RU2481369C1 - Method of gluing rubber - Google Patents

Abstract

FIELD: chemistry.

SUBSTANCE: method involves applying onto the glued surfaces a solution based on chlorinated natural rubber in an organic solvent, drying and bringing the surfaces into contact. The rubber used is rubber which is pre-ozonised for 0.5-2.0 hours at room temperature to obtain a product with acid number of 9.14-30.87 mgKOH/g. The solvent used is ethyl acetate. The glue is applied in two steps while drying the adhesive film at room temperature for 10 minutes after applying the first layer and for 1-2 minutes after applying the second layer.

EFFECT: high strength of the glue joint when gluing vulcanised rubber and simplification of the gluing process.

1 cl, 1 tbl, 9 ex

Description

The invention relates to a method for attaching vulcanized rubbers to each other, and can be used in the rubber industry.

There is a method of attaching rubbers based on natural, styrene-butadiene, butadiene-acrylonitrile rubbers to a steel substrate (Pat. No. 1799393 of the USSR, class C09J 115/02; Publ. 05.02.88).

However, this method is intended for fixing rubber to metal during vulcanization.

A known method of fastening rubbers based on natural, isoprene, butadiene, butadiene-nitrile, styrene-butadiene, chloroprene and butyl rubber to metal (Pat. 2266940 Russia, C09J 115/02; Publ. 27.12.2005).

However, this method is provided for fixing rubber to metal during vulcanization and requires the application of an adhesive undercoat in combination with Chemosil brand adhesive.

A known method of fastening rubbers based on various rubbers with metal in the process of vulcanization, characterized by the consistent application of Chemosil 211 and adhesive composition (Pat. 2266943 Russia, C09J 175/02; Publ. 27.12.2005).

However, this method is intended for hot fixing of raw rubber compounds to metal and requires prior application of Chemosil and subsequent application of an adhesive sublayer.

The closest is the method of bonding vulcanized rubbers to each other, which consists in a one-time application of the prepared glue on the prepared rubber surface, drying the adhesive film at room temperature (20 ° C) for 1-2 minutes and tightly pressing the glued surfaces, moreover, as an adhesive composition use chlorinated natural rubber brand CR-20 in toluene, epoxy Diane resin ED-20 in the amount of 5-15 wt.h. and additionally as an FBM modifier in an amount of 3-10 parts by weight (Pat. 2435818 Russia, C09J 115/02; Publ. 10.12.2011).

However, this method does not provide high bonding strength of rubbers with each other and requires the use of a more complex formulation.

Objective: to develop a method of attaching rubbers to each other, providing increased bonding strength of vulcanized rubbers to each other.

The technical result is to provide increased strength of the adhesive joint when fixing vulcanized rubbers to each other.

The technical result is achieved by the fact that the method of attaching vulcanized rubbers based on one rubber to each other by applying to the surfaces to be bonded a solution based on chlorinated natural rubber in an organic solvent, drying and subsequent contacting of the surfaces, moreover, as the rubber used is pre-ozonized for 0, 5-2.0 hours at room temperature, the rubber to obtain a product with an acid number of 9.14-30.87 mg KOH / g, and ethyl acetate and a solvent as a solvent Glue is carried out in two stages with drying of the adhesive film at room temperature for 10 minutes after applying the first layer and within 1-2 minutes after the application of the second layer.

Chlorinated natural rubber (TU 6-01-1092-76) grades CR-10, CR-20, S-20 is the main film-forming in adhesive adhesives.

Organic solvent: ethyl acetate (GOST 8981-78).

The use of ozonated rubber significantly increases the adhesive properties of the adhesive composition. This is due to an increase in the content of functional groups in the adhesive composition. This explains the increase in strength when bonding vulcanized rubbers to each other.

The stated time limits for ozonation are due to the fact that with a decrease in the time of ozonation, a preliminary destruction of rubber macromolecules occurs, as a result of which the adhesion strength when bonding rubbers to each other decreases, the increase in ozonation time does not lead to an increase in adhesive strength.

The method of attaching rubbers to each other is as follows.

Before applying the solution based on chlorinated natural rubber (CNS) and ethyl acetate to the surfaces to be bonded, this rubber was preliminarily ozonized at room temperature in an ozone chamber with an ozone concentration of 5 · 10 ^-5 . This method was used to fasten vulcanized rubbers based on polyisoprene rubber (SKI-3), ethylene propylene rubber (SKEPT-40), nitrile butadiene rubber (SKN-18M) and chloroprene rubber (Neoprene AC) to each other. Two-time application of the prepared adhesive on the prepared surface, drying of the adhesive film at room temperature (20 ° C) for 10 minutes after applying the first layer and 1-2 minutes after applying the second, after which the glued surfaces were pressed tightly and held under a load of 2 kg in within 24 hours.

Shear adhesion was determined using an MPC-250 tensile testing machine (RTM 1.2.126-88). Various grades of chlorinated natural rubber were studied at different ozonation times (Table 1).

The method is illustrated by the following example.

Example 1. Before applying a solution based on chlorinated natural rubber brand CR-10 in ethyl acetate on the bonded surface, the rubber was pre-ozonated for 1 hour at room temperature in an ozone chamber at an ozone concentration of 5 · 10 ^-5 . Then determine the acid number of the product (patent RU 2373998, MKI B01J 39/20, C08J 11/04, publ. 11/27/2009; Kalinina LS Analysis of condensation polymers. - M .: Chemistry, 1984. - 296 S.), which is presented in table 1. This method was used for fixing vulcanized rubbers based on SKI-3, SKEPT-40, SKN-18M and Neoprene AC to each other. Two-time application of the prepared adhesive on the prepared surface, drying of the adhesive film at room temperature for 10 minutes after applying the first layer and 1-2 minutes after applying the second, after which the glued surfaces were pressed tightly and kept under a load of 2 kg for 24 hours. After that, shear strength was determined.

Example 2. Obtain adhesive compounds as described in example 1, but as the basis of the adhesive used pre-ozonated for 1 hour at room temperature, chlorinated natural rubber brand CR-20.

Example 3. Get adhesive compounds as described in example 1, but as the basis of the glue used pre-ozonated for 1 hour at room temperature, chlorinated natural rubber brand S-20.

Example 4 is similar to example 1, but the rubber is pre-ozonized for 0.5 hours.

Example 5 is similar to example 3, but the rubber is pre-ozonized for 0.5 hours.

Example 6 is similar to example 1, but the rubber is pre-ozonized for 1.5 hours.

Example 7 is similar to example 3, but the rubber is pre-ozonized for 1.5 hours.

Example 8 is similar to example 1, but the rubber is pre-ozonized for 2 hours.

Example 9 is similar to example 3, but the rubber is pre-ozonized for 2 hours.

As can be seen from table 1, the proposed method of attaching vulcanized rubbers to each other provides high strength properties of adhesive joints. So the strength of the adhesive joint in shear when bonding vulcanized rubber based on SKI-3 with glue based on ozonated chlorinated natural rubber of the CR-10 brand according to the prototype is 0.239 (prototype), and with the use of ozonized HCN 0.268 MPa (composition 1).

We found that the reason for the increase in the adhesive characteristics of the adhesive composition is the reactivity of the macroradicals formed during ozonation, which leads to hardening of the adhesive film.

Table 1 Substrate Type Metric for composition Prototype one 2 3 four 5 6 7 8 9 Ozonation time, hour 0 1,0 0.5 1,5 2.0 Acid number, mg KOH / g 10,229 11,105 9,142 13,124 21,648 28,132 20,359 21,620 21,058 15,134 SKI-3 0.204 0.268 0.282 0.256 - - 0.260 0.276 0.244 0.269 SKEPT-40 0.220 0.278 0.265 0.313 - 0.257 - - - - SKN-18 0.434 0.435 - 0.878 0.279 - 0.291 - - 0.803 Neoprene speaker 0.485 0.389 0.388 0.885 - - - - - -

The technical and economic effect obtained from the application of the fastening method lies in the fact that its application can significantly improve the quality of fastening of products from vulcanized rubbers based on various rubbers, and improve the technological parameters of the bonding process.

Claims (1)

A method of attaching vulcanized rubbers based on one rubber to each other by applying to a surface to be bonded a solution based on chlorinated natural rubber in an organic solvent, drying and subsequent contacting the surfaces, characterized in that the rubber used is pre-ozonized for 0.5-2, 0 hours at room temperature, the rubber to obtain a product with an acid number of 9.14-30.87 mg KOH / g, and as a solvent - ethyl acetate and the application of glue is carried out in two stages with the drying of adhesives film at room temperature for 10 minutes after applying the first layer and for 1-2 minutes after applying the second layer.