阅读说明：本技术 自密封橡胶组合物及其制备方法和具有防刺穿功能的充气轮胎 (Self-sealing rubber composition, preparation method thereof and pneumatic tire with puncture-proof function ) 是由 刘育哲 于 2021-08-27 设计创作，主要内容包括：自密封橡胶组合物及其制备方法和具有防刺穿功能的充气轮胎。本发明提供了一种自密封橡胶组合物,包括：丁基橡胶,聚异丁烯,填料,增塑剂,交联体系。本发明提供的上述自密封橡胶组合物具有高粘性,可以附着于轮胎内衬层的内侧,制备得到具有防刺穿功能的充气轮胎,当充气轮胎胎面受到物件穿刺时,自密封橡胶组合物能够粘附在穿刺物上,以防止气压泄漏,在从胎面去除穿刺物的情况下,自密封橡胶组合物具有适宜的流动性能够流入穿刺孔并使轮胎气密,防止内压降低使充气轮胎达到安全防穿刺的效果。同时所述安全轮胎具有较佳的舒适性,且胎噪低、滚动阻力低,具有广阔的市场应用前景。(A self-sealing rubber composition, a method for producing the same, and a pneumatic tire having a puncture-preventing function. The invention provides a self-sealing rubber composition, which comprises the following components: butyl rubber, polyisobutylene, a filler, a plasticizer and a crosslinking system. The self-sealing rubber composition provided by the invention has high viscosity, can be attached to the inner side of a tire inner liner, and can be used for preparing a pneumatic tire with a puncture-proof function. Meanwhile, the safety tire has better comfort, low tire noise and low rolling resistance, and has wide market application prospect.)

1. A self-sealing rubber composition comprising:

butyl rubber, polyisobutylene, a filler, a plasticizer and a crosslinking system.

2. The self-sealing rubber composition as claimed in claim 1, comprising a first component and a second component, wherein the first component comprises:

the second component comprises:

0 wt% -40 wt% of polyisobutylene;

0-20 wt% of a plasticizer;

0.5 wt% -15 wt% of a crosslinking system;

the total amount of the first component and the second component is 100 percent.

3. The self-sealing rubber composition as claimed in claim 1, wherein the butyl rubber is a halogenated butyl rubber;

the cross-linked system is one or more of thiazole accelerator, thiuram accelerator, zinc oxide and stearic acid.

4. The self-sealing rubber composition as claimed in claim 1, wherein the butyl rubber is a non-halogenated butyl rubber;

the crosslinking system is one or more of a quinoid crosslinking agent, an organic peroxide and a phenolic resin crosslinking agent.

5. The self-sealing rubber composition according to claim 1, wherein the polyisobutylene is one or more polyisobutylenes of different molecular weights;

the filler is carbon black;

the plasticizer is processing oil.

6. A method for preparing the self-sealing rubber composition as claimed in any one of claims 1 to 5, comprising the steps of:

A) preparing a first component:

mixing butyl rubber, a filler and a plasticizer for the first time to obtain a premixed rubber composition; mixing the premixed rubber composition with polyisobutylene, adding the polyisobutylene for multiple times, and mixing for the second time to obtain a component I mixture;

B) preparing a second component:

mixing polyisobutylene, a plasticizer and a crosslinking system at one time to obtain a mixture of the two components;

C) and (3) spraying:

and (2) feeding the mixture of the first component after metering at the first feeding port, feeding the mixture of the second component after metering at the second feeding port, mixing the materials of the two feeding ports in a spraying pipeline according to a certain proportion, spraying, and obtaining the self-sealing rubber composition after completing the crosslinking reaction.

7. The production method according to claim 6,

the temperature of the first mixing in the preparation of the first component is 60-160 ℃; the temperature of the second mixing is 50-130 ℃;

the mixing temperature in the preparation of the second component is 20-70 ℃;

the heating temperature of the first supply port in the spraying stage is 50-150 ℃; the heating temperature of the second supply port is 20-70 ℃; the weight ratio of the materials sprayed out of the first supply port and the second supply port is 60: 40-95: 5; the spraying temperature is 50-150 ℃.

8. A pneumatic tire having a puncture-proof function, characterized in that the self-sealing rubber composition according to any one of claims 1 to 5 is adhered to the inner liner of the pneumatic tire.

9. A method for producing a pneumatic tire having a puncture prevention function according to claim 8, comprising the steps of:

A) preparing a first component:

mixing butyl rubber, a filler and a plasticizer for the first time to obtain a premixed rubber composition; mixing the premixed rubber composition with polyisobutylene, adding the polyisobutylene for multiple times, and mixing for the second time to obtain a component I mixture;

B) preparing a second component:

mixing polyisobutylene, a plasticizer and a crosslinking system at one time to obtain a mixture of the two components;

C) and (3) spraying:

the first component mixture is fed after being metered at the first feeding port, the second component mixture is fed after being metered at the second feeding port, and then the materials at the two feeding ports are mixed in a spraying pipeline according to a certain proportion and then sprayed into the tire;

D) and (3) a crosslinking reaction stage:

keeping the tire rotating, keeping the temperature or heating the tire according to the condition of the rubber material crosslinking reaction, and obtaining the pneumatic tire with the puncture-proof function after the crosslinking reaction is finished.

Technical Field

The invention relates to the technical field of rubber compositions, in particular to a self-sealing rubber composition, a preparation method thereof and a pneumatic tire with a puncture-proof function.

Background

In recent years, due to rapid development of new energy vehicles, the problems of increasing driving range and reducing vehicle weight are generally encountered, and in order to reduce the weight of a vehicle, it is necessary to cancel the arrangement of a spare tire, and further, a demand for developing a safety tire has arisen. When the tire tread is punctured by a foreign object, the run flat tire can continue to travel at least to a location where the tire can be disposed of.

Run-flat tire (Run-flat tire) is a safety tire commonly used at present, and has a reinforced sidewall layer, so that even if the tire pressure is reduced after the tire is punctured, the high-strength sidewall layer can maintain the running of the tire to a place where the tire can be disposed. However, because of the thick wall and the high hardness of the tire, the comfort is poor, the tire noise is large, the rolling resistance of the tire is not good, and the tire is not suitable for new energy automobiles.

Disclosure of Invention

In view of the above, the present invention is directed to a self-sealing rubber composition, a method for preparing the same, and a pneumatic tire having a puncture prevention function, in which a pneumatic tire prepared from the self-sealing rubber composition is punctured by a foreign object to be self-sealed and prevent air pressure from leaking.

In order to achieve the above object, the present invention provides a self-sealing rubber composition comprising:

butyl rubber, polyisobutylene, a filler, a plasticizer and a crosslinking system.

Preferably, the self-sealing rubber composition comprises a component one and a component two, wherein the component one comprises:

the second component comprises:

in the present invention, the content of the butyl rubber of component one is preferably 10 to 50 wt%, more preferably 15 to 30 wt%.

In the invention, the content of the crosslinking system in the component two is preferably 0.5 wt% to 15 wt%, and more preferably 1 wt% to 10 wt%.

Preferably, the butyl rubber of the component one is halogenated butyl rubber; the cross-linked system of the component II is one or more of thiazole accelerator, thiuram accelerator, zinc oxide and stearic acid.

In some embodiments of the invention, component one said butyl rubber is selected from the group consisting of BROMOBUTYL 2222; component two the crosslinking system is selected from dibenzothiazyl disulfide, zinc oxide and stearic acid.

Preferably, the butyl rubber of component one is non-halogenated butyl rubber; the crosslinking system of the component two is one or more of quinoid crosslinking agent, organic peroxide and phenolic resin crosslinking agent.

In the present invention, the content of the polyisobutylene, component one, is preferably 10 to 70 wt%, more preferably 20 to 60 wt%.

Preferably, component one of said polyisobutenes may be selected from one or more polyisobutenes of different molecular weights.

Preferably, the average molecular weight Mn of the polyisobutene of component one is 400-40000. In some embodiments of the invention, the polyisobutylene is selected from GlissopalV640 and oppanol b 12N.

In the present invention, the content of the filler of component one is preferably 0 to 15 wt%, and more preferably 5 to 12 wt%.

Preferably, component one of said fillers is selected from carbon black. In some embodiments of the invention, the filler is selected from N330.

In the present invention, the content of the plasticizer of component one is preferably 0 to 6 wt%, and more preferably 0 to 4 wt%. Preferably, component one of said plasticizers is selected from process oils. In some embodiments of the invention, the plasticizer is selected from rubber process oil No. 3.

In the invention, the content of the polyisobutylene plasticizer in the component two is preferably 0-40 wt%, and more preferably 0-30 wt%.

Preferably, the average molecular weight Mn of the polyisobutylene in the second component is 400-2000. In some embodiments of the invention, the polyisobutylene of component two is selected from Glissopal V640.

In the invention, the content of the plasticizer in the component two is preferably 0-20 wt%, and more preferably 0-15 wt%. Preferably, the plasticizer of component two is selected from processing oils. In some embodiments of the invention, the plasticizer is selected from rubber process oil No. 3.

The invention provides a preparation method of the self-sealing rubber composition, which comprises the following steps:

A) preparing a first component:

mixing butyl rubber, a filler and a plasticizer for the first time to obtain a premixed rubber composition; mixing the premixed rubber composition with polyisobutylene, adding the polyisobutylene for multiple times, and mixing for the second time to obtain a component I mixture;

B) preparing a second component:

mixing polyisobutylene, a plasticizer and a crosslinking system at one time to obtain a mixture of the two components;

C) and (3) spraying:

and (2) feeding the mixture of the first component after metering at the first feeding port, feeding the mixture of the second component after metering at the second feeding port, mixing the materials of the two feeding ports in a spraying pipeline according to a certain proportion, spraying, and obtaining the self-sealing rubber composition after completing the crosslinking reaction.

Preferably, the step a) is specifically: and (3) adding and mixing the butyl rubber, the filler and the plasticizer according to a proportion by using a Banbury mixer, and carrying out primary mixing to obtain the premixed rubber composition. The temperature of the first mixing of the first preparation of the component is preferably 60-160 ℃.

Adding the premixed rubber composition into a Kneader, adding the polyisobutylene for multiple times, preferably 5% -35% of the polyisobutylene is added for each time, and mixing for the second time to obtain a component one mixture.

According to the invention, the rotor for preparing the Kneader of the first component is a Z-shaped rotor.

According to the invention, the polyisobutylene prepared by the first component is added for 3-20 times, and is added and mixed for a small number of times, so as to achieve the optimal mixing effect.

The present invention adds a large amount of polyisobutylene to the component one mixture to ensure that the self-sealing rubber composition is effective over a very wide operating temperature range. But the relatively high tack of the compound makes it difficult to mix and process. The polyisobutylene is added for a plurality of times, only a small amount of polyisobutylene is added each time, the shearing force of a mixing rotor is reduced when the polyisobutylene is added, the shearing force is increased after the polyisobutylene is fully mixed, a small amount of polyisobutylene is added until the required polyisobutylene is completely added, and finally other residual components are added to complete mixing. According to the invention, the temperature for the first mixing preparation of the component is preferably 50-130 ℃.

Preferably, step B) is specifically: and adding polyisobutylene, a plasticizer and a crosslinking system into a Kneader, and mixing to obtain a mixture of the two components.

According to the invention, the rotor of the Kneader prepared by the component two is preferably a Z-shaped rotor. According to the invention, the temperature for mixing the second component is preferably 20-70 ℃.

Preferably, in the step C), the component one mixture is introduced into the first supply port by using a metering pump, the component two mixture is introduced into the second supply port by using a metering pump, the first supply port and the second supply port simultaneously feed the metered materials, and then the materials are mixed and sprayed to perform the crosslinking reaction.

Preferably, the heating temperature of the first supply port is 50 to 150 ℃.

Preferably, the heating temperature of the second supply port is 20 to 70 ℃.

Preferably, the weight ratio of the materials metered by the first supply port and the second supply port is 60: 40-95: 5.

Preferably, the metering pump may be a gear-based metering pump or a piston-based metering pump.

Preferably, the materials of the two supply ports are mixed using a static mixer or a dynamic mixer.

Preferably, the spraying temperature is 50-150 ℃.

Preferably, the spray nozzle has a geometric shape.

Preferably, the thickness of the self-sealing rubber composition after spraying is 1-10 mm.

The rubber composition provided by the invention needs to be added with a proper amount of cross-linking agent to generate chemical bonding and endow the rubber material with enough physical strength besides adding polyisobutylene to provide adhesiveness, so that how to enable the rubber material not to generate an advanced cross-linking reaction before high-temperature spraying but to perform the cross-linking reaction after spraying is an important issue in processing.

The invention adopts the process steps of respectively feeding materials through the first feeding port and the second feeding port, then mixing, spraying and carrying out a crosslinking reaction, so that the complete components are mixed during the spraying of the sizing material, and the crosslinking reaction is started after the mixing and spraying, thereby solving the technical problems.

The invention also provides a pneumatic tire with a puncture-proof function, wherein the self-sealing rubber composition is adhered to the inner liner of the pneumatic tire.

The schematic view of the self-sealing rubber composition attached to the inner side of the inner liner of the safety tire is shown in fig. 1.

Fig. 1 shows the self-sealing rubber composition compounded inside a pneumatic tire inner liner.

The invention provides a preparation method of the pneumatic tire with the puncture-proof function, which comprises the following steps:

A) preparing a first component:

mixing butyl rubber, a filler and a plasticizer for the first time to obtain a premixed rubber composition; mixing the premixed rubber composition with polyisobutylene, adding the polyisobutylene for multiple times, and mixing for the second time to obtain a component I mixture;

B) preparing a second component:

mixing polyisobutylene, a plasticizer and a crosslinking system at one time to obtain a mixture of the two components;

C) and (3) spraying:

the first component mixture is fed after being metered at the first feeding port, the second component mixture is fed after being metered at the second feeding port, and then the materials at the two feeding ports are mixed in a spraying pipeline according to a certain proportion and then sprayed into the tire;

D) and (3) a crosslinking reaction stage:

keeping the tire rotating, keeping the temperature or heating the tire according to the condition of the rubber material crosslinking reaction, and obtaining the pneumatic tire with the puncture-proof function after the crosslinking reaction is finished.

The conditions of the steps A), B) and C) are the same as above, and are not described again.

The rubber material sprayed in the tire is at the temperature of 50-150 ℃, the tire is kept rotating to prevent unreacted rubber material from generating vertical flow, the tire can be insulated or heated according to the cross-linking reaction condition of the rubber material, and the tire stops rotating after the rubber material finishes the cross-linking reaction.

Preferably, in the rubber material reaction stage, the tire can be placed in a heat preservation chamber to keep rotating, and the temperature in the heat preservation chamber is 50-130 ℃, so that the rubber material can maintain the temperature to generate sufficient crosslinking reaction.

The preparation method provided by the invention solves the problem of processability of the rubber material under high adhesion, and solves the problem of advanced crosslinking reaction which is easily generated before high-temperature spraying of the rubber material, so that the crosslinking reaction is carried out after the rubber material is sprayed on the tire.

Compared with the prior art, the invention provides a self-sealing rubber composition, which comprises the following components in percentage by weight: butyl rubber, polyisobutylene, a filler, a plasticizer and a crosslinking system. The self-sealing rubber composition provided by the invention has high viscosity, can be attached to the inner side of a tire inner liner, and can be used for preparing a pneumatic tire with a puncture-proof function. Meanwhile, the safety tire has better comfort, low tire noise and low rolling resistance, and has wide market application prospect.

Drawings

FIG. 1 is a schematic view of the attachment of a self-sealing rubber composition to the inside of a liner layer of a safety tire.

Detailed Description

In order to further illustrate the present invention, the self-sealing rubber composition provided by the present invention, a method for preparing the same, and a pneumatic tire having a puncture preventing function will be described in detail with reference to examples.

Examples 1 to 4

1) Preparation of component one

TABLE 1 first mixing of the materials and their proportions

Wherein the butyl rubber is BROMOBUTYL2222 manufactured by EXXON CHEM CO.;

the carbon black is N330;

the plasticizer is rubber process oil No. 3.

The above raw materials were mixed using a Banbury mixer at a discharge temperature of 135 ℃.

TABLE 2 second mixing of the materials and their proportions

Wherein the polyisobutylene A is Glissopal V640 manufactured by BASF;

polyisobutylene B is Oppanol B12N manufactured by BASF;

the above components were mixed in a Kneader, and kneading was completed at a mixing temperature of 80 ℃.

2) Preparation of component two

TABLE 3 mixing of the two components

Composition comprising a metal oxide and a metal oxide	Example 1	Example 2	Example 3	Example 4
					Plasticizer	6.71	6.71	—	—
Polyisobutylene A	—	—	26.71	26.71
					Crosslinking agent A	0.51	0.51	0.51	0.51
Crosslinking agent B	1.39	1.39	1.39	1.39
					Crosslinking agent C	1.39	1.39	1.39	1.39

Wherein the plasticizer is No. 3 rubber process oil;

polyisobutylene A is Glissopal V640 manufactured by BASF;

the cross-linking agent A is dibenzothiazyl disulfide;

the cross-linking agent B is zinc oxide;

the crosslinking agent C is stearic acid.

The above components were mixed in a Kneader, and kneading was completed at a mixing temperature of 30 ℃.

3) Spraying of paint

TABLE 4 spraying stage materials and proportions

Introducing the mixed main material into a supply port 1 by using a metering pump, wherein the heating temperature is 130 ℃; the supply port 2 is supplied with the crosslinking agent and the plasticizer mixed by a stirring device by using a metering pump, and the heating temperature is 50 ℃. The materials of the two supply ports are mixed by a static mixer and then are uniformly sprayed into the tire.

4) Reaction of sizing material

The self-sealing rubber composition mixed by the static mixer was uniformly applied to the inside of the tire using a nozzle having a geometric shape, and the tire was placed in a holding chamber and kept rotating for 20 minutes to complete the crosslinking reaction.

Performance detection

After a pneumatic tire with the self-sealing rubber composition is inflated to the pressure of 2.5bar, nails with the diameter of 5mm are respectively punctured at 6 positions in the circumferential direction at the bottom of a tread groove, the sealing performance of the pneumatic tire is evaluated in air at different temperatures, wherein the normal temperature is 25 ℃, the low temperature is-35 ℃, after the nails are pulled out at different temperatures, air leakage detection spray is used for testing whether air leakage occurs at the punctured points, and the evaluation is carried out according to the following standards:

'number of completely sealed and no air leakage/total number of puncture nails'

Table 5 data table of examples

The above description of the embodiments is only intended to facilitate the understanding of the method of the invention and its core idea. It should be noted that, for those skilled in the art, it is possible to make various improvements and modifications to the present invention without departing from the principle of the present invention, and those improvements and modifications also fall within the scope of the claims of the present invention.