Environment-friendly rubber material capable of being vulcanized at room temperature and preparation method thereof

Abstract

The invention relates to an environment-friendly rubber material capable of being vulcanized at room temperature and a preparation method thereof. The formula comprises natural rubber or bio-based synthetic rubber, filler, microbeads, zinc oxide, stearic acid, vegetable oil, wax, an anti-aging agent, sulfur and an accelerant. Through the design of the formula, the product can be slowly vulcanized at about room temperature, so that the energy consumption is reduced, and the processing equipment is simplified. The preparation method comprises the steps of material weighing, material mixing, pre-forming and vulcanization forming, and it is ensured that the material has the characteristics of being light, soft, resistant to abrasion and environmentally friendly. The content of the selected bio-based material is high, the product is more environment-friendly, and the dependence on the petroleum-based raw material is reduced. The material disclosed by the invention can be gradually shaped according to the shape or pressure distribution of a matched body part of a user, provides personalized supporting and fitting effects, is an ideal material which is high in environmental protection and low in energy consumption and has a personalized fitting function, and is suitable for the fields of flexible medical instruments, clothes, insoles, sole supports, sports protectors and other wearable equipment.

Description

Technical Field

[0001] The present invention relates to the technical field of environmentally friendly rubber materials, and in particular to an environmentally friendly rubber material that can be vulcanized at room temperature and a preparation method thereof. Background Art

[0002] Most existing rubber products use a hot vulcanization process, with a typical vulcanization temperature usually above 140°C. Heating causes the rubber material to undergo a cross-linking reaction, ultimately forming a stable solid elastomer. However, this high-temperature vulcanization method has several obvious limitations: (1) High energy consumption and equipment dependence: The high-temperature vulcanization process requires the use of equipment such as vulcanizers or injection molding machines, which consumes a lot of energy and has high equipment costs, increasing the production costs of manufacturers; (2) Environmental pollution: The rubber materials used in the traditional vulcanization process usually contain petroleum-based components, such as synthetic rubber and plasticizers, and the production and disposal processes are prone to environmental pollution. In addition, the vulcanized rubber material is difficult to degrade naturally and does not meet the requirements of sustainable development; (3) Difficulty in achieving personalized fit: After the traditional rubber products are molded, the material structure is fixed and cannot be dynamically adjusted according to the user's body shape needs. Therefore, many rubber products are difficult to provide fit support that matches the user's body shape, affecting the comfort of use.

[0003] To address these challenges, the field of materials science has recently conducted extensive research on bio-based rubber materials and low-temperature vulcanization technology. Bio-based materials, such as natural rubber, vegetable oils, and plant waxes, have garnered widespread attention due to their renewable nature. Compared to petroleum-based materials, bio-based materials have lower carbon emissions and are able to naturally degrade under certain conditions, contributing to environmental benefits.

[0004] The development of low-temperature vulcanization technology has also brought new possibilities for personalized molding and low-energy production of materials. Compared with traditional high-temperature vulcanization, low-temperature vulcanized materials can complete cross-linking reactions at room temperature, which not only reduces production energy consumption, but also enables the material to slowly form during use. Especially in the fields of insoles and sports protective gear, low-temperature vulcanization technology allows the material to gradually vulcanize and shape while the user wears it, thereby achieving a perfect fit with the user's shape and improving wearing comfort. However, existing low-temperature vulcanized materials still have the following problems: (1) Difficulty in controlling the vulcanization speed: The reaction speed of low-temperature vulcanized materials is difficult to control, especially in the use scenario. How to complete the material molding within an appropriate time without affecting the user experience is still a technical difficulty; (2) Limited proportion of bio-based components: The bio-based components of existing low-temperature vulcanized materials are generally low, and it is difficult to achieve a balance between high strength and high elasticity, which affects the actual use performance of the material; (3) Poor compatibility in mass production: The production process of low-temperature vulcanized materials often requires special treatment and control, and is not easy to be compatible with traditional high-temperature vulcanization equipment, which limits its feasibility of large-scale application. Summary of the Invention

[0005] To address the high energy consumption, high pollution, and difficulty in lamination associated with existing technologies, this invention provides an environmentally friendly rubber material that can be vulcanized at room temperature. This invention proposes a bio-based, environmentally friendly rubber material that can be slowly vulcanized at room temperature. This material not only exhibits low-temperature vulcanization molding properties but also utilizes a high proportion of bio-based ingredients.

[0006] The first object of the present invention is to provide an environmentally friendly rubber material that can be vulcanized at room temperature, comprising 100 parts of natural rubber or bio-based synthetic rubber, 20-50 parts of filler, 0-100 parts of microbeads, 2-5 parts of zinc oxide, 1-5 parts of stearic acid, 0-20 parts of vegetable oil, 0-1.5 parts of wax, 0-5 parts of antioxidant, 0.5-3 parts of sulfur and 0-5 parts of accelerator.

[0007] In some embodiments of the present invention, the bio-based rubber includes one or more of polyitaconate rubber, dandelion rubber, styrene-butadiene rubber, and butadiene rubber.

[0008] In some embodiments of the present invention, the filler is one or more of carbon black, white carbon black, lignin and calcium carbonate.

[0009] In some embodiments of the present invention, the microspheres are hollow glass microspheres. The hollow microspheres used in the present invention are all commercially available and are conventional materials in the art.

[0010] In some embodiments of the present invention, the vegetable oil is selected from one or more of naphthenic oil, soybean oil, palm oil and rapeseed oil.

[0011] In some embodiments of the present invention, the wax is selected from one or more of paraffin wax, microcrystalline wax, rice bran wax and coconut wax.

[0012] In some embodiments of the present invention, the accelerator includes one or more thiazole, sulfenamide, or dithiocarbamate accelerators.

[0013] In some embodiments of the present invention, the antioxidant is selected from one or more of RD, 6PPD and lignin antioxidant.

[0014] In some embodiments of the present invention, the vulcanization temperature of the environmentally friendly rubber material is 15-35° C., and the vulcanization time is 1-30 days; and the bio-based components of the environmentally friendly rubber material account for 80 wt % or more of the total components.

[0015] A second object of the present invention is to provide a method for preparing the environmentally friendly rubber material that can be vulcanized at room temperature, comprising the following steps:

[0016] S1. Weighing: Take all raw materials;

[0017] S2. Mixing: Using an open mixer or internal mixer, mix the above raw materials uniformly at a temperature not exceeding 70° C. to obtain a rubber compound;

[0018] S3, molding: placing the obtained rubber material into a mold and pressing it into shape to obtain an environmentally friendly rubber material.

[0019] In some embodiments of the present invention, the temperature of the compression molding is above 140°C.

[0020] The above technical solution of the present invention has the following advantages over the prior art:

[0021] 1. Reduce energy consumption. Traditional rubber materials usually use a molding temperature above 140°C; the material of the present invention can be gradually vulcanized and molded at room temperature or slightly above room temperature, reducing dependence on high-temperature equipment and reducing energy consumption in the production process.

[0022] 2. Simplify processing equipment and reduce investment costs. Traditional rubber materials require a vulcanizer / injection molding machine and molds to heat and pressurize the material; however, the equipment required by this invention is very simple, thus significantly saving equipment investment costs.

[0023] 3. Reduce environmental pollution. The bio-based materials selected in the present invention are high in content, green, environmentally friendly, and low in carbon, greatly reducing dependence on petroleum-based raw materials.

[0024] In summary, the material of the present invention has good environmental protection and low energy consumption characteristics, and provides a new technical solution for the wide application of rubber materials in the modern market. BRIEF DESCRIPTION OF THE DRAWINGS

[0025] In order to make the content of the present invention more clearly understood, the present invention is further described in detail below based on specific embodiments of the present invention in conjunction with the accompanying drawings, wherein:

[0026] Figure 1 It is the vulcanization curve of the rubber compound of the embodiment of the present invention at 80 ℃. DETAILED DESCRIPTION

[0027] The present invention will be further described below with reference to the accompanying drawings and specific embodiments so that those skilled in the art can better understand the present invention and implement it. However, the embodiments are not intended to limit the present invention.

[0028] Example 1

[0029] This embodiment provides a raw material formula and preparation method of an environmentally friendly rubber material that can be vulcanized at room temperature, as follows:

[0030] 1. The main ingredients and quantities are as follows:

[0031]

[0032]

[0033] 2. Preparation steps:

[0034] (1) Raw material pretreatment: All raw materials are dried to ensure the dryness of the raw materials.

[0035] (2) Mixing and plasticizing: Heat and soften the pretreated natural rubber on an open mill, add zinc oxide, stearic acid, white carbon black, soybean oil, rice bran wax, and lignin antioxidant in small amounts and multiple times, and perform preliminary mixing and plasticizing until the mixture is uniform and soft, and the temperature is controlled between 65±5℃.

[0036] (3) Adding vulcanizing agent and accelerator: Finally, after the temperature drops to room temperature, add the vulcanizing agent sulfur and the accelerator in the formula, and mix again for 5 minutes to avoid premature reaction of the vulcanizing agent.

[0037] (4) Molding and vulcanization: The mixed rubber material is sheeted and slowly vulcanized and molded within 2-4 days.

[0038] 3. Performance Testing

[0039] The curing time (T95) of the rubber compound of this formula is about 55 minutes at a curing temperature of 80°C.

[0040] The density of the rubber compound is about 1.10 g / cm3 as measured by a densitometer. 3 .

[0041] Example 2

[0042] This embodiment provides a raw material formula and preparation method for an environmentally friendly rubber material that can be vulcanized at room temperature. The main raw materials and the proportions thereof are as follows:

[0043] 1. The main ingredients and quantities are as follows:

[0044]

[0045]

[0046] 2. Preparation steps:

[0047] The preparation steps are the same as those in Example 1.

[0048] 3. Performance Testing

[0049] The curing time of the rubber compound of this formula is about 72 minutes at a curing temperature of 80°C.

[0050] Due to the addition of hollow glass microspheres, the density of the rubber compound is reduced to 0.78g / cm 3 .

[0051] Example 3

[0052] This embodiment provides a raw material formula and preparation method for an environmentally friendly rubber material that can be vulcanized at room temperature. The main raw materials and the proportions thereof are as follows:

[0053] 1. Raw material formula:

[0054]

[0055]

[0056] 2. Preparation steps:

[0057] The preparation steps are the same as those in Example 1.

[0058] 3. Performance Testing

[0059] The curing time of the rubber compound of this formula is about 81 minutes at a curing temperature of 80°C.

[0060] Due to the addition of hollow glass microspheres, the density of the rubber compound is reduced to 0.90g / cm 3 .

[0061] Example 4

[0062] 1. Formula composition

[0063] This embodiment provides a method for preparing an environmentally friendly rubber material that can be vulcanized at room temperature. The main raw materials and their quantities are as follows:

[0064] natural rubber 100 zinc oxide 3 stearic acid 1 Lignin 30 soybean oil 10 Lignin antioxidant 2 sulfur 3 Accelerator BZ 3 Accelerator EZ 3 Accelerator CBS 2

[0065] 2. Preparation steps

[0066] The preparation steps are the same as those in Example 1.

[0067] 3. Performance Testing

[0068] The curing time of the rubber compound of this formula is about 60 minutes at a curing temperature of 80°C.

[0069] Example 5

[0070] 1. Formula composition

[0071] This embodiment provides a method for preparing an environmentally friendly rubber material that can be vulcanized at room temperature. The main raw materials and their quantities are as follows:

[0072] Dandelion rubber 100 zinc oxide 3 stearic acid 1 Silica 40 soybean oil 15 Lignin antioxidant 1.5 sulfur 2.5 Accelerator PZ 3 Accelerator EZ 3 Accelerator CBS 2

[0073] 2. Preparation steps

[0074] The preparation steps are the same as those in Example 1.

[0075] 3. Performance Testing

[0076] To test the vulcanization characteristics of the rubber compound, the mixed rubber compound was subjected to a rotorless rheometer for vulcanization performance characterization. To speed up the experiment, the vulcanization temperature was set to 80°C.

[0077] The curing time of the rubber compound of this formula is about 63 minutes at a curing temperature of 80°C.

[0078] The vulcanization time of the rubber compound can be adjusted by adjusting the type and combination of accelerators. To this end, the following comparative examples are used to verify this.

[0079] Comparative Example 1

[0080] 1. Formula composition

[0081] This comparative example provides a method for preparing an environmentally friendly rubber material that can be vulcanized at room temperature. The main raw materials and quantities are as follows:

[0082] raw material Weight (parts) Styrene-butadiene rubber 100 zinc oxide 3 stearic acid 1 Silica 40 soybean oil 10 Rice bran wax 0.5 Lignin antioxidant 0.5 sulfur 3 Accelerator EZ 2 Accelerator CBS 2

[0083] 2. Preparation steps

[0084] The preparation steps are the same as those in Example 1.

[0085] 3. Performance Testing

[0086] The curing time of this rubber compound at a curing temperature of 80°C is approximately 82 minutes. Compared to Example 1, this formulation uses only two accelerators, EZ and CBS, and its curing time is significantly increased. Compared to Example 1, this formulation uses styrene-butadiene rubber instead of natural rubber, significantly reducing the proportion of sustainable materials.

[0087] Comparative Example 2

[0088] 1. Formula composition

[0089] This comparative example provides a method for preparing an environmentally friendly rubber material that can be vulcanized at room temperature. The main raw materials and quantities are as follows:

[0090]

[0091] 2. Preparation steps

[0092] The preparation steps are the same as those in Example 1.

[0093] 3. Performance Testing

[0094] The curing time of the rubber compound of this formula is about 78 minutes at a curing temperature of 80° C. Compared with Example 2, this formula only uses two accelerators, BZ and CBS, and its curing time is significantly increased.

[0095] Comparative Example 3

[0096] 1. Formula composition

[0097] This comparative example provides a method for preparing an environmentally friendly rubber material that can be vulcanized at room temperature. The main raw materials and the quantities thereof are as follows:

[0098]

[0099]

[0100] 2. Preparation steps

[0101] The preparation steps are the same as those in Example 1.

[0102] 3. Performance Testing

[0103] The curing time of this rubber compound at a curing temperature of 80°C is approximately 130 minutes. Compared with Example 3, this formulation uses only two accelerators, PZ and CBS, and its curing time is significantly increased. Compared with Example 3, this formulation uses butadiene rubber instead of natural rubber, significantly reducing the proportion of sustainable materials.

[0104] Comparative Example 4

[0105] 1. Formula composition

[0106] This comparative example provides a method for preparing an environmentally friendly rubber material that can be vulcanized at room temperature. The main raw materials and the quantities thereof are as follows:

[0107]

[0108]

[0109] 2. Preparation steps

[0110] The preparation steps are the same as those in Example 1.

[0111] 3. Performance Testing

[0112] The curing time of the rubber compound of this formula is about 73 minutes at a curing temperature of 80° C. Compared with Example 4, this formula only uses the same two accelerators, but the proportions are slightly reduced, and its curing time is significantly increased.

[0113] Table 1

[0114]

[0115] The results of the density, vulcanization time (T95) at 80° C. and sustainable material content of the samples of the above examples and comparative examples are shown in Table 1.

[0116] As shown in Table 1, the curing time of the rubber compound can be varied by combining different accelerators. Combining a conventional accelerator with two or more ultra-fast accelerators (PZ, EZ, BZ), and using a high dosage of the ultra-fast accelerators, significantly increases the curing rate of the rubber compound. Based on the relationship between curing reaction time and reaction temperature, it can be inferred that the above examples require approximately 2-4 days for complete curing at 25°C.

[0117] In rubber formulations, due to the addition of fillers, the density is usually greater than 1.1g / cm 3 . In Examples 2 and 3, the density of the rubber compound can be further reduced by adding hollow microspheres. At the same time, sustainable materials (such as natural rubber, vegetable wax, rice husk ash white carbon black, vegetable oil, lignin filler and antioxidant) are selected as much as possible in the examples, thereby avoiding the product's dependence on petroleum-based raw materials and being green and environmentally friendly. Among them, the sustainable material content of Examples 1, 4, and 5 is all above 90%. In Examples 2 and 3, the addition of hollow glass microspheres reduces the sustainable material content, and they can be added as needed.

[0118] Obviously, the above embodiments are merely examples for clarity of explanation and are not intended to limit the implementation methods. Those skilled in the art will appreciate that other variations or modifications can be made based on the above description. It is not necessary and impossible to enumerate all implementation methods here. Obvious variations or modifications arising therefrom remain within the scope of protection of the present invention.

Claims

1. An environmentally friendly rubber material that can be vulcanized at room temperature, characterized in that: It contains 100 parts of natural rubber or bio-based synthetic rubber, 20-50 parts of filler, 0-100 parts of microbeads, 2-5 parts of zinc oxide, 1-5 parts of stearic acid, 0-20 parts of vegetable oil, 0-1.5 parts of wax, 0-5 parts of antioxidant, 0.5-3 parts of sulfur and 0-5 parts of accelerator.

2. The environmentally friendly rubber material that can be vulcanized at room temperature according to claim 1, characterized in that: The bio-based rubber includes one or more of polyitaconate rubber, dandelion rubber, styrene-butadiene rubber, and butadiene rubber.

3. The environmentally friendly rubber material that can be vulcanized at room temperature according to claim 1, characterized in that: The filler is one or more of carbon black, white carbon black, lignin and calcium carbonate.

4. The environmentally friendly rubber material that can be vulcanized at room temperature according to claim 1, characterized in that: The microbeads are hollow microbeads.

5. The environmentally friendly rubber material that can be vulcanized at room temperature according to claim 1, characterized in that: The vegetable oil is selected from one or more of naphthenic oil, soybean oil, palm oil and rapeseed oil.

6. The environmentally friendly rubber material vulcanizable at room temperature according to claim 1, characterized in that: The wax is selected from one or more of paraffin wax, microcrystalline wax, rice bran wax and coconut wax.

7. The environmentally friendly rubber material vulcanizable at room temperature according to claim 1, characterized in that: The accelerator includes one or more thiazole, sulfenamide or dithiocarbamate accelerators.

8. The environmentally friendly rubber material vulcanizable at room temperature according to claim 1, characterized in that: The antioxidant is selected from one or more of RD, 6PPD and lignin antioxidant.

9. The environmentally friendly rubber material vulcanizable at room temperature according to claim 1, characterized in that: The vulcanization temperature of the environmentally friendly rubber material is 15-35° C., and the vulcanization time is 1-30 days; the bio-based components of the environmentally friendly rubber material account for 80wt% or more of the total components.

10. The method for preparing an environmentally friendly rubber material capable of vulcanization at room temperature according to any one of claims 1 to 9, characterized in that: The following steps are involved: S1. Weighing: Take all raw materials; S2. Mixing: Using an open mixer or internal mixer, mix the above raw materials uniformly at a temperature not exceeding 70° C. to obtain a rubber compound; S3, molding: placing the obtained rubber material into a mold and pressing it into shape to obtain an environmentally friendly rubber material.

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