RU2408624C1 - Rubber mixture based on ethylene propylene diene rubber - Google Patents

Abstract

FIELD: chemistry.

SUBSTANCE: rubber mixture based on ethylene propylene diene rubber SKEPT-40 contains the following, pts. wt: SKEPT-40 100, sulphur 2, zinc oxide 5, stearic acid 1, technical carbon P-234 100, tetramethylthiuram disulphide 1.5, mercaptobenzthiazole 0.5, modifier 2. The modifier is preferably obtained from reacting epoxy diane resin ED-20, epichlorohydrin and aniline in weight ratio 4:1:2.5, respectively, at temperature 150°C.

EFFECT: invention increases rubber adhesion when gluing with chloroprene adhesives 88CA and 88H, improved physical and mechanical properties.

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Description

The invention relates to the rubber industry, in particular to the development of a rubber compound based on ethylene-propylene rubber, the rubber of which is characterized by increased adhesion.

A rubber mixture is known, including ethylene propylene diene rubber, a filler, a plasticizer and an adhesive additive, which is a product of the thermal decomposition of ethylene propylene or ethylene propylene diene rubber (USSR Author's Certificate No. 765307, class C08L 23/16; publ. 23.09.80).

However, this rubber compound has good adhesion to fiberglass.

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 rubber compound is intended to be attached to the metal in its raw form with subsequent vulcanization.

Known rubber mixture based on ethylene propylene rubber, including a vulcanization activator, organic peroxide, filler and oligodienisoprenurethane acrylate, which additionally contains methyl phenyl dimethoxylan (USSR Author's Certificate No. 711066, class C08L 23/16; publ. 25.01.80).

However, this rubber compound is intended to be attached to the metal in its raw form, followed by vulcanization and additional lubrication with Leikonat glue.

Known vulcanizable rubber mixture based on ethylene-propylene copolymer with hydroxyl groups, including a vulcanizing agent and a vulcanization catalyst, as a vulcanizing agent contains an epoxy resin and dicarboxylic acid anhydride, contains tin dialkyl diacyl compound or tertiary amine (USSR Copyright Certificate No. 798136, cl. C08L 23/16; publ. 23.01.81).

However, this rubber compound after vulcanization is characterized by low adhesive performance when attaching rubber to metal.

Known rubber mixture based on ethylene propylene diene rubber SKEPT-30, including sulfur, tetramethylthiuram disulfide, mercaptobenzthiazole, zinc oxide, stearic acid and carbon black PM-75 (Koshelev F.F. et al. General rubber technology. M .: Chemistry, - 1978, 1978, p. 90).

However, this rubber compound after vulcanization is characterized by low adhesive performance when attaching rubber to metal (the achieved strength with a uniform separation does not exceed 0.9 MPa).

The closest is a rubber compound based on ethylene propylene diene rubber of the SKEPT-40 brand, including sulfur, zinc oxide, stearic acid, tetramethylthiuram disulfide, mercaptobenzthiazole and a filler - carbon black, characterized in that the mixture contains carbon black P-514 and an additional modifier as a filler, 1.66-3.34 parts by weight previously obtained as a result of interaction at 150 ° C. 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 (Patent No. 2307850, class C08L 23/16; publ. 10.10.07).

However, this rubber compound after vulcanization is characterized by low adhesive performance when bonding rubber to each other (the achieved shear strength does not exceed 1.15 MPa).

Objective: the development of a rubber mixture based on ethylene propylene diene rubber, which is characterized by increased adhesion during bonding.

The technical result is the development of a rubber mixture based on ethylene propylene diene rubber, which is characterized by increased adhesion when bonding using chloroprene adhesives 88CA and 88HT, improved physical and mechanical properties.

The technical result is achieved in that the rubber mixture based on ethylene propylene diene rubber of the SKEPT-40 brand, including sulfur, zinc oxide, stearic acid, tetramethylthiuramdisulfide, mercaptobenzthiazole and carbon black filler, the mixture also contains P-234 carbon black and, in addition, a modifier preliminarily obtained as a result of the interaction at 150 ° С of epoxy diane resin ED-20, epichohydrin and aniline in a mass ratio of 4: 1: 2.5, respectively, with the following the corresponding ratio of components, parts by weight: SKEPT-40 ethylene propylene diene rubber -100.0, sulfur 2.0, zinc oxide 5.0, stearic acid 1.0, tetramethylthiuramdisulfide 1.5, mercaptobenzthiazole 0, 5, carbon black P-234 - 100.0, modifier 2.0.

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-234 - 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).

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 used as a modifier of epoxy dianovy resin ED-20, epichlorohydrin and aniline in a mass ratio of 4: 1: 2.5, the adhesive and physico-mechanical properties of vulcanizates based on the proposed rubber composition are increased. When the ratio of the 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.

The modifier is obtained by direct interaction of the epoxy Dianova resin ED-20, epichlorohydrin and aniline in a mass ratio of 4: 1: 2.5, at 150 ° C for 3 hours. The modifier is a fragile transparent granules of irregular shape golden brown.

An example of the preparation of a rubber compound.

The rubber mixture (a mixture of SKEPT-40 ethylene propylene diene rubber, sulfur, zinc oxide, stearic acid, P-234 carbon black, tetramethylthiuram disulfide, mercaptobenzthiazole and this modifier) is prepared on rollers at a roll temperature of 65-70 ° C.

Mixing time 25 minutes. Then the vulcanization of the rubber mixture is carried out at a temperature of 160 ° C for 30 minutes.

Get the rubber mixture, the composition of which is shown in table 1.

Table 2 shows the physical and mechanical properties of the vulcanizates based on the proposed rubber compound and the prototype.

Physico-mechanical properties - elongation, conditional tensile strength is determined in accordance with GOST 270-75, shore hardness A (GOST 263-75), tear resistance (GOST 262-79).

The proposed vulcanizates were tested for adhesive shear strength, achieved when kept under a load of 2 kg, at room temperature (20 ° C) for 24 hours.

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.

Shear adhesion was determined using an MPC-250 tensile testing machine (GOST 16971-71).

Table 3 shows the strength characteristics of vulcanizates based on the proposed rubber compound and according to the prototype when gluing them to each other with chloroprene adhesives 88HT and 88CA. The data are presented in table 3, which shows that the best results were obtained using the proposed rubber compound. So, the shear strength when bonding vulcanized rubber according to the prototype with 88CA glue is 1.14 MPa, and when bonding vulcanized rubber according to the proposed recipe is 2.0 MPa.

Table 1 Mixture components The content of the components of the mixture in the compositions, parts by weight Prototype The proposed composition Ethylene propylene diene rubber SKEPT-40 100.0 100.0 Sulfur 2.0 2.0 Zinc oxide 5,0 5,0 Stearic acid 1,0 1,0 Carbon black P-234 100.0 100.0 Tetramethylthiuram disulfide 1,5 1,5 Mercaptobenzthiazole 0.5 0.5 Prototype modifier 2.0 - Modifier - 2.0

table 2 Composition Test Results The name of indicators Prototype The proposed composition Conditional Strength, MPa 17.0 20,0 Relative extension, % 140 160 Hardness, units Shore a 91 95 Tear resistance, kgf / cm 43 56

Table 3 Glue brand Metric for composition Prototype The proposed composition Shear Strength, MPa 88nt 1.15 1.9 88CA 1.14 2.0

The declared amount of the modifier is 2.0 due to the fact that with an increase or decrease in the indicated dosage, the adhesive strength when bonding the vulcanizates to each other and the physical and mechanical properties decrease, thus, it is optimal.

The technical and economic effect obtained from the use of the proposed rubber mixture based on ethylene propylene diene rubber is that its use can significantly increase the bonding strength of vulcanized rubber products based on ethylene propylene diene rubber, and improve the physicomechanical properties of vulcanizates.

Claims (1)

SKEPT-40 brand ethylene-propylene diene rubber compound, including sulfur, zinc oxide, stearic acid, tetramethylthiuram disulfide, mercaptobenzthiazole and carbon black filler, characterized in that the mixture contains carbon black P-234 and an additional modifier previously obtained as a result the interaction at 150 ° C of the epoxy Dianova resin ED-20, epichlorohydrin and aniline in a mass ratio of 4: 1: 2.5, respectively, in the following ratio of components, parts by weight:
SKEPT-40 ethylene propylene diene rubber one hundred sulfur 2 zinc oxide 5 stearic acid one carbon black P-234 one hundred tetramethylthiuram disulfide 1,5 mercaptobenzthiazole 0.5 modifier 2