Introduction of rubber antiaging agent and its types and functions

What is rubber anti-aging agent?

Rubber and its products in the long-term storage and use of the process, because of heat, oxygen, ozone, variable metal ions, mechanical stress, light, high-energy rays, as well as other chemical substances and mold erosion, will gradually become sticky, hard brittle or cracked. This decrease in physical and mechanical properties and elasticity over time is called aging. With the aging process and development, the performance of rubber and its products will gradually reduce to completely lose the use value. To this end, it is necessary to add some chemical substances in rubber and its products to improve its resistance to all kinds of damage, delay or inhibit the aging process, so as to extend the storage period and service life of rubber and its products, this kind of substance is called antiaging agent.

Antiaging agent classification by chemical structure, can be divided into the following 5 categories

1. Amine antiaging agent (subdivided into 6 categories: aldehyde amine antiaging agent, ketone amine antiaging agent, two aryl secondary amine, phenylenediamine, diphenylaniline, alkyl aryl secondary amine)

2. Phenolic antiaging agents (divided into monophenol, bisphenol, polyphenol)

3. Heterocyclic anti-aging agent

4. Phosphite ester anti-aging agent

5. Other types of antiaging agent (long-acting antiaging agent, nickel salt, wax, thiourea, newly developed antiaging agent)

Antiaging agent effect and representative products

1. Amine anti-aging agent

The most prominent protective effect, the most varieties. Main protective effects: thermal oxygen aging, ozone aging, catalytic oxidation of hot heavy metals and ultraviolet light and fatigue aging have significant protective effects. The protective effect of this kind of antiaging agent is incomparable to phenolic antiaging agent, far better than phenolic antiaging agent. Disadvantages: pollution, not suitable for white or light colored rubber products. The molecular structure of the stabilizer contains amino (NH2, - NH - and - N <), some varieties can directly generate carcinogenic substance, nitrosamines, some species can cause carcinogens produced, some varieties can also cause serious color rubber products, rubber some varieties are easy to form a bloom phenomenon, at the same time have a polluting,Irritating to human body (skin) to varying degrees. So this kind of product can only be used in dark or black rubber products. The main products are: antiaging agent D (D), antiaging agent A (A), antiaging agent DNP, antiaging agent 4010NA/IPPD, antiaging agent 4020/6PPD, antiaging agent TMQ/RD, antiaging agent BLE.

1.1 Aldehydes and amines for aging. It is the reaction product of aliphatic aldehyde and primary aromatic amine. It is the oldest category of antiaging agent. Aldehyde amine antiaging agent is effective for aging caused by heat, oxygen and light. There are anti-aging agents AH and AP.

1.2 Ketone amine antiaging agent. It has the best effect of anti-aging agent. There are: anti-aging RD, anti-aging AW, anti-aging BLE.

1.3 Diaryl secondary amine antiaging agent. This is one of the ancient varieties, A few days ago in all the antiaging agents still ranked the first, antiaging agent D (D), antiaging agent A (A), antiaging agent DNP.

1.4 P-phenylenediamine antiaging agent. Including the most important kind of antiaging agent, but also a promising kind of antiaging agent. There are 4010NA/IPPD, 4020/6ppD, 4010/CPPD, ODA, DPPD, 7PPD, 8PPD, 3100/DTPD, 445.

1.5 diphenylamine antiaging agent. Fewer varieties, less outstanding performance, less application. Diphenylamine itself is a good anti-aging agent, but it is very easy to volatilize, usually using its derivatives as anti-aging agent, the main varieties are 4, 4-dimethoxy diphenylamine, with outstanding performance of fatigue aging.

1.6 alkyl aryl secondary amine antiaging agent. This kind of antiaging agent is less polluting and can be used for light-colored products, but the protection effect is poor. The main varieties are anti-aging agent DPD, anti-aging agent CMA.

2. Phenolic antiaging agents

Phenolic antioxidant protection and other stabilizer are not as good as amine stabilizer, only has the outstanding performance of the pollution, not change color, no pollution, no spray frost, but the rubber protective protective effect in general, the price is expensive, little consumption, in Western Europe, phenolic antioxidant account for only 8.1% antiager, while China accounted for only 6%. Phenolic antiaging agent molecular structure contains phenolic base, will not produce harmful substances to human body, belongs to non-toxic additives, can be used in the food industry and contact with rubber products (animals), but this kind of antiaging agent has peculiar smell, poor storage safety, easy to deteriorate in light conditions. Representative products are antiaging agent 2246, antiaging agent BHT (264), antiaging agent SP, BHA.

3. Heterocyclic anti-aging agent (sulfur type)

It has good non-discoloration and good thermal oxidation resistance. It is best to be used with other anti-aging agents. But there is a bitter taste, slightly pollution, large amount of easy to produce spray frost, at the same time to vulcanization (in addition to chloroprene rubber) has delayed effect, belong to non-environmental protection products, in the rubber industry, less consumption. There are anti-aging agent MB, anti-aging agent MMB, anti-aging agent MBZ, anti-aging agent MMBZ.

4. Phosphite ester anti-aging agent

It has good stability and thermal oxidation resistance, as well as certain plasticity, but it has certain toxicity, odor and estrogen-like sex, and is also easy to spray frost, which is greatly limited in the rubber industry. There is the anti-aging agent TNP. Phosphite hydroperoxide decomposers and free radical catchers, which play an auxiliary antioxidant role in polymer systems. They are mostly used with hindered phenols, but rarely used alone.

5. Other kinds of anti-aging agents

5.1 Long-acting anti-aging agent. When rubber products are used in high temperature and vacuum environment, the antiaging agent in rubber will reduce or lose its protective effect because of volatilization. And if rubber products are used in contact with liquid medium for a long time, they will reduce or lose protective efficacy because of rapid extraction. For this development of non-volatile or low volatile, non-extraction or low extraction type of antiaging agent, according to the current open products are nitroso diphenylamine (NDPA), allyl substituted phenol (TAP) and so on.

5.2 Nickel salt antiaging agent. There are anti-aging agent NDBC, anti-aging agent NDIBC, anti-aging agent NDMC. All green powder. With good ozone resistance and thermal oxidation resistance, expensive (due to nickel on the earth less storage, but a wide range of uses), but also a certain toxicity, deep color, easy to spray frost, not suitable for light color rubber products, in the rubber industry consumption is very few.

5.3 Wax anti-aging agents. When the amount of the rubber in excess of the solubility in rubber, vulcanization is transferred to the surface, forming a layer of protective film, can effectively prevent static ozone cracking products, paraffin wax, microcrystalline wax.

5.4 Thiourea antiaging agents. Thiourea organic thiourea derivatives were first used as vulcanizing promoters of oxygen-containing rubber in the rubber industry. With the application research, it is found that some of them have good anti-ozone aging properties on other rubber besides chlorine rubber. Thiourea antiaging agents have good ozone aging resistance and thermal oxidation resistance under dynamic and static conditions, and can significantly improve the service life of rubber products. This kind of product is non-toxic, tasteless, non-pollution, non-frosting, can be used in white or black products, belongs to the environmental harmless green variety, especially suitable for light colored products and food, medicine, health rubber products, rubber industry has a huge market potential. Representative products are DBTU, DETU, butyl urea derivatives.

5.5 Newly developed anti-aging agent. Lactam derivatives, non-flexion (anti-flexion)LAS(LAS-P), sulfurized triazine derivatives, 6-QDI, Durazone37 and other types