Moisture-curing latent curing agent and preparation method thereof, and polyurethane modified epoxy cold-mixed asphalt and preparation method thereof

Abstract

The invention provides a moisture-curing latent curing agent and a preparation method thereof, and polyurethane modified epoxy cold-mixed asphalt and a preparation method thereof. The moisture curing latent curing agent is N, N '-bis (2-octanone)-pentanedione imine; the polyurethane modified epoxy cold-mixed asphalt is prepared from the following raw materials: asphalt, a solvent, epoxy resin, a polyurethane prepolymer, a diluent and a curing agent, the curing agent is a moisture-curing latent curing agent; the polyurethane modified epoxy asphalt provided by the invention can be mixed and paved at normal temperature or low temperature, has better dynamic stability and flexibility, and is low in activation difficulty, capable of being cured at room temperature, small in environmental pollution, long in storage period and simple and convenient to construct by using a brand-new synthesized moisture curing latent curing agent; the curing is further realized when meeting water; the ketone generated by the reverse reaction and the polyurethane elastomer can provide better low-temperature toughness for the whole asphalt resin system in the form of a plasticizer.

Description

Technical Field

[0001] The present invention relates to the technical field of asphalt materials, and in particular to a moisture-curing latent curing agent and a preparation method thereof, and a polyurethane-modified epoxy cold-mix asphalt and a preparation method thereof. Background Art

[0002] Potholes on asphalt pavement affect the normal passage of vehicles and endanger traffic safety. The traditional maintenance method is to use hot-mix asphalt to re-pave the road surface. The production and paving temperature is high, the energy consumption is large, and the pollution is serious. Cold-mix asphalt mixture is not affected by weather, can be stored, and is available for use at any time. It is environmentally friendly and pollution-free. It can quickly repair potholes on the road surface. It is widely used in road maintenance work and has gradually become a new type of asphalt pavement material for the promotion and application of green transportation projects. However, the current mainstream technical solution for this cold-mix asphalt mixture is to use petroleum-based dilution solvents to prepare diluted asphalt, or to use emulsification technology to mix asphalt with water to prepare emulsified asphalt. There are two problems that have not been well solved: (1) The petroleum-based solvent or water in cold-mix asphalt is difficult to evaporate quickly, the mixture strength formation process is slow, the initial stability is low, and the curing time is long; and petroleum-based solvent oil is flammable. Too much low-boiling distillate oil precipitates from the asphalt mixture and is exposed on the top layer of the road surface, which will have a potential impact on road transportation safety. (2) Since the binder in cold-mix asphalt has a low viscosity and is not very resistant to water intrusion, initial water damage is more likely to occur in harsh environments such as low temperature seasons, rainy and snowy weather, and some key indicators of road performance are difficult to meet.

[0003] At present, the road performance of cold-mix asphalt can be improved to a certain extent by modifying cold-mix asphalt with polymer materials such as epoxy resin. However, epoxy resin itself has the disadvantages of high brittleness and poor flexibility, which leads to poor low-temperature performance of epoxy asphalt. Pavements paved with epoxy asphalt mixtures are prone to low-temperature cracking, which affects the performance. Therefore, the development and large-scale engineering application of cold-mix epoxy asphalt mixtures are limited. To solve these defects, epoxy toughening is a common traditional method. For example, the prior art discloses a waste rubber powder modified epoxy asphalt material and a preparation method thereof, which uses waste rubber powder to add to epoxy asphalt, first modify the asphalt, and then mix the asphalt with epoxy resin to obtain the preparation method of epoxy asphalt to increase the toughness of epoxy asphalt. However, this method has a complicated process, is difficult to produce on a large scale, and is not suitable for the production of environmentally friendly cold-mix asphalt. The prior art discloses a polyurethane-modified epoxy cold-mix asphalt and a preparation method thereof, but the isocyanate and curing agent of the polyurethane prepolymer used are not bio-based materials, have certain environmental pollution, do not have a moisture-curing latent curing agent, have a short storage period, and cannot be constructed in a water environment.

[0004] Based on this, a moisture-curing latent curing agent and a preparation method thereof, a polyurethane-modified epoxy cold-mix asphalt and a preparation method thereof are now provided, which can eliminate the drawbacks of the prior art. Summary of the invention

[0005] In view of this, the present invention provides a moisture-curing latent curing agent and a preparation method thereof, a polyurethane-modified epoxy cold mix asphalt and a preparation method thereof, in order to solve or at least partially solve the defects existing in the prior art.

[0006] In order to achieve the above object, the present invention adopts the following technical solutions:

[0007] In a first aspect, the present invention provides a moisture-curing latent curing agent, wherein the moisture-curing latent curing agent is N,N'-bis(2-octanone)-pentanedione imine, and its chemical structural formula is:

[0008]

[0009] In a second aspect, the present invention also provides a method for preparing the moisture-curing latent curing agent, comprising the following steps: mixing 1,5-pentanediamine and 2-octanone, and reacting to obtain N,N'-bis(2-octanone)-pentanedioneimine, which is a moisture-curing latent curing agent.

[0010] In a third aspect, the present invention also provides a polyurethane modified epoxy cold mix asphalt, comprising the following raw materials in parts by weight: 80 to 100 parts of asphalt, 50 to 90 parts of solvent, 15 to 25 parts of epoxy resin, 5 to 15 parts of polyurethane prepolymer, 5 to 10 parts of diluent, and 5 to 15 parts of curing agent;

[0011] The curing agent comprises the moisture-curing latent curing agent according to claim 1.

[0012] Preferably, the polyurethane prepolymer is an isocyanate-terminated polymer synthesized by reacting isocyanate with oligomer polyol, namely, a polyurethane prepolymer;

[0013] Wherein, the isocyanate is blocked PDI;

[0014] Alternatively, the isocyanate comprises blocked PDI and at least one of TDI, polymeric MDI and IPDI.

[0015] Preferably, the polymeric MDI comprises PM400 and / or PM200;

[0016] and / or, the oligomer polyol comprises polyether polyol and / or polyester polyol;

[0017] The polyether polyol comprises at least one of polyoxypropylene glycol and polytetrahydrofuran diol;

[0018] The polyester polyol includes at least one of polyacrylate polyol and polycarbonate diol;

[0019] And / or, the preparation method of the closed PDI is:

[0020] After mixing PDI monomer and organic solvent, the temperature is controlled to be 50-55° C., and then a blocking agent is added, and the mixture is reacted at 80-85° C. until the NCO weight percentage content is 10-15%, and after removing the organic solvent, a blocked PDI is obtained;

[0021] Wherein, the blocking agent includes methyl ethyl ketoxime and / or 3,5-dimethylpyrazole.

[0022] Preferably, the asphalt is No. 70 petroleum asphalt;

[0023] and / or, the solvent comprises at least one of cardanol, cashew nut shell liquid, turpentine, and limonene;

[0024] And / or, the epoxy resin includes at least one of bisphenol A epoxy resin E51 and bisphenol A epoxy resin E44;

[0025] And / or, the diluent includes at least one of acetone, sorbitol glycidyl ether, butyl glycidyl ether, and ethylene glycol diglycidyl ether;

[0026] And / or, the curing agent further includes at least one of an aliphatic polyamine curing agent, an aromatic polyamine curing agent, and a polyamide curing agent.

[0027] Preferably, the aromatic polyamine curing agent includes at least one of dimethylthiotoluenediamine and diethyltoluenediamine;

[0028] And / or, the aliphatic polyamine curing agent is N,N'-bis(3-aminopropyl)-1,5-pentanediamine, whose chemical structural formula is

[0029] And / or, the organic solvent is propylene glycol methyl ether acetate.

[0030] In a fourth aspect, the present invention further provides a method for preparing the polyurethane modified epoxy cold mix asphalt, comprising the following steps:

[0031] The epoxy resin and the polyurethane prepolymer are mixed and reacted to obtain an epoxy-polyurethane mixture;

[0032] The asphalt is heated to make it melt, and then a solvent is added and stirred to obtain diluted asphalt;

[0033] The epoxy-polyurethane mixture, the diluent and the curing agent are added to the diluted asphalt to react and obtain the polyurethane-modified epoxy cold mix asphalt.

[0034] Preferably, the specific preparation method of the epoxy-polyurethane mixture comprises:

[0035] After mixing epoxy resin and polyurethane prepolymer, shear mixing is performed at 80-90° C. and a rate of 1000-4000 r / min for 4-5 hours, and vacuum degassing is performed to obtain an epoxy-polyurethane mixture;

[0036] And / or, the specific preparation method of the diluted asphalt comprises:

[0037] The asphalt is heated to 120-130°C to be melted, and then a solvent is added, and shearing and stirring is performed at a rate of 1000-2000 r / min to obtain diluted asphalt;

[0038] And / or, the specific preparation method of the polyurethane modified epoxy cold mix asphalt comprises:

[0039] The diluted asphalt is cooled to 60-80°C, and then the epoxy-polyurethane mixture, diluent and curing agent are added, and shear reaction is carried out at a rate of 1000-2000 r / min for 10-15 minutes to obtain polyurethane-modified epoxy cold mix asphalt.

[0040] Preferably, the method for preparing the polyurethane prepolymer comprises the following steps:

[0041] The oligomer polyol is heated to 110-120°C and then vacuum dehydrated, then cooled to 60-70°C, and blocked PDI and at least one of TDI, polymeric MDI and IPDI are added under an inert atmosphere, and the temperature is raised to 75-80°C, and stirred for reaction for 2-3 hours to obtain a terminal isocyanate polymer, i.e., a polyurethane prepolymer;

[0042] Wherein, the mass ratio of the oligomer polyol, blocked PDI, and at least one of optional TDI, polymeric MDI, and IPDI is (15-20):(3-4):(0-1);

[0043] The inert atmosphere includes at least one of nitrogen, helium, neon and argon.

[0044] The moisture-curing latent curing agent and preparation method thereof, polyurethane-modified epoxy cold-mix asphalt and preparation method thereof of the present invention have the following beneficial effects compared with the prior art:

[0045] 1. Compared with other epoxy curing agents, the moisture-curing latent curing agent of the present invention has a certain storage stability when added to the epoxy resin to form a single-component system at room temperature. In a humid environment or by adding water and moisture externally, N,N'-bis(2-octanone)-pentanedione imine will react and decompose into pentamethylenediamine and 2-octanone. Pentamethylenediamine reacts and cures with the epoxy resin, continuing to provide late reaction strength for cold-mix asphalt. At the same time, the presence of macromolecular 2-octanone can also provide further plasticization space for polyurethane molecules, and has better compatibility with asphalt mixtures;

[0046] 2. The polyurethane modified epoxy cold mix asphalt of the present invention grafts the flexible chain segments in the polyurethane into the epoxy resin, so that the cold mix asphalt modified by the polyurethane-epoxy resin composite has the advantages of high strength and good high temperature performance of the epoxy resin, and good low temperature flexibility of the polyurethane, thereby further improving the road performance of the asphalt mixture; the polyurethane modified epoxy cold mix asphalt used in the present invention is a single component, which can save the AB two-component weight ratio link during construction, and can be cured at room temperature, which is easy to use; the special feature of the present invention is that a relatively high proportion of biomass diluted asphalt solvent is used, which is one or more of the solvents selected from cardanol, cashew nut shell liquid, turpentine, and limonene The combination of several of them, after reacting with epoxy resin, greatly improves the elastic mechanical properties of polyurethane-modified epoxy asphalt; compared with other polyurethane-modified epoxy resins, in addition to the known bio-based polyols, the present invention is special in that more bio-based isocyanates and bio-based special amines are introduced, including bio-based aliphatic pentamethylene diisocyanate monomer (PDI), bio-based moisture-type latent curing agent N,N'-bis(2-octanone)-pentanedione imine and bio-based N,N'-bis(3-aminopropyl)-1,5-pentanediamine, which replace petroleum-based raw materials, significantly reduce carbon emissions, and have a high sustainable environmental protection advantage;

[0047] 3. The polyurethane modified epoxy cold mix asphalt of the present invention uses closed PDI as prepolymer, and the deblocking temperature varies according to different types of sealants. This characteristic gives the polyurethane modified epoxy asphalt the possibility of further reaction and curing in different temperature ranges. Isocyanate can continue to react with water in the environment to generate a three-dimensional interpenetrating structure. At the same time, the separated long-chain ketone molecules can also provide certain thermoplastic support, which is very suitable for road construction under complex climatic conditions. BRIEF DESCRIPTION OF THE DRAWINGS

[0048] In order to more clearly illustrate the embodiments of the present invention or the technical solutions in the prior art, the following briefly introduces the drawings required for use in the embodiments or the prior art descriptions. Obviously, the drawings described below are only some embodiments of the present invention, and for ordinary technicians in this field, other drawings can be obtained based on these drawings without creative work.

[0049] Figure 1 is the infrared spectrum of the moisture-curing latent curing agent prepared in Example 1;

[0050] Figure 2 is the nuclear magnetic resonance image of the moisture-curing latent curing agent prepared in Example 1;

[0051] Figure 3 This is a chromatogram of the purified product after hydrogenation of the curing agent N,N'-bis(3-aminopropyl)-1,5-pentanediamine prepared in Example 1. DETAILED DESCRIPTION

[0052] To make the purpose, technical solution and advantages of the embodiments of the present invention clearer, the technical solution in the embodiments of the present invention will be described clearly and completely below in conjunction with the drawings in the embodiments of the present invention. Obviously, the described embodiments are only part of the embodiments of the present invention, not all of them.

[0053] The following will be combined with the embodiments of the present invention to clearly and completely describe the technical solutions in the embodiments of the present invention. Obviously, the described embodiments are only part of the embodiments of the present invention, not all of the embodiments. Based on the embodiments of the present invention, all other embodiments obtained by ordinary technicians in this field without creative work are within the scope of protection of the present invention.

[0054] It should be noted that the order of description of the following embodiments is not intended to limit the preferred order of the embodiments. In addition, in the description of the present application, the term "including" means "including but not limited to". Various embodiments of the present invention may be in the form of a range; it should be understood that the description in the form of a range is only for convenience and brevity, and should not be understood as a rigid limitation on the scope of the present invention; therefore, it should be considered that the range description has specifically disclosed all possible sub-ranges and single values ​​within the range. For example, it should be considered that the range description from 1 to 6 has specifically disclosed sub-ranges, such as from 1 to 3, from 1 to 4, from 1 to 5, from 2 to 4, from 2 to 6, from 3 to 6, etc., as well as single numbers within the numbered ranges, such as 1, 2, 3, 4, 5 and 6, which apply regardless of the range. In addition, whenever a numerical range is indicated in this article, it is meant to include any quoted numbers (fractions or integers) within the indicated range.

[0055] The present application provides a moisture-curing latent curing agent, which is N,N'-bis(2-octanone)-pentanedione imine, and its chemical structure is:

[0056]

[0057] Based on the same inventive concept, the present invention also provides a method for preparing the above-mentioned moisture-curing latent curing agent, comprising the following steps: mixing 1,5-pentanediamine and 2-octanone, reacting to obtain N,N'-bis(2-octanone)-pentanedioneimine, which is a moisture-curing latent curing agent.

[0058] Specifically, in a single-mouth round-bottom flask equipped with a water separator and a spherical condenser, the measured 1,5-pentanediamine and excess 2-octanone are added and mixed, and slowly heated to 105-110°C in an oil bath, and stirred by a magnetic stirrer. The molar ratio of amine to ketone (pentanediamine: 2-octanone) is set to 1:4. At the same time, the upper and lower cooling water of the spherical condenser are turned on, and the obtained gas phase condensate (1,5-pentanediamine and water) is separated into gas and liquid phases in the water separator, and 1,5-pentanediamine is returned to the round-bottom flask. The condensed water is collected and weighed separately to calculate the conversion rate and evaluate whether the reaction is terminal. The entire reaction process is carried out under nitrogen protection. The reaction can be stopped when the amount of water in the reflux water separator is close to the theoretical amount of water. The product is then cooled to room temperature and transferred to a vacuum distiller, the rotary evaporation temperature range is raised to 150-170°C, and the product is cooled and refluxed to remove excess 2-octanone from the product. The pressure was reduced until no distillate appeared and then maintained for 1 hour to obtain the final product, N,N'-bis(2-octanone)-pentanedione imine, which was set aside.

[0059] Specifically, the reaction formula for the reaction of 1,5-pentanediamine with 2-octanone to obtain N,N'-bis(2-octanone)-pentanedione imine is as follows:

[0060]

[0061] Preferably, the molar ratio of 1,5-pentanediamine to 2-octanone is 1:(3-4).

[0062] The present invention adopts a moisture-curing latent curing agent N,N'-bis(2-octanone)-pentanedione imine. Compared with other epoxy curing agents, the single-component system formed by adding the epoxy resin to the epoxy resin has certain storage stability at room temperature. In a humid environment or by adding water and moisture externally, the N,N'-bis(2-octanone)-pentanedione imine will reversely react and decompose into pentamethylenediamine and 2-octanone. Pentamethylenediamine reacts with the epoxy resin to cure, and continues to provide late reaction strength for cold-mix asphalt. At the same time, the presence of macromolecular 2-octanone can also provide further plasticization space for polyurethane molecules, and has better compatibility with asphalt mixture.

[0063] Based on the same inventive concept, the present invention also provides a polyurethane modified epoxy cold mix asphalt, comprising the following raw materials in parts by weight: 80-100 parts of asphalt, 50-90 parts of solvent, 15-25 parts of epoxy resin, 5-15 parts of polyurethane prepolymer, 5-10 parts of diluent, and 5-15 parts of curing agent;

[0064] The curing agent includes the moisture curing latent curing agent mentioned above.

[0065] The polyurethane modified epoxy asphalt provided by the present invention can be mixed and spread at room temperature or low temperature, and has good dynamic stability and flexibility. The use of a newly synthesized bio-based ketimine moisture-type latent curing agent makes the single-component polyurethane modified epoxy cold mix asphalt not only have the advantages of low activation difficulty, room temperature curing, low environmental pollution, long storage period, simple construction, and further curing when exposed to water; it can also make the ketone generated by the reverse reaction, together with the polyurethane elastomer, provide the entire asphalt resin system with better low-temperature toughness in the form of a plasticizer.

[0066] In some embodiments, the polyurethane prepolymer is an isocyanate-terminated polymer synthesized by reacting an isocyanate with an oligomer polyol, namely, a polyurethane prepolymer;

[0067] Among them, the isocyanate is blocked PDI;

[0068] Alternatively, the isocyanate includes blocked PDI and at least one of TDI, polymeric MDI, and IPDI.

[0069] Specifically, PDI (also known as pentamethylene diisocyanate, chemical formula: C7H 10 N2O2) is bio-based aliphatic 1,5-pentanediisocyanate (PDI). Its main raw materials are made from biomass materials such as corn and straw through bio-enzyme fermentation and chemical synthesis. It replaces petroleum-based raw materials, effectively reduces carbon emissions, and has a high sustainable environmental advantage. The production process is as follows:

[0070]

[0071] TDI is toluene diisocyanate, chemical formula: C9H6N2O2.

[0072] IPDI is isophorone diisocyanate, chemical formula: C 12 H 18 N2O2.

[0073] In some embodiments, the polymeric MDI includes PM400 and / or PM200; specifically, PM400 is Wanhua WANNATE PM400 polymeric MDI, and PM200 is polymeric MDI, Wanhua PM20.

[0074] In some embodiments, the oligomer polyol comprises a polyether polyol and / or a polyester polyol;

[0075] The polyether polyol includes at least one of polyoxypropylene glycol PPG and polytetramethylene glycol PTMEG;

[0076] The polyester polyol includes at least one of polyacrylate polyol and polycarbonate diol.

[0077] In some embodiments, the oligomer polyol has a molecular weight of 500-2000.

[0078] In some embodiments, a typical preparation method of the blocked PDI is:

[0079] About 76g of PDI monomer and solvent propylene glycol methyl ether acetate are mixed and heated to 50-55°C, 41g of methyl ethyl ketoxime is added while stirring under nitrogen protection, the temperature is raised to 80-85°C, and the reaction is carried out for 2h until the NCO weight percentage content is 10-15%, and then the solvent is removed by reduced pressure distillation to obtain the closed PDI;

[0080] Wherein, the blocking agent includes methyl ethyl ketoxime MEKO and / or 3,5-dimethylpyrazole DMP.

[0081] In some embodiments, the asphalt is No. 70 petroleum asphalt.

[0082] In some embodiments, the solvent includes cardanol (Formula C 21 H 34 O), cashew nut shell liquid, turpentine, limonene (molecular formula C 10 H 16 ) at least one of.

[0083] In some embodiments, the epoxy resin includes at least one of bisphenol A epoxy resin E51 and bisphenol A epoxy resin E44.

[0084] In some embodiments, the diluent includes acetone, sorbitol glycidyl ether (molecular formula C9H 19 ClO7), butyl glycidyl ether (i.e. n-butyl glycidyl ether, molecular formula: C7H 14 O2), at least one of ethylene glycol diglycidyl ether.

[0085] In some embodiments, the curing agent further comprises at least one of an aliphatic polyamine curing agent, an aromatic polyamine curing agent, and a polyamide curing agent.

[0086] In some embodiments, the aromatic polyamine curing agent includes at least one of dimethylthiotoluenediamine (DMTDA) and diethyltoluenediamine (DETDA).

[0087] In some embodiments, the aliphatic polyamine curing agent is N,N'-bis(3-aminopropyl)-1,5-pentanediamine, whose chemical formula is

[0088] Specifically, the preparation method of N,N'-bis(3-aminopropyl)-1,5-pentanediamine is as follows: using tert-butyl alcohol as solvent, pentamethylenediamine and acrylonitrile are subjected to Michael addition reaction at a molar ratio of 1:2 (reaction temperature is 80°C, reaction pressure is 0.2MPa), to generate 1,5-imino-pentamethylenediamine-1,5-dipropionitrile, and after filtering and separating the solvent, the final product is introduced into a fixed bed hydrogenation reactor, the catalyst used is Raney nickel, the reaction pressure is 6.0-7.0MPa, and the hydrogenation product is distilled to obtain N,N'-bis(3-aminopropyl)-1,5-pentanediamine, and the chemical reaction formula is:

[0089]

[0090] In some embodiments, the organic solvent is propylene glycol methyl ether acetate.

[0091] Based on the same inventive concept, the present invention also provides a method for preparing the above-mentioned polyurethane modified epoxy cold mix asphalt, comprising the following steps:

[0092] S1, mixing epoxy resin and polyurethane prepolymer, and reacting them to obtain an epoxy-polyurethane mixture;

[0093] S2, heating the asphalt to make it melt, adding a solvent, stirring, and obtaining diluted asphalt;

[0094] S3. Add the epoxy-polyurethane mixture, diluent and curing agent to the diluted asphalt to react and obtain polyurethane-modified epoxy cold mix asphalt.

[0095] In some embodiments, the specific preparation method of the epoxy-polyurethane mixture includes:

[0096] After epoxy resin and polyurethane prepolymer are mixed, they are shear-mixed at 80-90° C. and a rate of 1000-4000 r / min for 4-5 hours, and vacuum degassing is performed to obtain an epoxy-polyurethane mixture.

[0097] In some embodiments, a specific method for preparing diluted asphalt includes:

[0098] The asphalt is heated to 120-130°C to melt it, and then a solvent is added, and sheared and stirred at a rate of 1000-2000 r / min to obtain diluted asphalt.

[0099] In some embodiments, the specific preparation method of polyurethane modified epoxy cold mix asphalt includes:

[0100] The diluted asphalt is cooled to 60-80°C, and then the epoxy-polyurethane mixture, diluent and curing agent are added, and shear reaction is carried out at a rate of 1000-2000 r / min for 10-15 minutes to obtain polyurethane-modified epoxy cold mix asphalt.

[0101] In some embodiments, the method for preparing the polyurethane prepolymer comprises the following steps:

[0102] The oligomer polyol is heated to 110-120°C and vacuum dehydrated, then cooled to 60-70°C, and blocked PDI and optional TDI, polymeric MDI, and IPDI are added under an inert atmosphere. The temperature is raised to 75-80°C, and the reaction is stirred for 2-3 hours to obtain a terminal isocyanate polymer, which is a polyurethane prepolymer.

[0103] Wherein, the mass ratio of oligomer polyol, blocked PDI, and at least one of optional TDI, polymeric MDI, and IPDI is (15-20):(3-4):(0-1);

[0104] The inert atmosphere includes at least one of nitrogen, helium, neon and argon.

[0105] Specifically, the oligomer polyol is heated to 110-120° C. and then vacuum dehydrated, then cooled to 60-70° C., and blocked PDI and optional TDI, polymeric MDI, and IPDI are added under an inert atmosphere. The temperature is raised to 75-80° C. and stirred for reaction for 2-3 hours. The isocyanate content is detected, and the R value control range (R=NCO / OH, ratio of the amount of substance) is controlled to be 2-3 as the judgment condition to obtain a terminal isocyanate polyurethane prepolymer.

[0106] The polyurethane modified epoxy cold mix asphalt of the present invention grafts the flexible chain segments in the polyurethane into the epoxy resin, so that the cold mix asphalt modified by the polyurethane-epoxy resin composite has the advantages of high strength and good high temperature performance of the epoxy resin, and has good low temperature flexibility of the polyurethane, thereby further improving the road performance of the asphalt mixture; the polyurethane modified epoxy cold mix asphalt used in the present invention is a single component, which can save the AB two-component weight ratio link during construction, and can be cured at room temperature, and is easy to use; the present invention uses a moisture-curing latent curing agent N, N'-bis (2-octanone)-pentanedione imine, and compared with other epoxy curing agents, the single-component system formed by adding it to the epoxy resin has certain storage stability at room temperature, and in a humid environment or by adding water and moisture externally, N, N'-bis (2-octanone)-pentanedione imine will reversely react and decompose into pentamethylenediamine and 2-octanone, and pentamethylenediamine reacts with the epoxy resin to cure, which is the cold mix asphalt. It provides late reaction strength, and the presence of macromolecular 2-octanone can also provide further plasticization space for polyurethane molecules, and has better compatibility with asphalt mixture; the special feature of the present invention is that a higher proportion of biomass diluted asphalt solvents such as cashew phenol, cashew nut shell liquid, turpentine, and limonene or a combination of several of them are used, and after reacting with epoxy resin, the elastic mechanical properties of polyurethane modified epoxy asphalt are greatly improved; compared with other polyurethane modified epoxy resins, in addition to the known bio-based polyols, the special feature of the present invention is that more bio-based isocyanates and bio-based special amines are introduced, including bio-based aliphatic pentamethylene diisocyanate monomer (PDI), bio-based moisture-type latent curing agent N,N'-bis(2-octanone)-pentanedione imine and bio-based N,N'-bis(3-aminopropyl)-1,5-pentanediamine, which replace petroleum-based raw materials, significantly reduce carbon emissions, and have a higher sustainable environmental protection advantage.

[0107] The following further describes the wet-curing latent curing agent and its preparation method, polyurethane-modified epoxy cold-mix asphalt and its preparation method of the present application with specific examples. This section further describes the content of the present invention in conjunction with specific examples, but should not be construed as limiting the present invention. Unless otherwise specified, the technical means used in the examples are conventional means well known to those skilled in the art. Unless otherwise specified, the reagents, methods and equipment used in the present invention are conventional reagents, methods and equipment in the art.

[0108] In the following examples, polyether polyol N230 represents polyoxypropylene glycol with a functionality of 2 and a molecular weight of 3000, and polyether polyol N210 represents polyoxypropylene glycol with a functionality of 2 and a molecular weight of 1000. Polyether polyol N230 and polyether polyol N210 were purchased from Changshu Yitong Polyurethane Products Co., Ltd.

[0109] Bisphenol A epoxy resin E-51, purchased from Changchun Chemical (Jiangsu) Co., Ltd.;

[0110] No. 70 petroleum asphalt, purchased from Sinopec.

[0111] Example 1

[0112] The embodiment of the present application provides a moisture-curing latent curing agent, and the moisture-curing latent curing agent is N,N'-bis(2-octanone)-pentanedione imine;

[0113] The preparation method of the moisture-curing latent curing agent comprises the following steps: in a single-mouth round-bottom flask equipped with a water separator and a spherical condenser, the measured 1,5-pentanediamine and excess 2-octanone are added separately (specifically, the molar ratio of 1,5-pentanediamine to 2-octanone is 1:4), and the mixture is heated to 105-110°C in an oil bath, and stirred by a magnetic stirrer. At the same time, the upper and lower cooling water of the spherical condenser are turned on, and the obtained condensate (1,5-pentanediamine and water) is separated into vapor and liquid phases in the water separator, and the 1,5-pentanediamine is returned to the round-bottom flask, and the condensed water is collected and weighed separately for calculating the conversion rate and evaluating whether the reaction is at the end point. The entire reaction process is carried out under nitrogen protection; the reaction can be stopped when the amount of water in the reflux water separator is close to the theoretical amount of water. The product is then cooled to room temperature and transferred to a vacuum distiller, the rotary evaporation temperature range is raised to 150-170°C, and the product is cooled and refluxed to remove excess 2-octanone from the product. The pressure was reduced until no distillate appeared and then maintained for 1 hour to obtain the final product, N,N'-bis(2-octanone)-pentanedioneimine.

[0114] Example 2

[0115] The present application provides a method for preparing a curing agent N,N'-bis(3-aminopropyl)-1,5-pentanediamine, comprising the following steps:

[0116] With tert-butyl alcohol as solvent, pentamethylenediamine and acrylonitrile are subjected to Michael addition reaction at a molar ratio of 1:2 (reaction temperature is 80°C, reaction pressure is 0.2 MPa) to generate 1,5-imino-pentamethylenediamine-1,5-dipropionitrile. After filtering and separating the solvent, the final product is introduced into a fixed bed hydrogenation reactor. The catalyst used is Raney nickel. The reaction pressure is 6.0-7.0 MPa. The hydrogenated product is distilled to obtain N,N'-bis(3-aminopropyl)-1,5-pentamethylenediamine.

[0117] Example 3

[0118] The present application provides a method for preparing polyurethane-modified epoxy cold mix asphalt, comprising the following steps:

[0119] S1, about 76g of PDI monomer and solvent propylene glycol methyl ether acetate are mixed and heated to 50-55°C, 41g of methyl ethyl ketoxime is added while stirring under nitrogen protection, the temperature is raised to 80-85°C, and the reaction is carried out for 2h until the mass NCO weight percentage content is 10-15%, and then the solvent is removed by reduced pressure distillation to obtain the closed PDI;

[0120] S2, adding 15 parts by weight of oligomer polyether polyol N230 to a stirred kettle, heating to 110° C., vacuum dehydrating for 3 hours, and then cooling to 65° C.; adding 4 parts by weight of PDI blocked with methyl ethyl ketoxime under nitrogen protection, and mixing, raising the reaction temperature to 80° C., stirring and reacting for 3 hours to obtain an isocyanate-terminated polyurethane prepolymer;

[0121] S3, adding 15 parts by weight of bisphenol A epoxy resin E-51 to the polyurethane prepolymer in S2, shear mixing at 80° C. at a rate of 2000 r / min for 4 hours, and obtaining an epoxy-polyurethane mixture after vacuum degassing;

[0122] S4, heating 100 parts by weight of No. 70 petroleum asphalt to 120°C to completely melt it, adding 80 parts by weight of cardanol, and shearing and stirring at a rate of 1500 r / min until it is uniform, and it is worth diluting the asphalt;

[0123] S5. Cool the diluted asphalt to 60°C, then add the epoxy-polyurethane mixture in S3, 5 parts by weight of diluent acetone, 3 parts by weight of N,N'-bis(2-octanone)-pentanedioneimine, and 2 parts by weight of N,N'-bis(3-aminopropyl)-1,5-pentanediamine curing agent, and shear react at a rate of 1500 r / min for 12 minutes to obtain polyurethane-modified epoxy cold mix asphalt.

[0124] Example 4

[0125] The present application provides a method for preparing polyurethane-modified epoxy cold mix asphalt, comprising the following steps:

[0126] S1, about 76g of PDI monomer and solvent propylene glycol methyl ether acetate are mixed and heated to 50-55°C, 41g of methyl ethyl ketoxime is added while stirring under nitrogen protection, the temperature is raised to 80-85°C, and the reaction is carried out for 2h until the mass NCO weight percentage content is 10-15%, and then the solvent is removed by reduced pressure distillation to obtain the closed PDI;

[0127] S2, adding 15 parts by weight of oligomer polyol (specifically polytetrahydrofuran diol PTMEG) to a stirred tank, heating to 110° C., vacuum dehydrating for 3 hours, and then cooling to 65° C.; under nitrogen protection, adding 3 parts by weight of methyl ethyl ketoxime-blocked PDI and 1 part by weight of TDI, mixing, raising the reaction temperature to 80° C., stirring and reacting for 3 hours, to obtain an isocyanate-terminated polyurethane prepolymer;

[0128] S3, adding 20 parts by weight of bisphenol A epoxy resin E-51 to the polyurethane prepolymer in S2, shear mixing at 80° C. at a rate of 2000 r / min for 4 h, and obtaining an epoxy-polyurethane mixture after vacuum degassing;

[0129] S4, heating 100 parts by weight of No. 70 petroleum asphalt to 120°C to completely melt it, adding 90 parts by weight of cardanol, shearing and stirring at a rate of 1500 r / min until it is uniform, and diluting the asphalt;

[0130] S5. Cool the diluted asphalt to 60°C, then add the epoxy-polyurethane mixture in S3, 5 parts by weight of diluent sorbitol glycidyl ether, 4 parts by weight of N,N'-bis(2-octanone)-pentanedione imine, and 2 parts by weight of N,N'-bis(3-aminopropyl)-1,5-pentanediamine curing agent, and shear react at a rate of 1500 r / min for 12 minutes to obtain polyurethane-modified epoxy cold mix asphalt.

[0131] Example 5

[0132] The present application provides a method for preparing polyurethane-modified epoxy cold mix asphalt, comprising the following steps:

[0133] S1, about 76g of PDI monomer and solvent propylene glycol methyl ether acetate are mixed and heated to 50-55°C, 41g of methyl ethyl ketoxime is added while stirring under nitrogen protection, the temperature is raised to 80-85°C, and the reaction is carried out for 2h until the weight percentage NCO content is 10-15%, and then the solvent is removed by reduced pressure distillation to obtain the closed PDI;

[0134] S2, adding 15 parts by weight of oligomer polyether polyol N210 to a stirred tank, heating to 110°C, vacuum dehydrating for 3 hours, and then cooling to 65°C; adding 3 parts by weight of PDI blocked with methyl ethyl ketoxime and 1 part by weight of PM200 under nitrogen protection, mixing, raising the reaction temperature to 80°C, stirring and reacting for 3 hours to obtain an isocyanate-terminated polyurethane prepolymer;

[0135] S3, adding 25 parts by weight of bisphenol A epoxy resin E-51 to the polyurethane prepolymer in S2, shear mixing at 80° C. at a rate of 2000 r / min for 4 hours, and obtaining an epoxy-polyurethane mixture after vacuum degassing;

[0136] S4, heating 100 parts by weight of No. 70 petroleum asphalt to 120°C to completely melt it, adding 80 parts by weight of limonene, and shearing and stirring at a rate of 1500 r / min until it is uniform, and it is worth diluting the asphalt;

[0137] S5. Cool the diluted asphalt to 60°C, then add the epoxy-polyurethane mixture in S3, 2 parts by weight of diluent acetone, 3 parts by weight of diluent butyl glycidyl ether, 3 parts by weight of N,N'-bis(2-octanone)-pentanedioneimine, 2 parts by weight of N,N'-bis(3-aminopropyl)-1,5-pentanediamine, and 2 parts by weight of diethyltoluenediamine (DETDA), and carry out shear reaction at a rate of 1500 r / min for 12 minutes to obtain polyurethane-modified epoxy cold mix asphalt.

[0138] Comparative Example 1

[0139] This comparative example 1 provides a method for preparing a conventional epoxy modified cold mix asphalt, comprising the following steps:

[0140] S1. Heat 100 parts by weight of No. 70 petroleum asphalt to 100°C to completely melt it, add 15 parts by weight of No. 200 solvent oil, and shear and stir at a rate of 1500r / min until it is uniform, and dilute the asphalt;

[0141] S5. Cool the diluted asphalt to 60°C, then add 15 parts by weight of bisphenol A epoxy resin E44, 5 parts by weight of diluent butyl glycidyl ether and 5 parts by weight of diethyltoluenediamine curing agent, and shear mix at a rate of 1500 r / min for 12 minutes to obtain conventional epoxy modified cold mix asphalt.

[0142] Performance Testing

[0143] Figure 1 is the infrared spectrum of the moisture-curing latent curing agent prepared in Example 1; Figure 1 The position of the middle peak is 2924.64cm -1 、2855.62cm -1 、1718.04cm -1 、1658.62cm -1 .

[0144] from Figure 1 It can be seen that at 3300~3500cm -1 There is only a very weak NH stretching vibration peak between them, indicating that the reaction of pentamethylenediamine is basically complete; at 1658cm -1The presence of a very obvious CN stretching vibration peak indicates that a large number of imine groups are generated after the reaction of the primary amine group and the ketone group, indicating that the target product N,N'-bis(2-octanone)-pentanedione imine is successfully synthesized. -1 The CO stretching vibration peak appears at 2900-3000cm, indicating that the ketimine product after vacuum distillation still contains a small amount of raw material octanone, but the peak intensity is small, indicating that vacuum distillation can effectively recover the residual 2-octanone. -1 and 2800-2900cm -1 Strong stretching vibration peaks appear in the regions, which are the characteristic peak positions of CH stretching vibration of methyl (-CH3) and methylene (-CH2-), respectively, indicating that the product contains long aliphatic carbon chains.

[0145] Figure 2 is the nuclear magnetic resonance image of the moisture-curing latent curing agent prepared in Example 1; Figure 2 It can be seen that the moisture curing latent curing agent was successfully synthesized.

[0146] Figure 3 This is a gas chromatogram of the purified product after hydrogenation of the curing agent N,N'-bis(3-aminopropyl)-1,5-pentanediamine prepared in Example 1.

[0147] from Figure 3 It can be seen that after hydrogenation, the mixture generated by the Michael addition reaction of 1,5-pentanediamine and acrylonitrile has only three peaks in the chromatogram, among which the long-chain N,N'-bis(3-aminopropyl)-1,5-pentanediamine formed after addition and reduction at both ends has the highest purity, indicating that the conversion rate of the target product is high.

[0148] The polyurethane modified epoxy cold mix asphalt prepared in Examples 3 to 5 and the conventional epoxy modified cold mix asphalt obtained in Comparative Example 1 were mixed with aggregates according to the "Mineral Aggregate LB-13 for Cold Patch Asphalt Mixture" in JTG F40-2004 "Technical Specifications for Highway Asphalt Pavement Construction", with an oil-stone ratio of 6.0%, to obtain a polyurethane modified epoxy cold mix asphalt mixture. In order to further compare the application effects of the embodiments of the present invention, the dynamic stability and failure strain of the epoxy asphalt mixture were tested. The test method is the test method in JTG E20-2011 "Test Procedures for Highway Engineering Asphalt and Asphalt Mixtures", and the test results are shown in Table 1.

[0149] Table 1 - Properties of polyurethane modified epoxy cold mix asphalt prepared in different embodiments

[0150]

[0151] Table 1 is a comparison of the dynamic stability and low-temperature bending test failure strain of the asphalt mixtures prepared in Examples 3 to 5 and Comparative Example 1. The test temperature for dynamic stability is 60°C, the tire ground contact pressure is 0.7 MPa, the test temperature for low-temperature bending test failure strain is -18°C, and the test loading speed is 50 mm / min; the freeze-thaw splitting strength ratio is tested according to T0716.

[0152] As shown in Table 1, the mixture prepared by the polyurethane modified epoxy cold mix asphalt in the present invention has greatly improved various indicators such as Marshall stability and low temperature performance compared with the standard requirements of the "Technical Specifications for Highway Asphalt Pavement Construction" (JTG F40-2004). Even compared with the two-component epoxy modified asphalt cold patch material commonly used in the current market, it also has superior performance. This is because the introduction of polyurethane thermoplastic functional groups brings better high and low temperature balance to the overall modified asphalt. In particular, due to the use of a newly synthesized wet curing latent curing agent N, N'-bis (2-octanone) -pentanedione imine, the traditional epoxy modified asphalt has a single-component construction condition, which meets the requirements for rapid paving and curing at the construction site, and has great practical application value.

[0153] The above description is only a preferred embodiment of the present invention and is not intended to limit the present invention. Any modifications, equivalent substitutions, improvements, etc. made within the spirit and principles of the present invention should be included in the protection scope of the present invention.

Claims

1. A moisture curing latent curing agent, characterized in that: The moisture curing latent curing agent is N,N'-bis(2-octanone)-pentanedione imine, and its chemical structural formula is:

2. The method for preparing a moisture curing latent curing agent according to claim 1, characterized in that: The method comprises the following steps: mixing 1,5-pentanediamine and 2-octanone, and reacting them to obtain N,N'-bis(2-octanone)-pentanedioneimine, which is a moisture curing latent curing agent.

3. A polyurethane modified epoxy cold mix asphalt, characterized in that: The method comprises the following raw materials in parts by weight: 80 to 100 parts of asphalt, 50 to 90 parts of solvent, 15 to 25 parts of epoxy resin, 5 to 15 parts of polyurethane prepolymer, 5 to 10 parts of diluent, and 5 to 15 parts of curing agent; The curing agent comprises the moisture-curing latent curing agent according to claim 1.

4. The polyurethane modified epoxy cold mix asphalt according to claim 3, characterized in that: The polyurethane prepolymer is a terminal isocyanate polymer synthesized by the reaction of isocyanate and oligomer polyol, namely the polyurethane prepolymer; Wherein, the isocyanate is blocked PDI; Alternatively, the isocyanate comprises blocked PDI and at least one of TDI, polymeric MDI and IPDI.

5. The polyurethane modified epoxy cold mix asphalt according to claim 4, characterized in that: The polymeric MDI comprises PM400 and / or PM200; and / or, the oligomer polyol comprises polyether polyol and / or polyester polyol; The polyether polyol comprises at least one of polyoxypropylene glycol and polytetrahydrofuran diol; The polyester polyol includes at least one of polyacrylate polyol and polycarbonate diol; And / or, the preparation method of the closed PDI is: After mixing PDI monomer and organic solvent, the temperature is controlled to be 50-55° C., and then a blocking agent is added, and the mixture is reacted at 80-85° C. until the NCO weight percentage content is 10-15%, and after removing the organic solvent, a blocked PDI is obtained; Wherein, the blocking agent includes methyl ethyl ketoxime and / or 3,5-dimethylpyrazole.

6. The polyurethane modified epoxy cold mix asphalt according to claim 5, characterized in that: The asphalt is No. 70 petroleum asphalt; and / or, the solvent comprises at least one of cardanol, cashew nut shell liquid, turpentine, and limonene; And / or, the epoxy resin includes at least one of bisphenol A epoxy resin E51 and bisphenol A epoxy resin E44; And / or, the diluent includes at least one of acetone, sorbitol glycidyl ether, butyl glycidyl ether, and ethylene glycol diglycidyl ether; And / or, the curing agent further includes at least one of an aliphatic polyamine curing agent, an aromatic polyamine curing agent, and a polyamide curing agent.

7. The polyurethane modified epoxy cold mix asphalt according to claim 6, characterized in that: The aromatic polyamine curing agent includes at least one of dimethylthiotoluenediamine and diethyltoluenediamine; And / or, the aliphatic polyamine curing agent is N,N'-bis(3-aminopropyl)-1,5-pentanediamine, whose chemical structural formula is And / or, the organic solvent is propylene glycol methyl ether acetate.

8. A method for preparing polyurethane modified epoxy cold mix asphalt according to any one of claims 3 to 7, characterized in that: The following steps are involved: The epoxy resin and the polyurethane prepolymer are mixed and reacted to obtain an epoxy-polyurethane mixture; The asphalt is heated to make it melt, and then a solvent is added and stirred to obtain diluted asphalt; The epoxy-polyurethane mixture, the diluent and the curing agent are added to the diluted asphalt to react and obtain the polyurethane-modified epoxy cold mix asphalt.

9. The method for preparing polyurethane modified epoxy cold mix asphalt according to claim 8, characterized in that: The specific preparation method of the epoxy-polyurethane mixture comprises: After mixing epoxy resin and polyurethane prepolymer, shear mixing is performed at 80-90° C. and a rate of 1000-4000 r / min for 4-5 hours, and vacuum degassing is performed to obtain an epoxy-polyurethane mixture; And / or, the specific preparation method of the diluted asphalt comprises: The asphalt is heated to 120-130°C to be melted, and then a solvent is added, and shearing and stirring is performed at a rate of 1000-2000 r / min to obtain diluted asphalt; And / or, the specific preparation method of the polyurethane modified epoxy cold mix asphalt comprises: The diluted asphalt is cooled to 60-80°C, and then the epoxy-polyurethane mixture, diluent and curing agent are added, and shear reaction is carried out at a rate of 1000-2000 r / min for 10-15 minutes to obtain polyurethane-modified epoxy cold mix asphalt.

10. The method for preparing polyurethane modified epoxy cold mix asphalt according to claim 8, characterized in that: The preparation method of the polyurethane prepolymer comprises the following steps: The oligomer polyol is heated to 110-120°C and then vacuum dehydrated, then cooled to 60-70°C, and blocked PDI and at least one of TDI, polymeric MDI and IPDI are added under an inert atmosphere, and the temperature is raised to 75-80°C, and stirred for reaction for 2-3 hours to obtain a terminal isocyanate polymer, i.e., a polyurethane prepolymer; Wherein, the mass ratio of the oligomer polyol, blocked PDI, and at least one of optional TDI, polymeric MDI, and IPDI is (15-20):(3-4):(0-1); The inert atmosphere includes at least one of nitrogen, helium, neon and argon.

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