Polyurethane adhesive and preparation method thereof
By optimizing the formulation and preparation process of polyurethane adhesives, reducing the activation temperature and crystallization speed, the problems of high temperature and rapid crystallization in the preparation process of traditional polyurethane adhesives are solved, and production efficiency and product quality are improved.
Patent Information
- Application Number
- CN202510300796.0
- Authority / Receiving Office
- CN · China
- Patent Type
- Applications(China)
- Current Assignee / Owner
- Filing Date
- 2025-03-14
- Publication Date
- 2025-06-13
AI Technical Summary
During the preparation of traditional polyurethane adhesives, the activation temperature is high and the crystallization speed is fast, resulting in large energy consumption, poor controllability of the production process, and high temperatures may damage the structure of the bonded material.
The activation temperature and crystallization rate of the polyurethane adhesive are reduced by optimizing the weight ratio of the polyol polymer to the chain extender and the weight ratio of the polyol polymer to the chain extender and the ratio to isocyanate. The specific method includes heating and melting the polyol polymer and chain extender under nitrogen protection, adding isocyanate after cooling, and finally adding a catalyst solution for neutralization and emulsification.
The low activation temperature and slow crystallization speed of polyurethane adhesives are achieved, which improves production flexibility and energy consumption efficiency, reduces the generation of by-products, and improves product consistency and quality.
Smart Images
Figure BDA0005311457330000061
Abstract
Description
Technical Field
[0001] This application relates to the field of adhesives, and particularly to a polyurethane adhesive and its preparation method. Background Art
[0002] At present, polyurethane adhesives are widely used in many industries due to their good bonding strength, flexibility and weather resistance. However, in the preparation process of traditional polyurethane adhesives, the activation temperature is high and the crystallization speed is fast, which not only consumes more energy, but also makes the controllability of the production process poor, affecting the product quality and stability. The high activation temperature and rapid crystallization reduce the flexibility and energy consumption efficiency of polyurethane adhesive production, and also limit its application on some sensitive materials, because too high processing temperature may damage the structure of the bonded materials. Although there are studies on reducing the activation temperature by adding specific additives, it often leads to a decrease in the performance of the adhesive or other adverse consequences, such as increased cost or weakened environmental protection. In addition, attempts to extend the crystallization time usually sacrifice the production rate, which is not conducive to large-scale industrial production. Summary of the Invention
[0003] In order to reduce the activation temperature and delay the crystallization speed, this application provides a polyurethane adhesive and its preparation method.
[0004] In the first aspect, a polyurethane adhesive provided by this application adopts the following technical solution: A polyurethane adhesive, the raw materials of the polyurethane adhesive include polyol polymer, isocyanate, chain extender, catalyst; wherein the weight ratio of the polyol polymer to the chain extender is (14 - 6):6; the ratio of the sum of the weights of the polyol polymer and the chain extender to the weight of the isocyanate is (0.98 - 1.02).
[0005] By adopting the above technical solution, the weight ratio of the polyol polymer to the chain extender is preferably (14 - 6):6, and the ratio of the sum of the weights of the polyol polymer and the chain extender to the weight of the isocyanate is preferably (0.98 - 1.02), and the obtained polyurethane adhesive has a low activation temperature and a slow crystallization speed.
[0006] In a specific feasible embodiment, the polyol polymer includes one or more of poly(ε-caprolactone)diol, polytetrahydrofuran diol, polypropylene glycol, polytetrahydrofuran triol, poly(1,4-butylene adipate)diol.
[0007] In a specific feasible embodiment, the polyol polymer includes poly(ε-caprolactone)diol with a molecular weight of 1000 - 1500.
[0008] By adopting the above technical solution, the polyol polymer is preferably poly(ε-caprolactone) diol with a molecular weight of 1000 - 1500, which provides good reaction activity while maintaining a sufficient chain segment length to ensure that the polyurethane adhesive has the required physical properties such as toughness, viscosity, and heat resistance; it also has better processing efficiency, reduces the generation of by-products, and improves the consistency and quality of the product.
[0009] In a specific feasible embodiment, the isocyanate includes one or more of isophthalic diisocyanate, terephthalic diisocyanate, toluene diisocyanate, diphenylmethane diisocyanate, and hexamethylene diisocyanate.
[0010] In a specific feasible embodiment, the isocyanate includes a mixture composed of isophthalic diisocyanate and terephthalic diisocyanate.
[0011] By adopting the above technical solution, using the composite isocyanate composed of isophthalic diisocyanate and terephthalic diisocyanate to form hard segments in the polyurethane structure, these hard segments endow the polyurethane adhesive with high strength, high hardness, and good chemical resistance, and can also improve the viscosity, wear resistance, and mechanical strength of the finally obtained product.
[0012] In a specific feasible embodiment, the chain extender includes one or more of 1,4 - butanediol, 1,6 - hexanediol, propylene glycol, neopentyl glycol, glycerol, and hexanetriol.
[0013] In a specific feasible embodiment, the chain extender includes a mixture composed of 1,4 - butanediol and 1,6 - hexanediol.
[0014] By adopting the above technical solution, using the composite chain extender composed of 1,4 - butanediol and 1,6 - hexanediol can not only improve the elongation at break and adhesion strength of the obtained polyurethane adhesive, but also improve the flexibility of the polyurethane adhesive.
[0015] In a specific feasible embodiment, the catalyst includes triethylamine.
[0016] In the second aspect, a preparation method of a polyurethane adhesive provided by the present application adopts the following technical solution: A preparation method of a polyurethane adhesive includes the following steps: Put the polyol polymer and the chain extender into a reaction kettle. Under the protection of nitrogen, first heat up to melt the chain extender, then cool down, add the isocyanate, keep the temperature for reaction. After the reaction solution has a certain viscosity, stop heating, cool down, and add the catalyst solution under stirring to neutralize and emulsify to obtain the polyurethane adhesive.
[0017] By adopting the above technical solution, first heat and stir to melt the polyol polymer and the chain extender, then cool down and add the isocyanate, keep the temperature for reaction, and finally add the catalyst solution, neutralize and emulsify to obtain the polyurethane adhesive.
[0018] In a specific feasible embodiment, the weight fraction of the catalyst in the catalyst solution is 3%-5%, and the weight ratio of the catalyst to the polyol polymer is (0.16-0.24):1.
[0019] By adopting the above technical solution, the weight fraction of the catalyst in the catalyst solution and the dosage of the catalyst are further defined, thereby improving the performance of the obtained polyurethane adhesive.
[0020] In summary, the present application includes at least one of the following beneficial technical effects: 1. In the present application, the weight ratio of the polyol polymer to the chain extender is preferably (14-6):6, and the ratio of the sum of the weights of the polyol polymer and the chain extender to the weight of the isocyanate is preferably (0.98-1.02), and the obtained polyurethane adhesive has a low activation temperature and a slow crystallization rate; 2. In the present application, the polyol polymer is preferably poly(ε-caprolactone)diol with a molecular weight of 1000-1500, which provides good reaction activity, while maintaining a sufficient chain segment length to ensure that the polyurethane adhesive has the required physical properties such as toughness, viscosity and heat resistance; it also has better processing efficiency, reduces the generation of by-products, and improves the consistency and quality of the product; 3. In the method of the present application, first heat and stir to melt the polyol polymer and the chain extender, then cool down and add the isocyanate, keep the temperature for reaction, and finally add the catalyst solution, neutralize and emulsify to obtain the polyurethane adhesive. Specific Embodiments
[0021] The following further elaborates on the present application with reference to examples.
[0022] All raw materials in the examples can be obtained commercially. The polyol polymers include, but are not limited to, a mixture composed of one or more of poly(ε-caprolactone)diol, polytetrahydrofuran diol, poly(propylene oxide)diol, polytetrahydrofuran triol, poly(1,4-butylene adipate)diol. In this application, poly(ε-caprolactone)diol is preferably used, and the molecular weight of poly(ε-caprolactone)diol is 1000 - 1500; the isocyanates include, but are not limited to, a mixture composed of one or more of isophthalic diisocyanate, terephthalic diisocyanate, toluene diisocyanate, diphenylmethane diisocyanate, hexamethylene diisocyanate. In this application, a mixture of isophthalic diisocyanate and terephthalic diisocyanate is preferably used; the chain extenders include, but are not limited to, a mixture composed of one or more of 1,4-butanediol, 1,6-hexanediol, propylene glycol, neopentyl glycol, glycerol, hexanetriol. In this application, a mixture of 1,4-butanediol and 1,6-hexanediol is preferably used. Example
[0023] Example 1 Example 1 provides a preparation method of a polyurethane adhesive, which includes the following steps: Put the polyol polymer and the chain extender into a reaction kettle. Under the protection of nitrogen, first stir and heat up to 60 °C until the chain extender melts, then cool down to 55 °C, add the isocyanate, and then keep the temperature at 75 °C for heat preservation reaction for 2.5 h. After the reaction solution has a certain viscosity, stop heating, cool down to 45 °C, stop introducing nitrogen, and add the catalyst solution under stirring to neutralize and emulsify to obtain the polyurethane adhesive; where the weight ratio of the polyol polymer to the chain extender is 14:6; the ratio of the sum of the weights of the polyol polymer and the chain extender to the weight of the isocyanate is 0.98; the polyol polymer is poly(ε-caprolactone)diol with a molecular weight of 1000 - 1500; the chain extender is a mixture composed of 1,4-butanediol and 1,6-hexanediol, and the weight ratio of 1,4-butanediol to 1,6-hexanediol is 1:1; the isocyanate is a mixture composed of isophthalic diisocyanate and terephthalic diisocyanate, and the weight ratio of isophthalic diisocyanate to terephthalic diisocyanate is 1:1; the catalyst in the catalyst solution is triethylamine, and the weight fraction of triethylamine is 3%, and the weight ratio of triethylamine to the polyol polymer is 0.16:1.
[0024] Example 2 Example 2 provides a preparation method of a polyurethane adhesive, which includes the following steps: Put the polyol polymer and chain extender into the reaction kettle. Under the protection of nitrogen, first stir and heat up to 60°C until the chain extender melts, then cool down to 55°C, add isocyanate, and then keep the temperature at 75°C for 2.5 h of heat preservation reaction. After the reaction solution has a certain viscosity, stop heating, cool down to 45°C, stop introducing nitrogen, and add the catalyst solution under stirring for neutralization and emulsification to obtain the polyurethane adhesive; wherein the weight ratio of the polyol polymer to the chain extender is 9:6; the ratio of the sum of the weights of the polyol polymer and the chain extender to the weight of the isocyanate is 0.98; the polyol polymer is poly(ε-caprolactone) diol with a molecular weight of 1000 - 1500; the chain extender is a mixture composed of 1,4-butanediol and 1,6-hexanediol, and the weight ratio of 1,4-butanediol to 1,6-hexanediol is 1:1; the isocyanate is a mixture composed of isophthalic diisocyanate and terephthalic diisocyanate, and the weight ratio of isophthalic diisocyanate to terephthalic diisocyanate is 1:1; the catalyst in the catalyst solution is triethylamine, and the weight fraction of triethylamine is 3%, and the weight ratio of triethylamine to the polyol polymer is 0.16:1.
[0025] Example 3 Example 3 provides a preparation method of a polyurethane adhesive, including the following steps: Put the polyol polymer and chain extender into the reaction kettle. Under the protection of nitrogen, first stir and heat up to 60°C until the chain extender melts, then cool down to 55°C, add isocyanate, and then keep the temperature at 75°C for 2.5 h of heat preservation reaction. After the reaction solution has a certain viscosity, stop heating, cool down to 45°C, stop introducing nitrogen, and add the catalyst solution under stirring for neutralization and emulsification to obtain the polyurethane adhesive; wherein the weight ratio of the polyol polymer to the chain extender is 6:6; the ratio of the sum of the weights of the polyol polymer and the chain extender to the weight of the isocyanate is 0.98; the polyol polymer is poly(ε-caprolactone) diol with a molecular weight of 1000 - 1500; the chain extender is a mixture composed of 1,4-butanediol and 1,6-hexanediol, and the weight ratio of 1,4-butanediol to 1,6-hexanediol is 1:1; the isocyanate is a mixture composed of isophthalic diisocyanate and terephthalic diisocyanate, and the weight ratio of isophthalic diisocyanate to terephthalic diisocyanate is 1:1; the catalyst in the catalyst solution is triethylamine, and the weight fraction of triethylamine is 3%, and the weight ratio of triethylamine to the polyol polymer is 0.16:1.
[0026] Example 4 Example 4 provides a preparation method of a polyurethane adhesive, including the following steps: Put the polyol polymer and chain extender into a reaction kettle. Under the protection of nitrogen, first stir and heat up to 60 °C until the chain extender melts, then cool down to 55 °C, add isocyanate, and then keep the temperature at 75 °C for 2.5 h of heat preservation reaction. After the reaction solution has a certain viscosity, stop heating, cool down to 45 °C, stop introducing nitrogen, and add the catalyst solution under stirring for neutralization and emulsification to obtain the polyurethane adhesive; where the weight ratio of the polyol polymer to the chain extender is 9:6; the ratio of the sum of the weights of the polyol polymer and the chain extender to the weight of the isocyanate is 0.99; the polyol polymer is poly(ε-caprolactone) diol with a molecular weight of 1000 - 1500; the chain extender is a mixture composed of 1,4-butanediol and 1,6-hexanediol, and the weight ratio of 1,4-butanediol to 1,6-hexanediol is 1:1; the isocyanate is a mixture composed of isophthalic diisocyanate and terephthalic diisocyanate, and the weight ratio of isophthalic diisocyanate to terephthalic diisocyanate is 1:1; the catalyst in the catalyst solution is triethylamine, and the weight fraction of triethylamine is 3%, and the weight ratio of triethylamine to the polyol polymer is 0.16:1.
[0027] Example 5 Example 5 provides a method for preparing a polyurethane adhesive, including the following steps: Put the polyol polymer and chain extender into a reaction kettle. Under the protection of nitrogen, first stir and heat up to 60 °C until the chain extender melts, then cool down to 55 °C, add isocyanate, and then keep the temperature at 75 °C for 2.5 h of heat preservation reaction. After the reaction solution has a certain viscosity, stop heating, cool down to 45 °C, stop introducing nitrogen, and add the catalyst solution under stirring for neutralization and emulsification to obtain the polyurethane adhesive; where the weight ratio of the polyol polymer to the chain extender is 9:6; the ratio of the sum of the weights of the polyol polymer and the chain extender to the weight of the isocyanate is 1.02; the polyol polymer is poly(ε-caprolactone) diol with a molecular weight of 1000 - 1500; the chain extender is a mixture composed of 1,4-butanediol and 1,6-hexanediol, and the weight ratio of 1,4-butanediol to 1,6-hexanediol is 1:1; the isocyanate is a mixture composed of isophthalic diisocyanate and terephthalic diisocyanate, and the weight ratio of isophthalic diisocyanate to terephthalic diisocyanate is 1:1; the catalyst in the catalyst solution is triethylamine, and the weight fraction of triethylamine is 3%, and the weight ratio of triethylamine to the polyol polymer is 0.16:1.
[0028] Example 6 The difference between Example 6 and Example 4 is that the isocyanate is isophthalic diisocyanate; the remaining steps are the same as those in Example 4.
[0029] Example 7 The difference between Example 7 and Example 4 is that the isocyanate is terephthalic diisocyanate; the remaining steps are the same as those in Example 4.
[0030] Example 8 The difference between Example 8 and Example 4 is that the chain extender is 1,4 - butanediol; the remaining steps are the same as those in Example 4.
[0031] Example 9 The difference between Example 9 and Example 4 is that the chain extender is 1,6 - hexanediol; the remaining steps are the same as those in Example 4.
[0032] Example 10 The difference between Example 10 and Example 4 is that the catalyst in the catalyst solution is triethylamine, and the weight fraction of triethylamine is 4%, and the weight ratio of triethylamine to the polyol polymer is 0.2:1; the remaining steps are the same as those in Example 4.
[0033] Example 11 The difference between Example 11 and Example 4 is that the catalyst in the catalyst solution is triethylamine, and the weight fraction of triethylamine is 5%, and the weight ratio of triethylamine to the polyol polymer is 0.24:1; the remaining steps are the same as those in Example 4.
[0034] Comparative Example Comparative Example 1 The difference between Comparative Example 1 and Example 1 is that the weight ratio of the polyol polymer to the chain extender is 17:6; the remaining steps are the same as those in Example 1.
[0035] Comparative Example 2 The difference between Comparative Example 2 and Example 1 is that the weight ratio of the polyol polymer to the chain extender is 3:6; the remaining steps are the same as those in Example 1.
[0036] Comparative Example 3 The difference between Comparative Example 3 and Example 1 is that the ratio of the sum of the weights of the polyol polymer and the chain extender to the weight of the isocyanate is 0.97; the remaining steps are the same as those in Example 1.
[0037] Comparative Example 4 The difference between Comparative Example 4 and Example 1 is that the ratio of the sum of the weights of the polyol polymer and the chain extender to the weight of the isocyanate is 1.03; the remaining steps are the same as those in Example 1.
[0038] Operability of performance detection test: Detect the activation temperature and crystallization rate of the polyurethane adhesive in each example and comparative example. If the activation temperature is low and the crystallization rate is slow, the operability of the polyurethane adhesive is high.
[0039] Mechanical properties: Detect the Shore hardness, tensile strength, and compression deformation of the polyurethane adhesive.
[0040] Table 1 Performance detection results of polyurethane adhesives Combined with Examples 1-5 and Comparative Examples 1-4, the activation temperature of the polyurethane adhesive in Examples 1-5 is low and the crystallization rate is slow. It can be seen that when preparing the polyurethane adhesive, the weight ratio of the polyol polymer to the chain extender is preferably (14-6):6, and the ratio of the sum of the weights of the polyol polymer and the chain extender to the weight of the isocyanate is preferably (0.98-1.02), which can reduce the activation temperature of the obtained polyurethane adhesive and reduce the crystallization rate.
[0041] Combined with Example 4, Example 6 and Example 7, the performance of the polyurethane adhesive in Example 4 is the best. It can be seen that when preparing the polyurethane adhesive, the isocyanate is preferably a mixture composed of isophthalic diisocyanate and terephthalic diisocyanate. By using the composite isocyanate composed of isophthalic diisocyanate and terephthalic diisocyanate, the performance of the obtained polyurethane adhesive can be improved.
[0042] Combined with Example 4, Example 8 and Example 9, the performance of the polyurethane adhesive in Example 4 is the best. It can be seen that when preparing the polyurethane adhesive, the chain extender is preferably a mixture composed of 1,4-butanediol and 1,6-hexanediol, which can further improve the performance of the obtained polyurethane adhesive.
[0043] Combined with Example 4, Example 10 and Example 11, the performance of the polyurethane adhesive in Example 10 is the best. It can be seen that when adding the catalyst solution, the concentration of the catalyst solution and the usage amount of the catalyst in Example 10 are the best, so that the polyurethane can be better formed, and therefore the performance of the obtained polyurethane adhesive is the best.
[0044] This specific embodiment is only an interpretation of the present application and does not limit the present application. After reading this specification, those skilled in the art can make modifications without creative contributions to this embodiment as needed, but as long as it is within the scope of the claims of the present application, it is protected by the patent law.
Claims
1. A polyurethane adhesive, characterized in that: The raw materials of the polyurethane adhesive include polyol polymer, isocyanate, chain extender, and catalyst; wherein the weight ratio of the polyol polymer to the chain extender is (14-6):6; and the ratio of the sum of the weights of the polyol polymer and the chain extender to the weight of the isocyanate is (0.98-1.02).
2. A polyurethane adhesive according to claim 1, characterized in that: The polyol polymer includes one or more of poly-ε-caprolactone diol, polytetramethylene glycol, polyoxypropylene glycol, polytetramethylene glycol, and polybutylene adipate diol.
3. A polyurethane adhesive according to claim 2, characterized in that: The polyol polymer includes poly-ε-caprolactone diol with a molecular weight of 1000-1500.
4. The polyurethane adhesive according to claim 1, characterized in that: The isocyanate includes one or more of meta-xylylene diisocyanate, para-xylylene diisocyanate, toluene diisocyanate, diphenylmethane diisocyanate, and hexamethylene diisocyanate.
5. A polyurethane adhesive according to claim 4, characterized in that: The isocyanate comprises a mixture of meta-xylylene diisocyanate and para-xylylene diisocyanate.
6. The polyurethane adhesive according to claim 1, characterized in that: The chain extender includes one or more of 1.4-butanediol, 1.6-hexanediol, propylene glycol, neopentyl glycol, glycerol, and hexanetriol.
7. A polyurethane adhesive according to claim 6, characterized in that: The chain extender comprises a mixture of 1.4 butanediol and 1.6 hexanediol.
8. The polyurethane adhesive according to claim 1, characterized in that: The catalyst includes triethylamine.
9. A method for preparing the polyurethane adhesive according to any one of claims 1 to 8, characterized in that: The following steps are involved: Put the polyol polymer and chain extender into the reactor, under the protection of nitrogen, first heat up until the chain extender melts, then cool down, add isocyanate, keep warm for reaction, stop heating when the reaction liquid has a certain viscosity, cool, add catalyst solution under stirring, neutralize and emulsify to obtain polyurethane adhesive.
10. The method for preparing a polyurethane adhesive according to claim 9, characterized in that: The weight fraction of the catalyst in the catalyst solution is 3%-5%, and the weight ratio of the catalyst to the polyol polymer is (0.16-0.24):1.