阅读说明：本技术 一种叠层弹簧的橡胶胶料及其制备方法 (Rubber material of laminated spring and preparation method thereof ) 是由 王付胜 万纪君 曹江勇 刘志国 徐雯学 马宗斌 刘金朋 于 2020-05-28 设计创作，主要内容包括：本发明公开了一种叠层弹簧的橡胶胶料,包括以下质量份数的各组份：天然橡胶60-80份、低顺式聚丁二烯橡胶20-40份、补强剂30-45份、活性剂5-12份、防老剂2-8份、改性剂1-3份、阻燃剂3-10份,增塑剂3-15份、硫化剂1-3、促进剂2-5份；其中所述天然橡胶与低顺式聚丁二烯橡胶总和为100份。本发明的叠层弹簧橡胶胶料的机械性能、燃烧性能均能满足技术指标要求,由此解决了现有技术中叠层弹簧的橡胶胶料无法同时满足燃烧性能及机械性能的要求的技术问题,从而导致现有技术中的胶料无法用于铁路车辆叠层弹簧等橡胶弹性元件。(The invention discloses a rubber material of a laminated spring, which comprises the following components in parts by mass: 60-80 parts of natural rubber, 20-40 parts of low cis-polybutadiene rubber, 30-45 parts of reinforcing agent, 5-12 parts of active agent, 2-8 parts of anti-aging agent, 1-3 parts of modifier, 3-10 parts of flame retardant, 3-15 parts of plasticizer, 1-3 parts of vulcanizing agent and 2-5 parts of accelerator; wherein the total of the natural rubber and the low cis-polybutadiene rubber is 100 parts. The mechanical property and the combustion property of the laminated spring rubber material can meet the technical index requirements, so that the technical problem that the rubber material of the laminated spring in the prior art cannot meet the requirements of the combustion property and the mechanical property at the same time is solved, and the rubber material in the prior art cannot be used for rubber elastic elements such as laminated springs of railway vehicles and the like.)

1. The rubber material of the laminated spring is characterized by comprising the following components in parts by mass:

60-80 parts of natural rubber, 20-40 parts of low cis-polybutadiene rubber, 30-45 parts of reinforcing agent, 5-12 parts of active agent, 2-8 parts of anti-aging agent, 1-3 parts of modifier, 3-10 parts of flame retardant, 3-15 parts of plasticizer, 1-3 parts of vulcanizing agent and 2-5 parts of accelerator; wherein the total mass part of the natural rubber and the low cis-polybutadiene rubber is 100 parts.

2. The rubber compound of the laminated spring according to claim 1, characterized by comprising the following components in parts by mass: 70 parts of natural rubber, 30 parts of low cis-polybutadiene rubber, 30-45 parts of reinforcing agent, 5-12 parts of activator, 2-8 parts of anti-aging agent, 1-3 parts of modifier, 3-10 parts of flame retardant, 3-15 parts of plasticizer, 1-3 parts of vulcanizing agent and 2-5 parts of accelerator.

3. The rubber compound of the laminated spring according to claim 1 or 2, wherein the reinforcing agent comprises 8-28 parts of carbon black and 10-30 parts of white carbon black.

4. Rubber compound for laminated springs according to claim 1, characterized in that the low-cis polybutadiene rubber has a cis 1, 4-butadiene content of preferably 35% and a vinyl content of preferably 10%.

5. Rubber compound for laminated springs according to claim 3, characterised in that the white carbon black is preferably selected with a specific surface area of more than 110m²White carbon black in a ratio of/g.

6. The rubber compound for laminated springs according to claim 1, wherein the flame retardant is ammonium polyphosphate.

7. The rubber compound for laminated springs according to claim 5, characterized in that the flame retardant is preferably a microencapsulated surface-coating-modified high molecular weight form II ammonium polyphosphate.

8. The rubber compound for laminated springs according to claim 3, wherein the modifier is a silane coupling agent, and the mass of the silane coupling agent is 10% of the mass of the white carbon black.

9. The rubber compound for laminated springs according to claim 1, wherein the plasticizer comprises tolylene diphenyl phosphate and naphthenic oil, and the mass ratio of tolylene diphenyl phosphate to naphthenic oil is 1: 1.

10. Rubber compound for laminated springs according to claim 1, characterized in that the vulcanizing agent is preferably sulfur and the accelerator is preferably a combination of tetramethyl monothiothiuram and N-cyclohexyl-2-benzothiazolesulfenamide.

11. The preparation method of the rubber compound of the laminated spring is characterized by comprising the following steps of:

s1: putting natural rubber and low cis-polybutadiene rubber into an internal mixer, and mixing for 30-45 s;

s2: putting the active agent and the anti-aging agent into an internal mixer, and mixing for 30-40 s;

s3: simultaneously putting the modifier, the reinforcing agent and the flame retardant into an internal mixer, and mixing for 45-60 s;

s4: putting the plasticizer into an internal mixer, mixing to 143 ℃, and continuously mixing for 60-70s at the temperature of 143-153 ℃ by using an equipment temperature control module;

s5: discharging the rubber, discharging the rubber to a sheet discharging machine, performing air cooling to obtain master batch, and standing for more than 2 hours;

s6: putting the cooled and parked master batch into an internal mixer, and mixing for 30-40 s;

s7: and (3) putting a vulcanizing agent and an accelerant into an internal mixer, mixing for 30-40s, lifting and lifting a top plug for 1 time, mixing to 105 ℃, discharging rubber, discharging the rubber from a sheet discharging machine, and cooling by air cooling to obtain the rubber material of the laminated spring.

Technical Field

The invention belongs to the field of high polymer materials, and particularly relates to a rubber material of a laminated spring and a preparation method thereof.

Background

Modern railway vehicles use a large number of various rubber-elastic elements in the suspension systems, equipment mounting systems, connections, stops, etc. However, the rubber elements belong to flammable or combustible materials, once a fire disaster occurs, the rubber material can be combusted, a large amount of heat and smoke can be emitted, the smoke often has certain toxicity, evacuation and escape of people in the case of the fire disaster of the vehicle are not facilitated, and fire safety hazards in the case of the fire disaster are increased.

Currently, the standard EN45545-2 is used in many countries to regulate the fire performance requirements of materials and components for railway vehicles. The EN45545-2 standard imposes definite requirements on the combustion behaviour of rubber-metal elastic elements used on railway vehicle bogies.

However, the laminated spring or flat rubber pile is an important shock-absorbing elastic element, and is widely applied to high-speed trains such as subway vehicles, urban light rail vehicles and motor train units. However, the combustion performance of the rubber spring manufactured in the prior art does not meet the requirements of the standard EN45545-2, so that the fire safety hazard is serious.

Disclosure of Invention

The invention aims to provide a rubber material of a laminated spring and a preparation method thereof, and aims to solve the technical problem that the rubber material of the laminated spring in the prior art cannot enable the combustion performance and the mechanical performance to simultaneously meet the standard requirements.

In order to realize the purpose, the invention adopts the following technical scheme:

the rubber material of the laminated spring comprises the following components in parts by mass:

60-80 parts of natural rubber, 20-40 parts of low cis-polybutadiene rubber, 30-45 parts of reinforcing agent, 5-12 parts of active agent, 2-8 parts of anti-aging agent, 1-3 parts of modifier, 3-10 parts of flame retardant, 3-15 parts of plasticizer, 1-3 parts of vulcanizing agent and 2-5 parts of accelerator; wherein the total mass part of the natural rubber and the low cis-polybutadiene rubber is 100 parts.

Preferably, the composition comprises the following components in parts by mass: 70 parts of natural rubber, 30 parts of low cis-polybutadiene rubber, 30-45 parts of reinforcing agent, 5-12 parts of activator, 2-8 parts of anti-aging agent, 1-3 parts of modifier, 3-10 parts of flame retardant, 3-15 parts of plasticizer, 1-3 parts of vulcanizing agent and 2-5 parts of accelerator.

Preferably, the reinforcing agent comprises 8-28 parts of carbon black and 10-30 parts of white carbon black.

Preferably, the low-cis polybutadiene rubber preferably has a cis-1, 4-butadiene content of 35% and a vinyl content of 10%.

Preferably, the white carbon black is preferably that the specific surface area of the white carbon black is more than 110m²White carbon black in a ratio of/g.

Preferably, the flame retardant is ammonium polyphosphate.

Preferably, the flame retardant is high molecular weight crystal form II ammonium polyphosphate modified by microencapsulation surface coating.

Preferably, the modifier is a silane coupling agent, and the mass of the silane coupling agent is 10% of the mass of the white carbon black.

Preferably, the plasticizer comprises diphenyl cresyl phosphate and naphthenic oil, and the mass ratio of the diphenyl cresyl phosphate to the naphthenic oil is 1: 1.

Preferably, the vulcanizing agent is sulfur, and the accelerator is a combination of tetramethyl thiuram and N-cyclohexyl-2-benzothiazole sulfonamide.

A preparation method of a rubber compound of a laminated spring comprises the following steps:

s1: putting natural rubber and low cis-polybutadiene rubber into an internal mixer, and mixing for 30-45 s;

s2: putting the active agent and the anti-aging agent into an internal mixer, and mixing for 30-40 s;

s3: simultaneously putting the modifier, the reinforcing agent and the flame retardant into an internal mixer, and mixing for 45-60 s;

s4: putting the plasticizer into an internal mixer, mixing to 143 ℃, and continuously mixing for 60-70s at the temperature of 143-153 ℃ by using an equipment temperature control module;

s5: discharging the rubber, discharging the rubber to a sheet discharging machine, performing air cooling to obtain master batch, and standing for more than 2 hours;

s6: putting the cooled and parked master batch into an internal mixer, and mixing for 30-40 s;

s7: and (3) putting a vulcanizing agent and an accelerant into an internal mixer, mixing for 30-40s, lifting and lifting a top plug for 1 time, mixing to 105 ℃, discharging rubber, discharging the rubber from a sheet discharging machine, and cooling by air cooling to obtain the rubber material of the laminated spring.

Compared with the prior art, the invention has the advantages and beneficial effects that:

the invention prepares the rubber compound suitable for the laminated spring by adopting the natural rubber and the low cis-polybutadiene rubber for mixing and reasonably optimizing and matching with the reinforcing agent and the flame retardant, and the prepared laminated spring also meets the requirement of combustion performance on the premise of meeting various mechanical properties by utilizing the rubber compound, namely the combustion performance meets the requirement of EN45545-2R 9H L2, and the mechanical properties also meet the requirements of the standards of TB/T2841 and TB/T2843 and 2015.

Detailed Description

The technical solutions in the embodiments of the present invention will be clearly and completely described below, and it is obvious that the described embodiments are only a part of the embodiments of the present invention, and not all embodiments. All other embodiments, which can be derived by a person skilled in the art from the embodiments given herein without making any creative effort, shall fall within the protection scope of the present invention.

The invention prepares the rubber material suitable for the laminated spring by adopting the natural rubber and the low cis-polybutadiene rubber for mixing and reasonably optimizing and matching with the reinforcing agent and the flame retardant, and the prepared laminated spring also meets the requirement of combustion performance on the premise of meeting various mechanical properties by utilizing the rubber material, namely the combustion performance meets the requirement of EN45545-2R 9H L2, and the mechanical properties also meet the requirements of the standards of TB/T2841 and TB/T2843 and 2015.

Specifically, the coating comprises the following components in parts by mass:

60-80 parts of natural rubber, 20-40 parts of low cis-polybutadiene rubber, 30-45 parts of reinforcing agent, 5-12 parts of active agent, 2-8 parts of anti-aging agent, 1-3 parts of modifier, 3-10 parts of flame retardant, 3-15 parts of plasticizer, 1-3 parts of vulcanizing agent and 2-5 parts of accelerator; wherein the total of the natural rubber and the low cis-polybutadiene rubber is 100 parts.

In a preferred embodiment, the natural rubber is 70 parts and the low cis polybutadiene rubber is 30 parts.

Further, the natural rubber can be selected from constant-viscosity rubber or smoked sheet rubber, wherein the natural rubber is preferably constant-viscosity rubber CV 60; the cis-1, 4-butadiene content of the low cis-polybutadiene rubber is 30-40%, and the vinyl content is 8-10%.

In a preferred embodiment, the low cis polybutadiene rubber is further preferably 35% cis 1, 4-butadiene and 10% vinyl.

Furthermore, the end group of the low cis-polybutadiene rubber is functionally modified, and the end group of the low cis-polybutadiene rubber can improve the dispersibility of the carbon black and the interface bonding capability between the rubber and the carbon black after the functional modification. Specifically, the low cis-polybutadiene rubber has better rebound resilience, low temperature performance, heat resistance and aging resistance, and is good in compatibility with natural rubber. The low cis-polybutadiene rubber is used together to replace partial natural rubber, and can achieve good blending modification effect on the natural rubber. The low cis-polybutadiene rubber has high thermal decomposition temperature and better heat resistance than natural rubber. The low cis-polybutadiene rubber reduces the proportion of natural rubber in rubber materials and improves the heat resistance and the thermal decomposition temperature of the rubber materials. And the carbon layer can be changed from a dispersed state to a continuous compact state after the rubber material is combusted, the continuous compact carbon layer can play a better heat insulation protection role on the unburned polymer at the lower layer, and the combustion performance of the rubber is greatly improved.

In a preferred embodiment, the white carbon black preferably has a specific surface area of more than 110m²White carbon black in a ratio of/g.

In a preferred embodiment, the modifier is a silane coupling agent, and the dosage of the silane coupling agent is 10% of the dosage of the white carbon black.

In a preferred embodiment, the reinforcing agent includes 8 to 28 parts of carbon black and 10 to 30 parts of white carbon black. Specifically, the white carbon black has the synergistic effects of reinforcement and flame retardance, and can improve the mechanical property and the combustion property of the rubber material. In addition, besides the blending ratio of the carbon black and the white carbon black needs to be controlled, the selection of the specific surface area and the dispersion characteristic of the white carbon black is also critical, and the specific surface area needs to be controlled at 110m²More than g and has high dispersion property. To obtain good dispersing effect and mechanical properties.

In a preferred embodiment, the flame retardant is ammonium polyphosphate. The addition of a small amount of ammonium polyphosphate hardly affects the mechanical properties of the rubber material, but can play a role in stabilizing char formation and preventing a combustion layer from cracking during combustion. The char layer formed during combustion protects the underlying unburned polymer. And the ammonium polyphosphate is preferably a high molecular weight crystal form-II ammonium polyphosphate which is modified by microencapsulation surface coating.

In a preferred embodiment, the plasticizer is a mixture of cresyldiphenyl phosphate and naphthenic oil; the mass ratio of the toluene diphenyl phosphate to the naphthenic oil is 1: 1. Naphthenic oil is a common plasticizer for natural rubber, but belongs to small molecule combustible substances; the diphenyl cresyl phosphate has a certain flame-retardant effect, and rubber sizing materials can promote charring and improve the combustion performance of the rubber sizing materials when being combusted, but the diphenyl cresyl phosphate belongs to polar substances and has poor compatibility with natural rubber and low cis-polybutadiene rubber, so the dosage of the diphenyl cresyl phosphate needs to be strictly controlled. Therefore, the diphenyl cresyl phosphate and the naphthenic oil are matched for use, the expected plasticizing effect is achieved, and the combustibility is also considered, so that the rubber compound meeting the mechanical property and the combustion property simultaneously can be obtained through reasonable matching of the formulas, and the rubber compound of the laminated spring with the fireproof function can be obtained.

In order to better explain a rubber compound for a laminated spring and a method for preparing the same, a detailed description will be given below with reference to comparative examples and examples.

Comparative example

The rubber compound of the laminated spring comprises the following components in parts by mass:

70 parts of natural rubber, 30 parts of high cis-polybutadiene rubber, 5 parts of zinc oxide, 2 parts of stearic acid, 1.8 parts of sulfur, 0.4 part of accelerator MBTS, 1.5 parts of accelerator CBS, 38 parts of carbon black, 4010NA2 parts of anti-aging agent RD, 1.5 parts of paraffin and 8 parts of naphthenic oil.

The preparation method comprises the following specific steps:

the manufacturing equipment and technological parameters are that the temperature of a temperature control unit of the meshed internal mixer with the nominal volume of more than 90L is set within the range of 30-40 ℃, the top plug pressure is 0.5MPa, the rotating speed of the rotor of the internal mixer in the steps 1-5 is 35-45r/min, and the rotating speed of the rotor of the internal mixer in the steps 6-7 is 15-20 r/min.

Step 1: putting natural rubber and low cis-polybutadiene rubber into an internal mixer, and mixing for 30-45 s;

step 2: putting the active agent and the anti-aging agent into an internal mixer, and mixing for 30-40 s;

and step 3: putting the modifier, the reinforcing agent and the flame retardant into an internal mixer together, and mixing for 45-60 s;

and 4, step 4: putting the plasticizer into an internal mixer, mixing to 143 ℃, and continuously mixing for 60-70s at the temperature of 143-153 ℃ by using an equipment temperature control module;

and 5: discharging the rubber, discharging the rubber to a sheet discharging machine, performing air cooling to obtain master batch, and standing for more than 2 hours;

step 6: putting the cooled and parked master batch into an internal mixer, and mixing for 30-40 s;

and 7: and (3) putting a vulcanizing agent and an accelerant into an internal mixer, mixing for 30-40s, lifting and lifting a top plug for 1 time, mixing to 105 ℃, discharging rubber, discharging the rubber from a sheet discharging machine, and cooling by air cooling to obtain the rubber material of the laminated spring.