RU2375401C1 - Adhesive composition - Google Patents

Abstract

FIELD: chemistry.

SUBSTANCE: invention relates to adhesive composition based on chloroprene rubber, and can be used in the rubber industry when gluing vulcanised rubber. The adhesive composition contains polychloroprene rubber nairite DP, butylphenolformaldehyde resin 101K, water, zinc oxide, magnesium oxide, organic solvent, which is a mixture of ethylacetate and nefras. The composition contains N-nitrosodiphenylamine as a modifier, with the following ratio of components, pts. wt: polychloroprene rubber nairite DP - 90.0, butylphenolformaldehyde resin 101K - 90.0, water - 3.0, zinc oxide - 5.0, magnesium oxide - 11.0, said organic solvent - 800.0, N-nitrosodiphenylamine - 5.0 to 20.0. The composition can be used in the rubber industry when gluing vulcanised rubber.

EFFECT: increased strength when gluing 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 of 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-dibenzothiazole disulfide, zinc oxide, magnesium oxide, organic solvent (Pat. 2028358 Russia, MKI ⁶ C09J 111/00; Publish. 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 88CA (TU 381051760-89), which includes (mass parts):

polychloroprene rubber Nairit DP - 90.0, butylphenol formaldehyde resin 101K - 90.0, zinc oxide - 5.0, magnesium oxide - 11.0, water - 3.0, organic solvent - 800.0. A mixture of nefras and ethyl acetate in a percentage of 50:50 is used as an organic solvent.

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 1.02 MPa )

Objective: the development of the composition of the adhesive composition having increased strength when bonding vulcanized rubber to each other.

The technical result is to increase the strength when bonding vulcanized rubber to each other.

The technical result is achieved by the fact that the adhesive composition comprising polychloroprene rubber Nairit DP, butylphenol formaldehyde resin 101K, water, zinc oxide, magnesium oxide, an organic solvent, which is a mixture of ethyl acetate and nefras, and it additionally contains N-nitrosodiphenylamine as a modifier, the following ratio of components, parts by weight:

polychloroprene rubber Nairit DP - 90.0, butylphenol formaldehyde resin 101K - 90.0, water - 3.0, zinc oxide - 5.0, magnesium oxide - 11.0, the indicated organic solvent - 800.0, N-nitrosodiphenylamine - 5 0-20.0.

Polychloroprene rubber Nairit DP (TU-6-01-1319-85) is the main film-forming in adhesive adhesives.

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

Vulcanizing group: zinc oxide (zinc white GOST 202-84), magnesium oxide (burnt magnesia GOST 844-79) were previously used in adhesive compositions (Kardashov D.A., Petrova A.V. Polymer adhesives. M: Chemistry, 1983 )

Organic solvent: a mixture of ethyl acetate (GOST 8981-78) and nefras (GOST 3840167109-92).

N-nitrosodiphenylamine (TU 6-09-3154-76) is used in the rubber industry as a moderator of vulcanization and structuring of rubber compounds. When using the specified N-nitrosodiphenylamine 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 N-nitrosodiphenylamine 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, the rubber mixture 31С-1-ДП is prepared - a mixture of Nairite DP, magnesium oxide, zinc oxide (ЕТР 8857-91) 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: butylphenol formaldehyde resin, water, N-nitrosodiphenylamine, 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 introduction of the modifier can be carried out after preparation of the adhesive composition based on the remaining components.

An example of the preparation of the adhesive composition. A calculated amount of modifier 5 is added to the glue mixer containing 88A nairite glue 88CA (TU 381051760-89) prepared in a known manner, including polychloroprene rubber, Nairit DP, butylphenol formaldehyde resin, zinc oxide, magnesium oxide, water and the indicated organic solvent. 10 min until a homogeneous mass.

Get the adhesive composition 1-3, the compositions of which are given in table 1. The glue is a light gray liquid. The glue is technological, it is well applied to the surface of rubber. Various N-nitrosodiphenylamine contents were investigated (Table 2).

The declared limits of the modifier 5.0-20.0 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) and ethylene-propylene rubber (SKEPT-40) are given in table 2. For comparative tests, three variants of the compositions were prepared (according to the method described in the example) and the composition of the prototype 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) within 24 hours. The data are presented in table 2, from which it is seen that the best results were obtained using the composition of compositions 2 and 3.

Shear adhesion was determined using 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.

As can be seen from table 2, the proposed adhesive compositions provide an 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 SKI-3 according to the prototype is 1.02 MPa, and using the proposed modifier - 1.57 MPa.

Thus, as can be seen from Table 2, when N-nitrosodiphenylamine is used in the proposed adhesive composition, the adhesive strength of vulcanized rubber products based on various rubbers increases within the indicated limits, due to the participation of this modifier in improving the adhesive properties of the adhesive.

Table 1 Component The content of components in the composition, parts by weight one 2 3 prototype Polychloroprene rubber Nairit DP 90.0 90.0 90.0 90.0 Butylphenol formaldehyde resin 101 K 90.0 90.0 90.0 90.0 Water 3.0 3.0 3.0 3.0 Zinc oxide 5,0 5,0 5,0 5,0 Magnesium oxide 11.0 11.0 11.0 11.0 Organic solvent (a mixture of ethyl acetate and nefras in a percentage ratio of 50:50) 800,0 800,0 800,0 800,0 N-nitrosodiphenylamine 5,0 10.0 20,0 -

table 2 Substrate Type Shear Strength, MPa Metric for composition Prototype 88CA one 2 3 SKI-3 1,07 1.34 1,57 1,02 SKEPT-40 1.05 1.15 1,08 0.70

We found that the reason for the increase in adhesive performance of the adhesive composition is not only an increase in the concentration of polar groups when introduced into the composition of the modifier, but also the formation of additional chemical bonds during the interaction of the amine-containing modifier with mobile allylic chlorine atoms in the macromolecules of chloroprene rubber, 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 including polychloroprene rubber Nairit DP, butylphenol formaldehyde resin 101 K, water, zinc oxide, magnesium oxide, an organic solvent, which is a mixture of ethyl acetate and nefras, characterized in that it additionally contains N-nitrosodiphenylamine as a modifier in the following ratio of components wt.h .:
Polychloroprene rubber Nairit DP 90.0 Butylphenol formaldehyde resin 101 K 90.0 Water 3.0 Zinc oxide 5,0 Magnesium oxide 11.0 Specified Organic Solvent 800,0 N-nitrosodiphenylamine 5.0-20.0