Modifying composition for rubber compounds based on 4,4"-bis(3-hydroxycarbonyl-2-propenyl-1-carbamoyl)-3,3"-dichlorodiphenylmethane

Abstract

FIELD: tire and rubber industry.SUBSTANCE: multifunctional modifiers used in the tire and rubber industry for rubber mixtures based on unsaturated and hydrogenated rubbers. Modifying composition for rubber compounds includes component A 10-90 wt.% and component B 10-90 wt.%. Component A based on 4,4'-bis(3-hydroxycarbonyl-2-propenyl-1-carbamoyl)-3,3'-dichlorodiphenylmethane was obtained by reacting 4,4'-methylene-bis-(2-chloroaniline) with maleic anhydride in an acetone solution in the presence of a plasticizer. Component B contains aromatic maleamide of the general formula , where is obtained by the interaction in an acetone solution of aminobenzoic acid or aminophenol with maleic anhydride in the presence or without a plasticizer. The plasticizer is selected from rapeseed oil or oleic acid.EFFECT: increase in the physical-mechanical and physical-chemical properties of rubbers based on the proposed modifying composition, an improvement in the processability of rubber mixtures due to better compatibility of the modifier, the prevention of spraying of the modifier when introduced into the rubber mixture, and an increase in resistance to aging and thermal-oxidative effects of rubbers.1 cl, 6 tbl

Description

[0001] The invention relates to multifunctional modifiers used in the tire and rubber industry for rubber mixtures based on unsaturated rubbers and hydrogenated rubbers.

[0002] The production of rubber products involves a wide variety of ingredients. Among them, a group of substances (processing additives) can be distinguished, which exhibit the properties of modifiers (substances that improve the manufacturing process of rubber and finished products) at relatively low levels compared to the rubber itself.

[0003] The components (ingredients) used to produce rubber have different chemical natures. Therefore, they can have different effects on the compounding process (improving compatibility, dispersion, mixing, etc.). At the same time, some properties of the finished vulcanizates may deteriorate slightly, especially at high temperatures and loads. To address this issue and improve the vulcanizate production process, processing aids (modifiers) are added to rubber compound formulations, which also enhance the final properties of the resulting rubber products. This approach is widely used abroad. The use of processing aids improves the processing of rubber compounds, as well as extends the service life, heat and weather resistance of rubber products, and improves the adhesion of rubber to reinforcing materials.

[0004] The use of process additives is determined by the following requirements: compatibility with rubbers and various fillers; not to impair the flowability and vulcanization properties of rubber compounds; to improve light and ozone resistance; to disperse well in the mixture at low mixing temperatures for use on rollers or during injection; the possibility of use in automatic dispensers.

[0005] The effectiveness of processing additives depends on their mechanism of action when mixed into rubber compounds. Depending on the chemical structure of the processing additives and their state of aggregation, when added to rubber compounds, compounds with improved processability (plasticization effect) can be formed. After vulcanization of the mixtures, rubbers with improved properties are obtained. Modifiers containing several reactive groups are particularly effective.

[0006] The correct selection of processing additives, their dosage, and vulcanization parameters allows for the fullest possible modification of rubber compounds and vulcanizates based on them. Multifunctional additives, which belong to groups with different chemical natures, can improve various rubber performance properties, such as strength, hardness, chemical resistance, heat resistance, etc.

[0007] The currently existing traditional technology for the production of rubber compounds by rolling and “dry” mixing in batch mixers (for example, injection) does not allow for the production of new elastomeric materials, including filled and reinforced compounds, with ever-increasing demands on the technological properties of rubber.

[0008] Furthermore, there are production (technological) issues in the production of rubber products, both in Russia and abroad. For example, the manufacture of rubber compounds for tires requires the addition of large quantities of carbon black (up to 50 or more parts by weight per 100 parts by weight of rubber). This requires significant energy to evenly distribute the ingredients. This also involves heating the mixture to 160°C, which can cause premature vulcanization and requires an additional cooling step before the next step. All of this increases the time required for rubber manufacturing processes. Furthermore, the additional production steps increase the cost of the final product.

[0009] In this regard, one of the most important tasks in formulating rubber products is the search for new modifiers (process additives) that can improve the dispersion of ingredients in highly filled rubber compounds and thereby reduce their heating. This will allow tire and other rubber product manufacturers to reduce the number of stages in the preparation of rubber compounds.

[0010] Triallyl isocyanurate (TAIC) is used as a vulcanization coagent in rubber compounds (RU2559512, RU2612938, RU2671321, RU2714351, etc.). One of the disadvantages of using TAIC is its high cost and the relatively complex, multi-stage production process. Furthermore, improving the resistance of rubber to aging and the thermal-oxidative effects of the rubber is a pressing issue.

[0011] The use of N,N'-bis(hydroxyphenyl)maleamide of the formula is known in rubber compounds (EP085225A1, IPC C08K5 / 20; C08L21 / 00, published 25.02.1998).

[0012] A disadvantage of these modifiers is their poor compatibility with rubber compounds. Furthermore, the properties of rubber products obtained using the above-mentioned vulcanization coagents do not always meet the requirements of rubber products.

[0013] The closest is the rubber compound modifier, which is 4,4'-bis(3-hydroxycarbonyl-2-propenyl-1-carbamoyl)-3,3'-dichlorodiphenylmethane (RU2828472).

[0014] The disadvantage of this modifier is its increased volatility (dust formation) during the production of rubber compounds, which impairs the process technology and the ability to accurately dose the modifier.

[0015] The objective of the technical solution is to create a comprehensive rubber compound modifier capable of enhancing the physical and mechanical properties of rubber; improving the processability of rubber compounds due to improved compatibility of the modifier, especially with polar rubbers; and possessing resistance to aging and thermal-oxidative effects.

[0016] The technical result is an expansion of the arsenal of similarly designed products, an increase in the physical, mechanical, and physical, chemical properties, and improved processability of rubber compounds due to improved modifier compatibility; prevention of modifier dispersion when introduced into the rubber compound; and an increase in the resistance to aging and thermal-oxidative effects of rubbers based on the new modifier.

[0017] The technical result is achieved in that the modifying composition for rubber compounds includes component A based on 4,4'-bis(3-hydroxycarbonyl-2-propenyl-1-carbamayl)-3,3'-dichlorodiphenylmethane, obtained by reacting 4,4'-methylene-bis-(2-chloroaniline) with maleic anhydride in an acetone solution and 1-15% of a plasticizer selected from the group: rapeseed oil, oleic acid, from the weight of 4,4'-methylene-bis-(2-chloroaniline), and component B containing 85-100% of an aromatic maleamide of the general formula , Where , with the following ratio of components, wt. %:

[0018] Component A based on 4,4'-bis(3-hydroxycarbonyl-2-propenyl-1-carbamoyl)-

[0019] 3,3'-dichlorodiphenylmethane 10-90;

[0020] component B 10-90.

[0021] In this case, component B can be obtained by reacting 4,4'-methylene-bis-(2-chloroaniline) in an acetone solution, selected from the group: n-aminobenzoic acid, m-aminobenzoic acid, n-aminophenol, m-aminophenol, with maleic anhydride and

[0022] 1-15 wt. % of a plasticizer selected from the group: rapeseed oil, oleic acid, by weight of 4,4'-methylene-bis-(2-chloroaniline).

[0023] A two-component blend of two amides with added plasticizers improves compatibility with rubbers. The presence of highly active unsaturated bonds in the amides facilitates effective crosslinking of both unsaturated and hydrogenated rubber macromolecules during peroxide and sulfur-peroxide vulcanization. The phenolic, carbonyl, and amide groups of the modifier, through the formation of additional physical bonds (polar dipole and hydrogen), contribute to increased thermal resistance of the rubbers. They can exhibit antioxidant properties due to the presence of phenolic groups.

[0024] The following ingredients are used to obtain a modifying composition for rubber compounds: 4,4'-methylene-bis-(2-chloroaniline) (MOCA, Diamet X, CUAMINE M (CUAMINE M), CURALONE K (CURALONE K), maleic anhydride (GOST 11153-75), acetone, n-aminobenzoic acid (TU 6-36-04691277-17-96), m-aminobenzoic acid (GOST 14310-78), 4-aminophenol (GOST 5209-77), 2-aminophenol (TU 6-09-2919-73), plasticizers rapeseed oil (GOST 31759-2012), oleic acid (GOST 7580-91).

[0025] The synthesis of a modifying composition for rubber compounds is carried out as follows.

[0026] To obtain component A:

[0027] 1) in a conical flask with a stopper, dissolve 13.3 g (0.05 mol) of MOCA in 70 ml of acetone by stirring on a magnetic stirrer until all the granules are completely dissolved;

[0028] 2) in a conical flask with a stopper, dissolve 9.8 g (0.1 mol) of maleic anhydride in 70 ml of acetone by stirring on a magnetic stirrer until all crystals are completely dissolved, then add a plasticizer (rapeseed oil or oleic acid) in an amount of 5-15% of the mass of MOCA and stir until a homogeneous solution is obtained;

[0029] 3) add a solution of maleic anhydride with a plasticizer in portions to the MOCA solution while stirring;

[0030] 4) after the appearance of a yellow precipitate, the solution is heated to 40°C, stirring is continued for 2 hours;

[0031] 5) The precipitate is filtered either with a Buchner funnel or by filtration through a funnel with filter paper, the resulting yellow precipitate is dried in air for 10 - 12 hours, then weighed.

[0032] Next, component B is obtained - aromatic maleimide, for this:

[0033] 1) in a conical flask with a stopper, dissolve 13.7 g (0.1 mol) of aminobenzoic acid or aminophenol in 70 ml of acetone by stirring on a magnetic stirrer until a homogeneous suspension of a brown solution is formed;

[0034] 2) in a conical flask with a stopper, dissolve 9.8 g (0.1 mol) of maleic anhydride in 70 ml of acetone by stirring on a magnetic stirrer until all crystals are completely dissolved;

[0035] 3) add maleic anhydride solution in portions to the aminobenzoic acid or aminophenol solution while stirring;

[0036] 4) after the color changes and a light brown precipitate appears, the solution is heated to 30°C, stirring is continued for 2 hours;

[0037] 5) the precipitate is filtered either with a Buchner funnel or by filtration through a funnel with filter paper, the resulting yellow precipitate is dried in air for 6 - 12 hours, then weighed.

[0038] Or component B - aromatic maleamide with a plasticizer, for this:

[0039] 1) in a conical flask with a stopper, dissolve 13.7 g (0.1 mol) of aminobenzoic acid or aminophenol in 70 ml of acetone by stirring on a magnetic stirrer until a homogeneous suspension of a brown solution is formed;

[0040] 2) in a conical flask with a stopper, dissolve 9.8 g (0.1 mol) of maleic anhydride in 70 ml of acetone by stirring on a magnetic stirrer until all crystals are completely dissolved, then add a plasticizer, rapeseed oil or oleic acid in an amount of 5-15% of the mass of aminobenzoic acid or aminophenol and stir until a homogeneous solution is obtained;

[0041] 3) a solution of maleic anhydride with a plasticizer is added in portions to a solution of aminobenzoic acid or aminophenol while stirring;

[0042] 4) after the color changes and a light brown precipitate appears, the solution is heated to 30°C, stirring is continued for 2 hours;

[0043] 5) the precipitate is filtered either with a Buchner funnel or by filtration through a funnel with filter paper, the resulting yellow precipitate is dried in air for 6 - 12 hours, then weighed.

[0044] After this, component A and component B are mixed in different weight ratios. The compositions of the modifying composition for rubber compounds are given in Tables 1-2. The yield is 90-96%.

[0045] The modifying compositions are powders of light yellow, gray and light brown color with a main substance content of 85-98%.

[0046] Table 1 - Compositions of components A and B of the modifying composition for rubber compounds

[0047] Ingredients Component A, wt.% Component B, wt.% 1 2 3 4 1 2 3 4 5 6 MOSA 100 100 100 100 - - - - - - rapeseed oil 1 15 - - 1 15 - - - - oleic acid - - 1 15 - - 1 15 - - p- or m-aminobenzoic acid - - - - 100 100 100 - p- or m-aminophenol - - - - - - 100 100 - 100

[0048] Table 2 - Compositions and properties of the modifying composition for rubber compounds

[0049] Designation Content, wt. % 1 2 3 4 5 6 7 8 9 10 11 12 13 14 15 16 Component A 1 10 90 10 90 2 10 90 10 90 3 10 90 10 90 4 10 90 10 90 Component B 1 90 10 2 90 10 3 90 10 4 90 10 5 90 10 90 10 6 90 10 90 10 Exit, % 91 89 92 94 90 95 92 90 96 92 88 93 94 90 95 92 Content of the main substance, % 98 98 98 98 85 85 85 85 98 98 98 98 85 85 85 85 Appearance powders of light yellow, gray and light brown colors

[0050] Table 3 - Compositions of rubber compounds based on unsaturated rubbers with sulfur-peroxide vulcanization type (using BNK NBR 6280 as an example)

[0051] Components Content, wt. h. Prototype 1 2 3 4 5 6 7 8 Nitrile butadiene rubber NBR 6280 100,0 100,0 100,0 100,0 100,0 100,0 100,0 100,0 100,0 Modifier 1 1 1 1 1 1 1 1 1 Sulfur 9,0 9,0 9,0 9,0 9,0 9,0 9,0 9,0 9,0 Diproxide 4,5 4,5 4,5 4,5 4,5 4,5 4,5 4,5 4,5

[0052] Table 4 - Properties of vulcanizates based on unsaturated rubbers with sulfur-peroxide vulcanization type (using BNK NBR 6280 as an example)

[0053] Characteristics Samples prototype 1 2 3 4 5 6 7 8 fp, MPa 16,2 16,5 16,4 17,2 17,1 16,9 16,7 17 17,1 εp, % 120 110 60 112 110 80 90 95 98 N (according to Shore A), arb. units 91 91 92 90 91 92 91 89 90 B, kN / m 52 56 68 65 58 59 61 54 57 Change in the mass of vulcanizates after exposure to a mixture of isooctane + toluene (70:30) at 23°C×24 h +6,3 +5,3 +5 +4,7 +5,2 +3,7 +4,3 +2,2 +3,3 Changes in parameters after aging in air at 150°C×24 h fp, MPa +24 +6,5 +6 +4 +5 +3,5 +4,5 +2,5 +1,5 εp, % -16,6 -26,6 -33,3 -38 -35 -30 -25 -10 -15 N (according to Shore A), arb. units +5 +5 +5 +3 +3 +4 +3 +1 +3 Changes in indicators after exposure to SZhR-1 at 150°C×72 h fp, MPa +2,4 -0,9 -0,6 +0,5 +0,7 +0,5 +0,7 -0,5 -1,6 εp, % -50 0 0 +37,5 +35 +37,5 +35 0 0 N (according to Shore A), arb. units +5 +3 +3 +3 +4 +3 +4 +2 +1

[0054] Table 5 - Compositions of rubber compounds based on saturated rubbers with peroxide vulcanization (using the example of hydrogenated BNK Therban 3406)

[0055] Components Content, wt. h. Prototype 9 10 11 12 13 14 15 16 Therban 3406 Hydrogenated Butadiene Nitrile Rubber 100,0 100,0 100,0 100,0 100,0 100,0 100,0 100,0 100,0 Modifier 1 1 1 1 1 1 1 1 1 Novoperox BP-40 12 12 12 12 12 12 12 12 12

[0056] Table 6 - Properties of vulcanizates based on unsaturated rubbers with peroxide vulcanization type (using the example of hydrogenated BNR Therban 3406)

[0057] Characteristics Samples prototype 9 10 11 12 13 14 15 16 fp, MPa 24,8 28,2 28,8 29,4 27,5 28,8 29,2 29,9 29,8 εp, % 147 174 170 158 150 158 144 162 160 N (according to Shore A), arb. units 93 93 93 93 93 93 94 94 93 B, kN / m 101 108 114 121 98 101 99 93 94 Change in the mass of vulcanizates after exposure to a mixture of isooctane + toluene (70:30) at 23°C×24 h +18,1 +18,7 +18,8 +18,8 +19, +19,4 +18,8 +19,3 +19,1 Changes in parameters after aging in air at 150°C×24 h fp, MPa +1,19 -7,64 +1,36 -23 -5,71 +2,04 -3,7 -9,84 -9,1 εp, % +3,4 -13,8 -10,6 -3,8 0 +7,6 +23,6 -27,16 -26,6 N (according to Shore A), arb. units 0 +2 +1 +1 +1 +1 0 0 0 Changes in indicators after exposure to SZhR-1 at 150°C×72 h fp, MPa +9,9 -5,55 -18,03 -1 +9,29 0 -5,03 -21,64 -20,4 εp, % +17 -4,6 -11,7 +34,2 +20 +11,4 +19,4 -20,1 -19,6 N (according to Shore A), arb. units -2 -2 -3 -1 -2 0 -2 -2 -2

[0058] The proposed modifier was tested in rubber compounds based on NBR 6280 nitrile butadiene rubber and Therban 3406 hydrogenated nitrile butadiene rubber.

[0059] Various unsaturated rubbers (for example, various grades of BNK SKN 1865 / NBR 1865, SKN 1855 / NBR 1855, SKN 3335 / NBR 3335, SKN 2655 / NBR 2655, SKN 3335, SKN 3345, SKN 3355, SKN 3365, SKN 3375) and hydrogenated rubbers (for example, various grades of HNBR 3406, HNBR 3408, HNBR 3409) and other components of rubber compounds can also be used to obtain rubber compounds:

[0060] To study the effect of modifying compositions for rubber compounds on rubber properties, various rubber compound variants were prepared. Examples of rubber compound compositions are shown in Tables 3 and 5.

[0061] Rubber compound based on butadiene - nitrile rubber includes:

[0062] Nitrile butadiene rubber NBR 6280 (LG Chemical);

[0063] vulcanizing agents: technical sulfur (GOST 127.1-93), diproxide (TU 6-14-21-75);

[0064] the claimed modifying compositions for rubber compounds based on 4,4'-bis(3-hydroxycarbonyl-2-propenyl-1-carbamoyl)-3,3'-dichlorodiphenylmethane.

[0065] Hydrogenated nitrile butadiene rubber compound includes:

[0066] Hydrogenated butadiene - nitrile rubber (Therban 3406);

[0067] Vulcanizing agent: Novoperox BP-40;

[0068] the claimed modifying compositions for rubber compounds based on 4,4'-bis(3-hydroxycarbonyl-2-propenyl-1-carbamoyl)-3,3'-dichlorodiphenylmethane.

[0069] The rubber mixture and rubber were prepared as follows:

[0070] 1) The rubber was mixed with the components on laboratory rollers for 25 minutes at a roller temperature of 60-70°C;

[0071] 2) The rubber mixture was vulcanized in a rubber vulcanization press at 170°C for 30 min.

[0072] Testing of the modifier for rubber compounds and rubbers using it is carried out according to standard methods. Determination of conventional tensile strength and relative elongation at break according to GOST 10362-2017 and GOST 270-75. Determination of Shore A hardness was carried out according to GOST 263-75. Determination of tear resistance according to GOST 262-93. Determination of changes in conventional tensile strength, relative elongation at break, hardness, and mass of vulcanizates after exposure to aggressive environments according to GOST 9.030-74. Determination of changes in conventional tensile strength and relative elongation at break after aging in air according to GOST R 56803-2015 and GOST 9.024-74. The properties of vulcanizates are presented in Tables 4 and 6.

[0073] Tables 4 and 6 demonstrate that the addition of the claimed modifying compositions based on 4,4'-bis(3-hydroxycarbonyl-2-propenyl-1-carbamoyl)-3,3'-dichlorodiphenylmethane enables the production of rubbers with high physical and mechanical properties, aging resistance, and thermal stability due to improved compatibility of the modifier with polar rubbers. The addition of plasticizers virtually eliminates dust formation during dosing during the rubber compound production process, improving the processability of the rubber compounds.

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