A composite curing agent and a preparation method thereof

Abstract

The application discloses a composite curing agent and belongs to the technical field of curing agents.The curing agent comprises the following components in parts by mass: 5-25 parts of t-butyl peroxybenzoate, 3-9 parts of t-butyl peroxy-2-ethylhexanoate, 0.5-4.5 parts of methyl ethyl ketone peroxide, 4-10 parts of a curing agent A and 50-70 parts of a solvent.The curing agent can be stored at room temperature, and artificial stone prepared from the curing agent has good wear resistance, acid and alkali resistance and weather resistance, and is favorable for application of the artificial stone.

Description

Technical Field

[0001] This invention relates to the field of curing agent technology, specifically to a composite curing agent and its preparation method. Background Technology

[0002] Artificial stone is a type of stone manufactured through artificial means. It is primarily composed of natural stone powder, resin, and other additives. It not only possesses a similar appearance and texture to natural stone but also boasts energy-saving and environmentally friendly characteristics, posing no adverse effects on human health. The curing agent is an essential chemical reagent in the production process of artificial stone. Its function is to bind the resin, fillers, pigments, and other components in the artificial stone raw materials together, forming a hard stone. Therefore, the performance of the artificial stone curing agent directly affects the quality and performance of the artificial stone.

[0003] Traditional artificial stone hardeners primarily rely on organic resins as binders; however, this type of binder has several drawbacks. First, organic resins have poor high-temperature resistance, generally beginning to decompose around 200℃, limiting the application of artificial stone in high-temperature environments. Second, organic resins are expensive, increasing the production cost of artificial stone. Furthermore, traditional artificial stone hardeners also suffer from long curing times, high post-curing hardness, and susceptibility to cracking, further restricting their application.

[0004] In recent years, with the continuous development of polymer materials and nanotechnology, some new types of artificial stone curing agents have gradually been applied in production. These new curing agents mainly use polymer or nanomaterials as binders, and through special production processes and formulations, they improve the high-temperature resistance of artificial stone, reduce production costs, and shorten curing time. Currently, some problems still exist with artificial stone curing agents on the market. First, the high price of some high-end artificial stone curing agents limits their widespread application; second, the high-temperature resistance of some curing agents still needs further improvement to meet the requirements of some special environments. In addition, the environmental performance of some curing agents needs improvement; for example, some curing agents contain harmful volatile organic compounds. Therefore, it is necessary to continuously improve the production process and formulation of artificial stone curing agents to enhance their performance and environmental friendliness to meet the needs of the market and users. Summary of the Invention

[0005] This invention prepares a composite curing agent to solve the problems of instability and low performance of curing agents at room temperature.

[0006] To achieve the above objectives, the present invention provides the following technical solution to address the technical problem: On one hand, the present invention provides a composite curing agent, which, by weight, comprises 5-25 parts of tert-butyl peroxide, 3-9 parts of tert-butyl peroxide-2-ethylhexanoate, 0.5-4.5 parts of methyl ethyl ketone peroxide, 4-10 parts of curing agent A, and 50-70 parts of solvent.

[0007] Preferably, by weight, the curing agent comprises 10-20 parts of tert-butyl peroxide, 5-7 parts of tert-butyl peroxide-2-ethylhexanoate, 1-3 parts of methyl ethyl ketone peroxide, 6-8 parts of curing agent A, and 55-65 parts of solvent.

[0008] Preferably, by weight, the curing agent comprises 15 parts tert-butyl peroxide, 6 parts tert-butyl peroxide-2-ethylhexanoate, 2 parts methyl ethyl ketone peroxide, 7 parts curing agent A, and 60 parts solvent.

[0009] On the other hand, the present invention provides a method for preparing the aforementioned composite curing agent, the method comprising: S1. Modified triethylenetetramine is prepared by reacting ethyl acrylate with triethylenetetramine. S2. Under alkaline conditions, 3-nitrophenol and epichlorohydrin are reacted at 55-65℃ for 1-3 hours, followed by vacuum distillation. Then, modified triethylenetetramine, tert-butylhydroquinone, and sodium dihydrogen phosphate are added and reacted at 60-70℃ for 3-5 hours. After the reaction is completed, the mixture is cooled to room temperature to obtain curing agent A. S3. Add methyl ethyl ketone peroxide to the solvent, then add tert-butyl peroxide, tert-butyl peroxide-2-ethylhexanoate, and curing agent A, and stir evenly to obtain a composite curing agent.

[0010] Preferably, in step S1, the ethyl acrylate is added to triethylenetetramine at a rate of 1 drop / 3 seconds, the reaction temperature is 60-70°C, and the reaction time is 1-2 hours.

[0011] Preferably, in step S2, the mass ratio of 3-nitrophenol to epichlorohydrin is (4.5-5.5):(12-17).

[0012] Preferably, in step S2, the mass ratio of the modified triethylenetetramine, tert-butylhydroquinone, and sodium dihydrogen phosphate is (8-10):(0.06-0.16):(0.02-0.04).

[0013] Preferably, in step S3, the solvent is one or more of dimethyl phthalate, ethylene glycol methyl ether, dibutyl phthalate, and methyl benzoate.

[0014] Furthermore, the present invention also provides the application of the composite curing agent described above or the composite curing agent prepared by the method described above in the production of artificial stone.

[0015] Compared with the prior art, the present invention has the following beneficial effects: This invention provides a composite curing agent, which comprises, by weight, tert-butyl peroxide, tert-butyl peroxide-2-ethylhexanoate, methyl ethyl ketone peroxide, curing agent A, and a solvent. This curing agent can be stored at room temperature, and artificial stone made with it exhibits good wear resistance, acid and alkali resistance, and weather resistance, which is beneficial for the application of artificial stone.

[0016] Furthermore, the present invention also provides a method for preparing the composite curing agent, which is simple to operate, uses readily available raw materials, has low cost, and is suitable for large-scale industrial production. Detailed Implementation

[0017] The technical solutions of the embodiments of the present invention will be clearly and completely described below with reference to specific examples. Obviously, the described embodiments are only some embodiments of the present invention, and not all embodiments. Based on the embodiments of the present invention, all other embodiments obtained by those skilled in the art without creative effort are within the scope of protection of the present invention.

[0018] In this invention, numerical ranges are involved. Unless otherwise specified, the numerical ranges are considered continuous and include the minimum and maximum values ​​of the range, as well as every value between the minimum and maximum values. Furthermore, when the range refers to integers, it includes every integer between the minimum and maximum values ​​of the range. Additionally, when multiple ranges are provided to describe features or characteristics, the ranges may be merged. In other words, unless otherwise specified, all ranges disclosed herein should be understood to include any and all subranges to which they are included.

[0019] In this invention, there are no particular limitations on the specific dispersion and stirring methods.

[0020] Unless otherwise specified, the experimental methods used in the following examples are conventional methods; the materials and reagents used are commercially available unless otherwise specified.

[0021] Example 1 A composite curing agent, by weight, comprises 15 parts tert-butyl peroxide (TBPB), 6 parts tert-butyl peroxide-2-ethylhexanoate (TBPO), 2 parts methyl ethyl ketone peroxide (MEKP), 7 parts curing agent A, and 60 parts solvent (dimethyl phthalate).

[0022] The preparation method of the composite curing agent includes the following steps: 1. Preparation of curing agent A: (1) Place 150 mL of triethylenetetramine into a three-necked flask, and then add ethyl acrylate at a rate of 1 drop / 3 s. The reaction temperature is 65 °C. Measure the amine value after 1.5 h, and measure it every 0.5 h. When the amine value no longer decreases, the reaction ends, and the modified triethylenetetramine is obtained.

[0023] (2) Under nitrogen protection, add 50g of 3-nitrophenol and 150g of epichlorohydrin, heat in an oil bath until fully dissolved, then add 70g of 50% sodium hydroxide solution and heat to 60℃ for 2h. After the reaction is completed, remove the solvent by vacuum distillation, then add 45g of modified triethylenetetramine, 0.5g of tert-butylhydroquinone and 0.15g of sodium dihydrogen phosphate and react at 65℃ for 4h. Then cool to room temperature to obtain curing agent A.

[0024] 2. At room temperature, dissolve methyl ethyl ketone peroxide in dimethyl phthalate, then add tert-butyl peroxide, tert-butyl peroxide-2-ethylhexanoate, and curing agent A and stir until homogeneous to obtain a composite curing agent.

[0025] Example 2 A composite curing agent, by weight, comprises 10 parts tert-butyl peroxide (TBPB), 7 parts tert-butyl peroxide-2-ethylhexanoate (TBPO), 1 part methyl ethyl ketone peroxide (MEKP), 8 parts curing agent A, and 65 parts solvent (diethyl phthalate).

[0026] The preparation method of the composite curing agent includes the following steps: 1. Preparation of curing agent A: (1) Place 150 mL of triethylenetetramine into a three-necked flask, and then add ethyl acrylate at a rate of 1 drop / 3 s. The reaction temperature is 60 °C. Measure the amine value after 1 h. Measure once every 0.5 h. When the amine value no longer decreases, the reaction ends and the modified triethylenetetramine is obtained.

[0027] (2) Under nitrogen protection, add 45g of 3-nitrophenol and 120g of epichlorohydrin, heat in an oil bath until fully dissolved, then add 70g of 50% sodium hydroxide solution and heat to 55℃ for 1h. After the reaction is completed, remove the solvent by vacuum distillation, then add 40g of modified triethylenetetramine, 0.8g of tert-butylhydroquinone and 0.1g of sodium dihydrogen phosphate and react at 60℃ for 3h. Then cool to room temperature to obtain curing agent A.

[0028] 2. At room temperature, dissolve methyl ethyl ketone peroxide in diethyl phthalate, then add tert-butyl peroxide, tert-butyl peroxide-2-ethylhexanoate, and curing agent A and stir until homogeneous to obtain a composite curing agent.

[0029] Example 3 A composite curing agent, by weight, comprises 20 parts tert-butyl peroxide (TBPB), 5 parts tert-butyl peroxide-2-ethylhexanoate (TBPO), 3 parts methyl ethyl ketone peroxide (MEKP), 6 parts curing agent A, and 55 parts solvent (ethylene glycol methyl ether).

[0030] The preparation method of the composite curing agent includes the following steps: 1. Preparation of curing agent A: (1) Place 150 mL of triethylenetetramine into a three-necked flask, and then add ethyl acrylate at a rate of 1 drop / 3 s. The reaction temperature is 70 °C. Measure the amine value after 2 h. Measure once every 0.5 h. When the amine value no longer decreases, the reaction ends and the modified triethylenetetramine is obtained.

[0031] (2) Under nitrogen protection, add 55g of 3-nitrophenol and 170g of epichlorohydrin, heat in an oil bath until fully dissolved, then add 70g of 50% sodium hydroxide solution and heat to 65℃ for 3h. After the reaction is completed, remove the solvent by vacuum distillation, then add 50g of modified triethylenetetramine, 0.3g of tert-butylhydroquinone and 0.2g of sodium dihydrogen phosphate and react at 70℃ for 5h. Then cool to room temperature to obtain curing agent A.

[0032] 2. At room temperature, dissolve methyl ethyl ketone peroxide in ethylene glycol methyl ether, then add tert-butyl peroxide, tert-butyl peroxide-2-ethylhexanoate, and curing agent A and stir until homogeneous to obtain a composite curing agent.

[0033] Comparative Example 1 The difference between Comparative Example 1 and Example 1 is that Comparative Example 1 does not contain curing agent A, but everything else is the same.

[0034] Comparative Example 2 Comparative Example 2 is commercially available tert-butyl peroxide-2-ethylhexanoate (TBPO).

[0035] Comparative Example 3 Comparative Example 3 was commercially available methyl ethyl ketone peroxide (MEKP).

[0036] Comparative Example 4 Comparative Example 4 is commercially available tert-butyl peroxide (TBPB).

[0037] Test Example 1 The performance of the curing agents of Examples 1-3 and Comparative Examples 1-4 was tested separately, and the procedures are as follows: The curing agents of Examples 1-3 and Comparative Examples 1-4 were diluted to 75% with deionized water, respectively. Artificial stone prepared without curing agent was set as a blank group. The test results are shown in Tables 1 and 2 below: Table 1. Test Results of Physicochemical Properties of Curing Agent

[0038] 2. Preparation of artificial stone Artificial stone is made by uniformly mixing 60% natural marble chips (>100 mesh), 24.5% quartz powder (≤150 mesh), 10% furfuryl alcohol resin, 5% curing agent, and 0.5% color paste, and then putting the mixture into a vacuum polymerization kettle with a vacuum degree of 0.09 MPa and a temperature of 70℃. Stirring is stopped when the temperature of the reactants no longer rises, and after removing air bubbles, a mixture is obtained. The mixture is then slowly poured into the pre-treated mold cavity and leveled with a scraper. The mold with the mixture is then sent into a vacuum chamber, vacuumed again, and left to stand to obtain a semi-finished artificial stone product. After demolding the semi-finished artificial stone product, it is placed in an oven for curing at 95℃. After grinding and polishing, the artificial stone product is obtained.

[0039] Table 2 Test results of artificial stone prepared with curing agent

[0040] Note: In the table, weather resistance 1-3 indicates the quality of performance, with 1 being excellent, 2 being good, and 3 being moderate.

[0041] As shown in Tables 1 and 2, the artificial stone prepared using the curing agents of Examples 1-3 exhibits good wear resistance, acid and alkali resistance, and weather resistance, and has a short curing time. Moreover, compared with Comparative Example 1 and Example 1, curing agent A can improve the weather resistance of the curing agent, making it suitable as an outdoor building material and expanding the application range of artificial stone. Furthermore, the preparation method is simple, the raw materials are readily available, and it is suitable for large-scale industrial production.

[0042] Furthermore, it should be understood that although this specification describes embodiments, not every embodiment contains only one independent technical solution. This narrative style is merely for clarity. Those skilled in the art should consider the specification as a whole, and the technical solutions in each embodiment can also be appropriately combined to form other embodiments that can be understood by those skilled in the art.

Claims

1. A composite curing agent, characterized in that, By weight, the curing agent comprises 10-20 parts of tert-butyl peroxide, 5-7 parts of tert-butyl peroxide-2-ethylhexanoate, 1-3 parts of methyl ethyl ketone peroxide, 6-8 parts of curing agent A, and 55-65 parts of solvent. The preparation method of the composite curing agent includes the following steps: S1. Modified triethylenetetramine is prepared by reacting ethyl acrylate with triethylenetetramine. S2. Under alkaline conditions, 3-nitrophenol and epichlorohydrin are reacted at 55-65℃ for 1-3 hours, followed by vacuum distillation. Then, modified triethylenetetramine, tert-butylhydroquinone, and sodium dihydrogen phosphate are added and reacted at 60-70℃ for 3-5 hours. After the reaction is completed, the mixture is cooled to room temperature to obtain curing agent A. S3. Add methyl ethyl ketone peroxide to the solvent, then add tert-butyl peroxide, tert-butyl peroxide-2-ethylhexanoate, and curing agent A, and stir evenly to obtain a composite curing agent.

2. The composite curing agent according to claim 1, characterized in that, By weight, the curing agent comprises 15 parts tert-butyl peroxide, 6 parts tert-butyl peroxide-2-ethylhexanoate, 2 parts methyl ethyl ketone peroxide, 7 parts curing agent A, and 60 parts solvent.

3. The composite curing agent according to claim 1, characterized in that, In step S1, the ethyl acrylate is added to triethylenetetramine at a rate of 1 drop / 3 seconds, the reaction temperature is 60-70°C, and the reaction time is 1-2 hours.

4. The composite curing agent according to claim 1, characterized in that, In step S2, the mass ratio of 3-nitrophenol to epichlorohydrin is (4.5-5.5):(12-17).

5. The composite curing agent according to claim 1, characterized in that, In step S2, the mass ratio of the modified triethylenetetramine, tert-butylhydroquinone, and sodium dihydrogen phosphate is (8-10):(0.06-0.16):(0.02-0.04).

6. The composite curing agent according to claim 1, characterized in that, In step S3, the solvent is one or more of dimethyl phthalate, ethylene glycol methyl ether, dibutyl phthalate, and methyl benzoate.

7. The application of the composite curing agent according to any one of claims 1-6 in the production of artificial stone.

Images