M n ) of 3,000 Da, with a mixture of 2,4'-MDI and 4,4'-MDI.

[0128] 33. The prepolymer is any one of the previous embodiments produced by reacting a poly(C n alkylene oxide) polyol having a molecular weight (M n ) of more than 2,500 Da, more preferably a molecular weight (M 2~4 ) of 3,000 Da, with a mixture of 2,4'-MDI and 4,4'-MDI.

[0129] 34. The prepolymer is any one of the previous embodiments produced by reacting a poly(propylene oxide) polyol having a molecular weight (M n ) of more than 2,500 Da, more preferably a molecular weight (M n ) of 3,000 Da, with a mixture of 2,4'-MDI and 4,4'-MDI.

[0130] 35. The prepolymer is any one of the previous embodiments produced by reacting a polyether polyol having a molecular weight (M n ) of more than 2,500 Da, more preferably a molecular weight (M n ) of 3,000 Da, and a functionality of 2.5 to 3, preferably 3, with a mixture of 2,4'-MDI and 4,4'-MDI.

[0131] 36. The prepolymer is any one of the previous embodiments produced by reacting a polyether polyol having a molecular weight (M n ) of more than 2,500 Da, more preferably a molecular weight (M n ) of 3,000 Da, and a functionality of 2.5 to 3, preferably 3, with a mixture of 2,4'-MDI and 4,4'-MDI.

[0132] 37. The prepolymer is any one of the previous embodiments produced by reacting a poly(C n alkylene oxide) polyol having a molecular weight (M n ) of more than 2,500 Da, more preferably a molecular weight (M 2~4 ) of 3,000 Da, and a functionality of 2.5 to 3, preferably 3, with a mixture of 2,4'-MDI and 4,4'-MDI.

[0133] 38. The prepolymer is any one of the previous embodiments produced by reacting a poly(propylene oxide) polyol having a molecular weight (M n ) of more than 2,500 Da, more preferably a molecular weight (M n ) of 3,000 Da, and a functionality of 2.5 to 3, preferably 3, with a mixture of 2,4'-MDI and 4,4'-MDI.

[0134] 39. The prepolymer is any one of the previous embodiments produced by reacting a polyether polyol having a molecular weight (M n ) of more than 2,500 Da, more preferably a molecular weight (M nOne of the prior embodiments, which is produced by reacting a polyether polyol having a functional value of 2.5 to 3, preferably 3, with a mixture of 2,4'-MDI and 4,4'-MDI.

[0135] 40. The prepolymer is produced by reacting a poly(propylene oxide) polyol having a molecular weight (Mn) of 3,000 Da and a functional value of 3 with a 1:1 (weight:weight) mixture of 2,4'-MDI and 4,4'-MDI, one of the prior embodiments.

[0136] 41. Any one of the prior embodiments, wherein at least one polyol is used in component A in an amount of 10 to 40% by weight, more preferably 25 to 35% by weight, and particularly preferably 28 to 29% by weight, based on the total weight of component A.

[0137] 42. Any one of the prior embodiments, wherein at least one polyisocyanate is used in component A in an amount of 20-50% by weight, more preferably 30-40% by weight, and even more preferably 34-36% by weight, based on the total weight of component A.

[0138] 43. The NCO-terminated prepolymer preferably contains 40-50% by weight, more preferably 42-48% by weight, and particularly preferably 43-45% by weight of polyol, based on the total weight of the prepolymer, one of the prior embodiments.

[0139] 44. The NCO-terminated prepolymer preferably contains 50-60% by weight, more preferably 52-58% by weight, and particularly preferably 54-56% by weight of diisocyanate, based on the total weight of the prepolymer, one of the prior embodiments.

[0140] 45. Any one of the prior embodiments, in which the prepolymer is used without purification.

[0141] 46. ​​The prepolymer mixture is used in component A in an amount of 50-75% by weight, more preferably 55-70% by weight, and even more preferably 60-66% by weight, based on the total weight of component A, according to any one of the prior embodiments.

[0142] 47. Any one of the prior embodiments wherein component A additionally contains talc.

[0143] 48. Component A comprises 25-40% by weight, more preferably 30-40% by weight, and particularly preferably 32-37% by weight of talc, based on the total weight of component A, one of the prior embodiments.

[0144] 49. At least one polyol in component B is a polyol having a molecular weight (Mn) greater than 400 Da, one of the prior embodiments.

[0145] 50. At least one polyol in component B comprises a polyol having a molecular weight (Mn) of 400 to 1,000 Da, more preferably 500 to 1,000 Da, according to any one of the prior embodiments.

[0146] 51. At least one polyol in component B is a polyol having a functional value of 3 or more, one of the prior embodiments.

[0147] 52. One of the prior embodiments, wherein at least one polyol in component B has a functional value of 3 or more and a molecular weight (Mn) of 400 to 1,000 Da, more preferably 500 to 1,000 Da.

[0148] 53. At least one polyol in component B is any one of the prior embodiments, comprising a mixed polyol, in particular a mixture of a polyol having a functional value of 3 and a polyol having a functional value greater than 3.

[0149] 54. Any one of the prior embodiments wherein at least one polyol in component B comprises a polyether polyol.

[0150] 55. At least one polyol in component B is poly(C) 2~4 Any one of the prior embodiments includes an alkylene oxide polyol, particularly a poly(ethylene oxide), poly(propylene oxide), poly(butylene oxide) polyol, and a polyol selected from mixtures thereof.

[0151] 56. One of the prior embodiments wherein at least one polyol in component B is a polyol selected from poly(propylene oxide) polyols.

[0152] 57. Any one of the prior embodiments wherein at least one polyol in component B comprises a triol.

[0153] 58. At least one polyol in component B is poly(C) 2~4 One of the prior embodiments comprising an alkylene oxide-based triol, particularly a poly(propylene oxide)-based triol, or a triol selected from castor oil.

[0154] 59. Any one of the prior embodiments wherein at least one polyol in component B contains castor oil.

[0155] 60. At least one polyol in component B is any one of the prior embodiments, comprising a mixture of a polyether polyol and castor oil, particularly having a functional value of greater than 3, more preferably greater than 4, and especially preferably greater than 5.

[0156] Embodiment 60: A polyether polyol having a functional value greater than 61.3, more preferably greater than 4, and particularly preferably greater than 5, is a poly(propylene oxide) polyol.

[0157] 62. Component B is any one of the prior embodiments, comprising 40-60% by weight of a triol based on the total weight of component B.

[0158] 63. Component B comprises 0 to 10% by weight of a polyol having a functional value greater than 3, more preferably greater than 4, according to any one of the prior embodiments.

[0159] 64. Component B comprises 0 to 20% by weight of any one of the prior embodiments, comprising a polyol having a functional value greater than 2, more preferably 3, and a molecular weight of less than 500 Da, more preferably less than 400 Da.

[0160] 65. Component B is any one of the prior embodiments, comprising 40 to 60% by weight of a triol based on the total weight of component B, 0 to 10% by weight of a polyol having a functional value greater than 3, more preferably greater than 4, and 0 to 20% by weight of a polyol having a functional value greater than 2, more preferably 3, and a molecular weight of less than 500 Da, more preferably less than 400 Da.

[0161] 66. At least one polyol in component B comprises a mixture of 80-97% by weight, more preferably 85-95% by weight, and particularly preferably 91-94% by weight of castor oil and 3-20% by weight, more preferably 5-15% by weight, and particularly preferably 6-9% by weight of a polyether polyol, particularly having a functional value of greater than 3, more preferably greater than 4, and particularly preferably greater than 5 (where weight % is based on the total weight of the polyols in component B), one of the prior embodiments.

[0162] 67. One of the prior embodiments wherein at least one polyol in component B comprises a mixture of a triol in 80-97% by weight, more preferably 85-95% by weight, and particularly preferably 91-94% by weight, and a polyether polyol having a functional value greater than 3, more preferably greater than 4, and particularly preferably greater than 5, in 3-20% by weight, more preferably 5-15% by weight, and particularly preferably 6-9% by weight, based on the total weight of polyols in component B.

[0163] 68. At least one polyol in component B comprises any one of the prior embodiments, wherein the polyol comprises a mixture of poly(propylene oxide) having a functional value of 6 and castor oil.

[0164] 69. One of the prior embodiments wherein at least one polyol in component B comprises a mixture of castor oil in 80-97% by weight, more preferably 85-95% by weight, and particularly preferably 91-94% by weight, and a poly(propylene oxide) polyol having a functional value of 6 in 3-20% by weight, more preferably 5-15% by weight, and particularly preferably 6-9% by weight (where weight % is based on the total weight of the polyol in component B).

[0165] 70. Component B is any one of the prior embodiments, further comprising a catalyst capable of catalyzing the reaction between an isocyanate group and an OH group.

[0166] 71. The catalyst is any one of the prior embodiments, wherein the catalyst is a dioctyl tin mercaptide.

[0167] 72. The catalyst is used in any one of the prior embodiments at a concentration of 0.0005 to 0.002% by weight, more preferably 0.00075 to 0.0015% by weight, based on the total weight of component B.

[0168] 73. The catalyst is any one of the prior embodiments, which is a dioctyl tin mercaptide used in an amount of 0.0005 to 0.002% by weight, more preferably 0.00075 to 0.0015% by weight, based on the total weight of component B.

[0169] 74. Any one of the prior embodiments, wherein component B additionally contains talc.

[0170] 75. Any one of the prior embodiments wherein component B additionally comprises 20 to 50% by weight, more preferably 30 to 40% by weight, and particularly preferably 30 to 34% by weight of talc, based on the total weight of component B.

[0171] 76. The base material may be any one of the prior embodiments, including metal and plastic.

[0172] 77. The substrate is one of the prior embodiments, selected from e-coated steel, PET film, aluminum-deposited plastic film, and aluminum.

[0173] 78. The curing adhesive of the present invention (preferably with a volume ratio of 1:1 between component A and component B, curing time: 7 days, 23°C, 50%RH) has a bonding area of ​​250 mm² when measured according to DIN EN 1465. 2 One of the prior embodiments, which has a 10 x 25 mm, adhesive layer thickness of 1 mm, and uses e-coated steel on both substrates, exhibiting a lap shear strength of 4 MPa or more.

[0174] 79. Any one of the prior embodiments, wherein the pot life of the adhesive mixture obtained by mixing component A and component B (preferably in a volume ratio of 0.8:1 to 1.2:1, more preferably 1:1) is greater than 60 minutes, more preferably greater than 65 minutes.

[0175] 80. Any one of the prior embodiments, wherein an adhesive mixture obtained by mixing component A and component B (preferably in a volume ratio of 0.8:1 to 1.2:1, more preferably 1:1) has a tensile strength of 5 MPa or less when the sample is pulled at 50 mm / min, as measured according to DIN EN ISO 527-2 after curing at 23°C and 50% RH for 7 days.

[0176] 81. Any one of the prior embodiments, wherein an adhesive mixture obtained by mixing component A and component B (preferably in a volume ratio of 0.8:1 to 1.2:1, more preferably 1:1) has an E modulus of 15 or less when the sample is pulled at 50 mm / min, after being cured at 23°C and 50% RH for 7 days, as measured according to DIN EN ISO 527-2.

[0177] 82. Any one of the prior embodiments, wherein an adhesive mixture obtained by mixing component A and component B (preferably in a volume ratio of 0.8:1 to 1.2:1, more preferably 1:1) has a breaking elongation of 100% or more when the sample is pulled at 50 mm / min, measured according to DIN EN ISO 527-2 after curing at 23°C and 50% RH for 7 days. [Examples]

[0178] [Table 1]

[0179] Adhesive compounds Component A (Isocyanate) Preparation of prepolymers The prepolymers were prepared in a 2 L four-necked flask equipped with a mechanical stirring rod and a thermometer. The isocyanate-terminated prepolymer was first prepared by mixing the polyol raw material of component A and stirring under reduced pressure at 120°C for 1 hour. The polyol was cooled to 80°C, the isocyanate raw material was added, and the mixture was reacted under reduced pressure at 80°C for 2 hours. Next, the material was cooled to below 30°C. The vacuum was broken under nitrogen, and the prepolymer was sealed and stored until use.

[0180] A specific description of the prepolymerization process is given with respect to Example 6 of the present invention. 568 g of NJ-330 was added to a four-necked flask equipped with a mechanical stirring rod and a thermometer at room temperature. NJ-300 was dried under reduced pressure at 120°C for 1 hour. NJ-300 was cooled to 80°C, 712 g of MDI-50 was added to the flask, and the mixture was reacted under reduced pressure at 80°C for 2 hours. The material was cooled to below 30°C. The vacuum was broken under nitrogen, and the prepolymer was sealed and stored until use. The prepolymer was prepared with an excess of isocyanate, mainly yielding an NCO-terminated prepolymer.

[0181] To prepare component A using the quantities listed in Table 2, talc and fumed silica were dried in an oven at 120°C for at least 24 hours until the moisture content was less than 300 ppm. The prepolymer was added to a 2 L planetary mixer and mixed for 10 minutes. The dried talc and silica were added, and stirring was continued at room temperature for a further 30 minutes. The vacuum was then broken under nitrogen, and component A was packaged in a sealed cartridge and stored until use.

[0182] A specific description of the preparation of component A is given in relation to Example 6 of the present invention. Solid talc and CAB-O-SIL TS-720 were dried in an oven at 120°C for at least 24 hours until the moisture content was less than 300 ppm. 640 g of prepolymer, 345 g of talc, and 15 g of CAB-O-SIL were added together with red pigment to a 2 L planetary mixer. After mixing at room temperature for 30 minutes, the vacuum was broken with nitrogen and the adhesive component could be filled into appropriate packaging sizes.

[0183] Component B (Polyol) To prepare component B (polyol) using the quantities listed in Table 2, talc and CAB-O-SIL TS-720 were dried in an oven at 120°C for at least 24 hours until the moisture content was less than 300 ppm. The polyol was dried using a molecular sieve until the moisture content was less than 300 ppm. The dried raw materials were mixed with the polyol and stirred for 30 minutes. The molecular sieve and Fomrez UL-29 were added and stirred for another 30 minutes. The vacuum was broken under nitrogen and component B was filled into a sealed cartridge until use.

[0184] Components A and B were stored separately until use. Immediately before use, the components were mixed in a 1:1 volume ratio, and the following tests were performed.

[0185] pot life Pot life is defined as the time it takes for the rheological viscosity to simultaneously reach 900 Pas at a shear rate of 0.25 / second, 500 Pas at a shear rate of 1 / second, and 300 Pas at a shear rate of 2.5 / second. The results are listed in Table 2.

[0186] Rheological viscosity The rheological viscosity is measured 60 minutes after mixing components A and B, using a TA rheometer with 25 mm parallel plates and a 0.2 mm gap.

[0187] The results are listed in Table 2.

[0188] lap shear strength The overlap shear strength was determined using DIN EN 1465, with a bonding area of ​​250 mm². 2 Measurements were taken using e-coated steel (10 × 25 mm), with an adhesive layer thickness of 1 mm on both substrates. All surfaces were prepared by cleaning with isopropanol before applying the adhesive. Curing conditions were 7 days at 23°C with 50% RH. During the test, the shear specimens were pulled at 5 mm / min. The results are listed in Table 2.

[0189] Tensile properties Tensile strength, E modulus, and elongation were measured according to DIN EN ISO 527-2. Curing conditions: 7 days at 23°C with 50% RH. During the test process, the tensile specimen was pulled at 50 mm / min. The results are listed in Table 2.

[0190] [Table 2]

[0191] [Table 3]

[0192] result Example 6 of the present invention exhibits a pot life of more than 60 minutes, while the comparative example exhibits a pot life of less than 60 minutes.

[0193] Example 6 of the present invention shows a more gradual increase in viscosity than the comparative example.

[0194] Example 6 of the present invention exhibits higher elasticity than the comparative example (lower E modulus and higher elongation at fracture).

Claims

1. A two-component thermally conductive polyurethane adhesive, (A) Component A: (ai) An NCO-terminated prepolymer produced by reacting at least one polyol having a molecular weight (Mn) greater than 2,000 Da and an OH functional value of 2 to 3, in an amount of 25 to 35% by weight based on the total weight of component A, with a polyisocyanate which is a mixture of 2,4'-methylene-bis-(phenylisocyanate) (MDI) and 4,4'-MDI, in an amount of 30 to 45% by weight based on the total weight of component A, and (aii) Based on the total weight of component A, 30-40% by weight of talc, (B) Component B: (bi) At least one polyol having a molecular weight (Mn) of less than 1,000 Da and an OH functional value of at least 2, (bii) A catalyst capable of selectively catalyzing the reaction between an OH group and an NCO group, and (biiii) Based on the total weight of component B, 30-40% by weight of talc, Adhesives, including adhesives.

2. The adhesive according to claim 1, wherein the polyol used to produce the prepolymer is selected from polyether polyols.

3. The adhesive according to claim 2, wherein the polyol used to produce the prepolymer is selected from poly(propylene oxide) polyols.

4. The adhesive according to claim 1, wherein the polyol used to produce the prepolymer has a functional value of 2.5 to 3.

5. The polyol used to produce the prepolymer is a poly(C) having a functional value of 2.5 to 3. ２～４ The adhesive according to claim 4, wherein the adhesive is an alkylene oxide polyol.

6. The adhesive according to claim 4, wherein the polyol used to produce the prepolymer is a poly(propylene oxide) polyol having a functional value of 2.5 to 3.

7. The adhesive according to claim 1, wherein the polyol used to produce the prepolymer has a molecular weight (Mn) greater than 2,500 Da.

8. The adhesive according to claim 1, wherein the weight ratio of 2,4'-MDI to 4,4'-MDI is 0.667 to 1.

5.

9. The adhesive according to claim 1, wherein the polyisocyanate is used in component A at a concentration of 30 to 40% by weight based on the total weight of component A.

10. The adhesive according to claim 1, wherein the at least one polyol in component B comprises a polyol having a molecular weight (Mn) greater than 400 Da.

11. The adhesive according to claim 10, wherein the at least one polyol in component B comprises a polyol having a molecular weight (Mn) of 400 to 1,000 Da.

12. The adhesive according to claim 10, wherein the at least one polyol in component B includes a polyol having a functional value of 3 or more.

13. The adhesive according to claim 2, wherein the at least one polyol in component B comprises a mixture of polyols comprising at least one polyol having a functional value of 3 and at least one other polyol having a functional value greater than 3.

14. The at least one polyol in component B is poly(C) ２～４ The adhesive according to claim 2, comprising an alkylene oxide triol or a triol selected from castor oil.

15. The adhesive according to claim 2, wherein the at least one polyol in component B comprises a mixture of a polyether polyol having a functional value greater than 3 and castor oil.

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