CN116355008B - Treatment process for recycling silicone rubber - Google Patents

Abstract

The invention relates to a treatment process for recycling silicon rubber, and belongs to the technical field of silicon rubber. The invention provides a treatment process for recycling silicon rubber, which realizes effective recycling of waste silicon rubber by a cracking process taking methanol, diethylamine and hexane as filler recycling agents, tetramethylammonium hydroxide as a catalyst and n-octadecanol as a solvent and a filler recycling method; the invention uses the solvent cracking process to treat the waste silicone rubber, reduces the carbonization probability of the siloxane chain units, and is beneficial to improving the generation rate of cyclosiloxane to a certain extent; the invention uses the tetramethyl ammonium hydroxide as the catalyst, and the tetramethyl ammonium hydroxide as the catalyst overcomes the problem that KOH catalyst remains in dimethyl siloxane so as to not meet the production requirement of high-quality silicon rubber, improves the yield of the ring body, and effectively separates the filler; after the polydimethylsiloxane is cracked to reach an equilibrium stage, buffer solution potassium dihydrogen phosphate is added to promote the polydimethylsiloxane to form a ring structure.

Description

A processing technology for recycling silicone rubber

Technical field

The present invention belongs to the technical field of silicone rubber, and specifically relates to a processing technology for recycling silicone rubber.

Background technique

With the development of industrial production, transportation, urban construction, and the increase in population density, the problems of noise pollution, air pollution, water pollution, and solid waste emissions have become increasingly serious and have been listed as the four major pollution problems in the world. Silicone rubber is a synthetic rubber with silicon-oxygen bonds as the main chain. It has properties such as high and low temperature resistance, radiation resistance, high pressure resistance, physiological inertness, ozone aging resistance, weather resistance, and high breathability. It is also resistant to solvents, lubricants and other media. Exhibits excellent chemical inertness. Silicone rubber production and consumption have experienced rapid growth in recent years. In 2013, my country's thermal vulcanization silicone rubber consumption reached 328kt, and it is growing at an average annual rate of 7%-8%. Subsequently, the amount of waste silicone rubber raw rubber generated during production, silicone rubber waste and scraps formed during vulcanization and molding processing, and waste silicone rubber products formed during the application process increased rapidly. Based on an annual elimination rate of 10%, the amount of waste silicone rubber products produced will exceed 30kt, which is a problem that cannot be ignored. Silicone compounds cannot decompose naturally, so waste silicone rubber cannot be decomposed into landfills. The process of converting waste silicone rubber into silica through combustion consumes huge amounts of energy. The price of silicone rubber raw materials is high. The generation and accumulation of waste silicone rubber will not only occupy a large number of factories and pollute the environment, but also lead to rising costs and put great economic pressure on enterprises. Therefore, recycling waste silicone rubber is of great significance to reducing environmental pollution and improving economic benefits.

At present, the main methods for recycling waste silicone rubber include physical methods, chemical methods and biological methods. Among them, physical methods mainly include crushing, crushing, and hot pressing methods to convert waste silicone rubber into reusable powder or particles. However, because this method cannot change the molecular structure and properties of waste silicone rubber, it can only be used as filler or inferior raw materials. It is no longer applicable after the silicone rubber gradually oxidizes after repeated use, and will cause energy consumption and equipment losses. Chemical methods mainly include solvent methods, catalytic cracking methods and other methods to decompose waste silicone rubber into silicone monomers or other low molecular weight substances.

In addition, some disproportionation side reactions occur during the reaction to form cross-linked polymers, which also affect the formation of cyclodimethylcyclosiloxane to a certain extent. Monomethyltrichlorosilane easily forms trifunctional groups during the hydrolysis step. The hydrolyzate is over-cross-linked and produces a large number of silanol groups. The hydroxyl groups are hydrophilic and the molecular skeleton is hydrophobic, causing hydrolysis and cementation, resulting in an increase in the viscosity of the hydrolyzate, increasing the difficulty of separating chloride ions in the hydrolyzate, and even the occurrence of hydrolyzate Adhesion hydrolysis equipment. At the same time, when the trifunctional hydrolyzate is brought to cracking, the material is easy to cement. During intermittent cracking in a single tank, it is difficult to force dryness and the amount of wet residue is large, which can easily cause octamethylcyclotetrasiloxane in dimethylcyclosiloxane (DMC). The content of alkane (D4) is reduced; and the high viscosity hydrolyzate will cause high impurity content such as acid value, terminal chlorine, and trifunctional linkage in the hydrolyzate, which cannot meet the production requirements of high-quality silicone rubber.

Contents of the invention

The invention provides a treatment process for recycling silicone rubber, which uses methanol, diethylamine, and hexane as filler recovery agents, tetramethylammonium hydroxide as a catalyst, and n-octadecanol as a solvent. A cracking process + a filler recovery method , realizing the effective recycling of waste silicone rubber; the present invention uses a solvent cracking process to process waste silicone rubber, which reduces the probability of carbonization of siloxane chain links and is conducive to increasing the cyclosiloxane generation rate to a certain extent; this invention The invention uses tetramethylammonium hydroxide as a catalyst. Tetramethylammonium hydroxide as a catalyst overcomes the problem that the KOH catalyst remains in dimethylsiloxane and cannot meet the production requirements of high-quality silicone rubber, and improves the ring body recovery. efficiency, and effectively separates the filler; in the present invention, after the polydimethylsiloxane cleavage reaches the equilibrium stage, the buffer potassium dihydrogen phosphate is added to promote the formation of a ring structure.

The object of the present invention can be achieved through the following technical solutions:

A processing process for recycling silicone rubber, including the following steps:

Step 1: Crush the waste silicone rubber into powder and put it into the reaction kettle;

Step 2: Add methanol, diethylamine, hexane and tetramethylammonium hydroxide to the reaction kettle, stir at room temperature to obtain a suspension;

Step 3: Filter the suspension and separate the solid;

Step 4: Add n-octadecanol to the reaction kettle and heat up the reaction;

Step 5: Add potassium dihydrogen phosphate buffer to the reaction kettle, continue to heat up the reaction, collect the condensate, and dry it with anhydrous sodium sulfate to obtain dimethylsiloxane;

Step 6: Treat the solid recovered in step 3 with a mixture of diethylamine and hexane to obtain filler.

As a preferred embodiment of the present invention, the dosage ratio of silicone rubber powder, methanol, diethylamine, and tetramethylammonium hydroxide in step 2 is 5g:3mL-5mL:2.5-10mL:0.4-0.6g.

As a preferred embodiment of the present invention, the volume ratio of the added amount of hexane and diethylamine in step 4 is 1:1.

As a preferred embodiment of the present invention, the ratio of the addition volume of n-octadecanol to the volume of the reaction kettle described in step 4 is 1:20-25.

As a preferred embodiment of the present invention, the temperature of the reaction kettle in step 4 after heating is controlled at 120-130°C, and the pressure of the reaction kettle is controlled at 5-10kPa.

As a preferred embodiment of the present invention, the molar ratio of potassium dihydrogen phosphate described in step five to tetramethylammonium hydroxide described in step two is 0.8-1:1.

As a preferred embodiment of the present invention, the temperature after heating in step five is 180°C.

As a preferred embodiment of the present invention, the reaction time in step five is 90-120 minutes.

Beneficial effects of the present invention:

1. The present invention provides a treatment process for recycling silicone rubber, which uses methanol, diethylamine, and hexane as filler recovery agents, tetramethylammonium hydroxide as the catalyst, and n-octadecanol as the solvent. The cracking process + filler recovery This method realizes the effective recycling of waste silicone rubber, and the recovered dimethylsiloxane has a high content of ring bodies.

2. In the treatment process for recycling silicone rubber provided by the present invention, a solvent cracking process is used to process waste silicone rubber. The solvent is n-octadecanol, which is an inert substance with the advantages of high boiling point, low viscosity, and strong heat transfer ability. It can effectively reduce the viscosity of the reaction system in the cracking kettle, make the heat transfer of the system more uniform, and eliminate local overheating. Reduces the occurrence of cracking side reactions and the breakage of carbon-silicon bonds and carbon-hydrogen bonds in the siloxane chain to generate C and H ₂ reactions, reduces the probability of carbonization of the siloxane chain, and to a certain extent helps to increase the generation of cyclosiloxane rate.

3. In the treatment process for recycling silicone rubber provided by the present invention, tetramethylammonium hydroxide is used as a catalyst. Tetramethylammonium hydroxide exists stably at a temperature that does not exceed the decomposition point. When the decomposition point is exceeded, it quickly decomposes into trimethylammonium hydroxide. amines and methanol. When the catalysis is completed, it is easy to remove without leaving any residue. It has no pollution to silicone products, so it is also called a "temporary catalyst". Tetramethylammonium hydroxide as a catalyst overcomes the problem of traditional strong alkali KOH catalysis that remains in dimethylsiloxane and cannot meet the production requirements of high-quality silicone rubber.

4. In the present invention, diethylamine and methanol can effectively swell the silicone rubber, causing the separation of the filler and the polydimethylsiloxane chain. The mixture of diethylamine, methanol and hexane not only very effectively promotes the separation of the silicone rubber containing Depolymerization of silicone and alumina silicone rubber, and complete separation of fillers by filtration before removal of monomers and solvents. After removal of the solvent, a higher content of cyclosiloxane is obtained in the distillation. At the same time, using tetramethylammonium hydroxide instead of KOH not only improves the cyclosiloxane yield, but also effectively separates the filler.

5. In the present invention, after the polydimethylsiloxane cleavage reaches the equilibrium stage, the buffer potassium dihydrogen phosphate is gradually added to neutralize the excess disilanolate and convert it into monosilanolate, thereby reducing the amount of disilanolate produced by one or The smaller number of silicon alkoxides composed of two Si-O units promotes its formation of a ring structure.

6. The present invention effectively recycles waste silicone rubber fillers in the process, realizes the resource treatment of waste materials, avoids waste of resources, and is green and environmentally friendly.

Detailed ways

The technical solutions in the embodiments of the present invention will be clearly and completely described below with reference to the embodiments of the present invention. Obviously, the described embodiments are only some, not all, of the embodiments of the present invention. Based on the embodiments of the present invention, all other embodiments obtained by those of ordinary skill in the art without creative efforts fall within the scope of protection of the present invention.

Example 1

A processing process for recycling silicone rubber, including the following steps:

Step 1: Crush 5kg of waste silicone rubber into powder and put it into the reaction kettle;

Step 2: Add 3L methanol, 2.5L diethylamine, 2.5L hexane, and 0.4kg tetramethylammonium hydroxide into the reaction kettle, and stir at room temperature to obtain a suspension;

Step 3: Filter the suspension and separate the solid;

Step 4: Add n-octadecyl alcohol to the reaction kettle. The volume ratio of n-octadecanol to the volume of the reaction kettle is 1:20. The temperature is raised to 120°C for reaction, and the pressure of the reaction kettle is controlled at 5kPa;

Step 5: Add potassium dihydrogen phosphate buffer to the reaction kettle and heat up the reaction for 90 minutes. Control the molar ratio of potassium dihydrogen phosphate to tetramethylammonium hydroxide described in step 2 to 0.8:1, and control the temperature after heating to 180°C. , collect the condensate and dry it with anhydrous sodium sulfate to obtain dimethylsiloxane;

Step 6: Treat the solid recovered in step 3 with a mixture of diethylamine and hexane to treat the filter residue to obtain filler.

Example 2

A processing process for recycling silicone rubber, including the following steps:

Step 1: Crush 5kg of waste silicone rubber into powder and put it into the reaction kettle;

Step 2: Add 3.5L methanol, 4.5L diethylamine, 4.5L hexane, and 0.45kg tetramethylammonium hydroxide into the reaction kettle, and stir at room temperature to obtain a mixed solution;

Step 3: Filter the suspension and separate the solid;

Step 4: Add n-octadecyl alcohol to the reaction kettle. The volume ratio of n-octadecanol to the volume of the reaction kettle is 1:21. The temperature is raised to 122°C for reaction, and the pressure of the reaction kettle is controlled at 6kPa;

Step 5: Add potassium dihydrogen phosphate buffer to the reaction kettle and heat up the reaction for 97 minutes. Control the molar ratio of potassium dihydrogen phosphate to tetramethylammonium hydroxide described in step 2 to 0.85:1, and control the temperature after heating to 180°C. , collect the condensate and dry it with anhydrous sodium sulfate to obtain dimethylsiloxane;

Step 6: Treat the solid recovered in step 3 with a mixture of diethylamine and hexane to treat the filter residue to obtain filler.

Example 3

A processing process for recycling silicone rubber, including the following steps:

Step 1: Crush 5kg of waste silicone rubber into powder and put it into the reaction kettle;

Step 2: Add 4L methanol, 6.8L diethylamine, 6.8L hexane, and 0.5kg tetramethylammonium hydroxide into the reaction kettle, and stir at room temperature to obtain a suspension;

Step 3: Filter the suspension and separate the solid;

Step 4: Add n-octadecanol to the reaction kettle. The volume ratio of n-octadecanol to the volume of the reaction kettle is 1:23. The temperature is raised to 125°C for reaction, and the pressure of the reaction kettle is controlled at 7kPa;

Step 5: Add potassium dihydrogen phosphate buffer to the reaction kettle and heat up the reaction for 105 minutes. Control the molar ratio of potassium dihydrogen phosphate to tetramethylammonium hydroxide described in step 2 to 0.9:1, and control the temperature after heating to 180°C. , collect the condensate and dry it with anhydrous sodium sulfate to obtain dimethylsiloxane;

Step 6: Treat the solid recovered in step 3 with a mixture of diethylamine and hexane to treat the filter residue to obtain filler.

Example 4

A processing process for recycling silicone rubber, including the following steps:

Step 1: Crush 5kg of waste silicone rubber into powder and put it into the reaction kettle;

Step 2: Add 3L methanol, 2.5L diethylamine, 2.5L hexane, and 0.4kg tetramethylammonium hydroxide into the reaction kettle, and stir at room temperature to obtain a mixed solution;

Step 3: Filter the suspension and separate the solid;

Step 4: Add n-octadecanol to the reaction kettle. The volume ratio of n-octadecanol to the volume of the reaction kettle is 1:24. The temperature is raised to 127°C for reaction, and the pressure of the reaction kettle is controlled at 8kPa;

Step 5: Add potassium dihydrogen phosphate buffer to the reaction kettle and heat up the reaction for 112 minutes. Control the molar ratio of potassium dihydrogen phosphate to tetramethylammonium hydroxide described in step 2 to 0.95:1, and control the temperature after heating to 180°C. , collect the condensate and dry it with anhydrous sodium sulfate to obtain dimethylsiloxane;

Step 6: Treat the solid recovered in step 3 with a mixture of diethylamine and hexane to treat the filter residue to obtain filler.

Example 5

A processing process for recycling silicone rubber, including the following steps:

Step 1: Crush 5kg of waste silicone rubber into powder and put it into the reaction kettle;

Step 2: Add 3L methanol, 2.5L diethylamine, 2.5L hexane, and 0.4kg tetramethylammonium hydroxide into the reaction kettle, and stir at room temperature to obtain a suspension;

Step 3: Filter the suspension and separate the solid;

Step 4: Add n-octadecanol to the reaction kettle. The volume ratio of n-octadecanol to the volume of the reaction kettle is 1:25. The temperature is raised to 130°C for reaction, and the pressure of the reaction kettle is controlled at 10kPa;

Step 5: Add potassium dihydrogen phosphate buffer to the reaction kettle and heat up the reaction for 120 minutes. Control the molar ratio of potassium dihydrogen phosphate to tetramethylammonium hydroxide described in step 2 to 1:1, and control the temperature after heating to 180°C. , collect the condensate and dry it with anhydrous sodium sulfate to obtain dimethylsiloxane;

Step 6: Treat the solid recovered in step 3 with a mixture of diethylamine and hexane to treat the filter residue to obtain filler.

Comparative example 1

A treatment process for recycling silicone rubber, compared with Example 1, does not add ethylenediamine, and includes the following steps:

Step 1: Crush 5kg of waste silicone rubber into powder and put it into the reaction kettle;

Step 2: Add 3L methanol, 2.5L hexane, and 0.4kg tetramethylammonium hydroxide into the reaction kettle, and stir at room temperature to obtain a suspension;

Step 3: Filter the suspension and separate the solid;

Step 4: Add n-octadecyl alcohol to the reaction kettle. The volume ratio of n-octadecanol to the volume of the reaction kettle is 1:20. The temperature is raised to 120°C for reaction, and the pressure of the reaction kettle is controlled at 5kPa;

Step 5: Add potassium dihydrogen phosphate buffer to the reaction kettle and heat up the reaction for 90 minutes. Control the molar ratio of potassium dihydrogen phosphate to tetramethylammonium hydroxide described in step 2 to 0.8:1, and control the temperature after heating to 180°C. , collect the condensate and dry it with anhydrous sodium sulfate to obtain dimethylsiloxane;

Step 6: Treat the solid recovered in step 3 with a mixture of diethylamine and hexane to treat the filter residue to obtain filler.

The remaining steps are the same as in Example 1.

Comparative example 2

A processing process for recovering silicone rubber, compared with Example 2, does not add hexane, and includes the following steps:

Step 1: Crush 5kg of waste silicone rubber into powder and put it into the reaction kettle;

Step 2: Add 3.5L methanol, 4.5L diethylamine, and 0.45kg tetramethylammonium hydroxide into the reaction kettle, and stir at room temperature to obtain a mixed solution;

Step 3: Filter the suspension and separate the solid;

Step 4: Add n-octadecyl alcohol to the reaction kettle. The volume ratio of n-octadecanol to the volume of the reaction kettle is 1:21. The temperature is raised to 122°C for reaction, and the pressure of the reaction kettle is controlled at 6kPa;

Step 5: Add potassium dihydrogen phosphate buffer to the reaction kettle and heat up the reaction for 97 minutes. Control the molar ratio of potassium dihydrogen phosphate to tetramethylammonium hydroxide described in step 2 to 0.85:1, and control the temperature after heating to 180°C. , collect the condensate and dry it with anhydrous sodium sulfate to obtain dimethylsiloxane;

Step 6: Treat the solid recovered in step 3 with a mixture of diethylamine and hexane to treat the filter residue to obtain filler.

The remaining steps are the same as in Example 2.

Comparative example 3

A treatment process for recycling silicone rubber, compared with Example 3, does not add diethylamine + hexane, and includes the following steps:

Step 1: Crush 5kg of waste silicone rubber into powder and put it into the reaction kettle;

Step 2: Add 4L methanol and 0.5kg tetramethylammonium hydroxide into the reaction kettle, stir at room temperature to obtain a suspension;

Step 3: Filter the suspension and separate the solid;

Step 4: Add n-octadecanol to the reaction kettle. The volume ratio of n-octadecanol to the volume of the reaction kettle is 1:23. The temperature is raised to 125°C for reaction, and the pressure of the reaction kettle is controlled at 7kPa;

Step 5: Add potassium dihydrogen phosphate buffer to the reaction kettle and heat up the reaction for 105 minutes. Control the molar ratio of potassium dihydrogen phosphate to tetramethylammonium hydroxide described in step 2 to 0.9:1, and control the temperature after heating to 180°C. , collect the condensate and dry it with anhydrous sodium sulfate to obtain dimethylsiloxane;

Step 6: Treat the solid recovered in step 3 with a mixture of diethylamine and hexane to treat the filter residue to obtain filler.

The remaining steps are the same as in Example 3.

Comparative example 4

A processing process for recovering silicone rubber, compared with Example 4, does not add potassium dihydrogen phosphate buffer, and includes the following steps:

Step 1: Crush 5kg of waste silicone rubber into powder and put it into the reaction kettle;

Step 2: Add 3L methanol, 2.5L diethylamine, 2.5L hexane, and 0.4kg tetramethylammonium hydroxide into the reaction kettle, and stir at room temperature to obtain a mixed solution;

Step 3: Filter the suspension and separate the solid;

Step 4: Add n-octadecanol to the reaction kettle. The volume ratio of n-octadecanol to the volume of the reaction kettle is 1:24. The temperature is raised to 127°C for reaction, and the pressure of the reaction kettle is controlled at 8kPa;

Step 5: Increase the temperature in the reactor for 112 minutes and control the temperature to 180°C. Collect the condensate and dry it with anhydrous sodium sulfate to obtain dimethylsiloxane;

Step 6: Treat the solid recovered in step 3 with a mixture of diethylamine and hexane to treat the filter residue to obtain filler.

The remaining steps are the same as in Example 4.

Comparative example 5

A process for recycling silicone rubber. Compared with Example 5, KOH is used instead of tetramethylammonium hydroxide, and the process includes the following steps:

Step 1: Crush 5kg of waste silicone rubber into powder and put it into the reaction kettle;

Step 2: Add 3L methanol, 2.5L diethylamine, 2.5L hexane, and 0.4kg KOH into the reaction kettle, and stir at room temperature to obtain a suspension;

Step 3: Filter the suspension and separate the solid;

Step 4: Add n-octadecanol to the reaction kettle. The volume ratio of n-octadecanol to the volume of the reaction kettle is 1:25. The temperature is raised to 130°C for reaction, and the pressure of the reaction kettle is controlled at 10kPa;

Step 5: Add potassium dihydrogen phosphate buffer to the reaction kettle and heat up the reaction for 120 minutes. Control the molar ratio of potassium dihydrogen phosphate to tetramethylammonium hydroxide described in step 2 to 1:1, and control the temperature after heating to 180°C. , collect the condensate and dry it with anhydrous sodium sulfate to obtain dimethylsiloxane;

Step 6: Treat the solid recovered in step 3 with a mixture of diethylamine and hexane to treat the filter residue to obtain filler.

The remaining steps are the same as in Example 5.

The recovery rate of the filler and the recovery rate of dimethylcyclosiloxane in Examples 1-5 and Comparative Examples 1-5 are shown in Table 1.

Table 1

It can be seen from Table 1 that the processing technology for recycling silicone rubber provided in Examples 1-5 has good filler recovery rate and dimethylsiloxane recovery rate. The recovery silicone rubber provided by Comparative Examples 1-4 The processing technology has different degrees of reduction in the recovery rate of the filler and the recovery rate of dimethylsiloxane. The processing technology for recycling silicone rubber provided in Examples 1-5 and the recycling silicone rubber provided in Comparative Example 5 The recovery rate of the filler obtained from the treatment process is comparable to the recovery rate of dimethylsiloxane.

In the description of the specification, reference to the terms "one embodiment," "example," "specific example," etc., means that a particular feature, structure, material, or characteristic described in connection with the embodiment or example is included in at least one aspect of the invention. in an embodiment or example. In this specification, schematic representations of the above terms do not necessarily refer to the same embodiment or example. Furthermore, the specific features, structures, materials or characteristics described may be combined in any suitable manner in any one or more embodiments or examples.

The above contents are only examples and explanations of the present invention. Those skilled in the art may make various modifications or supplements to the described specific embodiments or substitute them in similar ways, as long as they do not deviate from the invention or exceed the rights of the present invention. The scope defined in the claims shall belong to the protection scope of the present invention.

Claims (6)

1. A treatment process for recycling silicon rubber is characterized by comprising the following steps: the treatment process comprises the following steps:

step one: crushing waste silicone rubber into powder, and placing the powder into a reaction kettle;

step two: adding methanol, diethylamine, hexane and tetramethylammonium hydroxide into a reaction kettle, and stirring at room temperature to obtain a suspension;

step three: filtering the suspension to separate out solid;

step four: adding n-octadecanol into a reaction kettle, and heating for reaction;

step five: adding potassium dihydrogen phosphate buffer solution into a reaction kettle, continuing to heat up for reaction, collecting condensate at 180 ℃, and drying with anhydrous sodium sulfate to obtain dimethyl siloxane; the molar ratio of the potassium dihydrogen phosphate to the tetramethylammonium hydroxide in the second step is 0.8-1:1;

step six: the solid recovered in step three was treated with a mixture of diethylamine and hexane to give a filler.

2. The process for treating recycled silicone rubber according to claim 1, wherein: in the second step, the dosage ratio of the silicon rubber powder, the methanol, the diethylamine and the tetramethylammonium hydroxide is 5g to 3mL-5mL to 2.5-10mL to 0.4-0.6g.

3. The process for treating recycled silicone rubber according to claim 1, wherein: and in the second step, the volume ratio of the addition amount of the hexane to the diethylamine is 1:1.

4. The process for treating recycled silicone rubber according to claim 1, wherein: and in the fourth step, the ratio of the added volume of the n-octadecanol to the volume of the reaction kettle is 1:20-25.

5. The process for treating recycled silicone rubber according to claim 1, wherein: in the fourth step, the temperature of the reaction kettle after temperature rise is controlled to be 120-130 ℃, and the pressure of the reaction kettle is controlled to be 5-10kPa.

6. The process for treating recycled silicone rubber according to claim 1, wherein: and step five, the reaction time is 90-120min.