RU2235740C2 - Rubber compound - Google Patents

Abstract

FIELD: rubber industry.

SUBSTANCE: tire-destination rubber compound comprises: (i) copolymer of butadiene or butadiene and styrene (α-vrthylstyrene) with (meth)acrylic acid methyl ester, β-hydroxyethyl ester, β-hydroxypropyl ester, β-(N,N-dimethylamino)ethyl ester, β-(N,N-diethylamino)ethyl ester, β-(N,N-dimethylamino)propyl ester, or β-(N,N-diethylamino)propyl ester at weight ratio of butadiene/styrene(α-methylstyrene)/ester (99.5-40.0):(0-40.0):(0.5-20.0), respectively; (ii) 2-10 wt parts of aminosilane coupler selected from group including β-aminoethoxytriethoxysilane, reaction product of monoethanolamine with tetraethoxysilane or polyphenylethoxysilane, or polyethoxysiloxane at weight ratio 1:(1-4), or mixture of aminosilane coupler with bis(3-triethoxysilylpropyl)tetrasulfide at weight ratio (1-10): 1; (iii) 5-80 wt parts of silicic acid filler; (iv) 0-80 wt parts of carbon black; and (v) 10-45 wt parts of special-destination additives, in particular plasticizers, sulfur, accelerators and activators of sulfur vulcanization.

EFFECT: improved elasto-viscosity, elastic, and wear-resistant characteristics, and reduced heat buildup.

2 tbl, 32 ex

Description

The invention relates to the field of production of rubber compounds for tire use containing silicic acid fillers and providing the manufacture of tires with enhanced performance properties, specifically rubber compounds based on unsaturated rubbers containing silicic acid fillers and coupling agents, providing the formation of bridge structures between silicic acid fillers and rubber macromolecules.

Known vulcanizable rubber composition comprising unsaturated rubber, for example styrene butadiene rubber emulsion polymerization, 5-100 wt.h. filler - silicon oxide - per 100 wt.h. rubber, 0.1-15.0 parts by weight an organic coupling agent containing functional groups, one of which is a sulfur-containing mercapto group capable of attaching to rubber, and the other is nitrogen-containing (isocyanate, carbodiimide, imino or amino group), and if the nitrogen-containing group is of the amine type, then the coupling agent contains at least two of these groups [US patent 3884285, IPC 60 With 5/100, With 08 11/10, With 08 11/12, publ. 05/20/1975], for example, such a coupling agent is the product of the interaction of polyethylene polyamine with ethylene sulfide.

This rubber compound provides vulcanizates with high wear resistance.

However, it has significant disadvantages - high viscosity unvulcanized mixture, low strength at 300% tensile. In addition, the products used in the rubber composition are obtained from highly toxic compounds - polyethylene polyamine, ethylene sulfide - substances of the 1st and 2nd hazard class.

Also known is a rubber mixture comprising 100 parts by weight of natural or synthetic rubber or a mixture of rubbers, 0.75-35.00 wt.h. triazole type benztriazole, tolyltriazole, naphthyltriazole or other similar compounds, 2-35 parts by weight brass powder, or conductive carbon black, or mixtures thereof, a silicic acid filler and a silane coupling agent selected from the group of 3,3'-bis (triethoxysilylpropyl) tetrasulfide, 3-mercaptopropyltri-methoxysilane [US Patent 6014998, IPC C 08 K 003/34, B 60 C 011/00, B 60 C 001/00, publ. January 18, 2000].

This composition of the rubber compound provides a high vulcanization rate, increased hardness and strength properties, high dynamic modules of rubber based on it.

The disadvantages of the rubber mixture are the high tendency to vulcanization, the need to use, in addition to the amine-containing and silane agents, a combination of additionally brass-soot powder. So, in the best case, 3.1 parts by weight are present in the rubber composition. benztriazole, 3.1 wt.h. carbon black powder and 4.8 wt.h. 3,3'-bis (triethoxysilylpropyl) tetrasulfide.

Also known is a rubber mixture comprising 100 parts by weight of diene rubber or a mixture of rubbers, of which at least one is diene rubber, 5-100 wt.h. a filler consisting of precipitated silica and carbon black, where the precipitated silica is in an amount of 10-80 wt.h. per 100 parts by weight rubber, an amine-containing agent of a combination of N, N'-dithiobis (benzenesulfonamide) or a combination of 95-25% by weight of sulfonamide and 5-75% by weight of 3,3'-bis (triethoxysilylpropyl) tetrasulfide, wherein the weight ratios of the coupling agent and silicon dioxide are from 0.01: 1 to 0.20: 1 [US patent 5981633, IPC 60 C 011/00, publ. November 9, 1999].

Such a rubber mixture allows vulcanization of both individual diene rubbers and a mixture of rubbers, resulting in vulcanizates with good elastic strength properties, low tangential loss and good wear resistance.

The disadvantages of the rubber mixture include the following: insufficiently high strength of the vulcanizate when using large quantities of silicic acid filler and one combination agent - sulfonamide; the synthesis of N, N'-dithiobis (sulfonamide) is a complex, multi-stage process based on expensive and highly toxic products.

The closest in technical essence and the achieved result to the proposed one is a rubber mixture containing 100 parts by weight at least one sulfur vulcanizable rubber selected from the group of polymers of conjugated dienes or diene copolymers and vinyl aromatic compounds, 10-250 wt.h. precipitated silica, 0.05-10.00 parts by weight aminosilane of the general formula I:

where R ₁ , R ₂ and R ₃ is an alkoxyl radical containing 1-8 carbon atoms, R ₄ is an alkylene group containing 1-18 carbon atoms or an arylene or alkylene substituted group with 6-10 carbon atoms, R ₅ is hydrogen or alkyl group, 0.05-10.00 parts by weight sulfur-containing organosiloxane of the general formula II or III:

where n = 2-8, R ₁ , R ₂ , R ₃ are alkoxy radicals with 1-3 carbon atoms, R ₄ is an alkylene group with 1-3 carbon atoms, and the rubber mixture includes rubber selected from the group: natural rubber, polychloroprene, polyisoprene, polybutadiene, styrene-butadiene copolymer, acrylonitrile-isoprene copolymer, nitrile-butadiene rubber, ethylene-propylene-diene rubber, methyl methacrylate-butadiene copolymer, methyl methacrylate-isoprene or a mixture thereof; the rubber mixture may also include carbon black, aluminosilicates [US patent No. 5698619, IPC C 08 L 7/00, C 08 L 9/06, C 08 K 5/16, C 08 K 5/54, publ. December 16, 1977].

Such a rubber mixture due to the presence of both tetrasulfide and amino-containing silanes provides the manufacture of rubbers with improved wear resistance, increased elasticity and reduced hysteresis losses. In addition, the introduction of the composition of the rubber mixture of aminoalkyltrialkoxysilane can reduce the dosage of the polysulfide silane coupling agent. For example, it is possible to use γ-aminopropyltriethoxysilane at a dosage of 2.0 parts by weight and product Si-69 (bis (3-triethoxysilylpropyl) tetrasulfide) in a dosage of 6 parts by weight

The disadvantage of this rubber compound is the need to use aminoalkyltrialkoxysilanes, because compounds of this class are difficult to access expensive products. For example, the synthesis of γ-aminopropyltriethoxysilane (the most, judging by the description of the known technical solution, optimal product) is carried out by reacting allylamine with triethoxysilane in a mixture of isopropyl alcohol and allylglycidyl ether in the presence of a catalyst - platinum chloride.

The technical task of the invention is to obtain a rubber mixture using an aminosilane coupling agent, synthesized by simple technology from low-toxic available products, the vulcanizates based on which have good elastic strength characteristics, high elastic properties and wear resistance, low heat generation, which makes it possible to successfully use the inventive rubber mixture for rubbers tire destination.

The stated technical problem is solved in that the rubber mixture comprising a copolymer of diene and ether α, β-unsaturated carboxylic acid, silicic acid filler, aminosilane coupling agent and target additives, as a copolymer of diene and ether α, β-unsaturated carboxylic acid contains a copolymer of butadiene or butadiene and styrene (α-methylstyrene) with methacrylic acid (methyl) methyl ester, or methacrylic acid β-hydroxyethyl ether, or methacrylic acid β-hydroxypropyl ether, or β (N, N-dimethylamino) ethyl methacrylic acid ester, or β (N, N-diethylamino) ethyl methacrylic acid ester, or β (N, N-dimethylamino) methacrylic acid propyl ester, or β (N, N-diethylamino) methacrylic acid propyl ester in a weight ratio of bound monomers in said copolymer butadiene: styrene (α-methylstyrene): said ether of α, β-unsaturated carboxylic acid 99.5-40.0: 0-40.0: 0.5-20.0, respectively, and as an aminosilane agent, combinations the mixture contains a product selected from the group of β-aminoethoxytriethoxysilane, the product of the interaction of mono tanolamine with tetraethoxysilane, or polyphenylethoxysilane, or polyethoxysiloxane in a mass ratio of 1: 1-4, respectively, or a mixture of an aminosilane coupling agent from this group with bis (3-triethoxysilylpropyl) tetrasulfide in a mass ratio of 1-10: 1, respectively, and possibly contains carbon black in the following the content of components in the rubber mixture, parts by weight:

The specified copolymer of butadiene or butadiene and styrene (α-methylstyrene) with ether α, β-unsaturated carboxylic acid 100

Silica filler 5-80

Carbon black 0-80

The specified aminosilane coupling agent or the specified mixture of the aminosilane coupling agent with bis (3-triethoxysilylpropyl) tetrasulfide 2-10

Target Supplements 10-45

As a silicic acid filler, the composition of the rubber composition includes finely divided precipitated silicon oxide, for example BS-120 according to GOST 18307-78 (manufactured in Russia), Ultrasil VN ₃ (manufactured by Ron Pulinc Co.); HiSil (PPG Indastries).

The use of silica filler in combination with carbon black allows you to control the elastic and dynamic properties of vulcanizates. In the preparation of rubber mixtures according to examples, carbon black of grade P-234 is used according to GOST 7885-86.

The inventive rubber mixture also contains targeted additives plasticizers, sulfur, accelerators and activators of sulfur vulcanization, dispersing agents, antioxidants, etc. As antioxidants, N, N'-diphenylphenylenediamine, N-isopropyl-N'-phenyl-n-phenylenediamine or a mixture thereof with acetonanil are used.

Examples 1-10

The copolymers of butadiene or isoprene or butadiene and styrene (α-methylstyrene) with α, β-unsaturated acid ester are obtained by water-emulsion polymerization using an oxidation-reduction iron-trilon-rongalite system as an initiator, and a mixture of rosin soaps and emulsifiers as an emulsifier fatty acids. The polymerization temperature is 5 ± 2 ° C, the reaction time is 10-16 hours, the conversion of monomers to the polymer is 60-70%. A method of obtaining a copolymer of butadiene, styrene and methyl methacrylate is described in RF patent No. 21115664. Degassed rubbers are isolated from latexes with a mixture of electrolytes: salt + acid. The rubbers are pressed out of moisture and dried in an air dryer. The monomer composition of the rubbers is shown in table 1.

Example 10 describes a method for producing a copolymer of isoprene and methyl methacrylate used to prepare the rubber mixture in examples 31, 32 of the prototype.

Example 11

A mixture of 416 g of tetraethoxysilane and 122 g of monoethanolamine (weight ratio 3.4: 1) is heated to a temperature of 90-160 ° C under stirring with continuous distillation of the ethanol produced by the reaction. The reaction time is 2.5 hours. Receive 446 g of the target product - β-aminoethoxytriethoxysilane. The composition and structure of the product are proven by elemental and spectral analysis. The nitrogen content found by the Kjeldahl method is 6.7% (calculated - 6.3%). In the H1 NMR spectrum, there are bands with chemical shifts: 1.0-1.12 ppm. (protons of the CH ₃ group); 3.67-3.73 ppm (CH ₃ group), 2.7 ppm. (NH ₂ group). The following characteristic absorption bands are present in the IR spectrum: at 1100 cm ^-1 (Si-0), at 1590 cm ^-1 and 3330 cm ^-1 (NH).

Example 12

An aminosilane coupling agent is prepared as described in Example 11, but the weight ratio of tetraethoxysilane to monoethanolamine is 2: 1.

Example 13

An aminosilane coupling agent is prepared as described in Example 11, but the weight ratio of tetraethoxysilane to monoethanolamine is 4: 1.

Examples 14 and 15.

In accordance with example 11, the products of the interaction of polyphenylethoxysilane with monoethanolamine are obtained at mass ratios of polyphenylethoxysilane and amino alcohol 2: 1 and 4: 1. Industrial products FES-50 or FES-80 (TU 6-01-20-52-90) are used as polyphenylethoxysilane.

Examples 16-18.

In accordance with example 11, the products of the interaction of polyethoxysiloxane with monoethanolamine are obtained at various mass ratios of siloxane and amino alcohol of 2: 1, 3: 1 and 4: 1. Ethyl silicate-32, ethyl silicate-40, ethyl silicate-50 (GOST26371-84) industrial products are used as polyethoxysiloxane.

Example 19

A rubber mixture is prepared on the basis of rubber obtained in Example 1, which is an emulsion copolymer containing 81.5% butadiene, 14% styrene and 4.5% methyl methacrylate.

As the coupling agent in the composition of the rubber compound, β-aminoethoxytriethoxysilane obtained in accordance with Example 11 is used.

The components are mixed in two stages, the first stage is in the rubber mixer, and the second is on the rollers. The following is the rubber preparation mode:

The mixture is discharged from the rubber mixer in the 11th minute and cooled to 50 ± 5 ° C on a roll.

The rubber mixture is removed from the rollers in the 9th minute.

The full rubber compound recipe is shown in table 2.

Physico-mechanical properties of rubber compounds and vulcanizates are determined according to GOST 23492-83, abrasion resistance - according to GOST 23509-79.

The properties of rubber compounds and vulcanizates are also shown in table 2.

The rubber mixture has fairly good technological properties, normal vulcanization parameters, the vulcanizate is characterized by high elastic strength properties, high elasticity and good dynamic characteristics.

Examples 20-30.

Rubber mixtures are prepared analogously to example 19, while using different types of rubbers, different dosages and combinations of fillers, coupling agents and other ingredients. The composition and properties of rubber compounds are shown in table 2.

Examples 31, 32 (prototype).

Preparing rubber mixtures based on a copolymer of isoprene with methyl methacrylate obtained in example 10.

As a combination agent, the rubber mixture includes bis (3-triethoxysilylpropyl) tetrasulfide (product Si-69, manufactured by Degussa) and γ-aminopropyltriethoxysilane (product AGM-9, manufactured by Khimprom JSC, Slavgorod, TU RF P- 8-62).

The preparation of rubber compounds is carried out according to example 19. The full formulation of rubber compounds and their properties are shown in table 2.

As can be seen from the data given in examples 1-32 and tables 1, 2, the set of essential features of the claimed invention allows us to solve the technical problem - obtaining a rubber mixture using an aminosilane coupling agent synthesized by simple technology from low-toxic available products, the vulcanizates based on which have good elastic and strength characteristics, high elastic properties and wear resistance, low heat generation.

Claims (1)

A rubber mixture comprising a copolymer of diene and an ester of α, β-unsaturated carboxylic acid, a silica filler, an aminosilane coupling agent and target additives, characterized in that the rubber mixture contains a copolymer of butadiene or butadiene as a copolymer of diene and an ester of α, β-unsaturated carboxylic acid and styrene (α-methylstyrene) with methacrylic acid (methyl acrylic acid) methyl ester, or methacrylic acid β-hydroxyethyl ether, or methacrylic acid β-hydroxypropyl ether, or β (N, N-dimethylamino) metha ethyl ester acid, or β (N, N-diethylamino) methacrylic acid ethyl ester, or β (N, N-dimethylamino) methacrylic acid propyl ester, or β (N, N-diethylamino) methacrylic acid propyl ester in a weight ratio of bound monomers to the specified copolymer of butadiene: styrene (α-methylstyrene): the specified ester of α, β-unsaturated acid 99.5-40.0: 0-40: 0.5-20.0, and as the aminosilane coupling agent, the rubber mixture contains the product, selected from the group of β-aminoethoxytriethoxysilane, the reaction product of monoethanolamine with tetraethoxysil ohm, or with polyphenylethoxysilane, or with polyethoxysiloxane in a mass ratio of 1: 2-4, respectively, or a mixture of an aminosilane coupling agent from this group with bis (3-triethoxysilylpropyl) tetrasulfide in a mass ratio of 1-10: 1, respectively, and possibly contains technical carbon in the following components in the rubber mixture, parts by weight: said copolymer of butadiene or butadiene and styrene (α-methylstyrene) with α, β-unsaturated carboxylic acid ester 100 silica filler 5-80 carbon black 0-80 the specified aminosilane coupling agent or the specified mixture of aminosilane coupling agent with bis (3-triethoxysilylpropyl) tetrasulfide 2-10 targeted supplements 10-45