Triazine ring-containing metal ion complex cross-linking agent and preparation method thereof

Abstract

The invention discloses a zinc-containing complex, a preparation method thereof and application of the zinc-containing complex in rubber, namely a foaming material. The preparation method comprises the following steps: (1) adding zinc oxide, zinc carbonate, basic zinc carbonate or any mixture thereof and melamine into water, and pulping; (2) reacting the slurry in the step (1) at 0-100 DEG C for 0.5-24 hours; and (3) drying and crushing the suspension obtained in the step (2) to obtain the zinc-containing complex cross-linking agent. The zinc complex can equivalently replace pure zinc oxide in rubber or a foaming material to participate in vulcanization reaction of the rubber; after the zinc oxide is compounded with calcium carbonate, a product compounded with pure zinc oxide and calcium carbonate is consistent in rubber vulcanization performance, and the use amount of zinc oxide is effectively reduced.

Description

Technical Field

[0001] This invention relates to crosslinking technology for polymer materials. Specifically, this invention relates to a zinc-containing complex crosslinking agent, its preparation method, and its application in rubber and foam materials. Background Technology

[0002] Zinc oxide, zinc carbonate, and basic zinc carbonate are indispensable additives in the vulcanization of various rubbers and the foaming process of AC / OBSH and other foaming agents. These zinc compounds can promote vulcanization, accelerate the decomposition of foaming agents, and absorb acidic substances in these materials.

[0003] Zinc oxide production can be divided into three methods: direct method, indirect method, and wet method. The direct method involves directly calcining lead-zinc ore; the indirect method uses purified zinc ingots for direct oxidation; and the wet method generally refers to using various soluble zinc sources, purifying them to prepare zinc carbonate or basic zinc carbonate, and then calcining them. As for zinc carbonate, it is currently rarely produced or used in large quantities on the market.

[0004] Reducing the use of zinc oxide has been a long-standing demand in the rubber industry. This is significant for several reasons: First, zinc is often found in conjunction with various heavy metal ores, so reducing zinc usage helps reduce heavy metal pollution. Second, rubber products, especially tires, experience wear and tear during use, and zinc is released into the environment as the products wear down, causing pollution. Third, reducing the use of zinc oxide helps reduce costs.

[0005] In response to the rubber industry's requirements to reduce zinc consumption, the zinc chemical industry typically makes the following improvements: 1: Increase the specific surface area of ​​zinc oxide; 2: Immobilize zinc oxide on the surface of low-value materials, such as calcium carbonate; 3: Directly mix zinc oxide with low-value substances such as calcium carbonate.

[0006] The methods described above can effectively reduce the amount of zinc oxide used, but zinc is still added to the rubber in the form of zinc oxide. The reactions involving zinc oxide during rubber vulcanization are all multiphase reactions. During the reaction, the particle size of zinc oxide continuously decreases, while the fluidity of the rubber continuously decreases as the vulcanization reaction proceeds. This process means that the surface energy required to react with the residual zinc oxide particles becomes increasingly higher, and the molecular mobility of the rubber phase becomes increasingly lower. Both of these factors determine that, near the end of vulcanization, a large amount of zinc oxide remains and cannot participate in the vulcanization process.

[0007] Zinc is an essential accelerator in the foaming process of AC foaming agents, effectively lowering the foaming temperature and promoting foaming. Conventional foaming processes also involve cross-linking reactions of polymer materials. The reaction process involving zinc oxide is similar to the rubber vulcanization process described above, resulting in a large amount of residual zinc oxide that cannot participate in the vulcanization process. Summary of the Invention

[0008] In view of this, the present invention proposes a novel zinc-containing complex and its application in rubber, foam, and other materials. The present invention employs a zinc-melamine complex. The complex disrupts the crystal structure of zinc oxide, zinc carbonate, and basic zinc carbonate, while the basicity of the triazine ring enhances the acid absorption capacity of the material. This structure can replace pure zinc oxide / zinc carbonate in the production of rubber or foam materials. The technical solution of the present invention is implemented as follows: A zinc-containing complex crosslinking agent is obtained by reacting zinc oxide, zinc carbonate, basic zinc carbonate, or a mixture thereof in any proportion with melamine. The structural formula of the zinc-containing complex is as follows:

[0009] Where X can be any one of oxygen atom, carbonate ion, hydroxide ion or basic carbonate ion, and m, n and k are all natural numbers greater than 1.

[0010] A method for preparing a zinc-containing complex crosslinking agent includes the following steps: (1) Add zinc oxide, zinc carbonate, basic zinc carbonate, or a mixture thereof in any proportion to water and slurry. (2) Selectively bubble carbon dioxide gas into the water as needed; (3) Add melamine to the slurry from step (2), stir, and react at 0~100℃ for 0.1~48 hours; (4) The slurry obtained in step (3) is then heated, dried, and pulverized; Furthermore, the heating temperature is 0℃~160℃, and the heating time is 0.1~48 hours.

[0011] Furthermore, the molar ratio of melamine to zinc is 1:1 to 2:1, and the molar ratio of carbon dioxide to zinc is 0:1 to 2:1.

[0012] An application of a zinc-containing complex crosslinking agent, which replaces zinc oxide, for the vulcanization of rubber materials and as an accelerator for foaming materials.

[0013] The rubber materials mentioned include, but are not limited to, nitrile rubber (NBR), chloroprene rubber (CR), brominated butyl rubber (BIIR), ethylene propylene diene monomer (EPDM), natural rubber, butadiene rubber, and styrene-butadiene rubber, or any mixture thereof in any proportion. The foaming materials mentioned include, but are not limited to, EVA foaming, foaming of the various rubber materials mentioned above, SBS foaming, or any mixture thereof in any proportion.

[0014] Based on the rubber or foam material formulation, the complex crosslinking agent replaces pure zinc oxide or zinc carbonate in equal amounts for the vulcanization of rubber materials or the foaming of foam materials.

[0015] For example, in the following formula: 100 parts of rubber; Plasticizer: 0~200 parts; Stabilizer: 0-5 parts; Calcium carbonate: 0~120 parts; Carbon black: 0-200 parts; Silica: 0~200 parts; Antioxidant: 0.1~0.5 parts; Various lubricants: 1-4 parts; Cross-linking agent for complex: 2-8 parts.

[0016] Sulfur: 0.1~3; Various accelerators: 0.1~3.

[0017] The lubricant may be stearic acid, and the accelerator may be an NS accelerator.

[0018] After preparing rubber samples using the above formula, they were tested and passed through a two-roll mill, and then pressed into sheets at 150-180°C on a flat vulcanizing machine. Experiments showed that the zinc-melamine complex prepared using this invention can replace zinc oxide in equal amounts under various conditions for rubber vulcanization.

[0019] Compared with existing technologies, the zinc complex of the present invention has the following advantages: (1) Simple synthesis: The synthesis of zinc complex uses water as a solvent. The synthesis process is pollution-free and produces no by-products or waste. It is a green synthesis process. (2) This invention can absorb carbon dioxide and has an extremely low carbon footprint; it plays an important role in reducing the carbon footprint of rubber and foam products. (3) The present invention can replace zinc oxide in equal amounts, and no formula adjustment is required in subsequent processes. Attached Figure Description

[0020] Figure 1 The infrared spectrum of melamine; Figure 2 The infrared spectrum of basic zinc carbonate; Figure 3 Infrared spectrum of basic zinc carbonate-melamine complex; Figure 4 The image shows the infrared spectrum of the zinc oxide-melamine complex. Detailed Implementation

[0021] To make the above-mentioned objects, features and advantages of the present invention more apparent and understandable, specific embodiments of the present invention will be described in detail below. Example

[0022] (1) Add 252g of melamine to 500g of water and stir and beat at room temperature for 0.5 hours; (2) Add 350 grams of basic zinc carbonate containing 56.5% zinc to 1; (3) After heating and stirring at 85℃ for 8 hours, dry directly; (4) The dried powder is pulverized to obtain basic zinc carbonate-melamine complex powder.

[0023] The obtained dried powder, according to GB / T3185-2016, has a zinc oxide content of 39.8%, which is consistent with the actual feed.

[0024] In this embodiment, infrared analysis was performed on the obtained complex. The infrared spectra show that the obtained product is significantly different from the infrared spectra of zinc carbonate and melamine. Example

[0025] (1) Add 252g of melamine to 500g of water and stir at room temperature for 0.5 hours; (2) Add 242 grams of zinc oxide to 1 and stir vigorously; (3) After heating and stirring at 85°C for 8 hours, dry directly.

[0026] (4) The dried powder is pulverized to obtain zinc oxide-melamine complex powder.

[0027] The obtained dried powder, according to GB / T3185-2016, has a zinc oxide content of 48.5%, which is consistent with the actual feed.

[0028] In this embodiment, the infrared spectrum of the obtained zinc oxide-melamine complex was also examined. Example

[0029] (1) Add 242 g of zinc oxide to 500 g of water and stir and beat at room temperature for 0.5 hours; (2) Slowly bubble 88 grams of carbon dioxide into 1; (3) After all the carbon dioxide has been absorbed, add 252 grams of melamine to (2) and start stirring vigorously; (4) After heating and stirring at 85℃ for 8 hours, dry directly; (5) The dried powder is pulverized to obtain zinc carbonate-melamine complex powder.

[0030] The obtained dried powder, according to GB / T3185-2016, has a zinc oxide content of 45.0%, which is consistent with the actual feed.

[0031] Application Example 1 Formulate according to the following Table 1: Table 1 Application Example 1 Formulation

[0032] Rubber samples were prepared, and their vulcanization curves were measured using a dynamic vulcanizer at 160℃ for 20 minutes. After vulcanization at 160℃ for 10 minutes using a flat vulcanizer, the samples were pressed into sheets, then shaped and their mechanical properties were measured.

[0033] The performance test results for the above examples are shown in Table 2 below: Table 2 Performance Test of Application Example 1

[0034] The test results above show that, whether from the vulcanization curve or from the comparison of mechanical properties, the zinc-melamine complex prepared by the present invention can completely and equally replace zinc oxide for rubber vulcanization.

[0035] Application Example 2 According to the following formula: Table 3 Application Example 2 Formulation

[0036] Rubber samples were prepared, and their vulcanization curves were measured using a dynamic vulcanizer at 160℃ for 20 minutes. After vulcanization at 160℃ for 10 minutes using a flat vulcanizer, the samples were pressed into sheets, then shaped and their mechanical properties were measured.

[0037] The performance test results for the above examples are as follows: Table 4 Performance Test of Application Example 2

[0038] The test results above show that even when the dosage is reduced to 3 phr, the zinc-melamine complex prepared by this invention can completely and equally replace zinc oxide for rubber vulcanization, both in terms of vulcanization curves and mechanical properties.

[0039] Application Example 3 Considering that some manufacturers use a compound of zinc oxide and calcium carbonate in a certain proportion to replace pure zinc oxide in rubber vulcanization, this invention addresses this application by comparing the effects of zinc-melamine complex / calcium carbonate mixtures and zinc oxide / calcium carbonate mixtures on rubber vulcanization.

[0040] A mixture containing calcium carbonate was prepared according to the following formula: Table 5 Application Example 3: Calcium Carbonate Mixture

[0041] Then follow the formula below: Table 6 Application Example 3 Formulation

[0042] Rubber samples were prepared, and their vulcanization curves were measured using a dynamic vulcanizer at 160℃ for 20 minutes. The samples were then vulcanized at 160℃ for 10 minutes using a flat vulcanizer, pressed into sheets, and then cut and measured for their mechanical properties.

[0043] The performance test results for the above examples are as follows: Table 7 Performance Test of Application Example 3

[0044] The test results above show that, whether from the vulcanization curve or from the comparison of mechanical properties, the zinc-melamine complex prepared by the present invention, when mixed with calcium carbonate, can completely and equally replace the calcium carbonate complex prepared with zinc oxide under the same ratio for rubber vulcanization.

[0045] Application Example 4: According to the following formula: Table 8 Application Example 4 Formulation

[0046] Rubber samples were prepared, and their vulcanization curves were measured using a dynamic vulcanizer at 160℃ for 20 minutes. The samples were then vulcanized at 160℃ for 10 minutes using a flat vulcanizer, pressed into sheets, and then cut and measured for their mechanical properties.

[0047] The performance test results for the above examples are as follows: Table 9 Performance Test of Application Example 4

[0048] The test results above show that, whether from the vulcanization curve or the comparison of mechanical properties, even when the addition amount is 3 phr, the zinc-melamine complex prepared by the present invention, after being mixed with calcium carbonate, can completely and equally replace the calcium carbonate complex prepared by zinc oxide under the same ratio for rubber vulcanization.

[0049] While the present invention has been disclosed above, it is not limited thereto. Any person skilled in the art can make various modifications and alterations without departing from the spirit and scope of the invention; therefore, the scope of protection of the present invention should be determined by the scope defined in the claims.

Claims

1. A zinc-containing complex crosslinking agent, characterized in that, The complex is obtained by reacting zinc oxide, zinc carbonate, basic zinc carbonate, or a mixture thereof in any proportion with melamine. The structural formula of the complex is as follows: ； Where X is any one of oxygen atom, carbonate ion, hydroxide ion or basic carbonate ion, and m, n and k are all natural numbers greater than 1.

2. A method for preparing a zinc-containing complex crosslinking agent, characterized in that, The method for preparing the zinc-containing complex crosslinking agent according to claim 1 comprises the following steps: (1) Add zinc oxide, zinc carbonate, basic zinc carbonate, or a mixture thereof in any proportion to water and slurry. (2) Selectively bubble carbon dioxide gas into the water as needed; (3) Add melamine to the slurry from step (2), stir, and react at 0~100℃ for 0.1~48 hours; (4) The slurry obtained in step (3) is then heated, dried and crushed.

3. The method for preparing the zinc-containing complex crosslinking agent according to claim 2, characterized in that, The heating temperature is 0℃~160℃, and the heating time is 0.1~48 hours.

4. The method for preparing the zinc-containing complex crosslinking agent according to claim 2, characterized in that, The molar ratio of melamine to zinc is 1:1 to 2:

1.

5. The method for preparing the zinc-containing complex crosslinking agent according to claim 2, characterized in that, The molar ratio of carbon dioxide to zinc is 0:1 to 2:

1.

6. The application of the zinc-containing complex crosslinking agent according to claim 1, wherein the zinc-containing complex crosslinking agent replaces zinc oxide and is used for the vulcanization of rubber materials and as an accelerator for foaming materials.

7. The application of the zinc-containing complex crosslinking agent according to claim 6, characterized in that, The rubber material includes one of nitrile rubber (NBR), chloroprene rubber (CR), brominated butyl rubber (BIIR), ethylene propylene diene monomer (EPDM), natural rubber, butadiene rubber, and styrene-butadiene rubber, or a mixture thereof in any proportion. The foaming material is one of EVA foaming, rubber material foaming, and SBS foaming, or a mixture thereof in any proportion.

8. The application of the zinc-containing complex crosslinking agent according to claim 6, characterized in that, Based on the rubber or foam material formulation, the complex crosslinking agent replaces pure zinc oxide or zinc carbonate in equal amounts for the vulcanization of rubber materials or the foaming of foam materials.

9. The application of the zinc-containing complex crosslinking agent according to claim 6, characterized in that, The vulcanization formula for the rubber material is as follows: Rubber: 100 parts; Plasticizer: 0~200 parts; Stabilizer: 0-5 parts; Calcium carbonate: 0~120 parts; Carbon black: 0-200 parts; Silica: 0~200 parts; Antioxidant: 0.1~0.5 parts; Lubricant: 1-4 parts; Crosslinking agent for complex: 2-8 parts; Sulfur: 0.1~3 parts; Various accelerators: 0.1~3 parts.

10. The application of the zinc-containing complex crosslinking agent according to claim 9, characterized in that, The lubricant is stearic acid, and the accelerator is NS.

Images