RU2385890C2 - Method of gluing rubber to each other - Google Patents

Abstract

FIELD: chemistry.

SUBSTANCE: method of bonding vulcanised rubber of the same type to each other involves depositing glue based on polychloroprene rubber on the surfaces to be glued together, as well as 88NT or 88SA glue based on polychloroprene rubber nairite NT or nairite DP combined with butylphenol formaldehyde resin. Before depositing onto the surface, a modifier which is paraoxydiphenylamine is added to the glue in amount of 0.3-4.0 pts. wt per 100 pts. wt of glue, and after depositing, the glue film is dried at room temperature for 1-2 minutes, and the surfaces are brought into contact under a load for 24 hours. Rubber based on SKI-3, SKEPT-40, SKN-18M and neoprene AS is glued together.

EFFECT: increased strength of the glued joint when gluing vulcanised rubber of the same type, simplification of the gluing process.

2 tbl, 2 ex

Description

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

A known method of bonding and sealing rubbers by applying nitrogen-containing monoacrylates to the bonded surfaces of the adhesive material with the addition of a polymerization initiator followed by contacting the surfaces under anaerobic conditions, the product of condensation of esters of acrylic acids and mono-, di- or trialkanolamines is used as nitrogen-containing monoacrylates (USSR Copyright Certificate No. 378401, class C09J 5/00; Published on April 18, 73).

However, this method, although it provides high strength when bonding rubber products, is intended for bonding products under anaerobic conditions, which complicates the technology.

A known method of bonding various materials with adhesives based on epoxy resins with hardeners using radiation treatment of the cured adhesive, which are additionally introduced plasticizer. (USSR author's certificate No. 2148593, class C09J 5/00; Publ. 10.05.00).

However, this method requires subjecting the parts to be glued to radiation in moderate doses, which complicates the bonding process.

There is a method of bonding and sealing rubbers by applying oligoester acrylates with the addition of a polymerization initiator followed by contacting the surfaces under anaerobic conditions onto the bonded surfaces of the adhesive material (USSR Author's Certificate No. 378402, class C09J 5/00; Published on April 18, 73).

However, this method, although it provides high strength when bonding rubber products, is intended for bonding products under anaerobic conditions, which complicates bonding.

The closest is the method of fixing rubbers to each other and to metals by applying polymerizable monomers on the surfaces to be bonded and then contacting the surfaces to be bonded, 2-methyl-4-halohexatrienes are used as the polymerizable monomer - 1,3,5 one or with the addition of a radical type initiator , or with their own polymers or polychloroprene dissolved in them (USSR Author's Certificate No. 426490, class C09J 5/00; Publ. 15.09.75).

However, this method, although it provides a sufficiently high strength when bonding products made of vulcanized rubber, requires additional heating of the samples at high temperature.

Objective: to develop a method of attaching rubbers to each other, providing increased strength of the adhesive joint at the rubber-glue border.

The technical result is to provide increased strength of the adhesive joint when attaching vulcanized rubbers to each other, simplifying the bonding technology.

The technical result achieved is achieved by the fact that according to the method of fixing vulcanized rubbers based on one rubber to each other by applying glue based on polychloroprene rubber to the glued surfaces and then contacting the surfaces, 88NT or 88CA glue based on polychloroprene rubber using nairit NT or nairite DP in combination with butylphenol formaldehyde resin, while before applying to the surface, an additional modifier is introduced into the adhesive, which is paraoxydiphenyl amine, in an amount of 0.3-4.0 parts by weight per 100 parts by weight glue, and after applying glue, the glue film is dried at room temperature for 1-2 minutes, and the bonded surfaces are contacted under load for 24 hours.

Adhesive 88NT (TU2252-033-45539771-2000) which includes (parts by weight): polychloroprene rubber Nairit NT - 100, butylphenol formaldehyde resin 101K - 90, zinc oxide - 5, magnesium oxide - 12, thiuram - 2, organic the solvent is 800. As a solvent, a mixture of nephras and ethyl acetate in a ratio of 1: 1 is used.

Adhesive 88CA (TU 381051760-89), which contains (parts by weight): polychloroprene rubber Nairit DP - 90, butylphenol formaldehyde resin 101K - 90, zinc oxide - 5, magnesium oxide - 11, water - 3 and organic solvent - 800 A mixture of nephras and ethyl acetate in a ratio of 1: 1 is used as an organic solvent.

Polychloroprene rubbers Nairit NT with a high crystallization rate (TU-601781-73), Nairit DP with an average crystallization rate (TU-6-01-1319-85) are 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 (TU 3840167109-92).

The modifier - paraoxydiphenylamine (TU 6-09-07-569-76) is used in lubricating oils and fuels as an antioxidant.

As a result of the interaction of paraoxydiphenylamine with a macromolecule of chloroprene rubber, an increase in the concentration of polar groups and the formation of additional chemical bonds during the interaction of an amine-containing modifier with mobile allylic chlorine atoms in the macromolecules of chloroprene rubber, which increases the strength at the rubber-adhesive interface when bonding vulcanized rubber to each other.

The declared limits of the quantities of the introduced modifier are due to the fact that with a decrease in the indicated dosages, the adhesive strength during gluing decreases, with an increase, there is no further increase in strength.

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

The calculated amount of modifier is introduced into the adhesive based on polychloroprene rubber before application to the surfaces to be glued and the contents are mixed for 5-10 minutes until a homogeneous mass is obtained. 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. One-time application of the prepared adhesive on the prepared surface, drying of the adhesive film at room temperature (20 ° C) for 1-2 minutes, after which the glued surfaces were pressed tightly and kept under load 2 kg for 24 hours.

Shear adhesion was determined on an MPC-250 tensile testing machine (RTM 1.2.126-88). The various contents of paraoxydiphenylamine in adhesives of 88HT and 88CA grades were studied (Tables 1, 2).

The method is illustrated by the following example.

Example 1. The calculated amount of modifier is introduced into 88NT adhesive prior to application onto the surfaces to be glued and the contents are mixed for 5-10 minutes until a homogeneous mass is obtained. This method was used for fixing vulcanized rubbers based on SKI-3, SKEPT-40, SKN-18M and Neoprene AC to each other. One-time application of the prepared adhesive on the prepared surface, drying of the adhesive film at room temperature (20 ° C) for 1-2 minutes, after which the glued surfaces were pressed tightly and kept under load for 2 kg for 24 hours. After that, shear strength was determined.

Example 2. Obtain adhesive compounds, as described in example 1, but as the adhesive used adhesive brand 88CA.

As can be seen from table 1, 2, the proposed method of attaching vulcanized rubbers to each other provides high strength properties of adhesive joints. So the strength of the adhesive joint under shear when bonding vulcanized rubber based on SKI-3 with 88NT adhesive according to the prototype is 0.61 MPa, and using the proposed modifier 1.10 MPa.

It was found that the reason for the increase in adhesion indicators with this method of attachment is not only an increase in the concentration of polar groups when a modifier is introduced into the adhesive, 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 mobility macromolecules and deeper diffusion of its sections deep into the surface of the vulcanizate.

Table 1 Substrate Type Shear Strength, MPa The content of the modifier, parts by weight per 100 parts by weight glue Test Example 88NT Adhesive 0.5 1,0 2.0 3.0 4.0 SKI-3 0.71 1.10 0.98 0.86 0.70 0.61 SKEPT-40 1.15 1.21 1.27 1.43 1.32 0.99 SKN-18M 1.00 1.31 1.21 1.12 0.95 0.46 Neoprene speaker 1.20 1,50 1.28 2,55 2.10 0.73

table 2 Substrate Type Shear Strength, MPa The content of the modifier, parts by weight per 100 parts by weight glue Test Example Adhesive 88CA 0.3 0.5 1,0 SKI-3 1,07 1,11 1,04 1,02 SKEPT-40 0.90 0.99 0.97 0.70

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)

The method of attaching vulcanized rubbers based on one rubber to each other by applying glue based on polychloroprene rubber to the surfaces to be bonded and then contacting the surfaces, characterized in that they use 88NT or 88CA glue based on polychloroprene rubber Nairit NT or Nairit DP in combination with butylphenol formaldehyde resin in this case, before applying to the surface, a modifier is additionally introduced into the adhesive, which is a paraoxydiphenylamine in an amount of 0.3-4.0 parts by weight per 100 parts by weight glue, and after applying the glue, the glue film is dried at room temperature for 1-2 minutes, and the bonded surfaces are contacted under load for 24 hours.