Serinol derivative damp-heat latent curing single-component polyurethane pouring sealant and preparation method thereof

Abstract

The invention belongs to the technical field of preparation of polyurethane adhesives, and relates to a serinol derivative damp-heat latent curing single-component polyurethane pouring sealant and a preparation method thereof. The problem that the bonding strength is affected due to embrittlement of a cured adhesive layer formed by a common technology is solved. Comprising a serinol derivative damp-heat latent curing agent, a polyurethane prepolymer, a cross-linking agent and a catalyst. The pouring sealant prepared by the invention is free of VOCs emission, safe, environment-friendly and convenient to use, can be continuously cured at room temperature by utilizing moisture in air after being pre-cured at 100 DEG C for 1 hour, is free of bubbles after being cured, is strong in adhesive strength and resistant to damp-heat aging, and can meet the pouring requirements in the fields of electronic component and power battery assembly and the like.

Description

Technical Field

[0001] The invention belongs to the technical field of polyurethane adhesive preparation, and relates to a serinol derivative wet heat latent curing single-component polyurethane potting adhesive and a preparation method thereof. Background Art

[0002] In recent years, with the advancement of industrial technology and the improvement of environmental protection requirements, traditional solvent-based and two-component adhesives have gradually been eliminated by the market due to their complicated use process and potential impact on the environment. One-component polyurethane adhesives have gradually become a research hotspot due to their convenience and environmental protection characteristics. In particular, the one-component moisture-heat curing type can be directly cured at a lower heating temperature or in an environment with a certain humidity, which greatly improves its application flexibility and reliability. In addition, the one-component moisture-curing polyurethane potting adhesive has excellent mechanical strength and chemical resistance, can maintain good bonding properties in extreme environments, can strengthen the integrity of electronic devices, and improve resistance to external shocks and vibrations, which makes them receive special attention in the fields of electronic component potting and power battery assembly.

[0003] The promotion and use of one-component polyurethane adhesives will help improve production efficiency and reduce production costs. At the same time, one-component polyurethane adhesives do not require the addition of additional solvents and curing agents, which can effectively reduce the use of organic solvents, is environmentally friendly, and is in line with current green chemistry and sustainable development strategies. Although one-component polyurethane adhesives have the above advantages, the production of CO2 during the moisture curing process of one-component polyurethane will cause the adhesive layer to foam and expand, and micropores to form, which will affect the bonding strength. Researchers mainly inhibit the production of CO2 by adding latent curing agents. Currently, the common latent curing agents are mainly oxazolidine type and imine type. The latent curing agent first reacts with water in the air to generate -OH or -NH2, and then cross-links with isocyanate to cure.

[0004] During the storage of the adhesive, the imide latent curing agent can slowly react with isocyanate, causing the storage performance of the one-component polyurethane adhesive to decrease. At the same time, the imide latent curing agent also affects the bonding strength of the adhesive to the metal substrate to a certain extent. The general oxazolidine latent curing agent has a limited reaction rate with moisture, so that there are still many microbubbles in the adhesive layer after the adhesive is cured. In addition, it will make the cured adhesive layer brittle, affecting the bonding strength and reliability during use.

[0005] Therefore, it is urgent to propose a serinol derivative wet heat latent curing one-component polyurethane potting adhesive and a preparation method to solve the above technical problems. Summary of the invention

[0006] The present invention is to solve the problem that the adhesive layer formed by the conventional technology becomes brittle after curing and affects the bonding strength. A brief summary of the present invention is given below to provide a basic understanding of certain aspects of the present invention. It should be understood that this summary is not an exhaustive summary of the present invention. It is not intended to determine the key or important parts of the present invention, nor is it intended to limit the scope of the present invention.

[0007] The technical solution of the present invention:

[0008] A serinol derivative latent heat curing one-component polyurethane potting adhesive, wherein the serinol derivative latent heat curing one-component polyurethane potting adhesive comprises a serinol derivative latent heat curing agent, a polyurethane prepolymer, a crosslinking agent, and a catalyst;

[0009] The mass fraction of the serinol derivative wet heat latent curing agent is 6.65-15.21 parts, the mass fraction of the polyurethane prepolymer is 70-75 parts, the mass fraction of the crosslinking agent is 0.3-0.6 parts, and the mass fraction of the catalyst is 0-0.1 parts.

[0010] Preferably, the serinol derivative latent curing agent is 4a,6a-dimethyl-hexahydro-1,4-dioxa-6-azacyclopentane[cd]pentalene synthesized by the reaction of serinol and 2,5-hexanedione, and the reaction formula is as follows:

[0011]

[0012] Preferably, the polyurethane prepolymer is a mixture of one or more of poly(1,4-butylene adipate), poly(hexane adipate), polyethylene glycol and one or more of polyphenyl polymethylene polyisocyanate, diphenylmethane diisocyanate, toluene diisocyanate, and isophorone diisocyanate.

[0013] Preferably, the crosslinking agent is one or more of diethanolamine, triethanolamine and trimethylolpropane.

[0014] Preferably, the catalyst is one or more of bismorpholine divinyl ether, dibutyltin dilaurate, and stannous octoate.

[0015] A method for preparing a serinol derivative latently cured one-component polyurethane potting adhesive comprises the following steps:

[0016] Step 1: Put serinol and 2,5-hexanedione in a four-necked flask, set the reaction temperature and stirring speed, and after the reaction is completed, heat up, reduce pressure, remove water and keep warm, and cool to room temperature to obtain a serinol derivative wet heat latent curing agent;

[0017] Step 2: Place the polyester polyol in an open reactor, heat it up and remove water in a vacuum, then cool it down to the reaction temperature, add polyisocyanate, stir and react, and cool it down to room temperature after the reaction is completed to obtain an isocyanate-terminated polyurethane prepolymer;

[0018] Step 3: Evenly mix the serinol derivative latent heat curing agent and the polyurethane prepolymer to prepare the serinol derivative latent heat curing one-component polyurethane potting adhesive.

[0019] Preferably, in step 1, the stirring rate is 100 r / min, the reaction temperature is 40° C., and the reaction time is 1.5 to 2 h.

[0020] Preferably: the vacuum degree is 1000 Pa, the stirring rate is 150 r / min, the dehydration temperature is 125±5°C, and the reaction temperature is 75±5°C.

[0021] The present invention has the following beneficial effects:

[0022] The present invention solves the problem of the complicated use process of the traditional two-component polyurethane adhesive and overcomes the inherent defects of the existing single-component polyurethane adhesive.

[0023] The potting glue prepared by the present invention has no VOCs emission, is safe, environmentally friendly, and easy to use. After pre-curing at 100° C. for 1 hour, it can continue to cure at room temperature using moisture in the air. After curing, the glue layer has no bubbles, strong bonding strength, and resistance to moisture and heat aging, and can meet the potting needs in the fields of electronic components and power battery assembly. DETAILED DESCRIPTION

[0024] In order to make the purpose, technical scheme and advantages of the present invention clearer, the present invention is described below by specific embodiments. However, it should be understood that these descriptions are only exemplary and are not intended to limit the scope of the present invention. In addition, in the following description, the description of well-known structures and technologies is omitted to avoid unnecessary confusion of the concept of the present invention.

[0025] Specific implementation method 1: A serinol derivative latent heat curing one-component polyurethane potting adhesive in this implementation method, the serinol derivative latent heat curing one-component polyurethane potting adhesive comprises a serinol derivative latent heat curing agent, a polyurethane prepolymer, a cross-linking agent, and a catalyst;

[0026] The mass fraction of the serinol derivative wet heat latent curing agent is 6.65-15.21 parts, the mass fraction of the polyurethane prepolymer is 70-75 parts, the mass fraction of the crosslinking agent is 0.3-0.6 parts, and the mass fraction of the catalyst is 0-0.1 parts.

[0027] The design of this formula enables the potting compound to have good latent curing ability under wet heat, and can stably cure in a wet heat environment to form a solid packaging material with high insulation and durability, making it suitable for use in electronic packaging and other similar fields.

[0028] Specific implementation method 2: A serinol derivative latent heat curing one-component polyurethane potting glue in this implementation method, wherein the serinol derivative latent heat curing agent is 4a,6a-dimethyl-hexahydro-1,4-dioxa-6-azacyclopentane [cd] cyclopentadiene synthesized by the reaction of serinol and 2,5-hexanedione, and the reaction formula is as follows:

[0029]

[0030] The derivative can self-cure in a wet and hot environment to form a more stable and strong cross-linked network. This special wet and hot latent curing agent can significantly improve the curing speed and performance of polyurethane potting adhesive in a humid environment. Due to its special structure, the derivative may have better tolerance to chemical corrosion, moisture erosion, etc.

[0031] Specific implementation method three: In this implementation method, a serinol derivative is a wet heat latent curing one-component polyurethane potting glue, and the polyurethane prepolymer is made of poly (1,4-butylene adipate) (PBA1000, M n =1000), poly(hexanediol adipate) (PHA1000, M n =1000), polyethylene glycol (PEG800, M n =800) and one or more of polyphenyl polymethylene polyisocyanate (PM400), diphenylmethane diisocyanate (MDI-50), toluene diisocyanate (TDI-80), and isophorone diisocyanate (IPDI) are mixed. By selecting different polyols and isocyanates to synthesize the polyurethane prepolymer, the performance of the potting glue can be adjusted according to needs to achieve the best effect in multiple aspects.

[0032] Specific implementation method 4: In this implementation method, a serinol derivative latent heat curing one-component polyurethane potting glue, the crosslinking agent is one or more of diethanolamine, triethanolamine, and trimethylolpropane, which can significantly improve the curing speed, mechanical properties, chemical stability, weather resistance, wet and hot environment adaptability, flexibility and fluidity of the serinol derivative latent heat curing one-component polyurethane potting glue. This makes the potting glue have more excellent comprehensive performance in the fields of electronic equipment packaging, sealing, protection, etc., and can provide efficient and reliable protection in a variety of complex environments.

[0033] Specific implementation mode 5: In this implementation mode, a serinol derivative latently cured one-component polyurethane potting glue, the catalyst is one or more of bismorpholine divinyl ether, dibutyltin dilaurate, and stannous octoate, which can significantly improve the curing rate, physical properties, processability, and chemical stability of the serinol derivative latently cured one-component polyurethane potting glue. This enables the potting glue to work stably in high humidity and high temperature environments and provide good protection effects, and is particularly suitable for packaging and sealing of electronic products.

[0034] Specific embodiment 6: A method for preparing a serinol derivative wet heat latent curing one-component polyurethane potting adhesive in this embodiment comprises the following steps:

[0035] Step 1: Put serinol and 2,5-hexanedione in a four-necked flask, set the reaction temperature and stirring speed, and after the reaction is completed, heat up, reduce pressure, remove water and keep warm, and cool to room temperature to obtain a serinol derivative wet heat latent curing agent;

[0036] Step 2: Place the polyester polyol in an open reactor, heat it up and remove water in a vacuum, then cool it down to the reaction temperature, add polyisocyanate, stir and react, and cool it down to room temperature after the reaction is completed to obtain an isocyanate-terminated polyurethane prepolymer;

[0037] Step 3: Evenly mix the serinol derivative latent heat curing agent and the polyurethane prepolymer to prepare the serinol derivative latent heat curing one-component polyurethane potting adhesive.

[0038] This method can prepare a one-component polyurethane potting compound with latent heat curing properties by controlling the reaction temperature, time and proportion of ingredients, which is suitable for the packaging of electronic components. By adding serinol derivatives, the potting compound can not only cure quickly in a humid environment, but also has excellent chemical stability and mechanical properties, and is widely used in high-performance packaging materials.

[0039] Specific embodiment 7: In the preparation method of a serinol derivative latently cured one-component polyurethane potting adhesive of this embodiment, the stirring rate in step 1 is 100r / min, the reaction temperature is 40°C, and the reaction time is 1.5-2h, which helps to control the temperature, time and stirring rate during the reaction, ensure the complete and stable reaction and improve the product quality, while optimizing energy consumption and equipment requirements. These favorable conditions can provide ideal raw materials for the preparation of high-performance latently cured one-component polyurethane potting adhesives.

[0040] Specific implementation eight: In this implementation, a method for preparing a serinol derivative wet heat latent curing one-component polyurethane potting adhesive has a vacuum degree of 1000 Pa, a stirring rate of 150 r / min, a water removal temperature of 125±5°C, and a reaction temperature of 75±5°C.

[0041] The above parameters can effectively improve the efficiency of the preparation process and the quality of the product. The optimization of these parameters helps to ensure the removal of moisture and impurities, promote the full reaction of raw materials, and avoid the occurrence of side reactions, thereby obtaining an excellent and stable moisture-heat latent curing one-component polyurethane potting adhesive suitable for high-performance packaging and protection applications.

[0042] Example 1

[0043] A method for preparing a serinol derivative latently cured one-component polyurethane potting adhesive comprises the following steps:

[0044] Step 1: Weigh 28.5 parts of serinol and 22.75 parts of 2,5-hexanedione in a 150 mL four-necked flask, stir at a rate of 100 r / min, react at an oil bath temperature of 35°C for 2 hours, then raise the temperature to 55°C, reduce the pressure to 100 Pa, remove water and keep warm for 3 hours, and cool to room temperature to obtain a serinol derivative wet heat latent curing agent;

[0045] Step 2: Weigh 50 parts of PBA1000 in an open reactor, start stirring, heat to 125°C, reduce pressure to 1000Pa and keep warm for 2h, remove moisture from the polyester polyol, cool to 75°C, add 0.3 parts of triethanolamine, 0.1 parts of dibutyltin dilaurate, 20 parts of polyphenyl polymethylene polyisocyanate (PM400), and 5 parts of isophorone diisocyanate (IPDI) under nitrogen, stir at a rate of 150r / min and react for 2.5h, cool to room temperature, and obtain an isocyanate-terminated polyurethane prepolymer.

[0046] Step 3: Weigh 75 parts of isocyanate-terminated polyurethane prepolymer, 0.02 parts of bismorpholine divinyl ether, heat to 55°C and stir evenly, weigh 6.65 parts of serinol derivative wet heat latent curing agent and slowly add them into the system, continue to keep warm and stir for 1 hour to obtain serinol wet heat latent curing one-component polyurethane potting glue.

[0047] Example 2

[0048] A method for preparing a serinol derivative latently cured one-component polyurethane potting adhesive comprises the following steps:

[0049] Step 1: Weigh 28.5 parts of serinol and 22.75 parts of 2,5-hexanedione in a 150 mL four-necked flask, stir at a rate of 100 r / min, react at an oil bath temperature of 35°C for 2 hours, then raise the temperature to 55°C, reduce the pressure to 100 Pa, remove water and keep warm for 3 hours, and cool to room temperature to obtain a serinol derivative wet heat latent curing agent;

[0050] Step 2: Weigh 35 parts of PHA1000 in an open reactor, start stirring, heat to 125°C, reduce the pressure to 1000Pa and keep warm for 2h, remove moisture from the polyester polyol, cool to 75°C, add 0.6 parts of diethanolamine, 0.03 parts of stannous octoate, 30 parts of polyphenyl polymethylene polyisocyanate (PM400), and 5 parts of toluene diisocyanate (TDI-80) under nitrogen, stir at a rate of 150r / min and react for 2.5h, cool to room temperature, and obtain an isocyanate-terminated polyurethane prepolymer;

[0051] Step 3: Weigh 70 parts of isocyanate-terminated polyurethane prepolymer and 0.02 parts of bismorpholine divinyl ether, heat to 55°C and stir evenly, weigh 15.21 parts of serinol derivative wet heat latent curing agent and slowly add them into the system, continue to keep warm and stir for 1 hour to obtain serinol wet heat latent curing one-component polyurethane potting glue.

[0052] Example 3

[0053] A method for preparing a serinol derivative latently cured one-component polyurethane potting adhesive comprises the following steps:

[0054] Step 1: Weigh 28.5 parts of serinol and 22.75 parts of 2,5-hexanedione in a 150 mL four-necked flask, stir at a rate of 100 r / min, react at an oil bath temperature of 35°C for 2 hours, then raise the temperature to 55°C, reduce the pressure to 100 Pa, remove water and keep warm for 3 hours, and cool to room temperature to obtain a serinol derivative wet heat latent curing agent;

[0055] Step 2: Weigh 25 parts of PBA1000 and 15 parts of PHA1000 in an open reactor, start stirring, heat to 125°C, reduce the pressure to 1000Pa and keep warm for 2h, remove moisture from the polyester polyol, cool to 75°C, add 0.4 parts of trimethylolpropane, 0.03 parts of dibutyltin dilaurate, 25 parts of polyphenyl polymethylene polyisocyanate (PM400), and 5 parts of diphenylmethane diisocyanate (liquefied MDI-50) under nitrogen, stir at a rate of 150r / min and react for 2.5h, cool to room temperature, and obtain an isocyanate-terminated polyurethane prepolymer;

[0056] Step 3: Weigh 70 parts of isocyanate-terminated polyurethane prepolymer and 0.02 parts of bismorpholine divinyl ether, heat to 55°C and stir evenly, weigh 11.35 parts of serinol derivative wet heat latent curing agent and slowly add them into the system, continue to keep warm and stir for 1 hour to obtain serinol wet heat latent curing one-component polyurethane potting glue.

[0057] Example 4

[0058] A method for preparing a serinol derivative latently cured one-component polyurethane potting adhesive comprises the following steps:

[0059] Step 1: Weigh 28.5 parts of serinol and 22.75 parts of 2,5-hexanedione in a 150 mL four-necked flask, stir at a rate of 100 r / min, react at an oil bath temperature of 35°C for 2 hours, then raise the temperature to 55°C, reduce the pressure to 100 Pa, remove water and keep warm for 3 hours, and cool to room temperature to obtain a serinol derivative wet heat latent curing agent;

[0060] Step 2: Weigh 38 parts of PBA1000 and 2 parts of PEG800 in an open reactor, start stirring, heat to 125°C, reduce the pressure to 1000Pa and keep warm for 2h, remove moisture from the polyester polyol, cool to 75°C, add 0.5 parts of trimethylolpropane, 25 parts of polyphenyl polymethylene polyisocyanate (PM400), and 5 parts of diphenylmethane diisocyanate (liquefied MDI-50) under nitrogen, stir at a rate of 150r / min and react for 2.5h, cool to room temperature, and obtain an isocyanate-terminated polyurethane prepolymer;

[0061] Step 3: Weigh 70 parts of isocyanate-terminated polyurethane prepolymer, heat to 55°C and stir evenly, weigh 11.35 parts of serinol derivative wet heat latent curing agent and slowly add it into the system, continue to keep warm and stir for 1 hour to obtain serinol wet heat latent curing one-component polyurethane potting glue.

[0062] Example 5

[0063] A method for preparing a serinol derivative latently cured one-component polyurethane potting adhesive comprises the following steps:

[0064] Step 1: Weigh 28.5 parts of serinol and 22.75 parts of 2,5-hexanedione in a 150 mL four-necked flask, stir at a rate of 100 r / min, react at an oil bath temperature of 35°C for 2 hours, then raise the temperature to 55°C, reduce the pressure to 100 Pa, remove water and keep warm for 3 hours, and cool to room temperature to obtain a serinol derivative wet heat latent curing agent;

[0065] Step 2: Weigh 40 parts of PBA1000 in an open reactor, start stirring, heat to 125°C, reduce pressure to 1000Pa and keep warm for 2 hours, remove moisture from the polyester polyol, cool to 75°C, add 0.5 parts of trimethylolpropane and 25 parts of diphenylmethane diisocyanate (liquefied MDI-50) under nitrogen, stir at 150r / min and react for 2.5 hours. Cool to room temperature to obtain an isocyanate-terminated polyurethane prepolymer;

[0066] Step 3: Weigh 70 parts of isocyanate-terminated polyurethane prepolymer, heat to 55°C and stir evenly, weigh 9.5 parts of serinol derivative wet heat latent curing agent and slowly add it into the system, continue to keep warm and stir for 1 hour to obtain serinol wet heat latent curing one-component polyurethane potting glue.

[0067] Example 6

[0068] A method for preparing a serinol derivative latently cured one-component polyurethane potting adhesive comprises the following steps:

[0069] Step 1: Weigh 28.5 parts of serinol and 22.75 parts of 2,5-hexanedione in a 150 mL four-necked flask, stir at a rate of 100 r / min, react at an oil bath temperature of 35°C for 2 hours, then raise the temperature to 55°C, reduce the pressure to 100 Pa, remove water and keep warm for 3 hours, and cool to room temperature to obtain a serinol derivative wet heat latent curing agent;

[0070] Step 2: Weigh 35 parts of PBA1000 in an open reactor, start stirring, heat to 125°C, reduce the pressure to 1000 Pa and keep warm for 2 hours, remove moisture from the polyester polyol, cool to 75°C, add 0.3 parts of diethanolamine, 0.1 parts of dibutyltin dilaurate, and 35 parts of polyphenyl polymethylene polyisocyanate (PM400) under nitrogen, stir at a rate of 150 r / min and react for 2.5 hours, cool to room temperature, and obtain an isocyanate-terminated polyurethane prepolymer;

[0071] Step 3: Weigh 70 parts of isocyanate-terminated polyurethane prepolymer and 0.02 parts of bismorpholine divinyl ether, heat to 55°C and stir evenly, weigh 15.21 parts of serinol derivative wet heat latent curing agent and slowly add them into the system, continue to keep warm and stir for 1 hour to obtain serinol wet heat latent curing one-component polyurethane potting glue.

[0072] Comparative Example 1

[0073] Weigh 25 parts of PBA1000 and 15 parts of PHA1000 in an open reactor, start stirring, heat to 125°C, reduce the pressure to 1000 Pa and keep warm for 2 hours, remove moisture from the polyester polyol, cool to 75°C, add 0.4 parts of trimethylolpropane, 0.03 parts of dibutyltin dilaurate, 25 parts of polyphenyl polymethylene polyisocyanate (PM400), and 5 parts of diphenylmethane diisocyanate (liquefied MDI-50) under nitrogen, stir at a rate of 150 r / min and react for 2.5 hours, add 0.02 parts of bismorpholine divinyl ether and continue stirring and cooling to room temperature to obtain an isocyanate-terminated polyurethane prepolymer.

[0074] Comparative Example 2

[0075] Weigh 25 parts of PBA1000 and 15 parts of PHA1000 in an open reactor, start stirring, heat to 125°C, reduce pressure to 1000 Pa and keep warm for 2 hours, remove moisture from the polyester polyol, cool to 75°C, add 0.4 parts of trimethylolpropane, 0.03 parts of dibutyltin dilaurate, 25 parts of polyphenyl polymethylene polyisocyanate (PM400), and 5 parts of diphenylmethane diisocyanate (liquefied MDI-50) under nitrogen, stir at a rate of 150 r / min and react for 2.5 hours, add 0.02 parts of bismorpholine divinyl ether, continue stirring and cool to room temperature to obtain an isocyanate-terminated polyurethane prepolymer;

[0076] Weigh 20 parts of aldimine latent curing agent and add it to the polyurethane prepolymer, stir and disperse it evenly to obtain the aldimine latent curing single-component polyurethane adhesive.

[0077] Comparative Example 3

[0078] Weigh 25 parts of PBA1000 and 15 parts of PHA1000 in an open reactor, start stirring, heat to 125°C, reduce pressure to 1000 Pa and keep warm for 2 hours, remove moisture from the polyester polyol, cool to 75°C, add 0.4 parts of trimethylolpropane, 0.03 parts of dibutyltin dilaurate, 25 parts of polyphenyl polymethylene polyisocyanate (PM400), and 5 parts of diphenylmethane diisocyanate (liquefied MDI-50) under nitrogen, stir at a rate of 150 r / min and react for 2.5 hours, add 0.02 parts of bismorpholine divinyl ether, continue stirring and cool to room temperature to obtain an isocyanate-terminated polyurethane prepolymer;

[0079] Weigh 20 parts of aldimine latent curing agent and add it to the polyurethane prepolymer, stir and disperse it evenly to obtain aldimine latent curing one-component polyurethane adhesive. Weigh 20 parts of oxazolidine latent curing agent and add it to the polyurethane prepolymer, stir and disperse it evenly to obtain aldimine latent curing one-component polyurethane adhesive.

[0080] Comparative Example 4

[0081] Preparation of polyurethane adhesive with traditional curing agent, including component A and component B, the preparation of component A includes the following method: weigh 55 parts of PBA1000 and 15 parts of PHA1000 in an open reactor, start stirring, heat to 125°C, reduce pressure to 1000Pa and keep warm for 2 hours to remove moisture in polyester polyol. Cool to 75°C, add 0.4 parts of trimethylolpropane, 0.03 parts of dibutyltin dilaurate, 10 parts of polyphenyl polymethylene polyisocyanate (PM400), 5 parts of diphenylmethane diisocyanate (liquefied MDI-50) under nitrogen, stir at a rate of 150r / min and react for 2.5 hours;

[0082] Component B is an aromatic isocyanate curing agent TMP-TDI adduct, and the dosage of components A and B is 4.5 to 5:1.

[0083] The products prepared in Examples 1 to 6 and Comparative Examples 1 to 4 were tested, and the performance indicators are as follows:

[0084]

[0085]

[0086] The curing methods of Examples 1 to 4 and Comparative Examples 1 to 3 all adopt 120°C curing for 1 hour and room temperature curing for 7 days. It can be seen from the above table that Examples 1 to 4 all achieve surface dryness after curing at 120°C for 1 hour, while Comparative Examples 1 to 3 without adding serinol wet heat latent curing agent all need to continue room temperature curing for 12 hours before they can be surface dry. Only Comparative Example 1 without adding latent curing agent has more bubbles after curing, indicating that the addition of latent curing agent can effectively inhibit the generation of carbon dioxide during the curing process.

[0087] Thermal stability test: The cured adhesive was tested using a differential scanning calorimeter produced by NETZSCH, Germany. Test conditions: -70℃~180℃, heating rate 10℃ / min under nitrogen. From the above table, it can be seen that the addition of serinol derivatives as latent curing agents does not cause changes in the thermal stability of the adhesive, while the addition of traditional aldimine and oxazolidine latent curing agents will reduce the initial thermal decomposition temperature of the adhesive.

[0088] After fully curing, shear tests were performed on AI-Al, PET-PET and PC-PC bonded on Examples 1 to 4 and Comparative Examples 1 to 3. The results are shown in the following table:

[0089]

[0090] After curing at 120°C for 1 hour and then continuing to cure at room temperature and 40% air humidity for 7 days, the shear strength test was performed according to GB / T7124-2008.

[0091] From the table above, we can see that the addition of serinol derivatives as latent curing agent significantly improves the bonding strength of one-component polyurethane potting glue to various substrates. Compared with traditional aldimine and oxazolidine latent curing agents, it can not only effectively inhibit the generation of carbon dioxide but also does not affect the bonding strength of the glue to the substrate.

[0092] After storing for 30 days and aging for 1000 hours with double 85, the Al-PET bonding shear strength test was performed on Examples 1 to 6 and Comparative Examples 1 to 4. The results are shown in the following table:

[0093]

[0094] The addition of serinol derivatives as latent curing agent improves the storage performance of the one-component polyurethane potting adhesive. At the same time, after aging at double 85 for 1000 hours, the bonding shear strength decay is less than 20%.

[0095] From the above test results, it can be seen that the prepared serinol derivative latent curing one-component polyurethane adhesive has good bonding performance and excellent resistance to moisture and heat aging during use. The present invention uses serinol derivatives as latent curing agents for one-component polyurethane for the first time, and prepares potting applications that can meet complex environments.

[0096] It should be noted that in the above embodiments, as long as the technical solutions are not contradictory, they can be arranged and combined, and those skilled in the art can exhaust all possibilities based on the mathematical knowledge of arrangement and combination. Therefore, the present invention will no longer describe the technical solutions after arrangement and combination one by one, but it should be understood that the technical solutions after arrangement and combination have been disclosed by the present invention.

[0097] The above description is only a preferred embodiment of the present invention and is not intended to limit the present invention. For those skilled in the art, the present invention may have various modifications and variations. Any modification, equivalent replacement, improvement, etc. made within the spirit and principle of the present invention shall be included in the protection scope of the present invention.

Claims

1. A serinol derivative latently cured one-component polyurethane potting adhesive, characterized in that: The serinol derivative latent heat curing one-component polyurethane potting glue is composed of a serinol derivative latent heat curing agent, a polyurethane prepolymer, a crosslinking agent, and a catalyst; The mass fraction of the serinol derivative wet heat latent curing agent is 6.65-15.21 parts, the mass fraction of the polyurethane prepolymer is 70-75 parts, the mass fraction of the crosslinking agent is 0.3-0.6 parts, and the mass fraction of the catalyst is 0-0.1 parts.

2. The serinol derivative latently cured one-component polyurethane potting adhesive according to claim 1, characterized in that: The serinol derivative latent curing agent is 4a,6a-dimethyl-hexahydro-1,4-dioxa-6-azacyclopentane[cd]pentalene synthesized by the reaction of serinol and 2,5-hexanedione, and the reaction formula is as follows:

3. The serinol derivative latently cured one-component polyurethane potting adhesive according to claim 1, characterized in that: The polyurethane prepolymer is prepared by mixing one or more of poly(1,4-butylene adipate), poly(hexane adipate), polyethylene glycol and one or more of polyphenyl polymethylene polyisocyanate, diphenylmethane diisocyanate, toluene diisocyanate and isophorone diisocyanate.

4. The serinol derivative latently cured one-component polyurethane potting adhesive according to claim 1, characterized in that: The cross-linking agent is one or more of diethanolamine, triethanolamine and trimethylolpropane.

5. The serinol derivative latently cured one-component polyurethane potting adhesive according to claim 1, characterized in that: The catalyst is one or more of bismorpholine divinyl ether, dibutyltin dilaurate and stannous octoate.

6. A method for preparing a serinol derivative latently cured one-component polyurethane potting adhesive, characterized in that: The steps include: Step 1: Put serinol and 2,5-hexanedione in a four-necked flask, set the reaction temperature and stirring speed, and after the reaction is completed, heat up, reduce pressure, remove water and keep warm, and cool to room temperature to obtain a serinol derivative wet heat latent curing agent; Step 2: Place the polyester polyol in an open reactor, heat it up and remove water in a vacuum, then cool it down to the reaction temperature, add polyisocyanate, stir and react, and cool it down to room temperature after the reaction is completed to obtain an isocyanate-terminated polyurethane prepolymer; Step 3: Evenly mix the serinol derivative latent heat curing agent and the polyurethane prepolymer to prepare the serinol derivative latent heat curing one-component polyurethane potting adhesive.

7. The method for preparing a serinol derivative latently cured one-component polyurethane potting adhesive according to claim 6, characterized in that: In step 1, the stirring rate is 100 r / min, the reaction temperature is 40° C., and the reaction time is 1.5 to 2 h.

8. The method for preparing a serinol derivative latently cured one-component polyurethane potting adhesive according to claim 6, characterized in that: The vacuum degree is 1000Pa, the stirring rate is 150r / min, the dehydration temperature is 125±5℃, and the reaction temperature is 75±5℃.

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