Polyurethane-epoxy resin composition and preparation method thereof

Abstract

The present invention provides a polyurethane-epoxy resin composition and a preparation method thereof. The polyurethane-epoxy resin composition comprises the following components by weight: 30-50 parts epoxy resin, 10-30 parts multifunctional polyurethane, 4-5 parts thixotropic agent, 15-25 parts inorganic filler, and 1-5 parts curing agent. The polyurethane-epoxy resin composition provided by the present invention exhibits not only good toughness but also excellent mechanical and tensile properties.

Description

Technical Field

[0001] The present invention belongs to the technical field of polymer materials, and in particular relates to a polyurethane-epoxy resin composition and a preparation method thereof. Background Art

[0002] As one of the three major general-purpose thermosetting resins, epoxy resin has become an indispensable material in the economic development of various countries. Due to its excellent bonding properties, mechanical properties, electrical properties, corrosion resistance and heat resistance, epoxy resin plays an important role in electronics, electrical engineering, mechanical manufacturing, chemical corrosion protection, aerospace, shipping, chemical building materials, water conservancy and electricity, and many other industrial fields. Epoxy resin is a thermosetting resin with an organic compound as the skeleton. After the cross-linking reaction between the thermosetting polymer and the curing agent, an insoluble three-dimensional network structure polymer is formed. The rigidity of the cross-linked network skeleton of the cured epoxy resin makes it difficult for the molecular chains to slide relative to each other, which easily causes the accumulation of stress inside the coating, leading to cracking of the coating. As a result, it has the disadvantages of being brittle, and having poor fatigue resistance, heat resistance, and impact toughness.

[0003] Polyurethane elastomers primarily refer to highly elastic polymers containing urethane (-NHCOO-) or isocyanate (-NCO) groups in their molecular chains. Adding polyurethane elastomers to epoxy resins can significantly improve their toughness. This is primarily due to microscopic phase separation during the epoxy resin's curing process, forming a "sea-island structure" with the epoxy resin as the continuous phase and the polyurethane soft segments as the dispersed phase. When subjected to external impact, these polyurethane sea-island structures can induce the formation of "silver crazing" and "shear bands" in the epoxy resin substrate, absorbing some of the energy and achieving toughening.

[0004] Traditional polyurethane elastomers are usually prepared by cross-linking reactions of diols, diisocyanates, cross-linking agents and other additives. Currently commonly used cross-linking agents such as 1,3-butanediol, 1,4-butanediol, trimethylolpropane, propylene glycol, etc. are all low-functionality polyol molecules, which will result in a low degree of cross-linking of polyurethane elastomers. Although the molecular structure of polyurethane elastomers can be optimized by adjusting the ratio of soft and hard segments, it is still difficult to balance mechanical properties and tensile properties. Therefore, how to provide a polyurethane-epoxy resin composition with better mechanical properties has become a technical problem that needs to be solved urgently. Summary of the Invention

[0005] To address the shortcomings of the prior art, the present invention provides a polyurethane-epoxy resin composition and a method for preparing the same. By designing the specific composition of the polyurethane-epoxy resin composition and further utilizing a multifunctional polyurethane, the resulting polyurethane-epoxy resin composition exhibits not only excellent toughness but also superior mechanical and tensile properties.

[0006] To achieve this object, the present invention adopts the following technical solutions:

[0007] In a first aspect, the present invention provides a polyurethane-epoxy resin composition, wherein the polyurethane-epoxy resin composition comprises the following components in parts by weight:

[0008] 30-50 parts of epoxy resin, 10-30 parts of multifunctional polyurethane, 4-5 parts of thixotropic agent, 15-25 parts of inorganic filler and 1-5 parts of curing agent.

[0009] In the present invention, by designing the specific composition of the polyurethane-epoxy resin composition and further using multifunctional polyurethane, the prepared polyurethane-epoxy resin composition not only has good toughness, but also has good mechanical properties and tensile properties.

[0010] In the present invention, by controlling the amount of the multifunctional polyurethane within a specific range, the resulting polyurethane-epoxy resin composition exhibits excellent mechanical properties. If the amount of the multifunctional polyurethane is too small, the resulting polyurethane-epoxy resin composition exhibits poor toughness. If the amount of the multifunctional polyurethane is too large, the glass transition temperature of the resulting polyurethane-epoxy resin composition decreases significantly, resulting in poor mechanical properties.

[0011] In the present invention, in the epoxy resin composition, the weight parts of the epoxy resin can be 30 parts, 33 parts, 35 parts, 37 parts, 40 parts, 42 parts, 45 parts, 48 ​​parts or 50 parts.

[0012] The weight proportions of the multifunctional polyurethane can be 10 parts, 12 parts, 14 parts, 16 parts, 18 parts, 20 parts, 22 parts, 24 parts, 26 parts, 28 parts or 30 parts, etc.

[0013] The weight parts of the thixotropic agent can be 4 parts, 4.1 parts, 4.2 parts, 4.3 parts, 4.4 parts, 4.5 parts, 4.6 parts, 4.7 parts, 4.8 parts, 4.9 parts or 5 parts, etc.

[0014] The weight proportion of the inorganic filler can be 15 parts, 16 parts, 17 parts, 18 parts, 19 parts, 20 parts, 21 parts, 22 parts, 23 parts, 24 parts or 25 parts, etc.

[0015] The weight proportions of the curing agent may be 1 part, 1.5 parts, 2 parts, 2.5 parts, 3 parts, 3.5 parts, 4 parts, 4.5 parts or 5 parts, etc.

[0016] The following are preferred technical solutions of the present invention, but are not intended to limit the technical solutions provided by the present invention. Through the following preferred technical solutions, the objectives and beneficial effects of the present invention can be better achieved and realized.

[0017] As a preferred technical solution of the present invention, the raw materials for preparing the multifunctional polyurethane include the following components in parts by mass:

[0018] 60-95 parts of polymer diol, 10-25 parts of diisocyanate, and 0.6-1.3 parts of multifunctional crosslinking agent.

[0019] In the present invention, a linear prepolymer is obtained by reacting a polymer diol with a diisocyanate, and then a highly cross-linked, multifunctional polyurethane is obtained by using a multifunctional crosslinking agent. The multifunctional polyurethane provided by the present invention has good toughness and can be used as a toughening material to prepare a polyurethane-epoxy resin composition with high toughness. The use of the specific multifunctional polyurethane in the present invention not only improves the toughness of the polyurethane-epoxy resin composition, but also enhances its mechanical and tensile properties.

[0020] In the present invention, the mass fraction of the polymer diol in the raw materials for preparing the multifunctional polyurethane can be 60 parts, 65 parts, 70 parts, 75 parts, 80 parts, 85 parts, 90 parts or 95 parts.

[0021] The mass parts of diisocyanate can be 10 parts, 15.5 parts, 17 parts, 18 parts, 19 parts, 20.5 parts, 22 parts, 23.5 parts, 24 parts, 24.5 parts or 25 parts, etc.

[0022] The mass fraction of the multifunctional cross-linking agent can be 0.6 parts, 0.7 parts, 0.8 parts, 0.9 parts, 1 parts, 1.1 parts, 1.2 parts or 1.3 parts.

[0023] Preferably, the raw materials for preparing the multifunctional polyurethane include the following components in parts by mass:

[0024] 70-90 parts of polymer diol, 20-22 parts of diisocyanate, and 0.8-1.1 parts of multifunctional crosslinking agent.

[0025] Preferably, the number average molecular weight of the polymer diol is 1500-4000, for example, 1500, 1800, 2000, 2200, 2400, 2600, 2800, 3000, 3200, 3400, 3600, 3800 or 4000.

[0026] Preferably, the polymer diol is selected from any one of polycarbonate diol, polyester diol or polyether diol, or a combination of at least two thereof, and more preferably is polyether diol.

[0027] Preferably, the diisocyanate is selected from any one of isophorone diisocyanate, toluene diisocyanate or diphenylmethane diisocyanate, or a combination of at least two thereof, and isophorone diisocyanate is more preferably selected.

[0028] Preferably, the multifunctional cross-linking agent is selected from a polyol cross-linking agent and / or a polyisocyanate cross-linking agent, and more preferably is a combination of a polyol cross-linking agent and a polyisocyanate cross-linking agent.

[0029] In the present invention, compared with low-functionality linear polymers, by selecting a combination of a polyol crosslinker and a polyisocyanate crosslinker as a multifunctional crosslinker, the degree of polymerization of the hardness structure and the polyol soft satin structure in the polyurethane prepolymer can be increased, and the mechanical properties of the polyurethane-epoxy resin composition can be further improved.

[0030] Preferably, the mass ratio of the polyol crosslinking agent to the polyisocyanate crosslinking agent is 1:(0.5-1.5), for example, it can be 1:0.5, 1:0.6, 1:0.7, 1:0.8, 1:0.9, 1:1, 1:1.1, 1:1.2, 1:1.3, 1:1.4 or 1:1.5, etc., more preferably 1:1.

[0031] In the present invention, the mechanical properties of the polyurethane-epoxy resin composition can be further improved by controlling the mass ratio of the polyol crosslinker to the polyisocyanate crosslinker within a specific range. If the mass ratio of the polyol crosslinker to the polyisocyanate crosslinker is too high or too low, it is not conducive to significantly improving the mechanical properties of the polyurethane-epoxy resin composition.

[0032] Preferably, the polyol cross-linking agent is selected from any one of pentaerythritol, pentaerythritol tetrakis(3-mercaptopropionate) or dipentaerythritol, or a combination of at least two thereof, and more preferably pentaerythritol tetrakis(3-mercaptopropionate).

[0033] Preferably, the polyisocyanate crosslinking agent is selected from any one of triphenylmethane triisocyanate, dimethyltriphenylmethane tetraisocyanate or polymethyl polyphenyl isocyanate (PM-200) or a combination of at least two thereof, and more preferably dimethyltriphenylmethane tetraisocyanate.

[0034] As a preferred technical solution of the present invention, the raw materials for preparing the multifunctional polyurethane also include 0.005 to 0.05 parts by mass of a catalyst (for example, 0.005 parts by mass, 0.01 parts by mass, 0.02 parts by mass, 0.022 parts by mass, 0.025 parts by mass, 0.03 parts by mass, 0.04 parts by mass or 0.05 parts by mass, etc.), and more preferably 0.005 to 0.015 parts by mass.

[0035] Preferably, the catalyst comprises a zinc-containing compound.

[0036] Preferably, the zinc-containing compound is selected from any one or a combination of at least two of zinc 2-ethylhexanoate, zinc neodecanoate or zinc naphthenate.

[0037] Preferably, the raw materials for preparing the multifunctional polyurethane further include 0.005 to 0.05 parts by mass of triphenylbismuth, for example, 0.005 parts by mass, 0.01 parts by mass, 0.02 parts by mass, 0.022 parts by mass, 0.025 parts by mass, 0.03 parts by mass, 0.04 parts by mass or 0.05 parts by mass, etc., more preferably 0.005 to 0.015 parts by mass.

[0038] As a preferred technical solution of the present invention, the method for preparing the multifunctional polyurethane comprises the following steps:

[0039] (1) mixing a polymer diol, a diisocyanate, a first solvent, an optional catalyst, and triphenylbismuth, and reacting the mixture to obtain a prepolymer;

[0040] (2) The prepolymer obtained in step (1) is mixed with a multifunctional cross-linking agent and a second solvent, and reacted to obtain the multifunctional polyurethane.

[0041] Preferably, the first solvent and the second solvent are each independently selected from any one or a combination of at least two of ethyl acetate, acetone or dichloromethane, more preferably ethyl acetate.

[0042] Preferably, the mass ratio of the polymer diol to the first solvent is 100:(1-3), for example, it can be 100:1, 100:1.2, 100:1.4, 100:1.6, 100:1.8, 100:2, 100:2.2, 100:2.4, 100:2.6, 100:2.8 or 100:3, etc.

[0043] Preferably, the mass ratio of the polymer diol to the second solvent is 100:(1-3), for example, it can be 100:1, 100:1.2, 100:1.4, 100:1.6, 100:1.8, 100:2, 100:2.2, 100:2.4, 100:2.6, 100:2.8 or 100:3, etc.

[0044] Preferably, the reaction temperature in step (1) is 80-90°C, for example, it can be 80°C, 81°C, 82°C, 83°C, 84°C, 85°C, 86°C, 87°C, 88°C, 89°C or 90°C.

[0045] Preferably, the reaction time of step (1) is 60 to 90 min, for example, 60 min, 65 min, 70 min, 75 min, 80 min, 85 min or 90 min.

[0046] Preferably, step (1) includes a pretreatment step before the mixing, and the pretreatment method includes: uniformly mixing the polymer diol, the first solvent, and the optional catalyst and triphenylbismuth.

[0047] Preferably, the reaction temperature in step (2) is 75-85°C, for example, it can be 75°C, 76°C, 77°C, 78°C, 79°C, 80°C, 81°C, 82°C, 83°C, 84°C or 85°C.

[0048] Preferably, the reaction time of step (2) is 90 to 120 min, for example, it can be 90 min, 95 min, 100 min, 105 min, 110 min, 115 min or 120 min.

[0049] Preferably, the method for preparing the multifunctional polyurethane comprises the following steps:

[0050] (1) After uniformly mixing a polymer diol, a first solvent, an optional catalyst, and triphenyl bismuth, diisocyanate is added thereto, and the mixture is reacted at 80 to 90° C. for 60 to 90 minutes to obtain a prepolymer;

[0051] (2) mixing the prepolymer obtained in step (1) with a multifunctional crosslinking agent and a second solvent, and reacting at 75 to 85° C. for 90 to 120 minutes to obtain the multifunctional polyurethane.

[0052] As a preferred technical solution of the present invention, the epoxy resin includes bisphenol A epoxy resin and liquid nitrile rubber modified epoxy resin;

[0053] Taking the mass percentage of the epoxy resin as 100%, the mass percentage of the bisphenol A epoxy resin is 70-90% (for example, it can be 70%, 72%, 74%, 76%, 78%, 80%, 82%, 84%, 86%, 88% or 90%, etc.), and the mass percentage of the liquid nitrile rubber modified epoxy resin is 10-30% (for example, it can be 10%, 12%, 14%, 16%, 18%, 20%, 22%, 24%, 26%, 28% or 30%, etc.).

[0054] Preferably, the number average molecular weight of the bisphenol A epoxy resin is 300-600, for example, 300, 330, 360, 380, 400, 420, 460, 480, 500, 520, 540, 560 or 600.

[0055] Preferably, the bisphenol A epoxy resin is selected from any one of Yueyang Petrochemical CYD-128, Nanya NPEL-128 or Nanya NPEF-127, or a combination of at least two thereof.

[0056] Preferably, the number average molecular weight of the liquid nitrile rubber modified epoxy resin is 2990 to 9900, for example, 2990, 4000, 5000, 6000, 7000, 8000, 9000 or 9900.

[0057] The liquid nitrile rubber modified epoxy resin can be used as a toughening agent in an epoxy resin system. The molecular main chain of the liquid nitrile rubber modified epoxy resin is a high-viscosity addition product of butadiene monomer and acrylonitrile monomer, which is then modified with epoxy resin.

[0058] As a preferred technical solution of the present invention, the thixotropic agent is selected from fumed silica with a particle size of 100 to 800 nm (for example, 100 nm, 200 nm, 300 nm, 400 nm, 500 nm, 600 nm, 700 nm or 800 nm, etc.) and / or an organic bentonite powder with a particle size of 50 to 400 mesh (for example, 50 mesh, 100 mesh, 150 mesh, 200 mesh, 250 mesh, 300 mesh or 350 mesh, etc.), preferably fumed silica with a particle size of 200 to 700 nm.

[0059] As a preferred technical solution of the present invention, the inorganic filler is selected from any one or a combination of at least two of micron-sized aluminum hydroxide, micron-sized silicon powder, micron-sized calcium carbonate or micron-sized kaolin, and is more preferably micron-sized silicon powder.

[0060] As a preferred technical solution of the present invention, the curing agent is a latent curing agent.

[0061] Preferably, the latent curing agent is selected from any one of dicyandiamide, boron trifluoride amine complex, and diaminomaleonitrile, or a combination of at least two thereof, and more preferably is Dyhard 100S dicyandiamide curing agent.

[0062] In the present invention, after the latent curing agent is combined with the epoxy resin, the composition can be left at room temperature for a long time and is relatively stable. However, when subjected to heat, a curing reaction can be initiated to crosslink the epoxy resin into a cured product.

[0063] It should be noted that dicyandiamide derivatives and diaminomaleonitrile derivatives can also be used as latent curing agents.

[0064] As a preferred technical solution of the present invention, the epoxy resin composition also includes 0.1 to 0.3 parts of a curing accelerator, for example, 0.1 parts, 0.12 parts, 0.14 parts, 0.16 parts, 0.18 parts, 0.2 parts, 0.22 parts, 0.24 parts, 0.26 parts, 0.28 parts or 0.3 parts, etc.

[0065] Preferably, the curing accelerator is selected from urea compounds and / or imidazole compounds, and more preferably is Dyhard UR300 urea accelerator.

[0066] In a second aspect, the present invention provides a method for preparing the polyurethane-epoxy resin composition according to the first aspect, the preparation method comprising the following steps:

[0067] (A) mixing a multifunctional polyurethane, an epoxy resin, a thixotropic agent and an inorganic filler to obtain a mixture;

[0068] (B) mixing the mixture obtained in step (A) with a curing agent and an optional curing accelerator to obtain the polyurethane-epoxy resin composition.

[0069] As a preferred technical solution of the present invention, the mixing method in step (A) is to use a dynamic mixer to stir and mix;

[0070] Preferably, the revolution frequency of the dynamic mixer is 10 to 50 Hz, for example, it can be 10 Hz, 15 Hz, 20 Hz, 25 Hz, 30 Hz, 35 Hz, 40 Hz, 45 Hz or 50 Hz.

[0071] Preferably, the rotation frequency of the dynamic mixer is 15 to 55 Hz, for example, it can be 15 Hz, 20 Hz, 25 Hz, 30 Hz, 35 Hz, 40 Hz, 45 Hz, 50 Hz or 55 Hz.

[0072] Preferably, the mixing temperature in step (A) is 30-40°C, for example, it can be 30°C, 31°C, 32°C, 33°C, 34°C, 35°C, 36°C, 37°C, 38°C, 39°C or 40°C.

[0073] As a preferred technical solution of the present invention, the mixing method in step (B) is to use a dynamic mixer for stirring and mixing.

[0074] Preferably, the revolution frequency of the dynamic mixer is 10 to 20 Hz, for example, it can be 10 Hz, 11 Hz, 12 Hz, 13 Hz, 14 Hz, 15 Hz, 16 Hz, 17 Hz, 18 Hz, 19 Hz or 20 Hz.

[0075] Preferably, the rotation frequency of the dynamic mixer is 5 to 15 Hz, for example, it can be 5 Hz, 6 Hz, 7 Hz, 8 Hz, 9 Hz, 10 Hz, 11 Hz, 12 Hz, 13 Hz, 14 Hz or 15 Hz.

[0076] Preferably, the mixing temperature in step (B) is 30-40°C, for example, 30°C, 31°C, 32°C, 33°C, 34°C, 35°C, 36°C, 37°C, 38°C, 39°C or 40°C.

[0077] Preferably, step (B) further includes a post-processing step after the mixing, and the post-processing method includes: vacuum degassing.

[0078] As a preferred technical solution of the present invention, the preparation method of the polyurethane-epoxy resin composition specifically comprises the following steps:

[0079] (A) mixing a multifunctional polyurethane, an epoxy resin, a thixotropic agent, and an inorganic filler at 30 to 40° C. using a dynamic mixer having an orbital frequency of 10 to 20 Hz and an autorotational frequency of 25 to 35 Hz to obtain a mixture;

[0080] (B) mixing the mixture obtained in step (A) with a curing agent and an optional curing accelerator at 30-40° C. using a dynamic mixer with an orbital frequency of 10-20 Hz and an autorotation frequency of 5-15 Hz, and vacuum degassing to obtain the polyurethane-epoxy resin composition.

[0081] Compared with the prior art, the present invention has the following beneficial effects:

[0082] The present invention designs the specific composition of the polyurethane-epoxy resin composition, further uses a specific multifunctional polyurethane, and controls the content of the multifunctional polyurethane within a specific range, thereby improving the toughness, mechanical properties, and tensile properties of the epoxy resin composition. The composition has a shear strength of 11.0 to 17.5 MPa, a T-peel strength of 3.1 to 7.9 N / mm, an impact peel strength of 7.4 to 13.2 N / mm, a bulk tensile strength of 8.4 to 15.5 MPa, and an elongation at break of 3.2 to 6.9%. DETAILED DESCRIPTION

[0083] For the convenience of understanding the present invention, the present invention is given below with examples. It should be understood by those skilled in the art that the examples are only for the purpose of helping to understand the present invention and should not be regarded as specific limitations of the present invention.

[0084] The sources of some components in the Examples and Comparative Examples are as follows:

[0085] Polymer diol: polyether diol with a molecular weight of 3000D, Bluestar Dongda DL-3000D;

[0086] Epoxy resin: bisphenol A epoxy resin, Nan Ya NPEL-128;

[0087] Liquid nitrile rubber modified epoxy resin: Huntsman HYPOX-RA1340;

[0088] Fumed silica: R202 from Evonik, Germany;

[0089] Silica powder: spherical silica powder, Jiangsu Lianrui New Materials;

[0090] Curing agent: Latent Dyhard 100S dicyandiamide compound, AlzChem;

[0091] Curing accelerator: UR300 urea compound, AlzChem.

[0092] Preparation Example 1

[0093] This preparation example provides a multifunctional polyurethane 1 and a preparation method thereof. The multifunctional polyurethane 1 comprises the following raw materials in parts by weight:

[0094] 95 parts of polymer diol, 20 parts of isophorone diisocyanate, 1.3 parts of pentaerythritol tetrakis(3-mercaptopropionate), 0.01 parts of zinc 2-ethylhexanoate, 0.01 parts of triphenylbismuth, 2 parts of the first solvent (ethyl acetate), and 2 parts of the second solvent (ethyl acetate).

[0095] The preparation method of the multifunctional polyurethane 1 is as follows:

[0096] (1) After uniformly mixing the polymer diol, the first solvent (ethyl acetate), zinc 2-ethylhexanoate, and triphenyl bismuth, isophorone diisocyanate is added thereto under stirring, and the mixture is reacted at 85° C. for 72 minutes to obtain a prepolymer;

[0097] (2) The prepolymer obtained in step (1) was mixed with pentaerythritol tetrakis(3-mercaptopropionate) and a second solvent (ethyl acetate), and the mixture was reacted at 80° C. for 100 min to obtain the multifunctional polyurethane 1.

[0098] Preparation Example 2

[0099] This preparation example provides a multifunctional polyurethane 2 and a preparation method thereof. The multifunctional polyurethane 2 comprises the following raw materials in parts by weight:

[0100] 95 parts of polymer diol, 20 parts of isophorone diisocyanate, 1.3 parts of dimethyltriphenylmethane tetraisocyanate, 0.011 parts of zinc 2-ethylhexanoate, 0.009 parts of triphenylbismuth, 2 parts of the first solvent (ethyl acetate), and 2 parts of the second solvent (ethyl acetate).

[0101] The preparation method of the multifunctional polyurethane 2 is as follows:

[0102] (1) After uniformly mixing a polymer diol, a first solvent (ethyl acetate), zinc 2-ethylhexanoate, and triphenyl bismuth, isophorone diisocyanate is added thereto under stirring, the mixture is stirred and mixed, and the mixture is reacted at 80° C. for 90 minutes to obtain a prepolymer;

[0103] (2) The prepolymer obtained in step (1) was mixed with dimethyltriphenylmethane tetraisocyanate and a second solvent (ethyl acetate), and the mixture was reacted at 75° C. for 120 min to obtain the multifunctional polyurethane 2.

[0104] Preparation Example 3

[0105] This preparation example provides a multifunctional polyurethane 3 and a preparation method thereof. The multifunctional polyurethane 3 comprises the following raw materials in parts by weight:

[0106] 95 parts of polymer diol, 20 parts of isophorone diisocyanate, 0.65 parts of dimethyltriphenylmethane tetraisocyanate, 0.65 parts of pentaerythritol tetrakis(3-mercaptopropionate), 0.009 parts of zinc 2-ethylhexanoate, 0.008 parts of triphenylbismuth, 2 parts of the first solvent (ethyl acetate), and 2 parts of the second solvent (ethyl acetate).

[0107] The preparation method of the multifunctional polyurethane 3 is as follows:

[0108] (1) After uniformly mixing a polymer diol, a first solvent (ethyl acetate), zinc 2-ethylhexanoate, and triphenyl bismuth, isophorone diisocyanate is added thereto, and the mixture is reacted at 90° C. for 60 minutes to obtain a prepolymer;

[0109] (2) The prepolymer obtained in step (1) is mixed with a multifunctional crosslinking agent and a second solvent (ethyl acetate), and the mixture is reacted at 85° C. for 90 minutes to obtain the multifunctional polyurethane 3.

[0110] Preparation Example 4

[0111] This preparation example provides a multifunctional polyurethane 4 and a preparation method thereof. The difference from Preparation Example 3 is that the raw materials for preparing the multifunctional polyurethane 4 include: 0.44 parts of dimethyltriphenylmethane tetraisocyanate and 0.86 parts of pentaerythritol tetrakis(3-mercaptopropionate). Other conditions are the same as those in Preparation Example 3.

[0112] Preparation Example 5

[0113] This preparation example provides a multifunctional polyurethane 5 and a preparation method thereof. The difference from Preparation Example 3 is that the raw materials for preparing the multifunctional polyurethane 5 include: 0.78 parts of dimethyltriphenylmethane tetraisocyanate and 0.52 parts of pentaerythritol tetrakis(3-mercaptopropionate). Other conditions are the same as those in Preparation Example 3.

[0114] Preparation Example 6

[0115] This preparation example provides a multifunctional polyurethane 6 and a preparation method thereof. The difference from Preparation Example 3 is that the raw materials for preparing the multifunctional polyurethane 6 include: 0.22 parts of dimethyltriphenylmethane tetraisocyanate and 1.08 parts of pentaerythritol tetrakis(3-mercaptopropionate). Other conditions are the same as those in Preparation Example 3.

[0116] Preparation Example 7

[0117] This preparation example provides a multifunctional polyurethane 7 and a preparation method thereof. The difference from Preparation Example 3 is that the raw materials for preparing the multifunctional polyurethane 7 include: 0.87 parts of dimethyltriphenylmethane tetraisocyanate and 0.43 parts of pentaerythritol tetrakis(3-mercaptopropionate). Other conditions are the same as those in Preparation Example 3.

[0118] Preparation Example 8

[0119] This preparation example provides a multifunctional polyurethane 8 and a preparation method thereof. The multifunctional polyurethane 8 comprises the following raw materials in parts by weight:

[0120] 60 parts of polymer diol, 10 parts of isophorone diisocyanate, 0.3 parts of dimethyltriphenylmethane tetraisocyanate, 0.3 parts of pentaerythritol tetrakis(3-mercaptopropionate), 0.009 parts of zinc 2-ethylhexanoate, 0.008 parts of triphenylbismuth, 2 parts of the first solvent (ethyl acetate), and 2 parts of the second solvent (ethyl acetate).

[0121] The preparation method of the multifunctional polyurethane 8 is the same as that of Preparation Example 3.

[0122] Preparation Example 9

[0123] This preparation example provides a multifunctional polyurethane 9 and a preparation method thereof. The multifunctional polyurethane 9 comprises the following raw materials in parts by weight:

[0124] 90 parts of polymer diol, 25 parts of isophorone diisocyanate, 0.6 parts of dimethyltriphenylmethane tetraisocyanate, 0.6 parts of pentaerythritol tetrakis(3-mercaptopropionate), 0.009 parts of zinc 2-ethylhexanoate, 0.008 parts of triphenylbismuth, 2 parts of the first solvent (ethyl acetate), and 2 parts of the second solvent (ethyl acetate).

[0125] The preparation method of the multifunctional polyurethane 9 is the same as that of Preparation Example 3.

[0126] Comparative Preparation Example 1

[0127] This preparation example provides a multifunctional polyurethane A and a preparation method thereof. The difference from Preparation Example 1 is that 1.3 parts of pentaerythritol tetrakis(3-mercaptopropionate) is replaced with 1.3 parts of 1,4-butanediol, and other conditions are the same as those in Preparation Example 3.

[0128] Examples 1 to 12 and Comparative Examples 1 to 2

[0129] Examples 1 to 12 and Comparative Examples 1 to 2 respectively provide an epoxy resin composition. The specific composition of the epoxy resin composition is shown in Table 1 below.

[0130] The preparation method of the above-mentioned epoxy resin composition is as follows:

[0131] (A) mixing a multifunctional polyurethane, an epoxy resin, a thixotropic agent, and an inorganic filler at 35° C. using a dynamic mixer having an orbital frequency of 15 Hz and an autorotational frequency of 20 Hz to obtain a mixture;

[0132] (B) The mixture obtained in step (A) was mixed with a curing agent and an optional curing accelerator at 35° C. using a dynamic mixer with an orbital frequency of 15 Hz and an autorotation frequency of 10 Hz, and vacuum degassing was performed for 10 minutes to obtain the epoxy resin composition.

[0133] Table 1

[0134]

[0135]

[0136] Table 2

[0137]

[0138] It should be noted that the amounts of each component in Table 1 and Table 2 are all in parts by weight.

[0139] The properties of the epoxy resin compositions provided in the above examples and comparative examples were tested, and the specific testing methods are as follows:

[0140] Shear strength: GB / T 7124-2008, Determination of tensile shear strength of adhesives (rigid material to rigid material Al-Al);

[0141] T-peel strength: GB / T 2791~1995, Adhesive T-peel strength test method - Flexible material to flexible material;

[0142] Impact peel strength: ISO 11343~2003, Adhesives–Determination of dynamic resistance to cleavage of high strength adhesive bonds under impactconditions–Wedge impact method;

[0143] Bulk tensile strength and elongation at break: GB / T 528~2009, Determination of tensile stress-strain properties of vulcanized rubber or thermoplastic rubber.

[0144] The test results are shown in Table 3 below:

[0145] Table 3

[0146]

[0147] As can be seen from the above content, the present invention improves the toughness, mechanical properties and tensile properties of the epoxy resin composition by designing the specific composition of the epoxy resin composition, further using a multifunctional polyurethane prepared from a specific multifunctional crosslinking agent, and controlling the content of the multifunctional polyurethane within a specific range. The shear strength, T-peel strength and impact peel strength are 11.0 to 17.5 MPa, 3.1 to 7.9 N / mm, 7.4 to 13.2 N / mm, bulk tensile strength and elongation at break are 3.2 to 6.9%.

[0148] The present invention further improves the comprehensive performance of the epoxy resin composition by controlling the mass ratio of the polyol crosslinking agent to the polyisocyanate crosslinking agent within a specific range. The comprehensive performance of the epoxy resin composition is improved, and the shear strength is 11.4 to 17.5 MPa, the T-peel strength is 3.1 to 7.9 N / mm, the impact peel strength is 7.9 to 13.2 N / mm, the bulk tensile strength is 9.1 to 15.5 MPa, and the elongation at break is 4.8 to 6.9%.

[0149] From the comparison between Examples 1-2 and 3-9, it can be seen that in the present invention, by selecting a combination of a polyol crosslinker and a polyisocyanate crosslinker as a multifunctional crosslinker for a multifunctional polyurethane (Examples 3-9), the overall performance of the epoxy resin composition can be further improved.

[0150] From the comparison between Examples 3-5 and Examples 6-7, it can be seen that in the present invention, by further controlling the mass ratio of the polyol crosslinking agent to the polyisocyanate crosslinking agent within a specific range, the comprehensive performance of the epoxy resin composition can be further improved.

[0151] From the contents of Examples 1-9 and Example 10, it can be seen that the present invention uses a specific multifunctional crosslinking agent to prepare a multifunctional polyurethane with excellent properties, and further can prepare an epoxy resin composition with excellent properties.

[0152] It can be seen from the contents of Comparative Examples 1-2 that if the amount of multifunctional polyurethane in the epoxy resin composition is too small (Comparative Example 1) or the amount of polyurethane is too large (Comparative Example 2), the performance of the prepared epoxy resin is poor.

[0153] In summary, the present invention designs the specific composition of the epoxy resin composition, further uses a specific multifunctional polyurethane, and controls the content of the multifunctional polyurethane within a specific range to prepare an epoxy resin composition with excellent performance.

[0154] The applicant declares that the present invention uses the above-described embodiments to illustrate the detailed process flow of the present invention, but the present invention is not limited to the above-described detailed process flow, that is, it does not mean that the present invention must rely on the above-described detailed process flow to be implemented. Those skilled in the art should understand that any improvements to the present invention, equivalent replacements for various raw materials in the products of the present invention, addition of auxiliary ingredients, and selection of specific methods, etc., are all within the scope of protection and disclosure of the present invention.

Claims

1. A polyurethane-epoxy resin composition, characterized in that The epoxy resin composition comprises the following components in parts by weight: 30-50 parts of epoxy resin, 10-30 parts of multifunctional polyurethane, 4-5 parts of thixotropic agent, 15-25 parts of inorganic filler and 1-5 parts of curing agent; The raw materials for preparing the multifunctional polyurethane include the following components in parts by mass: 60-95 parts of polymer diol, 10-25 parts of diisocyanate, 0.6-1.3 parts of multifunctional crosslinking agent; The multifunctional cross-linking agent is a combination of a polyol cross-linking agent and a polyisocyanate cross-linking agent; The mass ratio of the polyol crosslinking agent to the polyisocyanate crosslinking agent is 1:(0.5-1.5); The polyol cross-linking agent is selected from any one of pentaerythritol, pentaerythritol tetrakis (3-mercaptopropionate) or dipentaerythritol, or a combination of at least two thereof; The polyisocyanate crosslinking agent is selected from any one of triphenylmethane triisocyanate, dimethyltriphenylmethane tetraisocyanate or polymethyl polyphenyl isocyanate or a combination of at least two thereof.

2. The polyurethane-epoxy resin composition according to claim 1, characterized in that The number average molecular weight of the polymer diol is 1500-4000.

3. The polyurethane-epoxy resin composition according to claim 1, characterized in that The polymer diol is selected from any one of polycarbonate diol, polyester diol or polyether diol, or a combination of at least two of them.

4. The polyurethane-epoxy resin composition according to claim 3, characterized in that The polymer diol is a polyether diol.

5. The polyurethane-epoxy resin composition according to claim 1, characterized in that The diisocyanate is selected from any one of isophorone diisocyanate, toluene diisocyanate or diphenylmethane diisocyanate, or a combination of at least two thereof.

6. The polyurethane-epoxy resin composition according to claim 5, characterized in that The diisocyanate is isophorone diisocyanate.

7. The polyurethane-epoxy resin composition according to claim 1, characterized in that The polyol cross-linking agent is pentaerythritol tetrakis(3-mercaptopropionate).

8. The polyurethane-epoxy resin composition according to claim 1, characterized in that The polyisocyanate crosslinking agent is dimethyltriphenylmethane tetraisocyanate.

9. The polyurethane-epoxy resin composition according to claim 1, characterized in that The raw materials for preparing the multifunctional polyurethane further include 0.005 to 0.05 parts by mass of a catalyst.

10. The polyurethane-epoxy resin composition according to claim 9, characterized in that The catalyst includes a zinc-containing compound.

11. The polyurethane-epoxy resin composition according to claim 10, characterized in that The zinc-containing compound is selected from any one of zinc 2-ethylhexanoate, zinc neodecanoate or zinc naphthenate, or a combination of at least two thereof.

12. The polyurethane-epoxy resin composition according to claim 1, characterized in that The raw materials for preparing the multifunctional polyurethane further include 0.005 to 0.03 parts by mass of triphenylbismuth.

13. The polyurethane-epoxy resin composition according to claim 1, characterized in that The preparation method of the multifunctional polyurethane comprises the following steps: (1) mixing a polymer diol, a diisocyanate, a first solvent, an optional catalyst, and triphenylbismuth, and reacting the mixture to obtain a prepolymer; (2) The prepolymer obtained in step (1) is mixed with a multifunctional cross-linking agent and a second solvent, and reacted to obtain the multifunctional polyurethane.

14. The polyurethane-epoxy resin composition according to claim 13, characterized in that The reaction temperature in step (1) is 80-90°C.

15. The polyurethane-epoxy resin composition according to claim 13, characterized in that The reaction time of step (1) is 60 to 90 minutes.

16. The polyurethane-epoxy resin composition according to claim 13, characterized in that The reaction temperature in step (2) is 75-85°C.

17. The polyurethane-epoxy resin composition according to claim 13, characterized in that The reaction time of step (2) is 90 to 120 minutes.

18. The polyurethane-epoxy resin composition according to claim 1, characterized in that The epoxy resin includes bisphenol A epoxy resin and liquid nitrile rubber modified epoxy resin; Taking the mass percentage of the epoxy resin as 100%, the mass percentage of the bisphenol A epoxy resin is 70-90%, and the mass percentage of the liquid nitrile rubber modified epoxy resin is 10-30%.

19. The polyurethane-epoxy resin composition according to claim 18, characterized in that The number average molecular weight of the bisphenol A epoxy resin is 300-600.

20. The polyurethane-epoxy resin composition according to claim 18, characterized in that The bisphenol A epoxy resin is selected from any one of Yueyang Petrochemical CYD-128, Nanya NPEL-128, and Nanya NPEF-127, or a combination of at least two thereof.

21. The polyurethane-epoxy resin composition according to claim 18, characterized in that The number average molecular weight of the liquid nitrile rubber modified epoxy resin is 2990-9900.

22. The polyurethane-epoxy resin composition according to claim 1, characterized in that The thixotropic agent is selected from fumed silica with a particle size of 100 to 800 nm and / or organic bentonite powder with a particle size of 50 to 400 meshes.

23. The polyurethane-epoxy resin composition according to claim 22, characterized in that The thixotropic agent is fumed silica with a particle size of 200 to 700 nm.

24. The polyurethane-epoxy resin composition according to claim 1, characterized in that The inorganic filler is selected from any one of micron-sized aluminum hydroxide, micron-sized silicon powder, micron-sized calcium carbonate or micron-sized kaolin, or a combination of at least two thereof.

25. The polyurethane-epoxy resin composition according to claim 24, characterized in that The inorganic filler is micron-sized silicon powder.

26. The polyurethane-epoxy resin composition according to claim 1, characterized in that The curing agent is a latent curing agent.

27. The polyurethane-epoxy resin composition according to claim 26, characterized in that The latent curing agent is selected from any one of dicyandiamide, boron trifluoride amine complex, and diaminomaleonitrile, or a combination of at least two thereof.

28. The polyurethane-epoxy resin composition according to claim 27, wherein the latent curing agent is Dyhard 100S dicyandiamide curing agent.

29. The polyurethane-epoxy resin composition according to claim 1, characterized in that The epoxy resin composition further comprises 0.1 to 0.3 parts of a curing accelerator.

30. The polyurethane-epoxy resin composition according to claim 29, characterized in that The curing accelerator is selected from urea compounds and / or imidazole compounds.

31. The polyurethane-epoxy resin composition according to claim 30, characterized in that The curing accelerator is Dyhard UR300 urea accelerator.

32. A method for preparing the polyurethane-epoxy resin composition according to any one of claims 1 to 31, characterized in that: The preparation method comprises the following steps: (A) mixing a multifunctional polyurethane, an epoxy resin, a thixotropic agent and an inorganic filler to obtain a mixture; (B) mixing the mixture obtained in step (A) with a curing agent and an optional curing accelerator to obtain the polyurethane-epoxy resin composition.

33. The preparation method according to claim 32, characterized in that The mixing method in step (A) is to use a dynamic mixer to stir and mix.

34. The preparation method according to claim 33, characterized in that The revolution frequency of the dynamic mixer is 10 to 50 Hz.

35. The preparation method according to claim 33, characterized in that The rotation frequency of the dynamic mixer is 15 to 55 Hz.

36. The preparation method according to claim 32, characterized in that The mixing temperature in step (A) is 30-40°C.

37. The preparation method according to claim 32, characterized in that The mixing method in step (B) is to use a dynamic mixer to stir and mix.

38. The preparation method according to claim 37, characterized in that The revolution speed of the dynamic mixer is 10 to 40 Hz.

39. The preparation method according to claim 37, characterized in that The rotation speed of the dynamic mixer is 5 to 45 Hz.

40. The preparation method according to claim 32, characterized in that The mixing temperature in step (B) is 30-40°C.

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