Modified phenolic aldehyde amine curing agent and process method thereof

Abstract

The invention provides a modified phenolic aldehyde amine curing agent and a process method thereof, and relates to the technical field of phenolic aldehyde amine curing agents. A process method of a modified phenolic aldehyde amine curing agent comprises the following steps: S1, after cardanol and amine are uniformly mixed, aldehyde is added, and a mixture is obtained; s2, carrying out primary dehydration treatment, polymerization and secondary dehydration treatment on the mixture, and filtering and packaging to obtain the modified phenolic aldehyde amine curing agent. Through a unique process method, the prepared modified phenolic aldehyde amine curing agent is in an orange clear transparent liquid state, the curing time is short, the content of free ethylenediamine is low, the curing agent is more suitable for practical application, and the harm to a human body is small.

Description

Technical Field

[0001] The invention relates to the technical field of phenalkamine curing agents, in particular to a modified phenalkamine curing agent and a process method thereof. Background Art

[0002] As the main raw material of modified phenolic amine curing agent, ethylenediamine can quickly cure epoxy resin. However, if the free ethylenediamine content is too high, its vapor may cause severe irritation to the oral cavity, respiratory mucosa and lungs during the curing process. It may also cause allergies, itching, edema, and even erythema and ulceration after skin contact. Long-term exposure to ethylenediamine may cause damage to the liver and kidneys and may induce neurasthenia syndrome. In addition, although the amine group of ethylenediamine reacts with the epoxy group to cross-link the polymer, its mechanical properties are increased. However, when the cross-linking reaction is complete, increasing the amount of ethylenediamine will not further increase the degree of cross-linking, but will lead to an increase in free ethylenediamine, thereby reducing the corresponding mechanical properties.

[0003] Therefore, it is crucial to control the content of ethylenediamine in the modified phenalkamine curing agent to ensure the performance and safety of the cured product. Summary of the invention

[0004] Based on the technical problems existing in the background technology, the present invention proposes a modified phenolic amine curing agent and a process method thereof.

[0005] The process of modifying a phenalkamine curing agent proposed by the present invention comprises the following steps:

[0006] S1, mixing cardanol and amine evenly, and then adding aldehyde to obtain a mixture;

[0007] S2, subjecting the mixture to a primary dehydration treatment, polymerization, a secondary dehydration treatment, filtering and packaging to obtain a modified phenolic amine curing agent.

[0008] Preferably, in S1, the amine is selected from one or more of ethylenediamine, diethylenetriamine, triethylenetetramine and tetraethylenepentamine.

[0009] Preferably, in said S1, the aldehyde is paraformaldehyde.

[0010] Preferably, in S1, the aldehyde is added in batches of 3-5 times.

[0011] Preferably, in S1, the molar ratio of cardanol, amine and aldehyde is 1:(1-2):(1-2).

[0012] Preferably, in said S2, the primary dehydration treatment comprises first treating at 40-70°C and 0.0005-0.002MPa for 5-10min, and then treating at 70-95°C and 0.002-0.01MPa for 10-50min.

[0013] More preferably, in said S2, a dehydration treatment is performed so that the water content of the mixture is 0.5-10%.

[0014] Preferably, in S2, the polymerization process comprises reacting the mixture at 90-120° C. for 2-5 hours, then introducing ethylene oxide, adjusting the temperature to 120-150° C., and reacting for 1-3 hours.

[0015] More preferably, the ethylene oxide introduction temperature is 20-40° C., and the ethylene oxide ventilation rate is 1-50 mL / min.

[0016] Preferably, in said S2, the secondary dehydration treatment comprises removing the generated water by vacuuming at 95-110°C and 0.002-0.01MPa.

[0017] Preferably, in S2, the filter packaging uses a diatomaceous earth press plate filter with a filtering effect of more than 2000 meshes.

[0018] Preferably, the modified phenolic amine curing agent has a viscosity of 25000-50000 mPa·s at 25° C., an amine value of 280-320 mg KOH / g, and an appearance of an orange clear and transparent liquid.

[0019] The present invention also provides a modified phenolic amine curing agent prepared by the above preparation method.

[0020] The beneficial effects of the present invention are:

[0021] The modified phenolic amine curing agent prepared by the present invention is in an orange clear and transparent liquid state through a unique process method, has a short curing time, a low free ethylenediamine content, is more suitable for practical applications, and has little harm to the human body. The present invention controls the moisture content through two dehydration treatments, which is conducive to the reaction, and controls the moisture content through one dehydration treatment by controlling the temperature and vacuum degree, thereby ensuring that the polymerization process reacts fully. The present invention introduces a certain amount of ethylene oxide during the polymerization process, which helps to reduce the content of free ethylenediamine, and the synergistic effect between the raw materials and the process is conducive to improving the mechanical properties and corrosion resistance of the curing agent. DETAILED DESCRIPTION

[0022] The technical solution of the present invention is described in detail through specific embodiments.

[0023] Unless otherwise specified, the materials and reagents used in the following examples can be obtained from commercial sources.

[0024] Example 1

[0025] A process for modifying a phenalkamine curing agent comprises the following steps:

[0026] S1. Mix cardanol and ethylenediamine evenly and then add paraformaldehyde to obtain a mixture; the molar ratio of cardanol, ethylenediamine and paraformaldehyde is 1:1.05:1.05;

[0027] S2, the mixture was subjected to a primary dehydration treatment: first at 45 ° C, 0.0005MPa conditions for 10min, then at 85 ° C, 0.005MPa conditions to treat until the water content is 1%; polymerization reaction: at 110 ° C conditions for 4h, then ethylene oxide (introduction temperature is 30 ° C, ventilation rate is 1mL / min), the temperature is adjusted to 120 ° C reaction for 1h, secondary dehydration treatment: at 105 ° C, 0.002MPa conditions to remove the generated water by vacuum, using diatomaceous earth plate filter for filtering and packaging, to obtain a modified phenolic amine curing agent.

[0028] 25℃ viscosity: 28000mPa·s, amine value: 300mg KOH / g, appearance: orange clear transparent liquid, 25℃ drying time: 9h, free EDA: 0.03%.

[0029] Example 2

[0030] A process for modifying a phenalkamine curing agent comprises the following steps:

[0031] S1. After mixing cardanol and ethylenediamine evenly, add paraformaldehyde to obtain a mixture; the molar ratio of cardanol, ethylenediamine and paraformaldehyde is 1:1.3:1.3;

[0032] S2, the mixture was subjected to a primary dehydration treatment: first at 50 ° C, 0.0005MPa conditions for 10min, then at 85 ° C, 0.005MPa conditions to treat until the water content is 0.5%; polymerization reaction: at 110 ° C for 4h, then ethylene oxide (introduction temperature is 30 ° C, ventilation rate is 5mL / min), the temperature is adjusted to 120 ° C for 1h, secondary dehydration treatment: at 95 ° C, 0.002MPa conditions, vacuumize to remove the generated water, use diatomaceous earth plate filter to filter and package, and obtain a modified phenolic amine curing agent.

[0033] 25℃ viscosity: 32000mPa·s, amine value: 310mg KOH / g, appearance: orange clear transparent liquid, 25℃ drying time: 9h, free EDA: 0.05%.

[0034] Example 3

[0035] A process for modifying a phenalkamine curing agent comprises the following steps:

[0036] S1. After mixing cardanol and ethylenediamine evenly, add paraformaldehyde to obtain a mixture; the molar ratio of cardanol, ethylenediamine and paraformaldehyde is 1:1.1:1.1;

[0037] S2, the mixture was subjected to a primary dehydration treatment: first at 50 ° C, 0.001MPa conditions for 10min, then at 85 ° C, 0.005MPa conditions to a water content of 1%; polymerization reaction: at 110 ° C for 4h, then ethylene oxide (introduction temperature of 30 ° C, ventilation rate of 1.7mL / min), the temperature was adjusted to 120 ° C for 1h, and a secondary dehydration treatment was carried out: at 105 ° C, 0.002MPa conditions, vacuum was removed to remove the generated water, and diatomaceous earth plate filter was used for filtering and packaging to obtain a modified phenolic amine curing agent.

[0038] 25℃ viscosity: 30000mPa·s, amine value: 300mg KOH / g, appearance: orange clear transparent liquid, 25℃ drying time: 9h, free EDA: 0.05%.

[0039] Example 4

[0040] A process for modifying a phenalkamine curing agent comprises the following steps:

[0041] S1. After mixing cardanol and ethylenediamine evenly, add paraformaldehyde to obtain a mixture; the molar ratio of cardanol, ethylenediamine and paraformaldehyde is 1:1.1:1.15;

[0042] S2, the mixture was subjected to a primary dehydration treatment: first treated at 45 ° C, 0.0005MPa conditions for 10min, and then treated at 85 ° C, 0.005MPa conditions to a water content of 0.5%; a polymerization reaction was carried out: the reaction was carried out at 110 ° C for 4h, and then ethylene oxide was introduced (the introduction temperature was 30 ° C, and the ventilation speed was 1.5mL / min), and the temperature was adjusted to 120 ° C for 1h, and a secondary dehydration treatment was carried out: vacuum was removed at 105 ° C, 0.01MPa conditions to generate water, and a diatomaceous earth plate filter was used for filtering and packaging to obtain a modified phenolic amine curing agent.

[0043] 25℃ viscosity: 30000mPa·s, amine value: 320mg KOH / g, appearance: orange clear transparent liquid, 25℃ drying time: 9h, free EDA: 0.07%.

[0044] In summary, the modified phenolic amine curing agent provided by the present invention has high viscosity and high solid content, and appears as an orange clear and transparent liquid, and the free EDA content in the curing agent is less than 0.1%.

[0045] The above description is only a preferred specific implementation manner of the present invention, but the protection scope of the present invention is not limited thereto. Any technician familiar with the technical field can make equivalent replacements or changes according to the technical scheme and inventive concept of the present invention within the technical scope disclosed by the present invention, which should be covered by the protection scope of the present invention.

Claims

1. A process for modifying a phenalkamine curing agent, characterized in that: The following steps are involved: S1, mixing cardanol and amine evenly, and then adding aldehyde to obtain a mixture; S2, subjecting the mixture to a primary dehydration treatment, polymerization, a secondary dehydration treatment, filtering and packaging to obtain a modified phenolic amine curing agent.

2. The process according to claim 1, characterized in that: In the S1, the amine is selected from one or more of ethylenediamine, diethylenetriamine, triethylenetetramine, and tetraethylenepentamine; and the aldehyde is paraformaldehyde.

3. The process according to claim 1, characterized in that: In the S1, the molar ratio of cardanol, amine and aldehyde is 1:(1-2):(1-2).

4. The process according to claim 1, characterized in that: In the above-mentioned S2, the primary dehydration treatment comprises firstly treating at 40-70°C and 0.0005-0.002MPa for 5-10min, and then treating at 70-95°C and 0.002-0.01MPa for 10-50min.

5. The process according to claim 1, characterized in that: In the above-mentioned S2, the polymerization process comprises reacting the mixture at 90-120° C. for 2-5 hours, then introducing ethylene oxide, adjusting the temperature to 120-150° C., and reacting for 1-3 hours.

6. The process according to claim 5, characterized in that: The ethylene oxide introduction temperature is 20-40°C, and the ethylene oxide ventilation speed is 1-50mL / min.

7. The process according to claim 1, characterized in that: In the S2, the secondary dehydration treatment includes removing the generated water by vacuuming at 95-110°C and 0.002-0.01MPa.

8. A modified phenalkamine curing agent, characterized in that: The invention is prepared by the preparation method according to any one of claims 1 to 7.