RU2337929C1 - Method of obtaining regenerate - Google Patents

Abstract

FIELD: chemistry.

SUBSTANCE: invention relates to rubber technology, namely, to technology of rubber regeneration. Method includes single-phase forge-rolling of disinfected latex used medical gloves until cloth is obtained. cloth is recycled in rubber mixer in mode of self-heating during 25 minutes in presence of softening agent - oil "ПН" 6 in amount 10-35% from cloth weight and anti-ager - product "НГ" 2246 in amount 0.5-1% from cloth weight.

EFFECT: creation of economical and simple method of production of rubber regenerate using new type of raw material.

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Description

The invention relates to rubber technology for the rubber regeneration section.

Currently, in many industries much attention is paid to the processing and use of recycled materials. This is due both to the economic feasibility of using waste in the secondary market and to the need to pay great attention to the environmental problem.

The most important area of processing used rubber products is to obtain a regenerate.

Now a widespread method for producing regenerate, including devulcanization. Devulcanization is the heating of crushed rubber with softeners for several hours (B.C. Shane et al., Basic processes of rubber production, 1989, pp. 145-152).

The closest way to obtain a regenerate includes thermomechanical processing of rubber raw materials in the presence of a softener and a chemical reagent (RF Patent 2130952). The disadvantage of this method is that to obtain a regenerate it is necessary to conduct heating and use a chemical activator as a chemical reagent.

The objective of the invention was to develop an economical, simpler method of producing regenerate from a new type of raw material, which was superior to tire in its properties. Another objective of the work was the recycling of used latex medical gloves.

The technical result is achieved by using as a raw material the skin of the material from disinfected used latex gloves, which was obtained by passing the gloves once through the zero gap of the cold rollers. The skin is subsequently subjected to thermomechanical destruction for 25 minutes in the mode of self-heating in the presence of a softener and anti-aging agent.

Disinfected gloves were obtained by carrying out a full cleaning cycle of used latex medical gloves (chemical disinfection, rinsing with running water, pre-sterilization cleaning, washing off the detergent used in pre-sterilization cleaning, steam sterilization).

Example 1

Disinfected used gloves made of natural latex in the amount of 1 kg were passed through the zero gap of the cold rollers once. As a result of this process, the gloves turned into a latex skin. The resulting skin was loaded into a working cold rubber mixer. The rubber mixer worked in self-heating mode, i.e. its temperature gradually increased. The temperature at the end of the regenerate production cycle was 70 ° C. After 1 minute of stirring in 4 portions, 250 g of PN-6 oil (oil plasticizer) (GOST 38.1137-82) was introduced into the loading hole of the rubber mixer (GOST 38.1137-82). PN-6 oil refers to the extracts of the selective purification of mineral oils - by-products obtained in the process of oil refining components with solid adsorbents or selective solvents (phenol, furfural cresol, propane, etc.). It consists mainly of aromatic hydrocarbons. The time for introducing the oil was 16 minutes. After the introduction of the oil, the rubber mixer continued mixing the composition for another 8 minutes. Two minutes before the end of the process, an antioxidant was introduced into the rubber mixer (product NG 2246-bisphenol (2,2'-methylene-bis (4 methyl-6 tert-butylphenol) TU 38.101617-80) in an amount of 8 g. Thus, the total time for obtaining the regenerate was 25 minutes The total weight of the obtained product was 1.2 kg

After completion of the regeneration process, the resulting material, which is a light homogeneous mass, was discharged from the rubber mixer and cooled to room temperature.

After cooling, the regenerate was processed on cold rollers (temperature 20 ° С) in a thin gap to obtain a uniform skin without breaks (the time to obtain a uniform skin was 2 minutes).

Next, the regenerate was cooled for 15 minutes and re-processed on cold rollers (temperature 20 ° C) to obtain a uniform skin without breaks (rolling time 1.5 minutes).

After that, the material was given the necessary caliber (thickness) and shape on the molding equipment as the calender used.

Example 2

Disinfected gloves made of natural latex in the amount of 0.5 kg were passed through the zero gap of the cold rollers once. As a result of this process, the gloves turned into a latex skin. The resulting skin was loaded into a working cold rubber mixer. The rubber mixer worked in self-heating mode, i.e. its temperature gradually increased. The temperature at the end of the regenerate production cycle was 80 ° C. After 2 minutes of mixing in 4 portions, PN-6 oil (GOST 38.1137-82) in the amount of 0.15 kg was introduced into the loading hole of the rubber mixer. The oil injection time was 15 minutes. After the introduction of the oil, the rubber mixer continued mixing the composition for another 8 minutes. Two minutes before the end of the process, an antioxidant was introduced into the rubber mixer (product NG 2246 TU 38.101617-80) in an amount of 4 g. Thus, the total time for obtaining the regenerate was 25 minutes. The total weight of the obtained product was 650 g.

After completion of the regeneration process, the resulting material, which is a light homogeneous mass, was discharged from the rubber mixer and cooled to room temperature.

After cooling, the regenerate was processed on cold rollers (temperature 20 ° C) in a thin gap to obtain a homogeneous skin without breaks (the time to obtain a homogeneous skin was 1.5 minutes).

Next, the regenerate was cooled for 15 minutes and re-processed on cold rollers (temperature 20 ° C) to obtain a homogeneous skin without breaks (rolling time 2 minutes).

After that, the material was given the necessary caliber (thickness) and shape on the molding equipment, which was used as a roller.

Based on the experiments (examples 1, 2), the process of obtaining the regenerate can be described as follows.

The processing of medical gloves from natural latex to regenerate was carried out on a rubber mixer using a thermomechanical method in the self-heating mode.

The disinfected used latex gloves, before being loaded into the rubber mixer, were passed through the zero gap of the cold rollers once, resulting in a skin of material.

The resulting skin was loaded into a working cold rubber mixer. The rubber mixer worked in self-heating mode, that is, its temperature gradually increased due to the mechanical destruction of the skin. The temperature at the end of the regenerate production cycle was 70-80 ° C. After 1-2 minutes of mixing in 3-4 portions, PN 6 oil (GOST 38.1137-82) was introduced into the loading hole of the rubber mixer in an amount of 10-35% by weight of the skin. The time for introducing the oil was 15 minutes. Then the rubber mixer continued mixing the composition for another 8 minutes. Two minutes before the end of the process, an antioxidant was introduced into the rubber mixer (product PN 2246 TU 38.101617-80) in an amount of 0.5-1% by weight of the skin.

After completion of the regeneration process, the resulting material, which is a light homogeneous mass, was unloaded from the rubber mixer and cooled to room temperature.

After cooling, the regenerate was processed on cold rollers (temperature 20 ° C) in a thin gap to obtain a uniform skin without breaks (usually the time to obtain a uniform skin was 1.5-2 minutes).

Next, the regenerate was cooled for 10-15 minutes and re-processed on cold rollers (temperature 20 ° C) to obtain a homogeneous skin without breaks (rolling time 1.5-2 minutes).

After that, the material was given the necessary caliber and shape on any forming equipment (rollers, worm machine, calender).

Thus, as a result of mechanical action, a light, homogeneous, plastic material was obtained that did not contain undeveloped particles of “cereal”, having the following characteristics:

acetone extract - 23.7%;

ash content of 7%.

The technological properties of the obtained material are as follows:

Shrinkage 20%

Softness - 0.33

Plasticity - 0.13

Recoverability - 0.40

Elastic Recovery - 2.88

The minimum Mooney viscosity at a temperature of 100 ° C in the fourth minute is 39 Mooney units

The rubber compound of the following composition was made from the obtained regenerate

(bulk parts)

Regenerate - 130

Sulfur - 3.0

Mercaptobenzthiazole - 0.7

Zinc Oxide - 5.0

Stearic acid - 0.5

The viscosity and vulcanization characteristics of the resulting rubber compound are as follows:

The minimum Mooney viscosity at a temperature of 120 ° C is 19.5;

Vulcanization time - 10 minutes

Vulcanization rate 6 min

The optimum vulcanization time, determined on a Monsato rheometer at a temperature of 150 ° C, was 4 minutes.

At this temperature and time of vulcanization, rubber samples were made and their physical and mechanical tests were carried out.

The test results are as follows.

Elongation stress 200% - 0.15 MPa

                    300% - 0.3 MPa

                    500% -1.3 MPa

Conditional tensile strength - 7.2 MPa

Relative elongation - 800%;

Residual elongation - 4%

Tear resistance - 7.5 MPa

Thus, the regenerate obtained by the above method, in comparison with the regenerate obtained from conventional raw materials and by the method described in the closest analogue, has sufficient strength and elongation, which allows it to be used in compositions to increase the elongation and tear resistance.

Claims (1)

A method of producing a rubber regenerate, including thermomechanical processing of rubber raw materials in the presence of a softener and chemical reagents, characterized in that the raw material is a skin of material obtained from disinfected medical latex gloves by single rolling, the thermomechanical treatment of which proceeds in the mode of self-heating of the rubber mixer for 25 min, PN 6 oil is used as a softener in the amount of 10-35% by weight of the skin, and the antioxidant acts as a chemical reagent - p product NG 2246 in an amount of 0.5-1% by weight of the skin.