Single-component polyurethane adhesive as well as preparation method and application thereof

Abstract

The invention provides a single-component polyurethane adhesive as well as a preparation method and application thereof. The single-component polyurethane adhesive is prepared from the following raw materials: a polyurethane prepolymer A, a polyurethane prepolymer B, a plasticizer, a filler, carbon black, a water absorbent, a catalyst a and a catalyst b, the preparation raw materials of the polyurethane prepolymer A comprise polyether polyol and first isocyanate; and the polyurethane prepolymer B is prepared from the following raw materials: micromolecular dihydric alcohol and diisocyanate. The single-component polyurethane adhesive provided by the invention has the characteristics of high modulus and high elongation.

Description

Technical Field

[0001] The invention belongs to the technical field of polyurethane adhesives, and in particular relates to a single-component polyurethane adhesive and a preparation method and application thereof. Background Art

[0002] With the development of vehicle manufacturing technology and the improvement of glass production technology, sunroof glass is gradually replaced by larger skylight glass. The connection between skylight glass and the car body is similar to the front and rear windshields and traditional sunroof glass. In most cases, single-component polyurethane adhesives are used. According to CAE analysis, with the increase in the modulus of single-component polyurethane adhesives, the torsional stiffness of passenger cars equipped with skylight glass can be improved by a certain proportion (2% to 5%), and at the same time, the noise of the whole vehicle can also be reduced to a certain extent (2 to 4dB). Therefore, the development of single-component polyurethane adhesives with higher modulus has important practical significance and broad application prospects.

[0003] The tensile modulus (1% to 10% elongation) of the single-component polyurethane adhesive currently on the market is basically between 1.0 and 3.0 MPa, and its contribution to the torsional stiffness and noise of the vehicle is limited. The tensile modulus of the single-component polyurethane adhesive can be increased by adding multifunctional isocyanates, but at the same time it will lead to a rapid decrease in the elongation at break.

[0004] CN110423592A discloses a two-component polyurethane adhesive and a preparation method thereof, wherein the two-component polyurethane adhesive is mainly composed of two components A and B, wherein the mass ratio of the two components A and B is 1:1; wherein the component A comprises 10wt% to 35wt% of castor oil polyol, 10wt% to 40wt% of polyester polyol, 5wt% to 30wt% of polyether polyol, 1wt% to 10wt% of hindered amine chain extender, 10wt% to 40wt% of plasticizer, 1wt% to 15wt% of modulus reducer, and The organic filler comprises 30wt% to 60wt%, the coupling agent comprises 0.5wt% to 3wt%, the catalyst comprises 0.1wt% to 0.5wt%, and the thermosensitive catalyst comprises 0.1wt% to 0.5wt%; the B component comprises 5wt% to 40wt% of liquefied diphenylmethane diisocyanate, 10wt% to 60wt% of polymethylene polyphenyl polyisocyanate, 20wt% to 40wt% of polyether polyol, 10wt% to 80wt% of inorganic filler, 1wt% to 10wt% of thixotropic agent, and 0.5wt% to 3wt% of dewatering agent. The two-component polyurethane adhesive provided by the technical solution has the characteristics of rapid curing, high bonding strength, and high seismic requirements for attachment bonding, but the tensile modulus is still relatively low and needs to be further improved.

[0005] CN108587548A discloses a silane-terminated modified polycarbonate polyurethane adhesive resin and its preparation method and application. The silane-terminated modified polycarbonate polyurethane adhesive resin is characterized in that it is obtained by reacting the following raw materials: based on the weight of the resin, (a) polycarbonate resin, the glass transition temperature of which is lower than 30°C, the amount of which is 50wt% to 95wt%, preferably 70wt% to 90wt%; (b) silane coupling agent with primary amino group, the amount of which is 4wt% to 45wt%, preferably 9wt% to 29wt%; (c) catalyst, the amount of which is 0.1wt% to 10wt%, preferably 0.2wt% to 1wt%. The silane-terminated modified polycarbonate polyurethane adhesive resin has high modulus and high strength, and is suitable for the preparation of automobile windshield adhesive, but has low shear strength and the tensile modulus still needs to be further improved.

[0006] Therefore, it is necessary to develop a one-component polyurethane adhesive with high modulus and high elongation. Summary of the invention

[0007] In view of the shortcomings of the prior art, the present invention aims to provide a one-component polyurethane adhesive and a preparation method and application thereof. The one-component polyurethane adhesive has the characteristics of high tensile shear strength, high modulus and high elongation.

[0008] To achieve this object, the present invention adopts the following technical solutions:

[0009] In a first aspect, the present invention provides a one-component polyurethane adhesive, wherein the raw materials for preparing the one-component polyurethane adhesive include the following components: polyurethane prepolymer A, polyurethane prepolymer B, plasticizer, filler, carbon black, water absorbent, catalyst a and catalyst b;

[0010] The raw materials for preparing the polyurethane prepolymer A include polyether polyol and a first isocyanate;

[0011] The raw materials for preparing the polyurethane prepolymer B include small molecule diol and the second isocyanate.

[0012] In the present invention, the polyurethane prepolymer A and the polyurethane prepolymer B have a synergistic effect and are compounded with a plasticizer, a filler, carbon black, a water absorbent, a catalyst a and a catalyst b, so that the one-component polyurethane adhesive can achieve a higher tensile modulus while ensuring basic mechanical properties (tensile shear strength ≥5MPa, elongation at break ≥250%) and construction performance (pressure flow viscometer, 4mm pore diameter, extrudability under 0.4MPa pressure reaches 10g / min).

[0013] Preferably, the molar ratio of the isocyanate group of the first isocyanate to the hydroxyl group of the polyether polyol in the preparation raw material of the polyurethane prepolymer A is (2.1-2.5):1, for example, 2.15:1, 2.2:1, 2.25:1, 2.3:1, 2.35:1, 2.4:1 or 2.45:1, etc.

[0014] In the present invention, the molar ratio of the isocyanate group to the hydroxyl group is recorded as NCO / OH.

[0015] Preferably, the polyether polyol is a polyether triol.

[0016] Preferably, the weight average molecular weight of the polyether polyol is 3000-6000 (eg, 3300, 3600, 3900, 4200, 4500, 4800, 5100, 5400 or 5700, etc.), more preferably 4500-5000.

[0017] In the present invention, the weight average molecular weight of the polyether polyol is more preferably 4500 to 5000. If the weight average molecular weight of the polyether polyol is too large, the tensile strength decreases and the elongation at break increases; if the weight average molecular weight of the polyether polyol is too small, the tensile strength increases, but the elongation at break decreases significantly.

[0018] Preferably, the hydroxyl value of the polyether triol is 28 to 56 mgKOH / g (for example, 30 mgKOH / g, 33 mgKOH / g, 36 mgKOH / g, 39 mgKOH / g, 42 mgKOH / g, 45 mgKOH / g, 48 mgKOH / g, 51 mgKOH / g or 54 mgKOH / g, etc.), and more preferably 33.6 to 37.3 mgKOH / g.

[0019] Preferably, the first isocyanate and the second isocyanate each independently comprise an aromatic polyisocyanate and / or an aliphatic polyisocyanate.

[0020] Preferably, the aromatic polyisocyanate includes any one of toluene diisocyanate, diphenylmethane diisocyanate, 1,4-phenylene diisocyanate (PPDI), xylylene diisocyanate (XDI), tetramethylxylylene diisocyanate (TMXDI), toluidine diisocyanate (TODI) or 1,5-naphthalene diisocyanate (NDI) or a combination of at least two thereof.

[0021] Preferably, the toluene diisocyanate includes 2,4-toluene diisocyanate (2,4-TDI) and / or 2,6-toluene diisocyanate (2,6-TDI).

[0022] Preferably, the diphenylmethane diisocyanate includes 4,4'-diphenylmethane diisocyanate (4,4'-MDI) and / or 2,4'-diphenylmethane diisocyanate (2,4'-MDI).

[0023] Preferably, the aliphatic polyisocyanate includes any one or a combination of at least two of hexamethylene diisocyanate (HDI), trimethylhexamethylene diisocyanate (TMHDI), 1,5-pentane diisocyanate (PDI), lysine diisocyanate (LDI), norbornane diisocyanate (NBDI), trans-cyclohexane-1,4-diisocyanate (TCDI), isophorone diisocyanate (IPDI), bis(isocyanatemethyl)cyclohexane (H6XDI) or dicyclohexylmethane diisocyanate (H12MDI).

[0024] Preferably, the first isocyanate is diphenylmethane diisocyanate, and more preferably 4,4'-diphenylmethane diisocyanate.

[0025] Preferably, the second isocyanate is any one of xylylene diisocyanate, hexamethylene diisocyanate, lysine diisocyanate or 1,5-pentamethylene diisocyanate, or a combination of at least two thereof, and more preferably xylylene diisocyanate.

[0026] Preferably, the preparation method of the polyurethane prepolymer A comprises the following steps: heating the polyether polyol to dehydrate it, cooling it, mixing it with the first isocyanate and the catalyst c to react, so as to obtain the polyurethane prepolymer A.

[0027] Preferably, the heating dehydration in the preparation method of polyurethane prepolymer A includes heating to 110-130°C (e.g., 113°C, 116°C, 119°C, 122°C, 125°C or 128°C, etc.) under stirring for dehydration for 1.5-2.5h (e.g., 1.6h, 1.7h, 1.8h, 1.9h, 2.0h, 2.1h, 2.2h, 2.3h or 2.4h, etc.).

[0028] Preferably, in the method for preparing the polyurethane prepolymer A, the cooling is to 30-50° C. (eg, 33° C., 36° C., 39° C., 42° C., 45° C., or 48° C., etc.).

[0029] Preferably, the reaction temperature in the preparation method of polyurethane prepolymer A is 75-90°C (for example, 77°C, 79°C, 81°C, 83°C, 85°C, 87°C or 89°C, etc.), and the reaction time is 2-6h (for example, 2.5h, 3h, 3.5h, 4h, 4.5h, 5h or 5.5h, etc.).

[0030] Preferably, the catalyst c comprises any one of dioctyltin dilaurate, dibutyltin dilaurate, dimethyltin dilaurate, stannous octoate, dibutyltin oxide or dioctyltin oxide, or a combination of at least two thereof.

[0031] Preferably, the mass of the catalyst c is 0.001% to 0.05% (e.g., 0.005%, 0.01%, 0.015%, 0.02%, 0.025%, 0.03%, 0.035%, 0.04% or 0.045%) of the total mass of the polyether polyol and the first isocyanate.

[0032] Preferably, the molar ratio of the isocyanate group of the second isocyanate to the hydroxyl group of the small molecule diol in the preparation raw material of the polyurethane prepolymer B is (2.0-2.2):1, for example, 2.02:1, 2.04:1, 2.06:1, 2.08:1, 2.10:1, 2.12:1, 2.14:1, 2.16:1 or 2.18:1, etc.

[0033] Preferably, the small molecule diol includes a linear small molecule diol and / or a non-linear small molecule diol, and more preferably a non-linear small molecule diol.

[0034] In the present invention, the raw materials for preparing the polyurethane prepolymer B contain a relatively high content of isocyanate, which provides a higher modulus. At the same time, the addition of nonlinear small molecule diols enables the polyurethane prepolymer B to maintain a high modulus while also improving toughness compared to the use of linear small molecule diols.

[0035] Preferably, the linear small molecule diol includes any one of ethylene glycol, 1,4-butanediol, 1,6-hexanediol, bisphenol A or bisphenol-propylene oxide adduct, or a combination of at least two thereof.

[0036] Preferably, the nonlinear small molecule diol includes any one of 2-methyl-1,3-propanediol, 2-methyl-2,4-pentanediol, 2-ethyl-1,3-ethanediol or 2-ethyl-1,3-hexanediol, or a combination of at least two thereof, and more preferably 2-ethyl-1,3-hexanediol.

[0037] Preferably, the preparation method of the polyurethane prepolymer B comprises the following steps: heating and dehydrating the small molecule diol, cooling and mixing with the second isocyanate to react, so as to obtain the polyurethane prepolymer B.

[0038] Preferably, the heating dehydration in the preparation method of the polyurethane prepolymer B includes heating to 110-130°C (e.g., 113°C, 116°C, 119°C, 122°C, 125°C or 128°C, etc.) under stirring for dehydration for 1.5-2.5h (e.g., 1.6h, 1.7h, 1.8h, 1.9h, 2.0h, 2.1h, 2.2h, 2.3h or 2.4h, etc.).

[0039] Preferably, in the method for preparing the polyurethane prepolymer B, the cooling is to 30-50° C. (eg, 33° C., 36° C., 39° C., 42° C., 45° C., or 48° C., etc.).

[0040] Preferably, the reaction temperature in the preparation method of polyurethane prepolymer B is 75-90°C (for example, 77°C, 79°C, 81°C, 83°C, 85°C, 87°C or 89°C, etc.), and the reaction time is 2-6h (for example, 2.5h, 3h, 3.5h, 4h, 4.5h, 5h or 5.5h, etc.).

[0041] Preferably, the plasticizer includes any one of alkyl sulfonate, phthalate, tricresyl phosphate or trioctyl phosphate, or a combination of at least two thereof, and more preferably phthalate.

[0042] Preferably, the plasticizer is a plasticizer obtained by vacuum dehydration at 110-130°C (e.g., 113°C, 116°C, 119°C, 122°C, 125°C or 128°C, etc.) for 1.5-2.5h (e.g., 1.6h, 1.7h, 1.8h, 1.9h, 2.0h, 2.1h, 2.2h, 2.3h or 2.4h, etc.).

[0043] Preferably, the phthalate ester includes any one of dioctyl phthalate (DOP), butyl phthalate (DBP), diisooctyl phthalate (DIOP), diisodecyl phthalate (DIDP) or diisononyl phthalate (DINP) or a combination of at least two thereof, and more preferably diisodecyl phthalate.

[0044] Preferably, the filler comprises any one of silicon dioxide, heavy calcium carbonate, talc, clay, organic bentonite, hydrogenated castor oil or barium sulfate, or a combination of at least two thereof.

[0045] Preferably, the carbon black includes any one of gas furnace carbon black, oil furnace carbon black, oil-gas furnace carbon black, thermal cracking carbon black or acetylene carbon black, or a combination of at least two thereof.

[0046] Preferably, the water absorbent comprises any one of alkylsulfonic acid isocyanate, calcium oxide or molecular sieve, or a combination of at least two thereof.

[0047] Preferably, the catalyst a comprises an organic tin metal catalyst and / or an organic bismuth metal catalyst.

[0048] Preferably, the organotin metal catalyst includes any one of dioctyltin dilaurate, dibutyltin dilaurate, dimethyltin dilaurate, dioctyltin dimaleate, dibutyltin dimaleate, dimethyltin dimaleate, dioctyltin dithiol, dibutyltin dithiol, dimethyltin dithiol, stannous octoate, butyl tin oxide or octyl tin oxide, or a combination of at least two thereof.

[0049] Preferably, the organic bismuth metal catalyst includes any one of bismuth neodecanoate, bismuth laurate, bismuth isooctanoate or bismuth cyclohexaneate, or a combination of at least two thereof.

[0050] Preferably, the catalyst b comprises a tertiary amine catalyst.

[0051] Preferably, the tertiary amine catalyst includes any one or a combination of at least two of N,N-dimethylcyclohexylamine, bis(2-dimethylaminoethyl) ether, bismorpholine diethyl ether, N,N,N',N'-tetramethylalkylenediamine, triethylamine or N,N-dimethylbenzylamine.

[0052] Preferably, the raw materials for preparing the one-component polyurethane adhesive include the following components in parts by weight: 30-45 parts of polyurethane prepolymer A (for example, 32 parts, 34 parts, 36 parts, 38 parts, 40 parts, 42 parts or 44 parts, etc.), 3-5 parts of polyurethane prepolymer B (for example, 3.2 parts, 3.4 parts, 3.6 parts, 3.8 parts, 4 parts, 4.2 parts, 4.4 parts, 4.6 parts or 4.8 parts, etc.), 15-25 parts of plasticizer (for example, 16 parts, 17 parts, 18 parts, 19 parts, 20 parts, 21 parts, 22 parts, 23 parts or 24 parts, etc.), 10 parts of filler ~20 parts (for example, 11 parts, 12 parts, 13 parts, 14 parts, 15 parts, 16 parts, 17 parts, 18 parts or 19 parts, etc.), carbon black 15-25 parts (for example, 16 parts, 17 parts, 18 parts, 19 parts, 20 parts, 21 parts, 22 parts, 23 parts or 24 parts, etc.), water absorbent 0.1-1 part (for example, 0.2 parts, 0.3 parts, 0.4 parts, 0.5 parts, 0.6 parts, 0.7 parts, 0.8 parts or 0.9 parts, etc.), catalyst a 0.01 to 1 part (e.g. 0.1, 0.2, 0.3, 0.4, 0.5, 0.6, 0.7, 0.8 or 0.9 part, etc.) and catalyst a 0.01 to 1 part (e.g. 0.1, 0.2, 0.3, 0.4, 0.5, 0.6, 0.7, 0.8 or 0.9 part, etc.).

[0053] In a second aspect, the present invention provides a method for preparing the one-component polyurethane adhesive as described in the first aspect, the preparation method comprising the following steps: mixing polyurethane prepolymer A, polyurethane prepolymer B, plasticizer, filler, carbon black, water absorbent, catalyst a and catalyst b to obtain the one-component polyurethane adhesive.

[0054] Preferably, the moisture content in the filler is ≤1000 ppm, for example, 300 ppm, 400 ppm, 500 ppm, 600 ppm, 700 ppm, 800 ppm or 900 ppm.

[0055] Preferably, the moisture content in the carbon black is ≤1000 ppm, for example, 300 ppm, 400 ppm, 500 ppm, 600 ppm, 700 ppm, 800 ppm or 900 ppm.

[0056] Preferably, the preparation method specifically comprises the following steps: first mixing polyurethane prepolymer A, polyurethane prepolymer B, plasticizer, filler, carbon black and water absorbent under vacuum conditions, and secondly mixing by adding catalyst a and catalyst b to obtain the one-component polyurethane adhesive.

[0057] Preferably, the vacuum degree of the vacuum condition is -1000 to -950 mbar, for example, -995 mbar, -990 mbar, -985 mbar, -980 mbar, -975 mbar, -970 mbar, -965 mbar, -960 mbar or -955 mbar.

[0058] In a third aspect, the present invention provides a use of the one-component polyurethane adhesive as described in the first aspect in bonding skylight glass.

[0059] Compared with the prior art, the present invention has the following beneficial effects:

[0060] In the present invention, the one-component polyurethane adhesive prepared by compounding the polyurethane prepolymer A, polyurethane prepolymer B, plasticizer, filler, carbon black, water absorbent, catalyst a and catalyst b components has the characteristics of high modulus and high elongation under the premise of ensuring basic mechanical properties and construction performance. The tensile modulus of the one-component polyurethane adhesive is ≥9.5MPa, the tensile strength is ≥8.6MPa, the elongation at break is ≥250%, and the tensile shear strength is ≥5.6MPa. DETAILED DESCRIPTION

[0061] The technical solution of the present invention is further described below by specific implementation methods. It should be understood by those skilled in the art that the embodiments are only to help understand the present invention and should not be regarded as specific limitations of the present invention.

[0062] The sources of some raw materials in the preparation examples, embodiments and comparative examples are as follows:

[0063] Polyether triol: The average weight-average molecular weight is 4600, from Yantai Wanhua Chemical Group;

[0064] Polyether triol: The average weight-average molecular weight is 6000 and comes from Yantai Wanhua Chemical Group;

[0065] 2-Ethyl-1,3-hexanediol, from Jiangsu Runfeng Synthetic Technology Co., Ltd.;

[0066] 4,4'-diphenylmethane diisocyanate, MDI-50, from Yantai Wanhua Chemical Group;

[0067] xylylene diisocyanate, from Mitsui Chemicals;

[0068] Diisononyl phthalate, from ExxonMobil (China) Co., Ltd.;

[0069] Filler: Clay B-95, from Shanxi Jinyu Kelin Technology Co., Ltd.;

[0070] Carbon black: M-580 from Cabot;

[0071] Water absorbent: TI, from Bayer;

[0072] Catalyst a: bismorpholine diethyl ether, from Air Products and Chemicals, USA;

[0073] Catalyst b: UL-29, from Momentive High-Tech Materials.

[0074] Preparation Example 1

[0075] This preparation example provides a polyurethane prepolymer A, specifically a polyurethane prepolymer A1, which is prepared by the following method:

[0076] The polyether triol ( The average weight-average molecular weight is 4600) 1500g, heated to 130°C for dehydration for 2 hours, then cooled to 50°C, added with the first isocyanate (4,4'-diphenylmethane diisocyanate) 258g (at this time NCO / OH=2.2), dioctyltin dilaurate 0.82g, mixed, heated to 85°C for reaction for 2h, the tested NCO content reached 2.69%, cooled to 50°C, and the polyurethane prepolymer A1 was obtained.

[0077] Preparation Example 2

[0078] This preparation example provides a polyurethane prepolymer A, specifically a polyurethane prepolymer A2, which is prepared by the following method:

[0079] The polyether triol ( The average weight-average molecular weight is 6000) 1500g, heated to 130℃ for dehydration for 2 hours, then cooled to 50℃, added with the first isocyanate (4,4'-diphenylmethane diisocyanate) 206g (at this time NCO / OH=2.2), dioctyltin dilaurate 0.82g, mixed, heated to 85℃ for reaction for 2h, the tested NCO content reached 2.21%, cooled to 50℃, and the polyurethane prepolymer A2 was obtained.

[0080] Preparation Example 3

[0081] This preparation example provides a polyurethane prepolymer A, specifically a polyurethane prepolymer A3, which is prepared by the following method:

[0082] The polyether triol ( The average weight-average molecular weight is 4600) 1500g, heated to 130°C for dehydration for 2 hours, then cooled to 50°C, added with 173g of the first isocyanate (hexamethylene diisocyanate) (at this time NCO / OH=2.2), 0.82g of dioctyltin dilaurate, mixed, heated to 85°C for reaction for 2h, the tested NCO content reached 2.81%, cooled to 50°C, and the polyurethane prepolymer A3 was obtained.

[0083] Preparation Example 4

[0084] This preparation example provides a polyurethane prepolymer B, specifically a polyurethane prepolymer B1, which is prepared by the following method:

[0085] 500 g of a small molecule diol (2-ethyl-1,3-hexanediol) was heated to 130°C for dehydration for 2 hours, then cooled to 50°C and added with 1350 g of a second isocyanate (xylylene diisocyanate) (at this time NCO / OH=2.1). After mixing, the temperature was raised to 85°C for reaction for 2 hours. When the tested NCO content reached 17.30%, the temperature was lowered to 50°C to obtain the polyurethane prepolymer B1.

[0086] Preparation Example 5

[0087] This preparation example provides a polyurethane prepolymer B, specifically a polyurethane prepolymer B2, which is prepared by the following method:

[0088] 500 g of small molecule diol (2-ethyl-1,3-hexanediol) was heated to 130°C for dehydration for 2 hours, then cooled to 50°C and added with 1110 g of the second isocyanate (1,5-pentane diisocyanate) (NCO / OH=2.1 at this time). After mixing, the temperature was raised to 85°C for reaction for 2 hours. When the tested NCO content reached 19.7%, the temperature was lowered to 50°C to obtain the polyurethane prepolymer B2.

[0089] Preparation Example 6

[0090] This preparation example provides a polyurethane prepolymer B, specifically a polyurethane prepolymer B3, which is prepared by the following method:

[0091] 500 g of a small molecule diol (2-methyl-1,3-propanediol) was heated to 130°C for dehydration for 2 hours, then cooled to 50°C and added with 1478 g of a second isocyanate (xylene diisocyanate) (at this time NCO / OH=2.1). After mixing, the temperature was raised to 85°C for reaction for 2 hours. When the tested NCO content reached 18.6%, the temperature was lowered to 50°C to obtain the polyurethane prepolymer B3.

[0092] Preparation Example 7

[0093] This preparation example provides a polyurethane prepolymer B, specifically a polyurethane prepolymer B4, which is prepared by the following method:

[0094] 500 g of small molecule diol (1,6-hexanediol) was heated to 130°C for dehydration for 2 hours, then cooled to 50°C and added with 1673 g of the second isocyanate (xylene diisocyanate) (NCO / OH=2.1 at this time). After mixing, the temperature was raised to 85°C for reaction for 2 hours. When the tested NCO content reached 18.0%, the temperature was lowered to 50°C to obtain the polyurethane prepolymer B4.

[0095] Example 1

[0096] The present embodiment provides a one-component polyurethane adhesive and a preparation method thereof. The raw materials for preparing the one-component polyurethane adhesive include the following components in parts by weight: 40 parts of the polyurethane prepolymer A1 provided in Preparation Example 1, 4 parts of the polyurethane prepolymer B1 provided in Preparation Example 4, 20 parts of a plasticizer (diisononyl phthalate), 15 parts of a filler (clay B-95), 20 parts of carbon black (M-580), 0.5 parts of a water absorbent (TI), 0.1 parts of a catalyst a (bismorpholine diethyl ether), and 0.02 parts of a catalyst b (UL-29).

[0097] The preparation method comprises the following steps:

[0098] The polyurethane prepolymer A1 provided in Preparation Example 1, the polyurethane prepolymer B1 provided in Preparation Example 4, a plasticizer, a filler, carbon black and a water absorbent were mixed under vacuum conditions (vacuum degree of 980 mbar), and then catalyst a and catalyst b were added and stirred evenly to obtain the one-component polyurethane adhesive.

[0099] The above plasticizer is a plasticizer obtained by vacuum dehydration at 110°C for 2 hours;

[0100] The filler was dried in an oven at 120°C for 7 days, and the moisture content was 800 ppm;

[0101] The above carbon black is obtained by drying in an oven at 120°C for 7 days, and the moisture content is 800 ppm.

[0102] Example 2

[0103] This embodiment provides a one-component polyurethane adhesive and a preparation method thereof. The only difference between this embodiment and Example 1 is that the weight fraction of the polyurethane prepolymer B1 provided in Preparation Example 4 is adjusted to 3 parts, and other conditions are the same as those in Example 1.

[0104] Example 3

[0105] This embodiment provides a one-component polyurethane adhesive and a preparation method thereof, which differs from Example 1 only in that the raw materials for preparing the one-component polyurethane adhesive include the following components in parts by weight: 45 parts of the polyurethane prepolymer A1 provided in Preparation Example 1, 3 parts of the polyurethane prepolymer B1 provided in Preparation Example 4, 15 parts of a plasticizer (diisononyl phthalate), 15 parts of a filler (clay B-95), 20 parts of carbon black (M-580), 0.5 parts of a water absorbent (TI), 0.1 parts of a catalyst a (bismorpholine diethyl ether) and 0.02 parts of a catalyst b (UL-29), and other conditions are the same as in Example 1.

[0106] Example 4

[0107] This embodiment provides a one-component polyurethane adhesive and a preparation method thereof, which differs from Example 1 only in that the raw materials for preparing the one-component polyurethane adhesive include the following components in parts by weight: 30 parts of the polyurethane prepolymer A1 provided in Preparation Example 1, 5 parts of the polyurethane prepolymer B1 provided in Preparation Example 4, 20 parts of a plasticizer (diisononyl phthalate), 20 parts of a filler (clay B-95), 25 parts of carbon black (M-580), 0.5 parts of a water absorbent (TI), 0.1 parts of a catalyst a (bismorpholine diethyl ether) and 0.02 parts of a catalyst b (UL-29), and other conditions are the same as in Example 1.

[0108] Example 5

[0109] This embodiment provides a one-component polyurethane adhesive and a preparation method thereof, which differs from Example 1 only in that the raw materials for preparing the one-component polyurethane adhesive include the following components in parts by weight: 35 parts of the polyurethane prepolymer A1 provided in Preparation Example 1, 5 parts of the polyurethane prepolymer B1 provided in Preparation Example 4, 20 parts of a plasticizer (diisononyl phthalate), 20 parts of a filler (clay B-95), 20 parts of carbon black (M-580), 0.5 parts of a water absorbent (TI), 0.1 parts of a catalyst a (bismorpholine diethyl ether) and 0.02 parts of a catalyst b (UL-29), and other conditions are the same as in Example 1.

[0110] Example 6

[0111] This embodiment provides a one-component polyurethane adhesive and a preparation method thereof, which differs from Example 1 only in that the polyurethane prepolymer A1 provided in Preparation Example 1 is replaced with the polyurethane prepolymer A2 provided in Preparation Example 2 of the same mass, and other conditions are the same as in Example 1.

[0112] Example 7

[0113] This embodiment provides a one-component polyurethane adhesive and a preparation method thereof, which differs from Example 1 only in that the polyurethane prepolymer A1 provided in Preparation Example 1 is replaced with the polyurethane prepolymer A3 provided in Preparation Example 3 of the same mass, and other conditions are the same as in Example 1.

[0114] Example 8

[0115] This embodiment provides a one-component polyurethane adhesive and a preparation method thereof, which differs from Example 1 only in that the polyurethane prepolymer B1 provided in Preparation Example 1 is replaced with the polyurethane prepolymer B2 provided in Preparation Example 5 of the same mass, and other conditions are the same as in Example 1.

[0116] Example 9

[0117] This embodiment provides a one-component polyurethane adhesive and a preparation method thereof, which differs from Example 1 only in that the polyurethane prepolymer B1 provided in Preparation Example 1 is replaced with the polyurethane prepolymer B3 provided in Preparation Example 6 of the same mass, and other conditions are the same as in Example 1.

[0118] Example 10

[0119] This embodiment provides a one-component polyurethane adhesive and a preparation method thereof, which differs from Example 1 only in that the polyurethane prepolymer B1 provided in Preparation Example 1 is replaced with the polyurethane prepolymer B4 provided in Preparation Example 7 of the same mass, and other conditions are the same as in Example 1.

[0120] Embodiment 11

[0121] This embodiment provides a one-component polyurethane adhesive and a preparation method thereof, which is different from Example 1 only in that the weight fraction of the polyurethane prepolymer A1 provided in Preparation Example 1 is adjusted to 25 parts, and other conditions are the same as those in Example 1.

[0122] Example 12

[0123] This embodiment provides a one-component polyurethane adhesive and a preparation method thereof, which is different from Example 1 only in that the weight fraction of the polyurethane prepolymer A1 provided in Preparation Example 1 is adjusted to 50 parts, and other conditions are the same as those in Example 1.

[0124] Comparative Example 1

[0125] This comparative example provides a one-component polyurethane adhesive and a preparation method thereof, which differs from Example 1 only in that the polyurethane prepolymer B1 provided in Preparation Example 4 is replaced with a polyisocyanate (HDI trimer) of the same mass, and other conditions are the same as those in Example 1.

[0126] Comparative Example 2

[0127] This comparative example provides a one-component polyurethane adhesive and a preparation method thereof, which differs from Example 6 only in that the polyurethane prepolymer B1 provided in Preparation Example 4 is replaced with a polyisocyanate (HDI trimer) of the same mass, and other conditions are the same as those in Example 6.

[0128] The one-component polyurethane adhesives provided in the above Examples 1 to 12 and Comparative Examples 1 to 2 were tested as follows: tensile strength, elongation at break and tensile shear strength were tested according to the method in standard HG / T 4363-2012 One-component polyurethane adhesive for automotive window glass, wherein the tensile modulus was obtained by taking the slope of the tensile curve at the elongation of 1%-10% during the tensile strength and elongation at break tests.

[0129] The test results are shown in Table 1 below:

[0130] Table 1

[0131]

[0132]

[0133] From the contents of Table 1, it can be seen that the tensile modulus of the one-component polyurethane adhesive provided in Examples 1-12 is 9.5-11.5 MPa, the tensile strength is 8.6-11.2 MPa, the elongation at break is 250%-370%, and the tensile shear strength is 5.6-6.2 MPa, and it has the characteristics of high modulus and high elongation.

[0134] Compared with Example 1, if the polyurethane prepolymer A1 provided in Preparation Example 1 is replaced by the polyurethane prepolymer A2 provided in Preparation Example 2 of the same mass (Example 6), the tensile modulus and tensile strength of the prepared one-component polyurethane adhesive decrease. It can be seen that the weight average molecular weight of the polyether polyol is preferably 4500-5000, and the performance of the obtained one-component polyurethane adhesive is better.

[0135] Compared with Example 1, if the polyurethane prepolymer A1 provided in Preparation Example 1 is replaced by the polyurethane prepolymer A3 provided in Preparation Example 3 of the same mass (Example 7), the various indicators of the prepared one-component polyurethane adhesive are lower. It can be seen that the performance of the one-component polyurethane adhesive prepared by the first isocyanate preferably being 4,4'-diphenylmethane diisocyanate is better.

[0136] Compared with Example 1, if the polyurethane prepolymer B1 provided in Preparation Example 1 is replaced with the polyurethane prepolymer B2 provided in Preparation Example 5 of the same mass (Example 8), the various indicators of the prepared one-component polyurethane adhesive are lower. It can be seen that the performance of the one-component polyurethane adhesive prepared by the second isocyanate preferably being xylene diisocyanate is better.

[0137] Compared with Example 1, if the polyurethane prepolymer B1 provided in Preparation Example 1 is replaced by the polyurethane prepolymer B3 provided in Preparation Example 6 of the same mass (Example 9), the various indicators of the prepared one-component polyurethane adhesive are slightly reduced. It can be seen that the performance of the one-component polyurethane adhesive prepared by the nonlinear small molecule diol preferably being 2-ethyl-1,3-hexanediol is better.

[0138] Compared with Example 1, if the polyurethane prepolymer B1 provided in Preparation Example 1 is replaced with the polyurethane prepolymer B4 provided in Preparation Example 7 of the same mass (Example 10), the elongation at break of the prepared one-component polyurethane adhesive is greatly reduced. It can be seen that the performance of the one-component polyurethane adhesive prepared by the small molecule diol is preferably a nonlinear small molecule diol.

[0139] Compared with Example 1, if the weight fraction of the polyurethane prepolymer A1 is too low (Example 11), the tensile modulus and tensile strength of the prepared one-component polyurethane adhesive increase, but the elongation at break decreases significantly; if the weight fraction of the polyurethane prepolymer A1 is too high (Example 12), the elongation at break of the prepared one-component polyurethane adhesive increases, but the tensile modulus and tensile strength decrease significantly. It can be seen that the one-component polyurethane adhesive prepared with a weight fraction of 30 to 45 parts has better performance.

[0140] Compared with Example 1, if the polyurethane prepolymer B1 provided in Preparation Example 4 is replaced by the same mass of polyisocyanate (Comparative Example 1), the tensile modulus, tensile strength, elongation at break and tensile shear strength of the prepared one-component polyurethane adhesive are all reduced. Compared with Example 6, if the polyurethane prepolymer B1 provided in Preparation Example 4 is replaced by the same mass of polyisocyanate (Comparative Example 2), the tensile modulus, tensile strength, elongation at break and tensile shear strength of the prepared one-component polyurethane adhesive are all reduced. It can be seen that the one-component polyurethane adhesive prepared by compounding polyurethane prepolymer A and polyurethane prepolymer B has better performance.

[0141] The applicant declares that the present invention uses the above-mentioned embodiments to illustrate a one-component polyurethane adhesive and its preparation method and application, but the present invention is not limited to the above-mentioned embodiments, that is, it does not mean that the present invention must rely on the above-mentioned embodiments to be implemented. Those skilled in the art should understand that any improvement of the present invention, equivalent replacement of various raw materials of the product of the present invention, addition of auxiliary components, selection of specific methods, etc., all fall within the protection scope and disclosure scope of the present invention.

Claims

1. A one-component polyurethane adhesive, characterized in that: The raw materials for preparing the one-component polyurethane adhesive include the following components: polyurethane prepolymer A, polyurethane prepolymer B, plasticizer, filler, carbon black, water absorbent, catalyst a and catalyst b; The raw materials for preparing the polyurethane prepolymer A include polyether polyol and a first isocyanate; The raw materials for preparing the polyurethane prepolymer B include small molecule diol and the second isocyanate.

2. The one-component polyurethane adhesive according to claim 1, characterized in that: The molar ratio of the isocyanate group of the first isocyanate to the hydroxyl group of the polyether polyol in the raw material for preparing the polyurethane prepolymer A is (2.1-2.5):1; Preferably, the polyether polyol is a polyether triol; Preferably, the weight average molecular weight of the polyether polyol is 3000 to 6000, more preferably 4500 to 5000; Preferably, the hydroxyl value of the polyether triol is 28 to 56 mgKOH / g; Preferably, the first isocyanate and the second isocyanate each independently comprise an aromatic polyisocyanate and / or an aliphatic polyisocyanate; Preferably, the aromatic polyisocyanate includes any one or a combination of at least two of toluene diisocyanate, diphenylmethane diisocyanate, 1,4-phenylene diisocyanate, xylylene diisocyanate, tetramethylxylylene diisocyanate, toluidine diisocyanate or 1,5-naphthalene diisocyanate; Preferably, the toluene diisocyanate includes 2,4-toluene diisocyanate and / or 2,6-toluene diisocyanate; Preferably, the diphenylmethane diisocyanate comprises 4,4'-diphenylmethane diisocyanate and / or 2,4'-diphenylmethane diisocyanate; Preferably, the aliphatic polyisocyanate includes any one or a combination of at least two of hexamethylene diisocyanate, trimethylhexamethylene diisocyanate, 1,5-pentane diisocyanate, lysine diisocyanate, norbornane diisocyanate, trans-cyclohexane-1,4-diisocyanate, isophorone diisocyanate, bis(isocyanatomethyl)cyclohexane or dicyclohexylmethane diisocyanate.

3. The one-component polyurethane adhesive according to claim 1 or 2, characterized in that: The preparation method of the polyurethane prepolymer A comprises the following steps: heating the polyether polyol to dehydrate, cooling it, mixing it with the first isocyanate and the catalyst C to react, and obtaining the polyurethane prepolymer A; Preferably, the heating dehydration in the preparation method of the polyurethane prepolymer A comprises heating to 110-130° C. for dehydration for 1.5-2.5 hours under stirring; Preferably, the cooling in the preparation method of the polyurethane prepolymer A is cooling to 30-50°C; Preferably, the reaction temperature in the preparation method of polyurethane prepolymer A is 75 to 90° C. and the reaction time is 2 to 6 hours; Preferably, the catalyst c comprises any one of dioctyltin dilaurate, dibutyltin dilaurate, dimethyltin dilaurate, stannous octoate, dibutyltin oxide or dioctyltin oxide, or a combination of at least two thereof; Preferably, the mass of the catalyst c is 0.001% to 0.05% of the total mass of the polyether polyol and the first isocyanate.

4. The one-component polyurethane adhesive according to any one of claims 1 to 3, characterized in that: The molar ratio of the isocyanate group of the second isocyanate to the hydroxyl group of the small molecule diol in the raw material for preparing the polyurethane prepolymer B is (2.0-2.2):1; Preferably, the small molecule diol includes a linear small molecule diol and / or a non-linear small molecule diol, and more preferably a non-linear small molecule diol; Preferably, the linear small molecule diol includes any one or a combination of at least two of ethylene glycol, 1,4-butanediol, 1,6-hexanediol, bisphenol A or bisphenol-propylene oxide adduct; Preferably, the nonlinear small molecule diol includes any one of 2-methyl-1,3-propanediol, 2-methyl-2,4-pentanediol or 2-ethyl-1,3-hexanediol or a combination of at least two thereof, and more preferably 2-ethyl-1,3-hexanediol.

5. The one-component polyurethane adhesive according to any one of claims 1 to 4, characterized in that: The preparation method of the polyurethane prepolymer B comprises the following steps: heating and dehydrating a small molecule diol, cooling and mixing with a second isocyanate to react, thereby obtaining the polyurethane prepolymer B; Preferably, the heating dehydration in the preparation method of the polyurethane prepolymer B comprises heating to 110-130° C. for dehydration for 1.5-2.5 hours under stirring; Preferably, the cooling in the preparation method of the polyurethane prepolymer B is cooling to 30-50°C; Preferably, in the method for preparing the polyurethane prepolymer B, the reaction temperature is 75 to 90° C., and the reaction time is 2 to 6 hours.

6. The one-component polyurethane adhesive according to any one of claims 1 to 4, characterized in that: The plasticizer includes any one of alkyl sulfonate, phthalate, tricresyl phosphate or trioctyl phosphate or a combination of at least two thereof, and phthalate is more preferably used; Preferably, the plasticizer is a plasticizer obtained by vacuum dehydration at 110-130°C for 1.5-2.5h; Preferably, the phthalate includes any one of dioctyl phthalate, butyl phthalate, diisooctyl phthalate, diisodecyl phthalate or diisononyl phthalate, or a combination of at least two thereof, and more preferably diisodecyl phthalate; Preferably, the filler comprises any one or a combination of at least two of silicon dioxide, heavy calcium carbonate, talc, clay, organic bentonite, hydrogenated castor oil or barium sulfate; Preferably, the carbon black comprises any one of gas furnace carbon black, oil furnace carbon black, oil-gas furnace carbon black, thermal cracking carbon black or acetylene carbon black, or a combination of at least two thereof; Preferably, the water absorbent comprises any one of alkylsulfonic acid isocyanate, calcium oxide or molecular sieve, or a combination of at least two thereof.

7. The one-component polyurethane adhesive according to any one of claims 1 to 6, characterized in that: The catalyst a includes an organic tin metal catalyst and / or an organic bismuth metal catalyst; Preferably, the organotin metal catalyst includes any one of dioctyltin dilaurate, dibutyltin dilaurate, dimethyltin dilaurate, dioctyltin dimaleate, dibutyltin dimaleate, dimethyltin dimaleate, dioctyltin dithiol, dibutyltin dithiol, dimethyltin dithiol, stannous octoate, butyltin oxide or octyltin oxide, or a combination of at least two thereof; Preferably, the organic bismuth metal catalyst includes any one or a combination of at least two of bismuth neodecanoate, bismuth laurate, bismuth isooctanoate or bismuth cyclohexaneate; Preferably, the catalyst b comprises a tertiary amine catalyst; Preferably, the tertiary amine catalyst includes any one or a combination of at least two of N,N-dimethylcyclohexylamine, bis(2-dimethylaminoethyl) ether, bismorpholine diethyl ether, N,N,N',N'-tetramethylalkylenediamine, triethylamine or N,N-dimethylbenzylamine; Preferably, the raw materials for preparing the one-component polyurethane adhesive include the following components in parts by weight: 30-45 parts of polyurethane prepolymer A, 3-5 parts of polyurethane prepolymer B, 15-25 parts of plasticizer, 10-20 parts of filler, 15-25 parts of carbon black, 0.1-1 part of water absorbent, 0.01-1 part of catalyst a and 0.01-1 part of catalyst b.

8. A method for preparing a one-component polyurethane adhesive according to any one of claims 1 to 7, characterized in that: The preparation method comprises the following steps: mixing polyurethane prepolymer A, polyurethane prepolymer B, plasticizer, filler, carbon black, water absorbent, catalyst a and catalyst b to obtain the single-component polyurethane adhesive.

9. The preparation method according to claim 8, characterized in that: The moisture content of the filler is ≤1000ppm; Preferably, the moisture content in the carbon black is ≤1000ppm; Preferably, the preparation method specifically comprises the following steps: first mixing polyurethane prepolymer A, polyurethane prepolymer B, plasticizer, filler, carbon black and water absorbent under vacuum conditions, adding catalyst a and catalyst b for second mixing to obtain the one-component polyurethane adhesive; Preferably, the vacuum degree of the vacuum condition is -1000 to -950 mbar.

10. Use of the one-component polyurethane adhesive according to any one of claims 1 to 7 in bonding skylight glass.

Images