RU2479612C1 - Adhesive composition - Google Patents

Abstract

FIELD: chemistry.

SUBSTANCE: adhesive composition contains polychloroprene rubber nairit, butyl phenol-formaldehyde resin, water, zinc oxide, magnesium oxide, an organic solvent which is a mixture of ethyl acetate and nefras, and a modifier. The modifier is modified crushed polycaproamide fibre. The modified polycaproamide fibre is obtained by treating the crushed polycaproamide fibre with a mixture of methylphosphite borate and triethanolamine at temperature of 80°C.

EFFECT: invention increases strength of glued 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 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.

A 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; 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 an adhesive composition comprising polychloroprene rubber Nairit DP, butylphenol-formaldehyde resin 101K, water, zinc oxide, magnesium oxide, a modifier and an organic solvent, which is a mixture of ethyl acetate and nefras. As a modifier, methylphosphite borate is used (Pat. 2393194 Russia, C09J 111/00; publ., 06.27.10).

However, the specified adhesive composition has insufficient strength when bonding vulcanized rubber to each other.

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 in 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, a modifier, and it contains a modified chopped polycaprod as a modifier grade 23 KNTS, previously obtained by processing at a temperature of 80 ° C a mixture of methylphosphite borate and triethanolamine in a mass ratio of 1: 2 in the next the ratio of components, parts by weight: polyirprene 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 is 800,0, modified crushed polycaproamide fiber grade 23 KNTS - 1,0-5,0.

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), 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).

Crushed polycaproamide fiber grade 23 KNTS - 187 Tex - 1-3 mm in size is obtained by passing through an extruder.

Methylphosphite borate is a viscous unpainted liquid, readily soluble in water, dimethylformamide, acetone, alcohols (US Pat. No. 2190697). Widely known as a combustion inhibitor.

Triethanolamine (TU 2423-061-05807977-2002) is used for gas purification in the production of pure carbon dioxide, in the textile and cement industries, in the production of cutting fluids, cosmetics, household chemical goods, as raw materials in organic synthesis.

To modify the chopped polycaproamide fiber of grade 23 KNTS, a mixture is preliminarily prepared by mixing methylphosphite borate and triethanolamine in a weight ratio of 1: 2 at room temperature, which is a transparent, viscous mass of light yellow color.

When using modified crushed polycaproamide fiber of grade 23 KNTS in the adhesive composition, the adhesive properties of the adhesive composition are significantly increased. As a result of the modification of the fibers, functional groups capable of interacting with the macromolecule of the film-forming polymer are contained on their surface. In addition, an increase in the adhesion strength of glue with rubber occurs due to the effect of "mechanical jamming" of crushed polycaproamide fibers in an array of bonded vulcanized rubbers. In addition, there is an increase in the cohesive strength of the adhesive film.

This explains the increase in strength when bonding vulcanized rubber to each other.

The modification of crushed polycaproamide fibers of the KNTS grade 23 was carried out by treatment with a mixture of methylphosphite borate and triethanolamine at 80 ° for four hours.

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 ° С 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 a 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, along with other ingredients of the adhesive composition, with butylphenol formaldehyde resin, water, modified chopped polycaproamide fiber of grade 23 KNTS, 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 modified chopped polycaproamide fiber of grade 23 KNTS 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 the glue mixer containing the prepared adhesive composition as described above, which includes polychloroprene rubber Nairit DP, butylphenol formaldehyde resin 101K, zinc oxide, magnesium oxide, water and the indicated organic solvent, the calculated amount of modified crushed polycaproamide fiber of the 23 KNTS grade is added and the contents of KHC 10 minutes until smooth.

Get the adhesive composition 1-3, the compositions of which are shown in table 1. The glue is a light gray liquid. The glue is technological, it is well applied to the surface of rubber. Various contents of the modified crushed polycaproamide fiber of grade 23 KNTS were investigated (Table 2).

The stated limits of the modified chopped polycaproamide fiber grade 23 KNTS 1,0-5,0 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 a control example when bonding vulcanized rubber based on polyisoprene rubber (SKI-3) and nitrile butadiene rubber (SKN-18M), and chloroprene rubber (Neoprene AS) are given in Table 2. For comparative tests, 3 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.

Shear adhesion was determined using an MPC-250 tensile testing machine (RTM 12126-88). 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 Neoprene AC according to the prototype is 1.22 MPa, and using the proposed modified ground polycaproamide fiber grade 23 KNTS 1.89 MPa (composition 1).

Thus, as can be seen from table 2, the use in the proposed adhesive composition of the modified crushed polycaproamide fiber grade 23 KNTS within the specified limits increases the strength when bonding products from vulcanized rubber to each other, which is due to its participation in improving the adhesive properties of the adhesive.

Table 1 Components The content of components, parts by weight, in the composition one 2 3 Prototype Polychloroprene rubber Nairit DP 90.0 90.0 90.0 90.0 Butylphenol formaldehyde resin 101K 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 of 50:50) 800,0 800,0 800,0 800,0 Modified chopped polycaproamide fiber grade 23 KNTS 1,0 3.0 5,0 - Methyl Phosphite Borate - - - 30,0

table 2 Substrate Type Shear Strength, MPa Metric for composition Prototype one 2 3 SKI-3 1.28 1.32 1.35 1.30 SKN-18M 0.70 0.74 0.66 - Neoprene speaker 1.89 1.51 1.39 1.22

We found that the reason for the increase in the adhesive properties of adhesive compositions is an increase in the cohesive strength of the adhesive film when KNTS grade 23 modified polycaproamide fiber is introduced into the composition, as well as its partial penetration into the surface layers of rubber.

The use of the proposed adhesive composition can significantly improve the quality of fastening products from vulcanized rubber to each other.

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, a modifier, characterized in that it contains a modified chopped polycaproamide fiber as a modifier , previously obtained by processing at a temperature of 80 ° C with a mixture of methyl phosphite borate and triethanolamine in a mass ratio of 1: 2 in the following ratio of components, parts by weight:
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 Modified Ground Polycaproamide Fiber stamps 23 KNTS 1.0-5.0