CN115926328A

CN115926328A - EPDM rubber compound for rubber tube of automobile turbocharging system and preparation method thereof

Info

Publication number: CN115926328A
Application number: CN202211542699.5A
Authority: CN
Inventors: 孙琦岳; 张松峰; 王泽庆; 朱熠; 黄忆南; 滕腾; 吴世明; 麻文涛
Original assignee: FAW Group Corp
Current assignee: FAW Group Corp
Priority date: 2022-12-02
Filing date: 2022-12-02
Publication date: 2023-04-07
Anticipated expiration: 2042-12-02
Also published as: CN115926328B

Abstract

The specification discloses an EPDM rubber compound for an automobile turbocharging system rubber tube and a preparation method thereof; the rubber compound in the invention comprises EPDM rubber, NBR rubber, CM rubber, carbon black, pottery clay, BIPB, PL400, DM, S-80, paraffin oil, DOS, polyethylene glycol, zinc oxide, magnesium oxide, stearic acid, anti-aging agent (MB, TMDQ, NBC and DNP) and other auxiliary agents. The rubber compound disclosed by the invention adopts general oil-resistant rubber such as nitrile rubber and the like to be used together with EPDM rubber, and realizes good fusion and improvement of comprehensive performance of an EPDM combined system through measures such as pre-vulcanization, third rubber combination and the like, so that the EPDM combined system has certain oil resistance, can meet the use environment of a small amount of oil gas corrosion on the premise of not increasing the cost, and can realize large-scale production; the invention mainly solves the problem of oil resistance of EPDM rubber, and can meet the use requirement of the air outlet rubber tube of the intercooler.

Description

EPDM rubber compound for rubber tube of automobile turbocharging system and preparation method thereof

Technical Field

One or more embodiments of the specification relate to the field of automobiles, and particularly relate to an EPDM rubber compound for an automobile turbocharging system rubber tube and a preparation method thereof.

Background

With the stricter laws and regulations of energy conservation and emission reduction, the turbocharged engine is applied more and more. The hose for the automobile turbocharging system has very harsh use conditions, conveys high-temperature and high-pressure gas and plays a role in damping in the whole pipeline system. The use temperature of a pipeline (a turbocharger air outlet pipe) at the high temperature section of the turbocharging system is 150-220 ℃; the use temperature of the low-temperature section pipeline (an intercooler air outlet pipe) is 60-120 ℃. Different engine turbocharging systems have different design structures and different supercharging multiplying powers, and the temperature and the pressure in pipelines of the turbocharging systems are different. The service temperature of a pipeline at the high-temperature section of a turbocharging system of a common passenger car is 140-160 ℃; the service temperature of a high-temperature section pipeline of a turbocharging system of a light commercial vehicle (a light truck and a medium and small passenger car) is 150-170 ℃; the service temperature of a high-temperature section pipeline of a turbocharging system of a heavy commercial vehicle (a medium-heavy truck and a motor coach) is 160-210 ℃. Therefore, except that the high-temperature section pipeline of the turbocharging system of the heavy commercial vehicle must adopt a silicon rubber pipe, other high-temperature section hoses with the peak temperature below 170 ℃ can all adopt materials such as AEM, HT-ACM, EPDM and the like, and the low-temperature section hoses can adopt materials such as CR, EPDM, TPEE and the like.

At present, a hose for a turbocharging system generally adopts a silicon rubber composite pipe or an AEM rubber pipe, so that the cost is very high, the AEM resource is in short supply, and the neck nipping is serious. The EPDM rubber has good high and low temperature resistance and low price, but high-temperature oil gas discharged by an engine can also enter a pipeline system, the oil gas is basically filtered after passing through an oil-gas separator, but a few oil-gas mixed gas enters the pipeline, the oil gas can be deposited in the pipeline, oil is formed after a long time and is attached to the inner wall of a pipe to corrode the rubber, and therefore, the rubber pipe generally used for a turbocharging system adopts oil-resistant rubber (AEM rubber and the like), or a layer of fluororubber or fluorosilicone rubber is attached to the inner wall of the silicon rubber to improve the oil resistance of the rubber pipe. However, the silicone rubber and fluororubber composite hose is expensive and is generally used for pipelines at high temperature of 180 ℃ or above. Chloroprene rubber and acrylate rubber have poor low temperature resistance, cannot meet the requirements of northern application, and have high cost. The EPDM rubber has good high and low temperature resistance and relatively low price, and is the best choice for manufacturing the gas transmission rubber tube. The EPDM rubber has good temperature resistance and can be used at the temperature of-40-170 ℃; the EPDM rubber has good filling performance, good processing performance and moderate price of the original rubber, and the price of the finished rubber tube is only about half of that of a chloroprene rubber tube, about one third of that of an acrylate rubber tube and about one tenth of that of a silicon rubber tube. However, the oil resistance of the EPDM rubber is very poor, and although only a small amount of oil gas exists in the rubber tube of the turbocharging system, the rubber tube is gradually corroded to swell, and the rubber tube is in a risk of leakage or bursting after long-term use, namely the rubber tube is leaked or burst, so that the EPDM rubber tube is rarely used as an air outlet tube of the intercooler.

Disclosure of Invention

In view of the above, it is an object of one or more embodiments of the present disclosure to provide an EPDM compound for use in a rubber hose of a turbocharger system of an automobile. The rubber compound adopts general oil-resistant rubber such as nitrile rubber and the like to be used together with EPDM rubber, and realizes good fusion and improvement of comprehensive performance of an EPDM combined system through measures such as pre-vulcanization, third rubber combination and the like, so that the EPDM combined system has certain oil resistance, can meet the use environment of a small amount of oil gas corrosion on the premise of not increasing the cost, can realize large-scale production, and is an economic and feasible technical scheme; the invention mainly solves the problem of oil resistance of the EPDM rubber, and the EPDM rubber has certain oil resistance by using rubber and a special process method, so that the use requirement of the air outlet rubber pipe of the intercooler can be met.

The second purpose of the specification is to provide a preparation method of the EPDM mixed rubber for the rubber hose of the automobile turbocharging system.

Based on the first item, the present specification provides the following technical solutions:

the rubber compound for the EPDM rubber tube for the automobile turbocharging system comprises the following raw materials in parts by weight:

in one embodiment, the EPDM rubber is a high molecular weight and high ethylene content rubber, the third monomer is ENB, and the third monomer is a rubber with a high ENB content.

As a preferred embodiment, the EPDM rubber is selected from any one or more of NORDELIP4760P, 4770P available from Dow chemical (DOW), vistalon5601 available from Exxon Mobil, S512F, S5890F available from SK, and KEP-570F available from Jinhu petrochemical industry.

In one embodiment, the NBR rubber is a rubber having a moderate or slightly high acrylonitrile content, and the acrylonitrile content in the NBR rubber is 25 to 36%.

As a preferred embodiment, the NBR rubber is selected from one or more of Perbunan2830, 2845, 2865, 3445, 3465 manufactured by Bayer, europrene2860, 3335, 3360 manufactured by Italy Eini.

As an embodiment, the CM rubber virgin rubber is of a grade with 32-37% of chlorine content; preferably, the CM rubberis is a CM135B extrusion grade product of Weifang Arisaema chemistry.

As an embodiment, the carbon black is selected from fast extrusion furnace black or the fast extrusion furnace black and high-abrasion-resistance carbon black are used together; preferably, the carbon black is N550 or a mixture of N550 and N330.

As an embodiment, the kaolin is a calcined kaolin; preferably, the calcined kaolin has a particle size of 1.0 μm to 1.5 μm and a pH of 4.5 to 6.5.

As an embodiment, the antioxidant consists of antioxidant MB, antioxidant TMDQ, antioxidant NBC and antioxidant DNP.

In one embodiment, the paraffin oil is any one of Nypar330 from Nintes, plain 25110 from Dadale oil, and SUNPAR2280 from Sun.

As an embodiment, the other auxiliary agents include any one or more of scorch retarder N-cyclohexyl thiophthalimide, plasticizer dibutyl phthalate (DBP for short), coupling agent, adhesive resin, calcium hydroxide, microcrystalline wax.

Based on the second project, the present specification provides the following technical solutions:

a preparation method of EPDM rubber compound for a rubber tube of an automobile turbocharging system comprises the following steps:

1) Pre-mixing EPDM rubber:

adding a peroxide vulcanizing agent, a vulcanization accelerator, zinc oxide and stearic acid into EPDM rubber raw rubber, adding the peroxide vulcanizing agent, the vulcanization accelerator, the zinc oxide and the stearic acid according to a proportion of 55-65% of the total parts, and mixing to prepare premixed rubber; placing the premixed glue at 95-105 ℃ for 3-4 h;

2) Mixing: the EPDM premix gum is mixed with the rest of the raw materials.

Compared with the prior art, the invention has the following beneficial effects:

the EPDM rubber compound for the rubber tube of the automobile turbocharging system prepared by the invention has good comprehensive performance and can be used at the temperature of-40-160 ℃; the oil-resistant oil-gas composite material has the advantages of ozone resistance of 200pphm/72h, no cracking, good mechanical property, and good oil and gas resistance; shore A hardness is 60-70, tensile strength is more than 14MPa, and elongation at break is more than 250%; after heat resistance (160 ℃/24 h), the reduction rate of the tensile strength and the elongation at break is less than 40 percent; the compression set (150 ℃/24h, 25% compression) is less than 40%; after the rubber tube is resistant to the No. 1 standard oil, the volume change rate is less than or equal to 50% at normal temperature and less than or equal to 80% at high temperature (150 ℃/24 h), and the rubber tube meets the use requirements of high reliability, long service life and the like of the rubber tube of the automobile turbocharging system.

Detailed Description

To make the objects, technical solutions and advantages of the present disclosure more apparent, the present disclosure is further described in detail below with reference to specific embodiments.

It is to be noted that unless otherwise defined, technical or scientific terms used in one or more embodiments of the present specification should have the ordinary meaning as understood by those of ordinary skill in the art to which this disclosure belongs. The use of "first," "second," and similar terms in one or more embodiments of the specification is not intended to indicate any order, quantity, or importance, but rather is used to distinguish one element from another. The word "comprising" or "comprises", and the like, means that the element or item listed before the word covers the element or item listed after the word and its equivalents, but does not exclude other elements or items.

As one aspect of the invention, the rubber compound for the EPDM rubber tube for the automobile turbocharging system comprises the following raw materials in parts by weight:

virgin rubber

The rubber composition comprises three rubbers of EPDM rubber (ethylene propylene diene monomer), NBR rubber (nitrile rubber) and CM rubber (chlorinated polyethylene rubber). Wherein, the EPDM rubber virgin rubber has excellent heat resistance, weather resistance, high and low temperature resistance and mechanical property, and the oil resistance is poor; the NBR rubber raw rubber has excellent oil resistance; the CM rubber crude rubber has good oil resistance, weather resistance and flame retardance; the addition of the NBR rubber can improve the oil resistance of the EPDM rubber, the two performances are strong in complementarity, but the compatibility is poor, phase separation can be generated, and the mechanical performance of the rubber compound can be reduced; the CM rubber is prepared by polyethylene chlorination, has the same main chain structure as polyethylene, has good compatibility with EPDM rubber, and has good compatibility with NBR rubber, so that the CM rubber is selected as a bridge for blending the EPDM rubber and the NBR rubber, so that the rubber compound has good dispersibility, compact structure and improved comprehensive performance. All the three kinds of rubber can be vulcanized by peroxide, a vulcanization system can be shared, the co-vulcanization effect is good, and the rubber obtained by vulcanizing by the peroxide has better performance than sulfur vulcanization, and particularly has good high temperature resistance and lower compression permanent deformation performance.

In some embodiments of the present invention, the EPDM rubber is a high molecular weight, high ethylene content variety, the third monomer is ENB, and the variety with a higher ENB content is selected.

In some embodiments of the invention, the EPDM rubber may be any one or more of NORDELIP4760P, 4770P available from Dow chemical (DOW), vistalon5601 available from Exxon Mobil, S512F, S5890F available from SK, and KEP-570F available from Jinhu petrochemical.

In some embodiments of the present invention, the NBR rubber is selected from the NBR rubber having a medium or slightly high acrylonitrile content, and the acrylonitrile content in the NBR rubber is 25 to 36%.

In certain embodiments of the invention, the NBR rubber is selected from one or more of Perbunan2830, 2845, 2865, 3445, 3465 manufactured by Bayer, europrene2860, 3335, 3360 manufactured by Eini, italy.

In some embodiments of the invention, the CM rubber virgin rubber is selected from a grade having a chlorine content of 32-37%; preferably, the CM rubberis is a CM135B extrusion grade product of Weifang Arisaema chemistry.

In certain embodiments of the present invention, the EPDM rubber virgin rubber may be added in parts by weight of 40 parts, 45 parts, 50 parts.

In some embodiments of the invention, the NBR rubber raw rubber may be added in 20 parts, 25 parts, 30 parts by weight.

In certain embodiments of the present invention, the CM rubber base may be added in 20 parts, 25 parts, 30 parts by weight.

Reinforcement system

The EPDM rubber is not self-reinforcing rubber, the crude rubber strength is low, and a reinforcing agent needs to be added in the formula.

In some embodiments of the invention, the carbon black is selected from fast-extrusion furnace black or is selected from the fast-extrusion furnace black and high wear-resistant carbon black; preferably, the carbon black is N550 or a mixture of N550 and N330.

In the present invention, carbon black is used as a reinforcing agent, and the most excellent reinforcing effect is obtained, and particularly, furnace carbon black is more excellent in reinforcing effect of an EPDM compound, and it is preferable to rapidly extrude carbon black (N550). The N550 is easy to disperse, can endow the rubber material with higher stiffness, has high extrusion speed, smooth extrusion surface, low extrusion expansion rate, good high temperature resistance of vulcanized rubber, medium reinforcing property and good elasticity. Carbon black N550 and carbon black N330 (highly wear-resistant carbon black) can also be used together, so that the processability is better, the mechanical property of the rubber compound can be further improved, and the low-temperature resistance of the NBR rubber can be improved.

In certain embodiments of the invention, the carbon black may be added in 40, 50, 60, 70, 80, 90, or 100 parts by weight.

Filler

In the invention, the filler adopts argil, preferably calcined argil, and the filler has good activity and adsorbability, is favorable for dispersion and filling, is favorable for extrusion of rubber materials, has better reinforcing effect, and is superior to hard argil and soft argil, and the prepared rubber compound has better deformation resistance. EPDM is a rubber having particularly excellent filling properties, and can be filled in a large amount without significantly degrading the properties, while reducing the cost. However, the rubber compound is required to have better compression permanent deformation performance, the looseness of the joint of the rubber tube after long-term use is avoided, the hot tearing performance of the rubber compound is reduced due to large-amount filling, the demoulding yield of the rubber tube is reduced, the filling amount cannot be overlarge, and the rubber content of the rubber compound is over 35%.

In certain embodiments of the invention, the kaolin is a calcined kaolin; preferably, the particle size of the calcined pottery clay is 1.0 μm to 1.5 μm, and the pH value is 4.5 to 6.5. The weight portion of the argil can be 20, 30, 40 or 50.

Vulcanization system

In the invention, BIPB (namely di (tert-butyl peroxyisopropyl) benzene) is selected as a vulcanizing agent, also called odorless DCP, so that the discomfort of rubber tube production, installation and users caused by the pungent smell of the rubber tube is avoided. BIPB has high vulcanizing speed, high scorching safety, high vulcanized rubber weather resistance, heat resistance, compression set performance and physical and mechanical performance, moderate price and easy purchase, and meets the requirement of mass production. However, the rubber tube using BIPB as a vulcanizing agent is easy to blow, so PL400 (trimethylolpropane triacrylate, also known as TMPTA) is selected as an auxiliary crosslinking agent; PL400 is colorless transparent liquid, and the dispersity is good, is fit for cooperating the peroxide vulcanization and uses, can solve the rubber tube and spout the frost problem. PL400 is used as a vulcanization accelerator, can play a role in molecular bridging, can improve the bridging density, improve the strength of the rubber compound, reduce the compression permanent deformation and shorten the vulcanization time; meanwhile, the crosslinking efficiency can be improved, the usage amount of peroxide can be reduced, and the hardness of rubber compound can be adjusted; moreover, PL400 is suitable for simultaneous vulcanization of three rubbers, especially CM rubber. In order to increase the vulcanization effect of the rubber compound system, particularly the vulcanization activity of EPDM, a small amount of vulcanization accelerator DM is added; DM is a universal vulcanization accelerator, is generally used in combination with other accelerators, is easy to disperse in rubber materials, has a good vulcanization assisting effect, and has good aging resistance and high temperature resistance. Meanwhile, in order to promote the vulcanization of the NBR rubber, improve the vulcanization speed of the rubber compound and improve the physical and mechanical properties of the rubber compound, a small amount of vulcanizing agent S-80 is used, the vulcanizing agent S-80 is sulfur pre-dispersion medical rubber, contains 80 percent of sulfur and 20 percent of EPDM rubber, is better blended with the EPDM rubber, can adjust the vulcanization speed of different rubbers and promote the co-vulcanization of a rubber compound system.

In certain embodiments of the invention, the BIPB may be added in 3, 4, 5, 6, 7, or 8 parts by weight; the PL400 may be added in 2, 2.5, 3, 3.5, or 4 parts by weight; the weight portion of the DM addition may be 0.5, 1, 1.5, or 2 parts.

Active agent

In the invention, zinc oxide and magnesium oxide are used as the active agents. The zinc oxide is a good activator of an EPDM peroxide system, and can activate a vulcanizing agent and an accelerator to improve the vulcanizing efficiency. Magnesium oxide is mainly used as an acid acceptor to absorb and neutralize hydrogen chloride gas generated in the vulcanization process of CM rubber, and the hydrogen chloride gas inhibits vulcanization, so that the strength of vulcanized rubber is reduced, and equipment is corroded. Meanwhile, the magnesium oxide can promote rubber material crosslinking, improve the crosslinking density of rubber, improve the physical and mechanical properties and thermal stability of rubber compound, reduce compression set and is a good activator. The magnesium oxide and the zinc oxide are used together, so that the compression set of the rubber compound can be further reduced, and the heat aging resistance of the rubber compound is improved.

In certain embodiments of the present invention, the zinc oxide may be added in 4, 4.5, or 5 parts by weight; the magnesium oxide can be added in 3, 3.5, 4, 4.5 or 5 parts by weight.

Stearic acid

Stearic acid is an important vulcanization activator, can enhance the activity of zinc oxide and plays a role of a second accelerator; stearic acid also has the functions of a lubricant and a plasticizer, so that carbon black, argil and the like are easily dispersed; and meanwhile, stearic acid also has the function of tackifying, and is beneficial to the adhesion of rubber and reinforced fabric during the vulcanization of the rubber tube.

In certain embodiments of the invention, the stearic acid may be added in 1, 1.5, or 2 parts by weight.

Protective system

In certain embodiments of the invention, the antioxidant consists of antioxidant MB, antioxidant TMDQ, antioxidant NBC and antioxidant DNP. The antioxidant MB (2-mercaptobenzimidazole) can effectively inhibit the phenomenon of softening and stickiness after rubber aging, improve the flex fatigue performance of rubber compound and can also be used as a vulcanization retardant. However, the use amount of MB is not more than 2% because it causes a serious decrease in elongation at break after thermal aging of the rubber compound and also causes blooming of the hose. However, MB is used alone and has weak anti-aging effect, so that the aging inhibitor TMDQ (2, 4-trimethyl-1, 2-dihydroquinoline polymer, also abbreviated as RD or TMQ) is used together, the TMDQ has obvious thermo-oxidative aging protection effect on EPDM, NBR and CM rubber, the heat resistance and weather resistance of rubber compound can be obviously improved, the vulcanization effect is not influenced, and the blooming is not easy to generate, and the using amount is 1-4%. Meanwhile, a small amount of an anti-aging agent NBC (N, N-di-N-butyl nickel dithiocarbamate, also called NDBC for short) is added, the condition that the elongation at break is reduced after thermal aging is effectively improved, thermal aging and ozone aging can be effectively resisted, and the rubber is particularly suitable for improving the heat resistance and weather resistance of CM rubber and NBR rubber and improving the ozone resistance and light aging resistance of NBR rubber, but the frosting phenomenon of products can be caused by excessive use amount, so the use amount cannot exceed 1%. A small amount of an anti-aging agent DNP (N, N' -di (beta-naphthyl) p-phenylenediamine, also called DNPD for short) is added, the chain fracture inhibitor has the effects of improving the heat resistance, aging resistance and weather resistance of vulcanized rubber, has obvious activation effect on thiazole accelerators, has good synergistic effect when being used together with MB, can obviously improve the weather resistance of NBR rubber when being used together with TMDQ, and has the use amount of not more than 1 percent. The four kinds of anti-aging agents are applied in the same system, have protection effect on EPDM, NBR and CM rubber, have complementary effect, have good synergy, have no conflict or harmful condition, and can obtain excellent comprehensive protection effect.

In some embodiments of the present invention, the antioxidant MB may be added in an amount of 0.2, 0.5, 0.8, 1.0, 1.2, or 1.5 parts by weight; the weight portion of the antioxidant TMDQ can be 0.5, 1.0, 1.5, 2.0, 2.5, 3.0, 3.5 or 4.0; the weight portion of the anti-aging agent NBC can be 0.2, 0.3, 0.4, 0.5, 0.6, 0.7, 0.8, 0.9 or 1.0; the addition weight portion of the antioxidant DNP can be 0.2, 0.3, 0.4, 0.5, 0.6, 0.7, 0.8, 0.9 or 1.0 portion.

Plasticizing system

In order to improve the processability of the rubber compound, make the rubber compound suitable for rubber tube extrusion molding and increase the plasticity and fluidity of the three rubbers used together, the compound plasticizer is adopted in the formula of the invention, and the compound plasticizer consists of paraffin oil, DOS and polyethylene glycol. In EPDM peroxide cure systems, paraffin oil is suitably used as the plasticizer. The paraffin oil has good plasticizing effect, good compatibility with EPDM rubber, small volatility and weight loss, and vulcanized rubber filled with the paraffin oil has small compression permanent deformation, good heat resistance and excellent weather resistance; meanwhile, because the NBR rubber and the CM rubber are both suitable to adopt ester plasticizers, and the DOS can obviously improve the low-temperature resistance of the NBR rubber and the CM rubber, the ester plasticizer DOS (dioctyl sebacate) is used together, so that the DOS has good low-temperature resistance, small volatility and good weather resistance; the DOS has better compatibility with the EPDM rubber, and the DOS has good plasticizing effect on three rubbers in the rubber compound and has good compatibility; the DOS plasticized rubber compound is soft and easy to be rolled and extruded, and simultaneously, the low-temperature flexibility of the rubber compound can be improved. Meanwhile, a small amount of polyethylene glycol is added in the formula, so that the wettability of the filler can be improved, the components of the rubber material can be better dispersed, and the preferential adsorption of peroxide curing agent, accelerator and the like by the filler is reduced.

In some embodiments of the present invention, the paraffin oil is any one of Nypar330 from Nintes, plane 25110 from Dadale oil, sun SUNPAR 2280.

In certain embodiments of the invention, the paraffin oil may be added in 10, 15, 20, 25, or 30 parts by weight; the DOS can be added in 4, 5, 6, 7, 8, 9 or 10 parts by weight; the added weight portion of the polyethylene glycol can be 1.5, 2, 2.5 or 3.0 portions.

Other auxiliaries

Other additives can be added in the invention, and the other additives can comprise an anti-scorching agent N-cyclohexyl thiophthalimide (CTP or PVI for short, which is used for preventing rubber materials from scorching in the processing process and improving the production efficiency), a plasticizer dibutyl phthalate (DBP for short, which is used for improving the compatibility of DOS and CM rubber), a coupling agent (used for modifying the surface of pottery clay and increasing the dispersibility of the pottery clay), an adhesive resin (used for improving the adhesive property of rubber and increasing the adhesive strength of rubber and reinforced fabrics in a rubber hose), calcium hydroxide (used for increasing the alkalinity of a rubber compound and promoting the rubber materials to be further crosslinked), microcrystalline wax (used for improving the aging property of the rubber and effectively preventing roller sticking and playing a role of a release agent), and the like.

In certain embodiments of the present invention, the total amount of the other additives may be added in a weight part of 0, 0.5, 1,2, 3, 4, or 5 parts.

1) Pre-mixing EPDM rubber:

adding a peroxide vulcanizing agent, a vulcanization accelerator, zinc oxide and stearic acid (added according to the proportion of about 60 percent of the total parts) into EPDM rubber raw rubber, and mixing to prepare premixed rubber; placing the premixed glue at 95-105 ℃ for 3-4 h;

2) Mixing: and (3) conventionally mixing the EPDM premixed rubber with the rest raw materials.

Example 1

An EPDM rubber compound for a rubber tube of an automobile turbocharging system comprises the following raw materials in parts by weight:

wherein the EPDM rubber virgin rubber adopts NORDELIP4760P of Dow chemical; the NBR rubber virgin rubber adopts Europrene3360 of Italy Eynia company; the CM rubber virgin rubber adopts CM135B (extrusion type, mooney viscosity of about 60) of Weifang Yaxing chemistry; the carbon black is N550, and the argil is calcined argil; the paraffin oil is Nypar330 of Nines company, and other raw materials are commercially available products.

The preparation method of the EPDM rubber compound for the rubber tube of the automobile turbocharging system comprises the following steps:

1) Adding 2.5 parts of vulcanizing agent BIPB (2.5 parts), 1.5 parts of vulcanization accelerator PL400, 1 part of DM (1 part), 3 parts of zinc oxide and 1 part of stearic acid into 50 parts of EPDM rubber raw rubber, and mixing to prepare premixed rubber;

2) Placing the premixed glue at 100 ℃ for 3h;

3) And adding the rest raw materials into EPDM premixed rubber for mixing to obtain the rubber compound.

The results of the performance test of the obtained EPDM blended rubber are shown in table 1 below.

Example 2

wherein the EPDM rubber virgin rubber adopts KEP-570F of Tao lake petrochemistry of Dow chemical; the NBR rubber raw rubber adopts Perbunan2865 produced by Bayer company; the CM rubber virgin rubber adopts CM135B (extrusion type, mooney viscosity of about 60) of Weifang subsite chemistry; the carbon black is N550, and the argil is calcined argil; the paraffin oil is SUNPAR2280, and other raw materials are commercially available products.

1) Adding vulcanizing agent BIPB (3 parts), vulcanization accelerator PL400 (2 parts), DM (1 part), zinc oxide (3 parts) and stearic acid (1 part) into EPDM rubber virgin rubber (60 parts), and mixing to prepare premixed rubber;

2) Placing the premixed glue at 90 ℃ for 4h;

3) And adding the rest raw materials into the EPDM premixed rubber for mixing to obtain the rubber compound.

The results of the performance tests of the EPDM compounded rubber obtained are shown in table 1 below.

Comparative example 1

An EPDM rubber compound for a rubber tube of an automobile turbocharging system is as follows:

example 1 was repeated with the only difference that: 0 part of EPDM virgin rubber, 70 parts of NBR virgin rubber and 30 parts of CM virgin rubber; the other components, amounts and preparation methods were the same as in example 1. The results of the performance test of the prepared rubber compound are shown in the following table 1.

Comparative example 2

example 1 was repeated with the only difference that: 0 part of NBR rubber virgin rubber, 70 parts of EPDM virgin rubber and 30 parts of CM virgin rubber; the other components, amounts and preparation method were the same as in example 1. The results of the performance tests of the prepared rubber compound are shown in Table 1 below.

Comparative example 3

example 1 was repeated with the only difference that: 0 part of CM rubber virgin rubber, 60 parts of EPDM virgin rubber and 40 parts of NBR virgin rubber; the other components, amounts and preparation method were the same as in example 1.

The results of the performance tests of the prepared rubber compound are shown in Table 1 below.

Comparative example 4

example 1 was repeated with the only difference that: 1 part of antioxidant MB is not added; the other components, amounts and preparation methods were the same as in example 1.

Comparative example 5

example 1 was repeated with the only difference that: 2.5 parts of TMDQ (TMDQ) as an anti-aging agent is not added; the other components, amounts and preparation methods were the same as in example 1.

The results of the performance test of the prepared rubber compound are shown in the following table 1.

Comparative example 6

example 1 was repeated with the only difference that: 0.5 part of antioxidant DNP is not added; the other components, amounts and preparation methods were the same as in example 1.

The method for testing the performance of the invention comprises the following steps:

1) Shore A hardness: testing according to related test standards of GB/T531.1-2008;

2) Tensile strength, elongation at break: testing according to related testing standards of GB/T528-2009;

3) Heat resistance (shore a hardness change, tensile strength and elongation at break): testing according to relevant test standards of GB/T3512-2014 (160 ℃/24 h);

4) Compression set: testing according to GB/T7759.1-2015 (150 ℃/24h, compression rate 25%);

5) Low temperature bending (-40 ℃/24 h): and (3) keeping the test piece in a low-temperature test box with the temperature of minus 40 +/-2 ℃ for 24 hours, immediately manually bending the test piece after the test is finished, and checking the appearance of the test piece.

6) Ozone resistance (200 pphm/72h, 20% tensile) was tested according to the relevant test standards of GB/T7762-2003.

7) Volume change rate of 1# oil resistance: testing was carried out according to the relevant test standards of GB/T1690-2010.

The rubber compositions obtained in examples 1 to 2 and comparative examples 3 to 6 were tested according to the above test methods, and the test results are shown in Table 1 below.

TABLE 1

As can be seen from table 1:

1) The EPDM rubber compound for the rubber tube prepared in the embodiment 1 has good comprehensive performance and can be used at the temperature of-40-160 ℃; the oil-resistant oil-gas composite material has the advantages of ozone resistance of 200pphm/72h, no cracking, good mechanical property, and good oil and gas resistance; shore A hardness is 60-70, tensile strength is more than 14MPa, and elongation at break is more than 250%; after heat resistance (160 ℃/24 h), the reduction rate of the tensile strength and the elongation at break is less than 40 percent; the compression set (150 ℃/24h, 25% compression) is less than 40%; after the rubber hose resists the No. 1 standard oil, the volume change rate is less than or equal to 50% at normal temperature and less than or equal to 80% at high temperature (150 ℃/24 h), the use requirements of high reliability, long service life and the like of the rubber hose of the automobile turbocharging system are met, the material is easy to obtain, the rubber hose is environment-friendly, the operation is simple, and the rubber hose can be suitable for industrial production and application.

2) The EPDM rubber compound for the rubber tube prepared in the embodiment 2 has good comprehensive performance and can be used at the temperature of-40-160 ℃; the oil-resistant oil-gas composite material has the advantages of ozone resistance of 200pphm/72h, no cracking, good mechanical property, and good oil and gas resistance; shore A hardness is 60-70, tensile strength is more than 14MPa, and elongation at break is more than 250%; the reduction rate of the tensile strength and the elongation at break after heat resistance (160 ℃/24 h) is less than 40 percent; the compression set (150 ℃/24h, 25% compression) is less than 40%; after the rubber hose resists the No. 1 standard oil, the volume change rate is less than or equal to 50% at normal temperature and less than or equal to 80% at high temperature (150 ℃/24 h), the use requirements of high reliability, long service life and the like of the rubber hose of the automobile turbocharging system are met, the material is easy to obtain, the rubber hose is environment-friendly, the operation is simple, and the rubber hose can be suitable for industrial production and application. In the preparation of the EPDM rubber compound, the EPDM content is increased, the carbon black content is increased, the NBR content is reduced, the hardness and the strength are slightly increased, the strength is improved to a certain extent after heat resistance, and the oil resistance is slightly reduced.

3) Compared with the example 1, the EPDM is not added, and the cold resistance and the ozone resistance are poor, so that the rubber hose does not meet the use requirement of the rubber hose of the automobile turbocharging system.

4) Comparative example 2 without adding NBR, compared with example 1, the oil resistance is poor and does not meet the use requirement of the rubber hose of the automobile turbocharging system.

5) Comparative example 3 does not add CM, compare example 1, EPDM and NBR compatibility poor, the gross rubber phase separation appears, the performance obviously reduces, and the goods can't be extrusion molding at the same time, does not satisfy the car turbocharging system rubber tube operation requirement.

6) Compared with the example 1, the protection system is different from the protection system in the comparative example 4, the antioxidant MB is not added in the comparative example 4, the antioxidant TMDQ is not added in the comparative example 5, and the antioxidant DNP is not added in the comparative example 6, so that the protection performance is obviously reduced, the tensile property, the compression set property and the oil resistance after heat resistance are greatly reduced compared with the case of using four kinds of antioxidants together, and the use requirements of rubber hoses of automobile turbocharging systems cannot be met.

The foregoing description of specific embodiments has been presented for purposes of illustration and description. Other embodiments are within the scope of the following claims. In some cases, the actions or steps recited in the claims may be performed in a different order than in the embodiments and still achieve desirable results. Additionally, the processes depicted in the description do not necessarily require the particular order shown, or sequential order, to achieve desirable results. In some embodiments, multitasking and parallel processing may also be possible or may be advantageous.

Those of ordinary skill in the art will understand that: the discussion of any embodiment above is meant to be exemplary only, and is not intended to intimate that the scope of the disclosure, including the claims, is limited to these examples; features from the above embodiments, or from different embodiments, may also be combined, steps may be implemented in any order, and there are many other variations of the different aspects of one or more embodiments of the present description, as described above, which are not provided in detail for the sake of brevity.

In addition, where specific details are set forth in order to describe example embodiments of the disclosure, it will be apparent to one skilled in the art that one or more embodiments of the disclosure may be practiced without, or with variation of, these specific details for simplicity of illustration and discussion. Accordingly, the description is to be regarded as illustrative instead of restrictive.

While the present disclosure has been described in conjunction with specific embodiments thereof, many alternatives, modifications, and variations of these embodiments will be apparent to those of ordinary skill in the art in light of the foregoing description.

It is intended that the one or more embodiments of the present specification embrace all such alternatives, modifications and variations as fall within the broad scope of the appended claims. Therefore, any omissions, modifications, substitutions, improvements, and the like that may be made without departing from the spirit and principles of one or more embodiments of the present disclosure are intended to be included within the scope of the present disclosure.

Claims

1. The rubber compound for the EPDM rubber tube for the automobile turbocharging system is characterized by comprising the following raw materials in parts by weight:

2. the rubber compound for the EPDM rubber hose for the automobile turbocharging system according to claim 1, wherein: the EPDM rubber adopts a variety with high molecular weight and high ethylene content, the third monomer is ENB, and the variety with higher ENB content is selected.

3. The rubber compound for the EPDM rubber hose for the automobile turbocharging system according to claim 1, wherein: the EPDM rubber is any one or more of NORDELIP4760P and 4770P produced by Dow chemical, vistalon5601 of Exxon Mobil, S512F and S5890F of SK, and KEP-570F produced by Jinhu petrochemical industry.

4. The rubber compound for the EPDM rubber tube for the automobile turbocharging system according to claim 1, wherein: the NBR rubber is a variety with medium or slightly high acrylonitrile content, and the content of acrylonitrile in the NBR rubber is 25-36%.

5. The rubber compound for the EPDM rubber hose for the automobile turbocharging system according to claim 1, wherein: the NBR rubber is one or more of Perbunan2830, 2845, 2865, 3445 and 3465 produced by Bayer company and Europrene2860, 3335 and 3360 produced by Italy Eynia company.

6. The rubber compound for the EPDM rubber hose for the automobile turbocharging system according to claim 1, wherein: the CM rubber raw rubber is of a grade with the chlorine content of 32-37%; preferably, the CM rubberis is a CM135B extrusion grade product of Weifang Arisaema chemistry.

7. The rubber compound for the EPDM rubber hose for the automobile turbocharging system according to claim 1, wherein: the carbon black is selected from fast extrusion furnace black or the fast extrusion furnace black and high wear-resistant carbon black are used together; preferably, the carbon black is N550 or a mixture of N550 and N330.

8. The rubber compound for the EPDM rubber tube for the automobile turbocharging system according to claim 1, wherein: the argil is calcined argil; preferably, the particle size of the calcined pottery clay is 1.0 μm to 1.5 μm, and the pH value is 4.5 to 6.5.

9. The rubber compound for the EPDM rubber hose for the automobile turbocharging system according to claim 1, wherein: the anti-aging agent consists of an anti-aging agent MB, an anti-aging agent TMDQ, an anti-aging agent NBC and an anti-aging agent DNP;

the paraffin oil is any one of Nypar330 of Nintes corporation, plane 25110 of Dadale oil corporation and SUNPAR2280 of United states Sun brand;

the other auxiliary agents comprise any one or more of scorch retarder N-cyclohexyl thiophthalimide, plasticizer dibutyl phthalate, coupling agent, adhesive resin, calcium hydroxide and microcrystalline wax.

10. A method of preparing an EPDM compound for use in an automotive turbocharger system hose according to any one of claims 1 to 9, comprising the steps of:

1) Pre-mixing EPDM rubber:

adding a peroxide vulcanizing agent, a vulcanization accelerator, zinc oxide and stearic acid into EPDM rubber raw rubber, adding the peroxide vulcanizing agent, the vulcanization accelerator, the zinc oxide and the stearic acid according to the proportion of 55-65% of the total parts, and mixing to prepare premixed rubber; placing the premixed glue at 95-105 ℃ for 3-4 h;

2) Mixing: the EPDM premix gum is mixed with the rest of the raw materials.