News
Based on the principle of "Credit First, Excellent Quality, and Perfect Service", the company wholeheartedly serves customers and the rubber industry

What is a rubber accelerator? What does it do?

  • Author:
  • Origin:
  • Time of issue:2018-10-22 16:39
  • Pageviews:

(Summary description)At present, the development of accelerators in the world gradually tends to be environmentally friendly, functional and centralized. From a technical point of view. In recent years, international attention has been paid to the toxicity of certain accelerators that are prone to produce harmful nitrosamines in the rubber processing process. In view of this, many restrictive regulations around the world have been promulgated.

What is a rubber accelerator? What does it do?

(Summary description)At present, the development of accelerators in the world gradually tends to be environmentally friendly, functional and centralized. From a technical point of view. In recent years, international attention has been paid to the toxicity of certain accelerators that are prone to produce harmful nitrosamines in the rubber processing process. In view of this, many restrictive regulations around the world have been promulgated.

  • Categories:Technical Support
  • Author:
  • Origin:
  • Time of issue:2018-10-22 16:39
  • Views:0
Information

At present, the development of accelerators in the world gradually tends to be environmentally friendly, functional and centralized. From a technical point of view. In recent years, international attention has been paid to the toxicity of certain accelerators that are prone to produce harmful nitrosamines in the rubber processing process. In view of this, many restrictive regulations around the world have been promulgated. Germany as early as 1982 Regarding the promulgation of regulations to control the content of nitrosamines, the United States, Japan, France, and the United Kingdom are also actively developing new vulcanization accelerators that do not produce nitrosamines, and continue to stop using accelerators that can produce nitrosamines. Therefore, an environmentally friendly vulcanization accelerator has been formed. System, and develop and produce some environmentally friendly new varieties to replace products with tumorigenic hazards. From the marketing perspective, pay more attention to the application performance research of products, and develop functionalized cavity accelerator masterbatch and pre-dispersion. Increasing the compounding research and development efforts has become one of the main means for the major foreign accelerator manufacturers to occupy and expand the market. After many years of use, the global rubber additives have been used for many years. The production and application of rubber propellants are becoming more and more in the capsule, mainly focusing on some non-polluting, good-performance varieties. The accelerators are mainly TBBS, CBS and TMTD.

 

2. Domestic production and market

my country's rubber accelerator industry has developed rapidly between the "Eight Five-Year Plan" and the "Ninth Five-Year Plan". At present, it can not only meet the needs of the domestic market, but also has a certain amount of output. Zhenjiang Thorpe Group, Northeast Front Agent General Factory, Tianjin Organic Chemical Factory and other major production bases have been formed, and the domestic accelerant development in the 21st century has become more rapid . In recent years, there has been an upsurge in the construction of accelerators nationwide, and the production capacity has grown rapidly. According to incomplete statistics. In 2003, the total production of rubber cavity accelerators in my country was about 120,000 tons/year, and the output in 2003 was about 8350,000 tons/year. Table 4 shows the main manufacturers and varieties of rubber accelerators in my country: X5 is the output of the main rubber accelerator products in my country in recent years: due to the rapid development of the country’s rubber industry, coupled with the simplicity of the production process of the accelerator, except for the above introduction Outside the production enterprise. In recent years, many domestic companies have invested in the construction of accelerator production equipment or production accelerator compound products, such as Shandong Yanggu Huatai Chemical Co., Ltd. Shandong Sanyi Fine Chemical Co., Ltd. Qingdao Huaheng Auxiliary Factory, Shandong Huayang Shinco Chemical Co., Ltd. Jiangsu Yixing Kaou Chemical Co., Ltd., Shanghai Jinghai Chemical Co., Ltd. Shanghai Changjiang Chemical Plant, Shanghai Fengxian Joint Workers and Liu Plant. The total domestic output of accelerators such as Tianjin Labola Factory in 2003 was about 83,500 tons. The output of six major types of accelerators, M, DM, CBS, TBBS, NOBS, and TMTD, accounted for 88% of the total output. Production has increased. Little adjustment in product structure. However, the most obvious is that the production of secondary amine sulfenamide NOBS, which can produce nitros gum carcinogens, has been restricted, showing a slight downward trend, while the output of TBBS, a leading foreign primary amine sulfenamide accelerator, has increased year by year. In 2003, The output is 3800 tons, accounting for 15% of the sulfenamide accelerator, etc.

 

In the rubber processing process, certain quality problems often occur, which hinder the smooth progress of production operations. Due to the high labor costs now, the loss during the shutdown period is quite large. If most of the problems of the same type are taken correspondingly The measures can solve these

 

Problem. The following describes the solution based on the author’s experience.

Role:

1 Sulfur is unevenly dispersed, and there are pitting (agglutinates) phenomenon

This is an old and new problem. The problem that our predecessors should have solved is now revisited.

Putting the incoming sulfur on a cement board is not a good way from the point of view of moisture prevention. Be sure to put it on a mat or mat, and sieving it before measuring is an effective way to prevent agglomeration. At this time, There is no need to use a too fine sieve, just use 40 mesh or 20 mesh, as long as it can break the agglomerates in the powdered sulfur. In addition, when the amount of sulfur added at a time is small, on the open mill It is better to add while sieving. In this case, even if the mesh is thicker, it is ok.

 

When using the traditional method, first put the sulfur in the plate aside, then put in an equal volume of light calcium carbonate or white powder, stir it evenly and add it on the open mill, although this is a simple But there is no better way than this. Here is a brief introduction about what is white and powder. Put the bat shells and shells on the outdoor cement board, let the wind blow, the sun and the rain, and place it for 2-3 Years later, the organic matter inside is decomposed and removed, and it becomes a white substance with only calcium content. After crushing it, it becomes a white powder. In addition to rubber, the powder can also be used for other purposes.

 

In the rubber mixed with a large amount of hard clay, I don’t know what caused the uneven dispersion of sulfur. Although people have come up with many methods, it has not worked. We will match the mother of hard clay with the same mass as sulfur The rubber compound is mixed with a kneader, and then mixed with the company's self-made 40L kneader (rotating speed is about 30 rpm/min) for about 1 hour. Using such a masterbatch, no sulfur particles are found. It can be said that this It is an example of fluke success.

 

The self-made sulfur masterbatch is for the company's own use. However, once all the rubber in the company uses masterbatch, its amount will be too large, and there are many varieties. It requires a mixer for processing masterbatch. It takes time and effort to do it. Therefore, except for the rubber compounds that have not yet encountered problems and the rubber compounds that allow a small amount of sulfur particles, sulfur masterbatch is only used for the rubber materials that are really needed. We use 100 parts by mass of rubber, 50 parts by mass of sulfur masterbatch, therefore, the masterbatch contains one-third of sulfur, which is equivalent to three times the amount of sulfur added.

 

The rubber used to prepare the masterbatch is initially made of NR, but in winter, the rubber becomes hard and difficult to cut into small pieces. According to experience, we use 50 parts of NR and 50 parts of BR for blending to make this problem possible. Solved.

 

Sulfur masterbatch is now available on the market, which is very convenient to use. Although the cost is slightly increased, it can be decided whether to use it according to its cost performance.

 

In addition, there is also a resinous sulfur called polysulfide (manufactured by Toyo Chemical Co., Ltd.). This sulfur is a yellow brittle block that is melted on an open mill and then dispersed in rubber. It is often used in rubber balls and other rubbers. Products.

 

When the rubber compound mixed with the internal mixer is discharged onto the tablet press, its temperature can reach above 140°C. If sulfur is added to the rubber compound at a high temperature, a part of the sulfur will melt in the rubber and become a liquid state. There is no problem in dispersing sulfur in the rubber in a liquid state, but once the rubber material is cooled on the tablet press to reduce the temperature of the rubber, the molten sulfur will become lumps and enter the rubber in the form of agglomerates to form a match. Head-sized sulfur particles. In this way, the sulfur particles will not be further dispersed, but exist in the rubber in small pieces, and will not change even if the rubber is re-mixed. Therefore, wait until the rubber temperature drops to 70 It is better to add sulfur when the temperature is below ℃.

 

Sulfur powder sold on the market is divided into 200 mesh and 300 mesh. The particles of 300 mesh are fine, and people often think that it has good dispersibility and prefer to use it. But whether it is really so has to be proved by experiments.

 

In the test, we masticated 100 parts by mass of NR, (as far as possible using plastified rubber or SM RSL), and added 3 parts by mass of sulfur to the masticated rubber. Then put the rubber material on the open mixer for the test. Adjust the roller pitch to the minimum state. Cut the film wrapped on the front roller, the film shrinks, and no good-looking film can be obtained. For this reason, you can stop the rubber mixer and place it on the film wrapped on the front roller. Paste a sheet of cellophane about 10 cm square, and then cut the film to prevent the film from shrinking and make a test piece for microscope. If you use a microscope with a magnification of about 400 times, you can observe the sulfur particles. According to the 300 mesh sulfur The role of cost performance is self-evident. The author of this article believes that the use of 200 mesh sulfur can meet the requirements for most of the uses of rubber products.

 

More than 30 years ago, the raw material of sulfur powder for rubber was sulfur collected from sulfur mines, collectively referred to as mineral sulfur; almost all of the sulfur used now is recovered sulfur obtained from petroleum refining. The crystal particles of mineral sulfur are large and soft, and easy to crush. ;Recovered sulfur is difficult to crush due to the small and hard crystal particles. Since the sulfur powder from the recovered sulfur is easy to agglomerate, a small amount of anti-sticking agent should be added. In addition, there is also a package for tire factories that adds 3% of operating oil. Sulfur.

 

As we all know, sulfur is poorly dispersed in NBR, and it is not very noticeable when manufacturing black products, but dark brown spots appear when manufacturing light-colored rubber products, which is very ugly. Maybe this is an old problem, but now it can be Buy sulfur masterbatch in the market. If you have requirements that cannot be resolved during negotiation, you can try the following methods.

 

Put the NBR into the open mill, add sulfur for mixing, the temperature of the roller rises, and the sulfur is dissolved in the rubber. Then the rubber is discharged and cooled, and the next day is re-mixed with the open mill and added according to the conventional method. Various compounding agents, and finally add a vulcanization accelerator for uniform mixing. If this method is used, spots can be eliminated.

Scan the QR code to read on your phone

Dongguan Foster Rubber & Plastic Technology Co., Ltd.

This is the descriptive information

Fax:0769-88119080

Address: Guozhou Industrial Park, Zhongtang Town, Dongguan, Guangdong, China

QR code

Scan code to learn more

img img img

Copyright © 2021 Dongguan Foster Rubber & Plastic Technology Co., Ltd. All rights reserved    粤ICP备10022050号   Website building:300.cn Dongguan