RU2699098C1 - Rubber composition and method of its production - Google Patents

Abstract

FIELD: technological processes.

SUBSTANCE: invention relates to composition and technology of recycling rubber crumbs from rubber of general purpose and can be used in tire, rubber industry and for production of caoutchouc bituminous paste. Rubber composition contains, wt%: rubber chips 35–45 and solution containing solvent 45–53, modifying additive 3–4 and catalyst 7–8. Solvent used can be turpentine or a mixture of turpentine with a solvent, and catalyst can be used salts of cobalt, manganese, zirconium, calcium. Modifying additive contains, wt%: vegetable oil 72–75, monoethanolamine 7–10, citric acid 13–16, triethanolamine 1–2 and chalk 0.1–0.2. Sunflower oil may be used as vegetable oil. Rubber composition production method involves mixing rubber crumbs and a solution containing a solvent, a modifying additive and a catalyst, holding at 20–25 °C for 24 hours, squeezing crumbs of solution, then rubber crumbs are left at room temperature in a layer with thickness of not more than 10 cm and held for 12–48 hours. To press the solution out of rubber crumbs, presses are used.

EFFECT: invention simplifies the regeneration process, reduces energy consumption during grinding and processing, improves uniformity of the regenerate and reduces metal consumption of the equipment.

7 cl, 2 dwg, 1 ex

Description

Technical field

The invention relates to compositions and technologies for the regeneration of rubber crumb from general-purpose rubbers and can be used in the tire industry, the production of rubber products and rubber-bitumen mastics, based on which waterproofing materials used in construction can be obtained (roofing mastics, pipe insulation, road surfaces) , as well as for the manufacture of anti-corrosion automotive mastics.

State of the art

At present, rubber crumb regeneration methods are widely known and used in industry: water-neutral (neutral), thermomechanical (ricklemerator-process), steam and its modifications, high-temperature steam and steam [Makarov V.M. and others. The use of depreciated tires and waste rubber products. - L .: Chemistry, 1986, p.66 - 83.]. The vast majority of methods for the regeneration of rubber crumb (mainly worn tires and chambers, waste products from rubber products (RTI), etc.) for this "as a rule" use two sequential processes:

1. Mechanical grinding.

2. Obtaining regenerate through the use of emollients, activators and high temperatures (autoclaves).

Common disadvantages of these methods are:

1. Significant energy consumption during grinding and processing;

2. The regeneration process requires the use of metal-intensive equipment (mixers, extruders, rollers, etc.);

3. The regeneration process is accompanied by the release into the environment of vapors and fumes containing, in particular sulfur.

A known method of regeneration of rubber crumb, including the processing of rubber crumb in the environment of halogen-containing activators [USSR copyright certificate No. 421697, class. IPC C08J 11/20, C08K 5/02, publ. 03/30/1974]. In this method, as a halogen-containing activator take decachlor C ₁₀ Cl ₁₀ in an amount of 2-3 parts by weight per 100 parts by weight regenerated mixture and treated for 1 hour in air at 180 ° C.

A known method of regeneration of rubber [USSR copyright certificate No. 936799, class. IPC B29H 19/00, publ. 06/15/1982]. According to this invention, rubber crumb with a size of 0.4-0.8 mm is treated in a softener comprising dipentene, tall oil and aromatic oil, the treatment being carried out in a mixer at 2000 m / min, followed by the addition of a phenylhydrazine activator with ferric chloride.

However, this method also has the disadvantages of thermomechanical processing of rubber crumb.

A known method for the regeneration of vulcanized elastomeric waste (RF patent No. 2014339 for invention, class IPC C08J 11/28, B29B 17/00, C08J 11/28, C08L 9/00, publ. 15.06.1994), during which rubber waste is ground products up to 5 mm, mix crumbs on a standard mixing equipment with a paste-like regeneration activator. For 100 parts by weight a waste activator is introduced containing 2-mercaptobenzthiazole, urotropin, iron stearate and glycol in a molar ratio of 1: / 0.2 - 1.0 /: / 0.0017 - 0.017 /: / 0.37 - 0.61 /, respectively. Then for 1 to 3 minutes they are exposed to a high frequency electromagnetic field of the meter range. The temperature of the process is 110 - 130 ° C.

A known method of regeneration of rubber crumb [RF patent No. 2519476 for the invention, cl. IPC C08J 11/04, C08J 11/20, publ. 06/10/2014], which includes the processing of rubber crumb in the softener and activator, while the activator for the destruction of rubber crumb is used magnetic fluid obtained from production waste in an amount of 3-5%, and after processing the rubber crumb in the softener and activator, the resulting mixture kept in an autoclave at a temperature of 185 ° C and a pressure of 3-4 atm for 3 hours.

A common disadvantage of these methods and the compositions used by them are relatively high energy costs due to relatively high temperature conditions, as well as the use of an electromagnetic field or pressure for processing rubber.

Disclosure of invention

The objective of the invention is to obtain a paste-like regenerate without the use of high temperatures, autoclave equipment and sophisticated energy-consuming equipment.

The technical result consists in simplifying the regeneration process, reducing energy consumption during grinding and processing; the regeneration process does not require the use of metal-intensive equipment; the final product is a paste-like regenerate.

The specified technical result is achieved in that the rubber composition includes rubber crumb and a solution containing a solvent, a modifying additive and a catalyst, in the following ratio of components, in wt.%: Rubber crumb 35-45, solvent 45-53, modifying additive 3-4 and catalyst 7-8.

Turpentine or a mixture of turpentine with a solvent can be used as a solvent, and cobalt, manganese, zirconium, and calcium salts can be used as a catalyst.

The modifying additive contains vegetable oil, monoethanolamine, citric acid, triethanolamine and chalk, in the following ratio of components (100% finished additive, in wt.%): Vegetable oil 70-75, monoethanolamine 5-10, citric acid 12-16, triethanolamine 1-2 and chalk 0.1-0.2.

Sunflower oil can be used as a vegetable oil in the composition of the modifying additive.

The specified technical result is also achieved by the fact that the method of manufacturing a rubber composition includes mixing rubber crumb and a solution containing a solvent, a modifying additive and a catalyst, keeping it at a temperature of 20-25 ° C for 24 hours, squeezing the solution from the crumb, then leave the rubber crumb at room temperature in a layer with a thickness of not more than 10 cm and incubated for 12-48 hours.

Presses may be used to squeeze the solution out of the crumb rubber.

Brief Description of the Drawings

In FIG. 1 shows enlarged photographs of the rubber composition before the regeneration process.

In FIG. 2 shows enlarged photographs of the rubber composition after the regeneration process.

The implementation of the invention

The rubber composition includes rubber crumb and a solution containing a solvent modifying the additive and the catalyst, in the following ratio of components, in wt.%: Rubber crumb 35-45, solvent 45-53, modifying additive 3-4 and catalyst 7-8. As rubber crumb can be used crumb tires, waste rubber production.

Turpentine or a mixture of turpentine with solvent can be used as a solvent in the rubber composition.

The composition also includes excipients that are catalysts for oxidative polymerization. These are compounds of some transition and non-transition metals, soluble in oil and organic solvents, mainly salts of cobalt, manganese, zirconium, calcium and others.

The modifying additive contains vegetable oil, monoethanolamine, citric acid, triethanolamine and chalk, in the following ratio of components: (100% finished additive, in wt.%): Vegetable oil 70-75, monoethanolamine 5-10, citric acid 12-16, triethanolamine 1-2 and chalk 0.1-0.2.

Sunflower oil can be used as a vegetable oil in the composition of the modifying additive.

A method of manufacturing a rubber composition includes mixing rubber crumb and a solution containing a solvent, a modifying additive and a catalyst, keeping at a temperature of 20-25 ° C for 24 hours. It is possible to increase the temperature, and at the same time, reduce the swelling time of the crumbs in the solution. After the crumb swells, the crumb increases approximately 1.5 times.

The next step: squeezing out the crumb of the solution. Presses can be used to speed up the process of squeezing the solution out of rubber crumb.

The final stage of production: “wrung out” crumbs are left at room temperature to “liquefy” in a layer with a thickness of not more than 10 cm. In industrial design, baking sheets were used for this. The “liquefied" rubber is held for 12-48 hours.

A way to regenerate crumb rubber is to “liquefy” rubber at room temperature — this is a mild reaction because it does not affect the long rubber molecule from which the rubber was collected, but cuts S-S bonds. Known methods of vulcanization of sulfur rubber, which are usually carried out at high temperatures. In this case, such S-S and S-S-S-S bonds are formed, linking the elastic rubber molecules. In the proposed method, when the S-S bridge is cut, acids are formed with S-O (O) OH groups “hanging” on the rubber molecule.

Implementation example.

A rubber composition was prepared (see FIG. 1) containing rubber crumb (crumb size from 1 to 3 mm) 35 wt.%, Solvent (turpentine) 53 wt.%, Modifying additive 4 wt.% And catalyst 8 wt.% . Then this composition was aged at a temperature of 20-25 ° C for 24 hours. After that, the solution was squeezed out of the crumbs and then the rubber crumb was left on industrial baking sheets in a layer 8-10 cm thick at room temperature for 48 hours.

As a result, a homogeneous paste-like regenerate (see Fig. 2) of the required quality was obtained.

Thus, in the process of obtaining a paste-like regenerate, a simplification of the regeneration process and reduction of energy consumption during grinding and processing are achieved. The regeneration process does not require the use of metal-intensive, autoclave and sophisticated energy-consuming equipment; as well as the use of high temperatures.

The analysis of the prior art showed that the claimed combination of essential features set forth in the claims is unknown. This allows us to conclude that the claimed technical solution meets the condition of patentability “novelty”.

A comparative analysis showed that in the prior art no solutions have been identified that have features that match the distinctive features of the claimed invention, and the popularity of the influence of these signs on the technical result is not confirmed. Thus, the claimed technical solution satisfies the condition of patentability "inventive step".

The above information confirms the possibility of using the claimed composition and technology for the regeneration of rubber crumb in the tire industry, in the production of rubber products and rubber-bitumen mastics in construction, and therefore meets the patentability condition "Industrial Applicability".

Claims (16)

1. The rubber composition for obtaining a regenerate, including rubber crumb and a solution containing a solvent, a modifying additive and a catalyst, in the following ratio, wt.%:  rubber crumb 35-45  solvent 45-53  modifying additive 3-4  catalyst 7-8. 2. The composition according to p. 1, characterized in that turpentine or a mixture of turpentine with a solvent are used as a solvent. 3. The composition according to p. 1, characterized in that as a catalyst use salts of cobalt, manganese, zirconium, calcium. 4. The composition according to p. 1, characterized in that the modifying additive contains vegetable oil, monoethanolamine, citric acid, triethanolamine and chalk, in the following ratio, wt.%:  vegetable oil 72-75  monoethanolamine 7-10  citric acid 13-16  triethanolamine 1-2  chalk 0.1-0.2. 5. The composition according to p. 4, characterized in that sunflower oil is used as vegetable oil. 6. A method of manufacturing a rubber composition for producing a regenerate according to claim 1, comprising mixing crumb rubber and a solution containing a solvent, a modifying additive and a catalyst, keeping it at a temperature of 20-25 ° C for 24 hours, squeezing the solution out of the crumb, then rubber crumb leave at room temperature in a layer with a thickness of not more than 10 cm and incubated for 12-48 hours. 7. The method according to p. 6, characterized in that for pressing the rubber crumbs of the solution using the press.

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