WO2021159885A1 - Low-odor semi-steel carcass rubber composition - Google Patents

Abstract

Disclosed is a low-odor semi-steel carcass rubber composition. The raw material components thereof include, in parts by weight: 55-100 parts of natural rubber SCR 5, 1-45 parts of a copolymer material of styrene and butadiene, 20-80 parts of a reinforcement filler, 2-30 parts of an environmentally friendly aromatic hydrocarbon oil, 1-8 parts of sulfur, and 0.5-3.5 parts of an accelerator. Using the 5 natural rubber, which has fewer impurities and a lower odor, instead of a natural rubber and synthetic rubber mixture with a heavier odor, and further using a sulfenamide accelerator CBS, which has a lower odor, instead of the accelerator TBBS, make the rubber composition have a low odor.

Description

Low-odor semi-steel carcass rubber composition Technical field

The invention relates to a low-odor semi-steel carcass rubber composition.

Background technique

In order to meet the processing and use performance of the formula, some functional additives are often added during the mixing of the formula, such as a peptizer to improve the processing performance, and an adhesive to enhance the adhesion between the framework material, etc., resulting in The odor of the rubber formula becomes larger. Although some of these materials can volatilize during the high temperature vulcanization process, some of them will remain in the interior and surface of the tire, which will continue to emit unpleasant odors.

Because the spare tire of a car is generally placed in the trunk, the trunk is connected to the interior space of the car. With the air flow in the car, the odor emitted by the spare tire will be emitted in the car, which will affect the health of passengers. Now more and more automobile factories have put forward requirements on the odor of tire spare tires, and it is very important to study low-odor tires.

technical problem

Some add a certain deodorant to the rubber compound to reduce the odor of the rubber compound. For example, CN105860168A discloses an environmentally friendly low-odor nitrile rubber composition and a preparation method, which adds a certain deodorant SW120 to the nitrile rubber , And using aliphatic hydrocarbon ester BXA-R as plasticizer, the nitrile rubber product prepared not only has excellent physical and mechanical properties, but also has no pungent odor.

Some additives are added to the rubber compound to help eliminate the small molecule volatile substances in the rubber compound. For example, CN108276626A discloses a low-odor tire compound and its preparation method, which adds a certain amount of polyethylene glycol during the compound preparation process. , Produce moisture during high-temperature processing, which is conducive to the discharge of small molecule volatiles, thereby reducing the odor level of the rubber compound.

CN105860168A uses a deodorant that can reduce the odor of the rubber. This kind of auxiliary is not easy to disperse when the rubber is mixed, and is easy to agglomerate, which affects the performance of the rubber and the appearance of the finished tire.

In CN108276626A, polyethylene glycol is added to the rubber compound, which is easy to generate water vapor and entrain other small molecule volatiles to be discharged, thereby aggravating the VOC emission problem of the factory.

Technical solutions

In view of the above-mentioned shortcomings of the prior art, the present application provides a low-odor semi-steel carcass rubber composition. The rubber composition has low odor.

A low-odor semi-steel carcass rubber composition. The raw material components are calculated in parts by weight, including: 55-100 parts of natural rubber SCR5#, 1-45 parts of styrene and butadiene copolymer material, and 20-80 parts Reinforcing filler, 2-30 parts of environmentally friendly aromatic oil, 1-8 parts of sulfur, 0.5-3.5 parts of accelerator.

Furthermore, the styrene content in the styrene and butadiene copolymer material is within 0-40%, the Tg point is between -10°C and -85°C, and the Mooney viscosity ML1+4 (100°C) is within 39-49. Within.

Further, the accelerator is a sulfenamide accelerator CBS.

Beneficial effect

The invention uses 5# natural rubber with fewer impurities and lower odor instead of the heavier natural rubber and synthetic rubber mixture. 5# natural rubber has less impurities, fewer volatile small molecules, and low odor; it uses lower odor Sulfonamide accelerator CBS replaces accelerator TBBS. When accelerator CBS is vulcanized, it will produce cyclohexylamine. Its boiling point is about 134.5℃. It has low saturated vapor pressure in the air, is not easy to volatilize, and has a small smell. When accelerator TBBS is vulcanized, it will produce tert-butylamine. , Its boiling point is about 45℃, it is volatile, and its volatility and smell are higher than that of accelerator CBS. The invention reduces the amount of resorcinol-formaldehyde resin to reduce the content of unreacted resorcinol small molecules in the rubber compound, thereby reducing the smell of the rubber compound.

Embodiments of the present invention

The mixing of the rubber filling material can be accomplished by a method known to those skilled in the rubber mixing field. For example, under normal circumstances, mixing is carried out in at least two stages, namely at least one non-productive mixing stage and one productive mixing stage. Filler and rubber are mixed in one or more non-productive mixing stages.

Example: Prepare a rubber composition as specified in Table 1 in a BR Banbury internal mixer. The preparation process adopts two separate feeding and mixing stages, namely a non-productive mixing stage and a productive mixing stage. In the non-productive stage, mixing is carried out for about 2-3 minutes until the rubber temperature reaches 140°C, which is complete. The mixing time in the productive mixing stage is the time for the rubber temperature to reach 115°C.

This rubber composition is referred to as Comparative Example, Example 1 and Example 2 herein. The comparative example is used as a comparative sample here, that is, no optimized rubber material ratio is used in the rubber composition.

All samples were cured at about 151°C for about 30 minutes. Table 2 shows the odor test results of vulcanized samples.

Table 1 Rubber composition raw material composition table

Table 2 Performance test data

sample	Control example	Example 1	Example 2
Smell grade	5.5	4.5	4.0

Note: The odor level refers to the internal test method, the lower the result value, the better.

The odor test method is carried out as follows:

1. Store the vulcanized sample in an anhydrous jar with a volume of 1L, and then seal the jar.

2. Park the jars storing the samples at room temperature for 24 hours.

3. Five people evaluate the samples and take the median of the results.

See Table 3 for the specific odor evaluation grade table.

Table 3 Odor evaluation grade table

The results show that both Example 1 and Example 2 can effectively reduce the odor of the rubber compound. The reason is that materials with low content of small molecules are used in the tire rubber, and the temperature of the rubber is relatively high during the vulcanization process. Some small molecules are volatilized, and the content of small molecules remaining in the tire is reduced, which reduces the smell of the rubber. .

Industrial applicability

The present invention can be summarized in other specific forms that do not violate the spirit or main characteristics of the present invention. Therefore, no matter from which point of view, the above-mentioned embodiments of the present invention can only be regarded as descriptions of the present invention and cannot limit the present invention. The claims indicate the scope of the present invention, while the foregoing description does not indicate the scope of the present invention. Scope, therefore, any changes within the meaning and scope equivalent to the claims of the present invention should be considered to be included in the scope of the claims of the present invention.

Claims (3)

1. A low-odor semi-steel carcass rubber composition, characterized in that its raw material components, in parts by weight, include: 55-100 parts of natural rubber SCR5#, 1-45 parts of styrene and butadiene copolymer material, 20 to 80 parts of reinforcing filler, 2 to 30 parts of environmentally friendly aromatic oil, 1 to 8 parts of sulfur, 0.5 to 3.5 parts of accelerator.
2. The low-odor semi-steel carcass rubber composition according to claim 1, wherein the styrene content in the styrene and butadiene copolymer material is within 0-40%, and the Tg point is between -10°C and -85%. Between ℃, the Mooney viscosity ML1+4 (100℃) is within 39～49.
3. The low-odor semi-steel carcass rubber composition of claim 1, wherein the accelerator is a sulfenamide accelerator CBS.