Production process of high-flash-point plasticizer for rubber

Abstract

The invention discloses a production process of a high-flash-point plasticizer for rubber, and belongs to the technical field of rubber additives. According to the process, epoxidized vegetable oil and polyol are used as raw materials, the plasticizer is prepared through an esterification reaction, and the process specifically comprises the following steps that the epoxidized vegetable oil, the polyol and a catalyst are mixed and heated to 120-180 DEG C under the protection of nitrogen for the esterification reaction, after the reaction is completed, cooling and neutralizing are conducted, water washing and dewatering drying are conducted, and the high-flash-point plasticizer is obtained. The plasticizer prepared by the invention has the advantages of high flash point (245 DEG C or above), low volatility, good heat resistance, environmental protection, safety and the like, and can meet the use requirements of rubber products under high-temperature processing conditions. Meanwhile, the method is simple in process, wide in raw material source, low in cost and easy for industrial production, and has remarkable economic benefits and market competitiveness.

Description

Technical Field

[0001] The present invention relates to the technical field of rubber auxiliaries, and specifically to a production process of a high flash point plasticizer for rubber. Background Art

[0002] Plasticizers are indispensable auxiliaries in rubber processing. Their main function is to improve the processing performance of rubber and enhance the flexibility, cold resistance, etc. of rubber products. Traditional rubber plasticizers, such as phthalate esters (such as DOP, DBP), aliphatic dibasic acid esters (such as DOA, DOS), etc., although they can meet the requirements of rubber processing to a certain extent, generally have the problem of relatively low flash points. These plasticizers are prone to volatilization and decomposition during high-temperature processing, which not only causes loss of plasticizer, affects the performance of rubber products, but also produces pungent odors, pollutes the environment, and endangers human health.

[0003] In addition, with the increasingly strict environmental protection regulations and people's emphasis on health and safety, the environmental protection and safety of traditional plasticizers have also been questioned. For example, phthalate ester plasticizers are considered to have potential carcinogenicity and endocrine disrupting effects, and have been restricted or prohibited in certain fields in countries and regions such as the European Union. Therefore, developing a rubber plasticizer with high flash point, low volatility, environmental protection and safety has become an important research direction in the current field of rubber auxiliaries. Summary of the Invention

[0004] Aiming at the deficiencies of the prior art, the present invention provides a production process of a high flash point plasticizer for rubber, which solves the problems raised in the above background art.

[0005] To achieve the above objectives, the present invention is realized through the following technical solutions: A production process of a high flash point plasticizer for rubber includes the following steps:

[0006] S1. Mix epoxidized vegetable oil, polyol, and catalyst in proportion;

[0007] S2. Heat the mixture under nitrogen protection for esterification reaction;

[0008] S3. Cool the reaction product to 60 - 80 °C, add an acidic substance to neutralize to a pH value of 6 - 7, and then wash with water until neutral;

[0009] S4. Dehydrate and dry the water-washed product under vacuum conditions to obtain the high flash point plasticizer for rubber;

[0010] Furthermore, the epoxidized vegetable oil is one of epoxidized soybean oil, epoxidized linseed oil, and epoxidized castor oil.

[0011] Furthermore, the polyol is one of pentaerythritol, trimethylolpropane, and glycerol.

[0012] Further, the catalyst is a basic catalyst, preferably one of sodium hydroxide, potassium hydroxide, and sodium methoxide.

[0013] Further, the molar ratio of the epoxidized vegetable oil to the polyol is 1:1 - 1:2.

[0014] Further, the dosage of the catalyst is 0.1% - 1% of the total mass of the epoxidized vegetable oil and the polyol.

[0015] Further, the temperature of the esterification reaction is 140 - 160°C, and the reaction time is 3 - 5 hours.

[0016] Further, the acidic substance is one of hydrochloric acid, sulfuric acid, and phosphoric acid.

[0017] Further, the temperature of the dehydration and drying is 80 - 120°C, and the vacuum degree is -0.08 to -0.1 MPa.

[0018] The present invention provides a production process of a high flash point plasticizer for rubber. Compared with the prior art, it has the following beneficial effects:

[0019] 1. The flash point of the plasticizer prepared by the present invention is significantly higher than that of traditional plasticizers (such as DOP), with flash points all above 245°C, and the highest can reach 259°C. A high flash point means that the plasticizer is not easily volatilized and decomposed under high-temperature processing conditions, which can effectively reduce losses during the processing and improve the performance stability of rubber products;

[0020] 2. Due to the high flash point, the volatility of the plasticizer of the present invention is significantly reduced at high temperatures, reducing the release of harmful gases during the processing, improving the working environment, and reducing the health hazards to operators;

[0021] 3. The high flash point and low volatility enable the plasticizer of the present invention to have excellent thermal stability under high-temperature conditions, meeting the requirements of rubber products in high-temperature processing and use environments;

[0022] 4. The present invention uses epoxidized vegetable oil and polyol as raw materials, the raw materials are renewable, no toxic and harmful substances are generated during the production process, and the final product is non-toxic and harmless, meeting the development trend of green environmental protection;

[0023] 5. The plasticizer of the present invention has good compatibility with rubber, can effectively improve the processing performance of rubber, improve the flexibility, cold resistance, etc. of rubber products, and will not have a negative impact on the physical and mechanical properties of rubber;

[0024] In summary, the present invention provides a production process for a plasticizer for rubber with high flash point, low volatility, environmental protection and safety, which can effectively solve the problems of low flash point, easy volatilization and poor environmental protection of traditional plasticizers, and provides a high-performance and green plasticizer option for the production of rubber products. Detailed implementation manners

[0025] Next, the technical solutions of the present invention will be described in detail through specific embodiments. It should be clearly stated that these embodiments are for illustrative purposes only and are not construed as limiting the scope of the present invention.

[0026] Example 1

[0027] A production process for a high-flash-point plasticizer for rubber comprises the following steps:

[0028] S1. Mix 100 g of epoxidized soybean oil, 50 g of pentaerythritol, and 0.5 g of sodium hydroxide evenly;

[0029] S2. Under the protection of nitrogen, heat the mixture to 140 °C and carry out an esterification reaction for 3 hours;

[0030] S3. Cool the reaction product to 60 °C, add dilute hydrochloric acid to neutralize to a pH value of 6, and then wash with water until neutral;

[0031] S4. Dehydrate and dry the water-washed product under vacuum conditions. The temperature of dehydration and drying is 80 °C and the vacuum degree is -0.08 MPa to obtain the high-flash-point plasticizer for rubber.

[0032] Example 2

[0033] A production process for a high-flash-point plasticizer for rubber comprises the following steps:

[0034] S1. Mix 80 g of epoxidized linseed oil, 40 g of trimethylolpropane, and 0.8 g of sodium methoxide evenly;

[0035] S2. Under the protection of nitrogen, heat the mixture to 160 °C and react for 5 hours;

[0036] S3. Cool the reaction product to 80 °C, add dilute sulfuric acid to neutralize to a pH value of 6.8, and then wash with water until neutral;

[0037] S4. Dehydrate and dry the water-washed product under the conditions of 120 °C and -0.1 MPa to obtain the high-flash-point plasticizer for rubber.

[0038] Example 3

[0039] A production process for a high-flash-point plasticizer for rubber comprises the following steps:

[0040] S1. Mix 90 g of epoxidized castor oil, 45 g of glycerol, and 0.6 g of potassium hydroxide evenly.

[0041] S2. Under nitrogen protection, heat the mixture to 150 °C and react for 4 hours.

[0042] S3. Cool the reaction product to 65 °C, add dilute phosphoric acid to neutralize to a pH value of 6.7, and then wash with water until neutral.

[0043] S4. Dehydrate and dry the water-washed product at 90 °C and -0.085 MPa to obtain a high flash point plasticizer for rubber.

[0044] Example 4

[0045] A production process of a high flash point plasticizer for rubber includes the following steps:

[0046] S1. Mix 70 g of epoxidized soybean oil, 35 g of pentaerythritol, and 0.4 g of sodium methoxide evenly.

[0047] S2. Under nitrogen protection, heat the mixture to 155 °C and react for 3.5 hours.

[0048] S3. Cool the reaction product to 75 °C, add dilute hydrochloric acid to neutralize to a pH value of 6.6, and then wash with water until neutral.

[0049] S4. Dehydrate and dry the water-washed product at 110 °C and -0.095 MPa to obtain a high flash point plasticizer for rubber.

[0050] Experimental Part

[0051] I. Experimental Materials

[0052] 1. Plasticizer samples prepared in Examples 1 - 4;

[0053] 2. Commercially available ordinary plasticizer (dioctyl phthalate, DOP) as a control sample;

[0054] 3. Flash point tester (meeting ASTM D93 standard).

[0055] II. Experimental Methods

[0056] 1. According to ASTM D93 standard, use the Cleveland open cup method (COC) to measure the flash point of each plasticizer sample;

[0057] 2. Each sample is tested 3 times repeatedly, and the average value is taken as the final result.

[0058] III. Experimental Results

[0059] Sample Flash point (℃) Average value (℃) Example 1 245,247,246 246 Example 2 260,258,259 259 Example 3 250,252,251 251 Example 4 255,254,256 255 Commercially available DOP 195,196,194 195

[0060] IV. Experimental Analysis

[0061] 1. It can be seen from the experimental results that the flash points of the plasticizers prepared in Examples 1-4 are all significantly higher than that of the commercially available DOP. Among them, the flash point of Example 2 is the highest, reaching 259 °C;

[0062] 2. The flash points of Examples 1-4 are all above 245 °C, much higher than the flash points of traditional plasticizers (usually below 200 °C), which fully proves that the plasticizers prepared by the present invention have the characteristic of high flash point;

[0063] 3. The higher the flash point, the better the thermal stability of the plasticizer at high temperature, the lower the volatility, and the more suitable it is for rubber products under high-temperature processing conditions.

[0064] V. Conclusion

[0065] In this experiment, the flash points of the plasticizers prepared in Examples 1-4 were measured by the Cleveland open cup method. The results show that the plasticizers prepared by the present invention have the remarkable characteristic of high flash point, can meet the use requirements of rubber products under high-temperature processing conditions, and effectively solve the problems of low flash point and easy volatilization of traditional plasticizers.

Claims

1. A production process of a high flash point plasticizer for rubber, characterized in that, It includes the following steps: S1. Mix epoxidized vegetable oil, polyol, and catalyst in proportion; S2. Heat the mixture under nitrogen protection for esterification reaction; S3. Cool the reaction product to 60 - 80 °C, add an acidic substance to neutralize it to a pH value of 6 - 7, and then wash it with water until neutral; S4. Dehydrate and dry the water-washed product under vacuum conditions to obtain the high flash point plasticizer for rubber.

2. The production process of a high flash point plasticizer for rubber according to claim 1, characterized in that, The epoxidized vegetable oil is one of epoxidized soybean oil, epoxidized linseed oil, and epoxidized castor oil.

3. The production process of a high flash point plasticizer for rubber according to claim 1, characterized in that, The polyol is one of pentaerythritol, trimethylolpropane, and glycerol.

4. The production process of a high flash point plasticizer for rubber according to claim 1, characterized in that, The catalyst is a basic catalyst, preferably one of sodium hydroxide, potassium hydroxide, and sodium methoxide.

5. The production process of a high flash point plasticizer for rubber according to claim 1, characterized in that, The molar ratio of the epoxidized vegetable oil to the polyol is 1:1 - 1:

2.

6. The production process of a high flash point plasticizer for rubber according to claim 1, characterized in that, The dosage of the catalyst is 0.1% - 1% of the total mass of the epoxidized vegetable oil and the polyol.

7. The production process of a high flash point plasticizer for rubber according to claim 1, characterized in that, The temperature of the esterification reaction is 140 - 160 °C, and the reaction time is 3 - 5 hours.

8. The production process of a high flash point plasticizer for rubber according to claim 1, characterized in that, The acidic substance is one of hydrochloric acid, sulfuric acid, and phosphoric acid.

9. The production process of a high flash point plasticizer for rubber according to claim 1, characterized in that, The temperature of the dehydration and drying is 80 - 120 °C, and the vacuum degree is -0.08 to -0.1 MPa.