RU2307840C1 - Method of preparing rubber compound based on ethylene/propylene/diene rubber - Google Patents

Abstract

FIELD: rubber industry.

SUBSTANCE: method comprises mixing sulfur, zinc oxide, stearic acid, tetramethylthiuram disulfide, mercaptobenzothiazole, and carbon black. During the mixing process, a modifier is incorporated, said modifier having been preliminarily prepared via interaction, at 150^°C, of 1.66-3.34 wt parts epoxide dian resin "ED-20" and 0.83-1.67 wt parts aniline production bottom waste containing 15-18 wt parts aniline at weight ratio of components 2:1, respectively.

EFFECT: improved physico-mechanical characteristics of rubber and increased adhesion thereof to metal when using chloroprene glues.

5 tbl

Description

The invention relates to the rubber industry, in particular to a method for producing a rubber mixture based on ethylene-propylene rubber, which is characterized by increased adhesive performance.

Known rubber mixture, which is obtained by mixing ethylene propylene diene rubber, filler, plasticizer and adhesive additives, which is used as the thermal decomposition product of ethylene propylene or ethylene propylene diene rubber (USSR Author's Certificate No. 765307, class C08L 23/16; Publ. 23.09.80).

However, with this method, it is necessary to additionally carry out the process of thermal decomposition of ethylene propylene or ethylene propylene diene rubber in an autoclave type reactor, which complicates the technology.

Known vulcanizable rubber mixture based on unsaturated rubber (SKEPT) containing an adhesive additive is an organometallic compound of the formula: (organic ligand) -nickel (anion) (Patent No. 572207, class C08L 9/00; Publ. 05.09.77).

However, this method requires additional grinding of the rubber compound after mixing in a rubber mixer, which complicates the technology.

The closest is a method for producing a rubber mixture based on ethylene propylene diene rubber by mixing ethylene propylene diene rubber with sulfur, tetramethylthiuram disulfide, mercaptobenzthiazole, zinc oxide, stearic acid and carbon black (Koshelev F.F. et al. General rubber technology. 1978: Chemistry. Rubber. 1978. p. 90).

However, with this method of producing a rubber compound, vulcanizates based on it have low physical and mechanical properties.

Objective: to develop a method for producing a rubber mixture based on ethylene propylene diene rubber, the vulcanizates based on which are characterized by improved physical and mechanical properties and increased adhesion to metal.

The technical result is the development of a method for producing a rubber mixture based on ethylene propylene diene rubber, the vulcanizates based on which are characterized by improved physical and mechanical properties and increased adhesion to metal using chloroprene adhesives of 88CA and 88NT grades, utilization of waste from petrochemical production (aniline).

The technical result is achieved by the fact that in the method for producing a rubber mixture based on ethylene propylene diene rubber, comprising mixing sulfur, zinc oxide, stearic acid, tetramethylthiuramdisulfide, mercaptobenzthiazole and carbon black, a modifier previously obtained from the reaction at 150 ° C is additionally introduced during mixing within 5 hours 1.66-334 parts by weight epoxy Dianova resin ED-20 and 0.83-1.67 wt.h. VAT waste aniline production, with aniline content of 15-18 wt.h. in a mass ratio of 2: 1, respectively, in the following ratio of components, parts by weight: ethylene propylene diene rubber - 100.0, sulfur - 2.0, zinc oxide - 5.0, stearic acid - 1.0, carbon black - 100, 0-70.0, tetramethylthiuram disulfide - 1.5-1.0, mercaptobenzthiazole - 0.5-1.0, modifier - 2.5-5.0.

Ethylene propylene diene rubber SKEPT-40 (TU 38.103252-92).

Sulfur is a vulcanizing agent (GOST 127.4-93).

Zinc oxide is an activator of the vulcanization accelerator (GOST 202-84).

Stearic acid is a vulcanization activator (GOST 6484-96).

Carbon black P-514 - filler (GOST 7885-86).

Tetramethylthiuram disulfide (thiuram D) - vulcanization accelerator (GOST 740-76).

Mercaptobenzthiazole (captax) is a vulcanization accelerator (TU 113-00-05761631-23-91).

The modifier is preliminarily obtained by direct interaction of the ED-20 epoxy diane resin with distilled waste from the production of aniline (KPA) in a mass ratio of 2: 1, at 150 ° C for 5 hours. The modifier is fragile granules of irregular shape and is a cheap substance, since KPA are waste generated during the production of aniline (TP production of aniline, ZAO "Orgsintez" Volzhsky, stage of separation of commodity aniline). KPA are (parts by weight): aniline - 15-18, cyclohexylamine - 0-10, toluidine (solvent) - 2-4, sodium hydroxide (filler) - 1-3, diphenylamine - 3-20, metaphenyldiamine - 1 -3, o-, n-aminophenol - 1-6, high molecular weight resinous substances (reactants interacting with rubber) - 6-45.

It is established that the reason for the increase in the adhesion characteristics of vulcanizates is an increase in the content of polar functional groups due to the introduction of the proposed modifier into the rubber composition.

When using ED-20 epoxy resin and modifier aniline bottoms as a modifier, the physicomechanical and adhesive properties of vulcanizates based on the proposed rubber mixture are improved. When the ratio of modifier components changes, it becomes viscous, which makes it difficult to introduce it into the rubber mixture, while the adhesion properties of vulcanizates based on the rubber mixture are reduced.

An example of the preparation of a rubber compound.

The rubber mixture based on ethylene propylene diene rubber, including sulfur, zinc oxide, stearic acid, carbon black, tetramethylthiuram disulfide, mercaptobenzthiazole, is prepared on rollers at a roll temperature of 65-70 ° C. Mixing time 25 minutes. In the process of mixing on rollers, a modifier is additionally introduced into the rubber mixture, previously obtained as a result of the interaction of the ED-20 epoxy resin with bottoms from aniline production in a mass ratio of 2: 1 at 150 ° C for 5 hours, while bottoms contain 15- 18 parts by weight aniline. Then the vulcanization of the rubber mixture is carried out at a temperature of 160 ° C for 30 minutes.

Get rubber mixture 1-6, the compositions of which are shown in table 1.

The composition of the modifier is given in table 2.

Table 3 shows the physical and mechanical properties of vulcanizates based on the proposed rubber compounds and the prototype.

The technology for bonding samples is as follows. One-time application of glue on the prepared surface, drying of the adhesive film at room temperature (20 ° C) for 1-2 minutes, after which the adhesive surfaces were tightly pressed.

Table 4 shows the strength characteristics of vulcanizates based on the proposed rubber compounds and according to the prototype when gluing them to each other with chloroprene adhesives 88HT and 88CA. The data are presented in table 4, which shows that the best results were obtained using the composition of compositions 2 and 3. Thus, the shear strength when bonding vulcanized rubber according to the prototype with 88NT glue is 0.68 MPa, while bonding vulcanized rubber according to the recipe of composition 3 is 1 13 MPa.

The declared limits of the modifier are 2.5-5.0 due to the fact that with an increase or decrease in the indicated dosages, the adhesive strength when bonding vulcanizates to each other decreases, thus they are optimal. Shear adhesion was determined using an MPC-250 tensile testing machine (GOST 16971-71).

In further studies, compositions 2 and 3 were used.

Also, tests were carried out on the adhesive bonding of vulcanizates based on compositions 2, 3 and according to the prototype to steel (St3) (Table 5). Adhesion was determined by peeling. Strength at uniform separation was determined on the adhesion meter PSO MG4 (TU 4271-005-12585810-01).

From table 5 it is seen that the vulcanizates based on composition 2 and 3 provide an increase in the strength properties of adhesive joints in comparison with the prototype. The strength at separation of the adhesive joint when attaching vulcanized rubber according to the prototype to steel with 88CA adhesive is 0.9 MPa, and when attaching vulcanized rubber according to the recipe of composition 3 to steel (St3) is 1.35 MPa.

Table 1 Mixture components The content of the components of the mixture in the compositions, parts by weight prototype one 2 3 four 5 6 Ethylene propylene diene rubber SKEPT-40 100.0 100.0 100.0 100.0 100.0 100.0 100.0 Sulfur 2.0 2.0 2.0 2.0 2.0 2.0 2.0 Zinc oxide 5,0 5,0 5,0 5,0 5,0 5,0 5,0 Stearic acid 1,0 1,0 1,0 1,0 1,0 1,0 1,0 Carbon black 100.0 100.0 100.0 100.0 70.0 70.0 70.0 Tetramethylthiuram disulfide 1,5 1,5 1,5 1,5 1,5 1,5 1,0 Mercaptobenzthiazole 0.5 0.5 1,0 1,0 1,0 1,0 0.5 Modifier - 5,0 2,5 5,0 2,5 5,0 5,0

table 2 Modifier components The content of the components of the modifier for rubber one 2 3 four 5 6 Epoxy Dianovy resin ED-20 3.34 1.66 3.34 1.66 3.34 3.34 VAT waste aniline production with aniline content of 15-18 wt.h. 1,67 0.83 1,67 0.83 1,67 1,67

Table 3 The name of indicators Composition Test Results prototype one 2 3 four 5 6 Conditional Strength, MPa 18.0 18.1 19.3 20.3 19.7 18.1 18.0 Relative extension, % 140 170 150 140 230 210 230 Hardness, units Shore a 92 91 92 93 84 83 85 The temperature limit of brittleness, ° C corresponds to Tear resistance, kgf / cm 46 65 54 fifty 66 70 60

Table 4 Adhesive brand Metric for composition Prototype one 2 3 four 5 6 Shear Strength, MPa 88NT 0.68 1,04 1.10 1.13 0.85 0.87 0.75 88CA 1.20 1,61 1,63 1.79 1.45 1.25 1.30

Table 5 Adhesive brand Metric for composition Prototype The proposed composition 2 The proposed composition 3 Strength at uniform separation, MPa 88CA 0.90 1.28 1.35

The technical and economic effect obtained from the use of the proposed rubber mixture based on ethylene propylene diene rubber is that its application can significantly increase the strength of the fasteners made of vulcanized rubber based on ethylene propylene diene rubber and when attached to a metal surface, to improve the physical and mechanical properties of vulcanizates . In addition, its use allows the use of a by-product (waste) of petrochemical production (aniline).

Claims (1)

A method of producing a rubber mixture based on ethylene propylene diene rubber, comprising mixing sulfur, zinc oxide, stearic acid, tetramethylthiuramdisulfide, mercaptobenzthiazole and carbon black, characterized in that during the mixing process a modifier is additionally introduced that was previously obtained by reacting at 150 ° C for 5 hours 1.66-3.34 parts by weight epoxy Dianova resin ED-20 and 0.83-1.67 wt.h. VAT waste aniline production with aniline content of 15-18 wt.h. in a mass ratio of 2: 1, respectively, with the following ratio of components, parts by weight: Ethylene propylene diene rubber 100.0 Sulfur 2.0 Zinc Oxide 5.0 Stearic acid 1.0 Carbon black 70.0-100.0 Tetramethylthiuram disulfide 1.0-1.5 Mercaptobenzthiazole 0.5-1.0 Modifier 2.5-5.0