RU2374287C1 - Adhesive composition - Google Patents

Abstract

FIELD: chemistry.

SUBSTANCE: invention relates to adhesive compositions based on chloroprene rubber, and can be used in the rubber industry when gluing vulcanised rubber. The adhesive composition contains polychloroprene rubber nairit NT, butylphenolformaldehyde resin 101K, thiuram, zinc oxide, magnesium oxide and an organic solvent, which is a mixture of ethylacetate and nefras, and a modifier in form of ortho-phenylenediamine, with the following ratio of components, pts. wt: polychloroprene rubber nairit NT - 100.0, butylphenolformaldehyde resin 101K - 90.0, thiuram - 2.0, zinc oxide - 5.0, magnesium oxide - 12.0, said organic solvent - 800.0, ortho-phenylenediamine - 5.0 to 30.0.

EFFECT: invention increases adhesion strength when gluing different types of vulcanised rubber.

2 tbl, 1 ex

Description

The invention relates to adhesive compositions based on chloroprene rubber and can be used in the rubber industry for bonding vulcanized rubbers based on various rubbers to each other.

Known adhesive composition comprising chloroprene rubber, thiuram, zinc oxide, as a resin the product of the joint condensation of phenol acetaldehyde and acetanaphthene and a solvent (USSR Author's Certificate No. 1579920, class C09J 111/00. Publ. 23.07.90). As a solvent, a mixture of ethyl acetate and gasoline is used.

However, this adhesive composition does not provide a sufficiently high strength when bonding products from vulcanized rubber.

Known adhesive composition comprising polychloroprene rubber, epoxy resin, low molecular weight butadiene nitrile rubber, tertiary amine, solvent (USSR Author's Certificate No. 685673, class C08L 11/00. Publ. 15.09.79).

However, this adhesive composition has low strength when bonding rubber products based on various rubbers.

Known adhesive composition comprising polychloroprene rubber, butylphenol formaldehyde resin, a copolymer of styrene and piperylene, rosin esterified with glycerol; pine rosin, diphenylguanidine, 2,2-dibenzothiazoldisulfide, zinc oxide, magnesium oxide, organic solvent (Pat. 2028358 Russia, MKI ⁶ C09J 111/00. Publ. 09.02.95).

However, the specified adhesive composition, although it has a similar composition, is intended for bonding products from ferrites.

Closest to the invention in technical essence is adhesive 88HT (TU2252-033-45539771-2000), which includes, by weight, parts: polychloroprene rubber nairit NT - 100.0, butylphenol formaldehyde resin 101K - 90.0, zinc oxide - 5.0, magnesium oxide 12.0, thiuram 2.0 and an organic solvent 800.0. As a solvent, a mixture of nephras and ethyl acetate in a percentage ratio of 50:50 is used.

However, the specified adhesive composition (although it is widely used because of its low cost) does not provide a sufficiently high strength when bonding vulcanized rubber (the achieved shear strength when bonding vulcanized rubber based on polyisoprene rubber (SKI-3) does not exceed 0.61 MPa )

Objective: the development of the composition of the adhesive composition having increased strength when bonding vulcanized rubbers based on various rubbers with each other.

The technical result is to increase the strength when bonding vulcanized rubbers based on various rubbers with each other.

The technical result achieved is achieved by the fact that the adhesive composition including polychloroprene rubber Nairit NT, butylphenol formaldehyde resin 101K, thiuram, zinc oxide, magnesium oxide, an organic solvent, which is a mixture of ethyl acetate and nefras, additionally contains ortho-phenylenediamine as a modifier in the following ratio of components wt.h .: polychloroprene rubber nairit NT - 100.0, butylphenol formaldehyde resin 101K - 90.0, thiuram - 2.0, zinc oxide -5.0, magnesium oxide - 12.0, the specified organic solution the protector is 800.0, the ortho-phenylenediamine is 5.0-30.0.

Polychloroprene rubber nairit NT (TU-601781-73) is the main film-forming in adhesive adhesives.

Butylphenol formaldehyde resin 101K (TU-60004691277193-97).

Vulcanizing group: zinc oxide (zinc white), magnesium oxide (burnt magnesia GOST 844-79) were previously used in adhesive compositions (Kardashov DA, Petrova AV Polymer adhesives. M: Chemistry, 1983).

Organic solvent: a mixture of ethyl acetate (GOST 8981-78) and nefras (GOST 443-76).

Ortho-phenylenediamine (TU 6-09-0512-91) is used as a hardener of polymer compositions. When using the specified ortho-phenylenediamine as a modifier, the adhesive properties of the adhesive composition are significantly increased. This is due to an increase in the content of functional groups in the adhesive composition. As a result of the interaction of ortho-phenylenediamine with a macromolecule of chloroprene rubber, an increase in the concentration of polar groups and the formation of additional chemical bonds occur, which increases the mobility of the macromolecule and a deeper diffusion of its sections deeper into the surface of the vulcanizate. This explains the increase in strength when bonding vulcanized rubber to each other.

The adhesive composition is prepared as follows.

First, a rubber mixture is prepared (a mixture of Nairite NT, magnesium oxide, zinc oxide, thiuram) in a rubber mixer for 10 minutes, while the temperature of the mixer gradually rises (as the components of the mixture are introduced) from 50 ° C to 85 ° C. After unloading the mixture at a temperature of 105 ° C, it is paged for 5 minutes. Then the heated rubber mixture with part of the solvent (about 0.1 part of the total amount of solvent) is loaded into the glue mixer. The remaining amount of solvent, together with other ingredients of the adhesive composition, with butylphenol formaldehyde resin, ortho-phenylenediamine, are loaded in portions into the adhesive mixer as the rubber mixture swells. The total adhesive mixing time is 4.5-5 hours, while the administration of ortho-phenylenediamine can be carried out after preparation of the adhesive composition based on the remaining components.

An example of the preparation of the adhesive composition. Into a glue mixer containing 88HT nairite glue prepared in a known manner (TU-2252-033-45539771-2000), including polychloroprene rubber Nairit NT, 101K butylphenol formaldehyde resin, zinc oxide, magnesium oxide, thiuram and an organic solvent, the calculated amount is added and the amount of modifier and mix the contents for 5-10 minutes until a homogeneous mass is obtained.

Get the adhesive composition 1-4, the compositions of which are given in table 1.

The glue is a light brown liquid. The glue is technological, it is well applied to the surface of rubber.

Various contents of orthophenylenediamine were investigated (Table 2). The claimed limits of the modifier ortho-phenylenediamine 5.0-30.0 are due to the fact that with an increase or decrease in these dosages, the adhesive strength during bonding decreases.

Comparative tests of the strength properties of adhesive compositions for all variants of the claimed composition and prototype when bonding vulcanized rubber based on polyisoprene rubber (SKI-3), ethylene propylene rubber (SKEPT-40), butadiene nitrile rubber (SKN-18M) and chloroprene rubber (Neoprene AC) in table 2. For comparative tests, 4 variants of the compositions were prepared (by the method described in the example) and the composition of the prototype, the formulations of which are presented in table 1.

The proposed compositions were tested for adhesive shear strength, achieved when kept under a load of 2 kg, at room temperature (20 ° C) for 24 hours. The data are presented in table 2, which shows that the best results were obtained using the composition of composition 2.

Adhesive shear strength was determined on an MPC-250 tensile testing machine (RTM 1.2.126-88). The technology for bonding samples is as follows. One-time application of the prepared 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.

The proposed adhesive composition provides a significant increase in the strength properties of adhesive joints in comparison with the prototype. So, the shear strength of the adhesive joint when bonding vulcanized rubber based on SKEPT-40 according to the prototype is 0.99 MPa, and using the proposed modifier 1.52 MPa.

Thus, as can be seen from table 2, the use of ortho-phenylenediamine in the proposed adhesive composition within the specified limits allows to increase the strength when bonding products from vulcanized rubbers based on various rubbers, which is due to the participation of this modifier in improving the adhesive properties of the adhesive.

Table 1 Component The content of components, parts by weight, in the composition one 2 3 four prototype Polychloroprene rubber Nairit NT one hundred one hundred one hundred one hundred one hundred Butylphenol formaldehyde resin 101K 90 90 90 90 90 Tiuram 2 2 2 2 2 Zinc oxide 5 5 5 5 5 Magnesium oxide 12 12 12 12 12 Organic solvent (a mixture of ethyl acetate and nefras in a percentage of 50:50) 800 800 800 800 800 Ortho-phenylenediamine 5,0 10.0 20,0 30,0 -

table 2 Substrate Type Shear Strength, MPa Metric for composition Prototype 88NT one 2 3 four SKI-3 1,02 1.29 1,07 0.92 0.61 SKEPT-40 0.92 1,52 1.38 1.21 0.99 SKN-18M 0.96 1,56 1.27 1.18 0.46 Neoprene speaker 0.97 1.48 1.37 1.29 0.73

We found that the reason for the increase in the adhesive performance of adhesive compositions is an increase in the concentration of polar groups when a modifier is introduced into the composition, as well as the formation of additional chemical bonds during the interaction of an amine-containing modifier with mobile allylic chlorine atoms in chloroprene rubber macromolecules, which leads to an increase in the density of the spatial network and, apparently to hardening the adhesive film.

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

Claims (1)

An adhesive composition comprising polychloroprene rubber Nairit NT, butylphenol formaldehyde resin 101K, thiuram, zinc oxide, magnesium oxide, an organic solvent, which is a mixture of ethyl acetate and nefras, characterized in that it additionally contains orthophenylenediamine as a modifier in the following ratio of components, wt. .:
Polychloroprene rubber Nairit NT 100.0 Butylphenol formaldehyde resin 101K 90.0 Tiuram 2.0 Zinc oxide 5,0 Magnesium oxide 12.0 Specified Organic Solvent 800,0 Orthophenylenediamine 5.0-30.0